From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1950025AbcHRNRK (ORCPT ); Thu, 18 Aug 2016 09:17:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38768 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1949722AbcHRNRH (ORCPT ); Thu, 18 Aug 2016 09:17:07 -0400 From: Josh Poimboeuf To: Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Andy Lutomirski , Linus Torvalds , Steven Rostedt , Brian Gerst , Kees Cook , Peter Zijlstra , Frederic Weisbecker , Byungchul Park , Nilay Vaish Subject: [PATCH v4 04/57] x86/asm/head: use a common function for starting CPUs Date: Thu, 18 Aug 2016 08:05:44 -0500 Message-Id: In-Reply-To: References: X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Thu, 18 Aug 2016 13:06:49 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index e048142..a212310 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -264,13 +264,17 @@ 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 + jmp start_cpu +ENDPROC(secondary_startup_64) + +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 @@ -299,7 +303,7 @@ ENTRY(secondary_startup_64) pushq $__KERNEL_CS # set correct cs pushq %rax # target address in negative space lretq -ENDPROC(secondary_startup_64) +ENDPROC(start_cpu) #include "verify_cpu.S" @@ -307,15 +311,11 @@ ENDPROC(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 -- 2.7.4