backup 8.29.21

1 files changed, 17 insertions, 0 deletions

diff --git a/src/include/smp_sync.h b/src/include/smp_sync.h
new file mode 100644
index 0000000..92784b8
--- /dev/null
+++ b/src/include/smp_sync.h
@@ -0,0 +1,17 @@
+#ifndef SMP_SYNC_INCLUDED
+#define SMP_SYNC_INCLUDED
+
+static inline void lock(uint8_t *lock) {
+  asm("mov al, 1\n"
+      "spinlock:\n"
+      "lock xchgb [%0], al\n"
+      "test al, al\n"
+      "jnz spinlock\n"
+      ::"r"(lock):"al");
+} 
+
+static inline void unlock(uint8_t *lock) {
+  asm("lock andb [%0], 0"::"r"(lock));
+}
+
+#endif