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         u16 priv;
  24 };
  25
  26 /* total number of cpus in this system (may exceed NR_CPUS) */
  27 extern unsigned int total_cpus;
  28
  29 int smp_call_function_single(int cpuid, smp_call_func_t func, void *info,
  30                              int wait);
  31
  32 #ifdef CONFIG_SMP
  33
  34 #include <linux/preempt.h>
  35 #include <linux/kernel.h>
  36 #include <linux/compiler.h>
  37 #include <linux/thread_info.h>
  38 #include <asm/smp.h>
  39
  40 /*
  41  * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
  42  * (defined in asm header):
  43  */
  44
  45 /*
  46  * stops all CPUs but the current one:
  47  */
  48 extern void smp_send_stop(void);
  49
  50 /*
  51  * sends a 'reschedule' event to another CPU:
  52  */
  53 extern void smp_send_reschedule(int cpu);
  54
  55
  56 /*
  57  * Prepare machine for booting other CPUs.
  58  */
  59 extern void smp_prepare_cpus(unsigned int max_cpus);
  60
  61 /*
  62  * Bring a CPU up
  63  */
  64 extern int __cpu_up(unsigned int cpunum);
  65
  66 /*
  67  * Final polishing of CPUs
  68  */
  69 extern void smp_cpus_done(unsigned int max_cpus);
  70
  71 /*
  72  * Call a function on all other processors
  73  */
  74 int smp_call_function(smp_call_func_t func, void *info, int wait);
  75 void smp_call_function_many(const struct cpumask *mask,
  76                             smp_call_func_t func, void *info, bool wait);
  77
  78 void __smp_call_function_single(int cpuid, struct call_single_data *data,
  79                                 int wait);
  80
  81 int smp_call_function_any(const struct cpumask *mask,
  82                           smp_call_func_t func, void *info, int wait);
  83
  84 /*
  85  * Generic and arch helpers
  86  */
  87 #ifdef CONFIG_USE_GENERIC_SMP_HELPERS
  88 void generic_smp_call_function_single_interrupt(void);
  89 void generic_smp_call_function_interrupt(void);
  90 void ipi_call_lock(void);
  91 void ipi_call_unlock(void);
  92 void ipi_call_lock_irq(void);
  93 void ipi_call_unlock_irq(void);
  94 #endif
  95
  96 /*
  97  * Call a function on all processors
  98  */
  99 int on_each_cpu(smp_call_func_t func, void *info, int wait);
 100
 101 /*
 102  * Mark the boot cpu "online" so that it can call console drivers in
 103  * printk() and can access its per-cpu storage.
 104  */
 105 void smp_prepare_boot_cpu(void);
 106
 107 extern unsigned int setup_max_cpus;
 108 extern void __init setup_nr_cpu_ids(void);
 109 extern void __init smp_init(void);
 110
 111 #else /* !SMP */
 112
 113 static inline void smp_send_stop(void) { }
 114
 115 /*
 116  *      These macros fold the SMP functionality into a single CPU system
 117  */
 118 #define raw_smp_processor_id()                  0
 119 static inline int up_smp_call_function(smp_call_func_t func, void *info)
 120 {
 121         return 0;
 122 }
 123 #define smp_call_function(func, info, wait) \
 124                         (up_smp_call_function(func, info))
 125 #define on_each_cpu(func,info,wait)             \
 126         ({                                      \
 127                 local_irq_disable();            \
 128                 func(info);                     \
 129                 local_irq_enable();             \
 130                 0;                              \
 131         })
 132 static inline void smp_send_reschedule(int cpu) { }
 133 #define num_booting_cpus()                      1
 134 #define smp_prepare_boot_cpu()                  do {} while (0)
 135 #define smp_call_function_many(mask, func, info, wait) \
 136                         (up_smp_call_function(func, info))
 137 static inline void init_call_single_data(void) { }
 138
 139 static inline int
 140 smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
 141                       void *info, int wait)
 142 {
 143         return smp_call_function_single(0, func, info, wait);
 144 }
 145
 146 #endif /* !SMP */
 147
 148 /*
 149  * smp_processor_id(): get the current CPU ID.
 150  *
 151  * if DEBUG_PREEMPT is enabled then we check whether it is
 152  * used in a preemption-safe way. (smp_processor_id() is safe
 153  * if it's used in a preemption-off critical section, or in
 154  * a thread that is bound to the current CPU.)
 155  *
 156  * NOTE: raw_smp_processor_id() is for internal use only
 157  * (smp_processor_id() is the preferred variant), but in rare
 158  * instances it might also be used to turn off false positives
 159  * (i.e. smp_processor_id() use that the debugging code reports but
 160  * which use for some reason is legal). Don't use this to hack around
 161  * the warning message, as your code might not work under PREEMPT.
 162  */
 163 #ifdef CONFIG_DEBUG_PREEMPT
 164   extern unsigned int debug_smp_processor_id(void);
 165 # define smp_processor_id() debug_smp_processor_id()
 166 #else
 167 # define smp_processor_id() raw_smp_processor_id()
 168 #endif
 169
 170 #define get_cpu()               ({ preempt_disable(); smp_processor_id(); })
 171 #define put_cpu()               preempt_enable()
 172
 173 /*
 174  * Callback to arch code if there's nosmp or maxcpus=0 on the
 175  * boot command line:
 176  */
 177 extern void arch_disable_smp_support(void);
 178
 179 void smp_setup_processor_id(void);
 180
 181 #endif /* __LINUX_SMP_H */