[PATCH] PCI: Add pci_walk_bus function to PCI core (nonrecursive)

The PCI error recovery infrastructure needs to be able to contact all
the drivers affected by a PCI error event, which may mean traversing
all the devices under a given PCI-PCI bridge.  This patch adds a
function to the PCI core that traverses all the PCI devices on a PCI
bus and under any PCI-PCI bridges on that bus (and so on), calling a
given function for each device.  This provides a way for the error
recovery code to iterate through all devices that are affected by an
error event.

This version is not implemented as a recursive function.  Instead,
when we reach a PCI-PCI bridge, we set the pointers to start doing the
devices on the bus under the bridge, and when we reach the end of a
bus's devices, we use the bus->self pointer to go back up to the next
higher bus and continue doing its devices.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Paul Mackerras 2005-08-18 14:33:01 +10:00 committed by Greg Kroah-Hartman
parent 1d2450a4a6
commit cecf4864cf
2 changed files with 51 additions and 0 deletions

View File

@ -151,6 +151,54 @@ void pci_enable_bridges(struct pci_bus *bus)
}
}
/** pci_walk_bus - walk devices on/under bus, calling callback.
* @top bus whose devices should be walked
* @cb callback to be called for each device found
* @userdata arbitrary pointer to be passed to callback.
*
* Walk the given bus, including any bridged devices
* on buses under this bus. Call the provided callback
* on each device found.
*/
void pci_walk_bus(struct pci_bus *top, void (*cb)(struct pci_dev *, void *),
void *userdata)
{
struct pci_dev *dev;
struct pci_bus *bus;
struct list_head *next;
bus = top;
spin_lock(&pci_bus_lock);
next = top->devices.next;
for (;;) {
if (next == &bus->devices) {
/* end of this bus, go up or finish */
if (bus == top)
break;
next = bus->self->bus_list.next;
bus = bus->self->bus;
continue;
}
dev = list_entry(next, struct pci_dev, bus_list);
pci_dev_get(dev);
if (dev->subordinate) {
/* this is a pci-pci bridge, do its devices next */
next = dev->subordinate->devices.next;
bus = dev->subordinate;
} else
next = dev->bus_list.next;
spin_unlock(&pci_bus_lock);
/* Run device routines with the bus unlocked */
cb(dev, userdata);
spin_lock(&pci_bus_lock);
pci_dev_put(dev);
}
spin_unlock(&pci_bus_lock);
}
EXPORT_SYMBOL_GPL(pci_walk_bus);
EXPORT_SYMBOL(pci_bus_alloc_resource);
EXPORT_SYMBOL_GPL(pci_bus_add_device);
EXPORT_SYMBOL(pci_bus_add_devices);

View File

@ -434,6 +434,9 @@ const struct pci_device_id *pci_match_device(struct pci_driver *drv, struct pci_
const struct pci_device_id *pci_match_id(const struct pci_device_id *ids, struct pci_dev *dev);
int pci_scan_bridge(struct pci_bus *bus, struct pci_dev * dev, int max, int pass);
void pci_walk_bus(struct pci_bus *top, void (*cb)(struct pci_dev *, void *),
void *userdata);
/* kmem_cache style wrapper around pci_alloc_consistent() */
#include <linux/dmapool.h>