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irqchip/sifive-plic: Chain to parent IRQ after handlers are ready

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Now that the PLIC uses a platform driver, the driver is probed later in the
boot process, where interrupts from peripherals might already be pending.

As a result, plic_handle_irq() may be called as early as the call to
irq_set_chained_handler() completes. But this call happens before the
per-context handler is completely set up, so there is a window where
plic_handle_irq() can see incomplete per-context state and crash.

Avoid this by delaying the call to irq_set_chained_handler() until all
handlers from all PLICs are initialized.

Fixes: 8ec99b0331 ("irqchip/sifive-plic: Convert PLIC driver into a platform driver")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Anup Patel <anup@brainfault.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240529215458.937817-1-samuel.holland@sifive.com
Closes: https://lore.kernel.org/r/CAMuHMdVYFFR7K5SbHBLY-JHhb7YpgGMS_hnRWm8H0KD-wBo+4A@mail.gmail.com/
This commit is contained in:
Samuel Holland 2024-05-29 14:54:56 -07:00 committed by Thomas Gleixner
parent 0110c4b110
commit e306a894bd
1 changed files with 17 additions and 17 deletions
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34
drivers/irqchip/irq-sifive-plic.c
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@ -85,7 +85,7 @@ struct plic_handler {
struct plic_priv *priv;
};
static int plic_parent_irq __ro_after_init;
static bool plic_cpuhp_setup_done __ro_after_init;
static bool plic_global_setup_done __ro_after_init;
static DEFINE_PER_CPU(struct plic_handler, plic_handlers);
static int plic_irq_set_type(struct irq_data *d, unsigned int type);
@ -487,10 +487,8 @@ static int plic_probe(struct platform_device *pdev)
unsigned long plic_quirks = 0;
struct plic_handler *handler;
u32 nr_irqs, parent_hwirq;
struct irq_domain *domain;
struct plic_priv *priv;
irq_hw_number_t hwirq;
bool cpuhp_setup;
if (is_of_node(dev->fwnode)) {
const struct of_device_id *id;
@ -549,14 +547,6 @@ static int plic_probe(struct platform_device *pdev)
continue;
}
/* Find parent domain and register chained handler */
domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(), DOMAIN_BUS_ANY);
if (!plic_parent_irq && domain) {
plic_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
if (plic_parent_irq)
irq_set_chained_handler(plic_parent_irq, plic_handle_irq);
}
/*
* When running in M-mode we need to ignore the S-mode handler.
* Here we assume it always comes later, but that might be a
@ -597,25 +587,35 @@ done:
goto fail_cleanup_contexts;
/*
* We can have multiple PLIC instances so setup cpuhp state
* We can have multiple PLIC instances so setup global state
* and register syscore operations only once after context
* handlers of all online CPUs are initialized.
*/
if (!plic_cpuhp_setup_done) {
cpuhp_setup = true;
if (!plic_global_setup_done) {
struct irq_domain *domain;
bool global_setup = true;
for_each_online_cpu(cpu) {
handler = per_cpu_ptr(&plic_handlers, cpu);
if (!handler->present) {
cpuhp_setup = false;
global_setup = false;
break;
}
}
if (cpuhp_setup) {
if (global_setup) {
/* Find parent domain and register chained handler */
domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(), DOMAIN_BUS_ANY);
if (domain)
plic_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
if (plic_parent_irq)
irq_set_chained_handler(plic_parent_irq, plic_handle_irq);
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;
plic_global_setup_done = true;
}
}