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 static inline void 44 reinit_completion(struct completion *c) 45 { 46 c->done = 0; 47 } 48 49 #define INIT_COMPLETION(c) (c.done = 0) 50 51 /* 52 * Completion interlock and wakeup. Be careful not to execute the wakeup 53 * from inside the spinlock as this can deadlock if the IPIQ fifo is full. 54 * (also note that wakeup() is asynchronous anyway, so no point doing that). 55 */ 56 static inline void 57 complete(struct completion *c) 58 { 59 lockmgr(&c->wait.lock, LK_EXCLUSIVE); 60 c->done++; 61 lockmgr(&c->wait.lock, LK_RELEASE); 62 wakeup_one(&c->wait); 63 } 64 65 static inline void 66 complete_all(struct completion *c) 67 { 68 lockmgr(&c->wait.lock, LK_EXCLUSIVE); 69 c->done++; 70 lockmgr(&c->wait.lock, LK_RELEASE); 71 wakeup(&c->wait); 72 } 73 74 static inline long 75 wait_for_completion_interruptible_timeout(struct completion *c, 76 unsigned long timeout) 77 { 78 int start_jiffies, elapsed_jiffies, remaining_jiffies; 79 bool timeout_expired = false, awakened = false; 80 long ret = 1; 81 82 start_jiffies = ticks; 83 84 lockmgr(&c->wait.lock, LK_EXCLUSIVE); 85 while (c->done == 0 && !timeout_expired) { 86 ret = lksleep(&c->wait, &c->wait.lock, PCATCH, "wfcit", timeout); 87 switch(ret) { 88 case EWOULDBLOCK: 89 timeout_expired = true; 90 ret = 0; 91 break; 92 case ERESTART: 93 ret = -ERESTARTSYS; 94 break; 95 case 0: 96 awakened = true; 97 break; 98 } 99 } 100 lockmgr(&c->wait.lock, LK_RELEASE); 101 102 if (awakened) { 103 elapsed_jiffies = ticks - start_jiffies; 104 remaining_jiffies = timeout - elapsed_jiffies; 105 if (remaining_jiffies > 0) 106 ret = remaining_jiffies; 107 } 108 109 return ret; 110 } 111 112 #endif /* _LINUX_COMPLETION_H_ */ 113