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authorJoerg Roedel <joerg.roedel@amd.com>2010-05-31 13:05:20 (GMT)
committerJoerg Roedel <joerg.roedel@amd.com>2010-06-01 08:20:15 (GMT)
commitd7f0776975334070a93370ae048fda0c31a91c38 (patch)
treee1eb9681756be538f8108a1b1fd54f8b1eb0e294 /arch
parente82752d8b5a7e0a5e4d607fd8713549e2a4e2741 (diff)
downloadlinux-d7f0776975334070a93370ae048fda0c31a91c38.tar.xz
x86/amd-iommu: Fall back to GART if initialization fails
This patch implements a fallback to the GART IOMMU if this is possible and the AMD IOMMU initialization failed. Otherwise the fallback would be nommu which is very problematic on machines with more than 4GB of memory or swiotlb which hurts io-performance. Cc: stable@kernel.org Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/amd_iommu.c4
-rw-r--r--arch/x86/kernel/amd_iommu_init.c9
2 files changed, 9 insertions, 4 deletions
diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 8a9aaa8..0d20286 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -2330,10 +2330,6 @@ int __init amd_iommu_init_dma_ops(void)
iommu_detected = 1;
swiotlb = 0;
-#ifdef CONFIG_GART_IOMMU
- gart_iommu_aperture_disabled = 1;
- gart_iommu_aperture = 0;
-#endif
/* Make the driver finally visible to the drivers */
dma_ops = &amd_iommu_dma_ops;
diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c
index 1405346..3cc63e2 100644
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -1358,6 +1358,15 @@ free:
free_unity_maps();
+#ifdef CONFIG_GART_IOMMU
+ /*
+ * We failed to initialize the AMD IOMMU - try fallback to GART
+ * if possible.
+ */
+ gart_iommu_init();
+
+#endif
+
goto out;
}