linux-kernel - Re: [PATCH] dmaengine: add dma_ctrl_cmd to pass buffer stride configuration

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 for Android: free password hash cracker in your pocket

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

Message-ID: <CABb+yY2=CrA8=9ces=4ABjxrHieXjtJTGm6Q3Kg30eHye9_N2g@mail.gmail.com>
Date:	Sun, 24 Jul 2011 02:05:28 +0530
From:	Jassi Brar <jassisinghbrar@...il.com>
To:	"Raju, Sundaram" <sundaram@...com>
Cc:	Linus Walleij <linus.walleij@...aro.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"davinci-linux-open-source@...ux.davincidsp.com" 
	<davinci-linux-open-source@...ux.davincidsp.com>,
	"linux@....linux.org.uk" <linux@....linux.org.uk>,
	"dan.j.williams@...el.com" <dan.j.williams@...el.com>,
	"linux-omap@...r.kernel.org" <linux-omap@...r.kernel.org>
Subject: Re: [PATCH] dmaengine: add dma_ctrl_cmd to pass buffer stride configuration

On Mon, Jul 18, 2011 at 1:21 PM, Raju, Sundaram <sundaram@...com> wrote:
>>
>> Maybe a new api to pass fixed-format variable-length encoded message
>> to the DMAC drivers?
>> Which could be interpreted by DMAC drivers to extract all the needed xfer
>> parameters from the 'header' section and instructions to program the xfers
>> in the DMAC from the variable length body of the 'message' buffer.
>> It might sound complicated but we can have helpers to make the job easy.
>> Btw, the regular single/sg-list xfers could also be expressed by this method.
>
> Do you expect this variable length body of the message to be DMAC
> independent? I don't think so. In that case how is this different from what
> we have here already?
Yes, this whould be DMAC independent.

> If it can be DMAC independent, can you illustrate more on how this can
> be done? But the point to note is, if this can be made DMAC independent
> then the control command we have also can be made DMAC independent
> by generalizing the configuration structure passed to it.
The 'header' I suggest, would in fact be a structure body, only an extra pointer
would point to the 'instructions' to convey actual location and sizes
of mico-xfers.
I don't think it is possible to have general definition of such transfers fully
within a structure. If I understand what you ask.

I have just posted an RFC. I kept the terms same so that it is easier
to understand.
Please have a look. You are CC'ed too.

Thanks,
Jassi
--
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/