Revert "x86/PCI: allocate space from the end of a region, not the beginning"

This reverts commit dc9887dc02e37bcf83f4e792aa14b07782ef54cf.

Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 6 insertions, 11 deletions

diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c
index c4bb261c106e..8379c2c3d076 100644
--- a/arch/x86/pci/i386.c
+++ b/arch/x86/pci/i386.c
@@ -65,21 +65,16 @@ 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 = round_down(res->end - size + 1, align);
+        resource_size_t start = res->start;
 
         if (res->flags & IORESOURCE_IO) {
-
-                /*
-                 * 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;
+                if (skip_isa_ioresource_align(dev))
+                        return start;
+                if (start & 0x300)
+                        start = (start + 0x3ff) & ~0x3ff;
         } else if (res->flags & IORESOURCE_MEM) {
                 if (start < BIOS_END)
-                        start = res->end;       /* fail; no space */
+                        start = BIOS_END;
         }
         return start;
 }