[ARM] 3533/1: Implement the __raw_(read|write)_can_lock functions on ARM

Patch from Catalin Marinas

Recent patches introduced the write_can_lock() call in the kernel/ptrace.c
file. Implement the __raw_* variants on ARM (SMP) as well.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

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.
@@ -198,4 +201,7 @@ static inline void __raw_read_unlock(raw_rwlock_t *rw)
 
 #define __raw_read_trylock(lock) generic__raw_read_trylock(lock)
 
+/* read_can_lock - would read_trylock() succeed? */
+#define __raw_read_can_lock(x)		((x)->lock < 0x80000000)
+
 #endif /* __ASM_SPINLOCK_H */