Generic semaphore implementation
Semaphores are no longer performance-critical, so a generic C
implementation is better for maintainability, debuggability and
extensibility. Thanks to Peter Zijlstra for fixing the lockdep
warning. Thanks to Harvey Harrison for pointing out that the
unlikely() was unnecessary.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/asm-sparc/semaphore.h b/include/asm-sparc/semaphore.h
index 8018f9f..d9b2034 100644
--- a/include/asm-sparc/semaphore.h
+++ b/include/asm-sparc/semaphore.h
@@ -1,192 +1 @@
-#ifndef _SPARC_SEMAPHORE_H
-#define _SPARC_SEMAPHORE_H
-
-/* Dinky, good for nothing, just barely irq safe, Sparc semaphores. */
-
-#ifdef __KERNEL__
-
-#include <asm/atomic.h>
-#include <linux/wait.h>
-#include <linux/rwsem.h>
-
-struct semaphore {
- atomic24_t count;
- int sleepers;
- wait_queue_head_t wait;
-};
-
-#define __SEMAPHORE_INITIALIZER(name, n) \
-{ \
- .count = ATOMIC24_INIT(n), \
- .sleepers = 0, \
- .wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
-}
-
-#define __DECLARE_SEMAPHORE_GENERIC(name,count) \
- struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
-
-#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
-
-static inline void sema_init (struct semaphore *sem, int val)
-{
- atomic24_set(&sem->count, val);
- sem->sleepers = 0;
- init_waitqueue_head(&sem->wait);
-}
-
-static inline void init_MUTEX (struct semaphore *sem)
-{
- sema_init(sem, 1);
-}
-
-static inline void init_MUTEX_LOCKED (struct semaphore *sem)
-{
- sema_init(sem, 0);
-}
-
-extern void __down(struct semaphore * sem);
-extern int __down_interruptible(struct semaphore * sem);
-extern int __down_trylock(struct semaphore * sem);
-extern void __up(struct semaphore * sem);
-
-static inline void down(struct semaphore * sem)
-{
- register volatile int *ptr asm("g1");
- register int increment asm("g2");
-
- might_sleep();
-
- ptr = &(sem->count.counter);
- increment = 1;
-
- __asm__ __volatile__(
- "mov %%o7, %%g4\n\t"
- "call ___atomic24_sub\n\t"
- " add %%o7, 8, %%o7\n\t"
- "tst %%g2\n\t"
- "bl 2f\n\t"
- " nop\n"
- "1:\n\t"
- ".subsection 2\n"
- "2:\n\t"
- "save %%sp, -64, %%sp\n\t"
- "mov %%g1, %%l1\n\t"
- "mov %%g5, %%l5\n\t"
- "call %3\n\t"
- " mov %%g1, %%o0\n\t"
- "mov %%l1, %%g1\n\t"
- "ba 1b\n\t"
- " restore %%l5, %%g0, %%g5\n\t"
- ".previous\n"
- : "=&r" (increment)
- : "0" (increment), "r" (ptr), "i" (__down)
- : "g3", "g4", "g7", "memory", "cc");
-}
-
-static inline int down_interruptible(struct semaphore * sem)
-{
- register volatile int *ptr asm("g1");
- register int increment asm("g2");
-
- might_sleep();
-
- ptr = &(sem->count.counter);
- increment = 1;
-
- __asm__ __volatile__(
- "mov %%o7, %%g4\n\t"
- "call ___atomic24_sub\n\t"
- " add %%o7, 8, %%o7\n\t"
- "tst %%g2\n\t"
- "bl 2f\n\t"
- " clr %%g2\n"
- "1:\n\t"
- ".subsection 2\n"
- "2:\n\t"
- "save %%sp, -64, %%sp\n\t"
- "mov %%g1, %%l1\n\t"
- "mov %%g5, %%l5\n\t"
- "call %3\n\t"
- " mov %%g1, %%o0\n\t"
- "mov %%l1, %%g1\n\t"
- "mov %%l5, %%g5\n\t"
- "ba 1b\n\t"
- " restore %%o0, %%g0, %%g2\n\t"
- ".previous\n"
- : "=&r" (increment)
- : "0" (increment), "r" (ptr), "i" (__down_interruptible)
- : "g3", "g4", "g7", "memory", "cc");
-
- return increment;
-}
-
-static inline int down_trylock(struct semaphore * sem)
-{
- register volatile int *ptr asm("g1");
- register int increment asm("g2");
-
- ptr = &(sem->count.counter);
- increment = 1;
-
- __asm__ __volatile__(
- "mov %%o7, %%g4\n\t"
- "call ___atomic24_sub\n\t"
- " add %%o7, 8, %%o7\n\t"
- "tst %%g2\n\t"
- "bl 2f\n\t"
- " clr %%g2\n"
- "1:\n\t"
- ".subsection 2\n"
- "2:\n\t"
- "save %%sp, -64, %%sp\n\t"
- "mov %%g1, %%l1\n\t"
- "mov %%g5, %%l5\n\t"
- "call %3\n\t"
- " mov %%g1, %%o0\n\t"
- "mov %%l1, %%g1\n\t"
- "mov %%l5, %%g5\n\t"
- "ba 1b\n\t"
- " restore %%o0, %%g0, %%g2\n\t"
- ".previous\n"
- : "=&r" (increment)
- : "0" (increment), "r" (ptr), "i" (__down_trylock)
- : "g3", "g4", "g7", "memory", "cc");
-
- return increment;
-}
-
-static inline void up(struct semaphore * sem)
-{
- register volatile int *ptr asm("g1");
- register int increment asm("g2");
-
- ptr = &(sem->count.counter);
- increment = 1;
-
- __asm__ __volatile__(
- "mov %%o7, %%g4\n\t"
- "call ___atomic24_add\n\t"
- " add %%o7, 8, %%o7\n\t"
- "tst %%g2\n\t"
- "ble 2f\n\t"
- " nop\n"
- "1:\n\t"
- ".subsection 2\n"
- "2:\n\t"
- "save %%sp, -64, %%sp\n\t"
- "mov %%g1, %%l1\n\t"
- "mov %%g5, %%l5\n\t"
- "call %3\n\t"
- " mov %%g1, %%o0\n\t"
- "mov %%l1, %%g1\n\t"
- "ba 1b\n\t"
- " restore %%l5, %%g0, %%g5\n\t"
- ".previous\n"
- : "=&r" (increment)
- : "0" (increment), "r" (ptr), "i" (__up)
- : "g3", "g4", "g7", "memory", "cc");
-}
-
-#endif /* __KERNEL__ */
-
-#endif /* !(_SPARC_SEMAPHORE_H) */
+#include <linux/semaphore.h>