From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 40DE31A1D6E for ; Fri, 10 Jul 2015 06:42:34 +1000 (AEST) Received: from na01-bn1-obe.outbound.protection.outlook.com (mail-bn1on0119.outbound.protection.outlook.com [157.56.110.119]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 87DB6140273 for ; Fri, 10 Jul 2015 06:42:33 +1000 (AEST) Message-ID: <1436473657.2658.126.camel@freescale.com> Subject: Re: [PATCH 1/2] powerpc/kexec: Reset secondary cpu endianess before kexec From: Scott Wood To: Segher Boessenkool CC: Paul Mackerras , , "Samuel Mendoza-Jonas" Date: Thu, 9 Jul 2015 15:27:37 -0500 In-Reply-To: <20150709154211.GB2990@gate.crashing.org> References: <1436318605-13031-1-git-send-email-sam.mj@au1.ibm.com> <1436322938.2658.60.camel@freescale.com> <20150708040455.GA9086@pale.ozlabs.ibm.com> <1436329328.2658.75.camel@freescale.com> <20150709154211.GB2990@gate.crashing.org> Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, 2015-07-09 at 10:42 -0500, Segher Boessenkool wrote: > On Tue, Jul 07, 2015 at 11:22:08PM -0500, Scott Wood wrote: > > > I agree about using labels, but "bcl 20,31,foo" is not the same thing > > > as "bl foo". The former is a form of bl that doesn't perturb the link > > > stack and is therefore better for performance when you're not going to > > > do a matching blr later (not that performance is at all critical > > > here). > > > > If performance mattered I would have complained about the extra mfmsr. :-) > > > > I see that some other parts of the kernel are using that bcl instruction, > > but > > if it is actually worthwhile in those places, it'd be nice to at least > > stick > > it in a macro for readability... > > How is that going to help? It's just idiom; replacing it with some other > idiom only means people already used to the 20,31 thing (which is quite old > by now, btw.; 74xx days) will have to learn the new thing. That's fine for people who are used to it (especially if it's the only number- based bc they routinely come across), but I had to look up what it meant. Simplified mnemonics exist for a reason. > Unless you can think of a nice short name that can even be made an extended > mnemonic? For a macro I was thinking "BL_NORET" but for a mnemonic it'd probably be shortened to something like "blnr". -Scott