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28a4f91f5f
Here is a small set of driver core updates and additions for 6.6-rc1. Included in here are: - stable kernel documentation updates - class structure const work from Ivan on various subsystems - kernfs tweaks - driver core tests! - kobject sanity cleanups - kobject structure reordering to save space - driver core error code handling fixups - other minor driver core cleanups All of these have been in linux-next for a while with no reported problems. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> -----BEGIN PGP SIGNATURE----- iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCZPH77Q8cZ3JlZ0Brcm9h aC5jb20ACgkQMUfUDdst+ylZMACePk8SitfaJc6FfFf5I7YK7Nq0V8MAn0nUjgsR i8NcNpu/Yv4HGrDgTdh/ =PJbk -----END PGP SIGNATURE----- Merge tag 'driver-core-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is a small set of driver core updates and additions for 6.6-rc1. Included in here are: - stable kernel documentation updates - class structure const work from Ivan on various subsystems - kernfs tweaks - driver core tests! - kobject sanity cleanups - kobject structure reordering to save space - driver core error code handling fixups - other minor driver core cleanups All of these have been in linux-next for a while with no reported problems" * tag 'driver-core-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (32 commits) driver core: Call in reversed order in device_platform_notify_remove() driver core: Return proper error code when dev_set_name() fails kobject: Remove redundant checks for whether ktype is NULL kobject: Add sanity check for kset->kobj.ktype in kset_register() drivers: base: test: Add missing MODULE_* macros to root device tests drivers: base: test: Add missing MODULE_* macros for platform devices tests drivers: base: Free devm resources when unregistering a device drivers: base: Add basic devm tests for platform devices drivers: base: Add basic devm tests for root devices kernfs: fix missing kernfs_iattr_rwsem locking docs: stable-kernel-rules: mention that regressions must be prevented docs: stable-kernel-rules: fine-tune various details docs: stable-kernel-rules: make the examples for option 1 a proper list docs: stable-kernel-rules: move text around to improve flow docs: stable-kernel-rules: improve structure by changing headlines base/node: Remove duplicated include kernfs: attach uuid for every kernfs and report it in fsid kernfs: add stub helper for kernfs_generic_poll() x86/resctrl: make pseudo_lock_class a static const structure x86/MSR: make msr_class a static const structure ...
5109 lines
138 KiB
C
5109 lines
138 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* drivers/base/core.c - core driver model code (device registration, etc)
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*
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* Copyright (c) 2002-3 Patrick Mochel
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* Copyright (c) 2002-3 Open Source Development Labs
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* Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
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* Copyright (c) 2006 Novell, Inc.
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*/
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#include <linux/acpi.h>
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#include <linux/cpufreq.h>
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/fwnode.h>
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#include <linux/init.h>
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#include <linux/kstrtox.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/kdev_t.h>
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#include <linux/notifier.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <linux/blkdev.h>
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#include <linux/mutex.h>
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#include <linux/pm_runtime.h>
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#include <linux/netdevice.h>
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#include <linux/sched/signal.h>
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#include <linux/sched/mm.h>
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#include <linux/string_helpers.h>
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#include <linux/swiotlb.h>
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#include <linux/sysfs.h>
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#include <linux/dma-map-ops.h> /* for dma_default_coherent */
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#include "base.h"
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#include "physical_location.h"
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#include "power/power.h"
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/* Device links support. */
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static LIST_HEAD(deferred_sync);
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static unsigned int defer_sync_state_count = 1;
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static DEFINE_MUTEX(fwnode_link_lock);
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static bool fw_devlink_is_permissive(void);
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static void __fw_devlink_link_to_consumers(struct device *dev);
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static bool fw_devlink_drv_reg_done;
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static bool fw_devlink_best_effort;
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/**
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* __fwnode_link_add - Create a link between two fwnode_handles.
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* @con: Consumer end of the link.
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* @sup: Supplier end of the link.
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*
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* Create a fwnode link between fwnode handles @con and @sup. The fwnode link
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* represents the detail that the firmware lists @sup fwnode as supplying a
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* resource to @con.
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*
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* The driver core will use the fwnode link to create a device link between the
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* two device objects corresponding to @con and @sup when they are created. The
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* driver core will automatically delete the fwnode link between @con and @sup
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* after doing that.
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*
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* Attempts to create duplicate links between the same pair of fwnode handles
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* are ignored and there is no reference counting.
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*/
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static int __fwnode_link_add(struct fwnode_handle *con,
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struct fwnode_handle *sup, u8 flags)
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{
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struct fwnode_link *link;
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list_for_each_entry(link, &sup->consumers, s_hook)
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if (link->consumer == con) {
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link->flags |= flags;
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return 0;
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}
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link = kzalloc(sizeof(*link), GFP_KERNEL);
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if (!link)
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return -ENOMEM;
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link->supplier = sup;
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INIT_LIST_HEAD(&link->s_hook);
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link->consumer = con;
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INIT_LIST_HEAD(&link->c_hook);
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link->flags = flags;
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list_add(&link->s_hook, &sup->consumers);
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list_add(&link->c_hook, &con->suppliers);
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pr_debug("%pfwf Linked as a fwnode consumer to %pfwf\n",
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con, sup);
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return 0;
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}
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int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup)
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{
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int ret;
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mutex_lock(&fwnode_link_lock);
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ret = __fwnode_link_add(con, sup, 0);
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mutex_unlock(&fwnode_link_lock);
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return ret;
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}
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/**
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* __fwnode_link_del - Delete a link between two fwnode_handles.
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* @link: the fwnode_link to be deleted
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*
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* The fwnode_link_lock needs to be held when this function is called.
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*/
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static void __fwnode_link_del(struct fwnode_link *link)
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{
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pr_debug("%pfwf Dropping the fwnode link to %pfwf\n",
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link->consumer, link->supplier);
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list_del(&link->s_hook);
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list_del(&link->c_hook);
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kfree(link);
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}
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/**
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* __fwnode_link_cycle - Mark a fwnode link as being part of a cycle.
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* @link: the fwnode_link to be marked
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*
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* The fwnode_link_lock needs to be held when this function is called.
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*/
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static void __fwnode_link_cycle(struct fwnode_link *link)
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{
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pr_debug("%pfwf: Relaxing link with %pfwf\n",
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link->consumer, link->supplier);
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link->flags |= FWLINK_FLAG_CYCLE;
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}
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/**
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* fwnode_links_purge_suppliers - Delete all supplier links of fwnode_handle.
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* @fwnode: fwnode whose supplier links need to be deleted
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*
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* Deletes all supplier links connecting directly to @fwnode.
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*/
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static void fwnode_links_purge_suppliers(struct fwnode_handle *fwnode)
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{
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struct fwnode_link *link, *tmp;
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mutex_lock(&fwnode_link_lock);
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list_for_each_entry_safe(link, tmp, &fwnode->suppliers, c_hook)
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__fwnode_link_del(link);
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mutex_unlock(&fwnode_link_lock);
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}
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/**
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* fwnode_links_purge_consumers - Delete all consumer links of fwnode_handle.
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* @fwnode: fwnode whose consumer links need to be deleted
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*
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* Deletes all consumer links connecting directly to @fwnode.
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*/
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static void fwnode_links_purge_consumers(struct fwnode_handle *fwnode)
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{
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struct fwnode_link *link, *tmp;
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mutex_lock(&fwnode_link_lock);
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list_for_each_entry_safe(link, tmp, &fwnode->consumers, s_hook)
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__fwnode_link_del(link);
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mutex_unlock(&fwnode_link_lock);
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}
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/**
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* fwnode_links_purge - Delete all links connected to a fwnode_handle.
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* @fwnode: fwnode whose links needs to be deleted
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*
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* Deletes all links connecting directly to a fwnode.
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*/
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void fwnode_links_purge(struct fwnode_handle *fwnode)
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{
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fwnode_links_purge_suppliers(fwnode);
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fwnode_links_purge_consumers(fwnode);
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}
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void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode)
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{
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struct fwnode_handle *child;
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/* Don't purge consumer links of an added child */
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if (fwnode->dev)
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return;
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fwnode->flags |= FWNODE_FLAG_NOT_DEVICE;
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fwnode_links_purge_consumers(fwnode);
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fwnode_for_each_available_child_node(fwnode, child)
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fw_devlink_purge_absent_suppliers(child);
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}
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EXPORT_SYMBOL_GPL(fw_devlink_purge_absent_suppliers);
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/**
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* __fwnode_links_move_consumers - Move consumer from @from to @to fwnode_handle
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* @from: move consumers away from this fwnode
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* @to: move consumers to this fwnode
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*
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* Move all consumer links from @from fwnode to @to fwnode.
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*/
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static void __fwnode_links_move_consumers(struct fwnode_handle *from,
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struct fwnode_handle *to)
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{
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struct fwnode_link *link, *tmp;
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list_for_each_entry_safe(link, tmp, &from->consumers, s_hook) {
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__fwnode_link_add(link->consumer, to, link->flags);
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__fwnode_link_del(link);
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}
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}
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/**
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* __fw_devlink_pickup_dangling_consumers - Pick up dangling consumers
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* @fwnode: fwnode from which to pick up dangling consumers
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* @new_sup: fwnode of new supplier
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*
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* If the @fwnode has a corresponding struct device and the device supports
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* probing (that is, added to a bus), then we want to let fw_devlink create
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* MANAGED device links to this device, so leave @fwnode and its descendant's
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* fwnode links alone.
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*
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* Otherwise, move its consumers to the new supplier @new_sup.
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*/
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static void __fw_devlink_pickup_dangling_consumers(struct fwnode_handle *fwnode,
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struct fwnode_handle *new_sup)
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{
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struct fwnode_handle *child;
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if (fwnode->dev && fwnode->dev->bus)
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return;
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fwnode->flags |= FWNODE_FLAG_NOT_DEVICE;
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__fwnode_links_move_consumers(fwnode, new_sup);
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fwnode_for_each_available_child_node(fwnode, child)
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__fw_devlink_pickup_dangling_consumers(child, new_sup);
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}
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static DEFINE_MUTEX(device_links_lock);
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DEFINE_STATIC_SRCU(device_links_srcu);
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static inline void device_links_write_lock(void)
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{
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mutex_lock(&device_links_lock);
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}
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static inline void device_links_write_unlock(void)
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{
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mutex_unlock(&device_links_lock);
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}
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int device_links_read_lock(void) __acquires(&device_links_srcu)
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{
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return srcu_read_lock(&device_links_srcu);
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}
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void device_links_read_unlock(int idx) __releases(&device_links_srcu)
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{
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srcu_read_unlock(&device_links_srcu, idx);
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}
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int device_links_read_lock_held(void)
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{
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return srcu_read_lock_held(&device_links_srcu);
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}
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static void device_link_synchronize_removal(void)
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{
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synchronize_srcu(&device_links_srcu);
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}
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static void device_link_remove_from_lists(struct device_link *link)
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{
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list_del_rcu(&link->s_node);
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list_del_rcu(&link->c_node);
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}
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static bool device_is_ancestor(struct device *dev, struct device *target)
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{
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while (target->parent) {
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target = target->parent;
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if (dev == target)
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return true;
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}
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return false;
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}
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static inline bool device_link_flag_is_sync_state_only(u32 flags)
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{
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return (flags & ~(DL_FLAG_INFERRED | DL_FLAG_CYCLE)) ==
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(DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED);
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}
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/**
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* device_is_dependent - Check if one device depends on another one
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* @dev: Device to check dependencies for.
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* @target: Device to check against.
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*
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* Check if @target depends on @dev or any device dependent on it (its child or
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* its consumer etc). Return 1 if that is the case or 0 otherwise.
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*/
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int device_is_dependent(struct device *dev, void *target)
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{
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struct device_link *link;
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int ret;
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/*
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* The "ancestors" check is needed to catch the case when the target
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* device has not been completely initialized yet and it is still
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* missing from the list of children of its parent device.
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*/
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if (dev == target || device_is_ancestor(dev, target))
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return 1;
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ret = device_for_each_child(dev, target, device_is_dependent);
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if (ret)
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return ret;
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list_for_each_entry(link, &dev->links.consumers, s_node) {
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if (device_link_flag_is_sync_state_only(link->flags))
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continue;
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if (link->consumer == target)
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return 1;
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ret = device_is_dependent(link->consumer, target);
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if (ret)
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break;
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}
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return ret;
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}
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static void device_link_init_status(struct device_link *link,
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struct device *consumer,
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struct device *supplier)
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{
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switch (supplier->links.status) {
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case DL_DEV_PROBING:
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switch (consumer->links.status) {
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case DL_DEV_PROBING:
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/*
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* A consumer driver can create a link to a supplier
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* that has not completed its probing yet as long as it
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* knows that the supplier is already functional (for
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* example, it has just acquired some resources from the
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* supplier).
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*/
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link->status = DL_STATE_CONSUMER_PROBE;
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break;
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default:
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link->status = DL_STATE_DORMANT;
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break;
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}
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break;
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case DL_DEV_DRIVER_BOUND:
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switch (consumer->links.status) {
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case DL_DEV_PROBING:
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link->status = DL_STATE_CONSUMER_PROBE;
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break;
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case DL_DEV_DRIVER_BOUND:
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link->status = DL_STATE_ACTIVE;
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break;
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default:
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link->status = DL_STATE_AVAILABLE;
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break;
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}
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break;
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case DL_DEV_UNBINDING:
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link->status = DL_STATE_SUPPLIER_UNBIND;
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break;
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default:
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link->status = DL_STATE_DORMANT;
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break;
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}
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}
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static int device_reorder_to_tail(struct device *dev, void *not_used)
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{
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struct device_link *link;
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/*
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* Devices that have not been registered yet will be put to the ends
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* of the lists during the registration, so skip them here.
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*/
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if (device_is_registered(dev))
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devices_kset_move_last(dev);
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if (device_pm_initialized(dev))
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device_pm_move_last(dev);
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device_for_each_child(dev, NULL, device_reorder_to_tail);
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list_for_each_entry(link, &dev->links.consumers, s_node) {
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if (device_link_flag_is_sync_state_only(link->flags))
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continue;
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device_reorder_to_tail(link->consumer, NULL);
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}
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return 0;
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}
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/**
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* device_pm_move_to_tail - Move set of devices to the end of device lists
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* @dev: Device to move
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*
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* This is a device_reorder_to_tail() wrapper taking the requisite locks.
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*
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* It moves the @dev along with all of its children and all of its consumers
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* to the ends of the device_kset and dpm_list, recursively.
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*/
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void device_pm_move_to_tail(struct device *dev)
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{
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int idx;
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idx = device_links_read_lock();
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device_pm_lock();
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device_reorder_to_tail(dev, NULL);
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device_pm_unlock();
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device_links_read_unlock(idx);
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}
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#define to_devlink(dev) container_of((dev), struct device_link, link_dev)
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static ssize_t status_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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const char *output;
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switch (to_devlink(dev)->status) {
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case DL_STATE_NONE:
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output = "not tracked";
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break;
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case DL_STATE_DORMANT:
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output = "dormant";
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break;
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case DL_STATE_AVAILABLE:
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output = "available";
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break;
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case DL_STATE_CONSUMER_PROBE:
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output = "consumer probing";
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break;
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case DL_STATE_ACTIVE:
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output = "active";
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break;
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case DL_STATE_SUPPLIER_UNBIND:
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output = "supplier unbinding";
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break;
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default:
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output = "unknown";
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break;
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}
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return sysfs_emit(buf, "%s\n", output);
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}
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static DEVICE_ATTR_RO(status);
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static ssize_t auto_remove_on_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct device_link *link = to_devlink(dev);
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const char *output;
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if (link->flags & DL_FLAG_AUTOREMOVE_SUPPLIER)
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output = "supplier unbind";
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|
else if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER)
|
|
output = "consumer unbind";
|
|
else
|
|
output = "never";
|
|
|
|
return sysfs_emit(buf, "%s\n", output);
|
|
}
|
|
static DEVICE_ATTR_RO(auto_remove_on);
|
|
|
|
static ssize_t runtime_pm_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
struct device_link *link = to_devlink(dev);
|
|
|
|
return sysfs_emit(buf, "%d\n", !!(link->flags & DL_FLAG_PM_RUNTIME));
|
|
}
|
|
static DEVICE_ATTR_RO(runtime_pm);
|
|
|
|
static ssize_t sync_state_only_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
struct device_link *link = to_devlink(dev);
|
|
|
|
return sysfs_emit(buf, "%d\n",
|
|
!!(link->flags & DL_FLAG_SYNC_STATE_ONLY));
|
|
}
|
|
static DEVICE_ATTR_RO(sync_state_only);
|
|
|
|
static struct attribute *devlink_attrs[] = {
|
|
&dev_attr_status.attr,
|
|
&dev_attr_auto_remove_on.attr,
|
|
&dev_attr_runtime_pm.attr,
|
|
&dev_attr_sync_state_only.attr,
|
|
NULL,
|
|
};
|
|
ATTRIBUTE_GROUPS(devlink);
|
|
|
|
static void device_link_release_fn(struct work_struct *work)
|
|
{
|
|
struct device_link *link = container_of(work, struct device_link, rm_work);
|
|
|
|
/* Ensure that all references to the link object have been dropped. */
|
|
device_link_synchronize_removal();
|
|
|
|
pm_runtime_release_supplier(link);
|
|
/*
|
|
* If supplier_preactivated is set, the link has been dropped between
|
|
* the pm_runtime_get_suppliers() and pm_runtime_put_suppliers() calls
|
|
* in __driver_probe_device(). In that case, drop the supplier's
|
|
* PM-runtime usage counter to remove the reference taken by
|
|
* pm_runtime_get_suppliers().
|
|
*/
|
|
if (link->supplier_preactivated)
|
|
pm_runtime_put_noidle(link->supplier);
|
|
|
|
pm_request_idle(link->supplier);
|
|
|
|
put_device(link->consumer);
|
|
put_device(link->supplier);
|
|
kfree(link);
|
|
}
|
|
|
|
static void devlink_dev_release(struct device *dev)
|
|
{
|
|
struct device_link *link = to_devlink(dev);
|
|
|
|
INIT_WORK(&link->rm_work, device_link_release_fn);
|
|
/*
|
|
* It may take a while to complete this work because of the SRCU
|
|
* synchronization in device_link_release_fn() and if the consumer or
|
|
* supplier devices get deleted when it runs, so put it into the "long"
|
|
* workqueue.
|
|
*/
|
|
queue_work(system_long_wq, &link->rm_work);
|
|
}
|
|
|
|
static struct class devlink_class = {
|
|
.name = "devlink",
|
|
.dev_groups = devlink_groups,
|
|
.dev_release = devlink_dev_release,
|
|
};
|
|
|
|
static int devlink_add_symlinks(struct device *dev)
|
|
{
|
|
int ret;
|
|
size_t len;
|
|
struct device_link *link = to_devlink(dev);
|
|
struct device *sup = link->supplier;
|
|
struct device *con = link->consumer;
|
|
char *buf;
|
|
|
|
len = max(strlen(dev_bus_name(sup)) + strlen(dev_name(sup)),
|
|
strlen(dev_bus_name(con)) + strlen(dev_name(con)));
|
|
len += strlen(":");
|
|
len += strlen("supplier:") + 1;
|
|
buf = kzalloc(len, GFP_KERNEL);
|
|
if (!buf)
|
|
return -ENOMEM;
|
|
|
|
ret = sysfs_create_link(&link->link_dev.kobj, &sup->kobj, "supplier");
|
|
if (ret)
|
|
goto out;
|
|
|
|
ret = sysfs_create_link(&link->link_dev.kobj, &con->kobj, "consumer");
|
|
if (ret)
|
|
goto err_con;
|
|
|
|
snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con));
|
|
ret = sysfs_create_link(&sup->kobj, &link->link_dev.kobj, buf);
|
|
if (ret)
|
|
goto err_con_dev;
|
|
|
|
snprintf(buf, len, "supplier:%s:%s", dev_bus_name(sup), dev_name(sup));
|
|
ret = sysfs_create_link(&con->kobj, &link->link_dev.kobj, buf);
|
|
if (ret)
|
|
goto err_sup_dev;
|
|
|
|
goto out;
|
|
|
|
err_sup_dev:
|
|
snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con));
|
|
sysfs_remove_link(&sup->kobj, buf);
|
|
err_con_dev:
|
|
sysfs_remove_link(&link->link_dev.kobj, "consumer");
|
|
err_con:
|
|
sysfs_remove_link(&link->link_dev.kobj, "supplier");
|
|
out:
|
|
kfree(buf);
|
|
return ret;
|
|
}
|
|
|
|
static void devlink_remove_symlinks(struct device *dev)
|
|
{
|
|
struct device_link *link = to_devlink(dev);
|
|
size_t len;
|
|
struct device *sup = link->supplier;
|
|
struct device *con = link->consumer;
|
|
char *buf;
|
|
|
|
sysfs_remove_link(&link->link_dev.kobj, "consumer");
|
|
sysfs_remove_link(&link->link_dev.kobj, "supplier");
|
|
|
|
len = max(strlen(dev_bus_name(sup)) + strlen(dev_name(sup)),
|
|
strlen(dev_bus_name(con)) + strlen(dev_name(con)));
|
|
len += strlen(":");
|
|
len += strlen("supplier:") + 1;
|
|
buf = kzalloc(len, GFP_KERNEL);
|
|
if (!buf) {
|
|
WARN(1, "Unable to properly free device link symlinks!\n");
|
|
return;
|
|
}
|
|
|
|
if (device_is_registered(con)) {
|
|
snprintf(buf, len, "supplier:%s:%s", dev_bus_name(sup), dev_name(sup));
|
|
sysfs_remove_link(&con->kobj, buf);
|
|
}
|
|
snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con));
|
|
sysfs_remove_link(&sup->kobj, buf);
|
|
kfree(buf);
|
|
}
|
|
|
|
static struct class_interface devlink_class_intf = {
|
|
.class = &devlink_class,
|
|
.add_dev = devlink_add_symlinks,
|
|
.remove_dev = devlink_remove_symlinks,
|
|
};
|
|
|
|
static int __init devlink_class_init(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = class_register(&devlink_class);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = class_interface_register(&devlink_class_intf);
|
|
if (ret)
|
|
class_unregister(&devlink_class);
|
|
|
|
return ret;
|
|
}
|
|
postcore_initcall(devlink_class_init);
|
|
|
|
#define DL_MANAGED_LINK_FLAGS (DL_FLAG_AUTOREMOVE_CONSUMER | \
|
|
DL_FLAG_AUTOREMOVE_SUPPLIER | \
|
|
DL_FLAG_AUTOPROBE_CONSUMER | \
|
|
DL_FLAG_SYNC_STATE_ONLY | \
|
|
DL_FLAG_INFERRED | \
|
|
DL_FLAG_CYCLE)
|
|
|
|
#define DL_ADD_VALID_FLAGS (DL_MANAGED_LINK_FLAGS | DL_FLAG_STATELESS | \
|
|
DL_FLAG_PM_RUNTIME | DL_FLAG_RPM_ACTIVE)
|
|
|
|
/**
|
|
* device_link_add - Create a link between two devices.
|
|
* @consumer: Consumer end of the link.
|
|
* @supplier: Supplier end of the link.
|
|
* @flags: Link flags.
|
|
*
|
|
* The caller is responsible for the proper synchronization of the link creation
|
|
* with runtime PM. First, setting the DL_FLAG_PM_RUNTIME flag will cause the
|
|
* runtime PM framework to take the link into account. Second, if the
|
|
* DL_FLAG_RPM_ACTIVE flag is set in addition to it, the supplier devices will
|
|
* be forced into the active meta state and reference-counted upon the creation
|
|
* of the link. If DL_FLAG_PM_RUNTIME is not set, DL_FLAG_RPM_ACTIVE will be
|
|
* ignored.
|
|
*
|
|
* If DL_FLAG_STATELESS is set in @flags, the caller of this function is
|
|
* expected to release the link returned by it directly with the help of either
|
|
* device_link_del() or device_link_remove().
|
|
*
|
|
* If that flag is not set, however, the caller of this function is handing the
|
|
* management of the link over to the driver core entirely and its return value
|
|
* can only be used to check whether or not the link is present. In that case,
|
|
* the DL_FLAG_AUTOREMOVE_CONSUMER and DL_FLAG_AUTOREMOVE_SUPPLIER device link
|
|
* flags can be used to indicate to the driver core when the link can be safely
|
|
* deleted. Namely, setting one of them in @flags indicates to the driver core
|
|
* that the link is not going to be used (by the given caller of this function)
|
|
* after unbinding the consumer or supplier driver, respectively, from its
|
|
* device, so the link can be deleted at that point. If none of them is set,
|
|
* the link will be maintained until one of the devices pointed to by it (either
|
|
* the consumer or the supplier) is unregistered.
|
|
*
|
|
* Also, if DL_FLAG_STATELESS, DL_FLAG_AUTOREMOVE_CONSUMER and
|
|
* DL_FLAG_AUTOREMOVE_SUPPLIER are not set in @flags (that is, a persistent
|
|
* managed device link is being added), the DL_FLAG_AUTOPROBE_CONSUMER flag can
|
|
* be used to request the driver core to automatically probe for a consumer
|
|
* driver after successfully binding a driver to the supplier device.
|
|
*
|
|
* The combination of DL_FLAG_STATELESS and one of DL_FLAG_AUTOREMOVE_CONSUMER,
|
|
* DL_FLAG_AUTOREMOVE_SUPPLIER, or DL_FLAG_AUTOPROBE_CONSUMER set in @flags at
|
|
* the same time is invalid and will cause NULL to be returned upfront.
|
|
* However, if a device link between the given @consumer and @supplier pair
|
|
* exists already when this function is called for them, the existing link will
|
|
* be returned regardless of its current type and status (the link's flags may
|
|
* be modified then). The caller of this function is then expected to treat
|
|
* the link as though it has just been created, so (in particular) if
|
|
* DL_FLAG_STATELESS was passed in @flags, the link needs to be released
|
|
* explicitly when not needed any more (as stated above).
|
|
*
|
|
* A side effect of the link creation is re-ordering of dpm_list and the
|
|
* devices_kset list by moving the consumer device and all devices depending
|
|
* on it to the ends of these lists (that does not happen to devices that have
|
|
* not been registered when this function is called).
|
|
*
|
|
* The supplier device is required to be registered when this function is called
|
|
* and NULL will be returned if that is not the case. The consumer device need
|
|
* not be registered, however.
|
|
*/
|
|
struct device_link *device_link_add(struct device *consumer,
|
|
struct device *supplier, u32 flags)
|
|
{
|
|
struct device_link *link;
|
|
|
|
if (!consumer || !supplier || consumer == supplier ||
|
|
flags & ~DL_ADD_VALID_FLAGS ||
|
|
(flags & DL_FLAG_STATELESS && flags & DL_MANAGED_LINK_FLAGS) ||
|
|
(flags & DL_FLAG_AUTOPROBE_CONSUMER &&
|
|
flags & (DL_FLAG_AUTOREMOVE_CONSUMER |
|
|
DL_FLAG_AUTOREMOVE_SUPPLIER)))
|
|
return NULL;
|
|
|
|
if (flags & DL_FLAG_PM_RUNTIME && flags & DL_FLAG_RPM_ACTIVE) {
|
|
if (pm_runtime_get_sync(supplier) < 0) {
|
|
pm_runtime_put_noidle(supplier);
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
if (!(flags & DL_FLAG_STATELESS))
|
|
flags |= DL_FLAG_MANAGED;
|
|
|
|
if (flags & DL_FLAG_SYNC_STATE_ONLY &&
|
|
!device_link_flag_is_sync_state_only(flags))
|
|
return NULL;
|
|
|
|
device_links_write_lock();
|
|
device_pm_lock();
|
|
|
|
/*
|
|
* If the supplier has not been fully registered yet or there is a
|
|
* reverse (non-SYNC_STATE_ONLY) dependency between the consumer and
|
|
* the supplier already in the graph, return NULL. If the link is a
|
|
* SYNC_STATE_ONLY link, we don't check for reverse dependencies
|
|
* because it only affects sync_state() callbacks.
|
|
*/
|
|
if (!device_pm_initialized(supplier)
|
|
|| (!(flags & DL_FLAG_SYNC_STATE_ONLY) &&
|
|
device_is_dependent(consumer, supplier))) {
|
|
link = NULL;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* SYNC_STATE_ONLY links are useless once a consumer device has probed.
|
|
* So, only create it if the consumer hasn't probed yet.
|
|
*/
|
|
if (flags & DL_FLAG_SYNC_STATE_ONLY &&
|
|
consumer->links.status != DL_DEV_NO_DRIVER &&
|
|
consumer->links.status != DL_DEV_PROBING) {
|
|
link = NULL;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* DL_FLAG_AUTOREMOVE_SUPPLIER indicates that the link will be needed
|
|
* longer than for DL_FLAG_AUTOREMOVE_CONSUMER and setting them both
|
|
* together doesn't make sense, so prefer DL_FLAG_AUTOREMOVE_SUPPLIER.
|
|
*/
|
|
if (flags & DL_FLAG_AUTOREMOVE_SUPPLIER)
|
|
flags &= ~DL_FLAG_AUTOREMOVE_CONSUMER;
|
|
|
|
list_for_each_entry(link, &supplier->links.consumers, s_node) {
|
|
if (link->consumer != consumer)
|
|
continue;
|
|
|
|
if (link->flags & DL_FLAG_INFERRED &&
|
|
!(flags & DL_FLAG_INFERRED))
|
|
link->flags &= ~DL_FLAG_INFERRED;
|
|
|
|
if (flags & DL_FLAG_PM_RUNTIME) {
|
|
if (!(link->flags & DL_FLAG_PM_RUNTIME)) {
|
|
pm_runtime_new_link(consumer);
|
|
link->flags |= DL_FLAG_PM_RUNTIME;
|
|
}
|
|
if (flags & DL_FLAG_RPM_ACTIVE)
|
|
refcount_inc(&link->rpm_active);
|
|
}
|
|
|
|
if (flags & DL_FLAG_STATELESS) {
|
|
kref_get(&link->kref);
|
|
if (link->flags & DL_FLAG_SYNC_STATE_ONLY &&
|
|
!(link->flags & DL_FLAG_STATELESS)) {
|
|
link->flags |= DL_FLAG_STATELESS;
|
|
goto reorder;
|
|
} else {
|
|
link->flags |= DL_FLAG_STATELESS;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If the life time of the link following from the new flags is
|
|
* longer than indicated by the flags of the existing link,
|
|
* update the existing link to stay around longer.
|
|
*/
|
|
if (flags & DL_FLAG_AUTOREMOVE_SUPPLIER) {
|
|
if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER) {
|
|
link->flags &= ~DL_FLAG_AUTOREMOVE_CONSUMER;
|
|
link->flags |= DL_FLAG_AUTOREMOVE_SUPPLIER;
|
|
}
|
|
} else if (!(flags & DL_FLAG_AUTOREMOVE_CONSUMER)) {
|
|
link->flags &= ~(DL_FLAG_AUTOREMOVE_CONSUMER |
|
|
DL_FLAG_AUTOREMOVE_SUPPLIER);
|
|
}
|
|
if (!(link->flags & DL_FLAG_MANAGED)) {
|
|
kref_get(&link->kref);
|
|
link->flags |= DL_FLAG_MANAGED;
|
|
device_link_init_status(link, consumer, supplier);
|
|
}
|
|
if (link->flags & DL_FLAG_SYNC_STATE_ONLY &&
|
|
!(flags & DL_FLAG_SYNC_STATE_ONLY)) {
|
|
link->flags &= ~DL_FLAG_SYNC_STATE_ONLY;
|
|
goto reorder;
|
|
}
|
|
|
|
goto out;
|
|
}
|
|
|
|
link = kzalloc(sizeof(*link), GFP_KERNEL);
|
|
if (!link)
|
|
goto out;
|
|
|
|
refcount_set(&link->rpm_active, 1);
|
|
|
|
get_device(supplier);
|
|
link->supplier = supplier;
|
|
INIT_LIST_HEAD(&link->s_node);
|
|
get_device(consumer);
|
|
link->consumer = consumer;
|
|
INIT_LIST_HEAD(&link->c_node);
|
|
link->flags = flags;
|
|
kref_init(&link->kref);
|
|
|
|
link->link_dev.class = &devlink_class;
|
|
device_set_pm_not_required(&link->link_dev);
|
|
dev_set_name(&link->link_dev, "%s:%s--%s:%s",
|
|
dev_bus_name(supplier), dev_name(supplier),
|
|
dev_bus_name(consumer), dev_name(consumer));
|
|
if (device_register(&link->link_dev)) {
|
|
put_device(&link->link_dev);
|
|
link = NULL;
|
|
goto out;
|
|
}
|
|
|
|
if (flags & DL_FLAG_PM_RUNTIME) {
|
|
if (flags & DL_FLAG_RPM_ACTIVE)
|
|
refcount_inc(&link->rpm_active);
|
|
|
|
pm_runtime_new_link(consumer);
|
|
}
|
|
|
|
/* Determine the initial link state. */
|
|
if (flags & DL_FLAG_STATELESS)
|
|
link->status = DL_STATE_NONE;
|
|
else
|
|
device_link_init_status(link, consumer, supplier);
|
|
|
|
/*
|
|
* Some callers expect the link creation during consumer driver probe to
|
|
* resume the supplier even without DL_FLAG_RPM_ACTIVE.
|
|
*/
|
|
if (link->status == DL_STATE_CONSUMER_PROBE &&
|
|
flags & DL_FLAG_PM_RUNTIME)
|
|
pm_runtime_resume(supplier);
|
|
|
|
list_add_tail_rcu(&link->s_node, &supplier->links.consumers);
|
|
list_add_tail_rcu(&link->c_node, &consumer->links.suppliers);
|
|
|
|
if (flags & DL_FLAG_SYNC_STATE_ONLY) {
|
|
dev_dbg(consumer,
|
|
"Linked as a sync state only consumer to %s\n",
|
|
dev_name(supplier));
|
|
goto out;
|
|
}
|
|
|
|
reorder:
|
|
/*
|
|
* Move the consumer and all of the devices depending on it to the end
|
|
* of dpm_list and the devices_kset list.
|
|
*
|
|
* It is necessary to hold dpm_list locked throughout all that or else
|
|
* we may end up suspending with a wrong ordering of it.
|
|
*/
|
|
device_reorder_to_tail(consumer, NULL);
|
|
|
|
dev_dbg(consumer, "Linked as a consumer to %s\n", dev_name(supplier));
|
|
|
|
out:
|
|
device_pm_unlock();
|
|
device_links_write_unlock();
|
|
|
|
if ((flags & DL_FLAG_PM_RUNTIME && flags & DL_FLAG_RPM_ACTIVE) && !link)
|
|
pm_runtime_put(supplier);
|
|
|
|
return link;
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_link_add);
|
|
|
|
static void __device_link_del(struct kref *kref)
|
|
{
|
|
struct device_link *link = container_of(kref, struct device_link, kref);
|
|
|
|
dev_dbg(link->consumer, "Dropping the link to %s\n",
|
|
dev_name(link->supplier));
|
|
|
|
pm_runtime_drop_link(link);
|
|
|
|
device_link_remove_from_lists(link);
|
|
device_unregister(&link->link_dev);
|
|
}
|
|
|
|
static void device_link_put_kref(struct device_link *link)
|
|
{
|
|
if (link->flags & DL_FLAG_STATELESS)
|
|
kref_put(&link->kref, __device_link_del);
|
|
else if (!device_is_registered(link->consumer))
|
|
__device_link_del(&link->kref);
|
|
else
|
|
WARN(1, "Unable to drop a managed device link reference\n");
|
|
}
|
|
|
|
/**
|
|
* device_link_del - Delete a stateless link between two devices.
|
|
* @link: Device link to delete.
|
|
*
|
|
* The caller must ensure proper synchronization of this function with runtime
|
|
* PM. If the link was added multiple times, it needs to be deleted as often.
|
|
* Care is required for hotplugged devices: Their links are purged on removal
|
|
* and calling device_link_del() is then no longer allowed.
|
|
*/
|
|
void device_link_del(struct device_link *link)
|
|
{
|
|
device_links_write_lock();
|
|
device_link_put_kref(link);
|
|
device_links_write_unlock();
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_link_del);
|
|
|
|
/**
|
|
* device_link_remove - Delete a stateless link between two devices.
|
|
* @consumer: Consumer end of the link.
|
|
* @supplier: Supplier end of the link.
|
|
*
|
|
* The caller must ensure proper synchronization of this function with runtime
|
|
* PM.
|
|
*/
|
|
void device_link_remove(void *consumer, struct device *supplier)
|
|
{
|
|
struct device_link *link;
|
|
|
|
if (WARN_ON(consumer == supplier))
|
|
return;
|
|
|
|
device_links_write_lock();
|
|
|
|
list_for_each_entry(link, &supplier->links.consumers, s_node) {
|
|
if (link->consumer == consumer) {
|
|
device_link_put_kref(link);
|
|
break;
|
|
}
|
|
}
|
|
|
|
device_links_write_unlock();
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_link_remove);
|
|
|
|
static void device_links_missing_supplier(struct device *dev)
|
|
{
|
|
struct device_link *link;
|
|
|
|
list_for_each_entry(link, &dev->links.suppliers, c_node) {
|
|
if (link->status != DL_STATE_CONSUMER_PROBE)
|
|
continue;
|
|
|
|
if (link->supplier->links.status == DL_DEV_DRIVER_BOUND) {
|
|
WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
|
|
} else {
|
|
WARN_ON(!(link->flags & DL_FLAG_SYNC_STATE_ONLY));
|
|
WRITE_ONCE(link->status, DL_STATE_DORMANT);
|
|
}
|
|
}
|
|
}
|
|
|
|
static bool dev_is_best_effort(struct device *dev)
|
|
{
|
|
return (fw_devlink_best_effort && dev->can_match) ||
|
|
(dev->fwnode && (dev->fwnode->flags & FWNODE_FLAG_BEST_EFFORT));
|
|
}
|
|
|
|
static struct fwnode_handle *fwnode_links_check_suppliers(
|
|
struct fwnode_handle *fwnode)
|
|
{
|
|
struct fwnode_link *link;
|
|
|
|
if (!fwnode || fw_devlink_is_permissive())
|
|
return NULL;
|
|
|
|
list_for_each_entry(link, &fwnode->suppliers, c_hook)
|
|
if (!(link->flags & FWLINK_FLAG_CYCLE))
|
|
return link->supplier;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* device_links_check_suppliers - Check presence of supplier drivers.
|
|
* @dev: Consumer device.
|
|
*
|
|
* Check links from this device to any suppliers. Walk the list of the device's
|
|
* links to suppliers and see if all of them are available. If not, simply
|
|
* return -EPROBE_DEFER.
|
|
*
|
|
* We need to guarantee that the supplier will not go away after the check has
|
|
* been positive here. It only can go away in __device_release_driver() and
|
|
* that function checks the device's links to consumers. This means we need to
|
|
* mark the link as "consumer probe in progress" to make the supplier removal
|
|
* wait for us to complete (or bad things may happen).
|
|
*
|
|
* Links without the DL_FLAG_MANAGED flag set are ignored.
|
|
*/
|
|
int device_links_check_suppliers(struct device *dev)
|
|
{
|
|
struct device_link *link;
|
|
int ret = 0, fwnode_ret = 0;
|
|
struct fwnode_handle *sup_fw;
|
|
|
|
/*
|
|
* Device waiting for supplier to become available is not allowed to
|
|
* probe.
|
|
*/
|
|
mutex_lock(&fwnode_link_lock);
|
|
sup_fw = fwnode_links_check_suppliers(dev->fwnode);
|
|
if (sup_fw) {
|
|
if (!dev_is_best_effort(dev)) {
|
|
fwnode_ret = -EPROBE_DEFER;
|
|
dev_err_probe(dev, -EPROBE_DEFER,
|
|
"wait for supplier %pfwf\n", sup_fw);
|
|
} else {
|
|
fwnode_ret = -EAGAIN;
|
|
}
|
|
}
|
|
mutex_unlock(&fwnode_link_lock);
|
|
if (fwnode_ret == -EPROBE_DEFER)
|
|
return fwnode_ret;
|
|
|
|
device_links_write_lock();
|
|
|
|
list_for_each_entry(link, &dev->links.suppliers, c_node) {
|
|
if (!(link->flags & DL_FLAG_MANAGED))
|
|
continue;
|
|
|
|
if (link->status != DL_STATE_AVAILABLE &&
|
|
!(link->flags & DL_FLAG_SYNC_STATE_ONLY)) {
|
|
|
|
if (dev_is_best_effort(dev) &&
|
|
link->flags & DL_FLAG_INFERRED &&
|
|
!link->supplier->can_match) {
|
|
ret = -EAGAIN;
|
|
continue;
|
|
}
|
|
|
|
device_links_missing_supplier(dev);
|
|
dev_err_probe(dev, -EPROBE_DEFER,
|
|
"supplier %s not ready\n",
|
|
dev_name(link->supplier));
|
|
ret = -EPROBE_DEFER;
|
|
break;
|
|
}
|
|
WRITE_ONCE(link->status, DL_STATE_CONSUMER_PROBE);
|
|
}
|
|
dev->links.status = DL_DEV_PROBING;
|
|
|
|
device_links_write_unlock();
|
|
|
|
return ret ? ret : fwnode_ret;
|
|
}
|
|
|
|
/**
|
|
* __device_links_queue_sync_state - Queue a device for sync_state() callback
|
|
* @dev: Device to call sync_state() on
|
|
* @list: List head to queue the @dev on
|
|
*
|
|
* Queues a device for a sync_state() callback when the device links write lock
|
|
* isn't held. This allows the sync_state() execution flow to use device links
|
|
* APIs. The caller must ensure this function is called with
|
|
* device_links_write_lock() held.
|
|
*
|
|
* This function does a get_device() to make sure the device is not freed while
|
|
* on this list.
|
|
*
|
|
* So the caller must also ensure that device_links_flush_sync_list() is called
|
|
* as soon as the caller releases device_links_write_lock(). This is necessary
|
|
* to make sure the sync_state() is called in a timely fashion and the
|
|
* put_device() is called on this device.
|
|
*/
|
|
static void __device_links_queue_sync_state(struct device *dev,
|
|
struct list_head *list)
|
|
{
|
|
struct device_link *link;
|
|
|
|
if (!dev_has_sync_state(dev))
|
|
return;
|
|
if (dev->state_synced)
|
|
return;
|
|
|
|
list_for_each_entry(link, &dev->links.consumers, s_node) {
|
|
if (!(link->flags & DL_FLAG_MANAGED))
|
|
continue;
|
|
if (link->status != DL_STATE_ACTIVE)
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Set the flag here to avoid adding the same device to a list more
|
|
* than once. This can happen if new consumers get added to the device
|
|
* and probed before the list is flushed.
|
|
*/
|
|
dev->state_synced = true;
|
|
|
|
if (WARN_ON(!list_empty(&dev->links.defer_sync)))
|
|
return;
|
|
|
|
get_device(dev);
|
|
list_add_tail(&dev->links.defer_sync, list);
|
|
}
|
|
|
|
/**
|
|
* device_links_flush_sync_list - Call sync_state() on a list of devices
|
|
* @list: List of devices to call sync_state() on
|
|
* @dont_lock_dev: Device for which lock is already held by the caller
|
|
*
|
|
* Calls sync_state() on all the devices that have been queued for it. This
|
|
* function is used in conjunction with __device_links_queue_sync_state(). The
|
|
* @dont_lock_dev parameter is useful when this function is called from a
|
|
* context where a device lock is already held.
|
|
*/
|
|
static void device_links_flush_sync_list(struct list_head *list,
|
|
struct device *dont_lock_dev)
|
|
{
|
|
struct device *dev, *tmp;
|
|
|
|
list_for_each_entry_safe(dev, tmp, list, links.defer_sync) {
|
|
list_del_init(&dev->links.defer_sync);
|
|
|
|
if (dev != dont_lock_dev)
|
|
device_lock(dev);
|
|
|
|
dev_sync_state(dev);
|
|
|
|
if (dev != dont_lock_dev)
|
|
device_unlock(dev);
|
|
|
|
put_device(dev);
|
|
}
|
|
}
|
|
|
|
void device_links_supplier_sync_state_pause(void)
|
|
{
|
|
device_links_write_lock();
|
|
defer_sync_state_count++;
|
|
device_links_write_unlock();
|
|
}
|
|
|
|
void device_links_supplier_sync_state_resume(void)
|
|
{
|
|
struct device *dev, *tmp;
|
|
LIST_HEAD(sync_list);
|
|
|
|
device_links_write_lock();
|
|
if (!defer_sync_state_count) {
|
|
WARN(true, "Unmatched sync_state pause/resume!");
|
|
goto out;
|
|
}
|
|
defer_sync_state_count--;
|
|
if (defer_sync_state_count)
|
|
goto out;
|
|
|
|
list_for_each_entry_safe(dev, tmp, &deferred_sync, links.defer_sync) {
|
|
/*
|
|
* Delete from deferred_sync list before queuing it to
|
|
* sync_list because defer_sync is used for both lists.
|
|
*/
|
|
list_del_init(&dev->links.defer_sync);
|
|
__device_links_queue_sync_state(dev, &sync_list);
|
|
}
|
|
out:
|
|
device_links_write_unlock();
|
|
|
|
device_links_flush_sync_list(&sync_list, NULL);
|
|
}
|
|
|
|
static int sync_state_resume_initcall(void)
|
|
{
|
|
device_links_supplier_sync_state_resume();
|
|
return 0;
|
|
}
|
|
late_initcall(sync_state_resume_initcall);
|
|
|
|
static void __device_links_supplier_defer_sync(struct device *sup)
|
|
{
|
|
if (list_empty(&sup->links.defer_sync) && dev_has_sync_state(sup))
|
|
list_add_tail(&sup->links.defer_sync, &deferred_sync);
|
|
}
|
|
|
|
static void device_link_drop_managed(struct device_link *link)
|
|
{
|
|
link->flags &= ~DL_FLAG_MANAGED;
|
|
WRITE_ONCE(link->status, DL_STATE_NONE);
|
|
kref_put(&link->kref, __device_link_del);
|
|
}
|
|
|
|
static ssize_t waiting_for_supplier_show(struct device *dev,
|
|
struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
bool val;
|
|
|
|
device_lock(dev);
|
|
mutex_lock(&fwnode_link_lock);
|
|
val = !!fwnode_links_check_suppliers(dev->fwnode);
|
|
mutex_unlock(&fwnode_link_lock);
|
|
device_unlock(dev);
|
|
return sysfs_emit(buf, "%u\n", val);
|
|
}
|
|
static DEVICE_ATTR_RO(waiting_for_supplier);
|
|
|
|
/**
|
|
* device_links_force_bind - Prepares device to be force bound
|
|
* @dev: Consumer device.
|
|
*
|
|
* device_bind_driver() force binds a device to a driver without calling any
|
|
* driver probe functions. So the consumer really isn't going to wait for any
|
|
* supplier before it's bound to the driver. We still want the device link
|
|
* states to be sensible when this happens.
|
|
*
|
|
* In preparation for device_bind_driver(), this function goes through each
|
|
* supplier device links and checks if the supplier is bound. If it is, then
|
|
* the device link status is set to CONSUMER_PROBE. Otherwise, the device link
|
|
* is dropped. Links without the DL_FLAG_MANAGED flag set are ignored.
|
|
*/
|
|
void device_links_force_bind(struct device *dev)
|
|
{
|
|
struct device_link *link, *ln;
|
|
|
|
device_links_write_lock();
|
|
|
|
list_for_each_entry_safe(link, ln, &dev->links.suppliers, c_node) {
|
|
if (!(link->flags & DL_FLAG_MANAGED))
|
|
continue;
|
|
|
|
if (link->status != DL_STATE_AVAILABLE) {
|
|
device_link_drop_managed(link);
|
|
continue;
|
|
}
|
|
WRITE_ONCE(link->status, DL_STATE_CONSUMER_PROBE);
|
|
}
|
|
dev->links.status = DL_DEV_PROBING;
|
|
|
|
device_links_write_unlock();
|
|
}
|
|
|
|
/**
|
|
* device_links_driver_bound - Update device links after probing its driver.
|
|
* @dev: Device to update the links for.
|
|
*
|
|
* The probe has been successful, so update links from this device to any
|
|
* consumers by changing their status to "available".
|
|
*
|
|
* Also change the status of @dev's links to suppliers to "active".
|
|
*
|
|
* Links without the DL_FLAG_MANAGED flag set are ignored.
|
|
*/
|
|
void device_links_driver_bound(struct device *dev)
|
|
{
|
|
struct device_link *link, *ln;
|
|
LIST_HEAD(sync_list);
|
|
|
|
/*
|
|
* If a device binds successfully, it's expected to have created all
|
|
* the device links it needs to or make new device links as it needs
|
|
* them. So, fw_devlink no longer needs to create device links to any
|
|
* of the device's suppliers.
|
|
*
|
|
* Also, if a child firmware node of this bound device is not added as a
|
|
* device by now, assume it is never going to be added. Make this bound
|
|
* device the fallback supplier to the dangling consumers of the child
|
|
* firmware node because this bound device is probably implementing the
|
|
* child firmware node functionality and we don't want the dangling
|
|
* consumers to defer probe indefinitely waiting for a device for the
|
|
* child firmware node.
|
|
*/
|
|
if (dev->fwnode && dev->fwnode->dev == dev) {
|
|
struct fwnode_handle *child;
|
|
fwnode_links_purge_suppliers(dev->fwnode);
|
|
mutex_lock(&fwnode_link_lock);
|
|
fwnode_for_each_available_child_node(dev->fwnode, child)
|
|
__fw_devlink_pickup_dangling_consumers(child,
|
|
dev->fwnode);
|
|
__fw_devlink_link_to_consumers(dev);
|
|
mutex_unlock(&fwnode_link_lock);
|
|
}
|
|
device_remove_file(dev, &dev_attr_waiting_for_supplier);
|
|
|
|
device_links_write_lock();
|
|
|
|
list_for_each_entry(link, &dev->links.consumers, s_node) {
|
|
if (!(link->flags & DL_FLAG_MANAGED))
|
|
continue;
|
|
|
|
/*
|
|
* Links created during consumer probe may be in the "consumer
|
|
* probe" state to start with if the supplier is still probing
|
|
* when they are created and they may become "active" if the
|
|
* consumer probe returns first. Skip them here.
|
|
*/
|
|
if (link->status == DL_STATE_CONSUMER_PROBE ||
|
|
link->status == DL_STATE_ACTIVE)
|
|
continue;
|
|
|
|
WARN_ON(link->status != DL_STATE_DORMANT);
|
|
WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
|
|
|
|
if (link->flags & DL_FLAG_AUTOPROBE_CONSUMER)
|
|
driver_deferred_probe_add(link->consumer);
|
|
}
|
|
|
|
if (defer_sync_state_count)
|
|
__device_links_supplier_defer_sync(dev);
|
|
else
|
|
__device_links_queue_sync_state(dev, &sync_list);
|
|
|
|
list_for_each_entry_safe(link, ln, &dev->links.suppliers, c_node) {
|
|
struct device *supplier;
|
|
|
|
if (!(link->flags & DL_FLAG_MANAGED))
|
|
continue;
|
|
|
|
supplier = link->supplier;
|
|
if (link->flags & DL_FLAG_SYNC_STATE_ONLY) {
|
|
/*
|
|
* When DL_FLAG_SYNC_STATE_ONLY is set, it means no
|
|
* other DL_MANAGED_LINK_FLAGS have been set. So, it's
|
|
* save to drop the managed link completely.
|
|
*/
|
|
device_link_drop_managed(link);
|
|
} else if (dev_is_best_effort(dev) &&
|
|
link->flags & DL_FLAG_INFERRED &&
|
|
link->status != DL_STATE_CONSUMER_PROBE &&
|
|
!link->supplier->can_match) {
|
|
/*
|
|
* When dev_is_best_effort() is true, we ignore device
|
|
* links to suppliers that don't have a driver. If the
|
|
* consumer device still managed to probe, there's no
|
|
* point in maintaining a device link in a weird state
|
|
* (consumer probed before supplier). So delete it.
|
|
*/
|
|
device_link_drop_managed(link);
|
|
} else {
|
|
WARN_ON(link->status != DL_STATE_CONSUMER_PROBE);
|
|
WRITE_ONCE(link->status, DL_STATE_ACTIVE);
|
|
}
|
|
|
|
/*
|
|
* This needs to be done even for the deleted
|
|
* DL_FLAG_SYNC_STATE_ONLY device link in case it was the last
|
|
* device link that was preventing the supplier from getting a
|
|
* sync_state() call.
|
|
*/
|
|
if (defer_sync_state_count)
|
|
__device_links_supplier_defer_sync(supplier);
|
|
else
|
|
__device_links_queue_sync_state(supplier, &sync_list);
|
|
}
|
|
|
|
dev->links.status = DL_DEV_DRIVER_BOUND;
|
|
|
|
device_links_write_unlock();
|
|
|
|
device_links_flush_sync_list(&sync_list, dev);
|
|
}
|
|
|
|
/**
|
|
* __device_links_no_driver - Update links of a device without a driver.
|
|
* @dev: Device without a drvier.
|
|
*
|
|
* Delete all non-persistent links from this device to any suppliers.
|
|
*
|
|
* Persistent links stay around, but their status is changed to "available",
|
|
* unless they already are in the "supplier unbind in progress" state in which
|
|
* case they need not be updated.
|
|
*
|
|
* Links without the DL_FLAG_MANAGED flag set are ignored.
|
|
*/
|
|
static void __device_links_no_driver(struct device *dev)
|
|
{
|
|
struct device_link *link, *ln;
|
|
|
|
list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) {
|
|
if (!(link->flags & DL_FLAG_MANAGED))
|
|
continue;
|
|
|
|
if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER) {
|
|
device_link_drop_managed(link);
|
|
continue;
|
|
}
|
|
|
|
if (link->status != DL_STATE_CONSUMER_PROBE &&
|
|
link->status != DL_STATE_ACTIVE)
|
|
continue;
|
|
|
|
if (link->supplier->links.status == DL_DEV_DRIVER_BOUND) {
|
|
WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
|
|
} else {
|
|
WARN_ON(!(link->flags & DL_FLAG_SYNC_STATE_ONLY));
|
|
WRITE_ONCE(link->status, DL_STATE_DORMANT);
|
|
}
|
|
}
|
|
|
|
dev->links.status = DL_DEV_NO_DRIVER;
|
|
}
|
|
|
|
/**
|
|
* device_links_no_driver - Update links after failing driver probe.
|
|
* @dev: Device whose driver has just failed to probe.
|
|
*
|
|
* Clean up leftover links to consumers for @dev and invoke
|
|
* %__device_links_no_driver() to update links to suppliers for it as
|
|
* appropriate.
|
|
*
|
|
* Links without the DL_FLAG_MANAGED flag set are ignored.
|
|
*/
|
|
void device_links_no_driver(struct device *dev)
|
|
{
|
|
struct device_link *link;
|
|
|
|
device_links_write_lock();
|
|
|
|
list_for_each_entry(link, &dev->links.consumers, s_node) {
|
|
if (!(link->flags & DL_FLAG_MANAGED))
|
|
continue;
|
|
|
|
/*
|
|
* The probe has failed, so if the status of the link is
|
|
* "consumer probe" or "active", it must have been added by
|
|
* a probing consumer while this device was still probing.
|
|
* Change its state to "dormant", as it represents a valid
|
|
* relationship, but it is not functionally meaningful.
|
|
*/
|
|
if (link->status == DL_STATE_CONSUMER_PROBE ||
|
|
link->status == DL_STATE_ACTIVE)
|
|
WRITE_ONCE(link->status, DL_STATE_DORMANT);
|
|
}
|
|
|
|
__device_links_no_driver(dev);
|
|
|
|
device_links_write_unlock();
|
|
}
|
|
|
|
/**
|
|
* device_links_driver_cleanup - Update links after driver removal.
|
|
* @dev: Device whose driver has just gone away.
|
|
*
|
|
* Update links to consumers for @dev by changing their status to "dormant" and
|
|
* invoke %__device_links_no_driver() to update links to suppliers for it as
|
|
* appropriate.
|
|
*
|
|
* Links without the DL_FLAG_MANAGED flag set are ignored.
|
|
*/
|
|
void device_links_driver_cleanup(struct device *dev)
|
|
{
|
|
struct device_link *link, *ln;
|
|
|
|
device_links_write_lock();
|
|
|
|
list_for_each_entry_safe(link, ln, &dev->links.consumers, s_node) {
|
|
if (!(link->flags & DL_FLAG_MANAGED))
|
|
continue;
|
|
|
|
WARN_ON(link->flags & DL_FLAG_AUTOREMOVE_CONSUMER);
|
|
WARN_ON(link->status != DL_STATE_SUPPLIER_UNBIND);
|
|
|
|
/*
|
|
* autoremove the links between this @dev and its consumer
|
|
* devices that are not active, i.e. where the link state
|
|
* has moved to DL_STATE_SUPPLIER_UNBIND.
|
|
*/
|
|
if (link->status == DL_STATE_SUPPLIER_UNBIND &&
|
|
link->flags & DL_FLAG_AUTOREMOVE_SUPPLIER)
|
|
device_link_drop_managed(link);
|
|
|
|
WRITE_ONCE(link->status, DL_STATE_DORMANT);
|
|
}
|
|
|
|
list_del_init(&dev->links.defer_sync);
|
|
__device_links_no_driver(dev);
|
|
|
|
device_links_write_unlock();
|
|
}
|
|
|
|
/**
|
|
* device_links_busy - Check if there are any busy links to consumers.
|
|
* @dev: Device to check.
|
|
*
|
|
* Check each consumer of the device and return 'true' if its link's status
|
|
* is one of "consumer probe" or "active" (meaning that the given consumer is
|
|
* probing right now or its driver is present). Otherwise, change the link
|
|
* state to "supplier unbind" to prevent the consumer from being probed
|
|
* successfully going forward.
|
|
*
|
|
* Return 'false' if there are no probing or active consumers.
|
|
*
|
|
* Links without the DL_FLAG_MANAGED flag set are ignored.
|
|
*/
|
|
bool device_links_busy(struct device *dev)
|
|
{
|
|
struct device_link *link;
|
|
bool ret = false;
|
|
|
|
device_links_write_lock();
|
|
|
|
list_for_each_entry(link, &dev->links.consumers, s_node) {
|
|
if (!(link->flags & DL_FLAG_MANAGED))
|
|
continue;
|
|
|
|
if (link->status == DL_STATE_CONSUMER_PROBE
|
|
|| link->status == DL_STATE_ACTIVE) {
|
|
ret = true;
|
|
break;
|
|
}
|
|
WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND);
|
|
}
|
|
|
|
dev->links.status = DL_DEV_UNBINDING;
|
|
|
|
device_links_write_unlock();
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* device_links_unbind_consumers - Force unbind consumers of the given device.
|
|
* @dev: Device to unbind the consumers of.
|
|
*
|
|
* Walk the list of links to consumers for @dev and if any of them is in the
|
|
* "consumer probe" state, wait for all device probes in progress to complete
|
|
* and start over.
|
|
*
|
|
* If that's not the case, change the status of the link to "supplier unbind"
|
|
* and check if the link was in the "active" state. If so, force the consumer
|
|
* driver to unbind and start over (the consumer will not re-probe as we have
|
|
* changed the state of the link already).
|
|
*
|
|
* Links without the DL_FLAG_MANAGED flag set are ignored.
|
|
*/
|
|
void device_links_unbind_consumers(struct device *dev)
|
|
{
|
|
struct device_link *link;
|
|
|
|
start:
|
|
device_links_write_lock();
|
|
|
|
list_for_each_entry(link, &dev->links.consumers, s_node) {
|
|
enum device_link_state status;
|
|
|
|
if (!(link->flags & DL_FLAG_MANAGED) ||
|
|
link->flags & DL_FLAG_SYNC_STATE_ONLY)
|
|
continue;
|
|
|
|
status = link->status;
|
|
if (status == DL_STATE_CONSUMER_PROBE) {
|
|
device_links_write_unlock();
|
|
|
|
wait_for_device_probe();
|
|
goto start;
|
|
}
|
|
WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND);
|
|
if (status == DL_STATE_ACTIVE) {
|
|
struct device *consumer = link->consumer;
|
|
|
|
get_device(consumer);
|
|
|
|
device_links_write_unlock();
|
|
|
|
device_release_driver_internal(consumer, NULL,
|
|
consumer->parent);
|
|
put_device(consumer);
|
|
goto start;
|
|
}
|
|
}
|
|
|
|
device_links_write_unlock();
|
|
}
|
|
|
|
/**
|
|
* device_links_purge - Delete existing links to other devices.
|
|
* @dev: Target device.
|
|
*/
|
|
static void device_links_purge(struct device *dev)
|
|
{
|
|
struct device_link *link, *ln;
|
|
|
|
if (dev->class == &devlink_class)
|
|
return;
|
|
|
|
/*
|
|
* Delete all of the remaining links from this device to any other
|
|
* devices (either consumers or suppliers).
|
|
*/
|
|
device_links_write_lock();
|
|
|
|
list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) {
|
|
WARN_ON(link->status == DL_STATE_ACTIVE);
|
|
__device_link_del(&link->kref);
|
|
}
|
|
|
|
list_for_each_entry_safe_reverse(link, ln, &dev->links.consumers, s_node) {
|
|
WARN_ON(link->status != DL_STATE_DORMANT &&
|
|
link->status != DL_STATE_NONE);
|
|
__device_link_del(&link->kref);
|
|
}
|
|
|
|
device_links_write_unlock();
|
|
}
|
|
|
|
#define FW_DEVLINK_FLAGS_PERMISSIVE (DL_FLAG_INFERRED | \
|
|
DL_FLAG_SYNC_STATE_ONLY)
|
|
#define FW_DEVLINK_FLAGS_ON (DL_FLAG_INFERRED | \
|
|
DL_FLAG_AUTOPROBE_CONSUMER)
|
|
#define FW_DEVLINK_FLAGS_RPM (FW_DEVLINK_FLAGS_ON | \
|
|
DL_FLAG_PM_RUNTIME)
|
|
|
|
static u32 fw_devlink_flags = FW_DEVLINK_FLAGS_ON;
|
|
static int __init fw_devlink_setup(char *arg)
|
|
{
|
|
if (!arg)
|
|
return -EINVAL;
|
|
|
|
if (strcmp(arg, "off") == 0) {
|
|
fw_devlink_flags = 0;
|
|
} else if (strcmp(arg, "permissive") == 0) {
|
|
fw_devlink_flags = FW_DEVLINK_FLAGS_PERMISSIVE;
|
|
} else if (strcmp(arg, "on") == 0) {
|
|
fw_devlink_flags = FW_DEVLINK_FLAGS_ON;
|
|
} else if (strcmp(arg, "rpm") == 0) {
|
|
fw_devlink_flags = FW_DEVLINK_FLAGS_RPM;
|
|
}
|
|
return 0;
|
|
}
|
|
early_param("fw_devlink", fw_devlink_setup);
|
|
|
|
static bool fw_devlink_strict;
|
|
static int __init fw_devlink_strict_setup(char *arg)
|
|
{
|
|
return kstrtobool(arg, &fw_devlink_strict);
|
|
}
|
|
early_param("fw_devlink.strict", fw_devlink_strict_setup);
|
|
|
|
#define FW_DEVLINK_SYNC_STATE_STRICT 0
|
|
#define FW_DEVLINK_SYNC_STATE_TIMEOUT 1
|
|
|
|
#ifndef CONFIG_FW_DEVLINK_SYNC_STATE_TIMEOUT
|
|
static int fw_devlink_sync_state;
|
|
#else
|
|
static int fw_devlink_sync_state = FW_DEVLINK_SYNC_STATE_TIMEOUT;
|
|
#endif
|
|
|
|
static int __init fw_devlink_sync_state_setup(char *arg)
|
|
{
|
|
if (!arg)
|
|
return -EINVAL;
|
|
|
|
if (strcmp(arg, "strict") == 0) {
|
|
fw_devlink_sync_state = FW_DEVLINK_SYNC_STATE_STRICT;
|
|
return 0;
|
|
} else if (strcmp(arg, "timeout") == 0) {
|
|
fw_devlink_sync_state = FW_DEVLINK_SYNC_STATE_TIMEOUT;
|
|
return 0;
|
|
}
|
|
return -EINVAL;
|
|
}
|
|
early_param("fw_devlink.sync_state", fw_devlink_sync_state_setup);
|
|
|
|
static inline u32 fw_devlink_get_flags(u8 fwlink_flags)
|
|
{
|
|
if (fwlink_flags & FWLINK_FLAG_CYCLE)
|
|
return FW_DEVLINK_FLAGS_PERMISSIVE | DL_FLAG_CYCLE;
|
|
|
|
return fw_devlink_flags;
|
|
}
|
|
|
|
static bool fw_devlink_is_permissive(void)
|
|
{
|
|
return fw_devlink_flags == FW_DEVLINK_FLAGS_PERMISSIVE;
|
|
}
|
|
|
|
bool fw_devlink_is_strict(void)
|
|
{
|
|
return fw_devlink_strict && !fw_devlink_is_permissive();
|
|
}
|
|
|
|
static void fw_devlink_parse_fwnode(struct fwnode_handle *fwnode)
|
|
{
|
|
if (fwnode->flags & FWNODE_FLAG_LINKS_ADDED)
|
|
return;
|
|
|
|
fwnode_call_int_op(fwnode, add_links);
|
|
fwnode->flags |= FWNODE_FLAG_LINKS_ADDED;
|
|
}
|
|
|
|
static void fw_devlink_parse_fwtree(struct fwnode_handle *fwnode)
|
|
{
|
|
struct fwnode_handle *child = NULL;
|
|
|
|
fw_devlink_parse_fwnode(fwnode);
|
|
|
|
while ((child = fwnode_get_next_available_child_node(fwnode, child)))
|
|
fw_devlink_parse_fwtree(child);
|
|
}
|
|
|
|
static void fw_devlink_relax_link(struct device_link *link)
|
|
{
|
|
if (!(link->flags & DL_FLAG_INFERRED))
|
|
return;
|
|
|
|
if (device_link_flag_is_sync_state_only(link->flags))
|
|
return;
|
|
|
|
pm_runtime_drop_link(link);
|
|
link->flags = DL_FLAG_MANAGED | FW_DEVLINK_FLAGS_PERMISSIVE;
|
|
dev_dbg(link->consumer, "Relaxing link with %s\n",
|
|
dev_name(link->supplier));
|
|
}
|
|
|
|
static int fw_devlink_no_driver(struct device *dev, void *data)
|
|
{
|
|
struct device_link *link = to_devlink(dev);
|
|
|
|
if (!link->supplier->can_match)
|
|
fw_devlink_relax_link(link);
|
|
|
|
return 0;
|
|
}
|
|
|
|
void fw_devlink_drivers_done(void)
|
|
{
|
|
fw_devlink_drv_reg_done = true;
|
|
device_links_write_lock();
|
|
class_for_each_device(&devlink_class, NULL, NULL,
|
|
fw_devlink_no_driver);
|
|
device_links_write_unlock();
|
|
}
|
|
|
|
static int fw_devlink_dev_sync_state(struct device *dev, void *data)
|
|
{
|
|
struct device_link *link = to_devlink(dev);
|
|
struct device *sup = link->supplier;
|
|
|
|
if (!(link->flags & DL_FLAG_MANAGED) ||
|
|
link->status == DL_STATE_ACTIVE || sup->state_synced ||
|
|
!dev_has_sync_state(sup))
|
|
return 0;
|
|
|
|
if (fw_devlink_sync_state == FW_DEVLINK_SYNC_STATE_STRICT) {
|
|
dev_warn(sup, "sync_state() pending due to %s\n",
|
|
dev_name(link->consumer));
|
|
return 0;
|
|
}
|
|
|
|
if (!list_empty(&sup->links.defer_sync))
|
|
return 0;
|
|
|
|
dev_warn(sup, "Timed out. Forcing sync_state()\n");
|
|
sup->state_synced = true;
|
|
get_device(sup);
|
|
list_add_tail(&sup->links.defer_sync, data);
|
|
|
|
return 0;
|
|
}
|
|
|
|
void fw_devlink_probing_done(void)
|
|
{
|
|
LIST_HEAD(sync_list);
|
|
|
|
device_links_write_lock();
|
|
class_for_each_device(&devlink_class, NULL, &sync_list,
|
|
fw_devlink_dev_sync_state);
|
|
device_links_write_unlock();
|
|
device_links_flush_sync_list(&sync_list, NULL);
|
|
}
|
|
|
|
/**
|
|
* wait_for_init_devices_probe - Try to probe any device needed for init
|
|
*
|
|
* Some devices might need to be probed and bound successfully before the kernel
|
|
* boot sequence can finish and move on to init/userspace. For example, a
|
|
* network interface might need to be bound to be able to mount a NFS rootfs.
|
|
*
|
|
* With fw_devlink=on by default, some of these devices might be blocked from
|
|
* probing because they are waiting on a optional supplier that doesn't have a
|
|
* driver. While fw_devlink will eventually identify such devices and unblock
|
|
* the probing automatically, it might be too late by the time it unblocks the
|
|
* probing of devices. For example, the IP4 autoconfig might timeout before
|
|
* fw_devlink unblocks probing of the network interface.
|
|
*
|
|
* This function is available to temporarily try and probe all devices that have
|
|
* a driver even if some of their suppliers haven't been added or don't have
|
|
* drivers.
|
|
*
|
|
* The drivers can then decide which of the suppliers are optional vs mandatory
|
|
* and probe the device if possible. By the time this function returns, all such
|
|
* "best effort" probes are guaranteed to be completed. If a device successfully
|
|
* probes in this mode, we delete all fw_devlink discovered dependencies of that
|
|
* device where the supplier hasn't yet probed successfully because they have to
|
|
* be optional dependencies.
|
|
*
|
|
* Any devices that didn't successfully probe go back to being treated as if
|
|
* this function was never called.
|
|
*
|
|
* This also means that some devices that aren't needed for init and could have
|
|
* waited for their optional supplier to probe (when the supplier's module is
|
|
* loaded later on) would end up probing prematurely with limited functionality.
|
|
* So call this function only when boot would fail without it.
|
|
*/
|
|
void __init wait_for_init_devices_probe(void)
|
|
{
|
|
if (!fw_devlink_flags || fw_devlink_is_permissive())
|
|
return;
|
|
|
|
/*
|
|
* Wait for all ongoing probes to finish so that the "best effort" is
|
|
* only applied to devices that can't probe otherwise.
|
|
*/
|
|
wait_for_device_probe();
|
|
|
|
pr_info("Trying to probe devices needed for running init ...\n");
|
|
fw_devlink_best_effort = true;
|
|
driver_deferred_probe_trigger();
|
|
|
|
/*
|
|
* Wait for all "best effort" probes to finish before going back to
|
|
* normal enforcement.
|
|
*/
|
|
wait_for_device_probe();
|
|
fw_devlink_best_effort = false;
|
|
}
|
|
|
|
static void fw_devlink_unblock_consumers(struct device *dev)
|
|
{
|
|
struct device_link *link;
|
|
|
|
if (!fw_devlink_flags || fw_devlink_is_permissive())
|
|
return;
|
|
|
|
device_links_write_lock();
|
|
list_for_each_entry(link, &dev->links.consumers, s_node)
|
|
fw_devlink_relax_link(link);
|
|
device_links_write_unlock();
|
|
}
|
|
|
|
|
|
static bool fwnode_init_without_drv(struct fwnode_handle *fwnode)
|
|
{
|
|
struct device *dev;
|
|
bool ret;
|
|
|
|
if (!(fwnode->flags & FWNODE_FLAG_INITIALIZED))
|
|
return false;
|
|
|
|
dev = get_dev_from_fwnode(fwnode);
|
|
ret = !dev || dev->links.status == DL_DEV_NO_DRIVER;
|
|
put_device(dev);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static bool fwnode_ancestor_init_without_drv(struct fwnode_handle *fwnode)
|
|
{
|
|
struct fwnode_handle *parent;
|
|
|
|
fwnode_for_each_parent_node(fwnode, parent) {
|
|
if (fwnode_init_without_drv(parent)) {
|
|
fwnode_handle_put(parent);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* __fw_devlink_relax_cycles - Relax and mark dependency cycles.
|
|
* @con: Potential consumer device.
|
|
* @sup_handle: Potential supplier's fwnode.
|
|
*
|
|
* Needs to be called with fwnode_lock and device link lock held.
|
|
*
|
|
* Check if @sup_handle or any of its ancestors or suppliers direct/indirectly
|
|
* depend on @con. This function can detect multiple cyles between @sup_handle
|
|
* and @con. When such dependency cycles are found, convert all device links
|
|
* created solely by fw_devlink into SYNC_STATE_ONLY device links. Also, mark
|
|
* all fwnode links in the cycle with FWLINK_FLAG_CYCLE so that when they are
|
|
* converted into a device link in the future, they are created as
|
|
* SYNC_STATE_ONLY device links. This is the equivalent of doing
|
|
* fw_devlink=permissive just between the devices in the cycle. We need to do
|
|
* this because, at this point, fw_devlink can't tell which of these
|
|
* dependencies is not a real dependency.
|
|
*
|
|
* Return true if one or more cycles were found. Otherwise, return false.
|
|
*/
|
|
static bool __fw_devlink_relax_cycles(struct device *con,
|
|
struct fwnode_handle *sup_handle)
|
|
{
|
|
struct device *sup_dev = NULL, *par_dev = NULL;
|
|
struct fwnode_link *link;
|
|
struct device_link *dev_link;
|
|
bool ret = false;
|
|
|
|
if (!sup_handle)
|
|
return false;
|
|
|
|
/*
|
|
* We aren't trying to find all cycles. Just a cycle between con and
|
|
* sup_handle.
|
|
*/
|
|
if (sup_handle->flags & FWNODE_FLAG_VISITED)
|
|
return false;
|
|
|
|
sup_handle->flags |= FWNODE_FLAG_VISITED;
|
|
|
|
sup_dev = get_dev_from_fwnode(sup_handle);
|
|
|
|
/* Termination condition. */
|
|
if (sup_dev == con) {
|
|
ret = true;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* If sup_dev is bound to a driver and @con hasn't started binding to a
|
|
* driver, sup_dev can't be a consumer of @con. So, no need to check
|
|
* further.
|
|
*/
|
|
if (sup_dev && sup_dev->links.status == DL_DEV_DRIVER_BOUND &&
|
|
con->links.status == DL_DEV_NO_DRIVER) {
|
|
ret = false;
|
|
goto out;
|
|
}
|
|
|
|
list_for_each_entry(link, &sup_handle->suppliers, c_hook) {
|
|
if (__fw_devlink_relax_cycles(con, link->supplier)) {
|
|
__fwnode_link_cycle(link);
|
|
ret = true;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Give priority to device parent over fwnode parent to account for any
|
|
* quirks in how fwnodes are converted to devices.
|
|
*/
|
|
if (sup_dev)
|
|
par_dev = get_device(sup_dev->parent);
|
|
else
|
|
par_dev = fwnode_get_next_parent_dev(sup_handle);
|
|
|
|
if (par_dev && __fw_devlink_relax_cycles(con, par_dev->fwnode))
|
|
ret = true;
|
|
|
|
if (!sup_dev)
|
|
goto out;
|
|
|
|
list_for_each_entry(dev_link, &sup_dev->links.suppliers, c_node) {
|
|
/*
|
|
* Ignore a SYNC_STATE_ONLY flag only if it wasn't marked as
|
|
* such due to a cycle.
|
|
*/
|
|
if (device_link_flag_is_sync_state_only(dev_link->flags) &&
|
|
!(dev_link->flags & DL_FLAG_CYCLE))
|
|
continue;
|
|
|
|
if (__fw_devlink_relax_cycles(con,
|
|
dev_link->supplier->fwnode)) {
|
|
fw_devlink_relax_link(dev_link);
|
|
dev_link->flags |= DL_FLAG_CYCLE;
|
|
ret = true;
|
|
}
|
|
}
|
|
|
|
out:
|
|
sup_handle->flags &= ~FWNODE_FLAG_VISITED;
|
|
put_device(sup_dev);
|
|
put_device(par_dev);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* fw_devlink_create_devlink - Create a device link from a consumer to fwnode
|
|
* @con: consumer device for the device link
|
|
* @sup_handle: fwnode handle of supplier
|
|
* @link: fwnode link that's being converted to a device link
|
|
*
|
|
* This function will try to create a device link between the consumer device
|
|
* @con and the supplier device represented by @sup_handle.
|
|
*
|
|
* The supplier has to be provided as a fwnode because incorrect cycles in
|
|
* fwnode links can sometimes cause the supplier device to never be created.
|
|
* This function detects such cases and returns an error if it cannot create a
|
|
* device link from the consumer to a missing supplier.
|
|
*
|
|
* Returns,
|
|
* 0 on successfully creating a device link
|
|
* -EINVAL if the device link cannot be created as expected
|
|
* -EAGAIN if the device link cannot be created right now, but it may be
|
|
* possible to do that in the future
|
|
*/
|
|
static int fw_devlink_create_devlink(struct device *con,
|
|
struct fwnode_handle *sup_handle,
|
|
struct fwnode_link *link)
|
|
{
|
|
struct device *sup_dev;
|
|
int ret = 0;
|
|
u32 flags;
|
|
|
|
if (con->fwnode == link->consumer)
|
|
flags = fw_devlink_get_flags(link->flags);
|
|
else
|
|
flags = FW_DEVLINK_FLAGS_PERMISSIVE;
|
|
|
|
/*
|
|
* In some cases, a device P might also be a supplier to its child node
|
|
* C. However, this would defer the probe of C until the probe of P
|
|
* completes successfully. This is perfectly fine in the device driver
|
|
* model. device_add() doesn't guarantee probe completion of the device
|
|
* by the time it returns.
|
|
*
|
|
* However, there are a few drivers that assume C will finish probing
|
|
* as soon as it's added and before P finishes probing. So, we provide
|
|
* a flag to let fw_devlink know not to delay the probe of C until the
|
|
* probe of P completes successfully.
|
|
*
|
|
* When such a flag is set, we can't create device links where P is the
|
|
* supplier of C as that would delay the probe of C.
|
|
*/
|
|
if (sup_handle->flags & FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD &&
|
|
fwnode_is_ancestor_of(sup_handle, con->fwnode))
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* SYNC_STATE_ONLY device links don't block probing and supports cycles.
|
|
* So cycle detection isn't necessary and shouldn't be done.
|
|
*/
|
|
if (!(flags & DL_FLAG_SYNC_STATE_ONLY)) {
|
|
device_links_write_lock();
|
|
if (__fw_devlink_relax_cycles(con, sup_handle)) {
|
|
__fwnode_link_cycle(link);
|
|
flags = fw_devlink_get_flags(link->flags);
|
|
dev_info(con, "Fixed dependency cycle(s) with %pfwf\n",
|
|
sup_handle);
|
|
}
|
|
device_links_write_unlock();
|
|
}
|
|
|
|
if (sup_handle->flags & FWNODE_FLAG_NOT_DEVICE)
|
|
sup_dev = fwnode_get_next_parent_dev(sup_handle);
|
|
else
|
|
sup_dev = get_dev_from_fwnode(sup_handle);
|
|
|
|
if (sup_dev) {
|
|
/*
|
|
* If it's one of those drivers that don't actually bind to
|
|
* their device using driver core, then don't wait on this
|
|
* supplier device indefinitely.
|
|
*/
|
|
if (sup_dev->links.status == DL_DEV_NO_DRIVER &&
|
|
sup_handle->flags & FWNODE_FLAG_INITIALIZED) {
|
|
dev_dbg(con,
|
|
"Not linking %pfwf - dev might never probe\n",
|
|
sup_handle);
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
if (con != sup_dev && !device_link_add(con, sup_dev, flags)) {
|
|
dev_err(con, "Failed to create device link (0x%x) with %s\n",
|
|
flags, dev_name(sup_dev));
|
|
ret = -EINVAL;
|
|
}
|
|
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Supplier or supplier's ancestor already initialized without a struct
|
|
* device or being probed by a driver.
|
|
*/
|
|
if (fwnode_init_without_drv(sup_handle) ||
|
|
fwnode_ancestor_init_without_drv(sup_handle)) {
|
|
dev_dbg(con, "Not linking %pfwf - might never become dev\n",
|
|
sup_handle);
|
|
return -EINVAL;
|
|
}
|
|
|
|
ret = -EAGAIN;
|
|
out:
|
|
put_device(sup_dev);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* __fw_devlink_link_to_consumers - Create device links to consumers of a device
|
|
* @dev: Device that needs to be linked to its consumers
|
|
*
|
|
* This function looks at all the consumer fwnodes of @dev and creates device
|
|
* links between the consumer device and @dev (supplier).
|
|
*
|
|
* If the consumer device has not been added yet, then this function creates a
|
|
* SYNC_STATE_ONLY link between @dev (supplier) and the closest ancestor device
|
|
* of the consumer fwnode. This is necessary to make sure @dev doesn't get a
|
|
* sync_state() callback before the real consumer device gets to be added and
|
|
* then probed.
|
|
*
|
|
* Once device links are created from the real consumer to @dev (supplier), the
|
|
* fwnode links are deleted.
|
|
*/
|
|
static void __fw_devlink_link_to_consumers(struct device *dev)
|
|
{
|
|
struct fwnode_handle *fwnode = dev->fwnode;
|
|
struct fwnode_link *link, *tmp;
|
|
|
|
list_for_each_entry_safe(link, tmp, &fwnode->consumers, s_hook) {
|
|
struct device *con_dev;
|
|
bool own_link = true;
|
|
int ret;
|
|
|
|
con_dev = get_dev_from_fwnode(link->consumer);
|
|
/*
|
|
* If consumer device is not available yet, make a "proxy"
|
|
* SYNC_STATE_ONLY link from the consumer's parent device to
|
|
* the supplier device. This is necessary to make sure the
|
|
* supplier doesn't get a sync_state() callback before the real
|
|
* consumer can create a device link to the supplier.
|
|
*
|
|
* This proxy link step is needed to handle the case where the
|
|
* consumer's parent device is added before the supplier.
|
|
*/
|
|
if (!con_dev) {
|
|
con_dev = fwnode_get_next_parent_dev(link->consumer);
|
|
/*
|
|
* However, if the consumer's parent device is also the
|
|
* parent of the supplier, don't create a
|
|
* consumer-supplier link from the parent to its child
|
|
* device. Such a dependency is impossible.
|
|
*/
|
|
if (con_dev &&
|
|
fwnode_is_ancestor_of(con_dev->fwnode, fwnode)) {
|
|
put_device(con_dev);
|
|
con_dev = NULL;
|
|
} else {
|
|
own_link = false;
|
|
}
|
|
}
|
|
|
|
if (!con_dev)
|
|
continue;
|
|
|
|
ret = fw_devlink_create_devlink(con_dev, fwnode, link);
|
|
put_device(con_dev);
|
|
if (!own_link || ret == -EAGAIN)
|
|
continue;
|
|
|
|
__fwnode_link_del(link);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* __fw_devlink_link_to_suppliers - Create device links to suppliers of a device
|
|
* @dev: The consumer device that needs to be linked to its suppliers
|
|
* @fwnode: Root of the fwnode tree that is used to create device links
|
|
*
|
|
* This function looks at all the supplier fwnodes of fwnode tree rooted at
|
|
* @fwnode and creates device links between @dev (consumer) and all the
|
|
* supplier devices of the entire fwnode tree at @fwnode.
|
|
*
|
|
* The function creates normal (non-SYNC_STATE_ONLY) device links between @dev
|
|
* and the real suppliers of @dev. Once these device links are created, the
|
|
* fwnode links are deleted.
|
|
*
|
|
* In addition, it also looks at all the suppliers of the entire fwnode tree
|
|
* because some of the child devices of @dev that have not been added yet
|
|
* (because @dev hasn't probed) might already have their suppliers added to
|
|
* driver core. So, this function creates SYNC_STATE_ONLY device links between
|
|
* @dev (consumer) and these suppliers to make sure they don't execute their
|
|
* sync_state() callbacks before these child devices have a chance to create
|
|
* their device links. The fwnode links that correspond to the child devices
|
|
* aren't delete because they are needed later to create the device links
|
|
* between the real consumer and supplier devices.
|
|
*/
|
|
static void __fw_devlink_link_to_suppliers(struct device *dev,
|
|
struct fwnode_handle *fwnode)
|
|
{
|
|
bool own_link = (dev->fwnode == fwnode);
|
|
struct fwnode_link *link, *tmp;
|
|
struct fwnode_handle *child = NULL;
|
|
|
|
list_for_each_entry_safe(link, tmp, &fwnode->suppliers, c_hook) {
|
|
int ret;
|
|
struct fwnode_handle *sup = link->supplier;
|
|
|
|
ret = fw_devlink_create_devlink(dev, sup, link);
|
|
if (!own_link || ret == -EAGAIN)
|
|
continue;
|
|
|
|
__fwnode_link_del(link);
|
|
}
|
|
|
|
/*
|
|
* Make "proxy" SYNC_STATE_ONLY device links to represent the needs of
|
|
* all the descendants. This proxy link step is needed to handle the
|
|
* case where the supplier is added before the consumer's parent device
|
|
* (@dev).
|
|
*/
|
|
while ((child = fwnode_get_next_available_child_node(fwnode, child)))
|
|
__fw_devlink_link_to_suppliers(dev, child);
|
|
}
|
|
|
|
static void fw_devlink_link_device(struct device *dev)
|
|
{
|
|
struct fwnode_handle *fwnode = dev->fwnode;
|
|
|
|
if (!fw_devlink_flags)
|
|
return;
|
|
|
|
fw_devlink_parse_fwtree(fwnode);
|
|
|
|
mutex_lock(&fwnode_link_lock);
|
|
__fw_devlink_link_to_consumers(dev);
|
|
__fw_devlink_link_to_suppliers(dev, fwnode);
|
|
mutex_unlock(&fwnode_link_lock);
|
|
}
|
|
|
|
/* Device links support end. */
|
|
|
|
int (*platform_notify)(struct device *dev) = NULL;
|
|
int (*platform_notify_remove)(struct device *dev) = NULL;
|
|
static struct kobject *dev_kobj;
|
|
|
|
/* /sys/dev/char */
|
|
static struct kobject *sysfs_dev_char_kobj;
|
|
|
|
/* /sys/dev/block */
|
|
static struct kobject *sysfs_dev_block_kobj;
|
|
|
|
static DEFINE_MUTEX(device_hotplug_lock);
|
|
|
|
void lock_device_hotplug(void)
|
|
{
|
|
mutex_lock(&device_hotplug_lock);
|
|
}
|
|
|
|
void unlock_device_hotplug(void)
|
|
{
|
|
mutex_unlock(&device_hotplug_lock);
|
|
}
|
|
|
|
int lock_device_hotplug_sysfs(void)
|
|
{
|
|
if (mutex_trylock(&device_hotplug_lock))
|
|
return 0;
|
|
|
|
/* Avoid busy looping (5 ms of sleep should do). */
|
|
msleep(5);
|
|
return restart_syscall();
|
|
}
|
|
|
|
#ifdef CONFIG_BLOCK
|
|
static inline int device_is_not_partition(struct device *dev)
|
|
{
|
|
return !(dev->type == &part_type);
|
|
}
|
|
#else
|
|
static inline int device_is_not_partition(struct device *dev)
|
|
{
|
|
return 1;
|
|
}
|
|
#endif
|
|
|
|
static void device_platform_notify(struct device *dev)
|
|
{
|
|
acpi_device_notify(dev);
|
|
|
|
software_node_notify(dev);
|
|
|
|
if (platform_notify)
|
|
platform_notify(dev);
|
|
}
|
|
|
|
static void device_platform_notify_remove(struct device *dev)
|
|
{
|
|
if (platform_notify_remove)
|
|
platform_notify_remove(dev);
|
|
|
|
software_node_notify_remove(dev);
|
|
|
|
acpi_device_notify_remove(dev);
|
|
}
|
|
|
|
/**
|
|
* dev_driver_string - Return a device's driver name, if at all possible
|
|
* @dev: struct device to get the name of
|
|
*
|
|
* Will return the device's driver's name if it is bound to a device. If
|
|
* the device is not bound to a driver, it will return the name of the bus
|
|
* it is attached to. If it is not attached to a bus either, an empty
|
|
* string will be returned.
|
|
*/
|
|
const char *dev_driver_string(const struct device *dev)
|
|
{
|
|
struct device_driver *drv;
|
|
|
|
/* dev->driver can change to NULL underneath us because of unbinding,
|
|
* so be careful about accessing it. dev->bus and dev->class should
|
|
* never change once they are set, so they don't need special care.
|
|
*/
|
|
drv = READ_ONCE(dev->driver);
|
|
return drv ? drv->name : dev_bus_name(dev);
|
|
}
|
|
EXPORT_SYMBOL(dev_driver_string);
|
|
|
|
#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
|
|
|
|
static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
|
|
char *buf)
|
|
{
|
|
struct device_attribute *dev_attr = to_dev_attr(attr);
|
|
struct device *dev = kobj_to_dev(kobj);
|
|
ssize_t ret = -EIO;
|
|
|
|
if (dev_attr->show)
|
|
ret = dev_attr->show(dev, dev_attr, buf);
|
|
if (ret >= (ssize_t)PAGE_SIZE) {
|
|
printk("dev_attr_show: %pS returned bad count\n",
|
|
dev_attr->show);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
struct device_attribute *dev_attr = to_dev_attr(attr);
|
|
struct device *dev = kobj_to_dev(kobj);
|
|
ssize_t ret = -EIO;
|
|
|
|
if (dev_attr->store)
|
|
ret = dev_attr->store(dev, dev_attr, buf, count);
|
|
return ret;
|
|
}
|
|
|
|
static const struct sysfs_ops dev_sysfs_ops = {
|
|
.show = dev_attr_show,
|
|
.store = dev_attr_store,
|
|
};
|
|
|
|
#define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
|
|
|
|
ssize_t device_store_ulong(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *buf, size_t size)
|
|
{
|
|
struct dev_ext_attribute *ea = to_ext_attr(attr);
|
|
int ret;
|
|
unsigned long new;
|
|
|
|
ret = kstrtoul(buf, 0, &new);
|
|
if (ret)
|
|
return ret;
|
|
*(unsigned long *)(ea->var) = new;
|
|
/* Always return full write size even if we didn't consume all */
|
|
return size;
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_store_ulong);
|
|
|
|
ssize_t device_show_ulong(struct device *dev,
|
|
struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
struct dev_ext_attribute *ea = to_ext_attr(attr);
|
|
return sysfs_emit(buf, "%lx\n", *(unsigned long *)(ea->var));
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_show_ulong);
|
|
|
|
ssize_t device_store_int(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *buf, size_t size)
|
|
{
|
|
struct dev_ext_attribute *ea = to_ext_attr(attr);
|
|
int ret;
|
|
long new;
|
|
|
|
ret = kstrtol(buf, 0, &new);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (new > INT_MAX || new < INT_MIN)
|
|
return -EINVAL;
|
|
*(int *)(ea->var) = new;
|
|
/* Always return full write size even if we didn't consume all */
|
|
return size;
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_store_int);
|
|
|
|
ssize_t device_show_int(struct device *dev,
|
|
struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
struct dev_ext_attribute *ea = to_ext_attr(attr);
|
|
|
|
return sysfs_emit(buf, "%d\n", *(int *)(ea->var));
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_show_int);
|
|
|
|
ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
|
|
const char *buf, size_t size)
|
|
{
|
|
struct dev_ext_attribute *ea = to_ext_attr(attr);
|
|
|
|
if (kstrtobool(buf, ea->var) < 0)
|
|
return -EINVAL;
|
|
|
|
return size;
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_store_bool);
|
|
|
|
ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
struct dev_ext_attribute *ea = to_ext_attr(attr);
|
|
|
|
return sysfs_emit(buf, "%d\n", *(bool *)(ea->var));
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_show_bool);
|
|
|
|
/**
|
|
* device_release - free device structure.
|
|
* @kobj: device's kobject.
|
|
*
|
|
* This is called once the reference count for the object
|
|
* reaches 0. We forward the call to the device's release
|
|
* method, which should handle actually freeing the structure.
|
|
*/
|
|
static void device_release(struct kobject *kobj)
|
|
{
|
|
struct device *dev = kobj_to_dev(kobj);
|
|
struct device_private *p = dev->p;
|
|
|
|
/*
|
|
* Some platform devices are driven without driver attached
|
|
* and managed resources may have been acquired. Make sure
|
|
* all resources are released.
|
|
*
|
|
* Drivers still can add resources into device after device
|
|
* is deleted but alive, so release devres here to avoid
|
|
* possible memory leak.
|
|
*/
|
|
devres_release_all(dev);
|
|
|
|
kfree(dev->dma_range_map);
|
|
|
|
if (dev->release)
|
|
dev->release(dev);
|
|
else if (dev->type && dev->type->release)
|
|
dev->type->release(dev);
|
|
else if (dev->class && dev->class->dev_release)
|
|
dev->class->dev_release(dev);
|
|
else
|
|
WARN(1, KERN_ERR "Device '%s' does not have a release() function, it is broken and must be fixed. See Documentation/core-api/kobject.rst.\n",
|
|
dev_name(dev));
|
|
kfree(p);
|
|
}
|
|
|
|
static const void *device_namespace(const struct kobject *kobj)
|
|
{
|
|
const struct device *dev = kobj_to_dev(kobj);
|
|
const void *ns = NULL;
|
|
|
|
if (dev->class && dev->class->ns_type)
|
|
ns = dev->class->namespace(dev);
|
|
|
|
return ns;
|
|
}
|
|
|
|
static void device_get_ownership(const struct kobject *kobj, kuid_t *uid, kgid_t *gid)
|
|
{
|
|
const struct device *dev = kobj_to_dev(kobj);
|
|
|
|
if (dev->class && dev->class->get_ownership)
|
|
dev->class->get_ownership(dev, uid, gid);
|
|
}
|
|
|
|
static const struct kobj_type device_ktype = {
|
|
.release = device_release,
|
|
.sysfs_ops = &dev_sysfs_ops,
|
|
.namespace = device_namespace,
|
|
.get_ownership = device_get_ownership,
|
|
};
|
|
|
|
|
|
static int dev_uevent_filter(const struct kobject *kobj)
|
|
{
|
|
const struct kobj_type *ktype = get_ktype(kobj);
|
|
|
|
if (ktype == &device_ktype) {
|
|
const struct device *dev = kobj_to_dev(kobj);
|
|
if (dev->bus)
|
|
return 1;
|
|
if (dev->class)
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static const char *dev_uevent_name(const struct kobject *kobj)
|
|
{
|
|
const struct device *dev = kobj_to_dev(kobj);
|
|
|
|
if (dev->bus)
|
|
return dev->bus->name;
|
|
if (dev->class)
|
|
return dev->class->name;
|
|
return NULL;
|
|
}
|
|
|
|
static int dev_uevent(const struct kobject *kobj, struct kobj_uevent_env *env)
|
|
{
|
|
const struct device *dev = kobj_to_dev(kobj);
|
|
int retval = 0;
|
|
|
|
/* add device node properties if present */
|
|
if (MAJOR(dev->devt)) {
|
|
const char *tmp;
|
|
const char *name;
|
|
umode_t mode = 0;
|
|
kuid_t uid = GLOBAL_ROOT_UID;
|
|
kgid_t gid = GLOBAL_ROOT_GID;
|
|
|
|
add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
|
|
add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
|
|
name = device_get_devnode(dev, &mode, &uid, &gid, &tmp);
|
|
if (name) {
|
|
add_uevent_var(env, "DEVNAME=%s", name);
|
|
if (mode)
|
|
add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
|
|
if (!uid_eq(uid, GLOBAL_ROOT_UID))
|
|
add_uevent_var(env, "DEVUID=%u", from_kuid(&init_user_ns, uid));
|
|
if (!gid_eq(gid, GLOBAL_ROOT_GID))
|
|
add_uevent_var(env, "DEVGID=%u", from_kgid(&init_user_ns, gid));
|
|
kfree(tmp);
|
|
}
|
|
}
|
|
|
|
if (dev->type && dev->type->name)
|
|
add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
|
|
|
|
if (dev->driver)
|
|
add_uevent_var(env, "DRIVER=%s", dev->driver->name);
|
|
|
|
/* Add common DT information about the device */
|
|
of_device_uevent(dev, env);
|
|
|
|
/* have the bus specific function add its stuff */
|
|
if (dev->bus && dev->bus->uevent) {
|
|
retval = dev->bus->uevent(dev, env);
|
|
if (retval)
|
|
pr_debug("device: '%s': %s: bus uevent() returned %d\n",
|
|
dev_name(dev), __func__, retval);
|
|
}
|
|
|
|
/* have the class specific function add its stuff */
|
|
if (dev->class && dev->class->dev_uevent) {
|
|
retval = dev->class->dev_uevent(dev, env);
|
|
if (retval)
|
|
pr_debug("device: '%s': %s: class uevent() "
|
|
"returned %d\n", dev_name(dev),
|
|
__func__, retval);
|
|
}
|
|
|
|
/* have the device type specific function add its stuff */
|
|
if (dev->type && dev->type->uevent) {
|
|
retval = dev->type->uevent(dev, env);
|
|
if (retval)
|
|
pr_debug("device: '%s': %s: dev_type uevent() "
|
|
"returned %d\n", dev_name(dev),
|
|
__func__, retval);
|
|
}
|
|
|
|
return retval;
|
|
}
|
|
|
|
static const struct kset_uevent_ops device_uevent_ops = {
|
|
.filter = dev_uevent_filter,
|
|
.name = dev_uevent_name,
|
|
.uevent = dev_uevent,
|
|
};
|
|
|
|
static ssize_t uevent_show(struct device *dev, struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
struct kobject *top_kobj;
|
|
struct kset *kset;
|
|
struct kobj_uevent_env *env = NULL;
|
|
int i;
|
|
int len = 0;
|
|
int retval;
|
|
|
|
/* search the kset, the device belongs to */
|
|
top_kobj = &dev->kobj;
|
|
while (!top_kobj->kset && top_kobj->parent)
|
|
top_kobj = top_kobj->parent;
|
|
if (!top_kobj->kset)
|
|
goto out;
|
|
|
|
kset = top_kobj->kset;
|
|
if (!kset->uevent_ops || !kset->uevent_ops->uevent)
|
|
goto out;
|
|
|
|
/* respect filter */
|
|
if (kset->uevent_ops && kset->uevent_ops->filter)
|
|
if (!kset->uevent_ops->filter(&dev->kobj))
|
|
goto out;
|
|
|
|
env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
|
|
if (!env)
|
|
return -ENOMEM;
|
|
|
|
/* let the kset specific function add its keys */
|
|
retval = kset->uevent_ops->uevent(&dev->kobj, env);
|
|
if (retval)
|
|
goto out;
|
|
|
|
/* copy keys to file */
|
|
for (i = 0; i < env->envp_idx; i++)
|
|
len += sysfs_emit_at(buf, len, "%s\n", env->envp[i]);
|
|
out:
|
|
kfree(env);
|
|
return len;
|
|
}
|
|
|
|
static ssize_t uevent_store(struct device *dev, struct device_attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
int rc;
|
|
|
|
rc = kobject_synth_uevent(&dev->kobj, buf, count);
|
|
|
|
if (rc) {
|
|
dev_err(dev, "uevent: failed to send synthetic uevent: %d\n", rc);
|
|
return rc;
|
|
}
|
|
|
|
return count;
|
|
}
|
|
static DEVICE_ATTR_RW(uevent);
|
|
|
|
static ssize_t online_show(struct device *dev, struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
bool val;
|
|
|
|
device_lock(dev);
|
|
val = !dev->offline;
|
|
device_unlock(dev);
|
|
return sysfs_emit(buf, "%u\n", val);
|
|
}
|
|
|
|
static ssize_t online_store(struct device *dev, struct device_attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
bool val;
|
|
int ret;
|
|
|
|
ret = kstrtobool(buf, &val);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ret = lock_device_hotplug_sysfs();
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = val ? device_online(dev) : device_offline(dev);
|
|
unlock_device_hotplug();
|
|
return ret < 0 ? ret : count;
|
|
}
|
|
static DEVICE_ATTR_RW(online);
|
|
|
|
static ssize_t removable_show(struct device *dev, struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
const char *loc;
|
|
|
|
switch (dev->removable) {
|
|
case DEVICE_REMOVABLE:
|
|
loc = "removable";
|
|
break;
|
|
case DEVICE_FIXED:
|
|
loc = "fixed";
|
|
break;
|
|
default:
|
|
loc = "unknown";
|
|
}
|
|
return sysfs_emit(buf, "%s\n", loc);
|
|
}
|
|
static DEVICE_ATTR_RO(removable);
|
|
|
|
int device_add_groups(struct device *dev, const struct attribute_group **groups)
|
|
{
|
|
return sysfs_create_groups(&dev->kobj, groups);
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_add_groups);
|
|
|
|
void device_remove_groups(struct device *dev,
|
|
const struct attribute_group **groups)
|
|
{
|
|
sysfs_remove_groups(&dev->kobj, groups);
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_remove_groups);
|
|
|
|
union device_attr_group_devres {
|
|
const struct attribute_group *group;
|
|
const struct attribute_group **groups;
|
|
};
|
|
|
|
static void devm_attr_group_remove(struct device *dev, void *res)
|
|
{
|
|
union device_attr_group_devres *devres = res;
|
|
const struct attribute_group *group = devres->group;
|
|
|
|
dev_dbg(dev, "%s: removing group %p\n", __func__, group);
|
|
sysfs_remove_group(&dev->kobj, group);
|
|
}
|
|
|
|
static void devm_attr_groups_remove(struct device *dev, void *res)
|
|
{
|
|
union device_attr_group_devres *devres = res;
|
|
const struct attribute_group **groups = devres->groups;
|
|
|
|
dev_dbg(dev, "%s: removing groups %p\n", __func__, groups);
|
|
sysfs_remove_groups(&dev->kobj, groups);
|
|
}
|
|
|
|
/**
|
|
* devm_device_add_group - given a device, create a managed attribute group
|
|
* @dev: The device to create the group for
|
|
* @grp: The attribute group to create
|
|
*
|
|
* This function creates a group for the first time. It will explicitly
|
|
* warn and error if any of the attribute files being created already exist.
|
|
*
|
|
* Returns 0 on success or error code on failure.
|
|
*/
|
|
int devm_device_add_group(struct device *dev, const struct attribute_group *grp)
|
|
{
|
|
union device_attr_group_devres *devres;
|
|
int error;
|
|
|
|
devres = devres_alloc(devm_attr_group_remove,
|
|
sizeof(*devres), GFP_KERNEL);
|
|
if (!devres)
|
|
return -ENOMEM;
|
|
|
|
error = sysfs_create_group(&dev->kobj, grp);
|
|
if (error) {
|
|
devres_free(devres);
|
|
return error;
|
|
}
|
|
|
|
devres->group = grp;
|
|
devres_add(dev, devres);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_device_add_group);
|
|
|
|
/**
|
|
* devm_device_add_groups - create a bunch of managed attribute groups
|
|
* @dev: The device to create the group for
|
|
* @groups: The attribute groups to create, NULL terminated
|
|
*
|
|
* This function creates a bunch of managed attribute groups. If an error
|
|
* occurs when creating a group, all previously created groups will be
|
|
* removed, unwinding everything back to the original state when this
|
|
* function was called. It will explicitly warn and error if any of the
|
|
* attribute files being created already exist.
|
|
*
|
|
* Returns 0 on success or error code from sysfs_create_group on failure.
|
|
*/
|
|
int devm_device_add_groups(struct device *dev,
|
|
const struct attribute_group **groups)
|
|
{
|
|
union device_attr_group_devres *devres;
|
|
int error;
|
|
|
|
devres = devres_alloc(devm_attr_groups_remove,
|
|
sizeof(*devres), GFP_KERNEL);
|
|
if (!devres)
|
|
return -ENOMEM;
|
|
|
|
error = sysfs_create_groups(&dev->kobj, groups);
|
|
if (error) {
|
|
devres_free(devres);
|
|
return error;
|
|
}
|
|
|
|
devres->groups = groups;
|
|
devres_add(dev, devres);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_device_add_groups);
|
|
|
|
static int device_add_attrs(struct device *dev)
|
|
{
|
|
const struct class *class = dev->class;
|
|
const struct device_type *type = dev->type;
|
|
int error;
|
|
|
|
if (class) {
|
|
error = device_add_groups(dev, class->dev_groups);
|
|
if (error)
|
|
return error;
|
|
}
|
|
|
|
if (type) {
|
|
error = device_add_groups(dev, type->groups);
|
|
if (error)
|
|
goto err_remove_class_groups;
|
|
}
|
|
|
|
error = device_add_groups(dev, dev->groups);
|
|
if (error)
|
|
goto err_remove_type_groups;
|
|
|
|
if (device_supports_offline(dev) && !dev->offline_disabled) {
|
|
error = device_create_file(dev, &dev_attr_online);
|
|
if (error)
|
|
goto err_remove_dev_groups;
|
|
}
|
|
|
|
if (fw_devlink_flags && !fw_devlink_is_permissive() && dev->fwnode) {
|
|
error = device_create_file(dev, &dev_attr_waiting_for_supplier);
|
|
if (error)
|
|
goto err_remove_dev_online;
|
|
}
|
|
|
|
if (dev_removable_is_valid(dev)) {
|
|
error = device_create_file(dev, &dev_attr_removable);
|
|
if (error)
|
|
goto err_remove_dev_waiting_for_supplier;
|
|
}
|
|
|
|
if (dev_add_physical_location(dev)) {
|
|
error = device_add_group(dev,
|
|
&dev_attr_physical_location_group);
|
|
if (error)
|
|
goto err_remove_dev_removable;
|
|
}
|
|
|
|
return 0;
|
|
|
|
err_remove_dev_removable:
|
|
device_remove_file(dev, &dev_attr_removable);
|
|
err_remove_dev_waiting_for_supplier:
|
|
device_remove_file(dev, &dev_attr_waiting_for_supplier);
|
|
err_remove_dev_online:
|
|
device_remove_file(dev, &dev_attr_online);
|
|
err_remove_dev_groups:
|
|
device_remove_groups(dev, dev->groups);
|
|
err_remove_type_groups:
|
|
if (type)
|
|
device_remove_groups(dev, type->groups);
|
|
err_remove_class_groups:
|
|
if (class)
|
|
device_remove_groups(dev, class->dev_groups);
|
|
|
|
return error;
|
|
}
|
|
|
|
static void device_remove_attrs(struct device *dev)
|
|
{
|
|
const struct class *class = dev->class;
|
|
const struct device_type *type = dev->type;
|
|
|
|
if (dev->physical_location) {
|
|
device_remove_group(dev, &dev_attr_physical_location_group);
|
|
kfree(dev->physical_location);
|
|
}
|
|
|
|
device_remove_file(dev, &dev_attr_removable);
|
|
device_remove_file(dev, &dev_attr_waiting_for_supplier);
|
|
device_remove_file(dev, &dev_attr_online);
|
|
device_remove_groups(dev, dev->groups);
|
|
|
|
if (type)
|
|
device_remove_groups(dev, type->groups);
|
|
|
|
if (class)
|
|
device_remove_groups(dev, class->dev_groups);
|
|
}
|
|
|
|
static ssize_t dev_show(struct device *dev, struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
return print_dev_t(buf, dev->devt);
|
|
}
|
|
static DEVICE_ATTR_RO(dev);
|
|
|
|
/* /sys/devices/ */
|
|
struct kset *devices_kset;
|
|
|
|
/**
|
|
* devices_kset_move_before - Move device in the devices_kset's list.
|
|
* @deva: Device to move.
|
|
* @devb: Device @deva should come before.
|
|
*/
|
|
static void devices_kset_move_before(struct device *deva, struct device *devb)
|
|
{
|
|
if (!devices_kset)
|
|
return;
|
|
pr_debug("devices_kset: Moving %s before %s\n",
|
|
dev_name(deva), dev_name(devb));
|
|
spin_lock(&devices_kset->list_lock);
|
|
list_move_tail(&deva->kobj.entry, &devb->kobj.entry);
|
|
spin_unlock(&devices_kset->list_lock);
|
|
}
|
|
|
|
/**
|
|
* devices_kset_move_after - Move device in the devices_kset's list.
|
|
* @deva: Device to move
|
|
* @devb: Device @deva should come after.
|
|
*/
|
|
static void devices_kset_move_after(struct device *deva, struct device *devb)
|
|
{
|
|
if (!devices_kset)
|
|
return;
|
|
pr_debug("devices_kset: Moving %s after %s\n",
|
|
dev_name(deva), dev_name(devb));
|
|
spin_lock(&devices_kset->list_lock);
|
|
list_move(&deva->kobj.entry, &devb->kobj.entry);
|
|
spin_unlock(&devices_kset->list_lock);
|
|
}
|
|
|
|
/**
|
|
* devices_kset_move_last - move the device to the end of devices_kset's list.
|
|
* @dev: device to move
|
|
*/
|
|
void devices_kset_move_last(struct device *dev)
|
|
{
|
|
if (!devices_kset)
|
|
return;
|
|
pr_debug("devices_kset: Moving %s to end of list\n", dev_name(dev));
|
|
spin_lock(&devices_kset->list_lock);
|
|
list_move_tail(&dev->kobj.entry, &devices_kset->list);
|
|
spin_unlock(&devices_kset->list_lock);
|
|
}
|
|
|
|
/**
|
|
* device_create_file - create sysfs attribute file for device.
|
|
* @dev: device.
|
|
* @attr: device attribute descriptor.
|
|
*/
|
|
int device_create_file(struct device *dev,
|
|
const struct device_attribute *attr)
|
|
{
|
|
int error = 0;
|
|
|
|
if (dev) {
|
|
WARN(((attr->attr.mode & S_IWUGO) && !attr->store),
|
|
"Attribute %s: write permission without 'store'\n",
|
|
attr->attr.name);
|
|
WARN(((attr->attr.mode & S_IRUGO) && !attr->show),
|
|
"Attribute %s: read permission without 'show'\n",
|
|
attr->attr.name);
|
|
error = sysfs_create_file(&dev->kobj, &attr->attr);
|
|
}
|
|
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_create_file);
|
|
|
|
/**
|
|
* device_remove_file - remove sysfs attribute file.
|
|
* @dev: device.
|
|
* @attr: device attribute descriptor.
|
|
*/
|
|
void device_remove_file(struct device *dev,
|
|
const struct device_attribute *attr)
|
|
{
|
|
if (dev)
|
|
sysfs_remove_file(&dev->kobj, &attr->attr);
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_remove_file);
|
|
|
|
/**
|
|
* device_remove_file_self - remove sysfs attribute file from its own method.
|
|
* @dev: device.
|
|
* @attr: device attribute descriptor.
|
|
*
|
|
* See kernfs_remove_self() for details.
|
|
*/
|
|
bool device_remove_file_self(struct device *dev,
|
|
const struct device_attribute *attr)
|
|
{
|
|
if (dev)
|
|
return sysfs_remove_file_self(&dev->kobj, &attr->attr);
|
|
else
|
|
return false;
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_remove_file_self);
|
|
|
|
/**
|
|
* device_create_bin_file - create sysfs binary attribute file for device.
|
|
* @dev: device.
|
|
* @attr: device binary attribute descriptor.
|
|
*/
|
|
int device_create_bin_file(struct device *dev,
|
|
const struct bin_attribute *attr)
|
|
{
|
|
int error = -EINVAL;
|
|
if (dev)
|
|
error = sysfs_create_bin_file(&dev->kobj, attr);
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_create_bin_file);
|
|
|
|
/**
|
|
* device_remove_bin_file - remove sysfs binary attribute file
|
|
* @dev: device.
|
|
* @attr: device binary attribute descriptor.
|
|
*/
|
|
void device_remove_bin_file(struct device *dev,
|
|
const struct bin_attribute *attr)
|
|
{
|
|
if (dev)
|
|
sysfs_remove_bin_file(&dev->kobj, attr);
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_remove_bin_file);
|
|
|
|
static void klist_children_get(struct klist_node *n)
|
|
{
|
|
struct device_private *p = to_device_private_parent(n);
|
|
struct device *dev = p->device;
|
|
|
|
get_device(dev);
|
|
}
|
|
|
|
static void klist_children_put(struct klist_node *n)
|
|
{
|
|
struct device_private *p = to_device_private_parent(n);
|
|
struct device *dev = p->device;
|
|
|
|
put_device(dev);
|
|
}
|
|
|
|
/**
|
|
* device_initialize - init device structure.
|
|
* @dev: device.
|
|
*
|
|
* This prepares the device for use by other layers by initializing
|
|
* its fields.
|
|
* It is the first half of device_register(), if called by
|
|
* that function, though it can also be called separately, so one
|
|
* may use @dev's fields. In particular, get_device()/put_device()
|
|
* may be used for reference counting of @dev after calling this
|
|
* function.
|
|
*
|
|
* All fields in @dev must be initialized by the caller to 0, except
|
|
* for those explicitly set to some other value. The simplest
|
|
* approach is to use kzalloc() to allocate the structure containing
|
|
* @dev.
|
|
*
|
|
* NOTE: Use put_device() to give up your reference instead of freeing
|
|
* @dev directly once you have called this function.
|
|
*/
|
|
void device_initialize(struct device *dev)
|
|
{
|
|
dev->kobj.kset = devices_kset;
|
|
kobject_init(&dev->kobj, &device_ktype);
|
|
INIT_LIST_HEAD(&dev->dma_pools);
|
|
mutex_init(&dev->mutex);
|
|
lockdep_set_novalidate_class(&dev->mutex);
|
|
spin_lock_init(&dev->devres_lock);
|
|
INIT_LIST_HEAD(&dev->devres_head);
|
|
device_pm_init(dev);
|
|
set_dev_node(dev, NUMA_NO_NODE);
|
|
INIT_LIST_HEAD(&dev->links.consumers);
|
|
INIT_LIST_HEAD(&dev->links.suppliers);
|
|
INIT_LIST_HEAD(&dev->links.defer_sync);
|
|
dev->links.status = DL_DEV_NO_DRIVER;
|
|
#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
|
|
defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
|
|
defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
|
|
dev->dma_coherent = dma_default_coherent;
|
|
#endif
|
|
swiotlb_dev_init(dev);
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_initialize);
|
|
|
|
struct kobject *virtual_device_parent(struct device *dev)
|
|
{
|
|
static struct kobject *virtual_dir = NULL;
|
|
|
|
if (!virtual_dir)
|
|
virtual_dir = kobject_create_and_add("virtual",
|
|
&devices_kset->kobj);
|
|
|
|
return virtual_dir;
|
|
}
|
|
|
|
struct class_dir {
|
|
struct kobject kobj;
|
|
const struct class *class;
|
|
};
|
|
|
|
#define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
|
|
|
|
static void class_dir_release(struct kobject *kobj)
|
|
{
|
|
struct class_dir *dir = to_class_dir(kobj);
|
|
kfree(dir);
|
|
}
|
|
|
|
static const
|
|
struct kobj_ns_type_operations *class_dir_child_ns_type(const struct kobject *kobj)
|
|
{
|
|
const struct class_dir *dir = to_class_dir(kobj);
|
|
return dir->class->ns_type;
|
|
}
|
|
|
|
static const struct kobj_type class_dir_ktype = {
|
|
.release = class_dir_release,
|
|
.sysfs_ops = &kobj_sysfs_ops,
|
|
.child_ns_type = class_dir_child_ns_type
|
|
};
|
|
|
|
static struct kobject *class_dir_create_and_add(struct subsys_private *sp,
|
|
struct kobject *parent_kobj)
|
|
{
|
|
struct class_dir *dir;
|
|
int retval;
|
|
|
|
dir = kzalloc(sizeof(*dir), GFP_KERNEL);
|
|
if (!dir)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
dir->class = sp->class;
|
|
kobject_init(&dir->kobj, &class_dir_ktype);
|
|
|
|
dir->kobj.kset = &sp->glue_dirs;
|
|
|
|
retval = kobject_add(&dir->kobj, parent_kobj, "%s", sp->class->name);
|
|
if (retval < 0) {
|
|
kobject_put(&dir->kobj);
|
|
return ERR_PTR(retval);
|
|
}
|
|
return &dir->kobj;
|
|
}
|
|
|
|
static DEFINE_MUTEX(gdp_mutex);
|
|
|
|
static struct kobject *get_device_parent(struct device *dev,
|
|
struct device *parent)
|
|
{
|
|
struct subsys_private *sp = class_to_subsys(dev->class);
|
|
struct kobject *kobj = NULL;
|
|
|
|
if (sp) {
|
|
struct kobject *parent_kobj;
|
|
struct kobject *k;
|
|
|
|
/*
|
|
* If we have no parent, we live in "virtual".
|
|
* Class-devices with a non class-device as parent, live
|
|
* in a "glue" directory to prevent namespace collisions.
|
|
*/
|
|
if (parent == NULL)
|
|
parent_kobj = virtual_device_parent(dev);
|
|
else if (parent->class && !dev->class->ns_type) {
|
|
subsys_put(sp);
|
|
return &parent->kobj;
|
|
} else {
|
|
parent_kobj = &parent->kobj;
|
|
}
|
|
|
|
mutex_lock(&gdp_mutex);
|
|
|
|
/* find our class-directory at the parent and reference it */
|
|
spin_lock(&sp->glue_dirs.list_lock);
|
|
list_for_each_entry(k, &sp->glue_dirs.list, entry)
|
|
if (k->parent == parent_kobj) {
|
|
kobj = kobject_get(k);
|
|
break;
|
|
}
|
|
spin_unlock(&sp->glue_dirs.list_lock);
|
|
if (kobj) {
|
|
mutex_unlock(&gdp_mutex);
|
|
subsys_put(sp);
|
|
return kobj;
|
|
}
|
|
|
|
/* or create a new class-directory at the parent device */
|
|
k = class_dir_create_and_add(sp, parent_kobj);
|
|
/* do not emit an uevent for this simple "glue" directory */
|
|
mutex_unlock(&gdp_mutex);
|
|
subsys_put(sp);
|
|
return k;
|
|
}
|
|
|
|
/* subsystems can specify a default root directory for their devices */
|
|
if (!parent && dev->bus) {
|
|
struct device *dev_root = bus_get_dev_root(dev->bus);
|
|
|
|
if (dev_root) {
|
|
kobj = &dev_root->kobj;
|
|
put_device(dev_root);
|
|
return kobj;
|
|
}
|
|
}
|
|
|
|
if (parent)
|
|
return &parent->kobj;
|
|
return NULL;
|
|
}
|
|
|
|
static inline bool live_in_glue_dir(struct kobject *kobj,
|
|
struct device *dev)
|
|
{
|
|
struct subsys_private *sp;
|
|
bool retval;
|
|
|
|
if (!kobj || !dev->class)
|
|
return false;
|
|
|
|
sp = class_to_subsys(dev->class);
|
|
if (!sp)
|
|
return false;
|
|
|
|
if (kobj->kset == &sp->glue_dirs)
|
|
retval = true;
|
|
else
|
|
retval = false;
|
|
|
|
subsys_put(sp);
|
|
return retval;
|
|
}
|
|
|
|
static inline struct kobject *get_glue_dir(struct device *dev)
|
|
{
|
|
return dev->kobj.parent;
|
|
}
|
|
|
|
/**
|
|
* kobject_has_children - Returns whether a kobject has children.
|
|
* @kobj: the object to test
|
|
*
|
|
* This will return whether a kobject has other kobjects as children.
|
|
*
|
|
* It does NOT account for the presence of attribute files, only sub
|
|
* directories. It also assumes there is no concurrent addition or
|
|
* removal of such children, and thus relies on external locking.
|
|
*/
|
|
static inline bool kobject_has_children(struct kobject *kobj)
|
|
{
|
|
WARN_ON_ONCE(kref_read(&kobj->kref) == 0);
|
|
|
|
return kobj->sd && kobj->sd->dir.subdirs;
|
|
}
|
|
|
|
/*
|
|
* make sure cleaning up dir as the last step, we need to make
|
|
* sure .release handler of kobject is run with holding the
|
|
* global lock
|
|
*/
|
|
static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
|
|
{
|
|
unsigned int ref;
|
|
|
|
/* see if we live in a "glue" directory */
|
|
if (!live_in_glue_dir(glue_dir, dev))
|
|
return;
|
|
|
|
mutex_lock(&gdp_mutex);
|
|
/**
|
|
* There is a race condition between removing glue directory
|
|
* and adding a new device under the glue directory.
|
|
*
|
|
* CPU1: CPU2:
|
|
*
|
|
* device_add()
|
|
* get_device_parent()
|
|
* class_dir_create_and_add()
|
|
* kobject_add_internal()
|
|
* create_dir() // create glue_dir
|
|
*
|
|
* device_add()
|
|
* get_device_parent()
|
|
* kobject_get() // get glue_dir
|
|
*
|
|
* device_del()
|
|
* cleanup_glue_dir()
|
|
* kobject_del(glue_dir)
|
|
*
|
|
* kobject_add()
|
|
* kobject_add_internal()
|
|
* create_dir() // in glue_dir
|
|
* sysfs_create_dir_ns()
|
|
* kernfs_create_dir_ns(sd)
|
|
*
|
|
* sysfs_remove_dir() // glue_dir->sd=NULL
|
|
* sysfs_put() // free glue_dir->sd
|
|
*
|
|
* // sd is freed
|
|
* kernfs_new_node(sd)
|
|
* kernfs_get(glue_dir)
|
|
* kernfs_add_one()
|
|
* kernfs_put()
|
|
*
|
|
* Before CPU1 remove last child device under glue dir, if CPU2 add
|
|
* a new device under glue dir, the glue_dir kobject reference count
|
|
* will be increase to 2 in kobject_get(k). And CPU2 has been called
|
|
* kernfs_create_dir_ns(). Meanwhile, CPU1 call sysfs_remove_dir()
|
|
* and sysfs_put(). This result in glue_dir->sd is freed.
|
|
*
|
|
* Then the CPU2 will see a stale "empty" but still potentially used
|
|
* glue dir around in kernfs_new_node().
|
|
*
|
|
* In order to avoid this happening, we also should make sure that
|
|
* kernfs_node for glue_dir is released in CPU1 only when refcount
|
|
* for glue_dir kobj is 1.
|
|
*/
|
|
ref = kref_read(&glue_dir->kref);
|
|
if (!kobject_has_children(glue_dir) && !--ref)
|
|
kobject_del(glue_dir);
|
|
kobject_put(glue_dir);
|
|
mutex_unlock(&gdp_mutex);
|
|
}
|
|
|
|
static int device_add_class_symlinks(struct device *dev)
|
|
{
|
|
struct device_node *of_node = dev_of_node(dev);
|
|
struct subsys_private *sp;
|
|
int error;
|
|
|
|
if (of_node) {
|
|
error = sysfs_create_link(&dev->kobj, of_node_kobj(of_node), "of_node");
|
|
if (error)
|
|
dev_warn(dev, "Error %d creating of_node link\n",error);
|
|
/* An error here doesn't warrant bringing down the device */
|
|
}
|
|
|
|
sp = class_to_subsys(dev->class);
|
|
if (!sp)
|
|
return 0;
|
|
|
|
error = sysfs_create_link(&dev->kobj, &sp->subsys.kobj, "subsystem");
|
|
if (error)
|
|
goto out_devnode;
|
|
|
|
if (dev->parent && device_is_not_partition(dev)) {
|
|
error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
|
|
"device");
|
|
if (error)
|
|
goto out_subsys;
|
|
}
|
|
|
|
/* link in the class directory pointing to the device */
|
|
error = sysfs_create_link(&sp->subsys.kobj, &dev->kobj, dev_name(dev));
|
|
if (error)
|
|
goto out_device;
|
|
goto exit;
|
|
|
|
out_device:
|
|
sysfs_remove_link(&dev->kobj, "device");
|
|
out_subsys:
|
|
sysfs_remove_link(&dev->kobj, "subsystem");
|
|
out_devnode:
|
|
sysfs_remove_link(&dev->kobj, "of_node");
|
|
exit:
|
|
subsys_put(sp);
|
|
return error;
|
|
}
|
|
|
|
static void device_remove_class_symlinks(struct device *dev)
|
|
{
|
|
struct subsys_private *sp = class_to_subsys(dev->class);
|
|
|
|
if (dev_of_node(dev))
|
|
sysfs_remove_link(&dev->kobj, "of_node");
|
|
|
|
if (!sp)
|
|
return;
|
|
|
|
if (dev->parent && device_is_not_partition(dev))
|
|
sysfs_remove_link(&dev->kobj, "device");
|
|
sysfs_remove_link(&dev->kobj, "subsystem");
|
|
sysfs_delete_link(&sp->subsys.kobj, &dev->kobj, dev_name(dev));
|
|
subsys_put(sp);
|
|
}
|
|
|
|
/**
|
|
* dev_set_name - set a device name
|
|
* @dev: device
|
|
* @fmt: format string for the device's name
|
|
*/
|
|
int dev_set_name(struct device *dev, const char *fmt, ...)
|
|
{
|
|
va_list vargs;
|
|
int err;
|
|
|
|
va_start(vargs, fmt);
|
|
err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
|
|
va_end(vargs);
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dev_set_name);
|
|
|
|
/* select a /sys/dev/ directory for the device */
|
|
static struct kobject *device_to_dev_kobj(struct device *dev)
|
|
{
|
|
if (is_blockdev(dev))
|
|
return sysfs_dev_block_kobj;
|
|
else
|
|
return sysfs_dev_char_kobj;
|
|
}
|
|
|
|
static int device_create_sys_dev_entry(struct device *dev)
|
|
{
|
|
struct kobject *kobj = device_to_dev_kobj(dev);
|
|
int error = 0;
|
|
char devt_str[15];
|
|
|
|
if (kobj) {
|
|
format_dev_t(devt_str, dev->devt);
|
|
error = sysfs_create_link(kobj, &dev->kobj, devt_str);
|
|
}
|
|
|
|
return error;
|
|
}
|
|
|
|
static void device_remove_sys_dev_entry(struct device *dev)
|
|
{
|
|
struct kobject *kobj = device_to_dev_kobj(dev);
|
|
char devt_str[15];
|
|
|
|
if (kobj) {
|
|
format_dev_t(devt_str, dev->devt);
|
|
sysfs_remove_link(kobj, devt_str);
|
|
}
|
|
}
|
|
|
|
static int device_private_init(struct device *dev)
|
|
{
|
|
dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
|
|
if (!dev->p)
|
|
return -ENOMEM;
|
|
dev->p->device = dev;
|
|
klist_init(&dev->p->klist_children, klist_children_get,
|
|
klist_children_put);
|
|
INIT_LIST_HEAD(&dev->p->deferred_probe);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* device_add - add device to device hierarchy.
|
|
* @dev: device.
|
|
*
|
|
* This is part 2 of device_register(), though may be called
|
|
* separately _iff_ device_initialize() has been called separately.
|
|
*
|
|
* This adds @dev to the kobject hierarchy via kobject_add(), adds it
|
|
* to the global and sibling lists for the device, then
|
|
* adds it to the other relevant subsystems of the driver model.
|
|
*
|
|
* Do not call this routine or device_register() more than once for
|
|
* any device structure. The driver model core is not designed to work
|
|
* with devices that get unregistered and then spring back to life.
|
|
* (Among other things, it's very hard to guarantee that all references
|
|
* to the previous incarnation of @dev have been dropped.) Allocate
|
|
* and register a fresh new struct device instead.
|
|
*
|
|
* NOTE: _Never_ directly free @dev after calling this function, even
|
|
* if it returned an error! Always use put_device() to give up your
|
|
* reference instead.
|
|
*
|
|
* Rule of thumb is: if device_add() succeeds, you should call
|
|
* device_del() when you want to get rid of it. If device_add() has
|
|
* *not* succeeded, use *only* put_device() to drop the reference
|
|
* count.
|
|
*/
|
|
int device_add(struct device *dev)
|
|
{
|
|
struct subsys_private *sp;
|
|
struct device *parent;
|
|
struct kobject *kobj;
|
|
struct class_interface *class_intf;
|
|
int error = -EINVAL;
|
|
struct kobject *glue_dir = NULL;
|
|
|
|
dev = get_device(dev);
|
|
if (!dev)
|
|
goto done;
|
|
|
|
if (!dev->p) {
|
|
error = device_private_init(dev);
|
|
if (error)
|
|
goto done;
|
|
}
|
|
|
|
/*
|
|
* for statically allocated devices, which should all be converted
|
|
* some day, we need to initialize the name. We prevent reading back
|
|
* the name, and force the use of dev_name()
|
|
*/
|
|
if (dev->init_name) {
|
|
error = dev_set_name(dev, "%s", dev->init_name);
|
|
dev->init_name = NULL;
|
|
}
|
|
|
|
if (dev_name(dev))
|
|
error = 0;
|
|
/* subsystems can specify simple device enumeration */
|
|
else if (dev->bus && dev->bus->dev_name)
|
|
error = dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
|
|
if (error)
|
|
goto name_error;
|
|
|
|
pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
|
|
|
|
parent = get_device(dev->parent);
|
|
kobj = get_device_parent(dev, parent);
|
|
if (IS_ERR(kobj)) {
|
|
error = PTR_ERR(kobj);
|
|
goto parent_error;
|
|
}
|
|
if (kobj)
|
|
dev->kobj.parent = kobj;
|
|
|
|
/* use parent numa_node */
|
|
if (parent && (dev_to_node(dev) == NUMA_NO_NODE))
|
|
set_dev_node(dev, dev_to_node(parent));
|
|
|
|
/* first, register with generic layer. */
|
|
/* we require the name to be set before, and pass NULL */
|
|
error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
|
|
if (error) {
|
|
glue_dir = kobj;
|
|
goto Error;
|
|
}
|
|
|
|
/* notify platform of device entry */
|
|
device_platform_notify(dev);
|
|
|
|
error = device_create_file(dev, &dev_attr_uevent);
|
|
if (error)
|
|
goto attrError;
|
|
|
|
error = device_add_class_symlinks(dev);
|
|
if (error)
|
|
goto SymlinkError;
|
|
error = device_add_attrs(dev);
|
|
if (error)
|
|
goto AttrsError;
|
|
error = bus_add_device(dev);
|
|
if (error)
|
|
goto BusError;
|
|
error = dpm_sysfs_add(dev);
|
|
if (error)
|
|
goto DPMError;
|
|
device_pm_add(dev);
|
|
|
|
if (MAJOR(dev->devt)) {
|
|
error = device_create_file(dev, &dev_attr_dev);
|
|
if (error)
|
|
goto DevAttrError;
|
|
|
|
error = device_create_sys_dev_entry(dev);
|
|
if (error)
|
|
goto SysEntryError;
|
|
|
|
devtmpfs_create_node(dev);
|
|
}
|
|
|
|
/* Notify clients of device addition. This call must come
|
|
* after dpm_sysfs_add() and before kobject_uevent().
|
|
*/
|
|
bus_notify(dev, BUS_NOTIFY_ADD_DEVICE);
|
|
kobject_uevent(&dev->kobj, KOBJ_ADD);
|
|
|
|
/*
|
|
* Check if any of the other devices (consumers) have been waiting for
|
|
* this device (supplier) to be added so that they can create a device
|
|
* link to it.
|
|
*
|
|
* This needs to happen after device_pm_add() because device_link_add()
|
|
* requires the supplier be registered before it's called.
|
|
*
|
|
* But this also needs to happen before bus_probe_device() to make sure
|
|
* waiting consumers can link to it before the driver is bound to the
|
|
* device and the driver sync_state callback is called for this device.
|
|
*/
|
|
if (dev->fwnode && !dev->fwnode->dev) {
|
|
dev->fwnode->dev = dev;
|
|
fw_devlink_link_device(dev);
|
|
}
|
|
|
|
bus_probe_device(dev);
|
|
|
|
/*
|
|
* If all driver registration is done and a newly added device doesn't
|
|
* match with any driver, don't block its consumers from probing in
|
|
* case the consumer device is able to operate without this supplier.
|
|
*/
|
|
if (dev->fwnode && fw_devlink_drv_reg_done && !dev->can_match)
|
|
fw_devlink_unblock_consumers(dev);
|
|
|
|
if (parent)
|
|
klist_add_tail(&dev->p->knode_parent,
|
|
&parent->p->klist_children);
|
|
|
|
sp = class_to_subsys(dev->class);
|
|
if (sp) {
|
|
mutex_lock(&sp->mutex);
|
|
/* tie the class to the device */
|
|
klist_add_tail(&dev->p->knode_class, &sp->klist_devices);
|
|
|
|
/* notify any interfaces that the device is here */
|
|
list_for_each_entry(class_intf, &sp->interfaces, node)
|
|
if (class_intf->add_dev)
|
|
class_intf->add_dev(dev);
|
|
mutex_unlock(&sp->mutex);
|
|
subsys_put(sp);
|
|
}
|
|
done:
|
|
put_device(dev);
|
|
return error;
|
|
SysEntryError:
|
|
if (MAJOR(dev->devt))
|
|
device_remove_file(dev, &dev_attr_dev);
|
|
DevAttrError:
|
|
device_pm_remove(dev);
|
|
dpm_sysfs_remove(dev);
|
|
DPMError:
|
|
dev->driver = NULL;
|
|
bus_remove_device(dev);
|
|
BusError:
|
|
device_remove_attrs(dev);
|
|
AttrsError:
|
|
device_remove_class_symlinks(dev);
|
|
SymlinkError:
|
|
device_remove_file(dev, &dev_attr_uevent);
|
|
attrError:
|
|
device_platform_notify_remove(dev);
|
|
kobject_uevent(&dev->kobj, KOBJ_REMOVE);
|
|
glue_dir = get_glue_dir(dev);
|
|
kobject_del(&dev->kobj);
|
|
Error:
|
|
cleanup_glue_dir(dev, glue_dir);
|
|
parent_error:
|
|
put_device(parent);
|
|
name_error:
|
|
kfree(dev->p);
|
|
dev->p = NULL;
|
|
goto done;
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_add);
|
|
|
|
/**
|
|
* device_register - register a device with the system.
|
|
* @dev: pointer to the device structure
|
|
*
|
|
* This happens in two clean steps - initialize the device
|
|
* and add it to the system. The two steps can be called
|
|
* separately, but this is the easiest and most common.
|
|
* I.e. you should only call the two helpers separately if
|
|
* have a clearly defined need to use and refcount the device
|
|
* before it is added to the hierarchy.
|
|
*
|
|
* For more information, see the kerneldoc for device_initialize()
|
|
* and device_add().
|
|
*
|
|
* NOTE: _Never_ directly free @dev after calling this function, even
|
|
* if it returned an error! Always use put_device() to give up the
|
|
* reference initialized in this function instead.
|
|
*/
|
|
int device_register(struct device *dev)
|
|
{
|
|
device_initialize(dev);
|
|
return device_add(dev);
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_register);
|
|
|
|
/**
|
|
* get_device - increment reference count for device.
|
|
* @dev: device.
|
|
*
|
|
* This simply forwards the call to kobject_get(), though
|
|
* we do take care to provide for the case that we get a NULL
|
|
* pointer passed in.
|
|
*/
|
|
struct device *get_device(struct device *dev)
|
|
{
|
|
return dev ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(get_device);
|
|
|
|
/**
|
|
* put_device - decrement reference count.
|
|
* @dev: device in question.
|
|
*/
|
|
void put_device(struct device *dev)
|
|
{
|
|
/* might_sleep(); */
|
|
if (dev)
|
|
kobject_put(&dev->kobj);
|
|
}
|
|
EXPORT_SYMBOL_GPL(put_device);
|
|
|
|
bool kill_device(struct device *dev)
|
|
{
|
|
/*
|
|
* Require the device lock and set the "dead" flag to guarantee that
|
|
* the update behavior is consistent with the other bitfields near
|
|
* it and that we cannot have an asynchronous probe routine trying
|
|
* to run while we are tearing out the bus/class/sysfs from
|
|
* underneath the device.
|
|
*/
|
|
device_lock_assert(dev);
|
|
|
|
if (dev->p->dead)
|
|
return false;
|
|
dev->p->dead = true;
|
|
return true;
|
|
}
|
|
EXPORT_SYMBOL_GPL(kill_device);
|
|
|
|
/**
|
|
* device_del - delete device from system.
|
|
* @dev: device.
|
|
*
|
|
* This is the first part of the device unregistration
|
|
* sequence. This removes the device from the lists we control
|
|
* from here, has it removed from the other driver model
|
|
* subsystems it was added to in device_add(), and removes it
|
|
* from the kobject hierarchy.
|
|
*
|
|
* NOTE: this should be called manually _iff_ device_add() was
|
|
* also called manually.
|
|
*/
|
|
void device_del(struct device *dev)
|
|
{
|
|
struct subsys_private *sp;
|
|
struct device *parent = dev->parent;
|
|
struct kobject *glue_dir = NULL;
|
|
struct class_interface *class_intf;
|
|
unsigned int noio_flag;
|
|
|
|
device_lock(dev);
|
|
kill_device(dev);
|
|
device_unlock(dev);
|
|
|
|
if (dev->fwnode && dev->fwnode->dev == dev)
|
|
dev->fwnode->dev = NULL;
|
|
|
|
/* Notify clients of device removal. This call must come
|
|
* before dpm_sysfs_remove().
|
|
*/
|
|
noio_flag = memalloc_noio_save();
|
|
bus_notify(dev, BUS_NOTIFY_DEL_DEVICE);
|
|
|
|
dpm_sysfs_remove(dev);
|
|
if (parent)
|
|
klist_del(&dev->p->knode_parent);
|
|
if (MAJOR(dev->devt)) {
|
|
devtmpfs_delete_node(dev);
|
|
device_remove_sys_dev_entry(dev);
|
|
device_remove_file(dev, &dev_attr_dev);
|
|
}
|
|
|
|
sp = class_to_subsys(dev->class);
|
|
if (sp) {
|
|
device_remove_class_symlinks(dev);
|
|
|
|
mutex_lock(&sp->mutex);
|
|
/* notify any interfaces that the device is now gone */
|
|
list_for_each_entry(class_intf, &sp->interfaces, node)
|
|
if (class_intf->remove_dev)
|
|
class_intf->remove_dev(dev);
|
|
/* remove the device from the class list */
|
|
klist_del(&dev->p->knode_class);
|
|
mutex_unlock(&sp->mutex);
|
|
subsys_put(sp);
|
|
}
|
|
device_remove_file(dev, &dev_attr_uevent);
|
|
device_remove_attrs(dev);
|
|
bus_remove_device(dev);
|
|
device_pm_remove(dev);
|
|
driver_deferred_probe_del(dev);
|
|
device_platform_notify_remove(dev);
|
|
device_links_purge(dev);
|
|
|
|
/*
|
|
* If a device does not have a driver attached, we need to clean
|
|
* up any managed resources. We do this in device_release(), but
|
|
* it's never called (and we leak the device) if a managed
|
|
* resource holds a reference to the device. So release all
|
|
* managed resources here, like we do in driver_detach(). We
|
|
* still need to do so again in device_release() in case someone
|
|
* adds a new resource after this point, though.
|
|
*/
|
|
devres_release_all(dev);
|
|
|
|
bus_notify(dev, BUS_NOTIFY_REMOVED_DEVICE);
|
|
kobject_uevent(&dev->kobj, KOBJ_REMOVE);
|
|
glue_dir = get_glue_dir(dev);
|
|
kobject_del(&dev->kobj);
|
|
cleanup_glue_dir(dev, glue_dir);
|
|
memalloc_noio_restore(noio_flag);
|
|
put_device(parent);
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_del);
|
|
|
|
/**
|
|
* device_unregister - unregister device from system.
|
|
* @dev: device going away.
|
|
*
|
|
* We do this in two parts, like we do device_register(). First,
|
|
* we remove it from all the subsystems with device_del(), then
|
|
* we decrement the reference count via put_device(). If that
|
|
* is the final reference count, the device will be cleaned up
|
|
* via device_release() above. Otherwise, the structure will
|
|
* stick around until the final reference to the device is dropped.
|
|
*/
|
|
void device_unregister(struct device *dev)
|
|
{
|
|
pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
|
|
device_del(dev);
|
|
put_device(dev);
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_unregister);
|
|
|
|
static struct device *prev_device(struct klist_iter *i)
|
|
{
|
|
struct klist_node *n = klist_prev(i);
|
|
struct device *dev = NULL;
|
|
struct device_private *p;
|
|
|
|
if (n) {
|
|
p = to_device_private_parent(n);
|
|
dev = p->device;
|
|
}
|
|
return dev;
|
|
}
|
|
|
|
static struct device *next_device(struct klist_iter *i)
|
|
{
|
|
struct klist_node *n = klist_next(i);
|
|
struct device *dev = NULL;
|
|
struct device_private *p;
|
|
|
|
if (n) {
|
|
p = to_device_private_parent(n);
|
|
dev = p->device;
|
|
}
|
|
return dev;
|
|
}
|
|
|
|
/**
|
|
* device_get_devnode - path of device node file
|
|
* @dev: device
|
|
* @mode: returned file access mode
|
|
* @uid: returned file owner
|
|
* @gid: returned file group
|
|
* @tmp: possibly allocated string
|
|
*
|
|
* Return the relative path of a possible device node.
|
|
* Non-default names may need to allocate a memory to compose
|
|
* a name. This memory is returned in tmp and needs to be
|
|
* freed by the caller.
|
|
*/
|
|
const char *device_get_devnode(const struct device *dev,
|
|
umode_t *mode, kuid_t *uid, kgid_t *gid,
|
|
const char **tmp)
|
|
{
|
|
char *s;
|
|
|
|
*tmp = NULL;
|
|
|
|
/* the device type may provide a specific name */
|
|
if (dev->type && dev->type->devnode)
|
|
*tmp = dev->type->devnode(dev, mode, uid, gid);
|
|
if (*tmp)
|
|
return *tmp;
|
|
|
|
/* the class may provide a specific name */
|
|
if (dev->class && dev->class->devnode)
|
|
*tmp = dev->class->devnode(dev, mode);
|
|
if (*tmp)
|
|
return *tmp;
|
|
|
|
/* return name without allocation, tmp == NULL */
|
|
if (strchr(dev_name(dev), '!') == NULL)
|
|
return dev_name(dev);
|
|
|
|
/* replace '!' in the name with '/' */
|
|
s = kstrdup_and_replace(dev_name(dev), '!', '/', GFP_KERNEL);
|
|
if (!s)
|
|
return NULL;
|
|
return *tmp = s;
|
|
}
|
|
|
|
/**
|
|
* device_for_each_child - device child iterator.
|
|
* @parent: parent struct device.
|
|
* @fn: function to be called for each device.
|
|
* @data: data for the callback.
|
|
*
|
|
* Iterate over @parent's child devices, and call @fn for each,
|
|
* passing it @data.
|
|
*
|
|
* We check the return of @fn each time. If it returns anything
|
|
* other than 0, we break out and return that value.
|
|
*/
|
|
int device_for_each_child(struct device *parent, void *data,
|
|
int (*fn)(struct device *dev, void *data))
|
|
{
|
|
struct klist_iter i;
|
|
struct device *child;
|
|
int error = 0;
|
|
|
|
if (!parent->p)
|
|
return 0;
|
|
|
|
klist_iter_init(&parent->p->klist_children, &i);
|
|
while (!error && (child = next_device(&i)))
|
|
error = fn(child, data);
|
|
klist_iter_exit(&i);
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_for_each_child);
|
|
|
|
/**
|
|
* device_for_each_child_reverse - device child iterator in reversed order.
|
|
* @parent: parent struct device.
|
|
* @fn: function to be called for each device.
|
|
* @data: data for the callback.
|
|
*
|
|
* Iterate over @parent's child devices, and call @fn for each,
|
|
* passing it @data.
|
|
*
|
|
* We check the return of @fn each time. If it returns anything
|
|
* other than 0, we break out and return that value.
|
|
*/
|
|
int device_for_each_child_reverse(struct device *parent, void *data,
|
|
int (*fn)(struct device *dev, void *data))
|
|
{
|
|
struct klist_iter i;
|
|
struct device *child;
|
|
int error = 0;
|
|
|
|
if (!parent->p)
|
|
return 0;
|
|
|
|
klist_iter_init(&parent->p->klist_children, &i);
|
|
while ((child = prev_device(&i)) && !error)
|
|
error = fn(child, data);
|
|
klist_iter_exit(&i);
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_for_each_child_reverse);
|
|
|
|
/**
|
|
* device_find_child - device iterator for locating a particular device.
|
|
* @parent: parent struct device
|
|
* @match: Callback function to check device
|
|
* @data: Data to pass to match function
|
|
*
|
|
* This is similar to the device_for_each_child() function above, but it
|
|
* returns a reference to a device that is 'found' for later use, as
|
|
* determined by the @match callback.
|
|
*
|
|
* The callback should return 0 if the device doesn't match and non-zero
|
|
* if it does. If the callback returns non-zero and a reference to the
|
|
* current device can be obtained, this function will return to the caller
|
|
* and not iterate over any more devices.
|
|
*
|
|
* NOTE: you will need to drop the reference with put_device() after use.
|
|
*/
|
|
struct device *device_find_child(struct device *parent, void *data,
|
|
int (*match)(struct device *dev, void *data))
|
|
{
|
|
struct klist_iter i;
|
|
struct device *child;
|
|
|
|
if (!parent)
|
|
return NULL;
|
|
|
|
klist_iter_init(&parent->p->klist_children, &i);
|
|
while ((child = next_device(&i)))
|
|
if (match(child, data) && get_device(child))
|
|
break;
|
|
klist_iter_exit(&i);
|
|
return child;
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_find_child);
|
|
|
|
/**
|
|
* device_find_child_by_name - device iterator for locating a child device.
|
|
* @parent: parent struct device
|
|
* @name: name of the child device
|
|
*
|
|
* This is similar to the device_find_child() function above, but it
|
|
* returns a reference to a device that has the name @name.
|
|
*
|
|
* NOTE: you will need to drop the reference with put_device() after use.
|
|
*/
|
|
struct device *device_find_child_by_name(struct device *parent,
|
|
const char *name)
|
|
{
|
|
struct klist_iter i;
|
|
struct device *child;
|
|
|
|
if (!parent)
|
|
return NULL;
|
|
|
|
klist_iter_init(&parent->p->klist_children, &i);
|
|
while ((child = next_device(&i)))
|
|
if (sysfs_streq(dev_name(child), name) && get_device(child))
|
|
break;
|
|
klist_iter_exit(&i);
|
|
return child;
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_find_child_by_name);
|
|
|
|
static int match_any(struct device *dev, void *unused)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* device_find_any_child - device iterator for locating a child device, if any.
|
|
* @parent: parent struct device
|
|
*
|
|
* This is similar to the device_find_child() function above, but it
|
|
* returns a reference to a child device, if any.
|
|
*
|
|
* NOTE: you will need to drop the reference with put_device() after use.
|
|
*/
|
|
struct device *device_find_any_child(struct device *parent)
|
|
{
|
|
return device_find_child(parent, NULL, match_any);
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_find_any_child);
|
|
|
|
int __init devices_init(void)
|
|
{
|
|
devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
|
|
if (!devices_kset)
|
|
return -ENOMEM;
|
|
dev_kobj = kobject_create_and_add("dev", NULL);
|
|
if (!dev_kobj)
|
|
goto dev_kobj_err;
|
|
sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
|
|
if (!sysfs_dev_block_kobj)
|
|
goto block_kobj_err;
|
|
sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
|
|
if (!sysfs_dev_char_kobj)
|
|
goto char_kobj_err;
|
|
|
|
return 0;
|
|
|
|
char_kobj_err:
|
|
kobject_put(sysfs_dev_block_kobj);
|
|
block_kobj_err:
|
|
kobject_put(dev_kobj);
|
|
dev_kobj_err:
|
|
kset_unregister(devices_kset);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static int device_check_offline(struct device *dev, void *not_used)
|
|
{
|
|
int ret;
|
|
|
|
ret = device_for_each_child(dev, NULL, device_check_offline);
|
|
if (ret)
|
|
return ret;
|
|
|
|
return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0;
|
|
}
|
|
|
|
/**
|
|
* device_offline - Prepare the device for hot-removal.
|
|
* @dev: Device to be put offline.
|
|
*
|
|
* Execute the device bus type's .offline() callback, if present, to prepare
|
|
* the device for a subsequent hot-removal. If that succeeds, the device must
|
|
* not be used until either it is removed or its bus type's .online() callback
|
|
* is executed.
|
|
*
|
|
* Call under device_hotplug_lock.
|
|
*/
|
|
int device_offline(struct device *dev)
|
|
{
|
|
int ret;
|
|
|
|
if (dev->offline_disabled)
|
|
return -EPERM;
|
|
|
|
ret = device_for_each_child(dev, NULL, device_check_offline);
|
|
if (ret)
|
|
return ret;
|
|
|
|
device_lock(dev);
|
|
if (device_supports_offline(dev)) {
|
|
if (dev->offline) {
|
|
ret = 1;
|
|
} else {
|
|
ret = dev->bus->offline(dev);
|
|
if (!ret) {
|
|
kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
|
|
dev->offline = true;
|
|
}
|
|
}
|
|
}
|
|
device_unlock(dev);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* device_online - Put the device back online after successful device_offline().
|
|
* @dev: Device to be put back online.
|
|
*
|
|
* If device_offline() has been successfully executed for @dev, but the device
|
|
* has not been removed subsequently, execute its bus type's .online() callback
|
|
* to indicate that the device can be used again.
|
|
*
|
|
* Call under device_hotplug_lock.
|
|
*/
|
|
int device_online(struct device *dev)
|
|
{
|
|
int ret = 0;
|
|
|
|
device_lock(dev);
|
|
if (device_supports_offline(dev)) {
|
|
if (dev->offline) {
|
|
ret = dev->bus->online(dev);
|
|
if (!ret) {
|
|
kobject_uevent(&dev->kobj, KOBJ_ONLINE);
|
|
dev->offline = false;
|
|
}
|
|
} else {
|
|
ret = 1;
|
|
}
|
|
}
|
|
device_unlock(dev);
|
|
|
|
return ret;
|
|
}
|
|
|
|
struct root_device {
|
|
struct device dev;
|
|
struct module *owner;
|
|
};
|
|
|
|
static inline struct root_device *to_root_device(struct device *d)
|
|
{
|
|
return container_of(d, struct root_device, dev);
|
|
}
|
|
|
|
static void root_device_release(struct device *dev)
|
|
{
|
|
kfree(to_root_device(dev));
|
|
}
|
|
|
|
/**
|
|
* __root_device_register - allocate and register a root device
|
|
* @name: root device name
|
|
* @owner: owner module of the root device, usually THIS_MODULE
|
|
*
|
|
* This function allocates a root device and registers it
|
|
* using device_register(). In order to free the returned
|
|
* device, use root_device_unregister().
|
|
*
|
|
* Root devices are dummy devices which allow other devices
|
|
* to be grouped under /sys/devices. Use this function to
|
|
* allocate a root device and then use it as the parent of
|
|
* any device which should appear under /sys/devices/{name}
|
|
*
|
|
* The /sys/devices/{name} directory will also contain a
|
|
* 'module' symlink which points to the @owner directory
|
|
* in sysfs.
|
|
*
|
|
* Returns &struct device pointer on success, or ERR_PTR() on error.
|
|
*
|
|
* Note: You probably want to use root_device_register().
|
|
*/
|
|
struct device *__root_device_register(const char *name, struct module *owner)
|
|
{
|
|
struct root_device *root;
|
|
int err = -ENOMEM;
|
|
|
|
root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
|
|
if (!root)
|
|
return ERR_PTR(err);
|
|
|
|
err = dev_set_name(&root->dev, "%s", name);
|
|
if (err) {
|
|
kfree(root);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
root->dev.release = root_device_release;
|
|
|
|
err = device_register(&root->dev);
|
|
if (err) {
|
|
put_device(&root->dev);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
#ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
|
|
if (owner) {
|
|
struct module_kobject *mk = &owner->mkobj;
|
|
|
|
err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
|
|
if (err) {
|
|
device_unregister(&root->dev);
|
|
return ERR_PTR(err);
|
|
}
|
|
root->owner = owner;
|
|
}
|
|
#endif
|
|
|
|
return &root->dev;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__root_device_register);
|
|
|
|
/**
|
|
* root_device_unregister - unregister and free a root device
|
|
* @dev: device going away
|
|
*
|
|
* This function unregisters and cleans up a device that was created by
|
|
* root_device_register().
|
|
*/
|
|
void root_device_unregister(struct device *dev)
|
|
{
|
|
struct root_device *root = to_root_device(dev);
|
|
|
|
if (root->owner)
|
|
sysfs_remove_link(&root->dev.kobj, "module");
|
|
|
|
device_unregister(dev);
|
|
}
|
|
EXPORT_SYMBOL_GPL(root_device_unregister);
|
|
|
|
|
|
static void device_create_release(struct device *dev)
|
|
{
|
|
pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
|
|
kfree(dev);
|
|
}
|
|
|
|
static __printf(6, 0) struct device *
|
|
device_create_groups_vargs(const struct class *class, struct device *parent,
|
|
dev_t devt, void *drvdata,
|
|
const struct attribute_group **groups,
|
|
const char *fmt, va_list args)
|
|
{
|
|
struct device *dev = NULL;
|
|
int retval = -ENODEV;
|
|
|
|
if (IS_ERR_OR_NULL(class))
|
|
goto error;
|
|
|
|
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
|
|
if (!dev) {
|
|
retval = -ENOMEM;
|
|
goto error;
|
|
}
|
|
|
|
device_initialize(dev);
|
|
dev->devt = devt;
|
|
dev->class = class;
|
|
dev->parent = parent;
|
|
dev->groups = groups;
|
|
dev->release = device_create_release;
|
|
dev_set_drvdata(dev, drvdata);
|
|
|
|
retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
|
|
if (retval)
|
|
goto error;
|
|
|
|
retval = device_add(dev);
|
|
if (retval)
|
|
goto error;
|
|
|
|
return dev;
|
|
|
|
error:
|
|
put_device(dev);
|
|
return ERR_PTR(retval);
|
|
}
|
|
|
|
/**
|
|
* device_create - creates a device and registers it with sysfs
|
|
* @class: pointer to the struct class that this device should be registered to
|
|
* @parent: pointer to the parent struct device of this new device, if any
|
|
* @devt: the dev_t for the char device to be added
|
|
* @drvdata: the data to be added to the device for callbacks
|
|
* @fmt: string for the device's name
|
|
*
|
|
* This function can be used by char device classes. A struct device
|
|
* will be created in sysfs, registered to the specified class.
|
|
*
|
|
* A "dev" file will be created, showing the dev_t for the device, if
|
|
* the dev_t is not 0,0.
|
|
* If a pointer to a parent struct device is passed in, the newly created
|
|
* struct device will be a child of that device in sysfs.
|
|
* The pointer to the struct device will be returned from the call.
|
|
* Any further sysfs files that might be required can be created using this
|
|
* pointer.
|
|
*
|
|
* Returns &struct device pointer on success, or ERR_PTR() on error.
|
|
*/
|
|
struct device *device_create(const struct class *class, struct device *parent,
|
|
dev_t devt, void *drvdata, const char *fmt, ...)
|
|
{
|
|
va_list vargs;
|
|
struct device *dev;
|
|
|
|
va_start(vargs, fmt);
|
|
dev = device_create_groups_vargs(class, parent, devt, drvdata, NULL,
|
|
fmt, vargs);
|
|
va_end(vargs);
|
|
return dev;
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_create);
|
|
|
|
/**
|
|
* device_create_with_groups - creates a device and registers it with sysfs
|
|
* @class: pointer to the struct class that this device should be registered to
|
|
* @parent: pointer to the parent struct device of this new device, if any
|
|
* @devt: the dev_t for the char device to be added
|
|
* @drvdata: the data to be added to the device for callbacks
|
|
* @groups: NULL-terminated list of attribute groups to be created
|
|
* @fmt: string for the device's name
|
|
*
|
|
* This function can be used by char device classes. A struct device
|
|
* will be created in sysfs, registered to the specified class.
|
|
* Additional attributes specified in the groups parameter will also
|
|
* be created automatically.
|
|
*
|
|
* A "dev" file will be created, showing the dev_t for the device, if
|
|
* the dev_t is not 0,0.
|
|
* If a pointer to a parent struct device is passed in, the newly created
|
|
* struct device will be a child of that device in sysfs.
|
|
* The pointer to the struct device will be returned from the call.
|
|
* Any further sysfs files that might be required can be created using this
|
|
* pointer.
|
|
*
|
|
* Returns &struct device pointer on success, or ERR_PTR() on error.
|
|
*/
|
|
struct device *device_create_with_groups(const struct class *class,
|
|
struct device *parent, dev_t devt,
|
|
void *drvdata,
|
|
const struct attribute_group **groups,
|
|
const char *fmt, ...)
|
|
{
|
|
va_list vargs;
|
|
struct device *dev;
|
|
|
|
va_start(vargs, fmt);
|
|
dev = device_create_groups_vargs(class, parent, devt, drvdata, groups,
|
|
fmt, vargs);
|
|
va_end(vargs);
|
|
return dev;
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_create_with_groups);
|
|
|
|
/**
|
|
* device_destroy - removes a device that was created with device_create()
|
|
* @class: pointer to the struct class that this device was registered with
|
|
* @devt: the dev_t of the device that was previously registered
|
|
*
|
|
* This call unregisters and cleans up a device that was created with a
|
|
* call to device_create().
|
|
*/
|
|
void device_destroy(const struct class *class, dev_t devt)
|
|
{
|
|
struct device *dev;
|
|
|
|
dev = class_find_device_by_devt(class, devt);
|
|
if (dev) {
|
|
put_device(dev);
|
|
device_unregister(dev);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_destroy);
|
|
|
|
/**
|
|
* device_rename - renames a device
|
|
* @dev: the pointer to the struct device to be renamed
|
|
* @new_name: the new name of the device
|
|
*
|
|
* It is the responsibility of the caller to provide mutual
|
|
* exclusion between two different calls of device_rename
|
|
* on the same device to ensure that new_name is valid and
|
|
* won't conflict with other devices.
|
|
*
|
|
* Note: given that some subsystems (networking and infiniband) use this
|
|
* function, with no immediate plans for this to change, we cannot assume or
|
|
* require that this function not be called at all.
|
|
*
|
|
* However, if you're writing new code, do not call this function. The following
|
|
* text from Kay Sievers offers some insight:
|
|
*
|
|
* Renaming devices is racy at many levels, symlinks and other stuff are not
|
|
* replaced atomically, and you get a "move" uevent, but it's not easy to
|
|
* connect the event to the old and new device. Device nodes are not renamed at
|
|
* all, there isn't even support for that in the kernel now.
|
|
*
|
|
* In the meantime, during renaming, your target name might be taken by another
|
|
* driver, creating conflicts. Or the old name is taken directly after you
|
|
* renamed it -- then you get events for the same DEVPATH, before you even see
|
|
* the "move" event. It's just a mess, and nothing new should ever rely on
|
|
* kernel device renaming. Besides that, it's not even implemented now for
|
|
* other things than (driver-core wise very simple) network devices.
|
|
*
|
|
* Make up a "real" name in the driver before you register anything, or add
|
|
* some other attributes for userspace to find the device, or use udev to add
|
|
* symlinks -- but never rename kernel devices later, it's a complete mess. We
|
|
* don't even want to get into that and try to implement the missing pieces in
|
|
* the core. We really have other pieces to fix in the driver core mess. :)
|
|
*/
|
|
int device_rename(struct device *dev, const char *new_name)
|
|
{
|
|
struct kobject *kobj = &dev->kobj;
|
|
char *old_device_name = NULL;
|
|
int error;
|
|
|
|
dev = get_device(dev);
|
|
if (!dev)
|
|
return -EINVAL;
|
|
|
|
dev_dbg(dev, "renaming to %s\n", new_name);
|
|
|
|
old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
|
|
if (!old_device_name) {
|
|
error = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
if (dev->class) {
|
|
struct subsys_private *sp = class_to_subsys(dev->class);
|
|
|
|
if (!sp) {
|
|
error = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
error = sysfs_rename_link_ns(&sp->subsys.kobj, kobj, old_device_name,
|
|
new_name, kobject_namespace(kobj));
|
|
subsys_put(sp);
|
|
if (error)
|
|
goto out;
|
|
}
|
|
|
|
error = kobject_rename(kobj, new_name);
|
|
if (error)
|
|
goto out;
|
|
|
|
out:
|
|
put_device(dev);
|
|
|
|
kfree(old_device_name);
|
|
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_rename);
|
|
|
|
static int device_move_class_links(struct device *dev,
|
|
struct device *old_parent,
|
|
struct device *new_parent)
|
|
{
|
|
int error = 0;
|
|
|
|
if (old_parent)
|
|
sysfs_remove_link(&dev->kobj, "device");
|
|
if (new_parent)
|
|
error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
|
|
"device");
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* device_move - moves a device to a new parent
|
|
* @dev: the pointer to the struct device to be moved
|
|
* @new_parent: the new parent of the device (can be NULL)
|
|
* @dpm_order: how to reorder the dpm_list
|
|
*/
|
|
int device_move(struct device *dev, struct device *new_parent,
|
|
enum dpm_order dpm_order)
|
|
{
|
|
int error;
|
|
struct device *old_parent;
|
|
struct kobject *new_parent_kobj;
|
|
|
|
dev = get_device(dev);
|
|
if (!dev)
|
|
return -EINVAL;
|
|
|
|
device_pm_lock();
|
|
new_parent = get_device(new_parent);
|
|
new_parent_kobj = get_device_parent(dev, new_parent);
|
|
if (IS_ERR(new_parent_kobj)) {
|
|
error = PTR_ERR(new_parent_kobj);
|
|
put_device(new_parent);
|
|
goto out;
|
|
}
|
|
|
|
pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
|
|
__func__, new_parent ? dev_name(new_parent) : "<NULL>");
|
|
error = kobject_move(&dev->kobj, new_parent_kobj);
|
|
if (error) {
|
|
cleanup_glue_dir(dev, new_parent_kobj);
|
|
put_device(new_parent);
|
|
goto out;
|
|
}
|
|
old_parent = dev->parent;
|
|
dev->parent = new_parent;
|
|
if (old_parent)
|
|
klist_remove(&dev->p->knode_parent);
|
|
if (new_parent) {
|
|
klist_add_tail(&dev->p->knode_parent,
|
|
&new_parent->p->klist_children);
|
|
set_dev_node(dev, dev_to_node(new_parent));
|
|
}
|
|
|
|
if (dev->class) {
|
|
error = device_move_class_links(dev, old_parent, new_parent);
|
|
if (error) {
|
|
/* We ignore errors on cleanup since we're hosed anyway... */
|
|
device_move_class_links(dev, new_parent, old_parent);
|
|
if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
|
|
if (new_parent)
|
|
klist_remove(&dev->p->knode_parent);
|
|
dev->parent = old_parent;
|
|
if (old_parent) {
|
|
klist_add_tail(&dev->p->knode_parent,
|
|
&old_parent->p->klist_children);
|
|
set_dev_node(dev, dev_to_node(old_parent));
|
|
}
|
|
}
|
|
cleanup_glue_dir(dev, new_parent_kobj);
|
|
put_device(new_parent);
|
|
goto out;
|
|
}
|
|
}
|
|
switch (dpm_order) {
|
|
case DPM_ORDER_NONE:
|
|
break;
|
|
case DPM_ORDER_DEV_AFTER_PARENT:
|
|
device_pm_move_after(dev, new_parent);
|
|
devices_kset_move_after(dev, new_parent);
|
|
break;
|
|
case DPM_ORDER_PARENT_BEFORE_DEV:
|
|
device_pm_move_before(new_parent, dev);
|
|
devices_kset_move_before(new_parent, dev);
|
|
break;
|
|
case DPM_ORDER_DEV_LAST:
|
|
device_pm_move_last(dev);
|
|
devices_kset_move_last(dev);
|
|
break;
|
|
}
|
|
|
|
put_device(old_parent);
|
|
out:
|
|
device_pm_unlock();
|
|
put_device(dev);
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_move);
|
|
|
|
static int device_attrs_change_owner(struct device *dev, kuid_t kuid,
|
|
kgid_t kgid)
|
|
{
|
|
struct kobject *kobj = &dev->kobj;
|
|
const struct class *class = dev->class;
|
|
const struct device_type *type = dev->type;
|
|
int error;
|
|
|
|
if (class) {
|
|
/*
|
|
* Change the device groups of the device class for @dev to
|
|
* @kuid/@kgid.
|
|
*/
|
|
error = sysfs_groups_change_owner(kobj, class->dev_groups, kuid,
|
|
kgid);
|
|
if (error)
|
|
return error;
|
|
}
|
|
|
|
if (type) {
|
|
/*
|
|
* Change the device groups of the device type for @dev to
|
|
* @kuid/@kgid.
|
|
*/
|
|
error = sysfs_groups_change_owner(kobj, type->groups, kuid,
|
|
kgid);
|
|
if (error)
|
|
return error;
|
|
}
|
|
|
|
/* Change the device groups of @dev to @kuid/@kgid. */
|
|
error = sysfs_groups_change_owner(kobj, dev->groups, kuid, kgid);
|
|
if (error)
|
|
return error;
|
|
|
|
if (device_supports_offline(dev) && !dev->offline_disabled) {
|
|
/* Change online device attributes of @dev to @kuid/@kgid. */
|
|
error = sysfs_file_change_owner(kobj, dev_attr_online.attr.name,
|
|
kuid, kgid);
|
|
if (error)
|
|
return error;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* device_change_owner - change the owner of an existing device.
|
|
* @dev: device.
|
|
* @kuid: new owner's kuid
|
|
* @kgid: new owner's kgid
|
|
*
|
|
* This changes the owner of @dev and its corresponding sysfs entries to
|
|
* @kuid/@kgid. This function closely mirrors how @dev was added via driver
|
|
* core.
|
|
*
|
|
* Returns 0 on success or error code on failure.
|
|
*/
|
|
int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid)
|
|
{
|
|
int error;
|
|
struct kobject *kobj = &dev->kobj;
|
|
struct subsys_private *sp;
|
|
|
|
dev = get_device(dev);
|
|
if (!dev)
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* Change the kobject and the default attributes and groups of the
|
|
* ktype associated with it to @kuid/@kgid.
|
|
*/
|
|
error = sysfs_change_owner(kobj, kuid, kgid);
|
|
if (error)
|
|
goto out;
|
|
|
|
/*
|
|
* Change the uevent file for @dev to the new owner. The uevent file
|
|
* was created in a separate step when @dev got added and we mirror
|
|
* that step here.
|
|
*/
|
|
error = sysfs_file_change_owner(kobj, dev_attr_uevent.attr.name, kuid,
|
|
kgid);
|
|
if (error)
|
|
goto out;
|
|
|
|
/*
|
|
* Change the device groups, the device groups associated with the
|
|
* device class, and the groups associated with the device type of @dev
|
|
* to @kuid/@kgid.
|
|
*/
|
|
error = device_attrs_change_owner(dev, kuid, kgid);
|
|
if (error)
|
|
goto out;
|
|
|
|
error = dpm_sysfs_change_owner(dev, kuid, kgid);
|
|
if (error)
|
|
goto out;
|
|
|
|
/*
|
|
* Change the owner of the symlink located in the class directory of
|
|
* the device class associated with @dev which points to the actual
|
|
* directory entry for @dev to @kuid/@kgid. This ensures that the
|
|
* symlink shows the same permissions as its target.
|
|
*/
|
|
sp = class_to_subsys(dev->class);
|
|
if (!sp) {
|
|
error = -EINVAL;
|
|
goto out;
|
|
}
|
|
error = sysfs_link_change_owner(&sp->subsys.kobj, &dev->kobj, dev_name(dev), kuid, kgid);
|
|
subsys_put(sp);
|
|
|
|
out:
|
|
put_device(dev);
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_change_owner);
|
|
|
|
/**
|
|
* device_shutdown - call ->shutdown() on each device to shutdown.
|
|
*/
|
|
void device_shutdown(void)
|
|
{
|
|
struct device *dev, *parent;
|
|
|
|
wait_for_device_probe();
|
|
device_block_probing();
|
|
|
|
cpufreq_suspend();
|
|
|
|
spin_lock(&devices_kset->list_lock);
|
|
/*
|
|
* Walk the devices list backward, shutting down each in turn.
|
|
* Beware that device unplug events may also start pulling
|
|
* devices offline, even as the system is shutting down.
|
|
*/
|
|
while (!list_empty(&devices_kset->list)) {
|
|
dev = list_entry(devices_kset->list.prev, struct device,
|
|
kobj.entry);
|
|
|
|
/*
|
|
* hold reference count of device's parent to
|
|
* prevent it from being freed because parent's
|
|
* lock is to be held
|
|
*/
|
|
parent = get_device(dev->parent);
|
|
get_device(dev);
|
|
/*
|
|
* Make sure the device is off the kset list, in the
|
|
* event that dev->*->shutdown() doesn't remove it.
|
|
*/
|
|
list_del_init(&dev->kobj.entry);
|
|
spin_unlock(&devices_kset->list_lock);
|
|
|
|
/* hold lock to avoid race with probe/release */
|
|
if (parent)
|
|
device_lock(parent);
|
|
device_lock(dev);
|
|
|
|
/* Don't allow any more runtime suspends */
|
|
pm_runtime_get_noresume(dev);
|
|
pm_runtime_barrier(dev);
|
|
|
|
if (dev->class && dev->class->shutdown_pre) {
|
|
if (initcall_debug)
|
|
dev_info(dev, "shutdown_pre\n");
|
|
dev->class->shutdown_pre(dev);
|
|
}
|
|
if (dev->bus && dev->bus->shutdown) {
|
|
if (initcall_debug)
|
|
dev_info(dev, "shutdown\n");
|
|
dev->bus->shutdown(dev);
|
|
} else if (dev->driver && dev->driver->shutdown) {
|
|
if (initcall_debug)
|
|
dev_info(dev, "shutdown\n");
|
|
dev->driver->shutdown(dev);
|
|
}
|
|
|
|
device_unlock(dev);
|
|
if (parent)
|
|
device_unlock(parent);
|
|
|
|
put_device(dev);
|
|
put_device(parent);
|
|
|
|
spin_lock(&devices_kset->list_lock);
|
|
}
|
|
spin_unlock(&devices_kset->list_lock);
|
|
}
|
|
|
|
/*
|
|
* Device logging functions
|
|
*/
|
|
|
|
#ifdef CONFIG_PRINTK
|
|
static void
|
|
set_dev_info(const struct device *dev, struct dev_printk_info *dev_info)
|
|
{
|
|
const char *subsys;
|
|
|
|
memset(dev_info, 0, sizeof(*dev_info));
|
|
|
|
if (dev->class)
|
|
subsys = dev->class->name;
|
|
else if (dev->bus)
|
|
subsys = dev->bus->name;
|
|
else
|
|
return;
|
|
|
|
strscpy(dev_info->subsystem, subsys, sizeof(dev_info->subsystem));
|
|
|
|
/*
|
|
* Add device identifier DEVICE=:
|
|
* b12:8 block dev_t
|
|
* c127:3 char dev_t
|
|
* n8 netdev ifindex
|
|
* +sound:card0 subsystem:devname
|
|
*/
|
|
if (MAJOR(dev->devt)) {
|
|
char c;
|
|
|
|
if (strcmp(subsys, "block") == 0)
|
|
c = 'b';
|
|
else
|
|
c = 'c';
|
|
|
|
snprintf(dev_info->device, sizeof(dev_info->device),
|
|
"%c%u:%u", c, MAJOR(dev->devt), MINOR(dev->devt));
|
|
} else if (strcmp(subsys, "net") == 0) {
|
|
struct net_device *net = to_net_dev(dev);
|
|
|
|
snprintf(dev_info->device, sizeof(dev_info->device),
|
|
"n%u", net->ifindex);
|
|
} else {
|
|
snprintf(dev_info->device, sizeof(dev_info->device),
|
|
"+%s:%s", subsys, dev_name(dev));
|
|
}
|
|
}
|
|
|
|
int dev_vprintk_emit(int level, const struct device *dev,
|
|
const char *fmt, va_list args)
|
|
{
|
|
struct dev_printk_info dev_info;
|
|
|
|
set_dev_info(dev, &dev_info);
|
|
|
|
return vprintk_emit(0, level, &dev_info, fmt, args);
|
|
}
|
|
EXPORT_SYMBOL(dev_vprintk_emit);
|
|
|
|
int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
|
|
{
|
|
va_list args;
|
|
int r;
|
|
|
|
va_start(args, fmt);
|
|
|
|
r = dev_vprintk_emit(level, dev, fmt, args);
|
|
|
|
va_end(args);
|
|
|
|
return r;
|
|
}
|
|
EXPORT_SYMBOL(dev_printk_emit);
|
|
|
|
static void __dev_printk(const char *level, const struct device *dev,
|
|
struct va_format *vaf)
|
|
{
|
|
if (dev)
|
|
dev_printk_emit(level[1] - '0', dev, "%s %s: %pV",
|
|
dev_driver_string(dev), dev_name(dev), vaf);
|
|
else
|
|
printk("%s(NULL device *): %pV", level, vaf);
|
|
}
|
|
|
|
void _dev_printk(const char *level, const struct device *dev,
|
|
const char *fmt, ...)
|
|
{
|
|
struct va_format vaf;
|
|
va_list args;
|
|
|
|
va_start(args, fmt);
|
|
|
|
vaf.fmt = fmt;
|
|
vaf.va = &args;
|
|
|
|
__dev_printk(level, dev, &vaf);
|
|
|
|
va_end(args);
|
|
}
|
|
EXPORT_SYMBOL(_dev_printk);
|
|
|
|
#define define_dev_printk_level(func, kern_level) \
|
|
void func(const struct device *dev, const char *fmt, ...) \
|
|
{ \
|
|
struct va_format vaf; \
|
|
va_list args; \
|
|
\
|
|
va_start(args, fmt); \
|
|
\
|
|
vaf.fmt = fmt; \
|
|
vaf.va = &args; \
|
|
\
|
|
__dev_printk(kern_level, dev, &vaf); \
|
|
\
|
|
va_end(args); \
|
|
} \
|
|
EXPORT_SYMBOL(func);
|
|
|
|
define_dev_printk_level(_dev_emerg, KERN_EMERG);
|
|
define_dev_printk_level(_dev_alert, KERN_ALERT);
|
|
define_dev_printk_level(_dev_crit, KERN_CRIT);
|
|
define_dev_printk_level(_dev_err, KERN_ERR);
|
|
define_dev_printk_level(_dev_warn, KERN_WARNING);
|
|
define_dev_printk_level(_dev_notice, KERN_NOTICE);
|
|
define_dev_printk_level(_dev_info, KERN_INFO);
|
|
|
|
#endif
|
|
|
|
/**
|
|
* dev_err_probe - probe error check and log helper
|
|
* @dev: the pointer to the struct device
|
|
* @err: error value to test
|
|
* @fmt: printf-style format string
|
|
* @...: arguments as specified in the format string
|
|
*
|
|
* This helper implements common pattern present in probe functions for error
|
|
* checking: print debug or error message depending if the error value is
|
|
* -EPROBE_DEFER and propagate error upwards.
|
|
* In case of -EPROBE_DEFER it sets also defer probe reason, which can be
|
|
* checked later by reading devices_deferred debugfs attribute.
|
|
* It replaces code sequence::
|
|
*
|
|
* if (err != -EPROBE_DEFER)
|
|
* dev_err(dev, ...);
|
|
* else
|
|
* dev_dbg(dev, ...);
|
|
* return err;
|
|
*
|
|
* with::
|
|
*
|
|
* return dev_err_probe(dev, err, ...);
|
|
*
|
|
* Note that it is deemed acceptable to use this function for error
|
|
* prints during probe even if the @err is known to never be -EPROBE_DEFER.
|
|
* The benefit compared to a normal dev_err() is the standardized format
|
|
* of the error code and the fact that the error code is returned.
|
|
*
|
|
* Returns @err.
|
|
*
|
|
*/
|
|
int dev_err_probe(const struct device *dev, int err, const char *fmt, ...)
|
|
{
|
|
struct va_format vaf;
|
|
va_list args;
|
|
|
|
va_start(args, fmt);
|
|
vaf.fmt = fmt;
|
|
vaf.va = &args;
|
|
|
|
if (err != -EPROBE_DEFER) {
|
|
dev_err(dev, "error %pe: %pV", ERR_PTR(err), &vaf);
|
|
} else {
|
|
device_set_deferred_probe_reason(dev, &vaf);
|
|
dev_dbg(dev, "error %pe: %pV", ERR_PTR(err), &vaf);
|
|
}
|
|
|
|
va_end(args);
|
|
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL_GPL(dev_err_probe);
|
|
|
|
static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
|
|
{
|
|
return fwnode && !IS_ERR(fwnode->secondary);
|
|
}
|
|
|
|
/**
|
|
* set_primary_fwnode - Change the primary firmware node of a given device.
|
|
* @dev: Device to handle.
|
|
* @fwnode: New primary firmware node of the device.
|
|
*
|
|
* Set the device's firmware node pointer to @fwnode, but if a secondary
|
|
* firmware node of the device is present, preserve it.
|
|
*
|
|
* Valid fwnode cases are:
|
|
* - primary --> secondary --> -ENODEV
|
|
* - primary --> NULL
|
|
* - secondary --> -ENODEV
|
|
* - NULL
|
|
*/
|
|
void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
|
|
{
|
|
struct device *parent = dev->parent;
|
|
struct fwnode_handle *fn = dev->fwnode;
|
|
|
|
if (fwnode) {
|
|
if (fwnode_is_primary(fn))
|
|
fn = fn->secondary;
|
|
|
|
if (fn) {
|
|
WARN_ON(fwnode->secondary);
|
|
fwnode->secondary = fn;
|
|
}
|
|
dev->fwnode = fwnode;
|
|
} else {
|
|
if (fwnode_is_primary(fn)) {
|
|
dev->fwnode = fn->secondary;
|
|
|
|
/* Skip nullifying fn->secondary if the primary is shared */
|
|
if (parent && fn == parent->fwnode)
|
|
return;
|
|
|
|
/* Set fn->secondary = NULL, so fn remains the primary fwnode */
|
|
fn->secondary = NULL;
|
|
} else {
|
|
dev->fwnode = NULL;
|
|
}
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(set_primary_fwnode);
|
|
|
|
/**
|
|
* set_secondary_fwnode - Change the secondary firmware node of a given device.
|
|
* @dev: Device to handle.
|
|
* @fwnode: New secondary firmware node of the device.
|
|
*
|
|
* If a primary firmware node of the device is present, set its secondary
|
|
* pointer to @fwnode. Otherwise, set the device's firmware node pointer to
|
|
* @fwnode.
|
|
*/
|
|
void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
|
|
{
|
|
if (fwnode)
|
|
fwnode->secondary = ERR_PTR(-ENODEV);
|
|
|
|
if (fwnode_is_primary(dev->fwnode))
|
|
dev->fwnode->secondary = fwnode;
|
|
else
|
|
dev->fwnode = fwnode;
|
|
}
|
|
EXPORT_SYMBOL_GPL(set_secondary_fwnode);
|
|
|
|
/**
|
|
* device_set_of_node_from_dev - reuse device-tree node of another device
|
|
* @dev: device whose device-tree node is being set
|
|
* @dev2: device whose device-tree node is being reused
|
|
*
|
|
* Takes another reference to the new device-tree node after first dropping
|
|
* any reference held to the old node.
|
|
*/
|
|
void device_set_of_node_from_dev(struct device *dev, const struct device *dev2)
|
|
{
|
|
of_node_put(dev->of_node);
|
|
dev->of_node = of_node_get(dev2->of_node);
|
|
dev->of_node_reused = true;
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_set_of_node_from_dev);
|
|
|
|
void device_set_node(struct device *dev, struct fwnode_handle *fwnode)
|
|
{
|
|
dev->fwnode = fwnode;
|
|
dev->of_node = to_of_node(fwnode);
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_set_node);
|
|
|
|
int device_match_name(struct device *dev, const void *name)
|
|
{
|
|
return sysfs_streq(dev_name(dev), name);
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_match_name);
|
|
|
|
int device_match_of_node(struct device *dev, const void *np)
|
|
{
|
|
return dev->of_node == np;
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_match_of_node);
|
|
|
|
int device_match_fwnode(struct device *dev, const void *fwnode)
|
|
{
|
|
return dev_fwnode(dev) == fwnode;
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_match_fwnode);
|
|
|
|
int device_match_devt(struct device *dev, const void *pdevt)
|
|
{
|
|
return dev->devt == *(dev_t *)pdevt;
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_match_devt);
|
|
|
|
int device_match_acpi_dev(struct device *dev, const void *adev)
|
|
{
|
|
return ACPI_COMPANION(dev) == adev;
|
|
}
|
|
EXPORT_SYMBOL(device_match_acpi_dev);
|
|
|
|
int device_match_acpi_handle(struct device *dev, const void *handle)
|
|
{
|
|
return ACPI_HANDLE(dev) == handle;
|
|
}
|
|
EXPORT_SYMBOL(device_match_acpi_handle);
|
|
|
|
int device_match_any(struct device *dev, const void *unused)
|
|
{
|
|
return 1;
|
|
}
|
|
EXPORT_SYMBOL_GPL(device_match_any);
|