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/irqflags.h>
  15
  16 extern void cpu_idle(void);
  17
  18 typedef void (*smp_call_func_t)(void *info);
  19 struct call_single_data {
  20         struct list_head list;
  21         smp_call_func_t func;
  22         void *info;
  23         u16 flags;
  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, struct task_struct *tidle);
  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 void kick_all_cpus_sync(void);
  85
  86 /*
  87  * Generic and arch helpers
  88  */
  89 #ifdef CONFIG_USE_GENERIC_SMP_HELPERS
  90 void __init call_function_init(void);
  91 void generic_smp_call_function_single_interrupt(void);
  92 #define generic_smp_call_function_interrupt \
  93         generic_smp_call_function_single_interrupt
  94 #else
  95 static inline void call_function_init(void) { }
  96 #endif
  97
  98 /*
  99  * Call a function on all processors
 100  */
 101 int on_each_cpu(smp_call_func_t func, void *info, int wait);
 102
 103 /*
 104  * Call a function on processors specified by mask, which might include
 105  * the local one.
 106  */
 107 void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
 108                 void *info, bool wait);
 109
 110 /*
 111  * Call a function on each processor for which the supplied function
 112  * cond_func returns a positive value. This may include the local
 113  * processor.
 114  */
 115 void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
 116                 smp_call_func_t func, void *info, bool wait,
 117                 gfp_t gfp_flags);
 118
 119 /*
 120  * Mark the boot cpu "online" so that it can call console drivers in
 121  * printk() and can access its per-cpu storage.
 122  */
 123 void smp_prepare_boot_cpu(void);
 124
 125 extern unsigned int setup_max_cpus;
 126 extern void __init setup_nr_cpu_ids(void);
 127 extern void __init smp_init(void);
 128
 129 #else /* !SMP */
 130
 131 static inline void smp_send_stop(void) { }
 132
 133 /*
 134  *      These macros fold the SMP functionality into a single CPU system
 135  */
 136 #define raw_smp_processor_id()                  0
 137 static inline int up_smp_call_function(smp_call_func_t func, void *info)
 138 {
 139         return 0;
 140 }
 141 #define smp_call_function(func, info, wait) \
 142                         (up_smp_call_function(func, info))
 143
 144 static inline int on_each_cpu(smp_call_func_t func, void *info, int wait)
 145 {
 146         unsigned long flags;
 147
 148         local_irq_save(flags);
 149         func(info);
 150         local_irq_restore(flags);
 151         return 0;
 152 }
 153
 154 /*
 155  * Note we still need to test the mask even for UP
 156  * because we actually can get an empty mask from
 157  * code that on SMP might call us without the local
 158  * CPU in the mask.
 159  */
 160 #define on_each_cpu_mask(mask, func, info, wait) \
 161         do {                                            \
 162                 if (cpumask_test_cpu(0, (mask))) {      \
 163                         local_irq_disable();            \
 164                         (func)(info);                   \
 165                         local_irq_enable();             \
 166                 }                                       \
 167         } while (0)
 168 /*
 169  * Preemption is disabled here to make sure the cond_func is called under the
 170  * same condtions in UP and SMP.
 171  */
 172 #define on_each_cpu_cond(cond_func, func, info, wait, gfp_flags)\
 173         do {                                                    \
 174                 void *__info = (info);                          \
 175                 preempt_disable();                              \
 176                 if ((cond_func)(0, __info)) {                   \
 177                         local_irq_disable();                    \
 178                         (func)(__info);                         \
 179                         local_irq_enable();                     \
 180                 }                                               \
 181                 preempt_enable();                               \
 182         } while (0)
 183
 184 static inline void smp_send_reschedule(int cpu) { }
 185 #define smp_prepare_boot_cpu()                  do {} while (0)
 186 #define smp_call_function_many(mask, func, info, wait) \
 187                         (up_smp_call_function(func, info))
 188 static inline void call_function_init(void) { }
 189
 190 static inline int
 191 smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
 192                       void *info, int wait)
 193 {
 194         return smp_call_function_single(0, func, info, wait);
 195 }
 196
 197 static inline void kick_all_cpus_sync(void) {  }
 198
 199 #endif /* !SMP */
 200
 201 /*
 202  * smp_processor_id(): get the current CPU ID.
 203  *
 204  * if DEBUG_PREEMPT is enabled then we check whether it is
 205  * used in a preemption-safe way. (smp_processor_id() is safe
 206  * if it's used in a preemption-off critical section, or in
 207  * a thread that is bound to the current CPU.)
 208  *
 209  * NOTE: raw_smp_processor_id() is for internal use only
 210  * (smp_processor_id() is the preferred variant), but in rare
 211  * instances it might also be used to turn off false positives
 212  * (i.e. smp_processor_id() use that the debugging code reports but
 213  * which use for some reason is legal). Don't use this to hack around
 214  * the warning message, as your code might not work under PREEMPT.
 215  */
 216 #ifdef CONFIG_DEBUG_PREEMPT
 217   extern unsigned int debug_smp_processor_id(void);
 218 # define smp_processor_id() debug_smp_processor_id()
 219 #else
 220 # define smp_processor_id() raw_smp_processor_id()
 221 #endif
 222
 223 #define get_cpu()               ({ preempt_disable(); smp_processor_id(); })
 224 #define put_cpu()               preempt_enable()
 225
 226 /*
 227  * Callback to arch code if there's nosmp or maxcpus=0 on the
 228  * boot command line:
 229  */
 230 extern void arch_disable_smp_support(void);
 231
 232 void smp_setup_processor_id(void);
 233
 234 #endif /* __LINUX_SMP_H */