// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2006 Matthew Wilcox <matthew@wil.cx>
* Copyright (C) 2006-2009 Hewlett-Packard Development Company, L.P.
* Alex Chiang <achiang@hp.com>
*/
#include <linux/kobject.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/err.h>
#include "pci.h"
struct kset *pci_slots_kset;
EXPORT_SYMBOL_GPL(pci_slots_kset);
static ssize_t pci_slot_attr_show(struct kobject *kobj,
struct attribute *attr, char *buf)
{
struct pci_slot *slot = to_pci_slot(kobj);
struct pci_slot_attribute *attribute = to_pci_slot_attr(attr);
return attribute->show ? attribute->show(slot, buf) : -EIO;
}
static ssize_t pci_slot_attr_store(struct kobject *kobj,
struct attribute *attr, const char *buf, size_t len)
{
struct pci_slot *slot = to_pci_slot(kobj);
struct pci_slot_attribute *attribute = to_pci_slot_attr(attr);
return attribute->store ? attribute->store(slot, buf, len) : -EIO;
}
static const struct sysfs_ops pci_slot_sysfs_ops = {
.show = pci_slot_attr_show,
.store = pci_slot_attr_store,
};
static ssize_t address_read_file(struct pci_slot *slot, char *buf)
{
if (slot->number == 0xff)
return sprintf(buf, "%04x:%02x\n",
pci_domain_nr(slot->bus),
slot->bus->number);
else
return sprintf(buf, "%04x:%02x:%02x\n",
pci_domain_nr(slot->bus),
slot->bus->number,
slot->number);
}
/* these strings match up with the values in pci_bus_speed */
static const char *pci_bus_speed_strings[] = {
"33 MHz PCI", /* 0x00 */
"66 MHz PCI", /* 0x01 */
"66 MHz PCI-X", /* 0x02 */
"100 MHz PCI-X", /* 0x03 */
"133 MHz PCI-X", /* 0x04 */
NULL, /* 0x05 */
NULL, /* 0x06 */
NULL, /* 0x07 */
NULL, /* 0x08 */
"66 MHz PCI-X 266", /* 0x09 */
"100 MHz PCI-X 266", /* 0x0a */
"133 MHz PCI-X 266", /* 0x0b */
"Unknown AGP", /* 0x0c */
"1x AGP", /* 0x0d */
"2x AGP", /* 0x0e */
"4x AGP", /* 0x0f */
"8x AGP", /* 0x10 */
"66 MHz PCI-X 533", /* 0x11 */
"100 MHz PCI-X 533", /* 0x12 */
"133 MHz PCI-X 533", /* 0x13 */
"2.5 GT/s PCIe", /* 0x14 */
"5.0 GT/s PCIe", /* 0x15 */
"8.0 GT/s PCIe", /* 0x16 */
"16.0 GT/s PCIe", /* 0x17 */
};
static ssize_t bus_speed_read(enum pci_bus_speed speed, char *buf)
{
const char *speed_string;
if (speed < ARRAY_SIZE(pci_bus_speed_strings))
speed_string = pci_bus_speed_strings[speed];
else
speed_string = "Unknown";
return sprintf(buf, "%s\n", speed_string);
}
static ssize_t max_speed_read_file(struct pci_slot *slot, char *buf)
{
return bus_speed_read(slot->bus->max_bus_speed, buf);
}
static ssize_t cur_speed_read_file(struct pci_slot *slot, char *buf)
{
return bus_speed_read(slot->bus->cur_bus_speed, buf);
}
static void pci_slot_release(struct kobject *kobj)
{
struct pci_dev *dev;
struct pci_slot *slot = to_pci_slot(kobj);
dev_dbg(&slot->bus->dev, "dev %02x, released physical slot %s\n",
slot->number, pci_slot_name(slot));
down_read(&pci_bus_sem);
list_for_each_entry(dev, &slot->bus->devices, bus_list)
if (PCI_SLOT(dev->devfn) == slot->number)
dev->slot = NULL;
up_read(&pci_bus_sem);
list_del(&slot->list);
kfree(slot);
}
static struct pci_slot_attribute pci_slot_attr_address =
__ATTR(address, S_IRUGO, address_read_file, NULL);
static struct pci_slot_attribute pci_slot_attr_max_speed =
__ATTR(max_bus_speed, S_IRUGO, max_speed_read_file, NULL);
static struct pci_slot_attribute pci_slot_attr_cur_speed =
__ATTR(cur_bus_speed, S_IRUGO, cur_speed_read_file, NULL);
static struct attribute *pci_slot_default_attrs[] = {
&pci_slot_attr_address.attr,
&pci_slot_attr_max_speed.attr,
&pci_slot_attr_cur_speed.attr,
NULL,
};
static struct kobj_type pci_slot_ktype = {
.sysfs_ops = &pci_slot_sysfs_ops,
.release = &pci_slot_release,
.default_attrs = pci_slot_default_attrs,
};
static char *make_slot_name(const char *name)
{
char *new_name;
int len, max, dup;
new_name = kstrdup(name, GFP_KERNEL);
if (!new_name)
return NULL;
/*
* Make sure we hit the realloc case the first time through the
* loop. 'len' will be strlen(name) + 3 at that point which is
* enough space for "name-X" and the trailing NUL.
*/
len = strlen(name) + 2;
max = 1;
dup = 1;
for (;;) {
struct kobject *dup_slot;
dup_slot = kset_find_obj(pci_slots_kset, new_name);
if (!dup_slot)
break;
kobject_put(dup_slot);
if (dup == max) {
len++;
max *= 10;
kfree(new_name);
new_name = kmalloc(len, GFP_KERNEL);
if (!new_name)
break;
}
sprintf(new_name, "%s-%d", name, dup++);
}
return new_name;
}
static int rename_slot(struct pci_slot *slot, const char *name)
{
int result = 0;
char *slot_name;
if (strcmp(pci_slot_name(slot), name) == 0)
return result;
slot_name = make_slot_name(name);
if (!slot_name)
return -ENOMEM;
result = kobject_rename(&slot->kobj, slot_name);
kfree(slot_name);
return result;
}
void pci_dev_assign_slot(struct pci_dev *dev)
{
struct pci_slot *slot;
mutex_lock(&pci_slot_mutex);
list_for_each_entry(slot, &dev->bus->slots, list)
if (PCI_SLOT(dev->devfn) == slot->number)
dev->slot = slot;
mutex_unlock(&pci_slot_mutex);
}
static struct pci_slot *get_slot(struct pci_bus *parent, int slot_nr)
{
struct pci_slot *slot;
/* We already hold pci_slot_mutex */
list_for_each_entry(slot, &parent->slots, list)
if (slot->number == slot_nr) {
kobject_get(&slot->kobj);
return slot;
}
return NULL;
}
/**
* pci_create_slot - create or increment refcount for physical PCI slot
* @parent: struct pci_bus of parent bridge
* @slot_nr: PCI_SLOT(pci_dev->devfn) or -1 for placeholder
* @name: user visible string presented in /sys/bus/pci/slots/<name>
* @hotplug: set if caller is hotplug driver, NULL otherwise
*
* PCI slots have first class attributes such as address, speed, width,
* and a &struct pci_slot is used to manage them. This interface will
* either return a new &struct pci_slot to the caller, or if the pci_slot
* already exists, its refcount will be incremented.
*
* Slots are uniquely identified by a @pci_bus, @slot_nr tuple.
*
* There are known platforms with broken firmware that assign the same
* name to multiple slots. Workaround these broken platforms by renaming
* the slots on behalf of the caller. If firmware assigns name N to
* multiple slots:
*
* The first slot is assigned N
* The second slot is assigned N-1
* The third slot is assigned N-2
* etc.
*
* Placeholder slots:
* In most cases, @pci_bus, @slot_nr will be sufficient to uniquely identify
* a slot. There is one notable exception - pSeries (rpaphp), where the
* @slot_nr cannot be determined until a device is actually inserted into
* the slot. In this scenario, the caller may pass -1 for @slot_nr.
*
* The following semantics are imposed when the caller passes @slot_nr ==
* -1. First, we no longer check for an existing %struct pci_slot, as there
* may be many slots with @slot_nr of -1. The other change in semantics is
* user-visible, which is the 'address' parameter presented in sysfs will
* consist solely of a dddd:bb tuple, where dddd is the PCI domain of the
* %struct pci_bus and bb is the bus number. In other words, the devfn of
* the 'placeholder' slot will not be displayed.
*/
struct pci_slot *pci_create_slot(struct pci_bus *parent, int slot_nr,
const char *name,
struct hotplug_slot *hotplug)
{
struct pci_dev *dev;
struct pci_slot *slot;
int err = 0;
char *slot_name = NULL;
mutex_lock(&pci_slot_mutex);
if (slot_nr == -1)
goto placeholder;
/*
* Hotplug drivers are allowed to rename an existing slot,
* but only if not already claimed.
*/
slot = get_slot(parent, slot_nr);
if (slot) {
if (hotplug) {
if ((err = slot->hotplug ? -EBUSY : 0)
|| (err = rename_slot(slot, name))) {
kobject_put(&slot->kobj);
slot = NULL;
goto err;
}
}
goto out;
}
placeholder:
slot = kzalloc(sizeof(*slot), GFP_KERNEL);
if (!slot) {
err = -ENOMEM;
goto err;
}
slot->bus = parent;
slot->number = slot_nr;
slot->kobj.kset = pci_slots_kset;
slot_name = make_slot_name(name);
if (!slot_name) {
err = -ENOMEM;
goto err;
}
err = kobject_init_and_add(&slot->kobj, &pci_slot_ktype, NULL,
"%s", slot_name);
if (err)
goto err;
INIT_LIST_HEAD(&slot->list);
list_add(&slot->list, &parent->slots);
down_read(&pci_bus_sem);
list_for_each_entry(dev, &parent->devices, bus_list)
if (PCI_SLOT(dev->devfn) == slot_nr)
dev->slot = slot;
up_read(&pci_bus_sem);
dev_dbg(&parent->dev, "dev %02x, created physical slot %s\n",
slot_nr, pci_slot_name(slot));
out:
kfree(slot_name);
mutex_unlock(&pci_slot_mutex);
return slot;
err:
kfree(slot);
slot = ERR_PTR(err);
goto out;
}
EXPORT_SYMBOL_GPL(pci_create_slot);
/**
* pci_destroy_slot - decrement refcount for physical PCI slot
* @slot: struct pci_slot to decrement
*
* %struct pci_slot is refcounted, so destroying them is really easy; we
* just call kobject_put on its kobj and let our release methods do the
* rest.
*/
void pci_destroy_slot(struct pci_slot *slot)
{
dev_dbg(&slot->bus->dev, "dev %02x, dec refcount to %d\n",
slot->number, kref_read(&slot->kobj.kref) - 1);
mutex_lock(&pci_slot_mutex);
kobject_put(&slot->kobj);
mutex_unlock(&pci_slot_mutex);
}
EXPORT_SYMBOL_GPL(pci_destroy_slot);
#if defined(CONFIG_HOTPLUG_PCI) || defined(CONFIG_HOTPLUG_PCI_MODULE)
#include <linux/pci_hotplug.h>
/**
* pci_hp_create_link - create symbolic link to the hotplug driver module.
* @pci_slot: struct pci_slot
*
* Helper function for pci_hotplug_core.c to create symbolic link to
* the hotplug driver module.
*/
void pci_hp_create_module_link(struct pci_slot *pci_slot)
{
struct hotplug_slot *slot = pci_slot->hotplug;
struct kobject *kobj = NULL;
int ret;
if (!slot || !slot->ops)
return;
kobj = kset_find_obj(module_kset, slot->mod_name);
if (!kobj)
return;
ret = sysfs_create_link(&pci_slot->kobj, kobj, "module");
if (ret)
dev_err(&pci_slot->bus->dev, "Error creating sysfs link (%d)\n",
ret);
kobject_put(kobj);
}
EXPORT_SYMBOL_GPL(pci_hp_create_module_link);
/**
* pci_hp_remove_link - remove symbolic link to the hotplug driver module.
* @pci_slot: struct pci_slot
*
* Helper function for pci_hotplug_core.c to remove symbolic link to
* the hotplug driver module.
*/
void pci_hp_remove_module_link(struct pci_slot *pci_slot)
{
sysfs_remove_link(&pci_slot->kobj, "module");
}
EXPORT_SYMBOL_GPL(pci_hp_remove_module_link);
#endif
static int pci_slot_init(void)
{
struct kset *pci_bus_kset;
pci_bus_kset = bus_get_kset(&pci_bus_type);
pci_slots_kset = kset_create_and_add("slots", NULL,
&pci_bus_kset->kobj);
if (!pci_slots_kset) {
pr_err("PCI: Slot initialization failure\n");
return -ENOMEM;
}
return 0;
}
subsys_initcall(pci_slot_init);
