tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1#ifndef __LINUX_SMP_H
2#define __LINUX_SMP_H
3
4/*
5 * Generic SMP support
6 * Alan Cox. <alan@redhat.com>
7 */
8
9#include <linux/config.h>
10
11extern void cpu_idle(void);
12
13#ifdef CONFIG_SMP
14
15#include <linux/preempt.h>
16#include <linux/kernel.h>
17#include <linux/compiler.h>
18#include <linux/thread_info.h>
19#include <asm/smp.h>
20#include <asm/bug.h>
21
22/*
23 * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
24 * (defined in asm header):
25 */
26
27/*
28 * stops all CPUs but the current one:
29 */
30extern void smp_send_stop(void);
31
32/*
33 * sends a 'reschedule' event to another CPU:
34 */
35extern void smp_send_reschedule(int cpu);
36
37
38/*
39 * Prepare machine for booting other CPUs.
40 */
41extern void smp_prepare_cpus(unsigned int max_cpus);
42
43/*
44 * Bring a CPU up
45 */
46extern int __cpu_up(unsigned int cpunum);
47
48/*
49 * Final polishing of CPUs
50 */
51extern void smp_cpus_done(unsigned int max_cpus);
52
53/*
54 * Call a function on all other processors
55 */
56extern int smp_call_function (void (*func) (void *info), void *info,
57 int retry, int wait);
58
59/*
60 * Call a function on all processors
61 */
62static inline int on_each_cpu(void (*func) (void *info), void *info,
63 int retry, int wait)
64{
65 int ret = 0;
66
67 preempt_disable();
68 ret = smp_call_function(func, info, retry, wait);
69 func(info);
70 preempt_enable();
71 return ret;
72}
73
74#define MSG_ALL_BUT_SELF 0x8000 /* Assume <32768 CPU's */
75#define MSG_ALL 0x8001
76
77#define MSG_INVALIDATE_TLB 0x0001 /* Remote processor TLB invalidate */
78#define MSG_STOP_CPU 0x0002 /* Sent to shut down slave CPU's
79 * when rebooting
80 */
81#define MSG_RESCHEDULE 0x0003 /* Reschedule request from master CPU*/
82#define MSG_CALL_FUNCTION 0x0004 /* Call function on all other CPUs */
83
84/*
85 * Mark the boot cpu "online" so that it can call console drivers in
86 * printk() and can access its per-cpu storage.
87 */
88void smp_prepare_boot_cpu(void);
89
90#else /* !SMP */
91
92/*
93 * These macros fold the SMP functionality into a single CPU system
94 */
95#define raw_smp_processor_id() 0
96#define hard_smp_processor_id() 0
97
98static inline int smp_call_function(void (*func) (void *info), void *info,
99 int retry, int wait)
100{
101 return 0;
102}
103
104#define on_each_cpu(func,info,retry,wait) ({ func(info); 0; })
105static inline void smp_send_reschedule(int cpu) { }
106#define num_booting_cpus() 1
107#define smp_prepare_boot_cpu() do {} while (0)
108
109#endif /* !SMP */
110
111/*
112 * smp_processor_id(): get the current CPU ID.
113 *
114 * if DEBUG_PREEMPT is enabled the we check whether it is
115 * used in a preemption-safe way. (smp_processor_id() is safe
116 * if it's used in a preemption-off critical section, or in
117 * a thread that is bound to the current CPU.)
118 *
119 * NOTE: raw_smp_processor_id() is for internal use only
120 * (smp_processor_id() is the preferred variant), but in rare
121 * instances it might also be used to turn off false positives
122 * (i.e. smp_processor_id() use that the debugging code reports but
123 * which use for some reason is legal). Don't use this to hack around
124 * the warning message, as your code might not work under PREEMPT.
125 */
126#ifdef CONFIG_DEBUG_PREEMPT
127 extern unsigned int debug_smp_processor_id(void);
128# define smp_processor_id() debug_smp_processor_id()
129#else
130# define smp_processor_id() raw_smp_processor_id()
131#endif
132
133#define get_cpu() ({ preempt_disable(); smp_processor_id(); })
134#define put_cpu() preempt_enable()
135#define put_cpu_no_resched() preempt_enable_no_resched()
136
137#endif /* __LINUX_SMP_H */