From patchwork Thu Apr 28 20:44:33 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josh Poimboeuf X-Patchwork-Id: 616409 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [103.22.144.68]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3qwpqP6pRdz9t8f for ; Fri, 29 Apr 2016 06:49:53 +1000 (AEST) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3qwpqP6334zDqfb for ; Fri, 29 Apr 2016 06:49:53 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3qwpk00D58zDqB3 for ; Fri, 29 Apr 2016 06:45:12 +1000 (AEST) Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 5EFEF37E62; Thu, 28 Apr 2016 20:45:10 +0000 (UTC) Received: from treble.redhat.com (ovpn-113-171.phx2.redhat.com [10.3.113.171]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u3SKj3lt008776; Thu, 28 Apr 2016 16:45:08 -0400 From: Josh Poimboeuf To: Jessica Yu , Jiri Kosina , Miroslav Benes , Ingo Molnar , Peter Zijlstra , Michael Ellerman , Heiko Carstens Subject: [RFC PATCH v2 02/18] x86/asm/head: use a common function for starting CPUs Date: Thu, 28 Apr 2016 15:44:33 -0500 Message-Id: In-Reply-To: References: X-Scanned-By: MIMEDefang 2.68 on 10.5.11.27 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-s390@vger.kernel.org, Vojtech Pavlik , Petr Mladek , Jiri Slaby , x86@kernel.org, linux-kernel@vger.kernel.org, Andy Lutomirski , live-patching@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Chris J Arges MIME-Version: 1.0 Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" There are two different pieces of code for starting a CPU: start_cpu0() and the end of secondary_startup_64(). They're identical except for the stack setup. Combine the common parts into a shared start_cpu() function. Signed-off-by: Josh Poimboeuf --- arch/x86/kernel/head_64.S | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 792c3bb..6dbd2c0 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -264,13 +264,15 @@ ENTRY(secondary_startup_64) movl $MSR_GS_BASE,%ecx movl initial_gs(%rip),%eax movl initial_gs+4(%rip),%edx - wrmsr + wrmsr /* rsi is pointer to real mode structure with interesting info. pass it to C */ movq %rsi, %rdi - - /* Finally jump to run C code and to be on real kernel address + +ENTRY(start_cpu) + /* + * Jump to run C code and to be on a real kernel address. * Since we are running on identity-mapped space we have to jump * to the full 64bit address, this is only possible as indirect * jump. In addition we need to ensure %cs is set so we make this @@ -299,6 +301,7 @@ ENTRY(secondary_startup_64) pushq $__KERNEL_CS # set correct cs pushq %rax # target address in negative space lretq +ENDPROC(start_cpu) #include "verify_cpu.S" @@ -306,15 +309,11 @@ ENTRY(secondary_startup_64) /* * Boot CPU0 entry point. It's called from play_dead(). Everything has been set * up already except stack. We just set up stack here. Then call - * start_secondary(). + * start_secondary() via start_cpu(). */ ENTRY(start_cpu0) - movq initial_stack(%rip),%rsp - movq initial_code(%rip),%rax - pushq $0 # fake return address to stop unwinder - pushq $__KERNEL_CS # set correct cs - pushq %rax # target address in negative space - lretq + movq initial_stack(%rip), %rsp + jmp start_cpu ENDPROC(start_cpu0) #endif