1 /* SPDX-License-Identifier: GPL-2.0 */
7 * Alan Cox. <alan@redhat.com>
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>
17 typedef void (*smp_call_func_t
)(void *info
);
18 typedef bool (*smp_cond_func_t
)(int cpu
, void *info
);
19 struct __call_single_data
{
20 struct llist_node llist
;
26 /* Use __aligned() to avoid to use 2 cache lines for 1 csd */
27 typedef struct __call_single_data call_single_data_t
28 __aligned(sizeof(struct __call_single_data
));
30 /* total number of cpus in this system (may exceed NR_CPUS) */
31 extern unsigned int total_cpus
;
33 int smp_call_function_single(int cpuid
, smp_call_func_t func
, void *info
,
37 * Call a function on all processors
39 void on_each_cpu(smp_call_func_t func
, void *info
, int wait
);
42 * Call a function on processors specified by mask, which might include
45 void on_each_cpu_mask(const struct cpumask
*mask
, smp_call_func_t func
,
46 void *info
, bool wait
);
49 * Call a function on each processor for which the supplied function
50 * cond_func returns a positive value. This may include the local
53 void on_each_cpu_cond(smp_cond_func_t cond_func
, smp_call_func_t func
,
54 void *info
, bool wait
);
56 void on_each_cpu_cond_mask(smp_cond_func_t cond_func
, smp_call_func_t func
,
57 void *info
, bool wait
, const struct cpumask
*mask
);
59 int smp_call_function_single_async(int cpu
, call_single_data_t
*csd
);
63 #include <linux/preempt.h>
64 #include <linux/kernel.h>
65 #include <linux/compiler.h>
66 #include <linux/thread_info.h>
70 * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
71 * (defined in asm header):
75 * stops all CPUs but the current one:
77 extern void smp_send_stop(void);
80 * sends a 'reschedule' event to another CPU:
82 extern void smp_send_reschedule(int cpu
);
86 * Prepare machine for booting other CPUs.
88 extern void smp_prepare_cpus(unsigned int max_cpus
);
93 extern int __cpu_up(unsigned int cpunum
, struct task_struct
*tidle
);
96 * Final polishing of CPUs
98 extern void smp_cpus_done(unsigned int max_cpus
);
101 * Call a function on all other processors
103 void smp_call_function(smp_call_func_t func
, void *info
, int wait
);
104 void smp_call_function_many(const struct cpumask
*mask
,
105 smp_call_func_t func
, void *info
, bool wait
);
107 int smp_call_function_any(const struct cpumask
*mask
,
108 smp_call_func_t func
, void *info
, int wait
);
110 void kick_all_cpus_sync(void);
111 void wake_up_all_idle_cpus(void);
114 * Generic and arch helpers
116 void __init
call_function_init(void);
117 void generic_smp_call_function_single_interrupt(void);
118 #define generic_smp_call_function_interrupt \
119 generic_smp_call_function_single_interrupt
122 * Mark the boot cpu "online" so that it can call console drivers in
123 * printk() and can access its per-cpu storage.
125 void smp_prepare_boot_cpu(void);
127 extern unsigned int setup_max_cpus
;
128 extern void __init
setup_nr_cpu_ids(void);
129 extern void __init
smp_init(void);
131 extern int __boot_cpu_id
;
133 static inline int get_boot_cpu_id(void)
135 return __boot_cpu_id
;
140 static inline void smp_send_stop(void) { }
143 * These macros fold the SMP functionality into a single CPU system
145 #define raw_smp_processor_id() 0
146 static inline void up_smp_call_function(smp_call_func_t func
, void *info
)
149 #define smp_call_function(func, info, wait) \
150 (up_smp_call_function(func, info))
152 static inline void smp_send_reschedule(int cpu
) { }
153 #define smp_prepare_boot_cpu() do {} while (0)
154 #define smp_call_function_many(mask, func, info, wait) \
155 (up_smp_call_function(func, info))
156 static inline void call_function_init(void) { }
159 smp_call_function_any(const struct cpumask
*mask
, smp_call_func_t func
,
160 void *info
, int wait
)
162 return smp_call_function_single(0, func
, info
, wait
);
165 static inline void kick_all_cpus_sync(void) { }
166 static inline void wake_up_all_idle_cpus(void) { }
168 #ifdef CONFIG_UP_LATE_INIT
169 extern void __init
up_late_init(void);
170 static inline void smp_init(void) { up_late_init(); }
172 static inline void smp_init(void) { }
175 static inline int get_boot_cpu_id(void)
183 * raw_processor_id() - get the current (unstable) CPU id
185 * For then you know what you are doing and need an unstable
190 * smp_processor_id() - get the current (stable) CPU id
192 * This is the normal accessor to the CPU id and should be used
195 * The CPU id is stable when:
197 * - IRQs are disabled;
198 * - preemption is disabled;
199 * - the task is CPU affine.
201 * When CONFIG_DEBUG_PREEMPT; we verify these assumption and WARN
202 * when smp_processor_id() is used when the CPU id is not stable.
206 * Allow the architecture to differentiate between a stable and unstable read.
207 * For example, x86 uses an IRQ-safe asm-volatile read for the unstable but a
208 * regular asm read for the stable.
210 #ifndef __smp_processor_id
211 #define __smp_processor_id(x) raw_smp_processor_id(x)
214 #ifdef CONFIG_DEBUG_PREEMPT
215 extern unsigned int debug_smp_processor_id(void);
216 # define smp_processor_id() debug_smp_processor_id()
218 # define smp_processor_id() __smp_processor_id()
221 #define get_cpu() ({ preempt_disable(); __smp_processor_id(); })
222 #define put_cpu() preempt_enable()
225 * Callback to arch code if there's nosmp or maxcpus=0 on the
228 extern void arch_disable_smp_support(void);
230 extern void arch_enable_nonboot_cpus_begin(void);
231 extern void arch_enable_nonboot_cpus_end(void);
233 void smp_setup_processor_id(void);
235 int smp_call_on_cpu(unsigned int cpu
, int (*func
)(void *), void *par
,
238 /* SMP core functions */
239 int smpcfd_prepare_cpu(unsigned int cpu
);
240 int smpcfd_dead_cpu(unsigned int cpu
);
241 int smpcfd_dying_cpu(unsigned int cpu
);
243 #endif /* __LINUX_SMP_H */