[RFC PATCH v2 02/12] ARM: smp_twd: add support for remapped PPI interrupts
From: Marc Zyngier <hidden>
Date: 2011-05-06 10:33:07
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
When CONFIG_ARM_GIC_VPPI is enabled, let smp_twd request interrupts the normal way (ie using request_irq()). This involves letting PPIs go via the same code path as SPIs and having normal interrupt handler for the local timer code. The previous ad-hoc code is still supported when CONFIG_ARM_GIC_VPPI is not defined. Signed-off-by: Marc Zyngier <redacted> Reviewed-by: Will Deacon <redacted> --- arch/arm/include/asm/localtimer.h | 6 ++++++ arch/arm/kernel/smp.c | 12 ++++++++++++ arch/arm/kernel/smp_twd.c | 20 +++++++++++++++++++- 3 files changed, 37 insertions(+), 1 deletions(-)
diff --git a/arch/arm/include/asm/localtimer.h b/arch/arm/include/asm/localtimer.h
index 080d74f..bef44b3 100644
--- a/arch/arm/include/asm/localtimer.h
+++ b/arch/arm/include/asm/localtimer.h@@ -10,6 +10,8 @@ #ifndef __ASM_ARM_LOCALTIMER_H #define __ASM_ARM_LOCALTIMER_H +#include <linux/interrupt.h> + struct clock_event_device; /*
@@ -22,6 +24,10 @@ void percpu_timer_setup(void); */ asmlinkage void do_local_timer(struct pt_regs *); +/* + * Per-cpu timer IRQ handler + */ +irqreturn_t percpu_timer_handler(int irq, void *dev_id); #ifdef CONFIG_LOCAL_TIMERS
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index f29b8a2..30201a0 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c@@ -452,6 +452,18 @@ asmlinkage void __exception_irq_entry do_local_timer(struct pt_regs *regs) set_irq_regs(old_regs); } +irqreturn_t percpu_timer_handler(int irq, void *dev_id) +{ + struct clock_event_device *evt = dev_id; + + if (local_timer_ack()) { + evt->event_handler(evt); + return IRQ_HANDLED; + } + + return IRQ_NONE; +} + void show_local_irqs(struct seq_file *p, int prec) { unsigned int cpu;
diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c
index 60636f4..2256360 100644
--- a/arch/arm/kernel/smp_twd.c
+++ b/arch/arm/kernel/smp_twd.c@@ -15,10 +15,11 @@ #include <linux/smp.h> #include <linux/jiffies.h> #include <linux/clockchips.h> -#include <linux/irq.h> +#include <linux/interrupt.h> #include <linux/io.h> #include <asm/smp_twd.h> +#include <asm/localtimer.h> #include <asm/hardware/gic.h> /* set up by the platform code */
@@ -43,6 +44,10 @@ static void twd_set_mode(enum clock_event_mode mode, ctrl = TWD_TIMER_CONTROL_IT_ENABLE | TWD_TIMER_CONTROL_ONESHOT; break; case CLOCK_EVT_MODE_UNUSED: +#ifdef CONFIG_ARM_GIC_VPPI + free_irq(clk->irq, clk); + /* fall through */ +#endif case CLOCK_EVT_MODE_SHUTDOWN: default: ctrl = 0;
@@ -124,6 +129,8 @@ static void __cpuinit twd_calibrate_rate(void) */ void __cpuinit twd_timer_setup(struct clock_event_device *clk) { + int err; + twd_calibrate_rate(); clk->name = "local_timer";
@@ -137,8 +144,19 @@ void __cpuinit twd_timer_setup(struct clock_event_device *clk) clk->max_delta_ns = clockevent_delta2ns(0xffffffff, clk); clk->min_delta_ns = clockevent_delta2ns(0xf, clk); +#ifdef CONFIG_ARM_GIC_VPPI + err = request_irq(clk->irq, percpu_timer_handler, + IRQF_PERCPU | IRQF_NOBALANCING | IRQF_TIMER, + clk->name, clk); + if (err) { + pr_err("%s: can't register interrupt %d on cpu %d (%d)\n", + clk->name, clk->irq, smp_processor_id(), err); + return; + } +#else /* Make sure our local interrupt controller has this enabled */ gic_enable_ppi(clk->irq); +#endif clockevents_register_device(clk); }
--
1.7.0.4