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

Hi Thomas,

On Wed, 05 Jun 2024 16:17:53 +0200
Thomas Gleixner [off-list ref] wrote:

On Mon, May 27 2024 at 18:14, Herve Codina wrote:

quoted

+struct lan966x_oic_data {
+	struct irq_domain *domain;
+	void __iomem *regs;
+	int irq;
+};  

Please read Documentation/process/maintainers-tip.rst

I suppose you pointed out the un-tabular struct member names here.
I will fix that in the next iteration.

quoted

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

Please use the 100 character limit

Sure, will be fixed.

quoted

+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.

Will be fixed.

quoted

+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

Will be changed.

quoted

+	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;

Will be changed.

quoted

+
+	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.

quoted

+
+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?

Perfectly.
I will rework patches in this way.
Again, thanks for pointing out this solution.

Best regards,
Hervé

Thanks,

        tglx

-- 
Hervé Codina, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com