bitkeeper revision 1.530 (3f9d4b50eBCuXVk_ImRaxIb9MV1j3g)

time.c:
  new file
Many files:
  Major fixes to time in Xen and Xenolinux. DOM0 can now set the wallclock time, perhaps using ntpd, for all other domains.

1 files changed, 173 insertions, 397 deletions

diff --git a/xen/common/timer.c b/xen/common/timer.c
index bdcda32d89..c0e7d3a393 100644
--- a/xen/common/timer.c
+++ b/xen/common/timer.c
@@ -22,58 +22,15 @@
 #include <linux/timex.h>
 #include <linux/tqueue.h>
 #include <linux/delay.h>
-//#include <linux/smp_lock.h>
 #include <linux/interrupt.h>
-//#include <linux/kernel_stat.h>
 
 #include <xeno/event.h>
 
 #include <asm/uaccess.h>
 
-/*
- * Timekeeping variables
- */
-
-long tick = (1000000 + HZ/2) / HZ;	/* timer interrupt period */
-
-/* The current time */
 struct timeval xtime __attribute__ ((aligned (16)));
-
-/* Don't completely fail for HZ > 500.  */
-int tickadj = 500/HZ ? : 1;		/* microsecs */
-
-DECLARE_TASK_QUEUE(tq_timer);
-DECLARE_TASK_QUEUE(tq_immediate);
-
-/*
- * phase-lock loop variables
- */
-/* TIME_ERROR prevents overwriting the CMOS clock */
-int time_state = TIME_OK;		/* clock synchronization status	*/
-int time_status = STA_UNSYNC;		/* clock status bits		*/
-long time_offset;			/* time adjustment (us)		*/
-long time_constant = 2;			/* pll time constant		*/
-long time_tolerance = MAXFREQ;		/* frequency tolerance (ppm)	*/
-long time_precision = 1;		/* clock precision (us)		*/
-long time_maxerror = NTP_PHASE_LIMIT;	/* maximum error (us)		*/
-long time_esterror = NTP_PHASE_LIMIT;	/* estimated error (us)		*/
-long time_phase;			/* phase offset (scaled us)	*/
-long time_freq = ((1000000 + HZ/2) % HZ - HZ/2) << SHIFT_USEC;
-					/* frequency offset (scaled ppm)*/
-long time_adj;				/* tick adjust (scaled 1 / HZ)	*/
-long time_reftime;			/* time at last adjustment (s)	*/
-
-long time_adjust;
-long time_adjust_step;
-
-unsigned long event;
-
 unsigned long volatile jiffies;
 
-unsigned int * prof_buffer;
-unsigned long prof_len;
-unsigned long prof_shift;
-
 /*
  * Event timer code
  */
@@ -85,13 +42,13 @@ unsigned long prof_shift;
 #define TVR_MASK (TVR_SIZE - 1)
 
 struct timer_vec {
-	int index;
-	struct list_head vec[TVN_SIZE];
+    int index;
+    struct list_head vec[TVN_SIZE];
 };
 
 struct timer_vec_root {
-	int index;
-	struct list_head vec[TVR_SIZE];
+    int index;
+    struct list_head vec[TVR_SIZE];
 };
 
 static struct timer_vec tv5;
@@ -101,65 +58,65 @@ static struct timer_vec tv2;
 static struct timer_vec_root tv1;
 
 static struct timer_vec * const tvecs[] = {
-	(struct timer_vec *)&tv1, &tv2, &tv3, &tv4, &tv5
+    (struct timer_vec *)&tv1, &tv2, &tv3, &tv4, &tv5
 };
 
 #define NOOF_TVECS (sizeof(tvecs) / sizeof(tvecs[0]))
 
 void init_timervecs (void)
 {
-	int i;
-
-	for (i = 0; i < TVN_SIZE; i++) {
-		INIT_LIST_HEAD(tv5.vec + i);
-		INIT_LIST_HEAD(tv4.vec + i);
-		INIT_LIST_HEAD(tv3.vec + i);
-		INIT_LIST_HEAD(tv2.vec + i);
-	}
-	for (i = 0; i < TVR_SIZE; i++)
-		INIT_LIST_HEAD(tv1.vec + i);
+    int i;
+
+    for (i = 0; i < TVN_SIZE; i++) {
+        INIT_LIST_HEAD(tv5.vec + i);
+        INIT_LIST_HEAD(tv4.vec + i);
+        INIT_LIST_HEAD(tv3.vec + i);
+        INIT_LIST_HEAD(tv2.vec + i);
+    }
+    for (i = 0; i < TVR_SIZE; i++)
+        INIT_LIST_HEAD(tv1.vec + i);
 }
 
 static unsigned long timer_jiffies;
 
 static inline void internal_add_timer(struct timer_list *timer)
 {
-	/*
-	 * must be cli-ed when calling this
-	 */
-	unsigned long expires = timer->expires;
-	unsigned long idx = expires - timer_jiffies;
-	struct list_head * vec;
-
-	if (idx < TVR_SIZE) {
-		int i = expires & TVR_MASK;
-		vec = tv1.vec + i;
-	} else if (idx < 1 << (TVR_BITS + TVN_BITS)) {
-		int i = (expires >> TVR_BITS) & TVN_MASK;
-		vec = tv2.vec + i;
-	} else if (idx < 1 << (TVR_BITS + 2 * TVN_BITS)) {
-		int i = (expires >> (TVR_BITS + TVN_BITS)) & TVN_MASK;
-		vec =  tv3.vec + i;
-	} else if (idx < 1 << (TVR_BITS + 3 * TVN_BITS)) {
-		int i = (expires >> (TVR_BITS + 2 * TVN_BITS)) & TVN_MASK;
-		vec = tv4.vec + i;
-	} else if ((signed long) idx < 0) {
-		/* can happen if you add a timer with expires == jiffies,
+    /*
+     * must be cli-ed when calling this
+     */
+    unsigned long expires = timer->expires;
+    unsigned long idx = expires - timer_jiffies;
+    struct list_head * vec;
+
+    if (idx < TVR_SIZE) {
+        int i = expires & TVR_MASK;
+        vec = tv1.vec + i;
+    } else if (idx < 1 << (TVR_BITS + TVN_BITS)) {
+        int i = (expires >> TVR_BITS) & TVN_MASK;
+        vec = tv2.vec + i;
+    } else if (idx < 1 << (TVR_BITS + 2 * TVN_BITS)) {
+        int i = (expires >> (TVR_BITS + TVN_BITS)) & TVN_MASK;
+        vec =  tv3.vec + i;
+    } else if (idx < 1 << (TVR_BITS + 3 * TVN_BITS)) {
+        int i = (expires >> (TVR_BITS + 2 * TVN_BITS)) & TVN_MASK;
+        vec = tv4.vec + i;
+    } else if ((signed long) idx < 0) {
+        /* can happen if you add a timer with expires == jiffies,
 		 * or you set a timer to go off in the past
 		 */
-		vec = tv1.vec + tv1.index;
-	} else if (idx <= 0xffffffffUL) {
-		int i = (expires >> (TVR_BITS + 3 * TVN_BITS)) & TVN_MASK;
-		vec = tv5.vec + i;
-	} else {
-		/* Can only get here on architectures with 64-bit jiffies */
-		INIT_LIST_HEAD(&timer->list);
-		return;
-	}
-	/*
+        vec = tv1.vec + tv1.index;
+    } else if (idx <= 0xffffffffUL) {
+        int i = (expires >> (TVR_BITS + 3 * TVN_BITS)) & TVN_MASK;
+        vec = tv5.vec + i;
+    } else {
+        /* Can only get here on architectures with 64-bit jiffies */
+        INIT_LIST_HEAD(&timer->list);
+        return;
+    }
+    /*
 	 * Timers are FIFO!
 	 */
-	list_add(&timer->list, vec->prev);
+    list_add(&timer->list, vec->prev);
 }
 
 /* Initialize both explicitly - let's try to have them in the same cache line */
@@ -178,57 +135,57 @@ volatile struct timer_list * volatile running_timer;
 
 void add_timer(struct timer_list *timer)
 {
-	unsigned long flags;
-
-	spin_lock_irqsave(&timerlist_lock, flags);
-	if (timer_pending(timer))
-		goto bug;
-	internal_add_timer(timer);
-	spin_unlock_irqrestore(&timerlist_lock, flags);
-	return;
-bug:
-	spin_unlock_irqrestore(&timerlist_lock, flags);
-	printk("bug: kernel timer added twice at %p.\n",
-			__builtin_return_address(0));
+    unsigned long flags;
+
+    spin_lock_irqsave(&timerlist_lock, flags);
+    if (timer_pending(timer))
+        goto bug;
+    internal_add_timer(timer);
+    spin_unlock_irqrestore(&timerlist_lock, flags);
+    return;
+ bug:
+    spin_unlock_irqrestore(&timerlist_lock, flags);
+    printk("bug: kernel timer added twice at %p.\n",
+           __builtin_return_address(0));
 }
 
 static inline int detach_timer (struct timer_list *timer)
 {
-	if (!timer_pending(timer))
-		return 0;
-	list_del(&timer->list);
-	return 1;
+    if (!timer_pending(timer))
+        return 0;
+    list_del(&timer->list);
+    return 1;
 }
 
 int mod_timer(struct timer_list *timer, unsigned long expires)
 {
-	int ret;
-	unsigned long flags;
-
-	spin_lock_irqsave(&timerlist_lock, flags);
-	timer->expires = expires;
-	ret = detach_timer(timer);
-	internal_add_timer(timer);
-	spin_unlock_irqrestore(&timerlist_lock, flags);
-	return ret;
+    int ret;
+    unsigned long flags;
+
+    spin_lock_irqsave(&timerlist_lock, flags);
+    timer->expires = expires;
+    ret = detach_timer(timer);
+    internal_add_timer(timer);
+    spin_unlock_irqrestore(&timerlist_lock, flags);
+    return ret;
 }
 
 int del_timer(struct timer_list * timer)
 {
-	int ret;
-	unsigned long flags;
-
-	spin_lock_irqsave(&timerlist_lock, flags);
-	ret = detach_timer(timer);
-	timer->list.next = timer->list.prev = NULL;
-	spin_unlock_irqrestore(&timerlist_lock, flags);
-	return ret;
+    int ret;
+    unsigned long flags;
+
+    spin_lock_irqsave(&timerlist_lock, flags);
+    ret = detach_timer(timer);
+    timer->list.next = timer->list.prev = NULL;
+    spin_unlock_irqrestore(&timerlist_lock, flags);
+    return ret;
 }
 
 #ifdef CONFIG_SMP
 void sync_timers(void)
 {
-	spin_unlock_wait(&global_bh_lock);
+    spin_unlock_wait(&global_bh_lock);
 }
 
 /*
@@ -241,269 +198,104 @@ void sync_timers(void)
 
 int del_timer_sync(struct timer_list * timer)
 {
-	int ret = 0;
+    int ret = 0;
 
-	for (;;) {
-		unsigned long flags;
-		int running;
+    for (;;) {
+        unsigned long flags;
+        int running;
 
-		spin_lock_irqsave(&timerlist_lock, flags);
-		ret += detach_timer(timer);
-		timer->list.next = timer->list.prev = 0;
-		running = timer_is_running(timer);
-		spin_unlock_irqrestore(&timerlist_lock, flags);
+        spin_lock_irqsave(&timerlist_lock, flags);
+        ret += detach_timer(timer);
+        timer->list.next = timer->list.prev = 0;
+        running = timer_is_running(timer);
+        spin_unlock_irqrestore(&timerlist_lock, flags);
 
-		if (!running)
-			break;
+        if (!running)
+            break;
 
-		timer_synchronize(timer);
-	}
+        timer_synchronize(timer);
+    }
 
-	return ret;
+    return ret;
 }
 #endif
 
 
 static inline void cascade_timers(struct timer_vec *tv)
 {
-	/* cascade all the timers from tv up one level */
-	struct list_head *head, *curr, *next;
-
-	head = tv->vec + tv->index;
-	curr = head->next;
-	/*
-	 * We are removing _all_ timers from the list, so we don't  have to
-	 * detach them individually, just clear the list afterwards.
+    /* cascade all the timers from tv up one level */
+    struct list_head *head, *curr, *next;
+
+    head = tv->vec + tv->index;
+    curr = head->next;
+    /*
+     * We are removing _all_ timers from the list, so we don't  have to
+     * detach them individually, just clear the list afterwards.
 	 */
-	while (curr != head) {
-		struct timer_list *tmp;
-
-		tmp = list_entry(curr, struct timer_list, list);
-		next = curr->next;
-		list_del(curr); /* not needed */
-		internal_add_timer(tmp);
-		curr = next;
-	}
-	INIT_LIST_HEAD(head);
-	tv->index = (tv->index + 1) & TVN_MASK;
+    while (curr != head) {
+        struct timer_list *tmp;
+
+        tmp = list_entry(curr, struct timer_list, list);
+        next = curr->next;
+        list_del(curr); /* not needed */
+        internal_add_timer(tmp);
+        curr = next;
+    }
+    INIT_LIST_HEAD(head);
+    tv->index = (tv->index + 1) & TVN_MASK;
 }
 
 static inline void run_timer_list(void)
 {
-	spin_lock_irq(&timerlist_lock);
-	while ((long)(jiffies - timer_jiffies) >= 0) {
-		struct list_head *head, *curr;
-		if (!tv1.index) {
-			int n = 1;
-			do {
-				cascade_timers(tvecs[n]);
-			} while (tvecs[n]->index == 1 && ++n < NOOF_TVECS);
-		}
-repeat:
-		head = tv1.vec + tv1.index;
-		curr = head->next;
-		if (curr != head) {
-			struct timer_list *timer;
-			void (*fn)(unsigned long);
-			unsigned long data;
-
-			timer = list_entry(curr, struct timer_list, list);
- 			fn = timer->function;
- 			data= timer->data;
-
-			detach_timer(timer);
-			timer->list.next = timer->list.prev = NULL;
-			timer_enter(timer);
-			spin_unlock_irq(&timerlist_lock);
-			fn(data);
-			spin_lock_irq(&timerlist_lock);
-			timer_exit();
-			goto repeat;
-		}
-		++timer_jiffies; 
-		tv1.index = (tv1.index + 1) & TVR_MASK;
-	}
-	spin_unlock_irq(&timerlist_lock);
-}
-
-spinlock_t tqueue_lock = SPIN_LOCK_UNLOCKED;
-
-void tqueue_bh(void)
-{
-	run_task_queue(&tq_timer);
-}
-
-void immediate_bh(void)
-{
-	run_task_queue(&tq_immediate);
-}
-
-/*
- * this routine handles the overflow of the microsecond field
- *
- * The tricky bits of code to handle the accurate clock support
- * were provided by Dave Mills (Mills@UDEL.EDU) of NTP fame.
- * They were originally developed for SUN and DEC kernels.
- * All the kudos should go to Dave for this stuff.
- *
- */
-static void second_overflow(void)
-{
-    long ltemp;
-
-    /* Bump the maxerror field */
-    time_maxerror += time_tolerance >> SHIFT_USEC;
-    if ( time_maxerror > NTP_PHASE_LIMIT ) {
-	time_maxerror = NTP_PHASE_LIMIT;
-	time_status |= STA_UNSYNC;
+    spin_lock_irq(&timerlist_lock);
+    while ((long)(jiffies - timer_jiffies) >= 0) {
+        struct list_head *head, *curr;
+        if (!tv1.index) {
+            int n = 1;
+            do {
+                cascade_timers(tvecs[n]);
+            } while (tvecs[n]->index == 1 && ++n < NOOF_TVECS);
+        }
+    repeat:
+        head = tv1.vec + tv1.index;
+        curr = head->next;
+        if (curr != head) {
+            struct timer_list *timer;
+            void (*fn)(unsigned long);
+            unsigned long data;
+
+            timer = list_entry(curr, struct timer_list, list);
+            fn = timer->function;
+            data= timer->data;
+
+            detach_timer(timer);
+            timer->list.next = timer->list.prev = NULL;
+            timer_enter(timer);
+            spin_unlock_irq(&timerlist_lock);
+            fn(data);
+            spin_lock_irq(&timerlist_lock);
+            timer_exit();
+            goto repeat;
+        }
+        ++timer_jiffies; 
+        tv1.index = (tv1.index + 1) & TVR_MASK;
     }
-
-    /*
-     * Leap second processing. If in leap-insert state at
-     * the end of the day, the system clock is set back one
-     * second; if in leap-delete state, the system clock is
-     * set ahead one second. The microtime() routine or
-     * external clock driver will insure that reported time
-     * is always monotonic. The ugly divides should be
-     * replaced.
-     */
-    switch (time_state) {
-
-    case TIME_OK:
-	if (time_status & STA_INS)
-	    time_state = TIME_INS;
-	else if (time_status & STA_DEL)
-	    time_state = TIME_DEL;
-	break;
-
-    case TIME_INS:
-	if (xtime.tv_sec % 86400 == 0) {
-	    xtime.tv_sec--;
-	    time_state = TIME_OOP;
-	    printk(KERN_NOTICE "Clock: inserting leap second 23:59:60 UTC\n");
-	}
-	break;
-
-    case TIME_DEL:
-	if ((xtime.tv_sec + 1) % 86400 == 0) {
-	    xtime.tv_sec++;
-	    time_state = TIME_WAIT;
-	    printk(KERN_NOTICE "Clock: deleting leap second 23:59:59 UTC\n");
-	}
-	break;
-
-    case TIME_OOP:
-	time_state = TIME_WAIT;
-	break;
-
-    case TIME_WAIT:
-	if (!(time_status & (STA_INS | STA_DEL)))
-	    time_state = TIME_OK;
-    }
-
-    /*
-     * Compute the phase adjustment for the next second. In
-     * PLL mode, the offset is reduced by a fixed factor
-     * times the time constant. In FLL mode the offset is
-     * used directly. In either mode, the maximum phase
-     * adjustment for each second is clamped so as to spread
-     * the adjustment over not more than the number of
-     * seconds between updates.
-     */
-    if (time_offset < 0) {
-	ltemp = -time_offset;
-	if (!(time_status & STA_FLL))
-	    ltemp >>= SHIFT_KG + time_constant;
-	if (ltemp > (MAXPHASE / MINSEC) << SHIFT_UPDATE)
-	    ltemp = (MAXPHASE / MINSEC) << SHIFT_UPDATE;
-	time_offset += ltemp;
-	time_adj = -ltemp << (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE);
-    } else {
-	ltemp = time_offset;
-	if (!(time_status & STA_FLL))
-	    ltemp >>= SHIFT_KG + time_constant;
-	if (ltemp > (MAXPHASE / MINSEC) << SHIFT_UPDATE)
-	    ltemp = (MAXPHASE / MINSEC) << SHIFT_UPDATE;
-	time_offset -= ltemp;
-	time_adj = ltemp << (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE);
-    }
-
-    if (ltemp < 0)
-	time_adj -= -ltemp >>
-	    (SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE);
-    else
-	time_adj += ltemp >>
-	    (SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE);
-
-#if HZ == 100
-    /* Compensate for (HZ==100) != (1 << SHIFT_HZ).
-     * Add 25% and 3.125% to get 128.125; => only 0.125% error (p. 14)
-     */
-    if (time_adj < 0)
-	time_adj -= (-time_adj >> 2) + (-time_adj >> 5);
-    else
-	time_adj += (time_adj >> 2) + (time_adj >> 5);
-#endif
+    spin_unlock_irq(&timerlist_lock);
 }
 
-/* in the NTP reference this is called "hardclock()" */
-static void update_wall_time_one_tick(void)
-{
-	if ( (time_adjust_step = time_adjust) != 0 ) {
-	    /* We are doing an adjtime thing. 
-	     *
-	     * Prepare time_adjust_step to be within bounds.
-	     * Note that a positive time_adjust means we want the clock
-	     * to run faster.
-	     *
-	     * Limit the amount of the step to be in the range
-	     * -tickadj .. +tickadj
-	     */
-	     if (time_adjust > tickadj)
-		time_adjust_step = tickadj;
-	     else if (time_adjust < -tickadj)
-		time_adjust_step = -tickadj;
-	     
-	    /* Reduce by this step the amount of time left  */
-	    time_adjust -= time_adjust_step;
-	}
-	xtime.tv_usec += tick + time_adjust_step;
-	/*
-	 * Advance the phase, once it gets to one microsecond, then
-	 * advance the tick more.
-	 */
-	time_phase += time_adj;
-	if (time_phase <= -FINEUSEC) {
-		long ltemp = -time_phase >> SHIFT_SCALE;
-		time_phase += ltemp << SHIFT_SCALE;
-		xtime.tv_usec -= ltemp;
-	}
-	else if (time_phase >= FINEUSEC) {
-		long ltemp = time_phase >> SHIFT_SCALE;
-		time_phase -= ltemp << SHIFT_SCALE;
-		xtime.tv_usec += ltemp;
-	}
-}
+spinlock_t tqueue_lock = SPIN_LOCK_UNLOCKED;
 
-/*
- * Using a loop looks inefficient, but "ticks" is
- * usually just one (we shouldn't be losing ticks,
- * we're doing this this way mainly for interrupt
- * latency reasons, not because we think we'll
- * have lots of lost timer ticks
- */
 static void update_wall_time(unsigned long ticks)
 {
-	do {
-		ticks--;
-		update_wall_time_one_tick();
-	} while (ticks);
-
-	if (xtime.tv_usec >= 1000000) {
-	    xtime.tv_usec -= 1000000;
-	    xtime.tv_sec++;
-	    second_overflow();
-	}
+    do {
+        ticks--;
+        xtime.tv_usec += 1000000/HZ;
+    } while (ticks);
+
+    if (xtime.tv_usec >= 1000000) {
+        xtime.tv_usec -= 1000000;
+        xtime.tv_sec++;
+    }
 }
 
 /* jiffies at the most recent update of wall time */
@@ -516,47 +308,31 @@ rwlock_t xtime_lock = RW_LOCK_UNLOCKED;
 
 static inline void update_times(void)
 {
-	unsigned long ticks;
+    unsigned long ticks;
 
-	/*
-	 * update_times() is run from the raw timer_bh handler so we
-	 * just know that the irqs are locally enabled and so we don't
-	 * need to save/restore the flags of the local CPU here. -arca
-	 */
-	write_lock_irq(&xtime_lock);
-
-	ticks = jiffies - wall_jiffies;
-	if (ticks) {
-		wall_jiffies += ticks;
-		update_wall_time(ticks);
-	}
-	write_unlock_irq(&xtime_lock);
+    /*
+     * update_times() is run from the raw timer_bh handler so we
+     * just know that the irqs are locally enabled and so we don't
+     * need to save/restore the flags of the local CPU here. -arca
+     */
+    write_lock_irq(&xtime_lock);
+
+    ticks = jiffies - wall_jiffies;
+    if (ticks) {
+        wall_jiffies += ticks;
+        update_wall_time(ticks);
+    }
+    write_unlock_irq(&xtime_lock);
 }
 
 void timer_bh(void)
 {
-	update_times();
-	run_timer_list();
+    update_times();
+    run_timer_list();
 }
 
-#include <xeno/errno.h>
-#include <xeno/sched.h>
-#include <xeno/lib.h>
-#include <xeno/config.h>
-#include <xeno/smp.h>
-#include <xeno/irq.h>
-#include <asm/msr.h>
-
 void do_timer(struct pt_regs *regs)
 {
     (*(unsigned long *)&jiffies)++;
-
     mark_bh(TIMER_BH);
-    if (TQ_ACTIVE(tq_timer))
-        mark_bh(TQUEUE_BH);
-}
-
-void get_fast_time(struct timeval * tm)
-{
-        *tm=xtime;
 }