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authorJoerg Roedel <joerg.roedel@amd.com>2010-05-31 15:05:20 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2010-07-05 11:22:24 -0700
commitd3c0c33429f930d2934fa7597e874306c07521f2 (patch)
treeda5f8402de403674b56f839c261645f8a25626c2 /arch
parentfdb4f05da375cad6e74a6ba5d07dbb7a97d5c8c7 (diff)
x86/amd-iommu: Fall back to GART if initialization fails
commit d7f0776975334070a93370ae048fda0c31a91c38 upstream. 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. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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 f854d89b7edf..b9ce0fdf2cb5 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -2257,10 +2257,6 @@ 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 890af003488c..6f8ce7516b7a 100644
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -1357,6 +1357,15 @@ 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;
}