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authorJoachim Deguara <joachim.deguara@amd.com>2007-04-24 13:05:36 +0200
committerAndi Kleen <andi@basil.nowhere.org>2007-04-24 13:05:36 +0200
commitcf6387daf8858bdcb3e123034ca422e8979d73f1 (patch)
tree3b3d83f375539fa17b65ef659245b24e6c0eae3e /arch/x86_64/kernel
parentc445a31cd7f469d77acc37538ab43a99530968b8 (diff)
[PATCH] x86-64: make GART PTEs uncacheable
This patches fixes the silent data corruption problems being seen using the GART iommu where 4kB of data where incorrect (seen mostly on Nvidia CK804 systems). This fix, to mark the memory regin the GART PTEs reside on as uncacheable, also brings the code in line with the AGP specification. Signed-off-by: Joachim Deguara <joachim.deguara@amd.com> Signed-off-by: Andi Kleen <ak@suse.de>
Diffstat (limited to 'arch/x86_64/kernel')
-rw-r--r--arch/x86_64/kernel/pci-gart.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86_64/kernel/pci-gart.c b/arch/x86_64/kernel/pci-gart.c
index 2bac8c60ad61..0bae862e9a55 100644
--- a/arch/x86_64/kernel/pci-gart.c
+++ b/arch/x86_64/kernel/pci-gart.c
@@ -519,7 +519,11 @@ static __init int init_k8_gatt(struct agp_kern_info *info)
gatt_size = (aper_size >> PAGE_SHIFT) * sizeof(u32);
gatt = (void *)__get_free_pages(GFP_KERNEL, get_order(gatt_size));
if (!gatt)
- panic("Cannot allocate GATT table");
+ panic("Cannot allocate GATT table");
+ if (change_page_attr_addr((unsigned long)gatt, gatt_size >> PAGE_SHIFT, PAGE_KERNEL_NOCACHE))
+ panic("Could not set GART PTEs to uncacheable pages");
+ global_flush_tlb();
+
memset(gatt, 0, gatt_size);
agp_gatt_table = gatt;