Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752608AbaBCKfE (ORCPT ); Mon, 3 Feb 2014 05:35:04 -0500 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:50197 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752391AbaBCKfA (ORCPT ); Mon, 3 Feb 2014 05:35:00 -0500 Date: Mon, 3 Feb 2014 10:34:15 +0000 From: Will Deacon To: Leif Lindholm Cc: "msalter@redhat.com" , "linux-kernel@vger.kernel.org" , "grant.likely@secretlab.ca" , "linux-efi@vger.kernel.org" , "linux@arm.linux.org.uk" , "patches@linaro.org" , "roy.franz@linaro.org" , "matt.fleming@intel.com" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCH v4 2/5] arm: add new asm macro update_sctlr Message-ID: <20140203103415.GA12187@mudshark.cambridge.arm.com> References: <1389445524-30623-1-git-send-email-leif.lindholm@linaro.org> <1389445524-30623-3-git-send-email-leif.lindholm@linaro.org> <20140122112055.GF1621@mudshark.cambridge.arm.com> <20140129182805.GF11329@bivouac.eciton.net> <1391029124.2488.50.camel@deneb.redhat.com> <20140130131247.GG11329@bivouac.eciton.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140130131247.GG11329@bivouac.eciton.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 30, 2014 at 01:12:47PM +0000, Leif Lindholm wrote: > Oh, that's neat - thanks! > > Well, given that, I can think of two less horrible options: > 1) > .macro update_sctlr, tmp:req, set=, clear= > mrc p15, 0, \tmp, c1, c0, 0 > .ifnc \set, > orr \tmp, \set > .endif > .ifnc \clear, > mvn \clear, \clear > and \tmp, \tmp, \clear Can't you use bic here? > .endif > mcr p15, 0, \tmp, c1, c0, 0 > .endm > > With the two call sites in uefi_phys.S as: > > ldr r5, =(CR_M) > update_sctlr r12, , r5 > and > ldr r4, =(CR_I | CR_C | CR_M) > update_sctlr r12, r4 These ldr= could be movs, right? If so, I definitely prefer this to putting an ldr = into the macro itself (option 2). Cheers, Will -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/