3 files changed, 21 insertions, 14 deletions

diff --git a/arch/x86/include/asm/gart.h b/arch/x86/include/asm/gart.h
index 43085bfc99c3..156cd5d18d2a 100644
--- a/arch/x86/include/asm/gart.h
+++ b/arch/x86/include/asm/gart.h
@@ -66,7 +66,7 @@ static inline void gart_set_size_and_enable(struct pci_dev *dev, u32 order)
          * Don't enable translation but enable GART IO and CPU accesses.
          * Also, set DISTLBWALKPRB since GART tables memory is UC.
          */
-        ctl = DISTLBWALKPRB | order << 1;
+        ctl = order << 1;
 
         pci_write_config_dword(dev, AMD64_GARTAPERTURECTL, ctl);
 }
@@ -75,17 +75,17 @@ static inline void enable_gart_translation(struct pci_dev *dev, u64 addr)
 {
         u32 tmp, ctl;
 
-        /* address of the mappings table */
-        addr >>= 12;
-        tmp = (u32) addr<<4;
-        tmp &= ~0xf;
-        pci_write_config_dword(dev, AMD64_GARTTABLEBASE, tmp);
-
-        /* Enable GART translation for this hammer. */
-        pci_read_config_dword(dev, AMD64_GARTAPERTURECTL, &ctl);
-        ctl |= GARTEN;
-        ctl &= ~(DISGARTCPU | DISGARTIO);
-        pci_write_config_dword(dev, AMD64_GARTAPERTURECTL, ctl);
+        /* address of the mappings table */
+        addr >>= 12;
+        tmp = (u32) addr<<4;
+        tmp &= ~0xf;
+        pci_write_config_dword(dev, AMD64_GARTTABLEBASE, tmp);
+
+        /* Enable GART translation for this hammer. */
+        pci_read_config_dword(dev, AMD64_GARTAPERTURECTL, &ctl);
+        ctl |= GARTEN | DISTLBWALKPRB;
+        ctl &= ~(DISGARTCPU | DISGARTIO);
+        pci_write_config_dword(dev, AMD64_GARTAPERTURECTL, ctl);
 }
 
 static inline int aperture_valid(u64 aper_base, u32 aper_size, u32 min_size)
diff --git a/arch/x86/kernel/aperture_64.c b/arch/x86/kernel/aperture_64.c
index 86d1ad4962a7..73fb469908c6 100644
--- a/arch/x86/kernel/aperture_64.c
+++ b/arch/x86/kernel/aperture_64.c
@@ -499,7 +499,7 @@ out:
                  * Don't enable translation yet but enable GART IO and CPU
                  * accesses and set DISTLBWALKPRB since GART table memory is UC.
                  */
-                u32 ctl = DISTLBWALKPRB | aper_order << 1;
+                u32 ctl = aper_order << 1;
 
                 bus = amd_nb_bus_dev_ranges[i].bus;
                 dev_base = amd_nb_bus_dev_ranges[i].dev_base;
diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c
index 82ada01625b9..b117efd24f71 100644
--- a/arch/x86/kernel/pci-gart_64.c
+++ b/arch/x86/kernel/pci-gart_64.c
@@ -81,6 +81,9 @@ static u32 gart_unmapped_entry;
 #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 @@ static dma_addr_t dma_map_area(struct device *dev, dma_addr_t phys_mem,
                                 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;