From 31ccc1f524b626abcf5e043ad32b881219223c34 Mon Sep 17 00:00:00 2001 From: Jeff Dike Date: Tue, 16 Oct 2007 01:27:24 -0700 Subject: uml: GENERIC_CLOCKEVENTS support Enable CONFIG_GENERIC_CLOCKEVENTS. timer_irq gets its name changed to timer_handler, and becomes the recipient of timer signals. The clock_event_device is set up to imitate the current ticking clock, i.e. CLOCK_EVT_FEAT_ONESHOT is not enabled yet. disable_timer now doesn't ignore SIGALRM and SIGVTALRM because that breaks delay calibration. Signed-off-by: Jeff Dike Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/um/kernel/time.c | 101 ++++++++++++++++++++++++-------------------------- 1 file changed, 48 insertions(+), 53 deletions(-) (limited to 'arch/um/kernel') diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c index 7678bcf830b..01678487b99 100644 --- a/arch/um/kernel/time.c +++ b/arch/um/kernel/time.c @@ -3,6 +3,7 @@ * Licensed under the GPL */ +#include "linux/clockchips.h" #include "linux/interrupt.h" #include "linux/jiffies.h" #include "linux/threads.h" @@ -24,9 +25,10 @@ static unsigned long long prev_nsecs[NR_CPUS]; static long long delta[NR_CPUS]; /* Deviation per interval */ #endif -void timer_irq(struct uml_pt_regs *regs) +void timer_handler(int sig, struct uml_pt_regs *regs) { unsigned long long ticks = 0; + unsigned long flags; #ifdef CONFIG_UML_REAL_TIME_CLOCK int c = cpu(); if (prev_nsecs[c]) { @@ -47,89 +49,82 @@ void timer_irq(struct uml_pt_regs *regs) #else ticks = 1; #endif + + local_irq_save(flags); while (ticks > 0) { do_IRQ(TIMER_IRQ, regs); ticks--; } + local_irq_restore(flags); } -/* Protects local_offset */ -static DEFINE_SPINLOCK(timer_spinlock); -static unsigned long long local_offset = 0; - -static inline unsigned long long get_time(void) +static void itimer_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) { - unsigned long long nsecs; - unsigned long flags; - - spin_lock_irqsave(&timer_spinlock, flags); - nsecs = os_nsecs(); - nsecs += local_offset; - spin_unlock_irqrestore(&timer_spinlock, flags); - - return nsecs; + switch(mode) { + case CLOCK_EVT_MODE_PERIODIC: + set_interval(); + break; + + case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_UNUSED: + disable_timer(); + break; + case CLOCK_EVT_MODE_ONESHOT: + BUG(); + break; + + case CLOCK_EVT_MODE_RESUME: + break; + } } -irqreturn_t um_timer(int irq, void *dev) +static struct clock_event_device itimer_clockevent = { + .name = "itimer", + .rating = 250, + .cpumask = CPU_MASK_ALL, + .features = CLOCK_EVT_FEAT_PERIODIC, + .set_mode = itimer_set_mode, + .set_next_event = NULL, + .shift = 32, + .irq = 0, +}; + +static irqreturn_t um_timer(int irq, void *dev) { - unsigned long long nsecs; - unsigned long flags; - - write_seqlock_irqsave(&xtime_lock, flags); - - do_timer(1); - -#ifdef CONFIG_UML_REAL_TIME_CLOCK - nsecs = get_time(); -#else - nsecs = (unsigned long long) xtime.tv_sec * BILLION + xtime.tv_nsec + - BILLION / HZ; -#endif - xtime.tv_sec = nsecs / NSEC_PER_SEC; - xtime.tv_nsec = nsecs - xtime.tv_sec * NSEC_PER_SEC; - - write_sequnlock_irqrestore(&xtime_lock, flags); + (*itimer_clockevent.event_handler)(&itimer_clockevent); return IRQ_HANDLED; } -static void register_timer(void) +static void __init setup_itimer(void) { int err; - timer_init(); - err = request_irq(TIMER_IRQ, um_timer, IRQF_DISABLED, "timer", NULL); if (err != 0) printk(KERN_ERR "register_timer : request_irq failed - " "errno = %d\n", -err); - err = set_interval(); - if (err != 0) - printk(KERN_ERR "register_timer : set_interval failed - " - "errno = %d\n", -err); + itimer_clockevent.mult = div_sc(HZ, NSEC_PER_SEC, 32); + itimer_clockevent.max_delta_ns = + clockevent_delta2ns(60 * HZ, &itimer_clockevent); + itimer_clockevent.min_delta_ns = + clockevent_delta2ns(1, &itimer_clockevent); + clockevents_register_device(&itimer_clockevent); } extern void (*late_time_init)(void); -void time_init(void) +void __init time_init(void) { long long nsecs; + timer_init(); + nsecs = os_nsecs(); set_normalized_timespec(&wall_to_monotonic, -nsecs / BILLION, -nsecs % BILLION); set_normalized_timespec(&xtime, nsecs / BILLION, nsecs % BILLION); - late_time_init = register_timer; -} - -void timer_handler(int sig, struct uml_pt_regs *regs) -{ - if (current_thread->cpu == 0) - timer_irq(regs); - local_irq_disable(); - irq_enter(); - update_process_times(regs->is_user); - irq_exit(); - local_irq_enable(); + late_time_init = setup_itimer; } -- cgit v1.2.3