1 files changed, 30 insertions, 75 deletions

diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 522bb1dfc353..567dd7c3ac2a 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -86,8 +86,6 @@ static struct clocksource clocksource_rtc = {
         .rating       = 400,
         .flags        = CLOCK_SOURCE_IS_CONTINUOUS,
         .mask         = CLOCKSOURCE_MASK(64),
-        .shift        = 22,
-        .mult         = 0,      /* To be filled in */
         .read         = rtc_read,
 };
 
@@ -97,8 +95,6 @@ static struct clocksource clocksource_timebase = {
         .rating       = 400,
         .flags        = CLOCK_SOURCE_IS_CONTINUOUS,
         .mask         = CLOCKSOURCE_MASK(64),
-        .shift        = 22,
-        .mult         = 0,      /* To be filled in */
         .read         = timebase_read,
 };
 
@@ -110,22 +106,16 @@ static void decrementer_set_mode(enum clock_event_mode mode,
                                  struct clock_event_device *dev);
 
 static struct clock_event_device decrementer_clockevent = {
-       .name           = "decrementer",
-       .rating         = 200,
-       .shift          = 0,     /* To be filled in */
-       .mult           = 0,     /* To be filled in */
-       .irq            = 0,
-       .set_next_event = decrementer_set_next_event,
-       .set_mode       = decrementer_set_mode,
-       .features       = CLOCK_EVT_FEAT_ONESHOT,
+        .name           = "decrementer",
+        .rating         = 200,
+        .irq            = 0,
+        .set_next_event = decrementer_set_next_event,
+        .set_mode       = decrementer_set_mode,
+        .features       = CLOCK_EVT_FEAT_ONESHOT,
 };
 
-struct decrementer_clock {
-        struct clock_event_device event;
-        u64 next_tb;
-};
-
-static DEFINE_PER_CPU(struct decrementer_clock, decrementers);
+DEFINE_PER_CPU(u64, decrementers_next_tb);
+static DEFINE_PER_CPU(struct clock_event_device, decrementers);
 
 #ifdef CONFIG_PPC_ISERIES
 static unsigned long __initdata iSeries_recal_titan;
@@ -168,13 +158,13 @@ EXPORT_SYMBOL_GPL(ppc_tb_freq);
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
 /*
  * Factors for converting from cputime_t (timebase ticks) to
- * jiffies, milliseconds, seconds, and clock_t (1/USER_HZ seconds).
+ * jiffies, microseconds, seconds, and clock_t (1/USER_HZ seconds).
  * These are all stored as 0.64 fixed-point binary fractions.
  */
 u64 __cputime_jiffies_factor;
 EXPORT_SYMBOL(__cputime_jiffies_factor);
-u64 __cputime_msec_factor;
-EXPORT_SYMBOL(__cputime_msec_factor);
+u64 __cputime_usec_factor;
+EXPORT_SYMBOL(__cputime_usec_factor);
 u64 __cputime_sec_factor;
 EXPORT_SYMBOL(__cputime_sec_factor);
 u64 __cputime_clockt_factor;
@@ -192,8 +182,8 @@ static void calc_cputime_factors(void)
 
         div128_by_32(HZ, 0, tb_ticks_per_sec, &res);
         __cputime_jiffies_factor = res.result_low;
-        div128_by_32(1000, 0, tb_ticks_per_sec, &res);
-        __cputime_msec_factor = res.result_low;
+        div128_by_32(1000000, 0, tb_ticks_per_sec, &res);
+        __cputime_usec_factor = res.result_low;
         div128_by_32(1, 0, tb_ticks_per_sec, &res);
         __cputime_sec_factor = res.result_low;
         div128_by_32(USER_HZ, 0, tb_ticks_per_sec, &res);
@@ -441,7 +431,7 @@ EXPORT_SYMBOL(profile_pc);
 /* 
  * This function recalibrates the timebase based on the 49-bit time-of-day
  * value in the Titan chip.  The Titan is much more accurate than the value
- * returned by the service processor for the timebase frequency.  
+ * returned by the service processor for the timebase frequency.
  */
 
 static int __init iSeries_tb_recal(void)
@@ -576,9 +566,8 @@ void arch_irq_work_raise(void)
 void timer_interrupt(struct pt_regs * regs)
 {
         struct pt_regs *old_regs;
-        struct decrementer_clock *decrementer =  &__get_cpu_var(decrementers);
-        struct clock_event_device *evt = &decrementer->event;
-        u64 now;
+        u64 *next_tb = &__get_cpu_var(decrementers_next_tb);
+        struct clock_event_device *evt = &__get_cpu_var(decrementers);
 
         /* Ensure a positive value is written to the decrementer, or else
          * some CPUs will continue to take decrementer exceptions.
@@ -613,16 +602,9 @@ void timer_interrupt(struct pt_regs * regs)
                 get_lppaca()->int_dword.fields.decr_int = 0;
 #endif
 
-        now = get_tb_or_rtc();
-        if (now >= decrementer->next_tb) {
-                decrementer->next_tb = ~(u64)0;
-                if (evt->event_handler)
-                        evt->event_handler(evt);
-        } else {
-                now = decrementer->next_tb - now;
-                if (now <= DECREMENTER_MAX)
-                        set_dec((int)now);
-        }
+        *next_tb = ~(u64)0;
+        if (evt->event_handler)
+                evt->event_handler(evt);
 
 #ifdef CONFIG_PPC_ISERIES
         if (firmware_has_feature(FW_FEATURE_ISERIES) && hvlpevent_is_pending())
@@ -650,9 +632,9 @@ static void generic_suspend_disable_irqs(void)
          * with suspending.
          */
 
-        set_dec(0x7fffffff);
+        set_dec(DECREMENTER_MAX);
         local_irq_disable();
-        set_dec(0x7fffffff);
+        set_dec(DECREMENTER_MAX);
 }
 
 static void generic_suspend_enable_irqs(void)
@@ -824,9 +806,8 @@ void update_vsyscall(struct timespec *wall_time, struct timespec *wtm,
         ++vdso_data->tb_update_count;
         smp_mb();
 
-        /* XXX this assumes clock->shift == 22 */
-        /* 4611686018 ~= 2^(20+64-22) / 1e9 */
-        new_tb_to_xs = (u64) mult * 4611686018ULL;
+        /* 19342813113834067 ~= 2^(20+64) / 1e9 */
+        new_tb_to_xs = (u64) mult * (19342813113834067ULL >> clock->shift);
         new_stamp_xsec = (u64) wall_time->tv_nsec * XSEC_PER_SEC;
         do_div(new_stamp_xsec, 1000000000);
         new_stamp_xsec += (u64) wall_time->tv_sec * XSEC_PER_SEC;
@@ -877,9 +858,7 @@ static void __init clocksource_init(void)
         else
                 clock = &clocksource_timebase;
 
-        clock->mult = clocksource_hz2mult(tb_ticks_per_sec, clock->shift);
-
-        if (clocksource_register(clock)) {
+        if (clocksource_register_hz(clock, tb_ticks_per_sec)) {
                 printk(KERN_ERR "clocksource: %s is already registered\n",
                        clock->name);
                 return;
@@ -892,7 +871,7 @@ static void __init clocksource_init(void)
 static int decrementer_set_next_event(unsigned long evt,
                                       struct clock_event_device *dev)
 {
-        __get_cpu_var(decrementers).next_tb = get_tb_or_rtc() + evt;
+        __get_cpu_var(decrementers_next_tb) = get_tb_or_rtc() + evt;
         set_dec(evt);
         return 0;
 }
@@ -904,34 +883,9 @@ static void decrementer_set_mode(enum clock_event_mode mode,
                 decrementer_set_next_event(DECREMENTER_MAX, dev);
 }
 
-static inline uint64_t div_sc64(unsigned long ticks, unsigned long nsec,
-                                int shift)
-{
-        uint64_t tmp = ((uint64_t)ticks) << shift;
-
-        do_div(tmp, nsec);
-        return tmp;
-}
-
-static void __init setup_clockevent_multiplier(unsigned long hz)
-{
-        u64 mult, shift = 32;
-
-        while (1) {
-                mult = div_sc64(hz, NSEC_PER_SEC, shift);
-                if (mult && (mult >> 32UL) == 0UL)
-                        break;
-
-                shift--;
-        }
-
-        decrementer_clockevent.shift = shift;
-        decrementer_clockevent.mult = mult;
-}
-
 static void register_decrementer_clockevent(int cpu)
 {
-        struct clock_event_device *dec = &per_cpu(decrementers, cpu).event;
+        struct clock_event_device *dec = &per_cpu(decrementers, cpu);
 
         *dec = decrementer_clockevent;
         dec->cpumask = cpumask_of(cpu);
@@ -946,7 +900,8 @@ static void __init init_decrementer_clockevent(void)
 {
         int cpu = smp_processor_id();
 
-        setup_clockevent_multiplier(ppc_tb_freq);
+        clockevents_calc_mult_shift(&decrementer_clockevent, ppc_tb_freq, 4);
+
         decrementer_clockevent.max_delta_ns =
                 clockevent_delta2ns(DECREMENTER_MAX, &decrementer_clockevent);
         decrementer_clockevent.min_delta_ns =
@@ -1014,10 +969,10 @@ void __init time_init(void)
         boot_tb = get_tb_or_rtc();
 
         /* If platform provided a timezone (pmac), we correct the time */
-        if (timezone_offset) {
+        if (timezone_offset) {
                 sys_tz.tz_minuteswest = -timezone_offset / 60;
                 sys_tz.tz_dsttime = 0;
-        }
+        }
 
         vdso_data->tb_update_count = 0;
         vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;