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