[PATCH 3.12 101/111] iommu/amd: Correctly encode huge pages in iommu page tables

[Jiri Slaby]

From: Joerg Roedel <jroedel@xxxxxxx>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

commit d4b036648402bb4ef6d4a0df51375a2fb705b6cc upstream.

When a default page-size for given level should be mapped,
the level encoding must be 0 rather than 7. This fixes an
issue seen on IOMMUv2 hardware, where this encoding is
enforced.

Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 drivers/iommu/amd_iommu.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index db84a3c1254a..27f9b8d433a3 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -1444,19 +1444,20 @@ static int iommu_map_page(struct protection_domain *dom,
 	u64 __pte, *pte;
 	int i, count;
 
+	BUG_ON(!IS_ALIGNED(bus_addr, page_size));
+	BUG_ON(!IS_ALIGNED(phys_addr, page_size));
+
 	if (!(prot & IOMMU_PROT_MASK))
 		return -EINVAL;
 
-	bus_addr  = PAGE_ALIGN(bus_addr);
-	phys_addr = PAGE_ALIGN(phys_addr);
-	count     = PAGE_SIZE_PTE_COUNT(page_size);
-	pte       = alloc_pte(dom, bus_addr, page_size, NULL, GFP_KERNEL);
+	count = PAGE_SIZE_PTE_COUNT(page_size);
+	pte   = alloc_pte(dom, bus_addr, page_size, NULL, GFP_KERNEL);
 
 	for (i = 0; i < count; ++i)
 		if (IOMMU_PTE_PRESENT(pte[i]))
 			return -EBUSY;
 
-	if (page_size > PAGE_SIZE) {
+	if (count > 1) {
 		__pte = PAGE_SIZE_PTE(phys_addr, page_size);
 		__pte |= PM_LEVEL_ENC(7) | IOMMU_PTE_P | IOMMU_PTE_FC;
 	} else
-- 
2.4.2

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