Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/fs/proc/page.c b/fs/proc/page.c
index 792c78a..7c952ee 100644
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
-#include <linux/bootmem.h>
+#include <linux/memblock.h>
 #include <linux/compiler.h>
 #include <linux/fs.h>
 #include <linux/init.h>
@@ -42,11 +42,13 @@
 		return -EINVAL;
 
 	while (count > 0) {
-		if (pfn_valid(pfn))
-			ppage = pfn_to_page(pfn);
-		else
-			ppage = NULL;
-		if (!ppage || PageSlab(ppage))
+		/*
+		 * TODO: ZONE_DEVICE support requires to identify
+		 * memmaps that were actually initialized.
+		 */
+		ppage = pfn_to_online_page(pfn);
+
+		if (!ppage || PageSlab(ppage) || page_has_type(ppage))
 			pcount = 0;
 		else
 			pcount = page_mapcount(ppage);
@@ -152,8 +154,8 @@
 	else if (page_count(page) == 0 && is_free_buddy_page(page))
 		u |= 1 << KPF_BUDDY;
 
-	if (PageBalloon(page))
-		u |= 1 << KPF_BALLOON;
+	if (PageOffline(page))
+		u |= 1 << KPF_OFFLINE;
 	if (PageTable(page))
 		u |= 1 << KPF_PGTABLE;
 
@@ -216,10 +218,11 @@
 		return -EINVAL;
 
 	while (count > 0) {
-		if (pfn_valid(pfn))
-			ppage = pfn_to_page(pfn);
-		else
-			ppage = NULL;
+		/*
+		 * TODO: ZONE_DEVICE support requires to identify
+		 * memmaps that were actually initialized.
+		 */
+		ppage = pfn_to_online_page(pfn);
 
 		if (put_user(stable_page_flags(ppage), out)) {
 			ret = -EFAULT;
@@ -261,10 +264,11 @@
 		return -EINVAL;
 
 	while (count > 0) {
-		if (pfn_valid(pfn))
-			ppage = pfn_to_page(pfn);
-		else
-			ppage = NULL;
+		/*
+		 * TODO: ZONE_DEVICE support requires to identify
+		 * memmaps that were actually initialized.
+		 */
+		ppage = pfn_to_online_page(pfn);
 
 		if (ppage)
 			ino = page_cgroup_ino(ppage);