From: Jon Loeliger Date: Thu, 22 Sep 2005 19:55:30 +0000 (-0500) Subject: [PATCH] powerpc: Merge asm-ppc*/rwsem.h X-Git-Tag: v2.6.15-rc1~59^2~252 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=342e73b3d6fd1321d1eaaa6a935f267a300ceebd;p=linux-2.6 [PATCH] powerpc: Merge asm-ppc*/rwsem.h Merge asm-ppc*/rwsem.h into include/asm-powerpc. Removed smp_*mb() memory barriers from the ppc32 code as they are now burried in the atomic_*() functions as suggested by Paul, implemented by Arnd, and pushed out by Becky. I am not the droid you are looking for. This patch depends on Becky's atomic.h merge patch. Signed-off-by: Jon Loeliger Signed-off-by: Kumar Gala Signed-off-by: Paul Mackerras --- diff --git a/include/asm-ppc64/rwsem.h b/include/asm-powerpc/rwsem.h similarity index 91% rename from include/asm-ppc64/rwsem.h rename to include/asm-powerpc/rwsem.h index bd5c2f0935..0a5b83a3c9 100644 --- a/include/asm-ppc64/rwsem.h +++ b/include/asm-powerpc/rwsem.h @@ -1,18 +1,14 @@ +#ifndef _ASM_POWERPC_RWSEM_H +#define _ASM_POWERPC_RWSEM_H + +#ifdef __KERNEL__ + /* * include/asm-ppc64/rwsem.h: R/W semaphores for PPC using the stuff * in lib/rwsem.c. Adapted largely from include/asm-i386/rwsem.h * by Paul Mackerras . - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version - * 2 of the License, or (at your option) any later version. */ -#ifndef _PPC64_RWSEM_H -#define _PPC64_RWSEM_H - -#ifdef __KERNEL__ #include #include #include @@ -163,5 +159,5 @@ static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem) return atomic_add_return(delta, (atomic_t *)(&sem->count)); } -#endif /* __KERNEL__ */ -#endif /* _PPC_RWSEM_XADD_H */ +#endif /* __KERNEL__ */ +#endif /* _ASM_POWERPC_RWSEM_H */ diff --git a/include/asm-ppc/rwsem.h b/include/asm-ppc/rwsem.h deleted file mode 100644 index 3e738f483c..0000000000 --- a/include/asm-ppc/rwsem.h +++ /dev/null @@ -1,172 +0,0 @@ -/* - * include/asm-ppc/rwsem.h: R/W semaphores for PPC using the stuff - * in lib/rwsem.c. Adapted largely from include/asm-i386/rwsem.h - * by Paul Mackerras . - */ - -#ifndef _PPC_RWSEM_H -#define _PPC_RWSEM_H - -#ifdef __KERNEL__ -#include -#include -#include -#include - -/* - * the semaphore definition - */ -struct rw_semaphore { - /* XXX this should be able to be an atomic_t -- paulus */ - 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) - spinlock_t wait_lock; - struct list_head wait_list; -#if RWSEM_DEBUG - int debug; -#endif -}; - -/* - * initialisation - */ -#if RWSEM_DEBUG -#define __RWSEM_DEBUG_INIT , 0 -#else -#define __RWSEM_DEBUG_INIT /* */ -#endif - -#define __RWSEM_INITIALIZER(name) \ - { RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, \ - LIST_HEAD_INIT((name).wait_list) \ - __RWSEM_DEBUG_INIT } - -#define DECLARE_RWSEM(name) \ - struct rw_semaphore name = __RWSEM_INITIALIZER(name) - -extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem); -extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem); -extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem); -extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem); - -static inline void init_rwsem(struct rw_semaphore *sem) -{ - sem->count = RWSEM_UNLOCKED_VALUE; - spin_lock_init(&sem->wait_lock); - INIT_LIST_HEAD(&sem->wait_list); -#if RWSEM_DEBUG - sem->debug = 0; -#endif -} - -/* - * lock for reading - */ -static inline void __down_read(struct rw_semaphore *sem) -{ - if (atomic_inc_return((atomic_t *)(&sem->count)) > 0) - smp_wmb(); - else - rwsem_down_read_failed(sem); -} - -static inline int __down_read_trylock(struct rw_semaphore *sem) -{ - int tmp; - - while ((tmp = sem->count) >= 0) { - if (tmp == cmpxchg(&sem->count, tmp, - tmp + RWSEM_ACTIVE_READ_BIAS)) { - smp_wmb(); - return 1; - } - } - return 0; -} - -/* - * lock for writing - */ -static inline void __down_write(struct rw_semaphore *sem) -{ - int tmp; - - tmp = atomic_add_return(RWSEM_ACTIVE_WRITE_BIAS, - (atomic_t *)(&sem->count)); - if (tmp == RWSEM_ACTIVE_WRITE_BIAS) - smp_wmb(); - else - rwsem_down_write_failed(sem); -} - -static inline int __down_write_trylock(struct rw_semaphore *sem) -{ - int tmp; - - tmp = cmpxchg(&sem->count, RWSEM_UNLOCKED_VALUE, - RWSEM_ACTIVE_WRITE_BIAS); - smp_wmb(); - return tmp == RWSEM_UNLOCKED_VALUE; -} - -/* - * unlock after reading - */ -static inline void __up_read(struct rw_semaphore *sem) -{ - int tmp; - - smp_wmb(); - tmp = atomic_dec_return((atomic_t *)(&sem->count)); - if (tmp < -1 && (tmp & RWSEM_ACTIVE_MASK) == 0) - rwsem_wake(sem); -} - -/* - * unlock after writing - */ -static inline void __up_write(struct rw_semaphore *sem) -{ - smp_wmb(); - if (atomic_sub_return(RWSEM_ACTIVE_WRITE_BIAS, - (atomic_t *)(&sem->count)) < 0) - rwsem_wake(sem); -} - -/* - * implement atomic add functionality - */ -static inline void rwsem_atomic_add(int delta, struct rw_semaphore *sem) -{ - atomic_add(delta, (atomic_t *)(&sem->count)); -} - -/* - * downgrade write lock to read lock - */ -static inline void __downgrade_write(struct rw_semaphore *sem) -{ - int tmp; - - smp_wmb(); - tmp = atomic_add_return(-RWSEM_WAITING_BIAS, (atomic_t *)(&sem->count)); - if (tmp < 0) - rwsem_downgrade_wake(sem); -} - -/* - * implement exchange and add functionality - */ -static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem) -{ - smp_mb(); - return atomic_add_return(delta, (atomic_t *)(&sem->count)); -} - -#endif /* __KERNEL__ */ -#endif /* _PPC_RWSEM_XADD_H */