From f8e04d854506ddfeba9cb41b601972b28521f104 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Thu, 7 Apr 2016 17:12:21 +0200 Subject: locking/rwsem: Get rid of __down_write_nested() This is no longer used anywhere and all callers (__down_write()) use 0 as a subclass. Ditch __down_write_nested() to make the code easier to follow. This shouldn't introduce any functional change. Signed-off-by: Michal Hocko Acked-by: Davidlohr Bueso Cc: Andrew Morton Cc: Chris Zankel Cc: David S. Miller Cc: Linus Torvalds Cc: Max Filippov Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Signed-off-by: Davidlohr Bueso Cc: Signed-off-by: Jason Low Cc: Thomas Gleixner Cc: Tony Luck Cc: linux-alpha@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-ia64@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linux-sh@vger.kernel.org Cc: linux-xtensa@linux-xtensa.org Cc: sparclinux@vger.kernel.org Link: http://lkml.kernel.org/r/1460041951-22347-2-git-send-email-mhocko@kernel.org Signed-off-by: Ingo Molnar --- arch/sparc/include/asm/rwsem.h | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) (limited to 'arch/sparc') diff --git a/arch/sparc/include/asm/rwsem.h b/arch/sparc/include/asm/rwsem.h index 069bf4d663a1..e5a0d575bc7f 100644 --- a/arch/sparc/include/asm/rwsem.h +++ b/arch/sparc/include/asm/rwsem.h @@ -45,7 +45,7 @@ static inline int __down_read_trylock(struct rw_semaphore *sem) /* * lock for writing */ -static inline void __down_write_nested(struct rw_semaphore *sem, int subclass) +static inline void __down_write(struct rw_semaphore *sem) { long tmp; @@ -55,11 +55,6 @@ static inline void __down_write_nested(struct rw_semaphore *sem, int subclass) 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; -- cgit v1.2.3 From 938072e32ce13e5537ef001cdabcb8a6932b09a0 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Thu, 7 Apr 2016 17:12:25 +0200 Subject: locking/rwsem, sparc: Drop superfluous arch specific implementation sparc basically reuses the generic implementation of rwsem so we can reuse the code rather than duplicate it. Signed-off-by: Michal Hocko Cc: Andrew Morton Cc: Chris Zankel Cc: David S. Miller Cc: Linus Torvalds Cc: Max Filippov Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Signed-off-by: Davidlohr Bueso Cc: Signed-off-by: Jason Low Cc: Thomas Gleixner Cc: Tony Luck Cc: linux-alpha@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-ia64@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linux-sh@vger.kernel.org Cc: linux-xtensa@linux-xtensa.org Cc: sparclinux@vger.kernel.org Link: http://lkml.kernel.org/r/1460041951-22347-6-git-send-email-mhocko@kernel.org Signed-off-by: Ingo Molnar --- arch/sparc/include/asm/Kbuild | 1 + arch/sparc/include/asm/rwsem.h | 119 ----------------------------------------- 2 files changed, 1 insertion(+), 119 deletions(-) delete mode 100644 arch/sparc/include/asm/rwsem.h (limited to 'arch/sparc') diff --git a/arch/sparc/include/asm/Kbuild b/arch/sparc/include/asm/Kbuild index e928618838bc..6024c26c0585 100644 --- a/arch/sparc/include/asm/Kbuild +++ b/arch/sparc/include/asm/Kbuild @@ -16,6 +16,7 @@ generic-y += mm-arch-hooks.h generic-y += module.h generic-y += mutex.h generic-y += preempt.h +generic-y += rwsem.h generic-y += serial.h generic-y += trace_clock.h generic-y += types.h diff --git a/arch/sparc/include/asm/rwsem.h b/arch/sparc/include/asm/rwsem.h deleted file mode 100644 index e5a0d575bc7f..000000000000 --- a/arch/sparc/include/asm/rwsem.h +++ /dev/null @@ -1,119 +0,0 @@ -/* - * rwsem.h: R/W semaphores implemented using CAS - * - * Written by David S. Miller (davem@redhat.com), 2001. - * Derived from asm-i386/rwsem.h - */ -#ifndef _SPARC64_RWSEM_H -#define _SPARC64_RWSEM_H - -#ifndef _LINUX_RWSEM_H -#error "please don't include asm/rwsem.h directly, use linux/rwsem.h instead" -#endif - -#ifdef __KERNEL__ - -#define RWSEM_UNLOCKED_VALUE 0x00000000L -#define RWSEM_ACTIVE_BIAS 0x00000001L -#define RWSEM_ACTIVE_MASK 0xffffffffL -#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(atomic64_inc_return((atomic64_t *)(&sem->count)) <= 0L)) - rwsem_down_read_failed(sem); -} - -static inline int __down_read_trylock(struct rw_semaphore *sem) -{ - long tmp; - - while ((tmp = sem->count) >= 0L) { - if (tmp == cmpxchg(&sem->count, tmp, - tmp + RWSEM_ACTIVE_READ_BIAS)) { - return 1; - } - } - return 0; -} - -/* - * lock for writing - */ -static inline void __down_write(struct rw_semaphore *sem) -{ - long tmp; - - tmp = atomic64_add_return(RWSEM_ACTIVE_WRITE_BIAS, - (atomic64_t *)(&sem->count)); - if (unlikely(tmp != RWSEM_ACTIVE_WRITE_BIAS)) - rwsem_down_write_failed(sem); -} - -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 = atomic64_dec_return((atomic64_t *)(&sem->count)); - if (unlikely(tmp < -1L && (tmp & RWSEM_ACTIVE_MASK) == 0L)) - rwsem_wake(sem); -} - -/* - * unlock after writing - */ -static inline void __up_write(struct rw_semaphore *sem) -{ - if (unlikely(atomic64_sub_return(RWSEM_ACTIVE_WRITE_BIAS, - (atomic64_t *)(&sem->count)) < 0L)) - rwsem_wake(sem); -} - -/* - * implement atomic add functionality - */ -static inline void rwsem_atomic_add(long delta, struct rw_semaphore *sem) -{ - atomic64_add(delta, (atomic64_t *)(&sem->count)); -} - -/* - * downgrade write lock to read lock - */ -static inline void __downgrade_write(struct rw_semaphore *sem) -{ - long tmp; - - tmp = atomic64_add_return(-RWSEM_WAITING_BIAS, (atomic64_t *)(&sem->count)); - if (tmp < 0L) - rwsem_downgrade_wake(sem); -} - -/* - * implement exchange and add functionality - */ -static inline long rwsem_atomic_update(long delta, struct rw_semaphore *sem) -{ - return atomic64_add_return(delta, (atomic64_t *)(&sem->count)); -} - -#endif /* __KERNEL__ */ - -#endif /* _SPARC64_RWSEM_H */ -- cgit v1.2.3