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
17 typedef void (*smp_call_func_t)(void *info);
18 struct __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 */
26 typedef 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) */
30 extern unsigned int total_cpus;
31
32 int 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 */
38 int 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 */
44 void 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 */
52 void 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
56 int smp_call_function_single_async(int cpu, struct __call_single_data *csd);
57
58 #ifdef CONFIG_SMP
59
60 #include <linux/preempt.h>
61 #include <linux/kernel.h>
62 #include <linux/compiler.h>
63 #include <linux/thread_info.h>
64 #include <asm/smp.h>
65
66 /*
67 * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
68 * (defined in asm header):
69 */
70
71 /*
72 * stops all CPUs but the current one:
73 */
74 extern void smp_send_stop(void);
75
76 /*
77 * sends a 'reschedule' event to another CPU:
78 */
79 extern void smp_send_reschedule(int cpu);
80
81
82 /*
83 * Prepare machine for booting other CPUs.
84 */
85 extern void smp_prepare_cpus(unsigned int max_cpus);
86
87 /*
88 * Bring a CPU up
89 */
90 extern int __cpu_up(unsigned int cpunum, struct task_struct *tidle);
91
92 /*
93 * Final polishing of CPUs
94 */
95 extern void smp_cpus_done(unsigned int max_cpus);
96
97 /*
98 * Call a function on all other processors
99 */
100 int smp_call_function(smp_call_func_t func, void *info, int wait);
101 void smp_call_function_many(const struct cpumask *mask,
102 smp_call_func_t func, void *info, bool wait);
103
104 int smp_call_function_any(const struct cpumask *mask,
105 smp_call_func_t func, void *info, int wait);
106
107 void kick_all_cpus_sync(void);
108 void wake_up_all_idle_cpus(void);
109
110 /*
111 * Generic and arch helpers
112 */
113 void __init call_function_init(void);
114 void 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 */
122 void smp_prepare_boot_cpu(void);
123
124 extern unsigned int setup_max_cpus;
125 extern void __init setup_nr_cpu_ids(void);
126 extern void __init smp_init(void);
127
128 extern int __boot_cpu_id;
129
get_boot_cpu_id(void)130 static inline int get_boot_cpu_id(void)
131 {
132 return __boot_cpu_id;
133 }
134
135 #else /* !SMP */
136
smp_send_stop(void)137 static inline void smp_send_stop(void) { }
138
139 /*
140 * These macros fold the SMP functionality into a single CPU system
141 */
142 #define raw_smp_processor_id() 0
up_smp_call_function(smp_call_func_t func,void * info)143 static inline int up_smp_call_function(smp_call_func_t func, void *info)
144 {
145 return 0;
146 }
147 #define smp_call_function(func, info, wait) \
148 (up_smp_call_function(func, info))
149
smp_send_reschedule(int cpu)150 static inline void smp_send_reschedule(int cpu) { }
151 #define smp_prepare_boot_cpu() do {} while (0)
152 #define smp_call_function_many(mask, func, info, wait) \
153 (up_smp_call_function(func, info))
call_function_init(void)154 static inline void call_function_init(void) { }
155
156 static inline int
smp_call_function_any(const struct cpumask * mask,smp_call_func_t func,void * info,int wait)157 smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
158 void *info, int wait)
159 {
160 return smp_call_function_single(0, func, info, wait);
161 }
162
kick_all_cpus_sync(void)163 static inline void kick_all_cpus_sync(void) { }
wake_up_all_idle_cpus(void)164 static inline void wake_up_all_idle_cpus(void) { }
165
166 #ifdef CONFIG_UP_LATE_INIT
167 extern void __init up_late_init(void);
smp_init(void)168 static inline void smp_init(void) { up_late_init(); }
169 #else
smp_init(void)170 static inline void smp_init(void) { }
171 #endif
172
get_boot_cpu_id(void)173 static inline int get_boot_cpu_id(void)
174 {
175 return 0;
176 }
177
178 #endif /* !SMP */
179
180 /*
181 * smp_processor_id(): get the current CPU ID.
182 *
183 * if DEBUG_PREEMPT is enabled then we check whether it is
184 * used in a preemption-safe way. (smp_processor_id() is safe
185 * if it's used in a preemption-off critical section, or in
186 * a thread that is bound to the current CPU.)
187 *
188 * NOTE: raw_smp_processor_id() is for internal use only
189 * (smp_processor_id() is the preferred variant), but in rare
190 * instances it might also be used to turn off false positives
191 * (i.e. smp_processor_id() use that the debugging code reports but
192 * which use for some reason is legal). Don't use this to hack around
193 * the warning message, as your code might not work under PREEMPT.
194 */
195 #ifdef CONFIG_DEBUG_PREEMPT
196 extern unsigned int debug_smp_processor_id(void);
197 # define smp_processor_id() debug_smp_processor_id()
198 #else
199 # define smp_processor_id() raw_smp_processor_id()
200 #endif
201
202 #define get_cpu() ({ preempt_disable(); smp_processor_id(); })
203 #define put_cpu() preempt_enable()
204
205 /*
206 * Callback to arch code if there's nosmp or maxcpus=0 on the
207 * boot command line:
208 */
209 extern void arch_disable_smp_support(void);
210
211 extern void arch_enable_nonboot_cpus_begin(void);
212 extern void arch_enable_nonboot_cpus_end(void);
213
214 void smp_setup_processor_id(void);
215
216 int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par,
217 bool phys);
218
219 /* SMP core functions */
220 int smpcfd_prepare_cpu(unsigned int cpu);
221 int smpcfd_dead_cpu(unsigned int cpu);
222 int smpcfd_dying_cpu(unsigned int cpu);
223
224 #endif /* __LINUX_SMP_H */
225