1 /* $NetBSD: sleeptab.h,v 1.3 2023/10/15 10:27:11 riastradh Exp $ */ 2 3 /*- 4 * Copyright (c) 2002, 2006, 2007, 2008, 2009, 2019, 2020 5 * The NetBSD Foundation, Inc. 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to The NetBSD Foundation 9 * by Jason R. Thorpe and Andrew Doran. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #ifndef _SYS_SLEEPTAB_H_ 34 #define _SYS_SLEEPTAB_H_ 35 36 #include <sys/wchan.h> 37 38 struct syncobj; 39 40 #define SLEEPTAB_HASH_SHIFT 7 41 #define SLEEPTAB_HASH_SIZE (1 << SLEEPTAB_HASH_SHIFT) 42 #define SLEEPTAB_HASH_MASK (SLEEPTAB_HASH_SIZE - 1) 43 #define SLEEPTAB_HASH(wchan) (((uintptr_t)(wchan) >> 8) & SLEEPTAB_HASH_MASK) 44 45 LIST_HEAD(sleepq, lwp); 46 47 typedef struct sleeptab { 48 sleepq_t st_queue[SLEEPTAB_HASH_SIZE]; 49 } sleeptab_t; 50 51 void sleeptab_init(sleeptab_t *); 52 53 extern sleeptab_t sleeptab; 54 55 #ifdef _KERNEL 56 /* 57 * Find the correct sleep queue for the specified wait channel. This 58 * acquires and holds the per-queue interlock. 59 */ 60 static __inline sleepq_t * 61 sleeptab_lookup(sleeptab_t *st, wchan_t wchan, kmutex_t **mp) 62 { 63 extern sleepqlock_t sleepq_locks[SLEEPTAB_HASH_SIZE]; 64 sleepq_t *sq; 65 u_int hash; 66 67 hash = SLEEPTAB_HASH(wchan); 68 sq = &st->st_queue[hash]; 69 *mp = &sleepq_locks[hash].lock; 70 mutex_spin_enter(*mp); 71 return sq; 72 } 73 74 static __inline kmutex_t * 75 sleepq_hashlock(wchan_t wchan) 76 { 77 extern sleepqlock_t sleepq_locks[SLEEPTAB_HASH_SIZE]; 78 kmutex_t *mp; 79 80 mp = &sleepq_locks[SLEEPTAB_HASH(wchan)].lock; 81 mutex_spin_enter(mp); 82 return mp; 83 } 84 85 #define sleepq_destroy(a) __nothing 86 87 #endif 88 89 /* 90 * Turnstiles, specialized sleep queues for use by kernel locks. 91 */ 92 93 typedef struct turnstile { 94 LIST_ENTRY(turnstile) ts_chain; /* link on hash chain */ 95 struct turnstile *ts_free; /* turnstile free list */ 96 wchan_t ts_obj; /* lock object */ 97 sleepq_t ts_sleepq[2]; /* sleep queues */ 98 u_int ts_waiters[2]; /* count of waiters */ 99 100 /* priority inheritance */ 101 pri_t ts_eprio; 102 lwp_t *ts_inheritor; 103 SLIST_ENTRY(turnstile) ts_pichain; 104 } turnstile_t; 105 106 LIST_HEAD(tschain, turnstile); 107 108 typedef struct tschain tschain_t; 109 110 #define TS_READER_Q 0 /* reader sleep queue */ 111 #define TS_WRITER_Q 1 /* writer sleep queue */ 112 113 #define TS_WAITERS(ts, q) \ 114 (ts)->ts_waiters[(q)] 115 116 #define TS_ALL_WAITERS(ts) \ 117 ((ts)->ts_waiters[TS_READER_Q] + \ 118 (ts)->ts_waiters[TS_WRITER_Q]) 119 120 #define TS_FIRST(ts, q) (LIST_FIRST(&(ts)->ts_sleepq[(q)])) 121 122 #ifdef _KERNEL 123 124 void turnstile_init(void); 125 turnstile_t *turnstile_lookup(wchan_t); 126 void turnstile_ctor(turnstile_t *); 127 void turnstile_exit(wchan_t); 128 void turnstile_block(turnstile_t *, int, wchan_t, const struct syncobj *); 129 void turnstile_wakeup(turnstile_t *, int, int, lwp_t *); 130 void turnstile_print(volatile void *, void (*)(const char *, ...) 131 __printflike(1, 2)); 132 void turnstile_unsleep(lwp_t *, bool); 133 void turnstile_changepri(lwp_t *, pri_t); 134 135 extern struct pool turnstile_pool; 136 extern turnstile_t turnstile0; 137 138 #endif /* _KERNEL */ 139 140 #endif /* _SYS_SLEEPTAB_H_ */ 141