1 #ifndef __LINUX_SMP_H 2 #define __LINUX_SMP_H 3 4 /* 5 * Generic SMP support 6 * Alan Cox. <[email protected]> 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 15 extern void cpu_idle(void); 16 17 typedef void (*smp_call_func_t)(void *info); 18 struct call_single_data { 19 struct list_head list; 20 smp_call_func_t func; 21 void *info; 22 u16 flags; 23 }; 24 25 /* total number of cpus in this system (may exceed NR_CPUS) */ 26 extern unsigned int total_cpus; 27 28 int smp_call_function_single(int cpuid, smp_call_func_t func, void *info, 29 int wait); 30 31 #ifdef CONFIG_SMP 32 33 #include <linux/preempt.h> 34 #include <linux/kernel.h> 35 #include <linux/compiler.h> 36 #include <linux/thread_info.h> 37 #include <asm/smp.h> 38 39 /* 40 * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc. 41 * (defined in asm header): 42 */ 43 44 /* 45 * stops all CPUs but the current one: 46 */ 47 extern void smp_send_stop(void); 48 49 /* 50 * sends a 'reschedule' event to another CPU: 51 */ 52 extern void smp_send_reschedule(int cpu); 53 54 55 /* 56 * Prepare machine for booting other CPUs. 57 */ 58 extern void smp_prepare_cpus(unsigned int max_cpus); 59 60 /* 61 * Bring a CPU up 62 */ 63 extern int __cpu_up(unsigned int cpunum, struct task_struct *tidle); 64 65 /* 66 * Final polishing of CPUs 67 */ 68 extern void smp_cpus_done(unsigned int max_cpus); 69 70 /* 71 * Call a function on all other processors 72 */ 73 int smp_call_function(smp_call_func_t func, void *info, int wait); 74 void smp_call_function_many(const struct cpumask *mask, 75 smp_call_func_t func, void *info, bool wait); 76 77 void __smp_call_function_single(int cpuid, struct call_single_data *data, 78 int wait); 79 80 int smp_call_function_any(const struct cpumask *mask, 81 smp_call_func_t func, void *info, int wait); 82 83 void kick_all_cpus_sync(void); 84 85 /* 86 * Generic and arch helpers 87 */ 88 #ifdef CONFIG_USE_GENERIC_SMP_HELPERS 89 void __init call_function_init(void); 90 void generic_smp_call_function_single_interrupt(void); 91 #define generic_smp_call_function_interrupt \ 92 generic_smp_call_function_single_interrupt 93 #else 94 static inline void call_function_init(void) { } 95 #endif 96 97 /* 98 * Call a function on all processors 99 */ 100 int on_each_cpu(smp_call_func_t func, void *info, int wait); 101 102 /* 103 * Call a function on processors specified by mask, which might include 104 * the local one. 105 */ 106 void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func, 107 void *info, bool wait); 108 109 /* 110 * Call a function on each processor for which the supplied function 111 * cond_func returns a positive value. This may include the local 112 * processor. 113 */ 114 void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info), 115 smp_call_func_t func, void *info, bool wait, 116 gfp_t gfp_flags); 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 #else /* !SMP */ 129 130 static inline void smp_send_stop(void) { } 131 132 /* 133 * These macros fold the SMP functionality into a single CPU system 134 */ 135 #define raw_smp_processor_id() 0 136 static inline int up_smp_call_function(smp_call_func_t func, void *info) 137 { 138 return 0; 139 } 140 #define smp_call_function(func, info, wait) \ 141 (up_smp_call_function(func, info)) 142 #define on_each_cpu(func, info, wait) \ 143 ({ \ 144 unsigned long __flags; \ 145 local_irq_save(__flags); \ 146 func(info); \ 147 local_irq_restore(__flags); \ 148 0; \ 149 }) 150 /* 151 * Note we still need to test the mask even for UP 152 * because we actually can get an empty mask from 153 * code that on SMP might call us without the local 154 * CPU in the mask. 155 */ 156 #define on_each_cpu_mask(mask, func, info, wait) \ 157 do { \ 158 if (cpumask_test_cpu(0, (mask))) { \ 159 local_irq_disable(); \ 160 (func)(info); \ 161 local_irq_enable(); \ 162 } \ 163 } while (0) 164 /* 165 * Preemption is disabled here to make sure the cond_func is called under the 166 * same condtions in UP and SMP. 167 */ 168 #define on_each_cpu_cond(cond_func, func, info, wait, gfp_flags)\ 169 do { \ 170 void *__info = (info); \ 171 preempt_disable(); \ 172 if ((cond_func)(0, __info)) { \ 173 local_irq_disable(); \ 174 (func)(__info); \ 175 local_irq_enable(); \ 176 } \ 177 preempt_enable(); \ 178 } while (0) 179 180 static inline void smp_send_reschedule(int cpu) { } 181 #define smp_prepare_boot_cpu() do {} while (0) 182 #define smp_call_function_many(mask, func, info, wait) \ 183 (up_smp_call_function(func, info)) 184 static inline void call_function_init(void) { } 185 186 static inline int 187 smp_call_function_any(const struct cpumask *mask, smp_call_func_t func, 188 void *info, int wait) 189 { 190 return smp_call_function_single(0, func, info, wait); 191 } 192 193 static inline void kick_all_cpus_sync(void) { } 194 195 #endif /* !SMP */ 196 197 /* 198 * smp_processor_id(): get the current CPU ID. 199 * 200 * if DEBUG_PREEMPT is enabled then we check whether it is 201 * used in a preemption-safe way. (smp_processor_id() is safe 202 * if it's used in a preemption-off critical section, or in 203 * a thread that is bound to the current CPU.) 204 * 205 * NOTE: raw_smp_processor_id() is for internal use only 206 * (smp_processor_id() is the preferred variant), but in rare 207 * instances it might also be used to turn off false positives 208 * (i.e. smp_processor_id() use that the debugging code reports but 209 * which use for some reason is legal). Don't use this to hack around 210 * the warning message, as your code might not work under PREEMPT. 211 */ 212 #ifdef CONFIG_DEBUG_PREEMPT 213 extern unsigned int debug_smp_processor_id(void); 214 # define smp_processor_id() debug_smp_processor_id() 215 #else 216 # define smp_processor_id() raw_smp_processor_id() 217 #endif 218 219 #define get_cpu() ({ preempt_disable(); smp_processor_id(); }) 220 #define put_cpu() preempt_enable() 221 222 /* 223 * Callback to arch code if there's nosmp or maxcpus=0 on the 224 * boot command line: 225 */ 226 extern void arch_disable_smp_support(void); 227 228 void smp_setup_processor_id(void); 229 230 #endif /* __LINUX_SMP_H */ 231