| 1 | /*
|
|---|
| 2 | * Copyright (C) 2001-2004 Jakub Jermar
|
|---|
| 3 | * All rights reserved.
|
|---|
| 4 | *
|
|---|
| 5 | * Redistribution and use in source and binary forms, with or without
|
|---|
| 6 | * modification, are permitted provided that the following conditions
|
|---|
| 7 | * are met:
|
|---|
| 8 | *
|
|---|
| 9 | * - Redistributions of source code must retain the above copyright
|
|---|
| 10 | * notice, this list of conditions and the following disclaimer.
|
|---|
| 11 | * - Redistributions in binary form must reproduce the above copyright
|
|---|
| 12 | * notice, this list of conditions and the following disclaimer in the
|
|---|
| 13 | * documentation and/or other materials provided with the distribution.
|
|---|
| 14 | * - The name of the author may not be used to endorse or promote products
|
|---|
| 15 | * derived from this software without specific prior written permission.
|
|---|
| 16 | *
|
|---|
| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
|
|---|
| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
|
|---|
| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
|
|---|
| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|---|
| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
|
|---|
| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|---|
| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|---|
| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|---|
| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
|---|
| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|---|
| 27 | */
|
|---|
| 28 |
|
|---|
| 29 | #include <arch.h>
|
|---|
| 30 |
|
|---|
| 31 | #include <arch/atomic.h>
|
|---|
| 32 | #include <arch/barrier.h>
|
|---|
| 33 | #include <synch/spinlock.h>
|
|---|
| 34 |
|
|---|
| 35 | #ifdef __SMP__
|
|---|
| 36 |
|
|---|
| 37 | void spinlock_initialize(spinlock_t *sl)
|
|---|
| 38 | {
|
|---|
| 39 | sl->val = 0;
|
|---|
| 40 | }
|
|---|
| 41 |
|
|---|
| 42 | #ifdef DEBUG_SPINLOCK
|
|---|
| 43 | void spinlock_lock(spinlock_t *sl)
|
|---|
| 44 | {
|
|---|
| 45 | int i = 0;
|
|---|
| 46 | __address caller = ((__u32 *) &sl)[-1];
|
|---|
| 47 |
|
|---|
| 48 | while (test_and_set(&sl->val)) {
|
|---|
| 49 | if (i++ > 300000) {
|
|---|
| 50 | printf("cpu%d: looping on spinlock %X, caller=%X\n", CPU->id, sl, caller);
|
|---|
| 51 | i = 0;
|
|---|
| 52 | }
|
|---|
| 53 | }
|
|---|
| 54 | CS_ENTER_BARRIER();
|
|---|
| 55 |
|
|---|
| 56 | }
|
|---|
| 57 | #else
|
|---|
| 58 | void spinlock_lock(spinlock_t *sl)
|
|---|
| 59 | {
|
|---|
| 60 | /*
|
|---|
| 61 | * Each architecture has its own efficient/recommended
|
|---|
| 62 | * implementation of spinlock.
|
|---|
| 63 | */
|
|---|
| 64 | spinlock_arch(&sl->val);
|
|---|
| 65 | CS_ENTER_BARRIER();
|
|---|
| 66 | }
|
|---|
| 67 | #endif
|
|---|
| 68 |
|
|---|
| 69 | int spinlock_trylock(spinlock_t *sl)
|
|---|
| 70 | {
|
|---|
| 71 | int rc;
|
|---|
| 72 |
|
|---|
| 73 | rc = !test_and_set(&sl->val);
|
|---|
| 74 | CS_ENTER_BARRIER();
|
|---|
| 75 |
|
|---|
| 76 | return rc;
|
|---|
| 77 | }
|
|---|
| 78 |
|
|---|
| 79 | void spinlock_unlock(spinlock_t *sl)
|
|---|
| 80 | {
|
|---|
| 81 | CS_LEAVE_BARRIER();
|
|---|
| 82 | sl->val = 0;
|
|---|
| 83 | }
|
|---|
| 84 |
|
|---|
| 85 | #endif
|
|---|
