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| author | Joerg Roedel <jroedel@suse.de> | 2016-07-01 16:42:55 +0200 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2016-07-06 18:04:55 +0200 |
| commit | 522e5cb76d0663c88f96b6a8301451c8efa37207 (patch) | |
| tree | acdc27a0aaf522cc2f7441cbcbe11251e3029679 /drivers/iommu | |
| parent | 0caa7616a6aca449dd68b58cb29bd491d296c2d5 (diff) | |
| download | linux-522e5cb76d0663c88f96b6a8301451c8efa37207.tar.bz2 | |
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 <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu')
| -rw-r--r-- | drivers/iommu/amd_iommu_init.c | 14 |
1 files changed, 12 insertions, 2 deletions
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(); |