Commit 620de546 authored by David S. Miller's avatar David S. Miller

[SPARC64]: Simplify asm/rwsem.h slightly.

rwsem_atomic_update and rwsem_atomic_add can be implemented
straightly using atomic_*() routines.

Also, rwsem_cmpxchgw() is totally unused, kill it.
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6593eaed
...@@ -46,54 +46,14 @@ extern void __up_read(struct rw_semaphore *sem); ...@@ -46,54 +46,14 @@ extern void __up_read(struct rw_semaphore *sem);
extern void __up_write(struct rw_semaphore *sem); extern void __up_write(struct rw_semaphore *sem);
extern void __downgrade_write(struct rw_semaphore *sem); extern void __downgrade_write(struct rw_semaphore *sem);
static __inline__ int rwsem_atomic_update(int delta, struct rw_semaphore *sem) static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem)
{ {
int tmp = delta; return atomic_add_return(delta, (atomic_t *)(&sem->count));
__asm__ __volatile__(
"1:\tlduw [%2], %%g1\n\t"
"add %%g1, %1, %%g7\n\t"
"cas [%2], %%g1, %%g7\n\t"
"cmp %%g1, %%g7\n\t"
"membar #StoreLoad | #StoreStore\n\t"
"bne,pn %%icc, 1b\n\t"
" nop\n\t"
"mov %%g7, %0\n\t"
: "=&r" (tmp)
: "0" (tmp), "r" (sem)
: "g1", "g7", "memory", "cc");
return tmp + delta;
}
#define rwsem_atomic_add rwsem_atomic_update
static __inline__ __u16 rwsem_cmpxchgw(struct rw_semaphore *sem, __u16 __old, __u16 __new)
{
u32 old = (sem->count & 0xffff0000) | (u32) __old;
u32 new = (old & 0xffff0000) | (u32) __new;
u32 prev;
again:
__asm__ __volatile__("cas [%2], %3, %0\n\t"
"membar #StoreLoad | #StoreStore"
: "=&r" (prev)
: "0" (new), "r" (sem), "r" (old)
: "memory");
/* To give the same semantics as x86 cmpxchgw, keep trying
* if only the upper 16-bits changed.
*/
if (prev != old &&
((prev & 0xffff) == (old & 0xffff)))
goto again;
return prev & 0xffff;
} }
static __inline__ signed long rwsem_cmpxchg(struct rw_semaphore *sem, signed long old, signed long new) static inline void rwsem_atomic_add(int delta, struct rw_semaphore *sem)
{ {
return cmpxchg(&sem->count,old,new); atomic_add(delta, (atomic_t *)(&sem->count));
} }
#endif /* __KERNEL__ */ #endif /* __KERNEL__ */
......
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