From 3ca3712a42f9e632eb41da94ca4eab4f1fb06fcb Mon Sep 17 00:00:00 2001 From: Peng Fan Date: Tue, 3 May 2016 21:50:30 +0800 Subject: [PATCH] iommu/arm-smmu: Clear cache lock bit of ACR 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. Reviewed-by: Robin Murphy Signed-off-by: Peng Fan Signed-off-by: Will Deacon --- 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 72dea314f9a1..2fb9c33a4a08 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 @@ -146,6 +149,9 @@ #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 @@ -237,6 +243,8 @@ #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) @@ -1531,7 +1539,7 @@ 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); @@ -1544,6 +1552,19 @@ 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); + } + /* 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); -- 2.20.1