From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- arch/ia64/kernel/time.c | 456 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 456 insertions(+) create mode 100644 arch/ia64/kernel/time.c (limited to 'arch/ia64/kernel/time.c') diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c new file mode 100644 index 000000000..9a0104a38 --- /dev/null +++ b/arch/ia64/kernel/time.c @@ -0,0 +1,456 @@ +/* + * linux/arch/ia64/kernel/time.c + * + * Copyright (C) 1998-2003 Hewlett-Packard Co + * Stephane Eranian + * David Mosberger + * Copyright (C) 1999 Don Dugger + * Copyright (C) 1999-2000 VA Linux Systems + * Copyright (C) 1999-2000 Walt Drummond + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include + +#include "fsyscall_gtod_data.h" + +static cycle_t itc_get_cycles(struct clocksource *cs); + +struct fsyscall_gtod_data_t fsyscall_gtod_data; + +struct itc_jitter_data_t itc_jitter_data; + +volatile int time_keeper_id = 0; /* smp_processor_id() of time-keeper */ + +#ifdef CONFIG_IA64_DEBUG_IRQ + +unsigned long last_cli_ip; +EXPORT_SYMBOL(last_cli_ip); + +#endif + +#ifdef CONFIG_PARAVIRT +/* We need to define a real function for sched_clock, to override the + weak default version */ +unsigned long long sched_clock(void) +{ + return paravirt_sched_clock(); +} +#endif + +#ifdef CONFIG_PARAVIRT +static void +paravirt_clocksource_resume(struct clocksource *cs) +{ + if (pv_time_ops.clocksource_resume) + pv_time_ops.clocksource_resume(); +} +#endif + +static struct clocksource clocksource_itc = { + .name = "itc", + .rating = 350, + .read = itc_get_cycles, + .mask = CLOCKSOURCE_MASK(64), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +#ifdef CONFIG_PARAVIRT + .resume = paravirt_clocksource_resume, +#endif +}; +static struct clocksource *itc_clocksource; + +#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE + +#include + +extern cputime_t cycle_to_cputime(u64 cyc); + +void vtime_account_user(struct task_struct *tsk) +{ + cputime_t delta_utime; + struct thread_info *ti = task_thread_info(tsk); + + if (ti->ac_utime) { + delta_utime = cycle_to_cputime(ti->ac_utime); + account_user_time(tsk, delta_utime, delta_utime); + ti->ac_utime = 0; + } +} + +/* + * Called from the context switch with interrupts disabled, to charge all + * accumulated times to the current process, and to prepare accounting on + * the next process. + */ +void arch_vtime_task_switch(struct task_struct *prev) +{ + struct thread_info *pi = task_thread_info(prev); + struct thread_info *ni = task_thread_info(current); + + pi->ac_stamp = ni->ac_stamp; + ni->ac_stime = ni->ac_utime = 0; +} + +/* + * Account time for a transition between system, hard irq or soft irq state. + * Note that this function is called with interrupts enabled. + */ +static cputime_t vtime_delta(struct task_struct *tsk) +{ + struct thread_info *ti = task_thread_info(tsk); + cputime_t delta_stime; + __u64 now; + + WARN_ON_ONCE(!irqs_disabled()); + + now = ia64_get_itc(); + + delta_stime = cycle_to_cputime(ti->ac_stime + (now - ti->ac_stamp)); + ti->ac_stime = 0; + ti->ac_stamp = now; + + return delta_stime; +} + +void vtime_account_system(struct task_struct *tsk) +{ + cputime_t delta = vtime_delta(tsk); + + account_system_time(tsk, 0, delta, delta); +} +EXPORT_SYMBOL_GPL(vtime_account_system); + +void vtime_account_idle(struct task_struct *tsk) +{ + account_idle_time(vtime_delta(tsk)); +} + +#endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */ + +static irqreturn_t +timer_interrupt (int irq, void *dev_id) +{ + unsigned long new_itm; + + if (cpu_is_offline(smp_processor_id())) { + return IRQ_HANDLED; + } + + platform_timer_interrupt(irq, dev_id); + + new_itm = local_cpu_data->itm_next; + + if (!time_after(ia64_get_itc(), new_itm)) + printk(KERN_ERR "Oops: timer tick before it's due (itc=%lx,itm=%lx)\n", + ia64_get_itc(), new_itm); + + profile_tick(CPU_PROFILING); + + if (paravirt_do_steal_accounting(&new_itm)) + goto skip_process_time_accounting; + + while (1) { + update_process_times(user_mode(get_irq_regs())); + + new_itm += local_cpu_data->itm_delta; + + if (smp_processor_id() == time_keeper_id) + xtime_update(1); + + local_cpu_data->itm_next = new_itm; + + if (time_after(new_itm, ia64_get_itc())) + break; + + /* + * Allow IPIs to interrupt the timer loop. + */ + local_irq_enable(); + local_irq_disable(); + } + +skip_process_time_accounting: + + do { + /* + * If we're too close to the next clock tick for + * comfort, we increase the safety margin by + * intentionally dropping the next tick(s). We do NOT + * update itm.next because that would force us to call + * xtime_update() which in turn would let our clock run + * too fast (with the potentially devastating effect + * of losing monotony of time). + */ + while (!time_after(new_itm, ia64_get_itc() + local_cpu_data->itm_delta/2)) + new_itm += local_cpu_data->itm_delta; + ia64_set_itm(new_itm); + /* double check, in case we got hit by a (slow) PMI: */ + } while (time_after_eq(ia64_get_itc(), new_itm)); + return IRQ_HANDLED; +} + +/* + * Encapsulate access to the itm structure for SMP. + */ +void +ia64_cpu_local_tick (void) +{ + int cpu = smp_processor_id(); + unsigned long shift = 0, delta; + + /* arrange for the cycle counter to generate a timer interrupt: */ + ia64_set_itv(IA64_TIMER_VECTOR); + + delta = local_cpu_data->itm_delta; + /* + * Stagger the timer tick for each CPU so they don't occur all at (almost) the + * same time: + */ + if (cpu) { + unsigned long hi = 1UL << ia64_fls(cpu); + shift = (2*(cpu - hi) + 1) * delta/hi/2; + } + local_cpu_data->itm_next = ia64_get_itc() + delta + shift; + ia64_set_itm(local_cpu_data->itm_next); +} + +static int nojitter; + +static int __init nojitter_setup(char *str) +{ + nojitter = 1; + printk("Jitter checking for ITC timers disabled\n"); + return 1; +} + +__setup("nojitter", nojitter_setup); + + +void ia64_init_itm(void) +{ + unsigned long platform_base_freq, itc_freq; + struct pal_freq_ratio itc_ratio, proc_ratio; + long status, platform_base_drift, itc_drift; + + /* + * According to SAL v2.6, we need to use a SAL call to determine the platform base + * frequency and then a PAL call to determine the frequency ratio between the ITC + * and the base frequency. + */ + status = ia64_sal_freq_base(SAL_FREQ_BASE_PLATFORM, + &platform_base_freq, &platform_base_drift); + if (status != 0) { + printk(KERN_ERR "SAL_FREQ_BASE_PLATFORM failed: %s\n", ia64_sal_strerror(status)); + } else { + status = ia64_pal_freq_ratios(&proc_ratio, NULL, &itc_ratio); + if (status != 0) + printk(KERN_ERR "PAL_FREQ_RATIOS failed with status=%ld\n", status); + } + if (status != 0) { + /* invent "random" values */ + printk(KERN_ERR + "SAL/PAL failed to obtain frequency info---inventing reasonable values\n"); + platform_base_freq = 100000000; + platform_base_drift = -1; /* no drift info */ + itc_ratio.num = 3; + itc_ratio.den = 1; + } + if (platform_base_freq < 40000000) { + printk(KERN_ERR "Platform base frequency %lu bogus---resetting to 75MHz!\n", + platform_base_freq); + platform_base_freq = 75000000; + platform_base_drift = -1; + } + if (!proc_ratio.den) + proc_ratio.den = 1; /* avoid division by zero */ + if (!itc_ratio.den) + itc_ratio.den = 1; /* avoid division by zero */ + + itc_freq = (platform_base_freq*itc_ratio.num)/itc_ratio.den; + + local_cpu_data->itm_delta = (itc_freq + HZ/2) / HZ; + printk(KERN_DEBUG "CPU %d: base freq=%lu.%03luMHz, ITC ratio=%u/%u, " + "ITC freq=%lu.%03luMHz", smp_processor_id(), + platform_base_freq / 1000000, (platform_base_freq / 1000) % 1000, + itc_ratio.num, itc_ratio.den, itc_freq / 1000000, (itc_freq / 1000) % 1000); + + if (platform_base_drift != -1) { + itc_drift = platform_base_drift*itc_ratio.num/itc_ratio.den; + printk("+/-%ldppm\n", itc_drift); + } else { + itc_drift = -1; + printk("\n"); + } + + local_cpu_data->proc_freq = (platform_base_freq*proc_ratio.num)/proc_ratio.den; + local_cpu_data->itc_freq = itc_freq; + local_cpu_data->cyc_per_usec = (itc_freq + USEC_PER_SEC/2) / USEC_PER_SEC; + local_cpu_data->nsec_per_cyc = ((NSEC_PER_SEC<itc_freq); + itc_clocksource = &clocksource_itc; + } +} + +static cycle_t itc_get_cycles(struct clocksource *cs) +{ + unsigned long lcycle, now, ret; + + if (!itc_jitter_data.itc_jitter) + return get_cycles(); + + lcycle = itc_jitter_data.itc_lastcycle; + now = get_cycles(); + if (lcycle && time_after(lcycle, now)) + return lcycle; + + /* + * Keep track of the last timer value returned. + * In an SMP environment, you could lose out in contention of + * cmpxchg. If so, your cmpxchg returns new value which the + * winner of contention updated to. Use the new value instead. + */ + ret = cmpxchg(&itc_jitter_data.itc_lastcycle, lcycle, now); + if (unlikely(ret != lcycle)) + return ret; + + return now; +} + + +static struct irqaction timer_irqaction = { + .handler = timer_interrupt, + .flags = IRQF_IRQPOLL, + .name = "timer" +}; + +void read_persistent_clock(struct timespec *ts) +{ + efi_gettimeofday(ts); +} + +void __init +time_init (void) +{ + register_percpu_irq(IA64_TIMER_VECTOR, &timer_irqaction); + ia64_init_itm(); +} + +/* + * Generic udelay assumes that if preemption is allowed and the thread + * migrates to another CPU, that the ITC values are synchronized across + * all CPUs. + */ +static void +ia64_itc_udelay (unsigned long usecs) +{ + unsigned long start = ia64_get_itc(); + unsigned long end = start + usecs*local_cpu_data->cyc_per_usec; + + while (time_before(ia64_get_itc(), end)) + cpu_relax(); +} + +void (*ia64_udelay)(unsigned long usecs) = &ia64_itc_udelay; + +void +udelay (unsigned long usecs) +{ + (*ia64_udelay)(usecs); +} +EXPORT_SYMBOL(udelay); + +/* IA64 doesn't cache the timezone */ +void update_vsyscall_tz(void) +{ +} + +void update_vsyscall_old(struct timespec *wall, struct timespec *wtm, + struct clocksource *c, u32 mult, cycle_t cycle_last) +{ + write_seqcount_begin(&fsyscall_gtod_data.seq); + + /* copy fsyscall clock data */ + fsyscall_gtod_data.clk_mask = c->mask; + fsyscall_gtod_data.clk_mult = mult; + fsyscall_gtod_data.clk_shift = c->shift; + fsyscall_gtod_data.clk_fsys_mmio = c->archdata.fsys_mmio; + fsyscall_gtod_data.clk_cycle_last = cycle_last; + + /* copy kernel time structures */ + fsyscall_gtod_data.wall_time.tv_sec = wall->tv_sec; + fsyscall_gtod_data.wall_time.tv_nsec = wall->tv_nsec; + fsyscall_gtod_data.monotonic_time.tv_sec = wtm->tv_sec + + wall->tv_sec; + fsyscall_gtod_data.monotonic_time.tv_nsec = wtm->tv_nsec + + wall->tv_nsec; + + /* normalize */ + while (fsyscall_gtod_data.monotonic_time.tv_nsec >= NSEC_PER_SEC) { + fsyscall_gtod_data.monotonic_time.tv_nsec -= NSEC_PER_SEC; + fsyscall_gtod_data.monotonic_time.tv_sec++; + } + + write_seqcount_end(&fsyscall_gtod_data.seq); +} + -- cgit v1.2.3-54-g00ecf