From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754053AbbIKVfc (ORCPT ); Fri, 11 Sep 2015 17:35:32 -0400 Received: from mail-by2on0144.outbound.protection.outlook.com ([207.46.100.144]:36736 "EHLO na01-by2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751411AbbIKVf1 (ORCPT ); Fri, 11 Sep 2015 17:35:27 -0400 Authentication-Results: spf=none (sender IP is ) smtp.mailfrom=scottwood@freescale.com; Message-ID: <1442007315.2909.49.camel@freescale.com> Subject: Re: [PATCH v3] powerpc32: memcpy: only use dcbz once cache is enabled From: Scott Wood To: Christophe Leroy CC: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , , , Date: Fri, 11 Sep 2015 16:35:15 -0500 In-Reply-To: <20150911143348.F1D9F1A2420@localhost.localdomain> References: <20150911143348.F1D9F1A2420@localhost.localdomain> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.16.0-fta1 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Originating-IP: [2601:448:8100:f9f:12bf:48ff:fe84:c9a0] X-ClientProxiedBy: BY2PR02CA0032.namprd02.prod.outlook.com (10.141.216.22) To CY1PR03MB1485.namprd03.prod.outlook.com (25.163.17.158) X-Microsoft-Exchange-Diagnostics: 1;CY1PR03MB1485;2:fAR2r0oF/8m7hMP9tF31/OYQqwNmgZ1GEnaAyCOXp7Un7NizwuLVokvvtBHeocfBCbsUaod1dEPOpdl0d16JLFSc4SiHwCWRFDHpfX6y1OoHlWkwouOHI6pM0Z27HGUTYp3+tszF9XHlX8rMmz/+6gAMH5FiTGYRzxWMOocR1YE=;3:XPzHWbfUsEfu96mriY3dS3VTPfJ6p2r7e6g5PUGWfBNbjJ8N9ZZqFZBDQ2zMf2QsD71xZ+agKgJqx1tJEWj6OJ66Efoz6rAEUUJ53aVwRxefAq/GNGO1XKmORbZIF+qaU13yFp65tMX16xLh7Xnh3g==;25:+YDacLsbr5TpM3OmssCVUVAr9Z3xJCKhdBVRw7Viy+Jk3chmD4qd5dH0s7W5/a7diPV+POf+IF+hP6kXD8ghu0tLmx8nP/xxnCol9yZwsnePYa7Em1AmdNI2gzfGFaoFg675IucYrAMKQ/9KWKfgmp/Dm/MT+vUYYf7pyncFpzXMbpHWI86taCdBbwzexBPdPC8TRbOWQaplBdRGgW5PDABxvV0slMbYMKWh08RnTVmPJzoy3BbA62L1vrfM8tZ5rzZOxRDP/LKvZXaZqyHTvw== X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:;SRVR:CY1PR03MB1485; X-Microsoft-Exchange-Diagnostics: 1;CY1PR03MB1485;20: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;4:6ZtUXEbdrSyDR5hFFw71aHMqE1ngOHNuJtjm99h8SaBaYM0RRJoGRwX6BXdg7s5Z6M9OHdNZk/di1cbn5UVIcLpDzM9trR+45W3RNd8cwCKT+bI3uPpm5KvPgAQYygOCRfTCwwdh22GbdcMSgI8eH0/MW7d41sgCymB3zaN8ZUWgCQHhSm+YQwzDOZd1fKJoT5yCZ7vMHXU+X4bS0pMjx331yJTwSFVBWo3DXW0EBT5E0gdYz3zOY0xNgdw/OCuJBLCmgVSdRIAjBn/w1DhVpjODpKQSV5l7/qNLvvbXB094esTA3PfGOcyGztsM23Kd X-Microsoft-Antispam-PRVS: X-Exchange-Antispam-Report-Test: UriScan:; X-Exchange-Antispam-Report-CFA-Test: BCL:0;PCL:0;RULEID:(601004)(5005006)(8121501046)(3002001);SRVR:CY1PR03MB1485;BCL:0;PCL:0;RULEID:;SRVR:CY1PR03MB1485; X-Forefront-PRVS: 06968FD8C4 X-Forefront-Antispam-Report: SFV:NSPM;SFS:(10019020)(6009001)(189002)(199003)(377424004)(24454002)(62966003)(103116003)(86362001)(50986999)(81156007)(77156002)(5001960100002)(33646002)(19580395003)(19580405001)(76176999)(40100003)(189998001)(5001830100001)(5001860100001)(42186005)(97736004)(64706001)(47776003)(92566002)(2950100001)(5007970100001)(68736005)(5004730100002)(87976001)(4001540100001)(5820100001)(23676002)(50466002)(110136002)(122386002)(106356001)(101416001)(77096005)(46102003)(36756003)(105586002)(50226001)(99106002)(3826002)(5001840100002);DIR:OUT;SFP:1102;SCL:1;SRVR:CY1PR03MB1485;H:[IPv6:2601:448:8100:f9f:12bf:48ff:fe84:c9a0];FPR:;SPF:None;PTR:InfoNoRecords;MX:1;A:1;LANG:en; X-Microsoft-Exchange-Diagnostics: =?utf-8?B?MTtDWTFQUjAzTUIxNDg1OzIzOngvajZWYWd5ME5PSlpueW1zSnRQUVRRdStl?= =?utf-8?B?bDk4T3krRDZoZTZ5bWIxVldPb2ZrRjZhRmNMM3hyY1Y1QUl4VFlMSDl3dXNT?= =?utf-8?B?NHoxb0NkT0VWbTRxTiszR0ZlM2ZnZE5FdUI0L3Rib3VsODd5cXoveUpOdXdS?= =?utf-8?B?S3BKYUUyZGRvLzFaNjROK2hvOXBZckdvSXBJVEEreklBMysyZVBTeFp4Skhj?= =?utf-8?B?V0xoTjUxUUx5cyszcWsxRjFsbUowd2N4QVJudkZ5d2VGaEYrMHNyaWM4aEha?= =?utf-8?B?M0NxaXRGWjF0aUFxZDNvcURyNWVwenRpOTVYVEdxR09XQUVyWC9SVm9UZGE1?= =?utf-8?B?S0lwNUhJM2VFU0pGYTc5bVJtVGpXcVpEa00xa216aHNNc21BVE84am5pRzFO?= =?utf-8?B?R0N4MFdWRW9IdTRpQ0h4elREdDBJZzRFL3RuWlJtaTRkQWhJTDNsMTF4Q3FJ?= =?utf-8?B?eGhNZ3pUZEZhZkdjbGlQU21pS1BQdVo2L0lvaUZMVUNuaUpDS1kreUw4OE1I?= =?utf-8?B?UjMyWm1PNUhabkNteCtSTGtUSlFVemwwbWZTaW1OUjdCTnlSNXNTcXZOSUpB?= =?utf-8?B?WnZIaE5TcDZJdTlsbHhwRW1SakRwWFRuNU8xN0RsODFNZzR3ejZWMWFXRm9J?= =?utf-8?B?V3c3K0dIa0JLL3hHa3pma0txRnM1UmpGSHpsSEhoZk5HNzk0bnBneXBXTkpS?= =?utf-8?B?MXhNRHRieXlJTTlJMmsyZ3ZRSzZWRk1xMC9MS3hBNXlsWnVZY0J2YVIrRThE?= =?utf-8?B?YjJTK09sa01iaFRIcW1FdmQwbVJhYVNpdG0rRm9INFVJSmIyYUxNTUpPZ0lh?= =?utf-8?B?aG9aa3VjMktDRlp2dFFWZVB5YUllMjFFZXhHVW5CMEpFY2o0VCtqUEZJSU5M?= =?utf-8?B?TjJYNDY5cDdINU5Rdmltb0Zmb3pxT0hVcFV3SXNtRlVGclFJK1oraDkyMWpN?= =?utf-8?B?WVVzN3N2S1VCTVkxQkZZT2NORm50UllOdUxINlZnTVRIbTdFNk8yTS84MjV0?= =?utf-8?B?TC8vcEw2dXl6YzA0aTJXNVBLM3c2STlrcDRQVldTUWkvN2Fjby9yYlJhVFdH?= =?utf-8?B?a2FpM1YwbHRGQmt5R1NNZ2pRVkFBMStUQ250ckdVOE9ERnpVQ2t5N1lBNFZj?= =?utf-8?B?elIvS3VobDVERlh1aUg2Y25xTWg5STJOamg4cXVmb0VHVjh6WGdWc3daM2hV?= =?utf-8?B?Mzlibm44RFpQZFV4WFl4TDlVbk9tL0NNZ2FkV1dsMlUydC9HMU04RzFSSDMr?= =?utf-8?B?OVM5clNXdEpoUUprV2g0dVZ4aDBoanZ6MWVudW5oejA4enNGTzRYZ3RMTklE?= =?utf-8?B?b0w4bG5wcENydnVHaDZ2TUtpcFl1KzhUdXhjTHQ4dkdkSzBpcFJqemIrMHBV?= =?utf-8?B?a0VOUytyRnk4NE1PNkwzMndacjBQTmE0N09wWHB0TE1SSHFaR0Vyd0UvRmtZ?= =?utf-8?B?NnllK1pUa0hSWWlKQmt6SFpVV3hHZnNaRFZSWXRtRVBHU0VqRjN2NW1xUllK?= =?utf-8?B?bnFiVWJmMGZxMEZCd3ZxNFVLMk9Vb0tHR0dObkw0ajZEQVVYQVdaU05LaVJv?= =?utf-8?B?L1lSbWpBWTBqZ1NvNElDTjNQV09xWmU4VFBVRXhJS3hOWEVRT1B0SkJobHFr?= =?utf-8?B?ZE9mTmpzTlBWc3FrZnhLVEEyTlRQZlV2RXhYYTdzV2RVRE93MjlkcHNyT3p1?= =?utf-8?Q?tceEu00iaAwIgiglZo=3D?= X-Microsoft-Exchange-Diagnostics: 1;CY1PR03MB1485;5:zLycw/A8bAe9DTUFtCLn6OO571Q72j4KYzpgkeTJGXRvkZt+9UZ+Wppz5IAyxNGsBQ1SAaBHJtAnZ6OLoIxUtzUgwUVDZGVTulxA6LxgeVXBOibHgC02KkZTZ0daFw7grCHFWNhNZ2bnoOtf5m7jAQ==;24:wEduNz4tHEUEN62W5cO51qQdtQFL2oOkAZ8ZR31zzdM6ZKCcP7Zj8Rhu50fMsPPx4eSsddDGTmtevuLAxdot0tUz0xdzyY9A/IaNNNQwE4c=;20:MDlu08ZhYxmlt/sqh2Ww6D25MVHtleAsSGv0VMeMdYNSLPbixj69+fD6XDJgYqS2BsobD6hjetEEIIFHXPj8lg== SpamDiagnosticOutput: 1:23 SpamDiagnosticMetadata: NSPM X-MS-Exchange-CrossTenant-OriginalArrivalTime: 11 Sep 2015 21:35:23.5966 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY1PR03MB1485 X-Microsoft-Exchange-Diagnostics: 1;CY1PR03MB1453;2:eAqYRxfCplMZj2AW/TFI3dJtzP6GDXGtn4T8rboWg6O9R1xn07ekpWncNLcwWGCVShiHFV2liqUYKylcs9EExHqxHD3OLByAJDgcFNlXsiBnpuc+0UB8pI50dip/R8hrx38eICtZSSncJMu5X6mh5Gdo9zUFjwG9pmvcimzAmJw=;23:OiuA5RhI+oP4Dy3ZdT/Uqj0GM9d4Js5EkBCBDIVIYbON0JE4+Dc5riVh9MHeTCJkC1y37ETeB0A6JTbGmEyEE2iqxgypx2TSd/TDoWA8v2u1wStkzgxS0xqIOowWEorMyKp102kPpG+jIUFwZNLPIzjExfmNs2kWmcPPw2SjR7t5zK5HwM1ouK5KWIU6SMnQ X-OriginatorOrg: freescale.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2015-09-11 at 16:33 +0200, Christophe Leroy wrote: > memcpy() uses instruction dcbz to speed up copy by not wasting time > loading cache line with data that will be overwritten. > Some platform like mpc52xx do no have cache active at startup and > can therefore not use memcpy(). Allthough no part of the code > explicitly uses memcpy(), GCC makes calls to it. > > This patch modifies memcpy() such that at startup, memcpy() > unconditionally jumps to generic_memcpy() which doesn't use > the dcbz instruction. > > Once the initial MMU is set up, in machine_init() we patch memcpy() > by replacing this inconditional jump by a NOP > > Reported-by: Michal Sojka > Signed-off-by: Christophe Leroy > --- > changes in v2: > Using feature-fixups instead of hardcoded call to patch_instruction() > Handling of memset() added > changes in v3: > Not using anymore feature-fixups > Handling of memset() removed Why was handling of memset() removed? -Scott