From: Chris Wright Date: Sat, 3 Apr 2010 01:27:52 +0000 (-0700) Subject: x86/amd-iommu: enable iommu before attaching devices X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=75f66533bc883f761a7adcab3281fe3323efbc90;p=deliverable%2Flinux.git x86/amd-iommu: enable iommu before attaching devices Hit another kdump problem as reported by Neil Horman. When initializaing the IOMMU, we attach devices to their domains before the IOMMU is fully (re)initialized. Attaching a device will issue some important invalidations. In the context of the newly kexec'd kdump kernel, the IOMMU may have stale cached data from the original kernel. Because we do the attach too early, the invalidation commands are placed in the new command buffer before the IOMMU is updated w/ that buffer. This leaves the stale entries in the kdump context and can renders device unusable. Simply enable the IOMMU before we do the attach. Cc: stable@kernel.org Cc: Neil Horman Cc: Vivek Goyal Signed-off-by: Chris Wright Signed-off-by: Joerg Roedel --- diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c index feaf47184900..8975965f3e67 100644 --- a/arch/x86/kernel/amd_iommu_init.c +++ b/arch/x86/kernel/amd_iommu_init.c @@ -1304,6 +1304,8 @@ static int __init amd_iommu_init(void) if (ret) goto free; + enable_iommus(); + if (iommu_pass_through) ret = amd_iommu_init_passthrough(); else @@ -1316,8 +1318,6 @@ static int __init amd_iommu_init(void) amd_iommu_init_notifier(); - enable_iommus(); - if (iommu_pass_through) goto out; @@ -1331,6 +1331,7 @@ out: return ret; free: + disable_iommus(); amd_iommu_uninit_devices();