Commit 95652106 authored by Anup Patel's avatar Anup Patel Committed by Thomas Gleixner
Browse files

irqchip/sifive-plic: Parse number of interrupts and contexts early in plic_probe() 



The SiFive PLIC driver needs to know the number of interrupts and contexts
to complete initialization. Parse these details early in plic_probe() to
avoid unnecessary memory allocations and register mappings if these details
are not available.

Signed-off-by: default avatarAnup Patel <apatel@ventanamicro.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240222094006.1030709-7-apatel@ventanamicro.com
parent a1558727

drivers/irqchip/irq-sifive-plic.c

+33 −10
Original line number Diff line number Diff line
@@ -417,6 +417,34 @@ static const struct of_device_id plic_match[] = { 
	{}

};



static int plic_parse_nr_irqs_and_contexts(struct platform_device *pdev,

					   u32 *nr_irqs, u32 *nr_contexts)

{

	struct device *dev = &pdev->dev;

	int rc;



	/*

	 * Currently, only OF fwnode is supported so extend this

	 * function for ACPI support.

	 */

	if (!is_of_node(dev->fwnode))

		return -EINVAL;



	rc = of_property_read_u32(to_of_node(dev->fwnode), "riscv,ndev", nr_irqs);

	if (rc) {

		dev_err(dev, "riscv,ndev property not available\n");

		return rc;

	}



	*nr_contexts = of_irq_count(to_of_node(dev->fwnode));

	if (WARN_ON(!(*nr_contexts))) {

		dev_err(dev, "no PLIC context available\n");

		return -EINVAL;

	}



	return 0;

}



static int plic_parse_context_parent(struct platform_device *pdev, u32 context,

				     u32 *parent_hwirq, int *parent_cpu)

{
@@ -465,31 +493,26 @@ static int plic_probe(struct platform_device *pdev) 
			plic_quirks = (unsigned long)id->data;

	}



	error = plic_parse_nr_irqs_and_contexts(pdev, &nr_irqs, &nr_contexts);

	if (error)

		return error;



	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);

	if (!priv)

		return -ENOMEM;



	priv->dev = dev;

	priv->plic_quirks = plic_quirks;

	priv->nr_irqs = nr_irqs;



	priv->regs = devm_platform_ioremap_resource(pdev, 0);

	if (WARN_ON(!priv->regs))

		return -EIO;



	of_property_read_u32(to_of_node(dev->fwnode), "riscv,ndev", &nr_irqs);

	if (WARN_ON(!nr_irqs))

		return -EINVAL;



	priv->nr_irqs = nr_irqs;



	priv->prio_save = devm_bitmap_zalloc(dev, nr_irqs, GFP_KERNEL);

	if (!priv->prio_save)

		return -ENOMEM;



	nr_contexts = of_irq_count(to_of_node(dev->fwnode));

	if (WARN_ON(!nr_contexts))

		return -EINVAL;



	for (i = 0; i < nr_contexts; i++) {

		error = plic_parse_context_parent(pdev, i, &parent_hwirq, &cpu);

		if (error) {