linux-kernel - Re: [PATCH v2 2/2] Crypto: Talitos: Support for Async

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

Message-Id: <C0E3E9A1-7B65-4D57-8813-C2F4B4E2060B@kernel.crashing.org>
Date:	Thu, 17 Dec 2009 11:29:26 -0600
From:	Kumar Gala <galak@...nel.crashing.org>
To:	"Ira W. Snyder" <iws@...o.caltech.edu>
Cc:	Dan Williams <dan.j.williams@...el.com>,
	"herbert@...dor.apana.org.au" <herbert@...dor.apana.org.au>,
	"B04825@...escale.com" <B04825@...escale.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-raid@...r.kernel.org" <linux-raid@...r.kernel.org>,
	"linuxppc-dev@...abs.org" <linuxppc-dev@...abs.org>,
	Vishnu Suresh <Vishnu@...escale.com>,
	"linux-crypto@...r.kernel.org" <linux-crypto@...r.kernel.org>,
	Dipen Dudhat <Dipen.Dudhat@...escale.com>,
	Maneesh Gupta <Maneesh.Gupta@...escale.com>,
	"R58472@...escale.com" <R58472@...escale.com>
Subject: Re: [PATCH v2 2/2] Crypto: Talitos: Support for Async_tx XOR offload


On Dec 17, 2009, at 11:09 AM, Ira W. Snyder wrote:

> On Wed, Dec 16, 2009 at 03:47:48PM -0700, Dan Williams wrote:
>> Kumar Gala wrote:
>>>>> Changes with respect to v1 as per comments received
>>>>> o. Rebased to linux-next as of 20091216
>>>>> o. The selection is based exclusive of fsldma
>>>>> o. Intoduced a new Kernel Configuration variable
>>>>>  *. This enables selecting the Cryptographic functionality
>>>>>     of Talitos along with fsldma.
>>>>>  *. Disables the XOR parity calculation offload, if fsldma enabled
>>>>>     either as kernel in-built or as a module
>>>>>  *. Once the inter-operability with fsldma is resolved, this option
>>>>>     can be removed
>>>> wait, why can't the interoperability bug be fixed in the first place?
>>> 
>>> I agree w/Kim.  We need to better understand what the bug is and how to reproduce it so we can get to the root cause.
>>> 
>>> Paper taping over it by disabling fsldma is not the right solution.
>> 
>> Hopefully this prompts fsldma authors to get involved because the 
>> interoperability issue has been out there without comment*, just 
>> band-aids, since October.
>> 
>> --
>> Dan
>> 
>> * well one comment from Ira saying the interrupt functionality worked 
>> for him.
> 
> Yes, I have used the device_prep_dma_interrupt() functionality quite a
> while back. However, I found it to be pretty much useless. Any
> functionality I need is covered by adding a callback to the last DMA
> memcpy() operation. Since the operations happen in-order, I can be sure
> that the entire set of memcpy()s cas completed. I never needed the
> capability to generate an interrupt without a memcpy().
> 
> I agree that the fsldma driver could use some love. There are places
> where I am still not confident in the locking. Perhaps I can find some
> time over Christmas to work on it, but I need someone with 85xx/86xx
> hardware to test the changes. I only have 83xx hardware.

I can test on 85xx/86xx if you work up some patches.

- k--
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/