diff options
Diffstat (limited to 'include/asm-sh/spinlock.h')
| -rw-r--r-- | include/asm-sh/spinlock.h | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/include/asm-sh/spinlock.h b/include/asm-sh/spinlock.h index 16f70ffd7..8db187a29 100644 --- a/include/asm-sh/spinlock.h +++ b/include/asm-sh/spinlock.h @@ -1,6 +1,53 @@ #ifndef __ASM_SH_SPINLOCK_H #define __ASM_SH_SPINLOCK_H +#ifndef __SMP__ + +typedef struct { } spinlock_t; +#define SPIN_LOCK_UNLOCKED { } + +#define spin_lock_init(lock) do { } while(0) +#define spin_lock(lock) do { } while(0) +#define spin_trylock(lock) (1) +#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) save_and_cli(flags) +#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. + */ +typedef struct { } rwlock_t; +#define RW_LOCK_UNLOCKED (rwlock_t) { } + +#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) save_and_cli(flags) +#define read_unlock_irqrestore(lock, flags) restore_flags(flags) +#define write_lock_irqsave(lock, flags) save_and_cli(flags) +#define write_unlock_irqrestore(lock, flags) restore_flags(flags) + +#else + #error "No SMP on SH" +#endif /* SMP */ + #endif /* __ASM_SH_SPINLOCK_H */ |