From: dillon.minfei@gmail.com
To: robh+dt@kernel.org, mcoquelin.stm32@gmail.com,
alexandre.torgue@st.com, linux@armlinux.org.uk,
vladimir.murzin@arm.com, kstewart@linuxfoundation.org,
allison@lohutok.net, info@metux.net, tglx@linutronix.de
Cc: devicetree@vger.kernel.org,
linux-stm32@st-md-mailman.stormreply.com,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
dillon min <dillon.minfei@gmail.com>
Subject: [PATCH 0/2] Use 'arm_nommu_dma_ops' to handle dma memroy if device offer consistent dma memory region
Date: Mon, 8 Jun 2020 16:30:36 +0800 [thread overview]
Message-ID: <1591605038-8682-1-git-send-email-dillon.minfei@gmail.com> (raw)
From: dillon min <dillon.minfei@gmail.com>
when do mmap on /dev/fb0, we will get -6 error on cortex-m3/m4 or armv7m
platform without cache support, this is caused by following reason:
on armv7m platform, if no cache support, we will use dma direct mapping,
but, this is not support on !MMU hardware, just return '-ENXIO' error
so, add use_reserved_mem() for these armv7m hardware but no-cache support.
eg, stm32f429/stm32f469.
verified on stm32f469-disco board, mmap frambuffer to userspace.
dillon min (2):
ARM: dts: stm32: Setup 4M bytes reserved memory for mmap
arm-nommu: Add use_reserved_mem() to check if device support reserved
memory
arch/arm/boot/dts/stm32f469-disco.dts | 14 ++++++++++++++
arch/arm/mm/dma-mapping-nommu.c | 28 +++++++++++++++++++++++++++-
2 files changed, 41 insertions(+), 1 deletion(-)
--
2.7.4
next reply other threads:[~2020-06-08 8:30 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-08 8:30 dillon.minfei [this message]
2020-06-08 8:30 ` [PATCH 1/2] ARM: dts: stm32: Setup 4M bytes reserved memory for mmap dillon.minfei
2020-06-09 15:58 ` dillon min
2020-06-08 8:30 ` [PATCH 2/2] arm-nommu: Add use_reserved_mem() to check if device support reserved memory dillon.minfei
2020-06-09 14:08 ` Vladimir Murzin
2020-06-09 15:22 ` dillon min
2020-06-09 15:36 ` Christoph Hellwig
2020-06-09 15:43 ` Vladimir Murzin
2020-06-09 16:25 ` Vladimir Murzin
2020-06-09 17:34 ` Christoph Hellwig
2020-06-10 2:24 ` dillon min
2020-06-10 7:24 ` Christoph Hellwig
2020-06-10 8:19 ` Vladimir Murzin
2020-06-11 15:45 ` Vladimir Murzin
2020-06-12 2:15 ` dillon min
2020-06-09 15:58 ` [PATCH 0/2] Use 'arm_nommu_dma_ops' to handle dma memroy if device offer consistent dma memory region dillon min
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