diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.yaml b/Documentation/devicetree/bindings/iommu/arm,smmu.yaml index 2ffc48a276dfb..e66bd01321550 100644 --- a/Documentation/devicetree/bindings/iommu/arm,smmu.yaml +++ b/Documentation/devicetree/bindings/iommu/arm,smmu.yaml @@ -239,6 +239,15 @@ properties: minItems: 1 maxItems: 3 + interconnects: + maxItems: 1 + description: + Optional interconnect path to the SMMU register space. On some SoCs + the SMMU registers are only accessible after a bandwidth vote has been + placed on the interconnect fabric. When present the driver votes for + bandwidth on this path before accessing any SMMU registers and releases + the vote on runtime suspend. + nvidia,memory-controller: description: | A phandle to the memory controller on NVIDIA Tegra186 and later SoCs. diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c index 54ddcb709885d..20ae3cf30441c 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c @@ -53,6 +53,11 @@ #define MSI_IOVA_BASE 0x8000000 #define MSI_IOVA_LENGTH 0x100000 +/* Interconnect bandwidth vote values for the SMMU register access path */ +#define ARM_SMMU_ICC_AVG_BW 0 +#define ARM_SMMU_ICC_PEAK_BW_HIGH 1000 +#define ARM_SMMU_ICC_PEAK_BW_LOW 0 + static int force_stage; module_param(force_stage, int, S_IRUGO); MODULE_PARM_DESC(force_stage, @@ -86,6 +91,36 @@ static inline void arm_smmu_rpm_put(struct arm_smmu_device *smmu) } } +static int arm_smmu_icc_get(struct arm_smmu_device *smmu) +{ + smmu->icc_path = devm_of_icc_get(smmu->dev, NULL); + if (IS_ERR(smmu->icc_path)) { + int err = PTR_ERR(smmu->icc_path); + + if (err == -ENODATA) { + smmu->icc_path = NULL; + return 0; + } + return dev_err_probe(smmu->dev, err, + "failed to get interconnect path\n"); + } + return 0; +} + +static void arm_smmu_icc_enable(struct arm_smmu_device *smmu) +{ + if (smmu->icc_path) + WARN_ON(icc_set_bw(smmu->icc_path, ARM_SMMU_ICC_AVG_BW, + ARM_SMMU_ICC_PEAK_BW_HIGH)); +} + +static void arm_smmu_icc_disable(struct arm_smmu_device *smmu) +{ + if (smmu->icc_path) + WARN_ON(icc_set_bw(smmu->icc_path, ARM_SMMU_ICC_AVG_BW, + ARM_SMMU_ICC_PEAK_BW_LOW)); +} + static void arm_smmu_rpm_use_autosuspend(struct arm_smmu_device *smmu) { /* @@ -2209,6 +2244,17 @@ static int arm_smmu_device_probe(struct platform_device *pdev) if (err) return err; + /* + * Acquire and vote the interconnect path before accessing any SMMU + * registers (including ARM_SMMU_GR0_ID0 in arm_smmu_device_cfg_probe). + */ + err = arm_smmu_icc_get(smmu); + if (err) { + clk_bulk_disable_unprepare(smmu->num_clks, smmu->clks); + return err; + } + arm_smmu_icc_enable(smmu); + err = arm_smmu_device_cfg_probe(smmu); if (err) return err; @@ -2309,9 +2355,13 @@ static int __maybe_unused arm_smmu_runtime_resume(struct device *dev) struct arm_smmu_device *smmu = dev_get_drvdata(dev); int ret; + arm_smmu_icc_enable(smmu); + ret = clk_bulk_enable(smmu->num_clks, smmu->clks); - if (ret) + if (ret) { + arm_smmu_icc_disable(smmu); return ret; + } arm_smmu_device_reset(smmu); @@ -2323,6 +2373,7 @@ static int __maybe_unused arm_smmu_runtime_suspend(struct device *dev) struct arm_smmu_device *smmu = dev_get_drvdata(dev); clk_bulk_disable(smmu->num_clks, smmu->clks); + arm_smmu_icc_disable(smmu); return 0; } diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.h b/drivers/iommu/arm/arm-smmu/arm-smmu.h index 26d2e33cd328b..c00606a416b2f 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu.h +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.h @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -335,6 +336,7 @@ struct arm_smmu_device { int num_clks; unsigned int *irqs; struct clk_bulk_data *clks; + struct icc_path *icc_path; spinlock_t global_sync_lock;