tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1/*
2 * linux/arch/cris/kernel/process.c
3 *
4 * Copyright (C) 1995 Linus Torvalds
5 * Copyright (C) 2000-2002 Axis Communications AB
6 *
7 * Authors: Bjorn Wesen (bjornw@axis.com)
8 *
9 */
10
11/*
12 * This file handles the architecture-dependent parts of process handling..
13 */
14
15#include <linux/atomic.h>
16#include <asm/pgtable.h>
17#include <asm/uaccess.h>
18#include <asm/irq.h>
19#include <linux/module.h>
20#include <linux/spinlock.h>
21#include <linux/init_task.h>
22#include <linux/sched.h>
23#include <linux/fs.h>
24#include <linux/user.h>
25#include <linux/elfcore.h>
26#include <linux/mqueue.h>
27#include <linux/reboot.h>
28
29//#define DEBUG
30
31/*
32 * The hlt_counter, disable_hlt and enable_hlt is just here as a hook if
33 * there would ever be a halt sequence (for power save when idle) with
34 * some largish delay when halting or resuming *and* a driver that can't
35 * afford that delay. The hlt_counter would then be checked before
36 * executing the halt sequence, and the driver marks the unhaltable
37 * region by enable_hlt/disable_hlt.
38 */
39
40int cris_hlt_counter=0;
41
42void disable_hlt(void)
43{
44 cris_hlt_counter++;
45}
46
47EXPORT_SYMBOL(disable_hlt);
48
49void enable_hlt(void)
50{
51 cris_hlt_counter--;
52}
53
54EXPORT_SYMBOL(enable_hlt);
55
56/*
57 * The following aren't currently used.
58 */
59void (*pm_idle)(void);
60
61extern void default_idle(void);
62
63void (*pm_power_off)(void);
64EXPORT_SYMBOL(pm_power_off);
65
66/*
67 * The idle thread. There's no useful work to be
68 * done, so just try to conserve power and have a
69 * low exit latency (ie sit in a loop waiting for
70 * somebody to say that they'd like to reschedule)
71 */
72
73void cpu_idle (void)
74{
75 /* endless idle loop with no priority at all */
76 while (1) {
77 while (!need_resched()) {
78 void (*idle)(void);
79 /*
80 * Mark this as an RCU critical section so that
81 * synchronize_kernel() in the unload path waits
82 * for our completion.
83 */
84 idle = pm_idle;
85 if (!idle)
86 idle = default_idle;
87 idle();
88 }
89 schedule_preempt_disabled();
90 }
91}
92
93void hard_reset_now (void);
94
95void machine_restart(char *cmd)
96{
97 hard_reset_now();
98}
99
100/*
101 * Similar to machine_power_off, but don't shut off power. Add code
102 * here to freeze the system for e.g. post-mortem debug purpose when
103 * possible. This halt has nothing to do with the idle halt.
104 */
105
106void machine_halt(void)
107{
108}
109
110/* If or when software power-off is implemented, add code here. */
111
112void machine_power_off(void)
113{
114}
115
116/*
117 * When a process does an "exec", machine state like FPU and debug
118 * registers need to be reset. This is a hook function for that.
119 * Currently we don't have any such state to reset, so this is empty.
120 */
121
122void flush_thread(void)
123{
124}
125
126/* Fill in the fpu structure for a core dump. */
127int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
128{
129 return 0;
130}