Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754342AbYGMBBR (ORCPT ); Sat, 12 Jul 2008 21:01:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752431AbYGMBBB (ORCPT ); Sat, 12 Jul 2008 21:01:01 -0400 Received: from mga11.intel.com ([192.55.52.93]:1331 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752131AbYGMBBB (ORCPT ); Sat, 12 Jul 2008 21:01:01 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.30,352,1212390000"; d="scan'208";a="357780840" Date: Sat, 12 Jul 2008 18:01:00 -0700 From: Suresh Siddha To: Yinghai Lu Cc: "Eric W. Biederman" , "Siddha, Suresh B" , Ingo Molnar , "hpa@zytor.com" , "tglx@linutronix.de" , "akpm@linux-foundation.org" , "arjan@linux.intel.com" , "andi@firstfloor.org" , "jbarnes@virtuousgeek.org" , "steiner@sgi.com" , "linux-kernel@vger.kernel.org" , "jeremy@goop.org" Subject: Re: [patch 00/26] x64, x2apic/intr-remap: Interrupt-remapping and x2apic support Message-ID: <20080713010059.GB1678@linux-os.sc.intel.com> References: <20080711203151.GU1678@linux-os.sc.intel.com> <86802c440807111342j5fbf21e1ibd5129718cde4e43@mail.gmail.com> <20080711204521.GA15689@elte.hu> <20080711212418.GV1678@linux-os.sc.intel.com> <86802c440807111502n9835b5fybd99ed388bb71b7d@mail.gmail.com> <86802c440807112016k38c8161aq143463ee57b24c35@mail.gmail.com> <86802c440807112317h23118e29j51113a052720d8db@mail.gmail.com> <86802c440807120049t2aaec131l4c735712f2befb2@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <86802c440807120049t2aaec131l4c735712f2befb2@mail.gmail.com> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2400 Lines: 60 On Sat, Jul 12, 2008 at 12:49:53AM -0700, Yinghai Lu wrote: > On Sat, Jul 12, 2008 at 12:02 AM, Eric W. Biederman > wrote: > > "Yinghai Lu" writes: > > > >> On Fri, Jul 11, 2008 at 8:52 PM, Eric W. Biederman > >> wrote: > >>> "Yinghai Lu" writes: > >>> > >>>> 1. wonder if x2apic can be use with uniprocessor. > >>>> > >>>> in APIC_init_uniprocessor, it will try to enable x2apic, but later > >>>> > >>>> apic_write(APIC_ID, SET_APIC_ID(boot_cpu_physical_apicid)); > >>>> > >>>> but SET_APIC_ID is still for xapic version. so need to GET_APIC_ID, > >>>> SET_APIC_ID for different > >>>> genapic like 32bit. > >>>> > >>>> 2 check_x2apic is called in setup_arch, but it only set apic_ops, > >>>> and genapic still not changed, aka apic_flat... > >>>> wonder if you need to call setup_apic_routing to set genapic. > >>>> > >>>> otherwise read_apic_id could have use the one from apic_flat....need > >>>> to shift...... > >>>> > >>>> 3.or move read_apic_id to apic_ops intead...together with GET_APIC_ID too. > >>>> but 32bit version seems like to put GET_APIC_ID with genapic... > >>>> > >>>> which one is better? 2 or 3 > >>> > >>> Z finish untangle SMP support from apic initialization and move the apic > >>> initialization up into init_IRQ. > >>> > >>> That is better but is likely the wrong short term approach. > >> > >> plan to add get_apic_id(x) into 64bit genapic, and will use > >> #define GET_APIC_ID(x) genapic->get_apic_id(x) > >> #define read_apic_id() GET_APIC_ID(apic_read(APIC_ID)) > >> > >> so it is identical to 32bit, and we smooth the merging of 32/64 apic code > >> > >> also read the x2APIC spec pdf, it doesn't say anything about interrupt > >> remapping...need to be used with x2apic... > > > > Clustered logical mode won't work as it requires > 16 bits of apicid. > > So only flat physical mode will work. > > current read_apic_id in genx2apic_cluster and genx2apic_phys is the same... read_apic_id() corresponds to physical apic id and it is same irrespective of whether we use logical cluster mode or physical mode. thanks, suresh -- 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/