On 30/07/15 16:05, Jon Hunter wrote: > > On 30/07/15 15:33, Marc Zyngier wrote: >> On 30/07/15 15:11, Jon Hunter wrote: >>> The gic_init_bases() function initialises an array that stores the mapping >>> between the GIC and CPUs. This array is a global array that is >>> unconditionally initialised on every call to gic_init_bases(). Although, >>> it is not common for there to be more than one GIC instance, there are >>> some devices that do support nested GIC controllers and gic_init_bases() >>> can be called more than once. >>> >>> A 2nd call to gic_init_bases() will clear the previous CPU mapping and >>> will only setup the mapping again for the CPU calling gic_init_bases(). >>> Fix this by only allowing the CPU map to be configured for the primary GIC. >>> >>> For secondary GICs the CPU map is not relevant because these GICs do not >>> directly route the interrupts to the main CPU(s) but to other GICs or >>> devices. >>> >>> Signed-off-by: Jon Hunter <[email protected]> >>> --- >>> This is a follow-up to the patch titled "irqchip: gic: Add a cpu map for >>> each GIC instance" and discussed here [1]. Based upon the discussion I have >>> re-worked and re-titled it approriately. >>> >>> [1] http://www.spinics.net/lists/kernel/msg2044421.html >>> >>> drivers/irqchip/irq-gic.c | 43 +++++++++++++++++++++++++------------------ >>> 1 file changed, 25 insertions(+), 18 deletions(-) >>> >>> diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c >>> index a530d9a9b810..7566fe259d27 100644 >>> --- a/drivers/irqchip/irq-gic.c >>> +++ b/drivers/irqchip/irq-gic.c >>> @@ -416,19 +416,26 @@ static void gic_cpu_init(struct gic_chip_data *gic) >>> int i; >>> >>> /* >>> - * Get what the GIC says our CPU mask is. >>> + * Setting up the CPU map is only relevant for the primary GIC >>> + * because any nested/secondary GICs do not directly interface >>> + * with the CPU(s). >>> */ >>> - BUG_ON(cpu >= NR_GIC_CPU_IF); >>> - cpu_mask = gic_get_cpumask(gic); >>> - gic_cpu_map[cpu] = cpu_mask; >>> + if (gic == &gic_data[0]) { >>> + /* >>> + * Get what the GIC says our CPU mask is. >>> + */ >>> + BUG_ON(cpu >= NR_GIC_CPU_IF); >>> + cpu_mask = gic_get_cpumask(gic); >>> + gic_cpu_map[cpu] = cpu_mask; >>> >>> - /* >>> - * Clear our mask from the other map entries in case they're >>> - * still undefined. >>> - */ >>> - for (i = 0; i < NR_GIC_CPU_IF; i++) >>> - if (i != cpu) >>> - gic_cpu_map[i] &= ~cpu_mask; >>> + /* >>> + * Clear our mask from the other map entries in case they're >>> + * still undefined. >>> + */ >>> + for (i = 0; i < NR_GIC_CPU_IF; i++) >>> + if (i != cpu) >>> + gic_cpu_map[i] &= ~cpu_mask; >>> + } >>> >>> gic_cpu_config(dist_base, NULL); >>> >>> @@ -977,13 +984,6 @@ void __init gic_init_bases(unsigned int gic_nr, int >>> irq_start, >>> } >>> >>> /* >>> - * Initialize the CPU interface map to all CPUs. >>> - * It will be refined as each CPU probes its ID. >>> - */ >>> - for (i = 0; i < NR_GIC_CPU_IF; i++) >>> - gic_cpu_map[i] = 0xff; >>> - >>> - /* >>> * Find out how many interrupts are supported. >>> * The GIC only supports up to 1020 interrupt sources. >>> */ >>> @@ -1028,6 +1028,13 @@ void __init gic_init_bases(unsigned int gic_nr, int >>> irq_start, >>> return; >>> >>> if (gic_nr == 0) { >>> + /* >>> + * Initialize the CPU interface map to all CPUs. >>> + * It will be refined as each CPU probes its ID. >>> + * This is only necessary for the primary GIC. >>> + */ >>> + for (i = 0; i < NR_GIC_CPU_IF; i++) >>> + gic_cpu_map[i] = 0xff; >>> #ifdef CONFIG_SMP >>> set_smp_cross_call(gic_raise_softirq); >>> register_cpu_notifier(&gic_cpu_notifier); >>> >> >> Looks good. >> >> I think there is a another bug caused by 322895062 ("irqchip: gic: >> Preserve gic V2 bypass bits in cpu ctrl register"), where >> gic_cpu_if_up() only acts on the primary GIC. In the secondary GIC case, >> it will stay disabled. >> >> Mind fixing this while you're at it? > > Ah yes, I see. Ok, I will resend this with the other fix as a series.
Hmmm, what about gic_cpu_if_down()? Looks like the only user is vexpress-tc2. Ideally it should pass the gic_nr. I could make it pass 0 by default. Jon -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
