xref: /openbmc/linux/kernel/up.c (revision b868a02e)
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,
13 				int wait)
14 {
15 	unsigned long flags;
16 
17 	if (cpu != 0)
18 		return -ENXIO;
19 
20 	local_irq_save(flags);
21 	func(info);
22 	local_irq_restore(flags);
23 
24 	return 0;
25 }
26 EXPORT_SYMBOL(smp_call_function_single);
27 
28 int smp_call_function_single_async(int cpu, struct __call_single_data *csd)
29 {
30 	unsigned long flags;
31 
32 	local_irq_save(flags);
33 	csd->func(csd->info);
34 	local_irq_restore(flags);
35 	return 0;
36 }
37 EXPORT_SYMBOL(smp_call_function_single_async);
38 
39 /*
40  * Preemption is disabled here to make sure the cond_func is called under the
41  * same conditions in UP and SMP.
42  */
43 void on_each_cpu_cond_mask(smp_cond_func_t cond_func, smp_call_func_t func,
44 			   void *info, bool wait, const struct cpumask *mask)
45 {
46 	unsigned long flags;
47 
48 	preempt_disable();
49 	if ((!cond_func || cond_func(0, info)) && cpumask_test_cpu(0, mask)) {
50 		local_irq_save(flags);
51 		func(info);
52 		local_irq_restore(flags);
53 	}
54 	preempt_enable();
55 }
56 EXPORT_SYMBOL(on_each_cpu_cond_mask);
57 
58 int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par, bool phys)
59 {
60 	int ret;
61 
62 	if (cpu != 0)
63 		return -ENXIO;
64 
65 	if (phys)
66 		hypervisor_pin_vcpu(0);
67 	ret = func(par);
68 	if (phys)
69 		hypervisor_pin_vcpu(-1);
70 
71 	return ret;
72 }
73 EXPORT_SYMBOL_GPL(smp_call_on_cpu);
74