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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 union {
21 struct list_head list;
22 struct llist_node llist;
23 };
24 smp_call_func_t func;
25 void *info;
26 u16 flags;
27};
28
29/* total number of cpus in this system (may exceed NR_CPUS) */
30extern unsigned int total_cpus;
31
32int smp_call_function_single(int cpuid, smp_call_func_t func, void *info,
33 int wait);
34
35/*
36 * Call a function on all processors
37 */
38int on_each_cpu(smp_call_func_t func, void *info, int wait);
39
40/*
41 * Call a function on processors specified by mask, which might include
42 * the local one.
43 */
44void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
45 void *info, bool wait);
46
47/*
48 * Call a function on each processor for which the supplied function
49 * cond_func returns a positive value. This may include the local
50 * processor.
51 */
52void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
53 smp_call_func_t func, void *info, bool wait,
54 gfp_t gfp_flags);
55
56void __smp_call_function_single(int cpuid, struct call_single_data *data,
57 int wait);
58
59#ifdef CONFIG_SMP
60
61#include <linux/preempt.h>
62#include <linux/kernel.h>
63#include <linux/compiler.h>
64#include <linux/thread_info.h>
65#include <asm/smp.h>
66
67/*
68 * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
69 * (defined in asm header):
70 */
71
72/*
73 * stops all CPUs but the current one:
74 */
75extern void smp_send_stop(void);
76
77/*
78 * sends a 'reschedule' event to another CPU:
79 */
80extern void smp_send_reschedule(int cpu);
81
82
83/*
84 * Prepare machine for booting other CPUs.
85 */
86extern void smp_prepare_cpus(unsigned int max_cpus);
87
88/*
89 * Bring a CPU up
90 */
91extern int __cpu_up(unsigned int cpunum, struct task_struct *tidle);
92
93/*
94 * Final polishing of CPUs
95 */
96extern void smp_cpus_done(unsigned int max_cpus);
97
98/*
99 * Call a function on all other processors
100 */
101int smp_call_function(smp_call_func_t func, void *info, int wait);
102void smp_call_function_many(const struct cpumask *mask,
103 smp_call_func_t func, void *info, bool wait);
104
105int smp_call_function_any(const struct cpumask *mask,
106 smp_call_func_t func, void *info, int wait);
107
108void kick_all_cpus_sync(void);
109
110/*
111 * Generic and arch helpers
112 */
113void __init call_function_init(void);
114void generic_smp_call_function_single_interrupt(void);
115#define generic_smp_call_function_interrupt \
116 generic_smp_call_function_single_interrupt
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 */
122void smp_prepare_boot_cpu(void);
123
124extern unsigned int setup_max_cpus;
125extern void __init setup_nr_cpu_ids(void);
126extern void __init smp_init(void);
127
128#else /* !SMP */
129
130static 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
136static 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
143static inline void smp_send_reschedule(int cpu) { }
144#define smp_prepare_boot_cpu() do {} while (0)
145#define smp_call_function_many(mask, func, info, wait) \
146 (up_smp_call_function(func, info))
147static inline void call_function_init(void) { }
148
149static inline int
150smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
151 void *info, int wait)
152{
153 return smp_call_function_single(0, func, info, wait);
154}
155
156static inline void kick_all_cpus_sync(void) { }
157
158#endif /* !SMP */
159
160/*
161 * smp_processor_id(): get the current CPU ID.
162 *
163 * if DEBUG_PREEMPT is enabled then we check whether it is
164 * used in a preemption-safe way. (smp_processor_id() is safe
165 * if it's used in a preemption-off critical section, or in
166 * a thread that is bound to the current CPU.)
167 *
168 * NOTE: raw_smp_processor_id() is for internal use only
169 * (smp_processor_id() is the preferred variant), but in rare
170 * instances it might also be used to turn off false positives
171 * (i.e. smp_processor_id() use that the debugging code reports but
172 * which use for some reason is legal). Don't use this to hack around
173 * the warning message, as your code might not work under PREEMPT.
174 */
175#ifdef CONFIG_DEBUG_PREEMPT
176 extern unsigned int debug_smp_processor_id(void);
177# define smp_processor_id() debug_smp_processor_id()
178#else
179# define smp_processor_id() raw_smp_processor_id()
180#endif
181
182#define get_cpu() ({ preempt_disable(); smp_processor_id(); })
183#define put_cpu() preempt_enable()
184
185/*
186 * Callback to arch code if there's nosmp or maxcpus=0 on the
187 * boot command line:
188 */
189extern void arch_disable_smp_support(void);
190
191extern void arch_enable_nonboot_cpus_begin(void);
192extern void arch_enable_nonboot_cpus_end(void);
193
194void smp_setup_processor_id(void);
195
196#endif /* __LINUX_SMP_H */