1 files changed, 140 insertions, 20 deletions

diff --git a/arch/sh/kernel/smp.c b/arch/sh/kernel/smp.c
index 002cc612deef..509b36b45115 100644
--- a/arch/sh/kernel/smp.c
+++ b/arch/sh/kernel/smp.c
@@ -3,7 +3,7 @@
  *
  * SMP support for the SuperH processors.
  *
- * Copyright (C) 2002 - 2008 Paul Mundt
+ * Copyright (C) 2002 - 2010 Paul Mundt
  * Copyright (C) 2006 - 2007 Akio Idehara
  *
  * This file is subject to the terms and conditions of the GNU General Public
@@ -31,7 +31,20 @@
 int __cpu_number_map[NR_CPUS];          /* Map physical to logical */
 int __cpu_logical_map[NR_CPUS];         /* Map logical to physical */
 
-static inline void __init smp_store_cpu_info(unsigned int cpu)
+struct plat_smp_ops *mp_ops = NULL;
+
+/* State of each CPU */
+DEFINE_PER_CPU(int, cpu_state) = { 0 };
+
+void __cpuinit register_smp_ops(struct plat_smp_ops *ops)
+{
+        if (mp_ops)
+                printk(KERN_WARNING "Overriding previously set SMP ops\n");
+
+        mp_ops = ops;
+}
+
+static inline void __cpuinit smp_store_cpu_info(unsigned int cpu)
 {
         struct sh_cpuinfo *c = cpu_data + cpu;
 
@@ -46,14 +59,14 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
 
         init_new_context(current, &init_mm);
         current_thread_info()->cpu = cpu;
-        plat_prepare_cpus(max_cpus);
+        mp_ops->prepare_cpus(max_cpus);
 
 #ifndef CONFIG_HOTPLUG_CPU
         init_cpu_present(&cpu_possible_map);
 #endif
 }
 
-void __devinit smp_prepare_boot_cpu(void)
+void __init smp_prepare_boot_cpu(void)
 {
         unsigned int cpu = smp_processor_id();
 
@@ -62,37 +75,137 @@ void __devinit smp_prepare_boot_cpu(void)
 
         set_cpu_online(cpu, true);
         set_cpu_possible(cpu, true);
+
+        per_cpu(cpu_state, cpu) = CPU_ONLINE;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+void native_cpu_die(unsigned int cpu)
+{
+        unsigned int i;
+
+        for (i = 0; i < 10; i++) {
+                smp_rmb();
+                if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
+                        if (system_state == SYSTEM_RUNNING)
+                                pr_info("CPU %u is now offline\n", cpu);
+
+                        return;
+                }
+
+                msleep(100);
+        }
+
+        pr_err("CPU %u didn't die...\n", cpu);
+}
+
+int native_cpu_disable(unsigned int cpu)
+{
+        return cpu == 0 ? -EPERM : 0;
+}
+
+void play_dead_common(void)
+{
+        idle_task_exit();
+        irq_ctx_exit(raw_smp_processor_id());
+        mb();
+
+        __get_cpu_var(cpu_state) = CPU_DEAD;
+        local_irq_disable();
+}
+
+void native_play_dead(void)
+{
+        play_dead_common();
 }
 
+int __cpu_disable(void)
+{
+        unsigned int cpu = smp_processor_id();
+        struct task_struct *p;
+        int ret;
+
+        ret = mp_ops->cpu_disable(cpu);
+        if (ret)
+                return ret;
+
+        /*
+         * Take this CPU offline.  Once we clear this, we can't return,
+         * and we must not schedule until we're ready to give up the cpu.
+         */
+        set_cpu_online(cpu, false);
+
+        /*
+         * OK - migrate IRQs away from this CPU
+         */
+        migrate_irqs();
+
+        /*
+         * Stop the local timer for this CPU.
+         */
+        local_timer_stop(cpu);
+
+        /*
+         * Flush user cache and TLB mappings, and then remove this CPU
+         * from the vm mask set of all processes.
+         */
+        flush_cache_all();
+        local_flush_tlb_all();
+
+        read_lock(&tasklist_lock);
+        for_each_process(p)
+                if (p->mm)
+                        cpumask_clear_cpu(cpu, mm_cpumask(p->mm));
+        read_unlock(&tasklist_lock);
+
+        return 0;
+}
+#else /* ... !CONFIG_HOTPLUG_CPU */
+int native_cpu_disable(unsigned int cpu)
+{
+        return -ENOSYS;
+}
+
+void native_cpu_die(unsigned int cpu)
+{
+        /* We said "no" in __cpu_disable */
+        BUG();
+}
+
+void native_play_dead(void)
+{
+        BUG();
+}
+#endif
+
 asmlinkage void __cpuinit start_secondary(void)
 {
-        unsigned int cpu;
+        unsigned int cpu = smp_processor_id();
         struct mm_struct *mm = &init_mm;
 
         enable_mmu();
         atomic_inc(&mm->mm_count);
         atomic_inc(&mm->mm_users);
         current->active_mm = mm;
-        BUG_ON(current->mm);
         enter_lazy_tlb(mm, current);
+        local_flush_tlb_all();
 
         per_cpu_trap_init();
 
         preempt_disable();
 
-        notify_cpu_starting(smp_processor_id());
+        notify_cpu_starting(cpu);
 
         local_irq_enable();
 
-        cpu = smp_processor_id();
-
         /* Enable local timers */
         local_timer_setup(cpu);
         calibrate_delay();
 
         smp_store_cpu_info(cpu);
 
-        cpu_set(cpu, cpu_online_map);
+        set_cpu_online(cpu, true);
+        per_cpu(cpu_state, cpu) = CPU_ONLINE;
 
         cpu_idle();
 }
@@ -111,12 +224,19 @@ int __cpuinit __cpu_up(unsigned int cpu)
         struct task_struct *tsk;
         unsigned long timeout;
 
-        tsk = fork_idle(cpu);
-        if (IS_ERR(tsk)) {
-                printk(KERN_ERR "Failed forking idle task for cpu %d\n", cpu);
-                return PTR_ERR(tsk);
+        tsk = cpu_data[cpu].idle;
+        if (!tsk) {
+                tsk = fork_idle(cpu);
+                if (IS_ERR(tsk)) {
+                        pr_err("Failed forking idle task for cpu %d\n", cpu);
+                        return PTR_ERR(tsk);
+                }
+
+                cpu_data[cpu].idle = tsk;
         }
 
+        per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
+
         /* Fill in data in head.S for secondary cpus */
         stack_start.sp = tsk->thread.sp;
         stack_start.thread_info = tsk->stack;
@@ -127,7 +247,7 @@ int __cpuinit __cpu_up(unsigned int cpu)
                            (unsigned long)&stack_start + sizeof(stack_start));
         wmb();
 
-        plat_start_cpu(cpu, (unsigned long)_stext);
+        mp_ops->start_cpu(cpu, (unsigned long)_stext);
 
         timeout = jiffies + HZ;
         while (time_before(jiffies, timeout)) {
@@ -135,6 +255,7 @@ int __cpuinit __cpu_up(unsigned int cpu)
                         break;
 
                 udelay(10);
+                barrier();
         }
 
         if (cpu_online(cpu))
@@ -159,7 +280,7 @@ void __init smp_cpus_done(unsigned int max_cpus)
 
 void smp_send_reschedule(int cpu)
 {
-        plat_send_ipi(cpu, SMP_MSG_RESCHEDULE);
+        mp_ops->send_ipi(cpu, SMP_MSG_RESCHEDULE);
 }
 
 void smp_send_stop(void)
@@ -172,12 +293,12 @@ void arch_send_call_function_ipi_mask(const struct cpumask *mask)
         int cpu;
 
         for_each_cpu(cpu, mask)
-                plat_send_ipi(cpu, SMP_MSG_FUNCTION);
+                mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION);
 }
 
 void arch_send_call_function_single_ipi(int cpu)
 {
-        plat_send_ipi(cpu, SMP_MSG_FUNCTION_SINGLE);
+        mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION_SINGLE);
 }
 
 void smp_timer_broadcast(const struct cpumask *mask)
@@ -185,7 +306,7 @@ void smp_timer_broadcast(const struct cpumask *mask)
         int cpu;
 
         for_each_cpu(cpu, mask)
-                plat_send_ipi(cpu, SMP_MSG_TIMER);
+                mp_ops->send_ipi(cpu, SMP_MSG_TIMER);
 }
 
 static void ipi_timer(void)
@@ -249,7 +370,6 @@ static void flush_tlb_mm_ipi(void *mm)
  * behalf of debugees, kswapd stealing pages from another process etc).
  * Kanoj 07/00.
  */
-
 void flush_tlb_mm(struct mm_struct *mm)
 {
         preempt_disable();