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/llist.h>
  15
  16 typedef void (*smp_call_func_t)(void *info);
  17 struct call_single_data {
  18         struct llist_node llist;
  19         smp_call_func_t func;
  20         void *info;
  21         unsigned int flags;
  22 };
  23
  24 /* total number of cpus in this system (may exceed NR_CPUS) */
  25 extern unsigned int total_cpus;
  26
  27 int smp_call_function_single(int cpuid, smp_call_func_t func, void *info,
  28                              int wait);
  29
  30 /*
  31  * Call a function on all processors
  32  */
  33 int on_each_cpu(smp_call_func_t func, void *info, int wait);
  34
  35 /*
  36  * Call a function on processors specified by mask, which might include
  37  * the local one.
  38  */
  39 void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
  40                 void *info, bool wait);
  41
  42 /*
  43  * Call a function on each processor for which the supplied function
  44  * cond_func returns a positive value. This may include the local
  45  * processor.
  46  */
  47 void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
  48                 smp_call_func_t func, void *info, bool wait,
  49                 gfp_t gfp_flags);
  50
  51 int smp_call_function_single_async(int cpu, struct call_single_data *csd);
  52
  53 #ifdef CONFIG_X86
  54 /* indicate usage of IBRS to control execution speculation */
  55 extern int use_ibrs;
  56 extern u32 sysctl_ibrs_enabled;
  57 extern struct mutex spec_ctrl_mutex;
  58 #define ibrs_supported          (use_ibrs & 0x2)
  59 #define ibrs_disabled           (use_ibrs & 0x4)
  60 static inline void set_ibrs_inuse(void)
  61 {
  62         if (ibrs_supported)
  63                 use_ibrs |= 0x1;
  64 }
  65 static inline void clear_ibrs_inuse(void)
  66 {
  67         use_ibrs &= ~0x1;
  68 }
  69 static inline int check_ibrs_inuse(void)
  70 {
  71         if (use_ibrs & 0x1)
  72                 return 1;
  73         else
  74                 /* rmb to prevent wrong speculation for security */
  75                 rmb();
  76         return 0;
  77 }
  78 static inline void set_ibrs_supported(void)
  79 {
  80         use_ibrs |= 0x2;
  81         if (!ibrs_disabled)
  82                 set_ibrs_inuse();
  83 }
  84 static inline void set_ibrs_disabled(void)
  85 {
  86         use_ibrs |= 0x4;
  87         if (check_ibrs_inuse())
  88                 clear_ibrs_inuse();
  89 }
  90 static inline void clear_ibrs_disabled(void)
  91 {
  92         use_ibrs &= ~0x4;
  93         set_ibrs_inuse();
  94 }
  95 #define ibrs_inuse              (check_ibrs_inuse())
  96
  97 /* indicate usage of IBPB to control execution speculation */
  98 extern int use_ibpb;
  99 extern u32 sysctl_ibpb_enabled;
 100 #define ibpb_supported          (use_ibpb & 0x2)
 101 #define ibpb_disabled           (use_ibpb & 0x4)
 102 static inline void set_ibpb_inuse(void)
 103 {
 104         if (ibpb_supported)
 105                 use_ibpb |= 0x1;
 106 }
 107 static inline void clear_ibpb_inuse(void)
 108 {
 109         use_ibpb &= ~0x1;
 110 }
 111 static inline int check_ibpb_inuse(void)
 112 {
 113         if (use_ibpb & 0x1)
 114                 return 1;
 115         else
 116                 /* rmb to prevent wrong speculation for security */
 117                 rmb();
 118         return 0;
 119 }
 120 static inline void set_ibpb_supported(void)
 121 {
 122         use_ibpb |= 0x2;
 123         if (!ibpb_disabled)
 124                 set_ibpb_inuse();
 125 }
 126 static inline void set_ibpb_disabled(void)
 127 {
 128         use_ibpb |= 0x4;
 129         if (check_ibpb_inuse())
 130                 clear_ibpb_inuse();
 131 }
 132 static inline void clear_ibpb_disabled(void)
 133 {
 134         use_ibpb &= ~0x4;
 135         set_ibpb_inuse();
 136 }
 137 #define ibpb_inuse              (check_ibpb_inuse())
 138 #endif
 139
 140 #ifdef CONFIG_SMP
 141
 142 #include <linux/preempt.h>
 143 #include <linux/kernel.h>
 144 #include <linux/compiler.h>
 145 #include <linux/thread_info.h>
 146 #include <asm/smp.h>
 147
 148 /*
 149  * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
 150  * (defined in asm header):
 151  */
 152
 153 /*
 154  * stops all CPUs but the current one:
 155  */
 156 extern void smp_send_stop(void);
 157
 158 /*
 159  * sends a 'reschedule' event to another CPU:
 160  */
 161 extern void smp_send_reschedule(int cpu);
 162
 163
 164 /*
 165  * Prepare machine for booting other CPUs.
 166  */
 167 extern void smp_prepare_cpus(unsigned int max_cpus);
 168
 169 /*
 170  * Bring a CPU up
 171  */
 172 extern int __cpu_up(unsigned int cpunum, struct task_struct *tidle);
 173
 174 /*
 175  * Final polishing of CPUs
 176  */
 177 extern void smp_cpus_done(unsigned int max_cpus);
 178
 179 /*
 180  * Call a function on all other processors
 181  */
 182 int smp_call_function(smp_call_func_t func, void *info, int wait);
 183 void smp_call_function_many(const struct cpumask *mask,
 184                             smp_call_func_t func, void *info, bool wait);
 185
 186 int smp_call_function_any(const struct cpumask *mask,
 187                           smp_call_func_t func, void *info, int wait);
 188
 189 void kick_all_cpus_sync(void);
 190 void wake_up_all_idle_cpus(void);
 191
 192 /*
 193  * Generic and arch helpers
 194  */
 195 void __init call_function_init(void);
 196 void generic_smp_call_function_single_interrupt(void);
 197 #define generic_smp_call_function_interrupt \
 198         generic_smp_call_function_single_interrupt
 199
 200 /*
 201  * Mark the boot cpu "online" so that it can call console drivers in
 202  * printk() and can access its per-cpu storage.
 203  */
 204 void smp_prepare_boot_cpu(void);
 205
 206 extern unsigned int setup_max_cpus;
 207 extern void __init setup_nr_cpu_ids(void);
 208 extern void __init smp_init(void);
 209
 210 extern int __boot_cpu_id;
 211
 212 static inline int get_boot_cpu_id(void)
 213 {
 214         return __boot_cpu_id;
 215 }
 216
 217 #else /* !SMP */
 218
 219 static inline void smp_send_stop(void) { }
 220
 221 /*
 222  *      These macros fold the SMP functionality into a single CPU system
 223  */
 224 #define raw_smp_processor_id()                  0
 225 static inline int up_smp_call_function(smp_call_func_t func, void *info)
 226 {
 227         return 0;
 228 }
 229 #define smp_call_function(func, info, wait) \
 230                         (up_smp_call_function(func, info))
 231
 232 static inline void smp_send_reschedule(int cpu) { }
 233 #define smp_prepare_boot_cpu()                  do {} while (0)
 234 #define smp_call_function_many(mask, func, info, wait) \
 235                         (up_smp_call_function(func, info))
 236 static inline void call_function_init(void) { }
 237
 238 static inline int
 239 smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
 240                       void *info, int wait)
 241 {
 242         return smp_call_function_single(0, func, info, wait);
 243 }
 244
 245 static inline void kick_all_cpus_sync(void) {  }
 246 static inline void wake_up_all_idle_cpus(void) {  }
 247
 248 #ifdef CONFIG_UP_LATE_INIT
 249 extern void __init up_late_init(void);
 250 static inline void smp_init(void) { up_late_init(); }
 251 #else
 252 static inline void smp_init(void) { }
 253 #endif
 254
 255 static inline int get_boot_cpu_id(void)
 256 {
 257         return 0;
 258 }
 259
 260 #endif /* !SMP */
 261
 262 /*
 263  * smp_processor_id(): get the current CPU ID.
 264  *
 265  * if DEBUG_PREEMPT is enabled then we check whether it is
 266  * used in a preemption-safe way. (smp_processor_id() is safe
 267  * if it's used in a preemption-off critical section, or in
 268  * a thread that is bound to the current CPU.)
 269  *
 270  * NOTE: raw_smp_processor_id() is for internal use only
 271  * (smp_processor_id() is the preferred variant), but in rare
 272  * instances it might also be used to turn off false positives
 273  * (i.e. smp_processor_id() use that the debugging code reports but
 274  * which use for some reason is legal). Don't use this to hack around
 275  * the warning message, as your code might not work under PREEMPT.
 276  */
 277 #ifdef CONFIG_DEBUG_PREEMPT
 278   extern unsigned int debug_smp_processor_id(void);
 279 # define smp_processor_id() debug_smp_processor_id()
 280 #else
 281 # define smp_processor_id() raw_smp_processor_id()
 282 #endif
 283
 284 #define get_cpu()               ({ preempt_disable(); smp_processor_id(); })
 285 #define put_cpu()               preempt_enable()
 286
 287 /*
 288  * Callback to arch code if there's nosmp or maxcpus=0 on the
 289  * boot command line:
 290  */
 291 extern void arch_disable_smp_support(void);
 292
 293 extern void arch_enable_nonboot_cpus_begin(void);
 294 extern void arch_enable_nonboot_cpus_end(void);
 295
 296 void smp_setup_processor_id(void);
 297
 298 int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par,
 299                     bool phys);
 300
 301 /* SMP core functions */
 302 int smpcfd_prepare_cpu(unsigned int cpu);
 303 int smpcfd_dead_cpu(unsigned int cpu);
 304 int smpcfd_dying_cpu(unsigned int cpu);
 305
 306 #endif /* __LINUX_SMP_H */