x86_64: enable clockevents and dynticks

@@ -82,7 +82,7 @@
 #include <asm/uaccess.h>
 #include <asm/system.h>
 
-#if defined(__i386__)
+#if defined(__i386__) || defined(__x86_64__)
 #include <asm/hpet.h>
 #endif
 

@@ -9,7 +9,6 @@
 #include <asm/8253pit.h>
 #include <asm/msr.h>
 #include <asm/vsyscall.h>
-#include <asm/hpet.h>
 #include <asm/system.h>
 #include <asm/processor.h>
 #include <asm/tsc.h>

@@ -84,6 +84,7 @@ extern int APIC_init_uniprocessor (void)
 extern void disable_APIC_timer(void);
 extern void enable_APIC_timer(void);
 extern void clustered_apic_check(void);
+extern int apic_is_clustered_box(void);
 
 extern void setup_APIC_extened_lvt(unsigned char lvt_off, unsigned char vector,
 				   unsigned char msg_type, unsigned char mask);

@@ -55,7 +55,6 @@
 
 extern int is_hpet_enabled(void);
 extern int hpet_rtc_timer_init(void);
-extern int apic_is_clustered_box(void);
 extern int hpet_arch_init(void);
 extern int hpet_timer_stop_set_go(unsigned long tick);
 extern int hpet_reenable(void);

@@ -81,8 +81,9 @@ EXPORT_SYMBOL(profile_pc);
  * sheet for details.
  */
 
-static void set_rtc_mmss(unsigned long nowtime)
+static int set_rtc_mmss(unsigned long nowtime)
 {
+	int retval = 0;
 	int real_seconds, real_minutes, cmos_minutes;
 	unsigned char control, freq_select;
 

@@ -122,6 +123,7 @@ static void set_rtc_mmss(unsigned long n
 	if (abs(real_minutes - cmos_minutes) >= 30) {
 		printk(KERN_WARNING "time.c: can't update CMOS clock "
 		       "from %d to %d\n", cmos_minutes, real_minutes);
+		retval = -1;
 	} else {
 		BIN_TO_BCD(real_seconds);
 		BIN_TO_BCD(real_minutes);

@@ -141,12 +143,60 @@ static void set_rtc_mmss(unsigned long n
 	CMOS_WRITE(freq_select, RTC_FREQ_SELECT);
 
 	spin_unlock(&rtc_lock);
+
+	return retval;
+}
+
+static void sync_cmos_clock(unsigned long dummy);
+
+static DEFINE_TIMER(sync_cmos_timer, sync_cmos_clock, 0, 0);
+
+static void sync_cmos_clock(unsigned long dummy)
+{
+	struct timespec now, next;
+	int fail = 1;
+
+	/*
+	 * If we have an externally synchronized Linux clock, then update
+	 * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
+	 * called as close as possible to 500 ms before the new second starts.
+	 * This code is run on a timer.  If the clock is set, that timer
+	 * may not expire at the correct time.  Thus, we adjust...
+	 */
+	if (!ntp_synced())
+		/*
+		 * Not synced, exit, do not restart a timer (if one is
+		 * running, let it run out).
+		 */
+		return;
+
+	getnstimeofday(&now);
+	if (abs(xtime.tv_nsec - 500000000) <= tick_nsec / 2)
+		fail = set_rtc_mmss(now.tv_sec);
+
+	next.tv_nsec = 500000000 - now.tv_nsec;
+	if (next.tv_nsec <= 0)
+		next.tv_nsec += NSEC_PER_SEC;
+
+	if (!fail)
+		next.tv_sec = 659;
+	else
+		next.tv_sec = 0;
+
+	if (next.tv_nsec >= NSEC_PER_SEC) {
+		next.tv_sec++;
+		next.tv_nsec -= NSEC_PER_SEC;
+	}
+	mod_timer(&sync_cmos_timer, jiffies + timespec_to_jiffies(&next));
 }
 
+void notify_arch_cmos_timer(void)
+{
+	mod_timer(&sync_cmos_timer, jiffies + 1);
+}
 
 void main_timer_handler(void)
 {
-	static unsigned long rtc_update = 0;
 /*
  * Here we are in the timer irq handler. We have irqs locally disabled (so we
  * don't need spin_lock_irqsave()) but we don't know if the timer_bh is running

@@ -174,20 +224,6 @@ void main_timer_handler(void)
 	if (!using_apic_timer)
 		smp_local_timer_interrupt();
 
-/*
- * If we have an externally synchronized Linux clock, then update CMOS clock
- * accordingly every ~11 minutes. set_rtc_mmss() will be called in the jiffy
- * closest to exactly 500 ms before the next second. If the update fails, we
- * don't care, as it'll be updated on the next turn, and the problem (time way
- * off) isn't likely to go away much sooner anyway.
- */
-
-	if (ntp_synced() && xtime.tv_sec > rtc_update &&
-		abs(xtime.tv_nsec - 500000000) <= tick_nsec / 2) {
-		set_rtc_mmss(xtime.tv_sec);
-		rtc_update = xtime.tv_sec + 660;
-	}
- 
 	write_sequnlock(&xtime_lock);
 }
 

@@ -42,10 +42,19 @@
 #include <linux/cpufreq.h>
 #include <linux/hpet.h>
 #include <asm/apic.h>
+#include <linux/clockchips.h>
+#include <asm/delay.h>
 #include <asm/hpet.h>
 
 extern void i8254_timer_resume(void);
 extern int using_apic_timer;
+extern struct clock_event_device pit_clockevent;
+/*
+ * HPET replaces the PIT, when enabled. So we need to know, which of
+ * the two timers is used
+ */
+struct clock_event_device *global_clock_event;
+
 
 static char *timename = NULL;
 

@@ -197,34 +206,7 @@ void notify_arch_cmos_timer(void)
 
 void main_timer_handler(void)
 {
-/*
- * Here we are in the timer irq handler. We have irqs locally disabled (so we
- * don't need spin_lock_irqsave()) but we don't know if the timer_bh is running
- * on the other CPU, so we need a lock. We also need to lock the vsyscall
- * variables, because both do_timer() and us change them -arca+vojtech
- */
-
-	write_seqlock(&xtime_lock);
-
-/*
- * Do the timer stuff.
- */
-
-	do_timer(1);
-#ifndef CONFIG_SMP
-	update_process_times(user_mode(get_irq_regs()));
-#endif
-
-/*
- * In the SMP case we use the local APIC timer interrupt to do the profiling,
- * except when we simulate SMP mode on a uniprocessor system, in that case we
- * have to call the local interrupt handler.
- */
-
-	if (!using_apic_timer)
-		smp_local_timer_interrupt();
-
-	write_sequnlock(&xtime_lock);
+	global_clock_event->event_handler(global_clock_event);
 }
 
 static irqreturn_t timer_interrupt(int irq, void *dev_id)

@@ -237,7 +219,7 @@ static irqreturn_t timer_interrupt(int i
 	return IRQ_HANDLED;
 }
 
-static unsigned long get_cmos_time(void)
+unsigned long read_persistent_clock(void)
 {
 	unsigned int year, mon, day, hour, min, sec;
 	unsigned long flags;

@@ -321,38 +303,80 @@ static unsigned int __init pit_calibrate
 #define PIT_MODE 0x43
 #define PIT_CH0  0x40
 
-static void __init __pit_init(int val, u8 mode)
+static void init_pit_timer(enum clock_event_mode mode,
+			   struct clock_event_device *evt)
 {
 	unsigned long flags;
 
 	spin_lock_irqsave(&i8253_lock, flags);
-	outb_p(mode, PIT_MODE);
-	outb_p(val & 0xff, PIT_CH0);	/* LSB */
-	outb_p(val >> 8, PIT_CH0);	/* MSB */
+
+	switch(mode) {
+	case CLOCK_EVT_MODE_PERIODIC:
+		/* binary, mode 2, LSB/MSB, ch 0 */
+		outb_p(0x34, PIT_MODE);
+		udelay(10);
+		outb_p(LATCH & 0xff , PIT_CH0); /* LSB */
+		outb(LATCH >> 8 , PIT_CH0);     /* MSB */
+		break;
+
+	case CLOCK_EVT_MODE_ONESHOT:
+		/* One shot setup */
+		outb_p(0x38, PIT_MODE);
+		udelay(10);
+		break;
+	case CLOCK_EVT_MODE_SHUTDOWN:
+	case CLOCK_EVT_MODE_UNUSED:
+		outb_p(0x30, PIT_MODE);
+		outb_p(0, PIT_CH0);	/* LSB */
+		outb_p(0, PIT_CH0);	/* MSB */
+		break;
+	}
 	spin_unlock_irqrestore(&i8253_lock, flags);
 }
 
-void __init pit_init(void)
+static int pit_next_event(unsigned long delta, struct clock_event_device *evt)
 {
-	__pit_init(LATCH, 0x34); /* binary, mode 2, LSB/MSB, ch 0 */
+	unsigned long flags;
+
+	spin_lock_irqsave(&i8253_lock, flags);
+	outb_p(delta & 0xff , PIT_CH0); /* LSB */
+	outb(delta >> 8 , PIT_CH0);     /* MSB */
+	spin_unlock_irqrestore(&i8253_lock, flags);
+
+	return 0;
 }
 
-void __init pit_stop_interrupt(void)
+struct clock_event_device pit_clockevent = {
+	.name		= "pit",
+	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+	.set_mode       = init_pit_timer,
+	.set_next_event = pit_next_event,
+	.shift		= 32,
+	.irq		= 0,
+};
+
+void __init stop_timer_interrupt(void)
 {
-	__pit_init(0, 0x30); /* mode 0 */
+	/* XXX this is bogus */
+	clockevents_set_mode(global_clock_event, CLOCK_EVT_MODE_SHUTDOWN);
+	printk(KERN_INFO "timer: %s interrupt stopped.\n", global_clock_event->name);
 }
 
-void __init stop_timer_interrupt(void)
+static void __init setup_pit_timer(void)
 {
-	char *name;
-	if (hpet_address) {
-		name = "HPET";
-		hpet_timer_stop_set_go(0);
-	} else {
-		name = "PIT";
-		pit_stop_interrupt();
-	}
-	printk(KERN_INFO "timer: %s interrupt stopped.\n", name);
+	/*
+	 * Start pit with the boot cpu mask and make it global after the
+	 * IO_APIC has been initialized.
+	 */
+	pit_clockevent.cpumask = cpumask_of_cpu(0);
+
+	pit_clockevent.mult = div_sc(CLOCK_TICK_RATE, NSEC_PER_SEC, 32);
+	pit_clockevent.max_delta_ns =
+		clockevent_delta2ns(0x7FFF, &pit_clockevent);
+	pit_clockevent.min_delta_ns =
+		clockevent_delta2ns(0xF, &pit_clockevent);
+	clockevents_register_device(&pit_clockevent);
+	global_clock_event = &pit_clockevent;
 }
 
 static struct irqaction irq0 = {

@@ -361,16 +385,8 @@ static struct irqaction irq0 = {
 
 void __init time_init(void)
 {
-	if (nohpet)
-		hpet_address = 0;
-	xtime.tv_sec = get_cmos_time();
-	xtime.tv_nsec = 0;
-
-	set_normalized_timespec(&wall_to_monotonic,
-	                        -xtime.tv_sec, -xtime.tv_nsec);
-
-	if (hpet_arch_init())
-		hpet_address = 0;
+	if (!hpet_arch_init())
+		setup_pit_timer();
 
 	if (hpet_use_timer) {
 		/* set tick_nsec to use the proper rate for HPET */

@@ -378,7 +394,6 @@ void __init time_init(void)
 		cpu_khz = hpet_calibrate_tsc();
 		timename = "HPET";
 	} else {
-		pit_init();
 		cpu_khz = pit_calibrate_tsc();
 		timename = "PIT";
 	}

@@ -398,76 +413,3 @@ void __init time_init(void)
 
 	setup_irq(0, &irq0);
 }
-
-
-static long clock_cmos_diff;
-static unsigned long sleep_start;
-
-/*
- * sysfs support for the timer.
- */
-
-static int timer_suspend(struct sys_device *dev, pm_message_t state)
-{
-	/*
-	 * Estimate time zone so that set_time can update the clock
-	 */
-	long cmos_time =  get_cmos_time();
-
-	clock_cmos_diff = -cmos_time;
-	clock_cmos_diff += get_seconds();
-	sleep_start = cmos_time;
-	return 0;
-}
-
-static int timer_resume(struct sys_device *dev)
-{
-	unsigned long flags;
-	unsigned long sec;
-	unsigned long ctime = get_cmos_time();
-	long sleep_length = (ctime - sleep_start) * HZ;
-
-	if (sleep_length < 0) {
-		printk(KERN_WARNING "Time skew detected in timer resume!\n");
-		/* The time after the resume must not be earlier than the time
-		 * before the suspend or some nasty things will happen
-		 */
-		sleep_length = 0;
-		ctime = sleep_start;
-	}
-	if (hpet_address)
-		hpet_reenable();
-	else
-		i8254_timer_resume();
-
-	sec = ctime + clock_cmos_diff;
-	write_seqlock_irqsave(&xtime_lock,flags);
-	xtime.tv_sec = sec;
-	xtime.tv_nsec = 0;
-	jiffies += sleep_length;
-	write_sequnlock_irqrestore(&xtime_lock,flags);
-	touch_softlockup_watchdog();
-	return 0;
-}
-
-static struct sysdev_class timer_sysclass = {
-	.resume = timer_resume,
-	.suspend = timer_suspend,
-	set_kset_name("timer"),
-};
-
-/* XXX this sysfs stuff should probably go elsewhere later -john */
-static struct sys_device device_timer = {
-	.id	= 0,
-	.cls	= &timer_sysclass,
-};
-
-static int time_init_device(void)
-{
-	int error = sysdev_class_register(&timer_sysclass);
-	if (!error)
-		error = sysdev_register(&device_timer);
-	return error;
-}
-
-device_initcall(time_init_device);

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229 lines not on this page · raw message

@@ -56,8 +56,6 @@
 extern int is_hpet_enabled(void);
 extern int hpet_rtc_timer_init(void);
 extern int hpet_arch_init(void);
-extern int hpet_timer_stop_set_go(unsigned long tick);
-extern int hpet_reenable(void);
 extern unsigned int hpet_calibrate_tsc(void);
 
 extern int hpet_use_timer;

@@ -36,6 +36,7 @@
 #include <linux/random.h>
 #include <linux/notifier.h>
 #include <linux/kprobes.h>
+#include <linux/tick.h>
 
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>

@@ -201,6 +202,7 @@ void cpu_idle (void)
 	current_thread_info()->status |= TS_POLLING;
 	/* endless idle loop with no priority at all */
 	while (1) {
+		tick_nohz_stop_sched_tick();
 		while (!need_resched()) {
 			void (*idle)(void);
 

@@ -227,6 +229,7 @@ void cpu_idle (void)
 			__exit_idle();
 		}
 
+		tick_nohz_restart_sched_tick();
 		preempt_enable_no_resched();
 		schedule();
 		preempt_disable();