From e9d90cad7ab8b4009e2cfbf39360bdfeee775743 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Sun, 27 Jan 2008 19:35:00 -0500 Subject: [PATCH] frv: Implement down_killable Signed-off-by: Matthew Wilcox --- arch/frv/kernel/semaphore.c | 51 +++++++++++++++++++++++++++++++++++++++++++ include/asm-frv/semaphore.h | 21 +++++++++++++++++ 2 files changed, 72 insertions(+), 0 deletions(-) diff --git a/arch/frv/kernel/semaphore.c b/arch/frv/kernel/semaphore.c index 7ee3a14..80150e5 100644 --- a/arch/frv/kernel/semaphore.c +++ b/arch/frv/kernel/semaphore.c @@ -124,6 +124,57 @@ int __down_interruptible(struct semaphore *sem, unsigned long flags) EXPORT_SYMBOL(__down_interruptible); +int __down_killable(struct semaphore *sem, unsigned long flags) +{ + struct task_struct *tsk = current; + struct sem_waiter waiter; + int ret; + + semtrace(sem,"Entering __down_killable"); + + /* set up my own style of waitqueue */ + waiter.task = tsk; + get_task_struct(tsk); + + list_add_tail(&waiter.list, &sem->wait_list); + + /* we don't need to touch the semaphore struct anymore */ + set_task_state(tsk, TASK_KILLABLE); + + spin_unlock_irqrestore(&sem->wait_lock, flags); + + /* wait to be given the semaphore */ + ret = 0; + for (;;) { + if (list_empty(&waiter.list)) + break; + if (unlikely(fatal_signal_pending(current))) + goto interrupted; + schedule(); + set_task_state(tsk, TASK_KILLABLE); + } + + out: + tsk->state = TASK_RUNNING; + semtrace(sem, "Leaving __down_killable"); + return ret; + + interrupted: + spin_lock_irqsave(&sem->wait_lock, flags); + + if (!list_empty(&waiter.list)) { + list_del(&waiter.list); + ret = -EINTR; + } + + spin_unlock_irqrestore(&sem->wait_lock, flags); + if (ret == -EINTR) + put_task_struct(current); + goto out; +} + +EXPORT_SYMBOL(__down_killable); + /* * release a single token back to a semaphore * - entered with lock held and interrupts disabled diff --git a/include/asm-frv/semaphore.h b/include/asm-frv/semaphore.h index d7aaa19..559814b 100644 --- a/include/asm-frv/semaphore.h +++ b/include/asm-frv/semaphore.h @@ -67,6 +67,7 @@ static inline void init_MUTEX_LOCKED (struct semaphore *sem) extern void __down(struct semaphore *sem, unsigned long flags); extern int __down_interruptible(struct semaphore *sem, unsigned long flags); +extern int __down_killable(struct semaphore *sem, unsigned long flags); extern void __up(struct semaphore *sem); static inline void down(struct semaphore *sem) @@ -107,6 +108,26 @@ static inline int down_interruptible(struct semaphore *sem) return ret; } +static inline int down_killable(struct semaphore *sem) +{ + unsigned long flags; + int ret = 0; + +#ifdef CONFIG_DEBUG_SEMAPHORE + CHECK_MAGIC(sem->__magic); +#endif + + spin_lock_irqsave(&sem->wait_lock, flags); + if (likely(sem->counter > 0)) { + sem->counter--; + spin_unlock_irqrestore(&sem->wait_lock, flags); + } + else { + ret = __down_killable(sem, flags); + } + return ret; +} + /* * non-blockingly attempt to down() a semaphore. * - returns zero if we acquired it -- 1.5.3.8