From: Zhao Chenhui <chenhui.zhao@freescale.com>
Date: Fri, 20 Jul 2012 12:42:34 +0000 (+0800)
Subject: powerpc/smp: add generic_set_cpu_up() to set cpu_state as CPU_UP_PREPARE
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=ae5cab476342bc7311945cf89d5cbd8d57f4a5a9;p=deliverable%2Flinux.git

powerpc/smp: add generic_set_cpu_up() to set cpu_state as CPU_UP_PREPARE

In the case of cpu hotplug, the cpu_state should be set to CPU_UP_PREPARE
when kicking cpu.  Otherwise, the cpu_state is always CPU_DEAD after
calling generic_set_cpu_dead(), which makes the delay in generic_cpu_die()
not happen.

Signed-off-by: Zhao Chenhui <chenhui.zhao@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
---

diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h
index ebc24dc5b1a1..ce8e2bdf84ed 100644
--- a/arch/powerpc/include/asm/smp.h
+++ b/arch/powerpc/include/asm/smp.h
@@ -65,6 +65,7 @@ int generic_cpu_disable(void);
 void generic_cpu_die(unsigned int cpu);
 void generic_mach_cpu_die(void);
 void generic_set_cpu_dead(unsigned int cpu);
+void generic_set_cpu_up(unsigned int cpu);
 int generic_check_cpu_restart(unsigned int cpu);
 #endif
 
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 8d4214afc21d..a51ed205016e 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -102,7 +102,7 @@ int __devinit smp_generic_kick_cpu(int nr)
 	 * Ok it's not there, so it might be soft-unplugged, let's
 	 * try to bring it back
 	 */
-	per_cpu(cpu_state, nr) = CPU_UP_PREPARE;
+	generic_set_cpu_up(nr);
 	smp_wmb();
 	smp_send_reschedule(nr);
 #endif /* CONFIG_HOTPLUG_CPU */
@@ -413,6 +413,16 @@ void generic_set_cpu_dead(unsigned int cpu)
 	per_cpu(cpu_state, cpu) = CPU_DEAD;
 }
 
+/*
+ * The cpu_state should be set to CPU_UP_PREPARE in kick_cpu(), otherwise
+ * the cpu_state is always CPU_DEAD after calling generic_set_cpu_dead(),
+ * which makes the delay in generic_cpu_die() not happen.
+ */
+void generic_set_cpu_up(unsigned int cpu)
+{
+	per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
+}
+
 int generic_check_cpu_restart(unsigned int cpu)
 {
 	return per_cpu(cpu_state, cpu) == CPU_UP_PREPARE;