From 07c75d7a6b9eae24ab72c6eb2fbd39963775b0bf Mon Sep 17 00:00:00 2001
From: Vladimir Murzin <vladimir.murzin@arm.com>
Date: Wed, 28 Jun 2017 10:16:57 +0100
Subject: [PATCH] drivers: dma-mapping: allow dma_common_mmap() for NOMMU
Currently, internals of dma_common_mmap() is compiled out if build is
done for either NOMMU or target which explicitly says it does not
have/want coherent DMA mmap. It turned out that dma_common_mmap() can
be handy in NOMMU setup (at least for ARM).
This patch converts exitent NOMMU targets to use ARCH_NO_COHERENT_DMA_MMAP,
thus when CONFIG_MMU is gone from dma_common_mmap() their behaviour stays
unchanged.
ARM is not converted to ARCH_NO_COHERENT_DMA_MMAP because it 1)
already has mmap callback which can handle (at some extent) NOMMU 2)
already defines dummy pgprot_noncached() for NOMMU build.
c6x and frv stay untouched since they already have ARCH_NO_COHERENT_DMA_MMAP.
Cc: Steven Miao <realmz6@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
---
arch/blackfin/Kconfig | 1 +
arch/m32r/Kconfig | 1 +
arch/m68k/Kconfig | 1 +
arch/microblaze/Kconfig | 1 +
arch/sh/Kconfig | 1 +
arch/xtensa/Kconfig | 1 +
drivers/base/dma-mapping.c | 4 ++--
7 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index 3c1bd640042a0d..89bdb8264305c6 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -41,6 +41,7 @@ config BLACKFIN
select MODULES_USE_ELF_RELA
select HAVE_DEBUG_STACKOVERFLOW
select HAVE_NMI
+ select ARCH_NO_COHERENT_DMA_MMAP
config GENERIC_CSUM
def_bool y
diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig
index 95474460b36720..87cde1e4b38ca0 100644
--- a/arch/m32r/Kconfig
+++ b/arch/m32r/Kconfig
@@ -19,6 +19,7 @@ config M32R
select HAVE_DEBUG_STACKOVERFLOW
select CPU_NO_EFFICIENT_FFS
select DMA_NOOP_OPS
+ select ARCH_NO_COHERENT_DMA_MMAP if !MMU
config SBUS
bool
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index d140206d5d2924..5abb548f0e7075 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -2,6 +2,7 @@ config M68K
bool
default y
select ARCH_MIGHT_HAVE_PC_PARPORT if ISA
+ select ARCH_NO_COHERENT_DMA_MMAP if !MMU
select HAVE_IDE
select HAVE_AOUT if MMU
select HAVE_DEBUG_BUGVERBOSE
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 85885a501dcec9..8ba7b7c01418df 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -2,6 +2,7 @@ config MICROBLAZE
def_bool y
select ARCH_HAS_GCOV_PROFILE_ALL
select ARCH_MIGHT_HAVE_PC_PARPORT
+ select ARCH_NO_COHERENT_DMA_MMAP if !MMU
select ARCH_WANT_IPC_PARSE_VERSION
select BUILDTIME_EXTABLE_SORT
select CLKSRC_OF
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index ee086958b2b21f..640a85925060ef 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -2,6 +2,7 @@ config SUPERH
def_bool y
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_MIGHT_HAVE_PC_PARPORT
+ select ARCH_NO_COHERENT_DMA_MMAP if !MMU
select HAVE_PATA_PLATFORM
select CLKDEV_LOOKUP
select HAVE_IDE if HAS_IOPORT_MAP
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index f4126cf997a469..7ad6d77b2f223b 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -3,6 +3,7 @@ config ZONE_DMA
config XTENSA
def_bool y
+ select ARCH_NO_COHERENT_DMA_MMAP if !MMU
select ARCH_WANT_FRAME_POINTERS
select ARCH_WANT_IPC_PARSE_VERSION
select BUILDTIME_EXTABLE_SORT
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index 10e7c022e8cf4a..ce1e02b567c3a2 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c
@@ -227,7 +227,7 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size)
{
int ret = -ENXIO;
-#if defined(CONFIG_MMU) && !defined(CONFIG_ARCH_NO_COHERENT_DMA_MMAP)
+#ifndef CONFIG_ARCH_NO_COHERENT_DMA_MMAP
unsigned long user_count = vma_pages(vma);
unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
unsigned long pfn = page_to_pfn(virt_to_page(cpu_addr));
@@ -244,7 +244,7 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
user_count << PAGE_SHIFT,
vma->vm_page_prot);
}
-#endif /* CONFIG_MMU && !CONFIG_ARCH_NO_COHERENT_DMA_MMAP */
+#endif /* !CONFIG_ARCH_NO_COHERENT_DMA_MMAP */
return ret;
}
--
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