[PATCH v2 2/2] Remove rwsem_atomic_add() and rwsem_atomic_update()

From: Jason Low
Date: Sat Jun 04 2016 - 01:39:21 EST


The rwsem-xadd count has been converted to an atomic variable and the
rwsem code now directly uses atomic_long_add() and
atomic_long_add_return(), so we can remove the arch implementations of
rwsem_atomic_add() and rwsem_atomic_update().

Signed-off-by: Jason Low <jason.low2@xxxxxxx>
---
arch/alpha/include/asm/rwsem.h | 42 ------------------------------------------
arch/ia64/include/asm/rwsem.h | 7 -------
arch/s390/include/asm/rwsem.h | 37 -------------------------------------
arch/x86/include/asm/rwsem.h | 18 ------------------
include/asm-generic/rwsem.h | 16 ----------------
5 files changed, 120 deletions(-)

diff --git a/arch/alpha/include/asm/rwsem.h b/arch/alpha/include/asm/rwsem.h
index b40021a..77873d0 100644
--- a/arch/alpha/include/asm/rwsem.h
+++ b/arch/alpha/include/asm/rwsem.h
@@ -191,47 +191,5 @@ static inline void __downgrade_write(struct rw_semaphore *sem)
rwsem_downgrade_wake(sem);
}

-static inline void rwsem_atomic_add(long val, struct rw_semaphore *sem)
-{
-#ifndef CONFIG_SMP
- sem->count += val;
-#else
- long temp;
- __asm__ __volatile__(
- "1: ldq_l %0,%1\n"
- " addq %0,%2,%0\n"
- " stq_c %0,%1\n"
- " beq %0,2f\n"
- ".subsection 2\n"
- "2: br 1b\n"
- ".previous"
- :"=&r" (temp), "=m" (sem->count)
- :"Ir" (val), "m" (sem->count));
-#endif
-}
-
-static inline long rwsem_atomic_update(long val, struct rw_semaphore *sem)
-{
-#ifndef CONFIG_SMP
- sem->count += val;
- return sem->count;
-#else
- long ret, temp;
- __asm__ __volatile__(
- "1: ldq_l %0,%1\n"
- " addq %0,%3,%2\n"
- " addq %0,%3,%0\n"
- " stq_c %2,%1\n"
- " beq %2,2f\n"
- ".subsection 2\n"
- "2: br 1b\n"
- ".previous"
- :"=&r" (ret), "=m" (sem->count), "=&r" (temp)
- :"Ir" (val), "m" (sem->count));
-
- return ret;
-#endif
-}
-
#endif /* __KERNEL__ */
#endif /* _ALPHA_RWSEM_H */
diff --git a/arch/ia64/include/asm/rwsem.h b/arch/ia64/include/asm/rwsem.h
index c5d544f..8fa98dd 100644
--- a/arch/ia64/include/asm/rwsem.h
+++ b/arch/ia64/include/asm/rwsem.h
@@ -151,11 +151,4 @@ __downgrade_write (struct rw_semaphore *sem)
rwsem_downgrade_wake(sem);
}

-/*
- * Implement atomic add functionality. These used to be "inline" functions, but GCC v3.1
- * doesn't quite optimize this stuff right and ends up with bad calls to fetchandadd.
- */
-#define rwsem_atomic_add(delta, sem) atomic64_add(delta, (atomic64_t *)(&(sem)->count))
-#define rwsem_atomic_update(delta, sem) atomic64_add_return(delta, (atomic64_t *)(&(sem)->count))
-
#endif /* _ASM_IA64_RWSEM_H */
diff --git a/arch/s390/include/asm/rwsem.h b/arch/s390/include/asm/rwsem.h
index c75e447..597e7e9 100644
--- a/arch/s390/include/asm/rwsem.h
+++ b/arch/s390/include/asm/rwsem.h
@@ -207,41 +207,4 @@ static inline void __downgrade_write(struct rw_semaphore *sem)
rwsem_downgrade_wake(sem);
}

-/*
- * implement atomic add functionality
- */
-static inline void rwsem_atomic_add(long delta, struct rw_semaphore *sem)
-{
- signed long old, new;
-
- asm volatile(
- " lg %0,%2\n"
- "0: lgr %1,%0\n"
- " agr %1,%4\n"
- " csg %0,%1,%2\n"
- " jl 0b"
- : "=&d" (old), "=&d" (new), "=Q" (sem->count)
- : "Q" (sem->count), "d" (delta)
- : "cc", "memory");
-}
-
-/*
- * implement exchange and add functionality
- */
-static inline long rwsem_atomic_update(long delta, struct rw_semaphore *sem)
-{
- signed long old, new;
-
- asm volatile(
- " lg %0,%2\n"
- "0: lgr %1,%0\n"
- " agr %1,%4\n"
- " csg %0,%1,%2\n"
- " jl 0b"
- : "=&d" (old), "=&d" (new), "=Q" (sem->count)
- : "Q" (sem->count), "d" (delta)
- : "cc", "memory");
- return new;
-}
-
#endif /* _S390_RWSEM_H */
diff --git a/arch/x86/include/asm/rwsem.h b/arch/x86/include/asm/rwsem.h
index 453744c..089ced4 100644
--- a/arch/x86/include/asm/rwsem.h
+++ b/arch/x86/include/asm/rwsem.h
@@ -213,23 +213,5 @@ static inline void __downgrade_write(struct rw_semaphore *sem)
: "memory", "cc");
}

-/*
- * implement atomic add functionality
- */
-static inline void rwsem_atomic_add(long delta, struct rw_semaphore *sem)
-{
- asm volatile(LOCK_PREFIX _ASM_ADD "%1,%0"
- : "+m" (sem->count)
- : "er" (delta));
-}
-
-/*
- * implement exchange and add functionality
- */
-static inline long rwsem_atomic_update(long delta, struct rw_semaphore *sem)
-{
- return delta + xadd(&sem->count, delta);
-}
-
#endif /* __KERNEL__ */
#endif /* _ASM_X86_RWSEM_H */
diff --git a/include/asm-generic/rwsem.h b/include/asm-generic/rwsem.h
index a3a93ec..5be122e 100644
--- a/include/asm-generic/rwsem.h
+++ b/include/asm-generic/rwsem.h
@@ -107,14 +107,6 @@ static inline void __up_write(struct rw_semaphore *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)
@@ -134,13 +126,5 @@ static inline void __downgrade_write(struct rw_semaphore *sem)
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_GENERIC_RWSEM_H */
--
2.1.4