From 1270b2ca8f57b70ce6a000a3165b5b5e5d7fe112 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Sun, 27 Jan 2008 23:00:04 -0500 Subject: [PATCH] v850: Implement down_killable Signed-off-by: Matthew Wilcox --- arch/v850/kernel/semaphore.c | 51 +++++++++++++++++++++++++++++++++++++++++ arch/v850/kernel/v850_ksyms.c | 1 + include/asm-v850/semaphore.h | 11 +++++++++ 3 files changed, 63 insertions(+), 0 deletions(-) diff --git a/arch/v850/kernel/semaphore.c b/arch/v850/kernel/semaphore.c index fc89fd6..d72a39e 100644 --- a/arch/v850/kernel/semaphore.c +++ b/arch/v850/kernel/semaphore.c @@ -141,6 +141,57 @@ int __sched __down_interruptible(struct semaphore * sem) return retval; } +int __sched __down_killable(struct semaphore * sem) +{ + int retval = 0; + struct task_struct *tsk = current; + DECLARE_WAITQUEUE(wait, tsk); + tsk->state = TASK_KILLABLE; + add_wait_queue_exclusive(&sem->wait, &wait); + + spin_lock_irq(&semaphore_lock); + sem->sleepers ++; + for (;;) { + int sleepers = sem->sleepers; + + /* + * With signals pending, this turns into + * the trylock failure case - we won't be + * sleeping, and we* can't get the lock as + * it has contention. Just correct the count + * and exit. + */ + if (fatal_signal_pending(current)) { + retval = -EINTR; + sem->sleepers = 0; + atomic_add(sleepers, &sem->count); + break; + } + + /* + * Add "everybody else" into it. They aren't + * playing, because we own the spinlock. The + * "-1" is because we're still hoping to get + * the lock. + */ + if (!atomic_add_negative(sleepers - 1, &sem->count)) { + sem->sleepers = 0; + break; + } + sem->sleepers = 1; /* us - see -1 above */ + spin_unlock_irq(&semaphore_lock); + + schedule(); + tsk->state = TASK_KILLABLE; + spin_lock_irq(&semaphore_lock); + } + spin_unlock_irq(&semaphore_lock); + tsk->state = TASK_RUNNING; + remove_wait_queue(&sem->wait, &wait); + wake_up(&sem->wait); + return retval; +} + /* * Trylock failed - make sure we correct for * having decremented the count. diff --git a/arch/v850/kernel/v850_ksyms.c b/arch/v850/kernel/v850_ksyms.c index 93575fd..31de366 100644 --- a/arch/v850/kernel/v850_ksyms.c +++ b/arch/v850/kernel/v850_ksyms.c @@ -37,6 +37,7 @@ EXPORT_SYMBOL (memmove); /* semaphores */ EXPORT_SYMBOL (__down); EXPORT_SYMBOL (__down_interruptible); +EXPORT_SYMBOL (__down_killable); EXPORT_SYMBOL (__down_trylock); EXPORT_SYMBOL (__up); diff --git a/include/asm-v850/semaphore.h b/include/asm-v850/semaphore.h index 10ed0cc..5804fb8 100644 --- a/include/asm-v850/semaphore.h +++ b/include/asm-v850/semaphore.h @@ -43,11 +43,13 @@ static inline void init_MUTEX_LOCKED (struct semaphore *sem) */ asmlinkage void __down_failed (void); asmlinkage int __down_interruptible_failed (void); +asmlinkage int __down_killable_failed (void); asmlinkage int __down_trylock_failed (void); asmlinkage void __up_wakeup (void); extern void __down (struct semaphore * sem); extern int __down_interruptible (struct semaphore * sem); +extern int __down_killable (struct semaphore * sem); extern int __down_trylock (struct semaphore * sem); extern void __up (struct semaphore * sem); @@ -67,6 +69,15 @@ static inline int down_interruptible (struct semaphore * sem) return ret; } +static inline int down_killable (struct semaphore * sem) +{ + int ret = 0; + might_sleep(); + if (atomic_dec_return (&sem->count) < 0) + ret = __down_killable (sem); + return ret; +} + static inline int down_trylock (struct semaphore *sem) { int ret = 0; -- 1.5.3.8