iommu/arm-smmu: Account for PMU interrupts

In preparation for SMMUv2 PMU support, rejig our IRQ setup code to
account for PMU interrupts as additional resources. We can simplify the
whole flow by only storing the context IRQs, since the global IRQs are
devres-managed and we never refer to them beyond the initial request.

CC: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/b2a40caaf1622eb35c555074a0d72f4f0513cff9.1645106346.git.robin.murphy@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

Author: rmurphy-arm

drivers/iommu/arm/arm-smmu/arm-smmu.c

@@ -807,7 +807,7 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
 	 * Request context fault interrupt. Do this last to avoid the
 	 * handler seeing a half-initialised domain state.
 	 */
-	irq = smmu->irqs[smmu->num_global_irqs + cfg->irptndx];
+	irq = smmu->irqs[cfg->irptndx];
 
 	if (smmu->impl && smmu->impl->context_fault)
 		context_fault = smmu->impl->context_fault;
@@ -858,7 +858,7 @@ static void arm_smmu_destroy_domain_context(struct iommu_domain *domain)
 	arm_smmu_write_context_bank(smmu, cfg->cbndx);
 
 	if (cfg->irptndx != ARM_SMMU_INVALID_IRPTNDX) {
-		irq = smmu->irqs[smmu->num_global_irqs + cfg->irptndx];
+		irq = smmu->irqs[cfg->irptndx];
 		devm_free_irq(smmu->dev, irq, domain);
 	}
 
@@ -1951,8 +1951,8 @@ static int acpi_smmu_get_data(u32 model, struct arm_smmu_device *smmu)
 	return ret;
 }
 
-static int arm_smmu_device_acpi_probe(struct platform_device *pdev,
-				      struct arm_smmu_device *smmu)
+static int arm_smmu_device_acpi_probe(struct arm_smmu_device *smmu,
+				      u32 *global_irqs, u32 *pmu_irqs)
 {
 	struct device *dev = smmu->dev;
 	struct acpi_iort_node *node =
@@ -1968,33 +1968,33 @@ static int arm_smmu_device_acpi_probe(struct platform_device *pdev,
 		return ret;
 
 	/* Ignore the configuration access interrupt */
-	smmu->num_global_irqs = 1;
+	*global_irqs = 1;
+	*pmu_irqs = 0;
 
 	if (iort_smmu->flags & ACPI_IORT_SMMU_COHERENT_WALK)
 		smmu->features |= ARM_SMMU_FEAT_COHERENT_WALK;
 
 	return 0;
 }
 #else
-static inline int arm_smmu_device_acpi_probe(struct platform_device *pdev,
-					     struct arm_smmu_device *smmu)
+static inline int arm_smmu_device_acpi_probe(struct arm_smmu_device *smmu,
+					     u32 *global_irqs, u32 *pmu_irqs)
 {
 	return -ENODEV;
 }
 #endif
 
-static int arm_smmu_device_dt_probe(struct platform_device *pdev,
-				    struct arm_smmu_device *smmu)
+static int arm_smmu_device_dt_probe(struct arm_smmu_device *smmu,
+				    u32 *global_irqs, u32 *pmu_irqs)
 {
 	const struct arm_smmu_match_data *data;
-	struct device *dev = &pdev->dev;
+	struct device *dev = smmu->dev;
 	bool legacy_binding;
 
-	if (of_property_read_u32(dev->of_node, "#global-interrupts",
-				 &smmu->num_global_irqs)) {
-		dev_err(dev, "missing #global-interrupts property\n");
-		return -ENODEV;
-	}
+	if (of_property_read_u32(dev->of_node, "#global-interrupts", global_irqs))
+		return dev_err_probe(dev, -ENODEV,
+				     "missing #global-interrupts property\n");
+	*pmu_irqs = 0;
 
 	data = of_device_get_match_data(dev);
 	smmu->version = data->version;
@@ -2073,6 +2073,7 @@ 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;
+	u32 global_irqs, pmu_irqs;
 	irqreturn_t (*global_fault)(int irq, void *dev);
 
 	smmu = devm_kzalloc(dev, sizeof(*smmu), GFP_KERNEL);
@@ -2083,10 +2084,9 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
 	smmu->dev = dev;
 
 	if (dev->of_node)
-		err = arm_smmu_device_dt_probe(pdev, smmu);
+		err = arm_smmu_device_dt_probe(smmu, &global_irqs, &pmu_irqs);
 	else
-		err = arm_smmu_device_acpi_probe(pdev, smmu);
-
+		err = arm_smmu_device_acpi_probe(smmu, &global_irqs, &pmu_irqs);
 	if (err)
 		return err;
 
@@ -2105,31 +2105,25 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
 	if (IS_ERR(smmu))
 		return PTR_ERR(smmu);
 
-	num_irqs = 0;
-	while ((res = platform_get_resource(pdev, IORESOURCE_IRQ, num_irqs))) {
-		num_irqs++;
-		if (num_irqs > smmu->num_global_irqs)
-			smmu->num_context_irqs++;
-	}
+	num_irqs = platform_irq_count(pdev);
 
-	if (!smmu->num_context_irqs) {
-		dev_err(dev, "found %d interrupts but expected at least %d\n",
-			num_irqs, smmu->num_global_irqs + 1);
-		return -ENODEV;
-	}
+	smmu->num_context_irqs = num_irqs - global_irqs - pmu_irqs;
+	if (smmu->num_context_irqs <= 0)
+		return dev_err_probe(dev, -ENODEV,
+				"found %d interrupts but expected at least %d\n",
+				num_irqs, global_irqs + pmu_irqs + 1);
 
-	smmu->irqs = devm_kcalloc(dev, num_irqs, sizeof(*smmu->irqs),
-				  GFP_KERNEL);
-	if (!smmu->irqs) {
-		dev_err(dev, "failed to allocate %d irqs\n", num_irqs);
-		return -ENOMEM;
-	}
+	smmu->irqs = devm_kcalloc(dev, smmu->num_context_irqs,
+				  sizeof(*smmu->irqs), GFP_KERNEL);
+	if (!smmu->irqs)
+		return dev_err_probe(dev, -ENOMEM, "failed to allocate %d irqs\n",
+				     smmu->num_context_irqs);
 
-	for (i = 0; i < num_irqs; ++i) {
-		int irq = platform_get_irq(pdev, i);
+	for (i = 0; i < smmu->num_context_irqs; i++) {
+		int irq = platform_get_irq(pdev, global_irqs + pmu_irqs + i);
 
 		if (irq < 0)
-			return -ENODEV;
+			return irq;
 		smmu->irqs[i] = irq;
 	}
 
@@ -2165,17 +2159,18 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
 	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],
-				       global_fault,
-				       IRQF_SHARED,
-				       "arm-smmu global fault",
-				       smmu);
-		if (err) {
-			dev_err(dev, "failed to request global IRQ %d (%u)\n",
-				i, smmu->irqs[i]);
-			return err;
-		}
+	for (i = 0; i < global_irqs; i++) {
+		int irq = platform_get_irq(pdev, i);
+
+		if (irq < 0)
+			return irq;
+
+		err = devm_request_irq(dev, irq, global_fault, IRQF_SHARED,
+				       "arm-smmu global fault", smmu);
+		if (err)
+			return dev_err_probe(dev, err,
+					"failed to request global IRQ %d (%u)\n",
+					i, irq);
 	}
 
 	err = iommu_device_sysfs_add(&smmu->iommu, smmu->dev, NULL,

drivers/iommu/arm/arm-smmu/arm-smmu.h

@@ -318,11 +318,10 @@ struct arm_smmu_device {
 	unsigned long			pa_size;
 	unsigned long			pgsize_bitmap;
 
-	u32				num_global_irqs;
-	u32				num_context_irqs;
+	int				num_context_irqs;
+	int				num_clks;
 	unsigned int			*irqs;
 	struct clk_bulk_data		*clks;
-	int				num_clks;
 
 	spinlock_t			global_sync_lock;