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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 1BD62C43381 for ; Fri, 29 Mar 2019 03:35:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DE75521871 for ; Fri, 29 Mar 2019 03:35:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728557AbfC2DfM convert rfc822-to-8bit (ORCPT ); Thu, 28 Mar 2019 23:35:12 -0400 Received: from tyo161.gate.nec.co.jp ([114.179.232.161]:55886 "EHLO tyo161.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726250AbfC2DfM (ORCPT ); Thu, 28 Mar 2019 23:35:12 -0400 Received: from mailgate02.nec.co.jp ([114.179.233.122]) by tyo161.gate.nec.co.jp (8.15.1/8.15.1) with ESMTPS id x2T3YfHq003577 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Fri, 29 Mar 2019 12:34:41 +0900 Received: from mailsv01.nec.co.jp (mailgate-v.nec.co.jp [10.204.236.94]) by mailgate02.nec.co.jp (8.15.1/8.15.1) with ESMTP id x2T3YfBb004327; Fri, 29 Mar 2019 12:34:41 +0900 Received: from mail01b.kamome.nec.co.jp (mail01b.kamome.nec.co.jp [10.25.43.2]) by mailsv01.nec.co.jp (8.15.1/8.15.1) with ESMTP id x2T3Yedh026395; Fri, 29 Mar 2019 12:34:41 +0900 Received: from bpxc99gp.gisp.nec.co.jp ([10.38.151.135] [10.38.151.135]) by mail01b.kamome.nec.co.jp with ESMTP id BT-MMP-3794402; Fri, 29 Mar 2019 12:34:25 +0900 Received: from BPXM12GP.gisp.nec.co.jp ([10.38.151.204]) by BPXC07GP.gisp.nec.co.jp ([10.38.151.135]) with mapi id 14.03.0319.002; Fri, 29 Mar 2019 12:34:24 +0900 From: Junichi Nomura To: "bhe@redhat.com" CC: Borislav Petkov , Dave Young , "fanc.fnst@cn.fujitsu.com" , "kasong@redhat.com" , "x86@kernel.org" , "kexec@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v2] x86/boot: Use EFI setup data if provided Thread-Topic: [PATCH v2] x86/boot: Use EFI setup data if provided Thread-Index: AQHU5R0gSF49+PGwf02T2oxnk4CVXaYgAhGAgAAQvICAAQMcAIAASZeA Date: Fri, 29 Mar 2019 03:34:23 +0000 Message-ID: References: <701c8e69-e1d4-c653-1d87-1c41789d3d54@ce.jp.nec.com> <20190325120149.GI12016@zn.tnic> <20190325122302.GC13160@dhcp-128-65.nay.redhat.com> <20190325123229.GL12016@zn.tnic> <20190325231000.GA9184@jeru.linux.bs1.fc.nec.co.jp> <20190326135714.GG1867@zn.tnic> <20190327014852.GA3659@MiWiFi-R3L-srv> <73322ba9-e436-68db-7863-afd31607d969@ce.jp.nec.com> <20190328064343.GA1877@MiWiFi-R3L-srv> <20190328074337.GA9470@jeru.linux.bs1.fc.nec.co.jp> <20190328231100.GC1877@MiWiFi-R3L-srv> In-Reply-To: <20190328231100.GC1877@MiWiFi-R3L-srv> Accept-Language: en-US, ja-JP Content-Language: ja-JP X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.34.125.85] Content-Type: text/plain; charset="iso-2022-jp" Content-ID: Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-TM-AS-MML: disable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/29/19 8:11 AM, bhe@redhat.com wrote: > On 03/28/19 at 07:43am, Junichi Nomura wrote: >> /* Search EFI system tables for RSDP. */ >> -static acpi_physical_address efi_get_rsdp_addr(void) >> +static acpi_physical_address __efi_get_rsdp_addr(unsigned long config_tables, unsigned int nr_tables, int size, bool efi_64) > > Here parameter 'size' and 'efi_64' seems a little duplicated on > functionality. Only passing efi_64 can deduce the size? Personal > opinion. Yes. But I'm not sure which is preferred. The current code is: __efi_get_rsdp_addr() { for (i = 0; i < nr_tables; i++) { config_tables += size; if (efi_64) { efi_config_table_64_t *tbl = (efi_config_table_64_t *)config_tables; // get guid and table } else { efi_config_table_32_t *tbl = (efi_config_table_32_t *)config_tables; // get guid and table } // check guid and return table if it's valid } } If we remove "size" parameter, that will become: __efi_get_rsdp_addr() { for (i = 0; i < nr_tables; i++) { if (efi_64) { efi_config_table_64_t *tbl; config_tables += sizeof(efi_config_table_64_t); tbl = (efi_config_table_64_t *)config_tables; // get guid and table } else { efi_config_table_32_t *tbl; config_tables += sizeof(efi_config_table_32_t); tbl = (efi_config_table_32_t *)config_tables; // get guid and table } // check guid and return table if it's valid } } Or we could create 2 functions, __efi_get_rsdp_addr32() and __efi_get_rsdp_addr64(), and let efi_get_rsdp_addr() to choose which one to use based on signature. > It might be worth adding code comments here to tell why we only care > about 64bit kexec booting? I think so. I'll add a comment. -- Jun'ichi Nomura, NEC Corporation / NEC Solution Innovators, Ltd.