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