+/*
+ * VMEM_MAX_PHYS is the highest physical address that can be added to the 1:1
+ * mapping. This needs to be calculated at compile time since the size of the
+ * VMEM_MAP is static but the size of struct page can change.
+ */
+#define VMEM_MAX_PHYS min(VMALLOC_START, ((VMEM_MAP_END - VMALLOC_END) / \
+ sizeof(struct page) * PAGE_SIZE) & ~((16 << 20) - 1))