* Copyright (C) 2004 Hirokazu Takata <takata at linux-m32r.org>
*/
-#include <linux/config.h> /* CONFIG_DEBUG_SPINLOCK, CONFIG_SMP */
#include <linux/compiler.h>
#include <asm/atomic.h>
#include <asm/page.h>
-extern int printk(const char * fmt, ...)
- __attribute__ ((format (printf, 1, 2)));
-
-#define RW_LOCK_BIAS 0x01000000
-#define RW_LOCK_BIAS_STR "0x01000000"
-
-/* It seems that people are forgetting to
- * initialize their spinlocks properly, tsk tsk.
- * Remember to turn this off in 2.4. -ben
- */
-#if defined(CONFIG_DEBUG_SPINLOCK)
-#define SPINLOCK_DEBUG 1
-#else
-#define SPINLOCK_DEBUG 0
-#endif
-
/*
* Your basic SMP spinlocks, allowing only a single CPU anywhere
- */
-
-typedef struct {
- volatile int lock;
-#if SPINLOCK_DEBUG
- unsigned magic;
-#endif
-#ifdef CONFIG_PREEMPT
- unsigned int break_lock;
-#endif
-} spinlock_t;
-
-#define SPINLOCK_MAGIC 0xdead4ead
-
-#if SPINLOCK_DEBUG
-#define SPINLOCK_MAGIC_INIT , SPINLOCK_MAGIC
-#else
-#define SPINLOCK_MAGIC_INIT /* */
-#endif
-
-#define SPIN_LOCK_UNLOCKED (spinlock_t) { 1 SPINLOCK_MAGIC_INIT }
-
-#define spin_lock_init(x) do { *(x) = SPIN_LOCK_UNLOCKED; } while(0)
-
-/*
+ *
+ * (the type definitions are in asm/spinlock_types.h)
+ *
* Simple spin lock operations. There are two variants, one clears IRQ's
* on the local processor, one does not.
*
* We make no fairness assumptions. They have a cost.
*/
-#define spin_is_locked(x) (*(volatile int *)(&(x)->lock) <= 0)
-#define spin_unlock_wait(x) do { barrier(); } while(spin_is_locked(x))
-#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
+#define __raw_spin_is_locked(x) (*(volatile int *)(&(x)->slock) <= 0)
+#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock)
+#define __raw_spin_unlock_wait(x) \
+ do { cpu_relax(); } while (__raw_spin_is_locked(x))
/**
- * _raw_spin_trylock - Try spin lock and return a result
+ * __raw_spin_trylock - Try spin lock and return a result
* @lock: Pointer to the lock variable
*
- * _raw_spin_trylock() tries to get the lock and returns a result.
+ * __raw_spin_trylock() tries to get the lock and returns a result.
* On the m32r, the result value is 1 (= Success) or 0 (= Failure).
*/
-static inline int _raw_spin_trylock(spinlock_t *lock)
+static inline int __raw_spin_trylock(raw_spinlock_t *lock)
{
int oldval;
unsigned long tmp1, tmp2;
/*
- * lock->lock : =1 : unlock
- * : <=0 : lock
+ * lock->slock : =1 : unlock
+ * : <=0 : lock
* {
- * oldval = lock->lock; <--+ need atomic operation
- * lock->lock = 0; <--+
+ * oldval = lock->slock; <--+ need atomic operation
+ * lock->slock = 0; <--+
* }
*/
__asm__ __volatile__ (
- "# spin_trylock \n\t"
+ "# __raw_spin_trylock \n\t"
"ldi %1, #0; \n\t"
"mvfc %2, psw; \n\t"
"clrpsw #0x40 -> nop; \n\t"
"unlock %1, @%3; \n\t"
"mvtc %2, psw; \n\t"
: "=&r" (oldval), "=&r" (tmp1), "=&r" (tmp2)
- : "r" (&lock->lock)
+ : "r" (&lock->slock)
: "memory"
#ifdef CONFIG_CHIP_M32700_TS1
, "r6"
return (oldval > 0);
}
-static inline void _raw_spin_lock(spinlock_t *lock)
+static inline void __raw_spin_lock(raw_spinlock_t *lock)
{
unsigned long tmp0, tmp1;
-#if SPINLOCK_DEBUG
- __label__ here;
-here:
- if (lock->magic != SPINLOCK_MAGIC) {
- printk("eip: %p\n", &&here);
- BUG();
- }
-#endif
/*
- * lock->lock : =1 : unlock
- * : <=0 : lock
+ * lock->slock : =1 : unlock
+ * : <=0 : lock
*
* for ( ; ; ) {
- * lock->lock -= 1; <-- need atomic operation
- * if (lock->lock == 0) break;
- * for ( ; lock->lock <= 0 ; );
+ * lock->slock -= 1; <-- need atomic operation
+ * if (lock->slock == 0) break;
+ * for ( ; lock->slock <= 0 ; );
* }
*/
__asm__ __volatile__ (
- "# spin_lock \n\t"
+ "# __raw_spin_lock \n\t"
".fillinsn \n"
"1: \n\t"
"mvfc %1, psw; \n\t"
"bra 2b; \n\t"
LOCK_SECTION_END
: "=&r" (tmp0), "=&r" (tmp1)
- : "r" (&lock->lock)
+ : "r" (&lock->slock)
: "memory"
#ifdef CONFIG_CHIP_M32700_TS1
, "r6"
);
}
-static inline void _raw_spin_unlock(spinlock_t *lock)
+static inline void __raw_spin_unlock(raw_spinlock_t *lock)
{
-#if SPINLOCK_DEBUG
- BUG_ON(lock->magic != SPINLOCK_MAGIC);
- BUG_ON(!spin_is_locked(lock));
-#endif
mb();
- lock->lock = 1;
+ lock->slock = 1;
}
/*
* 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 {
- volatile int lock;
-#if SPINLOCK_DEBUG
- unsigned magic;
-#endif
-#ifdef CONFIG_PREEMPT
- unsigned int break_lock;
-#endif
-} rwlock_t;
-
-#define RWLOCK_MAGIC 0xdeaf1eed
-
-#if SPINLOCK_DEBUG
-#define RWLOCK_MAGIC_INIT , RWLOCK_MAGIC
-#else
-#define RWLOCK_MAGIC_INIT /* */
-#endif
-
-#define RW_LOCK_UNLOCKED (rwlock_t) { RW_LOCK_BIAS RWLOCK_MAGIC_INIT }
-
-#define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while(0)
-
-#define rwlock_is_locked(x) ((x)->lock != RW_LOCK_BIAS)
-
-/*
+ *
* On x86, we implement read-write locks as a 32-bit counter
* with the high bit (sign) being the "contended" bit.
*
* Changed to use the same technique as rw semaphores. See
* semaphore.h for details. -ben
*/
-/* the spinlock helpers are in arch/i386/kernel/semaphore.c */
-static inline void _raw_read_lock(rwlock_t *rw)
+/**
+ * read_can_lock - would read_trylock() succeed?
+ * @lock: the rwlock in question.
+ */
+#define __raw_read_can_lock(x) ((int)(x)->lock > 0)
+
+/**
+ * write_can_lock - would write_trylock() succeed?
+ * @lock: the rwlock in question.
+ */
+#define __raw_write_can_lock(x) ((x)->lock == RW_LOCK_BIAS)
+
+static inline void __raw_read_lock(raw_rwlock_t *rw)
{
unsigned long tmp0, tmp1;
-#if SPINLOCK_DEBUG
- BUG_ON(rw->magic != RWLOCK_MAGIC);
-#endif
/*
* rw->lock : >0 : unlock
* : <=0 : lock
);
}
-static inline void _raw_write_lock(rwlock_t *rw)
+static inline void __raw_write_lock(raw_rwlock_t *rw)
{
unsigned long tmp0, tmp1, tmp2;
-#if SPINLOCK_DEBUG
- BUG_ON(rw->magic != RWLOCK_MAGIC);
-#endif
/*
* rw->lock : =RW_LOCK_BIAS_STR : unlock
* : !=RW_LOCK_BIAS_STR : lock
);
}
-static inline void _raw_read_unlock(rwlock_t *rw)
+static inline void __raw_read_unlock(raw_rwlock_t *rw)
{
unsigned long tmp0, tmp1;
);
}
-static inline void _raw_write_unlock(rwlock_t *rw)
+static inline void __raw_write_unlock(raw_rwlock_t *rw)
{
unsigned long tmp0, tmp1, tmp2;
);
}
-#define _raw_read_trylock(lock) generic_raw_read_trylock(lock)
+static inline int __raw_read_trylock(raw_rwlock_t *lock)
+{
+ atomic_t *count = (atomic_t*)lock;
+ if (atomic_dec_return(count) >= 0)
+ return 1;
+ atomic_inc(count);
+ return 0;
+}
-static inline int _raw_write_trylock(rwlock_t *lock)
+static inline int __raw_write_trylock(raw_rwlock_t *lock)
{
atomic_t *count = (atomic_t *)lock;
if (atomic_sub_and_test(RW_LOCK_BIAS, count))
return 0;
}
+#define _raw_spin_relax(lock) cpu_relax()
+#define _raw_read_relax(lock) cpu_relax()
+#define _raw_write_relax(lock) cpu_relax()
+
#endif /* _ASM_M32R_SPINLOCK_H */
git://git.onelab.eu / linux-2.6.git / blobdiff