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Commit 0766387b authored by Richard Kuo's avatar Richard Kuo Committed by Benjamin Herrenschmidt
Browse files

powerpc: Use rwsem.h from generic location 



As of commit dd472da3, rwsem.h was moved into asm-generic.
This patch removes the arch file and points the build at
its new location.

Signed-off-by: default avatarRichard Kuo <rkuo@codeaurora.org>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 1e7342e7

arch/powerpc/include/asm/Kbuild

+2 −0
Original line number Diff line number Diff line
@@ -34,3 +34,5 @@ header-y += termios.h 
header-y += types.h

header-y += ucontext.h

header-y += unistd.h



generic-y += rwsem.h

arch/powerpc/include/asm/rwsem.h

deleted100644 → 0
+0 −132
Original line number Diff line number Diff line 
#ifndef _ASM_POWERPC_RWSEM_H

#define _ASM_POWERPC_RWSEM_H



#ifndef _LINUX_RWSEM_H

#error "Please don't include <asm/rwsem.h> directly, use <linux/rwsem.h> instead."

#endif



#ifdef __KERNEL__



/*

 * R/W semaphores for PPC using the stuff in lib/rwsem.c.

 * Adapted largely from include/asm-i386/rwsem.h

 * by Paul Mackerras <paulus@samba.org>.

 */



/*

 * the semaphore definition

 */

#ifdef CONFIG_PPC64

# define RWSEM_ACTIVE_MASK		0xffffffffL

#else

# define RWSEM_ACTIVE_MASK		0x0000ffffL

#endif



#define RWSEM_UNLOCKED_VALUE		0x00000000L

#define RWSEM_ACTIVE_BIAS		0x00000001L

#define RWSEM_WAITING_BIAS		(-RWSEM_ACTIVE_MASK-1)

#define RWSEM_ACTIVE_READ_BIAS		RWSEM_ACTIVE_BIAS

#define RWSEM_ACTIVE_WRITE_BIAS		(RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)



/*

 * lock for reading

 */

static inline void __down_read(struct rw_semaphore *sem)

{

	if (unlikely(atomic_long_inc_return((atomic_long_t *)&sem->count) <= 0))

		rwsem_down_read_failed(sem);

}



static inline int __down_read_trylock(struct rw_semaphore *sem)

{

	long tmp;



	while ((tmp = sem->count) >= 0) {

		if (tmp == cmpxchg(&sem->count, tmp,

				   tmp + RWSEM_ACTIVE_READ_BIAS)) {

			return 1;

		}

	}

	return 0;

}



/*

 * lock for writing

 */

static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)

{

	long tmp;



	tmp = atomic_long_add_return(RWSEM_ACTIVE_WRITE_BIAS,

				     (atomic_long_t *)&sem->count);

	if (unlikely(tmp != RWSEM_ACTIVE_WRITE_BIAS))

		rwsem_down_write_failed(sem);

}



static inline void __down_write(struct rw_semaphore *sem)

{

	__down_write_nested(sem, 0);

}



static inline int __down_write_trylock(struct rw_semaphore *sem)

{

	long tmp;



	tmp = cmpxchg(&sem->count, RWSEM_UNLOCKED_VALUE,

		      RWSEM_ACTIVE_WRITE_BIAS);

	return tmp == RWSEM_UNLOCKED_VALUE;

}



/*

 * unlock after reading

 */

static inline void __up_read(struct rw_semaphore *sem)

{

	long tmp;



	tmp = atomic_long_dec_return((atomic_long_t *)&sem->count);

	if (unlikely(tmp < -1 && (tmp & RWSEM_ACTIVE_MASK) == 0))

		rwsem_wake(sem);

}



/*

 * unlock after writing

 */

static inline void __up_write(struct rw_semaphore *sem)

{

	if (unlikely(atomic_long_sub_return(RWSEM_ACTIVE_WRITE_BIAS,

				 (atomic_long_t *)&sem->count) < 0))

		rwsem_wake(sem);

}



/*

 * implement atomic add functionality

 */

static inline void rwsem_atomic_add(long delta, struct rw_semaphore *sem)

{

	atomic_long_add(delta, (atomic_long_t *)&sem->count);

}



/*

 * downgrade write lock to read lock

 */

static inline void __downgrade_write(struct rw_semaphore *sem)

{

	long tmp;



	tmp = atomic_long_add_return(-RWSEM_WAITING_BIAS,

				     (atomic_long_t *)&sem->count);

	if (tmp < 0)

		rwsem_downgrade_wake(sem);

}



/*

 * implement exchange and add functionality

 */

static inline long rwsem_atomic_update(long delta, struct rw_semaphore *sem)

{

	return atomic_long_add_return(delta, (atomic_long_t *)&sem->count);

}



#endif	/* __KERNEL__ */

#endif	/* _ASM_POWERPC_RWSEM_H */