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