X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=include%2Fasm-x86%2Frwsem.h;h=750f2a3542b3931044e77835dceac28457bbece8;hb=13c48c490208d9e70d8d66d56f96c5054db69af7;hp=041906f3c6df73375abda597ba38e63922ffb542;hpb=4fa435018d740cb83d74c92306aa1f796da91ddd;p=linux-2.6 diff --git a/include/asm-x86/rwsem.h b/include/asm-x86/rwsem.h index 041906f3c6..750f2a3542 100644 --- a/include/asm-x86/rwsem.h +++ b/include/asm-x86/rwsem.h @@ -2,7 +2,7 @@ * * Written by David Howells (dhowells@redhat.com). * - * Derived from asm-i386/semaphore.h + * Derived from asm-x86/semaphore.h * * * The MSW of the count is the negated number of active writers and waiting @@ -44,22 +44,28 @@ struct rwsem_waiter; -extern struct rw_semaphore *FASTCALL(rwsem_down_read_failed(struct rw_semaphore *sem)); -extern struct rw_semaphore *FASTCALL(rwsem_down_write_failed(struct rw_semaphore *sem)); -extern struct rw_semaphore *FASTCALL(rwsem_wake(struct rw_semaphore *)); -extern struct rw_semaphore *FASTCALL(rwsem_downgrade_wake(struct rw_semaphore *sem)); +extern asmregparm struct rw_semaphore * + rwsem_down_read_failed(struct rw_semaphore *sem); +extern asmregparm struct rw_semaphore * + rwsem_down_write_failed(struct rw_semaphore *sem); +extern asmregparm struct rw_semaphore * + rwsem_wake(struct rw_semaphore *); +extern asmregparm struct rw_semaphore * + rwsem_downgrade_wake(struct rw_semaphore *sem); /* * the semaphore definition */ -struct rw_semaphore { - signed long count; + #define RWSEM_UNLOCKED_VALUE 0x00000000 #define RWSEM_ACTIVE_BIAS 0x00000001 #define RWSEM_ACTIVE_MASK 0x0000ffff #define RWSEM_WAITING_BIAS (-0x00010000) #define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS #define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS) + +struct rw_semaphore { + signed long count; spinlock_t wait_lock; struct list_head wait_list; #ifdef CONFIG_DEBUG_LOCK_ALLOC @@ -74,11 +80,13 @@ struct rw_semaphore { #endif -#define __RWSEM_INITIALIZER(name) \ -{ RWSEM_UNLOCKED_VALUE, __SPIN_LOCK_UNLOCKED((name).wait_lock), \ - LIST_HEAD_INIT((name).wait_list) __RWSEM_DEP_MAP_INIT(name) } +#define __RWSEM_INITIALIZER(name) \ +{ \ + RWSEM_UNLOCKED_VALUE, __SPIN_LOCK_UNLOCKED((name).wait_lock), \ + LIST_HEAD_INIT((name).wait_list) __RWSEM_DEP_MAP_INIT(name) \ +} -#define DECLARE_RWSEM(name) \ +#define DECLARE_RWSEM(name) \ struct rw_semaphore name = __RWSEM_INITIALIZER(name) extern void __init_rwsem(struct rw_semaphore *sem, const char *name, @@ -96,16 +104,16 @@ do { \ */ 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 */ - " jns 1f\n" - " call call_rwsem_down_read_failed\n" - "1:\n\t" - "# ending down_read\n\t" - : "+m" (sem->count) - : "a" (sem) - : "memory", "cc"); + asm volatile("# beginning down_read\n\t" + LOCK_PREFIX " incl (%%eax)\n\t" + /* adds 0x00000001, returns the old value */ + " jns 1f\n" + " call call_rwsem_down_read_failed\n" + "1:\n\t" + "# ending down_read\n\t" + : "+m" (sem->count) + : "a" (sem) + : "memory", "cc"); } /* @@ -114,21 +122,20 @@ LOCK_PREFIX " incl (%%eax)\n\t" /* adds 0x00000001, returns the old value static inline int __down_read_trylock(struct rw_semaphore *sem) { __s32 result, tmp; - __asm__ __volatile__( - "# beginning __down_read_trylock\n\t" - " movl %0,%1\n\t" - "1:\n\t" - " movl %1,%2\n\t" - " addl %3,%2\n\t" - " jle 2f\n\t" -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) - : "memory", "cc"); - return result>=0 ? 1 : 0; + asm volatile("# beginning __down_read_trylock\n\t" + " movl %0,%1\n\t" + "1:\n\t" + " movl %1,%2\n\t" + " addl %3,%2\n\t" + " jle 2f\n\t" + 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) + : "memory", "cc"); + return result >= 0 ? 1 : 0; } /* @@ -139,17 +146,18 @@ static inline void __down_write_nested(struct rw_semaphore *sem, int subclass) int tmp; tmp = RWSEM_ACTIVE_WRITE_BIAS; - __asm__ __volatile__( - "# 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? */ - " jz 1f\n" - " call call_rwsem_down_write_failed\n" - "1:\n" - "# ending down_write" - : "+m" (sem->count), "=d" (tmp) - : "a" (sem), "1" (tmp) - : "memory", "cc"); + asm volatile("# 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? */ + " jz 1f\n" + " call call_rwsem_down_write_failed\n" + "1:\n" + "# ending down_write" + : "+m" (sem->count), "=d" (tmp) + : "a" (sem), "1" (tmp) + : "memory", "cc"); } static inline void __down_write(struct rw_semaphore *sem) @@ -163,7 +171,7 @@ static inline void __down_write(struct rw_semaphore *sem) static inline int __down_write_trylock(struct rw_semaphore *sem) { signed long ret = cmpxchg(&sem->count, - RWSEM_UNLOCKED_VALUE, + RWSEM_UNLOCKED_VALUE, RWSEM_ACTIVE_WRITE_BIAS); if (ret == RWSEM_UNLOCKED_VALUE) return 1; @@ -176,16 +184,16 @@ static inline int __down_write_trylock(struct rw_semaphore *sem) static inline void __up_read(struct rw_semaphore *sem) { __s32 tmp = -RWSEM_ACTIVE_READ_BIAS; - __asm__ __volatile__( - "# beginning __up_read\n\t" -LOCK_PREFIX " xadd %%edx,(%%eax)\n\t" /* subtracts 1, returns the old value */ - " jns 1f\n\t" - " call call_rwsem_wake\n" - "1:\n" - "# ending __up_read\n" - : "+m" (sem->count), "=d" (tmp) - : "a" (sem), "1" (tmp) - : "memory", "cc"); + asm volatile("# beginning __up_read\n\t" + LOCK_PREFIX " xadd %%edx,(%%eax)\n\t" + /* subtracts 1, returns the old value */ + " jns 1f\n\t" + " call call_rwsem_wake\n" + "1:\n" + "# ending __up_read\n" + : "+m" (sem->count), "=d" (tmp) + : "a" (sem), "1" (tmp) + : "memory", "cc"); } /* @@ -193,17 +201,18 @@ LOCK_PREFIX " xadd %%edx,(%%eax)\n\t" /* subtracts 1, returns the old valu */ static inline void __up_write(struct rw_semaphore *sem) { - __asm__ __volatile__( - "# beginning __up_write\n\t" - " movl %2,%%edx\n\t" -LOCK_PREFIX " xaddl %%edx,(%%eax)\n\t" /* tries to transition 0xffff0001 -> 0x00000000 */ - " jz 1f\n" - " call call_rwsem_wake\n" - "1:\n\t" - "# ending __up_write\n" - : "+m" (sem->count) - : "a" (sem), "i" (-RWSEM_ACTIVE_WRITE_BIAS) - : "memory", "cc", "edx"); + asm volatile("# beginning __up_write\n\t" + " movl %2,%%edx\n\t" + LOCK_PREFIX " xaddl %%edx,(%%eax)\n\t" + /* tries to transition + 0xffff0001 -> 0x00000000 */ + " jz 1f\n" + " call call_rwsem_wake\n" + "1:\n\t" + "# ending __up_write\n" + : "+m" (sem->count) + : "a" (sem), "i" (-RWSEM_ACTIVE_WRITE_BIAS) + : "memory", "cc", "edx"); } /* @@ -211,16 +220,16 @@ LOCK_PREFIX " xaddl %%edx,(%%eax)\n\t" /* tries to transition 0xffff0001 -> */ 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 */ - " 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) - : "memory", "cc"); + asm volatile("# beginning __downgrade_write\n\t" + LOCK_PREFIX " addl %2,(%%eax)\n\t" + /* transitions 0xZZZZ0001 -> 0xYYYY0001 */ + " 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) + : "memory", "cc"); } /* @@ -228,10 +237,9 @@ LOCK_PREFIX " addl %2,(%%eax)\n\t" /* transitions 0xZZZZ0001 -> 0xYYYY0001 */ static inline void rwsem_atomic_add(int delta, struct rw_semaphore *sem) { - __asm__ __volatile__( -LOCK_PREFIX "addl %1,%0" - : "+m" (sem->count) - : "ir" (delta)); + asm volatile(LOCK_PREFIX "addl %1,%0" + : "+m" (sem->count) + : "ir" (delta)); } /* @@ -241,12 +249,11 @@ static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem) { int tmp = delta; - __asm__ __volatile__( -LOCK_PREFIX "xadd %0,%1" - : "+r" (tmp), "+m" (sem->count) - : : "memory"); + asm volatile(LOCK_PREFIX "xadd %0,%1" + : "+r" (tmp), "+m" (sem->count) + : : "memory"); - return tmp+delta; + return tmp + delta; } static inline int rwsem_is_locked(struct rw_semaphore *sem)