Contributors: 10
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Rich Felker |
201 |
60.91% |
1 |
6.25% |
| Paul Mundt |
70 |
21.21% |
3 |
18.75% |
| Peter Zijlstra |
23 |
6.97% |
1 |
6.25% |
| Thomas Gleixner |
17 |
5.15% |
4 |
25.00% |
| Andrew Morton |
10 |
3.03% |
2 |
12.50% |
| Ralf Baechle |
3 |
0.91% |
1 |
6.25% |
| Maciej W. Rozycki |
2 |
0.61% |
1 |
6.25% |
| Ingo Molnar |
2 |
0.61% |
1 |
6.25% |
| Evgeniy Polyakov |
1 |
0.30% |
1 |
6.25% |
| Kuninori Morimoto |
1 |
0.30% |
1 |
6.25% |
| Total |
330 |
|
16 |
|
/* SPDX-License-Identifier: GPL-2.0
*
* include/asm-sh/spinlock-cas.h
*
* Copyright (C) 2015 SEI
*/
#ifndef __ASM_SH_SPINLOCK_CAS_H
#define __ASM_SH_SPINLOCK_CAS_H
#include <asm/barrier.h>
#include <asm/processor.h>
static inline unsigned __sl_cas(volatile unsigned *p, unsigned old, unsigned new)
{
__asm__ __volatile__("cas.l %1,%0,@r0"
: "+r"(new)
: "r"(old), "z"(p)
: "t", "memory" );
return new;
}
/*
* Your basic SMP spinlocks, allowing only a single CPU anywhere
*/
#define arch_spin_is_locked(x) ((x)->lock <= 0)
static inline void arch_spin_lock(arch_spinlock_t *lock)
{
while (!__sl_cas(&lock->lock, 1, 0));
}
static inline void arch_spin_unlock(arch_spinlock_t *lock)
{
__sl_cas(&lock->lock, 0, 1);
}
static inline int arch_spin_trylock(arch_spinlock_t *lock)
{
return __sl_cas(&lock->lock, 1, 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.
*/
static inline void arch_read_lock(arch_rwlock_t *rw)
{
unsigned old;
do old = rw->lock;
while (!old || __sl_cas(&rw->lock, old, old-1) != old);
}
static inline void arch_read_unlock(arch_rwlock_t *rw)
{
unsigned old;
do old = rw->lock;
while (__sl_cas(&rw->lock, old, old+1) != old);
}
static inline void arch_write_lock(arch_rwlock_t *rw)
{
while (__sl_cas(&rw->lock, RW_LOCK_BIAS, 0) != RW_LOCK_BIAS);
}
static inline void arch_write_unlock(arch_rwlock_t *rw)
{
__sl_cas(&rw->lock, 0, RW_LOCK_BIAS);
}
static inline int arch_read_trylock(arch_rwlock_t *rw)
{
unsigned old;
do old = rw->lock;
while (old && __sl_cas(&rw->lock, old, old-1) != old);
return !!old;
}
static inline int arch_write_trylock(arch_rwlock_t *rw)
{
return __sl_cas(&rw->lock, RW_LOCK_BIAS, 0) == RW_LOCK_BIAS;
}
#endif /* __ASM_SH_SPINLOCK_CAS_H */