Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934728Ab0GOUoo (ORCPT ); Thu, 15 Jul 2010 16:44:44 -0400 Received: from rcsinet10.oracle.com ([148.87.113.121]:29499 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934699Ab0GOUom (ORCPT ); Thu, 15 Jul 2010 16:44:42 -0400 Message-ID: <4C3F7222.5040404@kernel.org> Date: Thu, 15 Jul 2010 13:40:02 -0700 From: Yinghai Lu User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.10) Gecko/20100520 SUSE/3.0.5 Thunderbird/3.0.5 MIME-Version: 1.0 To: Suresh Siddha CC: "H. Peter Anvin" , Ingo Molnar , Thomas Gleixner , Andrew Morton , Don Zickus , Frederic Weisbecker , "linux-kernel@vger.kernel.org" , stable Subject: Re: [PATCH] x86: fix x2apic preenabled system with kexec References: <4C3BD6AA.3070908@kernel.org> <4C3CE210.2030902@zytor.com> <4C3CF650.30905@kernel.org> <4C3E1FA0.9000107@kernel.org> <4C3E2AE6.30406@kernel.org> <4C3E40EC.5060607@kernel.org> <1279152189.2849.260.camel@sbs-t61.sc.intel.com> <4C3EB22B.3000701@kernel.org> <1279217784.2751.7.camel@sbs-t61.sc.intel.com> <4C3F6B3D.7030303@kernel.org> In-Reply-To: <4C3F6B3D.7030303@kernel.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Source-IP: acsmt354.oracle.com [141.146.40.154] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090201.4C3F72FD.00E4,ss=1,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1451 Lines: 34 On 07/15/2010 01:10 PM, Yinghai Lu wrote: > On 07/15/2010 11:16 AM, Suresh Siddha wrote: >> On Thu, 2010-07-15 at 00:00 -0700, Yinghai Lu wrote: >> >>> BTW: is there any x2apic preenabled system with apicid of boot cpu > 255? >> >> I am not sure. There might be one. Is there any bug which can't handle >> this condition? > > We merged apic_ops into struct apic a while ago. > > so even for system with x2apic preenabled by BIOS, x2apic_cluster/phys is set to apic until smp_pare_cpus()::default_setup_apic_routing() after enable_IR_x2apic. > > that means the boot cpu x2apic is accessed via memmap instead msr based way at that point. > > not sure if the Boot apic id is bigger than 255. read_apic() for apic id could be wrong. ( in early_acpi_boot_init, acpi_boot_init, init_apic_mappings) > > looks like we need to re-read boot_cpu_physical_apicid > or we could assign x2apic_cluster/phys in check_x2apic(), and later if intr_remapping can not be enabed, we can revert back to phys_flat or flat? > never mind, early_acpi_boot_init::acpi_parse_madt::default_acpi_madt_oem_check() will handle the case. it will set the apic to apic_x2apic_... accordingly if x2apic is preenabled. Thanks Yinghai -- 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/