From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751273AbdAQUNQ (ORCPT ); Tue, 17 Jan 2017 15:13:16 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:33295 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751030AbdAQUNN (ORCPT ); Tue, 17 Jan 2017 15:13:13 -0500 Subject: Re: [PATCH v4 4/4] sparc64: Add support for ADI (Application Data Integrity) To: David Miller References: <0c08eb00e5a9735d7d0bcbeaadeacaa761011aab.1483999591.git.khalid.aziz@oracle.com> <20170116.233924.374841184595409216.davem@davemloft.net> <767310a9-d3bd-9721-2d20-ce2c60cddd06@oracle.com> <20170117.144254.1482863576417019498.davem@davemloft.net> Cc: corbet@lwn.net, viro@zeniv.linux.org.uk, nitin.m.gupta@oracle.com, mike.kravetz@oracle.com, akpm@linux-foundation.org, mingo@kernel.org, kirill.shutemov@linux.intel.com, adam.buchbinder@gmail.com, hughd@google.com, minchan@kernel.org, keescook@chromium.org, chris.hyser@oracle.com, atish.patra@oracle.com, cmetcalf@mellanox.com, atomlin@redhat.com, jslaby@suse.cz, joe@perches.com, paul.gortmaker@windriver.com, mhocko@suse.com, lstoakes@gmail.com, jack@suse.cz, dave.hansen@linux.intel.com, vbabka@suse.cz, dan.j.williams@intel.com, iamjoonsoo.kim@lge.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org, linux-mm@kvack.org, khalid@gonehiking.org From: Khalid Aziz Organization: Oracle Corp Message-ID: <7e2eb04c-99fc-0adc-5712-6307eedab214@oracle.com> Date: Tue, 17 Jan 2017 13:12:32 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <20170117.144254.1482863576417019498.davem@davemloft.net> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Source-IP: userv0022.oracle.com [156.151.31.74] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/17/2017 12:42 PM, David Miller wrote: > From: Khalid Aziz > Date: Tue, 17 Jan 2017 12:32:46 -0700 > >> On 01/16/2017 09:39 PM, David Miller wrote: >>> From: Khalid Aziz >>> Date: Wed, 11 Jan 2017 09:12:54 -0700 >>> >>>> + __asm__ __volatile__( >>>> + ".word 0xa1438000\n\t" /* rd %mcdper, %l0 */ >>> >>> Just use "rd %%asr14, %0" this way you don't have to play all of these >>> fixed register games which kill the code generated by gcc. If you >>> forcefully clobber a windowed register like %l0 it means the function >>> being emitted can never be a leaf function, tail calls are no longer >>> allowed, etc. >> >> Hi David, >> >> "rd %%asr14, %0" should work but does not due to bugs in assembler - >> , and >> . These bugs >> were fixed in binutils 2.27 but older assemblers will cause kernel >> build to fail. Using byte coded equivalent is the safest option. > > Fair enough. > > Then please at least use %g1 or another usable global register to > avoid at least some of the problems I mentioned. > Sure, I will do that. Thanks for the review and feedback. -- Khalid