1 /* $Id: smplock.h,v 1.2 1999/10/09 00:01:43 ralf Exp $
2 *
3 * This file is subject to the terms and conditions of the GNU General Public
4 * License. See the file "COPYING" in the main directory of this archive
5 * for more details.
6 *
7 * Default SMP lock implementation
8 */
9 #include <linux/interrupt.h>
10 #include <linux/spinlock.h>
11
12 extern spinlock_t kernel_flag;
13
14 #define kernel_locked() spin_is_locked(&kernel_flag)
15
16 /*
17 * Release global kernel lock and global interrupt lock
18 */
19 #define release_kernel_lock(task, cpu) \
20 do { \
21 if (task->lock_depth >= 0) \
22 spin_unlock(&kernel_flag); \
23 release_irqlock(cpu); \
24 __sti(); \
25 } while (0)
26
27 /*
28 * Re-acquire the kernel lock
29 */
30 #define reacquire_kernel_lock(task) \
31 do { \
32 if (task->lock_depth >= 0) \
33 spin_lock(&kernel_flag); \
34 } while (0)
35
36
37 /*
38 * Getting the big kernel lock.
39 *
40 * This cannot happen asynchronously,
41 * so we only need to worry about other
42 * CPU's.
43 */
44 extern __inline__ void lock_kernel(void)
45 {
46 if (!++current->lock_depth)
47 spin_lock(&kernel_flag);
48 }
49
50 extern __inline__ void unlock_kernel(void)
51 {
52 if (--current->lock_depth < 0)
53 spin_unlock(&kernel_flag);
54 }
55
This page was automatically generated by the
LXR engine.
Visit the LXR main site for more
information.