1 files changed, 214 insertions, 104 deletions

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 0008bc58e826..8ebc6700b98d 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -57,6 +57,25 @@
 #define DBG(fmt...)
 #endif
 
+
+/* Store all idle threads, this can be reused instead of creating
+* a new thread. Also avoids complicated thread destroy functionality
+* for idle threads.
+*/
+#ifdef CONFIG_HOTPLUG_CPU
+/*
+ * Needed only for CONFIG_HOTPLUG_CPU because __cpuinitdata is
+ * removed after init for !CONFIG_HOTPLUG_CPU.
+ */
+static DEFINE_PER_CPU(struct task_struct *, idle_thread_array);
+#define get_idle_for_cpu(x)      (per_cpu(idle_thread_array, x))
+#define set_idle_for_cpu(x, p)   (per_cpu(idle_thread_array, x) = (p))
+#else
+static struct task_struct *idle_thread_array[NR_CPUS] __cpuinitdata ;
+#define get_idle_for_cpu(x)      (idle_thread_array[(x)])
+#define set_idle_for_cpu(x, p)   (idle_thread_array[(x)] = (p))
+#endif
+
 struct thread_info *secondary_ti;
 
 DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map);
@@ -76,7 +95,7 @@ int smt_enabled_at_boot = 1;
 static void (*crash_ipi_function_ptr)(struct pt_regs *) = NULL;
 
 #ifdef CONFIG_PPC64
-void __devinit smp_generic_kick_cpu(int nr)
+int __devinit smp_generic_kick_cpu(int nr)
 {
         BUG_ON(nr < 0 || nr >= NR_CPUS);
 
@@ -87,37 +106,10 @@ void __devinit smp_generic_kick_cpu(int nr)
          */
         paca[nr].cpu_start = 1;
         smp_mb();
-}
-#endif
 
-void smp_message_recv(int msg)
-{
-        switch(msg) {
-        case PPC_MSG_CALL_FUNCTION:
-                generic_smp_call_function_interrupt();
-                break;
-        case PPC_MSG_RESCHEDULE:
-                /* we notice need_resched on exit */
-                break;
-        case PPC_MSG_CALL_FUNC_SINGLE:
-                generic_smp_call_function_single_interrupt();
-                break;
-        case PPC_MSG_DEBUGGER_BREAK:
-                if (crash_ipi_function_ptr) {
-                        crash_ipi_function_ptr(get_irq_regs());
-                        break;
-                }
-#ifdef CONFIG_DEBUGGER
-                debugger_ipi(get_irq_regs());
-                break;
-#endif /* CONFIG_DEBUGGER */
-                /* FALLTHROUGH */
-        default:
-                printk("SMP %d: smp_message_recv(): unknown msg %d\n",
-                       smp_processor_id(), msg);
-                break;
-        }
+        return 0;
 }
+#endif
 
 static irqreturn_t call_function_action(int irq, void *data)
 {
@@ -127,7 +119,7 @@ static irqreturn_t call_function_action(int irq, void *data)
 
 static irqreturn_t reschedule_action(int irq, void *data)
 {
-        /* we just need the return path side effect of checking need_resched */
+        scheduler_ipi();
         return IRQ_HANDLED;
 }
 
@@ -139,7 +131,15 @@ static irqreturn_t call_function_single_action(int irq, void *data)
 
 static irqreturn_t debug_ipi_action(int irq, void *data)
 {
-        smp_message_recv(PPC_MSG_DEBUGGER_BREAK);
+        if (crash_ipi_function_ptr) {
+                crash_ipi_function_ptr(get_irq_regs());
+                return IRQ_HANDLED;
+        }
+
+#ifdef CONFIG_DEBUGGER
+        debugger_ipi(get_irq_regs());
+#endif /* CONFIG_DEBUGGER */
+
         return IRQ_HANDLED;
 }
 
@@ -178,6 +178,66 @@ int smp_request_message_ipi(int virq, int msg)
         return err;
 }
 
+#ifdef CONFIG_PPC_SMP_MUXED_IPI
+struct cpu_messages {
+        int messages;                   /* current messages */
+        unsigned long data;             /* data for cause ipi */
+};
+static DEFINE_PER_CPU_SHARED_ALIGNED(struct cpu_messages, ipi_message);
+
+void smp_muxed_ipi_set_data(int cpu, unsigned long data)
+{
+        struct cpu_messages *info = &per_cpu(ipi_message, cpu);
+
+        info->data = data;
+}
+
+void smp_muxed_ipi_message_pass(int cpu, int msg)
+{
+        struct cpu_messages *info = &per_cpu(ipi_message, cpu);
+        char *message = (char *)&info->messages;
+
+        message[msg] = 1;
+        mb();
+        smp_ops->cause_ipi(cpu, info->data);
+}
+
+void smp_muxed_ipi_resend(void)
+{
+        struct cpu_messages *info = &__get_cpu_var(ipi_message);
+
+        if (info->messages)
+                smp_ops->cause_ipi(smp_processor_id(), info->data);
+}
+
+irqreturn_t smp_ipi_demux(void)
+{
+        struct cpu_messages *info = &__get_cpu_var(ipi_message);
+        unsigned int all;
+
+        mb();   /* order any irq clear */
+
+        do {
+                all = xchg_local(&info->messages, 0);
+
+#ifdef __BIG_ENDIAN
+                if (all & (1 << (24 - 8 * PPC_MSG_CALL_FUNCTION)))
+                        generic_smp_call_function_interrupt();
+                if (all & (1 << (24 - 8 * PPC_MSG_RESCHEDULE)))
+                        scheduler_ipi();
+                if (all & (1 << (24 - 8 * PPC_MSG_CALL_FUNC_SINGLE)))
+                        generic_smp_call_function_single_interrupt();
+                if (all & (1 << (24 - 8 * PPC_MSG_DEBUGGER_BREAK)))
+                        debug_ipi_action(0, NULL);
+#else
+#error Unsupported ENDIAN
+#endif
+        } while (info->messages);
+
+        return IRQ_HANDLED;
+}
+#endif /* CONFIG_PPC_SMP_MUXED_IPI */
+
 void smp_send_reschedule(int cpu)
 {
         if (likely(smp_ops))
@@ -197,11 +257,18 @@ void arch_send_call_function_ipi_mask(const struct cpumask *mask)
                 smp_ops->message_pass(cpu, PPC_MSG_CALL_FUNCTION);
 }
 
-#ifdef CONFIG_DEBUGGER
-void smp_send_debugger_break(int cpu)
+#if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
+void smp_send_debugger_break(void)
 {
-        if (likely(smp_ops))
-                smp_ops->message_pass(cpu, PPC_MSG_DEBUGGER_BREAK);
+        int cpu;
+        int me = raw_smp_processor_id();
+
+        if (unlikely(!smp_ops))
+                return;
+
+        for_each_online_cpu(cpu)
+                if (cpu != me)
+                        smp_ops->message_pass(cpu, PPC_MSG_DEBUGGER_BREAK);
 }
 #endif
 
@@ -209,9 +276,9 @@ void smp_send_debugger_break(int cpu)
 void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *))
 {
         crash_ipi_function_ptr = crash_ipi_callback;
-        if (crash_ipi_callback && smp_ops) {
+        if (crash_ipi_callback) {
                 mb();
-                smp_ops->message_pass(MSG_ALL_BUT_SELF, PPC_MSG_DEBUGGER_BREAK);
+                smp_send_debugger_break();
         }
 }
 #endif
@@ -238,23 +305,6 @@ static void __devinit smp_store_cpu_info(int id)
         per_cpu(cpu_pvr, id) = mfspr(SPRN_PVR);
 }
 
-static void __init smp_create_idle(unsigned int cpu)
-{
-        struct task_struct *p;
-
-        /* create a process for the processor */
-        p = fork_idle(cpu);
-        if (IS_ERR(p))
-                panic("failed fork for CPU %u: %li", cpu, PTR_ERR(p));
-#ifdef CONFIG_PPC64
-        paca[cpu].__current = p;
-        paca[cpu].kstack = (unsigned long) task_thread_info(p)
-                + THREAD_SIZE - STACK_FRAME_OVERHEAD;
-#endif
-        current_set[cpu] = task_thread_info(p);
-        task_thread_info(p)->cpu = cpu;
-}
-
 void __init smp_prepare_cpus(unsigned int max_cpus)
 {
         unsigned int cpu;
@@ -288,10 +338,6 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
                         max_cpus = NR_CPUS;
         else
                 max_cpus = 1;
-
-        for_each_possible_cpu(cpu)
-                if (cpu != boot_cpuid)
-                        smp_create_idle(cpu);
 }
 
 void __devinit smp_prepare_boot_cpu(void)
@@ -305,7 +351,7 @@ void __devinit smp_prepare_boot_cpu(void)
 
 #ifdef CONFIG_HOTPLUG_CPU
 /* State of each CPU during hotplug phases */
-DEFINE_PER_CPU(int, cpu_state) = { 0 };
+static DEFINE_PER_CPU(int, cpu_state) = { 0 };
 
 int generic_cpu_disable(void)
 {
@@ -317,30 +363,8 @@ int generic_cpu_disable(void)
         set_cpu_online(cpu, false);
 #ifdef CONFIG_PPC64
         vdso_data->processorCount--;
-        fixup_irqs(cpu_online_mask);
-#endif
-        return 0;
-}
-
-int generic_cpu_enable(unsigned int cpu)
-{
-        /* Do the normal bootup if we haven't
-         * already bootstrapped. */
-        if (system_state != SYSTEM_RUNNING)
-                return -ENOSYS;
-
-        /* get the target out of it's holding state */
-        per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
-        smp_wmb();
-
-        while (!cpu_online(cpu))
-                cpu_relax();
-
-#ifdef CONFIG_PPC64
-        fixup_irqs(cpu_online_mask);
-        /* counter the irq disable in fixup_irqs */
-        local_irq_enable();
 #endif
+        migrate_irqs();
         return 0;
 }
 
@@ -362,37 +386,89 @@ void generic_mach_cpu_die(void)
         unsigned int cpu;
 
         local_irq_disable();
+        idle_task_exit();
         cpu = smp_processor_id();
         printk(KERN_DEBUG "CPU%d offline\n", cpu);
         __get_cpu_var(cpu_state) = CPU_DEAD;
         smp_wmb();
         while (__get_cpu_var(cpu_state) != CPU_UP_PREPARE)
                 cpu_relax();
-        set_cpu_online(cpu, true);
-        local_irq_enable();
+}
+
+void generic_set_cpu_dead(unsigned int cpu)
+{
+        per_cpu(cpu_state, cpu) = CPU_DEAD;
 }
 #endif
 
-static int __devinit cpu_enable(unsigned int cpu)
+struct create_idle {
+        struct work_struct work;
+        struct task_struct *idle;
+        struct completion done;
+        int cpu;
+};
+
+static void __cpuinit do_fork_idle(struct work_struct *work)
 {
-        if (smp_ops && smp_ops->cpu_enable)
-                return smp_ops->cpu_enable(cpu);
+        struct create_idle *c_idle =
+                container_of(work, struct create_idle, work);
 
-        return -ENOSYS;
+        c_idle->idle = fork_idle(c_idle->cpu);
+        complete(&c_idle->done);
 }
 
-int __cpuinit __cpu_up(unsigned int cpu)
+static int __cpuinit create_idle(unsigned int cpu)
 {
-        int c;
+        struct thread_info *ti;
+        struct create_idle c_idle = {
+                .cpu    = cpu,
+                .done   = COMPLETION_INITIALIZER_ONSTACK(c_idle.done),
+        };
+        INIT_WORK_ONSTACK(&c_idle.work, do_fork_idle);
 
-        secondary_ti = current_set[cpu];
-        if (!cpu_enable(cpu))
-                return 0;
+        c_idle.idle = get_idle_for_cpu(cpu);
+
+        /* We can't use kernel_thread since we must avoid to
+         * reschedule the child. We use a workqueue because
+         * we want to fork from a kernel thread, not whatever
+         * userspace process happens to be trying to online us.
+         */
+        if (!c_idle.idle) {
+                schedule_work(&c_idle.work);
+                wait_for_completion(&c_idle.done);
+        } else
+                init_idle(c_idle.idle, cpu);
+        if (IS_ERR(c_idle.idle)) {              
+                pr_err("Failed fork for CPU %u: %li", cpu, PTR_ERR(c_idle.idle));
+                return PTR_ERR(c_idle.idle);
+        }
+        ti = task_thread_info(c_idle.idle);
+
+#ifdef CONFIG_PPC64
+        paca[cpu].__current = c_idle.idle;
+        paca[cpu].kstack = (unsigned long)ti + THREAD_SIZE - STACK_FRAME_OVERHEAD;
+#endif
+        ti->cpu = cpu;
+        current_set[cpu] = ti;
+
+        return 0;
+}
+
+int __cpuinit __cpu_up(unsigned int cpu)
+{
+        int rc, c;
 
         if (smp_ops == NULL ||
             (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)))
                 return -EINVAL;
 
+        /* Make sure we have an idle thread */
+        rc = create_idle(cpu);
+        if (rc)
+                return rc;
+
+        secondary_ti = current_set[cpu];
+
         /* Make sure callin-map entry is 0 (can be leftover a CPU
          * hotplug
          */
@@ -406,7 +482,11 @@ int __cpuinit __cpu_up(unsigned int cpu)
 
         /* wake up cpus */
         DBG("smp: kicking cpu %d\n", cpu);
-        smp_ops->kick_cpu(cpu);
+        rc = smp_ops->kick_cpu(cpu);
+        if (rc) {
+                pr_err("smp: failed starting cpu %d (rc %d)\n", cpu, rc);
+                return rc;
+        }
 
         /*
          * wait to see if the cpu made a callin (is actually up).
@@ -466,6 +546,19 @@ out:
         return id;
 }
 
+/* Helper routines for cpu to core mapping */
+int cpu_core_index_of_thread(int cpu)
+{
+        return cpu >> threads_shift;
+}
+EXPORT_SYMBOL_GPL(cpu_core_index_of_thread);
+
+int cpu_first_thread_of_core(int core)
+{
+        return core << threads_shift;
+}
+EXPORT_SYMBOL_GPL(cpu_first_thread_of_core);
+
 /* Must be called when no change can occur to cpu_present_mask,
  * i.e. during cpu online or offline.
  */
@@ -489,7 +582,7 @@ static struct device_node *cpu_to_l2cache(int cpu)
 }
 
 /* Activate a secondary processor. */
-int __devinit start_secondary(void *unused)
+void __devinit start_secondary(void *unused)
 {
         unsigned int cpu = smp_processor_id();
         struct device_node *l2_cache;
@@ -508,16 +601,17 @@ int __devinit start_secondary(void *unused)
         if (smp_ops->take_timebase)
                 smp_ops->take_timebase();
 
-        if (system_state > SYSTEM_BOOTING)
-                snapshot_timebase();
-
         secondary_cpu_time_init();
 
+#ifdef CONFIG_PPC64
+        if (system_state == SYSTEM_RUNNING)
+                vdso_data->processorCount++;
+#endif
         ipi_call_lock();
         notify_cpu_starting(cpu);
         set_cpu_online(cpu, true);
         /* Update sibling maps */
-        base = cpu_first_thread_in_core(cpu);
+        base = cpu_first_thread_sibling(cpu);
         for (i = 0; i < threads_per_core; i++) {
                 if (cpu_is_offline(base + i))
                         continue;
@@ -548,7 +642,8 @@ int __devinit start_secondary(void *unused)
         local_irq_enable();
 
         cpu_idle();
-        return 0;
+
+        BUG();
 }
 
 int setup_profiling_timer(unsigned int multiplier)
@@ -565,7 +660,7 @@ void __init smp_cpus_done(unsigned int max_cpus)
          * se we pin us down to CPU 0 for a short while
          */
         alloc_cpumask_var(&old_mask, GFP_NOWAIT);
-        cpumask_copy(old_mask, &current->cpus_allowed);
+        cpumask_copy(old_mask, tsk_cpus_allowed(current));
         set_cpus_allowed_ptr(current, cpumask_of(boot_cpuid));
         
         if (smp_ops && smp_ops->setup_cpu)
@@ -575,9 +670,20 @@ void __init smp_cpus_done(unsigned int max_cpus)
 
         free_cpumask_var(old_mask);
 
-        snapshot_timebases();
+        if (smp_ops && smp_ops->bringup_done)
+                smp_ops->bringup_done();
 
         dump_numa_cpu_topology();
+
+}
+
+int arch_sd_sibling_asym_packing(void)
+{
+        if (cpu_has_feature(CPU_FTR_ASYM_SMT)) {
+                printk_once(KERN_INFO "Enabling Asymmetric SMT scheduling\n");
+                return SD_ASYM_PACKING;
+        }
+        return 0;
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -596,7 +702,7 @@ int __cpu_disable(void)
                 return err;
 
         /* Update sibling maps */
-        base = cpu_first_thread_in_core(cpu);
+        base = cpu_first_thread_sibling(cpu);
         for (i = 0; i < threads_per_core; i++) {
                 cpumask_clear_cpu(cpu, cpu_sibling_mask(base + i));
                 cpumask_clear_cpu(base + i, cpu_sibling_mask(cpu));
@@ -643,5 +749,9 @@ void cpu_die(void)
 {
         if (ppc_md.cpu_die)
                 ppc_md.cpu_die();
+
+        /* If we return, we re-enter start_secondary */
+        start_secondary_resume();
 }
+
 #endif