[PATCH AUTOSEL 5.0 75/79] iommu/amd: Set exclusion range correctly

Sasha Levin
2019-04-27T01:52:16Z

From: Joerg Roedel <jroedel@suse.de>

[ Upstream commit 3c677d206210f53a4be972211066c0f1cd47fe12 ]

The exlcusion range limit register needs to contain the
base-address of the last page that is part of the range, as
bits 0-11 of this register are treated as 0xfff by the
hardware for comparisons.

So correctly set the exclusion range in the hardware to the
last page which is _in_ the range.

Fixes: b2026aa2dce44 ('x86, AMD IOMMU: add functions for programming IOMMU MMIO space')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/iommu/amd_iommu_init.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 66123b911ec8..8ae6b350e64c 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -358,7 +358,7 @@ static void iommu_write_l2(struct amd_iommu *iommu, u8 address, u32 val)
static void iommu_set_exclusion_range(struct amd_iommu *iommu)
{
u64 start = iommu->exclusion_start & PAGE_MASK;
- u64 limit = (start + iommu->exclusion_length) & PAGE_MASK;
+ u64 limit = (start + iommu->exclusion_length - 1) & PAGE_MASK;
u64 entry;

if (!iommu->exclusion_start)
--
2.19.1