From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [PATCH, DEBUG] x86/32: Add small delay after resume Date: Tue, 16 Jun 2015 14:33:10 -0700 Message-ID: <55809616.80204@zytor.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> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: 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 In-Reply-To: <1434384627.2353.47.camel@spandruv-DESK3.jf.intel.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org 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" 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