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