diff options
Diffstat (limited to 'include/asm-x86_64')
| -rw-r--r-- | include/asm-x86_64/rwlock.h | 68 | ||||
| -rw-r--r-- | include/asm-x86_64/spinlock.h | 11 |
2 files changed, 12 insertions, 67 deletions
diff --git a/include/asm-x86_64/rwlock.h b/include/asm-x86_64/rwlock.h index dea0e94..28a080d 100644 --- a/include/asm-x86_64/rwlock.h +++ b/include/asm-x86_64/rwlock.h @@ -18,69 +18,21 @@ #ifndef _ASM_X86_64_RWLOCK_H #define _ASM_X86_64_RWLOCK_H -#include <linux/stringify.h> - #define RW_LOCK_BIAS 0x01000000 -#define RW_LOCK_BIAS_STR "0x01000000" +#define RW_LOCK_BIAS_STR "0x01000000" -#define __build_read_lock_ptr(rw, helper) \ +#define __build_read_lock(rw) \ asm volatile(LOCK_PREFIX "subl $1,(%0)\n\t" \ - "js 2f\n" \ - "1:\n" \ - LOCK_SECTION_START("") \ - "2:\tcall " helper "\n\t" \ - "jmp 1b\n" \ - LOCK_SECTION_END \ - ::"a" (rw) : "memory") - -#define __build_read_lock_const(rw, helper) \ - asm volatile(LOCK_PREFIX "subl $1,%0\n\t" \ - "js 2f\n" \ + "jns 1f\n" \ + "call __read_lock_failed\n" \ "1:\n" \ - LOCK_SECTION_START("") \ - "2:\tpushq %%rax\n\t" \ - "leaq %0,%%rax\n\t" \ - "call " helper "\n\t" \ - "popq %%rax\n\t" \ - "jmp 1b\n" \ - LOCK_SECTION_END \ - :"=m" (*((volatile int *)rw))::"memory") - -#define __build_read_lock(rw, helper) do { \ - if (__builtin_constant_p(rw)) \ - __build_read_lock_const(rw, helper); \ - else \ - __build_read_lock_ptr(rw, helper); \ - } while (0) + ::"D" (rw), "i" (RW_LOCK_BIAS) : "memory") -#define __build_write_lock_ptr(rw, helper) \ - asm volatile(LOCK_PREFIX "subl $" RW_LOCK_BIAS_STR ",(%0)\n\t" \ - "jnz 2f\n" \ +#define __build_write_lock(rw) \ + asm volatile(LOCK_PREFIX "subl %1,(%0)\n\t" \ + "jz 1f\n" \ + "\tcall __write_lock_failed\n\t" \ "1:\n" \ - LOCK_SECTION_START("") \ - "2:\tcall " helper "\n\t" \ - "jmp 1b\n" \ - LOCK_SECTION_END \ - ::"a" (rw) : "memory") - -#define __build_write_lock_const(rw, helper) \ - asm volatile(LOCK_PREFIX "subl $" RW_LOCK_BIAS_STR ",%0\n\t" \ - "jnz 2f\n" \ - "1:\n" \ - LOCK_SECTION_START("") \ - "2:\tpushq %%rax\n\t" \ - "leaq %0,%%rax\n\t" \ - "call " helper "\n\t" \ - "popq %%rax\n\t" \ - "jmp 1b\n" \ - LOCK_SECTION_END \ - :"=m" (*((volatile long *)rw))::"memory") - -#define __build_write_lock(rw, helper) do { \ - if (__builtin_constant_p(rw)) \ - __build_write_lock_const(rw, helper); \ - else \ - __build_write_lock_ptr(rw, helper); \ - } while (0) + ::"D" (rw), "i" (RW_LOCK_BIAS) : "memory") #endif diff --git a/include/asm-x86_64/spinlock.h b/include/asm-x86_64/spinlock.h index 248a79f..a8e3d89 100644 --- a/include/asm-x86_64/spinlock.h +++ b/include/asm-x86_64/spinlock.h @@ -79,13 +79,6 @@ static inline void __raw_spin_unlock(raw_spinlock_t *lock) * * On x86, we implement read-write locks as a 32-bit counter * with the high bit (sign) being the "contended" bit. - * - * The inline assembly is non-obvious. Think about it. - * - * Changed to use the same technique as rw semaphores. See - * semaphore.h for details. -ben - * - * the helpers are in arch/i386/kernel/semaphore.c */ #define __raw_read_can_lock(x) ((int)(x)->lock > 0) @@ -93,12 +86,12 @@ static inline void __raw_spin_unlock(raw_spinlock_t *lock) static inline void __raw_read_lock(raw_rwlock_t *rw) { - __build_read_lock(rw, "__read_lock_failed"); + __build_read_lock(rw); } static inline void __raw_write_lock(raw_rwlock_t *rw) { - __build_write_lock(rw, "__write_lock_failed"); + __build_write_lock(rw); } static inline int __raw_read_trylock(raw_rwlock_t *lock) |
