/*
- *
* Common time routines among all ppc machines.
*
* Written by Cort Dougan (cort@cs.nmt.edu) to merge
#include <linux/interrupt.h>
#include <linux/timex.h>
#include <linux/kernel_stat.h>
-#include <linux/mc146818rtc.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/profile.h>
#include <linux/cpu.h>
#include <linux/security.h>
+#include <linux/percpu.h>
+#include <linux/rtc.h>
#include <asm/io.h>
#include <asm/processor.h>
#include <asm/nvram.h>
#include <asm/cache.h>
#include <asm/machdep.h>
-#ifdef CONFIG_PPC_ISERIES
-#include <asm/iSeries/ItLpQueue.h>
-#include <asm/iSeries/HvCallXm.h>
-#endif
#include <asm/uaccess.h>
#include <asm/time.h>
-#include <asm/ppcdebug.h>
#include <asm/prom.h>
-#include <asm/sections.h>
+#include <asm/irq.h>
+#include <asm/div64.h>
+#ifdef CONFIG_PPC64
#include <asm/systemcfg.h>
#include <asm/firmware.h>
+#endif
+#ifdef CONFIG_PPC_ISERIES
+#include <asm/iSeries/ItLpQueue.h>
+#include <asm/iSeries/HvCallXm.h>
+#endif
u64 jiffies_64 __cacheline_aligned_in_smp = INITIAL_JIFFIES;
static unsigned long first_settimeofday = 1;
#endif
+/* The decrementer counts down by 128 every 128ns on a 601. */
+#define DECREMENTER_COUNT_601 (1000000000 / HZ)
+
#define XSEC_PER_SEC (1024*1024)
+#ifdef CONFIG_PPC64
+#define SCALE_XSEC(xsec, max) (((xsec) * max) / XSEC_PER_SEC)
+#else
+/* compute ((xsec << 12) * max) >> 32 */
+#define SCALE_XSEC(xsec, max) mulhwu((xsec) << 12, max)
+#endif
+
unsigned long tb_ticks_per_jiffy;
unsigned long tb_ticks_per_usec = 100; /* sane default */
EXPORT_SYMBOL(tb_ticks_per_usec);
unsigned long tb_ticks_per_sec;
-unsigned long tb_to_xs;
-unsigned tb_to_us;
+u64 tb_to_xs;
+unsigned tb_to_us;
unsigned long processor_freq;
DEFINE_SPINLOCK(rtc_lock);
EXPORT_SYMBOL_GPL(rtc_lock);
-unsigned long tb_to_ns_scale;
-unsigned long tb_to_ns_shift;
+u64 tb_to_ns_scale;
+unsigned tb_to_ns_shift;
struct gettimeofday_struct do_gtod;
extern unsigned long wall_jiffies;
-extern int smp_tb_synchronized;
extern struct timezone sys_tz;
+static long timezone_offset;
void ppc_adjtimex(void);
unsigned long ppc_proc_freq;
unsigned long ppc_tb_freq;
+#ifdef CONFIG_PPC32 /* XXX for now */
+#define boot_cpuid 0
+#endif
+
static __inline__ void timer_check_rtc(void)
{
/*
* seconds like on Intel to avoid problems with non UTC clocks.
*/
if (ntp_synced() &&
- xtime.tv_sec - last_rtc_update >= 659 &&
- abs((xtime.tv_nsec/1000) - (1000000-1000000/HZ)) < 500000/HZ &&
- jiffies - wall_jiffies == 1) {
- struct rtc_time tm;
- to_tm(xtime.tv_sec+1, &tm);
- tm.tm_year -= 1900;
- tm.tm_mon -= 1;
- if (ppc_md.set_rtc_time(&tm) == 0)
- last_rtc_update = xtime.tv_sec+1;
- else
- /* Try again one minute later */
- last_rtc_update += 60;
+ xtime.tv_sec - last_rtc_update >= 659 &&
+ abs((xtime.tv_nsec/1000) - (1000000-1000000/HZ)) < 500000/HZ &&
+ jiffies - wall_jiffies == 1) {
+ struct rtc_time tm;
+ to_tm(xtime.tv_sec + 1 + timezone_offset, &tm);
+ tm.tm_year -= 1900;
+ tm.tm_mon -= 1;
+ if (ppc_md.set_rtc_time(&tm) == 0)
+ last_rtc_update = xtime.tv_sec + 1;
+ else
+ /* Try again one minute later */
+ last_rtc_update += 60;
}
}
/*
* This version of gettimeofday has microsecond resolution.
*/
-static inline void __do_gettimeofday(struct timeval *tv, unsigned long tb_val)
+static inline void __do_gettimeofday(struct timeval *tv, u64 tb_val)
{
- unsigned long sec, usec, tb_ticks;
- unsigned long xsec, tb_xsec;
- struct gettimeofday_vars * temp_varp;
- unsigned long temp_tb_to_xs, temp_stamp_xsec;
+ unsigned long sec, usec;
+ u64 tb_ticks, xsec;
+ struct gettimeofday_vars *temp_varp;
+ u64 temp_tb_to_xs, temp_stamp_xsec;
/*
* These calculations are faster (gets rid of divides)
tb_ticks = tb_val - temp_varp->tb_orig_stamp;
temp_tb_to_xs = temp_varp->tb_to_xs;
temp_stamp_xsec = temp_varp->stamp_xsec;
- tb_xsec = mulhdu( tb_ticks, temp_tb_to_xs );
- xsec = temp_stamp_xsec + tb_xsec;
+ xsec = temp_stamp_xsec + mulhdu(tb_ticks, temp_tb_to_xs);
sec = xsec / XSEC_PER_SEC;
- xsec -= sec * XSEC_PER_SEC;
- usec = (xsec * USEC_PER_SEC)/XSEC_PER_SEC;
+ usec = (unsigned long)xsec & (XSEC_PER_SEC - 1);
+ usec = SCALE_XSEC(usec, 1000000);
tv->tv_sec = sec;
tv->tv_usec = usec;
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);
xtime.tv_sec = my_tv.tv_sec;
xtime.tv_nsec = my_tv.tv_usec * 1000;
}
+#endif
}
/*
- * When the timebase - tb_orig_stamp gets too big, we do a manipulation
- * between tb_orig_stamp and stamp_xsec. The goal here is to keep the
- * difference tb - tb_orig_stamp small enough to always fit inside a
- * 32 bits number. This is a requirement of our fast 32 bits userland
- * implementation in the vdso. If we "miss" a call to this function
- * (interrupt latency, CPU locked in a spinlock, ...) and we end up
- * with a too big difference, then the vdso will fallback to calling
- * the syscall
+ * There are two copies of tb_to_xs and stamp_xsec so that no
+ * lock is needed to access and use these values in
+ * do_gettimeofday. We alternate the copies and as long as a
+ * reasonable time elapses between changes, there will never
+ * be inconsistent values. ntpd has a minimum of one minute
+ * between updates.
*/
-static __inline__ void timer_recalc_offset(unsigned long cur_tb)
+static inline void update_gtod(u64 new_tb_stamp, u64 new_stamp_xsec,
+ unsigned int new_tb_to_xs)
{
- struct gettimeofday_vars * temp_varp;
unsigned temp_idx;
- unsigned long offset, new_stamp_xsec, new_tb_orig_stamp;
-
- if (((cur_tb - do_gtod.varp->tb_orig_stamp) & 0x80000000u) == 0)
- return;
+ struct gettimeofday_vars *temp_varp;
temp_idx = (do_gtod.var_idx == 0);
temp_varp = &do_gtod.vars[temp_idx];
- new_tb_orig_stamp = cur_tb;
- offset = new_tb_orig_stamp - do_gtod.varp->tb_orig_stamp;
- new_stamp_xsec = do_gtod.varp->stamp_xsec + mulhdu(offset, do_gtod.varp->tb_to_xs);
-
- temp_varp->tb_to_xs = do_gtod.varp->tb_to_xs;
- temp_varp->tb_orig_stamp = new_tb_orig_stamp;
+ temp_varp->tb_to_xs = new_tb_to_xs;
+ temp_varp->tb_orig_stamp = new_tb_stamp;
temp_varp->stamp_xsec = new_stamp_xsec;
smp_mb();
do_gtod.varp = temp_varp;
do_gtod.var_idx = temp_idx;
+#ifdef CONFIG_PPC64
+ /*
+ * 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
+ * stamp_xsec variables. It reads the tb_update_count, then reads
+ * tb_to_xs and stamp_xsec and then reads tb_update_count again. If
+ * 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.
+ */
++(systemcfg->tb_update_count);
smp_wmb();
- systemcfg->tb_orig_stamp = new_tb_orig_stamp;
+ systemcfg->tb_orig_stamp = new_tb_stamp;
systemcfg->stamp_xsec = new_stamp_xsec;
+ systemcfg->tb_to_xs = new_tb_to_xs;
smp_wmb();
++(systemcfg->tb_update_count);
+#endif
+}
+
+/*
+ * When the timebase - tb_orig_stamp gets too big, we do a manipulation
+ * between tb_orig_stamp and stamp_xsec. The goal here is to keep the
+ * difference tb - tb_orig_stamp small enough to always fit inside a
+ * 32 bits number. This is a requirement of our fast 32 bits userland
+ * implementation in the vdso. If we "miss" a call to this function
+ * (interrupt latency, CPU locked in a spinlock, ...) and we end up
+ * with a too big difference, then the vdso will fallback to calling
+ * the syscall
+ */
+static __inline__ void timer_recalc_offset(u64 cur_tb)
+{
+ unsigned long offset;
+ u64 new_stamp_xsec;
+
+ offset = cur_tb - do_gtod.varp->tb_orig_stamp;
+ if ((offset & 0x80000000u) == 0)
+ 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);
}
#ifdef CONFIG_SMP
* call will not be needed)
*/
-unsigned long tb_last_stamp __cacheline_aligned_in_smp;
+u64 tb_last_stamp __cacheline_aligned_in_smp;
+
+/*
+ * 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.
+ */
+DEFINE_PER_CPU(unsigned long, last_jiffy);
/*
* timer_interrupt - gets called when the decrementer overflows,
void timer_interrupt(struct pt_regs * regs)
{
int next_dec;
- unsigned long cur_tb;
- struct paca_struct *lpaca = get_paca();
- unsigned long cpu = smp_processor_id();
+ int cpu = smp_processor_id();
+ unsigned long ticks;
+
+#ifdef CONFIG_PPC32
+ if (atomic_read(&ppc_n_lost_interrupts) != 0)
+ do_IRQ(regs);
+#endif
irq_enter();
profile_tick(CPU_PROFILING, regs);
- lpaca->lppaca.int_dword.fields.decr_int = 0;
+#ifdef CONFIG_PPC_ISERIES
+ get_paca()->lppaca.int_dword.fields.decr_int = 0;
+#endif
+
+ while ((ticks = tb_ticks_since(per_cpu(last_jiffy, cpu)))
+ >= tb_ticks_per_jiffy) {
+ /* Update last_jiffy */
+ per_cpu(last_jiffy, cpu) += tb_ticks_per_jiffy;
+ /* Handle RTCL overflow on 601 */
+ if (__USE_RTC() && per_cpu(last_jiffy, cpu) >= 1000000000)
+ per_cpu(last_jiffy, cpu) -= 1000000000;
- while (lpaca->next_jiffy_update_tb <= (cur_tb = get_tb())) {
/*
* We cannot disable the decrementer, so in the period
* between this cpu's being marked offline in cpu_online_map
*/
if (!cpu_is_offline(cpu))
update_process_times(user_mode(regs));
+
/*
* No need to check whether cpu is offline here; boot_cpuid
* should have been fixed up by now.
*/
- if (cpu == boot_cpuid) {
- write_seqlock(&xtime_lock);
- tb_last_stamp = lpaca->next_jiffy_update_tb;
- timer_recalc_offset(lpaca->next_jiffy_update_tb);
- do_timer(regs);
- timer_sync_xtime(lpaca->next_jiffy_update_tb);
- timer_check_rtc();
- write_sequnlock(&xtime_lock);
- if ( adjusting_time && (time_adjust == 0) )
- ppc_adjtimex();
- }
- lpaca->next_jiffy_update_tb += tb_ticks_per_jiffy;
+ if (cpu != boot_cpuid)
+ continue;
+
+ write_seqlock(&xtime_lock);
+ tb_last_stamp += tb_ticks_per_jiffy;
+ timer_recalc_offset(tb_last_stamp);
+ do_timer(regs);
+ timer_sync_xtime(tb_last_stamp);
+ timer_check_rtc();
+ write_sequnlock(&xtime_lock);
+ if (adjusting_time && (time_adjust == 0))
+ ppc_adjtimex();
}
- next_dec = lpaca->next_jiffy_update_tb - cur_tb;
- if (next_dec > lpaca->default_decr)
- next_dec = lpaca->default_decr;
+ next_dec = tb_ticks_per_jiffy - ticks;
set_dec(next_dec);
#ifdef CONFIG_PPC_ISERIES
process_hvlpevents(regs);
#endif
+#ifdef CONFIG_PPC64
/* collect purr register values often, for accurate calculations */
if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
cu->current_tb = mfspr(SPRN_PURR);
}
+#endif
irq_exit();
}
+void wakeup_decrementer(void)
+{
+ int i;
+
+ 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.
+ */
+ tb_last_stamp = get_tb();
+ for_each_cpu(i)
+ per_cpu(last_jiffy, i) = tb_last_stamp;
+}
+
+#ifdef CONFIG_SMPxxx
+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);
+
+ for_each_cpu(i) {
+ if (i != boot_cpuid) {
+ previous_tb += offset;
+ per_cpu(last_jiffy, i) = previous_tb;
+ }
+ }
+}
+#endif
+
/*
* Scheduler clock - returns current time in nanosec units.
*
time_t wtm_sec, new_sec = tv->tv_sec;
long wtm_nsec, new_nsec = tv->tv_nsec;
unsigned long flags;
- unsigned long delta_xsec;
long int tb_delta;
- unsigned long new_xsec;
+ u64 new_xsec;
if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
return -EINVAL;
write_seqlock_irqsave(&xtime_lock, flags);
- /* Updating the RTC is not the job of this code. If the time is
- * stepped under NTP, the RTC will be update after STA_UNSYNC
- * is cleared. Tool like clock/hwclock either copy the RTC
+
+ /*
+ * Updating the RTC is not the job of this code. If the time is
+ * stepped under NTP, the RTC will be updated after STA_UNSYNC
+ * is cleared. Tools like clock/hwclock either copy the RTC
* to the system time, in which case there is no point in writing
* to the RTC again, or write to the RTC but then they don't call
* settimeofday to perform this operation.
*/
#ifdef CONFIG_PPC_ISERIES
- if ( first_settimeofday ) {
+ if (first_settimeofday) {
iSeries_tb_recal();
first_settimeofday = 0;
}
tb_delta = tb_ticks_since(tb_last_stamp);
tb_delta += (jiffies - wall_jiffies) * tb_ticks_per_jiffy;
- new_nsec -= tb_delta / tb_ticks_per_usec / 1000;
+ new_nsec -= 1000 * mulhwu(tb_to_us, tb_delta);
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();
- delta_xsec = mulhdu( (tb_last_stamp-do_gtod.varp->tb_orig_stamp),
- do_gtod.varp->tb_to_xs );
-
- new_xsec = (new_nsec * XSEC_PER_SEC) / NSEC_PER_SEC;
- new_xsec += new_sec * XSEC_PER_SEC;
- if ( new_xsec > delta_xsec ) {
- do_gtod.varp->stamp_xsec = new_xsec - delta_xsec;
- systemcfg->stamp_xsec = new_xsec - delta_xsec;
- }
- else {
- /* This is only for the case where the user is setting the time
- * way back to a time such that the boot time would have been
- * before 1970 ... eg. we booted ten days ago, and we are setting
- * the time to Jan 5, 1970 */
- do_gtod.varp->stamp_xsec = new_xsec;
- do_gtod.varp->tb_orig_stamp = tb_last_stamp;
- systemcfg->stamp_xsec = new_xsec;
- systemcfg->tb_orig_stamp = tb_last_stamp;
- }
+ new_xsec = (u64)new_nsec * XSEC_PER_SEC;
+ do_div(new_xsec, NSEC_PER_SEC);
+ new_xsec += (u64)new_sec * XSEC_PER_SEC;
+ update_gtod(tb_last_stamp, new_xsec, do_gtod.varp->tb_to_xs);
+#ifdef CONFIG_PPC64
systemcfg->tz_minuteswest = sys_tz.tz_minuteswest;
systemcfg->tz_dsttime = sys_tz.tz_dsttime;
+#endif
write_sequnlock_irqrestore(&xtime_lock, flags);
clock_was_set();
tb_to_us = mulhwu_scale_factor(ppc_tb_freq, 1000000);
div128_by_32(1024*1024, 0, tb_ticks_per_sec, &divres);
tb_to_xs = divres.result_low;
-
- setup_default_decr();
}
#endif
+unsigned long get_boot_time(void)
+{
+ struct rtc_time tm;
+
+ if (ppc_md.get_boot_time)
+ return ppc_md.get_boot_time();
+ if (!ppc_md.get_rtc_time)
+ return 0;
+ ppc_md.get_rtc_time(&tm);
+ return mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday,
+ tm.tm_hour, tm.tm_min, tm.tm_sec);
+}
+
+/* This function is only called on the boot processor */
void __init time_init(void)
{
- /* This function is only called on the boot processor */
unsigned long flags;
- struct rtc_time tm;
+ unsigned long tm = 0;
struct div_result res;
- unsigned long scale, shift;
+ u64 scale;
+ unsigned shift;
+
+ if (ppc_md.time_init != NULL)
+ timezone_offset = ppc_md.time_init();
ppc_md.calibrate_decr();
+#ifdef CONFIG_PPC64
+ get_paca()->default_decr = tb_ticks_per_jiffy;
+#endif
+
/*
* Compute scale factor for sched_clock.
* The calibrate_decr() function has set tb_ticks_per_sec,
#ifdef CONFIG_PPC_ISERIES
if (!piranha_simulator)
#endif
- ppc_md.get_boot_time(&tm);
+ tm = get_boot_time();
write_seqlock_irqsave(&xtime_lock, flags);
- xtime.tv_sec = mktime(tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
- tm.tm_hour, tm.tm_min, tm.tm_sec);
+ xtime.tv_sec = tm;
+ xtime.tv_nsec = 0;
tb_last_stamp = get_tb();
do_gtod.varp = &do_gtod.vars[0];
do_gtod.var_idx = 0;
do_gtod.varp->tb_orig_stamp = tb_last_stamp;
- get_paca()->next_jiffy_update_tb = tb_last_stamp + tb_ticks_per_jiffy;
- do_gtod.varp->stamp_xsec = xtime.tv_sec * XSEC_PER_SEC;
+ __get_cpu_var(last_jiffy) = tb_last_stamp;
+ 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;
do_gtod.tb_to_us = tb_to_us;
+#ifdef CONFIG_PPC64
systemcfg->tb_orig_stamp = tb_last_stamp;
systemcfg->tb_update_count = 0;
systemcfg->tb_ticks_per_sec = tb_ticks_per_sec;
systemcfg->stamp_xsec = xtime.tv_sec * XSEC_PER_SEC;
systemcfg->tb_to_xs = tb_to_xs;
+#endif
time_freq = 0;
- xtime.tv_nsec = 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);
void ppc_adjtimex(void)
{
- unsigned long den, new_tb_ticks_per_sec, tb_ticks, old_xsec, new_tb_to_xs, new_xsec, new_stamp_xsec;
+#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;
- struct gettimeofday_vars * temp_varp;
- unsigned temp_idx;
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. */
+ /*
+ * 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 {
+ } else {
ltemp = time_offset;
ltemp <<= SHIFT_USEC - SHIFT_UPDATE;
ltemp >>= SHIFT_KG + time_constant;
adjusting_time = 1;
- /* Compute parts per million frequency adjustment to match time_adjust */
+ /*
+ * 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
* 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 */
+ /* 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;
/* 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 */
+ /*
+ * 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;
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 */
+
+ /*
+ * 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 );
+ 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 );
+ new_xsec = mulhdu(tb_ticks, new_tb_to_xs);
- old_xsec = mulhdu( tb_ticks, do_gtod.varp->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;
- /* There are two copies of tb_to_xs and stamp_xsec so that no lock is needed to access and use these
- values in do_gettimeofday. We alternate the copies and as long as a reasonable time elapses between
- changes, there will never be inconsistent values. ntpd has a minimum of one minute between updates */
-
- temp_idx = (do_gtod.var_idx == 0);
- temp_varp = &do_gtod.vars[temp_idx];
-
- temp_varp->tb_to_xs = new_tb_to_xs;
- temp_varp->stamp_xsec = new_stamp_xsec;
- temp_varp->tb_orig_stamp = do_gtod.varp->tb_orig_stamp;
- smp_mb();
- do_gtod.varp = temp_varp;
- do_gtod.var_idx = temp_idx;
-
- /*
- * tb_update_count is used to allow the problem state gettimeofday code
- * to assure itself that it sees a consistent view of the tb_to_xs and
- * stamp_xsec variables. It reads the tb_update_count, then reads
- * tb_to_xs and stamp_xsec and then reads tb_update_count again. If
- * 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.
- */
- ++(systemcfg->tb_update_count);
- smp_wmb();
- systemcfg->tb_to_xs = new_tb_to_xs;
- systemcfg->stamp_xsec = new_stamp_xsec;
- smp_wmb();
- ++(systemcfg->tb_update_count);
+ 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 TICK_SIZE tick
#define FEBRUARY 2
#define STARTOFTIME 1970
#define SECDAY 86400L
#define SECYR (SECDAY * 365)
-#define leapyear(year) ((year) % 4 == 0)
+#define leapyear(year) ((year) % 4 == 0 && \
+ ((year) % 100 != 0 || (year) % 400 == 0))
#define days_in_year(a) (leapyear(a) ? 366 : 365)
#define days_in_month(a) (month_days[(a) - 1])
int day;
int MonthOffset[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
- lastYear=tm->tm_year-1;
+ lastYear = tm->tm_year - 1;
/*
* Number of leap corrections to apply up to end of last year
*/
- leapsToDate = lastYear/4 - lastYear/100 + lastYear/400;
+ leapsToDate = lastYear / 4 - lastYear / 100 + lastYear / 400;
/*
* This year is a leap year if it is divisible by 4 except when it is
* divisible by 100 unless it is divisible by 400
*
- * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 will be
+ * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 was
*/
- if((tm->tm_year%4==0) &&
- ((tm->tm_year%100!=0) || (tm->tm_year%400==0)) &&
- (tm->tm_mon>2))
- {
- /*
- * We are past Feb. 29 in a leap year
- */
- day=1;
- }
- else
- {
- day=0;
- }
+ day = tm->tm_mon > 2 && leapyear(tm->tm_year);
day += lastYear*365 + leapsToDate + MonthOffset[tm->tm_mon-1] +
tm->tm_mday;
- tm->tm_wday=day%7;
+ tm->tm_wday = day % 7;
}
void to_tm(int tim, struct rtc_time * tm)
* oscillators and the precision with which the timebase frequency
* is measured but does not harm.
*/
-unsigned mulhwu_scale_factor(unsigned inscale, unsigned outscale) {
+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;
+ if (mulhwu(inscale, mlt|tmp) < outscale)
+ mlt |= tmp;
}
/* We might still be off by 1 for the best approximation.
* some might have been forgotten in the test however.
*/
- err = inscale*(mlt+1);
- if (err <= inscale/2) mlt++;
+ 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.
*/
-
-void div128_by_32( unsigned long dividend_high, unsigned long dividend_low,
- unsigned divisor, struct div_result *dr )
+void div128_by_32(u64 dividend_high, u64 dividend_low,
+ unsigned divisor, struct div_result *dr)
{
- unsigned long a,b,c,d, w,x,y,z, ra,rb,rc;
+ unsigned long a, b, c, d;
+ unsigned long w, x, y, z;
+ u64 ra, rb, rc;
a = dividend_high >> 32;
b = dividend_high & 0xffffffff;
c = dividend_low >> 32;
d = dividend_low & 0xffffffff;
- w = a/divisor;
- ra = (a - (w * divisor)) << 32;
+ w = a / divisor;
+ ra = ((u64)(a - (w * divisor)) << 32) + b;
+
+#ifdef CONFIG_PPC64
+ x = ra / divisor;
+ rb = ((ra - (x * divisor)) << 32) + c;
- x = (ra + b)/divisor;
- rb = ((ra + b) - (x * divisor)) << 32;
+ y = rb / divisor;
+ rc = ((rb - (y * divisor)) << 32) + d;
- y = (rb + c)/divisor;
- rc = ((rb + b) - (y * divisor)) << 32;
+ z = rc / divisor;
+#else
+ /* for 32-bit, use do_div from div64.h */
+ rb = ((u64) do_div(ra, divisor) << 32) + c;
+ x = ra;
- z = (rc + d)/divisor;
+ rc = ((u64) do_div(rb, divisor) << 32) + d;
+ y = rb;
+
+ do_div(rc, divisor);
+ z = rc;
+#endif
- dr->result_high = (w << 32) + x;
- dr->result_low = (y << 32) + z;
+ dr->result_high = ((u64)w << 32) + x;
+ dr->result_low = ((u64)y << 32) + z;
}
projects / linux-2.6 / commitdiff