From 3708d52fc6bb34ae16399fe998d515dd7d188ab0 Mon Sep 17 00:00:00 2001 From: Sudeep Holla Date: Tue, 26 Aug 2014 16:03:35 +0100 Subject: [PATCH] irqchip: gic-v3: Implement CPU PM notifier When a CPU enters a low power state, the contents of the GICv3/4 system registers are lost. They need to be saved and restored if required. For now, since most of the GICv3 register are set some initial values and not modified at runtime, it is better to re-initialise rather than saving and restoring them. It may need to be saved and restored in future if required. This patch adds a notifier to disable the redistributor(if allowed) and Group1 interrupts when powering down the processor and to re-initialise the system registers on wakeup. Cc: Lorenzo Pieralisi Signed-off-by: Sudeep Holla Signed-off-by: Marc Zyngier Acked-by: Marc Zyngier Link: https://lkml.kernel.org/r/1409065415-20176-3-git-send-email-sudeep.holla@arm.com Signed-off-by: Jason Cooper --- drivers/irqchip/irq-gic-v3.c | 57 +++++++++++++++++++++++++++++------- 1 file changed, 46 insertions(+), 11 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index 37062ba6704b..4afbbc835939 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -16,6 +16,7 @@ */ #include +#include #include #include #include @@ -383,6 +384,21 @@ static int gic_populate_rdist(void) return -ENODEV; } +static void gic_cpu_sys_reg_init(void) +{ + /* Enable system registers */ + gic_enable_sre(); + + /* Set priority mask register */ + gic_write_pmr(DEFAULT_PMR_VALUE); + + /* EOI deactivates interrupt too (mode 0) */ + gic_write_ctlr(ICC_CTLR_EL1_EOImode_drop_dir); + + /* ... and let's hit the road... */ + gic_write_grpen1(1); +} + static void gic_cpu_init(void) { void __iomem *rbase; @@ -397,17 +413,8 @@ static void gic_cpu_init(void) gic_cpu_config(rbase, gic_redist_wait_for_rwp); - /* Enable system registers */ - gic_enable_sre(); - - /* Set priority mask register */ - gic_write_pmr(DEFAULT_PMR_VALUE); - - /* EOI deactivates interrupt too (mode 0) */ - gic_write_ctlr(ICC_CTLR_EL1_EOImode_drop_dir); - - /* ... and let's hit the road... */ - gic_write_grpen1(1); + /* initialise system registers */ + gic_cpu_sys_reg_init(); } #ifdef CONFIG_SMP @@ -543,6 +550,33 @@ static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val, #define gic_smp_init() do { } while(0) #endif +#ifdef CONFIG_CPU_PM +static int gic_cpu_pm_notifier(struct notifier_block *self, + unsigned long cmd, void *v) +{ + if (cmd == CPU_PM_EXIT) { + gic_enable_redist(true); + gic_cpu_sys_reg_init(); + } else if (cmd == CPU_PM_ENTER) { + gic_write_grpen1(0); + gic_enable_redist(false); + } + return NOTIFY_OK; +} + +static struct notifier_block gic_cpu_pm_notifier_block = { + .notifier_call = gic_cpu_pm_notifier, +}; + +static void gic_cpu_pm_init(void) +{ + cpu_pm_register_notifier(&gic_cpu_pm_notifier_block); +} + +#else +static inline void gic_cpu_pm_init(void) { } +#endif /* CONFIG_CPU_PM */ + static struct irq_chip gic_chip = { .name = "GICv3", .irq_mask = gic_mask_irq, @@ -682,6 +716,7 @@ static int __init gic_of_init(struct device_node *node, struct device_node *pare gic_smp_init(); gic_dist_init(); gic_cpu_init(); + gic_cpu_pm_init(); return 0; -- 2.30.2