From d3c0c33429f930d2934fa7597e874306c07521f2 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Mon, 31 May 2010 15:05:20 +0200 Subject: [PATCH] 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 Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/amd_iommu.c | 4 ---- arch/x86/kernel/amd_iommu_init.c | 9 +++++++++ 2 files changed, 9 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c index f854d89b7edf6..b9ce0fdf2cb54 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 890af003488cb..6f8ce7516b7a3 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; } -- 2.47.2