diff options
Diffstat (limited to 'include/asm-sparc/spinlock.h')
| -rw-r--r-- | include/asm-sparc/spinlock.h | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/include/asm-sparc/spinlock.h b/include/asm-sparc/spinlock.h new file mode 100644 index 000000000000..0cbd87ad4912 --- /dev/null +++ b/include/asm-sparc/spinlock.h @@ -0,0 +1,238 @@ +/* spinlock.h: 32-bit Sparc spinlock support. + * + * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu) + */ + +#ifndef __SPARC_SPINLOCK_H +#define __SPARC_SPINLOCK_H + +#include <linux/threads.h> /* For NR_CPUS */ + +#ifndef __ASSEMBLY__ + +#include <asm/psr.h> + +#ifdef CONFIG_DEBUG_SPINLOCK +struct _spinlock_debug { + unsigned char lock; + unsigned long owner_pc; +#ifdef CONFIG_PREEMPT + unsigned int break_lock; +#endif +}; +typedef struct _spinlock_debug spinlock_t; + +#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0, 0 } +#define spin_lock_init(lp) do { *(lp)= SPIN_LOCK_UNLOCKED; } while(0) +#define spin_is_locked(lp) (*((volatile unsigned char *)(&((lp)->lock))) != 0) +#define spin_unlock_wait(lp) do { barrier(); } while(*(volatile unsigned char *)(&(lp)->lock)) + +extern void _do_spin_lock(spinlock_t *lock, char *str); +extern int _spin_trylock(spinlock_t *lock); +extern void _do_spin_unlock(spinlock_t *lock); + +#define _raw_spin_trylock(lp) _spin_trylock(lp) +#define _raw_spin_lock(lock) _do_spin_lock(lock, "spin_lock") +#define _raw_spin_unlock(lock) _do_spin_unlock(lock) + +struct _rwlock_debug { + volatile unsigned int lock; + unsigned long owner_pc; + unsigned long reader_pc[NR_CPUS]; +#ifdef CONFIG_PREEMPT + unsigned int break_lock; +#endif +}; +typedef struct _rwlock_debug rwlock_t; + +#define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0, {0} } + +#define rwlock_init(lp) do { *(lp)= RW_LOCK_UNLOCKED; } while(0) + +extern void _do_read_lock(rwlock_t *rw, char *str); +extern void _do_read_unlock(rwlock_t *rw, char *str); +extern void _do_write_lock(rwlock_t *rw, char *str); +extern void _do_write_unlock(rwlock_t *rw); + +#define _raw_read_lock(lock) \ +do { unsigned long flags; \ + local_irq_save(flags); \ + _do_read_lock(lock, "read_lock"); \ + local_irq_restore(flags); \ +} while(0) + +#define _raw_read_unlock(lock) \ +do { unsigned long flags; \ + local_irq_save(flags); \ + _do_read_unlock(lock, "read_unlock"); \ + local_irq_restore(flags); \ +} while(0) + +#define _raw_write_lock(lock) \ +do { unsigned long flags; \ + local_irq_save(flags); \ + _do_write_lock(lock, "write_lock"); \ + local_irq_restore(flags); \ +} while(0) + +#define _raw_write_unlock(lock) \ +do { unsigned long flags; \ + local_irq_save(flags); \ + _do_write_unlock(lock); \ + local_irq_restore(flags); \ +} while(0) + +#else /* !CONFIG_DEBUG_SPINLOCK */ + +typedef struct { + unsigned char lock; +#ifdef CONFIG_PREEMPT + unsigned int break_lock; +#endif +} spinlock_t; + +#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 } + +#define spin_lock_init(lock) (*((unsigned char *)(lock)) = 0) +#define spin_is_locked(lock) (*((volatile unsigned char *)(lock)) != 0) + +#define spin_unlock_wait(lock) \ +do { \ + barrier(); \ +} while(*((volatile unsigned char *)lock)) + +extern __inline__ void _raw_spin_lock(spinlock_t *lock) +{ + __asm__ __volatile__( + "\n1:\n\t" + "ldstub [%0], %%g2\n\t" + "orcc %%g2, 0x0, %%g0\n\t" + "bne,a 2f\n\t" + " ldub [%0], %%g2\n\t" + ".subsection 2\n" + "2:\n\t" + "orcc %%g2, 0x0, %%g0\n\t" + "bne,a 2b\n\t" + " ldub [%0], %%g2\n\t" + "b,a 1b\n\t" + ".previous\n" + : /* no outputs */ + : "r" (lock) + : "g2", "memory", "cc"); +} + +extern __inline__ int _raw_spin_trylock(spinlock_t *lock) +{ + unsigned int result; + __asm__ __volatile__("ldstub [%1], %0" + : "=r" (result) + : "r" (lock) + : "memory"); + return (result == 0); +} + +extern __inline__ void _raw_spin_unlock(spinlock_t *lock) +{ + __asm__ __volatile__("stb %%g0, [%0]" : : "r" (lock) : "memory"); +} + +/* 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. + * + * XXX This might create some problems with my dual spinlock + * XXX scheme, deadlocks etc. -DaveM + */ +typedef struct { + volatile unsigned int lock; +#ifdef CONFIG_PREEMPT + unsigned int break_lock; +#endif +} rwlock_t; + +#define RW_LOCK_UNLOCKED (rwlock_t) { 0 } + +#define rwlock_init(lp) do { *(lp)= RW_LOCK_UNLOCKED; } while(0) + + +/* Sort of like atomic_t's on Sparc, but even more clever. + * + * ------------------------------------ + * | 24-bit counter | wlock | rwlock_t + * ------------------------------------ + * 31 8 7 0 + * + * wlock signifies the one writer is in or somebody is updating + * counter. For a writer, if he successfully acquires the wlock, + * but counter is non-zero, he has to release the lock and wait, + * till both counter and wlock are zero. + * + * Unfortunately this scheme limits us to ~16,000,000 cpus. + */ +extern __inline__ void _read_lock(rwlock_t *rw) +{ + register rwlock_t *lp asm("g1"); + lp = rw; + __asm__ __volatile__( + "mov %%o7, %%g4\n\t" + "call ___rw_read_enter\n\t" + " ldstub [%%g1 + 3], %%g2\n" + : /* no outputs */ + : "r" (lp) + : "g2", "g4", "memory", "cc"); +} + +#define _raw_read_lock(lock) \ +do { unsigned long flags; \ + local_irq_save(flags); \ + _read_lock(lock); \ + local_irq_restore(flags); \ +} while(0) + +extern __inline__ void _read_unlock(rwlock_t *rw) +{ + register rwlock_t *lp asm("g1"); + lp = rw; + __asm__ __volatile__( + "mov %%o7, %%g4\n\t" + "call ___rw_read_exit\n\t" + " ldstub [%%g1 + 3], %%g2\n" + : /* no outputs */ + : "r" (lp) + : "g2", "g4", "memory", "cc"); +} + +#define _raw_read_unlock(lock) \ +do { unsigned long flags; \ + local_irq_save(flags); \ + _read_unlock(lock); \ + local_irq_restore(flags); \ +} while(0) + +extern __inline__ void _raw_write_lock(rwlock_t *rw) +{ + register rwlock_t *lp asm("g1"); + lp = rw; + __asm__ __volatile__( + "mov %%o7, %%g4\n\t" + "call ___rw_write_enter\n\t" + " ldstub [%%g1 + 3], %%g2\n" + : /* no outputs */ + : "r" (lp) + : "g2", "g4", "memory", "cc"); +} + +#define _raw_write_unlock(rw) do { (rw)->lock = 0; } while(0) + +#endif /* CONFIG_DEBUG_SPINLOCK */ + +#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock) + +#endif /* !(__ASSEMBLY__) */ + +#endif /* __SPARC_SPINLOCK_H */ |