xref: /openbmc/linux/kernel/up.c (revision 089a49b6)
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 on_each_cpu(smp_call_func_t func, void *info, int wait)
26 {
27 	unsigned long flags;
28 
29 	local_irq_save(flags);
30 	func(info);
31 	local_irq_restore(flags);
32 	return 0;
33 }
34 EXPORT_SYMBOL(on_each_cpu);
35 
36 /*
37  * Note we still need to test the mask even for UP
38  * because we actually can get an empty mask from
39  * code that on SMP might call us without the local
40  * CPU in the mask.
41  */
42 void on_each_cpu_mask(const struct cpumask *mask,
43 		      smp_call_func_t func, void *info, bool wait)
44 {
45 	unsigned long flags;
46 
47 	if (cpumask_test_cpu(0, mask)) {
48 		local_irq_save(flags);
49 		func(info);
50 		local_irq_restore(flags);
51 	}
52 }
53 EXPORT_SYMBOL(on_each_cpu_mask);
54 
55 /*
56  * Preemption is disabled here to make sure the cond_func is called under the
57  * same condtions in UP and SMP.
58  */
59 void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
60 		      smp_call_func_t func, void *info, bool wait,
61 		      gfp_t gfp_flags)
62 {
63 	unsigned long flags;
64 
65 	preempt_disable();
66 	if (cond_func(0, info)) {
67 		local_irq_save(flags);
68 		func(info);
69 		local_irq_restore(flags);
70 	}
71 	preempt_enable();
72 }
73 EXPORT_SYMBOL(on_each_cpu_cond);
74