[PATCH 3.2] iommu/amd: Initialize device table after dma_ops

Shuah Khan
2013-02-28T21:39:57Z

When dma_ops are initialized the unity mappings are created. The
init_device_table_dma() function makes sure DMA from all devices is
blocked by default. This opens a short window in time where DMA to
unity mapped regions is blocked by the IOMMU. Make sure this does not
happen by initializing the device table after dma_ops.

Back-port upstream commit: f528d980c17b8714aedc918ba86e058af914d66b
Tested on 3.2.38

Signed-off-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Shuah Khan <shuah.khan@hp.com>
CC: stable@vger.kernel.org 3.2
---
drivers/iommu/amd_iommu_init.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 62a4d5c..b7d1cdd 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -1396,6 +1396,7 @@ static struct syscore_ops amd_iommu_syscore_ops = {
*/
static int __init amd_iommu_init(void)
{
+ struct amd_iommu *iommu;
int i, ret = 0;

/*
@@ -1444,9 +1445,6 @@ static int __init amd_iommu_init(void)
if (amd_iommu_pd_alloc_bitmap == NULL)
goto free;

- /* init the device table */
- init_device_table();
-
/*
* let all alias entries point to itself
*/
@@ -1496,6 +1494,12 @@ static int __init amd_iommu_init(void)
if (ret)
goto free_disable;

+ /* init the device table */
+ init_device_table();
+
+ for_each_iommu(iommu)
+ iommu_flush_all_caches(iommu);
+
amd_iommu_init_api();

amd_iommu_init_notifier();
--
1.7.10.4