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
  10 extern void cpu_idle(void);
  11
  12 #ifdef CONFIG_SMP
  13
  14 #include <linux/preempt.h>
  15 #include <linux/kernel.h>
  16 #include <linux/compiler.h>
  17 #include <linux/thread_info.h>
  18 #include <asm/smp.h>
  19
  20 /*
  21  * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
  22  * (defined in asm header):
  23  */
  24
  25 /*
  26  * stops all CPUs but the current one:
  27  */
  28 extern void smp_send_stop(void);
  29
  30 /*
  31  * sends a 'reschedule' event to another CPU:
  32  */
  33 extern void smp_send_reschedule(int cpu);
  34
  35
  36 /*
  37  * Prepare machine for booting other CPUs.
  38  */
  39 extern void smp_prepare_cpus(unsigned int max_cpus);
  40
  41 /*
  42  * Bring a CPU up
  43  */
  44 extern int __cpu_up(unsigned int cpunum);
  45
  46 /*
  47  * Final polishing of CPUs
  48  */
  49 extern void smp_cpus_done(unsigned int max_cpus);
  50
  51 /*
  52  * Call a function on all other processors
  53  */
  54 int smp_call_function(void(*func)(void *info), void *info, int retry, int wait);
  55
  56 /*
  57  * Call a function on all processors
  58  */
  59 int on_each_cpu(void (*func) (void *info), void *info, int retry, int wait);
  60
  61 #define MSG_ALL_BUT_SELF        0x8000  /* Assume <32768 CPU's */
  62 #define MSG_ALL                 0x8001
  63
  64 #define MSG_INVALIDATE_TLB      0x0001  /* Remote processor TLB invalidate */
  65 #define MSG_STOP_CPU            0x0002  /* Sent to shut down slave CPU's
  66                                          * when rebooting
  67                                          */
  68 #define MSG_RESCHEDULE          0x0003  /* Reschedule request from master CPU*/
  69 #define MSG_CALL_FUNCTION       0x0004  /* Call function on all other CPUs */
  70
  71 /*
  72  * Mark the boot cpu "online" so that it can call console drivers in
  73  * printk() and can access its per-cpu storage.
  74  */
  75 void smp_prepare_boot_cpu(void);
  76
  77 #else /* !SMP */
  78
  79 /*
  80  *      These macros fold the SMP functionality into a single CPU system
  81  */
  82 #define raw_smp_processor_id()                  0
  83 #define hard_smp_processor_id()                 0
  84 static inline int up_smp_call_function(void)
  85 {
  86         return 0;
  87 }
  88 #define smp_call_function(func,info,retry,wait) (up_smp_call_function())
  89 #define on_each_cpu(func,info,retry,wait)       \
  90         ({                                      \
  91                 local_irq_disable();            \
  92                 func(info);                     \
  93                 local_irq_enable();             \
  94                 0;                              \
  95         })
  96 static inline void smp_send_reschedule(int cpu) { }
  97 #define num_booting_cpus()                      1
  98 #define smp_prepare_boot_cpu()                  do {} while (0)
  99
 100 #endif /* !SMP */
 101
 102 /*
 103  * smp_processor_id(): get the current CPU ID.
 104  *
 105  * if DEBUG_PREEMPT is enabled the we check whether it is
 106  * used in a preemption-safe way. (smp_processor_id() is safe
 107  * if it's used in a preemption-off critical section, or in
 108  * a thread that is bound to the current CPU.)
 109  *
 110  * NOTE: raw_smp_processor_id() is for internal use only
 111  * (smp_processor_id() is the preferred variant), but in rare
 112  * instances it might also be used to turn off false positives
 113  * (i.e. smp_processor_id() use that the debugging code reports but
 114  * which use for some reason is legal). Don't use this to hack around
 115  * the warning message, as your code might not work under PREEMPT.
 116  */
 117 #ifdef CONFIG_DEBUG_PREEMPT
 118   extern unsigned int debug_smp_processor_id(void);
 119 # define smp_processor_id() debug_smp_processor_id()
 120 #else
 121 # define smp_processor_id() raw_smp_processor_id()
 122 #endif
 123
 124 #define get_cpu()               ({ preempt_disable(); smp_processor_id(); })
 125 #define put_cpu()               preempt_enable()
 126 #define put_cpu_no_resched()    preempt_enable_no_resched()
 127
 128 #endif /* __LINUX_SMP_H */