diff options
Diffstat (limited to 'arch/x86/include/asm/rwsem.h')
| -rw-r--r-- | arch/x86/include/asm/rwsem.h | 25 |
1 files changed, 5 insertions, 20 deletions
diff --git a/arch/x86/include/asm/rwsem.h b/arch/x86/include/asm/rwsem.h index 10204a25bf93..606ede126972 100644 --- a/arch/x86/include/asm/rwsem.h +++ b/arch/x86/include/asm/rwsem.h @@ -232,34 +232,19 @@ static inline void __up_write(struct rw_semaphore *sem) */ static inline void __downgrade_write(struct rw_semaphore *sem) { -#ifdef CONFIG_X86_64 -# if RWSEM_WAITING_BIAS != -0x100000000 -# error "This code assumes RWSEM_WAITING_BIAS == -2^32" -# endif - - /* 64-bit immediates are special and expensive, and not needed here */ - asm volatile("# beginning __downgrade_write\n\t" - LOCK_PREFIX "incl 4(%1)\n\t" - /* transitions 0xZZZZZZZZ00000001 -> 0xYYYYYYYY00000001 */ - " jns 1f\n\t" - " call call_rwsem_downgrade_wake\n" - "1:\n\t" - "# ending __downgrade_write\n" - : "+m" (sem->count) - : "a" (sem) - : "memory", "cc"); -#else asm volatile("# beginning __downgrade_write\n\t" LOCK_PREFIX _ASM_ADD "%2,(%1)\n\t" - /* transitions 0xZZZZ0001 -> 0xYYYY0001 */ + /* + * transitions 0xZZZZ0001 -> 0xYYYY0001 (i386) + * 0xZZZZZZZZ00000001 -> 0xYYYYYYYY00000001 (x86_64) + */ " jns 1f\n\t" " call call_rwsem_downgrade_wake\n" "1:\n\t" "# ending __downgrade_write\n" : "+m" (sem->count) - : "a" (sem), "i" (-RWSEM_WAITING_BIAS) + : "a" (sem), "er" (-RWSEM_WAITING_BIAS) : "memory", "cc"); -#endif } /* |