linux/include/linux/smp.h
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   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
  14extern void cpu_idle(void);
  15
  16typedef void (*smp_call_func_t)(void *info);
  17struct call_single_data {
  18        struct list_head list;
  19        smp_call_func_t func;
  20        void *info;
  21        u16 flags;
  22        u16 priv;
  23};
  24
  25/* total number of cpus in this system (may exceed NR_CPUS) */
  26extern unsigned int total_cpus;
  27
  28int smp_call_function_single(int cpuid, smp_call_func_t func, void *info,
  29                             int wait);
  30
  31#ifdef CONFIG_SMP
  32
  33#include <linux/preempt.h>
  34#include <linux/kernel.h>
  35#include <linux/compiler.h>
  36#include <linux/thread_info.h>
  37#include <asm/smp.h>
  38
  39/*
  40 * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
  41 * (defined in asm header):
  42 */
  43
  44/*
  45 * stops all CPUs but the current one:
  46 */
  47extern void smp_send_stop(void);
  48
  49/*
  50 * sends a 'reschedule' event to another CPU:
  51 */
  52extern void smp_send_reschedule(int cpu);
  53
  54
  55/*
  56 * Prepare machine for booting other CPUs.
  57 */
  58extern void smp_prepare_cpus(unsigned int max_cpus);
  59
  60/*
  61 * Bring a CPU up
  62 */
  63extern int __cpu_up(unsigned int cpunum);
  64
  65/*
  66 * Final polishing of CPUs
  67 */
  68extern void smp_cpus_done(unsigned int max_cpus);
  69
  70/*
  71 * Call a function on all other processors
  72 */
  73int smp_call_function(smp_call_func_t func, void *info, int wait);
  74void smp_call_function_many(const struct cpumask *mask,
  75                            smp_call_func_t func, void *info, bool wait);
  76
  77void __smp_call_function_single(int cpuid, struct call_single_data *data,
  78                                int wait);
  79
  80int smp_call_function_any(const struct cpumask *mask,
  81                          smp_call_func_t func, void *info, int wait);
  82
  83/*
  84 * Generic and arch helpers
  85 */
  86#ifdef CONFIG_USE_GENERIC_SMP_HELPERS
  87void generic_smp_call_function_single_interrupt(void);
  88void generic_smp_call_function_interrupt(void);
  89void ipi_call_lock(void);
  90void ipi_call_unlock(void);
  91void ipi_call_lock_irq(void);
  92void ipi_call_unlock_irq(void);
  93#endif
  94
  95/*
  96 * Call a function on all processors
  97 */
  98int on_each_cpu(smp_call_func_t func, void *info, int wait);
  99
 100#define MSG_ALL_BUT_SELF        0x8000  /* Assume <32768 CPU's */
 101#define MSG_ALL                 0x8001
 102
 103#define MSG_INVALIDATE_TLB      0x0001  /* Remote processor TLB invalidate */
 104#define MSG_STOP_CPU            0x0002  /* Sent to shut down slave CPU's
 105                                         * when rebooting
 106                                         */
 107#define MSG_RESCHEDULE          0x0003  /* Reschedule request from master CPU*/
 108#define MSG_CALL_FUNCTION       0x0004  /* Call function on all other CPUs */
 109
 110/*
 111 * Mark the boot cpu "online" so that it can call console drivers in
 112 * printk() and can access its per-cpu storage.
 113 */
 114void smp_prepare_boot_cpu(void);
 115
 116extern unsigned int setup_max_cpus;
 117
 118#else /* !SMP */
 119
 120static inline void smp_send_stop(void) { }
 121
 122/*
 123 *      These macros fold the SMP functionality into a single CPU system
 124 */
 125#define raw_smp_processor_id()                  0
 126static inline int up_smp_call_function(smp_call_func_t func, void *info)
 127{
 128        return 0;
 129}
 130#define smp_call_function(func, info, wait) \
 131                        (up_smp_call_function(func, info))
 132#define on_each_cpu(func,info,wait)             \
 133        ({                                      \
 134                local_irq_disable();            \
 135                func(info);                     \
 136                local_irq_enable();             \
 137                0;                              \
 138        })
 139static inline void smp_send_reschedule(int cpu) { }
 140#define num_booting_cpus()                      1
 141#define smp_prepare_boot_cpu()                  do {} while (0)
 142#define smp_call_function_many(mask, func, info, wait) \
 143                        (up_smp_call_function(func, info))
 144static inline void init_call_single_data(void) { }
 145
 146static inline int
 147smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
 148                      void *info, int wait)
 149{
 150        return smp_call_function_single(0, func, info, wait);
 151}
 152
 153#endif /* !SMP */
 154
 155/*
 156 * smp_processor_id(): get the current CPU ID.
 157 *
 158 * if DEBUG_PREEMPT is enabled then we check whether it is
 159 * used in a preemption-safe way. (smp_processor_id() is safe
 160 * if it's used in a preemption-off critical section, or in
 161 * a thread that is bound to the current CPU.)
 162 *
 163 * NOTE: raw_smp_processor_id() is for internal use only
 164 * (smp_processor_id() is the preferred variant), but in rare
 165 * instances it might also be used to turn off false positives
 166 * (i.e. smp_processor_id() use that the debugging code reports but
 167 * which use for some reason is legal). Don't use this to hack around
 168 * the warning message, as your code might not work under PREEMPT.
 169 */
 170#ifdef CONFIG_DEBUG_PREEMPT
 171  extern unsigned int debug_smp_processor_id(void);
 172# define smp_processor_id() debug_smp_processor_id()
 173#else
 174# define smp_processor_id() raw_smp_processor_id()
 175#endif
 176
 177#define get_cpu()               ({ preempt_disable(); smp_processor_id(); })
 178#define put_cpu()               preempt_enable()
 179
 180/*
 181 * Callback to arch code if there's nosmp or maxcpus=0 on the
 182 * boot command line:
 183 */
 184extern void arch_disable_smp_support(void);
 185
 186void smp_setup_processor_id(void);
 187
 188#endif /* __LINUX_SMP_H */
 189