From 42e78e9719aa0c76711e2731b19c90fe5ae05278 Mon Sep 17 00:00:00 2001 From: Fenghua Yu Date: Tue, 13 Nov 2012 11:32:44 -0800 Subject: [PATCH] x86-64, hotplug: Add start_cpu0() entry point to head_64.S start_cpu0() is defined in head_64.S for 64-bit. The function sets up stack and jumps to start_secondary() for CPU0 wake up. Signed-off-by: Fenghua Yu Link: http://lkml.kernel.org/r/1352835171-3958-8-git-send-email-fenghua.yu@intel.com Signed-off-by: H. Peter Anvin --- arch/x86/kernel/head_64.S | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 94bf9cc..980053c 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -252,6 +252,22 @@ ENTRY(secondary_startup_64) pushq %rax # target address in negative space lretq +#ifdef CONFIG_HOTPLUG_CPU +/* + * 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(). + */ +ENTRY(start_cpu0) + movq stack_start(%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 +ENDPROC(start_cpu0) +#endif + /* SMP bootup changes these two */ __REFDATA .align 8 -- 2.7.4