From: Linus Torvalds Subject: Re: Crypto Update for 2.6.38 Date: Thu, 6 Jan 2011 10:05:46 -0800 Message-ID: References: <20081225001724.GA2813@gondor.apana.org.au> <20081225002020.GA2912@gondor.apana.org.au> <20090324044932.GA18245@gondor.apana.org.au> <20091204135530.GA29371@gondor.apana.org.au> <20100226004914.GA20812@gondor.apana.org.au> <20100519020603.GA19654@gondor.apana.org.au> <20100521104404.GA29530@gondor.apana.org.au> <20100804140448.GA4042@gondor.apana.org.au> <20101024061625.GA23715@gondor.apana.org.au> <20110106000157.GA16089@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: "David S. Miller" , Linux Kernel Mailing List , Linux Crypto Mailing List To: Herbert Xu Return-path: In-Reply-To: <20110106000157.GA16089@gondor.apana.org.au> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org On Wed, Jan 5, 2011 at 4:01 PM, Herbert Xu wrote: > > * Crypto API interface for user-space (hash + skcipher) Is there really any point to this? And can we get more explanation of what the interface is, and who would use it? If you need crypto in user space, it's almost invariably better done in user space. If the CPU can do crypto on its own, and doesn't expose those instructions to user space, it's just a stupid CPU - and the user/kernel transfer is likely going to make it slower than a pure software approach for any but the biggest transfers. And if the crypto engine is off-chip, the sw version is going to be faster anyway except for possible async versions that are hard to interface to user space. So I really need more convincing about the whole user-space interface. Adding new interfaces willy-nilly isn't a good idea. They need damn good reasons. Linus