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/llist.h>
16
17typedef void (*smp_call_func_t)(void *info);
18struct __call_single_data {
19 struct llist_node llist;
20 smp_call_func_t func;
21 void *info;
22 unsigned int flags;
23};
24
25/* Use __aligned() to avoid to use 2 cache lines for 1 csd */
26typedef struct __call_single_data call_single_data_t
27 __aligned(sizeof(struct __call_single_data));
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 on_each_cpu_cond_mask(bool (*cond_func)(int cpu, void *info),
57 smp_call_func_t func, void *info, bool wait,
58 gfp_t gfp_flags, const struct cpumask *mask);
59
60int smp_call_function_single_async(int cpu, call_single_data_t *csd);
61
62#ifdef CONFIG_SMP
63
64#include <linux/preempt.h>
65#include <linux/kernel.h>
66#include <linux/compiler.h>
67#include <linux/thread_info.h>
68#include <asm/smp.h>
69
70/*
71 * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
72 * (defined in asm header):
73 */
74
75/*
76 * stops all CPUs but the current one:
77 */
78extern void smp_send_stop(void);
79
80/*
81 * sends a 'reschedule' event to another CPU:
82 */
83extern void smp_send_reschedule(int cpu);
84
85
86/*
87 * Prepare machine for booting other CPUs.
88 */
89extern void smp_prepare_cpus(unsigned int max_cpus);
90
91/*
92 * Bring a CPU up
93 */
94extern int __cpu_up(unsigned int cpunum, struct task_struct *tidle);
95
96/*
97 * Final polishing of CPUs
98 */
99extern void smp_cpus_done(unsigned int max_cpus);
100
101/*
102 * Call a function on all other processors
103 */
104int smp_call_function(smp_call_func_t func, void *info, int wait);
105void smp_call_function_many(const struct cpumask *mask,
106 smp_call_func_t func, void *info, bool wait);
107
108int smp_call_function_any(const struct cpumask *mask,
109 smp_call_func_t func, void *info, int wait);
110
111void kick_all_cpus_sync(void);
112void wake_up_all_idle_cpus(void);
113
114/*
115 * Generic and arch helpers
116 */
117void __init call_function_init(void);
118void generic_smp_call_function_single_interrupt(void);
119#define generic_smp_call_function_interrupt \
120 generic_smp_call_function_single_interrupt
121
122/*
123 * Mark the boot cpu "online" so that it can call console drivers in
124 * printk() and can access its per-cpu storage.
125 */
126void smp_prepare_boot_cpu(void);
127
128extern unsigned int setup_max_cpus;
129extern void __init setup_nr_cpu_ids(void);
130extern void __init smp_init(void);
131
132extern int __boot_cpu_id;
133
134static inline int get_boot_cpu_id(void)
135{
136 return __boot_cpu_id;
137}
138
139#else /* !SMP */
140
141static inline void smp_send_stop(void) { }
142
143/*
144 * These macros fold the SMP functionality into a single CPU system
145 */
146#define raw_smp_processor_id() 0
147static inline int up_smp_call_function(smp_call_func_t func, void *info)
148{
149 return 0;
150}
151#define smp_call_function(func, info, wait) \
152 (up_smp_call_function(func, info))
153
154static inline void smp_send_reschedule(int cpu) { }
155#define smp_prepare_boot_cpu() do {} while (0)
156#define smp_call_function_many(mask, func, info, wait) \
157 (up_smp_call_function(func, info))
158static inline void call_function_init(void) { }
159
160static inline int
161smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
162 void *info, int wait)
163{
164 return smp_call_function_single(0, func, info, wait);
165}
166
167static inline void kick_all_cpus_sync(void) { }
168static inline void wake_up_all_idle_cpus(void) { }
169
170#ifdef CONFIG_UP_LATE_INIT
171extern void __init up_late_init(void);
172static inline void smp_init(void) { up_late_init(); }
173#else
174static inline void smp_init(void) { }
175#endif
176
177static inline int get_boot_cpu_id(void)
178{
179 return 0;
180}
181
182#endif /* !SMP */
183
184/*
185 * smp_processor_id(): get the current CPU ID.
186 *
187 * if DEBUG_PREEMPT is enabled then we check whether it is
188 * used in a preemption-safe way. (smp_processor_id() is safe
189 * if it's used in a preemption-off critical section, or in
190 * a thread that is bound to the current CPU.)
191 *
192 * NOTE: raw_smp_processor_id() is for internal use only
193 * (smp_processor_id() is the preferred variant), but in rare
194 * instances it might also be used to turn off false positives
195 * (i.e. smp_processor_id() use that the debugging code reports but
196 * which use for some reason is legal). Don't use this to hack around
197 * the warning message, as your code might not work under PREEMPT.
198 */
199#ifdef CONFIG_DEBUG_PREEMPT
200 extern unsigned int debug_smp_processor_id(void);
201# define smp_processor_id() debug_smp_processor_id()
202#else
203# define smp_processor_id() raw_smp_processor_id()
204#endif
205
206#define get_cpu() ({ preempt_disable(); smp_processor_id(); })
207#define put_cpu() preempt_enable()
208
209/*
210 * Callback to arch code if there's nosmp or maxcpus=0 on the
211 * boot command line:
212 */
213extern void arch_disable_smp_support(void);
214
215extern void arch_enable_nonboot_cpus_begin(void);
216extern void arch_enable_nonboot_cpus_end(void);
217
218void smp_setup_processor_id(void);
219
220int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par,
221 bool phys);
222
223/* SMP core functions */
224int smpcfd_prepare_cpu(unsigned int cpu);
225int smpcfd_dead_cpu(unsigned int cpu);
226int smpcfd_dying_cpu(unsigned int cpu);
227
228#endif /* __LINUX_SMP_H */
229