static int arm_smmu_device_probe()

in arm/arm-smmu/arm-smmu.c [2069:2227]

• 119 lines of code
• 26 McCabe index (conditional complexity)

static int arm_smmu_device_probe(struct platform_device *pdev)
{
	struct resource *res;
	resource_size_t ioaddr;
	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) {
		dev_err(dev, "failed to allocate arm_smmu_device\n");
		return -ENOMEM;
	}
	smmu->dev = dev;

	if (dev->of_node)
		err = arm_smmu_device_dt_probe(pdev, smmu);
	else
		err = arm_smmu_device_acpi_probe(pdev, smmu);

	if (err)
		return err;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	ioaddr = res->start;
	smmu->base = devm_ioremap_resource(dev, res);
	if (IS_ERR(smmu->base))
		return PTR_ERR(smmu->base);
	/*
	 * The resource size should effectively match the value of SMMU_TOP;
	 * stash that temporarily until we know PAGESIZE to validate it with.
	 */
	smmu->numpage = resource_size(res);

	smmu = arm_smmu_impl_init(smmu);
	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++;
	}

	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->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;
	}

	for (i = 0; i < num_irqs; ++i) {
		int irq = platform_get_irq(pdev, i);

		if (irq < 0)
			return -ENODEV;
		smmu->irqs[i] = irq;
	}

	err = devm_clk_bulk_get_all(dev, &smmu->clks);
	if (err < 0) {
		dev_err(dev, "failed to get clocks %d\n", err);
		return err;
	}
	smmu->num_clks = err;

	err = clk_bulk_prepare_enable(smmu->num_clks, smmu->clks);
	if (err)
		return err;

	err = arm_smmu_device_cfg_probe(smmu);
	if (err)
		return err;

	if (smmu->version == ARM_SMMU_V2) {
		if (smmu->num_context_banks > smmu->num_context_irqs) {
			dev_err(dev,
			      "found only %d context irq(s) but %d required\n",
			      smmu->num_context_irqs, smmu->num_context_banks);
			return -ENODEV;
		}

		/* Ignore superfluous interrupts */
		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],
				       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;
		}
	}

	err = iommu_device_sysfs_add(&smmu->iommu, smmu->dev, NULL,
				     "smmu.%pa", &ioaddr);
	if (err) {
		dev_err(dev, "Failed to register iommu in sysfs\n");
		return err;
	}

	err = iommu_device_register(&smmu->iommu, &arm_smmu_ops, dev);
	if (err) {
		dev_err(dev, "Failed to register iommu\n");
		goto err_sysfs_remove;
	}

	platform_set_drvdata(pdev, smmu);
	arm_smmu_device_reset(smmu);
	arm_smmu_test_smr_masks(smmu);

	/*
	 * We want to avoid touching dev->power.lock in fastpaths unless
	 * it's really going to do something useful - pm_runtime_enabled()
	 * can serve as an ideal proxy for that decision. So, conditionally
	 * enable pm_runtime.
	 */
	if (dev->pm_domain) {
		pm_runtime_set_active(dev);
		pm_runtime_enable(dev);
	}

	/*
	 * For ACPI and generic DT bindings, an SMMU will be probed before
	 * any device which might need it, so we want the bus ops in place
	 * ready to handle default domain setup as soon as any SMMU exists.
	 */
	if (!using_legacy_binding) {
		err = arm_smmu_bus_init(&arm_smmu_ops);
		if (err)
			goto err_unregister_device;
	}

	return 0;

err_unregister_device:
	iommu_device_unregister(&smmu->iommu);
err_sysfs_remove:
	iommu_device_sysfs_remove(&smmu->iommu);
	return err;
}