Commit ce58ae6f authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
Browse files

[S390] implement interrupt-enabling rwlocks 



arch backend for f5f7eac4
"Allow rwlocks to re-enable interrupts".

Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 76d4e00a

arch/s390/include/asm/spinlock.h

+16 −3
Original line number Diff line number Diff line
@@ -122,8 +122,10 @@ static inline void __raw_spin_unlock(raw_spinlock_t *lp) 
#define __raw_write_can_lock(x) ((x)->lock == 0)



extern void _raw_read_lock_wait(raw_rwlock_t *lp);

extern void _raw_read_lock_wait_flags(raw_rwlock_t *lp, unsigned long flags);

extern int _raw_read_trylock_retry(raw_rwlock_t *lp);

extern void _raw_write_lock_wait(raw_rwlock_t *lp);

extern void _raw_write_lock_wait_flags(raw_rwlock_t *lp, unsigned long flags);

extern int _raw_write_trylock_retry(raw_rwlock_t *lp);



static inline void __raw_read_lock(raw_rwlock_t *rw)
@@ -134,6 +136,14 @@ static inline void __raw_read_lock(raw_rwlock_t *rw) 
		_raw_read_lock_wait(rw);

}



static inline void __raw_read_lock_flags(raw_rwlock_t *rw, unsigned long flags)

{

	unsigned int old;

	old = rw->lock & 0x7fffffffU;

	if (_raw_compare_and_swap(&rw->lock, old, old + 1) != old)

		_raw_read_lock_wait_flags(rw, flags);

}



static inline void __raw_read_unlock(raw_rwlock_t *rw)

{

	unsigned int old, cmp;
@@ -151,6 +161,12 @@ static inline void __raw_write_lock(raw_rwlock_t *rw) 
		_raw_write_lock_wait(rw);

}



static inline void __raw_write_lock_flags(raw_rwlock_t *rw, unsigned long flags)

{

	if (unlikely(_raw_compare_and_swap(&rw->lock, 0, 0x80000000) != 0))

		_raw_write_lock_wait_flags(rw, flags);

}



static inline void __raw_write_unlock(raw_rwlock_t *rw)

{

	_raw_compare_and_swap(&rw->lock, 0x80000000, 0);
@@ -172,9 +188,6 @@ static inline int __raw_write_trylock(raw_rwlock_t *rw) 
	return _raw_write_trylock_retry(rw);

}



#define __raw_read_lock_flags(lock, flags) __raw_read_lock(lock)

#define __raw_write_lock_flags(lock, flags) __raw_write_lock(lock)



#define _raw_read_relax(lock)	cpu_relax()

#define _raw_write_relax(lock)	cpu_relax()

arch/s390/lib/spinlock.c

+40 −0
Original line number Diff line number Diff line
@@ -124,6 +124,27 @@ void _raw_read_lock_wait(raw_rwlock_t *rw) 
}

EXPORT_SYMBOL(_raw_read_lock_wait);



void _raw_read_lock_wait_flags(raw_rwlock_t *rw, unsigned long flags)

{

	unsigned int old;

	int count = spin_retry;



	local_irq_restore(flags);

	while (1) {

		if (count-- <= 0) {

			_raw_yield();

			count = spin_retry;

		}

		if (!__raw_read_can_lock(rw))

			continue;

		old = rw->lock & 0x7fffffffU;

		local_irq_disable();

		if (_raw_compare_and_swap(&rw->lock, old, old + 1) == old)

			return;

	}

}

EXPORT_SYMBOL(_raw_read_lock_wait_flags);



int _raw_read_trylock_retry(raw_rwlock_t *rw)

{

	unsigned int old;
@@ -157,6 +178,25 @@ void _raw_write_lock_wait(raw_rwlock_t *rw) 
}

EXPORT_SYMBOL(_raw_write_lock_wait);



void _raw_write_lock_wait_flags(raw_rwlock_t *rw, unsigned long flags)

{

	int count = spin_retry;



	local_irq_restore(flags);

	while (1) {

		if (count-- <= 0) {

			_raw_yield();

			count = spin_retry;

		}

		if (!__raw_write_can_lock(rw))

			continue;

		local_irq_disable();

		if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000) == 0)

			return;

	}

}

EXPORT_SYMBOL(_raw_write_lock_wait_flags);



int _raw_write_trylock_retry(raw_rwlock_t *rw)

{

	int count = spin_retry;