On 03/05/16 11:15, Peng Fan wrote:
According MMU-500 TRM, section 3.7.1 Auxiliary Control registers,
You can modify ACTLR only when the ACR.CACHE_LOCK bit is 0.
So before clearing ARM_MMU500_ACTLR_CPRE of each context bank,
need clear CACHE_LOCK bit of ACR register first.
Ah, good catch - I think I misread CACHE_LOCK as resetting to 0, and
proceeded to forget about it. However, it's only present in MMU-500r2
onwards, so we'd also want to check IDR7 before touching ACR.
Thanks,
Robin.
Signed-off-by: Peng Fan <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Robin Murphy <[email protected]>
---
Hi Will,
Patch based on iommu/devel branch.
drivers/iommu/arm-smmu.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index acff332..d094a5a 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -98,6 +98,9 @@
#define sCR0_BSU_SHIFT 14
#define sCR0_BSU_MASK 0x3
+/* Auxiliary Configuration register */
+#define ARM_SMMU_GR0_sACR 0x10
+
/* Identification registers */
#define ARM_SMMU_GR0_ID0 0x20
#define ARM_SMMU_GR0_ID1 0x24
@@ -235,6 +238,8 @@
#define ARM_MMU500_ACTLR_CPRE (1 << 1)
+#define ARM_MMU500_ACR_CACHE_LOCK (1 << 26)
+
#define CB_PAR_F (1 << 0)
#define ATSR_ACTIVE (1 << 0)
@@ -1506,6 +1511,16 @@ static void arm_smmu_device_reset(struct arm_smmu_device
*smmu)
writel_relaxed(reg, gr0_base + ARM_SMMU_GR0_S2CR(i));
}
+ /*
+ * Before clearing ARM_MMU500_ACTLR_CPRE, need to
+ * clear CACHE_LOCK bit of ACR first.
+ */
+ if (smmu->model == ARM_MMU500) {
+ reg = readl_relaxed(gr0_base + ARM_SMMU_GR0_sACR);
+ reg &= ~ARM_MMU500_ACR_CACHE_LOCK;
+ writel_relaxed(reg, gr0_base + ARM_SMMU_GR0_sACR);
+ }
+
/* Make sure all context banks are disabled and clear CB_FSR */
for (i = 0; i < smmu->num_context_banks; ++i) {
cb_base = ARM_SMMU_CB_BASE(smmu) + ARM_SMMU_CB(smmu, i);
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