From patchwork Thu Feb 23 19:11:40 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Usama Arif X-Patchwork-Id: 13150709 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 34C90C636D6 for ; Thu, 23 Feb 2023 19:14:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232400AbjBWTOI (ORCPT ); Thu, 23 Feb 2023 14:14:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60858 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232408AbjBWTNS (ORCPT ); Thu, 23 Feb 2023 14:13:18 -0500 Received: from mail-wr1-x42a.google.com (mail-wr1-x42a.google.com [IPv6:2a00:1450:4864:20::42a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E3B7051FBD for ; Thu, 23 Feb 2023 11:12:32 -0800 (PST) Received: by mail-wr1-x42a.google.com with SMTP id bo30so10998719wrb.0 for ; Thu, 23 Feb 2023 11:12:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=EwjBftfc3L0BBR8aaJYAfM/W208AZmDnuvLkbcbpYBc=; b=D6yXbUB9sco4X1VpFV6XERHwY2Jrdg2C/gnoW/DRwjyLLVrrxI1ywrohxmZRrJm091 pyvN1Hju8nZVLvJpgR9MegSvJlbBhzhD4yTgTKONC35c++3h/vbAyqsGVIcCxYjtPJb/ tggWnyVAoBa94JfCwJ6wYvG1/pp2c2t+m2b+McHBtAG54vrfvV8PsUW/GRtA+Wlg1RBV GBLI60u93gjpV6vPweKG3CwxbRegUHgsMZ2+2kfjBBN4dujoujM87ABiPwktktjExmO7 B/4Xuz+/aG30TSdTs0orGRkS9Bv/ooYZTvwdgfM4oBWX7zEfFUxgbwLY3cQKWTXxUFA3 Sjig== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=EwjBftfc3L0BBR8aaJYAfM/W208AZmDnuvLkbcbpYBc=; b=OIz1KV7Ro6pgtDg5Ikm04tbBgcW5LGEi2I3DySGCAE/1BZGSA28UM9mn1cFQ5YhaUh 72SG6th8rB9xyF5u3F/SltyXgN/044q/UMvKyRPaQmced4PeWnCr9hNXOajivXNQsjRZ JMFmETu25BbcpAmUFznmseygMXTfVQ5yX2HVKBVIg7oNVci4XyKsx7/ACIMlv0Y8BF7q prahw4XckPJpQZi8aPAi4mEuH9k0S+30EOSYou79qhqvc4UNbeednii2wZBL5pl08LUT k1FgYpf7208eVqb1aBg8TOt747v5jNSrHhUIKOav1PG2CaQ/6ggzSihgG3dfWRfGdIm+ hSkg== X-Gm-Message-State: AO0yUKUuCkfWLDVMAmMnEN6vzh1tQw7+C5d/2TaVrH1vqwZ37wQPVXnq pdJy58Q045tiALcvMirhdZGAAw== X-Google-Smtp-Source: AK7set/xfHojBdkCYIcXYqx9p8jYtcp9WgACEXYQEfIv8c7VVeVZ//shfgMfiUhm9UPrfDfWqNl2hw== X-Received: by 2002:a5d:6743:0:b0:2c7:a3b:4e76 with SMTP id l3-20020a5d6743000000b002c70a3b4e76mr5897330wrw.6.1677179513936; Thu, 23 Feb 2023 11:11:53 -0800 (PST) Received: from usaari01.cust.communityfibre.co.uk ([2a02:6b6a:b566:0:5ee0:5af0:64bd:6198]) by smtp.gmail.com with ESMTPSA id b15-20020a5d4b8f000000b002c561805a4csm12957286wrt.45.2023.02.23.11.11.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Feb 2023 11:11:53 -0800 (PST) From: Usama Arif To: dwmw2@infradead.org, tglx@linutronix.de, kim.phillips@amd.com, brgerst@gmail.com Cc: piotrgorski@cachyos.org, oleksandr@natalenko.name, arjan@linux.intel.com, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, x86@kernel.org, pbonzini@redhat.com, paulmck@kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, rcu@vger.kernel.org, mimoja@mimoja.de, hewenliang4@huawei.com, thomas.lendacky@amd.com, seanjc@google.com, pmenzel@molgen.mpg.de, fam.zheng@bytedance.com, punit.agrawal@bytedance.com, simon.evans@bytedance.com, liangma@liangbit.com, David Woodhouse , Usama Arif Subject: [PATCH v11 12/12] x86/smpboot: Simplify boot CPU setup Date: Thu, 23 Feb 2023 19:11:40 +0000 Message-Id: <20230223191140.4155012-13-usama.arif@bytedance.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230223191140.4155012-1-usama.arif@bytedance.com> References: <20230223191140.4155012-1-usama.arif@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org From: Brian Gerst Now that the per-cpu GSBASE, stack, and GDT descriptor can be derived dynamically by CPU number, the boot CPU can use a fixed CPU number and take the same path as secondary CPUs. Signed-off-by: Brian Gerst Reviewed-by: David Woodhouse Signed-off-by: David Woodhouse Tested-by: Usama Arif Signed-off-by: Usama Arif --- arch/x86/include/asm/smp.h | 5 ++--- arch/x86/kernel/head_64.S | 25 +++++++------------------ arch/x86/kernel/smpboot.c | 6 +++--- 3 files changed, 12 insertions(+), 24 deletions(-) diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h index b4b29e052b6e..97a36d029b0e 100644 --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -202,8 +202,7 @@ extern unsigned int smpboot_control; #endif /* !__ASSEMBLY__ */ /* Control bits for startup_64 */ -#define STARTUP_SECONDARY 0x80000000 -#define STARTUP_APICID_CPUID_0B 0x40000000 -#define STARTUP_APICID_CPUID_01 0x20000000 +#define STARTUP_APICID_CPUID_0B 0x80000000 +#define STARTUP_APICID_CPUID_01 0x40000000 #endif /* _ASM_X86_SMP_H */ diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 9ed87ba0609f..949c13b26811 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -235,28 +235,22 @@ SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL) ANNOTATE_NOENDBR // above #ifdef CONFIG_SMP - /* Is this the boot CPU coming up? */ - movl smpboot_control(%rip), %edx - testl $STARTUP_SECONDARY, %edx - jz .Linit_cpu0_data - /* * For parallel boot, the APIC ID is retrieved from CPUID, and then * used to look up the CPU number. For booting a single CPU, the * CPU number is encoded in smpboot_control. * - * Bit 31 STARTUP_SECONDARY flag (checked above) * Bit 30 STARTUP_APICID_CPUID_0B flag (use CPUID 0x0b) * Bit 29 STARTUP_APICID_CPUID_01 flag (use CPUID 0x01) * Bit 0-24 CPU# if STARTUP_APICID_CPUID_xx flags are not set */ - testl $STARTUP_APICID_CPUID_0B, %edx + movl smpboot_control(%rip), %ecx + testl $STARTUP_APICID_CPUID_0B, %ecx jnz .Luse_cpuid_0b - testl $STARTUP_APICID_CPUID_01, %edx + testl $STARTUP_APICID_CPUID_01, %ecx jnz .Luse_cpuid_01 - andl $0x0FFFFFFF, %edx - movl %edx, %ecx - jmp .Linit_cpu_data + andl $0x0FFFFFFF, %ecx + jmp .Lsetup_cpu .Luse_cpuid_01: mov $0x01, %eax @@ -277,7 +271,7 @@ SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL) .Lfind_cpunr: cmpl (%rbx,%rcx,4), %edx - jz .Linit_cpu_data + jz .Lsetup_cpu inc %ecx cmpl nr_cpu_ids(%rip), %ecx jb .Lfind_cpunr @@ -291,18 +285,13 @@ SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL) hlt jmp 1b -.Linit_cpu0_data: - movq __per_cpu_offset(%rip), %rdx - jmp .Lsetup_cpu - -.Linit_cpu_data: +.Lsetup_cpu: /* Get the per cpu offset for the given CPU# which is in ECX */ movq __per_cpu_offset(,%rcx,8), %rdx #else xorl %edx, %edx #endif /* CONFIG_SMP */ -.Lsetup_cpu: /* * Setup a boot time stack - Any secondary CPU will have lost its stack * by now because the cr3-switch above unmaps the real-mode stack diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 69ef0860feea..9d956571ecc1 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1140,7 +1140,7 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle, early_gdt_descr.address = (unsigned long)get_cpu_gdt_rw(cpu); initial_stack = idle->thread.sp; } else if (!do_parallel_bringup) { - smpboot_control = STARTUP_SECONDARY | cpu; + smpboot_control = cpu; } /* Enable the espfix hack for this CPU */ @@ -1580,7 +1580,7 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus) */ if (eax) { pr_debug("Using CPUID 0xb for parallel CPU startup\n"); - smpboot_control = STARTUP_SECONDARY | STARTUP_APICID_CPUID_0B; + smpboot_control = STARTUP_APICID_CPUID_0B; } else { pr_info("Disabling parallel bringup because CPUID 0xb looks untrustworthy\n"); do_parallel_bringup = false; @@ -1588,7 +1588,7 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus) } else if (do_parallel_bringup) { /* Without X2APIC, what's in CPUID 0x01 should suffice. */ pr_debug("Using CPUID 0x1 for parallel CPU startup\n"); - smpboot_control = STARTUP_SECONDARY | STARTUP_APICID_CPUID_01; + smpboot_control = STARTUP_APICID_CPUID_01; } if (do_parallel_bringup) {