mm: consolidate init_mm definition
[linux-block.git] / arch / cris / kernel / process.c
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f32bb79c 1/*
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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 *
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9 */
10
11/*
12 * This file handles the architecture-dependent parts of process handling..
13 */
14
15#include <asm/atomic.h>
16#include <asm/pgtable.h>
17#include <asm/uaccess.h>
18#include <asm/irq.h>
cdb04527 19#include <asm/system.h>
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20#include <linux/module.h>
21#include <linux/spinlock.h>
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22#include <linux/init_task.h>
23#include <linux/sched.h>
24#include <linux/fs.h>
25#include <linux/user.h>
26#include <linux/elfcore.h>
27#include <linux/mqueue.h>
16dcb4bb 28#include <linux/reboot.h>
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29
30//#define DEBUG
31
32/*
33 * Initial task structure. Make this a per-architecture thing,
34 * because different architectures tend to have different
35 * alignment requirements and potentially different initial
36 * setup.
37 */
38
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39static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
40static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
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41/*
42 * Initial thread structure.
43 *
44 * We need to make sure that this is 8192-byte aligned due to the
45 * way process stacks are handled. This is done by having a special
46 * "init_task" linker map entry..
47 */
48union thread_union init_thread_union
49 __attribute__((__section__(".data.init_task"))) =
50 { INIT_THREAD_INFO(init_task) };
51
52/*
53 * Initial task structure.
54 *
55 * All other task structs will be allocated on slabs in fork.c
56 */
57struct task_struct init_task = INIT_TASK(init_task);
58
59EXPORT_SYMBOL(init_task);
60
61/*
62 * The hlt_counter, disable_hlt and enable_hlt is just here as a hook if
63 * there would ever be a halt sequence (for power save when idle) with
64 * some largish delay when halting or resuming *and* a driver that can't
65 * afford that delay. The hlt_counter would then be checked before
66 * executing the halt sequence, and the driver marks the unhaltable
67 * region by enable_hlt/disable_hlt.
68 */
69
5d01e6ce 70int cris_hlt_counter=0;
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71
72void disable_hlt(void)
73{
5d01e6ce 74 cris_hlt_counter++;
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75}
76
77EXPORT_SYMBOL(disable_hlt);
78
79void enable_hlt(void)
80{
5d01e6ce 81 cris_hlt_counter--;
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82}
83
84EXPORT_SYMBOL(enable_hlt);
85
86/*
87 * The following aren't currently used.
88 */
89void (*pm_idle)(void);
90
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91extern void default_idle(void);
92
93void (*pm_power_off)(void);
94EXPORT_SYMBOL(pm_power_off);
95
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96/*
97 * The idle thread. There's no useful work to be
98 * done, so just try to conserve power and have a
99 * low exit latency (ie sit in a loop waiting for
100 * somebody to say that they'd like to reschedule)
101 */
f32bb79c 102
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103void cpu_idle (void)
104{
105 /* endless idle loop with no priority at all */
106 while (1) {
107 while (!need_resched()) {
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108 void (*idle)(void);
109 /*
110 * Mark this as an RCU critical section so that
111 * synchronize_kernel() in the unload path waits
112 * for our completion.
113 */
114 idle = pm_idle;
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115 if (!idle)
116 idle = default_idle;
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117 idle();
118 }
5bfb5d69 119 preempt_enable_no_resched();
1da177e4 120 schedule();
5bfb5d69 121 preempt_disable();
1da177e4 122 }
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123}
124
125void hard_reset_now (void);
126
16dcb4bb 127void machine_restart(char *cmd)
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128{
129 hard_reset_now();
130}
131
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132/*
133 * Similar to machine_power_off, but don't shut off power. Add code
134 * here to freeze the system for e.g. post-mortem debug purpose when
135 * possible. This halt has nothing to do with the idle halt.
136 */
137
138void machine_halt(void)
139{
140}
141
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142/* If or when software power-off is implemented, add code here. */
143
144void machine_power_off(void)
145{
146}
147
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148/*
149 * When a process does an "exec", machine state like FPU and debug
150 * registers need to be reset. This is a hook function for that.
151 * Currently we don't have any such state to reset, so this is empty.
152 */
153
154void flush_thread(void)
155{
156}
157
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158/* Fill in the fpu structure for a core dump. */
159int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
160{
161 return 0;
162}