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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#include <linux/llist.h>
15
16extern void cpu_idle(void);
17
18typedef void (*smp_call_func_t)(void *info);
19struct call_single_data {
20 struct llist_node llist;
21 smp_call_func_t func;
22 void *info;
23 u16 flags;
24};
25
26/* total number of cpus in this system (may exceed NR_CPUS) */
27extern unsigned int total_cpus;
28
29int smp_call_function_single(int cpuid, smp_call_func_t func, void *info,
30 int wait);
31
32/*
33 * Call a function on all processors
34 */
35int on_each_cpu(smp_call_func_t func, void *info, int wait);
36
37/*
38 * Call a function on processors specified by mask, which might include
39 * the local one.
40 */
41void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
42 void *info, bool wait);
43
44/*
45 * Call a function on each processor for which the supplied function
46 * cond_func returns a positive value. This may include the local
47 * processor.
48 */
49void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
50 smp_call_func_t func, void *info, bool wait,
51 gfp_t gfp_flags);
52
53int smp_call_function_single_async(int cpu, struct call_single_data *csd);
54
55#ifdef CONFIG_SMP
56
57#include <linux/preempt.h>
58#include <linux/kernel.h>
59#include <linux/compiler.h>
60#include <linux/thread_info.h>
61#include <asm/smp.h>
62
63/*
64 * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
65 * (defined in asm header):
66 */
67
68/*
69 * stops all CPUs but the current one:
70 */
71extern void smp_send_stop(void);
72
73/*
74 * sends a 'reschedule' event to another CPU:
75 */
76extern void smp_send_reschedule(int cpu);
77
78
79/*
80 * Prepare machine for booting other CPUs.
81 */
82extern void smp_prepare_cpus(unsigned int max_cpus);
83
84/*
85 * Bring a CPU up
86 */
87extern int __cpu_up(unsigned int cpunum, struct task_struct *tidle);
88
89/*
90 * Final polishing of CPUs
91 */
92extern void smp_cpus_done(unsigned int max_cpus);
93
94/*
95 * Call a function on all other processors
96 */
97int smp_call_function(smp_call_func_t func, void *info, int wait);
98void smp_call_function_many(const struct cpumask *mask,
99 smp_call_func_t func, void *info, bool wait);
100
101int smp_call_function_any(const struct cpumask *mask,
102 smp_call_func_t func, void *info, int wait);
103
104void kick_all_cpus_sync(void);
105
106/*
107 * Generic and arch helpers
108 */
109void __init call_function_init(void);
110void generic_smp_call_function_single_interrupt(void);
111#define generic_smp_call_function_interrupt \
112 generic_smp_call_function_single_interrupt
113
114/*
115 * Mark the boot cpu "online" so that it can call console drivers in
116 * printk() and can access its per-cpu storage.
117 */
118void smp_prepare_boot_cpu(void);
119
120extern unsigned int setup_max_cpus;
121extern void __init setup_nr_cpu_ids(void);
122extern void __init smp_init(void);
123
124#else /* !SMP */
125
126static inline void smp_send_stop(void) { }
127
128/*
129 * These macros fold the SMP functionality into a single CPU system
130 */
131#define raw_smp_processor_id() 0
132static inline int up_smp_call_function(smp_call_func_t func, void *info)
133{
134 return 0;
135}
136#define smp_call_function(func, info, wait) \
137 (up_smp_call_function(func, info))
138
139static inline void smp_send_reschedule(int cpu) { }
140#define smp_prepare_boot_cpu() do {} while (0)
141#define smp_call_function_many(mask, func, info, wait) \
142 (up_smp_call_function(func, info))
143static inline void call_function_init(void) { }
144
145static inline int
146smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
147 void *info, int wait)
148{
149 return smp_call_function_single(0, func, info, wait);
150}
151
152static inline void kick_all_cpus_sync(void) { }
153
154#endif /* !SMP */
155
156/*
157 * smp_processor_id(): get the current CPU ID.
158 *
159 * if DEBUG_PREEMPT is enabled then we check whether it is
160 * used in a preemption-safe way. (smp_processor_id() is safe
161 * if it's used in a preemption-off critical section, or in
162 * a thread that is bound to the current CPU.)
163 *
164 * NOTE: raw_smp_processor_id() is for internal use only
165 * (smp_processor_id() is the preferred variant), but in rare
166 * instances it might also be used to turn off false positives
167 * (i.e. smp_processor_id() use that the debugging code reports but
168 * which use for some reason is legal). Don't use this to hack around
169 * the warning message, as your code might not work under PREEMPT.
170 */
171#ifdef CONFIG_DEBUG_PREEMPT
172 extern unsigned int debug_smp_processor_id(void);
173# define smp_processor_id() debug_smp_processor_id()
174#else
175# define smp_processor_id() raw_smp_processor_id()
176#endif
177
178#define get_cpu() ({ preempt_disable(); smp_processor_id(); })
179#define put_cpu() preempt_enable()
180
181/*
182 * Callback to arch code if there's nosmp or maxcpus=0 on the
183 * boot command line:
184 */
185extern void arch_disable_smp_support(void);
186
187extern void arch_enable_nonboot_cpus_begin(void);
188extern void arch_enable_nonboot_cpus_end(void);
189
190void smp_setup_processor_id(void);
191
192#endif /* __LINUX_SMP_H */