linux/drivers/pci/hotplug/pciehp_core.c

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/*
* PCI Express Hot Plug Controller Driver
*
* Copyright (C) 1995,2001 Compaq Computer Corporation
* Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
* Copyright (C) 2001 IBM Corp.
* Copyright (C) 2003-2004 Intel Corporation
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
*
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/pci.h>
#include "pciehp.h"
#include <linux/interrupt.h>
#include <linux/time.h>
/* Global variables */
bool pciehp_debug;
bool pciehp_poll_mode;
int pciehp_poll_time;
static bool pciehp_force;
#define DRIVER_VERSION "0.4"
#define DRIVER_AUTHOR "Dan Zink <dan.zink@compaq.com>, Greg Kroah-Hartman <greg@kroah.com>, Dely Sy <dely.l.sy@intel.com>"
#define DRIVER_DESC "PCI Express Hot Plug Controller Driver"
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
module_param(pciehp_debug, bool, 0644);
module_param(pciehp_poll_mode, bool, 0644);
module_param(pciehp_poll_time, int, 0644);
module_param(pciehp_force, bool, 0644);
MODULE_PARM_DESC(pciehp_debug, "Debugging mode enabled or not");
MODULE_PARM_DESC(pciehp_poll_mode, "Using polling mechanism for hot-plug events or not");
MODULE_PARM_DESC(pciehp_poll_time, "Polling mechanism frequency, in seconds");
PCI: PCIe: Ask BIOS for control of all native services at once After commit 852972acff8f10f3a15679be2059bb94916cba5d (ACPI: Disable ASPM if the platform won't provide _OSC control for PCIe) control of the PCIe Capability Structure is unconditionally requested by acpi_pci_root_add(), which in principle may cause problems to happen in two ways. First, the BIOS may refuse to give control of the PCIe Capability Structure if it is not asked for any of the _OSC features depending on it at the same time. Second, the BIOS may assume that control of the _OSC features depending on the PCIe Capability Structure will be requested in the future and may behave incorrectly if that doesn't happen. For this reason, control of the PCIe Capability Structure should always be requested along with control of any other _OSC features that may depend on it (ie. PCIe native PME, PCIe native hot-plug, PCIe AER). Rework the PCIe port driver so that (1) it checks which native PCIe port services can be enabled, according to the BIOS, and (2) it requests control of all these services simultaneously. In particular, this causes pcie_portdrv_probe() to fail if the BIOS refuses to grant control of the PCIe Capability Structure, which means that no native PCIe port services can be enabled for the PCIe Root Complex the given port belongs to. If that happens, ASPM is disabled to avoid problems with mishandling it by the part of the PCIe hierarchy for which control of the PCIe Capability Structure has not been received. Make it possible to override this behavior using 'pcie_ports=native' (use the PCIe native services regardless of the BIOS response to the control request), or 'pcie_ports=compat' (do not use the PCIe native services at all). Accordingly, rework the existing PCIe port service drivers so that they don't request control of the services directly. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-08-22 04:02:38 +08:00
MODULE_PARM_DESC(pciehp_force, "Force pciehp, even if OSHP is missing");
#define PCIE_MODULE_NAME "pciehp"
static int set_attention_status (struct hotplug_slot *slot, u8 value);
static int enable_slot (struct hotplug_slot *slot);
static int disable_slot (struct hotplug_slot *slot);
static int get_power_status (struct hotplug_slot *slot, u8 *value);
static int get_attention_status (struct hotplug_slot *slot, u8 *value);
static int get_latch_status (struct hotplug_slot *slot, u8 *value);
static int get_adapter_status (struct hotplug_slot *slot, u8 *value);
static int reset_slot (struct hotplug_slot *slot, int probe);
/**
* release_slot - free up the memory used by a slot
* @hotplug_slot: slot to free
*/
static void release_slot(struct hotplug_slot *hotplug_slot)
{
struct slot *slot = hotplug_slot->private;
ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
__func__, hotplug_slot_name(hotplug_slot));
kfree(hotplug_slot->ops);
kfree(hotplug_slot->info);
kfree(hotplug_slot);
}
static int init_slot(struct controller *ctrl)
{
struct slot *slot = ctrl->slot;
struct hotplug_slot *hotplug = NULL;
struct hotplug_slot_info *info = NULL;
struct hotplug_slot_ops *ops = NULL;
char name[SLOT_NAME_SIZE];
int retval = -ENOMEM;
hotplug = kzalloc(sizeof(*hotplug), GFP_KERNEL);
if (!hotplug)
goto out;
info = kzalloc(sizeof(*info), GFP_KERNEL);
if (!info)
goto out;
/* Setup hotplug slot ops */
ops = kzalloc(sizeof(*ops), GFP_KERNEL);
if (!ops)
goto out;
ops->enable_slot = enable_slot;
ops->disable_slot = disable_slot;
ops->get_power_status = get_power_status;
ops->get_adapter_status = get_adapter_status;
ops->reset_slot = reset_slot;
if (MRL_SENS(ctrl))
ops->get_latch_status = get_latch_status;
if (ATTN_LED(ctrl)) {
ops->get_attention_status = get_attention_status;
ops->set_attention_status = set_attention_status;
}
/* register this slot with the hotplug pci core */
hotplug->info = info;
hotplug->private = slot;
hotplug->release = &release_slot;
hotplug->ops = ops;
slot->hotplug_slot = hotplug;
snprintf(name, SLOT_NAME_SIZE, "%u", PSN(ctrl));
ctrl_dbg(ctrl, "Registering domain:bus:dev=%04x:%02x:00 sun=%x\n",
pci_domain_nr(ctrl->pcie->port->subordinate),
ctrl->pcie->port->subordinate->number, PSN(ctrl));
retval = pci_hp_register(hotplug,
ctrl->pcie->port->subordinate, 0, name);
if (retval)
ctrl_err(ctrl,
"pci_hp_register failed with error %d\n", retval);
out:
if (retval) {
kfree(ops);
kfree(info);
kfree(hotplug);
}
return retval;
}
static void cleanup_slot(struct controller *ctrl)
{
pci_hp_deregister(ctrl->slot->hotplug_slot);
}
/*
* set_attention_status - Turns the Amber LED for a slot on, off or blink
*/
static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
{
struct slot *slot = hotplug_slot->private;
ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
__func__, slot_name(slot));
pciehp_set_attention_status(slot, status);
return 0;
}
static int enable_slot(struct hotplug_slot *hotplug_slot)
{
struct slot *slot = hotplug_slot->private;
ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
__func__, slot_name(slot));
return pciehp_sysfs_enable_slot(slot);
}
static int disable_slot(struct hotplug_slot *hotplug_slot)
{
struct slot *slot = hotplug_slot->private;
ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
__func__, slot_name(slot));
return pciehp_sysfs_disable_slot(slot);
}
static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
struct slot *slot = hotplug_slot->private;
ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
__func__, slot_name(slot));
pciehp_get_power_status(slot, value);
return 0;
}
static int get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
struct slot *slot = hotplug_slot->private;
ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
__func__, slot_name(slot));
pciehp_get_attention_status(slot, value);
return 0;
}
static int get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
struct slot *slot = hotplug_slot->private;
ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
__func__, slot_name(slot));
pciehp_get_latch_status(slot, value);
return 0;
}
static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
struct slot *slot = hotplug_slot->private;
ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
__func__, slot_name(slot));
pciehp_get_adapter_status(slot, value);
return 0;
}
static int reset_slot(struct hotplug_slot *hotplug_slot, int probe)
{
struct slot *slot = hotplug_slot->private;
ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
__func__, slot_name(slot));
return pciehp_reset_slot(slot, probe);
}
static int pciehp_probe(struct pcie_device *dev)
{
int rc;
struct controller *ctrl;
struct slot *slot;
u8 occupied, poweron;
if (pciehp_force)
dev_info(&dev->device,
"Bypassing BIOS check for pciehp use on %s\n",
pci_name(dev->port));
PCI: PCIe: Ask BIOS for control of all native services at once After commit 852972acff8f10f3a15679be2059bb94916cba5d (ACPI: Disable ASPM if the platform won't provide _OSC control for PCIe) control of the PCIe Capability Structure is unconditionally requested by acpi_pci_root_add(), which in principle may cause problems to happen in two ways. First, the BIOS may refuse to give control of the PCIe Capability Structure if it is not asked for any of the _OSC features depending on it at the same time. Second, the BIOS may assume that control of the _OSC features depending on the PCIe Capability Structure will be requested in the future and may behave incorrectly if that doesn't happen. For this reason, control of the PCIe Capability Structure should always be requested along with control of any other _OSC features that may depend on it (ie. PCIe native PME, PCIe native hot-plug, PCIe AER). Rework the PCIe port driver so that (1) it checks which native PCIe port services can be enabled, according to the BIOS, and (2) it requests control of all these services simultaneously. In particular, this causes pcie_portdrv_probe() to fail if the BIOS refuses to grant control of the PCIe Capability Structure, which means that no native PCIe port services can be enabled for the PCIe Root Complex the given port belongs to. If that happens, ASPM is disabled to avoid problems with mishandling it by the part of the PCIe hierarchy for which control of the PCIe Capability Structure has not been received. Make it possible to override this behavior using 'pcie_ports=native' (use the PCIe native services regardless of the BIOS response to the control request), or 'pcie_ports=compat' (do not use the PCIe native services at all). Accordingly, rework the existing PCIe port service drivers so that they don't request control of the services directly. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-08-22 04:02:38 +08:00
else if (pciehp_acpi_slot_detection_check(dev->port))
goto err_out_none;
if (!dev->port->subordinate) {
/* Can happen if we run out of bus numbers during probe */
dev_err(&dev->device,
"Hotplug bridge without secondary bus, ignoring\n");
goto err_out_none;
}
ctrl = pcie_init(dev);
if (!ctrl) {
dev_err(&dev->device, "Controller initialization failed\n");
goto err_out_none;
}
set_service_data(dev, ctrl);
/* Setup the slot information structures */
rc = init_slot(ctrl);
if (rc) {
PCI: introduce pci_slot Currently, /sys/bus/pci/slots/ only exposes hotplug attributes when a hotplug driver is loaded, but PCI slots have attributes such as address, speed, width, etc. that are not related to hotplug at all. Introduce pci_slot as the primary data structure and kobject model. Hotplug attributes described in hotplug_slot become a secondary structure associated with the pci_slot. This patch only creates the infrastructure that allows the separation of PCI slot attributes and hotplug attributes. In this patch, the PCI hotplug core remains the only user of this infrastructure, and thus, /sys/bus/pci/slots/ will still only become populated when a hotplug driver is loaded. A later patch in this series will add a second user of this new infrastructure and demonstrate splitting the task of exposing pci_slot attributes from hotplug_slot attributes. - Make pci_slot the primary sysfs entity. hotplug_slot becomes a subsidiary structure. o pci_create_slot() creates and registers a slot with the PCI core o pci_slot_add_hotplug() gives it hotplug capability - Change the prototype of pci_hp_register() to take the bus and slot number (on parent bus) as parameters. - Remove all the ->get_address methods since this functionality is now handled by pci_slot directly. [achiang@hp.com: rpaphp-correctly-pci_hp_register-for-empty-pci-slots] Tested-by: Badari Pulavarty <pbadari@us.ibm.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: make headers_check happy] [akpm@linux-foundation.org: nuther build fix] [akpm@linux-foundation.org: fix typo in #include] Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Matthew Wilcox <matthew@wil.cx> Cc: Greg KH <greg@kroah.com> Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com> Cc: Len Brown <lenb@kernel.org> Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-06-11 05:28:50 +08:00
if (rc == -EBUSY)
ctrl_warn(ctrl, "Slot already registered by another hotplug driver\n");
PCI: introduce pci_slot Currently, /sys/bus/pci/slots/ only exposes hotplug attributes when a hotplug driver is loaded, but PCI slots have attributes such as address, speed, width, etc. that are not related to hotplug at all. Introduce pci_slot as the primary data structure and kobject model. Hotplug attributes described in hotplug_slot become a secondary structure associated with the pci_slot. This patch only creates the infrastructure that allows the separation of PCI slot attributes and hotplug attributes. In this patch, the PCI hotplug core remains the only user of this infrastructure, and thus, /sys/bus/pci/slots/ will still only become populated when a hotplug driver is loaded. A later patch in this series will add a second user of this new infrastructure and demonstrate splitting the task of exposing pci_slot attributes from hotplug_slot attributes. - Make pci_slot the primary sysfs entity. hotplug_slot becomes a subsidiary structure. o pci_create_slot() creates and registers a slot with the PCI core o pci_slot_add_hotplug() gives it hotplug capability - Change the prototype of pci_hp_register() to take the bus and slot number (on parent bus) as parameters. - Remove all the ->get_address methods since this functionality is now handled by pci_slot directly. [achiang@hp.com: rpaphp-correctly-pci_hp_register-for-empty-pci-slots] Tested-by: Badari Pulavarty <pbadari@us.ibm.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: make headers_check happy] [akpm@linux-foundation.org: nuther build fix] [akpm@linux-foundation.org: fix typo in #include] Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Matthew Wilcox <matthew@wil.cx> Cc: Greg KH <greg@kroah.com> Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com> Cc: Len Brown <lenb@kernel.org> Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-06-11 05:28:50 +08:00
else
ctrl_err(ctrl, "Slot initialization failed\n");
goto err_out_release_ctlr;
}
/* Enable events after we have setup the data structures */
rc = pcie_init_notification(ctrl);
if (rc) {
ctrl_err(ctrl, "Notification initialization failed\n");
goto err_out_free_ctrl_slot;
}
/* Check if slot is occupied */
slot = ctrl->slot;
pciehp_get_adapter_status(slot, &occupied);
pciehp_get_power_status(slot, &poweron);
if (occupied && pciehp_force) {
mutex_lock(&slot->hotplug_lock);
pciehp_enable_slot(slot);
mutex_unlock(&slot->hotplug_lock);
}
/* If empty slot's power status is on, turn power off */
if (!occupied && poweron && POWER_CTRL(ctrl))
pciehp_power_off_slot(slot);
return 0;
err_out_free_ctrl_slot:
cleanup_slot(ctrl);
err_out_release_ctlr:
pciehp_release_ctrl(ctrl);
err_out_none:
return -ENODEV;
}
static void pciehp_remove(struct pcie_device *dev)
{
struct controller *ctrl = get_service_data(dev);
cleanup_slot(ctrl);
pciehp_release_ctrl(ctrl);
}
#ifdef CONFIG_PM
static int pciehp_suspend(struct pcie_device *dev)
{
return 0;
}
static int pciehp_resume(struct pcie_device *dev)
{
struct controller *ctrl;
struct slot *slot;
u8 status;
ctrl = get_service_data(dev);
/* reinitialize the chipset's event detection logic */
pcie_enable_notification(ctrl);
slot = ctrl->slot;
/* Check if slot is occupied */
pciehp_get_adapter_status(slot, &status);
mutex_lock(&slot->hotplug_lock);
if (status)
pciehp_enable_slot(slot);
else
pciehp_disable_slot(slot);
mutex_unlock(&slot->hotplug_lock);
return 0;
}
#endif /* PM */
static struct pcie_port_service_driver hpdriver_portdrv = {
.name = PCIE_MODULE_NAME,
.port_type = PCIE_ANY_PORT,
.service = PCIE_PORT_SERVICE_HP,
.probe = pciehp_probe,
.remove = pciehp_remove,
#ifdef CONFIG_PM
.suspend = pciehp_suspend,
.resume = pciehp_resume,
#endif /* PM */
};
static int __init pcied_init(void)
{
int retval = 0;
pciehp_firmware_init();
retval = pcie_port_service_register(&hpdriver_portdrv);
dbg("pcie_port_service_register = %d\n", retval);
info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
PCI: pciehp: Use per-slot workqueues to avoid deadlock When we have a hotplug-capable PCIe port with a second hotplug-capable PCIe port below it, removing the device below the upstream port causes a deadlock. The deadlock happens because we use the pciehp_wq workqueue to run pciehp_power_thread(), which uses pciehp_disable_slot() to remove devices below the upstream port. When we remove the downstream PCIe port, we call pciehp_remove(), the pciehp driver's .remove() method. That calls flush_workqueue(pciehp_wq), which deadlocks because the pciehp_power_thread() work item is still running. This patch avoids the deadlock by creating a workqueue for every PCIe port and removing the single shared workqueue. Here's the call path that leads to the deadlock: pciehp_queue_pushbutton_work queue_work(pciehp_wq) # queue pciehp_power_thread ... pciehp_power_thread pciehp_disable_slot remove_board pciehp_unconfigure_device pci_stop_and_remove_bus_device ... pciehp_remove # pciehp driver .remove method pciehp_release_ctrl pcie_cleanup_slot flush_workqueue(pciehp_wq) This is fairly urgent because it can be caused by simply unplugging a Thunderbolt adapter, as reported by Daniel below. [bhelgaas: changelog] Reference: http://lkml.kernel.org/r/CAMVG2ssiRgcTD1bej2tkUUfsWmpL5eNtPcNif9va2-Gzb2u8nQ@mail.gmail.com Reported-and-tested-by: Daniel J Blueman <daniel@quora.org> Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org
2013-01-11 10:15:54 +08:00
if (retval)
dbg("Failure to register service\n");
PCI: pciehp: Use per-slot workqueues to avoid deadlock When we have a hotplug-capable PCIe port with a second hotplug-capable PCIe port below it, removing the device below the upstream port causes a deadlock. The deadlock happens because we use the pciehp_wq workqueue to run pciehp_power_thread(), which uses pciehp_disable_slot() to remove devices below the upstream port. When we remove the downstream PCIe port, we call pciehp_remove(), the pciehp driver's .remove() method. That calls flush_workqueue(pciehp_wq), which deadlocks because the pciehp_power_thread() work item is still running. This patch avoids the deadlock by creating a workqueue for every PCIe port and removing the single shared workqueue. Here's the call path that leads to the deadlock: pciehp_queue_pushbutton_work queue_work(pciehp_wq) # queue pciehp_power_thread ... pciehp_power_thread pciehp_disable_slot remove_board pciehp_unconfigure_device pci_stop_and_remove_bus_device ... pciehp_remove # pciehp driver .remove method pciehp_release_ctrl pcie_cleanup_slot flush_workqueue(pciehp_wq) This is fairly urgent because it can be caused by simply unplugging a Thunderbolt adapter, as reported by Daniel below. [bhelgaas: changelog] Reference: http://lkml.kernel.org/r/CAMVG2ssiRgcTD1bej2tkUUfsWmpL5eNtPcNif9va2-Gzb2u8nQ@mail.gmail.com Reported-and-tested-by: Daniel J Blueman <daniel@quora.org> Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org
2013-01-11 10:15:54 +08:00
return retval;
}
static void __exit pcied_cleanup(void)
{
dbg("unload_pciehpd()\n");
pcie_port_service_unregister(&hpdriver_portdrv);
info(DRIVER_DESC " version: " DRIVER_VERSION " unloaded\n");
}
module_init(pcied_init);
module_exit(pcied_cleanup);