diff options
Diffstat (limited to 'include/asm-i386/rwsem.h')
| -rw-r--r-- | include/asm-i386/rwsem.h | 139 |
1 files changed, 52 insertions, 87 deletions
diff --git a/include/asm-i386/rwsem.h b/include/asm-i386/rwsem.h index be4ab859238..bc598d6388e 100644 --- a/include/asm-i386/rwsem.h +++ b/include/asm-i386/rwsem.h @@ -40,6 +40,7 @@ #include <linux/list.h> #include <linux/spinlock.h> +#include <linux/lockdep.h> struct rwsem_waiter; @@ -61,36 +62,34 @@ struct rw_semaphore { #define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS) spinlock_t wait_lock; struct list_head wait_list; -#if RWSEM_DEBUG - int debug; +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; #endif }; -/* - * initialisation - */ -#if RWSEM_DEBUG -#define __RWSEM_DEBUG_INIT , 0 +#ifdef CONFIG_DEBUG_LOCK_ALLOC +# define __RWSEM_DEP_MAP_INIT(lockname) , .dep_map = { .name = #lockname } #else -#define __RWSEM_DEBUG_INIT /* */ +# define __RWSEM_DEP_MAP_INIT(lockname) #endif + #define __RWSEM_INITIALIZER(name) \ { RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) \ - __RWSEM_DEBUG_INIT } + __RWSEM_DEP_MAP_INIT(name) } #define DECLARE_RWSEM(name) \ struct rw_semaphore name = __RWSEM_INITIALIZER(name) -static inline void init_rwsem(struct rw_semaphore *sem) -{ - sem->count = RWSEM_UNLOCKED_VALUE; - spin_lock_init(&sem->wait_lock); - INIT_LIST_HEAD(&sem->wait_list); -#if RWSEM_DEBUG - sem->debug = 0; -#endif -} +extern void __init_rwsem(struct rw_semaphore *sem, const char *name, + struct lock_class_key *key); + +#define init_rwsem(sem) \ +do { \ + static struct lock_class_key __key; \ + \ + __init_rwsem((sem), #sem, &__key); \ +} while (0) /* * lock for reading @@ -100,20 +99,12 @@ static inline void __down_read(struct rw_semaphore *sem) __asm__ __volatile__( "# beginning down_read\n\t" LOCK_PREFIX " incl (%%eax)\n\t" /* adds 0x00000001, returns the old value */ - " js 2f\n\t" /* jump if we weren't granted the lock */ + " jns 1f\n" + " call call_rwsem_down_read_failed\n" "1:\n\t" - LOCK_SECTION_START("") - "2:\n\t" - " pushl %%ecx\n\t" - " pushl %%edx\n\t" - " call rwsem_down_read_failed\n\t" - " popl %%edx\n\t" - " popl %%ecx\n\t" - " jmp 1b\n" - LOCK_SECTION_END "# ending down_read\n\t" - : "=m"(sem->count) - : "a"(sem), "m"(sem->count) + : "+m" (sem->count) + : "a" (sem) : "memory", "cc"); } @@ -134,8 +125,8 @@ LOCK_PREFIX " cmpxchgl %2,%0\n\t" " jnz 1b\n\t" "2:\n\t" "# ending __down_read_trylock\n\t" - : "+m"(sem->count), "=&a"(result), "=&r"(tmp) - : "i"(RWSEM_ACTIVE_READ_BIAS) + : "+m" (sem->count), "=&a" (result), "=&r" (tmp) + : "i" (RWSEM_ACTIVE_READ_BIAS) : "memory", "cc"); return result>=0 ? 1 : 0; } @@ -143,7 +134,7 @@ LOCK_PREFIX " cmpxchgl %2,%0\n\t" /* * lock for writing */ -static inline void __down_write(struct rw_semaphore *sem) +static inline void __down_write_nested(struct rw_semaphore *sem, int subclass) { int tmp; @@ -152,21 +143,20 @@ static inline void __down_write(struct rw_semaphore *sem) "# beginning down_write\n\t" LOCK_PREFIX " xadd %%edx,(%%eax)\n\t" /* subtract 0x0000ffff, returns the old value */ " testl %%edx,%%edx\n\t" /* was the count 0 before? */ - " jnz 2f\n\t" /* jump if we weren't granted the lock */ - "1:\n\t" - LOCK_SECTION_START("") - "2:\n\t" - " pushl %%ecx\n\t" - " call rwsem_down_write_failed\n\t" - " popl %%ecx\n\t" - " jmp 1b\n" - LOCK_SECTION_END + " jz 1f\n" + " call call_rwsem_down_write_failed\n" + "1:\n" "# ending down_write" - : "=m"(sem->count), "=d"(tmp) - : "a"(sem), "1"(tmp), "m"(sem->count) + : "+m" (sem->count), "=d" (tmp) + : "a" (sem), "1" (tmp) : "memory", "cc"); } +static inline void __down_write(struct rw_semaphore *sem) +{ + __down_write_nested(sem, 0); +} + /* * trylock for writing -- returns 1 if successful, 0 if contention */ @@ -189,20 +179,12 @@ static inline void __up_read(struct rw_semaphore *sem) __asm__ __volatile__( "# beginning __up_read\n\t" LOCK_PREFIX " xadd %%edx,(%%eax)\n\t" /* subtracts 1, returns the old value */ - " js 2f\n\t" /* jump if the lock is being waited upon */ - "1:\n\t" - LOCK_SECTION_START("") - "2:\n\t" - " decw %%dx\n\t" /* do nothing if still outstanding active readers */ - " jnz 1b\n\t" - " pushl %%ecx\n\t" - " call rwsem_wake\n\t" - " popl %%ecx\n\t" - " jmp 1b\n" - LOCK_SECTION_END + " jns 1f\n\t" + " call call_rwsem_wake\n" + "1:\n" "# ending __up_read\n" - : "=m"(sem->count), "=d"(tmp) - : "a"(sem), "1"(tmp), "m"(sem->count) + : "+m" (sem->count), "=d" (tmp) + : "a" (sem), "1" (tmp) : "memory", "cc"); } @@ -215,20 +197,12 @@ static inline void __up_write(struct rw_semaphore *sem) "# beginning __up_write\n\t" " movl %2,%%edx\n\t" LOCK_PREFIX " xaddl %%edx,(%%eax)\n\t" /* tries to transition 0xffff0001 -> 0x00000000 */ - " jnz 2f\n\t" /* jump if the lock is being waited upon */ + " jz 1f\n" + " call call_rwsem_wake\n" "1:\n\t" - LOCK_SECTION_START("") - "2:\n\t" - " decw %%dx\n\t" /* did the active count reduce to 0? */ - " jnz 1b\n\t" /* jump back if not */ - " pushl %%ecx\n\t" - " call rwsem_wake\n\t" - " popl %%ecx\n\t" - " jmp 1b\n" - LOCK_SECTION_END "# ending __up_write\n" - : "=m"(sem->count) - : "a"(sem), "i"(-RWSEM_ACTIVE_WRITE_BIAS), "m"(sem->count) + : "+m" (sem->count) + : "a" (sem), "i" (-RWSEM_ACTIVE_WRITE_BIAS) : "memory", "cc", "edx"); } @@ -240,20 +214,12 @@ static inline void __downgrade_write(struct rw_semaphore *sem) __asm__ __volatile__( "# beginning __downgrade_write\n\t" LOCK_PREFIX " addl %2,(%%eax)\n\t" /* transitions 0xZZZZ0001 -> 0xYYYY0001 */ - " js 2f\n\t" /* jump if the lock is being waited upon */ + " jns 1f\n\t" + " call call_rwsem_downgrade_wake\n" "1:\n\t" - LOCK_SECTION_START("") - "2:\n\t" - " pushl %%ecx\n\t" - " pushl %%edx\n\t" - " call rwsem_downgrade_wake\n\t" - " popl %%edx\n\t" - " popl %%ecx\n\t" - " jmp 1b\n" - LOCK_SECTION_END "# ending __downgrade_write\n" - : "=m"(sem->count) - : "a"(sem), "i"(-RWSEM_WAITING_BIAS), "m"(sem->count) + : "+m" (sem->count) + : "a" (sem), "i" (-RWSEM_WAITING_BIAS) : "memory", "cc"); } @@ -264,8 +230,8 @@ static inline void rwsem_atomic_add(int delta, struct rw_semaphore *sem) { __asm__ __volatile__( LOCK_PREFIX "addl %1,%0" - : "=m"(sem->count) - : "ir"(delta), "m"(sem->count)); + : "+m" (sem->count) + : "ir" (delta)); } /* @@ -276,10 +242,9 @@ static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem) int tmp = delta; __asm__ __volatile__( -LOCK_PREFIX "xadd %0,(%2)" - : "+r"(tmp), "=m"(sem->count) - : "r"(sem), "m"(sem->count) - : "memory"); +LOCK_PREFIX "xadd %0,%1" + : "+r" (tmp), "+m" (sem->count) + : : "memory"); return tmp+delta; } |