| /* |
| * This file is part of the coreboot project. |
| * |
| * Copyright (C) 2013 Google, Inc. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; version 2 of the License. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc. |
| */ |
| #ifndef TIMER_H |
| #define TIMER_H |
| |
| #define USECS_PER_SEC 1000000 |
| #define MSECS_PER_SEC 1000 |
| #define USECS_PER_MSEC (USECS_PER_SEC / MSECS_PER_SEC) |
| |
| /* The time structures are defined to be a representation of the time since |
| * coreboot started executing one of its stages. The reason for using structures |
| * is to allow for changes in the future. The structures' details are exposed |
| * so that the compiler can allocate space on the stack and use in other |
| * structures. In other words, accessing any field within this structure |
| * outside of the core timer code is not supported. */ |
| |
| struct mono_time { |
| long microseconds; |
| }; |
| |
| /* A timeout_callback structure is used for the book keeping for scheduling |
| * work in the future. When a callback is called the structure can be |
| * re-used for scheduling as it is not being tracked by the core timer |
| * library any more. */ |
| struct timeout_callback { |
| void *priv; |
| void (*callback)(struct timeout_callback *tocb); |
| /* Not for public use. The timer library uses the fields below. */ |
| struct mono_time expiration; |
| }; |
| |
| /* Obtain the current monotonic time. The assumption is that the time counts |
| * up from the value 0 with value 0 being the point when the timer was |
| * initialized. Additionally, the timer is assumed to only be valid for the |
| * duration of the boot. |
| * |
| * Note that any implementations of timer_monotonic_get() |
| * need to ensure its timesource does not roll over within 10 secs. The reason |
| * is that the time between calls to timer_monotonic_get() may be on order |
| * of 10 seconds. */ |
| void timer_monotonic_get(struct mono_time *mt); |
| |
| /* Returns 1 if callbacks still present in the queue. 0 if no timers left. */ |
| int timers_run(void); |
| |
| /* Schedule a callback to be ran microseconds from time of invocation. |
| * 0 returned on success, < 0 on error. */ |
| int timer_sched_callback(struct timeout_callback *tocb, unsigned long us); |
| |
| /* Set an absolute time to a number of microseconds. */ |
| static inline void mono_time_set_usecs(struct mono_time *mt, long us) |
| { |
| mt->microseconds = us; |
| } |
| |
| /* Set an absolute time to a number of milliseconds. */ |
| static inline void mono_time_set_msecs(struct mono_time *mt, long ms) |
| { |
| mt->microseconds = ms * USECS_PER_MSEC; |
| } |
| |
| /* Add microseconds to an absolute time. */ |
| static inline void mono_time_add_usecs(struct mono_time *mt, long us) |
| { |
| mt->microseconds += us; |
| } |
| |
| /* Add milliseconds to an absolute time. */ |
| static inline void mono_time_add_msecs(struct mono_time *mt, long ms) |
| { |
| mono_time_add_usecs(mt, ms * USECS_PER_MSEC); |
| } |
| |
| /* Compare two absolute times: Return -1, 0, or 1 if t1 is <, =, or > t2, |
| * respectively. */ |
| static inline int mono_time_cmp(const struct mono_time *t1, |
| const struct mono_time *t2) |
| { |
| if (t1->microseconds == t2->microseconds) |
| return 0; |
| |
| if (t1->microseconds < t2->microseconds) |
| return -1; |
| |
| return 1; |
| } |
| |
| /* Return true if t1 after t2 */ |
| static inline int mono_time_after(const struct mono_time *t1, |
| const struct mono_time *t2) |
| { |
| return mono_time_cmp(t1, t2) > 0; |
| } |
| |
| /* Return true if t1 before t2. */ |
| static inline int mono_time_before(const struct mono_time *t1, |
| const struct mono_time *t2) |
| { |
| return mono_time_cmp(t1, t2) < 0; |
| } |
| |
| /* Return time difference between t1 and t2. i.e. t2 - t1. */ |
| static inline long mono_time_diff_microseconds(const struct mono_time *t1, |
| const struct mono_time *t2) |
| { |
| return t2->microseconds - t1->microseconds; |
| } |
| |
| struct stopwatch { |
| struct mono_time start; |
| struct mono_time current; |
| struct mono_time expires; |
| }; |
| |
| static inline void stopwatch_init(struct stopwatch *sw) |
| { |
| if (IS_ENABLED(CONFIG_HAVE_MONOTONIC_TIMER)) |
| timer_monotonic_get(&sw->start); |
| else |
| sw->start.microseconds = 0; |
| |
| sw->current = sw->expires = sw->start; |
| } |
| |
| static inline void stopwatch_init_usecs_expire(struct stopwatch *sw, long us) |
| { |
| stopwatch_init(sw); |
| mono_time_add_usecs(&sw->expires, us); |
| } |
| |
| static inline void stopwatch_init_msecs_expire(struct stopwatch *sw, long ms) |
| { |
| stopwatch_init_usecs_expire(sw, USECS_PER_MSEC * ms); |
| } |
| |
| /* |
| * Tick the stopwatch to collect the current time. |
| */ |
| static inline void stopwatch_tick(struct stopwatch *sw) |
| { |
| if (IS_ENABLED(CONFIG_HAVE_MONOTONIC_TIMER)) |
| timer_monotonic_get(&sw->current); |
| else |
| sw->current.microseconds = 0; |
| } |
| |
| /* |
| * Tick and check the stopwatch for expiration. Returns non-zero on exipration. |
| */ |
| static inline int stopwatch_expired(struct stopwatch *sw) |
| { |
| stopwatch_tick(sw); |
| return !mono_time_before(&sw->current, &sw->expires); |
| } |
| |
| /* |
| * Return number of microseconds since starting the stopwatch. |
| */ |
| static inline long stopwatch_duration_usecs(struct stopwatch *sw) |
| { |
| /* |
| * If the stopwatch hasn't been ticked (current == start) tick |
| * the stopwatch to gather the accumulated time. |
| */ |
| if (!mono_time_cmp(&sw->start, &sw->current)) |
| stopwatch_tick(sw); |
| |
| return mono_time_diff_microseconds(&sw->start, &sw->current); |
| } |
| |
| static inline long stopwatch_duration_msecs(struct stopwatch *sw) |
| { |
| return stopwatch_duration_usecs(sw) / USECS_PER_MSEC; |
| } |
| |
| #endif /* TIMER_H */ |