Merge branch 'powerpc.cherry-picks' into timers/clocksource
Conflicts:
arch/powerpc/kernel/time.c
Reason: The powerpc next tree contains two commits which conflict with
the timekeeping changes:
8fd63a9e powerpc: Rework VDSO gettimeofday to prevent time going backwards
c1aa687d powerpc: Clean up obsolete code relating to decrementer and timebase
John Stultz identified them and provided the conflict resolution.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index e215f76..ce53dfa 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -149,16 +149,6 @@
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);
@@ -174,7 +164,6 @@
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
@@ -446,7 +435,6 @@
static int __init iSeries_tb_recal(void)
{
- struct div_result divres;
unsigned long titan, tb;
/* Make sure we only run on iSeries */
@@ -477,10 +465,7 @@
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 {
@@ -643,27 +628,9 @@
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.
*/
@@ -673,12 +640,9 @@
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 */
@@ -698,23 +662,6 @@
}
#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.
*
@@ -853,6 +800,7 @@
struct clocksource *clock, u32 mult)
{
u64 new_tb_to_xs, new_stamp_xsec;
+ u32 frac_sec;
if (clock != &clocksource_timebase)
return;
@@ -868,6 +816,10 @@
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
@@ -885,6 +837,7 @@
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);
}
@@ -1002,15 +955,13 @@
/* 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();
@@ -1018,50 +969,15 @@
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,
* which is the timebase frequency.
@@ -1082,21 +998,14 @@
/* 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
@@ -1190,39 +1099,6 @@
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.