diff options
Diffstat (limited to 'drivers/iommu')
| -rw-r--r-- | drivers/iommu/arm-smmu-v3.c | 48 |
1 files changed, 44 insertions, 4 deletions
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index 5db6931c715c..d7fef5f99bfc 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -123,6 +123,10 @@ #define CR2_RECINVSID (1 << 1) #define CR2_E2H (1 << 0) +#define ARM_SMMU_GBPA 0x44 +#define GBPA_ABORT (1 << 20) +#define GBPA_UPDATE (1 << 31) + #define ARM_SMMU_IRQ_CTRL 0x50 #define IRQ_CTRL_EVTQ_IRQEN (1 << 2) #define IRQ_CTRL_PRIQ_IRQEN (1 << 1) @@ -2124,6 +2128,24 @@ static int arm_smmu_write_reg_sync(struct arm_smmu_device *smmu, u32 val, 1, ARM_SMMU_POLL_TIMEOUT_US); } +/* GBPA is "special" */ +static int arm_smmu_update_gbpa(struct arm_smmu_device *smmu, u32 set, u32 clr) +{ + int ret; + u32 reg, __iomem *gbpa = smmu->base + ARM_SMMU_GBPA; + + ret = readl_relaxed_poll_timeout(gbpa, reg, !(reg & GBPA_UPDATE), + 1, ARM_SMMU_POLL_TIMEOUT_US); + if (ret) + return ret; + + reg &= ~clr; + reg |= set; + writel_relaxed(reg | GBPA_UPDATE, gbpa); + return readl_relaxed_poll_timeout(gbpa, reg, !(reg & GBPA_UPDATE), + 1, ARM_SMMU_POLL_TIMEOUT_US); +} + static void arm_smmu_free_msis(void *data) { struct device *dev = data; @@ -2269,7 +2291,7 @@ static int arm_smmu_device_disable(struct arm_smmu_device *smmu) return ret; } -static int arm_smmu_device_reset(struct arm_smmu_device *smmu) +static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass) { int ret; u32 reg, enables; @@ -2370,8 +2392,17 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu) return ret; } - /* Enable the SMMU interface */ - enables |= CR0_SMMUEN; + + /* Enable the SMMU interface, or ensure bypass */ + if (!bypass || disable_bypass) { + enables |= CR0_SMMUEN; + } else { + ret = arm_smmu_update_gbpa(smmu, 0, GBPA_ABORT); + if (ret) { + dev_err(smmu->dev, "GBPA not responding to update\n"); + return ret; + } + } ret = arm_smmu_write_reg_sync(smmu, enables, ARM_SMMU_CR0, ARM_SMMU_CR0ACK); if (ret) { @@ -2570,6 +2601,15 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev) struct resource *res; struct arm_smmu_device *smmu; struct device *dev = &pdev->dev; + bool bypass = true; + u32 cells; + + if (of_property_read_u32(dev->of_node, "#iommu-cells", &cells)) + dev_err(dev, "missing #iommu-cells property\n"); + else if (cells != 1) + dev_err(dev, "invalid #iommu-cells value (%d)\n", cells); + else + bypass = false; smmu = devm_kzalloc(dev, sizeof(*smmu), GFP_KERNEL); if (!smmu) { @@ -2622,7 +2662,7 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev) platform_set_drvdata(pdev, smmu); /* Reset the device */ - return arm_smmu_device_reset(smmu); + return arm_smmu_device_reset(smmu, bypass); } static int arm_smmu_device_remove(struct platform_device *pdev) |