Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757843AbbFQQfO (ORCPT ); Wed, 17 Jun 2015 12:35:14 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:45752 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932574AbbFQQe4 (ORCPT ); Wed, 17 Jun 2015 12:34:56 -0400 Date: Wed, 17 Jun 2015 12:33:50 -0400 From: Konrad Rzeszutek Wilk To: "H. Peter Anvin" Cc: Srinivas Pandruvada , Ingo Molnar , mingo@redhat.com, tglx@linutronix.de, pavel@ucw.cz, rjw@rjwysocki.net, x86@kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Denys Vlasenko , Andy Lutomirski , Borislav Petkov , Brian Gerst , Linus Torvalds , "Kleen, Andi" Subject: Re: [PATCH, DEBUG] x86/32: Add small delay after resume Message-ID: <20150617163350.GA7250@l.oracle.com> References: <1434066338-6619-1-git-send-email-srinivas.pandruvada@linux.intel.com> <20150612060747.GA25024@gmail.com> <1434125724.2353.19.camel@spandruv-DESK3.jf.intel.com> <20150613071547.GA27446@gmail.com> <1434384627.2353.47.camel@spandruv-DESK3.jf.intel.com> <55809616.80204@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <55809616.80204@zytor.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-Source-IP: aserv0022.oracle.com [141.146.126.234] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1584 Lines: 46 On Tue, Jun 16, 2015 at 02:33:10PM -0700, H. Peter Anvin wrote: > On 06/15/2015 09:10 AM, Srinivas Pandruvada wrote: > >> > >> So is it true that we always execute wakeup_pmode_return first after we return > >> from the BIOS? > >> > >> If so then the BIOS touching DS cannot be an issue, as we re-initialize all > >> segment selectors, which reloads the descriptors: > >> > >> ENTRY(wakeup_pmode_return) > >> wakeup_pmode_return: > >> movw $__KERNEL_DS, %ax > >> movw %ax, %ss > >> movw %ax, %ds > >> movw %ax, %es > >> movw %ax, %fs > >> movw %ax, %gs > >> > >> # reload the gdt, as we need the full 32 bit address > >> lidt saved_idt > >> lldt saved_ldt > >> ljmp $(__KERNEL_CS), $1f > >> > > Where does the GDT get initialized? > > -hpa mit 84e70971e67d97bc2db18a4e76d42846272a54bd Author: Konrad Rzeszutek Wilk Date: Fri Apr 5 16:42:22 2013 -0400 x86-32, gdt: Store/load GDT for ACPI S3 or hibernation/resume path is not needed > > > -- > 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/ -- 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/