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