diff options
| author | Bjorn Helgaas <bjorn.helgaas@hp.com> | 2010-10-26 15:41:44 -0600 |
|---|---|---|
| committer | Jesse Barnes <jbarnes@virtuousgeek.org> | 2010-10-26 15:33:42 -0700 |
| commit | dc9887dc02e37bcf83f4e792aa14b07782ef54cf (patch) | |
| tree | cf10eb9f7876eb41524ef95298913018f22535d6 /arch/x86 | |
| parent | b126b4703afa4010b161784a43650337676dd03b (diff) | |
| download | linux-dc9887dc02e37bcf83f4e792aa14b07782ef54cf.tar.gz linux-dc9887dc02e37bcf83f4e792aa14b07782ef54cf.tar.bz2 linux-dc9887dc02e37bcf83f4e792aa14b07782ef54cf.zip | |
x86/PCI: allocate space from the end of a region, not the beginning
Allocate from the end of a region, not the beginning.
For example, if we need to allocate 0x800 bytes for a device on bus
0000:00 given these resources:
[mem 0xbff00000-0xdfffffff] PCI Bus 0000:00
[mem 0xc0000000-0xdfffffff] PCI Bus 0000:02
the available space at [mem 0xbff00000-0xbfffffff] is passed to the
alignment callback (pcibios_align_resource()). Prior to this patch, we
would put the new 0x800 byte resource at the beginning of that available
space, i.e., at [mem 0xbff00000-0xbff007ff].
With this patch, we put it at the end, at [mem 0xbffff800-0xbfffffff].
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=16228#c41
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/pci/i386.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c index 55253095be84..826140af3c3c 100644 --- a/arch/x86/pci/i386.c +++ b/arch/x86/pci/i386.c @@ -65,16 +65,21 @@ pcibios_align_resource(void *data, const struct resource *res, resource_size_t size, resource_size_t align) { struct pci_dev *dev = data; - resource_size_t start = res->start; + resource_size_t start = round_down(res->end - size + 1, align); if (res->flags & IORESOURCE_IO) { - if (skip_isa_ioresource_align(dev)) - return start; - if (start & 0x300) - start = (start + 0x3ff) & ~0x3ff; + + /* + * If we're avoiding ISA aliases, the largest contiguous I/O + * port space is 256 bytes. Clearing bits 9 and 10 preserves + * all 256-byte and smaller alignments, so the result will + * still be correctly aligned. + */ + if (!skip_isa_ioresource_align(dev)) + start &= ~0x300; } else if (res->flags & IORESOURCE_MEM) { if (start < BIOS_END) - start = BIOS_END; + start = res->end; /* fail; no space */ } return start; } |