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 __init call_function_init(void);
  89 void generic_smp_call_function_single_interrupt(void);
  90 void generic_smp_call_function_interrupt(void);
  91 void ipi_call_lock(void);
  92 void ipi_call_unlock(void);
  93 void ipi_call_lock_irq(void);
  94 void ipi_call_unlock_irq(void);
  95 #else
  96 static inline void call_function_init(void) { }
  97 #endif
  98
  99 /*
 100  * Call a function on all processors
 101  */
 102 int on_each_cpu(smp_call_func_t func, void *info, int wait);
 103
 104 /*
 105  * Mark the boot cpu "online" so that it can call console drivers in
 106  * printk() and can access its per-cpu storage.
 107  */
 108 void smp_prepare_boot_cpu(void);
 109
 110 extern unsigned int setup_max_cpus;
 111 extern void __init setup_nr_cpu_ids(void);
 112 extern void __init smp_init(void);
 113
 114 #else /* !SMP */
 115
 116 static inline void smp_send_stop(void) { }
 117
 118 /*
 119  *      These macros fold the SMP functionality into a single CPU system
 120  */
 121 #define raw_smp_processor_id()                  0
 122 static inline int up_smp_call_function(smp_call_func_t func, void *info)
 123 {
 124         return 0;
 125 }
 126 #define smp_call_function(func, info, wait) \
 127                         (up_smp_call_function(func, info))
 128 #define on_each_cpu(func,info,wait)             \
 129         ({                                      \
 130                 local_irq_disable();            \
 131                 func(info);                     \
 132                 local_irq_enable();             \
 133                 0;                              \
 134         })
 135 static inline void smp_send_reschedule(int cpu) { }
 136 #define num_booting_cpus()                      1
 137 #define smp_prepare_boot_cpu()                  do {} while (0)
 138 #define smp_call_function_many(mask, func, info, wait) \
 139                         (up_smp_call_function(func, info))
 140 static inline void call_function_init(void) { }
 141
 142 static inline int
 143 smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
 144                       void *info, int wait)
 145 {
 146         return smp_call_function_single(0, func, info, wait);
 147 }
 148
 149 #endif /* !SMP */
 150
 151 /*
 152  * smp_processor_id(): get the current CPU ID.
 153  *
 154  * if DEBUG_PREEMPT is enabled then we check whether it is
 155  * used in a preemption-safe way. (smp_processor_id() is safe
 156  * if it's used in a preemption-off critical section, or in
 157  * a thread that is bound to the current CPU.)
 158  *
 159  * NOTE: raw_smp_processor_id() is for internal use only
 160  * (smp_processor_id() is the preferred variant), but in rare
 161  * instances it might also be used to turn off false positives
 162  * (i.e. smp_processor_id() use that the debugging code reports but
 163  * which use for some reason is legal). Don't use this to hack around
 164  * the warning message, as your code might not work under PREEMPT.
 165  */
 166 #ifdef CONFIG_DEBUG_PREEMPT
 167   extern unsigned int debug_smp_processor_id(void);
 168 # define smp_processor_id() debug_smp_processor_id()
 169 #else
 170 # define smp_processor_id() raw_smp_processor_id()
 171 #endif
 172
 173 #define get_cpu()               ({ preempt_disable(); smp_processor_id(); })
 174 #define put_cpu()               preempt_enable()
 175
 176 /*
 177  * Callback to arch code if there's nosmp or maxcpus=0 on the
 178  * boot command line:
 179  */
 180 extern void arch_disable_smp_support(void);
 181
 182 void smp_setup_processor_id(void);
 183
 184 #endif /* __LINUX_SMP_H */