* 2 of the License, or (at your option) any later version.
*/
-#include <linux/config.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/security.h>
#include <linux/percpu.h>
#include <linux/rtc.h>
+#include <linux/jiffies.h>
+#include <linux/posix-timers.h>
+#include <linux/irq.h>
#include <asm/io.h>
#include <asm/processor.h>
/* keep track of when we need to update the rtc */
time_t last_rtc_update;
-extern int piranha_simulator;
#ifdef CONFIG_PPC_ISERIES
unsigned long iSeries_recal_titan = 0;
unsigned long iSeries_recal_tb = 0;
unsigned long tb_ticks_per_usec = 100; /* sane default */
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;
-unsigned long processor_freq;
+
+#define TICKLEN_SCALE TICK_LENGTH_SHIFT
+u64 last_tick_len; /* units are ns / 2^TICKLEN_SCALE */
+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);
struct gettimeofday_struct do_gtod;
-extern unsigned long wall_jiffies;
-
extern struct timezone sys_tz;
static long timezone_offset;
-void ppc_adjtimex(void);
-
-static unsigned adjusting_time = 0;
-
unsigned long ppc_proc_freq;
unsigned long ppc_tb_freq;
-u64 tb_last_jiffy __cacheline_aligned_in_smp;
-unsigned long tb_last_stamp;
+static u64 tb_last_jiffy __cacheline_aligned_in_smp;
+static DEFINE_PER_CPU(u64, last_jiffy);
+
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+/*
+ * Factors for converting from cputime_t (timebase ticks) to
+ * jiffies, milliseconds, 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_sec_factor;
+EXPORT_SYMBOL(__cputime_sec_factor);
+u64 __cputime_clockt_factor;
+EXPORT_SYMBOL(__cputime_clockt_factor);
+
+static void calc_cputime_factors(void)
+{
+ struct div_result res;
+
+ 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(1, 0, tb_ticks_per_sec, &res);
+ __cputime_sec_factor = res.result_low;
+ div128_by_32(USER_HZ, 0, tb_ticks_per_sec, &res);
+ __cputime_clockt_factor = res.result_low;
+}
+
+/*
+ * Read the PURR on systems that have it, otherwise the timebase.
+ */
+static u64 read_purr(void)
+{
+ if (cpu_has_feature(CPU_FTR_PURR))
+ return mfspr(SPRN_PURR);
+ return mftb();
+}
+
+/*
+ * Account time for a transition between system, hard irq
+ * or soft irq state.
+ */
+void account_system_vtime(struct task_struct *tsk)
+{
+ u64 now, delta;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ now = read_purr();
+ delta = now - get_paca()->startpurr;
+ get_paca()->startpurr = now;
+ if (!in_interrupt()) {
+ delta += get_paca()->system_time;
+ get_paca()->system_time = 0;
+ }
+ account_system_time(tsk, 0, delta);
+ local_irq_restore(flags);
+}
+
+/*
+ * Transfer the user and system times accumulated in the paca
+ * by the exception entry and exit code to the generic process
+ * user and system time records.
+ * Must be called with interrupts disabled.
+ */
+void account_process_vtime(struct task_struct *tsk)
+{
+ cputime_t utime;
+
+ utime = get_paca()->user_time;
+ get_paca()->user_time = 0;
+ account_user_time(tsk, utime);
+}
+
+static void account_process_time(struct pt_regs *regs)
+{
+ int cpu = smp_processor_id();
+
+ account_process_vtime(current);
+ run_local_timers();
+ if (rcu_pending(cpu))
+ rcu_check_callbacks(cpu, user_mode(regs));
+ scheduler_tick();
+ run_posix_cpu_timers(current);
+}
+
+#ifdef CONFIG_PPC_SPLPAR
+/*
+ * Stuff for accounting stolen time.
+ */
+struct cpu_purr_data {
+ int initialized; /* thread is running */
+ u64 tb; /* last TB value read */
+ u64 purr; /* last PURR value read */
+ spinlock_t lock;
+};
+
+static DEFINE_PER_CPU(struct cpu_purr_data, cpu_purr_data);
+
+static void snapshot_tb_and_purr(void *data)
+{
+ struct cpu_purr_data *p = &__get_cpu_var(cpu_purr_data);
+
+ p->tb = mftb();
+ p->purr = mfspr(SPRN_PURR);
+ wmb();
+ p->initialized = 1;
+}
+
+/*
+ * Called during boot when all cpus have come up.
+ */
+void snapshot_timebases(void)
+{
+ int cpu;
+
+ if (!cpu_has_feature(CPU_FTR_PURR))
+ return;
+ for_each_possible_cpu(cpu)
+ spin_lock_init(&per_cpu(cpu_purr_data, cpu).lock);
+ on_each_cpu(snapshot_tb_and_purr, NULL, 0, 1);
+}
+
+void calculate_steal_time(void)
+{
+ u64 tb, purr;
+ s64 stolen;
+ struct cpu_purr_data *pme;
+
+ if (!cpu_has_feature(CPU_FTR_PURR))
+ return;
+ pme = &per_cpu(cpu_purr_data, smp_processor_id());
+ if (!pme->initialized)
+ return; /* this can happen in early boot */
+ spin_lock(&pme->lock);
+ tb = mftb();
+ purr = mfspr(SPRN_PURR);
+ stolen = (tb - pme->tb) - (purr - pme->purr);
+ if (stolen > 0)
+ account_steal_time(current, stolen);
+ pme->tb = tb;
+ pme->purr = purr;
+ spin_unlock(&pme->lock);
+}
/*
- * Note that on ppc32 this only stores the bottom 32 bits of
- * the timebase value, but that's enough to tell when a jiffy
- * has passed.
+ * Must be called before the cpu is added to the online map when
+ * a cpu is being brought up at runtime.
*/
-DEFINE_PER_CPU(unsigned long, last_jiffy);
+static void snapshot_purr(void)
+{
+ struct cpu_purr_data *pme;
+ unsigned long flags;
+
+ if (!cpu_has_feature(CPU_FTR_PURR))
+ return;
+ pme = &per_cpu(cpu_purr_data, smp_processor_id());
+ spin_lock_irqsave(&pme->lock, flags);
+ pme->tb = mftb();
+ pme->purr = mfspr(SPRN_PURR);
+ pme->initialized = 1;
+ spin_unlock_irqrestore(&pme->lock, flags);
+}
+
+#endif /* CONFIG_PPC_SPLPAR */
+
+#else /* ! CONFIG_VIRT_CPU_ACCOUNTING */
+#define calc_cputime_factors()
+#define account_process_time(regs) update_process_times(user_mode(regs))
+#define calculate_steal_time() do { } while (0)
+#endif
+
+#if !(defined(CONFIG_VIRT_CPU_ACCOUNTING) && defined(CONFIG_PPC_SPLPAR))
+#define snapshot_purr() do { } while (0)
+#endif
+
+/*
+ * Called when a cpu comes up after the system has finished booting,
+ * i.e. as a result of a hotplug cpu action.
+ */
+void snapshot_timebase(void)
+{
+ __get_cpu_var(last_jiffy) = get_tb();
+ snapshot_purr();
+}
void __delay(unsigned long loops)
{
*/
if (ppc_md.set_rtc_time && ntp_synced() &&
xtime.tv_sec - last_rtc_update >= 659 &&
- abs((xtime.tv_nsec/1000) - (1000000-1000000/HZ)) < 500000/HZ &&
- jiffies - wall_jiffies == 1) {
+ abs((xtime.tv_nsec/1000) - (1000000-1000000/HZ)) < 500000/HZ) {
struct rtc_time tm;
to_tm(xtime.tv_sec + 1 + timezone_offset, &tm);
tm.tm_year -= 1900;
/*
* This version of gettimeofday has microsecond resolution.
*/
-static inline void __do_gettimeofday(struct timeval *tv, u64 tb_val)
+static inline void __do_gettimeofday(struct timeval *tv)
{
unsigned long sec, usec;
u64 tb_ticks, xsec;
* without a divide (and in fact, without a multiply)
*/
temp_varp = do_gtod.varp;
- tb_ticks = tb_val - temp_varp->tb_orig_stamp;
+
+ /* Sampling the time base must be done after loading
+ * do_gtod.varp in order to avoid racing with update_gtod.
+ */
+ data_barrier(temp_varp);
+ tb_ticks = get_tb() - temp_varp->tb_orig_stamp;
temp_tb_to_xs = temp_varp->tb_to_xs;
temp_stamp_xsec = temp_varp->stamp_xsec;
xsec = temp_stamp_xsec + mulhdu(tb_ticks, temp_tb_to_xs);
if (__USE_RTC()) {
/* do this the old way */
unsigned long flags, seq;
- unsigned int sec, nsec, usec, lost;
+ unsigned int sec, nsec, usec;
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
sec = xtime.tv_sec;
- nsec = xtime.tv_nsec + tb_ticks_since(tb_last_stamp);
- lost = jiffies - wall_jiffies;
+ nsec = xtime.tv_nsec + tb_ticks_since(tb_last_jiffy);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
- usec = nsec / 1000 + lost * (1000000 / HZ);
+ usec = nsec / 1000;
while (usec >= 1000000) {
usec -= 1000000;
++sec;
tv->tv_usec = usec;
return;
}
- __do_gettimeofday(tv, get_tb());
+ __do_gettimeofday(tv);
}
EXPORT_SYMBOL(do_gettimeofday);
-/* Synchronize xtime with do_gettimeofday */
-
-static inline void timer_sync_xtime(unsigned long cur_tb)
-{
-#ifdef CONFIG_PPC64
- /* why do we do this? */
- struct timeval my_tv;
-
- __do_gettimeofday(&my_tv, cur_tb);
-
- if (xtime.tv_sec <= my_tv.tv_sec) {
- xtime.tv_sec = my_tv.tv_sec;
- xtime.tv_nsec = my_tv.tv_usec * 1000;
- }
-#endif
-}
-
/*
* There are two copies of tb_to_xs and stamp_xsec so that no
* lock is needed to access and use these values in
* the two values of tb_update_count match and are even then the
* tb_to_xs and stamp_xsec values are consistent. If not, then it
* loops back and reads them again until this criteria is met.
+ * We expect the caller to have done the first increment of
+ * vdso_data->tb_update_count already.
*/
- ++(vdso_data->tb_update_count);
- smp_wmb();
vdso_data->tb_orig_stamp = new_tb_stamp;
vdso_data->stamp_xsec = new_stamp_xsec;
vdso_data->tb_to_xs = new_tb_to_xs;
{
unsigned long offset;
u64 new_stamp_xsec;
+ u64 tlen, t2x;
+ u64 tb, xsec_old, xsec_new;
+ struct gettimeofday_vars *varp;
if (__USE_RTC())
return;
+ tlen = current_tick_length();
offset = cur_tb - do_gtod.varp->tb_orig_stamp;
- if ((offset & 0x80000000u) == 0)
+ if (tlen == last_tick_len && offset < 0x80000000u)
return;
- new_stamp_xsec = do_gtod.varp->stamp_xsec
- + mulhdu(offset, do_gtod.varp->tb_to_xs);
- update_gtod(cur_tb, new_stamp_xsec, do_gtod.varp->tb_to_xs);
+ if (tlen != last_tick_len) {
+ t2x = mulhdu(tlen << TICKLEN_SHIFT, ticklen_to_xs);
+ last_tick_len = tlen;
+ } else
+ t2x = do_gtod.varp->tb_to_xs;
+ new_stamp_xsec = (u64) xtime.tv_nsec * XSEC_PER_SEC;
+ do_div(new_stamp_xsec, 1000000000);
+ new_stamp_xsec += (u64) xtime.tv_sec * XSEC_PER_SEC;
+
+ ++vdso_data->tb_update_count;
+ smp_mb();
+
+ /*
+ * Make sure time doesn't go backwards for userspace gettimeofday.
+ */
+ tb = get_tb();
+ varp = do_gtod.varp;
+ xsec_old = mulhdu(tb - varp->tb_orig_stamp, varp->tb_to_xs)
+ + varp->stamp_xsec;
+ xsec_new = mulhdu(tb - cur_tb, t2x) + new_stamp_xsec;
+ if (xsec_new < xsec_old)
+ new_stamp_xsec += xsec_old - xsec_new;
+
+ update_gtod(cur_tb, new_stamp_xsec, t2x);
}
#ifdef CONFIG_SMP
new_tb_ticks_per_jiffy, sign, tick_diff );
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 );
do_gtod.tb_ticks_per_sec = tb_ticks_per_sec;
tb_to_xs = divres.result_low;
*/
void timer_interrupt(struct pt_regs * regs)
{
+ struct pt_regs *old_regs;
int next_dec;
int cpu = smp_processor_id();
unsigned long ticks;
+ u64 tb_next_jiffy;
#ifdef CONFIG_PPC32
if (atomic_read(&ppc_n_lost_interrupts) != 0)
do_IRQ(regs);
#endif
+ old_regs = set_irq_regs(regs);
irq_enter();
- profile_tick(CPU_PROFILING, regs);
+ profile_tick(CPU_PROFILING);
+ calculate_steal_time();
#ifdef CONFIG_PPC_ISERIES
- get_lppaca()->int_dword.fields.decr_int = 0;
+ if (firmware_has_feature(FW_FEATURE_ISERIES))
+ get_lppaca()->int_dword.fields.decr_int = 0;
#endif
while ((ticks = tb_ticks_since(per_cpu(last_jiffy, cpu)))
* is the case.
*/
if (!cpu_is_offline(cpu))
- update_process_times(user_mode(regs));
+ account_process_time(regs);
/*
* No need to check whether cpu is offline here; boot_cpuid
continue;
write_seqlock(&xtime_lock);
- tb_last_jiffy += tb_ticks_per_jiffy;
- tb_last_stamp = per_cpu(last_jiffy, cpu);
- timer_recalc_offset(tb_last_jiffy);
- do_timer(regs);
- timer_sync_xtime(tb_last_jiffy);
- timer_check_rtc();
+ 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(1);
+ timer_recalc_offset(tb_last_jiffy);
+ timer_check_rtc();
+ }
write_sequnlock(&xtime_lock);
- if (adjusting_time && (time_adjust == 0))
- ppc_adjtimex();
}
next_dec = tb_ticks_per_jiffy - ticks;
set_dec(next_dec);
#ifdef CONFIG_PPC_ISERIES
- if (hvlpevent_is_pending())
- process_hvlpevents(regs);
+ if (firmware_has_feature(FW_FEATURE_ISERIES) && hvlpevent_is_pending())
+ process_hvlpevents();
#endif
#ifdef CONFIG_PPC64
#endif
irq_exit();
+ set_irq_regs(old_regs);
}
void wakeup_decrementer(void)
{
- int i;
+ unsigned long ticks;
- set_dec(tb_ticks_per_jiffy);
/*
- * We don't expect this to be called on a machine with a 601,
- * so using get_tbl is fine.
+ * The timebase gets saved on sleep and restored on wakeup,
+ * so all we need to do is to reset the decrementer.
*/
- tb_last_stamp = tb_last_jiffy = get_tb();
- for_each_cpu(i)
- per_cpu(last_jiffy, i) = tb_last_stamp;
+ 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_SMP
void __init smp_space_timers(unsigned int max_cpus)
{
int i;
- unsigned long offset = tb_ticks_per_jiffy / max_cpus;
- unsigned long previous_tb = per_cpu(last_jiffy, boot_cpuid);
+ 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_cpu(i) {
- if (i != boot_cpuid) {
- previous_tb += offset;
- per_cpu(last_jiffy, i) = previous_tb;
- }
+
+ for_each_possible_cpu(i) {
+ if (i == boot_cpuid)
+ continue;
+ per_cpu(last_jiffy, i) = previous_tb;
}
}
#endif
time_t wtm_sec, new_sec = tv->tv_sec;
long wtm_nsec, new_nsec = tv->tv_nsec;
unsigned long flags;
- long int tb_delta;
- u64 new_xsec, tb_delta_xs;
+ u64 new_xsec;
+ unsigned long tb_delta;
if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
return -EINVAL;
* settimeofday to perform this operation.
*/
#ifdef CONFIG_PPC_ISERIES
- if (first_settimeofday) {
+ if (firmware_has_feature(FW_FEATURE_ISERIES) && first_settimeofday) {
iSeries_tb_recal();
first_settimeofday = 0;
}
#endif
- tb_delta = tb_ticks_since(tb_last_stamp);
- tb_delta += (jiffies - wall_jiffies) * tb_ticks_per_jiffy;
- tb_delta_xs = mulhdu(tb_delta, do_gtod.varp->tb_to_xs);
+
+ /* Make userspace gettimeofday spin until we're done. */
+ ++vdso_data->tb_update_count;
+ smp_mb();
+
+ /*
+ * Subtract off the number of nanoseconds since the
+ * beginning of the last tick.
+ */
+ tb_delta = tb_ticks_since(tb_last_jiffy);
+ tb_delta = mulhdu(tb_delta, do_gtod.varp->tb_to_xs); /* in xsec */
+ new_nsec -= SCALE_XSEC(tb_delta, 1000000000);
wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - new_sec);
wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - new_nsec);
ntp_clear();
- new_xsec = 0;
- if (new_nsec != 0) {
- new_xsec = (u64)new_nsec * XSEC_PER_SEC;
+ new_xsec = xtime.tv_nsec;
+ if (new_xsec != 0) {
+ new_xsec *= XSEC_PER_SEC;
do_div(new_xsec, NSEC_PER_SEC);
}
- new_xsec += (u64)new_sec * XSEC_PER_SEC - tb_delta_xs;
+ new_xsec += (u64)xtime.tv_sec * XSEC_PER_SEC;
update_gtod(tb_last_jiffy, new_xsec, do_gtod.varp->tb_to_xs);
vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
EXPORT_SYMBOL(do_settimeofday);
-void __init generic_calibrate_decr(void)
+static int __init get_freq(char *name, int cells, unsigned long *val)
{
struct device_node *cpu;
- unsigned int *fp;
- int node_found;
+ const unsigned int *fp;
+ int found = 0;
- /*
- * The cpu node should have a timebase-frequency property
- * to tell us the rate at which the decrementer counts.
- */
+ /* The cpu node should have timebase and clock frequency properties */
cpu = of_find_node_by_type(NULL, "cpu");
- ppc_tb_freq = DEFAULT_TB_FREQ; /* hardcoded default */
- node_found = 0;
if (cpu) {
- fp = (unsigned int *)get_property(cpu, "timebase-frequency",
- NULL);
+ fp = of_get_property(cpu, name, NULL);
if (fp) {
- node_found = 1;
- ppc_tb_freq = *fp;
+ found = 1;
+ *val = of_read_ulong(fp, cells);
}
+
+ of_node_put(cpu);
}
- if (!node_found)
+
+ return found;
+}
+
+void __init generic_calibrate_decr(void)
+{
+ ppc_tb_freq = DEFAULT_TB_FREQ; /* hardcoded default */
+
+ if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq) &&
+ !get_freq("timebase-frequency", 1, &ppc_tb_freq)) {
+
printk(KERN_ERR "WARNING: Estimating decrementer frequency "
"(not found)\n");
+ }
- ppc_proc_freq = DEFAULT_PROC_FREQ;
- node_found = 0;
- if (cpu) {
- fp = (unsigned int *)get_property(cpu, "clock-frequency",
- NULL);
- if (fp) {
- node_found = 1;
- ppc_proc_freq = *fp;
- }
+ ppc_proc_freq = DEFAULT_PROC_FREQ; /* hardcoded default */
+
+ if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq) &&
+ !get_freq("clock-frequency", 1, &ppc_proc_freq)) {
+
+ printk(KERN_ERR "WARNING: Estimating processor frequency "
+ "(not found)\n");
}
+
#ifdef CONFIG_BOOKE
/* Set the time base to zero */
mtspr(SPRN_TBWL, 0);
/* Enable decrementer interrupt */
mtspr(SPRN_TCR, TCR_DIE);
#endif
- if (!node_found)
- printk(KERN_ERR "WARNING: Estimating processor frequency "
- "(not found)\n");
-
- of_node_put(cpu);
}
unsigned long get_boot_time(void)
unsigned long flags;
unsigned long tm = 0;
struct div_result res;
- u64 scale;
+ u64 scale, x;
unsigned shift;
if (ppc_md.time_init != NULL)
if (__USE_RTC()) {
/* 601 processor: dec counts down by 128 every 128ns */
ppc_tb_freq = 1000000000;
- tb_last_stamp = get_rtcl();
- tb_last_jiffy = tb_last_stamp;
+ tb_last_jiffy = get_rtcl();
} else {
/* Normal PowerPC with timebase register */
ppc_md.calibrate_decr();
- printk(KERN_INFO "time_init: decrementer frequency = %lu.%.6lu MHz\n",
+ printk(KERN_DEBUG "time_init: decrementer frequency = %lu.%.6lu MHz\n",
ppc_tb_freq / 1000000, ppc_tb_freq % 1000000);
- printk(KERN_INFO "time_init: processor frequency = %lu.%.6lu MHz\n",
+ printk(KERN_DEBUG "time_init: processor frequency = %lu.%.6lu MHz\n",
ppc_proc_freq / 1000000, ppc_proc_freq % 1000000);
- tb_last_stamp = tb_last_jiffy = get_tb();
+ tb_last_jiffy = get_tb();
}
tb_ticks_per_jiffy = ppc_tb_freq / HZ;
- tb_ticks_per_sec = tb_ticks_per_jiffy * 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);
- div128_by_32(1024*1024, 0, tb_ticks_per_sec, &res);
- tb_to_xs = res.result_low;
+ calc_cputime_factors();
+
+ /*
+ * 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.
tb_to_ns_scale = scale;
tb_to_ns_shift = shift;
-#ifdef CONFIG_PPC_ISERIES
- if (!piranha_simulator)
-#endif
- tm = get_boot_time();
+ tm = get_boot_time();
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;
+ tm -= timezone_offset;
+ }
+
xtime.tv_sec = tm;
xtime.tv_nsec = 0;
do_gtod.varp = &do_gtod.vars[0];
do_gtod.var_idx = 0;
do_gtod.varp->tb_orig_stamp = tb_last_jiffy;
- __get_cpu_var(last_jiffy) = tb_last_stamp;
+ __get_cpu_var(last_jiffy) = tb_last_jiffy;
do_gtod.varp->stamp_xsec = (u64) xtime.tv_sec * XSEC_PER_SEC;
do_gtod.tb_ticks_per_sec = tb_ticks_per_sec;
do_gtod.varp->tb_to_xs = tb_to_xs;
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 = xtime.tv_sec * XSEC_PER_SEC;
+ vdso_data->stamp_xsec = (u64) xtime.tv_sec * XSEC_PER_SEC;
vdso_data->tb_to_xs = tb_to_xs;
time_freq = 0;
- /* 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;
- xtime.tv_sec -= timezone_offset;
- }
-
last_rtc_update = xtime.tv_sec;
set_normalized_timespec(&wall_to_monotonic,
-xtime.tv_sec, -xtime.tv_nsec);
set_dec(tb_ticks_per_jiffy);
}
-/*
- * After adjtimex is called, adjust the conversion of tb ticks
- * to microseconds to keep do_gettimeofday synchronized
- * with ntpd.
- *
- * Use the time_adjust, time_freq and time_offset computed by adjtimex to
- * adjust the frequency.
- */
-
-/* #define DEBUG_PPC_ADJTIMEX 1 */
-
-void ppc_adjtimex(void)
-{
-#ifdef CONFIG_PPC64
- unsigned long den, new_tb_ticks_per_sec, tb_ticks, old_xsec,
- new_tb_to_xs, new_xsec, new_stamp_xsec;
- unsigned long tb_ticks_per_sec_delta;
- long delta_freq, ltemp;
- struct div_result divres;
- unsigned long flags;
- long singleshot_ppm = 0;
-
- /*
- * Compute parts per million frequency adjustment to
- * accomplish the time adjustment implied by time_offset to be
- * applied over the elapsed time indicated by time_constant.
- * Use SHIFT_USEC to get it into the same units as
- * time_freq.
- */
- if ( time_offset < 0 ) {
- ltemp = -time_offset;
- ltemp <<= SHIFT_USEC - SHIFT_UPDATE;
- ltemp >>= SHIFT_KG + time_constant;
- ltemp = -ltemp;
- } else {
- ltemp = time_offset;
- ltemp <<= SHIFT_USEC - SHIFT_UPDATE;
- ltemp >>= SHIFT_KG + time_constant;
- }
-
- /* If there is a single shot time adjustment in progress */
- if ( time_adjust ) {
-#ifdef DEBUG_PPC_ADJTIMEX
- printk("ppc_adjtimex: ");
- if ( adjusting_time == 0 )
- printk("starting ");
- printk("single shot time_adjust = %ld\n", time_adjust);
-#endif
-
- adjusting_time = 1;
-
- /*
- * Compute parts per million frequency adjustment
- * to match time_adjust
- */
- singleshot_ppm = tickadj * HZ;
- /*
- * The adjustment should be tickadj*HZ to match the code in
- * linux/kernel/timer.c, but experiments show that this is too
- * large. 3/4 of tickadj*HZ seems about right
- */
- singleshot_ppm -= singleshot_ppm / 4;
- /* Use SHIFT_USEC to get it into the same units as time_freq */
- singleshot_ppm <<= SHIFT_USEC;
- if ( time_adjust < 0 )
- singleshot_ppm = -singleshot_ppm;
- }
- else {
-#ifdef DEBUG_PPC_ADJTIMEX
- if ( adjusting_time )
- printk("ppc_adjtimex: ending single shot time_adjust\n");
-#endif
- adjusting_time = 0;
- }
-
- /* Add up all of the frequency adjustments */
- delta_freq = time_freq + ltemp + singleshot_ppm;
-
- /*
- * Compute a new value for tb_ticks_per_sec based on
- * the frequency adjustment
- */
- den = 1000000 * (1 << (SHIFT_USEC - 8));
- if ( delta_freq < 0 ) {
- tb_ticks_per_sec_delta = ( tb_ticks_per_sec * ( (-delta_freq) >> (SHIFT_USEC - 8))) / den;
- new_tb_ticks_per_sec = tb_ticks_per_sec + tb_ticks_per_sec_delta;
- }
- else {
- tb_ticks_per_sec_delta = ( tb_ticks_per_sec * ( delta_freq >> (SHIFT_USEC - 8))) / den;
- new_tb_ticks_per_sec = tb_ticks_per_sec - tb_ticks_per_sec_delta;
- }
-
-#ifdef DEBUG_PPC_ADJTIMEX
- printk("ppc_adjtimex: ltemp = %ld, time_freq = %ld, singleshot_ppm = %ld\n", ltemp, time_freq, singleshot_ppm);
- printk("ppc_adjtimex: tb_ticks_per_sec - base = %ld new = %ld\n", tb_ticks_per_sec, new_tb_ticks_per_sec);
-#endif
-
- /*
- * Compute a new value of tb_to_xs (used to convert tb to
- * microseconds) and a new value of stamp_xsec which is the
- * time (in 1/2^20 second units) corresponding to
- * tb_orig_stamp. This new value of stamp_xsec compensates
- * for the change in frequency (implied by the new tb_to_xs)
- * which guarantees that the current time remains the same.
- */
- write_seqlock_irqsave( &xtime_lock, flags );
- tb_ticks = get_tb() - do_gtod.varp->tb_orig_stamp;
- div128_by_32(1024*1024, 0, new_tb_ticks_per_sec, &divres);
- new_tb_to_xs = divres.result_low;
- new_xsec = mulhdu(tb_ticks, new_tb_to_xs);
-
- old_xsec = mulhdu(tb_ticks, do_gtod.varp->tb_to_xs);
- new_stamp_xsec = do_gtod.varp->stamp_xsec + old_xsec - new_xsec;
-
- update_gtod(do_gtod.varp->tb_orig_stamp, new_stamp_xsec, new_tb_to_xs);
-
- write_sequnlock_irqrestore( &xtime_lock, flags );
-#endif /* CONFIG_PPC64 */
-}
-
#define FEBRUARY 2
#define STARTOFTIME 1970
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff