blob: 56f60957522a627a90e08eab747f5c9a4293f793 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
|
#ifndef __ASM_SPINLOCK_H
#define __ASM_SPINLOCK_H
#define _raw_read_unlock(l) \
BUILD_BUG_ON(sizeof((l)->lock) != 4); /* Clang doesn't support %z in asm. */ \
asm volatile ( "lock; decl %0" : "+m" ((l)->lock) :: "memory" )
/*
* On x86 the only reordering is of reads with older writes. In the
* lock case, the read in observe_head() can only be reordered with
* writes that precede it, and moving a write _into_ a locked section
* is OK. In the release case, the write in add_sized() can only be
* reordered with reads that follow it, and hoisting a read _into_ a
* locked region is OK.
*/
#define arch_lock_acquire_barrier() barrier()
#define arch_lock_release_barrier() barrier()
#define arch_lock_relax() cpu_relax()
#define arch_lock_signal()
#define arch_lock_signal_wmb() \
({ \
smp_wmb(); \
arch_lock_signal(); \
})
#endif /* __ASM_SPINLOCK_H */
|
