Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Christoph Hellwig <hch@lst.de>
To:     iommu@lists.linux-foundation.org,
        Marek Szyprowski <m.szyprowski@samsung.com>
Cc:     Vladimir Murzin <vladimir.murzin@arm.com>,
        Takashi Iwai <tiwai@suse.de>, Helge Deller <deller@gmx.de>,
        Robin Murphy <robin.murphy@arm.com>,
        Michal Simek <monstr@monstr.eu>,
        linux-arm-kernel@lists.infradead.org,
        linux-m68k@lists.linux-m68k.org, linux-parisc@vger.kernel.org,
        linux-sh@vger.kernel.org, linux-xtensa@linux-xtensa.org,
        linuxppc-dev@lists.ozlabs.org, x86@kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH 7/8] parisc: don't set ARCH_NO_COHERENT_DMA_MMAP
Date:   Thu,  8 Aug 2019 19:00:04 +0300
Message-Id: <20190808160005.10325-8-hch@lst.de>
In-Reply-To: <20190808160005.10325-1-hch@lst.de>
References: <20190808160005.10325-1-hch@lst.de>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

parisc is the only architecture that sets ARCH_NO_COHERENT_DMA_MMAP
when an MMU is enabled.  AFAIK this is because parisc CPUs use VIVT
caches, which means exporting normally cachable memory to userspace is
relatively dangrous due to cache aliasing.

But normally cachable memory is only allocated by dma_alloc_coherent
on parisc when using the sba_iommu or ccio_iommu drivers, so just
remove the .mmap implementation for them so that we don't have to set
ARCH_NO_COHERENT_DMA_MMAP, which I plan to get rid of.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/parisc/Kconfig        | 1 -
 drivers/parisc/ccio-dma.c  | 1 -
 drivers/parisc/sba_iommu.c | 1 -
 3 files changed, 3 deletions(-)

diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 6d732e451071..e9dd88b7f81e 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -52,7 +52,6 @@ config PARISC
 	select GENERIC_SCHED_CLOCK
 	select HAVE_UNSTABLE_SCHED_CLOCK if SMP
 	select GENERIC_CLOCKEVENTS
-	select ARCH_NO_COHERENT_DMA_MMAP
 	select CPU_NO_EFFICIENT_FFS
 	select NEED_DMA_MAP_STATE
 	select NEED_SG_DMA_LENGTH
diff --git a/drivers/parisc/ccio-dma.c b/drivers/parisc/ccio-dma.c
index 1d7125d29bee..ad290f79983b 100644
--- a/drivers/parisc/ccio-dma.c
+++ b/drivers/parisc/ccio-dma.c
@@ -1024,7 +1024,6 @@ static const struct dma_map_ops ccio_ops = {
 	.unmap_page =		ccio_unmap_page,
 	.map_sg = 		ccio_map_sg,
 	.unmap_sg = 		ccio_unmap_sg,
-	.mmap =			dma_common_mmap,
 	.get_sgtable =		dma_common_get_sgtable,
 };
 
diff --git a/drivers/parisc/sba_iommu.c b/drivers/parisc/sba_iommu.c
index fa4df65b7e28..ed50502cc65a 100644
--- a/drivers/parisc/sba_iommu.c
+++ b/drivers/parisc/sba_iommu.c
@@ -1084,7 +1084,6 @@ static const struct dma_map_ops sba_ops = {
 	.unmap_page =		sba_unmap_page,
 	.map_sg =		sba_map_sg,
 	.unmap_sg =		sba_unmap_sg,
-	.mmap =			dma_common_mmap,
 	.get_sgtable =		dma_common_get_sgtable,
 };
 
-- 
2.20.1