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 <linux/types.h>
  11 #include <linux/list.h>
  12 #include <linux/cpumask.h>
  13 #include <linux/init.h>
  14 #include <linux/llist.h>
  15
  16 extern void cpu_idle(void);
  17
  18 typedef void (*smp_call_func_t)(void *info);
  19 struct call_single_data {
  20         union {
  21                 struct list_head list;
  22                 struct llist_node llist;
  23         };
  24         smp_call_func_t func;
  25         void *info;
  26         u16 flags;
  27 };
  28
  29 /* total number of cpus in this system (may exceed NR_CPUS) */
  30 extern unsigned int total_cpus;
  31
  32 int smp_call_function_single(int cpuid, smp_call_func_t func, void *info,
  33                              int wait);
  34
  35 /*
  36  * Call a function on all processors
  37  */
  38 int on_each_cpu(smp_call_func_t func, void *info, int wait);
  39
  40 /*
  41  * Call a function on processors specified by mask, which might include
  42  * the local one.
  43  */
  44 void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
  45                 void *info, bool wait);
  46
  47 /*
  48  * Call a function on each processor for which the supplied function
  49  * cond_func returns a positive value. This may include the local
  50  * processor.
  51  */
  52 void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
  53                 smp_call_func_t func, void *info, bool wait,
  54                 gfp_t gfp_flags);
  55
  56 void __smp_call_function_single(int cpuid, struct call_single_data *data,
  57                                 int wait);
  58
  59 #ifdef CONFIG_SMP
  60
  61 #include <linux/preempt.h>
  62 #include <linux/kernel.h>
  63 #include <linux/compiler.h>
  64 #include <linux/thread_info.h>
  65 #include <asm/smp.h>
  66
  67 /*
  68  * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
  69  * (defined in asm header):
  70  */
  71
  72 /*
  73  * stops all CPUs but the current one:
  74  */
  75 extern void smp_send_stop(void);
  76
  77 /*
  78  * sends a 'reschedule' event to another CPU:
  79  */
  80 extern void smp_send_reschedule(int cpu);
  81
  82
  83 /*
  84  * Prepare machine for booting other CPUs.
  85  */
  86 extern void smp_prepare_cpus(unsigned int max_cpus);
  87
  88 /*
  89  * Bring a CPU up
  90  */
  91 extern int __cpu_up(unsigned int cpunum, struct task_struct *tidle);
  92
  93 /*
  94  * Final polishing of CPUs
  95  */
  96 extern void smp_cpus_done(unsigned int max_cpus);
  97
  98 /*
  99  * Call a function on all other processors
 100  */
 101 int smp_call_function(smp_call_func_t func, void *info, int wait);
 102 void smp_call_function_many(const struct cpumask *mask,
 103                             smp_call_func_t func, void *info, bool wait);
 104
 105 int smp_call_function_any(const struct cpumask *mask,
 106                           smp_call_func_t func, void *info, int wait);
 107
 108 void kick_all_cpus_sync(void);
 109
 110 /*
 111  * Generic and arch helpers
 112  */
 113 void __init call_function_init(void);
 114 void generic_smp_call_function_single_interrupt(void);
 115 #define generic_smp_call_function_interrupt \
 116         generic_smp_call_function_single_interrupt
 117
 118 /*
 119  * Mark the boot cpu "online" so that it can call console drivers in
 120  * printk() and can access its per-cpu storage.
 121  */
 122 void smp_prepare_boot_cpu(void);
 123
 124 extern unsigned int setup_max_cpus;
 125 extern void __init setup_nr_cpu_ids(void);
 126 extern void __init smp_init(void);
 127
 128 #else /* !SMP */
 129
 130 static inline void smp_send_stop(void) { }
 131
 132 /*
 133  *      These macros fold the SMP functionality into a single CPU system
 134  */
 135 #define raw_smp_processor_id()                  0
 136 static inline int up_smp_call_function(smp_call_func_t func, void *info)
 137 {
 138         return 0;
 139 }
 140 #define smp_call_function(func, info, wait) \
 141                         (up_smp_call_function(func, info))
 142
 143 static inline void smp_send_reschedule(int cpu) { }
 144 #define smp_prepare_boot_cpu()                  do {} while (0)
 145 #define smp_call_function_many(mask, func, info, wait) \
 146                         (up_smp_call_function(func, info))
 147 static inline void call_function_init(void) { }
 148
 149 static inline int
 150 smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
 151                       void *info, int wait)
 152 {
 153         return smp_call_function_single(0, func, info, wait);
 154 }
 155
 156 static inline void kick_all_cpus_sync(void) {  }
 157
 158 #endif /* !SMP */
 159
 160 /*
 161  * smp_processor_id(): get the current CPU ID.
 162  *
 163  * if DEBUG_PREEMPT is enabled then we check whether it is
 164  * used in a preemption-safe way. (smp_processor_id() is safe
 165  * if it's used in a preemption-off critical section, or in
 166  * a thread that is bound to the current CPU.)
 167  *
 168  * NOTE: raw_smp_processor_id() is for internal use only
 169  * (smp_processor_id() is the preferred variant), but in rare
 170  * instances it might also be used to turn off false positives
 171  * (i.e. smp_processor_id() use that the debugging code reports but
 172  * which use for some reason is legal). Don't use this to hack around
 173  * the warning message, as your code might not work under PREEMPT.
 174  */
 175 #ifdef CONFIG_DEBUG_PREEMPT
 176   extern unsigned int debug_smp_processor_id(void);
 177 # define smp_processor_id() debug_smp_processor_id()
 178 #else
 179 # define smp_processor_id() raw_smp_processor_id()
 180 #endif
 181
 182 #define get_cpu()               ({ preempt_disable(); smp_processor_id(); })
 183 #define put_cpu()               preempt_enable()
 184
 185 /*
 186  * Callback to arch code if there's nosmp or maxcpus=0 on the
 187  * boot command line:
 188  */
 189 extern void arch_disable_smp_support(void);
 190
 191 void smp_setup_processor_id(void);
 192
 193 #endif /* __LINUX_SMP_H */