diff options
| -rw-r--r-- | drivers/irqchip/irq-gic.c | 36 |
1 files changed, 33 insertions, 3 deletions
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c index fbc4ae2afd29..2c14eb047359 100644 --- a/drivers/irqchip/irq-gic.c +++ b/drivers/irqchip/irq-gic.c @@ -94,6 +94,27 @@ struct gic_chip_data { static DEFINE_RAW_SPINLOCK(irq_controller_lock); /* + * This lock is used by the big.LITTLE migration code to ensure no IPIs + * can be pended on the old core after the map has been updated. + */ +#ifdef CONFIG_BL_SWITCHER +static DEFINE_RAW_SPINLOCK(cpu_map_migration_lock); + +static inline void gic_migration_lock(unsigned long *flags) +{ + raw_spin_lock_irqsave(&cpu_map_migration_lock, *flags); +} + +static inline void gic_migration_unlock(unsigned long flags) +{ + raw_spin_unlock_irqrestore(&cpu_map_migration_lock, flags); +} +#else +static inline void gic_migration_lock(unsigned long *flags) {} +static inline void gic_migration_unlock(unsigned long flags) {} +#endif + +/* * The GIC mapping of CPU interfaces does not necessarily match * the logical CPU numbering. Let's use a mapping as returned * by the GIC itself. @@ -769,7 +790,7 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq) int cpu; unsigned long flags, map = 0; - raw_spin_lock_irqsave(&irq_controller_lock, flags); + gic_migration_lock(&flags); /* Convert our logical CPU mask into a physical one. */ for_each_cpu(cpu, mask) @@ -784,7 +805,7 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq) /* this always happens on GIC0 */ writel_relaxed(map << 16 | irq, gic_data_dist_base(&gic_data[0]) + GIC_DIST_SOFTINT); - raw_spin_unlock_irqrestore(&irq_controller_lock, flags); + gic_migration_unlock(flags); } #endif @@ -854,8 +875,17 @@ void gic_migrate_target(unsigned int new_cpu_id) raw_spin_lock(&irq_controller_lock); - /* Update the target interface for this logical CPU */ + /* + * Update the target interface for this logical CPU + * + * From the point we release the cpu_map_migration_lock any new + * SGIs will be pended on the new cpu which makes the set of SGIs + * pending on the old cpu static. That means we can defer the + * migration until after we have released the irq_controller_lock. + */ + raw_spin_lock(&cpu_map_migration_lock); gic_cpu_map[cpu] = 1 << new_cpu_id; + raw_spin_unlock(&cpu_map_migration_lock); /* * Find all the peripheral interrupts targetting the current |