From patchwork Thu Sep 11 08:05:50 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiang Liu X-Patchwork-Id: 388108 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id C8C0A14012A for ; Thu, 11 Sep 2014 18:10:40 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753302AbaIKIJi (ORCPT ); Thu, 11 Sep 2014 04:09:38 -0400 Received: from mga09.intel.com ([134.134.136.24]:35740 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752961AbaIKIDt (ORCPT ); Thu, 11 Sep 2014 04:03:49 -0400 Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga102.jf.intel.com with ESMTP; 11 Sep 2014 00:57:42 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,504,1406617200"; d="scan'208";a="601322405" Received: from gerry-dev.bj.intel.com ([10.238.158.74]) by orsmga002.jf.intel.com with ESMTP; 11 Sep 2014 01:03:44 -0700 From: Jiang Liu To: Benjamin Herrenschmidt , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , "Rafael J. Wysocki" , Bjorn Helgaas , Randy Dunlap , Yinghai Lu , Borislav Petkov , Grant Likely Cc: Konrad Rzeszutek Wilk , Andrew Morton , Tony Luck , Joerg Roedel , Greg Kroah-Hartman , x86@kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org, Sebastian Andrzej Siewior , Jiang Liu Subject: [Patch v5 07/15] x86, irq: Prefer assigned ID in APIC ID register for x86_64 Date: Thu, 11 Sep 2014 16:05:50 +0800 Message-Id: <1410422758-24942-8-git-send-email-jiang.liu@linux.intel.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1410422758-24942-1-git-send-email-jiang.liu@linux.intel.com> References: <1410422758-24942-1-git-send-email-jiang.liu@linux.intel.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Yinghai Lu Perfer the assigned ID in APIC ID register for x86_64 if it's still available. Signed-off-by: Yinghai Lu Cc: Joerg Roedel Cc: Konrad Rzeszutek Wilk Cc: Sebastian Andrzej Siewior Signed-off-by: Jiang Liu --- arch/x86/kernel/apic/io_apic.c | 35 ++++++++++++++++++++++++++++++----- 1 file changed, 30 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index 003945e71616..9011c5fa5aad 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -3575,26 +3575,51 @@ static int __init io_apic_get_unique_id(int ioapic, int apic_id) return apic_id; } -static u8 __init io_apic_unique_id(u8 id) +static u8 __init io_apic_unique_id(int idx, u8 id) { if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) && !APIC_XAPIC(apic_version[boot_cpu_physical_apicid])) - return io_apic_get_unique_id(nr_ioapics, id); + return io_apic_get_unique_id(idx, id); else return id; } #else -static u8 __init io_apic_unique_id(u8 id) +static u8 __init io_apic_unique_id(int idx, u8 id) { int i; + u8 new_id; + unsigned long flags; DECLARE_BITMAP(used, 256); + union IO_APIC_reg_00 reg_00; bitmap_zero(used, 256); for_each_ioapic(i) __set_bit(mpc_ioapic_id(i), used); if (!test_bit(id, used)) return id; - return find_first_zero_bit(used, 256); + + /* check register at first */ + raw_spin_lock_irqsave(&ioapic_lock, flags); + reg_00.raw = io_apic_read(idx, 0); + raw_spin_unlock_irqrestore(&ioapic_lock, flags); + new_id = reg_00.bits.ID; + if (!test_bit(new_id, used)) { + apic_printk(APIC_VERBOSE, KERN_INFO + "IOAPIC[%d]: Using reg apic_id %d instead of %d\n", + idx, new_id, id); + return new_id; + } + + new_id = find_first_zero_bit(used, 256); + reg_00.bits.ID = new_id; + raw_spin_lock_irqsave(&ioapic_lock, flags); + io_apic_write(idx, 0, reg_00.raw); + reg_00.raw = io_apic_read(idx, 0); + raw_spin_unlock_irqrestore(&ioapic_lock, flags); + /* Sanity check */ + BUG_ON(reg_00.bits.ID != new_id); + + return new_id; } #endif @@ -3860,7 +3885,7 @@ void __init mp_register_ioapic(int id, u32 address, u32 gsi_base, return; } - ioapics[idx].mp_config.apicid = io_apic_unique_id(id); + ioapics[idx].mp_config.apicid = io_apic_unique_id(idx, id); ioapics[idx].mp_config.apicver = io_apic_get_version(idx); /*