From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D0CF9C43381 for ; Thu, 28 Mar 2019 14:51:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9EE212075E for ; Thu, 28 Mar 2019 14:51:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726235AbfC1Ovu (ORCPT ); Thu, 28 Mar 2019 10:51:50 -0400 Received: from mga09.intel.com ([134.134.136.24]:49226 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725939AbfC1Ovt (ORCPT ); Thu, 28 Mar 2019 10:51:49 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Mar 2019 07:51:49 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,280,1549958400"; d="scan'208";a="332866189" Received: from smile.fi.intel.com (HELO smile) ([10.237.72.86]) by fmsmga005.fm.intel.com with ESMTP; 28 Mar 2019 07:51:47 -0700 Received: from andy by smile with local (Exim 4.92) (envelope-from ) id 1h9WNe-0003co-37; Thu, 28 Mar 2019 16:51:46 +0200 Date: Thu, 28 Mar 2019 16:51:46 +0200 From: Andy Shevchenko To: Borislav Petkov Cc: "H. Peter Anvin" , x86@kernel.org, Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 2/7] x86/boot: Introduce helpers for serial I/O Message-ID: <20190328145146.GH9224@smile.fi.intel.com> References: <20190319184325.72807-1-andriy.shevchenko@linux.intel.com> <20190319184325.72807-3-andriy.shevchenko@linux.intel.com> <20190328123250.GE22720@zn.tnic> <20190328131140.GX9224@smile.fi.intel.com> <20190328132855.GH22720@zn.tnic> <20190328135226.GB9224@smile.fi.intel.com> <20190328140508.GL22720@zn.tnic> <20190328142001.GD9224@smile.fi.intel.com> <20190328143447.GN22720@zn.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190328143447.GN22720@zn.tnic> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 28, 2019 at 03:34:47PM +0100, Borislav Petkov wrote: > On Thu, Mar 28, 2019 at 04:20:01PM +0200, Andy Shevchenko wrote: > > By name and by what it's handling (only byte accesses to I/O or MMIO). > > Your series does only byte accesses so you can use byte variant. > > > My point is, that doing branch(es) on each I/O call is not good as simple > > calling the proper (pre-defined) I/O accessor. > > What branches? Something like this at the end if (mmio32) ... else if (mmio) ... else if (whatever) ... else ... > You do a branch and *then* you do an IO call. Yes. > What does "not good" even mean? We still export global flag variable, on top of this we need an additional branch which we can avoid for free. -- With Best Regards, Andy Shevchenko