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-rw-r--r--drivers/iommu/arm-smmu.c25
1 files changed, 16 insertions, 9 deletions
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 2f15ffb6cb0c..79d54a6f7f9a 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -247,6 +247,7 @@ enum arm_smmu_s2cr_privcfg {
#define ARM_MMU500_ACTLR_CPRE (1 << 1)
#define ARM_MMU500_ACR_CACHE_LOCK (1 << 26)
+#define ARM_MMU500_ACR_SMTNMB_TLBEN (1 << 8)
#define CB_PAR_F (1 << 0)
@@ -1581,16 +1582,22 @@ static void arm_smmu_device_reset(struct arm_smmu_device *smmu)
for (i = 0; i < smmu->num_mapping_groups; ++i)
arm_smmu_write_sme(smmu, i);
- /*
- * Before clearing ARM_MMU500_ACTLR_CPRE, need to
- * clear CACHE_LOCK bit of ACR first. And, CACHE_LOCK
- * bit is only present in MMU-500r2 onwards.
- */
- reg = readl_relaxed(gr0_base + ARM_SMMU_GR0_ID7);
- major = (reg >> ID7_MAJOR_SHIFT) & ID7_MAJOR_MASK;
- if ((smmu->model == ARM_MMU500) && (major >= 2)) {
+ if (smmu->model == ARM_MMU500) {
+ /*
+ * Before clearing ARM_MMU500_ACTLR_CPRE, need to
+ * clear CACHE_LOCK bit of ACR first. And, CACHE_LOCK
+ * bit is only present in MMU-500r2 onwards.
+ */
+ reg = readl_relaxed(gr0_base + ARM_SMMU_GR0_ID7);
+ major = (reg >> ID7_MAJOR_SHIFT) & ID7_MAJOR_MASK;
reg = readl_relaxed(gr0_base + ARM_SMMU_GR0_sACR);
- reg &= ~ARM_MMU500_ACR_CACHE_LOCK;
+ if (major >= 2)
+ reg &= ~ARM_MMU500_ACR_CACHE_LOCK;
+ /*
+ * Allow unmatched Stream IDs to allocate bypass
+ * TLB entries for reduced latency.
+ */
+ reg |= ARM_MMU500_ACR_SMTNMB_TLBEN;
writel_relaxed(reg, gr0_base + ARM_SMMU_GR0_sACR);
}