--- zzzz-none-000/linux-4.4.60/include/linux/highmem.h	2017-04-08 07:53:53.000000000 +0000
+++ scorpion-1750e-727/linux-4.4.60/include/linux/highmem.h	2021-02-04 17:41:59.000000000 +0000
@@ -39,6 +39,12 @@
 
 void kmap_flush_unused(void);
 
+#ifdef CONFIG_ARCH_WANT_KMAP_ATOMIC_FLUSH
+void kmap_atomic_flush_unused(void);
+#else
+static inline void kmap_atomic_flush_unused(void) { }
+#endif
+
 struct page *kmap_to_page(void *addr);
 
 #else /* CONFIG_HIGHMEM */
@@ -80,6 +86,7 @@
 #define kmap_atomic_pfn(pfn)	kmap_atomic(pfn_to_page(pfn))
 
 #define kmap_flush_unused()	do {} while(0)
+#define kmap_atomic_flush_unused()	do {} while (0)
 #endif
 
 #endif /* CONFIG_HIGHMEM */