Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262872AbVEHNto (ORCPT ); Sun, 8 May 2005 09:49:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262869AbVEHNto (ORCPT ); Sun, 8 May 2005 09:49:44 -0400 Received: from mx2.suse.de ([195.135.220.15]:15312 "EHLO mx2.suse.de") by vger.kernel.org with ESMTP id S262872AbVEHNtg (ORCPT ); Sun, 8 May 2005 09:49:36 -0400 Date: Sun, 8 May 2005 15:49:32 +0200 From: Andi Kleen To: "Protasevich, Natalie" Cc: Andi Kleen , akpm@osdl.org, zwane@arm.linux.org.uk, len.brown@intel.com, venkatesh.pallipadi@intel.com, linux-kernel@vger.kernel.org Subject: Re: [patch 1/1] Do not enforce unique IO_APIC_ID for Xeon processors in EM64T mode (x86_64) Message-ID: <20050508134932.GE15724@wotan.suse.de> References: <19D0D50E9B1D0A40A9F0323DBFA04ACCE04B50@USRV-EXCH4.na.uis.unisys.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <19D0D50E9B1D0A40A9F0323DBFA04ACCE04B50@USRV-EXCH4.na.uis.unisys.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5596 Lines: 161 On Sun, May 08, 2005 at 12:01:22AM -0500, Protasevich, Natalie wrote: > > > > > > This patch disables unique IO_APIC_ID check for xAPIC > > systems running in EM64T mode. Xeon-based ES7000s panic > > failing this unnecessary check. I added IOAPIC_ID_CHECK > > config option and turned it off for Intel processors. Also > > added the boot option that overrides default and turnes this > > check on/off in case it is needed for some reason. Hope this > > is acceptable way to fix the problem. > > > > I think we can turn it off for all x86-64 systems. Near all > > EM64T systems have xAPIC. AMD processors don't need it > > neither. That would only leave the new IBM summit2 chipset, > > but I suppose they also don't need this (James please > > complain if I am wrong) > > So can you please do a new patch that just removes this code? > > Sure, I will remove the io_apic_get_unique_id() then. Perhaps, it will > be easy to put it back in if someone implements a chipset that needs it. I did it myself now. > > Andi, I submitted the patch for i386 a little while ago > http://www.ussg.iu.edu/hypermail/linux/kernel/0505.0/0195.html (I sent > it to you also, but just noticed that it was not your usual email > address - where did I get if from? have no idea...) Genapic in i386 has > a NO_IOAPIC_CHECK flag that is defined in every subarch, so it was easy > to fix the problem by making use of it in ACPI boot path just as it was > used in MP path. That will not help on the other systems who don't have an own subarchitecture but still run into problems with the check. I think the right strategy for i386 would be to remove this check thing from the subarchitecture and implement the heuristic described in the last mail. -Andi Remove unique APIC/IO-APIC ID check It is unnecessary on modern Intel or AMD systems, and that is all we support on x86-64 Also causes problems on various systems Signed-off-by: Andi Kleen Index: linux/arch/x86_64/kernel/io_apic.c =================================================================== --- linux.orig/arch/x86_64/kernel/io_apic.c +++ linux/arch/x86_64/kernel/io_apic.c @@ -1805,76 +1805,6 @@ device_initcall(ioapic_init_sysfs); #define IO_APIC_MAX_ID 0xFE -int __init io_apic_get_unique_id (int ioapic, int apic_id) -{ - union IO_APIC_reg_00 reg_00; - static physid_mask_t apic_id_map; - unsigned long flags; - int i = 0; - - /* - * The P4 platform supports up to 256 APIC IDs on two separate APIC - * buses (one for LAPICs, one for IOAPICs), where predecessors only - * supports up to 16 on one shared APIC bus. - * - * TBD: Expand LAPIC/IOAPIC support on P4-class systems to take full - * advantage of new APIC bus architecture. - */ - - if (physids_empty(apic_id_map)) - apic_id_map = phys_cpu_present_map; - - spin_lock_irqsave(&ioapic_lock, flags); - reg_00.raw = io_apic_read(ioapic, 0); - spin_unlock_irqrestore(&ioapic_lock, flags); - - if (apic_id >= IO_APIC_MAX_ID) { - apic_printk(APIC_QUIET, KERN_WARNING "IOAPIC[%d]: Invalid apic_id %d, trying " - "%d\n", ioapic, apic_id, reg_00.bits.ID); - apic_id = reg_00.bits.ID; - } - - /* - * Every APIC in a system must have a unique ID or we get lots of nice - * 'stuck on smp_invalidate_needed IPI wait' messages. - */ - if (physid_isset(apic_id, apic_id_map)) { - - for (i = 0; i < IO_APIC_MAX_ID; i++) { - if (!physid_isset(i, apic_id_map)) - break; - } - - if (i == IO_APIC_MAX_ID) - panic("Max apic_id exceeded!\n"); - - apic_printk(APIC_VERBOSE, KERN_WARNING "IOAPIC[%d]: apic_id %d already used, " - "trying %d\n", ioapic, apic_id, i); - - apic_id = i; - } - - physid_set(apic_id, apic_id_map); - - if (reg_00.bits.ID != apic_id) { - reg_00.bits.ID = apic_id; - - spin_lock_irqsave(&ioapic_lock, flags); - io_apic_write(ioapic, 0, reg_00.raw); - reg_00.raw = io_apic_read(ioapic, 0); - spin_unlock_irqrestore(&ioapic_lock, flags); - - /* Sanity check */ - if (reg_00.bits.ID != apic_id) - panic("IOAPIC[%d]: Unable change apic_id!\n", ioapic); - } - - apic_printk(APIC_VERBOSE,KERN_INFO "IOAPIC[%d]: Assigned apic_id %d\n", ioapic, apic_id); - - return apic_id; -} - - int __init io_apic_get_version (int ioapic) { union IO_APIC_reg_01 reg_01; Index: linux/arch/x86_64/kernel/mpparse.c =================================================================== --- linux.orig/arch/x86_64/kernel/mpparse.c +++ linux/arch/x86_64/kernel/mpparse.c @@ -763,7 +763,7 @@ void __init mp_register_ioapic ( mp_ioapics[idx].mpc_apicaddr = address; set_fixmap_nocache(FIX_IO_APIC_BASE_0 + idx, address); - mp_ioapics[idx].mpc_apicid = io_apic_get_unique_id(idx, id); + mp_ioapics[idx].mpc_apicid = id; mp_ioapics[idx].mpc_apicver = io_apic_get_version(idx); /* Index: linux/include/asm-x86_64/io_apic.h =================================================================== --- linux.orig/include/asm-x86_64/io_apic.h +++ linux/include/asm-x86_64/io_apic.h @@ -202,7 +202,6 @@ extern int skip_ioapic_setup; #define io_apic_assign_pci_irqs (mp_irq_entries && !skip_ioapic_setup && io_apic_irqs) #ifdef CONFIG_ACPI_BOOT -extern int io_apic_get_unique_id (int ioapic, int apic_id); extern int io_apic_get_version (int ioapic); extern int io_apic_get_redir_entries (int ioapic); extern int io_apic_set_pci_routing (int ioapic, int pin, int irq, int, int); - 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/