#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 __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 */