Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754421Ab2HRWos (ORCPT ); Sat, 18 Aug 2012 18:44:48 -0400 Received: from out5-smtp.messagingengine.com ([66.111.4.29]:44546 "EHLO out5-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752029Ab2HRWoq (ORCPT ); Sat, 18 Aug 2012 18:44:46 -0400 X-Sasl-enc: NgxvqMQrdf0jcD1dfQ3xmytlIO5TjfIYS8695ZMPK99h 1345329885 Date: Sat, 18 Aug 2012 19:44:42 -0300 From: Henrique de Moraes Holschuh To: Fenghua Yu Cc: H Peter Anvin , Ingo Molnar , Thomas Gleixner , Asit K Mallick , Tigran Aivazian , Andreas Herrmann , Borislav Petkov , linux-kernel , x86 Subject: Re: [PATCH 04/11] x86/microcode_core_early.c: Define interfaces for early load ucode Message-ID: <20120818224442.GB32120@khazad-dum.debian.net> References: <1345277729-8399-1-git-send-email-fenghua.yu@intel.com> <1345277729-8399-5-git-send-email-fenghua.yu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1345277729-8399-5-git-send-email-fenghua.yu@intel.com> X-GPG-Fingerprint: 1024D/1CDB0FE3 5422 5C61 F6B7 06FB 7E04 3738 EE25 DE3F 1CDB 0FE3 User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2266 Lines: 56 On Sat, 18 Aug 2012, Fenghua Yu wrote: > + char ucode_name[] = "kernel/x86/microcode/GenuineIntel/microcode.hex"; Why name it ".hex" when you're loading binary data? I suggest ".bin". It is confusing to have .hex there, since you're not dealing with the Intel HEX format, nor anything text-like. > +void __init load_ucode_bsp(char *real_mode_data) > +{ > + u64 ramdisk_image, ramdisk_size, ramdisk_end; > + unsigned long initrd_start, initrd_end; > + struct boot_params *boot_params; > + > + boot_params = (struct boot_params *)real_mode_data; > + ramdisk_image = boot_params->hdr.ramdisk_image; > + ramdisk_size = boot_params->hdr.ramdisk_size; > + > +#ifdef CONFIG_X86_64 > + ramdisk_end = PAGE_ALIGN(ramdisk_image + ramdisk_size); > + initrd_start = ramdisk_image + PAGE_OFFSET; > +#else > + ramdisk_end = ramdisk_image + ramdisk_size; > + initrd_start = ramdisk_image; > +#endif > + initrd_end = initrd_start + ramdisk_size; > + > + /* > + * It's early to get CPU vendor info at this point. > + * By searching initrd to find right name for vendor's microcode, > + * it's relative easier to get CPU vendor info. > + */ > + if (find_ucode_intel(initrd_start, initrd_end) == UCODE_OK) > + load_ucode_intel_bsp(real_mode_data); > +} I'd say something down the load_ucode_intel_bsp() chain better check the CPU vendor to make sure the Intel driver won't attempt to load microcode on some other vendor's processor. Or are cpu signatures a global namespace and x86 cpu vendors make sure (past, present and future) to never use the same cpu signature as someone else is going to use? Anyway, it would still might be a good thing to do the vendor check somewhere to avoid wasting time going over every microcode of the wrong vendor on generic boot images that have both AMD and Intel microcode. -- "One disk to rule them all, One disk to find them. One disk to bring them all and in the darkness grind them. In the Land of Redmond where the shadows lie." -- The Silicon Valley Tarot Henrique Holschuh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/