unsigned long vmem_altmap_offset(struct vmem_altmap *altmap);
void vmem_altmap_free(struct vmem_altmap *altmap, unsigned long nr_pfns);
-#if defined(CONFIG_SPARSEMEM_VMEMMAP) && defined(CONFIG_ZONE_DEVICE)
+#ifdef CONFIG_ZONE_DEVICE
struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start);
#else
static inline struct vmem_altmap *to_vmem_altmap(unsigned long memmap_start)