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linux-next/drivers/pci/bus.c
Paul Mackerras cecf4864cf [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>
2005-09-08 15:04:30 -07:00

206 lines
5.2 KiB
C

/*
* drivers/pci/bus.c
*
* From setup-res.c, by:
* Dave Rusling (david.rusling@reo.mts.dec.com)
* David Mosberger (davidm@cs.arizona.edu)
* David Miller (davem@redhat.com)
* Ivan Kokshaysky (ink@jurassic.park.msu.ru)
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include "pci.h"
/**
* pci_bus_alloc_resource - allocate a resource from a parent bus
* @bus: PCI bus
* @res: resource to allocate
* @size: size of resource to allocate
* @align: alignment of resource to allocate
* @min: minimum /proc/iomem address to allocate
* @type_mask: IORESOURCE_* type flags
* @alignf: resource alignment function
* @alignf_data: data argument for resource alignment function
*
* Given the PCI bus a device resides on, the size, minimum address,
* alignment and type, try to find an acceptable resource allocation
* for a specific device resource.
*/
int
pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
unsigned long size, unsigned long align, unsigned long min,
unsigned int type_mask,
void (*alignf)(void *, struct resource *,
unsigned long, unsigned long),
void *alignf_data)
{
int i, ret = -ENOMEM;
type_mask |= IORESOURCE_IO | IORESOURCE_MEM;
for (i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
struct resource *r = bus->resource[i];
if (!r)
continue;
/* type_mask must match */
if ((res->flags ^ r->flags) & type_mask)
continue;
/* We cannot allocate a non-prefetching resource
from a pre-fetching area */
if ((r->flags & IORESOURCE_PREFETCH) &&
!(res->flags & IORESOURCE_PREFETCH))
continue;
/* Ok, try it out.. */
ret = allocate_resource(r, res, size,
r->start ? : min,
-1, align,
alignf, alignf_data);
if (ret == 0)
break;
}
return ret;
}
/**
* add a single device
* @dev: device to add
*
* This adds a single pci device to the global
* device list and adds sysfs and procfs entries
*/
void __devinit pci_bus_add_device(struct pci_dev *dev)
{
device_add(&dev->dev);
spin_lock(&pci_bus_lock);
list_add_tail(&dev->global_list, &pci_devices);
spin_unlock(&pci_bus_lock);
pci_proc_attach_device(dev);
pci_create_sysfs_dev_files(dev);
}
/**
* pci_bus_add_devices - insert newly discovered PCI devices
* @bus: bus to check for new devices
*
* Add newly discovered PCI devices (which are on the bus->devices
* list) to the global PCI device list, add the sysfs and procfs
* entries. Where a bridge is found, add the discovered bus to
* the parents list of child buses, and recurse (breadth-first
* to be compatible with 2.4)
*
* Call hotplug for each new devices.
*/
void __devinit pci_bus_add_devices(struct pci_bus *bus)
{
struct pci_dev *dev;
list_for_each_entry(dev, &bus->devices, bus_list) {
/*
* Skip already-present devices (which are on the
* global device list.)
*/
if (!list_empty(&dev->global_list))
continue;
pci_bus_add_device(dev);
}
list_for_each_entry(dev, &bus->devices, bus_list) {
BUG_ON(list_empty(&dev->global_list));
/*
* If there is an unattached subordinate bus, attach
* it and then scan for unattached PCI devices.
*/
if (dev->subordinate) {
if (list_empty(&dev->subordinate->node)) {
spin_lock(&pci_bus_lock);
list_add_tail(&dev->subordinate->node,
&dev->bus->children);
spin_unlock(&pci_bus_lock);
}
pci_bus_add_devices(dev->subordinate);
sysfs_create_link(&dev->subordinate->class_dev.kobj, &dev->dev.kobj, "bridge");
}
}
}
void pci_enable_bridges(struct pci_bus *bus)
{
struct pci_dev *dev;
int retval;
list_for_each_entry(dev, &bus->devices, bus_list) {
if (dev->subordinate) {
retval = pci_enable_device(dev);
pci_set_master(dev);
pci_enable_bridges(dev->subordinate);
}
}
}
/** 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);
EXPORT_SYMBOL(pci_enable_bridges);