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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 EEB81C43457 for ; Tue, 13 Oct 2020 23:57:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A708622251 for ; Tue, 13 Oct 2020 23:57:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388705AbgJMX5C (ORCPT ); Tue, 13 Oct 2020 19:57:02 -0400 Received: from mga07.intel.com ([134.134.136.100]:3817 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387742AbgJMX5C (ORCPT ); Tue, 13 Oct 2020 19:57:02 -0400 IronPort-SDR: oEilyMO80P99tUtBvHQyfBsYB4QsCq0vGk+hR2alHfoiSdoawQZ4FytKdy52kewP9KCgT6aTHo l0/LYbpLM+vQ== X-IronPort-AV: E=McAfee;i="6000,8403,9773"; a="230182065" X-IronPort-AV: E=Sophos;i="5.77,372,1596524400"; d="scan'208";a="230182065" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Oct 2020 16:57:00 -0700 IronPort-SDR: lCvdsHw4cNTMWJa/vna7fQPxd5RyrFTF13wYh2AkHf4SXv0mM4ELq6g5e3ZAT7t1A0eXxCnwi8 qz1MFAWCB0PA== X-IronPort-AV: E=Sophos;i="5.77,372,1596524400"; d="scan'208";a="463687969" Received: from iweiny-desk2.sc.intel.com (HELO localhost) ([10.3.52.147]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Oct 2020 16:56:59 -0700 Date: Tue, 13 Oct 2020 16:56:59 -0700 From: Ira Weiny To: Dave Hansen Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Andy Lutomirski , Peter Zijlstra , Fenghua Yu , x86@kernel.org, Dave Hansen , Dan Williams , Andrew Morton , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH RFC V3 2/9] x86/fpu: Refactor arch_set_user_pkey_access() for PKS support Message-ID: <20201013235658.GL2046448@iweiny-DESK2.sc.intel.com> References: <20201009194258.3207172-1-ira.weiny@intel.com> <20201009194258.3207172-3-ira.weiny@intel.com> <7ed91cb5-93e5-67ad-ad35-8489d16d283f@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7ed91cb5-93e5-67ad-ad35-8489d16d283f@intel.com> User-Agent: Mutt/1.11.1 (2018-12-01) Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org On Tue, Oct 13, 2020 at 10:50:05AM -0700, Dave Hansen wrote: > On 10/9/20 12:42 PM, ira.weiny@intel.com wrote: > > +/* > > + * Update the pk_reg value and return it. > > How about: > > Replace disable bits for @pkey with values from @flags. Done. > > > + * Kernel users use the same flags as user space: > > + * PKEY_DISABLE_ACCESS > > + * PKEY_DISABLE_WRITE > > + */ > > +u32 update_pkey_val(u32 pk_reg, int pkey, unsigned int flags) > > +{ > > + int pkey_shift = pkey * PKR_BITS_PER_PKEY; > > + > > + pk_reg &= ~(((1 << PKR_BITS_PER_PKEY) - 1) << pkey_shift); > > + > > + if (flags & PKEY_DISABLE_ACCESS) > > + pk_reg |= PKR_AD_BIT << pkey_shift; > > + if (flags & PKEY_DISABLE_WRITE) > > + pk_reg |= PKR_WD_BIT << pkey_shift; > > I still think this deserves two lines of comments: > > /* Mask out old bit values */ > > /* Or in new values */ Sure, done. Ira