Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759410AbYGRQ0I (ORCPT ); Fri, 18 Jul 2008 12:26:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755036AbYGRQZ4 (ORCPT ); Fri, 18 Jul 2008 12:25:56 -0400 Received: from rv-out-0506.google.com ([209.85.198.236]:52610 "EHLO rv-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752681AbYGRQZ4 (ORCPT ); Fri, 18 Jul 2008 12:25:56 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=Hqq37z1nvxHQbDwy3ofDSngDwCEqPgDBVafiFg/9EWjTqnxUt6WTyZDe54awP4mwYy otnCTWd21U/wJaSwHRSIVfdZJjg+LDSGT7Po8LAWJSLeWeZh6vY9rQo1T8HzxNFWYxxv zSgMXoz1igyG67ocPZndrBRhUGkz3krZkFLzo= Message-ID: <86802c440807180925t6fadfa58r6bf7740f8145482e@mail.gmail.com> Date: Fri, 18 Jul 2008 09:25:55 -0700 From: "Yinghai Lu" To: "Ingo Molnar" Subject: Re: [PATCH] x86: APIC: Remove apic_write_around(); use alternatives Cc: "Maciej W. Rozycki" , x86@kernel.org, linux-kernel@vger.kernel.org, "Suresh Siddha" , "Jeremy Fitzhardinge" In-Reply-To: <20080718105259.GY6875@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080718105259.GY6875@elte.hu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1818 Lines: 38 On Fri, Jul 18, 2008 at 3:52 AM, Ingo Molnar wrote: > > * Maciej W. Rozycki wrote: > >> Use alternatives to select the workaround for the 11AP Pentium >> erratum for the affected steppings on the fly rather than build time. >> Remove the X86_GOOD_APIC configuration option and replace all the >> calls to apic_write_around() with plain apic_write(), protecting >> accesses to the ESR as appropriate due to the 3AP Pentium erratum. >> Remove apic_read_around() and all its invocations altogether as not >> needed. Remove apic_write_atomic() and all its implementing backends. >> The use of ASM_OUTPUT2() is not strictly needed for input constraints, >> but I have used it for readability's sake. > > wow, impressive patch! > >> I had the feeling no one else was brave enough to do it, so I went >> ahead and here it is. Verified by checking the generated assembly and >> tested with both a 32-bit and a 64-bit configuration, also with the >> 11AP "feature" forced on and verified with gdb on /proc/kcore to work >> as expected (as an 11AP machines are quite hard to get hands on these >> days). Some script complained about the use of "volatile", but >> apic_write() needs it for the same reason and is effectively a >> replacement for writel(), so I have disregarded it. > > kudos for pulling this off :-) > > applied to tip/x86/apic. This will interact with tip/x86/x2apic but that > topic is being worked on anyway. The interaction should be trivial. it seems we should start apic related merging after x2apic get merged? YH -- 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/