parisc: Improve spinlock handling

Use READ_ONCE() to check if spinlock is locked.
The other changes are cleanups.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>

diff --git a/arch/parisc/include/asm/spinlock.h b/arch/parisc/include/asm/spinlock.h
index 51b6c47f802fd6be637bb689f6159a7ec6d99eca..fa5ee8a45dbd69dc1c8ffd4667243efa25126950 100644 (file)
--- a/arch/parisc/include/asm/spinlock.h
+++ b/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;
 }
 
 /*