Rename dirs

lib/spin.c

@@ -0,0 +1,34 @@
+#include <zinnia/atomic.h>
+#include <zinnia/irq.h>
+#include <zinnia/spin.h>
+#include <arch/cpu.h>
+
+void spin_init(struct spinlock* spin) {
+    spin->next = 0;
+    spin->owner = 0;
+}
+
+void spin_lock(struct spinlock* spin) {
+    irq_lock();
+    uint32_t my = atomic_fetch_add(&spin->next, 1, ATOMIC_RELAXED);
+
+    while (atomic_load(&spin->owner, ATOMIC_ACQUIRE) != my) {
+        arch_cpu_pause();
+    }
+}
+
+bool spin_trylock(struct spinlock* spin) {
+    irq_lock();
+    uint32_t owner = atomic_load(&spin->owner, ATOMIC_RELAXED);
+    uint32_t expected = owner;
+    if (atomic_compare_exchange(&spin->next, &expected, owner + 1, ATOMIC_ACQUIRE, ATOMIC_RELAXED))
+        return true;
+    irq_unlock();
+    return false;
+}
+
+void spin_unlock(struct spinlock* spin) {
+    uint32_t val = atomic_load(&spin->owner, ATOMIC_RELAXED);
+    atomic_store(&spin->owner, val + 1, ATOMIC_RELEASE);
+    irq_unlock();
+}