From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S271597AbTGQW2q (ORCPT ); Thu, 17 Jul 2003 18:28:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S271601AbTGQW2q (ORCPT ); Thu, 17 Jul 2003 18:28:46 -0400 Received: from x35.xmailserver.org ([208.129.208.51]:53185 "EHLO x35.xmailserver.org") by vger.kernel.org with ESMTP id S271597AbTGQW2n (ORCPT ); Thu, 17 Jul 2003 18:28:43 -0400 X-AuthUser: davidel@xmailserver.org Date: Thu, 17 Jul 2003 15:36:19 -0700 (PDT) From: Davide Libenzi X-X-Sender: davide@bigblue.dev.mcafeelabs.com To: "Randy.Dunlap" cc: lkml Subject: Re: asm (lidt) question In-Reply-To: <20030717152819.66cfdbaf.rddunlap@osdl.org> Message-ID: References: <20030717152819.66cfdbaf.rddunlap@osdl.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 17 Jul 2003, Randy.Dunlap wrote: > > In arch/i386/kernel, inline asm for loading IDT (lidt) is used a few > times, but with slightly different constraints and output/input > definitions. Are these OK, equivalent, or what? > > [rddunlap@dragon kernel]$ findc lidt > ./cpu/common.c:484: __asm__ __volatile__("lidt %0": "=m" (idt_descr)); > ./traps.c:783: __asm__ __volatile__("lidt %0": "=m" (idt_descr)); > > vs. > > ./reboot.c:186: __asm__ __volatile__ ("lidt %0" : : "m" (real_mode_idt)); > ./reboot.c:261: __asm__ __volatile__("lidt %0": :"m" (no_idt)); > ./suspend.c:95: asm volatile ("lidt %0" :: "m" (saved_context.idt_limit)); I'd have said no looking at the syntax (input/output), but they indeed generate the same code (just checked). - Davide