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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __LINUX_SMP_H
3#define __LINUX_SMP_H
4
5/*
6 * Generic SMP support
7 * Alan Cox. <alan@redhat.com>
8 */
9
10#include <linux/errno.h>
11#include <linux/types.h>
12#include <linux/list.h>
13#include <linux/cpumask.h>
14#include <linux/init.h>
15#include <linux/smp_types.h>
16
17typedef void (*smp_call_func_t)(void *info);
18typedef bool (*smp_cond_func_t)(int cpu, void *info);
19
20/*
21 * structure shares (partial) layout with struct irq_work
22 */
23struct __call_single_data {
24 union {
25 struct __call_single_node node;
26 struct {
27 struct llist_node llist;
28 unsigned int flags;
29#ifdef CONFIG_64BIT
30 u16 src, dst;
31#endif
32 };
33 };
34 smp_call_func_t func;
35 void *info;
36};
37
38/* Use __aligned() to avoid to use 2 cache lines for 1 csd */
39typedef struct __call_single_data call_single_data_t
40 __aligned(sizeof(struct __call_single_data));
41
42/*
43 * Enqueue a llist_node on the call_single_queue; be very careful, read
44 * flush_smp_call_function_queue() in detail.
45 */
46extern void __smp_call_single_queue(int cpu, struct llist_node *node);
47
48/* total number of cpus in this system (may exceed NR_CPUS) */
49extern unsigned int total_cpus;
50
51int smp_call_function_single(int cpuid, smp_call_func_t func, void *info,
52 int wait);
53
54/*
55 * Call a function on all processors
56 */
57void on_each_cpu(smp_call_func_t func, void *info, int wait);
58
59/*
60 * Call a function on processors specified by mask, which might include
61 * the local one.
62 */
63void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
64 void *info, bool wait);
65
66/*
67 * Call a function on each processor for which the supplied function
68 * cond_func returns a positive value. This may include the local
69 * processor.
70 */
71void on_each_cpu_cond(smp_cond_func_t cond_func, smp_call_func_t func,
72 void *info, bool wait);
73
74void on_each_cpu_cond_mask(smp_cond_func_t cond_func, smp_call_func_t func,
75 void *info, bool wait, const struct cpumask *mask);
76
77int smp_call_function_single_async(int cpu, call_single_data_t *csd);
78
79#ifdef CONFIG_SMP
80
81#include <linux/preempt.h>
82#include <linux/kernel.h>
83#include <linux/compiler.h>
84#include <linux/thread_info.h>
85#include <asm/smp.h>
86
87/*
88 * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
89 * (defined in asm header):
90 */
91
92/*
93 * stops all CPUs but the current one:
94 */
95extern void smp_send_stop(void);
96
97/*
98 * sends a 'reschedule' event to another CPU:
99 */
100extern void smp_send_reschedule(int cpu);
101
102
103/*
104 * Prepare machine for booting other CPUs.
105 */
106extern void smp_prepare_cpus(unsigned int max_cpus);
107
108/*
109 * Bring a CPU up
110 */
111extern int __cpu_up(unsigned int cpunum, struct task_struct *tidle);
112
113/*
114 * Final polishing of CPUs
115 */
116extern void smp_cpus_done(unsigned int max_cpus);
117
118/*
119 * Call a function on all other processors
120 */
121void smp_call_function(smp_call_func_t func, void *info, int wait);
122void smp_call_function_many(const struct cpumask *mask,
123 smp_call_func_t func, void *info, bool wait);
124
125int smp_call_function_any(const struct cpumask *mask,
126 smp_call_func_t func, void *info, int wait);
127
128void kick_all_cpus_sync(void);
129void wake_up_all_idle_cpus(void);
130
131/*
132 * Generic and arch helpers
133 */
134void __init call_function_init(void);
135void generic_smp_call_function_single_interrupt(void);
136#define generic_smp_call_function_interrupt \
137 generic_smp_call_function_single_interrupt
138
139/*
140 * Mark the boot cpu "online" so that it can call console drivers in
141 * printk() and can access its per-cpu storage.
142 */
143void smp_prepare_boot_cpu(void);
144
145extern unsigned int setup_max_cpus;
146extern void __init setup_nr_cpu_ids(void);
147extern void __init smp_init(void);
148
149extern int __boot_cpu_id;
150
151static inline int get_boot_cpu_id(void)
152{
153 return __boot_cpu_id;
154}
155
156#else /* !SMP */
157
158static inline void smp_send_stop(void) { }
159
160/*
161 * These macros fold the SMP functionality into a single CPU system
162 */
163#define raw_smp_processor_id() 0
164static inline void up_smp_call_function(smp_call_func_t func, void *info)
165{
166}
167#define smp_call_function(func, info, wait) \
168 (up_smp_call_function(func, info))
169
170static inline void smp_send_reschedule(int cpu) { }
171#define smp_prepare_boot_cpu() do {} while (0)
172#define smp_call_function_many(mask, func, info, wait) \
173 (up_smp_call_function(func, info))
174static inline void call_function_init(void) { }
175
176static inline int
177smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
178 void *info, int wait)
179{
180 return smp_call_function_single(0, func, info, wait);
181}
182
183static inline void kick_all_cpus_sync(void) { }
184static inline void wake_up_all_idle_cpus(void) { }
185
186#ifdef CONFIG_UP_LATE_INIT
187extern void __init up_late_init(void);
188static inline void smp_init(void) { up_late_init(); }
189#else
190static inline void smp_init(void) { }
191#endif
192
193static inline int get_boot_cpu_id(void)
194{
195 return 0;
196}
197
198#endif /* !SMP */
199
200/**
201 * raw_processor_id() - get the current (unstable) CPU id
202 *
203 * For then you know what you are doing and need an unstable
204 * CPU id.
205 */
206
207/**
208 * smp_processor_id() - get the current (stable) CPU id
209 *
210 * This is the normal accessor to the CPU id and should be used
211 * whenever possible.
212 *
213 * The CPU id is stable when:
214 *
215 * - IRQs are disabled;
216 * - preemption is disabled;
217 * - the task is CPU affine.
218 *
219 * When CONFIG_DEBUG_PREEMPT; we verify these assumption and WARN
220 * when smp_processor_id() is used when the CPU id is not stable.
221 */
222
223/*
224 * Allow the architecture to differentiate between a stable and unstable read.
225 * For example, x86 uses an IRQ-safe asm-volatile read for the unstable but a
226 * regular asm read for the stable.
227 */
228#ifndef __smp_processor_id
229#define __smp_processor_id(x) raw_smp_processor_id(x)
230#endif
231
232#ifdef CONFIG_DEBUG_PREEMPT
233 extern unsigned int debug_smp_processor_id(void);
234# define smp_processor_id() debug_smp_processor_id()
235#else
236# define smp_processor_id() __smp_processor_id()
237#endif
238
239#define get_cpu() ({ preempt_disable(); __smp_processor_id(); })
240#define put_cpu() preempt_enable()
241
242/*
243 * Callback to arch code if there's nosmp or maxcpus=0 on the
244 * boot command line:
245 */
246extern void arch_disable_smp_support(void);
247
248extern void arch_thaw_secondary_cpus_begin(void);
249extern void arch_thaw_secondary_cpus_end(void);
250
251void smp_setup_processor_id(void);
252
253int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par,
254 bool phys);
255
256/* SMP core functions */
257int smpcfd_prepare_cpu(unsigned int cpu);
258int smpcfd_dead_cpu(unsigned int cpu);
259int smpcfd_dying_cpu(unsigned int cpu);
260
261#endif /* __LINUX_SMP_H */