smp.h 5.8 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/errno.h>
  8. #include <linux/types.h>
  9. #include <linux/list.h>
  10. #include <linux/cpumask.h>
  11. #include <linux/init.h>
  12. extern void cpu_idle(void);
  13. typedef void (*smp_call_func_t)(void *info);
  14. struct call_single_data {
  15. struct list_head list;
  16. smp_call_func_t func;
  17. void *info;
  18. u16 flags;
  19. u16 priv;
  20. };
  21. /* total number of cpus in this system (may exceed NR_CPUS) */
  22. extern unsigned int total_cpus;
  23. int smp_call_function_single(int cpuid, smp_call_func_t func, void *info,
  24. int wait);
  25. #ifdef CONFIG_SMP
  26. #include <linux/preempt.h>
  27. #include <linux/kernel.h>
  28. #include <linux/compiler.h>
  29. #include <linux/thread_info.h>
  30. #include <asm/smp.h>
  31. /*
  32. * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
  33. * (defined in asm header):
  34. */
  35. /*
  36. * stops all CPUs but the current one:
  37. */
  38. extern void smp_send_stop(void);
  39. /*
  40. * sends a 'reschedule' event to another CPU:
  41. */
  42. extern void smp_send_reschedule(int cpu);
  43. /*
  44. * Prepare machine for booting other CPUs.
  45. */
  46. extern void smp_prepare_cpus(unsigned int max_cpus);
  47. /*
  48. * Bring a CPU up
  49. */
  50. extern int __cpu_up(unsigned int cpunum, struct task_struct *tidle);
  51. /*
  52. * Final polishing of CPUs
  53. */
  54. extern void smp_cpus_done(unsigned int max_cpus);
  55. /*
  56. * Call a function on all other processors
  57. */
  58. int smp_call_function(smp_call_func_t func, void *info, int wait);
  59. void smp_call_function_many(const struct cpumask *mask,
  60. smp_call_func_t func, void *info, bool wait);
  61. void __smp_call_function_single(int cpuid, struct call_single_data *data,
  62. int wait);
  63. int smp_call_function_any(const struct cpumask *mask,
  64. smp_call_func_t func, void *info, int wait);
  65. void kick_all_cpus_sync(void);
  66. /*
  67. * Generic and arch helpers
  68. */
  69. #ifdef CONFIG_USE_GENERIC_SMP_HELPERS
  70. void __init call_function_init(void);
  71. void generic_smp_call_function_single_interrupt(void);
  72. void generic_smp_call_function_interrupt(void);
  73. #else
  74. static inline void call_function_init(void) { }
  75. #endif
  76. /*
  77. * Call a function on all processors
  78. */
  79. int on_each_cpu(smp_call_func_t func, void *info, int wait);
  80. /*
  81. * Call a function on processors specified by mask, which might include
  82. * the local one.
  83. */
  84. void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
  85. void *info, bool wait);
  86. /*
  87. * Call a function on each processor for which the supplied function
  88. * cond_func returns a positive value. This may include the local
  89. * processor.
  90. */
  91. void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
  92. smp_call_func_t func, void *info, bool wait,
  93. gfp_t gfp_flags);
  94. /*
  95. * Mark the boot cpu "online" so that it can call console drivers in
  96. * printk() and can access its per-cpu storage.
  97. */
  98. void smp_prepare_boot_cpu(void);
  99. extern unsigned int setup_max_cpus;
  100. extern void __init setup_nr_cpu_ids(void);
  101. extern void __init smp_init(void);
  102. #else /* !SMP */
  103. static inline void smp_send_stop(void) { }
  104. /*
  105. * These macros fold the SMP functionality into a single CPU system
  106. */
  107. #define raw_smp_processor_id() 0
  108. static inline int up_smp_call_function(smp_call_func_t func, void *info)
  109. {
  110. return 0;
  111. }
  112. #define smp_call_function(func, info, wait) \
  113. (up_smp_call_function(func, info))
  114. #define on_each_cpu(func,info,wait) \
  115. ({ \
  116. local_irq_disable(); \
  117. func(info); \
  118. local_irq_enable(); \
  119. 0; \
  120. })
  121. /*
  122. * Note we still need to test the mask even for UP
  123. * because we actually can get an empty mask from
  124. * code that on SMP might call us without the local
  125. * CPU in the mask.
  126. */
  127. #define on_each_cpu_mask(mask, func, info, wait) \
  128. do { \
  129. if (cpumask_test_cpu(0, (mask))) { \
  130. local_irq_disable(); \
  131. (func)(info); \
  132. local_irq_enable(); \
  133. } \
  134. } while (0)
  135. /*
  136. * Preemption is disabled here to make sure the cond_func is called under the
  137. * same condtions in UP and SMP.
  138. */
  139. #define on_each_cpu_cond(cond_func, func, info, wait, gfp_flags)\
  140. do { \
  141. void *__info = (info); \
  142. preempt_disable(); \
  143. if ((cond_func)(0, __info)) { \
  144. local_irq_disable(); \
  145. (func)(__info); \
  146. local_irq_enable(); \
  147. } \
  148. preempt_enable(); \
  149. } while (0)
  150. static inline void smp_send_reschedule(int cpu) { }
  151. #define num_booting_cpus() 1
  152. #define smp_prepare_boot_cpu() do {} while (0)
  153. #define smp_call_function_many(mask, func, info, wait) \
  154. (up_smp_call_function(func, info))
  155. static inline void call_function_init(void) { }
  156. static inline int
  157. smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
  158. void *info, int wait)
  159. {
  160. return smp_call_function_single(0, func, info, wait);
  161. }
  162. static inline void kick_all_cpus_sync(void) { }
  163. #endif /* !SMP */
  164. /*
  165. * smp_processor_id(): get the current CPU ID.
  166. *
  167. * if DEBUG_PREEMPT is enabled then we check whether it is
  168. * used in a preemption-safe way. (smp_processor_id() is safe
  169. * if it's used in a preemption-off critical section, or in
  170. * a thread that is bound to the current CPU.)
  171. *
  172. * NOTE: raw_smp_processor_id() is for internal use only
  173. * (smp_processor_id() is the preferred variant), but in rare
  174. * instances it might also be used to turn off false positives
  175. * (i.e. smp_processor_id() use that the debugging code reports but
  176. * which use for some reason is legal). Don't use this to hack around
  177. * the warning message, as your code might not work under PREEMPT.
  178. */
  179. #ifdef CONFIG_DEBUG_PREEMPT
  180. extern unsigned int debug_smp_processor_id(void);
  181. # define smp_processor_id() debug_smp_processor_id()
  182. #else
  183. # define smp_processor_id() raw_smp_processor_id()
  184. #endif
  185. #define get_cpu() ({ preempt_disable(); smp_processor_id(); })
  186. #define put_cpu() preempt_enable()
  187. /*
  188. * Callback to arch code if there's nosmp or maxcpus=0 on the
  189. * boot command line:
  190. */
  191. extern void arch_disable_smp_support(void);
  192. void smp_setup_processor_id(void);
  193. #endif /* __LINUX_SMP_H */