From 69878ef47562f32e02d0b7975c990e1c0339320d Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Tue, 25 Jun 2019 11:01:35 +0200
Subject: [PATCH] m68k: Implement arch_dma_prep_coherent()
When we remap memory as non-cached, to be used as a DMA coherent buffer,
we should writeback all cache and invalidate the cache lines so that we
make sure we have a clean slate. Implement this using the cache_push()
helper.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
arch/m68k/Kconfig | 1 +
arch/m68k/kernel/dma.c | 5 +++++
2 files changed, 6 insertions(+)
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index 3a52bf46e0433..00f5c98a5e05d 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -4,6 +4,7 @@ config M68K
default y
select ARCH_32BIT_OFF_T
select ARCH_HAS_DMA_MMAP_PGPROT if MMU && !COLDFIRE
+ select ARCH_HAS_DMA_PREP_COHERENT
select ARCH_HAS_SYNC_DMA_FOR_DEVICE if HAS_DMA
select ARCH_MIGHT_HAVE_PC_PARPORT if ISA
select ARCH_NO_COHERENT_DMA_MMAP if !MMU
diff --git a/arch/m68k/kernel/dma.c b/arch/m68k/kernel/dma.c
index e7bf355589e78..30cd59caf037e 100644
--- a/arch/m68k/kernel/dma.c
+++ b/arch/m68k/kernel/dma.c
@@ -18,6 +18,11 @@
#include <asm/pgalloc.h>
#if defined(CONFIG_MMU) && !defined(CONFIG_COLDFIRE)
+void arch_dma_prep_coherent(struct page *page, size_t size)
+{
+ cache_push(page_to_phys(page), size);
+}
+
pgprot_t arch_dma_mmap_pgprot(struct device *dev, pgprot_t prot,
unsigned long attrs)
{
--
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