Blackfin: SMP: add PM/CPU hotplug support

Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 35 insertions, 3 deletions

diff --git a/arch/blackfin/mach-common/smp.c b/arch/blackfin/mach-common/smp.c
index b343ab3764a1..efc47ffd066d 100644
--- a/arch/blackfin/mach-common/smp.c
+++ b/arch/blackfin/mach-common/smp.c
@@ -344,8 +344,11 @@ void smp_send_stop(void)
 
 int __cpuinit __cpu_up(unsigned int cpu)
 {
-        struct task_struct *idle;
         int ret;
+        static struct task_struct *idle;
+
+        if (idle)
+                free_task(idle);
 
         idle = fork_idle(cpu);
         if (IS_ERR(idle)) {
@@ -354,7 +357,6 @@ int __cpuinit __cpu_up(unsigned int cpu)
         }
 
         secondary_stack = task_stack_page(idle) + THREAD_SIZE;
-        smp_wmb();
 
         ret = platform_boot_secondary(cpu, idle);
 
@@ -413,7 +415,6 @@ void __cpuinit secondary_start_kernel(void)
         atomic_inc(&mm->mm_users);
         atomic_inc(&mm->mm_count);
         current->active_mm = mm;
-        BUG_ON(current->mm);    /* Can't be, but better be safe than sorry. */
 
         preempt_disable();
 
@@ -495,3 +496,34 @@ void resync_core_dcache(void)
 }
 EXPORT_SYMBOL(resync_core_dcache);
 #endif
+
+#ifdef CONFIG_HOTPLUG_CPU
+int __cpuexit __cpu_disable(void)
+{
+        unsigned int cpu = smp_processor_id();
+
+        if (cpu == 0)
+                return -EPERM;
+
+        set_cpu_online(cpu, false);
+        return 0;
+}
+
+static DECLARE_COMPLETION(cpu_killed);
+
+int __cpuexit __cpu_die(unsigned int cpu)
+{
+        return wait_for_completion_timeout(&cpu_killed, 5000);
+}
+
+void cpu_die(void)
+{
+        complete(&cpu_killed);
+
+        atomic_dec(&init_mm.mm_users);
+        atomic_dec(&init_mm.mm_count);
+
+        local_irq_disable();
+        platform_cpu_die();
+}
+#endif