summaryrefslogtreecommitdiff
path: root/include/linux/smp.h
blob: 9f13966d3d92d36a57faf3926a71bfa923a78a8d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_SMP_H
#define __LINUX_SMP_H

/*
 *	Generic SMP support
 *		Alan Cox. <alan@redhat.com>
 */

#include <linux/errno.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/cpumask.h>
#include <linux/init.h>
#include <linux/smp_types.h>

typedef void (*smp_call_func_t)(void *info);
typedef bool (*smp_cond_func_t)(int cpu, void *info);

/*
 * structure shares (partial) layout with struct irq_work
 */
struct __call_single_data {
	union {
		struct __call_single_node node;
		struct {
			struct llist_node llist;
			unsigned int flags;
#ifdef CONFIG_64BIT
			u16 src, dst;
#endif
		};
	};
	smp_call_func_t func;
	void *info;
};

/* Use __aligned() to avoid to use 2 cache lines for 1 csd */
typedef struct __call_single_data call_single_data_t
	__aligned(sizeof(struct __call_single_data));

/*
 * Enqueue a llist_node on the call_single_queue; be very careful, read
 * flush_smp_call_function_queue() in detail.
 */
extern void __smp_call_single_queue(int cpu, struct llist_node *node);

/* total number of cpus in this system (may exceed NR_CPUS) */
extern unsigned int total_cpus;

int smp_call_function_single(int cpuid, smp_call_func_t func, void *info,
			     int wait);

/*
 * Call a function on all processors
 */
void on_each_cpu(smp_call_func_t func, void *info, int wait);

/*
 * Call a function on processors specified by mask, which might include
 * the local one.
 */
void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
		void *info, bool wait);

/*
 * Call a function on each processor for which the supplied function
 * cond_func returns a positive value. This may include the local
 * processor.
 */
void on_each_cpu_cond(smp_cond_func_t cond_func, smp_call_func_t func,
		      void *info, bool wait);

void on_each_cpu_cond_mask(smp_cond_func_t cond_func, smp_call_func_t func,
			   void *info, bool wait, const struct cpumask *mask);

int smp_call_function_single_async(int cpu, call_single_data_t *csd);

#ifdef CONFIG_SMP

#include <linux/preempt.h>
#include <linux/kernel.h>
#include <linux/compiler.h>
#include <linux/thread_info.h>
#include <asm/smp.h>

/*
 * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
 * (defined in asm header):
 */

/*
 * stops all CPUs but the current one:
 */
extern void smp_send_stop(void);

/*
 * sends a 'reschedule' event to another CPU:
 */
extern void smp_send_reschedule(int cpu);


/*
 * Prepare machine for booting other CPUs.
 */
extern void smp_prepare_cpus(unsigned int max_cpus);

/*
 * Bring a CPU up
 */
extern int __cpu_up(unsigned int cpunum, struct task_struct *tidle);

/*
 * Final polishing of CPUs
 */
extern void smp_cpus_done(unsigned int max_cpus);

/*
 * Call a function on all other processors
 */
void smp_call_function(smp_call_func_t func, void *info, int wait);
void smp_call_function_many(const struct cpumask *mask,
			    smp_call_func_t func, void *info, bool wait);

int smp_call_function_any(const struct cpumask *mask,
			  smp_call_func_t func, void *info, int wait);

void kick_all_cpus_sync(void);
void wake_up_all_idle_cpus(void);

/*
 * Generic and arch helpers
 */
void __init call_function_init(void);
void generic_smp_call_function_single_interrupt(void);
#define generic_smp_call_function_interrupt \
	generic_smp_call_function_single_interrupt

/*
 * Mark the boot cpu "online" so that it can call console drivers in
 * printk() and can access its per-cpu storage.
 */
void smp_prepare_boot_cpu(void);

extern unsigned int setup_max_cpus;
extern void __init setup_nr_cpu_ids(void);
extern void __init smp_init(void);

extern int __boot_cpu_id;

static inline int get_boot_cpu_id(void)
{
	return __boot_cpu_id;
}

#else /* !SMP */

static inline void smp_send_stop(void) { }

/*
 *	These macros fold the SMP functionality into a single CPU system
 */
#define raw_smp_processor_id()			0
static inline void up_smp_call_function(smp_call_func_t func, void *info)
{
}
#define smp_call_function(func, info, wait) \
			(up_smp_call_function(func, info))

static inline void smp_send_reschedule(int cpu) { }
#define smp_prepare_boot_cpu()			do {} while (0)
#define smp_call_function_many(mask, func, info, wait) \
			(up_smp_call_function(func, info))
static inline void call_function_init(void) { }

static inline int
smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
		      void *info, int wait)
{
	return smp_call_function_single(0, func, info, wait);
}

static inline void kick_all_cpus_sync(void) {  }
static inline void wake_up_all_idle_cpus(void) {  }

#ifdef CONFIG_UP_LATE_INIT
extern void __init up_late_init(void);
static inline void smp_init(void) { up_late_init(); }
#else
static inline void smp_init(void) { }
#endif

static inline int get_boot_cpu_id(void)
{
	return 0;
}

#endif /* !SMP */

/**
 * raw_processor_id() - get the current (unstable) CPU id
 *
 * For then you know what you are doing and need an unstable
 * CPU id.
 */

/**
 * smp_processor_id() - get the current (stable) CPU id
 *
 * This is the normal accessor to the CPU id and should be used
 * whenever possible.
 *
 * The CPU id is stable when:
 *
 *  - IRQs are disabled;
 *  - preemption is disabled;
 *  - the task is CPU affine.
 *
 * When CONFIG_DEBUG_PREEMPT; we verify these assumption and WARN
 * when smp_processor_id() is used when the CPU id is not stable.
 */

/*
 * Allow the architecture to differentiate between a stable and unstable read.
 * For example, x86 uses an IRQ-safe asm-volatile read for the unstable but a
 * regular asm read for the stable.
 */
#ifndef __smp_processor_id
#define __smp_processor_id(x) raw_smp_processor_id(x)
#endif

#ifdef CONFIG_DEBUG_PREEMPT
  extern unsigned int debug_smp_processor_id(void);
# define smp_processor_id() debug_smp_processor_id()
#else
# define smp_processor_id() __smp_processor_id()
#endif

#define get_cpu()		({ preempt_disable(); __smp_processor_id(); })
#define put_cpu()		preempt_enable()

/*
 * Callback to arch code if there's nosmp or maxcpus=0 on the
 * boot command line:
 */
extern void arch_disable_smp_support(void);

extern void arch_thaw_secondary_cpus_begin(void);
extern void arch_thaw_secondary_cpus_end(void);

void smp_setup_processor_id(void);

int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par,
		    bool phys);

/* SMP core functions */
int smpcfd_prepare_cpu(unsigned int cpu);
int smpcfd_dead_cpu(unsigned int cpu);
int smpcfd_dying_cpu(unsigned int cpu);

#endif /* __LINUX_SMP_H */