Re: [RESEND PATCH 0/3] Add MEMREMAP_WC to fix dma_init_coherent_memory

From: Brian Starkey
Date: Fri Jan 29 2016 - 04:33:16 EST


Hi,

Are there any comments on these? Without them dma-coherent can't be used
on arm64 so it would be good to get them merged if there are no
objections.

I can resend with Michal's ack for patch 2 if needed.

Thanks,
Brian

On Tue, Jan 05, 2016 at 04:41:25PM +0000, Brian Starkey wrote:
Hi,

This may well have been buried with the holidays. It still applies
fine on next-20160105, but I notice patch 2 will trivially conflict
with [2] on some context lines.

As discussed here[1], 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.

Patch 3 makes sure that the appropriate memset function is used
when zeroing coherent allocations, which fixes an alignment fault on
arm64.

Best Regards,
Brian

[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2015-December/390857.html
[2] http://lists.infradead.org/pipermail/linux-arm-kernel/2016-January/397163.html

Brian Starkey (3):
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

drivers/base/dma-coherent.c | 25 ++++++++++++++++++++-----
include/linux/io.h | 1 +
kernel/memremap.c | 15 +++++++++++++--
3 files changed, 34 insertions(+), 7 deletions(-)

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