mirrors/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2025-11-04 02:30:34 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions
linux/drivers/pci/hotplug/acpiphp_core.c
D Scott Phillips 33883eeda4 PCI: acpiphp: Allow built-in drivers for Attention Indicators 
Since the introduction of the attention callback in acpiphp, a non-zero
struct module *owner has been required in acpiphp_register_attention(). The
intent seemed to be that the core code could hold a refcount on the module
while invoking a callback.

This check accidentally precludes the possibility of attention callbacks to
built-in drivers.

Remove the check on `struct module *owner` in acpiphp_register_attention()
so attention callbacks can also be registered from built-in drivers.

Link: https://lore.kernel.org/r/20230930002036.6491-1-scott@os.amperecomputing.com
Signed-off-by: D Scott Phillips <scott@os.amperecomputing.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2023-10-25 13:05:37 -05:00

310 lines
8.2 KiB
C
Raw Blame History

// SPDX-License-Identifier: GPL-2.0+
/*
* ACPI PCI 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) 2002 Hiroshi Aono (h-aono@ap.jp.nec.com)
* Copyright (C) 2002,2003 Takayoshi Kochi (t-kochi@bq.jp.nec.com)
* Copyright (C) 2002,2003 NEC Corporation
* Copyright (C) 2003-2005 Matthew Wilcox (willy@infradead.org)
* Copyright (C) 2003-2005 Hewlett Packard
*
* All rights reserved.
*
* Send feedback to <kristen.c.accardi@intel.com>
*
*/
#define pr_fmt(fmt) "acpiphp: " fmt
#include <linux/init.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/pci-acpi.h>
#include <linux/pci_hotplug.h>
#include <linux/slab.h>
#include <linux/smp.h>
#include "acpiphp.h"
/* name size which is used for entries in pcihpfs */
#define SLOT_NAME_SIZE 21 /* {_SUN} */
bool acpiphp_disabled;
/* local variables */
static struct acpiphp_attention_info *attention_info;
#define DRIVER_VERSION "0.5"
#define DRIVER_AUTHOR "Greg Kroah-Hartman <gregkh@us.ibm.com>, Takayoshi Kochi <t-kochi@bq.jp.nec.com>, Matthew Wilcox <willy@infradead.org>"
#define DRIVER_DESC "ACPI Hot Plug PCI Controller Driver"
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_PARM_DESC(disable, "disable acpiphp driver");
module_param_named(disable, acpiphp_disabled, bool, 0444);
static int enable_slot(struct hotplug_slot *slot);
static int disable_slot(struct hotplug_slot *slot);
static int set_attention_status(struct hotplug_slot *slot, u8 value);
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 acpi_hotplug_slot_ops = {
.enable_slot = enable_slot,
.disable_slot = disable_slot,
.set_attention_status = set_attention_status,
.get_power_status = get_power_status,
.get_attention_status = get_attention_status,
.get_latch_status = get_latch_status,
.get_adapter_status = get_adapter_status,
};
/**
* acpiphp_register_attention - set attention LED callback
* @info: must be completely filled with LED callbacks
*
* Description: This is used to register a hardware specific ACPI
* driver that manipulates the attention LED. All the fields in
* info must be set.
*/
int acpiphp_register_attention(struct acpiphp_attention_info *info)
{
int retval = -EINVAL;
if (info && info->set_attn && info->get_attn && !attention_info) {
retval = 0;
attention_info = info;
}
return retval;
}
EXPORT_SYMBOL_GPL(acpiphp_register_attention);
/**
* acpiphp_unregister_attention - unset attention LED callback
* @info: must match the pointer used to register
*
* Description: This is used to un-register a hardware specific acpi
* driver that manipulates the attention LED. The pointer to the
* info struct must be the same as the one used to set it.
*/
int acpiphp_unregister_attention(struct acpiphp_attention_info *info)
{
int retval = -EINVAL;
if (info && attention_info == info) {
attention_info = NULL;
retval = 0;
}
return retval;
}
EXPORT_SYMBOL_GPL(acpiphp_unregister_attention);
/**
* enable_slot - power on and enable a slot
* @hotplug_slot: slot to enable
*
* Actual tasks are done in acpiphp_enable_slot()
*/
static int enable_slot(struct hotplug_slot *hotplug_slot)
{
struct slot *slot = to_slot(hotplug_slot);
pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
/* enable the specified slot */
return acpiphp_enable_slot(slot->acpi_slot);
}
/**
* disable_slot - disable and power off a slot
* @hotplug_slot: slot to disable
*
* Actual tasks are done in acpiphp_disable_slot()
*/
static int disable_slot(struct hotplug_slot *hotplug_slot)
{
struct slot *slot = to_slot(hotplug_slot);
pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
/* disable the specified slot */
return acpiphp_disable_slot(slot->acpi_slot);
}
/**
* set_attention_status - set attention LED
* @hotplug_slot: slot to set attention LED on
* @status: value to set attention LED to (0 or 1)
*
* attention status LED, so we use a callback that
* was registered with us. This allows hardware specific
* ACPI implementations to blink the light for us.
*/
static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 status)
{
int retval = -ENODEV;
pr_debug("%s - physical_slot = %s\n", __func__,
hotplug_slot_name(hotplug_slot));
if (attention_info && try_module_get(attention_info->owner)) {
retval = attention_info->set_attn(hotplug_slot, status);
module_put(attention_info->owner);
} else
attention_info = NULL;
return retval;
}
/**
* get_power_status - get power status of a slot
* @hotplug_slot: slot to get status
* @value: pointer to store status
*
* Some platforms may not implement _STA method properly.
* In that case, the value returned may not be reliable.
*/
static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
struct slot *slot = to_slot(hotplug_slot);
pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
*value = acpiphp_get_power_status(slot->acpi_slot);
return 0;
}
/**
* get_attention_status - get attention LED status
* @hotplug_slot: slot to get status from
* @value: returns with value of attention LED
*
* ACPI doesn't have known method to determine the state
* of the attention status LED, so we use a callback that
* was registered with us. This allows hardware specific
* ACPI implementations to determine its state.
*/
static int get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
int retval = -EINVAL;
pr_debug("%s - physical_slot = %s\n", __func__,
hotplug_slot_name(hotplug_slot));
if (attention_info && try_module_get(attention_info->owner)) {
retval = attention_info->get_attn(hotplug_slot, value);
module_put(attention_info->owner);
} else
attention_info = NULL;
return retval;
}
/**
* get_latch_status - get latch status of a slot
* @hotplug_slot: slot to get status
* @value: pointer to store status
*
* ACPI doesn't provide any formal means to access latch status.
* Instead, we fake latch status from _STA.
*/
static int get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
struct slot *slot = to_slot(hotplug_slot);
pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
*value = acpiphp_get_latch_status(slot->acpi_slot);
return 0;
}
/**
* get_adapter_status - get adapter status of a slot
* @hotplug_slot: slot to get status
* @value: pointer to store status
*
* ACPI doesn't provide any formal means to access adapter status.
* Instead, we fake adapter status from _STA.
*/
static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
{
struct slot *slot = to_slot(hotplug_slot);
pr_debug("%s - physical_slot = %s\n", __func__, slot_name(slot));
*value = acpiphp_get_adapter_status(slot->acpi_slot);
return 0;
}
/* callback routine to initialize 'struct slot' for each slot */
int acpiphp_register_hotplug_slot(struct acpiphp_slot *acpiphp_slot,
unsigned int sun)
{
struct slot *slot;
int retval = -ENOMEM;
char name[SLOT_NAME_SIZE];
slot = kzalloc(sizeof(*slot), GFP_KERNEL);
if (!slot)
goto error;
slot->hotplug_slot.ops = &acpi_hotplug_slot_ops;
slot->acpi_slot = acpiphp_slot;
acpiphp_slot->slot = slot;
slot->sun = sun;
snprintf(name, SLOT_NAME_SIZE, "%u", sun);
retval = pci_hp_register(&slot->hotplug_slot, acpiphp_slot->bus,
acpiphp_slot->device, name);
if (retval == -EBUSY)
goto error_slot;
if (retval) {
pr_err("pci_hp_register failed with error %d\n", retval);
goto error_slot;
}
pr_info("Slot [%s] registered\n", slot_name(slot));
return 0;
error_slot:
kfree(slot);
error:
return retval;
}
void acpiphp_unregister_hotplug_slot(struct acpiphp_slot *acpiphp_slot)
{
struct slot *slot = acpiphp_slot->slot;
pr_info("Slot [%s] unregistered\n", slot_name(slot));
pci_hp_deregister(&slot->hotplug_slot);
kfree(slot);
}
void __init acpiphp_init(void)
{
pr_info(DRIVER_DESC " version: " DRIVER_VERSION "%s\n",
acpiphp_disabled ? ", disabled by user; please report a bug"
: "");
}
Reference in a new issue View git blame Copy permalink