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Commit 4e8fd22b authored by Russell King's avatar Russell King Committed by Russell King
Browse files

[PATCH] ARM SMP: Fix ARMv6 spinlock and semaphore implementations 



Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 2c2a68b8

include/asm-arm/locks.h

+2 −2
Original line number Diff line number Diff line
@@ -61,7 +61,7 @@ 
"	strex	ip, lr, [%0]\n"			\

"	teq	ip, #0\n"			\

"	bne	1b\n"				\

"	teq	lr, #0\n"			\

"	cmp	lr, #0\n"			\

"	movle	ip, %0\n"			\

"	blle	" #wake				\

	:					\
@@ -100,7 +100,7 @@ 
	__asm__ __volatile__(			\

	"@ up_op_read\n"			\

"1:	ldrex	lr, [%0]\n"			\

"	add	lr, lr, %1\n"			\

"	adds	lr, lr, %1\n"			\

"	strex	ip, lr, [%0]\n"			\

"	teq	ip, #0\n"			\

"	bne	1b\n"				\

include/asm-arm/spinlock.h

+19 −16
Original line number Diff line number Diff line
@@ -79,7 +79,8 @@ typedef struct { 
} rwlock_t;



#define RW_LOCK_UNLOCKED	(rwlock_t) { 0 }

#define rwlock_init(x)		do { *(x) + RW_LOCK_UNLOCKED; } while (0)

#define rwlock_init(x)		do { *(x) = RW_LOCK_UNLOCKED; } while (0)

#define rwlock_is_locked(x)	(*((volatile unsigned int *)(x)) != 0)



/*

 * Write locks are easy - we just set bit 31.  When unlocking, we can
@@ -100,6 +101,21 @@ static inline void _raw_write_lock(rwlock_t *rw) 
	: "cc", "memory");

}



static inline int _raw_write_trylock(rwlock_t *rw)

{

	unsigned long tmp;



	__asm__ __volatile__(

"1:	ldrex	%0, [%1]\n"

"	teq	%0, #0\n"

"	strexeq	%0, %2, [%1]"

	: "=&r" (tmp)

	: "r" (&rw->lock), "r" (0x80000000)

	: "cc", "memory");



	return tmp == 0;

}



static inline void _raw_write_unlock(rwlock_t *rw)

{

	__asm__ __volatile__(
@@ -138,6 +154,8 @@ static inline void _raw_read_lock(rwlock_t *rw) 


static inline void _raw_read_unlock(rwlock_t *rw)

{

	unsigned long tmp, tmp2;



	__asm__ __volatile__(

"1:	ldrex	%0, [%2]\n"

"	sub	%0, %0, #1\n"
@@ -151,19 +169,4 @@ static inline void _raw_read_unlock(rwlock_t *rw) 


#define _raw_read_trylock(lock) generic_raw_read_trylock(lock)



static inline int _raw_write_trylock(rwlock_t *rw)

{

	unsigned long tmp;



	__asm__ __volatile__(

"1:	ldrex	%0, [%1]\n"

"	teq	%0, #0\n"

"	strexeq	%0, %2, [%1]"

	: "=&r" (tmp)

	: "r" (&rw->lock), "r" (0x80000000)

	: "cc", "memory");



	return tmp == 0;

}



#endif /* __ASM_SPINLOCK_H */