linux/include/linux/smp.h
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   1#ifndef __LINUX_SMP_H
   2#define __LINUX_SMP_H
   3
   4/*
   5 *      Generic SMP support
   6 *              Alan Cox. <alan@redhat.com>
   7 */
   8
   9#include <linux/errno.h>
  10#include <linux/types.h>
  11#include <linux/list.h>
  12#include <linux/cpumask.h>
  13#include <linux/init.h>
  14#include <linux/llist.h>
  15
  16typedef void (*smp_call_func_t)(void *info);
  17struct call_single_data {
  18        struct llist_node llist;
  19        smp_call_func_t func;
  20        void *info;
  21        unsigned int flags;
  22};
  23
  24/* total number of cpus in this system (may exceed NR_CPUS) */
  25extern unsigned int total_cpus;
  26
  27int smp_call_function_single(int cpuid, smp_call_func_t func, void *info,
  28                             int wait);
  29
  30/*
  31 * Call a function on all processors
  32 */
  33int on_each_cpu(smp_call_func_t func, void *info, int wait);
  34
  35/*
  36 * Call a function on processors specified by mask, which might include
  37 * the local one.
  38 */
  39void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
  40                void *info, bool wait);
  41
  42/*
  43 * Call a function on each processor for which the supplied function
  44 * cond_func returns a positive value. This may include the local
  45 * processor.
  46 */
  47void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
  48                smp_call_func_t func, void *info, bool wait,
  49                gfp_t gfp_flags);
  50
  51int smp_call_function_single_async(int cpu, struct call_single_data *csd);
  52
  53#ifdef CONFIG_SMP
  54
  55#include <linux/preempt.h>
  56#include <linux/kernel.h>
  57#include <linux/compiler.h>
  58#include <linux/thread_info.h>
  59#include <asm/smp.h>
  60
  61/*
  62 * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
  63 * (defined in asm header):
  64 */
  65
  66/*
  67 * stops all CPUs but the current one:
  68 */
  69extern void smp_send_stop(void);
  70
  71/*
  72 * sends a 'reschedule' event to another CPU:
  73 */
  74extern void smp_send_reschedule(int cpu);
  75
  76
  77/*
  78 * Prepare machine for booting other CPUs.
  79 */
  80extern void smp_prepare_cpus(unsigned int max_cpus);
  81
  82/*
  83 * Bring a CPU up
  84 */
  85extern int __cpu_up(unsigned int cpunum, struct task_struct *tidle);
  86
  87/*
  88 * Final polishing of CPUs
  89 */
  90extern void smp_cpus_done(unsigned int max_cpus);
  91
  92/*
  93 * Call a function on all other processors
  94 */
  95int smp_call_function(smp_call_func_t func, void *info, int wait);
  96void smp_call_function_many(const struct cpumask *mask,
  97                            smp_call_func_t func, void *info, bool wait);
  98
  99int smp_call_function_any(const struct cpumask *mask,
 100                          smp_call_func_t func, void *info, int wait);
 101
 102void kick_all_cpus_sync(void);
 103void wake_up_all_idle_cpus(void);
 104
 105/*
 106 * Generic and arch helpers
 107 */
 108void __init call_function_init(void);
 109void generic_smp_call_function_single_interrupt(void);
 110#define generic_smp_call_function_interrupt \
 111        generic_smp_call_function_single_interrupt
 112
 113/*
 114 * Mark the boot cpu "online" so that it can call console drivers in
 115 * printk() and can access its per-cpu storage.
 116 */
 117void smp_prepare_boot_cpu(void);
 118
 119extern unsigned int setup_max_cpus;
 120extern void __init setup_nr_cpu_ids(void);
 121extern void __init smp_init(void);
 122
 123extern int __boot_cpu_id;
 124
 125static inline int get_boot_cpu_id(void)
 126{
 127        return __boot_cpu_id;
 128}
 129
 130#else /* !SMP */
 131
 132static inline void smp_send_stop(void) { }
 133
 134/*
 135 *      These macros fold the SMP functionality into a single CPU system
 136 */
 137#define raw_smp_processor_id()                  0
 138static inline int up_smp_call_function(smp_call_func_t func, void *info)
 139{
 140        return 0;
 141}
 142#define smp_call_function(func, info, wait) \
 143                        (up_smp_call_function(func, info))
 144
 145static inline void smp_send_reschedule(int cpu) { }
 146#define smp_prepare_boot_cpu()                  do {} while (0)
 147#define smp_call_function_many(mask, func, info, wait) \
 148                        (up_smp_call_function(func, info))
 149static inline void call_function_init(void) { }
 150
 151static inline int
 152smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
 153                      void *info, int wait)
 154{
 155        return smp_call_function_single(0, func, info, wait);
 156}
 157
 158static inline void kick_all_cpus_sync(void) {  }
 159static inline void wake_up_all_idle_cpus(void) {  }
 160
 161#ifdef CONFIG_UP_LATE_INIT
 162extern void __init up_late_init(void);
 163static inline void smp_init(void) { up_late_init(); }
 164#else
 165static inline void smp_init(void) { }
 166#endif
 167
 168static inline int get_boot_cpu_id(void)
 169{
 170        return 0;
 171}
 172
 173#endif /* !SMP */
 174
 175/*
 176 * smp_processor_id(): get the current CPU ID.
 177 *
 178 * if DEBUG_PREEMPT is enabled then we check whether it is
 179 * used in a preemption-safe way. (smp_processor_id() is safe
 180 * if it's used in a preemption-off critical section, or in
 181 * a thread that is bound to the current CPU.)
 182 *
 183 * NOTE: raw_smp_processor_id() is for internal use only
 184 * (smp_processor_id() is the preferred variant), but in rare
 185 * instances it might also be used to turn off false positives
 186 * (i.e. smp_processor_id() use that the debugging code reports but
 187 * which use for some reason is legal). Don't use this to hack around
 188 * the warning message, as your code might not work under PREEMPT.
 189 */
 190#ifdef CONFIG_DEBUG_PREEMPT
 191  extern unsigned int debug_smp_processor_id(void);
 192# define smp_processor_id() debug_smp_processor_id()
 193#else
 194# define smp_processor_id() raw_smp_processor_id()
 195#endif
 196
 197#define get_cpu()               ({ preempt_disable(); smp_processor_id(); })
 198#define put_cpu()               preempt_enable()
 199
 200/*
 201 * Callback to arch code if there's nosmp or maxcpus=0 on the
 202 * boot command line:
 203 */
 204extern void arch_disable_smp_support(void);
 205
 206extern void arch_enable_nonboot_cpus_begin(void);
 207extern void arch_enable_nonboot_cpus_end(void);
 208
 209void smp_setup_processor_id(void);
 210
 211int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par,
 212                    bool phys);
 213
 214/* SMP core functions */
 215int smpcfd_prepare_cpu(unsigned int cpu);
 216int smpcfd_dead_cpu(unsigned int cpu);
 217int smpcfd_dying_cpu(unsigned int cpu);
 218
 219#endif /* __LINUX_SMP_H */
 220