linux-kernel - Re: Dmaengine query

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Mon, 24 May 2010 02:01:34 +0200
From:	Linus Walleij <linus.ml.walleij@...il.com>
To:	rd bairva <rbairva@...il.com>
Cc:	Dan Williams <dan.j.williams@...el.com>,
	linux-arm-kernel@...ts.arm.linux.org.uk,
	linux-kernel@...r.kernel.org
Subject: Re: Dmaengine query

2010/4/19 rd bairva <rbairva@...il.com>:

>    My DMA controller supports device to device DMA transfers and we
> need it in some of our drivers. Existing DMA engine framework doesn't
> have support for device to device transfers.
>
> Do you have any plans for device to device support in DMA engine?
>
> Can you suggest me some other suggestion for doing this?

Extend the DMA engine with the stuff you need and propose nice
patches, provide them along with a driver that make use of this
feature.

What about a signature like this:

struct dma_async_tx_descriptor *(*device_prep_slave2slave)(
                struct dma_chan *chan1, struct dma_chan *chan2,
                enum dma_data_direction direction,
                unsigned long flags);

You'd have to add some semantics comment saying that
DMA_TO_DEVICE means chan1->chan2 and
DMA_FROM_DEVICE means chan1<-chan2.

Could be a bit of hacking but how hard can it be?

Yours,
Linus Walleij
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/