EXPORT_SYMBOL(tb_ticks_per_usec);
unsigned long tb_ticks_per_sec;
EXPORT_SYMBOL(tb_ticks_per_sec); /* for cputime_t conversions */
- u64 tb_to_xs;
- unsigned tb_to_us;
-
- #define TICKLEN_SCALE NTP_SCALE_SHIFT
- static u64 last_tick_len; /* units are ns / 2^TICKLEN_SCALE */
- static u64 ticklen_to_xs; /* 0.64 fraction */
-
- /* If last_tick_len corresponds to about 1/HZ seconds, then
- last_tick_len << TICKLEN_SHIFT will be about 2^63. */
- #define TICKLEN_SHIFT (63 - 30 - TICKLEN_SCALE + SHIFT_HZ)
DEFINE_SPINLOCK(rtc_lock);
EXPORT_SYMBOL_GPL(rtc_lock);
EXPORT_SYMBOL(ppc_proc_freq);
unsigned long ppc_tb_freq;
- static u64 tb_last_jiffy __cacheline_aligned_in_smp;
static DEFINE_PER_CPU(u64, last_jiffy);
#ifdef CONFIG_VIRT_CPU_ACCOUNTING
static int __init iSeries_tb_recal(void)
{
- struct div_result divres;
unsigned long titan, tb;
/* Make sure we only run on iSeries */
tb_ticks_per_jiffy = new_tb_ticks_per_jiffy;
tb_ticks_per_sec = new_tb_ticks_per_sec;
calc_cputime_factors();
- div128_by_32( XSEC_PER_SEC, 0, tb_ticks_per_sec, &divres );
- tb_to_xs = divres.result_low;
vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;
- vdso_data->tb_to_xs = tb_to_xs;
setup_cputime_one_jiffy();
}
else {
trace_timer_interrupt_exit(regs);
}
- void wakeup_decrementer(void)
- {
- unsigned long ticks;
-
- /*
- * The timebase gets saved on sleep and restored on wakeup,
- * so all we need to do is to reset the decrementer.
- */
- ticks = tb_ticks_since(__get_cpu_var(last_jiffy));
- if (ticks < tb_ticks_per_jiffy)
- ticks = tb_ticks_per_jiffy - ticks;
- else
- ticks = 1;
- set_dec(ticks);
- }
-
#ifdef CONFIG_SUSPEND
- void generic_suspend_disable_irqs(void)
+ static void generic_suspend_disable_irqs(void)
{
- preempt_disable();
-
/* Disable the decrementer, so that it doesn't interfere
* with suspending.
*/
set_dec(0x7fffffff);
}
- void generic_suspend_enable_irqs(void)
+ static void generic_suspend_enable_irqs(void)
{
- wakeup_decrementer();
-
local_irq_enable();
- preempt_enable();
}
/* Overrides the weak version in kernel/power/main.c */
}
#endif
- #ifdef CONFIG_SMP
- void __init smp_space_timers(unsigned int max_cpus)
- {
- int i;
- u64 previous_tb = per_cpu(last_jiffy, boot_cpuid);
-
- /* make sure tb > per_cpu(last_jiffy, cpu) for all cpus always */
- previous_tb -= tb_ticks_per_jiffy;
-
- for_each_possible_cpu(i) {
- if (i == boot_cpuid)
- continue;
- per_cpu(last_jiffy, i) = previous_tb;
- }
- }
- #endif
-
/*
* Scheduler clock - returns current time in nanosec units.
*
return (cycle_t)get_tb();
}
-static inline void update_gtod(u64 new_tb_stamp, u64 new_stamp_xsec,
- u64 new_tb_to_xs, struct timespec *now,
- u32 frac_sec)
+void update_vsyscall(struct timespec *wall_time, struct timespec *wtm,
+ struct clocksource *clock, u32 mult)
{
+ u64 new_tb_to_xs, new_stamp_xsec;
++ u32 frac_sec;
+
+ if (clock != &clocksource_timebase)
+ return;
+
+ /* Make userspace gettimeofday spin until we're done. */
+ ++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;
+ 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;
+
++ BUG_ON(wall_time->tv_nsec >= NSEC_PER_SEC);
++ /* this is tv_nsec / 1e9 as a 0.32 fraction */
++ frac_sec = ((u64) wall_time->tv_nsec * 18446744073ULL) >> 32;
++
/*
* tb_update_count is used to allow the userspace gettimeofday code
* to assure itself that it sees a consistent view of the tb_to_xs and
* We expect the caller to have done the first increment of
* vdso_data->tb_update_count already.
*/
- vdso_data->tb_orig_stamp = new_tb_stamp;
+ vdso_data->tb_orig_stamp = clock->cycle_last;
vdso_data->stamp_xsec = new_stamp_xsec;
vdso_data->tb_to_xs = new_tb_to_xs;
- vdso_data->wtom_clock_sec = wall_to_monotonic.tv_sec;
- vdso_data->wtom_clock_nsec = wall_to_monotonic.tv_nsec;
- vdso_data->stamp_xtime = *now;
+ vdso_data->wtom_clock_sec = wtm->tv_sec;
+ vdso_data->wtom_clock_nsec = wtm->tv_nsec;
+ vdso_data->stamp_xtime = *wall_time;
+ vdso_data->stamp_sec_fraction = frac_sec;
smp_wmb();
++(vdso_data->tb_update_count);
}
-void update_vsyscall(struct timespec *wall_time, struct clocksource *clock,
- u32 mult)
-{
- u64 t2x, stamp_xsec;
- u32 frac_sec;
-
- if (clock != &clocksource_timebase)
- return;
-
- /* Make userspace gettimeofday spin until we're done. */
- ++vdso_data->tb_update_count;
- smp_mb();
-
- /* XXX this assumes clock->shift == 22 */
- /* 4611686018 ~= 2^(20+64-22) / 1e9 */
- t2x = (u64) mult * 4611686018ULL;
- stamp_xsec = (u64) wall_time->tv_nsec * XSEC_PER_SEC;
- do_div(stamp_xsec, 1000000000);
- stamp_xsec += (u64) wall_time->tv_sec * XSEC_PER_SEC;
-
- BUG_ON(wall_time->tv_nsec >= NSEC_PER_SEC);
- /* this is tv_nsec / 1e9 as a 0.32 fraction */
- frac_sec = ((u64) wall_time->tv_nsec * 18446744073ULL) >> 32;
- update_gtod(clock->cycle_last, stamp_xsec, t2x, wall_time, frac_sec);
-}
-
void update_vsyscall_tz(void)
{
/* Make userspace gettimeofday spin until we're done. */
/* This function is only called on the boot processor */
void __init time_init(void)
{
- unsigned long flags;
struct div_result res;
- u64 scale, x;
+ u64 scale;
unsigned shift;
if (__USE_RTC()) {
/* 601 processor: dec counts down by 128 every 128ns */
ppc_tb_freq = 1000000000;
- tb_last_jiffy = get_rtcl();
} else {
/* Normal PowerPC with timebase register */
ppc_md.calibrate_decr();
ppc_tb_freq / 1000000, ppc_tb_freq % 1000000);
printk(KERN_DEBUG "time_init: processor frequency = %lu.%.6lu MHz\n",
ppc_proc_freq / 1000000, ppc_proc_freq % 1000000);
- tb_last_jiffy = get_tb();
}
tb_ticks_per_jiffy = ppc_tb_freq / HZ;
tb_ticks_per_sec = ppc_tb_freq;
tb_ticks_per_usec = ppc_tb_freq / 1000000;
- tb_to_us = mulhwu_scale_factor(ppc_tb_freq, 1000000);
calc_cputime_factors();
setup_cputime_one_jiffy();
- /*
- * Calculate the length of each tick in ns. It will not be
- * exactly 1e9/HZ unless ppc_tb_freq is divisible by HZ.
- * We compute 1e9 * tb_ticks_per_jiffy / ppc_tb_freq,
- * rounded up.
- */
- x = (u64) NSEC_PER_SEC * tb_ticks_per_jiffy + ppc_tb_freq - 1;
- do_div(x, ppc_tb_freq);
- tick_nsec = x;
- last_tick_len = x << TICKLEN_SCALE;
-
- /*
- * Compute ticklen_to_xs, which is a factor which gets multiplied
- * by (last_tick_len << TICKLEN_SHIFT) to get a tb_to_xs value.
- * It is computed as:
- * ticklen_to_xs = 2^N / (tb_ticks_per_jiffy * 1e9)
- * where N = 64 + 20 - TICKLEN_SCALE - TICKLEN_SHIFT
- * which turns out to be N = 51 - SHIFT_HZ.
- * This gives the result as a 0.64 fixed-point fraction.
- * That value is reduced by an offset amounting to 1 xsec per
- * 2^31 timebase ticks to avoid problems with time going backwards
- * by 1 xsec when we do timer_recalc_offset due to losing the
- * fractional xsec. That offset is equal to ppc_tb_freq/2^51
- * since there are 2^20 xsec in a second.
- */
- div128_by_32((1ULL << 51) - ppc_tb_freq, 0,
- tb_ticks_per_jiffy << SHIFT_HZ, &res);
- div128_by_32(res.result_high, res.result_low, NSEC_PER_SEC, &res);
- ticklen_to_xs = res.result_low;
-
- /* Compute tb_to_xs from tick_nsec */
- tb_to_xs = mulhdu(last_tick_len << TICKLEN_SHIFT, ticklen_to_xs);
-
/*
* Compute scale factor for sched_clock.
* The calibrate_decr() function has set tb_ticks_per_sec,
/* Save the current timebase to pretty up CONFIG_PRINTK_TIME */
boot_tb = get_tb_or_rtc();
- write_seqlock_irqsave(&xtime_lock, flags);
-
/* If platform provided a timezone (pmac), we correct the time */
if (timezone_offset) {
sys_tz.tz_minuteswest = -timezone_offset / 60;
sys_tz.tz_dsttime = 0;
}
- vdso_data->tb_orig_stamp = tb_last_jiffy;
vdso_data->tb_update_count = 0;
vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;
- vdso_data->stamp_xsec = (u64) get_seconds() * XSEC_PER_SEC;
- vdso_data->tb_to_xs = tb_to_xs;
-
- write_sequnlock_irqrestore(&xtime_lock, flags);
/* Start the decrementer on CPUs that have manual control
* such as BookE
GregorianDay(tm);
}
- /* Auxiliary function to compute scaling factors */
- /* Actually the choice of a timebase running at 1/4 the of the bus
- * frequency giving resolution of a few tens of nanoseconds is quite nice.
- * It makes this computation very precise (27-28 bits typically) which
- * is optimistic considering the stability of most processor clock
- * oscillators and the precision with which the timebase frequency
- * is measured but does not harm.
- */
- unsigned mulhwu_scale_factor(unsigned inscale, unsigned outscale)
- {
- unsigned mlt=0, tmp, err;
- /* No concern for performance, it's done once: use a stupid
- * but safe and compact method to find the multiplier.
- */
-
- for (tmp = 1U<<31; tmp != 0; tmp >>= 1) {
- if (mulhwu(inscale, mlt|tmp) < outscale)
- mlt |= tmp;
- }
-
- /* We might still be off by 1 for the best approximation.
- * A side effect of this is that if outscale is too large
- * the returned value will be zero.
- * Many corner cases have been checked and seem to work,
- * some might have been forgotten in the test however.
- */
-
- err = inscale * (mlt+1);
- if (err <= inscale/2)
- mlt++;
- return mlt;
- }
-
/*
* Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit
* result.
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