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authorFenghua Yu <fenghua.yu@intel.com>2012-11-13 20:32:44 +0100
committerH. Peter Anvin <hpa@linux.intel.com>2012-11-14 18:39:51 +0100
commit42e78e9719aa0c76711e2731b19c90fe5ae05278 (patch)
tree54b5a1bf71a4b2180247512c2a18d4c5927b8bd5 /arch/x86/kernel/head_64.S
parentkernel/cpu.c: Add comment for priority in cpu_hotplug_pm_callback (diff)
downloadlinux-42e78e9719aa0c76711e2731b19c90fe5ae05278.tar.xz
linux-42e78e9719aa0c76711e2731b19c90fe5ae05278.zip
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 <fenghua.yu@intel.com> Link: http://lkml.kernel.org/r/1352835171-3958-8-git-send-email-fenghua.yu@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86/kernel/head_64.S')
-rw-r--r--arch/x86/kernel/head_64.S16
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 94bf9cc2c7ee..980053c4b9cc 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