[kvm-unit-tests PATCH v1 1/3] lib: provide generic spinlock

[David Hildenbrand <david@redhat.com>]

Let's provide a basic lock implementation that should work on most
architectures.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 lib/asm-generic/spinlock.h | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/lib/asm-generic/spinlock.h b/lib/asm-generic/spinlock.h
index 3141744..e8c3a58 100644
--- a/lib/asm-generic/spinlock.h
+++ b/lib/asm-generic/spinlock.h
@@ -1,4 +1,18 @@
 #ifndef _ASM_GENERIC_SPINLOCK_H_
 #define _ASM_GENERIC_SPINLOCK_H_
-#error need architecture specific asm/spinlock.h
+
+struct spinlock {
+    unsigned int v;
+};
+
+static inline void spin_lock(struct spinlock *lock)
+{
+	while (!__sync_bool_compare_and_swap(&lock->v, 0, 1));
+}
+
+static inline void spin_unlock(struct spinlock *lock)
+{
+	__sync_bool_compare_and_swap(&lock->v, 1, 0);
+}
+
 #endif
-- 
2.9.3