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 void on_each_cpu_cond_mask(bool (*cond_func)(int cpu, void *info), 57 smp_call_func_t func, void *info, bool wait, 58 gfp_t gfp_flags, const struct cpumask *mask); 59 60 int smp_call_function_single_async(int cpu, call_single_data_t *csd); 61 62 #ifdef CONFIG_SMP 63 64 #include <linux/preempt.h> 65 #include <linux/kernel.h> 66 #include <linux/compiler.h> 67 #include <linux/thread_info.h> 68 #include <asm/smp.h> 69 70 /* 71 * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc. 72 * (defined in asm header): 73 */ 74 75 /* 76 * stops all CPUs but the current one: 77 */ 78 extern void smp_send_stop(void); 79 80 /* 81 * sends a 'reschedule' event to another CPU: 82 */ 83 extern void smp_send_reschedule(int cpu); 84 85 86 /* 87 * Prepare machine for booting other CPUs. 88 */ 89 extern void smp_prepare_cpus(unsigned int max_cpus); 90 91 /* 92 * Bring a CPU up 93 */ 94 extern int __cpu_up(unsigned int cpunum, struct task_struct *tidle); 95 96 /* 97 * Final polishing of CPUs 98 */ 99 extern void smp_cpus_done(unsigned int max_cpus); 100 101 /* 102 * Call a function on all other processors 103 */ 104 int smp_call_function(smp_call_func_t func, void *info, int wait); 105 void smp_call_function_many(const struct cpumask *mask, 106 smp_call_func_t func, void *info, bool wait); 107 108 int smp_call_function_any(const struct cpumask *mask, 109 smp_call_func_t func, void *info, int wait); 110 111 void kick_all_cpus_sync(void); 112 void wake_up_all_idle_cpus(void); 113 114 /* 115 * Generic and arch helpers 116 */ 117 void __init call_function_init(void); 118 void generic_smp_call_function_single_interrupt(void); 119 #define generic_smp_call_function_interrupt \ 120 generic_smp_call_function_single_interrupt 121 122 /* 123 * Mark the boot cpu "online" so that it can call console drivers in 124 * printk() and can access its per-cpu storage. 125 */ 126 void smp_prepare_boot_cpu(void); 127 128 extern unsigned int setup_max_cpus; 129 extern void __init setup_nr_cpu_ids(void); 130 extern void __init smp_init(void); 131 132 extern int __boot_cpu_id; 133 134 static inline int get_boot_cpu_id(void) 135 { 136 return __boot_cpu_id; 137 } 138 139 #else /* !SMP */ 140 141 static inline void smp_send_stop(void) { } 142 143 /* 144 * These macros fold the SMP functionality into a single CPU system 145 */ 146 #define raw_smp_processor_id() 0 147 static inline int up_smp_call_function(smp_call_func_t func, void *info) 148 { 149 return 0; 150 } 151 #define smp_call_function(func, info, wait) \ 152 (up_smp_call_function(func, info)) 153 154 static inline void smp_send_reschedule(int cpu) { } 155 #define smp_prepare_boot_cpu() do {} while (0) 156 #define smp_call_function_many(mask, func, info, wait) \ 157 (up_smp_call_function(func, info)) 158 static inline void call_function_init(void) { } 159 160 static inline int 161 smp_call_function_any(const struct cpumask *mask, smp_call_func_t func, 162 void *info, int wait) 163 { 164 return smp_call_function_single(0, func, info, wait); 165 } 166 167 static inline void kick_all_cpus_sync(void) { } 168 static inline void wake_up_all_idle_cpus(void) { } 169 170 #ifdef CONFIG_UP_LATE_INIT 171 extern void __init up_late_init(void); 172 static inline void smp_init(void) { up_late_init(); } 173 #else 174 static inline void smp_init(void) { } 175 #endif 176 177 static inline int get_boot_cpu_id(void) 178 { 179 return 0; 180 } 181 182 #endif /* !SMP */ 183 184 /* 185 * smp_processor_id(): get the current CPU ID. 186 * 187 * if DEBUG_PREEMPT is enabled then we check whether it is 188 * used in a preemption-safe way. (smp_processor_id() is safe 189 * if it's used in a preemption-off critical section, or in 190 * a thread that is bound to the current CPU.) 191 * 192 * NOTE: raw_smp_processor_id() is for internal use only 193 * (smp_processor_id() is the preferred variant), but in rare 194 * instances it might also be used to turn off false positives 195 * (i.e. smp_processor_id() use that the debugging code reports but 196 * which use for some reason is legal). Don't use this to hack around 197 * the warning message, as your code might not work under PREEMPT. 198 */ 199 #ifdef CONFIG_DEBUG_PREEMPT 200 extern unsigned int debug_smp_processor_id(void); 201 # define smp_processor_id() debug_smp_processor_id() 202 #else 203 # define smp_processor_id() raw_smp_processor_id() 204 #endif 205 206 #define get_cpu() ({ preempt_disable(); smp_processor_id(); }) 207 #define put_cpu() preempt_enable() 208 209 /* 210 * Callback to arch code if there's nosmp or maxcpus=0 on the 211 * boot command line: 212 */ 213 extern void arch_disable_smp_support(void); 214 215 extern void arch_enable_nonboot_cpus_begin(void); 216 extern void arch_enable_nonboot_cpus_end(void); 217 218 void smp_setup_processor_id(void); 219 220 int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par, 221 bool phys); 222 223 /* SMP core functions */ 224 int smpcfd_prepare_cpu(unsigned int cpu); 225 int smpcfd_dead_cpu(unsigned int cpu); 226 int smpcfd_dying_cpu(unsigned int cpu); 227 228 #endif /* __LINUX_SMP_H */ 229