[PATCH] Clean up read write lock assembly
[linux-2.6] / arch / x86_64 / lib / rwlock.S
1 /* Slow paths of read/write spinlocks. */
2
3 #include <linux/linkage.h>
4 #include <asm/rwlock.h>
5 #include <asm/alternative-asm.i>
6 #include <asm/dwarf2.h>
7
8 /* rdi: pointer to rwlock_t */
9 ENTRY(__write_lock_failed)
10         CFI_STARTPROC
11         LOCK_PREFIX
12         addl $RW_LOCK_BIAS,(%rdi)
13 1:      rep
14         nop
15         cmpl $RW_LOCK_BIAS,(%rdi)
16         jne 1b
17         LOCK_PREFIX
18         subl $RW_LOCK_BIAS,(%rdi)
19         jnz  __write_lock_failed
20         ret
21         CFI_ENDPROC
22 END(__write_lock_failed)
23
24 /* rdi: pointer to rwlock_t */
25 ENTRY(__read_lock_failed)
26         CFI_STARTPROC
27         LOCK_PREFIX
28         incl (%rdi)
29 1:      rep
30         nop
31         cmpl $1,(%rdi)
32         js 1b
33         LOCK_PREFIX
34         decl (%rdi)
35         js __read_lock_failed
36         ret
37         CFI_ENDPROC
38 END(__read_lock_failed)