iommu/amd: Don't use MSI address range for DMA addresses

[ upstream commit 17f5b569e09cfa3488eaa663cbf9feada2e789f5 ]

Reserve the MSI address range in the address allocator so
that MSI addresses are not handed out as dma handles.

Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 4424c73ba01e6a3998065aa50d9258bbe218e3d2..e26ac40357544b0597579f554a7e7c5404f47dac 100644 (file)
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -25,6 +25,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/iommu-helper.h>
 #include <linux/iommu.h>
+#include <asm/msidef.h>
 #include <asm/proto.h>
 #include <asm/iommu.h>
 #include <asm/gart.h>
@@ -1048,7 +1049,7 @@ static int alloc_new_range(struct dma_ops_domain *dma_dom,
 {
        int index = dma_dom->aperture_size >> APERTURE_RANGE_SHIFT;
        struct amd_iommu *iommu;
-       unsigned long i;
+       unsigned long i, old_size;
 
 #ifdef CONFIG_IOMMU_STRESS
        populate = false;
@@ -1084,8 +1085,21 @@ static int alloc_new_range(struct dma_ops_domain *dma_dom,
                }
        }
 
+       old_size                = dma_dom->aperture_size;
        dma_dom->aperture_size += APERTURE_RANGE_SIZE;
 
+       /* Reserve address range used for MSI messages */
+       if (old_size < MSI_ADDR_BASE_LO &&
+           dma_dom->aperture_size > MSI_ADDR_BASE_LO) {
+               unsigned long spage;
+               int pages;
+
+               pages = iommu_num_pages(MSI_ADDR_BASE_LO, 0x10000, PAGE_SIZE);
+               spage = MSI_ADDR_BASE_LO >> PAGE_SHIFT;
+
+               dma_ops_reserve_addresses(dma_dom, spage, pages);
+       }
+
        /* Intialize the exclusion range if necessary */
        for_each_iommu(iommu) {
                if (iommu->exclusion_start &&