[PATCH v5 07/12] x86/head_32.S: Define start_cpu0

["Fenghua Yu" <fenghua.yu@intel.com>]

From: Fenghua Yu <fenghua.yu@intel.com>

start_cpu0() is defined in head_32.S for 32-bit. The function sets up stack and
jumps to start_secondary() for CPU0 wake up.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 arch/x86/kernel/head_32.S |   17 ++++++++++++++---
 1 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index ce0be7c..5a38a1a 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -265,6 +265,20 @@ num_subarch_entries = (. - subarch_entries) / 4
 	jmp default_entry
 #endif /* CONFIG_PARAVIRT */
 
+__CPUINIT
+
+#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)
+	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
@@ -273,9 +287,6 @@ num_subarch_entries = (. - subarch_entries) / 4
  * If cpu hotplug is not supported then this code can go in init section
  * which will be freed later
  */
-
-__CPUINIT
-
 #ifdef CONFIG_SMP
 ENTRY(startup_32_smp)
 	cld
-- 
1.6.0.3