1 /* 2 * Copyright (c) 2014 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 #ifndef _LINUX_COMPLETION_H_ 27 #define _LINUX_COMPLETION_H_ 28 29 #include <linux/wait.h> 30 31 struct completion { 32 unsigned int done; 33 wait_queue_head_t wait; 34 }; 35 36 static inline void 37 init_completion(struct completion *c) 38 { 39 c->done = 0; 40 init_waitqueue_head(&c->wait); 41 } 42 43 #define INIT_COMPLETION(c) (c.done = 0) 44 45 static inline void 46 complete(struct completion *c) 47 { 48 spin_lock(&c->wait.lock); 49 c->done++; 50 wakeup_one(&c->wait); 51 spin_unlock(&c->wait.lock); 52 } 53 54 static inline void 55 complete_all(struct completion *c) 56 { 57 spin_lock(&c->wait.lock); 58 c->done++; 59 wakeup(&c->wait); 60 spin_unlock(&c->wait.lock); 61 } 62 63 static inline long 64 wait_for_completion_interruptible_timeout(struct completion *x, 65 unsigned long timeout) 66 { 67 int start_jiffies, elapsed_jiffies, remaining_jiffies; 68 bool timeout_expired = false, awakened = false; 69 long ret = 1; 70 71 start_jiffies = ticks; 72 73 spin_lock(&x->wait.lock); 74 while (x->done == 0 && !timeout_expired) { 75 ret = ssleep(&x->wait, &x->wait.lock, PCATCH, "wfcit", timeout); 76 switch(ret) { 77 case EWOULDBLOCK: 78 timeout_expired = true; 79 ret = 0; 80 break; 81 case ERESTART: 82 ret = -ERESTART; /* -ERESTARTSYS on Linux */ 83 break; 84 case 0: 85 awakened = true; 86 break; 87 } 88 } 89 spin_unlock(&x->wait.lock); 90 91 if (awakened) { 92 elapsed_jiffies = ticks - start_jiffies; 93 remaining_jiffies = timeout - elapsed_jiffies; 94 if (remaining_jiffies > 0) 95 ret = remaining_jiffies; 96 } 97 98 return ret; 99 } 100 101 #endif /* _LINUX_COMPLETION_H_ */ 102