Loading...
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}
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 <asm/system.h>
20#include <linux/module.h>
21#include <linux/spinlock.h>
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>
28#include <linux/reboot.h>
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
39static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
40static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
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 __init_task_data =
49 { INIT_THREAD_INFO(init_task) };
50
51/*
52 * Initial task structure.
53 *
54 * All other task structs will be allocated on slabs in fork.c
55 */
56struct task_struct init_task = INIT_TASK(init_task);
57
58EXPORT_SYMBOL(init_task);
59
60/*
61 * The hlt_counter, disable_hlt and enable_hlt is just here as a hook if
62 * there would ever be a halt sequence (for power save when idle) with
63 * some largish delay when halting or resuming *and* a driver that can't
64 * afford that delay. The hlt_counter would then be checked before
65 * executing the halt sequence, and the driver marks the unhaltable
66 * region by enable_hlt/disable_hlt.
67 */
68
69int cris_hlt_counter=0;
70
71void disable_hlt(void)
72{
73 cris_hlt_counter++;
74}
75
76EXPORT_SYMBOL(disable_hlt);
77
78void enable_hlt(void)
79{
80 cris_hlt_counter--;
81}
82
83EXPORT_SYMBOL(enable_hlt);
84
85/*
86 * The following aren't currently used.
87 */
88void (*pm_idle)(void);
89
90extern void default_idle(void);
91
92void (*pm_power_off)(void);
93EXPORT_SYMBOL(pm_power_off);
94
95/*
96 * The idle thread. There's no useful work to be
97 * done, so just try to conserve power and have a
98 * low exit latency (ie sit in a loop waiting for
99 * somebody to say that they'd like to reschedule)
100 */
101
102void cpu_idle (void)
103{
104 /* endless idle loop with no priority at all */
105 while (1) {
106 while (!need_resched()) {
107 void (*idle)(void);
108 /*
109 * Mark this as an RCU critical section so that
110 * synchronize_kernel() in the unload path waits
111 * for our completion.
112 */
113 idle = pm_idle;
114 if (!idle)
115 idle = default_idle;
116 idle();
117 }
118 preempt_enable_no_resched();
119 schedule();
120 preempt_disable();
121 }
122}
123
124void hard_reset_now (void);
125
126void machine_restart(char *cmd)
127{
128 hard_reset_now();
129}
130
131/*
132 * Similar to machine_power_off, but don't shut off power. Add code
133 * here to freeze the system for e.g. post-mortem debug purpose when
134 * possible. This halt has nothing to do with the idle halt.
135 */
136
137void machine_halt(void)
138{
139}
140
141/* If or when software power-off is implemented, add code here. */
142
143void machine_power_off(void)
144{
145}
146
147/*
148 * When a process does an "exec", machine state like FPU and debug
149 * registers need to be reset. This is a hook function for that.
150 * Currently we don't have any such state to reset, so this is empty.
151 */
152
153void flush_thread(void)
154{
155}
156
157/* Fill in the fpu structure for a core dump. */
158int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
159{
160 return 0;
161}