X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fpowerpc%2Fkernel%2Ftime.c;h=f6f0c6b07c4cf335e41357def28b7388bf07d793;hb=refs%2Fheads%2Fvserver;hp=24e3ad756de02ce124bb2ff05ea4eb9b04c9a033;hpb=16cf0ec7408f389279d413869e94c1a351392f97;p=linux-2.6.git diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 24e3ad756..f6f0c6b07 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -32,7 +32,6 @@ * 2 of the License, or (at your option) any later version. */ -#include #include #include #include @@ -52,6 +51,7 @@ #include #include #include +#include #include #include @@ -76,7 +76,6 @@ /* 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; @@ -103,7 +102,7 @@ EXPORT_SYMBOL(tb_ticks_per_sec); /* for cputime_t conversions */ u64 tb_to_xs; unsigned tb_to_us; -#define TICKLEN_SCALE (SHIFT_SCALE - 10) +#define TICKLEN_SCALE TICK_LENGTH_SHIFT u64 last_tick_len; /* units are ns / 2^TICKLEN_SCALE */ u64 ticklen_to_xs; /* 0.64 fraction */ @@ -119,23 +118,14 @@ unsigned tb_to_ns_shift; struct gettimeofday_struct do_gtod; -extern unsigned long wall_jiffies; - extern struct timezone sys_tz; static long timezone_offset; unsigned long ppc_proc_freq; unsigned long ppc_tb_freq; -u64 tb_last_jiffy __cacheline_aligned_in_smp; -unsigned long tb_last_stamp; - -/* - * 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); +static u64 tb_last_jiffy __cacheline_aligned_in_smp; +static DEFINE_PER_CPU(u64, last_jiffy); #ifdef CONFIG_VIRT_CPU_ACCOUNTING /* @@ -230,11 +220,8 @@ static void account_process_time(struct pt_regs *regs) */ struct cpu_purr_data { int initialized; /* thread is running */ - u64 tb0; /* timebase at origin time */ - u64 purr0; /* PURR at origin time */ u64 tb; /* last TB value read */ u64 purr; /* last PURR value read */ - u64 stolen; /* stolen time so far */ spinlock_t lock; }; @@ -244,10 +231,8 @@ static void snapshot_tb_and_purr(void *data) { struct cpu_purr_data *p = &__get_cpu_var(cpu_purr_data); - p->tb0 = mftb(); - p->purr0 = mfspr(SPRN_PURR); - p->tb = p->tb0; - p->purr = 0; + p->tb = mftb(); + p->purr = mfspr(SPRN_PURR); wmb(); p->initialized = 1; } @@ -268,37 +253,24 @@ void snapshot_timebases(void) void calculate_steal_time(void) { - u64 tb, purr, t0; + u64 tb, purr; s64 stolen; - struct cpu_purr_data *p0, *pme, *phim; - int cpu; + struct cpu_purr_data *pme; if (!cpu_has_feature(CPU_FTR_PURR)) return; - cpu = smp_processor_id(); - pme = &per_cpu(cpu_purr_data, cpu); + pme = &per_cpu(cpu_purr_data, smp_processor_id()); if (!pme->initialized) return; /* this can happen in early boot */ - p0 = &per_cpu(cpu_purr_data, cpu & ~1); - phim = &per_cpu(cpu_purr_data, cpu ^ 1); - spin_lock(&p0->lock); + spin_lock(&pme->lock); tb = mftb(); - purr = mfspr(SPRN_PURR) - pme->purr0; - if (!phim->initialized || !cpu_online(cpu ^ 1)) { - stolen = (tb - pme->tb) - (purr - pme->purr); - } else { - t0 = pme->tb0; - if (phim->tb0 < t0) - t0 = phim->tb0; - stolen = phim->tb - t0 - phim->purr - purr - p0->stolen; - } - if (stolen > 0) { + purr = mfspr(SPRN_PURR); + stolen = (tb - pme->tb) - (purr - pme->purr); + if (stolen > 0) account_steal_time(current, stolen); - p0->stolen += stolen; - } pme->tb = tb; pme->purr = purr; - spin_unlock(&p0->lock); + spin_unlock(&pme->lock); } /* @@ -307,30 +279,17 @@ void calculate_steal_time(void) */ static void snapshot_purr(void) { - int cpu; - u64 purr; - struct cpu_purr_data *p0, *pme, *phim; + struct cpu_purr_data *pme; unsigned long flags; if (!cpu_has_feature(CPU_FTR_PURR)) return; - cpu = smp_processor_id(); - pme = &per_cpu(cpu_purr_data, cpu); - p0 = &per_cpu(cpu_purr_data, cpu & ~1); - phim = &per_cpu(cpu_purr_data, cpu ^ 1); - spin_lock_irqsave(&p0->lock, flags); - pme->tb = pme->tb0 = mftb(); - purr = mfspr(SPRN_PURR); - if (!phim->initialized) { - pme->purr = 0; - pme->purr0 = purr; - } else { - /* set p->purr and p->purr0 for no change in p0->stolen */ - pme->purr = phim->tb - phim->tb0 - phim->purr - p0->stolen; - pme->purr0 = purr - pme->purr; - } + 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(&p0->lock, flags); + spin_unlock_irqrestore(&pme->lock, flags); } #endif /* CONFIG_PPC_SPLPAR */ @@ -419,7 +378,7 @@ static __inline__ void timer_check_rtc(void) /* * 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; @@ -433,7 +392,12 @@ static inline void __do_gettimeofday(struct timeval *tv, u64 tb_val) * 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); @@ -455,7 +419,7 @@ void do_gettimeofday(struct timeval *tv) do { seq = read_seqbegin_irqsave(&xtime_lock, flags); sec = xtime.tv_sec; - nsec = xtime.tv_nsec + tb_ticks_since(tb_last_stamp); + nsec = xtime.tv_nsec + tb_ticks_since(tb_last_jiffy); } while (read_seqretry_irqrestore(&xtime_lock, seq, flags)); usec = nsec / 1000; while (usec >= 1000000) { @@ -466,7 +430,7 @@ void do_gettimeofday(struct timeval *tv) tv->tv_usec = usec; return; } - __do_gettimeofday(tv, get_tb()); + __do_gettimeofday(tv); } EXPORT_SYMBOL(do_gettimeofday); @@ -649,22 +613,26 @@ static void iSeries_tb_recal(void) */ 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))) @@ -693,11 +661,13 @@ void timer_interrupt(struct pt_regs * regs) continue; write_seqlock(&xtime_lock); - tb_last_jiffy += tb_ticks_per_jiffy; - tb_last_stamp = per_cpu(last_jiffy, cpu); - do_timer(regs); - timer_recalc_offset(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); } @@ -705,8 +675,8 @@ void timer_interrupt(struct pt_regs * regs) 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 @@ -718,6 +688,7 @@ void timer_interrupt(struct pt_regs * regs) #endif irq_exit(); + set_irq_regs(old_regs); } void wakeup_decrementer(void) @@ -742,7 +713,7 @@ void __init smp_space_timers(unsigned int max_cpus) int i; unsigned long half = tb_ticks_per_jiffy / 2; 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; @@ -804,7 +775,7 @@ int do_settimeofday(struct timespec *tv) * 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; } @@ -817,13 +788,8 @@ int do_settimeofday(struct timespec *tv) /* * Subtract off the number of nanoseconds since the * beginning of the last tick. - * Note that since we don't increment jiffies_64 anywhere other - * than in do_timer (since we don't have a lost tick problem), - * wall_jiffies will always be the same as jiffies, - * and therefore the (jiffies - wall_jiffies) computation - * has been removed. */ - tb_delta = tb_ticks_since(tb_last_stamp); + 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); @@ -858,42 +824,48 @@ int do_settimeofday(struct timespec *tv) 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 = 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); @@ -905,11 +877,6 @@ void __init generic_calibrate_decr(void) /* 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) @@ -940,16 +907,15 @@ void __init time_init(void) 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; @@ -1010,10 +976,7 @@ void __init time_init(void) 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); @@ -1029,7 +992,7 @@ void __init time_init(void) 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;