x86, gart: Set DISTLBWALKPRB bit always

The DISTLBWALKPRB bit must be set for the GART because the
gatt table is mapped UC. But the current code does not set
the bit at boot when the BIOS setup the aperture correctly.
Fix that by setting this bit when enabling the GART instead
of the other places.

Cc: <stable@kernel.org>
Cc: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Link: http://lkml.kernel.org/r/1303134346-5805-4-git-send-email-joerg.roedel@amd.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

diff --git a/arch/x86/include/asm/gart.h b/arch/x86/include/asm/gart.h
index 88c1ebee0db2652cdb86dd83a09ab50d6d3182d9..156cd5d18d2abeabb26a0587cfffd15c52aa6f13 100644 (file)
--- 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);
 }
@@ -83,7 +83,7 @@ static inline void enable_gart_translation(struct pci_dev *dev, u64 addr)
 
        /* Enable GART translation for this hammer. */
        pci_read_config_dword(dev, AMD64_GARTAPERTURECTL, &ctl);
-       ctl |= GARTEN;
+       ctl |= GARTEN | DISTLBWALKPRB;
        ctl &= ~(DISGARTCPU | DISGARTIO);
        pci_write_config_dword(dev, AMD64_GARTAPERTURECTL, ctl);
 }

diff --git a/arch/x86/kernel/aperture_64.c b/arch/x86/kernel/aperture_64.c
index 86d1ad4962a73a352ec22625658bec7deca21d7c..73fb469908c6852476c10a75a05aa49329f386b8 100644 (file)
--- 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;