1 files changed, 75 insertions, 0 deletions
diff --git a/src/arch/riscv/include/arch/atomic.h b/src/arch/riscv/include/arch/atomic.h
new file mode 100644
index 0000000000..b3e5d24154
--- /dev/null
+++ b/src/arch/riscv/include/arch/atomic.h
@@ -0,0 +1,75 @@
+// See LICENSE for license details.
+
+#ifndef _RISCV_ATOMIC_H
+#define _RISCV_ATOMIC_H
+
+#include <arch/encoding.h>
+
+typedef struct { volatile long val; } atomic_t;
+typedef struct { atomic_t lock; } spinlock_t;
+#define SPINLOCK_INIT {{0}}
+
+#define mb() __sync_synchronize()
+
+static inline void atomic_set(atomic_t* a, long val)
+{
+  a->val = val;
+}
+
+static inline long atomic_read(atomic_t* a)
+{
+  return a->val;
+}
+
+static inline long atomic_add(atomic_t* a, long inc)
+{
+  long ret = atomic_read(a);
+  atomic_set(a, ret + inc);
+  return ret;
+}
+
+static inline long atomic_swap(atomic_t* a, long val)
+{
+  long ret = atomic_read(a);
+  atomic_set(a, val);
+  return ret;
+}
+
+static inline long atomic_cas(atomic_t* a, long compare, long swap)
+{
+  long ret = atomic_read(a);
+  if (ret == compare)
+    atomic_set(a, swap);
+  return ret;
+}
+
+static inline void spinlock_lock(spinlock_t* lock)
+{
+  do
+  {
+    while (atomic_read(&lock->lock))
+      ;
+  } while (atomic_swap(&lock->lock, -1));
+  mb();
+}
+
+static inline void spinlock_unlock(spinlock_t* lock)
+{
+  mb();
+  atomic_set(&lock->lock,0);
+}
+
+static inline long spinlock_lock_irqsave(spinlock_t* lock)
+{
+  long flags = clear_csr(status, SR_EI);
+  spinlock_lock(lock);
+  return flags;
+}
+
+static inline void spinlock_unlock_irqrestore(spinlock_t* lock, long flags)
+{
+  spinlock_unlock(lock);
+  set_csr(status, flags & SR_EI);
+}
+
+#endif