From mboxrd@z Thu Jan 1 00:00:00 1970 From: Herbert Xu Subject: Re: [PATCH 3/3] crypto: Add Allwinner Security System crypto accelerator Date: Thu, 24 Jul 2014 09:40:57 +0800 Message-ID: <20140724014057.GA2448@gondor.apana.org.au> References: <1400771396-9686-1-git-send-email-clabbe.montjoie@gmail.com> <201407231751.02050.marex@denx.de> <53D0045C.6090605@gmail.com> <201407232138.35268.marex@denx.de> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Corentin LABBE , robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, rdunlap@infradead.org, maxime.ripard@free-electrons.com, linux@arm.linux.org.uk, davem@davemloft.net, grant.likely@linaro.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org To: Marek Vasut Return-path: Received: from helcar.apana.org.au ([209.40.204.226]:37420 "EHLO helcar.apana.org.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755787AbaGXBlx (ORCPT ); Wed, 23 Jul 2014 21:41:53 -0400 Content-Disposition: inline In-Reply-To: <201407232138.35268.marex@denx.de> Sender: linux-crypto-owner@vger.kernel.org List-ID: On Wed, Jul 23, 2014 at 09:38:35PM +0200, Marek Vasut wrote: > On Wednesday, July 23, 2014 at 08:52:12 PM, Corentin LABBE wrote: > > Le 23/07/2014 17:51, Marek Vasut a =E9crit : > > > On Wednesday, July 23, 2014 at 04:13:09 PM, Herbert Xu wrote: > > >> On Wed, Jul 23, 2014 at 04:07:20PM +0200, Marek Vasut wrote: > > >>> On Wednesday, July 23, 2014 at 03:57:35 PM, Herbert Xu wrote: > > >>>> On Sat, May 24, 2014 at 02:00:03PM +0200, Marek Vasut wrote: > > >>>>>> + } > > >>>>>> +#endif > > >>>>>> + > > >>>>>> +#ifdef CONFIG_CRYPTO_DEV_SUNXI_SS_MD5 > > >>>>>> + err =3D crypto_register_shash(&sunxi_md5_alg); > > >>>>>=20 > > >>>>> Do not use shash for such device. This is clearly and ahash (= and > > >>>>> async in general) device. The rule of a thumb here is that yo= u use > > >>>>> sync algos only for devices which have dedicated instructions= for > > >>>>> computing the transformation. For devices which are attached = to some > > >>>>> kind of bus, you use async algos (ahash etc). > > >>>>=20 > > >>>> I'm sorry that I didn't catch this earlier but there is no suc= h > > >>>> rule. > > >>>>=20 > > >>>> Unless you need the async interface you should stick to the sy= nc > > >>>> interfaces for the sake of simplicity. > > >>>>=20 > > >>>> We have a number of existing drivers that are synchronous but > > >>>> using the async interface. They should either be converted > > >>>> over to the sync interface or made interrupt-driven if possibl= e. > > >>>=20 > > >>> Sure, but this device is interrupt driven and uses DMA to feed = the > > >>> crypto engine, therefore async, right ? > > >>=20 > > >> If it's interrupt-driven, then yes it would certainly make sense= to > > >> be async. But all I see is polling in the latest posting, was t= he > > >> first version different? > > >=20 > > > I stand corrected then, sorry. > > >=20 > > > Is it possible to use DMA to feed the crypto accelerator, Corenti= n? > > >=20 > > > Best regards, > > > Marek Vasut > >=20 > > Yes, DMA is possible and will be implemented soon. > > So if I have well understood, I keep using async interface. >=20 > Yeah, in this case, using DMA and async interface combo is the way to= go. OK fair enough. --=20 Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt From mboxrd@z Thu Jan 1 00:00:00 1970 From: herbert@gondor.apana.org.au (Herbert Xu) Date: Thu, 24 Jul 2014 09:40:57 +0800 Subject: [PATCH 3/3] crypto: Add Allwinner Security System crypto accelerator In-Reply-To: <201407232138.35268.marex@denx.de> References: <1400771396-9686-1-git-send-email-clabbe.montjoie@gmail.com> <201407231751.02050.marex@denx.de> <53D0045C.6090605@gmail.com> <201407232138.35268.marex@denx.de> Message-ID: <20140724014057.GA2448@gondor.apana.org.au> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Jul 23, 2014 at 09:38:35PM +0200, Marek Vasut wrote: > On Wednesday, July 23, 2014 at 08:52:12 PM, Corentin LABBE wrote: > > Le 23/07/2014 17:51, Marek Vasut a ?crit : > > > On Wednesday, July 23, 2014 at 04:13:09 PM, Herbert Xu wrote: > > >> On Wed, Jul 23, 2014 at 04:07:20PM +0200, Marek Vasut wrote: > > >>> On Wednesday, July 23, 2014 at 03:57:35 PM, Herbert Xu wrote: > > >>>> On Sat, May 24, 2014 at 02:00:03PM +0200, Marek Vasut wrote: > > >>>>>> + } > > >>>>>> +#endif > > >>>>>> + > > >>>>>> +#ifdef CONFIG_CRYPTO_DEV_SUNXI_SS_MD5 > > >>>>>> + err = crypto_register_shash(&sunxi_md5_alg); > > >>>>> > > >>>>> Do not use shash for such device. This is clearly and ahash (and > > >>>>> async in general) device. The rule of a thumb here is that you use > > >>>>> sync algos only for devices which have dedicated instructions for > > >>>>> computing the transformation. For devices which are attached to some > > >>>>> kind of bus, you use async algos (ahash etc). > > >>>> > > >>>> I'm sorry that I didn't catch this earlier but there is no such > > >>>> rule. > > >>>> > > >>>> Unless you need the async interface you should stick to the sync > > >>>> interfaces for the sake of simplicity. > > >>>> > > >>>> We have a number of existing drivers that are synchronous but > > >>>> using the async interface. They should either be converted > > >>>> over to the sync interface or made interrupt-driven if possible. > > >>> > > >>> Sure, but this device is interrupt driven and uses DMA to feed the > > >>> crypto engine, therefore async, right ? > > >> > > >> If it's interrupt-driven, then yes it would certainly make sense to > > >> be async. But all I see is polling in the latest posting, was the > > >> first version different? > > > > > > I stand corrected then, sorry. > > > > > > Is it possible to use DMA to feed the crypto accelerator, Corentin? > > > > > > Best regards, > > > Marek Vasut > > > > Yes, DMA is possible and will be implemented soon. > > So if I have well understood, I keep using async interface. > > Yeah, in this case, using DMA and async interface combo is the way to go. OK fair enough. -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt