On 03/05/16 14:50, Peng Fan wrote:
According MMU-500r2 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.
Since CACHE_LOCK bit is only present in MMU-500r2 onwards,
need to check the major number of IDR7.
Signed-off-by: Peng Fan <van.free...@gmail.com>
Cc: Will Deacon <will.dea...@arm.com>
Cc: Robin Murphy <robin.mur...@arm.com>
---
V2:
Following Robin's comments, need to check IDR7 before clearing
CACHE_LOCK bit of ACR.
V1:
Patch based on iommu/devel
drivers/iommu/arm-smmu.c | 23 ++++++++++++++++++++++-
1 file changed, 22 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index acff332..c7ad23e 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
@@ -144,6 +147,9 @@
#define ID2_PTFS_64K (1 << 14)
#define ID2_VMID16 (1 << 15)
+#define ID7_MAJOR_SHIFT 4
+#define ID7_MAJOR_MASK 0xf
+
/* Global TLB invalidation */
#define ARM_SMMU_GR0_TLBIVMID 0x64
#define ARM_SMMU_GR0_TLBIALLNSNH 0x68
@@ -235,6 +241,8 @@
#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)
@@ -1493,7 +1501,7 @@ static void arm_smmu_device_reset(struct arm_smmu_device
*smmu)
void __iomem *gr0_base = ARM_SMMU_GR0(smmu);
void __iomem *cb_base;
int i = 0;
- u32 reg;
+ u32 reg, major;
/* clear global FSR */
reg = readl_relaxed(ARM_SMMU_GR0_NS(smmu) + ARM_SMMU_GR0_sGFSR);
@@ -1506,6 +1514,19 @@ 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. 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)) {
+ reg = readl_relaxed(gr0_base + ARM_SMMU_GR0_sACR);
+ reg &= ~ARM_MMU500_ACR_CACHE_LOCK;
+ writel_relaxed(reg, gr0_base + ARM_SMMU_GR0_sACR);
+ }
+
I'd have been inclined to make the ID reg read conditional on ARM_MMU500
as well, but this way is marginally more compact, and it's not like
we're in a frequently-used hot path anyway.
Reviewed-by: Robin Murphy <robin.mur...@arm.com>
Thanks,
Robin.
/* 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);
