diff options
| author | Joerg Roedel <jroedel@suse.de> | 2016-07-01 16:42:55 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-07-27 09:47:32 -0700 |
| commit | e205592b31d0aed33edc1fbbb667dcba696aa173 (patch) | |
| tree | 5e2968d6b92e08de49cbd36d0ed3c68e5c5c2a51 /drivers/iommu | |
| parent | 72803a72a6b8444cf9cac844553056dae984dc3b (diff) | |
iommu/amd: Fix unity mapping initialization race
commit 522e5cb76d0663c88f96b6a8301451c8efa37207 upstream.
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')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 bf4959f4225b..94f1bf772ec9 100644 --- a/drivers/iommu/amd_iommu_init.c +++ b/drivers/iommu/amd_iommu_init.c @@ -1363,13 +1363,23 @@ 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(); |