diff options
authorMike Waychison <mikew@google.com>2006-04-22 02:36:06 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-04-22 09:19:52 -0700
commit5b20192727ef2c047343a043ee4fbda67e2beef4 (patch)
parent[PATCH] x86_64: Pass -32 to the assembler when compiling the 32bit vsyscall pages (diff)
[PATCH] x86_64: Fix a race in the free_iommu path
We do this by removing a micro-optimization that tries to avoid grabbing the iommu_bitmap_lock spinlock and using a bus-locked operation. This still races with other simultaneous alloc_iommu or free_iommu(size > 1) which both use bus-unlocked operations. The end result of this race is eventually ending up with an iommu_gart_bitmap that has bits errornously set all over, making large contiguous iommu space allocations fail with 'PCI-DMA: Out of IOMMU space'. Signed-off-by: Mike Waychison <mikew@google.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
1 files changed, 0 insertions, 4 deletions
diff --git a/arch/x86_64/kernel/pci-gart.c b/arch/x86_64/kernel/pci-gart.c
index a6c01e121266..9d3d76c85ae7 100644
--- a/arch/x86_64/kernel/pci-gart.c
+++ b/arch/x86_64/kernel/pci-gart.c
@@ -112,10 +112,6 @@ static unsigned long alloc_iommu(int size)
static void free_iommu(unsigned long offset, int size)
unsigned long flags;
- if (size == 1) {
- clear_bit(offset, iommu_gart_bitmap);
- return;
- }
spin_lock_irqsave(&iommu_bitmap_lock, flags);
__clear_bit_string(iommu_gart_bitmap, offset, size);
spin_unlock_irqrestore(&iommu_bitmap_lock, flags);