| Message ID | 20200518091441.94843-3-anup.patel@wdc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | More improvements for multiple PLICs | expand |
On Mon, 18 May 2020 02:14:40 PDT (-0700), Anup Patel wrote: > 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. > > This patch fixes both above issues. > > Fixes: f1ad1133b18f ("irqchip/sifive-plic: Add support for multiple PLICs") > Cc: stable@vger.kernel.org > Signed-off-by: Anup Patel <anup.patel@wdc.com> > --- > drivers/irqchip/irq-sifive-plic.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c > index 9f7f8ce88c00..6c54abf5cc5e 100644 > --- 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 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 @@ static int __init plic_init(struct device_node *node, > 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; So presumably something else is preventing multiple plic_init() calls from executing at the same time? Assuming that's the case Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com> > + } > + > pr_info("mapped %d interrupts with %d handlers for %d contexts.\n", > nr_irqs, nr_handlers, nr_contexts); > set_handle_irq(plic_handle_irq);
On Fri, May 22, 2020 at 3:36 AM Palmer Dabbelt <palmer@dabbelt.com> wrote: > > On Mon, 18 May 2020 02:14:40 PDT (-0700), Anup Patel wrote: > > 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. > > > > This patch fixes both above issues. > > > > Fixes: f1ad1133b18f ("irqchip/sifive-plic: Add support for multiple PLICs") > > Cc: stable@vger.kernel.org > > Signed-off-by: Anup Patel <anup.patel@wdc.com> > > --- > > drivers/irqchip/irq-sifive-plic.c | 14 ++++++++++++-- > > 1 file changed, 12 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c > > index 9f7f8ce88c00..6c54abf5cc5e 100644 > > --- 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 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 @@ static int __init plic_init(struct device_node *node, > > 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; > > So presumably something else is preventing multiple plic_init() calls from > executing at the same time? Assuming that's the case AFAIK, interrupt controller and timer probing happens sequentially on boot CPU before all secondary CPUs are brought-up. > > Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> > Acked-by: Palmer Dabbelt <palmerdabbelt@google.com> > > > + } > > + > > pr_info("mapped %d interrupts with %d handlers for %d contexts.\n", > > nr_irqs, nr_handlers, nr_contexts); > > set_handle_irq(plic_handle_irq); Thanks, Anup
diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c index 9f7f8ce88c00..6c54abf5cc5e 100644 --- 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 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 @@ static int __init plic_init(struct device_node *node, 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);
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. This patch fixes both above issues. Fixes: f1ad1133b18f ("irqchip/sifive-plic: Add support for multiple PLICs") Cc: stable@vger.kernel.org Signed-off-by: Anup Patel <anup.patel@wdc.com> --- drivers/irqchip/irq-sifive-plic.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)