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/config.h>
  10
  11extern void cpu_idle(void);
  12
  13#ifdef CONFIG_SMP
  14
  15#include <linux/preempt.h>
  16#include <linux/kernel.h>
  17#include <linux/compiler.h>
  18#include <linux/thread_info.h>
  19#include <asm/smp.h>
  20#include <asm/bug.h>
  21
  22/*
  23 * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
  24 * (defined in asm header):
  25 */ 
  26
  27/*
  28 * stops all CPUs but the current one:
  29 */
  30extern void smp_send_stop(void);
  31
  32/*
  33 * sends a 'reschedule' event to another CPU:
  34 */
  35extern void smp_send_reschedule(int cpu);
  36
  37
  38/*
  39 * Prepare machine for booting other CPUs.
  40 */
  41extern void smp_prepare_cpus(unsigned int max_cpus);
  42
  43/*
  44 * Bring a CPU up
  45 */
  46extern int __cpu_up(unsigned int cpunum);
  47
  48/*
  49 * Final polishing of CPUs
  50 */
  51extern void smp_cpus_done(unsigned int max_cpus);
  52
  53/*
  54 * Call a function on all other processors
  55 */
  56extern int smp_call_function (void (*func) (void *info), void *info,
  57                              int retry, int wait);
  58
  59/*
  60 * Call a function on all processors
  61 */
  62static inline int on_each_cpu(void (*func) (void *info), void *info,
  63                              int retry, int wait)
  64{
  65        int ret = 0;
  66
  67        preempt_disable();
  68        ret = smp_call_function(func, info, retry, wait);
  69        func(info);
  70        preempt_enable();
  71        return ret;
  72}
  73
  74/*
  75 * True once the per process idle is forked
  76 */
  77extern int smp_threads_ready;
  78
  79#define MSG_ALL_BUT_SELF        0x8000  /* Assume <32768 CPU's */
  80#define MSG_ALL                 0x8001
  81
  82#define MSG_INVALIDATE_TLB      0x0001  /* Remote processor TLB invalidate */
  83#define MSG_STOP_CPU            0x0002  /* Sent to shut down slave CPU's
  84                                         * when rebooting
  85                                         */
  86#define MSG_RESCHEDULE          0x0003  /* Reschedule request from master CPU*/
  87#define MSG_CALL_FUNCTION       0x0004  /* Call function on all other CPUs */
  88
  89/*
  90 * Mark the boot cpu "online" so that it can call console drivers in
  91 * printk() and can access its per-cpu storage.
  92 */
  93void smp_prepare_boot_cpu(void);
  94
  95#else /* !SMP */
  96
  97/*
  98 *      These macros fold the SMP functionality into a single CPU system
  99 */
 100
 101#if !defined(__smp_processor_id) || !defined(CONFIG_PREEMPT)
 102# define smp_processor_id()                     0
 103#endif
 104#define hard_smp_processor_id()                 0
 105#define smp_threads_ready                       1
 106#define smp_call_function(func,info,retry,wait) ({ 0; })
 107#define on_each_cpu(func,info,retry,wait)       ({ func(info); 0; })
 108static inline void smp_send_reschedule(int cpu) { }
 109#define num_booting_cpus()                      1
 110#define smp_prepare_boot_cpu()                  do {} while (0)
 111
 112#endif /* !SMP */
 113
 114/*
 115 * DEBUG_PREEMPT support: check whether smp_processor_id() is being
 116 * used in a preemption-safe way.
 117 *
 118 * An architecture has to enable this debugging code explicitly.
 119 * It can do so by renaming the smp_processor_id() macro to
 120 * __smp_processor_id().  This should only be done after some minimal
 121 * testing, because usually there are a number of false positives
 122 * that an architecture will trigger.
 123 *
 124 * To fix a false positive (i.e. smp_processor_id() use that the
 125 * debugging code reports but which use for some reason is legal),
 126 * change the smp_processor_id() reference to _smp_processor_id(),
 127 * which is the nondebug variant.  NOTE: don't use this to hack around
 128 * real bugs.
 129 */
 130#ifdef __smp_processor_id
 131# if defined(CONFIG_PREEMPT) && defined(CONFIG_DEBUG_PREEMPT)
 132   extern unsigned int smp_processor_id(void);
 133# else
 134#  define smp_processor_id() __smp_processor_id()
 135# endif
 136# define _smp_processor_id() __smp_processor_id()
 137#else
 138# define _smp_processor_id() smp_processor_id()
 139#endif
 140
 141#define get_cpu()               ({ preempt_disable(); smp_processor_id(); })
 142#define put_cpu()               preempt_enable()
 143#define put_cpu_no_resched()    preempt_enable_no_resched()
 144
 145#endif /* __LINUX_SMP_H */
 146