From 1fbf57d0530217b9f264eedc4867bf91479cdf3c Mon Sep 17 00:00:00 2001
From: Christoph Hellwig
Date: Wed, 10 Jun 2020 10:29:49 +0200
Subject: dma-direct: re-enable mmap for !CONFIG_MMU

nommu configfs can trivially map the coherent allocations to user space,
as no actual page table setup is required and the kernel and the user
space programs share the same address space.

Fixes: 62fcee9a3bd7 ("dma-mapping: remove CONFIG_ARCH_NO_COHERENT_DMA_MMAP")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: dillon min <dillon.minfei@gmail.com>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Tested-by: dillon min <dillon.minfei@gmail.com>
---
 kernel/dma/Kconfig | 1 +
 1 file changed, 1 insertion(+)

(limited to 'kernel/dma/Kconfig')

diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig
index a0ce3c1494fd..14ef8e1bdefe 100644
--- a/kernel/dma/Kconfig
+++ b/kernel/dma/Kconfig
@@ -71,6 +71,7 @@ config SWIOTLB
 # in the pagetables
 #
 config DMA_NONCOHERENT_MMAP
+	default y if !MMU
 	bool
 
 config DMA_COHERENT_POOL
-- 
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