diff options
Diffstat (limited to 'kernel/hrtimer.c')
| -rw-r--r-- | kernel/hrtimer.c | 1915 |
1 files changed, 0 insertions, 1915 deletions
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c deleted file mode 100644 index 3ab28993f6e0..000000000000 --- a/kernel/hrtimer.c +++ /dev/null @@ -1,1915 +0,0 @@ -/* - * linux/kernel/hrtimer.c - * - * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de> - * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar - * Copyright(C) 2006-2007 Timesys Corp., Thomas Gleixner - * - * High-resolution kernel timers - * - * In contrast to the low-resolution timeout API implemented in - * kernel/timer.c, hrtimers provide finer resolution and accuracy - * depending on system configuration and capabilities. - * - * These timers are currently used for: - * - itimers - * - POSIX timers - * - nanosleep - * - precise in-kernel timing - * - * Started by: Thomas Gleixner and Ingo Molnar - * - * Credits: - * based on kernel/timer.c - * - * Help, testing, suggestions, bugfixes, improvements were - * provided by: - * - * George Anzinger, Andrew Morton, Steven Rostedt, Roman Zippel - * et. al. - * - * For licencing details see kernel-base/COPYING - */ - -#include <linux/cpu.h> -#include <linux/export.h> -#include <linux/percpu.h> -#include <linux/hrtimer.h> -#include <linux/notifier.h> -#include <linux/syscalls.h> -#include <linux/kallsyms.h> -#include <linux/interrupt.h> -#include <linux/tick.h> -#include <linux/seq_file.h> -#include <linux/err.h> -#include <linux/debugobjects.h> -#include <linux/sched.h> -#include <linux/sched/sysctl.h> -#include <linux/sched/rt.h> -#include <linux/sched/deadline.h> -#include <linux/timer.h> -#include <linux/freezer.h> - -#include <asm/uaccess.h> - -#include <trace/events/timer.h> - -/* - * The timer bases: - * - * There are more clockids then hrtimer bases. Thus, we index - * into the timer bases by the hrtimer_base_type enum. When trying - * to reach a base using a clockid, hrtimer_clockid_to_base() - * is used to convert from clockid to the proper hrtimer_base_type. - */ -DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) = -{ - - .lock = __RAW_SPIN_LOCK_UNLOCKED(hrtimer_bases.lock), - .clock_base = - { - { - .index = HRTIMER_BASE_MONOTONIC, - .clockid = CLOCK_MONOTONIC, - .get_time = &ktime_get, - .resolution = KTIME_LOW_RES, - }, - { - .index = HRTIMER_BASE_REALTIME, - .clockid = CLOCK_REALTIME, - .get_time = &ktime_get_real, - .resolution = KTIME_LOW_RES, - }, - { - .index = HRTIMER_BASE_BOOTTIME, - .clockid = CLOCK_BOOTTIME, - .get_time = &ktime_get_boottime, - .resolution = KTIME_LOW_RES, - }, - { - .index = HRTIMER_BASE_TAI, - .clockid = CLOCK_TAI, - .get_time = &ktime_get_clocktai, - .resolution = KTIME_LOW_RES, - }, - } -}; - -static const int hrtimer_clock_to_base_table[MAX_CLOCKS] = { - [CLOCK_REALTIME] = HRTIMER_BASE_REALTIME, - [CLOCK_MONOTONIC] = HRTIMER_BASE_MONOTONIC, - [CLOCK_BOOTTIME] = HRTIMER_BASE_BOOTTIME, - [CLOCK_TAI] = HRTIMER_BASE_TAI, -}; - -static inline int hrtimer_clockid_to_base(clockid_t clock_id) -{ - return hrtimer_clock_to_base_table[clock_id]; -} - - -/* - * Get the coarse grained time at the softirq based on xtime and - * wall_to_monotonic. - */ -static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base) -{ - ktime_t xtim, mono, boot; - struct timespec xts, tom, slp; - s32 tai_offset; - - get_xtime_and_monotonic_and_sleep_offset(&xts, &tom, &slp); - tai_offset = timekeeping_get_tai_offset(); - - xtim = timespec_to_ktime(xts); - mono = ktime_add(xtim, timespec_to_ktime(tom)); - boot = ktime_add(mono, timespec_to_ktime(slp)); - base->clock_base[HRTIMER_BASE_REALTIME].softirq_time = xtim; - base->clock_base[HRTIMER_BASE_MONOTONIC].softirq_time = mono; - base->clock_base[HRTIMER_BASE_BOOTTIME].softirq_time = boot; - base->clock_base[HRTIMER_BASE_TAI].softirq_time = - ktime_add(xtim, ktime_set(tai_offset, 0)); -} - -/* - * Functions and macros which are different for UP/SMP systems are kept in a - * single place - */ -#ifdef CONFIG_SMP - -/* - * We are using hashed locking: holding per_cpu(hrtimer_bases)[n].lock - * means that all timers which are tied to this base via timer->base are - * locked, and the base itself is locked too. - * - * So __run_timers/migrate_timers can safely modify all timers which could - * be found on the lists/queues. - * - * When the timer's base is locked, and the timer removed from list, it is - * possible to set timer->base = NULL and drop the lock: the timer remains - * locked. - */ -static -struct hrtimer_clock_base *lock_hrtimer_base(const struct hrtimer *timer, - unsigned long *flags) -{ - struct hrtimer_clock_base *base; - - for (;;) { - base = timer->base; - if (likely(base != NULL)) { - raw_spin_lock_irqsave(&base->cpu_base->lock, *flags); - if (likely(base == timer->base)) - return base; - /* The timer has migrated to another CPU: */ - raw_spin_unlock_irqrestore(&base->cpu_base->lock, *flags); - } - cpu_relax(); - } -} - -/* - * With HIGHRES=y we do not migrate the timer when it is expiring - * before the next event on the target cpu because we cannot reprogram - * the target cpu hardware and we would cause it to fire late. - * - * Called with cpu_base->lock of target cpu held. - */ -static int -hrtimer_check_target(struct hrtimer *timer, struct hrtimer_clock_base *new_base) -{ -#ifdef CONFIG_HIGH_RES_TIMERS - ktime_t expires; - - if (!new_base->cpu_base->hres_active) - return 0; - - expires = ktime_sub(hrtimer_get_expires(timer), new_base->offset); - return expires.tv64 <= new_base->cpu_base->expires_next.tv64; -#else - return 0; -#endif -} - -/* - * Switch the timer base to the current CPU when possible. - */ -static inline struct hrtimer_clock_base * -switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_clock_base *base, - int pinned) -{ - struct hrtimer_clock_base *new_base; - struct hrtimer_cpu_base *new_cpu_base; - int this_cpu = smp_processor_id(); - int cpu = get_nohz_timer_target(pinned); - int basenum = base->index; - -again: - new_cpu_base = &per_cpu(hrtimer_bases, cpu); - new_base = &new_cpu_base->clock_base[basenum]; - - if (base != new_base) { - /* - * We are trying to move timer to new_base. - * However we can't change timer's base while it is running, - * so we keep it on the same CPU. No hassle vs. reprogramming - * the event source in the high resolution case. The softirq - * code will take care of this when the timer function has - * completed. There is no conflict as we hold the lock until - * the timer is enqueued. - */ - if (unlikely(hrtimer_callback_running(timer))) - return base; - - /* See the comment in lock_timer_base() */ - timer->base = NULL; - raw_spin_unlock(&base->cpu_base->lock); - raw_spin_lock(&new_base->cpu_base->lock); - - if (cpu != this_cpu && hrtimer_check_target(timer, new_base)) { - cpu = this_cpu; - raw_spin_unlock(&new_base->cpu_base->lock); - raw_spin_lock(&base->cpu_base->lock); - timer->base = base; - goto again; - } - timer->base = new_base; - } else { - if (cpu != this_cpu && hrtimer_check_target(timer, new_base)) { - cpu = this_cpu; - goto again; - } - } - return new_base; -} - -#else /* CONFIG_SMP */ - -static inline struct hrtimer_clock_base * -lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags) -{ - struct hrtimer_clock_base *base = timer->base; - - raw_spin_lock_irqsave(&base->cpu_base->lock, *flags); - - return base; -} - -# define switch_hrtimer_base(t, b, p) (b) - -#endif /* !CONFIG_SMP */ - -/* - * Functions for the union type storage format of ktime_t which are - * too large for inlining: - */ -#if BITS_PER_LONG < 64 -# ifndef CONFIG_KTIME_SCALAR -/** - * ktime_add_ns - Add a scalar nanoseconds value to a ktime_t variable - * @kt: addend - * @nsec: the scalar nsec value to add - * - * Returns the sum of kt and nsec in ktime_t format - */ -ktime_t ktime_add_ns(const ktime_t kt, u64 nsec) -{ - ktime_t tmp; - - if (likely(nsec < NSEC_PER_SEC)) { - tmp.tv64 = nsec; - } else { - unsigned long rem = do_div(nsec, NSEC_PER_SEC); - - /* Make sure nsec fits into long */ - if (unlikely(nsec > KTIME_SEC_MAX)) - return (ktime_t){ .tv64 = KTIME_MAX }; - - tmp = ktime_set((long)nsec, rem); - } - - return ktime_add(kt, tmp); -} - -EXPORT_SYMBOL_GPL(ktime_add_ns); - -/** - * ktime_sub_ns - Subtract a scalar nanoseconds value from a ktime_t variable - * @kt: minuend - * @nsec: the scalar nsec value to subtract - * - * Returns the subtraction of @nsec from @kt in ktime_t format - */ -ktime_t ktime_sub_ns(const ktime_t kt, u64 nsec) -{ - ktime_t tmp; - - if (likely(nsec < NSEC_PER_SEC)) { - tmp.tv64 = nsec; - } else { - unsigned long rem = do_div(nsec, NSEC_PER_SEC); - - tmp = ktime_set((long)nsec, rem); - } - - return ktime_sub(kt, tmp); -} - -EXPORT_SYMBOL_GPL(ktime_sub_ns); -# endif /* !CONFIG_KTIME_SCALAR */ - -/* - * Divide a ktime value by a nanosecond value - */ -u64 ktime_divns(const ktime_t kt, s64 div) -{ - u64 dclc; - int sft = 0; - - dclc = ktime_to_ns(kt); - /* Make sure the divisor is less than 2^32: */ - while (div >> 32) { - sft++; - div >>= 1; - } - dclc >>= sft; - do_div(dclc, (unsigned long) div); - - return dclc; -} -#endif /* BITS_PER_LONG >= 64 */ - -/* - * Add two ktime values and do a safety check for overflow: - */ -ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs) -{ - ktime_t res = ktime_add(lhs, rhs); - - /* - * We use KTIME_SEC_MAX here, the maximum timeout which we can - * return to user space in a timespec: - */ - if (res.tv64 < 0 || res.tv64 < lhs.tv64 || res.tv64 < rhs.tv64) - res = ktime_set(KTIME_SEC_MAX, 0); - - return res; -} - -EXPORT_SYMBOL_GPL(ktime_add_safe); - -#ifdef CONFIG_DEBUG_OBJECTS_TIMERS - -static struct debug_obj_descr hrtimer_debug_descr; - -static void *hrtimer_debug_hint(void *addr) -{ - return ((struct hrtimer *) addr)->function; -} - -/* - * fixup_init is called when: - * - an active object is initialized - */ -static int hrtimer_fixup_init(void *addr, enum debug_obj_state state) -{ - struct hrtimer *timer = addr; - - switch (state) { - case ODEBUG_STATE_ACTIVE: - hrtimer_cancel(timer); - debug_object_init(timer, &hrtimer_debug_descr); - return 1; - default: - return 0; - } -} - -/* - * fixup_activate is called when: - * - an active object is activated - * - an unknown object is activated (might be a statically initialized object) - */ -static int hrtimer_fixup_activate(void *addr, enum debug_obj_state state) -{ - switch (state) { - - case ODEBUG_STATE_NOTAVAILABLE: - WARN_ON_ONCE(1); - return 0; - - case ODEBUG_STATE_ACTIVE: - WARN_ON(1); - - default: - return 0; - } -} - -/* - * fixup_free is called when: - * - an active object is freed - */ -static int hrtimer_fixup_free(void *addr, enum debug_obj_state state) -{ - struct hrtimer *timer = addr; - - switch (state) { - case ODEBUG_STATE_ACTIVE: - hrtimer_cancel(timer); - debug_object_free(timer, &hrtimer_debug_descr); - return 1; - default: - return 0; - } -} - -static struct debug_obj_descr hrtimer_debug_descr = { - .name = "hrtimer", - .debug_hint = hrtimer_debug_hint, - .fixup_init = hrtimer_fixup_init, - .fixup_activate = hrtimer_fixup_activate, - .fixup_free = hrtimer_fixup_free, -}; - -static inline void debug_hrtimer_init(struct hrtimer *timer) -{ - debug_object_init(timer, &hrtimer_debug_descr); -} - -static inline void debug_hrtimer_activate(struct hrtimer *timer) -{ - debug_object_activate(timer, &hrtimer_debug_descr); -} - -static inline void debug_hrtimer_deactivate(struct hrtimer *timer) -{ - debug_object_deactivate(timer, &hrtimer_debug_descr); -} - -static inline void debug_hrtimer_free(struct hrtimer *timer) -{ - debug_object_free(timer, &hrtimer_debug_descr); -} - -static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id, - enum hrtimer_mode mode); - -void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t clock_id, - enum hrtimer_mode mode) -{ - debug_object_init_on_stack(timer, &hrtimer_debug_descr); - __hrtimer_init(timer, clock_id, mode); -} -EXPORT_SYMBOL_GPL(hrtimer_init_on_stack); - -void destroy_hrtimer_on_stack(struct hrtimer *timer) -{ - debug_object_free(timer, &hrtimer_debug_descr); -} - -#else -static inline void debug_hrtimer_init(struct hrtimer *timer) { } -static inline void debug_hrtimer_activate(struct hrtimer *timer) { } -static inline void debug_hrtimer_deactivate(struct hrtimer *timer) { } -#endif - -static inline void -debug_init(struct hrtimer *timer, clockid_t clockid, - enum hrtimer_mode mode) -{ - debug_hrtimer_init(timer); - trace_hrtimer_init(timer, clockid, mode); -} - -static inline void debug_activate(struct hrtimer *timer) -{ - debug_hrtimer_activate(timer); - trace_hrtimer_start(timer); -} - -static inline void debug_deactivate(struct hrtimer *timer) -{ - debug_hrtimer_deactivate(timer); - trace_hrtimer_cancel(timer); -} - -/* High resolution timer related functions */ -#ifdef CONFIG_HIGH_RES_TIMERS - -/* - * High resolution timer enabled ? - */ -static int hrtimer_hres_enabled __read_mostly = 1; - -/* - * Enable / Disable high resolution mode - */ -static int __init setup_hrtimer_hres(char *str) -{ - if (!strcmp(str, "off")) - hrtimer_hres_enabled = 0; - else if (!strcmp(str, "on")) - hrtimer_hres_enabled = 1; - else - return 0; - return 1; -} - -__setup("highres=", setup_hrtimer_hres); - -/* - * hrtimer_high_res_enabled - query, if the highres mode is enabled - */ -static inline int hrtimer_is_hres_enabled(void) -{ - return hrtimer_hres_enabled; -} - -/* - * Is the high resolution mode active ? - */ -static inline int hrtimer_hres_active(void) -{ - return __this_cpu_read(hrtimer_bases.hres_active); -} - -/* - * Reprogram the event source with checking both queues for the - * next event - * Called with interrupts disabled and base->lock held - */ -static void -hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal) -{ - int i; - struct hrtimer_clock_base *base = cpu_base->clock_base; - ktime_t expires, expires_next; - - expires_next.tv64 = KTIME_MAX; - - for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) { - struct hrtimer *timer; - struct timerqueue_node *next; - - next = timerqueue_getnext(&base->active); - if (!next) - continue; - timer = container_of(next, struct hrtimer, node); - - expires = ktime_sub(hrtimer_get_expires(timer), base->offset); - /* - * clock_was_set() has changed base->offset so the - * result might be negative. Fix it up to prevent a - * false positive in clockevents_program_event() - */ - if (expires.tv64 < 0) - expires.tv64 = 0; - if (expires.tv64 < expires_next.tv64) - expires_next = expires; - } - - if (skip_equal && expires_next.tv64 == cpu_base->expires_next.tv64) - return; - - cpu_base->expires_next.tv64 = expires_next.tv64; - - /* - * If a hang was detected in the last timer interrupt then we - * leave the hang delay active in the hardware. We want the - * system to make progress. That also prevents the following - * scenario: - * T1 expires 50ms from now - * T2 expires 5s from now - * - * T1 is removed, so this code is called and would reprogram - * the hardware to 5s from now. Any hrtimer_start after that - * will not reprogram the hardware due to hang_detected being - * set. So we'd effectivly block all timers until the T2 event - * fires. - */ - if (cpu_base->hang_detected) - return; - - if (cpu_base->expires_next.tv64 != KTIME_MAX) - tick_program_event(cpu_base->expires_next, 1); -} - -/* - * Shared reprogramming for clock_realtime and clock_monotonic - * - * When a timer is enqueued and expires earlier than the already enqueued - * timers, we have to check, whether it expires earlier than the timer for - * which the clock event device was armed. - * - * Called with interrupts disabled and base->cpu_base.lock held - */ -static int hrtimer_reprogram(struct hrtimer *timer, - struct hrtimer_clock_base *base) -{ - struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); - ktime_t expires = ktime_sub(hrtimer_get_expires(timer), base->offset); - int res; - - WARN_ON_ONCE(hrtimer_get_expires_tv64(timer) < 0); - - /* - * When the callback is running, we do not reprogram the clock event - * device. The timer callback is either running on a different CPU or - * the callback is executed in the hrtimer_interrupt context. The - * reprogramming is handled either by the softirq, which called the - * callback or at the end of the hrtimer_interrupt. - */ - if (hrtimer_callback_running(timer)) - return 0; - - /* - * CLOCK_REALTIME timer might be requested with an absolute - * expiry time which is less than base->offset. Nothing wrong - * about that, just avoid to call into the tick code, which - * has now objections against negative expiry values. - */ - if (expires.tv64 < 0) - return -ETIME; - - if (expires.tv64 >= cpu_base->expires_next.tv64) - return 0; - - /* - * If a hang was detected in the last timer interrupt then we - * do not schedule a timer which is earlier than the expiry - * which we enforced in the hang detection. We want the system - * to make progress. - */ - if (cpu_base->hang_detected) - return 0; - - /* - * Clockevents returns -ETIME, when the event was in the past. - */ - res = tick_program_event(expires, 0); - if (!IS_ERR_VALUE(res)) - cpu_base->expires_next = expires; - return res; -} - -/* - * Initialize the high resolution related parts of cpu_base - */ -static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) -{ - base->expires_next.tv64 = KTIME_MAX; - base->hres_active = 0; -} - -/* - * When High resolution timers are active, try to reprogram. Note, that in case - * the state has HRTIMER_STATE_CALLBACK set, no reprogramming and no expiry - * check happens. The timer gets enqueued into the rbtree. The reprogramming - * and expiry check is done in the hrtimer_interrupt or in the softirq. - */ -static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer, - struct hrtimer_clock_base *base) -{ - return base->cpu_base->hres_active && hrtimer_reprogram(timer, base); -} - -static inline ktime_t hrtimer_update_base(struct hrtimer_cpu_base *base) -{ - ktime_t *offs_real = &base->clock_base[HRTIMER_BASE_REALTIME].offset; - ktime_t *offs_boot = &base->clock_base[HRTIMER_BASE_BOOTTIME].offset; - ktime_t *offs_tai = &base->clock_base[HRTIMER_BASE_TAI].offset; - - return ktime_get_update_offsets(offs_real, offs_boot, offs_tai); -} - -/* - * Retrigger next event is called after clock was set - * - * Called with interrupts disabled via on_each_cpu() - */ -static void retrigger_next_event(void *arg) -{ - struct hrtimer_cpu_base *base = &__get_cpu_var(hrtimer_bases); - - if (!hrtimer_hres_active()) - return; - - raw_spin_lock(&base->lock); - hrtimer_update_base(base); - hrtimer_force_reprogram(base, 0); - raw_spin_unlock(&base->lock); -} - -/* - * Switch to high resolution mode - */ -static int hrtimer_switch_to_hres(void) -{ - int i, cpu = smp_processor_id(); - struct hrtimer_cpu_base *base = &per_cpu(hrtimer_bases, cpu); - unsigned long flags; - - if (base->hres_active) - return 1; - - local_irq_save(flags); - - if (tick_init_highres()) { - local_irq_restore(flags); - printk(KERN_WARNING "Could not switch to high resolution " - "mode on CPU %d\n", cpu); - return 0; - } - base->hres_active = 1; - for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) - base->clock_base[i].resolution = KTIME_HIGH_RES; - - tick_setup_sched_timer(); - /* "Retrigger" the interrupt to get things going */ - retrigger_next_event(NULL); - local_irq_restore(flags); - return 1; -} - -static void clock_was_set_work(struct work_struct *work) -{ - clock_was_set(); -} - -static DECLARE_WORK(hrtimer_work, clock_was_set_work); - -/* - * Called from timekeeping and resume code to reprogramm the hrtimer - * interrupt device on all cpus. - */ -void clock_was_set_delayed(void) -{ - schedule_work(&hrtimer_work); -} - -#else - -static inline int hrtimer_hres_active(void) { return 0; } -static inline int hrtimer_is_hres_enabled(void) { return 0; } -static inline int hrtimer_switch_to_hres(void) { return 0; } -static inline void -hrtimer_force_reprogram(struct hrtimer_cpu_base *base, int skip_equal) { } -static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer, - struct hrtimer_clock_base *base) -{ - return 0; -} -static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) { } -static inline void retrigger_next_event(void *arg) { } - -#endif /* CONFIG_HIGH_RES_TIMERS */ - -/* - * Clock realtime was set - * - * Change the offset of the realtime clock vs. the monotonic - * clock. - * - * We might have to reprogram the high resolution timer interrupt. On - * SMP we call the architecture specific code to retrigger _all_ high - * resolution timer interrupts. On UP we just disable interrupts and - * call the high resolution interrupt code. - */ -void clock_was_set(void) -{ -#ifdef CONFIG_HIGH_RES_TIMERS - /* Retrigger the CPU local events everywhere */ - on_each_cpu(retrigger_next_event, NULL, 1); -#endif - timerfd_clock_was_set(); -} - -/* - * During resume we might have to reprogram the high resolution timer - * interrupt on all online CPUs. However, all other CPUs will be - * stopped with IRQs interrupts disabled so the clock_was_set() call - * must be deferred. - */ -void hrtimers_resume(void) -{ - WARN_ONCE(!irqs_disabled(), - KERN_INFO "hrtimers_resume() called with IRQs enabled!"); - - /* Retrigger on the local CPU */ - retrigger_next_event(NULL); - /* And schedule a retrigger for all others */ - clock_was_set_delayed(); -} - -static inline void timer_stats_hrtimer_set_start_info(struct hrtimer *timer) -{ -#ifdef CONFIG_TIMER_STATS - if (timer->start_site) - return; - timer->start_site = __builtin_return_address(0); - memcpy(timer->start_comm, current->comm, TASK_COMM_LEN); - timer->start_pid = current->pid; -#endif -} - -static inline void timer_stats_hrtimer_clear_start_info(struct hrtimer *timer) -{ -#ifdef CONFIG_TIMER_STATS - timer->start_site = NULL; -#endif -} - -static inline void timer_stats_account_hrtimer(struct hrtimer *timer) -{ -#ifdef CONFIG_TIMER_STATS - if (likely(!timer_stats_active)) - return; - timer_stats_update_stats(timer, timer->start_pid, timer->start_site, - timer->function, timer->start_comm, 0); -#endif -} - -/* - * Counterpart to lock_hrtimer_base above: - */ -static inline -void unlock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags) -{ - raw_spin_unlock_irqrestore(&timer->base->cpu_base->lock, *flags); -} - -/** - * hrtimer_forward - forward the timer expiry - * @timer: hrtimer to forward - * @now: forward past this time - * @interval: the interval to forward - * - * Forward the timer expiry so it will expire in the future. - * Returns the number of overruns. - */ -u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval) -{ - u64 orun = 1; - ktime_t delta; - - delta = ktime_sub(now, hrtimer_get_expires(timer)); - - if (delta.tv64 < 0) - return 0; - - if (interval.tv64 < timer->base->resolution.tv64) - interval.tv64 = timer->base->resolution.tv64; - - if (unlikely(delta.tv64 >= interval.tv64)) { - s64 incr = ktime_to_ns(interval); - - orun = ktime_divns(delta, incr); - hrtimer_add_expires_ns(timer, incr * orun); - if (hrtimer_get_expires_tv64(timer) > now.tv64) - return orun; - /* - * This (and the ktime_add() below) is the - * correction for exact: - */ - orun++; - } - hrtimer_add_expires(timer, interval); - - return orun; -} -EXPORT_SYMBOL_GPL(hrtimer_forward); - -/* - * enqueue_hrtimer - internal function to (re)start a timer - * - * The timer is inserted in expiry order. Insertion into the - * red black tree is O(log(n)). Must hold the base lock. - * - * Returns 1 when the new timer is the leftmost timer in the tree. - */ -static int enqueue_hrtimer(struct hrtimer *timer, - struct hrtimer_clock_base *base) -{ - debug_activate(timer); - - timerqueue_add(&base->active, &timer->node); - base->cpu_base->active_bases |= 1 << base->index; - - /* - * HRTIMER_STATE_ENQUEUED is or'ed to the current state to preserve the - * state of a possibly running callback. - */ - timer->state |= HRTIMER_STATE_ENQUEUED; - - return (&timer->node == base->active.next); -} - -/* - * __remove_hrtimer - internal function to remove a timer - * - * Caller must hold the base lock. - * - * High resolution timer mode reprograms the clock event device when the - * timer is the one which expires next. The caller can disable this by setting - * reprogram to zero. This is useful, when the context does a reprogramming - * anyway (e.g. timer interrupt) - */ -static void __remove_hrtimer(struct hrtimer *timer, - struct hrtimer_clock_base *base, - unsigned long newstate, int reprogram) -{ - struct timerqueue_node *next_timer; - if (!(timer->state & HRTIMER_STATE_ENQUEUED)) - goto out; - - next_timer = timerqueue_getnext(&base->active); - timerqueue_del(&base->active, &timer->node); - if (&timer->node == next_timer) { -#ifdef CONFIG_HIGH_RES_TIMERS - /* Reprogram the clock event device. if enabled */ - if (reprogram && hrtimer_hres_active()) { - ktime_t expires; - - expires = ktime_sub(hrtimer_get_expires(timer), - base->offset); - if (base->cpu_base->expires_next.tv64 == expires.tv64) - hrtimer_force_reprogram(base->cpu_base, 1); - } -#endif - } - if (!timerqueue_getnext(&base->active)) - base->cpu_base->active_bases &= ~(1 << base->index); -out: - timer->state = newstate; -} - -/* - * remove hrtimer, called with base lock held - */ -static inline int -remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base) -{ - if (hrtimer_is_queued(timer)) { - unsigned long state; - int reprogram; - - /* - * Remove the timer and force reprogramming when high - * resolution mode is active and the timer is on the current - * CPU. If we remove a timer on another CPU, reprogramming is - * skipped. The interrupt event on this CPU is fired and - * reprogramming happens in the interrupt handler. This is a - * rare case and less expensive than a smp call. - */ - debug_deactivate(timer); - timer_stats_hrtimer_clear_start_info(timer); - reprogram = base->cpu_base == &__get_cpu_var(hrtimer_bases); - /* - * We must preserve the CALLBACK state flag here, - * otherwise we could move the timer base in - * switch_hrtimer_base. - */ - state = timer->state & HRTIMER_STATE_CALLBACK; - __remove_hrtimer(timer, base, state, reprogram); - return 1; - } - return 0; -} - -int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, - unsigned long delta_ns, const enum hrtimer_mode mode, - int wakeup) -{ - struct hrtimer_clock_base *base, *new_base; - unsigned long flags; - int ret, leftmost; - - base = lock_hrtimer_base(timer, &flags); - - /* Remove an active timer from the queue: */ - ret = remove_hrtimer(timer, base); - - if (mode & HRTIMER_MODE_REL) { - tim = ktime_add_safe(tim, base->get_time()); - /* - * CONFIG_TIME_LOW_RES is a temporary way for architectures - * to signal that they simply return xtime in - * do_gettimeoffset(). In this case we want to round up by - * resolution when starting a relative timer, to avoid short - * timeouts. This will go away with the GTOD framework. - */ -#ifdef CONFIG_TIME_LOW_RES - tim = ktime_add_safe(tim, base->resolution); -#endif - } - - hrtimer_set_expires_range_ns(timer, tim, delta_ns); - - /* Switch the timer base, if necessary: */ - new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED); - - timer_stats_hrtimer_set_start_info(timer); - - leftmost = enqueue_hrtimer(timer, new_base); - - /* - * Only allow reprogramming if the new base is on this CPU. - * (it might still be on another CPU if the timer was pending) - * - * XXX send_remote_softirq() ? - */ - if (leftmost && new_base->cpu_base == &__get_cpu_var(hrtimer_bases) - && hrtimer_enqueue_reprogram(timer, new_base)) { - if (wakeup) { - /* - * We need to drop cpu_base->lock to avoid a - * lock ordering issue vs. rq->lock. - */ - raw_spin_unlock(&new_base->cpu_base->lock); - raise_softirq_irqoff(HRTIMER_SOFTIRQ); - local_irq_restore(flags); - return ret; - } else { - __raise_softirq_irqoff(HRTIMER_SOFTIRQ); - } - } - - unlock_hrtimer_base(timer, &flags); - - return ret; -} -EXPORT_SYMBOL_GPL(__hrtimer_start_range_ns); - -/** - * hrtimer_start_range_ns - (re)start an hrtimer on the current CPU - * @timer: the timer to be added - * @tim: expiry time - * @delta_ns: "slack" range for the timer - * @mode: expiry mode: absolute (HRTIMER_MODE_ABS) or - * relative (HRTIMER_MODE_REL) - * - * Returns: - * 0 on success - * 1 when the timer was active - */ -int hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, - unsigned long delta_ns, const enum hrtimer_mode mode) -{ - return __hrtimer_start_range_ns(timer, tim, delta_ns, mode, 1); -} -EXPORT_SYMBOL_GPL(hrtimer_start_range_ns); - -/** - * hrtimer_start - (re)start an hrtimer on the current CPU - * @timer: the timer to be added - * @tim: expiry time - * @mode: expiry mode: absolute (HRTIMER_MODE_ABS) or - * relative (HRTIMER_MODE_REL) - * - * Returns: - * 0 on success - * 1 when the timer was active - */ -int -hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode) -{ - return __hrtimer_start_range_ns(timer, tim, 0, mode, 1); -} -EXPORT_SYMBOL_GPL(hrtimer_start); - - -/** - * hrtimer_try_to_cancel - try to deactivate a timer - * @timer: hrtimer to stop - * - * Returns: - * 0 when the timer was not active - * 1 when the timer was active - * -1 when the timer is currently excuting the callback function and - * cannot be stopped - */ -int hrtimer_try_to_cancel(struct hrtimer *timer) -{ - struct hrtimer_clock_base *base; - unsigned long flags; - int ret = -1; - - base = lock_hrtimer_base(timer, &flags); - - if (!hrtimer_callback_running(timer)) - ret = remove_hrtimer(timer, base); - - unlock_hrtimer_base(timer, &flags); - - return ret; - -} -EXPORT_SYMBOL_GPL(hrtimer_try_to_cancel); - -/** - * hrtimer_cancel - cancel a timer and wait for the handler to finish. - * @timer: the timer to be cancelled - * - * Returns: - * 0 when the timer was not active - * 1 when the timer was active - */ -int hrtimer_cancel(struct hrtimer *timer) -{ - for (;;) { - int ret = hrtimer_try_to_cancel(timer); - - if (ret >= 0) - return ret; - cpu_relax(); - } -} -EXPORT_SYMBOL_GPL(hrtimer_cancel); - -/** - * hrtimer_get_remaining - get remaining time for the timer - * @timer: the timer to read - */ -ktime_t hrtimer_get_remaining(const struct hrtimer *timer) -{ - unsigned long flags; - ktime_t rem; - - lock_hrtimer_base(timer, &flags); - rem = hrtimer_expires_remaining(timer); - unlock_hrtimer_base(timer, &flags); - - return rem; -} -EXPORT_SYMBOL_GPL(hrtimer_get_remaining); - -#ifdef CONFIG_NO_HZ_COMMON -/** - * hrtimer_get_next_event - get the time until next expiry event - * - * Returns the delta to the next expiry event or KTIME_MAX if no timer - * is pending. - */ -ktime_t hrtimer_get_next_event(void) -{ - struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); - struct hrtimer_clock_base *base = cpu_base->clock_base; - ktime_t delta, mindelta = { .tv64 = KTIME_MAX }; - unsigned long flags; - int i; - - raw_spin_lock_irqsave(&cpu_base->lock, flags); - - if (!hrtimer_hres_active()) { - for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) { - struct hrtimer *timer; - struct timerqueue_node *next; - - next = timerqueue_getnext(&base->active); - if (!next) - continue; - - timer = container_of(next, struct hrtimer, node); - delta.tv64 = hrtimer_get_expires_tv64(timer); - delta = ktime_sub(delta, base->get_time()); - if (delta.tv64 < mindelta.tv64) - mindelta.tv64 = delta.tv64; - } - } - - raw_spin_unlock_irqrestore(&cpu_base->lock, flags); - - if (mindelta.tv64 < 0) - mindelta.tv64 = 0; - return mindelta; -} -#endif - -static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id, - enum hrtimer_mode mode) -{ - struct hrtimer_cpu_base *cpu_base; - int base; - - memset(timer, 0, sizeof(struct hrtimer)); - - cpu_base = &__raw_get_cpu_var(hrtimer_bases); - - if (clock_id == CLOCK_REALTIME && mode != HRTIMER_MODE_ABS) - clock_id = CLOCK_MONOTONIC; - - base = hrtimer_clockid_to_base(clock_id); - timer->base = &cpu_base->clock_base[base]; - timerqueue_init(&timer->node); - -#ifdef CONFIG_TIMER_STATS - timer->start_site = NULL; - timer->start_pid = -1; - memset(timer->start_comm, 0, TASK_COMM_LEN); -#endif -} - -/** - * hrtimer_init - initialize a timer to the given clock - * @timer: the timer to be initialized - * @clock_id: the clock to be used - * @mode: timer mode abs/rel - */ -void hrtimer_init(struct hrtimer *timer, clockid_t clock_id, - enum hrtimer_mode mode) -{ - debug_init(timer, clock_id, mode); - __hrtimer_init(timer, clock_id, mode); -} -EXPORT_SYMBOL_GPL(hrtimer_init); - -/** - * hrtimer_get_res - get the timer resolution for a clock - * @which_clock: which clock to query - * @tp: pointer to timespec variable to store the resolution - * - * Store the resolution of the clock selected by @which_clock in the - * variable pointed to by @tp. - */ -int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp) -{ - struct hrtimer_cpu_base *cpu_base; - int base = hrtimer_clockid_to_base(which_clock); - - cpu_base = &__raw_get_cpu_var(hrtimer_bases); - *tp = ktime_to_timespec(cpu_base->clock_base[base].resolution); - - return 0; -} -EXPORT_SYMBOL_GPL(hrtimer_get_res); - -static void __run_hrtimer(struct hrtimer *timer, ktime_t *now) -{ - struct hrtimer_clock_base *base = timer->base; - struct hrtimer_cpu_base *cpu_base = base->cpu_base; - enum hrtimer_restart (*fn)(struct hrtimer *); - int restart; - - WARN_ON(!irqs_disabled()); - - debug_deactivate(timer); - __remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0); - timer_stats_account_hrtimer(timer); - fn = timer->function; - - /* - * Because we run timers from hardirq context, there is no chance - * they get migrated to another cpu, therefore its safe to unlock - * the timer base. - */ - raw_spin_unlock(&cpu_base->lock); - trace_hrtimer_expire_entry(timer, now); - restart = fn(timer); - trace_hrtimer_expire_exit(timer); - raw_spin_lock(&cpu_base->lock); - - /* - * Note: We clear the CALLBACK bit after enqueue_hrtimer and - * we do not reprogramm the event hardware. Happens either in - * hrtimer_start_range_ns() or in hrtimer_interrupt() - */ - if (restart != HRTIMER_NORESTART) { - BUG_ON(timer->state != HRTIMER_STATE_CALLBACK); - enqueue_hrtimer(timer, base); - } - - WARN_ON_ONCE(!(timer->state & HRTIMER_STATE_CALLBACK)); - - timer->state &= ~HRTIMER_STATE_CALLBACK; -} - -#ifdef CONFIG_HIGH_RES_TIMERS - -/* - * High resolution timer interrupt - * Called with interrupts disabled - */ -void hrtimer_interrupt(struct clock_event_device *dev) -{ - struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); - ktime_t expires_next, now, entry_time, delta; - int i, retries = 0; - - BUG_ON(!cpu_base->hres_active); - cpu_base->nr_events++; - dev->next_event.tv64 = KTIME_MAX; - - raw_spin_lock(&cpu_base->lock); - entry_time = now = hrtimer_update_base(cpu_base); -retry: - expires_next.tv64 = KTIME_MAX; - /* - * We set expires_next to KTIME_MAX here with cpu_base->lock - * held to prevent that a timer is enqueued in our queue via - * the migration code. This does not affect enqueueing of - * timers which run their callback and need to be requeued on - * this CPU. - */ - cpu_base->expires_next.tv64 = KTIME_MAX; - - for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { - struct hrtimer_clock_base *base; - struct timerqueue_node *node; - ktime_t basenow; - - if (!(cpu_base->active_bases & (1 << i))) - continue; - - base = cpu_base->clock_base + i; - basenow = ktime_add(now, base->offset); - - while ((node = timerqueue_getnext(&base->active))) { - struct hrtimer *timer; - - timer = container_of(node, struct hrtimer, node); - - /* - * The immediate goal for using the softexpires is - * minimizing wakeups, not running timers at the - * earliest interrupt after their soft expiration. - * This allows us to avoid using a Priority Search - * Tree, which can answer a stabbing querry for - * overlapping intervals and instead use the simple - * BST we already have. - * We don't add extra wakeups by delaying timers that - * are right-of a not yet expired timer, because that - * timer will have to trigger a wakeup anyway. - */ - - if (basenow.tv64 < hrtimer_get_softexpires_tv64(timer)) { - ktime_t expires; - - expires = ktime_sub(hrtimer_get_expires(timer), - base->offset); - if (expires.tv64 < 0) - expires.tv64 = KTIME_MAX; - if (expires.tv64 < expires_next.tv64) - expires_next = expires; - break; - } - - __run_hrtimer(timer, &basenow); - } - } - - /* - * Store the new expiry value so the migration code can verify - * against it. - */ - cpu_base->expires_next = expires_next; - raw_spin_unlock(&cpu_base->lock); - - /* Reprogramming necessary ? */ - if (expires_next.tv64 == KTIME_MAX || - !tick_program_event(expires_next, 0)) { - cpu_base->hang_detected = 0; - return; - } - - /* - * The next timer was already expired due to: - * - tracing - * - long lasting callbacks - * - being scheduled away when running in a VM - * - * We need to prevent that we loop forever in the hrtimer - * interrupt routine. We give it 3 attempts to avoid - * overreacting on some spurious event. - * - * Acquire base lock for updating the offsets and retrieving - * the current time. - */ - raw_spin_lock(&cpu_base->lock); - now = hrtimer_update_base(cpu_base); - cpu_base->nr_retries++; - if (++retries < 3) - goto retry; - /* - * Give the system a chance to do something else than looping - * here. We stored the entry time, so we know exactly how long - * we spent here. We schedule the next event this amount of - * time away. - */ - cpu_base->nr_hangs++; - cpu_base->hang_detected = 1; - raw_spin_unlock(&cpu_base->lock); - delta = ktime_sub(now, entry_time); - if (delta.tv64 > cpu_base->max_hang_time.tv64) - cpu_base->max_hang_time = delta; - /* - * Limit it to a sensible value as we enforce a longer - * delay. Give the CPU at least 100ms to catch up. - */ - if (delta.tv64 > 100 * NSEC_PER_MSEC) - expires_next = ktime_add_ns(now, 100 * NSEC_PER_MSEC); - else - expires_next = ktime_add(now, delta); - tick_program_event(expires_next, 1); - printk_once(KERN_WARNING "hrtimer: interrupt took %llu ns\n", - ktime_to_ns(delta)); -} - -/* - * local version of hrtimer_peek_ahead_timers() called with interrupts - * disabled. - */ -static void __hrtimer_peek_ahead_timers(void) -{ - struct tick_device *td; - - if (!hrtimer_hres_active()) - return; - - td = &__get_cpu_var(tick_cpu_device); - if (td && td->evtdev) - hrtimer_interrupt(td->evtdev); -} - -/** - * hrtimer_peek_ahead_timers -- run soft-expired timers now - * - * hrtimer_peek_ahead_timers will peek at the timer queue of - * the current cpu and check if there are any timers for which - * the soft expires time has passed. If any such timers exist, - * they are run immediately and then removed from the timer queue. - * - */ -void hrtimer_peek_ahead_timers(void) -{ - unsigned long flags; - - local_irq_save(flags); - __hrtimer_peek_ahead_timers(); - local_irq_restore(flags); -} - -static void run_hrtimer_softirq(struct softirq_action *h) -{ - hrtimer_peek_ahead_timers(); -} - -#else /* CONFIG_HIGH_RES_TIMERS */ - -static inline void __hrtimer_peek_ahead_timers(void) { } - -#endif /* !CONFIG_HIGH_RES_TIMERS */ - -/* - * Called from timer softirq every jiffy, expire hrtimers: - * - * For HRT its the fall back code to run the softirq in the timer - * softirq context in case the hrtimer initialization failed or has - * not been done yet. - */ -void hrtimer_run_pending(void) -{ - if (hrtimer_hres_active()) - return; - - /* - * This _is_ ugly: We have to check in the softirq context, - * whether we can switch to highres and / or nohz mode. The - * clocksource switch happens in the timer interrupt with - * xtime_lock held. Notification from there only sets the - * check bit in the tick_oneshot code, otherwise we might - * deadlock vs. xtime_lock. - */ - if (tick_check_oneshot_change(!hrtimer_is_hres_enabled())) - hrtimer_switch_to_hres(); -} - -/* - * Called from hardirq context every jiffy - */ -void hrtimer_run_queues(void) -{ - struct timerqueue_node *node; - struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases); - struct hrtimer_clock_base *base; - int index, gettime = 1; - - if (hrtimer_hres_active()) - return; - - for (index = 0; index < HRTIMER_MAX_CLOCK_BASES; index++) { - base = &cpu_base->clock_base[index]; - if (!timerqueue_getnext(&base->active)) - continue; - - if (gettime) { - hrtimer_get_softirq_time(cpu_base); - gettime = 0; - } - - raw_spin_lock(&cpu_base->lock); - - while ((node = timerqueue_getnext(&base->active))) { - struct hrtimer *timer; - - timer = container_of(node, struct hrtimer, node); - if (base->softirq_time.tv64 <= - hrtimer_get_expires_tv64(timer)) - break; - - __run_hrtimer(timer, &base->softirq_time); - } - raw_spin_unlock(&cpu_base->lock); - } -} - -/* - * Sleep related functions: - */ -static enum hrtimer_restart hrtimer_wakeup(struct hrtimer *timer) -{ - struct hrtimer_sleeper *t = - container_of(timer, struct hrtimer_sleeper, timer); - struct task_struct *task = t->task; - - t->task = NULL; - if (task) - wake_up_process(task); - - return HRTIMER_NORESTART; -} - -void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task) -{ - sl->timer.function = hrtimer_wakeup; - sl->task = task; -} -EXPORT_SYMBOL_GPL(hrtimer_init_sleeper); - -static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode) -{ - hrtimer_init_sleeper(t, current); - - do { - set_current_state(TASK_INTERRUPTIBLE); - hrtimer_start_expires(&t->timer, mode); - if (!hrtimer_active(&t->timer)) - t->task = NULL; - - if (likely(t->task)) - freezable_schedule(); - - hrtimer_cancel(&t->timer); - mode = HRTIMER_MODE_ABS; - - } while (t->task && !signal_pending(current)); - - __set_current_state(TASK_RUNNING); - - return t->task == NULL; -} - -static int update_rmtp(struct hrtimer *timer, struct timespec __user *rmtp) -{ - struct timespec rmt; - ktime_t rem; - - rem = hrtimer_expires_remaining(timer); - if (rem.tv64 <= 0) - return 0; - rmt = ktime_to_timespec(rem); - - if (copy_to_user(rmtp, &rmt, sizeof(*rmtp))) - return -EFAULT; - - return 1; -} - -long __sched hrtimer_nanosleep_restart(struct restart_block *restart) -{ - struct hrtimer_sleeper t; - struct timespec __user *rmtp; - int ret = 0; - - hrtimer_init_on_stack(&t.timer, restart->nanosleep.clockid, - HRTIMER_MODE_ABS); - hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires); - - if (do_nanosleep(&t, HRTIMER_MODE_ABS)) - goto out; - - rmtp = restart->nanosleep.rmtp; - if (rmtp) { - ret = update_rmtp(&t.timer, rmtp); - if (ret <= 0) - goto out; - } - - /* The other values in restart are already filled in */ - ret = -ERESTART_RESTARTBLOCK; -out: - destroy_hrtimer_on_stack(&t.timer); - return ret; -} - -long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, - const enum hrtimer_mode mode, const clockid_t clockid) -{ - struct restart_block *restart; - struct hrtimer_sleeper t; - int ret = 0; - unsigned long slack; - - slack = current->timer_slack_ns; - if (dl_task(current) || rt_task(current)) - slack = 0; - - hrtimer_init_on_stack(&t.timer, clockid, mode); - hrtimer_set_expires_range_ns(&t.timer, timespec_to_ktime(*rqtp), slack); - if (do_nanosleep(&t, mode)) - goto out; - - /* Absolute timers do not update the rmtp value and restart: */ - if (mode == HRTIMER_MODE_ABS) { - ret = -ERESTARTNOHAND; - goto out; - } - - if (rmtp) { - ret = update_rmtp(&t.timer, rmtp); - if (ret <= 0) - goto out; - } - - restart = ¤t_thread_info()->restart_block; - restart->fn = hrtimer_nanosleep_restart; - restart->nanosleep.clockid = t.timer.base->clockid; - restart->nanosleep.rmtp = rmtp; - restart->nanosleep.expires = hrtimer_get_expires_tv64(&t.timer); - - ret = -ERESTART_RESTARTBLOCK; -out: - destroy_hrtimer_on_stack(&t.timer); - return ret; -} - -SYSCALL_DEFINE2(nanosleep, struct timespec __user *, rqtp, - struct timespec __user *, rmtp) -{ - struct timespec tu; - - if (copy_from_user(&tu, rqtp, sizeof(tu))) - return -EFAULT; - - if (!timespec_valid(&tu)) - return -EINVAL; - - return hrtimer_nanosleep(&tu, rmtp, HRTIMER_MODE_REL, CLOCK_MONOTONIC); -} - -/* - * Functions related to boot-time initialization: - */ -static void init_hrtimers_cpu(int cpu) -{ - struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu); - int i; - - for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { - cpu_base->clock_base[i].cpu_base = cpu_base; - timerqueue_init_head(&cpu_base->clock_base[i].active); - } - - hrtimer_init_hres(cpu_base); -} - -#ifdef CONFIG_HOTPLUG_CPU - -static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base, - struct hrtimer_clock_base *new_base) -{ - struct hrtimer *timer; - struct timerqueue_node *node; - - while ((node = timerqueue_getnext(&old_base->active))) { - timer = container_of(node, struct hrtimer, node); - BUG_ON(hrtimer_callback_running(timer)); - debug_deactivate(timer); - - /* - * Mark it as STATE_MIGRATE not INACTIVE otherwise the - * timer could be seen as !active and just vanish away - * under us on another CPU - */ - __remove_hrtimer(timer, old_base, HRTIMER_STATE_MIGRATE, 0); - timer->base = new_base; - /* - * Enqueue the timers on the new cpu. This does not - * reprogram the event device in case the timer - * expires before the earliest on this CPU, but we run - * hrtimer_interrupt after we migrated everything to - * sort out already expired timers and reprogram the - * event device. - */ - enqueue_hrtimer(timer, new_base); - - /* Clear the migration state bit */ - timer->state &= ~HRTIMER_STATE_MIGRATE; - } -} - -static void migrate_hrtimers(int scpu) -{ - struct hrtimer_cpu_base *old_base, *new_base; - int i; - - BUG_ON(cpu_online(scpu)); - tick_cancel_sched_timer(scpu); - - local_irq_disable(); - old_base = &per_cpu(hrtimer_bases, scpu); - new_base = &__get_cpu_var(hrtimer_bases); - /* - * The caller is globally serialized and nobody else - * takes two locks at once, deadlock is not possible. - */ - raw_spin_lock(&new_base->lock); - raw_spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING); - - for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { - migrate_hrtimer_list(&old_base->clock_base[i], - &new_base->clock_base[i]); - } - - raw_spin_unlock(&old_base->lock); - raw_spin_unlock(&new_base->lock); - - /* Check, if we got expired work to do */ - __hrtimer_peek_ahead_timers(); - local_irq_enable(); -} - -#endif /* CONFIG_HOTPLUG_CPU */ - -static int hrtimer_cpu_notify(struct notifier_block *self, - unsigned long action, void *hcpu) -{ - int scpu = (long)hcpu; - - switch (action) { - - case CPU_UP_PREPARE: - case CPU_UP_PREPARE_FROZEN: - init_hrtimers_cpu(scpu); - break; - -#ifdef CONFIG_HOTPLUG_CPU - case CPU_DYING: - case CPU_DYING_FROZEN: - clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DYING, &scpu); - break; - case CPU_DEAD: - case CPU_DEAD_FROZEN: - { - clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DEAD, &scpu); - migrate_hrtimers(scpu); - break; - } -#endif - - default: - break; - } - - return NOTIFY_OK; -} - -static struct notifier_block hrtimers_nb = { - .notifier_call = hrtimer_cpu_notify, -}; - -void __init hrtimers_init(void) -{ - hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE, - (void *)(long)smp_processor_id()); - register_cpu_notifier(&hrtimers_nb); -#ifdef CONFIG_HIGH_RES_TIMERS - open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq); -#endif -} - -/** - * schedule_hrtimeout_range_clock - sleep until timeout - * @expires: timeout value (ktime_t) - * @delta: slack in expires timeout (ktime_t) - * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL - * @clock: timer clock, CLOCK_MONOTONIC or CLOCK_REALTIME - */ -int __sched -schedule_hrtimeout_range_clock(ktime_t *expires, unsigned long delta, - const enum hrtimer_mode mode, int clock) -{ - struct hrtimer_sleeper t; - - /* - * Optimize when a zero timeout value is given. It does not - * matter whether this is an absolute or a relative time. - */ - if (expires && !expires->tv64) { - __set_current_state(TASK_RUNNING); - return 0; - } - - /* - * A NULL parameter means "infinite" - */ - if (!expires) { - schedule(); - __set_current_state(TASK_RUNNING); - return -EINTR; - } - - hrtimer_init_on_stack(&t.timer, clock, mode); - hrtimer_set_expires_range_ns(&t.timer, *expires, delta); - - hrtimer_init_sleeper(&t, current); - - hrtimer_start_expires(&t.timer, mode); - if (!hrtimer_active(&t.timer)) - t.task = NULL; - - if (likely(t.task)) - schedule(); - - hrtimer_cancel(&t.timer); - destroy_hrtimer_on_stack(&t.timer); - - __set_current_state(TASK_RUNNING); - - return !t.task ? 0 : -EINTR; -} - -/** - * schedule_hrtimeout_range - sleep until timeout - * @expires: timeout value (ktime_t) - * @delta: slack in expires timeout (ktime_t) - * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL - * - * Make the current task sleep until the given expiry time has - * elapsed. The routine will return immediately unless - * the current task state has been set (see set_current_state()). - * - * The @delta argument gives the kernel the freedom to schedule the - * actual wakeup to a time that is both power and performance friendly. - * The kernel give the normal best effort behavior for "@expires+@delta", - * but may decide to fire the timer earlier, but no earlier than @expires. - * - * You can set the task state as follows - - * - * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to - * pass before the routine returns. - * - * %TASK_INTERRUPTIBLE - the routine may return early if a signal is - * delivered to the current task. - * - * The current task state is guaranteed to be TASK_RUNNING when this - * routine returns. - * - * Returns 0 when the timer has expired otherwise -EINTR - */ -int __sched schedule_hrtimeout_range(ktime_t *expires, unsigned long delta, - const enum hrtimer_mode mode) -{ - return schedule_hrtimeout_range_clock(expires, delta, mode, - CLOCK_MONOTONIC); -} -EXPORT_SYMBOL_GPL(schedule_hrtimeout_range); - -/** - * schedule_hrtimeout - sleep until timeout - * @expires: timeout value (ktime_t) - * @mode: timer mode, HRTIMER_MODE_ABS or HRTIMER_MODE_REL - * - * Make the current task sleep until the given expiry time has - * elapsed. The routine will return immediately unless - * the current task state has been set (see set_current_state()). - * - * You can set the task state as follows - - * - * %TASK_UNINTERRUPTIBLE - at least @timeout time is guaranteed to - * pass before the routine returns. - * - * %TASK_INTERRUPTIBLE - the routine may return early if a signal is - * delivered to the current task. - * - * The current task state is guaranteed to be TASK_RUNNING when this - * routine returns. - * - * Returns 0 when the timer has expired otherwise -EINTR - */ -int __sched schedule_hrtimeout(ktime_t *expires, - const enum hrtimer_mode mode) -{ - return schedule_hrtimeout_range(expires, 0, mode); -} -EXPORT_SYMBOL_GPL(schedule_hrtimeout); |
