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#include <linux/llist.h>
  15
  16extern void cpu_idle(void);
  17
  18typedef void (*smp_call_func_t)(void *info);
  19struct call_single_data {
  20        struct llist_node llist;
  21        smp_call_func_t func;
  22        void *info;
  23        u16 flags;
  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/*
  33 * Call a function on all processors
  34 */
  35int on_each_cpu(smp_call_func_t func, void *info, int wait);
  36
  37/*
  38 * Call a function on processors specified by mask, which might include
  39 * the local one.
  40 */
  41void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
  42                void *info, bool wait);
  43
  44/*
  45 * Call a function on each processor for which the supplied function
  46 * cond_func returns a positive value. This may include the local
  47 * processor.
  48 */
  49void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
  50                smp_call_func_t func, void *info, bool wait,
  51                gfp_t gfp_flags);
  52
  53int smp_call_function_single_async(int cpu, struct call_single_data *csd);
  54
  55#ifdef CONFIG_SMP
  56
  57#include <linux/preempt.h>
  58#include <linux/kernel.h>
  59#include <linux/compiler.h>
  60#include <linux/thread_info.h>
  61#include <asm/smp.h>
  62
  63/*
  64 * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
  65 * (defined in asm header):
  66 */
  67
  68/*
  69 * stops all CPUs but the current one:
  70 */
  71extern void smp_send_stop(void);
  72
  73/*
  74 * sends a 'reschedule' event to another CPU:
  75 */
  76extern void smp_send_reschedule(int cpu);
  77
  78
  79/*
  80 * Prepare machine for booting other CPUs.
  81 */
  82extern void smp_prepare_cpus(unsigned int max_cpus);
  83
  84/*
  85 * Bring a CPU up
  86 */
  87extern int __cpu_up(unsigned int cpunum, struct task_struct *tidle);
  88
  89/*
  90 * Final polishing of CPUs
  91 */
  92extern void smp_cpus_done(unsigned int max_cpus);
  93
  94/*
  95 * Call a function on all other processors
  96 */
  97int smp_call_function(smp_call_func_t func, void *info, int wait);
  98void smp_call_function_many(const struct cpumask *mask,
  99                            smp_call_func_t func, void *info, bool wait);
 100
 101int smp_call_function_any(const struct cpumask *mask,
 102                          smp_call_func_t func, void *info, int wait);
 103
 104void kick_all_cpus_sync(void);
 105
 106/*
 107 * Generic and arch helpers
 108 */
 109void __init call_function_init(void);
 110void generic_smp_call_function_single_interrupt(void);
 111#define generic_smp_call_function_interrupt \
 112        generic_smp_call_function_single_interrupt
 113
 114/*
 115 * Mark the boot cpu "online" so that it can call console drivers in
 116 * printk() and can access its per-cpu storage.
 117 */
 118void smp_prepare_boot_cpu(void);
 119
 120extern unsigned int setup_max_cpus;
 121extern void __init setup_nr_cpu_ids(void);
 122extern void __init smp_init(void);
 123
 124#else /* !SMP */
 125
 126static inline void smp_send_stop(void) { }
 127
 128/*
 129 *      These macros fold the SMP functionality into a single CPU system
 130 */
 131#define raw_smp_processor_id()                  0
 132static inline int up_smp_call_function(smp_call_func_t func, void *info)
 133{
 134        return 0;
 135}
 136#define smp_call_function(func, info, wait) \
 137                        (up_smp_call_function(func, info))
 138
 139static inline void smp_send_reschedule(int cpu) { }
 140#define smp_prepare_boot_cpu()                  do {} while (0)
 141#define smp_call_function_many(mask, func, info, wait) \
 142                        (up_smp_call_function(func, info))
 143static inline void call_function_init(void) { }
 144
 145static inline int
 146smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
 147                      void *info, int wait)
 148{
 149        return smp_call_function_single(0, func, info, wait);
 150}
 151
 152static inline void kick_all_cpus_sync(void) {  }
 153
 154#endif /* !SMP */
 155
 156/*
 157 * smp_processor_id(): get the current CPU ID.
 158 *
 159 * if DEBUG_PREEMPT is enabled then we check whether it is
 160 * used in a preemption-safe way. (smp_processor_id() is safe
 161 * if it's used in a preemption-off critical section, or in
 162 * a thread that is bound to the current CPU.)
 163 *
 164 * NOTE: raw_smp_processor_id() is for internal use only
 165 * (smp_processor_id() is the preferred variant), but in rare
 166 * instances it might also be used to turn off false positives
 167 * (i.e. smp_processor_id() use that the debugging code reports but
 168 * which use for some reason is legal). Don't use this to hack around
 169 * the warning message, as your code might not work under PREEMPT.
 170 */
 171#ifdef CONFIG_DEBUG_PREEMPT
 172  extern unsigned int debug_smp_processor_id(void);
 173# define smp_processor_id() debug_smp_processor_id()
 174#else
 175# define smp_processor_id() raw_smp_processor_id()
 176#endif
 177
 178#define get_cpu()               ({ preempt_disable(); smp_processor_id(); })
 179#define put_cpu()               preempt_enable()
 180
 181/*
 182 * Callback to arch code if there's nosmp or maxcpus=0 on the
 183 * boot command line:
 184 */
 185extern void arch_disable_smp_support(void);
 186
 187extern void arch_enable_nonboot_cpus_begin(void);
 188extern void arch_enable_nonboot_cpus_end(void);
 189
 190void smp_setup_processor_id(void);
 191
 192#endif /* __LINUX_SMP_H */
 193