Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/nios2/mm/dma-mapping.c b/arch/nios2/mm/dma-mapping.c
index 4af9e5b..9cb2386 100644
--- a/arch/nios2/mm/dma-mapping.c
+++ b/arch/nios2/mm/dma-mapping.c
@@ -60,32 +60,28 @@
 	}
 }
 
-void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
-		gfp_t gfp, unsigned long attrs)
+void arch_dma_prep_coherent(struct page *page, size_t size)
 {
-	void *ret;
+	unsigned long start = (unsigned long)page_address(page);
 
-	/* optimized page clearing */
-	gfp |= __GFP_ZERO;
-
-	if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
-		gfp |= GFP_DMA;
-
-	ret = (void *) __get_free_pages(gfp, get_order(size));
-	if (ret != NULL) {
-		*dma_handle = virt_to_phys(ret);
-		flush_dcache_range((unsigned long) ret,
-			(unsigned long) ret + size);
-		ret = UNCAC_ADDR(ret);
-	}
-
-	return ret;
+	flush_dcache_range(start, start + size);
 }
 
-void arch_dma_free(struct device *dev, size_t size, void *vaddr,
-		dma_addr_t dma_handle, unsigned long attrs)
+void *uncached_kernel_address(void *ptr)
 {
-	unsigned long addr = (unsigned long) CAC_ADDR((unsigned long) vaddr);
+	unsigned long addr = (unsigned long)ptr;
 
-	free_pages(addr, get_order(size));
+	addr |= CONFIG_NIOS2_IO_REGION_BASE;
+
+	return (void *)ptr;
+}
+
+void *cached_kernel_address(void *ptr)
+{
+	unsigned long addr = (unsigned long)ptr;
+
+	addr &= ~CONFIG_NIOS2_IO_REGION_BASE;
+	addr |= CONFIG_NIOS2_KERNEL_REGION_BASE;
+
+	return (void *)ptr;
 }