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
smp_call_function_single(int cpu,void (* func)(void * info),void * info,int wait)12 int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
13 int wait)
14 {
15 unsigned long flags;
16
17 WARN_ON(cpu != 0);
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
smp_call_function_single_async(int cpu,call_single_data_t * csd)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
on_each_cpu(smp_call_func_t func,void * info,int wait)38 void on_each_cpu(smp_call_func_t func, void *info, int wait)
39 {
40 unsigned long flags;
41
42 local_irq_save(flags);
43 func(info);
44 local_irq_restore(flags);
45 }
46 EXPORT_SYMBOL(on_each_cpu);
47
48 /*
49 * Note we still need to test the mask even for UP
50 * because we actually can get an empty mask from
51 * code that on SMP might call us without the local
52 * CPU in the mask.
53 */
on_each_cpu_mask(const struct cpumask * mask,smp_call_func_t func,void * info,bool wait)54 void on_each_cpu_mask(const struct cpumask *mask,
55 smp_call_func_t func, void *info, bool wait)
56 {
57 unsigned long flags;
58
59 if (cpumask_test_cpu(0, mask)) {
60 local_irq_save(flags);
61 func(info);
62 local_irq_restore(flags);
63 }
64 }
65 EXPORT_SYMBOL(on_each_cpu_mask);
66
67 /*
68 * Preemption is disabled here to make sure the cond_func is called under the
69 * same condtions in UP and SMP.
70 */
on_each_cpu_cond_mask(bool (* cond_func)(int cpu,void * info),smp_call_func_t func,void * info,bool wait,gfp_t gfp_flags,const struct cpumask * mask)71 void on_each_cpu_cond_mask(bool (*cond_func)(int cpu, void *info),
72 smp_call_func_t func, void *info, bool wait,
73 gfp_t gfp_flags, const struct cpumask *mask)
74 {
75 unsigned long flags;
76
77 preempt_disable();
78 if (cond_func(0, info)) {
79 local_irq_save(flags);
80 func(info);
81 local_irq_restore(flags);
82 }
83 preempt_enable();
84 }
85 EXPORT_SYMBOL(on_each_cpu_cond_mask);
86
on_each_cpu_cond(bool (* cond_func)(int cpu,void * info),smp_call_func_t func,void * info,bool wait,gfp_t gfp_flags)87 void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
88 smp_call_func_t func, void *info, bool wait,
89 gfp_t gfp_flags)
90 {
91 on_each_cpu_cond_mask(cond_func, func, info, wait, gfp_flags, NULL);
92 }
93 EXPORT_SYMBOL(on_each_cpu_cond);
94
smp_call_on_cpu(unsigned int cpu,int (* func)(void *),void * par,bool phys)95 int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par, bool phys)
96 {
97 int ret;
98
99 if (cpu != 0)
100 return -ENXIO;
101
102 if (phys)
103 hypervisor_pin_vcpu(0);
104 ret = func(par);
105 if (phys)
106 hypervisor_pin_vcpu(-1);
107
108 return ret;
109 }
110 EXPORT_SYMBOL_GPL(smp_call_on_cpu);
111