[tip: irq/msi] irqchip/sifive-plic: Convert PLIC driver into a platform driver

tip-bot2 for Anup Patel
2024-02-23T09:44:04Z

The following commit has been merged into the irq/msi branch of tip:

Commit-ID: 8ec99b033147ef3bb8f0a560c24eb1baec3bc0be
Gitweb: https://git.kernel.org/tip/8ec99b033147ef3bb8f0a560c24eb1baec3bc0be
Author: Anup Patel <apatel@ventanamicro.com>
AuthorDate: Thu, 22 Feb 2024 15:09:49 +05:30
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Fri, 23 Feb 2024 10:18:43 +01:00

irqchip/sifive-plic: Convert PLIC driver into a platform driver

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>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240222094006.1030709-2-apatel@ventanamicro.com

---
drivers/irqchip/irq-sifive-plic.c | 101 +++++++++++++++++------------
1 file changed, 61 insertions(+), 40 deletions(-)

diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
index 5b7bc4f..7400a07 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 @@ done:

/*
* 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 @@ out_free_priv:
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);