[PATCH] simplify update_times (avoid jiffies/jiffies_64 aliasing problem)

Pass ticks to do_timer() and update_times(), and adjust x86_64 and s390
timer interrupt handler with this change.

Currently update_times() calculates ticks by "jiffies - wall_jiffies", but
callers of do_timer() should know how many ticks to update.  Passing ticks
get rid of this redundant calculation.  Also there are another redundancy
pointed out by Martin Schwidefsky.

This cleanup make a barrier added by
5aee405c662ca644980c184774277fc6d0769a84 needless.  So this patch removes
it.

As a bonus, this cleanup make wall_jiffies can be removed easily, since now
wall_jiffies is always synced with jiffies.  (This patch does not really
remove wall_jiffies.  It would be another cleanup patch)

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Acked-by: Russell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
Cc: Mikael Starvik <starvik@axis.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Hirokazu Takata <takata.hirokazu@renesas.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Richard Curnow <rc@rc0.org.uk>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
Cc: Chris Zankel <chris@zankel.net>
Acked-by: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

31 files changed, 40 insertions, 41 deletions

diff --git a/arch/alpha/kernel/time.c b/arch/alpha/kernel/time.c
index b191cc7..7c1e444 100644
--- a/arch/alpha/kernel/time.c
+++ b/arch/alpha/kernel/time.c
@@ -132,7 +132,7 @@ irqreturn_t timer_interrupt(int irq, void *dev, struct pt_regs * regs)
 	nticks = delta >> FIX_SHIFT;
 
 	while (nticks > 0) {
-		do_timer(regs);
+		do_timer(1);
 #ifndef CONFIG_SMP
 		update_process_times(user_mode(regs));
 #endif
diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c
index d4dceb5..f7d5165 100644
--- a/arch/arm/kernel/time.c
+++ b/arch/arm/kernel/time.c
@@ -337,7 +337,7 @@ void timer_tick(struct pt_regs *regs)
 	profile_tick(CPU_PROFILING, regs);
 	do_leds();
 	do_set_rtc();
-	do_timer(regs);
+	do_timer(1);
 #ifndef CONFIG_SMP
 	update_process_times(user_mode(regs));
 #endif
diff --git a/arch/arm26/kernel/time.c b/arch/arm26/kernel/time.c
index db63d75..80adbd0 100644
--- a/arch/arm26/kernel/time.c
+++ b/arch/arm26/kernel/time.c
@@ -194,7 +194,7 @@ EXPORT_SYMBOL(do_settimeofday);
 
 static irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 {
-        do_timer(regs);
+        do_timer(1);
 #ifndef CONFIG_SMP
 	update_process_times(user_mode(regs));
 #endif
diff --git a/arch/avr32/kernel/time.c b/arch/avr32/kernel/time.c
index b0e6b58..3e56b9f 100644
--- a/arch/avr32/kernel/time.c
+++ b/arch/avr32/kernel/time.c
@@ -148,7 +148,7 @@ timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 	 * Call the generic timer interrupt handler
 	 */
 	write_seqlock(&xtime_lock);
-	do_timer(regs);
+	do_timer(1);
 	write_sequnlock(&xtime_lock);
 
 	/*
diff --git a/arch/cris/arch-v10/kernel/time.c b/arch/cris/arch-v10/kernel/time.c
index 9c22b76..ebacf14 100644
--- a/arch/cris/arch-v10/kernel/time.c
+++ b/arch/cris/arch-v10/kernel/time.c
@@ -227,7 +227,7 @@ timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 	
 	/* call the real timer interrupt handler */
 
-	do_timer(regs);
+	do_timer(1);
 	
         cris_do_profile(regs); /* Save profiling information */
 
diff --git a/arch/cris/arch-v32/kernel/time.c b/arch/cris/arch-v32/kernel/time.c
index 50f3f93..be0a016 100644
--- a/arch/cris/arch-v32/kernel/time.c
+++ b/arch/cris/arch-v32/kernel/time.c
@@ -219,7 +219,7 @@ timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 		return IRQ_HANDLED;
 
 	/* call the real timer interrupt handler */
-	do_timer(regs);
+	do_timer(1);
 
 	/*
 	 * If we have an externally synchronized Linux clock, then update
diff --git a/arch/frv/kernel/time.c b/arch/frv/kernel/time.c
index 3d0284b..7e55884 100644
--- a/arch/frv/kernel/time.c
+++ b/arch/frv/kernel/time.c
@@ -70,7 +70,7 @@ static irqreturn_t timer_interrupt(int irq, void *dummy, struct pt_regs * regs)
 	 */
 	write_seqlock(&xtime_lock);
 
-	do_timer(regs);
+	do_timer(1);
 	update_process_times(user_mode(regs));
 	profile_tick(CPU_PROFILING, regs);
 
diff --git a/arch/h8300/kernel/time.c b/arch/h8300/kernel/time.c
index 688a510..e569d17 100644
--- a/arch/h8300/kernel/time.c
+++ b/arch/h8300/kernel/time.c
@@ -41,7 +41,7 @@ static void timer_interrupt(int irq, void *dummy, struct pt_regs * regs)
 	/* may need to kick the hardware timer */
 	platform_timer_eoi();
 
-	do_timer(regs);
+	do_timer(1);
 #ifndef CONFIG_SMP
 	update_process_times(user_mode(regs));
 #endif
diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c
index 6928ef0..16262687 100644
--- a/arch/ia64/kernel/time.c
+++ b/arch/ia64/kernel/time.c
@@ -78,7 +78,7 @@ timer_interrupt (int irq, void *dev_id, struct pt_regs *regs)
 			 * xtime_lock.
 			 */
 			write_seqlock(&xtime_lock);
-			do_timer(regs);
+			do_timer(1);
 			local_cpu_data->itm_next = new_itm;
 			write_sequnlock(&xtime_lock);
 		} else
diff --git a/arch/m32r/kernel/time.c b/arch/m32r/kernel/time.c
index ded0be0..7a89689 100644
--- a/arch/m32r/kernel/time.c
+++ b/arch/m32r/kernel/time.c
@@ -202,7 +202,7 @@ irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 #ifndef CONFIG_SMP
 	profile_tick(CPU_PROFILING, regs);
 #endif
-	do_timer(regs);
+	do_timer(1);
 
 #ifndef CONFIG_SMP
 	update_process_times(user_mode(regs));
diff --git a/arch/m68k/kernel/time.c b/arch/m68k/kernel/time.c
index 98e4b1a..1072e49 100644
--- a/arch/m68k/kernel/time.c
+++ b/arch/m68k/kernel/time.c
@@ -40,7 +40,7 @@ static inline int set_rtc_mmss(unsigned long nowtime)
  */
 static irqreturn_t timer_interrupt(int irq, void *dummy, struct pt_regs * regs)
 {
-	do_timer(regs);
+	do_timer(1);
 #ifndef CONFIG_SMP
 	update_process_times(user_mode(regs));
 #endif
diff --git a/arch/m68k/sun3/sun3ints.c b/arch/m68k/sun3/sun3ints.c
index f18b9d3..dc4ea7e 100644
--- a/arch/m68k/sun3/sun3ints.c
+++ b/arch/m68k/sun3/sun3ints.c
@@ -65,7 +65,7 @@ static irqreturn_t sun3_int5(int irq, void *dev_id, struct pt_regs *fp)
 #ifdef CONFIG_SUN3
 	intersil_clear();
 #endif
-        do_timer(fp);
+        do_timer(1);
 #ifndef CONFIG_SMP
 	update_process_times(user_mode(fp));
 #endif
diff --git a/arch/m68knommu/kernel/time.c b/arch/m68knommu/kernel/time.c
index 1db9872..db1e1ce 100644
--- a/arch/m68knommu/kernel/time.c
+++ b/arch/m68knommu/kernel/time.c
@@ -51,7 +51,7 @@ static irqreturn_t timer_interrupt(int irq, void *dummy, struct pt_regs * regs)
 
 	write_seqlock(&xtime_lock);
 
-	do_timer(regs);
+	do_timer(1);
 #ifndef CONFIG_SMP
 	update_process_times(user_mode(regs));
 #endif
diff --git a/arch/mips/au1000/common/time.c b/arch/mips/au1000/common/time.c
index 7fbea1b..0a067f3 100644
--- a/arch/mips/au1000/common/time.c
+++ b/arch/mips/au1000/common/time.c
@@ -96,7 +96,7 @@ void mips_timer_interrupt(struct pt_regs *regs)
 		timerlo = count;
 
 		kstat_this_cpu.irqs[irq]++;
-		do_timer(regs);
+		do_timer(1);
 #ifndef CONFIG_SMP
 		update_process_times(user_mode(regs));
 #endif
@@ -137,7 +137,7 @@ irqreturn_t counter0_irq(int irq, void *dev_id, struct pt_regs *regs)
 	}
 
 	while (time_elapsed > 0) {
-		do_timer(regs);
+		do_timer(1);
 #ifndef CONFIG_SMP
 		update_process_times(user_mode(regs));
 #endif
@@ -156,7 +156,7 @@ irqreturn_t counter0_irq(int irq, void *dev_id, struct pt_regs *regs)
 
 	if (jiffie_drift >= 999) {
 		jiffie_drift -= 999;
-		do_timer(regs); /* increment jiffies by one */
+		do_timer(1); /* increment jiffies by one */
 #ifndef CONFIG_SMP
 		update_process_times(user_mode(regs));
 #endif
diff --git a/arch/mips/gt64120/common/time.c b/arch/mips/gt64120/common/time.c
index d837b26..7feca49 100644
--- a/arch/mips/gt64120/common/time.c
+++ b/arch/mips/gt64120/common/time.c
@@ -34,7 +34,7 @@ static void gt64120_irq(int irq, void *dev_id, struct pt_regs *regs)
 	if (irq_src & 0x00000800) {	/* Check for timer interrupt */
 		handled = 1;
 		irq_src &= ~0x00000800;
-		do_timer(regs);
+		do_timer(1);
 #ifndef CONFIG_SMP
 		update_process_times(user_mode(regs));
 #endif
diff --git a/arch/mips/kernel/time.c b/arch/mips/kernel/time.c
index 170cb67..6ab8d97 100644
--- a/arch/mips/kernel/time.c
+++ b/arch/mips/kernel/time.c
@@ -434,7 +434,7 @@ irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 	/*
 	 * call the generic timer interrupt handling
 	 */
-	do_timer(regs);
+	do_timer(1);
 
 	/*
 	 * If we have an externally synchronized Linux clock, then update
diff --git a/arch/mips/momentum/ocelot_g/gt-irq.c b/arch/mips/momentum/ocelot_g/gt-irq.c
index 9fb2493..6cd87cf 100644
--- a/arch/mips/momentum/ocelot_g/gt-irq.c
+++ b/arch/mips/momentum/ocelot_g/gt-irq.c
@@ -133,7 +133,7 @@ static irqreturn_t gt64240_p0int_irq(int irq, void *dev, struct pt_regs *regs)
 		MV_WRITE(TIMER_COUNTER_0_3_INTERRUPT_CAUSE, 0x0);
 
 		/* handle the timer call */
-		do_timer(regs);
+		do_timer(1);
 #ifndef CONFIG_SMP
 		update_process_times(user_mode(regs));
 #endif
diff --git a/arch/mips/sgi-ip27/ip27-timer.c b/arch/mips/sgi-ip27/ip27-timer.c
index b029ba7..c62a3a9 100644
--- a/arch/mips/sgi-ip27/ip27-timer.c
+++ b/arch/mips/sgi-ip27/ip27-timer.c
@@ -111,7 +111,7 @@ again:
 	kstat_this_cpu.irqs[irq]++;		/* kstat only for bootcpu? */
 
 	if (cpu == 0)
-		do_timer(regs);
+		do_timer(1);
 
 	update_process_times(user_mode(regs));
 
diff --git a/arch/parisc/kernel/time.c b/arch/parisc/kernel/time.c
index 5facc9b..700df10 100644
--- a/arch/parisc/kernel/time.c
+++ b/arch/parisc/kernel/time.c
@@ -79,7 +79,7 @@ irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 #endif
 		if (cpu == 0) {
 			write_seqlock(&xtime_lock);
-			do_timer(regs);
+			do_timer(1);
 			write_sequnlock(&xtime_lock);
 		}
 	}
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 7a3c3f79..71f71da 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -693,7 +693,7 @@ void timer_interrupt(struct pt_regs * regs)
 		tb_next_jiffy = tb_last_jiffy + tb_ticks_per_jiffy;
 		if (per_cpu(last_jiffy, cpu) >= tb_next_jiffy) {
 			tb_last_jiffy = tb_next_jiffy;
-			do_timer(regs);
+			do_timer(1);
 			timer_recalc_offset(tb_last_jiffy);
 			timer_check_rtc();
 		}
diff --git a/arch/ppc/kernel/time.c b/arch/ppc/kernel/time.c
index 6ab8cc7..1e1f315 100644
--- a/arch/ppc/kernel/time.c
+++ b/arch/ppc/kernel/time.c
@@ -153,7 +153,7 @@ void timer_interrupt(struct pt_regs * regs)
 		/* We are in an interrupt, no need to save/restore flags */
 		write_seqlock(&xtime_lock);
 		tb_last_stamp = jiffy_stamp;
-		do_timer(regs);
+		do_timer(1);
 
 		/*
 		 * update the rtc when needed, this should be performed on the
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index 1981c61..abab42e 100644
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -166,7 +166,7 @@ EXPORT_SYMBOL(do_settimeofday);
 void account_ticks(struct pt_regs *regs)
 {
 	__u64 tmp;
-	__u32 ticks, xticks;
+	__u32 ticks;
 
 	/* Calculate how many ticks have passed. */
 	if (S390_lowcore.int_clock < S390_lowcore.jiffy_timer) {
@@ -204,6 +204,7 @@ void account_ticks(struct pt_regs *regs)
 	 */
 	write_seqlock(&xtime_lock);
 	if (S390_lowcore.jiffy_timer > xtime_cc) {
+		__u32 xticks;
 		tmp = S390_lowcore.jiffy_timer - xtime_cc;
 		if (tmp >= 2*CLK_TICKS_PER_JIFFY) {
 			xticks = __div(tmp, CLK_TICKS_PER_JIFFY);
@@ -212,13 +213,11 @@ void account_ticks(struct pt_regs *regs)
 			xticks = 1;
 			xtime_cc += CLK_TICKS_PER_JIFFY;
 		}
-		while (xticks--)
-			do_timer(regs);
+		do_timer(xticks);
 	}
 	write_sequnlock(&xtime_lock);
 #else
-	for (xticks = ticks; xticks > 0; xticks--)
-		do_timer(regs);
+	do_timer(ticks);
 #endif
 
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
diff --git a/arch/sh/kernel/time.c b/arch/sh/kernel/time.c
index 149d971..f664a19 100644
--- a/arch/sh/kernel/time.c
+++ b/arch/sh/kernel/time.c
@@ -117,7 +117,7 @@ static long last_rtc_update;
  */
 void handle_timer_tick(struct pt_regs *regs)
 {
-	do_timer(regs);
+	do_timer(1);
 #ifndef CONFIG_SMP
 	update_process_times(user_mode(regs));
 #endif
diff --git a/arch/sh64/kernel/time.c b/arch/sh64/kernel/time.c
index b8162e5..3b61e06 100644
--- a/arch/sh64/kernel/time.c
+++ b/arch/sh64/kernel/time.c
@@ -298,7 +298,7 @@ static inline void do_timer_interrupt(int irq, struct pt_regs *regs)
 	asm ("getcon cr62, %0" : "=r" (current_ctc));
 	ctc_last_interrupt = (unsigned long) current_ctc;
 
-	do_timer(regs);
+	do_timer(1);
 #ifndef CONFIG_SMP
 	update_process_times(user_mode(regs));
 #endif
diff --git a/arch/sparc/kernel/pcic.c b/arch/sparc/kernel/pcic.c
index bfd31aa..e19b1ba 100644
--- a/arch/sparc/kernel/pcic.c
+++ b/arch/sparc/kernel/pcic.c
@@ -712,7 +712,7 @@ static irqreturn_t pcic_timer_handler (int irq, void *h, struct pt_regs *regs)
 {
 	write_seqlock(&xtime_lock);	/* Dummy, to show that we remember */
 	pcic_clear_clock_irq();
-	do_timer(regs);
+	do_timer(1);
 #ifndef CONFIG_SMP
 	update_process_times(user_mode(regs));
 #endif
diff --git a/arch/sparc/kernel/time.c b/arch/sparc/kernel/time.c
index 845081b0..6f84fa1 100644
--- a/arch/sparc/kernel/time.c
+++ b/arch/sparc/kernel/time.c
@@ -128,7 +128,7 @@ irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs * regs)
 #endif
 	clear_clock_irq();
 
-	do_timer(regs);
+	do_timer(1);
 #ifndef CONFIG_SMP
 	update_process_times(user_mode(regs));
 #endif
diff --git a/arch/sparc64/kernel/time.c b/arch/sparc64/kernel/time.c
index b0b4fee..ca11934 100644
--- a/arch/sparc64/kernel/time.c
+++ b/arch/sparc64/kernel/time.c
@@ -465,7 +465,7 @@ irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs * regs)
 		profile_tick(CPU_PROFILING, regs);
 		update_process_times(user_mode(regs));
 #endif
-		do_timer(regs);
+		do_timer(1);
 
 		/* Guarantee that the following sequences execute
 		 * uninterrupted.
@@ -496,7 +496,7 @@ void timer_tick_interrupt(struct pt_regs *regs)
 {
 	write_seqlock(&xtime_lock);
 
-	do_timer(regs);
+	do_timer(1);
 
 	timer_check_rtc();
 
diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c
index 820affb..a92965f 100644
--- a/arch/um/kernel/time.c
+++ b/arch/um/kernel/time.c
@@ -93,7 +93,7 @@ irqreturn_t um_timer(int irq, void *dev, struct pt_regs *regs)
 
 	write_seqlock_irqsave(&xtime_lock, flags);
 
-	do_timer(regs);
+	do_timer(1);
 
 	nsecs = get_time();
 	xtime.tv_sec = nsecs / NSEC_PER_SEC;
diff --git a/arch/v850/kernel/time.c b/arch/v850/kernel/time.c
index a0b4669..f4d1a4d 100644
--- a/arch/v850/kernel/time.c
+++ b/arch/v850/kernel/time.c
@@ -51,7 +51,7 @@ static irqreturn_t timer_interrupt (int irq, void *dummy, struct pt_regs *regs)
 	if (mach_tick)
 	  mach_tick ();
 
-	do_timer (regs);
+	do_timer (1);
 #ifndef CONFIG_SMP
 	update_process_times(user_mode(regs));
 #endif
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index 1c255ee..7ea3bf2 100644
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -415,16 +415,16 @@ void main_timer_handler(struct pt_regs *regs)
 				(((long) offset << US_SCALE) / vxtime.tsc_quot) - 1;
 	}
 
-	if (lost > 0) {
+	if (lost > 0)
 		handle_lost_ticks(lost, regs);
-		jiffies += lost;
-	}
+	else
+		lost = 0;
 
 /*
  * Do the timer stuff.
  */
 
-	do_timer(regs);
+	do_timer(lost + 1);
 #ifndef CONFIG_SMP
 	update_process_times(user_mode(regs));
 #endif
diff --git a/arch/xtensa/kernel/time.c b/arch/xtensa/kernel/time.c
index 412ab32..241db20 100644
--- a/arch/xtensa/kernel/time.c
+++ b/arch/xtensa/kernel/time.c
@@ -175,7 +175,7 @@ again:
 
 		last_ccount_stamp = next;
 		next += CCOUNT_PER_JIFFY;
-		do_timer (regs); /* Linux handler in kernel/timer.c */
+		do_timer (1); /* Linux handler in kernel/timer.c */
 
 		if (ntp_synced() &&
 		    xtime.tv_sec - last_rtc_update >= 659 &&