1 /* 2 * Copyright (c) 2009 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Matthew Dillon <dillon@backplane.com> 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 3. Neither the name of The DragonFly Project nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific, prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #ifndef _SYS_MUTEX_H_ 36 #define _SYS_MUTEX_H_ 37 38 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES) 39 40 #ifndef _SYS_TYPES_H_ 41 #include <sys/types.h> 42 #endif 43 #include <machine/atomic.h> 44 #include <machine/cpufunc.h> 45 46 /* 47 * The general mutex structure provides recursive shared and exclusive 48 * locks, downgrade, a non-blocking upgrade, and various other functions. 49 * 50 * The structure is 16-byte aligned and either 16 or 32 bytes, designed 51 * for 32 or 64 bit cpus. 52 */ 53 struct thread; 54 55 struct mtx_link { 56 struct mtx_link *next; 57 struct mtx_link *prev; 58 struct thread *owner; 59 int state; 60 void (*callback)(struct mtx_link *, void *arg, int error); 61 void *arg; 62 }; 63 64 typedef struct mtx_link mtx_link_t; 65 66 struct mtx { 67 volatile u_int mtx_lock; 68 int mtx_reserved01; /* future use & struct alignmnent */ 69 struct thread *mtx_owner; 70 mtx_link_t *mtx_exlink; 71 mtx_link_t *mtx_shlink; 72 const char *mtx_ident; 73 } __cachealign; 74 75 typedef struct mtx mtx_t; 76 typedef u_int mtx_state_t; 77 78 #define MTX_INITIALIZER(ident) { .mtx_lock = 0, .mtx_owner = NULL, \ 79 .mtx_exlink = NULL, .mtx_shlink = NULL, \ 80 .mtx_ident = ident } 81 82 #define MTX_EXCLUSIVE 0x80000000 83 #define MTX_SHWANTED 0x40000000 84 #define MTX_EXWANTED 0x20000000 85 #define MTX_LINKSPIN 0x10000000 86 #define MTX_MASK 0x0FFFFFFF 87 88 #define MTX_OWNER_NONE NULL 89 #define MTX_OWNER_ANON ((struct thread *)-2) 90 91 #define MTX_LINK_IDLE 0 92 #define MTX_LINK_LINKED_SH (MTX_LINK_LINKED | 1) 93 #define MTX_LINK_LINKED_EX (MTX_LINK_LINKED | 2) 94 #define MTX_LINK_ACQUIRED 3 95 #define MTX_LINK_CALLEDBACK 4 96 #define MTX_LINK_ABORTED 5 97 98 #define MTX_LINK_LINKED 0x1000 99 100 #endif 101 102 /* 103 * See also sys/mutex2.h 104 */ 105 #ifdef _KERNEL 106 107 int _mtx_lock_ex_link(mtx_t *mtx, mtx_link_t *link, int flags, int to); 108 int _mtx_lock_ex(mtx_t *mtx, int flags, int to); 109 int _mtx_lock_sh_link(mtx_t *mtx, mtx_link_t *link, int flags, int to); 110 int _mtx_lock_sh(mtx_t *mtx, int flags, int to); 111 int _mtx_lock_ex_quick(mtx_t *mtx); 112 int _mtx_lock_sh_quick(mtx_t *mtx); 113 void _mtx_spinlock(mtx_t *mtx); 114 int _mtx_spinlock_try(mtx_t *mtx); 115 int _mtx_lock_ex_try(mtx_t *mtx); 116 int _mtx_lock_sh_try(mtx_t *mtx); 117 void _mtx_downgrade(mtx_t *mtx); 118 int _mtx_upgrade_try(mtx_t *mtx); 119 void _mtx_unlock(mtx_t *mtx); 120 void mtx_abort_link(mtx_t *mtx, mtx_link_t *link); 121 int mtx_wait_link(mtx_t *mtx, mtx_link_t *link, int flags, int to); 122 123 #endif 124 125 #endif 126