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
  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        u16 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);
 103
 104/*
 105 * Generic and arch helpers
 106 */
 107void __init call_function_init(void);
 108void generic_smp_call_function_single_interrupt(void);
 109#define generic_smp_call_function_interrupt \
 110        generic_smp_call_function_single_interrupt
 111
 112/*
 113 * Mark the boot cpu "online" so that it can call console drivers in
 114 * printk() and can access its per-cpu storage.
 115 */
 116void smp_prepare_boot_cpu(void);
 117
 118extern unsigned int setup_max_cpus;
 119extern void __init setup_nr_cpu_ids(void);
 120extern void __init smp_init(void);
 121
 122#else /* !SMP */
 123
 124static inline void smp_send_stop(void) { }
 125
 126/*
 127 *      These macros fold the SMP functionality into a single CPU system
 128 */
 129#define raw_smp_processor_id()                  0
 130static inline int up_smp_call_function(smp_call_func_t func, void *info)
 131{
 132        return 0;
 133}
 134#define smp_call_function(func, info, wait) \
 135                        (up_smp_call_function(func, info))
 136
 137static inline void smp_send_reschedule(int cpu) { }
 138#define smp_prepare_boot_cpu()                  do {} while (0)
 139#define smp_call_function_many(mask, func, info, wait) \
 140                        (up_smp_call_function(func, info))
 141static inline void call_function_init(void) { }
 142
 143static inline int
 144smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
 145                      void *info, int wait)
 146{
 147        return smp_call_function_single(0, func, info, wait);
 148}
 149
 150static inline void kick_all_cpus_sync(void) {  }
 151
 152#endif /* !SMP */
 153
 154/*
 155 * smp_processor_id(): get the current CPU ID.
 156 *
 157 * if DEBUG_PREEMPT is enabled then we check whether it is
 158 * used in a preemption-safe way. (smp_processor_id() is safe
 159 * if it's used in a preemption-off critical section, or in
 160 * a thread that is bound to the current CPU.)
 161 *
 162 * NOTE: raw_smp_processor_id() is for internal use only
 163 * (smp_processor_id() is the preferred variant), but in rare
 164 * instances it might also be used to turn off false positives
 165 * (i.e. smp_processor_id() use that the debugging code reports but
 166 * which use for some reason is legal). Don't use this to hack around
 167 * the warning message, as your code might not work under PREEMPT.
 168 */
 169#ifdef CONFIG_DEBUG_PREEMPT
 170  extern unsigned int debug_smp_processor_id(void);
 171# define smp_processor_id() debug_smp_processor_id()
 172#else
 173# define smp_processor_id() raw_smp_processor_id()
 174#endif
 175
 176#define get_cpu()               ({ preempt_disable(); smp_processor_id(); })
 177#define put_cpu()               preempt_enable()
 178
 179/*
 180 * Callback to arch code if there's nosmp or maxcpus=0 on the
 181 * boot command line:
 182 */
 183extern void arch_disable_smp_support(void);
 184
 185extern void arch_enable_nonboot_cpus_begin(void);
 186extern void arch_enable_nonboot_cpus_end(void);
 187
 188void smp_setup_processor_id(void);
 189
 190#endif /* __LINUX_SMP_H */
 191