1 files changed, 330 insertions, 71 deletions

diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 264ea906db4c..66fe28930d82 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -42,6 +42,7 @@
 #include <asm/tlbflush.h>
 #include <asm/timer.h>
 #include <asm/lowcore.h>
+#include <asm/sclp.h>
 #include <asm/cpu.h>
 
 /*
@@ -58,6 +59,22 @@ EXPORT_SYMBOL(cpu_possible_map);
 
 static struct task_struct *current_set[NR_CPUS];
 
+static u8 smp_cpu_type;
+static int smp_use_sigp_detection;
+
+enum s390_cpu_state {
+        CPU_STATE_STANDBY,
+        CPU_STATE_CONFIGURED,
+};
+
+#ifdef CONFIG_HOTPLUG_CPU
+static DEFINE_MUTEX(smp_cpu_state_mutex);
+#endif
+static int smp_cpu_state[NR_CPUS];
+
+static DEFINE_PER_CPU(struct cpu, cpu_devices);
+DEFINE_PER_CPU(struct s390_idle_data, s390_idle);
+
 static void smp_ext_bitcall(int, ec_bit_sig);
 
 /*
@@ -355,6 +372,13 @@ void smp_ctl_clear_bit(int cr, int bit)
 }
 EXPORT_SYMBOL(smp_ctl_clear_bit);
 
+/*
+ * In early ipl state a temp. logically cpu number is needed, so the sigp
+ * functions can be used to sense other cpus. Since NR_CPUS is >= 2 on
+ * CONFIG_SMP and the ipl cpu is logical cpu 0, it must be 1.
+ */
+#define CPU_INIT_NO     1
+
 #if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_ZFCPDUMP_MODULE)
 
 /*
@@ -376,8 +400,9 @@ static void __init smp_get_save_area(unsigned int cpu, unsigned int phy_cpu)
                 return;
         }
         zfcpdump_save_areas[cpu] = alloc_bootmem(sizeof(union save_area));
-        __cpu_logical_map[1] = (__u16) phy_cpu;
-        while (signal_processor(1, sigp_stop_and_store_status) == sigp_busy)
+        __cpu_logical_map[CPU_INIT_NO] = (__u16) phy_cpu;
+        while (signal_processor(CPU_INIT_NO, sigp_stop_and_store_status) ==
+               sigp_busy)
                 cpu_relax();
         memcpy(zfcpdump_save_areas[cpu],
                (void *)(unsigned long) store_prefix() + SAVE_AREA_BASE,
@@ -397,32 +422,166 @@ static inline void smp_get_save_area(unsigned int cpu, unsigned int phy_cpu) { }
 
 #endif /* CONFIG_ZFCPDUMP || CONFIG_ZFCPDUMP_MODULE */
 
+static int cpu_stopped(int cpu)
+{
+        __u32 status;
+
+        /* Check for stopped state */
+        if (signal_processor_ps(&status, 0, cpu, sigp_sense) ==
+            sigp_status_stored) {
+                if (status & 0x40)
+                        return 1;
+        }
+        return 0;
+}
+
 /*
  * Lets check how many CPUs we have.
  */
-static unsigned int __init smp_count_cpus(void)
+static void __init smp_count_cpus(unsigned int *configured_cpus,
+                                  unsigned int *standby_cpus)
 {
-        unsigned int cpu, num_cpus;
-        __u16 boot_cpu_addr;
+        unsigned int cpu;
+        struct sclp_cpu_info *info;
+        u16 boot_cpu_addr, cpu_addr;
 
-        /*
-         * cpu 0 is the boot cpu. See smp_prepare_boot_cpu.
-         */
         boot_cpu_addr = S390_lowcore.cpu_data.cpu_addr;
         current_thread_info()->cpu = 0;
-        num_cpus = 1;
-        for (cpu = 0; cpu <= 65535; cpu++) {
-                if ((__u16) cpu == boot_cpu_addr)
+        *configured_cpus = 1;
+        *standby_cpus = 0;
+
+        info = alloc_bootmem_pages(sizeof(*info));
+        if (!info)
+                disabled_wait((unsigned long) __builtin_return_address(0));
+
+        /* Use sigp detection algorithm if sclp doesn't work. */
+        if (sclp_get_cpu_info(info)) {
+                smp_use_sigp_detection = 1;
+                for (cpu = 0; cpu <= 65535; cpu++) {
+                        if (cpu == boot_cpu_addr)
+                                continue;
+                        __cpu_logical_map[CPU_INIT_NO] = cpu;
+                        if (cpu_stopped(CPU_INIT_NO))
+                                (*configured_cpus)++;
+                }
+                goto out;
+        }
+
+        if (info->has_cpu_type) {
+                for (cpu = 0; cpu < info->combined; cpu++) {
+                        if (info->cpu[cpu].address == boot_cpu_addr) {
+                                smp_cpu_type = info->cpu[cpu].type;
+                                break;
+                        }
+                }
+        }
+        /* Count cpus. */
+        for (cpu = 0; cpu < info->combined; cpu++) {
+                if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
+                        continue;
+                cpu_addr = info->cpu[cpu].address;
+                if (cpu_addr == boot_cpu_addr)
                         continue;
-                __cpu_logical_map[1] = (__u16) cpu;
-                if (signal_processor(1, sigp_sense) == sigp_not_operational)
+                __cpu_logical_map[CPU_INIT_NO] = cpu_addr;
+                if (!cpu_stopped(CPU_INIT_NO)) {
+                        (*standby_cpus)++;
                         continue;
-                smp_get_save_area(num_cpus, cpu);
-                num_cpus++;
+                }
+                smp_get_save_area(*configured_cpus, cpu_addr);
+                (*configured_cpus)++;
         }
-        printk("Detected %d CPU's\n", (int) num_cpus);
-        printk("Boot cpu address %2X\n", boot_cpu_addr);
-        return num_cpus;
+out:
+        printk(KERN_INFO "CPUs: %d configured, %d standby\n",
+               *configured_cpus, *standby_cpus);
+        free_bootmem((unsigned long) info, sizeof(*info));
+}
+
+static int cpu_known(int cpu_id)
+{
+        int cpu;
+
+        for_each_present_cpu(cpu) {
+                if (__cpu_logical_map[cpu] == cpu_id)
+                        return 1;
+        }
+        return 0;
+}
+
+static int smp_rescan_cpus_sigp(cpumask_t avail)
+{
+        int cpu_id, logical_cpu;
+
+        logical_cpu = first_cpu(avail);
+        if (logical_cpu == NR_CPUS)
+                return 0;
+        for (cpu_id = 0; cpu_id <= 65535; cpu_id++) {
+                if (cpu_known(cpu_id))
+                        continue;
+                __cpu_logical_map[logical_cpu] = cpu_id;
+                if (!cpu_stopped(logical_cpu))
+                        continue;
+                cpu_set(logical_cpu, cpu_present_map);
+                smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
+                logical_cpu = next_cpu(logical_cpu, avail);
+                if (logical_cpu == NR_CPUS)
+                        break;
+        }
+        return 0;
+}
+
+static int __init_refok smp_rescan_cpus_sclp(cpumask_t avail)
+{
+        struct sclp_cpu_info *info;
+        int cpu_id, logical_cpu, cpu;
+        int rc;
+
+        logical_cpu = first_cpu(avail);
+        if (logical_cpu == NR_CPUS)
+                return 0;
+        if (slab_is_available())
+                info = kmalloc(sizeof(*info), GFP_KERNEL);
+        else
+                info = alloc_bootmem(sizeof(*info));
+        if (!info)
+                return -ENOMEM;
+        rc = sclp_get_cpu_info(info);
+        if (rc)
+                goto out;
+        for (cpu = 0; cpu < info->combined; cpu++) {
+                if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
+                        continue;
+                cpu_id = info->cpu[cpu].address;
+                if (cpu_known(cpu_id))
+                        continue;
+                __cpu_logical_map[logical_cpu] = cpu_id;
+                cpu_set(logical_cpu, cpu_present_map);
+                if (cpu >= info->configured)
+                        smp_cpu_state[logical_cpu] = CPU_STATE_STANDBY;
+                else
+                        smp_cpu_state[logical_cpu] = CPU_STATE_CONFIGURED;
+                logical_cpu = next_cpu(logical_cpu, avail);
+                if (logical_cpu == NR_CPUS)
+                        break;
+        }
+out:
+        if (slab_is_available())
+                kfree(info);
+        else
+                free_bootmem((unsigned long) info, sizeof(*info));
+        return rc;
+}
+
+static int smp_rescan_cpus(void)
+{
+        cpumask_t avail;
+
+        cpus_setall(avail);
+        cpus_and(avail, avail, cpu_possible_map);
+        cpus_andnot(avail, avail, cpu_present_map);
+        if (smp_use_sigp_detection)
+                return smp_rescan_cpus_sigp(avail);
+        else
+                return smp_rescan_cpus_sclp(avail);
 }
 
 /*
@@ -453,8 +612,6 @@ int __cpuinit start_secondary(void *cpuvoid)
         return 0;
 }
 
-DEFINE_PER_CPU(struct s390_idle_data, s390_idle);
-
 static void __init smp_create_idle(unsigned int cpu)
 {
         struct task_struct *p;
@@ -470,37 +627,16 @@ static void __init smp_create_idle(unsigned int cpu)
         spin_lock_init(&(&per_cpu(s390_idle, cpu))->lock);
 }
 
-static int cpu_stopped(int cpu)
-{
-        __u32 status;
-
-        /* Check for stopped state */
-        if (signal_processor_ps(&status, 0, cpu, sigp_sense) ==
-            sigp_status_stored) {
-                if (status & 0x40)
-                        return 1;
-        }
-        return 0;
-}
-
 /* Upping and downing of CPUs */
-
 int __cpu_up(unsigned int cpu)
 {
         struct task_struct *idle;
         struct _lowcore *cpu_lowcore;
         struct stack_frame *sf;
         sigp_ccode ccode;
-        int curr_cpu;
-
-        for (curr_cpu = 0; curr_cpu <= 65535; curr_cpu++) {
-                __cpu_logical_map[cpu] = (__u16) curr_cpu;
-                if (cpu_stopped(cpu))
-                        break;
-        }
 
-        if (!cpu_stopped(cpu))
-                return -ENODEV;
+        if (smp_cpu_state[cpu] != CPU_STATE_CONFIGURED)
+                return -EIO;
 
         ccode = signal_processor_p((__u32)(unsigned long)(lowcore_ptr[cpu]),
                                    cpu, sigp_set_prefix);
@@ -543,21 +679,18 @@ static unsigned int __initdata possible_cpus;
 
 void __init smp_setup_cpu_possible_map(void)
 {
-        unsigned int phy_cpus, pos_cpus, cpu;
-
-        phy_cpus = smp_count_cpus();
-        pos_cpus = min(phy_cpus + additional_cpus, (unsigned int) NR_CPUS);
+        unsigned int pos_cpus, cpu;
+        unsigned int configured_cpus, standby_cpus;
 
+        smp_count_cpus(&configured_cpus, &standby_cpus);
+        pos_cpus = min(configured_cpus + standby_cpus + additional_cpus,
+                       (unsigned int) NR_CPUS);
         if (possible_cpus)
                 pos_cpus = min(possible_cpus, (unsigned int) NR_CPUS);
-
         for (cpu = 0; cpu < pos_cpus; cpu++)
                 cpu_set(cpu, cpu_possible_map);
-
-        phy_cpus = min(phy_cpus, pos_cpus);
-
-        for (cpu = 0; cpu < phy_cpus; cpu++)
-                cpu_set(cpu, cpu_present_map);
+        cpu_present_map = cpumask_of_cpu(0);
+        smp_rescan_cpus();
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -612,7 +745,7 @@ void __cpu_die(unsigned int cpu)
         /* Wait until target cpu is down */
         while (!smp_cpu_not_running(cpu))
                 cpu_relax();
-        printk("Processor %d spun down\n", cpu);
+        printk(KERN_INFO "Processor %d spun down\n", cpu);
 }
 
 void cpu_die(void)
@@ -686,12 +819,12 @@ void __init smp_prepare_boot_cpu(void)
         cpu_set(0, cpu_online_map);
         S390_lowcore.percpu_offset = __per_cpu_offset[0];
         current_set[0] = current;
+        smp_cpu_state[0] = CPU_STATE_CONFIGURED;
         spin_lock_init(&(&__get_cpu_var(s390_idle))->lock);
 }
 
 void __init smp_cpus_done(unsigned int max_cpus)
 {
-        cpu_present_map = cpu_possible_map;
 }
 
 /*
@@ -705,7 +838,79 @@ int setup_profiling_timer(unsigned int multiplier)
         return 0;
 }
 
-static DEFINE_PER_CPU(struct cpu, cpu_devices);
+#ifdef CONFIG_HOTPLUG_CPU
+static ssize_t cpu_configure_show(struct sys_device *dev, char *buf)
+{
+        ssize_t count;
+
+        mutex_lock(&smp_cpu_state_mutex);
+        count = sprintf(buf, "%d\n", smp_cpu_state[dev->id]);
+        mutex_unlock(&smp_cpu_state_mutex);
+        return count;
+}
+
+static ssize_t cpu_configure_store(struct sys_device *dev, const char *buf,
+                                   size_t count)
+{
+        int cpu = dev->id;
+        int val, rc;
+        char delim;
+
+        if (sscanf(buf, "%d %c", &val, &delim) != 1)
+                return -EINVAL;
+        if (val != 0 && val != 1)
+                return -EINVAL;
+
+        mutex_lock(&smp_cpu_state_mutex);
+        lock_cpu_hotplug();
+        rc = -EBUSY;
+        if (cpu_online(cpu))
+                goto out;
+        rc = 0;
+        switch (val) {
+        case 0:
+                if (smp_cpu_state[cpu] == CPU_STATE_CONFIGURED) {
+                        rc = sclp_cpu_deconfigure(__cpu_logical_map[cpu]);
+                        if (!rc)
+                                smp_cpu_state[cpu] = CPU_STATE_STANDBY;
+                }
+                break;
+        case 1:
+                if (smp_cpu_state[cpu] == CPU_STATE_STANDBY) {
+                        rc = sclp_cpu_configure(__cpu_logical_map[cpu]);
+                        if (!rc)
+                                smp_cpu_state[cpu] = CPU_STATE_CONFIGURED;
+                }
+                break;
+        default:
+                break;
+        }
+out:
+        unlock_cpu_hotplug();
+        mutex_unlock(&smp_cpu_state_mutex);
+        return rc ? rc : count;
+}
+static SYSDEV_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
+#endif /* CONFIG_HOTPLUG_CPU */
+
+static ssize_t show_cpu_address(struct sys_device *dev, char *buf)
+{
+        return sprintf(buf, "%d\n", __cpu_logical_map[dev->id]);
+}
+static SYSDEV_ATTR(address, 0444, show_cpu_address, NULL);
+
+
+static struct attribute *cpu_common_attrs[] = {
+#ifdef CONFIG_HOTPLUG_CPU
+        &attr_configure.attr,
+#endif
+        &attr_address.attr,
+        NULL,
+};
+
+static struct attribute_group cpu_common_attr_group = {
+        .attrs = cpu_common_attrs,
+};
 
 static ssize_t show_capability(struct sys_device *dev, char *buf)
 {
@@ -750,15 +955,15 @@ static ssize_t show_idle_time(struct sys_device *dev, char *buf)
 }
 static SYSDEV_ATTR(idle_time_us, 0444, show_idle_time, NULL);
 
-static struct attribute *cpu_attrs[] = {
+static struct attribute *cpu_online_attrs[] = {
         &attr_capability.attr,
         &attr_idle_count.attr,
         &attr_idle_time_us.attr,
         NULL,
 };
 
-static struct attribute_group cpu_attr_group = {
-        .attrs = cpu_attrs,
+static struct attribute_group cpu_online_attr_group = {
+        .attrs = cpu_online_attrs,
 };
 
 static int __cpuinit smp_cpu_notify(struct notifier_block *self,
@@ -778,12 +983,12 @@ static int __cpuinit smp_cpu_notify(struct notifier_block *self,
                 idle->idle_time = 0;
                 idle->idle_count = 0;
                 spin_unlock_irq(&idle->lock);
-                if (sysfs_create_group(&s->kobj, &cpu_attr_group))
+                if (sysfs_create_group(&s->kobj, &cpu_online_attr_group))
                         return NOTIFY_BAD;
                 break;
         case CPU_DEAD:
         case CPU_DEAD_FROZEN:
-                sysfs_remove_group(&s->kobj, &cpu_attr_group);
+                sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
                 break;
         }
         return NOTIFY_OK;
@@ -793,6 +998,62 @@ static struct notifier_block __cpuinitdata smp_cpu_nb = {
         .notifier_call = smp_cpu_notify,
 };
 
+static int smp_add_present_cpu(int cpu)
+{
+        struct cpu *c = &per_cpu(cpu_devices, cpu);
+        struct sys_device *s = &c->sysdev;
+        int rc;
+
+        c->hotpluggable = 1;
+        rc = register_cpu(c, cpu);
+        if (rc)
+                goto out;
+        rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
+        if (rc)
+                goto out_cpu;
+        if (!cpu_online(cpu))
+                goto out;
+        rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
+        if (!rc)
+                return 0;
+        sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
+out_cpu:
+#ifdef CONFIG_HOTPLUG_CPU
+        unregister_cpu(c);
+#endif
+out:
+        return rc;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static ssize_t rescan_store(struct sys_device *dev, const char *buf,
+                            size_t count)
+{
+        cpumask_t newcpus;
+        int cpu;
+        int rc;
+
+        mutex_lock(&smp_cpu_state_mutex);
+        lock_cpu_hotplug();
+        newcpus = cpu_present_map;
+        rc = smp_rescan_cpus();
+        if (rc)
+                goto out;
+        cpus_andnot(newcpus, cpu_present_map, newcpus);
+        for_each_cpu_mask(cpu, newcpus) {
+                rc = smp_add_present_cpu(cpu);
+                if (rc)
+                        cpu_clear(cpu, cpu_present_map);
+        }
+        rc = 0;
+out:
+        unlock_cpu_hotplug();
+        mutex_unlock(&smp_cpu_state_mutex);
+        return rc ? rc : count;
+}
+static SYSDEV_ATTR(rescan, 0200, NULL, rescan_store);
+#endif /* CONFIG_HOTPLUG_CPU */
+
 static int __init topology_init(void)
 {
         int cpu;
@@ -800,16 +1061,14 @@ static int __init topology_init(void)
 
         register_cpu_notifier(&smp_cpu_nb);
 
-        for_each_possible_cpu(cpu) {
-                struct cpu *c = &per_cpu(cpu_devices, cpu);
-                struct sys_device *s = &c->sysdev;
-
-                c->hotpluggable = 1;
-                register_cpu(c, cpu);
-                if (!cpu_online(cpu))
-                        continue;
-                s = &c->sysdev;
-                rc = sysfs_create_group(&s->kobj, &cpu_attr_group);
+#ifdef CONFIG_HOTPLUG_CPU
+        rc = sysfs_create_file(&cpu_sysdev_class.kset.kobj,
+                               &attr_rescan.attr);
+        if (rc)
+                return rc;
+#endif
+        for_each_present_cpu(cpu) {
+                rc = smp_add_present_cpu(cpu);
                 if (rc)
                         return rc;
         }