xref: /linux/kernel/up.c (revision 59e6295fac26b8e85c1ea859cdd89fa1e47519d7)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Uniprocessor-only support functions.  The counterpart to kernel/smp.c
4  */
5 
6 #include <linux/interrupt.h>
7 #include <linux/kernel.h>
8 #include <linux/export.h>
9 #include <linux/smp.h>
10 #include <linux/hypervisor.h>
11 
12 int smp_call_function_single(int cpu, void (*func)(void *info), void *info, bool wait)
13 {
14 	unsigned long flags;
15 
16 	if (cpu != 0)
17 		return -ENXIO;
18 
19 	local_irq_save(flags);
20 	func(info);
21 	local_irq_restore(flags);
22 
23 	return 0;
24 }
25 EXPORT_SYMBOL(smp_call_function_single);
26 
27 int smp_call_function_single_async(int cpu, call_single_data_t *csd)
28 {
29 	unsigned long flags;
30 
31 	local_irq_save(flags);
32 	csd->func(csd->info);
33 	local_irq_restore(flags);
34 	return 0;
35 }
36 EXPORT_SYMBOL(smp_call_function_single_async);
37 
38 /*
39  * Preemption is disabled here to make sure the cond_func is called under the
40  * same conditions in UP and SMP.
41  */
42 void on_each_cpu_cond_mask(smp_cond_func_t cond_func, smp_call_func_t func,
43 			   void *info, bool wait, const struct cpumask *mask)
44 {
45 	unsigned long flags;
46 
47 	preempt_disable();
48 	if ((!cond_func || cond_func(0, info)) && cpumask_test_cpu(0, mask)) {
49 		local_irq_save(flags);
50 		func(info);
51 		local_irq_restore(flags);
52 	}
53 	preempt_enable();
54 }
55 EXPORT_SYMBOL(on_each_cpu_cond_mask);
56 
57 int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par, bool phys)
58 {
59 	int ret;
60 
61 	if (cpu != 0)
62 		return -ENXIO;
63 
64 	if (phys)
65 		hypervisor_pin_vcpu(0);
66 	ret = func(par);
67 	if (phys)
68 		hypervisor_pin_vcpu(-1);
69 
70 	return ret;
71 }
72 EXPORT_SYMBOL_GPL(smp_call_on_cpu);
73