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Diffstat (limited to 'include/asm-m32r/semaphore.h')
| -rw-r--r-- | include/asm-m32r/semaphore.h | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/include/asm-m32r/semaphore.h b/include/asm-m32r/semaphore.h new file mode 100644 index 000000000000..53e3c60f21ec --- /dev/null +++ b/include/asm-m32r/semaphore.h @@ -0,0 +1,205 @@ +#ifndef _ASM_M32R_SEMAPHORE_H +#define _ASM_M32R_SEMAPHORE_H + +#include <linux/linkage.h> + +#ifdef __KERNEL__ + +/* + * SMP- and interrupt-safe semaphores.. + * + * Copyright (C) 1996 Linus Torvalds + * Copyright (C) 2004 Hirokazu Takata <takata at linux-m32r.org> + */ + +#include <linux/config.h> +#include <linux/wait.h> +#include <linux/rwsem.h> +#include <asm/assembler.h> +#include <asm/system.h> +#include <asm/atomic.h> + +struct semaphore { + atomic_t count; + int sleepers; + wait_queue_head_t wait; +}; + +#define __SEMAPHORE_INITIALIZER(name, n) \ +{ \ + .count = ATOMIC_INIT(n), \ + .sleepers = 0, \ + .wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \ +} + +#define __MUTEX_INITIALIZER(name) \ + __SEMAPHORE_INITIALIZER(name,1) + +#define __DECLARE_SEMAPHORE_GENERIC(name,count) \ + struct semaphore name = __SEMAPHORE_INITIALIZER(name,count) + +#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1) +#define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0) + +static inline void sema_init (struct semaphore *sem, int val) +{ +/* + * *sem = (struct semaphore)__SEMAPHORE_INITIALIZER((*sem),val); + * + * i'd rather use the more flexible initialization above, but sadly + * GCC 2.7.2.3 emits a bogus warning. EGCS doesnt. Oh well. + */ + atomic_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); +} + +asmlinkage void __down_failed(void /* special register calling convention */); +asmlinkage int __down_failed_interruptible(void /* params in registers */); +asmlinkage int __down_failed_trylock(void /* params in registers */); +asmlinkage void __up_wakeup(void /* special register calling convention */); + +asmlinkage void __down(struct semaphore * sem); +asmlinkage int __down_interruptible(struct semaphore * sem); +asmlinkage int __down_trylock(struct semaphore * sem); +asmlinkage void __up(struct semaphore * sem); + +/* + * Atomically decrement the semaphore's count. If it goes negative, + * block the calling thread in the TASK_UNINTERRUPTIBLE state. + */ +static inline void down(struct semaphore * sem) +{ + unsigned long flags; + long count; + + might_sleep(); + local_irq_save(flags); + __asm__ __volatile__ ( + "# down \n\t" + DCACHE_CLEAR("%0", "r4", "%1") + M32R_LOCK" %0, @%1; \n\t" + "addi %0, #-1; \n\t" + M32R_UNLOCK" %0, @%1; \n\t" + : "=&r" (count) + : "r" (&sem->count) + : "memory" +#ifdef CONFIG_CHIP_M32700_TS1 + , "r4" +#endif /* CONFIG_CHIP_M32700_TS1 */ + ); + local_irq_restore(flags); + + if (unlikely(count < 0)) + __down(sem); +} + +/* + * Interruptible try to acquire a semaphore. If we obtained + * it, return zero. If we were interrupted, returns -EINTR + */ +static inline int down_interruptible(struct semaphore * sem) +{ + unsigned long flags; + long count; + int result = 0; + + might_sleep(); + local_irq_save(flags); + __asm__ __volatile__ ( + "# down_interruptible \n\t" + DCACHE_CLEAR("%0", "r4", "%1") + M32R_LOCK" %0, @%1; \n\t" + "addi %0, #-1; \n\t" + M32R_UNLOCK" %0, @%1; \n\t" + : "=&r" (count) + : "r" (&sem->count) + : "memory" +#ifdef CONFIG_CHIP_M32700_TS1 + , "r4" +#endif /* CONFIG_CHIP_M32700_TS1 */ + ); + local_irq_restore(flags); + + if (unlikely(count < 0)) + result = __down_interruptible(sem); + + return result; +} + +/* + * Non-blockingly attempt to down() a semaphore. + * Returns zero if we acquired it + */ +static inline int down_trylock(struct semaphore * sem) +{ + unsigned long flags; + long count; + int result = 0; + + local_irq_save(flags); + __asm__ __volatile__ ( + "# down_trylock \n\t" + DCACHE_CLEAR("%0", "r4", "%1") + M32R_LOCK" %0, @%1; \n\t" + "addi %0, #-1; \n\t" + M32R_UNLOCK" %0, @%1; \n\t" + : "=&r" (count) + : "r" (&sem->count) + : "memory" +#ifdef CONFIG_CHIP_M32700_TS1 + , "r4" +#endif /* CONFIG_CHIP_M32700_TS1 */ + ); + local_irq_restore(flags); + + if (unlikely(count < 0)) + result = __down_trylock(sem); + + return result; +} + +/* + * Note! This is subtle. We jump to wake people up only if + * the semaphore was negative (== somebody was waiting on it). + * The default case (no contention) will result in NO + * jumps for both down() and up(). + */ +static inline void up(struct semaphore * sem) +{ + unsigned long flags; + long count; + + local_irq_save(flags); + __asm__ __volatile__ ( + "# up \n\t" + DCACHE_CLEAR("%0", "r4", "%1") + M32R_LOCK" %0, @%1; \n\t" + "addi %0, #1; \n\t" + M32R_UNLOCK" %0, @%1; \n\t" + : "=&r" (count) + : "r" (&sem->count) + : "memory" +#ifdef CONFIG_CHIP_M32700_TS1 + , "r4" +#endif /* CONFIG_CHIP_M32700_TS1 */ + ); + local_irq_restore(flags); + + if (unlikely(count <= 0)) + __up(sem); +} + +#endif /* __KERNEL__ */ + +#endif /* _ASM_M32R_SEMAPHORE_H */ |