Re: [PATCH v14 01/18] irqchip/sifive-plic: Convert PLIC driver into a platform driver

Lad, Prabhakar
2024-04-03T08:31:34Z

Hi Anup,

On Thu, Feb 22, 2024 at 9:41 AM Anup Patel <apatel@ventanamicro.com> wrote:
>
> The PLIC driver does not require very early initialization so convert
> it into a platform driver.
>
> After conversion, the PLIC driver is probed after CPUs are brought-up
> so setup cpuhp state after context handler of all online CPUs are
> initialized otherwise PLIC driver crashes for platforms with multiple
> PLIC instances.
>
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
> drivers/irqchip/irq-sifive-plic.c | 101 ++++++++++++++++++------------
> 1 file changed, 61 insertions(+), 40 deletions(-)
>
This patch seems to have broken things on RZ/Five SoC, after reverting
this patch I get to boot it back again on v6.9-rc2. Looks like there
is some probe order issue after switching to platform driver?

Cheers,
Prabhakar

> diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
> index 5b7bc4fd9517..7400a07fc479 100644
> --- a/drivers/irqchip/irq-sifive-plic.c
> +++ b/drivers/irqchip/irq-sifive-plic.c
> @@ -64,6 +64,7 @@
> #define PLIC_QUIRK_EDGE_INTERRUPT 0
>
> struct plic_priv {
> + struct device *dev;
> struct cpumask lmask;
> struct irq_domain *irqdomain;
> void __iomem *regs;
> @@ -406,30 +407,50 @@ static int plic_starting_cpu(unsigned int cpu)
> return 0;
> }
>
> -static int __init __plic_init(struct device_node *node,
> - struct device_node *parent,
> - unsigned long plic_quirks)
> +static const struct of_device_id plic_match[] = {
> + { .compatible = "sifive,plic-1.0.0" },
> + { .compatible = "riscv,plic0" },
> + { .compatible = "andestech,nceplic100",
> + .data = (const void *)BIT(PLIC_QUIRK_EDGE_INTERRUPT) },
> + { .compatible = "thead,c900-plic",
> + .data = (const void *)BIT(PLIC_QUIRK_EDGE_INTERRUPT) },
> + {}
> +};
> +
> +static int plic_probe(struct platform_device *pdev)
> {
> int error = 0, nr_contexts, nr_handlers = 0, i;
> - u32 nr_irqs;
> - struct plic_priv *priv;
> + struct device *dev = &pdev->dev;
> + unsigned long plic_quirks = 0;
> struct plic_handler *handler;
> + struct plic_priv *priv;
> + bool cpuhp_setup;
> unsigned int cpu;
> + u32 nr_irqs;
> +
> + if (is_of_node(dev->fwnode)) {
> + const struct of_device_id *id;
> +
> + id = of_match_node(plic_match, to_of_node(dev->fwnode));
> + if (id)
> + plic_quirks = (unsigned long)id->data;
> + }
>
> priv = kzalloc(sizeof(*priv), GFP_KERNEL);
> if (!priv)
> return -ENOMEM;
>
> + priv->dev = dev;
> priv->plic_quirks = plic_quirks;
>
> - priv->regs = of_iomap(node, 0);
> + priv->regs = of_iomap(to_of_node(dev->fwnode), 0);
> if (WARN_ON(!priv->regs)) {
> error = -EIO;
> goto out_free_priv;
> }
>
> error = -EINVAL;
> - of_property_read_u32(node, "riscv,ndev", &nr_irqs);
> + of_property_read_u32(to_of_node(dev->fwnode), "riscv,ndev", &nr_irqs);
> if (WARN_ON(!nr_irqs))
> goto out_iounmap;
>
> @@ -439,13 +460,13 @@ static int __init __plic_init(struct device_node *node,
> if (!priv->prio_save)
> goto out_free_priority_reg;
>
> - nr_contexts = of_irq_count(node);
> + nr_contexts = of_irq_count(to_of_node(dev->fwnode));
> if (WARN_ON(!nr_contexts))
> goto out_free_priority_reg;
>
> error = -ENOMEM;
> - priv->irqdomain = irq_domain_add_linear(node, nr_irqs + 1,
> - &plic_irqdomain_ops, priv);
> + priv->irqdomain = irq_domain_add_linear(to_of_node(dev->fwnode), nr_irqs + 1,
> + &plic_irqdomain_ops, priv);
> if (WARN_ON(!priv->irqdomain))
> goto out_free_priority_reg;
>
> @@ -455,7 +476,7 @@ static int __init __plic_init(struct device_node *node,
> int cpu;
> unsigned long hartid;
>
> - if (of_irq_parse_one(node, i, &parent)) {
> + if (of_irq_parse_one(to_of_node(dev->fwnode), i, &parent)) {
> pr_err("failed to parse parent for context %d.\n", i);
> continue;
> }
> @@ -491,7 +512,7 @@ static int __init __plic_init(struct device_node *node,
>
> /* Find parent domain and register chained handler */
> if (!plic_parent_irq && irq_find_host(parent.np)) {
> - plic_parent_irq = irq_of_parse_and_map(node, i);
> + plic_parent_irq = irq_of_parse_and_map(to_of_node(dev->fwnode), i);
> if (plic_parent_irq)
> irq_set_chained_handler(plic_parent_irq,
> plic_handle_irq);
> @@ -533,20 +554,29 @@ static int __init __plic_init(struct device_node *node,
>
> /*
> * We can have multiple PLIC instances so setup cpuhp state
> - * and register syscore operations only when context handler
> - * for current/boot CPU is present.
> + * and register syscore operations only once after context
> + * handlers of all online CPUs are initialized.
> */
> - handler = this_cpu_ptr(&plic_handlers);
> - if (handler->present && !plic_cpuhp_setup_done) {
> - cpuhp_setup_state(CPUHP_AP_IRQ_SIFIVE_PLIC_STARTING,
> - "irqchip/sifive/plic:starting",
> - plic_starting_cpu, plic_dying_cpu);
> - register_syscore_ops(&plic_irq_syscore_ops);
> - plic_cpuhp_setup_done = true;
> + if (!plic_cpuhp_setup_done) {
> + cpuhp_setup = true;
> + for_each_online_cpu(cpu) {
> + handler = per_cpu_ptr(&plic_handlers, cpu);
> + if (!handler->present) {
> + cpuhp_setup = false;
> + break;
> + }
> + }
> + if (cpuhp_setup) {
> + cpuhp_setup_state(CPUHP_AP_IRQ_SIFIVE_PLIC_STARTING,
> + "irqchip/sifive/plic:starting",
> + plic_starting_cpu, plic_dying_cpu);
> + register_syscore_ops(&plic_irq_syscore_ops);
> + plic_cpuhp_setup_done = true;
> + }
> }
>
> - pr_info("%pOFP: mapped %d interrupts with %d handlers for"
> - " %d contexts.\n", node, nr_irqs, nr_handlers, nr_contexts);
> + pr_info("%pOFP: mapped %d interrupts with %d handlers for %d contexts.\n",
> + to_of_node(dev->fwnode), nr_irqs, nr_handlers, nr_contexts);
> return 0;
>
> out_free_enable_reg:
> @@ -563,20 +593,11 @@ static int __init __plic_init(struct device_node *node,
> return error;
> }
>
> -static int __init plic_init(struct device_node *node,
> - struct device_node *parent)
> -{
> - return __plic_init(node, parent, 0);
> -}
> -
> -IRQCHIP_DECLARE(sifive_plic, "sifive,plic-1.0.0", plic_init);
> -IRQCHIP_DECLARE(riscv_plic0, "riscv,plic0", plic_init); /* for legacy systems */
> -
> -static int __init plic_edge_init(struct device_node *node,
> - struct device_node *parent)
> -{
> - return __plic_init(node, parent, BIT(PLIC_QUIRK_EDGE_INTERRUPT));
> -}
> -
> -IRQCHIP_DECLARE(andestech_nceplic100, "andestech,nceplic100", plic_edge_init);
> -IRQCHIP_DECLARE(thead_c900_plic, "thead,c900-plic", plic_edge_init);
> +static struct platform_driver plic_driver = {
> + .driver = {
> + .name = "riscv-plic",
> + .of_match_table = plic_match,
> + },
> + .probe = plic_probe,
> +};
> +builtin_platform_driver(plic_driver);
> --
> 2.34.1
>
>
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