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 #define generic_smp_call_function_interrupt \ 93 generic_smp_call_function_single_interrupt 94 #else 95 static inline void call_function_init(void) { } 96 #endif 97 98 /* 99 * Call a function on all processors 100 */ 101 int on_each_cpu(smp_call_func_t func, void *info, int wait); 102 103 /* 104 * Call a function on processors specified by mask, which might include 105 * the local one. 106 */ 107 void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func, 108 void *info, bool wait); 109 110 /* 111 * Call a function on each processor for which the supplied function 112 * cond_func returns a positive value. This may include the local 113 * processor. 114 */ 115 void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info), 116 smp_call_func_t func, void *info, bool wait, 117 gfp_t gfp_flags); 118 119 /* 120 * Mark the boot cpu "online" so that it can call console drivers in 121 * printk() and can access its per-cpu storage. 122 */ 123 void smp_prepare_boot_cpu(void); 124 125 extern unsigned int setup_max_cpus; 126 extern void __init setup_nr_cpu_ids(void); 127 extern void __init smp_init(void); 128 129 #else /* !SMP */ 130 131 static inline void smp_send_stop(void) { } 132 133 /* 134 * These macros fold the SMP functionality into a single CPU system 135 */ 136 #define raw_smp_processor_id() 0 137 static inline int up_smp_call_function(smp_call_func_t func, void *info) 138 { 139 return 0; 140 } 141 #define smp_call_function(func, info, wait) \ 142 (up_smp_call_function(func, info)) 143 #define on_each_cpu(func,info,wait) \ 144 ({ \ 145 local_irq_disable(); \ 146 func(info); \ 147 local_irq_enable(); \ 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