2 * Copyright (c) 2005 Jeffrey M. Hsu. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of The DragonFly Project nor the names of its
16 * contributors may be used to endorse or promote products derived
17 * from this software without specific, prior written permission.
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
22 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
23 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
24 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
25 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
26 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
27 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
28 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
29 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * $DragonFly: src/sys/sys/spinlock2.h,v 1.12 2008/06/04 04:34:54 nth Exp $
35 #ifndef _SYS_SPINLOCK2_H_
36 #define _SYS_SPINLOCK2_H_
40 #error "This file should not be included by userland programs."
45 #include <sys/systm.h>
47 #ifndef _SYS_THREAD2_H_
48 #include <sys/thread2.h>
50 #ifndef _SYS_GLOBALDATA_H_
51 #include <sys/globaldata.h>
53 #ifndef _MACHINE_ATOMIC_H_
54 #include <machine/atomic.h>
56 #ifndef _MACHINE_CPUFUNC_H_
57 #include <machine/cpufunc.h>
62 extern int spin_trylock_wr_contested2(globaldata_t gd);
63 extern void spin_lock_wr_contested2(struct spinlock *mtx);
70 * Attempt to obtain an exclusive spinlock. Returns FALSE on failure,
73 static __inline boolean_t
74 spin_trylock(struct spinlock *mtx)
76 globaldata_t gd = mycpu;
79 ++gd->gd_curthread->td_critcount;
81 ++gd->gd_spinlocks_wr;
82 if ((value = atomic_swap_int(&mtx->lock, SPINLOCK_EXCLUSIVE)) != 0)
83 return (spin_trylock_wr_contested2(gd));
87 for (i = 0; i < SPINLOCK_DEBUG_ARRAY_SIZE; i++) {
88 if (gd->gd_curthread->td_spinlock_stack_id[i] == 0) {
89 gd->gd_curthread->td_spinlock_stack_id[i] = 1;
90 gd->gd_curthread->td_spinlock_stack[i] = mtx;
91 gd->gd_curthread->td_spinlock_caller_pc[i] =
92 __builtin_return_address(0);
103 static __inline boolean_t
104 spin_trylock(struct spinlock *mtx)
106 globaldata_t gd = mycpu;
108 ++gd->gd_curthread->td_critcount;
110 ++gd->gd_spinlocks_wr;
117 * Obtain an exclusive spinlock and return.
120 spin_lock_quick(globaldata_t gd, struct spinlock *mtx)
126 ++gd->gd_curthread->td_critcount;
128 ++gd->gd_spinlocks_wr;
130 if ((value = atomic_swap_int(&mtx->lock, SPINLOCK_EXCLUSIVE)) != 0)
131 spin_lock_wr_contested2(mtx);
134 for (i = 0; i < SPINLOCK_DEBUG_ARRAY_SIZE; i++) {
135 if (gd->gd_curthread->td_spinlock_stack_id[i] == 0) {
136 gd->gd_curthread->td_spinlock_stack_id[i] = 1;
137 gd->gd_curthread->td_spinlock_stack[i] = mtx;
138 gd->gd_curthread->td_spinlock_caller_pc[i] =
139 __builtin_return_address(0);
148 spin_lock(struct spinlock *mtx)
150 spin_lock_quick(mycpu, mtx);
154 * Release an exclusive spinlock. We can just do this passively, only
155 * ensuring that our spinlock count is left intact until the mutex is
159 spin_unlock_quick(globaldata_t gd, struct spinlock *mtx)
164 for (i = 0; i < SPINLOCK_DEBUG_ARRAY_SIZE; i++) {
165 if ((gd->gd_curthread->td_spinlock_stack_id[i] == 1) &&
166 (gd->gd_curthread->td_spinlock_stack[i] == mtx)) {
167 gd->gd_curthread->td_spinlock_stack_id[i] = 0;
168 gd->gd_curthread->td_spinlock_stack[i] = NULL;
169 gd->gd_curthread->td_spinlock_caller_pc[i] = NULL;
176 KKASSERT(gd->gd_spinlocks_wr > 0);
177 --gd->gd_spinlocks_wr;
179 --gd->gd_curthread->td_critcount;
183 spin_unlock(struct spinlock *mtx)
185 spin_unlock_quick(mycpu, mtx);
189 spin_init(struct spinlock *mtx)
195 spin_uninit(struct spinlock *mtx)
201 #endif /* _SYS_SPINLOCK2_H_ */