Root/kernel/up.c

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
10int 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}
23EXPORT_SYMBOL(smp_call_function_single);
24
25int 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}
34EXPORT_SYMBOL(smp_call_function_single_async);
35
36int 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}
45EXPORT_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 */
53void 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}
64EXPORT_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 */
70void 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}
84EXPORT_SYMBOL(on_each_cpu_cond);
85

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