![Bjorn Helgaas](/assets/img/avatar_default.png)
Allocate space from the highest-address PCI bus resource first, then work downward. Previously, we looked for space in PCI host bridge windows in the order we discovered the windows. For example, given the following windows (discovered via an ACPI _CRS method): pci_root PNP0A03:00: host bridge window [mem 0x000a0000-0x000bffff] pci_root PNP0A03:00: host bridge window [mem 0x000c0000-0x000effff] pci_root PNP0A03:00: host bridge window [mem 0x000f0000-0x000fffff] pci_root PNP0A03:00: host bridge window [mem 0xbff00000-0xf7ffffff] pci_root PNP0A03:00: host bridge window [mem 0xff980000-0xff980fff] pci_root PNP0A03:00: host bridge window [mem 0xff97c000-0xff97ffff] pci_root PNP0A03:00: host bridge window [mem 0xfed20000-0xfed9ffff] we attempted to allocate from [mem 0x000a0000-0x000bffff] first, then [mem 0x000c0000-0x000effff], and so on. With this patch, we allocate from [mem 0xff980000-0xff980fff] first, then [mem 0xff97c000-0xff97ffff], [mem 0xfed20000-0xfed9ffff], etc. Allocating top-down follows Windows practice, so we're less likely to trip over BIOS defects in the _CRS description. On the machine above (a Dell T3500), the [mem 0xbff00000-0xbfffffff] region doesn't actually work and is likely a BIOS defect. The symptom is that we move the AHCI controller to 0xbff00000, which leads to "Boot has failed, sleeping forever," a BUG in ahci_stop_engine(), or some other boot failure. Reference: https://bugzilla.kernel.org/show_bug.cgi?id=16228#c43 Reference: https://bugzilla.redhat.com/show_bug.cgi?id=620313 Reference: https://bugzilla.redhat.com/show_bug.cgi?id=629933 Reported-by: Brian Bloniarz <phunge0@hotmail.com> Reported-and-tested-by: Stefan Becker <chemobejk@gmail.com> Reported-by: Denys Vlasenko <dvlasenk@redhat.com> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
350 lines
8.3 KiB
C
350 lines
8.3 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 <linux/slab.h>
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#include "pci.h"
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void pci_bus_add_resource(struct pci_bus *bus, struct resource *res,
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unsigned int flags)
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{
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struct pci_bus_resource *bus_res;
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bus_res = kzalloc(sizeof(struct pci_bus_resource), GFP_KERNEL);
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if (!bus_res) {
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dev_err(&bus->dev, "can't add %pR resource\n", res);
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return;
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}
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bus_res->res = res;
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bus_res->flags = flags;
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list_add_tail(&bus_res->list, &bus->resources);
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}
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struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n)
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{
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struct pci_bus_resource *bus_res;
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if (n < PCI_BRIDGE_RESOURCE_NUM)
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return bus->resource[n];
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n -= PCI_BRIDGE_RESOURCE_NUM;
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list_for_each_entry(bus_res, &bus->resources, list) {
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if (n-- == 0)
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return bus_res->res;
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}
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return NULL;
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}
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EXPORT_SYMBOL_GPL(pci_bus_resource_n);
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void pci_bus_remove_resources(struct pci_bus *bus)
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{
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struct pci_bus_resource *bus_res, *tmp;
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int i;
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for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
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bus->resource[i] = NULL;
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list_for_each_entry_safe(bus_res, tmp, &bus->resources, list) {
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list_del(&bus_res->list);
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kfree(bus_res);
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}
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}
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/*
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* Find the highest-address bus resource below the cursor "res". If the
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* cursor is NULL, return the highest resource.
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*/
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static struct resource *pci_bus_find_resource_prev(struct pci_bus *bus,
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unsigned int type,
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struct resource *res)
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{
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struct resource *r, *prev = NULL;
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int i;
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pci_bus_for_each_resource(bus, r, i) {
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if (!r)
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continue;
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if ((r->flags & IORESOURCE_TYPE_BITS) != type)
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continue;
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/* If this resource is at or past the cursor, skip it */
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if (res) {
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if (r == res)
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continue;
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if (r->end > res->end)
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continue;
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if (r->end == res->end && r->start > res->start)
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continue;
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}
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if (!prev)
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prev = r;
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/*
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* A small resource is higher than a large one that ends at
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* the same address.
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*/
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if (r->end > prev->end ||
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(r->end == prev->end && r->start > prev->start))
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prev = r;
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}
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return prev;
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}
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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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resource_size_t size, resource_size_t align,
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resource_size_t min, unsigned int type_mask,
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resource_size_t (*alignf)(void *,
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const struct resource *,
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resource_size_t,
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resource_size_t),
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void *alignf_data)
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{
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int ret = -ENOMEM;
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struct resource *r;
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resource_size_t max = -1;
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unsigned int type = res->flags & IORESOURCE_TYPE_BITS;
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type_mask |= IORESOURCE_IO | IORESOURCE_MEM;
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/* don't allocate too high if the pref mem doesn't support 64bit*/
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if (!(res->flags & IORESOURCE_MEM_64))
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max = PCIBIOS_MAX_MEM_32;
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/* Look for space at highest addresses first */
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r = pci_bus_find_resource_prev(bus, type, NULL);
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for ( ; r; r = pci_bus_find_resource_prev(bus, type, r)) {
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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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max, 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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* pci_bus_add_device - 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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int pci_bus_add_device(struct pci_dev *dev)
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{
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int retval;
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retval = device_add(&dev->dev);
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if (retval)
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return retval;
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dev->is_added = 1;
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pci_proc_attach_device(dev);
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pci_create_sysfs_dev_files(dev);
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return 0;
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}
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/**
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* pci_bus_add_child - add a child bus
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* @bus: bus to add
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*
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* This adds sysfs entries for a single bus
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*/
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int pci_bus_add_child(struct pci_bus *bus)
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{
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int retval;
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if (bus->bridge)
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bus->dev.parent = bus->bridge;
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retval = device_register(&bus->dev);
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if (retval)
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return retval;
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bus->is_added = 1;
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retval = device_create_file(&bus->dev, &dev_attr_cpuaffinity);
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if (retval)
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return retval;
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retval = device_create_file(&bus->dev, &dev_attr_cpulistaffinity);
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/* Create legacy_io and legacy_mem files for this bus */
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pci_create_legacy_files(bus);
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return retval;
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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 pci_bus_add_devices(const struct pci_bus *bus)
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{
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struct pci_dev *dev;
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struct pci_bus *child;
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int retval;
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list_for_each_entry(dev, &bus->devices, bus_list) {
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/* Skip already-added devices */
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if (dev->is_added)
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continue;
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retval = pci_bus_add_device(dev);
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if (retval)
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dev_err(&dev->dev, "Error adding device, continuing\n");
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}
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list_for_each_entry(dev, &bus->devices, bus_list) {
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BUG_ON(!dev->is_added);
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child = dev->subordinate;
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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 (!child)
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continue;
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if (list_empty(&child->node)) {
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down_write(&pci_bus_sem);
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list_add_tail(&child->node, &dev->bus->children);
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up_write(&pci_bus_sem);
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}
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pci_bus_add_devices(child);
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/*
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* register the bus with sysfs as the parent is now
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* properly registered.
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*/
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if (child->is_added)
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continue;
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retval = pci_bus_add_child(child);
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if (retval)
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dev_err(&dev->dev, "Error adding bus, continuing\n");
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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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if (!pci_is_enabled(dev)) {
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retval = pci_enable_device(dev);
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if (retval)
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dev_err(&dev->dev, "Error enabling bridge (%d), continuing\n", retval);
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pci_set_master(dev);
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}
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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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* We check the return of @cb each time. If it returns anything
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* other than 0, we break out.
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*
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*/
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void pci_walk_bus(struct pci_bus *top, int (*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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int retval;
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bus = top;
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down_read(&pci_bus_sem);
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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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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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/* Run device routines with the device locked */
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device_lock(&dev->dev);
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retval = cb(dev, userdata);
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device_unlock(&dev->dev);
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if (retval)
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break;
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}
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up_read(&pci_bus_sem);
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}
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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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