include/linux/cpu.h

   1 /*
   2  * include/linux/cpu.h - generic cpu definition
   3  *
   4  * This is mainly for topological representation. We define the
   5  * basic 'struct cpu' here, which can be embedded in per-arch
   6  * definitions of processors.
   7  *
   8  * Basic handling of the devices is done in drivers/base/cpu.c
   9  * and system devices are handled in drivers/base/sys.c.
  10  *
  11  * CPUs are exported via sysfs in the class/cpu/devices/
  12  * directory.
  13  */
  14 #ifndef _LINUX_CPU_H_
  15 #define _LINUX_CPU_H_
  16
  17 #include <linux/sysdev.h>
  18 #include <linux/node.h>
  19 #include <linux/compiler.h>
  20 #include <linux/cpumask.h>
  21
  22 struct cpu {
  23         int node_id;            /* The node which contains the CPU */
  24         int hotpluggable;       /* creates sysfs control file if hotpluggable */
  25         struct sys_device sysdev;
  26 };
  27
  28 extern int register_cpu(struct cpu *cpu, int num);
  29 extern struct sys_device *get_cpu_sysdev(unsigned cpu);
  30
  31 extern int cpu_add_sysdev_attr(struct sysdev_attribute *attr);
  32 extern void cpu_remove_sysdev_attr(struct sysdev_attribute *attr);
  33
  34 extern int cpu_add_sysdev_attr_group(struct attribute_group *attrs);
  35 extern void cpu_remove_sysdev_attr_group(struct attribute_group *attrs);
  36
  37 extern int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls);
  38
  39 #ifdef CONFIG_HOTPLUG_CPU
  40 extern void unregister_cpu(struct cpu *cpu);
  41 extern ssize_t arch_cpu_probe(const char *, size_t);
  42 extern ssize_t arch_cpu_release(const char *, size_t);
  43 #endif
  44 struct notifier_block;
  45
  46 /*
  47  * CPU notifier priorities.
  48  */
  49 enum {
  50         /*
  51          * SCHED_ACTIVE marks a cpu which is coming up active during
  52          * CPU_ONLINE and CPU_DOWN_FAILED and must be the first
  53          * notifier.  CPUSET_ACTIVE adjusts cpuset according to
  54          * cpu_active mask right after SCHED_ACTIVE.  During
  55          * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are
  56          * ordered in the similar way.
  57          *
  58          * This ordering guarantees consistent cpu_active mask and
  59          * migration behavior to all cpu notifiers.
  60          */
  61         CPU_PRI_SCHED_ACTIVE    = INT_MAX,
  62         CPU_PRI_CPUSET_ACTIVE   = INT_MAX - 1,
  63         CPU_PRI_SCHED_INACTIVE  = INT_MIN + 1,
  64         CPU_PRI_CPUSET_INACTIVE = INT_MIN,
  65
  66         /* migration should happen before other stuff but after perf */
  67         CPU_PRI_PERF            = 20,
  68         CPU_PRI_MIGRATION       = 10,
  69         /* prepare workqueues for other notifiers */
  70         CPU_PRI_WORKQUEUE       = 5,
  71 };
  72
  73 #define CPU_ONLINE              0x0002 /* CPU (unsigned)v is up */
  74 #define CPU_UP_PREPARE          0x0003 /* CPU (unsigned)v coming up */
  75 #define CPU_UP_CANCELED         0x0004 /* CPU (unsigned)v NOT coming up */
  76 #define CPU_DOWN_PREPARE        0x0005 /* CPU (unsigned)v going down */
  77 #define CPU_DOWN_FAILED         0x0006 /* CPU (unsigned)v NOT going down */
  78 #define CPU_DEAD                0x0007 /* CPU (unsigned)v dead */
  79 #define CPU_DYING               0x0008 /* CPU (unsigned)v not running any task,
  80                                         * not handling interrupts, soon dead.
  81                                         * Called on the dying cpu, interrupts
  82                                         * are already disabled. Must not
  83                                         * sleep, must not fail */
  84 #define CPU_POST_DEAD           0x0009 /* CPU (unsigned)v dead, cpu_hotplug
  85                                         * lock is dropped */
  86 #define CPU_STARTING            0x000A /* CPU (unsigned)v soon running.
  87                                         * Called on the new cpu, just before
  88                                         * enabling interrupts. Must not sleep,
  89                                         * must not fail */
  90
  91 /* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
  92  * operation in progress
  93  */
  94 #define CPU_TASKS_FROZEN        0x0010
  95
  96 #define CPU_ONLINE_FROZEN       (CPU_ONLINE | CPU_TASKS_FROZEN)
  97 #define CPU_UP_PREPARE_FROZEN   (CPU_UP_PREPARE | CPU_TASKS_FROZEN)
  98 #define CPU_UP_CANCELED_FROZEN  (CPU_UP_CANCELED | CPU_TASKS_FROZEN)
  99 #define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
 100 #define CPU_DOWN_FAILED_FROZEN  (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
 101 #define CPU_DEAD_FROZEN         (CPU_DEAD | CPU_TASKS_FROZEN)
 102 #define CPU_DYING_FROZEN        (CPU_DYING | CPU_TASKS_FROZEN)
 103 #define CPU_STARTING_FROZEN     (CPU_STARTING | CPU_TASKS_FROZEN)
 104
 105
 106 #ifdef CONFIG_SMP
 107 /* Need to know about CPUs going up/down? */
 108 #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
 109 #define cpu_notifier(fn, pri) {                                 \
 110         static struct notifier_block fn##_nb __cpuinitdata =    \
 111                 { .notifier_call = fn, .priority = pri };       \
 112         register_cpu_notifier(&fn##_nb);                        \
 113 }
 114 #else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
 115 #define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
 116 #endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
 117 #ifdef CONFIG_HOTPLUG_CPU
 118 extern int register_cpu_notifier(struct notifier_block *nb);
 119 extern void unregister_cpu_notifier(struct notifier_block *nb);
 120 #else
 121
 122 #ifndef MODULE
 123 extern int register_cpu_notifier(struct notifier_block *nb);
 124 #else
 125 static inline int register_cpu_notifier(struct notifier_block *nb)
 126 {
 127         return 0;
 128 }
 129 #endif
 130
 131 static inline void unregister_cpu_notifier(struct notifier_block *nb)
 132 {
 133 }
 134 #endif
 135
 136 int cpu_up(unsigned int cpu);
 137 void notify_cpu_starting(unsigned int cpu);
 138 extern void cpu_maps_update_begin(void);
 139 extern void cpu_maps_update_done(void);
 140
 141 #else   /* CONFIG_SMP */
 142
 143 #define cpu_notifier(fn, pri)   do { (void)(fn); } while (0)
 144
 145 static inline int register_cpu_notifier(struct notifier_block *nb)
 146 {
 147         return 0;
 148 }
 149
 150 static inline void unregister_cpu_notifier(struct notifier_block *nb)
 151 {
 152 }
 153
 154 static inline void cpu_maps_update_begin(void)
 155 {
 156 }
 157
 158 static inline void cpu_maps_update_done(void)
 159 {
 160 }
 161
 162 #endif /* CONFIG_SMP */
 163 extern struct sysdev_class cpu_sysdev_class;
 164
 165 #ifdef CONFIG_HOTPLUG_CPU
 166 /* Stop CPUs going up and down. */
 167
 168 extern void get_online_cpus(void);
 169 extern void put_online_cpus(void);
 170 #define hotcpu_notifier(fn, pri)        cpu_notifier(fn, pri)
 171 #define register_hotcpu_notifier(nb)    register_cpu_notifier(nb)
 172 #define unregister_hotcpu_notifier(nb)  unregister_cpu_notifier(nb)
 173 int cpu_down(unsigned int cpu);
 174
 175 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
 176 extern void cpu_hotplug_driver_lock(void);
 177 extern void cpu_hotplug_driver_unlock(void);
 178 #else
 179 static inline void cpu_hotplug_driver_lock(void)
 180 {
 181 }
 182
 183 static inline void cpu_hotplug_driver_unlock(void)
 184 {
 185 }
 186 #endif
 187
 188 #else           /* CONFIG_HOTPLUG_CPU */
 189
 190 #define get_online_cpus()       do { } while (0)
 191 #define put_online_cpus()       do { } while (0)
 192 #define hotcpu_notifier(fn, pri)        do { (void)(fn); } while (0)
 193 /* These aren't inline functions due to a GCC bug. */
 194 #define register_hotcpu_notifier(nb)    ({ (void)(nb); 0; })
 195 #define unregister_hotcpu_notifier(nb)  ({ (void)(nb); })
 196 #endif          /* CONFIG_HOTPLUG_CPU */
 197
 198 #ifdef CONFIG_PM_SLEEP_SMP
 199 extern int suspend_cpu_hotplug;
 200
 201 extern int disable_nonboot_cpus(void);
 202 extern void enable_nonboot_cpus(void);
 203 #else /* !CONFIG_PM_SLEEP_SMP */
 204 #define suspend_cpu_hotplug     0
 205
 206 static inline int disable_nonboot_cpus(void) { return 0; }
 207 static inline void enable_nonboot_cpus(void) {}
 208 #endif /* !CONFIG_PM_SLEEP_SMP */
 209
 210 #endif /* _LINUX_CPU_H_ */