From: Russell King - ARM Linux Subject: Re: [PATCH v3 1/4] crypto: Add Allwinner Security System crypto accelerator Date: Sun, 22 Jun 2014 13:33:35 +0100 Message-ID: <20140622123335.GE32514@n2100.arm.linux.org.uk> References: <1402404197-4236-1-git-send-email-clabbe.montjoie@gmail.com> <201406142101.02747.marex@denx.de> <53A6C4D0.1030102@gmail.com> <201406221423.15193.marex@denx.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii 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, herbert@gondor.apana.org.au, davem@davemloft.net, grant.likely@linaro.org, devicetree@vger.kernel.org, linux-doc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, linux-sunxi@googlegroups.com To: Marek Vasut Return-path: Content-Disposition: inline In-Reply-To: <201406221423.15193.marex@denx.de> Sender: linux-doc-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org On Sun, Jun 22, 2014 at 02:23:15PM +0200, Marek Vasut wrote: > On Sunday, June 22, 2014 at 01:58:08 PM, Corentin LABBE wrote: > [...] > > >> + * This program is free software; you can redistribute it and/or modify > > >> + * it under the terms of the GNU General Public License as published by > > >> + * the Free Software Foundation version 2 of the License > > > > > > The license text seems incomplete. > > > [...] > > > > I will replace it with a simplier line "Licensed under the GPL-2." > > I'd suggest you to use the SPDX license identifiers then, but that's not > something the kernel crowd agreed upon yet IIRC.Therefore , just make the text > complete please. Marek, The full text of the first paragraph (in COPYING) is: This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. which is deemed to be entirely sufficient; quoting the full text is discouraged, especially when it includes the FSF address. It is also acceptable to restrict it to version 2 only, in which case something like this can be used: This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License version 2 as published by the Free Software Foundation. Of course, it's up to the author to make up their own mind at the end of the day. > Oh, ok, good question -- dear list, shall one use sg_page()+kmap or sg_virt()? sg_page() + kmap() is preferred, because sg_virt() fails with highmem. Using sg_virt() means you restrict the driver to non-highmem memory, and if the kernel wants to place the data into a highmem page, it will have to use bounce buffers (so it's inefficient). What's even better is to use the scatterlist iterator, which will handle this for you. See the sg_miter_*() functions. -- FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly improving, and getting towards what was expected from it.