irqchip/sifive-plic: Setup cpuhp once after boot CPU handler is present (2234ae84) · Commits · 戴 / test

For multiple PLIC instances, the plic_init() is called once for each PLIC instance. Due to this we have two issues: 1. cpuhp_setup_state() is called multiple times 2. plic_starting_cpu() can crash for boot CPU if cpuhp_setup_state() is called before boot CPU PLIC handler is available. Address both issues by only initializing the HP notifiers when the boot CPU setup is complete. Fixes: ("irqchip/sifive-plic: Add support for multiple PLICs") Signed-off-by:

Anup Patel <anup.patel@wdc.com> Signed-off-by:

Marc Zyngier <maz@kernel.org> Reviewed-by:

Palmer Dabbelt <palmerdabbelt@google.com> Acked-by:

Palmer Dabbelt <palmerdabbelt@google.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200518091441.94843-3-anup.patel@wdc.com

drivers/irqchip/irq-sifive-plic.c

+12 −2

Original line number	Diff line number	Diff line
		@@ -76,6 +76,7 @@ struct plic_handler {
		void __iomem *enable_base;
		struct plic_priv *priv;
		};
		static bool plic_cpuhp_setup_done;
		static DEFINE_PER_CPU(struct plic_handler, plic_handlers);

		static inline void plic_toggle(struct plic_handler *handler,
		@@ -285,6 +286,7 @@ static int __init plic_init(struct device_node *node,
		int error = 0, nr_contexts, nr_handlers = 0, i;
		u32 nr_irqs;
		struct plic_priv *priv;
		struct plic_handler *handler;

		priv = kzalloc(sizeof(*priv), GFP_KERNEL);
		if (!priv)
		@@ -313,7 +315,6 @@ static int __init plic_init(struct device_node *node,

		for (i = 0; i < nr_contexts; i++) {
		struct of_phandle_args parent;
		struct plic_handler *handler;
		irq_hw_number_t hwirq;
		int cpu, hartid;

		@@ -367,9 +368,18 @@ done:
		nr_handlers++;
		}

		/*
		* We can have multiple PLIC instances so setup cpuhp state only
		* when context handler for current/boot CPU is present.
		*/
		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);
		plic_cpuhp_setup_done = true;
		}

		pr_info("mapped %d interrupts with %d handlers for %d contexts.\n",
		nr_irqs, nr_handlers, nr_contexts);
		set_handle_irq(plic_handle_irq);

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