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
  15 extern void cpu_idle(void);
  16
  17 typedef void (*smp_call_func_t)(void *info);
  18 struct call_single_data {
  19         struct list_head list;
  20         smp_call_func_t func;
  21         void *info;
  22         u16 flags;
  23 };
  24
  25 /* total number of cpus in this system (may exceed NR_CPUS) */
  26 extern unsigned int total_cpus;
  27
  28 int smp_call_function_single(int cpuid, smp_call_func_t func, void *info,
  29                              int wait);
  30
  31 /*
  32  * Call a function on all processors
  33  */
  34 int on_each_cpu(smp_call_func_t func, void *info, int wait);
  35
  36 /*
  37  * Call a function on processors specified by mask, which might include
  38  * the local one.
  39  */
  40 void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
  41                 void *info, bool wait);
  42
  43 /*
  44  * Call a function on each processor for which the supplied function
  45  * cond_func returns a positive value. This may include the local
  46  * processor.
  47  */
  48 void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
  49                 smp_call_func_t func, void *info, bool wait,
  50                 gfp_t gfp_flags);
  51
  52 #ifdef CONFIG_SMP
  53
  54 #include <linux/preempt.h>
  55 #include <linux/kernel.h>
  56 #include <linux/compiler.h>
  57 #include <linux/thread_info.h>
  58 #include <asm/smp.h>
  59
  60 /*
  61  * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
  62  * (defined in asm header):
  63  */
  64
  65 /*
  66  * stops all CPUs but the current one:
  67  */
  68 extern void smp_send_stop(void);
  69
  70 /*
  71  * sends a 'reschedule' event to another CPU:
  72  */
  73 extern void smp_send_reschedule(int cpu);
  74
  75
  76 /*
  77  * Prepare machine for booting other CPUs.
  78  */
  79 extern void smp_prepare_cpus(unsigned int max_cpus);
  80
  81 /*
  82  * Bring a CPU up
  83  */
  84 extern int __cpu_up(unsigned int cpunum, struct task_struct *tidle);
  85
  86 /*
  87  * Final polishing of CPUs
  88  */
  89 extern void smp_cpus_done(unsigned int max_cpus);
  90
  91 /*
  92  * Call a function on all other processors
  93  */
  94 int smp_call_function(smp_call_func_t func, void *info, int wait);
  95 void smp_call_function_many(const struct cpumask *mask,
  96                             smp_call_func_t func, void *info, bool wait);
  97
  98 void __smp_call_function_single(int cpuid, struct call_single_data *data,
  99                                 int wait);
 100
 101 int smp_call_function_any(const struct cpumask *mask,
 102                           smp_call_func_t func, void *info, int wait);
 103
 104 void kick_all_cpus_sync(void);
 105
 106 /*
 107  * Generic and arch helpers
 108  */
 109 #ifdef CONFIG_USE_GENERIC_SMP_HELPERS
 110 void __init call_function_init(void);
 111 void generic_smp_call_function_single_interrupt(void);
 112 #define generic_smp_call_function_interrupt \
 113         generic_smp_call_function_single_interrupt
 114 #else
 115 static inline void call_function_init(void) { }
 116 #endif
 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 static inline void __smp_call_function_single(int cpuid,
 159                 struct call_single_data *data, int wait)
 160 {
 161         on_each_cpu(data->func, data->info, wait);
 162 }
 163
 164 #endif /* !SMP */
 165
 166 /*
 167  * smp_processor_id(): get the current CPU ID.
 168  *
 169  * if DEBUG_PREEMPT is enabled then we check whether it is
 170  * used in a preemption-safe way. (smp_processor_id() is safe
 171  * if it's used in a preemption-off critical section, or in
 172  * a thread that is bound to the current CPU.)
 173  *
 174  * NOTE: raw_smp_processor_id() is for internal use only
 175  * (smp_processor_id() is the preferred variant), but in rare
 176  * instances it might also be used to turn off false positives
 177  * (i.e. smp_processor_id() use that the debugging code reports but
 178  * which use for some reason is legal). Don't use this to hack around
 179  * the warning message, as your code might not work under PREEMPT.
 180  */
 181 #ifdef CONFIG_DEBUG_PREEMPT
 182   extern unsigned int debug_smp_processor_id(void);
 183 # define smp_processor_id() debug_smp_processor_id()
 184 #else
 185 # define smp_processor_id() raw_smp_processor_id()
 186 #endif
 187
 188 #define get_cpu()               ({ preempt_disable(); smp_processor_id(); })
 189 #define put_cpu()               preempt_enable()
 190
 191 /*
 192  * Callback to arch code if there's nosmp or maxcpus=0 on the
 193  * boot command line:
 194  */
 195 extern void arch_disable_smp_support(void);
 196
 197 void smp_setup_processor_id(void);
 198
 199 #endif /* __LINUX_SMP_H */