1 /* $NetBSD: sleeptab.h,v 1.2 2020/11/01 21:00:20 christos 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 #define SLEEPTAB_HASH_SHIFT 7 37 #define SLEEPTAB_HASH_SIZE (1 << SLEEPTAB_HASH_SHIFT) 38 #define SLEEPTAB_HASH_MASK (SLEEPTAB_HASH_SIZE - 1) 39 #define SLEEPTAB_HASH(wchan) (((uintptr_t)(wchan) >> 8) & SLEEPTAB_HASH_MASK) 40 41 LIST_HEAD(sleepq, lwp); 42 43 typedef struct sleeptab { 44 sleepq_t st_queue[SLEEPTAB_HASH_SIZE]; 45 } sleeptab_t; 46 47 void sleeptab_init(sleeptab_t *); 48 49 extern sleeptab_t sleeptab; 50 51 #ifdef _KERNEL 52 /* 53 * Find the correct sleep queue for the specified wait channel. This 54 * acquires and holds the per-queue interlock. 55 */ 56 static __inline sleepq_t * 57 sleeptab_lookup(sleeptab_t *st, wchan_t wchan, kmutex_t **mp) 58 { 59 extern sleepqlock_t sleepq_locks[SLEEPTAB_HASH_SIZE]; 60 sleepq_t *sq; 61 u_int hash; 62 63 hash = SLEEPTAB_HASH(wchan); 64 sq = &st->st_queue[hash]; 65 *mp = &sleepq_locks[hash].lock; 66 mutex_spin_enter(*mp); 67 return sq; 68 } 69 70 static __inline kmutex_t * 71 sleepq_hashlock(wchan_t wchan) 72 { 73 extern sleepqlock_t sleepq_locks[SLEEPTAB_HASH_SIZE]; 74 kmutex_t *mp; 75 76 mp = &sleepq_locks[SLEEPTAB_HASH(wchan)].lock; 77 mutex_spin_enter(mp); 78 return mp; 79 } 80 81 #define sleepq_destroy(a) __nothing 82 83 #endif 84 85 /* 86 * Turnstiles, specialized sleep queues for use by kernel locks. 87 */ 88 89 typedef struct turnstile { 90 LIST_ENTRY(turnstile) ts_chain; /* link on hash chain */ 91 struct turnstile *ts_free; /* turnstile free list */ 92 wchan_t ts_obj; /* lock object */ 93 sleepq_t ts_sleepq[2]; /* sleep queues */ 94 u_int ts_waiters[2]; /* count of waiters */ 95 96 /* priority inheritance */ 97 pri_t ts_eprio; 98 lwp_t *ts_inheritor; 99 SLIST_ENTRY(turnstile) ts_pichain; 100 } turnstile_t; 101 102 LIST_HEAD(tschain, turnstile); 103 104 typedef struct tschain tschain_t; 105 106 #define TS_READER_Q 0 /* reader sleep queue */ 107 #define TS_WRITER_Q 1 /* writer sleep queue */ 108 109 #define TS_WAITERS(ts, q) \ 110 (ts)->ts_waiters[(q)] 111 112 #define TS_ALL_WAITERS(ts) \ 113 ((ts)->ts_waiters[TS_READER_Q] + \ 114 (ts)->ts_waiters[TS_WRITER_Q]) 115 116 #define TS_FIRST(ts, q) (LIST_FIRST(&(ts)->ts_sleepq[(q)])) 117 118 #ifdef _KERNEL 119 120 void turnstile_init(void); 121 turnstile_t *turnstile_lookup(wchan_t); 122 void turnstile_ctor(turnstile_t *); 123 void turnstile_exit(wchan_t); 124 void turnstile_block(turnstile_t *, int, wchan_t, syncobj_t *); 125 void turnstile_wakeup(turnstile_t *, int, int, lwp_t *); 126 void turnstile_print(volatile void *, void (*)(const char *, ...) 127 __printflike(1, 2)); 128 void turnstile_unsleep(lwp_t *, bool); 129 void turnstile_changepri(lwp_t *, pri_t); 130 131 extern struct pool turnstile_pool; 132 extern turnstile_t turnstile0; 133 134 #endif /* _KERNEL */ 135 136 #endif /* _SYS_SLEEPTAB_H_ */ 137