Subject: Re: [PATCH v2 11/19] irqchip: Add support for LAN966x OIC

From: Thomas Gleixner <[email-masked]>
Date: Wed, 05 Jun 2024 16:17:53 +0200

On Mon, May 27 2024 at 18:14, Herve Codina wrote:
> +struct lan966x_oic_data {
> +	struct irq_domain *domain;
> +	void __iomem *regs;
> +	int irq;
> +};

Please read Documentation/process/maintainers-tip.rst

> +static int lan966x_oic_irq_set_type(struct irq_data *data,
> +				    unsigned int flow_type)

Please use the 100 character limit

> +static struct lan966x_oic_chip_regs lan966x_oic_chip_regs[3] = {
> +	{
> +		.reg_off_ena_set = LAN966X_OIC_INTR_ENA_SET,
> +		.reg_off_ena_clr = LAN966X_OIC_INTR_ENA_CLR,
> +		.reg_off_sticky = LAN966X_OIC_INTR_STICKY,
> +		.reg_off_ident = LAN966X_OIC_DST_INTR_IDENT(0),
> +		.reg_off_map = LAN966X_OIC_DST_INTR_MAP(0),

Please make this tabular. See doc.

> +static void lan966x_oic_chip_init(struct lan966x_oic_data *lan966x_oic,
> +				  struct irq_chip_generic *gc,
> +				  struct lan966x_oic_chip_regs *chip_regs)
> +{
> +	gc->reg_base = lan966x_oic->regs;
> +	gc->chip_types[0].regs.enable = chip_regs->reg_off_ena_set;
> +	gc->chip_types[0].regs.disable = chip_regs->reg_off_ena_clr;
> +	gc->chip_types[0].regs.ack = chip_regs->reg_off_sticky;
> +	gc->chip_types[0].chip.irq_startup = lan966x_oic_irq_startup;
> +	gc->chip_types[0].chip.irq_shutdown = lan966x_oic_irq_shutdown;
> +	gc->chip_types[0].chip.irq_set_type = lan966x_oic_irq_set_type;
> +	gc->chip_types[0].chip.irq_mask = irq_gc_mask_disable_reg;
> +	gc->chip_types[0].chip.irq_unmask = irq_gc_unmask_enable_reg;
> +	gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit;
> +	gc->private = chip_regs;
> +
> +	/* Disable all interrupts handled by this chip */
> +	irq_reg_writel(gc, ~0, chip_regs->reg_off_ena_clr);
> +}
> +
> +static void lan966x_oic_chip_exit(struct irq_chip_generic *gc)
> +{
> +	/* Disable and ack all interrupts handled by this chip */
> +	irq_reg_writel(gc, ~0, gc->chip_types[0].regs.disable);

~0U
  
> +	irq_reg_writel(gc, ~0, gc->chip_types[0].regs.ack);
> +}
> +
> +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;

int ret, 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);
> +	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) {
> +		ret = dev_err_probe(dev, lan966x_oic->irq,
> +				    "failed to get the IRQ\n");
> +		goto err_domain_free;
> +	}
> +
> +	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;

This is exactly what can be avoided.

> +
> +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));

This is just wrong. You cannot remove the chip when there are still interrupts
mapped.

I just did a quick conversion to the template approach. Unsurprisingly
it removes 30 lines of boiler plate code:

+static void lan966x_oic_chip_init(struct irq_chip_generic *gc)
+{
+	struct lan966x_oic_data *lan966x_oic = gc->domain->host_data;
+	struct lan966x_oic_chip_regs *chip_regs;
+
+	gc->reg_base = lan966x_oic->regs;
+
+	chip_regs = lan966x_oic_chip_regs + gc->irq_base / 32;
+	gc->chip_types[0].regs.enable = chip_regs->reg_off_ena_set;
+	gc->chip_types[0].regs.disable = chip_regs->reg_off_ena_clr;
+	gc->chip_types[0].regs.ack = chip_regs->reg_off_sticky;
+
+	gc->chip_types[0].chip.irq_startup = lan966x_oic_irq_startup;
+	gc->chip_types[0].chip.irq_shutdown = lan966x_oic_irq_shutdown;
+	gc->chip_types[0].chip.irq_set_type = lan966x_oic_irq_set_type;
+	gc->chip_types[0].chip.irq_mask = irq_gc_mask_disable_reg;
+	gc->chip_types[0].chip.irq_unmask = irq_gc_unmask_enable_reg;
+	gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit;
+	gc->private = chip_regs;
+
+	/* Disable all interrupts handled by this chip */
+	irq_reg_writel(gc, ~0, chip_regs->reg_off_ena_clr);
+}
+
+static void lan966x_oic_chip_exit(struct irq_chip_generic *gc)
+{
+	/* Disable and ack all interrupts handled by this chip */
+	irq_reg_writel(gc, ~0, gc->chip_types[0].regs.disable);
+	irq_reg_writel(gc, ~0, gc->chip_types[0].regs.ack);
+}
+
+static void lan966x_oic_domain_init(struct irq_domain *d)
+{
+	struct lan966x_oic_data *lan966x_oic = d->host_data;
+
+	irq_set_chained_handler_and_data(lan966x_oic->irq, lan966x_oic_irq_handler, d);
+}
+
+static int lan966x_oic_probe(struct platform_device *pdev)
+{
+	struct irq_domain_chip_generic_info gc_info = {
+		.irqs_per_chip		= 32,
+		.num_chips		= 1,
+		.name			= "lan966x-oic"
+		.handler		= handle_level_irq,
+		.init			= lan966x_oic_chip_init,
+		.destroy		= lan966x_oic_chip_exit,
+	};
+
+	struct irq_domain_info info = {
+		.fwnode			= of_node_to_fwnode(pdev->dev.of_node),
+		.size			= LAN966X_OIC_NR_IRQ,
+		.hwirq_max		= LAN966X_OIC_NR_IRQ,
+		.ops			= &irq_generic_chip_ops,
+		.gc_info		= &gc_info,
+		.init			= lan966x_oic_domain_init,
+	};
+	struct lan966x_oic_data *lan966x_oic;
+	struct device *dev = &pdev->dev;
+
+	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->irq = platform_get_irq(pdev, 0);
+	if (lan966x_oic->irq < 0)
+		return dev_err_probe(dev, lan966x_oic->irq, "failed to get the IRQ\n");
+
+	lan966x_oic->domain = irq_domain_instantiate(&info);
+	if (!lan966x_oic->domain)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, lan966x_oic);
+	return 0;
+}
+
+static void lan966x_oic_remove(struct platform_device *pdev)
+{
+	struct lan966x_oic_data *lan966x_oic = platform_get_drvdata(pdev);
+
+	irq_set_chained_handler_and_data(lan966x_oic->irq, NULL, NULL);
+	irq_domain_remove(lan966x_oic->domain);
+}

See?

Thanks,

        tglx