Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/openrisc/kernel/dma.c b/arch/openrisc/kernel/dma.c
index 159336a..4d5b8bd 100644
--- a/arch/openrisc/kernel/dma.c
+++ b/arch/openrisc/kernel/dma.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * OpenRISC Linux
  *
@@ -9,17 +10,13 @@
  * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
  * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
  *
- *      This program is free software; you can redistribute it and/or
- *      modify it under the terms of the GNU General Public License
- *      as published by the Free Software Foundation; either version
- *      2 of the License, or (at your option) any later version.
- *
  * DMA mapping callbacks...
  * As alloc_coherent is the only DMA callback being used currently, that's
  * the only thing implemented properly.  The rest need looking into...
  */
 
 #include <linux/dma-noncoherent.h>
+#include <linux/pagewalk.h>
 
 #include <asm/cpuinfo.h>
 #include <asm/spr_defs.h>
@@ -47,6 +44,10 @@
 	return 0;
 }
 
+static const struct mm_walk_ops set_nocache_walk_ops = {
+	.pte_entry		= page_set_nocache,
+};
+
 static int
 page_clear_nocache(pte_t *pte, unsigned long addr,
 		   unsigned long next, struct mm_walk *walk)
@@ -62,6 +63,10 @@
 	return 0;
 }
 
+static const struct mm_walk_ops clear_nocache_walk_ops = {
+	.pte_entry		= page_clear_nocache,
+};
+
 /*
  * Alloc "coherent" memory, which for OpenRISC means simply uncached.
  *
@@ -84,12 +89,8 @@
 {
 	unsigned long va;
 	void *page;
-	struct mm_walk walk = {
-		.pte_entry = page_set_nocache,
-		.mm = &init_mm
-	};
 
-	page = alloc_pages_exact(size, gfp);
+	page = alloc_pages_exact(size, gfp | __GFP_ZERO);
 	if (!page)
 		return NULL;
 
@@ -98,15 +99,14 @@
 
 	va = (unsigned long)page;
 
-	if ((attrs & DMA_ATTR_NON_CONSISTENT) == 0) {
-		/*
-		 * We need to iterate through the pages, clearing the dcache for
-		 * them and setting the cache-inhibit bit.
-		 */
-		if (walk_page_range(va, va + size, &walk)) {
-			free_pages_exact(page, size);
-			return NULL;
-		}
+	/*
+	 * We need to iterate through the pages, clearing the dcache for
+	 * them and setting the cache-inhibit bit.
+	 */
+	if (walk_page_range(&init_mm, va, va + size, &set_nocache_walk_ops,
+			NULL)) {
+		free_pages_exact(page, size);
+		return NULL;
 	}
 
 	return (void *)va;
@@ -117,15 +117,10 @@
 		dma_addr_t dma_handle, unsigned long attrs)
 {
 	unsigned long va = (unsigned long)vaddr;
-	struct mm_walk walk = {
-		.pte_entry = page_clear_nocache,
-		.mm = &init_mm
-	};
 
-	if ((attrs & DMA_ATTR_NON_CONSISTENT) == 0) {
-		/* walk_page_range shouldn't be able to fail here */
-		WARN_ON(walk_page_range(va, va + size, &walk));
-	}
+	/* walk_page_range shouldn't be able to fail here */
+	WARN_ON(walk_page_range(&init_mm, va, va + size,
+			&clear_nocache_walk_ops, NULL));
 
 	free_pages_exact(vaddr, size);
 }