Re: [PATCH 12/17] irqchip: Add support for LAN966x OIC

[Simon Horman <horms@kernel.org>]

On Tue, Apr 30, 2024 at 10:37:21AM +0200, Herve Codina wrote:
> The Microchip LAN966x outband interrupt controller (OIC) maps the
> internal interrupt sources of the LAN966x device to an external
> interrupt.
> When the LAN966x device is used as a PCI device, the external interrupt
> is routed to the PCI interrupt.
> 
> Signed-off-by: Herve Codina <herve.codina@bootlin.com>

Hi Herve,

> +static int lan966x_oic_probe(struct platform_device *pdev)
> +{
> +	struct device_node *node = pdev->dev.of_node;
> +	struct lan966x_oic_data *lan966x_oic;
> +	struct device *dev = &pdev->dev;
> +	struct irq_chip_generic *gc;
> +	int ret;
> +	int i;
> +
> +	lan966x_oic = devm_kmalloc(dev, sizeof(*lan966x_oic), GFP_KERNEL);
> +	if (!lan966x_oic)
> +		return -ENOMEM;
> +
> +	lan966x_oic->regs = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(lan966x_oic->regs))
> +		return dev_err_probe(dev, PTR_ERR(lan966x_oic->regs),
> +				     "failed to map resource\n");
> +
> +	lan966x_oic->domain = irq_domain_alloc_linear(of_node_to_fwnode(node),
> +						      LAN966X_OIC_NR_IRQ,
> +						      &irq_generic_chip_ops, NULL);

nit: Please consider limiting lines to 80 columns wide in Networking code.

> +	if (!lan966x_oic->domain) {
> +		dev_err(dev, "failed to create an IRQ domain\n");
> +		return -EINVAL;
> +	}
> +
> +	lan966x_oic->irq = platform_get_irq(pdev, 0);
> +	if (lan966x_oic->irq < 0) {
> +		dev_err_probe(dev, lan966x_oic->irq, "failed to get the IRQ\n");
> +		goto err_domain_free;

Hi,

This will result in the function returning ret.
However, ret is uninitialised here.

Flagged by W=1 builds with clang-18, and Smatch.

> +	}
> +
> +	ret = irq_alloc_domain_generic_chips(lan966x_oic->domain, 32, 1, "lan966x-oic",
> +					     handle_level_irq, 0, 0, 0);
> +	if (ret) {
> +		dev_err_probe(dev, ret, "failed to alloc irq domain gc\n");
> +		goto err_domain_free;
> +	}
> +
> +	/* Init chips */
> +	BUILD_BUG_ON(DIV_ROUND_UP(LAN966X_OIC_NR_IRQ, 32) != ARRAY_SIZE(lan966x_oic_chip_regs));
> +	for (i = 0; i < ARRAY_SIZE(lan966x_oic_chip_regs); i++) {
> +		gc = irq_get_domain_generic_chip(lan966x_oic->domain, i * 32);
> +		lan966x_oic_chip_init(lan966x_oic, gc, &lan966x_oic_chip_regs[i]);
> +	}
> +
> +	irq_set_chained_handler_and_data(lan966x_oic->irq, lan966x_oic_irq_handler,
> +					 lan966x_oic->domain);
> +
> +	irq_domain_publish(lan966x_oic->domain);
> +	platform_set_drvdata(pdev, lan966x_oic);
> +	return 0;
> +
> +err_domain_free:
> +	irq_domain_free(lan966x_oic->domain);
> +	return ret;
> +}
> +
> +static void lan966x_oic_remove(struct platform_device *pdev)
> +{
> +	struct lan966x_oic_data *lan966x_oic = platform_get_drvdata(pdev);
> +	struct irq_chip_generic *gc;
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(lan966x_oic_chip_regs); i++) {
> +		gc = irq_get_domain_generic_chip(lan966x_oic->domain, i * 32);
> +		lan966x_oic_chip_exit(gc);
> +	}
> +
> +	irq_set_chained_handler_and_data(lan966x_oic->irq, NULL, NULL);
> +
> +	for (i = 0; i < LAN966X_OIC_NR_IRQ; i++)
> +		irq_dispose_mapping(irq_find_mapping(lan966x_oic->domain, i));
> +
> +	irq_domain_unpublish(lan966x_oic->domain);
> +
> +	for (i = 0; i < ARRAY_SIZE(lan966x_oic_chip_regs); i++) {
> +		gc = irq_get_domain_generic_chip(lan966x_oic->domain, i * 32);
> +		irq_remove_generic_chip(gc, ~0, 0, 0);
> +	}
> +
> +	kfree(lan966x_oic->domain->gc);
> +	irq_domain_free(lan966x_oic->domain);
> +}

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