From bc43d6cff8c7d0f1490ed892363419a3ae3f0daa Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Sun, 27 Jan 2008 23:02:14 -0500 Subject: [PATCH] xtensa: Implement down_killable Signed-off-by: Matthew Wilcox --- arch/xtensa/kernel/semaphore.c | 37 +++++++++++++++++++++++++++++++++++++ arch/xtensa/kernel/xtensa_ksyms.c | 1 + include/asm-xtensa/semaphore.h | 12 ++++++++++++ 3 files changed, 50 insertions(+), 0 deletions(-) diff --git a/arch/xtensa/kernel/semaphore.c b/arch/xtensa/kernel/semaphore.c index 995c641..a1667e7 100644 --- a/arch/xtensa/kernel/semaphore.c +++ b/arch/xtensa/kernel/semaphore.c @@ -74,6 +74,24 @@ static __inline__ int waking_non_zero_interruptible(struct semaphore *sem, return ret; } +static __inline__ int waking_non_zero_killable(struct semaphore *sem, + struct task_struct *tsk) +{ + unsigned long flags; + int ret = 0; + + spin_lock_irqsave(&semaphore_wake_lock, flags); + if (sem->sleepers > 0) { + sem->sleepers--; + ret = 1; + } else if (fatal_signal_pending(tsk)) { + atomic_inc(&sem->count); + ret = -EINTR; + } + spin_unlock_irqrestore(&semaphore_wake_lock, flags); + return ret; +} + /* * waking_non_zero_trylock: * 1 failed to lock @@ -220,6 +238,25 @@ int __sched __down_interruptible(struct semaphore * sem) return ret; } +int __sched __down_killable(struct semaphore * sem) +{ + int ret = 0; + DOWN_VAR + DOWN_HEAD(TASK_KILLABLE) + + ret = waking_non_zero_killable(sem, tsk); + if (ret) + { + if (ret == 1) + /* ret != 0 only if we get interrupted -arca */ + ret = 0; + break; + } + schedule(); + DOWN_TAIL(TASK_KILLABLE) + return ret; +} + int __down_trylock(struct semaphore * sem) { return waking_non_zero_trylock(sem); diff --git a/arch/xtensa/kernel/xtensa_ksyms.c b/arch/xtensa/kernel/xtensa_ksyms.c index 60dbdb4..815b4a0 100644 --- a/arch/xtensa/kernel/xtensa_ksyms.c +++ b/arch/xtensa/kernel/xtensa_ksyms.c @@ -76,6 +76,7 @@ EXPORT_SYMBOL(__umoddi3); */ EXPORT_SYMBOL(__down); EXPORT_SYMBOL(__down_interruptible); +EXPORT_SYMBOL(__down_killable); EXPORT_SYMBOL(__down_trylock); EXPORT_SYMBOL(__up); diff --git a/include/asm-xtensa/semaphore.h b/include/asm-xtensa/semaphore.h index 3e04167..ebd52e4 100644 --- a/include/asm-xtensa/semaphore.h +++ b/include/asm-xtensa/semaphore.h @@ -53,6 +53,7 @@ static inline void init_MUTEX_LOCKED (struct semaphore *sem) asmlinkage void __down(struct semaphore * sem); asmlinkage int __down_interruptible(struct semaphore * sem); +asmlinkage int __down_killable(struct semaphore * sem); asmlinkage int __down_trylock(struct semaphore * sem); asmlinkage void __up(struct semaphore * sem); @@ -77,6 +78,17 @@ 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_sub_return(1, &sem->count) < 0) + ret = __down_killable(sem); + return ret; +} + static inline int down_trylock(struct semaphore * sem) { int ret = 0; -- 1.5.3.8