[PATCH 05/11] sparc, rwsem: drop superfluous arch specific implementation

Michal Hocko
2016-04-07T15:12:25Z

From: Michal Hocko <mhocko@suse.com>

sparc basically reuses generic implementation of rwsem so we can
reuse the code rather than duplicate it.

Signed-off-by: Michal Hocko <mhocko@suse.com>
---
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

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 */
--
2.8.0.rc3