parisc: Improve spinlock handling

Use READ_ONCE() to check if spinlock is locked.
The other changes are cleanups.
Signed-off-by: NJohn David Anglin <dave.anglin@bell.net>
Signed-off-by: NHelge Deller <deller@gmx.de>

arch/parisc/include/asm/spinlock.h

@@ -10,13 +10,21 @@
 static inline int arch_spin_is_locked(arch_spinlock_t *x)
 {
 	volatile unsigned int *a = __ldcw_align(x);
-	return *a == 0;
+	return READ_ONCE(*a) == 0;
 }
 
-#define arch_spin_lock(lock) arch_spin_lock_flags(lock, 0)
+static inline void arch_spin_lock(arch_spinlock_t *x)
+{
+	volatile unsigned int *a;
+
+	a = __ldcw_align(x);
+	while (__ldcw(a) == 0)
+		while (*a == 0)
+			continue;
+}
 
 static inline void arch_spin_lock_flags(arch_spinlock_t *x,
-					 unsigned long flags)
+					unsigned long flags)
 {
 	volatile unsigned int *a;
 
@@ -25,10 +33,8 @@ static inline void arch_spin_lock_flags(arch_spinlock_t *x,
 		while (*a == 0)
 			if (flags & PSW_SM_I) {
 				local_irq_enable();
-				cpu_relax();
 				local_irq_disable();
-			} else
-				cpu_relax();
+			}
 }
 #define arch_spin_lock_flags arch_spin_lock_flags
 
@@ -44,12 +50,9 @@ static inline void arch_spin_unlock(arch_spinlock_t *x)
 static inline int arch_spin_trylock(arch_spinlock_t *x)
 {
 	volatile unsigned int *a;
-	int ret;
 
 	a = __ldcw_align(x);
-        ret = __ldcw(a) != 0;
-
-	return ret;
+	return __ldcw(a) != 0;
 }
 
 /*