aboutsummaryrefslogtreecommitdiffstats
path: root/arch/cris/kernel/process.c
blob: 7c80afb1046077d2fb219d2542c3b815c7d3916d (plain) (blame)
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
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
/* $Id: process.c,v 1.21 2005/03/04 08:16:17 starvik Exp $
 * 
 *  linux/arch/cris/kernel/process.c
 *
 *  Copyright (C) 1995  Linus Torvalds
 *  Copyright (C) 2000-2002  Axis Communications AB
 *
 *  Authors:   Bjorn Wesen (bjornw@axis.com)
 *
 *  $Log: process.c,v $
 *  Revision 1.21  2005/03/04 08:16:17  starvik
 *  Merge of Linux 2.6.11.
 *
 *  Revision 1.20  2005/01/18 05:57:22  starvik
 *  Renamed hlt_counter to cris_hlt_counter and made it global.
 *
 *  Revision 1.19  2004/10/19 13:07:43  starvik
 *  Merge of Linux 2.6.9
 *
 *  Revision 1.18  2004/08/16 12:37:23  starvik
 *  Merge of Linux 2.6.8
 *
 *  Revision 1.17  2004/04/05 13:53:48  starvik
 *  Merge of Linux 2.6.5
 *
 *  Revision 1.16  2003/10/27 08:04:33  starvik
 *  Merge of Linux 2.6.0-test9
 *
 *  Revision 1.15  2003/09/11 07:29:52  starvik
 *  Merge of Linux 2.6.0-test5
 *
 *  Revision 1.14  2003/06/10 10:21:12  johana
 *  Moved thread_saved_pc() from arch/cris/kernel/process.c to
 *  subarch specific process.c. arch-v32 has an erp, no irp.
 *
 *  Revision 1.13  2003/04/09 05:20:47  starvik
 *  Merge of Linux 2.5.67
 *
 *  Revision 1.12  2002/12/11 15:41:11  starvik
 *  Extracted v10 (ETRAX 100LX) specific stuff to arch/cris/arch-v10/kernel
 *
 *  Revision 1.11  2002/12/10 09:00:10  starvik
 *  Merge of Linux 2.5.51
 *
 *  Revision 1.10  2002/11/27 08:42:34  starvik
 *  Argument to user_regs() is thread_info*
 *
 *  Revision 1.9  2002/11/26 09:44:21  starvik
 *  New threads exits through ret_from_fork (necessary for preemptive scheduling)
 *
 *  Revision 1.8  2002/11/19 14:35:24  starvik
 *  Changes from linux 2.4
 *  Changed struct initializer syntax to the currently prefered notation
 *
 *  Revision 1.7  2002/11/18 07:39:42  starvik
 *  thread_saved_pc moved here from processor.h
 *
 *  Revision 1.6  2002/11/14 06:51:27  starvik
 *  Made cpu_idle more similar with other archs
 *  init_task_union -> init_thread_union
 *  Updated for new interrupt macros
 *  sys_clone and do_fork have a new argument, user_tid
 *
 *  Revision 1.5  2002/11/05 06:45:11  starvik
 *  Merge of Linux 2.5.45
 *
 *  Revision 1.4  2002/02/05 15:37:44  bjornw
 *  Need init_task.h
 *
 *  Revision 1.3  2002/01/21 15:22:49  bjornw
 *  current->counter is gone
 *
 *  Revision 1.22  2001/11/13 09:40:43  orjanf
 *  Added dump_fpu (needed for core dumps).
 *
 *  Revision 1.21  2001/11/12 18:26:21  pkj
 *  Fixed compiler warnings.
 *
 *  Revision 1.20  2001/10/03 08:21:39  jonashg
 *  cause_of_death does not exist if CONFIG_SVINTO_SIM is defined.
 *
 *  Revision 1.19  2001/09/26 11:52:54  bjornw
 *  INIT_MMAP is gone in 2.4.10
 *
 *  Revision 1.18  2001/08/21 21:43:51  hp
 *  Move last watchdog fix inside #ifdef CONFIG_ETRAX_WATCHDOG
 *
 *  Revision 1.17  2001/08/21 13:48:01  jonashg
 *  Added fix by HP to avoid oops when doing a hard_reset_now.
 *
 *  Revision 1.16  2001/06/21 02:00:40  hp
 *  	* entry.S: Include asm/unistd.h.
 *  	(_sys_call_table): Use section .rodata, not .data.
 *  	(_kernel_thread): Move from...
 *  	* process.c: ... here.
 *  	* entryoffsets.c (VAL): Break out from...
 *  	(OF): Use VAL.
 *  	(LCLONE_VM): New asmified value from CLONE_VM.
 *
 *  Revision 1.15  2001/06/20 16:31:57  hp
 *  Add comments to describe empty functions according to review.
 *
 *  Revision 1.14  2001/05/29 11:27:59  markusl
 *  Fixed so that hard_reset_now will do reset even if watchdog wasn't enabled
 *
 *  Revision 1.13  2001/03/20 19:44:06  bjornw
 *  Use the 7th syscall argument for regs instead of current_regs
 *
 */

/*
 * This file handles the architecture-dependent parts of process handling..
 */

#include <asm/atomic.h>
#include <asm/pgtable.h>
#include <asm/uaccess.h>
#include <asm/irq.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/fs_struct.h>
#include <linux/init_task.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/user.h>
#include <linux/elfcore.h>
#include <linux/mqueue.h>
#include <linux/reboot.h>

//#define DEBUG

/*
 * Initial task structure. Make this a per-architecture thing,
 * because different architectures tend to have different
 * alignment requirements and potentially different initial
 * setup.
 */

static struct fs_struct init_fs = INIT_FS;
static struct files_struct init_files = INIT_FILES;
static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
struct mm_struct init_mm = INIT_MM(init_mm);

EXPORT_SYMBOL(init_mm);

/*
 * Initial thread structure.
 *
 * We need to make sure that this is 8192-byte aligned due to the
 * way process stacks are handled. This is done by having a special
 * "init_task" linker map entry..
 */
union thread_union init_thread_union 
	__attribute__((__section__(".data.init_task"))) =
		{ INIT_THREAD_INFO(init_task) };

/*
 * Initial task structure.
 *
 * All other task structs will be allocated on slabs in fork.c
 */
struct task_struct init_task = INIT_TASK(init_task);

EXPORT_SYMBOL(init_task);

/*
 * The hlt_counter, disable_hlt and enable_hlt is just here as a hook if
 * there would ever be a halt sequence (for power save when idle) with
 * some largish delay when halting or resuming *and* a driver that can't
 * afford that delay.  The hlt_counter would then be checked before
 * executing the halt sequence, and the driver marks the unhaltable
 * region by enable_hlt/disable_hlt.
 */

int cris_hlt_counter=0;

void disable_hlt(void)
{
	cris_hlt_counter++;
}

EXPORT_SYMBOL(disable_hlt);

void enable_hlt(void)
{
	cris_hlt_counter--;
}

EXPORT_SYMBOL(enable_hlt);
 
/*
 * The following aren't currently used.
 */
void (*pm_idle)(void);

extern void default_idle(void);

/*
 * The idle thread. There's no useful work to be
 * done, so just try to conserve power and have a
 * low exit latency (ie sit in a loop waiting for
 * somebody to say that they'd like to reschedule)
 */
void cpu_idle (void)
{
	/* endless idle loop with no priority at all */
	while (1) {
		while (!need_resched()) {
			void (*idle)(void);
			/*
			 * Mark this as an RCU critical section so that
			 * synchronize_kernel() in the unload path waits
			 * for our completion.
			 */
			idle = pm_idle;
			if (!idle)
				idle = default_idle;
			idle();
		}
		preempt_enable_no_resched();
		schedule();
		preempt_disable();
	}
}

void hard_reset_now (void);

void machine_restart(char *cmd)
{
	hard_reset_now();
}

/*
 * Similar to machine_power_off, but don't shut off power.  Add code
 * here to freeze the system for e.g. post-mortem debug purpose when
 * possible.  This halt has nothing to do with the idle halt.
 */

void machine_halt(void)
{
}

/* If or when software power-off is implemented, add code here.  */

void machine_power_off(void)
{
}

/*
 * When a process does an "exec", machine state like FPU and debug
 * registers need to be reset.  This is a hook function for that.
 * Currently we don't have any such state to reset, so this is empty.
 */

void flush_thread(void)
{
}

/*
 * fill in the user structure for a core dump..
 */
void dump_thread(struct pt_regs * regs, struct user * dump)
{
#if 0
	int i;

	/* changed the size calculations - should hopefully work better. lbt */
	dump->magic = CMAGIC;
	dump->start_code = 0;
	dump->start_stack = regs->esp & ~(PAGE_SIZE - 1);
	dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
	dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1))) >> PAGE_SHIFT;
	dump->u_dsize -= dump->u_tsize;
	dump->u_ssize = 0;
	for (i = 0; i < 8; i++)
		dump->u_debugreg[i] = current->debugreg[i];  

	if (dump->start_stack < TASK_SIZE)
		dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT;

	dump->regs = *regs;

	dump->u_fpvalid = dump_fpu (regs, &dump->i387);
#endif 
}

/* Fill in the fpu structure for a core dump. */
int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
{
        return 0;
}