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