From: Dave Gordon <david.s.gordon-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
To: Boris Brezillon
<boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>,
Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: David Woodhouse <dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>,
Brian Norris
<computersforpeace-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
linux-mtd-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
Andrew Morton
<akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>,
linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
Maxime Ripard
<maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>,
Chen-Yu Tsai <wens-jdAy2FN1RRM@public.gmane.org>,
linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org,
Vinod Koul <vinod.koul-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
Dan Williams
<dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
dmaengine-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Mauro Carvalho Chehab
<m.chehab-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>,
Hans Verkuil
<hans.verkuil-FYB4Gu1CFyUAvxtiuMwx3w@public.gmane.org>,
Laurent Pinchart
<laurent.pinchart-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org>,
linux-media-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Rob Herring <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
Pawel Moll <pawel.moll-5wv7dgnIgG8@public.gmane.org>,
Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>,
Ian Campbell
<ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org>,
Kumar Gala <galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>,
devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Richard Weinberger <richard-/L3Ra7n9ekc@public.gmane.org>
Subject: Re: [PATCH v2 4/7] scatterlist: add sg_alloc_table_from_buf() helper
Date: Tue, 5 Apr 2016 08:11:48 +0100 [thread overview]
Message-ID: <57036534.7010800@intel.com> (raw)
In-Reply-To: <20160330201831.38e1d6bd@bbrezillon>
On 30/03/16 19:18, Boris Brezillon wrote:
> On Wed, 30 Mar 2016 09:51:43 -0700
> Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> wrote:
>
>> On Wed, Mar 30, 2016 at 05:39:51PM +0200, Boris Brezillon wrote:
>>> sg_alloc_table_from_buf() provides an easy solution to create an sg_table
>>> from a virtual address pointer. This function takes care of dealing with
>>> vmallocated buffers, buffer alignment, or DMA engine limitations (maximum
>>> DMA transfer size).
>>
>> This seems nice. Should we also have a further helper on top of this
>> which will get constraints from a dmaengine, it seems like it'd be a
>> common need?
>
> Yep, we could create a wrapper extracting dma_slave caps info,
> converting it to sg_constraints and calling sg_alloc_table_from_buf().
> But let's try to get this function accepted first, and I'll send another
> patch providing this wrapper.
>
> BTW, do you see other things that should be added in sg_constraints?
>
You could compare with the things Solaris uses to describe the
restrictions on a DMA binding ...
http://docs.oracle.com/cd/E23824_01/html/821-1478/ddi-dma-attr-9s.html#REFMAN9Sddi-dma-attr-9s
.Dave.
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next prev parent reply other threads:[~2016-04-05 7:11 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-30 15:39 [PATCH v2 0/7] mtd: nand: sunxi: add support for DMA operations Boris Brezillon
[not found] ` <1459352394-22810-1-git-send-email-boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
2016-03-30 15:39 ` [PATCH v2 1/7] mtd: nand: sunxi: move some ECC related operations to their own functions Boris Brezillon
2016-03-30 15:39 ` [PATCH v2 2/7] mtd: nand: sunxi: make OOB retrieval optional Boris Brezillon
2016-03-30 15:39 ` [PATCH v2 3/7] mtd: nand: sunxi: make cur_off parameter optional in extra oob helpers Boris Brezillon
2016-03-30 15:39 ` [PATCH v2 4/7] scatterlist: add sg_alloc_table_from_buf() helper Boris Brezillon
[not found] ` <1459352394-22810-5-git-send-email-boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
2016-03-30 16:51 ` Mark Brown
[not found] ` <20160330165143.GI2350-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
2016-03-30 18:18 ` Boris Brezillon
2016-03-30 18:34 ` Mark Brown
2016-04-05 7:11 ` Dave Gordon [this message]
2016-03-31 4:56 ` [v2,4/7] " Vignesh R
[not found] ` <56FCAE1B.90206-l0cyMroinI0@public.gmane.org>
2016-03-31 7:26 ` Boris Brezillon
2016-03-30 15:39 ` [PATCH v2 5/7] mtd: provide helper to prepare buffers for DMA operations Boris Brezillon
2016-03-30 15:39 ` [PATCH v2 6/7] mtd: nand: sunxi: add support for DMA assisted operations Boris Brezillon
2016-03-30 15:39 ` [PATCH v2 7/7] mtd: nand: sunxi: update DT bindings Boris Brezillon
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