sandbox: vm: add cache allocator, generic size-N caches for kmalloc()

sandbox/vm/kmalloc.c

@@ -0,0 +1,63 @@
+#include <socks/vm.h>
+#include <string.h>
+
+#define SIZE_N_CACHE(s) \
+	{ .c_name = "size-" # s, .c_obj_size = s, .c_page_order = VM_PAGE_16K }
+
+/* reserve space for the size-N caches: */
+static vm_cache_t size_n_caches[] = {
+	SIZE_N_CACHE(16),
+	SIZE_N_CACHE(32),
+	SIZE_N_CACHE(48),
+	SIZE_N_CACHE(64),
+	SIZE_N_CACHE(96),
+	SIZE_N_CACHE(128),
+	SIZE_N_CACHE(160),
+	SIZE_N_CACHE(256),
+	SIZE_N_CACHE(388),
+	SIZE_N_CACHE(512),
+	SIZE_N_CACHE(576),
+	SIZE_N_CACHE(768),
+	SIZE_N_CACHE(1024),
+	SIZE_N_CACHE(1664),
+	SIZE_N_CACHE(2048),
+	SIZE_N_CACHE(3072),
+	SIZE_N_CACHE(4096),
+};
+static const size_t nr_size_n_caches = sizeof size_n_caches / sizeof size_n_caches[0];
+
+void *kmalloc(size_t count, vm_flags_t flags)
+{
+	vm_cache_t *best_fit = NULL;
+	for (size_t i = 0; i < nr_size_n_caches; i++) {
+		if (size_n_caches[i].c_obj_size >= count) {
+			best_fit = &size_n_caches[i];
+			break;
+		}
+	}
+
+	if (!best_fit) {
+		return NULL;
+	}
+
+	if (!VM_CACHE_INITIALISED(best_fit)) {
+		vm_cache_init(best_fit);
+	}
+	
+	return vm_cache_alloc(best_fit, flags);
+}
+
+void *kzalloc(size_t count, vm_flags_t flags)
+{
+	void *p = kmalloc(count, flags);
+	if (p) {
+		memset(p, 0x0, count);
+	}
+	
+	return p;
+}
+
+void kfree(void *p)
+{
+	/* TODO */
+}