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| author | Bjorn Helgaas <bhelgaas@google.com> | 2014-03-12 00:23:12 +0400 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2014-03-12 21:19:20 +0400 |
| commit | ac93ac7403493f8707b7734de9f40d5cb5db9045 (patch) | |
| tree | a75cae106cf2b399d18b72bc05856d0e3cc6aa48 /drivers/pci | |
| parent | 3cdeb713dc66057b50682048c151eae07b186c42 (diff) | |
| download | linux-ac93ac7403493f8707b7734de9f40d5cb5db9045.tar.xz | |
PCI: Don't check resource_size() in pci_bus_alloc_resource()
Paul reported that after f75b99d5a77d ("PCI: Enforce bus address limits in
resource allocation") on a 32-bit kernel (CONFIG_PHYS_ADDR_T_64BIT not
set), intel-gtt complained "can't ioremap flush page - no chipset
flushing". In addition, other PCI resource allocations, e.g., for bridge
windows, failed.
This happens because we incorrectly skip bus resources of
[mem 0x00000000-0xffffffff] because we think they are of size zero.
When resource_size_t is 32 bits wide, resource_size() on
[mem 0x00000000-0xffffffff] returns 0 because (r->end - r->start + 1)
overflows.
Therefore, we can't use "resource_size() == 0" to decide that allocation
from this resource will fail. allocate_resource() should fail anyway if it
can't satisfy the address constraints, so we should just depend on that.
A [mem 0x00000000-0xffffffff] bus resource is obviously not really valid,
but we do fall back to it as a default when we don't have information about
host bridge apertures.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=71611
Fixes: f75b99d5a77d PCI: Enforce bus address limits in resource allocation
Reported-and-tested-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/bus.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c index 00660cc502c5..38901665c770 100644 --- a/drivers/pci/bus.c +++ b/drivers/pci/bus.c @@ -162,8 +162,6 @@ static int pci_bus_alloc_from_region(struct pci_bus *bus, struct resource *res, avail = *r; pci_clip_resource_to_region(bus, &avail, region); - if (!resource_size(&avail)) - continue; /* * "min" is typically PCIBIOS_MIN_IO or PCIBIOS_MIN_MEM to |