diff options
Diffstat (limited to 'libdde_linux26/lib/src/kernel/timer.c')
| -rw-r--r-- | libdde_linux26/lib/src/kernel/timer.c | 1590 |
1 files changed, 0 insertions, 1590 deletions
diff --git a/libdde_linux26/lib/src/kernel/timer.c b/libdde_linux26/lib/src/kernel/timer.c deleted file mode 100644 index 951d6ffc..00000000 --- a/libdde_linux26/lib/src/kernel/timer.c +++ /dev/null @@ -1,1590 +0,0 @@ -/* - * linux/kernel/timer.c - * - * Kernel internal timers, basic process system calls - * - * Copyright (C) 1991, 1992 Linus Torvalds - * - * 1997-01-28 Modified by Finn Arne Gangstad to make timers scale better. - * - * 1997-09-10 Updated NTP code according to technical memorandum Jan '96 - * "A Kernel Model for Precision Timekeeping" by Dave Mills - * 1998-12-24 Fixed a xtime SMP race (we need the xtime_lock rw spinlock to - * serialize accesses to xtime/lost_ticks). - * Copyright (C) 1998 Andrea Arcangeli - * 1999-03-10 Improved NTP compatibility by Ulrich Windl - * 2002-05-31 Move sys_sysinfo here and make its locking sane, Robert Love - * 2000-10-05 Implemented scalable SMP per-CPU timer handling. - * Copyright (C) 2000, 2001, 2002 Ingo Molnar - * Designed by David S. Miller, Alexey Kuznetsov and Ingo Molnar - */ - -#include <linux/kernel_stat.h> -#include <linux/module.h> -#include <linux/interrupt.h> -#include <linux/percpu.h> -#include <linux/init.h> -#include <linux/mm.h> -#include <linux/swap.h> -#include <linux/pid_namespace.h> -#include <linux/notifier.h> -#include <linux/thread_info.h> -#include <linux/time.h> -#include <linux/jiffies.h> -#include <linux/posix-timers.h> -#include <linux/cpu.h> -#include <linux/syscalls.h> -#include <linux/delay.h> -#include <linux/tick.h> -#include <linux/kallsyms.h> - -#include <asm/uaccess.h> -#include <asm/unistd.h> -#include <asm/div64.h> -#include <asm/timex.h> -#include <asm/io.h> - -#include <ddekit/timer.h> - -#ifndef DDE_LINUX - -u64 jiffies_64 __cacheline_aligned_in_smp = INITIAL_JIFFIES; - -EXPORT_SYMBOL(jiffies_64); - -/* - * per-CPU timer vector definitions: - */ -#define TVN_BITS (CONFIG_BASE_SMALL ? 4 : 6) -#define TVR_BITS (CONFIG_BASE_SMALL ? 6 : 8) -#define TVN_SIZE (1 << TVN_BITS) -#define TVR_SIZE (1 << TVR_BITS) -#define TVN_MASK (TVN_SIZE - 1) -#define TVR_MASK (TVR_SIZE - 1) - -struct tvec { - struct list_head vec[TVN_SIZE]; -}; - -struct tvec_root { - struct list_head vec[TVR_SIZE]; -}; - -struct tvec_base { - spinlock_t lock; - struct timer_list *running_timer; - unsigned long timer_jiffies; - struct tvec_root tv1; - struct tvec tv2; - struct tvec tv3; - struct tvec tv4; - struct tvec tv5; -} ____cacheline_aligned; - -struct tvec_base boot_tvec_bases; -EXPORT_SYMBOL(boot_tvec_bases); -static DEFINE_PER_CPU(struct tvec_base *, tvec_bases) = &boot_tvec_bases; - -/* - * Note that all tvec_bases are 2 byte aligned and lower bit of - * base in timer_list is guaranteed to be zero. Use the LSB for - * the new flag to indicate whether the timer is deferrable - */ -#define TBASE_DEFERRABLE_FLAG (0x1) - -/* Functions below help us manage 'deferrable' flag */ -static inline unsigned int tbase_get_deferrable(struct tvec_base *base) -{ - return ((unsigned int)(unsigned long)base & TBASE_DEFERRABLE_FLAG); -} - -static inline struct tvec_base *tbase_get_base(struct tvec_base *base) -{ - return ((struct tvec_base *)((unsigned long)base & ~TBASE_DEFERRABLE_FLAG)); -} - -static inline void timer_set_deferrable(struct timer_list *timer) -{ - timer->base = ((struct tvec_base *)((unsigned long)(timer->base) | - TBASE_DEFERRABLE_FLAG)); -} - -static inline void -timer_set_base(struct timer_list *timer, struct tvec_base *new_base) -{ - timer->base = (struct tvec_base *)((unsigned long)(new_base) | - tbase_get_deferrable(timer->base)); -} -#endif /* DDE_LINUX */ - -static unsigned long round_jiffies_common(unsigned long j, int cpu, - bool force_up) -{ - int rem; - unsigned long original = j; - - /* - * We don't want all cpus firing their timers at once hitting the - * same lock or cachelines, so we skew each extra cpu with an extra - * 3 jiffies. This 3 jiffies came originally from the mm/ code which - * already did this. - * The skew is done by adding 3*cpunr, then round, then subtract this - * extra offset again. - */ - j += cpu * 3; - - rem = j % HZ; - - /* - * If the target jiffie is just after a whole second (which can happen - * due to delays of the timer irq, long irq off times etc etc) then - * we should round down to the whole second, not up. Use 1/4th second - * as cutoff for this rounding as an extreme upper bound for this. - * But never round down if @force_up is set. - */ - if (rem < HZ/4 && !force_up) /* round down */ - j = j - rem; - else /* round up */ - j = j - rem + HZ; - - /* now that we have rounded, subtract the extra skew again */ - j -= cpu * 3; - - if (j <= jiffies) /* rounding ate our timeout entirely; */ - return original; - return j; -} - -/** - * __round_jiffies - function to round jiffies to a full second - * @j: the time in (absolute) jiffies that should be rounded - * @cpu: the processor number on which the timeout will happen - * - * __round_jiffies() rounds an absolute time in the future (in jiffies) - * up or down to (approximately) full seconds. This is useful for timers - * for which the exact time they fire does not matter too much, as long as - * they fire approximately every X seconds. - * - * By rounding these timers to whole seconds, all such timers will fire - * at the same time, rather than at various times spread out. The goal - * of this is to have the CPU wake up less, which saves power. - * - * The exact rounding is skewed for each processor to avoid all - * processors firing at the exact same time, which could lead - * to lock contention or spurious cache line bouncing. - * - * The return value is the rounded version of the @j parameter. - */ -unsigned long __round_jiffies(unsigned long j, int cpu) -{ - return round_jiffies_common(j, cpu, false); -} -EXPORT_SYMBOL_GPL(__round_jiffies); - -/** - * __round_jiffies_relative - function to round jiffies to a full second - * @j: the time in (relative) jiffies that should be rounded - * @cpu: the processor number on which the timeout will happen - * - * __round_jiffies_relative() rounds a time delta in the future (in jiffies) - * up or down to (approximately) full seconds. This is useful for timers - * for which the exact time they fire does not matter too much, as long as - * they fire approximately every X seconds. - * - * By rounding these timers to whole seconds, all such timers will fire - * at the same time, rather than at various times spread out. The goal - * of this is to have the CPU wake up less, which saves power. - * - * The exact rounding is skewed for each processor to avoid all - * processors firing at the exact same time, which could lead - * to lock contention or spurious cache line bouncing. - * - * The return value is the rounded version of the @j parameter. - */ -unsigned long __round_jiffies_relative(unsigned long j, int cpu) -{ - unsigned long j0 = jiffies; - - /* Use j0 because jiffies might change while we run */ - return round_jiffies_common(j + j0, cpu, false) - j0; -} -EXPORT_SYMBOL_GPL(__round_jiffies_relative); - -/** - * round_jiffies - function to round jiffies to a full second - * @j: the time in (absolute) jiffies that should be rounded - * - * round_jiffies() rounds an absolute time in the future (in jiffies) - * up or down to (approximately) full seconds. This is useful for timers - * for which the exact time they fire does not matter too much, as long as - * they fire approximately every X seconds. - * - * By rounding these timers to whole seconds, all such timers will fire - * at the same time, rather than at various times spread out. The goal - * of this is to have the CPU wake up less, which saves power. - * - * The return value is the rounded version of the @j parameter. - */ -unsigned long round_jiffies(unsigned long j) -{ - return round_jiffies_common(j, raw_smp_processor_id(), false); -} -EXPORT_SYMBOL_GPL(round_jiffies); - -/** - * round_jiffies_relative - function to round jiffies to a full second - * @j: the time in (relative) jiffies that should be rounded - * - * round_jiffies_relative() rounds a time delta in the future (in jiffies) - * up or down to (approximately) full seconds. This is useful for timers - * for which the exact time they fire does not matter too much, as long as - * they fire approximately every X seconds. - * - * By rounding these timers to whole seconds, all such timers will fire - * at the same time, rather than at various times spread out. The goal - * of this is to have the CPU wake up less, which saves power. - * - * The return value is the rounded version of the @j parameter. - */ -unsigned long round_jiffies_relative(unsigned long j) -{ - return __round_jiffies_relative(j, raw_smp_processor_id()); -} -EXPORT_SYMBOL_GPL(round_jiffies_relative); - -/** - * __round_jiffies_up - function to round jiffies up to a full second - * @j: the time in (absolute) jiffies that should be rounded - * @cpu: the processor number on which the timeout will happen - * - * This is the same as __round_jiffies() except that it will never - * round down. This is useful for timeouts for which the exact time - * of firing does not matter too much, as long as they don't fire too - * early. - */ -unsigned long __round_jiffies_up(unsigned long j, int cpu) -{ - return round_jiffies_common(j, cpu, true); -} -EXPORT_SYMBOL_GPL(__round_jiffies_up); - -/** - * __round_jiffies_up_relative - function to round jiffies up to a full second - * @j: the time in (relative) jiffies that should be rounded - * @cpu: the processor number on which the timeout will happen - * - * This is the same as __round_jiffies_relative() except that it will never - * round down. This is useful for timeouts for which the exact time - * of firing does not matter too much, as long as they don't fire too - * early. - */ -unsigned long __round_jiffies_up_relative(unsigned long j, int cpu) -{ - unsigned long j0 = jiffies; - - /* Use j0 because jiffies might change while we run */ - return round_jiffies_common(j + j0, cpu, true) - j0; -} -EXPORT_SYMBOL_GPL(__round_jiffies_up_relative); - -/** - * round_jiffies_up - function to round jiffies up to a full second - * @j: the time in (absolute) jiffies that should be rounded - * - * This is the same as round_jiffies() except that it will never - * round down. This is useful for timeouts for which the exact time - * of firing does not matter too much, as long as they don't fire too - * early. - */ -unsigned long round_jiffies_up(unsigned long j) -{ - return round_jiffies_common(j, raw_smp_processor_id(), true); -} -EXPORT_SYMBOL_GPL(round_jiffies_up); - -/** - * round_jiffies_up_relative - function to round jiffies up to a full second - * @j: the time in (relative) jiffies that should be rounded - * - * This is the same as round_jiffies_relative() except that it will never - * round down. This is useful for timeouts for which the exact time - * of firing does not matter too much, as long as they don't fire too - * early. - */ -unsigned long round_jiffies_up_relative(unsigned long j) -{ - return __round_jiffies_up_relative(j, raw_smp_processor_id()); -} -EXPORT_SYMBOL_GPL(round_jiffies_up_relative); - - -#ifndef DDE_LINUX -static inline void set_running_timer(struct tvec_base *base, - struct timer_list *timer) -{ -#ifdef CONFIG_SMP - base->running_timer = timer; -#endif -} - -static void internal_add_timer(struct tvec_base *base, struct timer_list *timer) -{ - unsigned long expires = timer->expires; - unsigned long idx = expires - base->timer_jiffies; - struct list_head *vec; - - if (idx < TVR_SIZE) { - int i = expires & TVR_MASK; - vec = base->tv1.vec + i; - } else if (idx < 1 << (TVR_BITS + TVN_BITS)) { - int i = (expires >> TVR_BITS) & TVN_MASK; - vec = base->tv2.vec + i; - } else if (idx < 1 << (TVR_BITS + 2 * TVN_BITS)) { - int i = (expires >> (TVR_BITS + TVN_BITS)) & TVN_MASK; - vec = base->tv3.vec + i; - } else if (idx < 1 << (TVR_BITS + 3 * TVN_BITS)) { - int i = (expires >> (TVR_BITS + 2 * TVN_BITS)) & TVN_MASK; - vec = base->tv4.vec + i; - } else if ((signed long) idx < 0) { - /* - * Can happen if you add a timer with expires == jiffies, - * or you set a timer to go off in the past - */ - vec = base->tv1.vec + (base->timer_jiffies & TVR_MASK); - } else { - int i; - /* If the timeout is larger than 0xffffffff on 64-bit - * architectures then we use the maximum timeout: - */ - if (idx > 0xffffffffUL) { - idx = 0xffffffffUL; - expires = idx + base->timer_jiffies; - } - i = (expires >> (TVR_BITS + 3 * TVN_BITS)) & TVN_MASK; - vec = base->tv5.vec + i; - } - /* - * Timers are FIFO: - */ - list_add_tail(&timer->entry, vec); -} - -#ifdef CONFIG_TIMER_STATS -void __timer_stats_timer_set_start_info(struct timer_list *timer, void *addr) -{ - if (timer->start_site) - return; - - timer->start_site = addr; - memcpy(timer->start_comm, current->comm, TASK_COMM_LEN); - timer->start_pid = current->pid; -} - -static void timer_stats_account_timer(struct timer_list *timer) -{ - unsigned int flag = 0; - - if (unlikely(tbase_get_deferrable(timer->base))) - flag |= TIMER_STATS_FLAG_DEFERRABLE; - - timer_stats_update_stats(timer, timer->start_pid, timer->start_site, - timer->function, timer->start_comm, flag); -} - -#else -static void timer_stats_account_timer(struct timer_list *timer) {} -#endif - -#ifdef CONFIG_DEBUG_OBJECTS_TIMERS - -static struct debug_obj_descr timer_debug_descr; - -/* - * fixup_init is called when: - * - an active object is initialized - */ -static int timer_fixup_init(void *addr, enum debug_obj_state state) -{ - struct timer_list *timer = addr; - - switch (state) { - case ODEBUG_STATE_ACTIVE: - del_timer_sync(timer); - debug_object_init(timer, &timer_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 timer_fixup_activate(void *addr, enum debug_obj_state state) -{ - struct timer_list *timer = addr; - - switch (state) { - - case ODEBUG_STATE_NOTAVAILABLE: - /* - * This is not really a fixup. The timer was - * statically initialized. We just make sure that it - * is tracked in the object tracker. - */ - if (timer->entry.next == NULL && - timer->entry.prev == TIMER_ENTRY_STATIC) { - debug_object_init(timer, &timer_debug_descr); - debug_object_activate(timer, &timer_debug_descr); - return 0; - } else { - 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 timer_fixup_free(void *addr, enum debug_obj_state state) -{ - struct timer_list *timer = addr; - - switch (state) { - case ODEBUG_STATE_ACTIVE: - del_timer_sync(timer); - debug_object_free(timer, &timer_debug_descr); - return 1; - default: - return 0; - } -} - -static struct debug_obj_descr timer_debug_descr = { - .name = "timer_list", - .fixup_init = timer_fixup_init, - .fixup_activate = timer_fixup_activate, - .fixup_free = timer_fixup_free, -}; - -static inline void debug_timer_init(struct timer_list *timer) -{ - debug_object_init(timer, &timer_debug_descr); -} - -static inline void debug_timer_activate(struct timer_list *timer) -{ - debug_object_activate(timer, &timer_debug_descr); -} - -static inline void debug_timer_deactivate(struct timer_list *timer) -{ - debug_object_deactivate(timer, &timer_debug_descr); -} - -static inline void debug_timer_free(struct timer_list *timer) -{ - debug_object_free(timer, &timer_debug_descr); -} - -static void __init_timer(struct timer_list *timer); - -void init_timer_on_stack(struct timer_list *timer) -{ - debug_object_init_on_stack(timer, &timer_debug_descr); - __init_timer(timer); -} -EXPORT_SYMBOL_GPL(init_timer_on_stack); - -void destroy_timer_on_stack(struct timer_list *timer) -{ - debug_object_free(timer, &timer_debug_descr); -} -EXPORT_SYMBOL_GPL(destroy_timer_on_stack); - -#else -static inline void debug_timer_init(struct timer_list *timer) { } -static inline void debug_timer_activate(struct timer_list *timer) { } -static inline void debug_timer_deactivate(struct timer_list *timer) { } -#endif - -static void __init_timer(struct timer_list *timer) -{ - timer->entry.next = NULL; - timer->base = __raw_get_cpu_var(tvec_bases); -#ifdef CONFIG_TIMER_STATS - timer->start_site = NULL; - timer->start_pid = -1; - memset(timer->start_comm, 0, TASK_COMM_LEN); -#endif -} - -/** - * init_timer - initialize a timer. - * @timer: the timer to be initialized - * - * init_timer() must be done to a timer prior calling *any* of the - * other timer functions. - */ -void init_timer(struct timer_list *timer) -{ - debug_timer_init(timer); - __init_timer(timer); -} -EXPORT_SYMBOL(init_timer); - -void init_timer_deferrable(struct timer_list *timer) -{ - init_timer(timer); - timer_set_deferrable(timer); -} -EXPORT_SYMBOL(init_timer_deferrable); - -static inline void detach_timer(struct timer_list *timer, - int clear_pending) -{ - struct list_head *entry = &timer->entry; - - debug_timer_deactivate(timer); - - __list_del(entry->prev, entry->next); - if (clear_pending) - entry->next = NULL; - entry->prev = LIST_POISON2; -} - -/* - * We are using hashed locking: holding per_cpu(tvec_bases).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 ->tvX lists. - * - * 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 tvec_base *lock_timer_base(struct timer_list *timer, - unsigned long *flags) - __acquires(timer->base->lock) -{ - struct tvec_base *base; - - for (;;) { - struct tvec_base *prelock_base = timer->base; - base = tbase_get_base(prelock_base); - if (likely(base != NULL)) { - spin_lock_irqsave(&base->lock, *flags); - if (likely(prelock_base == timer->base)) - return base; - /* The timer has migrated to another CPU */ - spin_unlock_irqrestore(&base->lock, *flags); - } - cpu_relax(); - } -} - -int __mod_timer(struct timer_list *timer, unsigned long expires) -{ - struct tvec_base *base, *new_base; - unsigned long flags; - int ret = 0; - - timer_stats_timer_set_start_info(timer); - BUG_ON(!timer->function); - - base = lock_timer_base(timer, &flags); - - if (timer_pending(timer)) { - detach_timer(timer, 0); - ret = 1; - } - - debug_timer_activate(timer); - - new_base = __get_cpu_var(tvec_bases); - - if (base != new_base) { - /* - * We are trying to schedule the timer on the local CPU. - * However we can't change timer's base while it is running, - * otherwise del_timer_sync() can't detect that the timer's - * handler yet has not finished. This also guarantees that - * the timer is serialized wrt itself. - */ - if (likely(base->running_timer != timer)) { - /* See the comment in lock_timer_base() */ - timer_set_base(timer, NULL); - spin_unlock(&base->lock); - base = new_base; - spin_lock(&base->lock); - timer_set_base(timer, base); - } - } - - timer->expires = expires; - internal_add_timer(base, timer); - spin_unlock_irqrestore(&base->lock, flags); - - return ret; -} - -EXPORT_SYMBOL(__mod_timer); - -/** - * add_timer_on - start a timer on a particular CPU - * @timer: the timer to be added - * @cpu: the CPU to start it on - * - * This is not very scalable on SMP. Double adds are not possible. - */ -void add_timer_on(struct timer_list *timer, int cpu) -{ - struct tvec_base *base = per_cpu(tvec_bases, cpu); - unsigned long flags; - - timer_stats_timer_set_start_info(timer); - BUG_ON(timer_pending(timer) || !timer->function); - spin_lock_irqsave(&base->lock, flags); - timer_set_base(timer, base); - debug_timer_activate(timer); - internal_add_timer(base, timer); - /* - * Check whether the other CPU is idle and needs to be - * triggered to reevaluate the timer wheel when nohz is - * active. We are protected against the other CPU fiddling - * with the timer by holding the timer base lock. This also - * makes sure that a CPU on the way to idle can not evaluate - * the timer wheel. - */ - wake_up_idle_cpu(cpu); - spin_unlock_irqrestore(&base->lock, flags); -} - -/** - * mod_timer - modify a timer's timeout - * @timer: the timer to be modified - * @expires: new timeout in jiffies - * - * mod_timer() is a more efficient way to update the expire field of an - * active timer (if the timer is inactive it will be activated) - * - * mod_timer(timer, expires) is equivalent to: - * - * del_timer(timer); timer->expires = expires; add_timer(timer); - * - * Note that if there are multiple unserialized concurrent users of the - * same timer, then mod_timer() is the only safe way to modify the timeout, - * since add_timer() cannot modify an already running timer. - * - * The function returns whether it has modified a pending timer or not. - * (ie. mod_timer() of an inactive timer returns 0, mod_timer() of an - * active timer returns 1.) - */ -int mod_timer(struct timer_list *timer, unsigned long expires) -{ - BUG_ON(!timer->function); - - timer_stats_timer_set_start_info(timer); - /* - * This is a common optimization triggered by the - * networking code - if the timer is re-modified - * to be the same thing then just return: - */ - if (timer->expires == expires && timer_pending(timer)) - return 1; - - return __mod_timer(timer, expires); -} - -EXPORT_SYMBOL(mod_timer); - -/** - * del_timer - deactive a timer. - * @timer: the timer to be deactivated - * - * del_timer() deactivates a timer - this works on both active and inactive - * timers. - * - * The function returns whether it has deactivated a pending timer or not. - * (ie. del_timer() of an inactive timer returns 0, del_timer() of an - * active timer returns 1.) - */ -int del_timer(struct timer_list *timer) -{ - struct tvec_base *base; - unsigned long flags; - int ret = 0; - - timer_stats_timer_clear_start_info(timer); - if (timer_pending(timer)) { - base = lock_timer_base(timer, &flags); - if (timer_pending(timer)) { - detach_timer(timer, 1); - ret = 1; - } - spin_unlock_irqrestore(&base->lock, flags); - } - - return ret; -} - -EXPORT_SYMBOL(del_timer); - -#ifdef CONFIG_SMP -/** - * try_to_del_timer_sync - Try to deactivate a timer - * @timer: timer do del - * - * This function tries to deactivate a timer. Upon successful (ret >= 0) - * exit the timer is not queued and the handler is not running on any CPU. - * - * It must not be called from interrupt contexts. - */ -int try_to_del_timer_sync(struct timer_list *timer) -{ - struct tvec_base *base; - unsigned long flags; - int ret = -1; - - base = lock_timer_base(timer, &flags); - - if (base->running_timer == timer) - goto out; - - ret = 0; - if (timer_pending(timer)) { - detach_timer(timer, 1); - ret = 1; - } -out: - spin_unlock_irqrestore(&base->lock, flags); - - return ret; -} - -EXPORT_SYMBOL(try_to_del_timer_sync); - -/** - * del_timer_sync - deactivate a timer and wait for the handler to finish. - * @timer: the timer to be deactivated - * - * This function only differs from del_timer() on SMP: besides deactivating - * the timer it also makes sure the handler has finished executing on other - * CPUs. - * - * Synchronization rules: Callers must prevent restarting of the timer, - * otherwise this function is meaningless. It must not be called from - * interrupt contexts. The caller must not hold locks which would prevent - * completion of the timer's handler. The timer's handler must not call - * add_timer_on(). Upon exit the timer is not queued and the handler is - * not running on any CPU. - * - * The function returns whether it has deactivated a pending timer or not. - */ -int del_timer_sync(struct timer_list *timer) -{ - for (;;) { - int ret = try_to_del_timer_sync(timer); - if (ret >= 0) - return ret; - cpu_relax(); - } -} - -EXPORT_SYMBOL(del_timer_sync); -#endif - -static int cascade(struct tvec_base *base, struct tvec *tv, int index) -{ - /* cascade all the timers from tv up one level */ - struct timer_list *timer, *tmp; - struct list_head tv_list; - - list_replace_init(tv->vec + index, &tv_list); - - /* - * We are removing _all_ timers from the list, so we - * don't have to detach them individually. - */ - list_for_each_entry_safe(timer, tmp, &tv_list, entry) { - BUG_ON(tbase_get_base(timer->base) != base); - internal_add_timer(base, timer); - } - - return index; -} - -#define INDEX(N) ((base->timer_jiffies >> (TVR_BITS + (N) * TVN_BITS)) & TVN_MASK) - -/** - * __run_timers - run all expired timers (if any) on this CPU. - * @base: the timer vector to be processed. - * - * This function cascades all vectors and executes all expired timer - * vectors. - */ -static inline void __run_timers(struct tvec_base *base) -{ - struct timer_list *timer; - - spin_lock_irq(&base->lock); - while (time_after_eq(jiffies, base->timer_jiffies)) { - struct list_head work_list; - struct list_head *head = &work_list; - int index = base->timer_jiffies & TVR_MASK; - - /* - * Cascade timers: - */ - if (!index && - (!cascade(base, &base->tv2, INDEX(0))) && - (!cascade(base, &base->tv3, INDEX(1))) && - !cascade(base, &base->tv4, INDEX(2))) - cascade(base, &base->tv5, INDEX(3)); - ++base->timer_jiffies; - list_replace_init(base->tv1.vec + index, &work_list); - while (!list_empty(head)) { - void (*fn)(unsigned long); - unsigned long data; - - timer = list_first_entry(head, struct timer_list,entry); - fn = timer->function; - data = timer->data; - - timer_stats_account_timer(timer); - - set_running_timer(base, timer); - detach_timer(timer, 1); - spin_unlock_irq(&base->lock); - { - int preempt_count = preempt_count(); - fn(data); - if (preempt_count != preempt_count()) { - printk(KERN_ERR "huh, entered %p " - "with preempt_count %08x, exited" - " with %08x?\n", - fn, preempt_count, - preempt_count()); - BUG(); - } - } - spin_lock_irq(&base->lock); - } - } - set_running_timer(base, NULL); - spin_unlock_irq(&base->lock); -} - -#ifdef CONFIG_NO_HZ -/* - * Find out when the next timer event is due to happen. This - * is used on S/390 to stop all activity when a cpus is idle. - * This functions needs to be called disabled. - */ -static unsigned long __next_timer_interrupt(struct tvec_base *base) -{ - unsigned long timer_jiffies = base->timer_jiffies; - unsigned long expires = timer_jiffies + NEXT_TIMER_MAX_DELTA; - int index, slot, array, found = 0; - struct timer_list *nte; - struct tvec *varray[4]; - - /* Look for timer events in tv1. */ - index = slot = timer_jiffies & TVR_MASK; - do { - list_for_each_entry(nte, base->tv1.vec + slot, entry) { - if (tbase_get_deferrable(nte->base)) - continue; - - found = 1; - expires = nte->expires; - /* Look at the cascade bucket(s)? */ - if (!index || slot < index) - goto cascade; - return expires; - } - slot = (slot + 1) & TVR_MASK; - } while (slot != index); - -cascade: - /* Calculate the next cascade event */ - if (index) - timer_jiffies += TVR_SIZE - index; - timer_jiffies >>= TVR_BITS; - - /* Check tv2-tv5. */ - varray[0] = &base->tv2; - varray[1] = &base->tv3; - varray[2] = &base->tv4; - varray[3] = &base->tv5; - - for (array = 0; array < 4; array++) { - struct tvec *varp = varray[array]; - - index = slot = timer_jiffies & TVN_MASK; - do { - list_for_each_entry(nte, varp->vec + slot, entry) { - found = 1; - if (time_before(nte->expires, expires)) - expires = nte->expires; - } - /* - * Do we still search for the first timer or are - * we looking up the cascade buckets ? - */ - if (found) { - /* Look at the cascade bucket(s)? */ - if (!index || slot < index) - break; - return expires; - } - slot = (slot + 1) & TVN_MASK; - } while (slot != index); - - if (index) - timer_jiffies += TVN_SIZE - index; - timer_jiffies >>= TVN_BITS; - } - return expires; -} - -/* - * Check, if the next hrtimer event is before the next timer wheel - * event: - */ -static unsigned long cmp_next_hrtimer_event(unsigned long now, - unsigned long expires) -{ - ktime_t hr_delta = hrtimer_get_next_event(); - struct timespec tsdelta; - unsigned long delta; - - if (hr_delta.tv64 == KTIME_MAX) - return expires; - - /* - * Expired timer available, let it expire in the next tick - */ - if (hr_delta.tv64 <= 0) - return now + 1; - - tsdelta = ktime_to_timespec(hr_delta); - delta = timespec_to_jiffies(&tsdelta); - - /* - * Limit the delta to the max value, which is checked in - * tick_nohz_stop_sched_tick(): - */ - if (delta > NEXT_TIMER_MAX_DELTA) - delta = NEXT_TIMER_MAX_DELTA; - - /* - * Take rounding errors in to account and make sure, that it - * expires in the next tick. Otherwise we go into an endless - * ping pong due to tick_nohz_stop_sched_tick() retriggering - * the timer softirq - */ - if (delta < 1) - delta = 1; - now += delta; - if (time_before(now, expires)) - return now; - return expires; -} - -/** - * get_next_timer_interrupt - return the jiffy of the next pending timer - * @now: current time (in jiffies) - */ -unsigned long get_next_timer_interrupt(unsigned long now) -{ - struct tvec_base *base = __get_cpu_var(tvec_bases); - unsigned long expires; - - spin_lock(&base->lock); - expires = __next_timer_interrupt(base); - spin_unlock(&base->lock); - - if (time_before_eq(expires, now)) - return now; - - return cmp_next_hrtimer_event(now, expires); -} -#endif - -/* - * Called from the timer interrupt handler to charge one tick to the current - * process. user_tick is 1 if the tick is user time, 0 for system. - */ -void update_process_times(int user_tick) -{ - struct task_struct *p = current; - int cpu = smp_processor_id(); - - /* Note: this timer irq context must be accounted for as well. */ - account_process_tick(p, user_tick); - run_local_timers(); - if (rcu_pending(cpu)) - rcu_check_callbacks(cpu, user_tick); - printk_tick(); - scheduler_tick(); - run_posix_cpu_timers(p); -} - -/* - * Nr of active tasks - counted in fixed-point numbers - */ -static unsigned long count_active_tasks(void) -{ - return nr_active() * FIXED_1; -} - -/* - * Hmm.. Changed this, as the GNU make sources (load.c) seems to - * imply that avenrun[] is the standard name for this kind of thing. - * Nothing else seems to be standardized: the fractional size etc - * all seem to differ on different machines. - * - * Requires xtime_lock to access. - */ -unsigned long avenrun[3]; - -EXPORT_SYMBOL(avenrun); - -/* - * calc_load - given tick count, update the avenrun load estimates. - * This is called while holding a write_lock on xtime_lock. - */ -static inline void calc_load(unsigned long ticks) -{ - unsigned long active_tasks; /* fixed-point */ - static int count = LOAD_FREQ; - - count -= ticks; - if (unlikely(count < 0)) { - active_tasks = count_active_tasks(); - do { - CALC_LOAD(avenrun[0], EXP_1, active_tasks); - CALC_LOAD(avenrun[1], EXP_5, active_tasks); - CALC_LOAD(avenrun[2], EXP_15, active_tasks); - count += LOAD_FREQ; - } while (count < 0); - } -} - -/* - * This function runs timers and the timer-tq in bottom half context. - */ -static void run_timer_softirq(struct softirq_action *h) -{ - struct tvec_base *base = __get_cpu_var(tvec_bases); - - hrtimer_run_pending(); - - if (time_after_eq(jiffies, base->timer_jiffies)) - __run_timers(base); -} - -/* - * Called by the local, per-CPU timer interrupt on SMP. - */ -void run_local_timers(void) -{ - hrtimer_run_queues(); - raise_softirq(TIMER_SOFTIRQ); - softlockup_tick(); -} - -/* - * Called by the timer interrupt. xtime_lock must already be taken - * by the timer IRQ! - */ -static inline void update_times(unsigned long ticks) -{ - update_wall_time(); - calc_load(ticks); -} - -/* - * The 64-bit jiffies value is not atomic - you MUST NOT read it - * without sampling the sequence number in xtime_lock. - * jiffies is defined in the linker script... - */ - -void do_timer(unsigned long ticks) -{ - jiffies_64 += ticks; - update_times(ticks); -} - -#ifdef __ARCH_WANT_SYS_ALARM - -/* - * For backwards compatibility? This can be done in libc so Alpha - * and all newer ports shouldn't need it. - */ -SYSCALL_DEFINE1(alarm, unsigned int, seconds) -{ - return alarm_setitimer(seconds); -} - -#endif - -#ifndef __alpha__ - -/* - * The Alpha uses getxpid, getxuid, and getxgid instead. Maybe this - * should be moved into arch/i386 instead? - */ - -/** - * sys_getpid - return the thread group id of the current process - * - * Note, despite the name, this returns the tgid not the pid. The tgid and - * the pid are identical unless CLONE_THREAD was specified on clone() in - * which case the tgid is the same in all threads of the same group. - * - * This is SMP safe as current->tgid does not change. - */ -SYSCALL_DEFINE0(getpid) -{ - return task_tgid_vnr(current); -} - -/* - * Accessing ->real_parent is not SMP-safe, it could - * change from under us. However, we can use a stale - * value of ->real_parent under rcu_read_lock(), see - * release_task()->call_rcu(delayed_put_task_struct). - */ -SYSCALL_DEFINE0(getppid) -{ - int pid; - - rcu_read_lock(); - pid = task_tgid_vnr(current->real_parent); - rcu_read_unlock(); - - return pid; -} - -SYSCALL_DEFINE0(getuid) -{ - /* Only we change this so SMP safe */ - return current_uid(); -} - -SYSCALL_DEFINE0(geteuid) -{ - /* Only we change this so SMP safe */ - return current_euid(); -} - -SYSCALL_DEFINE0(getgid) -{ - /* Only we change this so SMP safe */ - return current_gid(); -} - -SYSCALL_DEFINE0(getegid) -{ - /* Only we change this so SMP safe */ - return current_egid(); -} - -#endif - -static void process_timeout(unsigned long __data) -{ - wake_up_process((struct task_struct *)__data); -} - -/** - * schedule_timeout - sleep until timeout - * @timeout: timeout value in jiffies - * - * Make the current task sleep until @timeout jiffies have - * 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 jiffies are guaranteed to - * pass before the routine returns. The routine will return 0 - * - * %TASK_INTERRUPTIBLE - the routine may return early if a signal is - * delivered to the current task. In this case the remaining time - * in jiffies will be returned, or 0 if the timer expired in time - * - * The current task state is guaranteed to be TASK_RUNNING when this - * routine returns. - * - * Specifying a @timeout value of %MAX_SCHEDULE_TIMEOUT will schedule - * the CPU away without a bound on the timeout. In this case the return - * value will be %MAX_SCHEDULE_TIMEOUT. - * - * In all cases the return value is guaranteed to be non-negative. - */ -signed long __sched schedule_timeout(signed long timeout) -{ - struct timer_list timer; - unsigned long expire; - - switch (timeout) - { - case MAX_SCHEDULE_TIMEOUT: - /* - * These two special cases are useful to be comfortable - * in the caller. Nothing more. We could take - * MAX_SCHEDULE_TIMEOUT from one of the negative value - * but I' d like to return a valid offset (>=0) to allow - * the caller to do everything it want with the retval. - */ - schedule(); - goto out; - default: - /* - * Another bit of PARANOID. Note that the retval will be - * 0 since no piece of kernel is supposed to do a check - * for a negative retval of schedule_timeout() (since it - * should never happens anyway). You just have the printk() - * that will tell you if something is gone wrong and where. - */ - if (timeout < 0) { - printk(KERN_ERR "schedule_timeout: wrong timeout " - "value %lx\n", timeout); - dump_stack(); - current->state = TASK_RUNNING; - goto out; - } - } - - expire = timeout + jiffies; - - setup_timer_on_stack(&timer, process_timeout, (unsigned long)current); - __mod_timer(&timer, expire); - schedule(); - del_singleshot_timer_sync(&timer); - - /* Remove the timer from the object tracker */ - destroy_timer_on_stack(&timer); - - timeout = expire - jiffies; - - out: - return timeout < 0 ? 0 : timeout; -} -EXPORT_SYMBOL(schedule_timeout); - -/* - * We can use __set_current_state() here because schedule_timeout() calls - * schedule() unconditionally. - */ -signed long __sched schedule_timeout_interruptible(signed long timeout) -{ - __set_current_state(TASK_INTERRUPTIBLE); - return schedule_timeout(timeout); -} -EXPORT_SYMBOL(schedule_timeout_interruptible); - -signed long __sched schedule_timeout_killable(signed long timeout) -{ - __set_current_state(TASK_KILLABLE); - return schedule_timeout(timeout); -} -EXPORT_SYMBOL(schedule_timeout_killable); - -signed long __sched schedule_timeout_uninterruptible(signed long timeout) -{ - __set_current_state(TASK_UNINTERRUPTIBLE); - return schedule_timeout(timeout); -} -EXPORT_SYMBOL(schedule_timeout_uninterruptible); - -/* Thread ID - the internal kernel "pid" */ -SYSCALL_DEFINE0(gettid) -{ - return task_pid_vnr(current); -} - -/** - * do_sysinfo - fill in sysinfo struct - * @info: pointer to buffer to fill - */ -int do_sysinfo(struct sysinfo *info) -{ - unsigned long mem_total, sav_total; - unsigned int mem_unit, bitcount; - unsigned long seq; - - memset(info, 0, sizeof(struct sysinfo)); - - do { - struct timespec tp; - seq = read_seqbegin(&xtime_lock); - - /* - * This is annoying. The below is the same thing - * posix_get_clock_monotonic() does, but it wants to - * take the lock which we want to cover the loads stuff - * too. - */ - - getnstimeofday(&tp); - tp.tv_sec += wall_to_monotonic.tv_sec; - tp.tv_nsec += wall_to_monotonic.tv_nsec; - monotonic_to_bootbased(&tp); - if (tp.tv_nsec - NSEC_PER_SEC >= 0) { - tp.tv_nsec = tp.tv_nsec - NSEC_PER_SEC; - tp.tv_sec++; - } - info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0); - - info->loads[0] = avenrun[0] << (SI_LOAD_SHIFT - FSHIFT); - info->loads[1] = avenrun[1] << (SI_LOAD_SHIFT - FSHIFT); - info->loads[2] = avenrun[2] << (SI_LOAD_SHIFT - FSHIFT); - - info->procs = nr_threads; - } while (read_seqretry(&xtime_lock, seq)); - - si_meminfo(info); - si_swapinfo(info); - - /* - * If the sum of all the available memory (i.e. ram + swap) - * is less than can be stored in a 32 bit unsigned long then - * we can be binary compatible with 2.2.x kernels. If not, - * well, in that case 2.2.x was broken anyways... - * - * -Erik Andersen <andersee@debian.org> - */ - - mem_total = info->totalram + info->totalswap; - if (mem_total < info->totalram || mem_total < info->totalswap) - goto out; - bitcount = 0; - mem_unit = info->mem_unit; - while (mem_unit > 1) { - bitcount++; - mem_unit >>= 1; - sav_total = mem_total; - mem_total <<= 1; - if (mem_total < sav_total) - goto out; - } - - /* - * If mem_total did not overflow, multiply all memory values by - * info->mem_unit and set it to 1. This leaves things compatible - * with 2.2.x, and also retains compatibility with earlier 2.4.x - * kernels... - */ - - info->mem_unit = 1; - info->totalram <<= bitcount; - info->freeram <<= bitcount; - info->sharedram <<= bitcount; - info->bufferram <<= bitcount; - info->totalswap <<= bitcount; - info->freeswap <<= bitcount; - info->totalhigh <<= bitcount; - info->freehigh <<= bitcount; - -out: - return 0; -} - -SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info) -{ - struct sysinfo val; - - do_sysinfo(&val); - - if (copy_to_user(info, &val, sizeof(struct sysinfo))) - return -EFAULT; - - return 0; -} - -static int __cpuinit init_timers_cpu(int cpu) -{ - int j; - struct tvec_base *base; - static char __cpuinitdata tvec_base_done[NR_CPUS]; - - if (!tvec_base_done[cpu]) { - static char boot_done; - - if (boot_done) { - /* - * The APs use this path later in boot - */ - base = kmalloc_node(sizeof(*base), - GFP_KERNEL | __GFP_ZERO, - cpu_to_node(cpu)); - if (!base) - return -ENOMEM; - - /* Make sure that tvec_base is 2 byte aligned */ - if (tbase_get_deferrable(base)) { - WARN_ON(1); - kfree(base); - return -ENOMEM; - } - per_cpu(tvec_bases, cpu) = base; - } else { - /* - * This is for the boot CPU - we use compile-time - * static initialisation because per-cpu memory isn't - * ready yet and because the memory allocators are not - * initialised either. - */ - boot_done = 1; - base = &boot_tvec_bases; - } - tvec_base_done[cpu] = 1; - } else { - base = per_cpu(tvec_bases, cpu); - } - - spin_lock_init(&base->lock); - - for (j = 0; j < TVN_SIZE; j++) { - INIT_LIST_HEAD(base->tv5.vec + j); - INIT_LIST_HEAD(base->tv4.vec + j); - INIT_LIST_HEAD(base->tv3.vec + j); - INIT_LIST_HEAD(base->tv2.vec + j); - } - for (j = 0; j < TVR_SIZE; j++) - INIT_LIST_HEAD(base->tv1.vec + j); - - base->timer_jiffies = jiffies; - return 0; -} - -#ifdef CONFIG_HOTPLUG_CPU -static void migrate_timer_list(struct tvec_base *new_base, struct list_head *head) -{ - struct timer_list *timer; - - while (!list_empty(head)) { - timer = list_first_entry(head, struct timer_list, entry); - detach_timer(timer, 0); - timer_set_base(timer, new_base); - internal_add_timer(new_base, timer); - } -} - -static void __cpuinit migrate_timers(int cpu) -{ - struct tvec_base *old_base; - struct tvec_base *new_base; - int i; - - BUG_ON(cpu_online(cpu)); - old_base = per_cpu(tvec_bases, cpu); - new_base = get_cpu_var(tvec_bases); - /* - * The caller is globally serialized and nobody else - * takes two locks at once, deadlock is not possible. - */ - spin_lock_irq(&new_base->lock); - spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING); - - BUG_ON(old_base->running_timer); - - for (i = 0; i < TVR_SIZE; i++) - migrate_timer_list(new_base, old_base->tv1.vec + i); - for (i = 0; i < TVN_SIZE; i++) { - migrate_timer_list(new_base, old_base->tv2.vec + i); - migrate_timer_list(new_base, old_base->tv3.vec + i); - migrate_timer_list(new_base, old_base->tv4.vec + i); - migrate_timer_list(new_base, old_base->tv5.vec + i); - } - - spin_unlock(&old_base->lock); - spin_unlock_irq(&new_base->lock); - put_cpu_var(tvec_bases); -} -#endif /* CONFIG_HOTPLUG_CPU */ - -static int __cpuinit timer_cpu_notify(struct notifier_block *self, - unsigned long action, void *hcpu) -{ - long cpu = (long)hcpu; - switch(action) { - case CPU_UP_PREPARE: - case CPU_UP_PREPARE_FROZEN: - if (init_timers_cpu(cpu) < 0) - return NOTIFY_BAD; - break; -#ifdef CONFIG_HOTPLUG_CPU - case CPU_DEAD: - case CPU_DEAD_FROZEN: - migrate_timers(cpu); - break; -#endif - default: - break; - } - return NOTIFY_OK; -} - -static struct notifier_block __cpuinitdata timers_nb = { - .notifier_call = timer_cpu_notify, -}; - - -void __init init_timers(void) -{ - int err = timer_cpu_notify(&timers_nb, (unsigned long)CPU_UP_PREPARE, - (void *)(long)smp_processor_id()); - - init_timer_stats(); - - BUG_ON(err == NOTIFY_BAD); - register_cpu_notifier(&timers_nb); - open_softirq(TIMER_SOFTIRQ, run_timer_softirq); -} - -/** - * msleep - sleep safely even with waitqueue interruptions - * @msecs: Time in milliseconds to sleep for - */ -void msleep(unsigned int msecs) -{ - unsigned long timeout = msecs_to_jiffies(msecs) + 1; - - while (timeout) - timeout = schedule_timeout_uninterruptible(timeout); -} - -EXPORT_SYMBOL(msleep); -#endif /* DDE */ - -/** - * msleep_interruptible - sleep waiting for signals - * @msecs: Time in milliseconds to sleep for - */ -unsigned long msleep_interruptible(unsigned int msecs) -{ - unsigned long timeout = msecs_to_jiffies(msecs) + 1; - - while (timeout && !signal_pending(current)) - timeout = schedule_timeout_interruptible(timeout); - return jiffies_to_msecs(timeout); -} - -EXPORT_SYMBOL(msleep_interruptible); |