On Tue, Feb 05, 2013 at 06:57:21AM -0700, Shuah Khan wrote:
> Thanks much. I will hang on to this test system for testing your fix.

Okay, here is the simple fix for v3.8-rc6. I guess it is not
straighforward to port it to v3.4, but it should be doable.

>From 2ecf57c85e67e0243b36b787d0490c0b47202ba8 Mon Sep 17 00:00:00 2001
From: Joerg Roedel <j...@8bytes.org>
Date: Wed, 6 Feb 2013 12:55:23 +0100
Subject: [PATCH] iommu/amd: Initialize device table after dma_ops

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.

Signed-off-by: Joerg Roedel <j...@8bytes.org>
---
 drivers/iommu/amd_iommu_init.c |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index faf10ba..b6ecddb 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -1876,11 +1876,6 @@ static int amd_iommu_init_dma(void)
        struct amd_iommu *iommu;
        int ret;
 
-       init_device_table_dma();
-
-       for_each_iommu(iommu)
-               iommu_flush_all_caches(iommu);
-
        if (iommu_pass_through)
                ret = amd_iommu_init_passthrough();
        else
@@ -1889,6 +1884,11 @@ static int amd_iommu_init_dma(void)
        if (ret)
                return ret;
 
+       init_device_table_dma();
+
+       for_each_iommu(iommu)
+               iommu_flush_all_caches(iommu);
+
        amd_iommu_init_api();
 
        amd_iommu_init_notifier();
-- 
1.7.9.5


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