--- zzzz-none-000/linux-3.10.107/include/asm-generic/memory_model.h	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/include/asm-generic/memory_model.h	2021-02-04 17:41:59.000000000 +0000
@@ -53,7 +53,7 @@
 
 #elif defined(CONFIG_SPARSEMEM)
 /*
- * Note: section's mem_map is encorded to reflect its start_pfn.
+ * Note: section's mem_map is encoded to reflect its start_pfn.
  * section[i].section_mem_map == mem_map's address - start_pfn;
  */
 #define __page_to_pfn(pg)					\
@@ -69,6 +69,12 @@
 })
 #endif /* CONFIG_FLATMEM/DISCONTIGMEM/SPARSEMEM */
 
+/*
+ * Convert a physical address to a Page Frame Number and back
+ */
+#define	__phys_to_pfn(paddr)	((unsigned long)((paddr) >> PAGE_SHIFT))
+#define	__pfn_to_phys(pfn)	PFN_PHYS(pfn)
+
 #define page_to_pfn __page_to_pfn
 #define pfn_to_page __pfn_to_page