[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 b191cc759737..7c1e44420a78 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 d4dceb5f06e9..f7d5165796ef 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 db63d75d0715..80adbd005fc5 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 b0e6b5855a38..3e56b9f4358a 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 9c22b76e129a..ebacf1457d91 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 50f3f93293d6..be0a01657d4f 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 3d0284bccb94..7e55884135ed 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 688a5100604c..e569d17b4ae6 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 6928ef0d64d8..16262687a103 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 ded0be07a476..7a896893cd28 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 98e4b1adfa29..1072e4946a4a 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 f18b9d3ef16d..dc4ea7e074a6 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 1db987272220..db1e1ce0a349 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 7fbea1bf7b48..0a067f3113a5 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 d837b26fbe51..7feca49350d1 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 170cb67f4ede..6ab8d975a974 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 9fb2493fff02..6cd87cf0195a 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 b029ba79c27a..c62a3a9ef867 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 5facc9bff4ef..700df10924dd 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 7a3c3f791ade..71f71da98e7d 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 6ab8cc7226ab..1e1f31554767 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 1981c6199fa2..abab42e9f5f8 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 149d9713eddf..f664a196c4f5 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 b8162e59030e..3b61e06f9d72 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 bfd31aac2df3..e19b1bad9bc5 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 845081b01267..6f84fa1b58e5 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 b0b4feeec098..ca1193482f07 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 820affbf3e16..a92965f8f9cd 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 a0b46695f186..f4d1a4d3cdc2 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 1c255ee76e7c..7ea3bf2a858c 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 412ab32de391..241db201f40e 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 &&