diff options
Diffstat (limited to 'drivers/iommu/arm-smmu.c')
| -rw-r--r-- | drivers/iommu/arm-smmu.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index 15b5856475fc..c38cf03c099e 100644 --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c @@ -56,6 +56,15 @@ #include "io-pgtable.h" #include "arm-smmu-regs.h" +/* + * Apparently, some Qualcomm arm64 platforms which appear to expose their SMMU + * global register space are still, in fact, using a hypervisor to mediate it + * by trapping and emulating register accesses. Sadly, some deployed versions + * of said trapping code have bugs wherein they go horribly wrong for stores + * using r31 (i.e. XZR/WZR) as the source register. + */ +#define QCOM_DUMMY_VAL -1 + #define ARM_MMU500_ACTLR_CPRE (1 << 1) #define ARM_MMU500_ACR_CACHE_LOCK (1 << 26) @@ -117,6 +126,7 @@ enum arm_smmu_implementation { GENERIC_SMMU, ARM_MMU500, CAVIUM_SMMUV2, + QCOM_SMMUV2, }; /* Until ACPICA headers cover IORT rev. C */ @@ -403,7 +413,7 @@ static void __arm_smmu_tlb_sync(struct arm_smmu_device *smmu, { unsigned int spin_cnt, delay; - writel_relaxed(0, sync); + writel_relaxed(QCOM_DUMMY_VAL, sync); for (delay = 1; delay < TLB_LOOP_TIMEOUT; delay *= 2) { for (spin_cnt = TLB_SPIN_COUNT; spin_cnt > 0; spin_cnt--) { if (!(readl_relaxed(status) & sTLBGSTATUS_GSACTIVE)) @@ -1634,8 +1644,8 @@ static void arm_smmu_device_reset(struct arm_smmu_device *smmu) } /* Invalidate the TLB, just in case */ - writel_relaxed(0, gr0_base + ARM_SMMU_GR0_TLBIALLH); - writel_relaxed(0, gr0_base + ARM_SMMU_GR0_TLBIALLNSNH); + writel_relaxed(QCOM_DUMMY_VAL, gr0_base + ARM_SMMU_GR0_TLBIALLH); + writel_relaxed(QCOM_DUMMY_VAL, gr0_base + ARM_SMMU_GR0_TLBIALLNSNH); reg = readl_relaxed(ARM_SMMU_GR0_NS(smmu) + ARM_SMMU_GR0_sCR0); @@ -1910,6 +1920,7 @@ ARM_SMMU_MATCH_DATA(smmu_generic_v2, ARM_SMMU_V2, GENERIC_SMMU); ARM_SMMU_MATCH_DATA(arm_mmu401, ARM_SMMU_V1_64K, GENERIC_SMMU); ARM_SMMU_MATCH_DATA(arm_mmu500, ARM_SMMU_V2, ARM_MMU500); ARM_SMMU_MATCH_DATA(cavium_smmuv2, ARM_SMMU_V2, CAVIUM_SMMUV2); +ARM_SMMU_MATCH_DATA(qcom_smmuv2, ARM_SMMU_V2, QCOM_SMMUV2); static const struct of_device_id arm_smmu_of_match[] = { { .compatible = "arm,smmu-v1", .data = &smmu_generic_v1 }, @@ -1918,6 +1929,7 @@ static const struct of_device_id arm_smmu_of_match[] = { { .compatible = "arm,mmu-401", .data = &arm_mmu401 }, { .compatible = "arm,mmu-500", .data = &arm_mmu500 }, { .compatible = "cavium,smmu-v2", .data = &cavium_smmuv2 }, + { .compatible = "qcom,smmu-v2", .data = &qcom_smmuv2 }, { }, }; MODULE_DEVICE_TABLE(of, arm_smmu_of_match); |