forked from luck/tmp_suning_uos_patched
[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 <jdl@freescale.com> Signed-off-by: Kumar Gala <kumar.gala@freescale.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
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@ -1,18 +1,14 @@
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#ifndef _ASM_POWERPC_RWSEM_H
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#define _ASM_POWERPC_RWSEM_H
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#ifdef __KERNEL__
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/*
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* include/asm-ppc64/rwsem.h: R/W semaphores for PPC using the stuff
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* in lib/rwsem.c. Adapted largely from include/asm-i386/rwsem.h
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* by Paul Mackerras <paulus@samba.org>.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef _PPC64_RWSEM_H
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#define _PPC64_RWSEM_H
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#ifdef __KERNEL__
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#include <linux/list.h>
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#include <linux/spinlock.h>
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#include <asm/atomic.h>
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@ -163,5 +159,5 @@ static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem)
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return atomic_add_return(delta, (atomic_t *)(&sem->count));
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}
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#endif /* __KERNEL__ */
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#endif /* _PPC_RWSEM_XADD_H */
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#endif /* __KERNEL__ */
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#endif /* _ASM_POWERPC_RWSEM_H */
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@ -1,172 +0,0 @@
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/*
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* include/asm-ppc/rwsem.h: R/W semaphores for PPC using the stuff
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* in lib/rwsem.c. Adapted largely from include/asm-i386/rwsem.h
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* by Paul Mackerras <paulus@samba.org>.
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*/
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#ifndef _PPC_RWSEM_H
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#define _PPC_RWSEM_H
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#ifdef __KERNEL__
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#include <linux/list.h>
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#include <linux/spinlock.h>
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#include <asm/atomic.h>
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#include <asm/system.h>
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/*
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* the semaphore definition
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*/
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struct rw_semaphore {
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/* XXX this should be able to be an atomic_t -- paulus */
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signed long count;
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#define RWSEM_UNLOCKED_VALUE 0x00000000
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#define RWSEM_ACTIVE_BIAS 0x00000001
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#define RWSEM_ACTIVE_MASK 0x0000ffff
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#define RWSEM_WAITING_BIAS (-0x00010000)
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#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS
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#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
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spinlock_t wait_lock;
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struct list_head wait_list;
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#if RWSEM_DEBUG
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int debug;
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#endif
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};
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/*
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* initialisation
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*/
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#if RWSEM_DEBUG
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#define __RWSEM_DEBUG_INIT , 0
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#else
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#define __RWSEM_DEBUG_INIT /* */
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#endif
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#define __RWSEM_INITIALIZER(name) \
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{ RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, \
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LIST_HEAD_INIT((name).wait_list) \
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__RWSEM_DEBUG_INIT }
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#define DECLARE_RWSEM(name) \
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struct rw_semaphore name = __RWSEM_INITIALIZER(name)
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extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem);
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extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem);
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extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem);
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extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem);
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static inline void init_rwsem(struct rw_semaphore *sem)
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{
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sem->count = RWSEM_UNLOCKED_VALUE;
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spin_lock_init(&sem->wait_lock);
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INIT_LIST_HEAD(&sem->wait_list);
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#if RWSEM_DEBUG
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sem->debug = 0;
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#endif
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}
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/*
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* lock for reading
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*/
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static inline void __down_read(struct rw_semaphore *sem)
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{
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if (atomic_inc_return((atomic_t *)(&sem->count)) > 0)
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smp_wmb();
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else
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rwsem_down_read_failed(sem);
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}
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static inline int __down_read_trylock(struct rw_semaphore *sem)
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{
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int tmp;
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while ((tmp = sem->count) >= 0) {
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if (tmp == cmpxchg(&sem->count, tmp,
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tmp + RWSEM_ACTIVE_READ_BIAS)) {
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smp_wmb();
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return 1;
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}
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}
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return 0;
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}
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/*
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* lock for writing
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*/
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static inline void __down_write(struct rw_semaphore *sem)
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{
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int tmp;
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tmp = atomic_add_return(RWSEM_ACTIVE_WRITE_BIAS,
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(atomic_t *)(&sem->count));
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if (tmp == RWSEM_ACTIVE_WRITE_BIAS)
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smp_wmb();
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else
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rwsem_down_write_failed(sem);
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}
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static inline int __down_write_trylock(struct rw_semaphore *sem)
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{
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int tmp;
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tmp = cmpxchg(&sem->count, RWSEM_UNLOCKED_VALUE,
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RWSEM_ACTIVE_WRITE_BIAS);
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smp_wmb();
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return tmp == RWSEM_UNLOCKED_VALUE;
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}
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/*
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* unlock after reading
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*/
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static inline void __up_read(struct rw_semaphore *sem)
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{
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int tmp;
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smp_wmb();
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tmp = atomic_dec_return((atomic_t *)(&sem->count));
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if (tmp < -1 && (tmp & RWSEM_ACTIVE_MASK) == 0)
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rwsem_wake(sem);
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}
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/*
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* unlock after writing
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*/
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static inline void __up_write(struct rw_semaphore *sem)
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{
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smp_wmb();
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if (atomic_sub_return(RWSEM_ACTIVE_WRITE_BIAS,
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(atomic_t *)(&sem->count)) < 0)
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rwsem_wake(sem);
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}
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/*
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* implement atomic add functionality
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*/
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static inline void rwsem_atomic_add(int delta, struct rw_semaphore *sem)
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{
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atomic_add(delta, (atomic_t *)(&sem->count));
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}
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/*
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* downgrade write lock to read lock
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*/
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static inline void __downgrade_write(struct rw_semaphore *sem)
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{
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int tmp;
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smp_wmb();
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tmp = atomic_add_return(-RWSEM_WAITING_BIAS, (atomic_t *)(&sem->count));
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if (tmp < 0)
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rwsem_downgrade_wake(sem);
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}
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/*
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* implement exchange and add functionality
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*/
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static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem)
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{
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smp_mb();
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return atomic_add_return(delta, (atomic_t *)(&sem->count));
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}
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#endif /* __KERNEL__ */
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#endif /* _PPC_RWSEM_XADD_H */
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