From ebc67da65fda03cbe5b4019d91229287fddd5c6e Mon Sep 17 00:00:00 2001 From: Tony Lindgren Date: Sun, 18 Jun 2006 16:26:58 +0100 Subject: [PATCH] [ARM] 3554/1: ARM: Fix dyntick locking Patch from Tony Lindgren This patch fixes some dyntick locking issues on ARM as pointed out by Russell King. Signed-off-by: Tony Lindgren Signed-off-by: Russell King --- arch/arm/kernel/irq.c | 4 ++-- arch/arm/kernel/time.c | 24 +++++++++++++++++------- include/asm-arm/mach/time.h | 1 + 3 files changed, 20 insertions(+), 9 deletions(-) diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c index 2d5896b361..bcc19fbb32 100644 --- a/arch/arm/kernel/irq.c +++ b/arch/arm/kernel/irq.c @@ -342,10 +342,10 @@ __do_irq(unsigned int irq, struct irqaction *action, struct pt_regs *regs) #ifdef CONFIG_NO_IDLE_HZ if (!(action->flags & SA_TIMER) && system_timer->dyn_tick != NULL) { - write_seqlock(&xtime_lock); + spin_lock(&system_timer->dyn_tick->lock); if (system_timer->dyn_tick->state & DYN_TICK_ENABLED) system_timer->dyn_tick->handler(irq, 0, regs); - write_sequnlock(&xtime_lock); + spin_unlock(&system_timer->dyn_tick->lock); } #endif diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c index d6bd435a68..9c12d4fefb 100644 --- a/arch/arm/kernel/time.c +++ b/arch/arm/kernel/time.c @@ -379,7 +379,7 @@ static int timer_dyn_tick_enable(void) int ret = -ENODEV; if (dyn_tick) { - write_seqlock_irqsave(&xtime_lock, flags); + spin_lock_irqsave(&dyn_tick->lock, flags); ret = 0; if (!(dyn_tick->state & DYN_TICK_ENABLED)) { ret = dyn_tick->enable(); @@ -387,7 +387,7 @@ static int timer_dyn_tick_enable(void) if (ret == 0) dyn_tick->state |= DYN_TICK_ENABLED; } - write_sequnlock_irqrestore(&xtime_lock, flags); + spin_unlock_irqrestore(&dyn_tick->lock, flags); } return ret; @@ -400,7 +400,7 @@ static int timer_dyn_tick_disable(void) int ret = -ENODEV; if (dyn_tick) { - write_seqlock_irqsave(&xtime_lock, flags); + spin_lock_irqsave(&dyn_tick->lock, flags); ret = 0; if (dyn_tick->state & DYN_TICK_ENABLED) { ret = dyn_tick->disable(); @@ -408,7 +408,7 @@ static int timer_dyn_tick_disable(void) if (ret == 0) dyn_tick->state &= ~DYN_TICK_ENABLED; } - write_sequnlock_irqrestore(&xtime_lock, flags); + spin_unlock_irqrestore(&dyn_tick->lock, flags); } return ret; @@ -422,15 +422,20 @@ static int timer_dyn_tick_disable(void) void timer_dyn_reprogram(void) { struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick; - unsigned long next, seq; + unsigned long next, seq, flags; - if (dyn_tick && (dyn_tick->state & DYN_TICK_ENABLED)) { + if (!dyn_tick) + return; + + spin_lock_irqsave(&dyn_tick->lock, flags); + if (dyn_tick->state & DYN_TICK_ENABLED) { next = next_timer_interrupt(); do { seq = read_seqbegin(&xtime_lock); - dyn_tick->reprogram(next_timer_interrupt() - jiffies); + dyn_tick->reprogram(next - jiffies); } while (read_seqretry(&xtime_lock, seq)); } + spin_unlock_irqrestore(&dyn_tick->lock, flags); } static ssize_t timer_show_dyn_tick(struct sys_device *dev, char *buf) @@ -499,5 +504,10 @@ void __init time_init(void) if (system_timer->offset == NULL) system_timer->offset = dummy_gettimeoffset; system_timer->init(); + +#ifdef CONFIG_NO_IDLE_HZ + if (system_timer->dyn_tick) + system_timer->dyn_tick->lock = SPIN_LOCK_UNLOCKED; +#endif } diff --git a/include/asm-arm/mach/time.h b/include/asm-arm/mach/time.h index 96c6db7dd0..9f28073559 100644 --- a/include/asm-arm/mach/time.h +++ b/include/asm-arm/mach/time.h @@ -50,6 +50,7 @@ struct sys_timer { #define DYN_TICK_ENABLED (1 << 1) struct dyn_tick_timer { + spinlock_t lock; unsigned int state; /* Current state */ int (*enable)(void); /* Enables dynamic tick */ int (*disable)(void); /* Disables dynamic tick */ -- 2.39.5