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// SPDX-License-Identifier: GPL-2.0+
/*
* PCI HotPlug Controller Core
*
* Copyright (C) 2001-2002 Greg Kroah-Hartman (greg@kroah.com)
* Copyright (C) 2001-2002 IBM Corp.
*
* All rights reserved.
*
* Send feedback to <kristen.c.accardi@intel.com>
*
* Authors:
* Greg Kroah-Hartman <greg@kroah.com>
* Scott Murray <scottm@somanetworks.com>
*/
#include <linux/module.h> /* try_module_get & module_put */
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/kobject.h>
#include <linux/sysfs.h>
#include <linux/pagemap.h>
#include <linux/init.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/mutex.h>
#include <linux/pci.h>
#include <linux/pci_hotplug.h>
#include <linux/uaccess.h>
#include "../pci.h"
#include "cpci_hotplug.h"
#define MY_NAME "pci_hotplug"
#define dbg(fmt, arg...) do { if (debug) printk(KERN_DEBUG "%s: %s: " fmt, MY_NAME, __func__, ## arg); } while (0)
#define err(format, arg...) printk(KERN_ERR "%s: " format, MY_NAME, ## arg)
#define info(format, arg...) printk(KERN_INFO "%s: " format, MY_NAME, ## arg)
#define warn(format, arg...) printk(KERN_WARNING "%s: " format, MY_NAME, ## arg)
/* local variables */
static bool debug;
static LIST_HEAD(pci_hotplug_slot_list);
static DEFINE_MUTEX(pci_hp_mutex);
/* Weee, fun with macros... */
#define GET_STATUS(name, type) \
static int get_##name(struct hotplug_slot *slot, type *value) \
{ \
struct hotplug_slot_ops *ops = slot->ops; \
int retval = 0; \
if (!try_module_get(ops->owner)) \
return -ENODEV; \
if (ops->get_##name) \
retval = ops->get_##name(slot, value); \
else \
*value = slot->info->name; \
module_put(ops->owner); \
return retval; \
}
GET_STATUS(power_status, u8)
GET_STATUS(attention_status, u8)
GET_STATUS(latch_status, u8)
GET_STATUS(adapter_status, u8)
static ssize_t power_read_file(struct pci_slot *pci_slot, char *buf)
{
int retval;
u8 value;
retval = get_power_status(pci_slot->hotplug, &value);
if (retval)
return retval;
return sprintf(buf, "%d\n", value);
}
static ssize_t power_write_file(struct pci_slot *pci_slot, const char *buf,
size_t count)
{
struct hotplug_slot *slot = pci_slot->hotplug;
unsigned long lpower;
u8 power;
int retval = 0;
lpower = simple_strtoul(buf, NULL, 10);
power = (u8)(lpower & 0xff);
dbg("power = %d\n", power);
if (!try_module_get(slot->ops->owner)) {
retval = -ENODEV;
goto exit;
}
switch (power) {
case 0:
if (slot->ops->disable_slot)
retval = slot->ops->disable_slot(slot);
break;
case 1:
if (slot->ops->enable_slot)
retval = slot->ops->enable_slot(slot);
break;
default:
err("Illegal value specified for power\n");
retval = -EINVAL;
}
module_put(slot->ops->owner);
exit:
if (retval)
return retval;
return count;
}
static struct pci_slot_attribute hotplug_slot_attr_power = {
.attr = {.name = "power", .mode = S_IFREG | S_IRUGO | S_IWUSR},
.show = power_read_file,
.store = power_write_file
};
static ssize_t attention_read_file(struct pci_slot *pci_slot, char *buf)
{
int retval;
u8 value;
retval = get_attention_status(pci_slot->hotplug, &value);
if (retval)
return retval;
return sprintf(buf, "%d\n", value);
}
static ssize_t attention_write_file(struct pci_slot *pci_slot, const char *buf,
size_t count)
{
struct hotplug_slot_ops *ops = pci_slot->hotplug->ops;
unsigned long lattention;
u8 attention;
int retval = 0;
lattention = simple_strtoul(buf, NULL, 10);
attention = (u8)(lattention & 0xff);
dbg(" - attention = %d\n", attention);
if (!try_module_get(ops->owner)) {
retval = -ENODEV;
goto exit;
}
if (ops->set_attention_status)
retval = ops->set_attention_status(pci_slot->hotplug, attention);
module_put(ops->owner);
exit:
if (retval)
return retval;
return count;
}
static struct pci_slot_attribute hotplug_slot_attr_attention = {
.attr = {.name = "attention", .mode = S_IFREG | S_IRUGO | S_IWUSR},
.show = attention_read_file,
.store = attention_write_file
};
static ssize_t latch_read_file(struct pci_slot *pci_slot, char *buf)
{
int retval;
u8 value;
retval = get_latch_status(pci_slot->hotplug, &value);
if (retval)
return retval;
return sprintf(buf, "%d\n", value);
}
static struct pci_slot_attribute hotplug_slot_attr_latch = {
.attr = {.name = "latch", .mode = S_IFREG | S_IRUGO},
.show = latch_read_file,
};
static ssize_t presence_read_file(struct pci_slot *pci_slot, char *buf)
{
int retval;
u8 value;
retval = get_adapter_status(pci_slot->hotplug, &value);
if (retval)
return retval;
return sprintf(buf, "%d\n", value);
}
static struct pci_slot_attribute hotplug_slot_attr_presence = {
.attr = {.name = "adapter", .mode = S_IFREG | S_IRUGO},
.show = presence_read_file,
};
static ssize_t test_write_file(struct pci_slot *pci_slot, const char *buf,
size_t count)
{
struct hotplug_slot *slot = pci_slot->hotplug;
unsigned long ltest;
u32 test;
int retval = 0;
ltest = simple_strtoul(buf, NULL, 10);
test = (u32)(ltest & 0xffffffff);
dbg("test = %d\n", test);
if (!try_module_get(slot->ops->owner)) {
retval = -ENODEV;
goto exit;
}
if (slot->ops->hardware_test)
retval = slot->ops->hardware_test(slot, test);
module_put(slot->ops->owner);
exit:
if (retval)
return retval;
return count;
}
static struct pci_slot_attribute hotplug_slot_attr_test = {
.attr = {.name = "test", .mode = S_IFREG | S_IRUGO | S_IWUSR},
.store = test_write_file
};
static bool has_power_file(struct pci_slot *pci_slot)
{
struct hotplug_slot *slot = pci_slot->hotplug;
if ((!slot) || (!slot->ops))
return false;
if ((slot->ops->enable_slot) ||
(slot->ops->disable_slot) ||
(slot->ops->get_power_status))
return true;
return false;
}
static bool has_attention_file(struct pci_slot *pci_slot)
{
struct hotplug_slot *slot = pci_slot->hotplug;
if ((!slot) || (!slot->ops))
return false;
if ((slot->ops->set_attention_status) ||
(slot->ops->get_attention_status))
return true;
return false;
}
static bool has_latch_file(struct pci_slot *pci_slot)
{
struct hotplug_slot *slot = pci_slot->hotplug;
if ((!slot) || (!slot->ops))
return false;
if (slot->ops->get_latch_status)
return true;
return false;
}
static bool has_adapter_file(struct pci_slot *pci_slot)
{
struct hotplug_slot *slot = pci_slot->hotplug;
if ((!slot) || (!slot->ops))
return false;
if (slot->ops->get_adapter_status)
return true;
return false;
}
static bool has_test_file(struct pci_slot *pci_slot)
{
struct hotplug_slot *slot = pci_slot->hotplug;
if ((!slot) || (!slot->ops))
return false;
if (slot->ops->hardware_test)
return true;
return false;
}
static int fs_add_slot(struct pci_slot *pci_slot)
{
int retval = 0;
/* Create symbolic link to the hotplug driver module */
pci_hp_create_module_link(pci_slot);
if (has_power_file(pci_slot)) {
retval = sysfs_create_file(&pci_slot->kobj,
&hotplug_slot_attr_power.attr);
if (retval)
goto exit_power;
}
if (has_attention_file(pci_slot)) {
retval = sysfs_create_file(&pci_slot->kobj,
&hotplug_slot_attr_attention.attr);
if (retval)
goto exit_attention;
}
if (has_latch_file(pci_slot)) {
retval = sysfs_create_file(&pci_slot->kobj,
&hotplug_slot_attr_latch.attr);
if (retval)
goto exit_latch;
}
if (has_adapter_file(pci_slot)) {
retval = sysfs_create_file(&pci_slot->kobj,
&hotplug_slot_attr_presence.attr);
if (retval)
goto exit_adapter;
}
if (has_test_file(pci_slot)) {
retval = sysfs_create_file(&pci_slot->kobj,
&hotplug_slot_attr_test.attr);
if (retval)
goto exit_test;
}
goto exit;
exit_test:
if (has_adapter_file(pci_slot))
sysfs_remove_file(&pci_slot->kobj,
&hotplug_slot_attr_presence.attr);
exit_adapter:
if (has_latch_file(pci_slot))
sysfs_remove_file(&pci_slot->kobj, &hotplug_slot_attr_latch.attr);
exit_latch:
if (has_attention_file(pci_slot))
sysfs_remove_file(&pci_slot->kobj,
&hotplug_slot_attr_attention.attr);
exit_attention:
if (has_power_file(pci_slot))
sysfs_remove_file(&pci_slot->kobj, &hotplug_slot_attr_power.attr);
exit_power:
pci_hp_remove_module_link(pci_slot);
exit:
return retval;
}
static void fs_remove_slot(struct pci_slot *pci_slot)
{
if (has_power_file(pci_slot))
sysfs_remove_file(&pci_slot->kobj, &hotplug_slot_attr_power.attr);
if (has_attention_file(pci_slot))
sysfs_remove_file(&pci_slot->kobj,
&hotplug_slot_attr_attention.attr);
if (has_latch_file(pci_slot))
sysfs_remove_file(&pci_slot->kobj, &hotplug_slot_attr_latch.attr);
if (has_adapter_file(pci_slot))
sysfs_remove_file(&pci_slot->kobj,
&hotplug_slot_attr_presence.attr);
if (has_test_file(pci_slot))
sysfs_remove_file(&pci_slot->kobj, &hotplug_slot_attr_test.attr);
pci_hp_remove_module_link(pci_slot);
}
static struct hotplug_slot *get_slot_from_name(const char *name)
{
struct hotplug_slot *slot;
list_for_each_entry(slot, &pci_hotplug_slot_list, slot_list) {
if (strcmp(hotplug_slot_name(slot), name) == 0)
return slot;
}
return NULL;
}
/**
* __pci_hp_register - register a hotplug_slot with the PCI hotplug subsystem
* @bus: bus this slot is on
* @slot: pointer to the &struct hotplug_slot to register
* @devnr: device number
* @name: name registered with kobject core
* @owner: caller module owner
* @mod_name: caller module name
*
* Prepares a hotplug slot for in-kernel use and immediately publishes it to
* user space in one go. Drivers may alternatively carry out the two steps
* separately by invoking pci_hp_initialize() and pci_hp_add().
*
* Returns 0 if successful, anything else for an error.
*/
int __pci_hp_register(struct hotplug_slot *slot, struct pci_bus *bus,
int devnr, const char *name,
struct module *owner, const char *mod_name)
{
int result;
result = __pci_hp_initialize(slot, bus, devnr, name, owner, mod_name);
if (result)
return result;
result = pci_hp_add(slot);
if (result)
pci_hp_destroy(slot);
return result;
}
EXPORT_SYMBOL_GPL(__pci_hp_register);
/**
* __pci_hp_initialize - prepare hotplug slot for in-kernel use
* @slot: pointer to the &struct hotplug_slot to initialize
* @bus: bus this slot is on
* @devnr: slot number
* @name: name registered with kobject core
* @owner: caller module owner
* @mod_name: caller module name
*
* Allocate and fill in a PCI slot for use by a hotplug driver. Once this has
* been called, the driver may invoke hotplug_slot_name() to get the slot's
* unique name. The driver must be prepared to handle a ->reset_slot callback
* from this point on.
*
* Returns 0 on success or a negative int on error.
*/
int __pci_hp_initialize(struct hotplug_slot *slot, struct pci_bus *bus,
int devnr, const char *name, struct module *owner,
const char *mod_name)
{
struct pci_slot *pci_slot;
if (slot == NULL)
return -ENODEV;
if ((slot->info == NULL) || (slot->ops == NULL))
return -EINVAL;
slot->ops->owner = owner;
slot->ops->mod_name = mod_name;
/*
* No problems if we call this interface from both ACPI_PCI_SLOT
* driver and call it here again. If we've already created the
* pci_slot, the interface will simply bump the refcount.
*/
pci_slot = pci_create_slot(bus, devnr, name, slot);
if (IS_ERR(pci_slot))
return PTR_ERR(pci_slot);
slot->pci_slot = pci_slot;
pci_slot->hotplug = slot;
return 0;
}
EXPORT_SYMBOL_GPL(__pci_hp_initialize);
/**
* pci_hp_add - publish hotplug slot to user space
* @slot: pointer to the &struct hotplug_slot to publish
*
* Make a hotplug slot's sysfs interface available and inform user space of its
* addition by sending a uevent. The hotplug driver must be prepared to handle
* all &struct hotplug_slot_ops callbacks from this point on.
*
* Returns 0 on success or a negative int on error.
*/
int pci_hp_add(struct hotplug_slot *slot)
{
struct pci_slot *pci_slot = slot->pci_slot;
int result;
result = fs_add_slot(pci_slot);
if (result)
return result;
kobject_uevent(&pci_slot->kobj, KOBJ_ADD);
mutex_lock(&pci_hp_mutex);
list_add(&slot->slot_list, &pci_hotplug_slot_list);
mutex_unlock(&pci_hp_mutex);
dbg("Added slot %s to the list\n", hotplug_slot_name(slot));
return 0;
}
EXPORT_SYMBOL_GPL(pci_hp_add);
/**
* pci_hp_deregister - deregister a hotplug_slot with the PCI hotplug subsystem
* @slot: pointer to the &struct hotplug_slot to deregister
*
* The @slot must have been registered with the pci hotplug subsystem
* previously with a call to pci_hp_register().
*
* Returns 0 if successful, anything else for an error.
*/
void pci_hp_deregister(struct hotplug_slot *slot)
{
pci_hp_del(slot);
pci_hp_destroy(slot);
}
EXPORT_SYMBOL_GPL(pci_hp_deregister);
/**
* pci_hp_del - unpublish hotplug slot from user space
* @slot: pointer to the &struct hotplug_slot to unpublish
*
* Remove a hotplug slot's sysfs interface.
*
* Returns 0 on success or a negative int on error.
*/
void pci_hp_del(struct hotplug_slot *slot)
{
struct hotplug_slot *temp;
if (WARN_ON(!slot))
return;
mutex_lock(&pci_hp_mutex);
temp = get_slot_from_name(hotplug_slot_name(slot));
if (WARN_ON(temp != slot)) {
mutex_unlock(&pci_hp_mutex);
return;
}
list_del(&slot->slot_list);
mutex_unlock(&pci_hp_mutex);
dbg("Removed slot %s from the list\n", hotplug_slot_name(slot));
fs_remove_slot(slot->pci_slot);
}
EXPORT_SYMBOL_GPL(pci_hp_del);
/**
* pci_hp_destroy - remove hotplug slot from in-kernel use
* @slot: pointer to the &struct hotplug_slot to destroy
*
* Destroy a PCI slot used by a hotplug driver. Once this has been called,
* the driver may no longer invoke hotplug_slot_name() to get the slot's
* unique name. The driver no longer needs to handle a ->reset_slot callback
* from this point on.
*
* Returns 0 on success or a negative int on error.
*/
void pci_hp_destroy(struct hotplug_slot *slot)
{
struct pci_slot *pci_slot = slot->pci_slot;
slot->pci_slot = NULL;
pci_slot->hotplug = NULL;
pci_destroy_slot(pci_slot);
}
EXPORT_SYMBOL_GPL(pci_hp_destroy);
/**
* pci_hp_change_slot_info - changes the slot's information structure in the core
* @slot: pointer to the slot whose info has changed
* @info: pointer to the info copy into the slot's info structure
*
* @slot must have been registered with the pci
* hotplug subsystem previously with a call to pci_hp_register().
*
* Returns 0 if successful, anything else for an error.
*/
int pci_hp_change_slot_info(struct hotplug_slot *slot,
struct hotplug_slot_info *info)
{
if (!slot || !info)
return -ENODEV;
memcpy(slot->info, info, sizeof(struct hotplug_slot_info));
return 0;
}
EXPORT_SYMBOL_GPL(pci_hp_change_slot_info);
static int __init pci_hotplug_init(void)
{
int result;
result = cpci_hotplug_init(debug);
if (result) {
err("cpci_hotplug_init with error %d\n", result);
return result;
}
return result;
}
device_initcall(pci_hotplug_init);
/*
* not really modular, but the easiest way to keep compat with existing
* bootargs behaviour is to continue using module_param here.
*/
module_param(debug, bool, 0644);
MODULE_PARM_DESC(debug, "Debugging mode enabled or not");