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