diff options
Diffstat (limited to 'include/linux/local_lock_internal.h')
| -rw-r--r-- | include/linux/local_lock_internal.h | 125 |
1 files changed, 119 insertions, 6 deletions
diff --git a/include/linux/local_lock_internal.h b/include/linux/local_lock_internal.h index 8dd71fbbb6d2..8d5ac16a9b17 100644 --- a/include/linux/local_lock_internal.h +++ b/include/linux/local_lock_internal.h @@ -15,6 +15,12 @@ typedef struct { #endif } local_lock_t; +/* local_trylock() and local_trylock_irqsave() only work with local_trylock_t */ +typedef struct { + local_lock_t llock; + u8 acquired; +} local_trylock_t; + #ifdef CONFIG_DEBUG_LOCK_ALLOC # define LOCAL_LOCK_DEBUG_INIT(lockname) \ .dep_map = { \ @@ -24,6 +30,9 @@ typedef struct { }, \ .owner = NULL, +# define LOCAL_TRYLOCK_DEBUG_INIT(lockname) \ + .llock = { LOCAL_LOCK_DEBUG_INIT((lockname).llock) }, + static inline void local_lock_acquire(local_lock_t *l) { lock_map_acquire(&l->dep_map); @@ -31,6 +40,13 @@ static inline void local_lock_acquire(local_lock_t *l) l->owner = current; } +static inline void local_trylock_acquire(local_lock_t *l) +{ + lock_map_acquire_try(&l->dep_map); + DEBUG_LOCKS_WARN_ON(l->owner); + l->owner = current; +} + static inline void local_lock_release(local_lock_t *l) { DEBUG_LOCKS_WARN_ON(l->owner != current); @@ -44,12 +60,15 @@ static inline void local_lock_debug_init(local_lock_t *l) } #else /* CONFIG_DEBUG_LOCK_ALLOC */ # define LOCAL_LOCK_DEBUG_INIT(lockname) +# define LOCAL_TRYLOCK_DEBUG_INIT(lockname) static inline void local_lock_acquire(local_lock_t *l) { } +static inline void local_trylock_acquire(local_lock_t *l) { } static inline void local_lock_release(local_lock_t *l) { } static inline void local_lock_debug_init(local_lock_t *l) { } #endif /* !CONFIG_DEBUG_LOCK_ALLOC */ #define INIT_LOCAL_LOCK(lockname) { LOCAL_LOCK_DEBUG_INIT(lockname) } +#define INIT_LOCAL_TRYLOCK(lockname) { LOCAL_TRYLOCK_DEBUG_INIT(lockname) } #define __local_lock_init(lock) \ do { \ @@ -62,6 +81,8 @@ do { \ local_lock_debug_init(lock); \ } while (0) +#define __local_trylock_init(lock) __local_lock_init(lock.llock) + #define __spinlock_nested_bh_init(lock) \ do { \ static struct lock_class_key __key; \ @@ -73,39 +94,105 @@ do { \ local_lock_debug_init(lock); \ } while (0) +#define __local_lock_acquire(lock) \ + do { \ + local_trylock_t *tl; \ + local_lock_t *l; \ + \ + l = (local_lock_t *)this_cpu_ptr(lock); \ + tl = (local_trylock_t *)l; \ + _Generic((lock), \ + __percpu local_trylock_t *: ({ \ + lockdep_assert(tl->acquired == 0); \ + WRITE_ONCE(tl->acquired, 1); \ + }), \ + __percpu local_lock_t *: (void)0); \ + local_lock_acquire(l); \ + } while (0) + #define __local_lock(lock) \ do { \ preempt_disable(); \ - local_lock_acquire(this_cpu_ptr(lock)); \ + __local_lock_acquire(lock); \ } while (0) #define __local_lock_irq(lock) \ do { \ local_irq_disable(); \ - local_lock_acquire(this_cpu_ptr(lock)); \ + __local_lock_acquire(lock); \ } while (0) #define __local_lock_irqsave(lock, flags) \ do { \ local_irq_save(flags); \ - local_lock_acquire(this_cpu_ptr(lock)); \ + __local_lock_acquire(lock); \ + } while (0) + +#define __local_trylock(lock) \ + ({ \ + local_trylock_t *tl; \ + \ + preempt_disable(); \ + tl = this_cpu_ptr(lock); \ + if (READ_ONCE(tl->acquired)) { \ + preempt_enable(); \ + tl = NULL; \ + } else { \ + WRITE_ONCE(tl->acquired, 1); \ + local_trylock_acquire( \ + (local_lock_t *)tl); \ + } \ + !!tl; \ + }) + +#define __local_trylock_irqsave(lock, flags) \ + ({ \ + local_trylock_t *tl; \ + \ + local_irq_save(flags); \ + tl = this_cpu_ptr(lock); \ + if (READ_ONCE(tl->acquired)) { \ + local_irq_restore(flags); \ + tl = NULL; \ + } else { \ + WRITE_ONCE(tl->acquired, 1); \ + local_trylock_acquire( \ + (local_lock_t *)tl); \ + } \ + !!tl; \ + }) + +#define __local_lock_release(lock) \ + do { \ + local_trylock_t *tl; \ + local_lock_t *l; \ + \ + l = (local_lock_t *)this_cpu_ptr(lock); \ + tl = (local_trylock_t *)l; \ + local_lock_release(l); \ + _Generic((lock), \ + __percpu local_trylock_t *: ({ \ + lockdep_assert(tl->acquired == 1); \ + WRITE_ONCE(tl->acquired, 0); \ + }), \ + __percpu local_lock_t *: (void)0); \ } while (0) #define __local_unlock(lock) \ do { \ - local_lock_release(this_cpu_ptr(lock)); \ + __local_lock_release(lock); \ preempt_enable(); \ } while (0) #define __local_unlock_irq(lock) \ do { \ - local_lock_release(this_cpu_ptr(lock)); \ + __local_lock_release(lock); \ local_irq_enable(); \ } while (0) #define __local_unlock_irqrestore(lock, flags) \ do { \ - local_lock_release(this_cpu_ptr(lock)); \ + __local_lock_release(lock); \ local_irq_restore(flags); \ } while (0) @@ -125,14 +212,18 @@ do { \ * critical section while staying preemptible. */ typedef spinlock_t local_lock_t; +typedef spinlock_t local_trylock_t; #define INIT_LOCAL_LOCK(lockname) __LOCAL_SPIN_LOCK_UNLOCKED((lockname)) +#define INIT_LOCAL_TRYLOCK(lockname) __LOCAL_SPIN_LOCK_UNLOCKED((lockname)) #define __local_lock_init(l) \ do { \ local_spin_lock_init((l)); \ } while (0) +#define __local_trylock_init(l) __local_lock_init(l) + #define __local_lock(__lock) \ do { \ migrate_disable(); \ @@ -169,4 +260,26 @@ do { \ spin_unlock(this_cpu_ptr((lock))); \ } while (0) +#define __local_trylock(lock) \ + ({ \ + int __locked; \ + \ + if (in_nmi() | in_hardirq()) { \ + __locked = 0; \ + } else { \ + migrate_disable(); \ + __locked = spin_trylock(this_cpu_ptr((lock))); \ + if (!__locked) \ + migrate_enable(); \ + } \ + __locked; \ + }) + +#define __local_trylock_irqsave(lock, flags) \ + ({ \ + typecheck(unsigned long, flags); \ + flags = 0; \ + __local_trylock(lock); \ + }) + #endif /* CONFIG_PREEMPT_RT */ |