1 files changed, 43 insertions, 0 deletions
diff --git a/mirai/memory/zone/gc/gc.zig b/mirai/memory/zone/gc/gc.zig
new file mode 100644
index 0000000..a2faaad
--- /dev/null
+++ b/mirai/memory/zone/gc/gc.zig
@@ -0,0 +1,43 @@
+//! Zone Garbage Collection
+
+const types = @import("../types/types.zig");
+const Zone = types.Zone;
+const ZonePageMeta = types.ZonePageMeta;
+
+const bootstrap = @import("../bootstrap/bootstrap.zig");
+const alloc_mod = @import("../alloc/alloc.zig");
+const pmm = @import("../../../pmm/pmm.zig");
+
+pub fn collect(zone: *Zone) usize {
+    var freed: usize = 0;
+    var prev: ?*ZonePageMeta = null;
+    var current = zone.partial_pages;
+
+    while (current) |page_meta| {
+        const next_page = page_meta.next;
+
+        if (page_meta.in_use == 0) {
+            if (prev) |prev_page| {
+                prev_page.next = next_page;
+            } else {
+                zone.partial_pages = next_page;
+            }
+
+            zone.page_count -|= 1;
+            pmm.free_page(page_meta.page_phys);
+
+            if (!bootstrap.is_early_meta(page_meta)) {
+                const page_meta_zone = bootstrap.get_page_meta_zone();
+                alloc_mod.zfree(page_meta_zone, @ptrCast(page_meta));
+            }
+
+            freed += 1;
+        } else {
+            prev = page_meta;
+        }
+
+        current = next_page;
+    }
+
+    return freed;
+}