Merge branch 'sh/smp'

7 files changed, 263 insertions, 32 deletions

diff --git a/arch/sh/kernel/cpu/sh4a/smp-shx3.c b/arch/sh/kernel/cpu/sh4a/smp-shx3.c
index c98b4574c44e..de865cac02ee 100644
--- a/arch/sh/kernel/cpu/sh4a/smp-shx3.c
+++ b/arch/sh/kernel/cpu/sh4a/smp-shx3.c
@@ -1,7 +1,7 @@
 /*
  * SH-X3 SMP
  *
- *  Copyright (C) 2007 - 2008  Paul Mundt
+ *  Copyright (C) 2007 - 2010  Paul Mundt
  *  Copyright (C) 2007  Magnus Damm
  *
  * This file is subject to the terms and conditions of the GNU General Public
@@ -9,16 +9,22 @@
  * for more details.
  */
 #include <linux/init.h>
+#include <linux/kernel.h>
 #include <linux/cpumask.h>
 #include <linux/smp.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/cpu.h>
+#include <asm/sections.h>
 
 #define STBCR_REG(phys_id) (0xfe400004 | (phys_id << 12))
 #define RESET_REG(phys_id) (0xfe400008 | (phys_id << 12))
 
 #define STBCR_MSTP      0x00000001
 #define STBCR_RESET     0x00000002
+#define STBCR_SLEEP     0x00000004
 #define STBCR_LTSLP     0x80000000
 
 static irqreturn_t ipi_interrupt_handler(int irq, void *arg)
@@ -37,7 +43,7 @@ static irqreturn_t ipi_interrupt_handler(int irq, void *arg)
         return IRQ_HANDLED;
 }
 
-void __init plat_smp_setup(void)
+static void shx3_smp_setup(void)
 {
         unsigned int cpu = 0;
         int i, num;
@@ -63,7 +69,7 @@ void __init plat_smp_setup(void)
         printk(KERN_INFO "Detected %i available secondary CPU(s)\n", num);
 }
 
-void __init plat_prepare_cpus(unsigned int max_cpus)
+static void shx3_prepare_cpus(unsigned int max_cpus)
 {
         int i;
 
@@ -74,9 +80,12 @@ void __init plat_prepare_cpus(unsigned int max_cpus)
         for (i = 0; i < SMP_MSG_NR; i++)
                 request_irq(104 + i, ipi_interrupt_handler,
                             IRQF_DISABLED | IRQF_PERCPU, "IPI", (void *)(long)i);
+
+        for (i = 0; i < max_cpus; i++)
+                set_cpu_present(i, true);
 }
 
-void plat_start_cpu(unsigned int cpu, unsigned long entry_point)
+static void shx3_start_cpu(unsigned int cpu, unsigned long entry_point)
 {
         if (__in_29bit_mode())
                 __raw_writel(entry_point, RESET_REG(cpu));
@@ -93,12 +102,12 @@ void plat_start_cpu(unsigned int cpu, unsigned long entry_point)
         __raw_writel(STBCR_RESET | STBCR_LTSLP, STBCR_REG(cpu));
 }
 
-int plat_smp_processor_id(void)
+static unsigned int shx3_smp_processor_id(void)
 {
         return __raw_readl(0xff000048); /* CPIDR */
 }
 
-void plat_send_ipi(unsigned int cpu, unsigned int message)
+static void shx3_send_ipi(unsigned int cpu, unsigned int message)
 {
         unsigned long addr = 0xfe410070 + (cpu * 4);
 
@@ -106,3 +115,52 @@ void plat_send_ipi(unsigned int cpu, unsigned int message)
 
         __raw_writel(1 << (message << 2), addr); /* C0INTICI..CnINTICI */
 }
+
+static void shx3_update_boot_vector(unsigned int cpu)
+{
+        __raw_writel(STBCR_MSTP, STBCR_REG(cpu));
+        while (!(__raw_readl(STBCR_REG(cpu)) & STBCR_MSTP))
+                cpu_relax();
+        __raw_writel(STBCR_RESET, STBCR_REG(cpu));
+}
+
+static int __cpuinit
+shx3_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
+{
+        unsigned int cpu = (unsigned int)hcpu;
+
+        switch (action) {
+        case CPU_UP_PREPARE:
+                shx3_update_boot_vector(cpu);
+                break;
+        case CPU_ONLINE:
+                pr_info("CPU %u is now online\n", cpu);
+                break;
+        case CPU_DEAD:
+                break;
+        }
+
+        return NOTIFY_OK;
+}
+
+static struct notifier_block __cpuinitdata shx3_cpu_notifier = {
+        .notifier_call          = shx3_cpu_callback,
+};
+
+static int __cpuinit register_shx3_cpu_notifier(void)
+{
+        register_hotcpu_notifier(&shx3_cpu_notifier);
+        return 0;
+}
+late_initcall(register_shx3_cpu_notifier);
+
+struct plat_smp_ops shx3_smp_ops = {
+        .smp_setup              = shx3_smp_setup,
+        .prepare_cpus           = shx3_prepare_cpus,
+        .start_cpu              = shx3_start_cpu,
+        .smp_processor_id       = shx3_smp_processor_id,
+        .send_ipi               = shx3_send_ipi,
+        .cpu_die                = native_cpu_die,
+        .cpu_disable            = native_cpu_disable,
+        .play_dead              = native_play_dead,
+};
diff --git a/arch/sh/kernel/idle.c b/arch/sh/kernel/idle.c
index 273f890b17ae..425d604e3a28 100644
--- a/arch/sh/kernel/idle.c
+++ b/arch/sh/kernel/idle.c
@@ -19,6 +19,7 @@
 #include <asm/pgalloc.h>
 #include <asm/system.h>
 #include <asm/atomic.h>
+#include <asm/smp.h>
 
 void (*pm_idle)(void) = NULL;
 
@@ -89,10 +90,13 @@ void cpu_idle(void)
         while (1) {
                 tick_nohz_stop_sched_tick(1);
 
-                while (!need_resched() && cpu_online(cpu)) {
+                while (!need_resched()) {
                         check_pgt_cache();
                         rmb();
 
+                        if (cpu_is_offline(cpu))
+                                play_dead();
+
                         local_irq_disable();
                         /* Don't trace irqs off for idle */
                         stop_critical_timings();
@@ -133,7 +137,7 @@ static void do_nothing(void *unused)
 void stop_this_cpu(void *unused)
 {
         local_irq_disable();
-        cpu_clear(smp_processor_id(), cpu_online_map);
+        set_cpu_online(smp_processor_id(), false);
 
         for (;;)
                 cpu_sleep();
diff --git a/arch/sh/kernel/irq.c b/arch/sh/kernel/irq.c
index f6a9319c28e2..257de1f0692b 100644
--- a/arch/sh/kernel/irq.c
+++ b/arch/sh/kernel/irq.c
@@ -12,6 +12,7 @@
 #include <linux/kernel_stat.h>
 #include <linux/seq_file.h>
 #include <linux/ftrace.h>
+#include <linux/delay.h>
 #include <asm/processor.h>
 #include <asm/machvec.h>
 #include <asm/uaccess.h>
@@ -292,3 +293,44 @@ int __init arch_probe_nr_irqs(void)
         return 0;
 }
 #endif
+
+#ifdef CONFIG_HOTPLUG_CPU
+static void route_irq(struct irq_desc *desc, unsigned int irq, unsigned int cpu)
+{
+        printk(KERN_INFO "IRQ%u: moving from cpu%u to cpu%u\n",
+               irq, desc->node, cpu);
+
+        raw_spin_lock_irq(&desc->lock);
+        desc->chip->set_affinity(irq, cpumask_of(cpu));
+        raw_spin_unlock_irq(&desc->lock);
+}
+
+/*
+ * The CPU has been marked offline.  Migrate IRQs off this CPU.  If
+ * the affinity settings do not allow other CPUs, force them onto any
+ * available CPU.
+ */
+void migrate_irqs(void)
+{
+        struct irq_desc *desc;
+        unsigned int irq, cpu = smp_processor_id();
+
+        for_each_irq_desc(irq, desc) {
+                if (desc->node == cpu) {
+                        unsigned int newcpu = cpumask_any_and(desc->affinity,
+                                                              cpu_online_mask);
+                        if (newcpu >= nr_cpu_ids) {
+                                if (printk_ratelimit())
+                                        printk(KERN_INFO "IRQ%u no longer affine to CPU%u\n",
+                                               irq, cpu);
+
+                                cpumask_setall(desc->affinity);
+                                newcpu = cpumask_any_and(desc->affinity,
+                                                         cpu_online_mask);
+                        }
+
+                        route_irq(desc, irq, newcpu);
+                }
+        }
+}
+#endif
diff --git a/arch/sh/kernel/localtimer.c b/arch/sh/kernel/localtimer.c
index 0b04e7d4a9b9..8bfc6dfa8b94 100644
--- a/arch/sh/kernel/localtimer.c
+++ b/arch/sh/kernel/localtimer.c
@@ -44,7 +44,7 @@ static void dummy_timer_set_mode(enum clock_event_mode mode,
 {
 }
 
-void __cpuinit local_timer_setup(unsigned int cpu)
+void local_timer_setup(unsigned int cpu)
 {
         struct clock_event_device *clk = &per_cpu(local_clockevent, cpu);
 
@@ -60,3 +60,7 @@ void __cpuinit local_timer_setup(unsigned int cpu)
 
         clockevents_register_device(clk);
 }
+
+void local_timer_stop(unsigned int cpu)
+{
+}
diff --git a/arch/sh/kernel/setup.c b/arch/sh/kernel/setup.c
index 8870d6ba64bf..14735d5ede52 100644
--- a/arch/sh/kernel/setup.c
+++ b/arch/sh/kernel/setup.c
@@ -39,6 +39,7 @@
 #include <asm/irq.h>
 #include <asm/setup.h>
 #include <asm/clock.h>
+#include <asm/smp.h>
 #include <asm/mmu_context.h>
 
 /*
@@ -459,9 +460,7 @@ void __init setup_arch(char **cmdline_p)
         if (likely(sh_mv.mv_setup))
                 sh_mv.mv_setup(cmdline_p);
 
-#ifdef CONFIG_SMP
         plat_smp_setup();
-#endif
 }
 
 /* processor boot mode configuration */
diff --git a/arch/sh/kernel/smp.c b/arch/sh/kernel/smp.c
index 002cc612deef..86cd6f94b53b 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(void)
+{
+        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();
diff --git a/arch/sh/kernel/topology.c b/arch/sh/kernel/topology.c
index 9b0b633b6c92..948fdb656933 100644
--- a/arch/sh/kernel/topology.c
+++ b/arch/sh/kernel/topology.c
@@ -52,7 +52,11 @@ static int __init topology_init(void)
 #endif
 
         for_each_present_cpu(i) {
-                ret = register_cpu(&per_cpu(cpu_devices, i), i);
+                struct cpu *c = &per_cpu(cpu_devices, i);
+
+                c->hotpluggable = 1;
+
+                ret = register_cpu(c, i);
                 if (unlikely(ret))
                         printk(KERN_WARNING "%s: register_cpu %d failed (%d)\n",
                                __func__, i, ret);