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@xxxxxx>
---
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 2571a8fba4b0..64b122595896 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 9c6a350a16d8..e720e6eed838 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)
{
--
2.20.1
