[PATCH] Clean up spin/rwlocks
- Inline spinlock strings into their inline functions - Convert macros to typesafe inlines - Replace some leftover __asm__ __volatile__s with asm volatile Signed-off-by: Andi Kleen <ak@suse.de>
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2 changed files with 41 additions and 44 deletions
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@ -21,18 +21,6 @@
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#define RW_LOCK_BIAS 0x01000000
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#define RW_LOCK_BIAS_STR "0x01000000"
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#define __build_read_lock(rw) \
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asm volatile(LOCK_PREFIX "subl $1,(%0)\n\t" \
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"jns 1f\n" \
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"call __read_lock_failed\n" \
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"1:\n" \
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::"D" (rw), "i" (RW_LOCK_BIAS) : "memory")
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#define __build_write_lock(rw) \
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asm volatile(LOCK_PREFIX "subl %1,(%0)\n\t" \
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"jz 1f\n" \
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"\tcall __write_lock_failed\n\t" \
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"1:\n" \
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::"D" (rw), "i" (RW_LOCK_BIAS) : "memory")
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/* Actual code is in asm/spinlock.h or in arch/x86_64/lib/rwlock.S */
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#endif
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@ -16,30 +16,23 @@
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* (the type definitions are in asm/spinlock_types.h)
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*/
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#define __raw_spin_is_locked(x) \
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(*(volatile signed int *)(&(x)->slock) <= 0)
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#define __raw_spin_lock_string \
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"\n1:\t" \
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LOCK_PREFIX " ; decl %0\n\t" \
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"jns 2f\n" \
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"3:\n" \
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"rep;nop\n\t" \
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"cmpl $0,%0\n\t" \
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"jle 3b\n\t" \
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"jmp 1b\n" \
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"2:\t" \
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#define __raw_spin_lock_string_up \
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"\n\tdecl %0"
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#define __raw_spin_unlock_string \
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"movl $1,%0" \
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:"=m" (lock->slock) : : "memory"
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static inline int __raw_spin_is_locked(raw_spinlock_t *lock)
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{
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return *(volatile signed int *)(&(lock)->slock) <= 0;
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}
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static inline void __raw_spin_lock(raw_spinlock_t *lock)
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{
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asm volatile(__raw_spin_lock_string : "=m" (lock->slock) : : "memory");
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asm volatile(
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"\n1:\t"
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LOCK_PREFIX " ; decl %0\n\t"
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"jns 2f\n"
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"3:\n"
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"rep;nop\n\t"
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"cmpl $0,%0\n\t"
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"jle 3b\n\t"
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"jmp 1b\n"
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"2:\t" : "=m" (lock->slock) : : "memory");
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}
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#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock)
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@ -48,7 +41,7 @@ static inline int __raw_spin_trylock(raw_spinlock_t *lock)
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{
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int oldval;
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__asm__ __volatile__(
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asm volatile(
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"xchgl %0,%1"
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:"=q" (oldval), "=m" (lock->slock)
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:"0" (0) : "memory");
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@ -58,13 +51,14 @@ static inline int __raw_spin_trylock(raw_spinlock_t *lock)
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static inline void __raw_spin_unlock(raw_spinlock_t *lock)
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{
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__asm__ __volatile__(
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__raw_spin_unlock_string
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);
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asm volatile("movl $1,%0" :"=m" (lock->slock) :: "memory");
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}
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#define __raw_spin_unlock_wait(lock) \
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do { while (__raw_spin_is_locked(lock)) cpu_relax(); } while (0)
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static inline void __raw_spin_unlock_wait(raw_spinlock_t *lock)
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{
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while (__raw_spin_is_locked(lock))
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cpu_relax();
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}
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/*
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* Read-write spinlocks, allowing multiple readers
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@ -80,17 +74,32 @@ static inline void __raw_spin_unlock(raw_spinlock_t *lock)
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* with the high bit (sign) being the "contended" bit.
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*/
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#define __raw_read_can_lock(x) ((int)(x)->lock > 0)
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#define __raw_write_can_lock(x) ((x)->lock == RW_LOCK_BIAS)
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static inline int __raw_read_can_lock(raw_rwlock_t *lock)
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{
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return (int)(lock)->lock > 0;
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}
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static inline int __raw_write_can_lock(raw_rwlock_t *lock)
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{
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return (lock)->lock == RW_LOCK_BIAS;
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}
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static inline void __raw_read_lock(raw_rwlock_t *rw)
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{
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__build_read_lock(rw);
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asm volatile(LOCK_PREFIX "subl $1,(%0)\n\t"
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"jns 1f\n"
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"call __read_lock_failed\n"
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"1:\n"
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::"D" (rw), "i" (RW_LOCK_BIAS) : "memory");
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}
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static inline void __raw_write_lock(raw_rwlock_t *rw)
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{
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__build_write_lock(rw);
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asm volatile(LOCK_PREFIX "subl %1,(%0)\n\t"
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"jz 1f\n"
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"\tcall __write_lock_failed\n\t"
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"1:\n"
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::"D" (rw), "i" (RW_LOCK_BIAS) : "memory");
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}
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static inline int __raw_read_trylock(raw_rwlock_t *lock)
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