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locking: Implement new raw_spinlock
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Now that the raw_spin name space is freed up, we can implement
raw_spinlock and the related functions which are used to annotate the
locks which are not converted to sleeping spinlocks in preempt-rt.

A side effect is that only such locks can be used with the low level
lock fsunctions which circumvent lockdep.

For !rt spin_* functions are mapped to the raw_spin* implementations.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
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Thomas Gleixner committed Dec 14, 2009
1 parent e593194 commit c2f21ce
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Showing 8 changed files with 297 additions and 135 deletions.
258 changes: 194 additions & 64 deletions include/linux/spinlock.h
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Original file line number Diff line number Diff line change
Expand Up @@ -80,7 +80,7 @@
#include <linux/spinlock_types.h>

/*
* Pull the __raw*() functions/declarations (UP-nondebug doesnt need them):
* Pull the arch_spin*() functions/declarations (UP-nondebug doesnt need them):
*/
#ifdef CONFIG_SMP
# include <asm/spinlock.h>
Expand All @@ -89,30 +89,30 @@
#endif

#ifdef CONFIG_DEBUG_SPINLOCK
extern void __spin_lock_init(spinlock_t *lock, const char *name,
struct lock_class_key *key);
# define spin_lock_init(lock) \
extern void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name,
struct lock_class_key *key);
# define raw_spin_lock_init(lock) \
do { \
static struct lock_class_key __key; \
\
__spin_lock_init((lock), #lock, &__key); \
__raw_spin_lock_init((lock), #lock, &__key); \
} while (0)

#else
# define spin_lock_init(lock) \
do { *(lock) = __SPIN_LOCK_UNLOCKED(lock); } while (0)
# define raw_spin_lock_init(lock) \
do { *(lock) = __RAW_SPIN_LOCK_UNLOCKED(lock); } while (0)
#endif

#define spin_is_locked(lock) arch_spin_is_locked(&(lock)->raw_lock)
#define raw_spin_is_locked(lock) arch_spin_is_locked(&(lock)->raw_lock)

#ifdef CONFIG_GENERIC_LOCKBREAK
#define spin_is_contended(lock) ((lock)->break_lock)
#define raw_spin_is_contended(lock) ((lock)->break_lock)
#else

#ifdef arch_spin_is_contended
#define spin_is_contended(lock) arch_spin_is_contended(&(lock)->raw_lock)
#define raw_spin_is_contended(lock) arch_spin_is_contended(&(lock)->raw_lock)
#else
#define spin_is_contended(lock) (((void)(lock), 0))
#define raw_spin_is_contended(lock) (((void)(lock), 0))
#endif /*arch_spin_is_contended*/
#endif

Expand All @@ -122,22 +122,37 @@ static inline void smp_mb__after_lock(void) { smp_mb(); }
#endif

/**
* spin_unlock_wait - wait until the spinlock gets unlocked
* raw_spin_unlock_wait - wait until the spinlock gets unlocked
* @lock: the spinlock in question.
*/
#define spin_unlock_wait(lock) arch_spin_unlock_wait(&(lock)->raw_lock)
#define raw_spin_unlock_wait(lock) arch_spin_unlock_wait(&(lock)->raw_lock)

#ifdef CONFIG_DEBUG_SPINLOCK
extern void _raw_spin_lock(spinlock_t *lock);
extern void _raw_spin_lock(raw_spinlock_t *lock);
#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
extern int _raw_spin_trylock(spinlock_t *lock);
extern void _raw_spin_unlock(spinlock_t *lock);
extern int _raw_spin_trylock(raw_spinlock_t *lock);
extern void _raw_spin_unlock(raw_spinlock_t *lock);
#else
# define _raw_spin_lock(lock) arch_spin_lock(&(lock)->raw_lock)
# define _raw_spin_lock_flags(lock, flags) \
arch_spin_lock_flags(&(lock)->raw_lock, *(flags))
# define _raw_spin_trylock(lock) arch_spin_trylock(&(lock)->raw_lock)
# define _raw_spin_unlock(lock) arch_spin_unlock(&(lock)->raw_lock)
static inline void _raw_spin_lock(raw_spinlock_t *lock)
{
arch_spin_lock(&lock->raw_lock);
}

static inline void
_raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long *flags)
{
arch_spin_lock_flags(&lock->raw_lock, *flags);
}

static inline int _raw_spin_trylock(raw_spinlock_t *lock)
{
return arch_spin_trylock(&(lock)->raw_lock);
}

static inline void _raw_spin_unlock(raw_spinlock_t *lock)
{
arch_spin_unlock(&lock->raw_lock);
}
#endif

/*
Expand All @@ -146,38 +161,38 @@ static inline void smp_mb__after_lock(void) { smp_mb(); }
* various methods are defined as nops in the case they are not
* required.
*/
#define spin_trylock(lock) __cond_lock(lock, _spin_trylock(lock))
#define raw_spin_trylock(lock) __cond_lock(lock, _spin_trylock(lock))

#define spin_lock(lock) _spin_lock(lock)
#define raw_spin_lock(lock) _spin_lock(lock)

#ifdef CONFIG_DEBUG_LOCK_ALLOC
# define spin_lock_nested(lock, subclass) _spin_lock_nested(lock, subclass)
# define spin_lock_nest_lock(lock, nest_lock) \
# define raw_spin_lock_nested(lock, subclass) _spin_lock_nested(lock, subclass)
# define raw_spin_lock_nest_lock(lock, nest_lock) \
do { \
typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\
_spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \
} while (0)
#else
# define spin_lock_nested(lock, subclass) _spin_lock(lock)
# define spin_lock_nest_lock(lock, nest_lock) _spin_lock(lock)
# define raw_spin_lock_nested(lock, subclass) _spin_lock(lock)
# define raw_spin_lock_nest_lock(lock, nest_lock) _spin_lock(lock)
#endif

#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)

#define spin_lock_irqsave(lock, flags) \
#define raw_spin_lock_irqsave(lock, flags) \
do { \
typecheck(unsigned long, flags); \
flags = _spin_lock_irqsave(lock); \
} while (0)

#ifdef CONFIG_DEBUG_LOCK_ALLOC
#define spin_lock_irqsave_nested(lock, flags, subclass) \
#define raw_spin_lock_irqsave_nested(lock, flags, subclass) \
do { \
typecheck(unsigned long, flags); \
flags = _spin_lock_irqsave_nested(lock, subclass); \
} while (0)
#else
#define spin_lock_irqsave_nested(lock, flags, subclass) \
#define raw_spin_lock_irqsave_nested(lock, flags, subclass) \
do { \
typecheck(unsigned long, flags); \
flags = _spin_lock_irqsave(lock); \
Expand All @@ -186,45 +201,178 @@ static inline void smp_mb__after_lock(void) { smp_mb(); }

#else

#define spin_lock_irqsave(lock, flags) \
#define raw_spin_lock_irqsave(lock, flags) \
do { \
typecheck(unsigned long, flags); \
_spin_lock_irqsave(lock, flags); \
} while (0)

#define spin_lock_irqsave_nested(lock, flags, subclass) \
spin_lock_irqsave(lock, flags)
#define raw_spin_lock_irqsave_nested(lock, flags, subclass) \
raw_spin_lock_irqsave(lock, flags)

#endif

#define spin_lock_irq(lock) _spin_lock_irq(lock)
#define spin_lock_bh(lock) _spin_lock_bh(lock)
#define spin_unlock(lock) _spin_unlock(lock)
#define spin_unlock_irq(lock) _spin_unlock_irq(lock)
#define raw_spin_lock_irq(lock) _spin_lock_irq(lock)
#define raw_spin_lock_bh(lock) _spin_lock_bh(lock)
#define raw_spin_unlock(lock) _spin_unlock(lock)
#define raw_spin_unlock_irq(lock) _spin_unlock_irq(lock)

#define spin_unlock_irqrestore(lock, flags) \
do { \
typecheck(unsigned long, flags); \
#define raw_spin_unlock_irqrestore(lock, flags) \
do { \
typecheck(unsigned long, flags); \
_spin_unlock_irqrestore(lock, flags); \
} while (0)
#define spin_unlock_bh(lock) _spin_unlock_bh(lock)
#define raw_spin_unlock_bh(lock) _spin_unlock_bh(lock)

#define spin_trylock_bh(lock) __cond_lock(lock, _spin_trylock_bh(lock))
#define raw_spin_trylock_bh(lock) __cond_lock(lock, _spin_trylock_bh(lock))

#define spin_trylock_irq(lock) \
#define raw_spin_trylock_irq(lock) \
({ \
local_irq_disable(); \
spin_trylock(lock) ? \
raw_spin_trylock(lock) ? \
1 : ({ local_irq_enable(); 0; }); \
})

#define spin_trylock_irqsave(lock, flags) \
#define raw_spin_trylock_irqsave(lock, flags) \
({ \
local_irq_save(flags); \
spin_trylock(lock) ? \
raw_spin_trylock(lock) ? \
1 : ({ local_irq_restore(flags); 0; }); \
})

/**
* raw_spin_can_lock - would raw_spin_trylock() succeed?
* @lock: the spinlock in question.
*/
#define raw_spin_can_lock(lock) (!raw_spin_is_locked(lock))

/* Include rwlock functions */
#include <linux/rwlock.h>

/*
* Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
*/
#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
# include <linux/spinlock_api_smp.h>
#else
# include <linux/spinlock_api_up.h>
#endif

/*
* Map the spin_lock functions to the raw variants for PREEMPT_RT=n
*/

static inline raw_spinlock_t *spinlock_check(spinlock_t *lock)
{
return &lock->rlock;
}

#define spin_lock_init(_lock) \
do { \
spinlock_check(_lock); \
raw_spin_lock_init(&(_lock)->rlock); \
} while (0)

static inline void spin_lock(spinlock_t *lock)
{
raw_spin_lock(&lock->rlock);
}

static inline void spin_lock_bh(spinlock_t *lock)
{
raw_spin_lock_bh(&lock->rlock);
}

static inline int spin_trylock(spinlock_t *lock)
{
return raw_spin_trylock(&lock->rlock);
}

#define spin_lock_nested(lock, subclass) \
do { \
raw_spin_lock_nested(spinlock_check(lock), subclass); \
} while (0)

#define spin_lock_nest_lock(lock, nest_lock) \
do { \
raw_spin_lock_nest_lock(spinlock_check(lock), nest_lock); \
} while (0)

static inline void spin_lock_irq(spinlock_t *lock)
{
raw_spin_lock_irq(&lock->rlock);
}

#define spin_lock_irqsave(lock, flags) \
do { \
raw_spin_lock_irqsave(spinlock_check(lock), flags); \
} while (0)

#define spin_lock_irqsave_nested(lock, flags, subclass) \
do { \
raw_spin_lock_irqsave_nested(spinlock_check(lock), flags, subclass); \
} while (0)

static inline void spin_unlock(spinlock_t *lock)
{
raw_spin_unlock(&lock->rlock);
}

static inline void spin_unlock_bh(spinlock_t *lock)
{
raw_spin_unlock_bh(&lock->rlock);
}

static inline void spin_unlock_irq(spinlock_t *lock)
{
raw_spin_unlock_irq(&lock->rlock);
}

static inline void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
{
raw_spin_unlock_irqrestore(&lock->rlock, flags);
}

static inline int spin_trylock_bh(spinlock_t *lock)
{
return raw_spin_trylock_bh(&lock->rlock);
}

static inline int spin_trylock_irq(spinlock_t *lock)
{
return raw_spin_trylock_irq(&lock->rlock);
}

#define spin_trylock_irqsave(lock, flags) \
({ \
raw_spin_trylock_irqsave(spinlock_check(lock), flags); \
})

static inline void spin_unlock_wait(spinlock_t *lock)
{
raw_spin_unlock_wait(&lock->rlock);
}

static inline int spin_is_locked(spinlock_t *lock)
{
return raw_spin_is_locked(&lock->rlock);
}

static inline int spin_is_contended(spinlock_t *lock)
{
return raw_spin_is_contended(&lock->rlock);
}

static inline int spin_can_lock(spinlock_t *lock)
{
return raw_spin_can_lock(&lock->rlock);
}

static inline void assert_spin_locked(spinlock_t *lock)
{
assert_raw_spin_locked(&lock->rlock);
}

/*
* Pull the atomic_t declaration:
* (asm-mips/atomic.h needs above definitions)
Expand All @@ -242,22 +390,4 @@ extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
#define atomic_dec_and_lock(atomic, lock) \
__cond_lock(lock, _atomic_dec_and_lock(atomic, lock))

/**
* spin_can_lock - would spin_trylock() succeed?
* @lock: the spinlock in question.
*/
#define spin_can_lock(lock) (!spin_is_locked(lock))

/* Include rwlock functions */
#include <linux/rwlock.h>

/*
* Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
*/
#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
# include <linux/spinlock_api_smp.h>
#else
# include <linux/spinlock_api_up.h>
#endif

#endif /* __LINUX_SPINLOCK_H */
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