From: Maxime Ripard Subject: Re: [PATCH v5 4/4] crypto: Add Allwinner Security System crypto accelerator Date: Thu, 6 Nov 2014 15:26:33 +0100 Message-ID: <20141106142633.GK2989@lukather> References: <20141021191149.GQ21108@lukather> <544A9FEA.6020304@gmail.com> <20141030171933.GR21251@lukather> <20141031072030.GA7563@gondor.apana.org.au> <20141031081323.GS21251@lukather> <20141031081803.GA8012@gondor.apana.org.au> <20141031095706.GA8054@lukather> <20141031100522.GA8655@gondor.apana.org.au> <20141103093446.GG11263@lukather> <20141103103528.GA30154@gondor.apana.org.au> Reply-To: linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="JvUS8mwutKMHKosv" Cc: Corentin LABBE , robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, pawel.moll-5wv7dgnIgG8@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org, galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org, davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org, grant.likely-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, joe-6d6DIl74uiNBDgjK7y7TUQ@public.gmane.org, mchehab-JPH+aEBZ4P+UEJcrhfAQsw@public.gmane.org, crope-X3B1VOXEql0@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-crypto-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To: Herbert Xu Return-path: Content-Disposition: inline In-Reply-To: <20141103103528.GA30154-lOAM2aK0SrRLBo1qDEOMRrpzq4S04n8Q@public.gmane.org> List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , List-Id: linux-crypto.vger.kernel.org --JvUS8mwutKMHKosv Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Nov 03, 2014 at 06:35:28PM +0800, Herbert Xu wrote: > On Mon, Nov 03, 2014 at 10:34:46AM +0100, Maxime Ripard wrote: > > What I mean is that since you are saying that drivers should do the > > kmap themselves, then *all* of the drivers are broken if they are not > > using it. And all of them are missing this kmap. >=20 > kmap is used by the software implementations to map the input/output > into virtual address space. Drivers typically use DMA and operate > on physical addresses so they don't need kmap. Yes, plus all memory allocated with GFP_KERNEL is in lowmem. But you still haven't explain why the driver, while it doesn't handle the user space buffer at any time, should be worried that the data the framework has given him are actually mapped. Maxime --=20 Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com --JvUS8mwutKMHKosv Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJUW4UZAAoJEBx+YmzsjxAgDMcP/1PI8AbGVPKn44oM9vlitRY2 zkR4bqd8Ka52kpPFiDzz8BMFjYXyLYxGZRydtAk78XM5WZy0diY5raC8TmU/nWVP oWjWlPbj9xmHTuUXhawzw71uSfNSAqyDaXGPGBDCovgi7Y5XD9mZmybDx9xqY73V FNNXyTmmkX+mn3i8pPMVzgPjWS/eWhs6zt3Sy8I8aI6BU+lnUmJAhutCX+F8+XX1 klD7+KQ1ABwaXed1nj3cHYx4pzDfqsCVx04GSuHD0DmLT5/bEv0WYM54kQ2gmXKy 2748Ec7hd07IH0ybcEXYQYCEV0hokF4udABo4XZpp8sqdz+O1jaYW7BLbGco8//g P+4wlHvHYMMNgqaKZHT9cBNKdB1pHP8iAaYlF3Gk4ekHZWq5K5sSRb8Z0elBJf/m Wk+XptdoX6Egrxg9O9wj9Ph29s5uDaLEP6Xtm6tmRjynSPWQqf3WEPuIGihD7CCP 7GPZ40LRUXK+9u7DxeBqZPAFBomtRQ1MEhTFjWNQV4wLFPxAEb752s5B8mETwJoo bqgD60RLVU1FT35VCpnZMcj9tgudR5cZ7O/TzeimUQsDgReix5CWCd25JKU5K8tR b/d2BIIa9iok6mttNXqCabQeROEdSPnUCDkGX8Ur4EBCwg0vhSOZzFnyPgYZ9vUH udGNo+6MjczuQVcXdlHu =AyfL -----END PGP SIGNATURE----- --JvUS8mwutKMHKosv--