Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/um/include/asm/pgalloc.h b/arch/um/include/asm/pgalloc.h
index bf90b2a..881e76d 100644
--- a/arch/um/include/asm/pgalloc.h
+++ b/arch/um/include/asm/pgalloc.h
@@ -1,8 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* 
  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
  * Copyright 2003 PathScale, Inc.
  * Derived from include/asm-i386/pgalloc.h and include/asm-i386/pgtable.h
- * Licensed under the GPL
  */
 
 #ifndef __UM_PGALLOC_H
@@ -10,6 +10,8 @@
 
 #include <linux/mm.h>
 
+#include <asm-generic/pgalloc.h>	/* for pte_{alloc,free}_one */
+
 #define pmd_populate_kernel(mm, pmd, pte) \
 	set_pmd(pmd, __pmd(_PAGE_TABLE + (unsigned long) __pa(pte)))
 
@@ -25,23 +27,9 @@
 extern pgd_t *pgd_alloc(struct mm_struct *);
 extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
 
-extern pte_t *pte_alloc_one_kernel(struct mm_struct *, unsigned long);
-extern pgtable_t pte_alloc_one(struct mm_struct *, unsigned long);
-
-static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
-{
-	free_page((unsigned long) pte);
-}
-
-static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
-{
-	pgtable_page_dtor(pte);
-	__free_page(pte);
-}
-
 #define __pte_free_tlb(tlb,pte, address)		\
 do {							\
-	pgtable_page_dtor(pte);				\
+	pgtable_pte_page_dtor(pte);			\
 	tlb_remove_page((tlb),(pte));			\
 } while (0)
 
@@ -55,7 +43,5 @@
 #define __pmd_free_tlb(tlb,x, address)   tlb_remove_page((tlb),virt_to_page(x))
 #endif
 
-#define check_pgt_cache()	do { } while (0)
-
 #endif