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
33 #ifndef _SYS_SPINLOCK2_H_
34 #define _SYS_SPINLOCK2_H_
38 #error "This file should not be included by userland programs."
43 #include <sys/systm.h>
45 #ifndef _SYS_THREAD2_H_
46 #include <sys/thread2.h>
48 #ifndef _SYS_GLOBALDATA_H_
49 #include <sys/globaldata.h>
51 #include <machine/atomic.h>
52 #include <machine/cpufunc.h>
56 extern int spin_trylock_wr_contested2(globaldata_t gd);
57 extern void spin_lock_wr_contested2(struct spinlock *mtx);
64 * Attempt to obtain an exclusive spinlock. Returns FALSE on failure,
67 static __inline boolean_t
68 spin_trylock(struct spinlock *mtx)
70 globaldata_t gd = mycpu;
73 ++gd->gd_curthread->td_critcount;
75 ++gd->gd_spinlocks_wr;
76 if ((value = atomic_swap_int(&mtx->lock, SPINLOCK_EXCLUSIVE)) != 0)
77 return (spin_trylock_wr_contested2(gd));
81 for (i = 0; i < SPINLOCK_DEBUG_ARRAY_SIZE; i++) {
82 if (gd->gd_curthread->td_spinlock_stack_id[i] == 0) {
83 gd->gd_curthread->td_spinlock_stack_id[i] = 1;
84 gd->gd_curthread->td_spinlock_stack[i] = mtx;
85 gd->gd_curthread->td_spinlock_caller_pc[i] =
86 __builtin_return_address(0);
97 static __inline boolean_t
98 spin_trylock(struct spinlock *mtx)
100 globaldata_t gd = mycpu;
102 ++gd->gd_curthread->td_critcount;
104 ++gd->gd_spinlocks_wr;
111 * Obtain an exclusive spinlock and return.
114 spin_lock_quick(globaldata_t gd, struct spinlock *mtx)
120 ++gd->gd_curthread->td_critcount;
122 ++gd->gd_spinlocks_wr;
124 if ((value = atomic_swap_int(&mtx->lock, SPINLOCK_EXCLUSIVE)) != 0)
125 spin_lock_wr_contested2(mtx);
128 for (i = 0; i < SPINLOCK_DEBUG_ARRAY_SIZE; i++) {
129 if (gd->gd_curthread->td_spinlock_stack_id[i] == 0) {
130 gd->gd_curthread->td_spinlock_stack_id[i] = 1;
131 gd->gd_curthread->td_spinlock_stack[i] = mtx;
132 gd->gd_curthread->td_spinlock_caller_pc[i] =
133 __builtin_return_address(0);
142 spin_lock(struct spinlock *mtx)
144 spin_lock_quick(mycpu, mtx);
148 * Release an exclusive spinlock. We can just do this passively, only
149 * ensuring that our spinlock count is left intact until the mutex is
153 spin_unlock_quick(globaldata_t gd, struct spinlock *mtx)
158 for (i = 0; i < SPINLOCK_DEBUG_ARRAY_SIZE; i++) {
159 if ((gd->gd_curthread->td_spinlock_stack_id[i] == 1) &&
160 (gd->gd_curthread->td_spinlock_stack[i] == mtx)) {
161 gd->gd_curthread->td_spinlock_stack_id[i] = 0;
162 gd->gd_curthread->td_spinlock_stack[i] = NULL;
163 gd->gd_curthread->td_spinlock_caller_pc[i] = NULL;
170 KKASSERT(gd->gd_spinlocks_wr > 0);
171 --gd->gd_spinlocks_wr;
173 --gd->gd_curthread->td_critcount;
177 spin_unlock(struct spinlock *mtx)
179 spin_unlock_quick(mycpu, mtx);
183 spin_init(struct spinlock *mtx)
189 spin_uninit(struct spinlock *mtx)
195 #endif /* _SYS_SPINLOCK2_H_ */