+struct efi_device_path *efi_dp_create_device_node(const u8 type,
+ const u8 sub_type,
+ const u16 length)
+{
+ struct efi_device_path *ret;
+
+ if (length < sizeof(struct efi_device_path))
+ return NULL;
+
+ ret = dp_alloc(length);
+ if (!ret)
+ return ret;
+ ret->type = type;
+ ret->sub_type = sub_type;
+ ret->length = length;
+ return ret;
+}
+
+struct efi_device_path *efi_dp_append_instance(
+ const struct efi_device_path *dp,
+ const struct efi_device_path *dpi)
+{
+ size_t sz, szi;
+ struct efi_device_path *p, *ret;
+
+ if (!dpi)
+ return NULL;
+ if (!dp)
+ return efi_dp_dup(dpi);
+ sz = efi_dp_size(dp);
+ szi = efi_dp_instance_size(dpi);
+ p = dp_alloc(sz + szi + 2 * sizeof(END));
+ if (!p)
+ return NULL;
+ ret = p;
+ memcpy(p, dp, sz + sizeof(END));
+ p = (void *)p + sz;
+ p->sub_type = DEVICE_PATH_SUB_TYPE_INSTANCE_END;
+ p = (void *)p + sizeof(END);
+ memcpy(p, dpi, szi);
+ p = (void *)p + szi;
+ memcpy(p, &END, sizeof(END));
+ return ret;
+}
+
+struct efi_device_path *efi_dp_get_next_instance(struct efi_device_path **dp,
+ efi_uintn_t *size)
+{
+ size_t sz;
+ struct efi_device_path *p;
+
+ if (size)
+ *size = 0;
+ if (!dp || !*dp)
+ return NULL;
+ sz = efi_dp_instance_size(*dp);
+ p = dp_alloc(sz + sizeof(END));
+ if (!p)
+ return NULL;
+ memcpy(p, *dp, sz + sizeof(END));
+ *dp = (void *)*dp + sz;
+ if ((*dp)->sub_type == DEVICE_PATH_SUB_TYPE_INSTANCE_END)
+ *dp = (void *)*dp + sizeof(END);
+ else
+ *dp = NULL;
+ if (size)
+ *size = sz + sizeof(END);
+ return p;
+}
+
+bool efi_dp_is_multi_instance(const struct efi_device_path *dp)
+{
+ const struct efi_device_path *p = dp;
+
+ if (!p)
+ return false;
+ while (p->type != DEVICE_PATH_TYPE_END)
+ p = (void *)p + p->length;
+ return p->sub_type == DEVICE_PATH_SUB_TYPE_INSTANCE_END;
+}
+