/* * Common time routines among all ppc machines. * * Written by Cort Dougan (cort@cs.nmt.edu) to merge * Paul Mackerras' version and mine for PReP and Pmac. * MPC8xx/MBX changes by Dan Malek (dmalek@jlc.net). * Converted for 64-bit by Mike Corrigan (mikejc@us.ibm.com) * * First round of bugfixes by Gabriel Paubert (paubert@iram.es) * to make clock more stable (2.4.0-test5). The only thing * that this code assumes is that the timebases have been synchronized * by firmware on SMP and are never stopped (never do sleep * on SMP then, nap and doze are OK). * * Speeded up do_gettimeofday by getting rid of references to * xtime (which required locks for consistency). (mikejc@us.ibm.com) * * TODO (not necessarily in this file): * - improve precision and reproducibility of timebase frequency * measurement at boot time. * - for astronomical applications: add a new function to get * non ambiguous timestamps even around leap seconds. This needs * a new timestamp format and a good name. * * 1997-09-10 Updated NTP code according to technical memorandum Jan '96 * "A Kernel Model for Precision Timekeeping" by Dave Mills * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* powerpc clocksource/clockevent code */ #include #include static cycle_t rtc_read(struct clocksource *); static struct clocksource clocksource_rtc = { .name = "rtc", .rating = 400, .flags = CLOCK_SOURCE_IS_CONTINUOUS, .mask = CLOCKSOURCE_MASK(64), .read = rtc_read, }; static cycle_t timebase_read(struct clocksource *); static struct clocksource clocksource_timebase = { .name = "timebase", .rating = 400, .flags = CLOCK_SOURCE_IS_CONTINUOUS, .mask = CLOCKSOURCE_MASK(64), .read = timebase_read, }; #define DECREMENTER_MAX 0x7fffffff static int decrementer_set_next_event(unsigned long evt, struct clock_event_device *dev); static void decrementer_set_mode(enum clock_event_mode mode, struct clock_event_device *dev); struct clock_event_device decrementer_clockevent = { .name = "decrementer", .rating = 200, .irq = 0, .set_next_event = decrementer_set_next_event, .set_mode = decrementer_set_mode, .features = CLOCK_EVT_FEAT_ONESHOT, }; EXPORT_SYMBOL(decrementer_clockevent); DEFINE_PER_CPU(u64, decrementers_next_tb); static DEFINE_PER_CPU(struct clock_event_device, decrementers); #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; EXPORT_SYMBOL(tb_ticks_per_sec); /* for cputime_t conversions */ DEFINE_SPINLOCK(rtc_lock); EXPORT_SYMBOL_GPL(rtc_lock); static u64 tb_to_ns_scale __read_mostly; static unsigned tb_to_ns_shift __read_mostly; static u64 boot_tb __read_mostly; extern struct timezone sys_tz; static long timezone_offset; unsigned long ppc_proc_freq; EXPORT_SYMBOL_GPL(ppc_proc_freq); unsigned long ppc_tb_freq; EXPORT_SYMBOL_GPL(ppc_tb_freq); #ifdef CONFIG_VIRT_CPU_ACCOUNTING /* * Factors for converting from cputime_t (timebase ticks) to * 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_usec_factor; EXPORT_SYMBOL(__cputime_usec_factor); u64 __cputime_sec_factor; EXPORT_SYMBOL(__cputime_sec_factor); u64 __cputime_clockt_factor; EXPORT_SYMBOL(__cputime_clockt_factor); DEFINE_PER_CPU(unsigned long, cputime_last_delta); DEFINE_PER_CPU(unsigned long, cputime_scaled_last_delta); cputime_t cputime_one_jiffy; void (*dtl_consumer)(struct dtl_entry *, u64); 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(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); __cputime_clockt_factor = res.result_low; } /* * Read the SPURR on systems that have it, otherwise the PURR, * or if that doesn't exist return the timebase value passed in. */ static u64 read_spurr(u64 tb) { if (cpu_has_feature(CPU_FTR_SPURR)) return mfspr(SPRN_SPURR); if (cpu_has_feature(CPU_FTR_PURR)) return mfspr(SPRN_PURR); return tb; } #ifdef CONFIG_PPC_SPLPAR /* * Scan the dispatch trace log and count up the stolen time. * Should be called with interrupts disabled. */ static u64 scan_dispatch_log(u64 stop_tb) { u64 i = local_paca->dtl_ridx; struct dtl_entry *dtl = local_paca->dtl_curr; struct dtl_entry *dtl_end = local_paca->dispatch_log_end; struct lppaca *vpa = local_paca->lppaca_ptr; u64 tb_delta; u64 stolen = 0; u64 dtb; if (!dtl) return 0; if (i == vpa->dtl_idx) return 0; while (i < vpa->dtl_idx) { if (dtl_consumer) dtl_consumer(dtl, i); dtb = dtl->timebase; tb_delta = dtl->enqueue_to_dispatch_time + dtl->ready_to_enqueue_time; barrier(); if (i + N_DISPATCH_LOG < vpa->dtl_idx) { /* buffer has overflowed */ i = vpa->dtl_idx - N_DISPATCH_LOG; dtl = local_paca->dispatch_log + (i % N_DISPATCH_LOG); continue; } if (dtb > stop_tb) break; stolen += tb_delta; ++i; ++dtl; if (dtl == dtl_end) dtl = local_paca->dispatch_log; } local_paca->dtl_ridx = i; local_paca->dtl_curr = dtl; return stolen; } /* * Accumulate stolen time by scanning the dispatch trace log. * Called on entry from user mode. */ void accumulate_stolen_time(void) { u64 sst, ust; u8 save_soft_enabled = local_paca->soft_enabled; /* We are called early in the exception entry, before * soft/hard_enabled are sync'ed to the expected state * for the exception. We are hard disabled but the PACA * needs to reflect that so various debug stuff doesn't * complain */ local_paca->soft_enabled = 0; sst = scan_dispatch_log(local_paca->starttime_user); ust = scan_dispatch_log(local_paca->starttime); local_paca->system_time -= sst; local_paca->user_time -= ust; local_paca->stolen_time += ust + sst; local_paca->soft_enabled = save_soft_enabled; } static inline u64 calculate_stolen_time(u64 stop_tb) { u64 stolen = 0; if (get_paca()->dtl_ridx != get_paca()->lppaca_ptr->dtl_idx) { stolen = scan_dispatch_log(stop_tb); get_paca()->system_time -= stolen; } stolen += get_paca()->stolen_time; get_paca()->stolen_time = 0; return stolen; } #else /* CONFIG_PPC_SPLPAR */ static inline u64 calculate_stolen_time(u64 stop_tb) { return 0; } #endif /* CONFIG_PPC_SPLPAR */ /* * Account time for a transition between system, hard irq * or soft irq state. */ static u64 vtime_delta(struct task_struct *tsk, u64 *sys_scaled, u64 *stolen) { u64 now, nowscaled, deltascaled; u64 udelta, delta, user_scaled; now = mftb(); nowscaled = read_spurr(now); get_paca()->system_time += now - get_paca()->starttime; get_paca()->starttime = now; deltascaled = nowscaled - get_paca()->startspurr; get_paca()->startspurr = nowscaled; *stolen = calculate_stolen_time(now); delta = get_paca()->system_time; get_paca()->system_time = 0; udelta = get_paca()->user_time - get_paca()->utime_sspurr; get_paca()->utime_sspurr = get_paca()->user_time; /* * Because we don't read the SPURR on every kernel entry/exit, * deltascaled includes both user and system SPURR ticks. * Apportion these ticks to system SPURR ticks and user * SPURR ticks in the same ratio as the system time (delta) * and user time (udelta) values obtained from the timebase * over the same interval. The system ticks get accounted here; * the user ticks get saved up in paca->user_time_scaled to be * used by account_process_tick. */ *sys_scaled = delta; user_scaled = udelta; if (deltascaled != delta + udelta) { if (udelta) { *sys_scaled = deltascaled * delta / (delta + udelta); user_scaled = deltascaled - *sys_scaled; } else { *sys_scaled = deltascaled; } } get_paca()->user_time_scaled += user_scaled; return delta; } void vtime_account_system(struct task_struct *tsk) { u64 delta, sys_scaled, stolen; delta = vtime_delta(tsk, &sys_scaled, &stolen); account_system_time(tsk, 0, delta, sys_scaled); if (stolen) account_steal_time(stolen); } void vtime_account_idle(struct task_struct *tsk) { u64 delta, sys_scaled, stolen; delta = vtime_delta(tsk, &sys_scaled, &stolen); account_idle_time(delta + stolen); } /* * 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. * Assumes that vtime_account() has been called recently * (i.e. since the last entry from usermode) so that * get_paca()->user_time_scaled is up to date. */ void account_process_tick(struct task_struct *tsk, int user_tick) { cputime_t utime, utimescaled; utime = get_paca()->user_time; utimescaled = get_paca()->user_time_scaled; get_paca()->user_time = 0; get_paca()->user_time_scaled = 0; get_paca()->utime_sspurr = 0; account_user_time(tsk, utime, utimescaled); } void vtime_task_switch(struct task_struct *prev) { vtime_account(prev); account_process_tick(prev, 0); } #else /* ! CONFIG_VIRT_CPU_ACCOUNTING */ #define calc_cputime_factors() #endif void __delay(unsigned long loops) { unsigned long start; int diff; if (__USE_RTC()) { start = get_rtcl(); do { /* the RTCL register wraps at 1000000000 */ diff = get_rtcl() - start; if (diff < 0) diff += 1000000000; } while (diff < loops); } else { start = get_tbl(); while (get_tbl() - start < loops) HMT_low(); HMT_medium(); } } EXPORT_SYMBOL(__delay); void udelay(unsigned long usecs) { __delay(tb_ticks_per_usec * usecs); } EXPORT_SYMBOL(udelay); #ifdef CONFIG_SMP unsigned long profile_pc(struct pt_regs *regs) { unsigned long pc = instruction_pointer(regs); if (in_lock_functions(pc)) return regs->link; return pc; } EXPORT_SYMBOL(profile_pc); #endif #ifdef CONFIG_IRQ_WORK /* * 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable... */ #ifdef CONFIG_PPC64 static inline unsigned long test_irq_work_pending(void) { unsigned long x; asm volatile("lbz %0,%1(13)" : "=r" (x) : "i" (offsetof(struct paca_struct, irq_work_pending))); return x; } static inline void set_irq_work_pending_flag(void) { asm volatile("stb %0,%1(13)" : : "r" (1), "i" (offsetof(struct paca_struct, irq_work_pending))); } static inline void clear_irq_work_pending(void) { asm volatile("stb %0,%1(13)" : : "r" (0), "i" (offsetof(struct paca_struct, irq_work_pending))); } #else /* 32-bit */ DEFINE_PER_CPU(u8, irq_work_pending); #define set_irq_work_pending_flag() __get_cpu_var(irq_work_pending) = 1 #define test_irq_work_pending() __get_cpu_var(irq_work_pending) #define clear_irq_work_pending() __get_cpu_var(irq_work_pending) = 0 #endif /* 32 vs 64 bit */ void arch_irq_work_raise(void) { preempt_disable(); set_irq_work_pending_flag(); set_dec(1); preempt_enable(); } #else /* CONFIG_IRQ_WORK */ #define test_irq_work_pending() 0 #define clear_irq_work_pending() #endif /* CONFIG_IRQ_WORK */ /* * timer_interrupt - gets called when the decrementer overflows, * with interrupts disabled. */ void timer_interrupt(struct pt_regs * regs) { struct pt_regs *old_regs; u64 *next_tb = &__get_cpu_var(decrementers_next_tb); struct clock_event_device *evt = &__get_cpu_var(decrementers); u64 now; /* Ensure a positive value is written to the decrementer, or else * some CPUs will continue to take decrementer exceptions. */ set_dec(DECREMENTER_MAX); /* Some implementations of hotplug will get timer interrupts while * offline, just ignore these */ if (!cpu_online(smp_processor_id())) return; /* Conditionally hard-enable interrupts now that the DEC has been * bumped to its maximum value */ may_hard_irq_enable(); __get_cpu_var(irq_stat).timer_irqs++; #if defined(CONFIG_PPC32) && defined(CONFIG_PMAC) if (atomic_read(&ppc_n_lost_interrupts) != 0) do_IRQ(regs); #endif old_regs = set_irq_regs(regs); irq_enter(); trace_timer_interrupt_entry(regs); if (test_irq_work_pending()) { clear_irq_work_pending(); irq_work_run(); } now = get_tb_or_rtc(); if (now >= *next_tb) { *next_tb = ~(u64)0; if (evt->event_handler) evt->event_handler(evt); } else { now = *next_tb - now; if (now <= DECREMENTER_MAX) set_dec((int)now); } #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 trace_timer_interrupt_exit(regs); irq_exit(); set_irq_regs(old_regs); } /* * Hypervisor decrementer interrupts shouldn't occur but are sometimes * left pending on exit from a KVM guest. We don't need to do anything * to clear them, as they are edge-triggered. */ void hdec_interrupt(struct pt_regs *regs) { } #ifdef CONFIG_SUSPEND static void generic_suspend_disable_irqs(void) { /* Disable the decrementer, so that it doesn't interfere * with suspending. */ set_dec(DECREMENTER_MAX); local_irq_disable(); set_dec(DECREMENTER_MAX); } static void generic_suspend_enable_irqs(void) { local_irq_enable(); } /* Overrides the weak version in kernel/power/main.c */ void arch_suspend_disable_irqs(void) { if (ppc_md.suspend_disable_irqs) ppc_md.suspend_disable_irqs(); generic_suspend_disable_irqs(); } /* Overrides the weak version in kernel/power/main.c */ void arch_suspend_enable_irqs(void) { generic_suspend_enable_irqs(); if (ppc_md.suspend_enable_irqs) ppc_md.suspend_enable_irqs(); } #endif /* * Scheduler clock - returns current time in nanosec units. * * Note: mulhdu(a, b) (multiply high double unsigned) returns * the high 64 bits of a * b, i.e. (a * b) >> 64, where a and b * are 64-bit unsigned numbers. */ unsigned long long sched_clock(void) { if (__USE_RTC()) return get_rtc(); return mulhdu(get_tb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift; } static int __init get_freq(char *name, int cells, unsigned long *val) { struct device_node *cpu; const unsigned int *fp; int found = 0; /* The cpu node should have timebase and clock frequency properties */ cpu = of_find_node_by_type(NULL, "cpu"); if (cpu) { fp = of_get_property(cpu, name, NULL); if (fp) { found = 1; *val = of_read_ulong(fp, cells); } of_node_put(cpu); } return found; } /* should become __cpuinit when secondary_cpu_time_init also is */ void start_cpu_decrementer(void) { #if defined(CONFIG_BOOKE) || defined(CONFIG_40x) /* Clear any pending timer interrupts */ mtspr(SPRN_TSR, TSR_ENW | TSR_WIS | TSR_DIS | TSR_FIS); /* Enable decrementer interrupt */ mtspr(SPRN_TCR, TCR_DIE); #endif /* defined(CONFIG_BOOKE) || defined(CONFIG_40x) */ } 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; /* 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"); } } int update_persistent_clock(struct timespec now) { struct rtc_time tm; if (!ppc_md.set_rtc_time) return 0; to_tm(now.tv_sec + 1 + timezone_offset, &tm); tm.tm_year -= 1900; tm.tm_mon -= 1; return ppc_md.set_rtc_time(&tm); } static void __read_persistent_clock(struct timespec *ts) { struct rtc_time tm; static int first = 1; ts->tv_nsec = 0; /* XXX this is a litle fragile but will work okay in the short term */ if (first) { first = 0; if (ppc_md.time_init) timezone_offset = ppc_md.time_init(); /* get_boot_time() isn't guaranteed to be safe to call late */ if (ppc_md.get_boot_time) { ts->tv_sec = ppc_md.get_boot_time() - timezone_offset; return; } } if (!ppc_md.get_rtc_time) { ts->tv_sec = 0; return; } ppc_md.get_rtc_time(&tm); ts->tv_sec = mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec); } void read_persistent_clock(struct timespec *ts) { __read_persistent_clock(ts); /* Sanitize it in case real time clock is set below EPOCH */ if (ts->tv_sec < 0) { ts->tv_sec = 0; ts->tv_nsec = 0; } } /* clocksource code */ static cycle_t rtc_read(struct clocksource *cs) { return (cycle_t)get_rtc(); } static cycle_t timebase_read(struct clocksource *cs) { return (cycle_t)get_tb(); } void update_vsyscall_old(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(); /* 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; 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 * 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. * We expect the caller to have done the first increment of * vdso_data->tb_update_count already. */ 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 = 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_tz(void) { /* Make userspace gettimeofday spin until we're done. */ ++vdso_data->tb_update_count; smp_mb(); vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; vdso_data->tz_dsttime = sys_tz.tz_dsttime; smp_mb(); ++vdso_data->tb_update_count; } static void __init clocksource_init(void) { struct clocksource *clock; if (__USE_RTC()) clock = &clocksource_rtc; else clock = &clocksource_timebase; if (clocksource_register_hz(clock, tb_ticks_per_sec)) { printk(KERN_ERR "clocksource: %s is already registered\n", clock->name); return; } printk(KERN_INFO "clocksource: %s mult[%x] shift[%d] registered\n", clock->name, clock->mult, clock->shift); } 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; set_dec(evt); return 0; } static void decrementer_set_mode(enum clock_event_mode mode, struct clock_event_device *dev) { if (mode != CLOCK_EVT_MODE_ONESHOT) decrementer_set_next_event(DECREMENTER_MAX, dev); } static void register_decrementer_clockevent(int cpu) { struct clock_event_device *dec = &per_cpu(decrementers, cpu); *dec = decrementer_clockevent; dec->cpumask = cpumask_of(cpu); printk_once(KERN_DEBUG "clockevent: %s mult[%x] shift[%d] cpu[%d]\n", dec->name, dec->mult, dec->shift, cpu); clockevents_register_device(dec); } static void __init init_decrementer_clockevent(void) { int cpu = smp_processor_id(); 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 = clockevent_delta2ns(2, &decrementer_clockevent); register_decrementer_clockevent(cpu); } void secondary_cpu_time_init(void) { /* Start the decrementer on CPUs that have manual control * such as BookE */ start_cpu_decrementer(); /* FIME: Should make unrelatred change to move snapshot_timebase * call here ! */ register_decrementer_clockevent(smp_processor_id()); } /* This function is only called on the boot processor */ void __init time_init(void) { struct div_result res; u64 scale; unsigned shift; if (__USE_RTC()) { /* 601 processor: dec counts down by 128 every 128ns */ ppc_tb_freq = 1000000000; } else { /* Normal PowerPC with timebase register */ ppc_md.calibrate_decr(); printk(KERN_DEBUG "time_init: decrementer frequency = %lu.%.6lu MHz\n", 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_ticks_per_jiffy = ppc_tb_freq / HZ; tb_ticks_per_sec = ppc_tb_freq; tb_ticks_per_usec = ppc_tb_freq / 1000000; calc_cputime_factors(); setup_cputime_one_jiffy(); /* * Compute scale factor for sched_clock. * The calibrate_decr() function has set tb_ticks_per_sec, * which is the timebase frequency. * We compute 1e9 * 2^64 / tb_ticks_per_sec and interpret * the 128-bit result as a 64.64 fixed-point number. * We then shift that number right until it is less than 1.0, * giving us the scale factor and shift count to use in * sched_clock(). */ div128_by_32(1000000000, 0, tb_ticks_per_sec, &res); scale = res.result_low; for (shift = 0; res.result_high != 0; ++shift) { scale = (scale >> 1) | (res.result_high << 63); res.result_high >>= 1; } tb_to_ns_scale = scale; tb_to_ns_shift = shift; /* Save the current timebase to pretty up CONFIG_PRINTK_TIME */ boot_tb = get_tb_or_rtc(); /* 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_update_count = 0; vdso_data->tb_ticks_per_sec = tb_ticks_per_sec; /* Start the decrementer on CPUs that have manual control * such as BookE */ start_cpu_decrementer(); /* Register the clocksource */ clocksource_init(); init_decrementer_clockevent(); } #define FEBRUARY 2 #define STARTOFTIME 1970 #define SECDAY 86400L #define SECYR (SECDAY * 365) #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]) static int month_days[12] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; /* * This only works for the Gregorian calendar - i.e. after 1752 (in the UK) */ void GregorianDay(struct rtc_time * tm) { int leapsToDate; int lastYear; int day; int MonthOffset[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 }; lastYear = tm->tm_year - 1; /* * Number of leap corrections to apply up to end of last year */ 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 was */ 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; } void to_tm(int tim, struct rtc_time * tm) { register int i; register long hms, day; day = tim / SECDAY; hms = tim % SECDAY; /* Hours, minutes, seconds are easy */ tm->tm_hour = hms / 3600; tm->tm_min = (hms % 3600) / 60; tm->tm_sec = (hms % 3600) % 60; /* Number of years in days */ for (i = STARTOFTIME; day >= days_in_year(i); i++) day -= days_in_year(i); tm->tm_year = i; /* Number of months in days left */ if (leapyear(tm->tm_year)) days_in_month(FEBRUARY) = 29; for (i = 1; day >= days_in_month(i); i++) day -= days_in_month(i); days_in_month(FEBRUARY) = 28; tm->tm_mon = i; /* Days are what is left over (+1) from all that. */ tm->tm_mday = day + 1; /* * Determine the day of week */ GregorianDay(tm); } /* * Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit * result. */ void div128_by_32(u64 dividend_high, u64 dividend_low, unsigned divisor, struct div_result *dr) { 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 = ((u64)(a - (w * divisor)) << 32) + b; rb = ((u64) do_div(ra, divisor) << 32) + c; x = ra; rc = ((u64) do_div(rb, divisor) << 32) + d; y = rb; do_div(rc, divisor); z = rc; dr->result_high = ((u64)w << 32) + x; dr->result_low = ((u64)y << 32) + z; } /* We don't need to calibrate delay, we use the CPU timebase for that */ void calibrate_delay(void) { /* Some generic code (such as spinlock debug) use loops_per_jiffy * as the number of __delay(1) in a jiffy, so make it so */ loops_per_jiffy = tb_ticks_per_jiffy; } static int __init rtc_init(void) { struct platform_device *pdev; if (!ppc_md.get_rtc_time) return -ENODEV; pdev = platform_device_register_simple("rtc-generic", -1, NULL, 0); if (IS_ERR(pdev)) return PTR_ERR(pdev); return 0; } module_init(rtc_init);