From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753245AbdEJNpV (ORCPT ); Wed, 10 May 2017 09:45:21 -0400 Received: from cn.fujitsu.com ([59.151.112.132]:34521 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752877AbdEJNpS (ORCPT ); Wed, 10 May 2017 09:45:18 -0400 X-IronPort-AV: E=Sophos;i="5.22,518,1449504000"; d="scan'208";a="18692954" From: Dou Liyang To: , CC: , , , , , , Dou Liyang Subject: [RFC PATCH v3 00/12] Unify interrupt mode and setup it as soon as possible Date: Wed, 10 May 2017 21:44:37 +0800 Message-ID: <1494423889-25799-1-git-send-email-douly.fnst@cn.fujitsu.com> X-Mailer: git-send-email 2.5.5 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.167.226.106] X-yoursite-MailScanner-ID: 2CFA847C6101.AFD56 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: douly.fnst@cn.fujitsu.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org According to Ingo's and Eric's advice[1,2], Try my best to optimize the init of interrupt delivery mode for x86. MP specification defines three different interrupt modes as follows: 1. PIC Mode 2. Virtual Wire Mode 3. Symmetric I/O Mode Currently, in kernel, 1. Setup Virtual Wire Mode during IRQ initialization( step 1 in the following figure). 2. Enable and Setup Symmetric I/O Mode either during the SMP-capable system prepares CPUs(step 2) or during the UP system initializes itself(step 3). start_kernel +---------------+ | +--> ....... | | setup_arch +--> +-------+ | | init_IRQ +-> +--+-----+ | | init_ISA_irqs | +------> +-+--------+ | | +----------------+ +---> +------> | 1.init_bsp_APIC| | ....... +----------------+ +---> | rest_init +--->---+-----+ | | kernel_init | +> ----+-----+ | | kernel_init_freeable | +-> ----+-------------+ | | smp_prepare_cpus | +---> +----+---------+ | | | +-------------------+ | | +-> |2. apic_bsp_setup | | | +-------------------+ | | v | smp_init +---> +---+----+ | +-------------------+ +--> |3. apic_bsp_setup | +-------------------+ The purpose of this patches is unifying these setup steps and executing as soon as possible as follows: start_kernel ---------------+ | | | | x86_late_time_init +---->---+------------+ | | | | +------------------------+ | +----> | 4. init_interrupt_mode | | +------------------------+ v And construct a selector to wrap all the switches and make them maintain and read easily. Original: +-----------------------------------------------------+ | smp_found_config || !boot_cpu_has(X86_FEATURE_APIC) | +-----------------------------------------------------+ |true, PIC MODE |false, VIRTUAL WIRE MODE | | +--v-----------------v-----------+ |!smp_found_config && !acpi_lapic+-----+ +--------------------------------+ | |false | | | +--v----------------------------+ | |!boot_cpu_has(X86_FEATURE_APIC)+ true | +------------------+------------+ | |false | | v | +------v-----+ true SYMMETRIC IO MODE | |disable_apic+------> PIC MODE | +------------+ |true |false | +---v---------------------------+ +------v------+ |!boot_cpu_has(X86_FEATURE_APIC)| |!disable_apic| +---------------------------+---+ +------+------+ |false |true | +----v------------+ v v |!smp_found_config+----+ PIC MODE PIC MODE +-----------------+ | |false |true v v SYMMETRIC IO MODE VIRTUAL WIRE MODE Now: +------------+ |disable_apic+--------------------+ +------------+ true | |false | | | +------------v------------------+ | |!boot_cpu_has(X86_FEATURE_APIC)+-------+ +-------------------------------+ true | |false | | | +-------v---------+ v |!smp_found_config| PIC MODE +---------------+-+ |false |true | | v +---v---------+ SYMMETRIC IO MODE | !acpi_lapic | +------+------+ | v VIRTUAL WIRE MODE By the way, Also fix a bug about kexec[3]. [1]. https://lkml.org/lkml/2016/8/2/929 [2]. https://lkml.org/lkml/2016/8/1/506 [3]. https://lkml.org/lkml/2016/7/25/1118 Changes V2 --> V3: - Rebase the patches. - Change two function name: apic_bsp_mode_check --> apic_interrupt_mode_select init_interrupt_mode --> apic_interrupt_mode_init - Find a new waiting way to check whether timer IRQs work or not - Refine the switch logic in apic_interrupt_mode_init() - Consistently start sentences with upper case letters - Fix some typos and comments - Try my best to rewrite some changelog again Changes since V1: - Move the initialization from init_IRQ() to x86_late_time_init() - Use a threshold to refactor the check logic in timer_irq_works() - Rename the framework to a selector - Split two patches - Consistently start sentences with upper case letters - Fix some typos - Rewrite the changelog Dou Liyang (12): x86/apic: Replace init_bsp_APIC() with apic_virtual_wire_mode_setup() x86/apic: Construct a selector for the interrupt delivery mode x86/apic: Prepare for unifying the interrupt delivery modes setup x86/time: Initialize interrupt mode behind timer init x86/ioapic: Refactor the delay logic in timer_irq_works() x86/apic: Split local APIC timer setup from the APIC setup x86/apic: Move the logical APIC ID setup from apic_bsp_setup() x86/apic: Make interrupt mode setup earlier for SMP-capable system x86/apic: Setup interrupt mode earlier in case of no SMP motherboard x86/apic: Make the interrupt mode setup earlier for UP system x86/apic: Mark the apic_interrupt_mode extern for disable_smp() x86/apic: Remove the apic_virtual_wire_mode_setup() arch/x86/include/asm/apic.h | 15 +++- arch/x86/kernel/apic/apic.c | 185 +++++++++++++++++++++-------------------- arch/x86/kernel/apic/io_apic.c | 46 +++++++++- arch/x86/kernel/irqinit.c | 3 - arch/x86/kernel/smpboot.c | 65 ++++----------- arch/x86/kernel/time.c | 8 ++ 6 files changed, 174 insertions(+), 148 deletions(-) -- 2.5.5