1 /* 2 * Copyright (c) 2017 François Tigeot 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice unmodified, this list of conditions, and the following 10 * disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include <linux/hrtimer.h> 28 #include <linux/bug.h> 29 30 static inline void 31 __hrtimer_function(void *arg) 32 { 33 struct hrtimer *timer = arg; 34 enum hrtimer_restart restart = HRTIMER_RESTART; 35 36 if (timer->function) { 37 restart = timer->function(timer); 38 } 39 40 if (restart == HRTIMER_RESTART) { 41 /* 42 * XXX Not implemented yet, we would need to store the 43 * expiration period, to do the callout_reset here. 44 */ 45 } else { 46 timer->active = false; 47 } 48 } 49 50 void hrtimer_init(struct hrtimer *timer, clockid_t clock_id, 51 enum hrtimer_mode mode) 52 { 53 BUG_ON(clock_id != CLOCK_MONOTONIC); 54 55 memset(timer, 0, sizeof(struct hrtimer)); 56 timer->clock_id = clock_id; 57 timer->ht_mode = mode; 58 59 lwkt_token_init(&timer->timer_token, "timer token"); 60 callout_init_mp(&(timer)->timer_callout); 61 } 62 63 void 64 hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, 65 u64 range_ns, const enum hrtimer_mode mode) 66 { 67 int expire_ticks = tim.tv64 / (NSEC_PER_SEC / hz); 68 69 if (mode == HRTIMER_MODE_ABS) 70 expire_ticks -= ticks; 71 72 if (expire_ticks <= 0) 73 expire_ticks = 1; 74 75 lwkt_gettoken(&timer->timer_token); 76 77 timer->active = true; 78 callout_reset(&timer->timer_callout, 79 expire_ticks, __hrtimer_function, timer); 80 81 lwkt_reltoken(&timer->timer_token); 82 } 83 84 int 85 hrtimer_cancel(struct hrtimer *timer) 86 { 87 return callout_drain(&timer->timer_callout) == 0; 88 } 89 90 /* Returns non-zero if the timer is already on the queue */ 91 bool 92 hrtimer_active(const struct hrtimer *timer) 93 { 94 return callout_pending(&timer->timer_callout); 95 } 96