Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757400AbbFPVeU (ORCPT ); Tue, 16 Jun 2015 17:34:20 -0400 Received: from terminus.zytor.com ([198.137.202.10]:35076 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757352AbbFPVdu (ORCPT ); Tue, 16 Jun 2015 17:33:50 -0400 Message-ID: <55809616.80204@zytor.com> Date: Tue, 16 Jun 2015 14:33:10 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Srinivas Pandruvada , Ingo Molnar CC: 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 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> In-Reply-To: <1434384627.2353.47.camel@spandruv-DESK3.jf.intel.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 983 Lines: 33 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 -- 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/