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
  96 #if !defined(__smp_processor_id) || !defined(CONFIG_PREEMPT)
  97 # define smp_processor_id()                     0
  98 #endif
  99 #define hard_smp_processor_id()                 0
 100 #define smp_call_function(func,info,retry,wait) ({ 0; })
 101 #define on_each_cpu(func,info,retry,wait)       ({ func(info); 0; })
 102 static inline void smp_send_reschedule(int cpu) { }
 103 #define num_booting_cpus()                      1
 104 #define smp_prepare_boot_cpu()                  do {} while (0)
 105
 106 #endif /* !SMP */
 107
 108 /*
 109  * DEBUG_PREEMPT support: check whether smp_processor_id() is being
 110  * used in a preemption-safe way.
 111  *
 112  * An architecture has to enable this debugging code explicitly.
 113  * It can do so by renaming the smp_processor_id() macro to
 114  * __smp_processor_id().  This should only be done after some minimal
 115  * testing, because usually there are a number of false positives
 116  * that an architecture will trigger.
 117  *
 118  * To fix a false positive (i.e. smp_processor_id() use that the
 119  * debugging code reports but which use for some reason is legal),
 120  * change the smp_processor_id() reference to _smp_processor_id(),
 121  * which is the nondebug variant.  NOTE: don't use this to hack around
 122  * real bugs.
 123  */
 124 #ifdef __smp_processor_id
 125 # if defined(CONFIG_PREEMPT) && defined(CONFIG_DEBUG_PREEMPT)
 126    extern unsigned int smp_processor_id(void);
 127 # else
 128 #  define smp_processor_id() __smp_processor_id()
 129 # endif
 130 # define _smp_processor_id() __smp_processor_id()
 131 #else
 132 # define _smp_processor_id() smp_processor_id()
 133 #endif
 134
 135 #define get_cpu()               ({ preempt_disable(); smp_processor_id(); })
 136 #define put_cpu()               preempt_enable()
 137 #define put_cpu_no_resched()    preempt_enable_no_resched()
 138
 139 #endif /* __LINUX_SMP_H */