linux/drivers/pci/hotplug/shpchp_core.c
Nick Alcock f98954b293 PCI: Remove MODULE_LICENSE so boolean drivers don't look like modules
Since 8b41fc4454 ("kbuild: create modules.builtin without
Makefile.modbuiltin or tristate.conf"), MODULE_LICENSE declarations are
used to identify modules. As a consequence, MODULE_LICENSE in non-modules
causes modprobe to misidentify the object file as a module when it is not,
and modprobe might succeed rather than failing with a suitable error
message.

For tristate modules that can be either built-in or loaded at runtime,
modprobe succeeds in both cases:

  # modprobe ext4
  [exit status zero if CONFIG_EXT4_FS=y or =m]

For boolean modules like the Standard Hot Plug Controller driver (shpchp)
that cannot be loaded at runtime, modprobe should always fail like this:

  # modprobe shpchp
  modprobe: FATAL: Module shpchp not found in directory /lib/modules/...
  [exit status non-zero regardless of CONFIG_HOTPLUG_PCI_SHPC]

but prior to this commit, shpchp_core.c contained MODULE_LICENSE, so
"modprobe shpchp" silently succeeded when it should have failed.

Remove MODULE_LICENSE in files that cannot be built as modules.

[bhelgaas: commit log, squash]
Suggested-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20230216152410.4312-1-nick.alcock@oracle.com/
Signed-off-by: Nick Alcock <nick.alcock@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Hitomi Hasegawa <hasegawa-hitomi@fujitsu.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
2023-02-17 08:47:58 -06:00

346 lines
8.5 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Standard 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.
*
* Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
*
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include "shpchp.h"
/* Global variables */
bool shpchp_debug;
bool shpchp_poll_mode;
int shpchp_poll_time;
#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 "Standard Hot Plug PCI Controller Driver"
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
module_param(shpchp_debug, bool, 0644);
module_param(shpchp_poll_mode, bool, 0644);
module_param(shpchp_poll_time, int, 0644);
MODULE_PARM_DESC(shpchp_debug, "Debugging mode enabled or not");
MODULE_PARM_DESC(shpchp_poll_mode, "Using polling mechanism for hot-plug events or not");
MODULE_PARM_DESC(shpchp_poll_time, "Polling mechanism frequency, in seconds");
#define SHPC_MODULE_NAME "shpchp"
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 const struct hotplug_slot_ops shpchp_hotplug_slot_ops = {
.set_attention_status = set_attention_status,
.enable_slot = enable_slot,
.disable_slot = disable_slot,
.get_power_status = get_power_status,
.get_attention_status = get_attention_status,
.get_latch_status = get_latch_status,
.get_adapter_status = get_adapter_status,
};
static int init_slots(struct controller *ctrl)
{
struct slot *slot;
struct hotplug_slot *hotplug_slot;
char name[SLOT_NAME_SIZE];
int retval;
int i;
for (i = 0; i < ctrl->num_slots; i++) {
slot = kzalloc(sizeof(*slot), GFP_KERNEL);
if (!slot) {
retval = -ENOMEM;
goto error;
}
hotplug_slot = &slot->hotplug_slot;
slot->hp_slot = i;
slot->ctrl = ctrl;
slot->bus = ctrl->pci_dev->subordinate->number;
slot->device = ctrl->slot_device_offset + i;
slot->hpc_ops = ctrl->hpc_ops;
slot->number = ctrl->first_slot + (ctrl->slot_num_inc * i);
slot->wq = alloc_workqueue("shpchp-%d", 0, 0, slot->number);
if (!slot->wq) {
retval = -ENOMEM;
goto error_slot;
}
mutex_init(&slot->lock);
INIT_DELAYED_WORK(&slot->work, shpchp_queue_pushbutton_work);
/* register this slot with the hotplug pci core */
snprintf(name, SLOT_NAME_SIZE, "%d", slot->number);
hotplug_slot->ops = &shpchp_hotplug_slot_ops;
ctrl_dbg(ctrl, "Registering domain:bus:dev=%04x:%02x:%02x hp_slot=%x sun=%x slot_device_offset=%x\n",
pci_domain_nr(ctrl->pci_dev->subordinate),
slot->bus, slot->device, slot->hp_slot, slot->number,
ctrl->slot_device_offset);
retval = pci_hp_register(hotplug_slot,
ctrl->pci_dev->subordinate, slot->device, name);
if (retval) {
ctrl_err(ctrl, "pci_hp_register failed with error %d\n",
retval);
goto error_slotwq;
}
get_power_status(hotplug_slot, &slot->pwr_save);
get_attention_status(hotplug_slot, &slot->attention_save);
get_latch_status(hotplug_slot, &slot->latch_save);
get_adapter_status(hotplug_slot, &slot->presence_save);
list_add(&slot->slot_list, &ctrl->slot_list);
}
return 0;
error_slotwq:
destroy_workqueue(slot->wq);
error_slot:
kfree(slot);
error:
return retval;
}
void cleanup_slots(struct controller *ctrl)
{
struct slot *slot, *next;
list_for_each_entry_safe(slot, next, &ctrl->slot_list, slot_list) {
list_del(&slot->slot_list);
cancel_delayed_work(&slot->work);
destroy_workqueue(slot->wq);
pci_hp_deregister(&slot->hotplug_slot);
kfree(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 = get_slot(hotplug_slot);
ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
__func__, slot_name(slot));
slot->attention_save = status;
slot->hpc_ops->set_attention_status(slot, status);
return 0;
}
static int enable_slot(struct hotplug_slot *hotplug_slot)
{
struct slot *slot = get_slot(hotplug_slot);
ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
__func__, slot_name(slot));
return shpchp_sysfs_enable_slot(slot);
}
static int disable_slot(struct hotplug_slot *hotplug_slot)
{
struct slot *slot = get_slot(hotplug_slot);
ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
__func__, slot_name(slot));
return shpchp_sysfs_disable_slot(slot);
}
static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
struct slot *slot = get_slot(hotplug_slot);
int retval;
ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
__func__, slot_name(slot));
retval = slot->hpc_ops->get_power_status(slot, value);
if (retval < 0)
*value = slot->pwr_save;
return 0;
}
static int get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
struct slot *slot = get_slot(hotplug_slot);
int retval;
ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
__func__, slot_name(slot));
retval = slot->hpc_ops->get_attention_status(slot, value);
if (retval < 0)
*value = slot->attention_save;
return 0;
}
static int get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
struct slot *slot = get_slot(hotplug_slot);
int retval;
ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
__func__, slot_name(slot));
retval = slot->hpc_ops->get_latch_status(slot, value);
if (retval < 0)
*value = slot->latch_save;
return 0;
}
static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
struct slot *slot = get_slot(hotplug_slot);
int retval;
ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
__func__, slot_name(slot));
retval = slot->hpc_ops->get_adapter_status(slot, value);
if (retval < 0)
*value = slot->presence_save;
return 0;
}
static bool shpc_capable(struct pci_dev *bridge)
{
/*
* It is assumed that AMD GOLAM chips support SHPC but they do not
* have SHPC capability.
*/
if (bridge->vendor == PCI_VENDOR_ID_AMD &&
bridge->device == PCI_DEVICE_ID_AMD_GOLAM_7450)
return true;
if (pci_find_capability(bridge, PCI_CAP_ID_SHPC))
return true;
return false;
}
static int shpc_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
{
int rc;
struct controller *ctrl;
if (!shpc_capable(pdev))
return -ENODEV;
if (acpi_get_hp_hw_control_from_firmware(pdev))
return -ENODEV;
ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
if (!ctrl)
goto err_out_none;
INIT_LIST_HEAD(&ctrl->slot_list);
rc = shpc_init(ctrl, pdev);
if (rc) {
ctrl_dbg(ctrl, "Controller initialization failed\n");
goto err_out_free_ctrl;
}
pci_set_drvdata(pdev, ctrl);
/* Setup the slot information structures */
rc = init_slots(ctrl);
if (rc) {
ctrl_err(ctrl, "Slot initialization failed\n");
goto err_out_release_ctlr;
}
rc = shpchp_create_ctrl_files(ctrl);
if (rc)
goto err_cleanup_slots;
pdev->shpc_managed = 1;
return 0;
err_cleanup_slots:
cleanup_slots(ctrl);
err_out_release_ctlr:
ctrl->hpc_ops->release_ctlr(ctrl);
err_out_free_ctrl:
kfree(ctrl);
err_out_none:
return -ENODEV;
}
static void shpc_remove(struct pci_dev *dev)
{
struct controller *ctrl = pci_get_drvdata(dev);
dev->shpc_managed = 0;
shpchp_remove_ctrl_files(ctrl);
ctrl->hpc_ops->release_ctlr(ctrl);
kfree(ctrl);
}
static const struct pci_device_id shpcd_pci_tbl[] = {
{PCI_DEVICE_CLASS(PCI_CLASS_BRIDGE_PCI_NORMAL, ~0)},
{ /* end: all zeroes */ }
};
MODULE_DEVICE_TABLE(pci, shpcd_pci_tbl);
static struct pci_driver shpc_driver = {
.name = SHPC_MODULE_NAME,
.id_table = shpcd_pci_tbl,
.probe = shpc_probe,
.remove = shpc_remove,
};
static int __init shpcd_init(void)
{
int retval;
retval = pci_register_driver(&shpc_driver);
dbg("%s: pci_register_driver = %d\n", __func__, retval);
info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
return retval;
}
static void __exit shpcd_cleanup(void)
{
dbg("unload_shpchpd()\n");
pci_unregister_driver(&shpc_driver);
info(DRIVER_DESC " version: " DRIVER_VERSION " unloaded\n");
}
module_init(shpcd_init);
module_exit(shpcd_cleanup);