1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
|
/*
* SMP stuff which is common to all sub-architectures.
*/
#include <linux/module.h>
#include <asm/smp.h>
DEFINE_PER_CPU(unsigned long, this_cpu_off);
EXPORT_PER_CPU_SYMBOL(this_cpu_off);
/* Initialize the CPU's GDT. This is either the boot CPU doing itself
(still using the master per-cpu area), or a CPU doing it for a
secondary which will soon come up. */
__cpuinit void init_gdt(int cpu)
{
struct desc_struct *gdt = get_cpu_gdt_table(cpu);
pack_descriptor(&gdt[GDT_ENTRY_PERCPU],
__per_cpu_offset[cpu], 0xFFFFF,
0x2 | DESCTYPE_S, 0x8);
gdt[GDT_ENTRY_PERCPU].s = 1;
per_cpu(this_cpu_off, cpu) = __per_cpu_offset[cpu];
per_cpu(cpu_number, cpu) = cpu;
}
/**
* smp_call_function(): Run a function on all other CPUs.
* @func: The function to run. This must be fast and non-blocking.
* @info: An arbitrary pointer to pass to the function.
* @nonatomic: Unused.
* @wait: If true, wait (atomically) until function has completed on other CPUs.
*
* Returns 0 on success, else a negative status code.
*
* If @wait is true, then returns once @func has returned; otherwise
* it returns just before the target cpu calls @func.
*
* You must not call this function with disabled interrupts or from a
* hardware interrupt handler or from a bottom half handler.
*/
int smp_call_function(void (*func) (void *info), void *info, int nonatomic,
int wait)
{
return smp_call_function_mask(cpu_online_map, func, info, wait);
}
EXPORT_SYMBOL(smp_call_function);
/**
* smp_call_function_single - Run a function on a specific CPU
* @cpu: The target CPU. Cannot be the calling CPU.
* @func: The function to run. This must be fast and non-blocking.
* @info: An arbitrary pointer to pass to the function.
* @nonatomic: Unused.
* @wait: If true, wait until function has completed on other CPUs.
*
* Returns 0 on success, else a negative status code.
*
* If @wait is true, then returns once @func has returned; otherwise
* it returns just before the target cpu calls @func.
*/
int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
int nonatomic, int wait)
{
/* prevent preemption and reschedule on another processor */
int ret;
int me = get_cpu();
if (cpu == me) {
local_irq_disable();
func(info);
local_irq_enable();
put_cpu();
return 0;
}
ret = smp_call_function_mask(cpumask_of_cpu(cpu), func, info, wait);
put_cpu();
return ret;
}
EXPORT_SYMBOL(smp_call_function_single);
|
