smp/spinlock: Do not define barrier() globally

It's not stricly related to spinlocks. If defined, a better
location should be found and the name collisions with other
barrier() defined in nb/intel solved.

Change-Id: Iae187b5bcc249c2a4bc7bee80d37e34c13d9e63d
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43810
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/arch/arm/include/armv4/arch/smp/spinlock.h

@@ -4,7 +4,6 @@
 #define _ARCH_SMP_SPINLOCK_H
 
 #define DECLARE_SPIN_LOCK(x)
-#define barrier()		do {} while (0)
 #define spin_is_locked(lock)	0
 #define spin_unlock_wait(lock)	do {} while (0)
 #define spin_lock(lock)		do {} while (0)

src/arch/x86/include/arch/smp/spinlock.h

@@ -29,6 +29,7 @@ typedef struct {
 #define barrier() __asm__ __volatile__("" : : : "memory")
 #define spin_is_locked(x)	(*(volatile char *)(&(x)->lock) <= 0)
 #define spin_unlock_wait(x)	do { barrier(); } while (spin_is_locked(x))
+#undef barrier
 
 #define spin_lock_string \
 	"\n1:\t" \
@@ -65,7 +66,6 @@ static __always_inline void spin_unlock(spinlock_t *lock)
 #else
 
 #define DECLARE_SPIN_LOCK(x)
-#define barrier()		do {} while (0)
 #define spin_is_locked(lock)	0
 #define spin_unlock_wait(lock)	do {} while (0)
 #define spin_lock(lock)		do {} while (0)

src/include/smp/spinlock.h

@@ -6,7 +6,6 @@
 #else /* !CONFIG_SMP */
 
 #define DECLARE_SPIN_LOCK(x)
-#define barrier()		do {} while (0)
 #define spin_is_locked(lock)	0
 #define spin_unlock_wait(lock)	do {} while (0)
 #define spin_lock(lock)		do {} while (0)

src/soc/amd/picasso/psp_verstage/include/arch/smp/spinlock.h

@@ -4,7 +4,6 @@
 #define _ARCH_SMP_SPINLOCK_H
 
 #define DECLARE_SPIN_LOCK(x)
-#define barrier()		do {} while (0)
 #define spin_is_locked(lock)	0
 #define spin_unlock_wait(lock)	do {} while (0)
 #define spin_lock(lock)		do {} while (0)