X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=include%2Fasm-arm%2Fspinlock.h;h=861092fbaa53283953bd41c9dbb6e840bb42ff02;hb=refs%2Fheads%2Fvserver;hp=43ad4e55878c7961a535e6ce427b842adecb2372;hpb=76828883507a47dae78837ab5dec5a5b4513c667;p=linux-2.6.git

diff --git a/include/asm-arm/spinlock.h b/include/asm-arm/spinlock.h
index 43ad4e558..861092fba 100644
--- a/include/asm-arm/spinlock.h
+++ b/include/asm-arm/spinlock.h
@@ -142,6 +142,9 @@ static inline void __raw_write_unlock(raw_rwlock_t *rw)
 	: "cc");
 }
 
+/* write_can_lock - would write_trylock() succeed? */
+#define __raw_write_can_lock(x)		((x)->lock == 0x80000000)
+
 /*
  * Read locks are a bit more hairy:
  *  - Exclusively load the lock value.
@@ -196,6 +199,27 @@ static inline void __raw_read_unlock(raw_rwlock_t *rw)
 	: "cc");
 }
 
-#define __raw_read_trylock(lock) generic__raw_read_trylock(lock)
+static inline int __raw_read_trylock(raw_rwlock_t *rw)
+{
+	unsigned long tmp, tmp2 = 1;
+
+	__asm__ __volatile__(
+"1:	ldrex	%0, [%2]\n"
+"	adds	%0, %0, #1\n"
+"	strexpl	%1, %0, [%2]\n"
+	: "=&r" (tmp), "+r" (tmp2)
+	: "r" (&rw->lock)
+	: "cc");
+
+	smp_mb();
+	return tmp2 == 0;
+}
+
+/* read_can_lock - would read_trylock() succeed? */
+#define __raw_read_can_lock(x)		((x)->lock < 0x80000000)
+
+#define _raw_spin_relax(lock)	cpu_relax()
+#define _raw_read_relax(lock)	cpu_relax()
+#define _raw_write_relax(lock)	cpu_relax()
 
 #endif /* __ASM_SPINLOCK_H */