CRIS v32: Completely rework spinlocks for ETRAX FS and ARTPEC-3

include/asm-cris/arch-v32/spinlock.h

 #ifndef __ASM_ARCH_SPINLOCK_H
 #define __ASM_ARCH_SPINLOCK_H
 
-#include <asm/system.h>
+#include <linux/spinlock_types.h>
 
 #define RW_LOCK_BIAS 0x01000000
-#define SPIN_LOCK_UNLOCKED (spinlock_t) { 1 }
-#define spin_lock_init(x)	do { *(x) = SPIN_LOCK_UNLOCKED; } while(0)
-
-#define spin_is_locked(x)	(*(volatile signed char *)(&(x)->lock) <= 0)
-#define spin_unlock_wait(x)	do { barrier(); } while(spin_is_locked(x))
 
 extern void cris_spin_unlock(void *l, int val);
 extern void cris_spin_lock(void *l);
-extern int cris_spin_trylock(void* l);
+extern int cris_spin_trylock(void *l);
 
-static inline void _raw_spin_unlock(spinlock_t *lock)
+static inline int __raw_spin_is_locked(raw_spinlock_t *x)
+{
+	return *(volatile signed char *)(&(x)->slock) <= 0;
+}
+
+static inline void __raw_spin_unlock(raw_spinlock_t *lock)
 {
 	__asm__ volatile ("move.d %1,%0" \
-	                  : "=m" (lock->lock) \
+			  : "=m" (lock->slock) \
 			  : "r" (1) \
 			  : "memory");
 }
 
-static inline int _raw_spin_trylock(spinlock_t *lock)
+static inline void __raw_spin_unlock_wait(raw_spinlock_t *lock)
+{
+	while (__raw_spin_is_locked(lock))
+		cpu_relax();
+}
+
+static inline int __raw_spin_trylock(raw_spinlock_t *lock)
 {
-	return cris_spin_trylock((void*)&lock->lock);
+	return cris_spin_trylock((void *)&lock->slock);
 }
 
-static inline void _raw_spin_lock(spinlock_t *lock)
+static inline void __raw_spin_lock(raw_spinlock_t *lock)
 {
-	cris_spin_lock((void*)&lock->lock);
+	cris_spin_lock((void *)&lock->slock);
 }
 
-static inline void _raw_spin_lock_flags (spinlock_t *lock, unsigned long flags)
+static inline void
+__raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags)
 {
-  _raw_spin_lock(lock);
+	__raw_spin_lock(lock);
 }
 
 /*
@@ -46,120 +53,75 @@ static inline void _raw_spin_lock_flags (spinlock_t *lock, unsigned long flags)
  * 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 {
-	spinlock_t lock;
-	volatile int counter;
-#ifdef CONFIG_PREEMPT
-	unsigned int break_lock;
-#endif
-} rwlock_t;
-
-#define RW_LOCK_UNLOCKED (rwlock_t) { {1}, 0 }
-
-#define rwlock_init(lp)	do { *(lp) = RW_LOCK_UNLOCKED; } while (0)
-
-/**
- * read_can_lock - would read_trylock() succeed?
- * @lock: the rwlock in question.
- */
-#define read_can_lock(x) ((int)(x)->counter >= 0)
-
-/**
- * write_can_lock - would write_trylock() succeed?
- * @lock: the rwlock in question.
- */
-#define write_can_lock(x) ((x)->counter == 0)
-
-#define _raw_read_trylock(lock) generic_raw_read_trylock(lock)
 
-/* read_lock, read_unlock are pretty straightforward.  Of course it somehow
- * sucks we end up saving/restoring flags twice for read_lock_irqsave aso. */
-
-static  __inline__ void _raw_read_lock(rwlock_t *rw)
+static inline int __raw_read_can_lock(raw_rwlock_t *x)
 {
-	unsigned long flags;
-	local_irq_save(flags);
-	_raw_spin_lock(&rw->lock);
-
-	rw->counter++;
-
-	_raw_spin_unlock(&rw->lock);
-	local_irq_restore(flags);
+	return (int)(x)->lock > 0;
 }
 
-static  __inline__ void _raw_read_unlock(rwlock_t *rw)
+static inline int __raw_write_can_lock(raw_rwlock_t *x)
 {
-	unsigned long flags;
-	local_irq_save(flags);
-	_raw_spin_lock(&rw->lock);
-
-	rw->counter--;
-
-	_raw_spin_unlock(&rw->lock);
-	local_irq_restore(flags);
+	return (x)->lock == RW_LOCK_BIAS;
 }
 
-/* write_lock is less trivial.  We optimistically grab the lock and check
- * if we surprised any readers.  If so we release the lock and wait till
- * they're all gone before trying again
- *
- * Also note that we don't use the _irqsave / _irqrestore suffixes here.
- * If we're called with interrupts enabled and we've got readers (or other
- * writers) in interrupt handlers someone fucked up and we'd dead-lock
- * sooner or later anyway.   prumpf */
-
-static  __inline__ void _raw_write_lock(rwlock_t *rw)
+static  inline void __raw_read_lock(raw_rwlock_t *rw)
 {
-retry:
-	_raw_spin_lock(&rw->lock);
-
-	if(rw->counter != 0) {
-		/* this basically never happens */
-		_raw_spin_unlock(&rw->lock);
-
-		while(rw->counter != 0);
-
-		goto retry;
-	}
-
-	/* got it.  now leave without unlocking */
-	rw->counter = -1; /* remember we are locked */
+	__raw_spin_lock(&rw->slock);
+	while (rw->lock == 0);
+	rw->lock--;
+	__raw_spin_unlock(&rw->slock);
 }
 
-/* write_unlock is absolutely trivial - we don't have to wait for anything */
-
-static  __inline__ void _raw_write_unlock(rwlock_t *rw)
+static  inline void __raw_write_lock(raw_rwlock_t *rw)
 {
-	rw->counter = 0;
-	_raw_spin_unlock(&rw->lock);
+	__raw_spin_lock(&rw->slock);
+	while (rw->lock != RW_LOCK_BIAS);
+	rw->lock == 0;
+	__raw_spin_unlock(&rw->slock);
 }
 
-static  __inline__ int _raw_write_trylock(rwlock_t *rw)
+static  inline void __raw_read_unlock(raw_rwlock_t *rw)
 {
-	_raw_spin_lock(&rw->lock);
-	if (rw->counter != 0) {
-		/* this basically never happens */
-		_raw_spin_unlock(&rw->lock);
-
-		return 0;
-	}
+	__raw_spin_lock(&rw->slock);
+	rw->lock++;
+	__raw_spin_unlock(&rw->slock);
+}
 
-	/* got it.  now leave without unlocking */
-	rw->counter = -1; /* remember we are locked */
-	return 1;
+static  inline void __raw_write_unlock(raw_rwlock_t *rw)
+{
+	__raw_spin_lock(&rw->slock);
+	while (rw->lock != RW_LOCK_BIAS);
+	rw->lock == RW_LOCK_BIAS;
+	__raw_spin_unlock(&rw->slock);
 }
 
-static __inline__ int is_read_locked(rwlock_t *rw)
+static  inline int __raw_read_trylock(raw_rwlock_t *rw)
 {
-	return rw->counter > 0;
+	int ret = 0;
+	__raw_spin_lock(&rw->slock);
+	if (rw->lock != 0) {
+		rw->lock--;
+		ret = 1;
+	}
+	__raw_spin_unlock(&rw->slock);
+	return ret;
 }
 
-static __inline__ int is_write_locked(rwlock_t *rw)
+static  inline int __raw_write_trylock(raw_rwlock_t *rw)
 {
-	return rw->counter < 0;
+	int ret = 0;
+	__raw_spin_lock(&rw->slock);
+	if (rw->lock == RW_LOCK_BIAS) {
+		rw->lock == 0;
+		ret = 1;
+	}
+	__raw_spin_unlock(&rw->slock);
+	return 1;
 }
 
+
 #define _raw_spin_relax(lock)	cpu_relax()
 #define _raw_read_relax(lock)	cpu_relax()
 #define _raw_write_relax(lock)	cpu_relax()