From 0caa7616a6aca449dd68b58cb29bd491d296c2d5 Mon Sep 17 00:00:00 2001 From: Aaron Campbell Date: Sat, 2 Jul 2016 21:23:24 -0300 Subject: iommu/vt-d: Fix infinite loop in free_all_cpu_cached_iovas Per VT-d spec Section 10.4.2 ("Capability Register"), the maximum number of possible domains is 64K; indeed this is the maximum value that the cap_ndoms() macro will expand to. Since the value 65536 will not fix in a u16, the 'did' variable must be promoted to an int, otherwise the test for < 65536 will always be true and the loop will never end. The symptom, in my case, was a hung machine during suspend. Fixes: 3bd4f9112f87 ("iommu/vt-d: Fix overflow of iommu->domains array") Signed-off-by: Aaron Campbell Signed-off-by: Joerg Roedel --- drivers/iommu/intel-iommu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index cfe410eedaf0..323dac9900ba 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -4602,13 +4602,13 @@ static void free_all_cpu_cached_iovas(unsigned int cpu) for (i = 0; i < g_num_of_iommus; i++) { struct intel_iommu *iommu = g_iommus[i]; struct dmar_domain *domain; - u16 did; + int did; if (!iommu) continue; for (did = 0; did < cap_ndoms(iommu->cap); did++) { - domain = get_iommu_domain(iommu, did); + domain = get_iommu_domain(iommu, (u16)did); if (!domain) continue; -- cgit v1.2.3 From 522e5cb76d0663c88f96b6a8301451c8efa37207 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 1 Jul 2016 16:42:55 +0200 Subject: iommu/amd: Fix unity mapping initialization race There is a race condition in the AMD IOMMU init code that causes requested unity mappings to be blocked by the IOMMU for a short period of time. This results on boot failures and IO_PAGE_FAULTs on some machines. Fix this by making sure the unity mappings are installed before all other DMA is blocked. Fixes: aafd8ba0ca74 ('iommu/amd: Implement add_device and remove_device') Cc: stable@vger.kernel.org # v4.2+ Signed-off-by: Joerg Roedel --- drivers/iommu/amd_iommu_init.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c index d091defc3426..59741ead7e15 100644 --- a/drivers/iommu/amd_iommu_init.c +++ b/drivers/iommu/amd_iommu_init.c @@ -1568,13 +1568,23 @@ static int __init amd_iommu_init_pci(void) break; } + /* + * Order is important here to make sure any unity map requirements are + * fulfilled. The unity mappings are created and written to the device + * table during the amd_iommu_init_api() call. + * + * After that we call init_device_table_dma() to make sure any + * uninitialized DTE will block DMA, and in the end we flush the caches + * of all IOMMUs to make sure the changes to the device table are + * active. + */ + ret = amd_iommu_init_api(); + init_device_table_dma(); for_each_iommu(iommu) iommu_flush_all_caches(iommu); - ret = amd_iommu_init_api(); - if (!ret) print_iommu_info(); -- cgit v1.2.3