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
  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
  21/*
  22 * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
  23 * (defined in asm header):
  24 */ 
  25
  26/*
  27 * stops all CPUs but the current one:
  28 */
  29extern void smp_send_stop(void);
  30
  31/*
  32 * sends a 'reschedule' event to another CPU:
  33 */
  34extern void smp_send_reschedule(int cpu);
  35
  36
  37/*
  38 * Prepare machine for booting other CPUs.
  39 */
  40extern void smp_prepare_cpus(unsigned int max_cpus);
  41
  42/*
  43 * Bring a CPU up
  44 */
  45extern int __cpu_up(unsigned int cpunum);
  46
  47/*
  48 * Final polishing of CPUs
  49 */
  50extern void smp_cpus_done(unsigned int max_cpus);
  51
  52/*
  53 * Call a function on all other processors
  54 */
  55int smp_call_function(void(*func)(void *info), void *info, int retry, int wait);
  56
  57int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
  58                                int retry, int wait);
  59
  60/*
  61 * Call a function on all processors
  62 */
  63int on_each_cpu(void (*func) (void *info), void *info, int retry, int wait);
  64
  65#define MSG_ALL_BUT_SELF        0x8000  /* Assume <32768 CPU's */
  66#define MSG_ALL                 0x8001
  67
  68#define MSG_INVALIDATE_TLB      0x0001  /* Remote processor TLB invalidate */
  69#define MSG_STOP_CPU            0x0002  /* Sent to shut down slave CPU's
  70                                         * when rebooting
  71                                         */
  72#define MSG_RESCHEDULE          0x0003  /* Reschedule request from master CPU*/
  73#define MSG_CALL_FUNCTION       0x0004  /* Call function on all other CPUs */
  74
  75/*
  76 * Mark the boot cpu "online" so that it can call console drivers in
  77 * printk() and can access its per-cpu storage.
  78 */
  79void smp_prepare_boot_cpu(void);
  80
  81extern unsigned int setup_max_cpus;
  82
  83#else /* !SMP */
  84
  85/*
  86 *      These macros fold the SMP functionality into a single CPU system
  87 */
  88#define raw_smp_processor_id()                  0
  89static inline int up_smp_call_function(void (*func)(void *), void *info)
  90{
  91        return 0;
  92}
  93#define smp_call_function(func, info, retry, wait) \
  94                        (up_smp_call_function(func, info))
  95#define on_each_cpu(func,info,retry,wait)       \
  96        ({                                      \
  97                local_irq_disable();            \
  98                func(info);                     \
  99                local_irq_enable();             \
 100                0;                              \
 101        })
 102static inline void smp_send_reschedule(int cpu) { }
 103#define num_booting_cpus()                      1
 104#define smp_prepare_boot_cpu()                  do {} while (0)
 105#define smp_call_function_single(cpuid, func, info, retry, wait) \
 106({ \
 107        WARN_ON(cpuid != 0);    \
 108        local_irq_disable();    \
 109        (func)(info);           \
 110        local_irq_enable();     \
 111        0;                      \
 112})
 113#define smp_call_function_mask(mask, func, info, wait) \
 114                        (up_smp_call_function(func, info))
 115
 116#endif /* !SMP */
 117
 118/*
 119 * smp_processor_id(): get the current CPU ID.
 120 *
 121 * if DEBUG_PREEMPT is enabled the we check whether it is
 122 * used in a preemption-safe way. (smp_processor_id() is safe
 123 * if it's used in a preemption-off critical section, or in
 124 * a thread that is bound to the current CPU.)
 125 *
 126 * NOTE: raw_smp_processor_id() is for internal use only
 127 * (smp_processor_id() is the preferred variant), but in rare
 128 * instances it might also be used to turn off false positives
 129 * (i.e. smp_processor_id() use that the debugging code reports but
 130 * which use for some reason is legal). Don't use this to hack around
 131 * the warning message, as your code might not work under PREEMPT.
 132 */
 133#ifdef CONFIG_DEBUG_PREEMPT
 134  extern unsigned int debug_smp_processor_id(void);
 135# define smp_processor_id() debug_smp_processor_id()
 136#else
 137# define smp_processor_id() raw_smp_processor_id()
 138#endif
 139
 140#define get_cpu()               ({ preempt_disable(); smp_processor_id(); })
 141#define put_cpu()               preempt_enable()
 142#define put_cpu_no_resched()    preempt_enable_no_resched()
 143
 144void smp_setup_processor_id(void);
 145
 146#endif /* __LINUX_SMP_H */
 147