ke+mm: add TLB shootdown and memory reclamation.

src/mm/heap.zig

@@ -16,8 +16,14 @@ pub fn alloc(size: usize) mm.Error!*anyopaque {
     mi.kernel_space.pmap.map_range_allocating(addr, size, .{
         .read = true,
         .write = true,
-        .global = true,
+        .global = false,
     });
 
     return @ptrFromInt(addr);
 }
+
+pub fn free(va: r.VAddr, size: usize) void {
+    const ipl = mi.kernel_space.lock.acquire();
+    mi.tlb.reclaim_range(&mi.kernel_space, va, size);
+    mi.kernel_space.lock.release(ipl);
+}