[PATCH 4/7] iommu/arm-smmu: Add global/context fault implementation hooks

Krishna Reddy
2019-08-29T22:47:41Z

Add global/context fault hooks to allow Nvidia SMMU implementation
handle faults across multiple SMMUs.

Signed-off-by: Krishna Reddy <vdumpa@nvidia.com>
---
drivers/iommu/arm-smmu-nvidia.c | 127 ++++++++++++++++++++++++++++++++++++++++
drivers/iommu/arm-smmu.c | 6 ++
drivers/iommu/arm-smmu.h | 4 ++
3 files changed, 137 insertions(+)

diff --git a/drivers/iommu/arm-smmu-nvidia.c b/drivers/iommu/arm-smmu-nvidia.c
index a429b2c..b2a3c49 100644
--- a/drivers/iommu/arm-smmu-nvidia.c
+++ b/drivers/iommu/arm-smmu-nvidia.c
@@ -14,6 +14,10 @@

#define NUM_SMMU_INSTANCES 3

+static irqreturn_t nsmmu_context_fault_inst(int irq,
+ struct arm_smmu_device *smmu,
+ int idx, int inst);
+
struct nvidia_smmu {
struct arm_smmu_device smmu;
int num_inst;
@@ -87,12 +91,135 @@ static void nsmmu_tlb_sync(struct arm_smmu_device *smmu, int page,
nsmmu_tlb_sync_wait(smmu, page, sync, status, i);
}

+static irqreturn_t nsmmu_global_fault_inst(int irq,
+ struct arm_smmu_device *smmu,
+ int inst)
+{
+ u32 gfsr, gfsynr0, gfsynr1, gfsynr2;
+
+ gfsr = readl_relaxed(nsmmu_page(smmu, inst, 0) + ARM_SMMU_GR0_sGFSR);
+ gfsynr0 = readl_relaxed(nsmmu_page(smmu, inst, 0) +
+ ARM_SMMU_GR0_sGFSYNR0);
+ gfsynr1 = readl_relaxed(nsmmu_page(smmu, inst, 0) +
+ ARM_SMMU_GR0_sGFSYNR1);
+ gfsynr2 = readl_relaxed(nsmmu_page(smmu, inst, 0) +
+ ARM_SMMU_GR0_sGFSYNR2);
+
+ if (!gfsr)
+ return IRQ_NONE;
+
+ 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, nsmmu_page(smmu, inst, 0) + ARM_SMMU_GR0_sGFSR);
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t nsmmu_global_fault(int irq, struct arm_smmu_device *smmu)
+{
+ int i;
+ irqreturn_t irq_ret = IRQ_NONE;
+
+ /* Interrupt line is shared between global and context faults.
+ * Check for both type of interrupts on either fault handlers.
+ */
+ for (i = 0; i < to_nsmmu(smmu)->num_inst; i++) {
+ irq_ret = nsmmu_context_fault_inst(irq, smmu, 0, i);
+ if (irq_ret == IRQ_HANDLED)
+ return irq_ret;
+ }
+
+ for (i = 0; i < to_nsmmu(smmu)->num_inst; i++) {
+ irq_ret = nsmmu_global_fault_inst(irq, smmu, i);
+ if (irq_ret == IRQ_HANDLED)
+ return irq_ret;
+ }
+
+ return irq_ret;
+}
+
+static irqreturn_t nsmmu_context_fault_bank(int irq,
+ struct arm_smmu_device *smmu,
+ int idx, int inst)
+{
+ u32 fsr, fsynr, cbfrsynra;
+ unsigned long iova;
+
+ fsr = arm_smmu_cb_read(smmu, idx, ARM_SMMU_CB_FSR);
+ if (!(fsr & FSR_FAULT))
+ return IRQ_NONE;
+
+ fsynr = readl_relaxed(nsmmu_page(smmu, inst, smmu->numpage + idx) +
+ ARM_SMMU_CB_FSYNR0);
+ iova = readq_relaxed(nsmmu_page(smmu, inst, smmu->numpage + idx) +
+ ARM_SMMU_CB_FAR);
+ cbfrsynra = readl_relaxed(nsmmu_page(smmu, inst, 1) +
+ 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, nsmmu_page(smmu, inst, smmu->numpage + idx) +
+ ARM_SMMU_CB_FSR);
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t nsmmu_context_fault_inst(int irq,
+ struct arm_smmu_device *smmu,
+ int idx, int inst)
+{
+ irqreturn_t irq_ret = IRQ_NONE;
+
+ /* Interrupt line shared between global and all context faults.
+ * Check for faults across all contexts.
+ */
+ for (idx = 0; idx < smmu->num_context_banks; idx++) {
+ irq_ret = nsmmu_context_fault_bank(irq, smmu, idx, inst);
+
+ if (irq_ret == IRQ_HANDLED)
+ break;
+ }
+
+ return irq_ret;
+}
+
+static irqreturn_t nsmmu_context_fault(int irq,
+ struct arm_smmu_device *smmu,
+ int cbndx)
+{
+ int i;
+ irqreturn_t irq_ret = IRQ_NONE;
+
+ /* Interrupt line is shared between global and context faults.
+ * Check for both type of interrupts on either fault handlers.
+ */
+ for (i = 0; i < to_nsmmu(smmu)->num_inst; i++) {
+ irq_ret = nsmmu_global_fault_inst(irq, smmu, i);
+ if (irq_ret == IRQ_HANDLED)
+ return irq_ret;
+ }
+
+ for (i = 0; i < to_nsmmu(smmu)->num_inst; i++) {
+ irq_ret = nsmmu_context_fault_inst(irq, smmu, cbndx, i);
+ if (irq_ret == IRQ_HANDLED)
+ return irq_ret;
+ }
+
+ return irq_ret;
+}
+
static const struct arm_smmu_impl nsmmu_impl = {
.read_reg = nsmmu_read_reg,
.write_reg = nsmmu_write_reg,
.read_reg64 = nsmmu_read_reg64,
.write_reg64 = nsmmu_write_reg64,
.tlb_sync = nsmmu_tlb_sync,
+ .global_fault = nsmmu_global_fault,
+ .context_fault = nsmmu_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 f5454e71..9cc532d 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -454,6 +454,9 @@ static irqreturn_t arm_smmu_context_fault(int irq, void *dev)
struct arm_smmu_device *smmu = smmu_domain->smmu;
int idx = smmu_domain->cfg.cbndx;

+ if (smmu->impl->context_fault)
+ return smmu->impl->context_fault(irq, smmu, idx);
+
fsr = arm_smmu_cb_read(smmu, idx, ARM_SMMU_CB_FSR);
if (!(fsr & FSR_FAULT))
return IRQ_NONE;
@@ -475,6 +478,9 @@ static irqreturn_t arm_smmu_global_fault(int irq, void *dev)
u32 gfsr, gfsynr0, gfsynr1, gfsynr2;
struct arm_smmu_device *smmu = dev;

+ if (smmu->impl->global_fault)
+ return smmu->impl->global_fault(irq, smmu);
+
gfsr = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_sGFSR);
gfsynr0 = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_sGFSYNR0);
gfsynr1 = arm_smmu_gr0_read(smmu, ARM_SMMU_GR0_sGFSYNR1);
diff --git a/drivers/iommu/arm-smmu.h b/drivers/iommu/arm-smmu.h
index d3217f1..dec5e1a 100644
--- a/drivers/iommu/arm-smmu.h
+++ b/drivers/iommu/arm-smmu.h
@@ -17,6 +17,7 @@
#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>
@@ -340,6 +341,9 @@ struct arm_smmu_impl {
int (*init_context)(struct arm_smmu_domain *smmu_domain);
void (*tlb_sync)(struct arm_smmu_device *smmu, int page, int sync,
int status);
+ irqreturn_t (*global_fault)(int irq, struct arm_smmu_device *smmu);
+ irqreturn_t (*context_fault)(int irq, struct arm_smmu_device *smmu,
+ int cbndx);
};

static inline void __iomem *arm_smmu_page(struct arm_smmu_device *smmu, int n)
--
2.1.4