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#ifndef __ASM_SPINLOCK_H
#define __ASM_SPINLOCK_H
#ifndef __SMP__
/*
* Your basic spinlocks, allowing only a single CPU anywhere
*
* Gcc-2.7.x has a nasty bug with empty initializers.
*/
#if (__GNUC__ > 2) || (__GNUC__ == 2 && __GNUC_MINOR__ >= 8)
typedef struct { } spinlock_t;
#define SPIN_LOCK_UNLOCKED (spinlock_t) { }
#else
typedef struct { int gcc_is_buggy; } spinlock_t;
#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 }
#endif
#define spin_lock_init(lock) do { } while(0)
#define spin_lock(lock) do { } while(0)
#define spin_trylock(lock) do { } while(0)
#define spin_unlock_wait(lock) do { } while(0)
#define spin_unlock(lock) do { } while(0)
#define spin_lock_irq(lock) cli()
#define spin_unlock_irq(lock) sti()
#define spin_lock_irqsave(lock, flags) \
do { save_flags(flags); cli(); } while (0)
#define spin_unlock_irqrestore(lock, flags) \
restore_flags(flags)
/*
* Read-write spinlocks, allowing multiple readers
* but only one writer.
*
* NOTE! it is quite common to have readers in interrupts
* but no interrupt writers. For those circumstances we
* can "mix" irq-safe locks - any writer needs to get a
* irq-safe write-lock, but readers can get non-irqsafe
* read-locks.
*
* Gcc-2.7.x has a nasty bug with empty initializers.
*/
#if (__GNUC__ > 2) || (__GNUC__ == 2 && __GNUC_MINOR__ >= 8)
typedef struct { } rwlock_t;
#define RW_LOCK_UNLOCKED (rwlock_t) { }
#else
typedef struct { int gcc_is_buggy; } rwlock_t;
#define RW_LOCK_UNLOCKED (rwlock_t) { 0 }
#endif
#define read_lock(lock) do { } while(0)
#define read_unlock(lock) do { } while(0)
#define write_lock(lock) do { } while(0)
#define write_unlock(lock) do { } while(0)
#define read_lock_irq(lock) cli()
#define read_unlock_irq(lock) sti()
#define write_lock_irq(lock) cli()
#define write_unlock_irq(lock) sti()
#define read_lock_irqsave(lock, flags) \
do { save_flags(flags); cli(); } while (0)
#define read_unlock_irqrestore(lock, flags) \
restore_flags(flags)
#define write_lock_irqsave(lock, flags) \
do { save_flags(flags); cli(); } while (0)
#define write_unlock_irqrestore(lock, flags) \
restore_flags(flags)
#else /* __SMP__ */
/* Simple spin lock operations. There are two variants, one clears IRQ's
* on the local processor, one does not.
*
* We make no fairness assumptions. They have a cost.
*/
typedef struct {
volatile unsigned long lock;
volatile unsigned long owner_pc;
volatile unsigned long owner_cpu;
} spinlock_t;
#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0, 0, 0 }
#define spin_lock_init(lp) do { (lp)->lock = 0; } while(0)
#define spin_unlock_wait(lp) do { barrier(); } while((lp)->lock)
extern void _spin_lock(spinlock_t *lock);
extern void _spin_unlock(spinlock_t *lock);
extern int spin_trylock(spinlock_t *lock);
#define spin_lock(lp) _spin_lock(lp)
#define spin_unlock(lp) _spin_unlock(lp)
#define spin_lock_irq(lock) \
do { __cli(); spin_lock(lock); } while (0)
#define spin_unlock_irq(lock) \
do { spin_unlock(lock); __sti(); } while (0)
#define spin_lock_irqsave(lock, flags) \
do { __save_flags(flags); __cli(); spin_lock(lock); } while (0)
#define spin_unlock_irqrestore(lock, flags) \
do { spin_unlock(lock); __restore_flags(flags); } while (0)
/*
* Read-write spinlocks, allowing multiple readers
* but only one writer.
*
* NOTE! it is quite common to have readers in interrupts
* but no interrupt writers. For those circumstances we
* can "mix" irq-safe locks - any writer needs to get a
* irq-safe write-lock, but readers can get non-irqsafe
* read-locks.
*/
typedef struct {
volatile unsigned long lock;
volatile unsigned long owner_pc;
} rwlock_t;
#define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0 }
extern void _read_lock(rwlock_t *rw);
extern void _read_unlock(rwlock_t *rw);
extern void _write_lock(rwlock_t *rw);
extern void _write_unlock(rwlock_t *rw);
#define read_lock(rw) _read_lock(rw)
#define write_lock(rw) _write_lock(rw)
#define write_unlock(rw) _write_unlock(rw)
#define read_unlock(rw) _read_unlock(rw)
#define read_lock_irq(lock) do { __cli(); read_lock(lock); } while (0)
#define read_unlock_irq(lock) do { read_unlock(lock); __sti(); } while (0)
#define write_lock_irq(lock) do { __cli(); write_lock(lock); } while (0)
#define write_unlock_irq(lock) do { write_unlock(lock); __sti(); } while (0)
#define read_lock_irqsave(lock, flags) \
do { __save_flags(flags); __cli(); read_lock(lock); } while (0)
#define read_unlock_irqrestore(lock, flags) \
do { read_unlock(lock); __restore_flags(flags); } while (0)
#define write_lock_irqsave(lock, flags) \
do { __save_flags(flags); __cli(); write_lock(lock); } while (0)
#define write_unlock_irqrestore(lock, flags) \
do { write_unlock(lock); __restore_flags(flags); } while (0)
#endif /* SMP */
#endif /* __ASM_SPINLOCK_H */
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