1 #ifndef __LINUX_SMP_H 2 #define __LINUX_SMP_H 3 4 /* 5 * Generic SMP support 6 * Alan Cox. <alan@redhat.com> 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); 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 /* 85 * Generic and arch helpers 86 */ 87 #ifdef CONFIG_USE_GENERIC_SMP_HELPERS 88 void __init call_function_init(void); 89 void generic_smp_call_function_single_interrupt(void); 90 void generic_smp_call_function_interrupt(void); 91 void ipi_call_lock(void); 92 void ipi_call_unlock(void); 93 void ipi_call_lock_irq(void); 94 void ipi_call_unlock_irq(void); 95 #else call_function_init(void)96 static inline void call_function_init(void) { } 97 #endif 98 99 /* 100 * Call a function on all processors 101 */ 102 int on_each_cpu(smp_call_func_t func, void *info, int wait); 103 104 /* 105 * Call a function on processors specified by mask, which might include 106 * the local one. 107 */ 108 void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func, 109 void *info, bool wait); 110 111 /* 112 * Call a function on each processor for which the supplied function 113 * cond_func returns a positive value. This may include the local 114 * processor. 115 */ 116 void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info), 117 smp_call_func_t func, void *info, bool wait, 118 gfp_t gfp_flags); 119 120 /* 121 * Mark the boot cpu "online" so that it can call console drivers in 122 * printk() and can access its per-cpu storage. 123 */ 124 void smp_prepare_boot_cpu(void); 125 126 extern unsigned int setup_max_cpus; 127 extern void __init setup_nr_cpu_ids(void); 128 extern void __init smp_init(void); 129 130 #else /* !SMP */ 131 smp_send_stop(void)132 static inline void smp_send_stop(void) { } 133 134 /* 135 * These macros fold the SMP functionality into a single CPU system 136 */ 137 #define raw_smp_processor_id() 0 up_smp_call_function(smp_call_func_t func,void * info)138 static inline int up_smp_call_function(smp_call_func_t func, void *info) 139 { 140 return 0; 141 } 142 #define smp_call_function(func, info, wait) \ 143 (up_smp_call_function(func, info)) 144 #define on_each_cpu(func,info,wait) \ 145 ({ \ 146 local_irq_disable(); \ 147 func(info); \ 148 local_irq_enable(); \ 149 0; \ 150 }) 151 /* 152 * Note we still need to test the mask even for UP 153 * because we actually can get an empty mask from 154 * code that on SMP might call us without the local 155 * CPU in the mask. 156 */ 157 #define on_each_cpu_mask(mask, func, info, wait) \ 158 do { \ 159 if (cpumask_test_cpu(0, (mask))) { \ 160 local_irq_disable(); \ 161 (func)(info); \ 162 local_irq_enable(); \ 163 } \ 164 } while (0) 165 /* 166 * Preemption is disabled here to make sure the cond_func is called under the 167 * same condtions in UP and SMP. 168 */ 169 #define on_each_cpu_cond(cond_func, func, info, wait, gfp_flags)\ 170 do { \ 171 void *__info = (info); \ 172 preempt_disable(); \ 173 if ((cond_func)(0, __info)) { \ 174 local_irq_disable(); \ 175 (func)(__info); \ 176 local_irq_enable(); \ 177 } \ 178 preempt_enable(); \ 179 } while (0) 180 smp_send_reschedule(int cpu)181 static inline void smp_send_reschedule(int cpu) { } 182 #define num_booting_cpus() 1 183 #define smp_prepare_boot_cpu() do {} while (0) 184 #define smp_call_function_many(mask, func, info, wait) \ 185 (up_smp_call_function(func, info)) call_function_init(void)186 static inline void call_function_init(void) { } 187 188 static inline int smp_call_function_any(const struct cpumask * mask,smp_call_func_t func,void * info,int wait)189 smp_call_function_any(const struct cpumask *mask, smp_call_func_t func, 190 void *info, int wait) 191 { 192 return smp_call_function_single(0, func, info, wait); 193 } 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