diff mbox

[3/5] iommu/arm-smmu: Invalidate TLBs properly

Message ID 2acaea8656f14a4421d7d466dd242fe5a3d0f6f6.1449246988.git.robin.murphy@arm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Robin Murphy Dec. 4, 2015, 5:53 p.m. UTC
When invalidating an IOVA range potentially spanning multiple pages,
such as when removing an entire intermediate-level table, we currently
only issue an invalidation for the first IOVA of that range. Since the
architecture specifies that address-based TLB maintenance operations
target a single entry, an SMMU could feasibly retain live entries for
subsequent pages within that unmapped range, which is not good.

Make sure we hit every possible entry by iterating over the whole range
at the granularity provided by the pagetable implementation.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 drivers/iommu/arm-smmu.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

Comments

Will Deacon Dec. 7, 2015, 11:09 a.m. UTC | #1
On Fri, Dec 04, 2015 at 05:53:00PM +0000, Robin Murphy wrote:
> When invalidating an IOVA range potentially spanning multiple pages,
> such as when removing an entire intermediate-level table, we currently
> only issue an invalidation for the first IOVA of that range. Since the
> architecture specifies that address-based TLB maintenance operations
> target a single entry, an SMMU could feasibly retain live entries for
> subsequent pages within that unmapped range, which is not good.
> 
> Make sure we hit every possible entry by iterating over the whole range
> at the granularity provided by the pagetable implementation.
> 
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
>  drivers/iommu/arm-smmu.c | 19 ++++++++++++++++---
>  1 file changed, 16 insertions(+), 3 deletions(-)

Can you do something similar for arm-smmu-v3.c as well, please?

Will
diff mbox

Patch

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 601e3dd..f1d6fa7 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -597,12 +597,20 @@  static void arm_smmu_tlb_inv_range_nosync(unsigned long iova, size_t size,
 		if (!IS_ENABLED(CONFIG_64BIT) || smmu->version == ARM_SMMU_V1) {
 			iova &= ~12UL;
 			iova |= ARM_SMMU_CB_ASID(cfg);
-			writel_relaxed(iova, reg);
+			while (size) {
+				writel_relaxed(iova, reg);
+				size -= granule;
+				iova += granule;
+			}
 #ifdef CONFIG_64BIT
 		} else {
 			iova >>= 12;
 			iova |= (u64)ARM_SMMU_CB_ASID(cfg) << 48;
-			writeq_relaxed(iova, reg);
+			while (size) {
+				writeq_relaxed(iova, reg);
+				size -= granule;
+				iova += granule >> 12;
+			}
 #endif
 		}
 #ifdef CONFIG_64BIT
@@ -610,7 +618,12 @@  static void arm_smmu_tlb_inv_range_nosync(unsigned long iova, size_t size,
 		reg = ARM_SMMU_CB_BASE(smmu) + ARM_SMMU_CB(smmu, cfg->cbndx);
 		reg += leaf ? ARM_SMMU_CB_S2_TLBIIPAS2L :
 			      ARM_SMMU_CB_S2_TLBIIPAS2;
-		writeq_relaxed(iova >> 12, reg);
+		iova >>= 12;
+		while (size) {
+			writeq_relaxed(iova, reg);
+			size -= granule;
+			iova += granule >> 12;
+		}
 #endif
 	} else {
 		reg = ARM_SMMU_GR0(smmu) + ARM_SMMU_GR0_TLBIVMID;