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. <[email protected]> 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/smp_types.h> 16 17 typedef void (*smp_call_func_t)(void *info); 18 typedef bool (*smp_cond_func_t)(int cpu, void *info); 19 20 /* 21 * structure shares (partial) layout with struct irq_work 22 */ 23 struct __call_single_data { 24 union { 25 struct __call_single_node node; 26 struct { 27 struct llist_node llist; 28 unsigned int flags; 29 #ifdef CONFIG_64BIT 30 u16 src, dst; 31 #endif 32 }; 33 }; 34 smp_call_func_t func; 35 void *info; 36 }; 37 38 /* Use __aligned() to avoid to use 2 cache lines for 1 csd */ 39 typedef struct __call_single_data call_single_data_t 40 __aligned(sizeof(struct __call_single_data)); 41 42 /* 43 * Enqueue a llist_node on the call_single_queue; be very careful, read 44 * flush_smp_call_function_queue() in detail. 45 */ 46 extern void __smp_call_single_queue(int cpu, struct llist_node *node); 47 48 /* total number of cpus in this system (may exceed NR_CPUS) */ 49 extern unsigned int total_cpus; 50 51 int smp_call_function_single(int cpuid, smp_call_func_t func, void *info, 52 int wait); 53 54 /* 55 * Call a function on all processors 56 */ 57 void on_each_cpu(smp_call_func_t func, void *info, int wait); 58 59 /* 60 * Call a function on processors specified by mask, which might include 61 * the local one. 62 */ 63 void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func, 64 void *info, bool wait); 65 66 /* 67 * Call a function on each processor for which the supplied function 68 * cond_func returns a positive value. This may include the local 69 * processor. 70 */ 71 void on_each_cpu_cond(smp_cond_func_t cond_func, smp_call_func_t func, 72 void *info, bool wait); 73 74 void on_each_cpu_cond_mask(smp_cond_func_t cond_func, smp_call_func_t func, 75 void *info, bool wait, const struct cpumask *mask); 76 77 int smp_call_function_single_async(int cpu, call_single_data_t *csd); 78 79 #ifdef CONFIG_SMP 80 81 #include <linux/preempt.h> 82 #include <linux/kernel.h> 83 #include <linux/compiler.h> 84 #include <linux/thread_info.h> 85 #include <asm/smp.h> 86 87 /* 88 * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc. 89 * (defined in asm header): 90 */ 91 92 /* 93 * stops all CPUs but the current one: 94 */ 95 extern void smp_send_stop(void); 96 97 /* 98 * sends a 'reschedule' event to another CPU: 99 */ 100 extern void smp_send_reschedule(int cpu); 101 102 103 /* 104 * Prepare machine for booting other CPUs. 105 */ 106 extern void smp_prepare_cpus(unsigned int max_cpus); 107 108 /* 109 * Bring a CPU up 110 */ 111 extern int __cpu_up(unsigned int cpunum, struct task_struct *tidle); 112 113 /* 114 * Final polishing of CPUs 115 */ 116 extern void smp_cpus_done(unsigned int max_cpus); 117 118 /* 119 * Call a function on all other processors 120 */ 121 void smp_call_function(smp_call_func_t func, void *info, int wait); 122 void smp_call_function_many(const struct cpumask *mask, 123 smp_call_func_t func, void *info, bool wait); 124 125 int smp_call_function_any(const struct cpumask *mask, 126 smp_call_func_t func, void *info, int wait); 127 128 void kick_all_cpus_sync(void); 129 void wake_up_all_idle_cpus(void); 130 131 /* 132 * Generic and arch helpers 133 */ 134 void __init call_function_init(void); 135 void generic_smp_call_function_single_interrupt(void); 136 #define generic_smp_call_function_interrupt \ 137 generic_smp_call_function_single_interrupt 138 139 /* 140 * Mark the boot cpu "online" so that it can call console drivers in 141 * printk() and can access its per-cpu storage. 142 */ 143 void smp_prepare_boot_cpu(void); 144 145 extern unsigned int setup_max_cpus; 146 extern void __init setup_nr_cpu_ids(void); 147 extern void __init smp_init(void); 148 149 extern int __boot_cpu_id; 150 151 static inline int get_boot_cpu_id(void) 152 { 153 return __boot_cpu_id; 154 } 155 156 #else /* !SMP */ 157 158 static inline void smp_send_stop(void) { } 159 160 /* 161 * These macros fold the SMP functionality into a single CPU system 162 */ 163 #define raw_smp_processor_id() 0 164 static inline void up_smp_call_function(smp_call_func_t func, void *info) 165 { 166 } 167 #define smp_call_function(func, info, wait) \ 168 (up_smp_call_function(func, info)) 169 170 static inline void smp_send_reschedule(int cpu) { } 171 #define smp_prepare_boot_cpu() do {} while (0) 172 #define smp_call_function_many(mask, func, info, wait) \ 173 (up_smp_call_function(func, info)) 174 static inline void call_function_init(void) { } 175 176 static inline int 177 smp_call_function_any(const struct cpumask *mask, smp_call_func_t func, 178 void *info, int wait) 179 { 180 return smp_call_function_single(0, func, info, wait); 181 } 182 183 static inline void kick_all_cpus_sync(void) { } 184 static inline void wake_up_all_idle_cpus(void) { } 185 186 #ifdef CONFIG_UP_LATE_INIT 187 extern void __init up_late_init(void); 188 static inline void smp_init(void) { up_late_init(); } 189 #else 190 static inline void smp_init(void) { } 191 #endif 192 193 static inline int get_boot_cpu_id(void) 194 { 195 return 0; 196 } 197 198 #endif /* !SMP */ 199 200 /** 201 * raw_processor_id() - get the current (unstable) CPU id 202 * 203 * For then you know what you are doing and need an unstable 204 * CPU id. 205 */ 206 207 /** 208 * smp_processor_id() - get the current (stable) CPU id 209 * 210 * This is the normal accessor to the CPU id and should be used 211 * whenever possible. 212 * 213 * The CPU id is stable when: 214 * 215 * - IRQs are disabled; 216 * - preemption is disabled; 217 * - the task is CPU affine. 218 * 219 * When CONFIG_DEBUG_PREEMPT; we verify these assumption and WARN 220 * when smp_processor_id() is used when the CPU id is not stable. 221 */ 222 223 /* 224 * Allow the architecture to differentiate between a stable and unstable read. 225 * For example, x86 uses an IRQ-safe asm-volatile read for the unstable but a 226 * regular asm read for the stable. 227 */ 228 #ifndef __smp_processor_id 229 #define __smp_processor_id(x) raw_smp_processor_id(x) 230 #endif 231 232 #ifdef CONFIG_DEBUG_PREEMPT 233 extern unsigned int debug_smp_processor_id(void); 234 # define smp_processor_id() debug_smp_processor_id() 235 #else 236 # define smp_processor_id() __smp_processor_id() 237 #endif 238 239 #define get_cpu() ({ preempt_disable(); __smp_processor_id(); }) 240 #define put_cpu() preempt_enable() 241 242 /* 243 * Callback to arch code if there's nosmp or maxcpus=0 on the 244 * boot command line: 245 */ 246 extern void arch_disable_smp_support(void); 247 248 extern void arch_thaw_secondary_cpus_begin(void); 249 extern void arch_thaw_secondary_cpus_end(void); 250 251 void smp_setup_processor_id(void); 252 253 int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par, 254 bool phys); 255 256 /* SMP core functions */ 257 int smpcfd_prepare_cpu(unsigned int cpu); 258 int smpcfd_dead_cpu(unsigned int cpu); 259 int smpcfd_dying_cpu(unsigned int cpu); 260 261 #endif /* __LINUX_SMP_H */ 262