From patchwork Thu Mar 16 22:21:05 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Usama Arif X-Patchwork-Id: 13178368 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 7BCB1C76196 for ; Thu, 16 Mar 2023 22:22:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230373AbjCPWWV (ORCPT ); Thu, 16 Mar 2023 18:22:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33168 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230236AbjCPWWI (ORCPT ); Thu, 16 Mar 2023 18:22:08 -0400 Received: from mail-wr1-x42f.google.com (mail-wr1-x42f.google.com [IPv6:2a00:1450:4864:20::42f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DDFF5B1B0B for ; Thu, 16 Mar 2023 15:21:19 -0700 (PDT) Received: by mail-wr1-x42f.google.com with SMTP id h17so2862893wrt.8 for ; Thu, 16 Mar 2023 15:21:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1679005279; 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=FULGw2JzzQsOYOrWK/IeWDfn0l3ZyQtosjohoUs52UM=; b=XJkZiiYe6qukEyVX/ujwP5etOZk592Q68jftwrVXpL4JMdoU251Sic4GKKxqoURB75 gfXMd+jOXjW5LK3dYpkUe8S2pEZcRggenTmD9+KE8eZgb7yDzwQ3EMBwGdAl5IPg5Svn 1adM4NXK26p396oaoPI2OcwyTLd5TOZ1YG6WQ6WmrT6yfgHUpju2g8gPjeQRxBtKMwN6 f/t0MCNQSMV0DnRW6aFDulqBtXy3RiaUMqnmpi5FlWc+3X8EyGqzmzqkqNLeFBvPnhqe IFrtkO2JXGZY1L74uXsj4Kv61nAuvl270HxBVyJPFpasxMgN+NUXU8heKCaGYPurMp14 C9jA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679005279; 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=FULGw2JzzQsOYOrWK/IeWDfn0l3ZyQtosjohoUs52UM=; b=vcYeD6ocvgrcCbfWZ/Dy/linx/dFFGp39wFB11B1JsBXkLECpUBIGLInWs99dx6zA+ itfJWUfAbsfiswdch49z6dAIJhBM7PO+Ze04JORIIStmnYTg/HhF4KNnH7F/gywis6NE tr0xwqv4F9cVnwDAlGXgTFny5U2C+7QBvaiqUTcHfWyTexEd2heKfUGdM1Nw7z8lzeFc WNJRGo82tGbf2mXbnKBF19aPi29RGNSRkBtFTFV6sBig7kmsnz8f7sClyR6tee4YOwXP pPvfNXSnF1r+fAWb2znZc861bD2ve5433AjhzLOhPf1e9JwTiyyqEAL1rSzK8dNDpn5h bnJg== X-Gm-Message-State: AO0yUKXfci39gDhc+CEsogbxfB0xIn9Zk/eWBR2ihofDAiWfLBjeTU6f Jf8ctWapw6yAEBpXzqqB04mWvw== X-Google-Smtp-Source: AK7set8t15sN4HACJlKDCZ3X/2n31Q8swA79q5+uZ+pUX6XrJ1YC59/G0zfyM+RQjP4WInYY4t29mA== X-Received: by 2002:adf:dc0f:0:b0:2cf:f0c3:79ba with SMTP id t15-20020adfdc0f000000b002cff0c379bamr5429317wri.67.1679005279217; Thu, 16 Mar 2023 15:21:19 -0700 (PDT) Received: from usaari01.cust.communityfibre.co.uk ([2a02:6b6a:b566:0:4b87:78c3:3abe:7b0d]) by smtp.gmail.com with ESMTPSA id f9-20020adff989000000b002cea392f000sm439256wrr.69.2023.03.16.15.21.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 16 Mar 2023 15:21:18 -0700 (PDT) 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, gpiccoli@igalia.com, David Woodhouse , Usama Arif Subject: [PATCH v15 08/12] x86/smpboot: Remove initial_gs Date: Thu, 16 Mar 2023 22:21:05 +0000 Message-Id: <20230316222109.1940300-9-usama.arif@bytedance.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230316222109.1940300-1-usama.arif@bytedance.com> References: <20230316222109.1940300-1-usama.arif@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org From: Brian Gerst Given its CPU#, each CPU can find its own per-cpu offset, and directly set GSBASE accordingly. The global variable can be eliminated. Signed-off-by: Brian Gerst Reviewed-by: David Woodhouse Signed-off-by: David Woodhouse Tested-by: Usama Arif Signed-off-by: Usama Arif Tested-by: Guilherme G. Piccoli --- arch/x86/include/asm/realmode.h | 1 - arch/x86/kernel/acpi/sleep.c | 1 - arch/x86/kernel/head_64.S | 22 ++++++++-------------- arch/x86/kernel/smpboot.c | 2 -- 4 files changed, 8 insertions(+), 18 deletions(-) diff --git a/arch/x86/include/asm/realmode.h b/arch/x86/include/asm/realmode.h index a336feef0af1..f6a1737c77be 100644 --- a/arch/x86/include/asm/realmode.h +++ b/arch/x86/include/asm/realmode.h @@ -59,7 +59,6 @@ extern struct real_mode_header *real_mode_header; extern unsigned char real_mode_blob_end[]; extern unsigned long initial_code; -extern unsigned long initial_gs; extern unsigned long initial_stack; #ifdef CONFIG_AMD_MEM_ENCRYPT extern unsigned long initial_vc_handler; diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c index de89bb4719d0..1328c221af30 100644 --- a/arch/x86/kernel/acpi/sleep.c +++ b/arch/x86/kernel/acpi/sleep.c @@ -127,7 +127,6 @@ int x86_acpi_suspend_lowlevel(void) * value is in the actual %rsp register. */ current->thread.sp = (unsigned long)temp_stack + sizeof(temp_stack); - initial_gs = per_cpu_offset(smp_processor_id()); smpboot_control = smp_processor_id(); #endif initial_code = (unsigned long)wakeup_long64; diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index a5b46c2fba05..6a8238702eab 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -66,18 +66,10 @@ SYM_CODE_START_NOALIGN(startup_64) leaq _text(%rip), %rdi - /* - * initial_gs points to initial fixed_percpu_data struct with storage for - * the stack protector canary. Global pointer fixups are needed at this - * stage, so apply them as is done in fixup_pointer(), and initialize %gs - * such that the canary can be accessed at %gs:40 for subsequent C calls. - */ + /* Setup GSBASE to allow stack canary access for C code */ movl $MSR_GS_BASE, %ecx - movq initial_gs(%rip), %rax - movq $_text, %rdx - subq %rdx, %rax - addq %rdi, %rax - movq %rax, %rdx + leaq INIT_PER_CPU_VAR(fixed_percpu_data)(%rip), %rdx + movl %edx, %eax shrq $32, %rdx wrmsr @@ -294,8 +286,11 @@ SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL) * the per cpu areas are set up. */ movl $MSR_GS_BASE,%ecx - movl initial_gs(%rip),%eax - movl initial_gs+4(%rip),%edx +#ifndef CONFIG_SMP + leaq INIT_PER_CPU_VAR(fixed_percpu_data)(%rip), %rdx +#endif + movl %edx, %eax + shrq $32, %rdx wrmsr /* Setup and Load IDT */ @@ -437,7 +432,6 @@ SYM_CODE_END(vc_boot_ghcb) __REFDATA .balign 8 SYM_DATA(initial_code, .quad x86_64_start_kernel) -SYM_DATA(initial_gs, .quad INIT_PER_CPU_VAR(fixed_percpu_data)) #ifdef CONFIG_AMD_MEM_ENCRYPT SYM_DATA(initial_vc_handler, .quad handle_vc_boot_ghcb) #endif diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 67224e61310c..28d1643eee99 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1084,8 +1084,6 @@ int common_cpu_up(unsigned int cpu, struct task_struct *idle) #ifdef CONFIG_X86_32 /* Stack for startup_32 can be just as for start_secondary onwards */ per_cpu(pcpu_hot.top_of_stack, cpu) = task_top_of_stack(idle); -#else - initial_gs = per_cpu_offset(cpu); #endif return 0; }