From mboxrd@z Thu Jan 1 00:00:00 1970 From: daniel.thompson@linaro.org (Daniel Thompson) Date: Wed, 26 Nov 2014 16:23:26 +0000 Subject: [PATCH 3.18-rc4 v10 2/6] irqchip: gic: Optimize locking in gic_raise_softirq In-Reply-To: <1417019010-9220-1-git-send-email-daniel.thompson@linaro.org> References: <1415968543-29469-1-git-send-email-daniel.thompson@linaro.org> <1417019010-9220-1-git-send-email-daniel.thompson@linaro.org> Message-ID: <1417019010-9220-3-git-send-email-daniel.thompson@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Currently gic_raise_softirq() unconditionally takes and releases a lock whose only purpose is to synchronize with the b.L switcher. Remove this lock if the b.L switcher is not compiled in. Signed-off-by: Daniel Thompson Cc: Thomas Gleixner Cc: Jason Cooper Cc: Russell King Cc: Marc Zyngier --- drivers/irqchip/irq-gic.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c index 94d77118efa8..e875da93f24a 100644 --- a/drivers/irqchip/irq-gic.c +++ b/drivers/irqchip/irq-gic.c @@ -76,8 +76,23 @@ 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 bl_migration_lock(unsigned long *flags) +{ + raw_spin_lock_irqsave(&cpu_map_migration_lock, *flags); +} + +static inline void bl_migration_unlock(unsigned long flags) +{ + raw_spin_unlock_irqrestore(&cpu_map_migration_lock, flags); +} +#else +static inline void bl_migration_lock(unsigned long *flags) {} +static inline void bl_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 @@ -630,7 +645,7 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq) int cpu; unsigned long flags, map = 0; - raw_spin_lock_irqsave(&cpu_map_migration_lock, flags); + bl_migration_lock(&flags); /* Convert our logical CPU mask into a physical one. */ for_each_cpu(cpu, mask) @@ -645,7 +660,7 @@ 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(&cpu_map_migration_lock, flags); + bl_migration_unlock(flags); } #endif -- 1.9.3