Messages in this thread Patch in this message | | | From | "Fenghua Yu" <> | Subject | [PATCH 2/6] x86/head_32.S/head_64.S: Kernel entry code after waking up offline CPU via mwait or nmi | Date | Mon, 4 Jun 2012 11:17:51 -0700 |
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From: Fenghua Yu <fenghua.yu@intel.com>
start_cpu() is CPU entry point after it's waken up via mwait or nmi. It's called from play_dead(). Everything has been set up already except stack. We just set up stack here. Then call start_secondary().
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> --- arch/x86/include/asm/cpu.h | 1 + arch/x86/kernel/head_32.S | 12 ++++++++++++ arch/x86/kernel/head_64.S | 14 ++++++++++++++ 3 files changed, 27 insertions(+), 0 deletions(-)
diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h index 4564c8e..c2ad71c 100644 --- a/arch/x86/include/asm/cpu.h +++ b/arch/x86/include/asm/cpu.h @@ -28,6 +28,7 @@ struct x86_cpu { #ifdef CONFIG_HOTPLUG_CPU extern int arch_register_cpu(int num); extern void arch_unregister_cpu(int); +extern void __cpuinit start_cpu(void); #endif DECLARE_PER_CPU(int, cpu_state); diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index d42ab17..55981a7 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -266,6 +266,18 @@ num_subarch_entries = (. - subarch_entries) / 4 jmp default_entry #endif /* CONFIG_PARAVIRT */ +#ifdef CONFIG_HOTPLUG_CPU +/* + * Boot CPU 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_cpu) + movl stack_start, %ecx + movl %ecx, %esp + jmp *(initial_code) +#endif + /* * Non-boot CPU entry point; entered from trampoline.S * We can't lgdt here, because lgdt itself uses a data segment, but diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 94bf9cc..84a8e1d 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -251,6 +251,20 @@ ENTRY(secondary_startup_64) pushq $__KERNEL_CS # set correct cs pushq %rax # target address in negative space lretq +#ifdef CONFIG_HOTPLUG_CPU +/* + * Boot CPU 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_cpu) + 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 +#endif /* SMP bootup changes these two */ __REFDATA -- 1.6.0.3
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