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430 lines
12 KiB
430 lines
12 KiB
#ifndef __LINUX_SPINLOCK_H |
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#define __LINUX_SPINLOCK_H |
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/* |
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* include/linux/spinlock.h - generic spinlock/rwlock declarations |
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* |
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* here's the role of the various spinlock/rwlock related include files: |
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* |
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* on SMP builds: |
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* |
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* asm/spinlock_types.h: contains the arch_spinlock_t/arch_rwlock_t and the |
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* initializers |
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* |
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* linux/spinlock_types.h: |
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* defines the generic type and initializers |
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* |
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* asm/spinlock.h: contains the arch_spin_*()/etc. lowlevel |
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* implementations, mostly inline assembly code |
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* |
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* (also included on UP-debug builds:) |
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* |
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* linux/spinlock_api_smp.h: |
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* contains the prototypes for the _spin_*() APIs. |
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* |
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* linux/spinlock.h: builds the final spin_*() APIs. |
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* |
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* on UP builds: |
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* |
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* linux/spinlock_type_up.h: |
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* contains the generic, simplified UP spinlock type. |
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* (which is an empty structure on non-debug builds) |
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* |
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* linux/spinlock_types.h: |
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* defines the generic type and initializers |
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* |
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* linux/spinlock_up.h: |
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* contains the arch_spin_*()/etc. version of UP |
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* builds. (which are NOPs on non-debug, non-preempt |
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* builds) |
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* |
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* (included on UP-non-debug builds:) |
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* |
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* linux/spinlock_api_up.h: |
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* builds the _spin_*() APIs. |
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* |
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* linux/spinlock.h: builds the final spin_*() APIs. |
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*/ |
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#include <linux/typecheck.h> |
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#include <linux/preempt.h> |
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#include <linux/linkage.h> |
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#include <linux/compiler.h> |
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#include <linux/irqflags.h> |
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#include <linux/thread_info.h> |
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#include <linux/kernel.h> |
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#include <linux/stringify.h> |
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#include <linux/bottom_half.h> |
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#include <asm/barrier.h> |
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/* |
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* Must define these before including other files, inline functions need them |
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*/ |
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#define LOCK_SECTION_NAME ".text..lock."KBUILD_BASENAME |
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#define LOCK_SECTION_START(extra) \ |
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".subsection 1\n\t" \ |
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extra \ |
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".ifndef " LOCK_SECTION_NAME "\n\t" \ |
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LOCK_SECTION_NAME ":\n\t" \ |
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".endif\n" |
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#define LOCK_SECTION_END \ |
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".previous\n\t" |
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#define __lockfunc __attribute__((section(".spinlock.text"))) |
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/* |
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* Pull the arch_spinlock_t and arch_rwlock_t definitions: |
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*/ |
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#include <linux/spinlock_types.h> |
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/* |
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* Pull the arch_spin*() functions/declarations (UP-nondebug doesn't need them): |
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*/ |
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#ifdef CONFIG_SMP |
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# include <asm/spinlock.h> |
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#else |
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# include <linux/spinlock_up.h> |
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#endif |
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#ifdef CONFIG_DEBUG_SPINLOCK |
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extern void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name, |
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struct lock_class_key *key); |
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# define raw_spin_lock_init(lock) \ |
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do { \ |
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static struct lock_class_key __key; \ |
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\ |
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__raw_spin_lock_init((lock), #lock, &__key); \ |
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} while (0) |
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#else |
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# define raw_spin_lock_init(lock) \ |
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do { *(lock) = __RAW_SPIN_LOCK_UNLOCKED(lock); } while (0) |
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#endif |
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#define raw_spin_is_locked(lock) arch_spin_is_locked(&(lock)->raw_lock) |
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#ifdef CONFIG_GENERIC_LOCKBREAK |
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#define raw_spin_is_contended(lock) ((lock)->break_lock) |
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#else |
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#ifdef arch_spin_is_contended |
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#define raw_spin_is_contended(lock) arch_spin_is_contended(&(lock)->raw_lock) |
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#else |
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#define raw_spin_is_contended(lock) (((void)(lock), 0)) |
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#endif /*arch_spin_is_contended*/ |
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#endif |
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/* |
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* Despite its name it doesn't necessarily has to be a full barrier. |
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* It should only guarantee that a STORE before the critical section |
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* can not be reordered with LOADs and STOREs inside this section. |
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* spin_lock() is the one-way barrier, this LOAD can not escape out |
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* of the region. So the default implementation simply ensures that |
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* a STORE can not move into the critical section, smp_wmb() should |
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* serialize it with another STORE done by spin_lock(). |
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*/ |
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#ifndef smp_mb__before_spinlock |
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#define smp_mb__before_spinlock() smp_wmb() |
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#endif |
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/** |
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* raw_spin_unlock_wait - wait until the spinlock gets unlocked |
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* @lock: the spinlock in question. |
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*/ |
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#define raw_spin_unlock_wait(lock) arch_spin_unlock_wait(&(lock)->raw_lock) |
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#ifdef CONFIG_DEBUG_SPINLOCK |
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extern void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock); |
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#define do_raw_spin_lock_flags(lock, flags) do_raw_spin_lock(lock) |
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extern int do_raw_spin_trylock(raw_spinlock_t *lock); |
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extern void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock); |
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#else |
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static inline void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock); |
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static inline void do_raw_spin_lock(raw_spinlock_t *lock) |
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{ |
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__acquire(lock); |
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arch_spin_lock(&lock->raw_lock); |
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} |
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static inline void |
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do_raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long *flags) __acquires(lock); |
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static inline void |
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do_raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long *flags) |
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{ |
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__acquire(lock); |
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arch_spin_lock_flags(&lock->raw_lock, *flags); |
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} |
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static inline int do_raw_spin_trylock(raw_spinlock_t *lock) |
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{ |
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return arch_spin_trylock(&(lock)->raw_lock); |
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} |
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static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock); |
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static inline void do_raw_spin_unlock(raw_spinlock_t *lock) |
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{ |
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arch_spin_unlock(&lock->raw_lock); |
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__release(lock); |
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} |
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#endif |
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/* |
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* Define the various spin_lock methods. Note we define these |
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* regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The |
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* various methods are defined as nops in the case they are not |
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* required. |
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*/ |
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#define raw_spin_trylock(lock) __cond_lock(lock, _raw_spin_trylock(lock)) |
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#define raw_spin_lock(lock) _raw_spin_lock(lock) |
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#ifdef CONFIG_DEBUG_LOCK_ALLOC |
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# define raw_spin_lock_nested(lock, subclass) \ |
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_raw_spin_lock_nested(lock, subclass) |
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# define raw_spin_lock_bh_nested(lock, subclass) \ |
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_raw_spin_lock_bh_nested(lock, subclass) |
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# define raw_spin_lock_nest_lock(lock, nest_lock) \ |
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do { \ |
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typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\ |
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_raw_spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \ |
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} while (0) |
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#else |
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/* |
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* Always evaluate the 'subclass' argument to avoid that the compiler |
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* warns about set-but-not-used variables when building with |
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* CONFIG_DEBUG_LOCK_ALLOC=n and with W=1. |
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*/ |
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# define raw_spin_lock_nested(lock, subclass) \ |
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_raw_spin_lock(((void)(subclass), (lock))) |
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# define raw_spin_lock_nest_lock(lock, nest_lock) _raw_spin_lock(lock) |
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# define raw_spin_lock_bh_nested(lock, subclass) _raw_spin_lock_bh(lock) |
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#endif |
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#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) |
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#define raw_spin_lock_irqsave(lock, flags) \ |
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do { \ |
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typecheck(unsigned long, flags); \ |
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flags = _raw_spin_lock_irqsave(lock); \ |
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} while (0) |
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#ifdef CONFIG_DEBUG_LOCK_ALLOC |
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#define raw_spin_lock_irqsave_nested(lock, flags, subclass) \ |
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do { \ |
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typecheck(unsigned long, flags); \ |
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flags = _raw_spin_lock_irqsave_nested(lock, subclass); \ |
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} while (0) |
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#else |
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#define raw_spin_lock_irqsave_nested(lock, flags, subclass) \ |
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do { \ |
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typecheck(unsigned long, flags); \ |
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flags = _raw_spin_lock_irqsave(lock); \ |
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} while (0) |
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#endif |
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#else |
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#define raw_spin_lock_irqsave(lock, flags) \ |
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do { \ |
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typecheck(unsigned long, flags); \ |
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_raw_spin_lock_irqsave(lock, flags); \ |
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} while (0) |
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#define raw_spin_lock_irqsave_nested(lock, flags, subclass) \ |
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raw_spin_lock_irqsave(lock, flags) |
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#endif |
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#define raw_spin_lock_irq(lock) _raw_spin_lock_irq(lock) |
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#define raw_spin_lock_bh(lock) _raw_spin_lock_bh(lock) |
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#define raw_spin_unlock(lock) _raw_spin_unlock(lock) |
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#define raw_spin_unlock_irq(lock) _raw_spin_unlock_irq(lock) |
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#define raw_spin_unlock_irqrestore(lock, flags) \ |
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do { \ |
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typecheck(unsigned long, flags); \ |
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_raw_spin_unlock_irqrestore(lock, flags); \ |
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} while (0) |
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#define raw_spin_unlock_bh(lock) _raw_spin_unlock_bh(lock) |
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#define raw_spin_trylock_bh(lock) \ |
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__cond_lock(lock, _raw_spin_trylock_bh(lock)) |
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#define raw_spin_trylock_irq(lock) \ |
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({ \ |
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local_irq_disable(); \ |
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raw_spin_trylock(lock) ? \ |
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1 : ({ local_irq_enable(); 0; }); \ |
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}) |
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#define raw_spin_trylock_irqsave(lock, flags) \ |
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({ \ |
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local_irq_save(flags); \ |
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raw_spin_trylock(lock) ? \ |
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1 : ({ local_irq_restore(flags); 0; }); \ |
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}) |
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/** |
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* raw_spin_can_lock - would raw_spin_trylock() succeed? |
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* @lock: the spinlock in question. |
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*/ |
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#define raw_spin_can_lock(lock) (!raw_spin_is_locked(lock)) |
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/* Include rwlock functions */ |
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#include <linux/rwlock.h> |
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/* |
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* Pull the _spin_*()/_read_*()/_write_*() functions/declarations: |
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*/ |
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#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) |
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# include <linux/spinlock_api_smp.h> |
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#else |
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# include <linux/spinlock_api_up.h> |
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#endif |
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/* |
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* Map the spin_lock functions to the raw variants for PREEMPT_RT=n |
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*/ |
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static __always_inline raw_spinlock_t *spinlock_check(spinlock_t *lock) |
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{ |
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return &lock->rlock; |
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} |
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#define spin_lock_init(_lock) \ |
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do { \ |
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spinlock_check(_lock); \ |
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raw_spin_lock_init(&(_lock)->rlock); \ |
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} while (0) |
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static __always_inline void spin_lock(spinlock_t *lock) __acquires(lock); |
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static __always_inline void spin_lock(spinlock_t *lock) |
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{ |
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raw_spin_lock(&lock->rlock); |
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} |
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static __always_inline void spin_lock_bh(spinlock_t *lock) __acquires(lock); |
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static __always_inline void spin_lock_bh(spinlock_t *lock) |
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{ |
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raw_spin_lock_bh(&lock->rlock); |
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} |
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static __always_inline int spin_trylock(spinlock_t *lock) |
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{ |
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return raw_spin_trylock(&lock->rlock); |
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} |
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#define spin_lock_nested(lock, subclass) \ |
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do { \ |
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raw_spin_lock_nested(spinlock_check(lock), subclass); \ |
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} while (0) |
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#define spin_lock_bh_nested(lock, subclass) \ |
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do { \ |
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raw_spin_lock_bh_nested(spinlock_check(lock), subclass);\ |
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} while (0) |
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#define spin_lock_nest_lock(lock, nest_lock) \ |
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do { \ |
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raw_spin_lock_nest_lock(spinlock_check(lock), nest_lock); \ |
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} while (0) |
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static __always_inline void spin_lock_irq(spinlock_t *lock) __acquires(lock); |
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static __always_inline void spin_lock_irq(spinlock_t *lock) |
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{ |
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raw_spin_lock_irq(&lock->rlock); |
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} |
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#define spin_lock_irqsave(lock, flags) \ |
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do { \ |
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raw_spin_lock_irqsave(spinlock_check(lock), flags); \ |
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} while (0) |
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#define spin_lock_irqsave_nested(lock, flags, subclass) \ |
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do { \ |
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raw_spin_lock_irqsave_nested(spinlock_check(lock), flags, subclass); \ |
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} while (0) |
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static __always_inline void spin_unlock(spinlock_t *lock) __releases(lock); |
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static __always_inline void spin_unlock(spinlock_t *lock) |
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{ |
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raw_spin_unlock(&lock->rlock); |
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} |
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static __always_inline void spin_unlock_bh(spinlock_t *lock) __releases(lock); |
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static __always_inline void spin_unlock_bh(spinlock_t *lock) |
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{ |
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raw_spin_unlock_bh(&lock->rlock); |
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} |
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static __always_inline void spin_unlock_irq(spinlock_t *lock) __releases(lock); |
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static __always_inline void spin_unlock_irq(spinlock_t *lock) |
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{ |
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raw_spin_unlock_irq(&lock->rlock); |
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} |
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static __always_inline void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags) __releases(lock); |
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static __always_inline void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags) |
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{ |
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raw_spin_unlock_irqrestore(&lock->rlock, flags); |
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} |
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static __always_inline int spin_trylock_bh(spinlock_t *lock) |
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{ |
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return raw_spin_trylock_bh(&lock->rlock); |
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} |
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static __always_inline int spin_trylock_irq(spinlock_t *lock) |
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{ |
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return raw_spin_trylock_irq(&lock->rlock); |
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} |
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#define spin_trylock_irqsave(lock, flags) \ |
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({ \ |
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raw_spin_trylock_irqsave(spinlock_check(lock), flags); \ |
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}) |
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static __always_inline void spin_unlock_wait(spinlock_t *lock) |
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{ |
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raw_spin_unlock_wait(&lock->rlock); |
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} |
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static __always_inline int spin_is_locked(spinlock_t *lock) |
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{ |
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return raw_spin_is_locked(&lock->rlock); |
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} |
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static __always_inline int spin_is_contended(spinlock_t *lock) |
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{ |
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return raw_spin_is_contended(&lock->rlock); |
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} |
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static __always_inline int spin_can_lock(spinlock_t *lock) |
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{ |
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return raw_spin_can_lock(&lock->rlock); |
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} |
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#define assert_spin_locked(lock) assert_raw_spin_locked(&(lock)->rlock) |
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/* |
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* Pull the atomic_t declaration: |
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* (asm-mips/atomic.h needs above definitions) |
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*/ |
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#include <linux/atomic.h> |
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/** |
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* atomic_dec_and_lock - lock on reaching reference count zero |
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* @atomic: the atomic counter |
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* @lock: the spinlock in question |
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* |
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* Decrements @atomic by 1. If the result is 0, returns true and locks |
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* @lock. Returns false for all other cases. |
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*/ |
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extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock); |
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#define atomic_dec_and_lock(atomic, lock) \ |
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__cond_lock(lock, _atomic_dec_and_lock(atomic, lock)) |
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#endif /* __LINUX_SPINLOCK_H */
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