x86, gart: Make sure GART does not map physmem above 1TB
The GART can only map physical memory below 1TB. Make sure
the gart driver in the kernel does not try to map memory
above 1TB.
Cc: <stable@kernel.org>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Link: http://lkml.kernel.org/r/1303134346-5805-5-git-send-email-joerg.roedel@amd.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c
index 82ada01..b117efd 100644
--- a/arch/x86/kernel/pci-gart_64.c
+++ b/arch/x86/kernel/pci-gart_64.c
@@ -81,6 +81,9 @@
#define AGPEXTERN
#endif
+/* GART can only remap to physical addresses < 1TB */
+#define GART_MAX_PHYS_ADDR (1ULL << 40)
+
/* backdoor interface to AGP driver */
AGPEXTERN int agp_memory_reserved;
AGPEXTERN __u32 *agp_gatt_table;
@@ -212,9 +215,13 @@
size_t size, int dir, unsigned long align_mask)
{
unsigned long npages = iommu_num_pages(phys_mem, size, PAGE_SIZE);
- unsigned long iommu_page = alloc_iommu(dev, npages, align_mask);
+ unsigned long iommu_page;
int i;
+ if (unlikely(phys_mem + size > GART_MAX_PHYS_ADDR))
+ return bad_dma_addr;
+
+ iommu_page = alloc_iommu(dev, npages, align_mask);
if (iommu_page == -1) {
if (!nonforced_iommu(dev, phys_mem, size))
return phys_mem;
