iommu/vt-d: Remove unnecassary qi clflushes

According to the manual: "Hardware access to ... invalidation queue ... are always coherent." Remove unnecassary clflushes accordingly. Signed-off-by: Nadav Amit <[email protected]> Signed-off-by: Joerg Roedel <[email protected]>
zhenyw · Jul 13, 2016 · 452014d · 452014d
1 parent ffb2d1e
commit 452014d
Showing 1 changed file with 0 additions and 5 deletions.
diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
@@ -1167,8 +1167,6 @@ static int qi_check_fault(struct intel_iommu *iommu, int index)
 				(unsigned long long)qi->desc[index].high);
 			memcpy(&qi->desc[index], &qi->desc[wait_index],
 					sizeof(struct qi_desc));
-			__iommu_flush_cache(iommu, &qi->desc[index],
-					sizeof(struct qi_desc));
 			writel(DMA_FSTS_IQE, iommu->reg + DMAR_FSTS_REG);
 			return -EINVAL;
 		}
@@ -1243,9 +1241,6 @@ int qi_submit_sync(struct qi_desc *desc, struct intel_iommu *iommu)
 
 	hw[wait_index] = wait_desc;
 
-	__iommu_flush_cache(iommu, &hw[index], sizeof(struct qi_desc));
-	__iommu_flush_cache(iommu, &hw[wait_index], sizeof(struct qi_desc));
-
 	qi->free_head = (qi->free_head + 2) % QI_LENGTH;
 	qi->free_cnt -= 2;