diff options
| -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; } |