smp.h 3.3 KB

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  1. #ifndef __LINUX_SMP_H
  2. #define __LINUX_SMP_H
  3. /*
  4. * Generic SMP support
  5. * Alan Cox. <alan@redhat.com>
  6. */
  7. #include <linux/config.h>
  8. extern void cpu_idle(void);
  9. #ifdef CONFIG_SMP
  10. #include <linux/preempt.h>
  11. #include <linux/kernel.h>
  12. #include <linux/compiler.h>
  13. #include <linux/thread_info.h>
  14. #include <asm/smp.h>
  15. #include <asm/bug.h>
  16. /*
  17. * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
  18. * (defined in asm header):
  19. */
  20. /*
  21. * stops all CPUs but the current one:
  22. */
  23. extern void smp_send_stop(void);
  24. /*
  25. * sends a 'reschedule' event to another CPU:
  26. */
  27. extern void smp_send_reschedule(int cpu);
  28. /*
  29. * Prepare machine for booting other CPUs.
  30. */
  31. extern void smp_prepare_cpus(unsigned int max_cpus);
  32. /*
  33. * Bring a CPU up
  34. */
  35. extern int __cpu_up(unsigned int cpunum);
  36. /*
  37. * Final polishing of CPUs
  38. */
  39. extern void smp_cpus_done(unsigned int max_cpus);
  40. /*
  41. * Call a function on all other processors
  42. */
  43. extern int smp_call_function (void (*func) (void *info), void *info,
  44. int retry, int wait);
  45. /*
  46. * Call a function on all processors
  47. */
  48. static inline int on_each_cpu(void (*func) (void *info), void *info,
  49. int retry, int wait)
  50. {
  51. int ret = 0;
  52. preempt_disable();
  53. ret = smp_call_function(func, info, retry, wait);
  54. func(info);
  55. preempt_enable();
  56. return ret;
  57. }
  58. #define MSG_ALL_BUT_SELF 0x8000 /* Assume <32768 CPU's */
  59. #define MSG_ALL 0x8001
  60. #define MSG_INVALIDATE_TLB 0x0001 /* Remote processor TLB invalidate */
  61. #define MSG_STOP_CPU 0x0002 /* Sent to shut down slave CPU's
  62. * when rebooting
  63. */
  64. #define MSG_RESCHEDULE 0x0003 /* Reschedule request from master CPU*/
  65. #define MSG_CALL_FUNCTION 0x0004 /* Call function on all other CPUs */
  66. /*
  67. * Mark the boot cpu "online" so that it can call console drivers in
  68. * printk() and can access its per-cpu storage.
  69. */
  70. void smp_prepare_boot_cpu(void);
  71. #else /* !SMP */
  72. /*
  73. * These macros fold the SMP functionality into a single CPU system
  74. */
  75. #define raw_smp_processor_id() 0
  76. #define hard_smp_processor_id() 0
  77. #define smp_call_function(func,info,retry,wait) ({ 0; })
  78. #define on_each_cpu(func,info,retry,wait) ({ func(info); 0; })
  79. static inline void smp_send_reschedule(int cpu) { }
  80. #define num_booting_cpus() 1
  81. #define smp_prepare_boot_cpu() do {} while (0)
  82. #endif /* !SMP */
  83. /*
  84. * smp_processor_id(): get the current CPU ID.
  85. *
  86. * if DEBUG_PREEMPT is enabled the we check whether it is
  87. * used in a preemption-safe way. (smp_processor_id() is safe
  88. * if it's used in a preemption-off critical section, or in
  89. * a thread that is bound to the current CPU.)
  90. *
  91. * NOTE: raw_smp_processor_id() is for internal use only
  92. * (smp_processor_id() is the preferred variant), but in rare
  93. * instances it might also be used to turn off false positives
  94. * (i.e. smp_processor_id() use that the debugging code reports but
  95. * which use for some reason is legal). Don't use this to hack around
  96. * the warning message, as your code might not work under PREEMPT.
  97. */
  98. #ifdef CONFIG_DEBUG_PREEMPT
  99. extern unsigned int debug_smp_processor_id(void);
  100. # define smp_processor_id() debug_smp_processor_id()
  101. #else
  102. # define smp_processor_id() raw_smp_processor_id()
  103. #endif
  104. #define get_cpu() ({ preempt_disable(); smp_processor_id(); })
  105. #define put_cpu() preempt_enable()
  106. #define put_cpu_no_resched() preempt_enable_no_resched()
  107. #endif /* __LINUX_SMP_H */