iommu/amd: Set exclusion range correctly

commit 3c677d206210f53a4be972211066c0f1cd47fe12 upstream.

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: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 48b726f4ad48b9ca66026eb08589ea4be12c578a..006f4f9a3170b123c65779e9ebed1dacea12c774 100644 (file)
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -293,7 +293,7 @@ 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)