[PATCH v2 0/4] Fix kernel panic in dma-coherent allocations

From	Brian Starkey <brian.starkey@arm.com>
Newsgroups	linux.kernel
Subject	[PATCH v2 0/4] Fix kernel panic in dma-coherent allocations
Date	2016-02-29 17:10 +0100
Message-ID	<r7yyu-5hu-25@gated-at.bofh.it> (permalink)
Organization	linux.* mail to news gateway

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Hi,

These patches implement a MEMREMAP_WC flag for memremap(), which can
be used to obtain writecombine mappings. This is then used for setting
up dma_coherent_mem regions which use the DMA_MEMORY_MAP flag.

The motivation is to fix an alignment fault on arm64, and the
suggestion to implement MEMREMAP_WC for this case was made at [1].
That particular issue is handled in patch 4, which makes sure that the
appropriate memset function is used when zeroing allocations mapped as
IO memory.

Best Regards,
Brian

[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2015-December/390857.html

Changes since v1:
* Added preparatory patch removing flag modifications in memremap()
  (Suggested by Andrew Morton)
* Rebase onto linux-next

Brian Starkey (4):
  memremap: don't modify flags
  memremap: add MEMREMAP_WC flag.
  drivers: dma-coherent: use MEMREMAP_WC for DMA_MEMORY_MAP
  drivers: dma-coherent: use memset_io for DMA_MEMORY_IO mappings

 drivers/base/dma-coherent.c |   25 ++++++++++++++++++++-----
 include/linux/io.h          |    1 +
 kernel/memremap.c           |   24 +++++++++++++++---------
 3 files changed, 36 insertions(+), 14 deletions(-)

-- 
1.7.9.5

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[PATCH v2 0/4] Fix kernel panic in dma-coherent allocations Brian Starkey <brian.starkey@arm.com> - 2016-02-29 17:10 +0100
  [PATCH v2 1/4] memremap: don't modify flags Brian Starkey <brian.starkey@arm.com> - 2016-02-29 17:20 +0100
  [PATCH v2 4/4] drivers: dma-coherent: use memset_io for DMA_MEMORY_IO mappings Brian Starkey <brian.starkey@arm.com> - 2016-02-29 17:20 +0100
    Re: [PATCH v2 4/4] drivers: dma-coherent: use memset_io for  DMA_MEMORY_IO mappings Andrew Morton <akpm@linux-foundation.org> - 2016-03-01 00:20 +0100
      Re: [PATCH v2 4/4] drivers: dma-coherent: use memset_io for  DMA_MEMORY_IO mappings Brian Starkey <brian.starkey@arm.com> - 2016-03-01 10:10 +0100
  [PATCH v2 3/4] drivers: dma-coherent: use MEMREMAP_WC for DMA_MEMORY_MAP Brian Starkey <brian.starkey@arm.com> - 2016-02-29 17:20 +0100
  [PATCH v2 2/4] memremap: add MEMREMAP_WC flag. Brian Starkey <brian.starkey@arm.com> - 2016-02-29 17:20 +0100

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