LXR linux/include/linux/smp.h

   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
  15extern void cpu_idle(void);
  16
  17typedef void (*smp_call_func_t)(void *info);
  18struct call_single_data {
  19        struct list_head list;
  20        smp_call_func_t func;
  21        void *info;
  22        u16 flags;
  23        u16 priv;
  24};
  25
  26/* total number of cpus in this system (may exceed NR_CPUS) */
  27extern unsigned int total_cpus;
  28
  29int smp_call_function_single(int cpuid, smp_call_func_t func, void *info,
  30                             int wait);
  31
  32#ifdef CONFIG_SMP
  33
  34#include <linux/preempt.h>
  35#include <linux/kernel.h>
  36#include <linux/compiler.h>
  37#include <linux/thread_info.h>
  38#include <asm/smp.h>
  39
  40/*
  41 * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
  42 * (defined in asm header):
  43 */
  44
  45/*
  46 * stops all CPUs but the current one:
  47 */
  48extern void smp_send_stop(void);
  49
  50/*
  51 * sends a 'reschedule' event to another CPU:
  52 */
  53extern void smp_send_reschedule(int cpu);
  54
  55
  56/*
  57 * Prepare machine for booting other CPUs.
  58 */
  59extern void smp_prepare_cpus(unsigned int max_cpus);
  60
  61/*
  62 * Bring a CPU up
  63 */
  64extern int __cpu_up(unsigned int cpunum);
  65
  66/*
  67 * Final polishing of CPUs
  68 */
  69extern void smp_cpus_done(unsigned int max_cpus);
  70
  71/*
  72 * Call a function on all other processors
  73 */
  74int smp_call_function(smp_call_func_t func, void *info, int wait);
  75void smp_call_function_many(const struct cpumask *mask,
  76                            smp_call_func_t func, void *info, bool wait);
  77
  78void __smp_call_function_single(int cpuid, struct call_single_data *data,
  79                                int wait);
  80
  81int smp_call_function_any(const struct cpumask *mask,
  82                          smp_call_func_t func, void *info, int wait);
  83
  84/*
  85 * Generic and arch helpers
  86 */
  87#ifdef CONFIG_USE_GENERIC_SMP_HELPERS
  88void __init call_function_init(void);
  89void generic_smp_call_function_single_interrupt(void);
  90void generic_smp_call_function_interrupt(void);
  91void ipi_call_lock(void);
  92void ipi_call_unlock(void);
  93void ipi_call_lock_irq(void);
  94void ipi_call_unlock_irq(void);
  95#else
  96static inline void call_function_init(void) { }
  97#endif
  98
  99/*
 100 * Call a function on all processors
 101 */
 102int on_each_cpu(smp_call_func_t func, void *info, int wait);
 103
 104/*
 105 * Mark the boot cpu "online" so that it can call console drivers in
 106 * printk() and can access its per-cpu storage.
 107 */
 108void smp_prepare_boot_cpu(void);
 109
 110extern unsigned int setup_max_cpus;
 111extern void __init setup_nr_cpu_ids(void);
 112extern void __init smp_init(void);
 113
 114#else /* !SMP */
 115
 116static inline void smp_send_stop(void) { }
 117
 118/*
 119 *      These macros fold the SMP functionality into a single CPU system
 120 */
 121#define raw_smp_processor_id()                  0
 122static inline int up_smp_call_function(smp_call_func_t func, void *info)
 123{
 124        return 0;
 125}
 126#define smp_call_function(func, info, wait) \
 127                        (up_smp_call_function(func, info))
 128#define on_each_cpu(func,info,wait)             \
 129        ({                                      \
 130                local_irq_disable();            \
 131                func(info);                     \
 132                local_irq_enable();             \
 133                0;                              \
 134        })
 135static inline void smp_send_reschedule(int cpu) { }
 136#define num_booting_cpus()                      1
 137#define smp_prepare_boot_cpu()                  do {} while (0)
 138#define smp_call_function_many(mask, func, info, wait) \
 139                        (up_smp_call_function(func, info))
 140static inline void call_function_init(void) { }
 141
 142static inline int
 143smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
 144                      void *info, int wait)
 145{
 146        return smp_call_function_single(0, func, info, wait);
 147}
 148
 149#endif /* !SMP */
 150
 151/*
 152 * smp_processor_id(): get the current CPU ID.
 153 *
 154 * if DEBUG_PREEMPT is enabled then we check whether it is
 155 * used in a preemption-safe way. (smp_processor_id() is safe
 156 * if it's used in a preemption-off critical section, or in
 157 * a thread that is bound to the current CPU.)
 158 *
 159 * NOTE: raw_smp_processor_id() is for internal use only
 160 * (smp_processor_id() is the preferred variant), but in rare
 161 * instances it might also be used to turn off false positives
 162 * (i.e. smp_processor_id() use that the debugging code reports but
 163 * which use for some reason is legal). Don't use this to hack around
 164 * the warning message, as your code might not work under PREEMPT.
 165 */
 166#ifdef CONFIG_DEBUG_PREEMPT
 167  extern unsigned int debug_smp_processor_id(void);
 168# define smp_processor_id() debug_smp_processor_id()
 169#else
 170# define smp_processor_id() raw_smp_processor_id()
 171#endif
 172
 173#define get_cpu()               ({ preempt_disable(); smp_processor_id(); })
 174#define put_cpu()               preempt_enable()
 175
 176/*
 177 * Callback to arch code if there's nosmp or maxcpus=0 on the
 178 * boot command line:
 179 */
 180extern void arch_disable_smp_support(void);
 181
 182void smp_setup_processor_id(void);
 183
 184#endif /* __LINUX_SMP_H */
 185