[PATCH v11 5/5] iommu/arm-smmu: Add global/context fault implementation hooks

Krishna Reddy
2020-07-18T19:35:24Z

Add global/context fault hooks to allow vendor specific implementations
override default fault interrupt handlers.

Update NVIDIA implementation to override the default global/context fault
interrupt handlers and handle interrupts across the two ARM MMU-500s that
are programmed identically.

Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Nicolin Chen <nicoleotsuka@gmail.com>
Reviewed-by: Pritesh Raithatha <praithatha@nvidia.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Krishna Reddy <vdumpa@nvidia.com>
---
drivers/iommu/arm-smmu-nvidia.c | 99 +++++++++++++++++++++++++++++++++
drivers/iommu/arm-smmu.c | 17 +++++-
drivers/iommu/arm-smmu.h | 3 +
3 files changed, 117 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/arm-smmu-nvidia.c b/drivers/iommu/arm-smmu-nvidia.c
index 2f55e5793d34..31368057e9be 100644
--- a/drivers/iommu/arm-smmu-nvidia.c
+++ b/drivers/iommu/arm-smmu-nvidia.c
@@ -127,6 +127,103 @@ static int nvidia_smmu_reset(struct arm_smmu_device *smmu)
return 0;
}

+static irqreturn_t nvidia_smmu_global_fault_inst(int irq,
+ struct arm_smmu_device *smmu,
+ int inst)
+{
+ u32 gfsr, gfsynr0, gfsynr1, gfsynr2;
+ void __iomem *gr0_base = nvidia_smmu_page(smmu, inst, 0);
+
+ gfsr = readl_relaxed(gr0_base + ARM_SMMU_GR0_sGFSR);
+ if (!gfsr)
+ return IRQ_NONE;
+
+ gfsynr0 = readl_relaxed(gr0_base + ARM_SMMU_GR0_sGFSYNR0);
+ gfsynr1 = readl_relaxed(gr0_base + ARM_SMMU_GR0_sGFSYNR1);
+ gfsynr2 = readl_relaxed(gr0_base + ARM_SMMU_GR0_sGFSYNR2);
+
+ dev_err_ratelimited(smmu->dev,
+ "Unexpected global fault, this could be serious\n");
+ dev_err_ratelimited(smmu->dev,
+ "\tGFSR 0x%08x, GFSYNR0 0x%08x, GFSYNR1 0x%08x, GFSYNR2 0x%08x\n",
+ gfsr, gfsynr0, gfsynr1, gfsynr2);
+
+ writel_relaxed(gfsr, gr0_base + ARM_SMMU_GR0_sGFSR);
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t nvidia_smmu_global_fault(int irq, void *dev)
+{
+ unsigned int inst;
+ irqreturn_t ret = IRQ_NONE;
+ struct arm_smmu_device *smmu = dev;
+
+ for (inst = 0; inst < NUM_SMMU_INSTANCES; inst++) {
+ irqreturn_t irq_ret;
+
+ irq_ret = nvidia_smmu_global_fault_inst(irq, smmu, inst);
+ if (irq_ret == IRQ_HANDLED)
+ ret = IRQ_HANDLED;
+ }
+
+ return ret;
+}
+
+static irqreturn_t nvidia_smmu_context_fault_bank(int irq,
+ struct arm_smmu_device *smmu,
+ int idx, int inst)
+{
+ u32 fsr, fsynr, cbfrsynra;
+ unsigned long iova;
+ void __iomem *gr1_base = nvidia_smmu_page(smmu, inst, 1);
+ void __iomem *cb_base = nvidia_smmu_page(smmu, inst, smmu->numpage + idx);
+
+ fsr = readl_relaxed(cb_base + ARM_SMMU_CB_FSR);
+ if (!(fsr & ARM_SMMU_FSR_FAULT))
+ return IRQ_NONE;
+
+ fsynr = readl_relaxed(cb_base + ARM_SMMU_CB_FSYNR0);
+ iova = readq_relaxed(cb_base + ARM_SMMU_CB_FAR);
+ cbfrsynra = readl_relaxed(gr1_base + ARM_SMMU_GR1_CBFRSYNRA(idx));
+
+ dev_err_ratelimited(smmu->dev,
+ "Unhandled context fault: fsr=0x%x, iova=0x%08lx, fsynr=0x%x, cbfrsynra=0x%x, cb=%d\n",
+ fsr, iova, fsynr, cbfrsynra, idx);
+
+ writel_relaxed(fsr, cb_base + ARM_SMMU_CB_FSR);
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t nvidia_smmu_context_fault(int irq, void *dev)
+{
+ int idx;
+ unsigned int inst;
+ irqreturn_t ret = IRQ_NONE;
+ struct arm_smmu_device *smmu;
+ struct iommu_domain *domain = dev;
+ struct arm_smmu_domain *smmu_domain;
+
+ smmu_domain = container_of(domain, struct arm_smmu_domain, domain);
+ smmu = smmu_domain->smmu;
+
+ for (inst = 0; inst < NUM_SMMU_INSTANCES; inst++) {
+ irqreturn_t irq_ret;
+
+ /*
+ * Interrupt line is shared between all contexts.
+ * Check for faults across all contexts.
+ */
+ for (idx = 0; idx < smmu->num_context_banks; idx++) {
+ irq_ret = nvidia_smmu_context_fault_bank(irq, smmu,
+ idx, inst);
+ if (irq_ret == IRQ_HANDLED)
+ ret = IRQ_HANDLED;
+ }
+ }
+
+ return ret;
+}
+
static const struct arm_smmu_impl nvidia_smmu_impl = {
.read_reg = nvidia_smmu_read_reg,
.write_reg = nvidia_smmu_write_reg,
@@ -134,6 +231,8 @@ static const struct arm_smmu_impl nvidia_smmu_impl = {
.write_reg64 = nvidia_smmu_write_reg64,
.reset = nvidia_smmu_reset,
.tlb_sync = nvidia_smmu_tlb_sync,
+ .global_fault = nvidia_smmu_global_fault,
+ .context_fault = nvidia_smmu_context_fault,
};

struct arm_smmu_device *nvidia_smmu_impl_init(struct arm_smmu_device *smmu)
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 35422a17f610..56b7103e1368 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -670,6 +670,7 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
enum io_pgtable_fmt fmt;
struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
+ irqreturn_t (*context_fault)(int irq, void *dev);

mutex_lock(&smmu_domain->init_mutex);
if (smmu_domain->smmu)
@@ -832,7 +833,13 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
* handler seeing a half-initialised domain state.
*/
irq = smmu->irqs[smmu->num_global_irqs + cfg->irptndx];
- ret = devm_request_irq(smmu->dev, irq, arm_smmu_context_fault,
+
+ if (smmu->impl && smmu->impl->context_fault)
+ context_fault = smmu->impl->context_fault;
+ else
+ context_fault = arm_smmu_context_fault;
+
+ ret = devm_request_irq(smmu->dev, irq, context_fault,
IRQF_SHARED, "arm-smmu-context-fault", domain);
if (ret < 0) {
dev_err(smmu->dev, "failed to request context IRQ %d (%u)\n",
@@ -2108,6 +2115,7 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
struct arm_smmu_device *smmu;
struct device *dev = &pdev->dev;
int num_irqs, i, err;
+ irqreturn_t (*global_fault)(int irq, void *dev);

smmu = devm_kzalloc(dev, sizeof(*smmu), GFP_KERNEL);
if (!smmu) {
@@ -2194,9 +2202,14 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
smmu->num_context_irqs = smmu->num_context_banks;
}

+ if (smmu->impl && smmu->impl->global_fault)
+ global_fault = smmu->impl->global_fault;
+ else
+ global_fault = arm_smmu_global_fault;
+
for (i = 0; i < smmu->num_global_irqs; ++i) {
err = devm_request_irq(smmu->dev, smmu->irqs[i],
- arm_smmu_global_fault,
+ global_fault,
IRQF_SHARED,
"arm-smmu global fault",
smmu);
diff --git a/drivers/iommu/arm-smmu.h b/drivers/iommu/arm-smmu.h
index fad63efa1a72..d890a4a968e8 100644
--- a/drivers/iommu/arm-smmu.h
+++ b/drivers/iommu/arm-smmu.h
@@ -18,6 +18,7 @@
#include <linux/io-64-nonatomic-hi-lo.h>
#include <linux/io-pgtable.h>
#include <linux/iommu.h>
+#include <linux/irqreturn.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/types.h>
@@ -389,6 +390,8 @@ struct arm_smmu_impl {
void (*tlb_sync)(struct arm_smmu_device *smmu, int page, int sync,
int status);
int (*def_domain_type)(struct device *dev);
+ irqreturn_t (*global_fault)(int irq, void *dev);
+ irqreturn_t (*context_fault)(int irq, void *dev);
};

static inline void __iomem *arm_smmu_page(struct arm_smmu_device *smmu, int n)