include/linux/smp.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __LINUX_SMP_H
   3 #define __LINUX_SMP_H
   4
   5 /*
   6  *      Generic SMP support
   7  *              Alan Cox. <alan@redhat.com>
   8  */
   9
  10 #include <linux/errno.h>
  11 #include <linux/types.h>
  12 #include <linux/list.h>
  13 #include <linux/cpumask.h>
  14 #include <linux/init.h>
  15 #include <linux/llist.h>
  16
  17 typedef void (*smp_call_func_t)(void *info);
  18 struct __call_single_data {
  19         struct llist_node llist;
  20         smp_call_func_t func;
  21         void *info;
  22         unsigned int flags;
  23 };
  24
  25 /* Use __aligned() to avoid to use 2 cache lines for 1 csd */
  26 typedef struct __call_single_data call_single_data_t
  27         __aligned(sizeof(struct __call_single_data));
  28
  29 /* total number of cpus in this system (may exceed NR_CPUS) */
  30 extern unsigned int total_cpus;
  31
  32 int smp_call_function_single(int cpuid, smp_call_func_t func, void *info,
  33                              int wait);
  34
  35 /*
  36  * Call a function on all processors
  37  */
  38 int on_each_cpu(smp_call_func_t func, void *info, int wait);
  39
  40 /*
  41  * Call a function on processors specified by mask, which might include
  42  * the local one.
  43  */
  44 void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
  45                 void *info, bool wait);
  46
  47 /*
  48  * Call a function on each processor for which the supplied function
  49  * cond_func returns a positive value. This may include the local
  50  * processor.
  51  */
  52 void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
  53                 smp_call_func_t func, void *info, bool wait,
  54                 gfp_t gfp_flags);
  55
  56 int smp_call_function_single_async(int cpu, call_single_data_t *csd);
  57
  58 #ifdef CONFIG_SMP
  59
  60 #include <linux/preempt.h>
  61 #include <linux/kernel.h>
  62 #include <linux/compiler.h>
  63 #include <linux/thread_info.h>
  64 #include <asm/smp.h>
  65
  66 /*
  67  * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
  68  * (defined in asm header):
  69  */
  70
  71 /*
  72  * stops all CPUs but the current one:
  73  */
  74 extern void smp_send_stop(void);
  75
  76 /*
  77  * sends a 'reschedule' event to another CPU:
  78  */
  79 extern void smp_send_reschedule(int cpu);
  80
  81
  82 /*
  83  * Prepare machine for booting other CPUs.
  84  */
  85 extern void smp_prepare_cpus(unsigned int max_cpus);
  86
  87 /*
  88  * Bring a CPU up
  89  */
  90 extern int __cpu_up(unsigned int cpunum, struct task_struct *tidle);
  91
  92 /*
  93  * Final polishing of CPUs
  94  */
  95 extern void smp_cpus_done(unsigned int max_cpus);
  96
  97 /*
  98  * Call a function on all other processors
  99  */
 100 int smp_call_function(smp_call_func_t func, void *info, int wait);
 101 void smp_call_function_many(const struct cpumask *mask,
 102                             smp_call_func_t func, void *info, bool wait);
 103
 104 int smp_call_function_any(const struct cpumask *mask,
 105                           smp_call_func_t func, void *info, int wait);
 106
 107 void kick_all_cpus_sync(void);
 108 void wake_up_all_idle_cpus(void);
 109
 110 /*
 111  * Generic and arch helpers
 112  */
 113 void __init call_function_init(void);
 114 void generic_smp_call_function_single_interrupt(void);
 115 #define generic_smp_call_function_interrupt \
 116         generic_smp_call_function_single_interrupt
 117
 118 /*
 119  * Mark the boot cpu "online" so that it can call console drivers in
 120  * printk() and can access its per-cpu storage.
 121  */
 122 void smp_prepare_boot_cpu(void);
 123
 124 extern unsigned int setup_max_cpus;
 125 extern void __init setup_nr_cpu_ids(void);
 126 extern void __init smp_init(void);
 127
 128 extern int __boot_cpu_id;
 129
 130 static inline int get_boot_cpu_id(void)
 131 {
 132         return __boot_cpu_id;
 133 }
 134
 135 #else /* !SMP */
 136
 137 static inline void smp_send_stop(void) { }
 138
 139 /*
 140  *      These macros fold the SMP functionality into a single CPU system
 141  */
 142 #define raw_smp_processor_id()                  0
 143 static inline int up_smp_call_function(smp_call_func_t func, void *info)
 144 {
 145         return 0;
 146 }
 147 #define smp_call_function(func, info, wait) \
 148                         (up_smp_call_function(func, info))
 149
 150 static inline void smp_send_reschedule(int cpu) { }
 151 #define smp_prepare_boot_cpu()                  do {} while (0)
 152 #define smp_call_function_many(mask, func, info, wait) \
 153                         (up_smp_call_function(func, info))
 154 static inline void call_function_init(void) { }
 155
 156 static inline int
 157 smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
 158                       void *info, int wait)
 159 {
 160         return smp_call_function_single(0, func, info, wait);
 161 }
 162
 163 static inline void kick_all_cpus_sync(void) {  }
 164 static inline void wake_up_all_idle_cpus(void) {  }
 165
 166 #ifdef CONFIG_UP_LATE_INIT
 167 extern void __init up_late_init(void);
 168 static inline void smp_init(void) { up_late_init(); }
 169 #else
 170 static inline void smp_init(void) { }
 171 #endif
 172
 173 static inline int get_boot_cpu_id(void)
 174 {
 175         return 0;
 176 }
 177
 178 #endif /* !SMP */
 179
 180 /*
 181  * smp_processor_id(): get the current CPU ID.
 182  *
 183  * if DEBUG_PREEMPT is enabled then we check whether it is
 184  * used in a preemption-safe way. (smp_processor_id() is safe
 185  * if it's used in a preemption-off critical section, or in
 186  * a thread that is bound to the current CPU.)
 187  *
 188  * NOTE: raw_smp_processor_id() is for internal use only
 189  * (smp_processor_id() is the preferred variant), but in rare
 190  * instances it might also be used to turn off false positives
 191  * (i.e. smp_processor_id() use that the debugging code reports but
 192  * which use for some reason is legal). Don't use this to hack around
 193  * the warning message, as your code might not work under PREEMPT.
 194  */
 195 #ifdef CONFIG_DEBUG_PREEMPT
 196   extern unsigned int debug_smp_processor_id(void);
 197 # define smp_processor_id() debug_smp_processor_id()
 198 #else
 199 # define smp_processor_id() raw_smp_processor_id()
 200 #endif
 201
 202 #define get_cpu()               ({ preempt_disable(); smp_processor_id(); })
 203 #define put_cpu()               preempt_enable()
 204
 205 /*
 206  * Callback to arch code if there's nosmp or maxcpus=0 on the
 207  * boot command line:
 208  */
 209 extern void arch_disable_smp_support(void);
 210
 211 extern void arch_enable_nonboot_cpus_begin(void);
 212 extern void arch_enable_nonboot_cpus_end(void);
 213
 214 void smp_setup_processor_id(void);
 215
 216 int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par,
 217                     bool phys);
 218
 219 /* SMP core functions */
 220 int smpcfd_prepare_cpu(unsigned int cpu);
 221 int smpcfd_dead_cpu(unsigned int cpu);
 222 int smpcfd_dying_cpu(unsigned int cpu);
 223
 224 #endif /* __LINUX_SMP_H */