Commit 4e359ed5 authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman

PCI: add locking to the pci device lists.

This also creates two new functions, pci_get_device() and pci_get_subsys()
which should be used from now on instead of pci_find_device() and
pci_find_subsys().

Thanks to Chris Wright and Andrew Morton for help in reviewing these changes.
parent a549a455
......@@ -173,6 +173,24 @@ int pci_visit_dev (struct pci_visit *fn, struct pci_dev_wrapped *wrapped_dev,
}
EXPORT_SYMBOL(pci_visit_dev);
static void pci_destroy_dev(struct pci_dev *dev)
{
pci_proc_detach_device(dev);
device_unregister(&dev->dev);
/* Remove the device from the device lists, and prevent any further
* list accesses from this device */
spin_lock(&pci_bus_lock);
list_del(&dev->bus_list);
list_del(&dev->global_list);
dev->bus_list.next = dev->bus_list.prev = NULL;
dev->global_list.next = dev->global_list.prev = NULL;
spin_unlock(&pci_bus_lock);
pci_free_resources(dev);
pci_put_dev(dev);
}
/**
* pci_remove_device_safe - remove an unused hotplug device
* @dev: the device to remove
......@@ -186,11 +204,7 @@ int pci_remove_device_safe(struct pci_dev *dev)
{
if (pci_dev_driver(dev))
return -EBUSY;
device_unregister(&dev->dev);
list_del(&dev->bus_list);
list_del(&dev->global_list);
pci_free_resources(dev);
pci_proc_detach_device(dev);
pci_destroy_dev(dev);
return 0;
}
EXPORT_SYMBOL(pci_remove_device_safe);
......@@ -237,17 +251,15 @@ void pci_remove_bus_device(struct pci_dev *dev)
pci_remove_behind_bridge(dev);
pci_proc_detach_bus(b);
spin_lock(&pci_bus_lock);
list_del(&b->node);
spin_unlock(&pci_bus_lock);
kfree(b);
dev->subordinate = NULL;
}
device_unregister(&dev->dev);
list_del(&dev->bus_list);
list_del(&dev->global_list);
pci_free_resources(dev);
pci_proc_detach_device(dev);
pci_put_dev(dev);
pci_destroy_dev(dev);
}
/**
......
......@@ -58,3 +58,6 @@ struct pci_visit {
extern int pci_visit_dev(struct pci_visit *fn,
struct pci_dev_wrapped *wrapped_dev,
struct pci_bus_wrapped *wrapped_parent);
/* Lock for read/write access to pci device and bus lists */
extern spinlock_t pci_bus_lock;
......@@ -308,39 +308,45 @@ static struct file_operations proc_bus_pci_operations = {
/* iterator */
static void *pci_seq_start(struct seq_file *m, loff_t *pos)
{
struct list_head *p = &pci_devices;
struct pci_dev *dev = NULL;
loff_t n = *pos;
/* XXX: surely we need some locking for traversing the list? */
dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev);
while (n--) {
p = p->next;
if (p == &pci_devices)
return NULL;
dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev);
if (dev == NULL)
goto exit;
}
return p;
exit:
return dev;
}
static void *pci_seq_next(struct seq_file *m, void *v, loff_t *pos)
{
struct list_head *p = v;
struct pci_dev *dev = v;
(*pos)++;
return p->next != &pci_devices ? (void *)p->next : NULL;
dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev);
return dev;
}
static void pci_seq_stop(struct seq_file *m, void *v)
{
/* release whatever locks we need */
if (v) {
struct pci_dev *dev = v;
pci_put_dev(dev);
}
}
static int show_device(struct seq_file *m, void *v)
{
struct list_head *p = v;
const struct pci_dev *dev;
const struct pci_dev *dev = v;
const struct pci_driver *drv;
int i;
if (p == &pci_devices)
if (dev == NULL)
return 0;
dev = pci_dev_g(p);
drv = pci_dev_driver(dev);
seq_printf(m, "%02x%02x\t%04x%04x\t%x",
dev->bus->number,
......@@ -455,19 +461,18 @@ int pci_proc_detach_bus(struct pci_bus* bus)
*/
static int show_dev_config(struct seq_file *m, void *v)
{
struct list_head *p = v;
struct pci_dev *dev;
struct pci_dev *dev = v;
struct pci_dev *first_dev;
struct pci_driver *drv;
u32 class_rev;
unsigned char latency, min_gnt, max_lat, *class;
int reg;
if (p == &pci_devices) {
first_dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, NULL);
if (dev == first_dev)
seq_puts(m, "PCI devices found:\n");
return 0;
}
pci_put_dev(first_dev);
dev = pci_dev_g(p);
drv = pci_dev_driver(dev);
pci_read_config_dword(dev, PCI_CLASS_REVISION, &class_rev);
......
/*
* PCI searching functions.
*
* Copyright 1993 -- 1997 Drew Eckhardt, Frederic Potter,
* David Mosberger-Tang
* Copyright 1997 -- 2000 Martin Mares <mj@ucw.cz>
* Copyright 2003 -- Greg Kroah-Hartman <greg@kroah.com>
*/
#include <linux/pci.h>
#include <linux/module.h>
spinlock_t pci_bus_lock = SPIN_LOCK_UNLOCKED;
static struct pci_bus *
pci_do_find_bus(struct pci_bus* bus, unsigned char busnr)
{
......@@ -52,11 +63,15 @@ pci_find_bus(unsigned char busnr)
struct pci_bus *
pci_find_next_bus(const struct pci_bus *from)
{
struct list_head *n = from ? from->node.next : pci_root_buses.next;
struct list_head *n;
struct pci_bus *b = NULL;
WARN_ON(irqs_disabled());
spin_lock(&pci_bus_lock);
n = from ? from->node.next : pci_root_buses.next;
if (n != &pci_root_buses)
b = pci_bus_b(n);
spin_unlock(&pci_bus_lock);
return b;
}
......@@ -97,24 +112,36 @@ pci_find_slot(unsigned int bus, unsigned int devfn)
* device structure is returned. Otherwise, %NULL is returned.
* A new search is initiated by passing %NULL to the @from argument.
* Otherwise if @from is not %NULL, searches continue from next device on the global list.
*
* NOTE: Do not use this function anymore, use pci_get_subsys() instead, as
* the pci device returned by this function can disappear at any moment in
* time.
*/
struct pci_dev *
pci_find_subsys(unsigned int vendor, unsigned int device,
unsigned int ss_vendor, unsigned int ss_device,
const struct pci_dev *from)
{
struct list_head *n = from ? from->global_list.next : pci_devices.next;
struct list_head *n;
struct pci_dev *dev;
WARN_ON(irqs_disabled());
spin_lock(&pci_bus_lock);
n = from ? from->global_list.next : pci_devices.next;
while (n != &pci_devices) {
struct pci_dev *dev = pci_dev_g(n);
while (n && (n != &pci_devices)) {
dev = pci_dev_g(n);
if ((vendor == PCI_ANY_ID || dev->vendor == vendor) &&
(device == PCI_ANY_ID || dev->device == device) &&
(ss_vendor == PCI_ANY_ID || dev->subsystem_vendor == ss_vendor) &&
(ss_device == PCI_ANY_ID || dev->subsystem_device == ss_device))
return dev;
goto exit;
n = n->next;
}
return NULL;
dev = NULL;
exit:
spin_unlock(&pci_bus_lock);
return dev;
}
/**
......@@ -128,6 +155,10 @@ pci_find_subsys(unsigned int vendor, unsigned int device,
* returned. Otherwise, %NULL is returned.
* A new search is initiated by passing %NULL to the @from argument.
* Otherwise if @from is not %NULL, searches continue from next device on the global list.
*
* NOTE: Do not use this function anymore, use pci_get_device() instead, as
* the pci device returned by this function can disappear at any moment in
* time.
*/
struct pci_dev *
pci_find_device(unsigned int vendor, unsigned int device, const struct pci_dev *from)
......@@ -135,6 +166,77 @@ pci_find_device(unsigned int vendor, unsigned int device, const struct pci_dev *
return pci_find_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from);
}
/**
* pci_get_subsys - begin or continue searching for a PCI device by vendor/subvendor/device/subdevice id
* @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
* @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
* @ss_vendor: PCI subsystem vendor id to match, or %PCI_ANY_ID to match all vendor ids
* @ss_device: PCI subsystem device id to match, or %PCI_ANY_ID to match all device ids
* @from: Previous PCI device found in search, or %NULL for new search.
*
* Iterates through the list of known PCI devices. If a PCI device is
* found with a matching @vendor, @device, @ss_vendor and @ss_device, a pointer to its
* device structure is returned, and the reference count to the device is
* incremented. Otherwise, %NULL is returned. A new search is initiated by
* passing %NULL to the @from argument. Otherwise if @from is not %NULL,
* searches continue from next device on the global list.
* The reference count for @from is always decremented if it is not %NULL.
*/
struct pci_dev *
pci_get_subsys(unsigned int vendor, unsigned int device,
unsigned int ss_vendor, unsigned int ss_device,
struct pci_dev *from)
{
struct list_head *n;
struct pci_dev *dev;
WARN_ON(irqs_disabled());
spin_lock(&pci_bus_lock);
n = from ? from->global_list.next : pci_devices.next;
while (n && (n != &pci_devices)) {
dev = pci_dev_g(n);
if ((vendor == PCI_ANY_ID || dev->vendor == vendor) &&
(device == PCI_ANY_ID || dev->device == device) &&
(ss_vendor == PCI_ANY_ID || dev->subsystem_vendor == ss_vendor) &&
(ss_device == PCI_ANY_ID || dev->subsystem_device == ss_device))
goto exit;
n = n->next;
}
dev = NULL;
exit:
pci_put_dev(from);
dev = pci_get_dev(dev);
spin_unlock(&pci_bus_lock);
return dev;
}
/**
* pci_get_device - begin or continue searching for a PCI device by vendor/device id
* @vendor: PCI vendor id to match, or %PCI_ANY_ID to match all vendor ids
* @device: PCI device id to match, or %PCI_ANY_ID to match all device ids
* @from: Previous PCI device found in search, or %NULL for new search.
*
* Iterates through the list of known PCI devices. If a PCI device is
* found with a matching @vendor and @device, a pointer to its device structure is
* returned. Otherwise, %NULL is returned.
* A new search is initiated by passing %NULL to the @from argument.
* Otherwise if @from is not %NULL, searches continue from next device on the global list.
*
* Iterates through the list of known PCI devices. If a PCI device is
* found with a matching @vendor and @device, the reference count to the
* device is incremented and a pointer to its device structure is returned.
* Otherwise, %NULL is returned. A new search is initiated by passing %NULL
* to the @from argument. Otherwise if @from is not %NULL, searches continue
* from next device on the global list. The reference count for @from is
* always decremented if it is not %NULL.
*/
struct pci_dev *
pci_get_device(unsigned int vendor, unsigned int device, struct pci_dev *from)
{
return pci_get_subsys(vendor, device, PCI_ANY_ID, PCI_ANY_ID, from);
}
/**
* pci_find_device_reverse - begin or continue searching for a PCI device by vendor/device id
......@@ -151,16 +253,24 @@ pci_find_device(unsigned int vendor, unsigned int device, const struct pci_dev *
struct pci_dev *
pci_find_device_reverse(unsigned int vendor, unsigned int device, const struct pci_dev *from)
{
struct list_head *n = from ? from->global_list.prev : pci_devices.prev;
struct list_head *n;
struct pci_dev *dev;
while (n != &pci_devices) {
struct pci_dev *dev = pci_dev_g(n);
WARN_ON(irqs_disabled());
spin_lock(&pci_bus_lock);
n = from ? from->global_list.prev : pci_devices.prev;
while (n && (n != &pci_devices)) {
dev = pci_dev_g(n);
if ((vendor == PCI_ANY_ID || dev->vendor == vendor) &&
(device == PCI_ANY_ID || dev->device == device))
return dev;
goto exit;
n = n->prev;
}
return NULL;
dev = NULL;
exit:
spin_unlock(&pci_bus_lock);
return dev;
}
......@@ -179,15 +289,22 @@ pci_find_device_reverse(unsigned int vendor, unsigned int device, const struct p
struct pci_dev *
pci_find_class(unsigned int class, const struct pci_dev *from)
{
struct list_head *n = from ? from->global_list.next : pci_devices.next;
struct list_head *n;
struct pci_dev *dev;
while (n != &pci_devices) {
struct pci_dev *dev = pci_dev_g(n);
spin_lock(&pci_bus_lock);
n = from ? from->global_list.next : pci_devices.next;
while (n && (n != &pci_devices)) {
dev = pci_dev_g(n);
if (dev->class == class)
return dev;
goto exit;
n = n->next;
}
return NULL;
dev = NULL;
exit:
spin_unlock(&pci_bus_lock);
return dev;
}
EXPORT_SYMBOL(pci_find_bus);
......@@ -196,3 +313,5 @@ EXPORT_SYMBOL(pci_find_device);
EXPORT_SYMBOL(pci_find_device_reverse);
EXPORT_SYMBOL(pci_find_slot);
EXPORT_SYMBOL(pci_find_subsys);
EXPORT_SYMBOL(pci_get_device);
EXPORT_SYMBOL(pci_get_subsys);
......@@ -566,6 +566,10 @@ struct pci_dev *pci_find_slot (unsigned int bus, unsigned int devfn);
int pci_find_capability (struct pci_dev *dev, int cap);
struct pci_bus * pci_find_next_bus(const struct pci_bus *from);
struct pci_dev *pci_get_device (unsigned int vendor, unsigned int device, struct pci_dev *from);
struct pci_dev *pci_get_subsys (unsigned int vendor, unsigned int device,
unsigned int ss_vendor, unsigned int ss_device,
struct pci_dev *from);
int pci_bus_read_config_byte (struct pci_bus *bus, unsigned int devfn, int where, u8 *val);
int pci_bus_read_config_word (struct pci_bus *bus, unsigned int devfn, int where, u16 *val);
int pci_bus_read_config_dword (struct pci_bus *bus, unsigned int devfn, int where, u32 *val);
......@@ -688,6 +692,13 @@ static inline struct pci_dev *pci_find_subsys(unsigned int vendor, unsigned int
unsigned int ss_vendor, unsigned int ss_device, const struct pci_dev *from)
{ return NULL; }
static inline struct pci_dev *pci_get_device (unsigned int vendor, unsigned int device, struct pci_dev *from)
{ return NULL; }
static inline struct pci_dev *pci_get_subsys (unsigned int vendor, unsigned int device,
unsigned int ss_vendor, unsigned int ss_device, struct pci_dev *from)
{ return NULL; }
static inline void pci_set_master(struct pci_dev *dev) { }
static inline int pci_enable_device(struct pci_dev *dev) { return -EIO; }
static inline void pci_disable_device(struct pci_dev *dev) { }
......
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