Commit 8b059d23 authored by Andi Kleen's avatar Andi Kleen Committed by Andi Kleen
Browse files

[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: default avatarAndi Kleen <ak@suse.de>
parent a752d719

include/asm-x86_64/rwlock.h

+1 −13
Original line number Diff line number Diff line
@@ -21,18 +21,6 @@ 
#define RW_LOCK_BIAS		 0x01000000

#define RW_LOCK_BIAS_STR	 "0x01000000"



#define __build_read_lock(rw)   \

	asm volatile(LOCK_PREFIX "subl $1,(%0)\n\t" \

		     "jns 1f\n" \

		     "call __read_lock_failed\n" \

		     "1:\n" \

		     ::"D" (rw), "i" (RW_LOCK_BIAS) : "memory")



#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" \

		     ::"D" (rw), "i" (RW_LOCK_BIAS) : "memory")

/* Actual code is in asm/spinlock.h or in arch/x86_64/lib/rwlock.S */



#endif

include/asm-x86_64/spinlock.h

+40 −31
Original line number Diff line number Diff line
@@ -16,30 +16,23 @@ 
 * (the type definitions are in asm/spinlock_types.h)

 */



#define __raw_spin_is_locked(x) \

		(*(volatile signed int *)(&(x)->slock) <= 0)



#define __raw_spin_lock_string \

	"\n1:\t" \

	LOCK_PREFIX " ; decl %0\n\t" \

	"jns 2f\n" \

	"3:\n" \

	"rep;nop\n\t" \

	"cmpl $0,%0\n\t" \

	"jle 3b\n\t" \

	"jmp 1b\n" \

	"2:\t" \



#define __raw_spin_lock_string_up \

	"\n\tdecl %0"



#define __raw_spin_unlock_string \

	"movl $1,%0" \

		:"=m" (lock->slock) : : "memory"

static inline int __raw_spin_is_locked(raw_spinlock_t *lock)

{

	return *(volatile signed int *)(&(lock)->slock) <= 0;

}



static inline void __raw_spin_lock(raw_spinlock_t *lock)

{

	asm volatile(__raw_spin_lock_string : "=m" (lock->slock) : : "memory");

	asm volatile(

		"\n1:\t"

		LOCK_PREFIX " ; decl %0\n\t"

		"jns 2f\n"

		"3:\n"

		"rep;nop\n\t"

		"cmpl $0,%0\n\t"

		"jle 3b\n\t"

		"jmp 1b\n"

		"2:\t" : "=m" (lock->slock) : : "memory");

}



#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock)
@@ -48,7 +41,7 @@ static inline int __raw_spin_trylock(raw_spinlock_t *lock) 
{

	int oldval;



	__asm__ __volatile__(

	asm volatile(

		"xchgl %0,%1"

		:"=q" (oldval), "=m" (lock->slock)

		:"0" (0) : "memory");
@@ -58,13 +51,14 @@ static inline int __raw_spin_trylock(raw_spinlock_t *lock) 


static inline void __raw_spin_unlock(raw_spinlock_t *lock)

{

	__asm__ __volatile__(

		__raw_spin_unlock_string

	);

	asm volatile("movl $1,%0" :"=m" (lock->slock) :: "memory");

}



#define __raw_spin_unlock_wait(lock) \

	do { while (__raw_spin_is_locked(lock)) cpu_relax(); } while (0)

static inline void __raw_spin_unlock_wait(raw_spinlock_t *lock)

{

	while (__raw_spin_is_locked(lock))

		cpu_relax();

}



/*

 * Read-write spinlocks, allowing multiple readers
@@ -80,17 +74,32 @@ static inline void __raw_spin_unlock(raw_spinlock_t *lock) 
 * with the high bit (sign) being the "contended" bit.

 */



#define __raw_read_can_lock(x)		((int)(x)->lock > 0)

#define __raw_write_can_lock(x)		((x)->lock == RW_LOCK_BIAS)

static inline int __raw_read_can_lock(raw_rwlock_t *lock)

{

	return (int)(lock)->lock > 0;

}



static inline int __raw_write_can_lock(raw_rwlock_t *lock)

{

	return (lock)->lock == RW_LOCK_BIAS;

}



static inline void __raw_read_lock(raw_rwlock_t *rw)

{

	__build_read_lock(rw);

	asm volatile(LOCK_PREFIX "subl $1,(%0)\n\t"

		     "jns 1f\n"

		     "call __read_lock_failed\n"

		     "1:\n"

		     ::"D" (rw), "i" (RW_LOCK_BIAS) : "memory");

}



static inline void __raw_write_lock(raw_rwlock_t *rw)

{

	__build_write_lock(rw);

	asm volatile(LOCK_PREFIX "subl %1,(%0)\n\t"

		     "jz 1f\n"

		     "\tcall __write_lock_failed\n\t"

		     "1:\n"

		     ::"D" (rw), "i" (RW_LOCK_BIAS) : "memory");

}



static inline int __raw_read_trylock(raw_rwlock_t *lock)