xref: /linux/kernel/up.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*
2  * Uniprocessor-only support functions.  The counterpart to kernel/smp.c
3  */
4 
5 #include <linux/interrupt.h>
6 #include <linux/kernel.h>
7 #include <linux/export.h>
8 #include <linux/smp.h>
9 
10 int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
11 				int wait)
12 {
13 	unsigned long flags;
14 
15 	WARN_ON(cpu != 0);
16 
17 	local_irq_save(flags);
18 	func(info);
19 	local_irq_restore(flags);
20 
21 	return 0;
22 }
23 EXPORT_SYMBOL(smp_call_function_single);
24 
25 int smp_call_function_single_async(int cpu, struct call_single_data *csd)
26 {
27 	unsigned long flags;
28 
29 	local_irq_save(flags);
30 	csd->func(csd->info);
31 	local_irq_restore(flags);
32 	return 0;
33 }
34 EXPORT_SYMBOL(smp_call_function_single_async);
35 
36 int on_each_cpu(smp_call_func_t func, void *info, int wait)
37 {
38 	unsigned long flags;
39 
40 	local_irq_save(flags);
41 	func(info);
42 	local_irq_restore(flags);
43 	return 0;
44 }
45 EXPORT_SYMBOL(on_each_cpu);
46 
47 /*
48  * Note we still need to test the mask even for UP
49  * because we actually can get an empty mask from
50  * code that on SMP might call us without the local
51  * CPU in the mask.
52  */
53 void on_each_cpu_mask(const struct cpumask *mask,
54 		      smp_call_func_t func, void *info, bool wait)
55 {
56 	unsigned long flags;
57 
58 	if (cpumask_test_cpu(0, mask)) {
59 		local_irq_save(flags);
60 		func(info);
61 		local_irq_restore(flags);
62 	}
63 }
64 EXPORT_SYMBOL(on_each_cpu_mask);
65 
66 /*
67  * Preemption is disabled here to make sure the cond_func is called under the
68  * same condtions in UP and SMP.
69  */
70 void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
71 		      smp_call_func_t func, void *info, bool wait,
72 		      gfp_t gfp_flags)
73 {
74 	unsigned long flags;
75 
76 	preempt_disable();
77 	if (cond_func(0, info)) {
78 		local_irq_save(flags);
79 		func(info);
80 		local_irq_restore(flags);
81 	}
82 	preempt_enable();
83 }
84 EXPORT_SYMBOL(on_each_cpu_cond);
85