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 #include <asm/system.h>
  11
  12 extern void cpu_idle(void);
  13
  14 #ifdef CONFIG_SMP
  15
  16 #include <linux/preempt.h>
  17 #include <linux/kernel.h>
  18 #include <linux/compiler.h>
  19 #include <linux/thread_info.h>
  20 #include <asm/smp.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 int smp_call_function(void(*func)(void *info), void *info, int retry, int wait);
  57
  58 int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
  59                                 int retry, int wait);
  60
  61 /*
  62  * Call a function on all processors
  63  */
  64 int on_each_cpu(void (*func) (void *info), void *info, int retry, int wait);
  65
  66 #define MSG_ALL_BUT_SELF        0x8000  /* Assume <32768 CPU's */
  67 #define MSG_ALL                 0x8001
  68
  69 #define MSG_INVALIDATE_TLB      0x0001  /* Remote processor TLB invalidate */
  70 #define MSG_STOP_CPU            0x0002  /* Sent to shut down slave CPU's
  71                                          * when rebooting
  72                                          */
  73 #define MSG_RESCHEDULE          0x0003  /* Reschedule request from master CPU*/
  74 #define MSG_CALL_FUNCTION       0x0004  /* Call function on all other CPUs */
  75
  76 /*
  77  * Mark the boot cpu "online" so that it can call console drivers in
  78  * printk() and can access its per-cpu storage.
  79  */
  80 void smp_prepare_boot_cpu(void);
  81
  82 #else /* !SMP */
  83
  84 /*
  85  *      These macros fold the SMP functionality into a single CPU system
  86  */
  87 #define raw_smp_processor_id()                  0
  88 static inline int up_smp_call_function(void)
  89 {
  90         return 0;
  91 }
  92 #define smp_call_function(func,info,retry,wait) (up_smp_call_function())
  93 #define on_each_cpu(func,info,retry,wait)       \
  94         ({                                      \
  95                 local_irq_disable();            \
  96                 func(info);                     \
  97                 local_irq_enable();             \
  98                 0;                              \
  99         })
 100 static inline void smp_send_reschedule(int cpu) { }
 101 #define num_booting_cpus()                      1
 102 #define smp_prepare_boot_cpu()                  do {} while (0)
 103 static inline int smp_call_function_single(int cpuid, void (*func) (void *info),
 104                                            void *info, int retry, int wait)
 105 {
 106         WARN_ON(cpuid != 0);
 107         local_irq_disable();
 108         func(info);
 109         local_irq_enable();
 110         return 0;
 111 }
 112
 113 #endif /* !SMP */
 114
 115 /*
 116  * smp_processor_id(): get the current CPU ID.
 117  *
 118  * if DEBUG_PREEMPT is enabled the we check whether it is
 119  * used in a preemption-safe way. (smp_processor_id() is safe
 120  * if it's used in a preemption-off critical section, or in
 121  * a thread that is bound to the current CPU.)
 122  *
 123  * NOTE: raw_smp_processor_id() is for internal use only
 124  * (smp_processor_id() is the preferred variant), but in rare
 125  * instances it might also be used to turn off false positives
 126  * (i.e. smp_processor_id() use that the debugging code reports but
 127  * which use for some reason is legal). Don't use this to hack around
 128  * the warning message, as your code might not work under PREEMPT.
 129  */
 130 #ifdef CONFIG_DEBUG_PREEMPT
 131   extern unsigned int debug_smp_processor_id(void);
 132 # define smp_processor_id() debug_smp_processor_id()
 133 #else
 134 # define smp_processor_id() raw_smp_processor_id()
 135 #endif
 136
 137 #define get_cpu()               ({ preempt_disable(); smp_processor_id(); })
 138 #define put_cpu()               preempt_enable()
 139 #define put_cpu_no_resched()    preempt_enable_no_resched()
 140
 141 void smp_setup_processor_id(void);
 142
 143 #endif /* __LINUX_SMP_H */