From 64ac24e738823161693bf791f87adc802cf529ff Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Fri, 7 Mar 2008 21:55:58 -0500 Subject: 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 Acked-by: Ingo Molnar --- include/asm-sparc/semaphore.h | 193 +----------------------------------------- 1 file changed, 1 insertion(+), 192 deletions(-) (limited to 'include/asm-sparc') diff --git a/include/asm-sparc/semaphore.h b/include/asm-sparc/semaphore.h index 8018f9f4d497..d9b2034ed1d2 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 -#include -#include - -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 -- cgit v1.2.3