From: Anup Patel anup.patel@wdc.com
commit 2234ae846ccb9ebdf4c391824cb79e73674dceda upstream.
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: f1ad1133b18f ("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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/irqchip/irq-sifive-plic.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)
--- a/drivers/irqchip/irq-sifive-plic.c +++ b/drivers/irqchip/irq-sifive-plic.c @@ -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 devic 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) @@ -315,7 +317,6 @@ static int __init plic_init(struct devic
for (i = 0; i < nr_contexts; i++) { struct of_phandle_args parent; - struct plic_handler *handler; irq_hw_number_t hwirq; int cpu, hartid;
@@ -369,9 +370,18 @@ done: nr_handlers++; }
- cpuhp_setup_state(CPUHP_AP_IRQ_SIFIVE_PLIC_STARTING, + /* + * 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);