From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= Subject: Re: [PATCH] ARM: add get_user() support for 8 byte types Date: Mon, 19 Nov 2012 17:18:47 +0200 Message-ID: <20121119151847.GB3296@intel.com> References: <1352495853-9790-1-git-send-email-rob.clark@linaro.org> <201211151339.08016.arnd@arndb.de> <201211151439.41393.arnd@arndb.de> <20121119143236.GA3296@intel.com> <20121119144806.GO3332@n2100.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <20121119144806.GO3332@n2100.arm.linux.org.uk> Sender: linux-omap-owner@vger.kernel.org To: Russell King - ARM Linux Cc: Arnd Bergmann , Rob Clark , patches@linaro.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Jamie Lokier List-Id: dri-devel@lists.freedesktop.org On Mon, Nov 19, 2012 at 02:48:06PM +0000, Russell King - ARM Linux wrot= e: > On Mon, Nov 19, 2012 at 04:32:36PM +0200, Ville Syrj=E4l=E4 wrote: > > On Thu, Nov 15, 2012 at 02:39:41PM +0000, Arnd Bergmann wrote: > > > On Thursday 15 November 2012, Rob Clark wrote: > > > > > I still haven't heard a conclusive argument why we need to us= e get_user() > > > > > rather than copy_from_user() in the DRM code. Is this about a= fast path > > > > > where you want to shave off a few cycles for each call, or do= es this > > > > > simplify the code structure, or something else? > > > >=20 > > > > well, it is mostly because it seemed like a good idea to first = try to > > > > solve the root issue, rather than having to fix things up in ea= ch > > > > driver when someone from x86-world introduces a 64b get_user().= =2E > > >=20 > > > As pointed out by hpa earlier, x86-32 doesn't have a 64b get_user > > > either. I don't think we have a lot of drivers that are used only > > > on 64-bit x86 and on 32-bit ARM but not on 32-bit x86. > >=20 > > Ouch. I didn't realize that x86-32 doesn't have it. All the systems > > where I've run the new code are 64bit so I never noticed the proble= m. > >=20 > > I see there was a patch [1] posted a long time ago to implement 64b= it > > get_user() on x86-32. I wonder what happened to it? > >=20 > > [1] https://lkml.org/lkml/2004/4/20/96 >=20 > Wonderful lkml.org after four "Negotiating SSL connection..." message= s > gives me under elinks... =20 > what a wonderful site... please choose another LKML archive, preferab= ly > one which works. Thanks. This one look like the same thing: http://article.gmane.org/gmane.linux.kernel/198823 --=20 Ville Syrj=E4l=E4 Intel OTC -- To unsubscribe from this list: send the line "unsubscribe linux-omap" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html