1 /* $Id: process.c,v 1.17 2004/04/05 13:53:48 starvik Exp $
3 * linux/arch/cris/kernel/process.c
5 * Copyright (C) 1995 Linus Torvalds
6 * Copyright (C) 2000-2002 Axis Communications AB
8 * Authors: Bjorn Wesen (bjornw@axis.com)
11 * Revision 1.17 2004/04/05 13:53:48 starvik
12 * Merge of Linux 2.6.5
14 * Revision 1.16 2003/10/27 08:04:33 starvik
15 * Merge of Linux 2.6.0-test9
17 * Revision 1.15 2003/09/11 07:29:52 starvik
18 * Merge of Linux 2.6.0-test5
20 * Revision 1.14 2003/06/10 10:21:12 johana
21 * Moved thread_saved_pc() from arch/cris/kernel/process.c to
22 * subarch specific process.c. arch-v32 has an erp, no irp.
24 * Revision 1.13 2003/04/09 05:20:47 starvik
25 * Merge of Linux 2.5.67
27 * Revision 1.12 2002/12/11 15:41:11 starvik
28 * Extracted v10 (ETRAX 100LX) specific stuff to arch/cris/arch-v10/kernel
30 * Revision 1.11 2002/12/10 09:00:10 starvik
31 * Merge of Linux 2.5.51
33 * Revision 1.10 2002/11/27 08:42:34 starvik
34 * Argument to user_regs() is thread_info*
36 * Revision 1.9 2002/11/26 09:44:21 starvik
37 * New threads exits through ret_from_fork (necessary for preemptive scheduling)
39 * Revision 1.8 2002/11/19 14:35:24 starvik
40 * Changes from linux 2.4
41 * Changed struct initializer syntax to the currently prefered notation
43 * Revision 1.7 2002/11/18 07:39:42 starvik
44 * thread_saved_pc moved here from processor.h
46 * Revision 1.6 2002/11/14 06:51:27 starvik
47 * Made cpu_idle more similar with other archs
48 * init_task_union -> init_thread_union
49 * Updated for new interrupt macros
50 * sys_clone and do_fork have a new argument, user_tid
52 * Revision 1.5 2002/11/05 06:45:11 starvik
53 * Merge of Linux 2.5.45
55 * Revision 1.4 2002/02/05 15:37:44 bjornw
58 * Revision 1.3 2002/01/21 15:22:49 bjornw
59 * current->counter is gone
61 * Revision 1.22 2001/11/13 09:40:43 orjanf
62 * Added dump_fpu (needed for core dumps).
64 * Revision 1.21 2001/11/12 18:26:21 pkj
65 * Fixed compiler warnings.
67 * Revision 1.20 2001/10/03 08:21:39 jonashg
68 * cause_of_death does not exist if CONFIG_SVINTO_SIM is defined.
70 * Revision 1.19 2001/09/26 11:52:54 bjornw
71 * INIT_MMAP is gone in 2.4.10
73 * Revision 1.18 2001/08/21 21:43:51 hp
74 * Move last watchdog fix inside #ifdef CONFIG_ETRAX_WATCHDOG
76 * Revision 1.17 2001/08/21 13:48:01 jonashg
77 * Added fix by HP to avoid oops when doing a hard_reset_now.
79 * Revision 1.16 2001/06/21 02:00:40 hp
80 * * entry.S: Include asm/unistd.h.
81 * (_sys_call_table): Use section .rodata, not .data.
82 * (_kernel_thread): Move from...
83 * * process.c: ... here.
84 * * entryoffsets.c (VAL): Break out from...
86 * (LCLONE_VM): New asmified value from CLONE_VM.
88 * Revision 1.15 2001/06/20 16:31:57 hp
89 * Add comments to describe empty functions according to review.
91 * Revision 1.14 2001/05/29 11:27:59 markusl
92 * Fixed so that hard_reset_now will do reset even if watchdog wasn't enabled
94 * Revision 1.13 2001/03/20 19:44:06 bjornw
95 * Use the 7th syscall argument for regs instead of current_regs
100 * This file handles the architecture-dependent parts of process handling..
103 #include <asm/atomic.h>
104 #include <asm/pgtable.h>
105 #include <asm/uaccess.h>
107 #include <linux/module.h>
108 #include <linux/spinlock.h>
109 #include <linux/fs_struct.h>
110 #include <linux/init_task.h>
111 #include <linux/sched.h>
112 #include <linux/fs.h>
113 #include <linux/user.h>
114 #include <linux/elfcore.h>
115 #include <linux/mqueue.h>
116 #include <linux/reboot.h>
121 * Initial task structure. Make this a per-architecture thing,
122 * because different architectures tend to have different
123 * alignment requirements and potentially different initial
127 static struct fs_struct init_fs
= INIT_FS
;
128 static struct files_struct init_files
= INIT_FILES
;
129 static struct signal_struct init_signals
= INIT_SIGNALS(init_signals
);
130 static struct sighand_struct init_sighand
= INIT_SIGHAND(init_sighand
);
131 struct mm_struct init_mm
= INIT_MM(init_mm
);
133 EXPORT_SYMBOL(init_mm
);
136 * Initial thread structure.
138 * We need to make sure that this is 8192-byte aligned due to the
139 * way process stacks are handled. This is done by having a special
140 * "init_task" linker map entry..
142 union thread_union init_thread_union
143 __attribute__((__section__(".data.init_task"))) =
144 { INIT_THREAD_INFO(init_task
) };
147 * Initial task structure.
149 * All other task structs will be allocated on slabs in fork.c
151 struct task_struct init_task
= INIT_TASK(init_task
);
153 EXPORT_SYMBOL(init_task
);
156 * The hlt_counter, disable_hlt and enable_hlt is just here as a hook if
157 * there would ever be a halt sequence (for power save when idle) with
158 * some largish delay when halting or resuming *and* a driver that can't
159 * afford that delay. The hlt_counter would then be checked before
160 * executing the halt sequence, and the driver marks the unhaltable
161 * region by enable_hlt/disable_hlt.
164 static int hlt_counter
=0;
166 void disable_hlt(void)
171 EXPORT_SYMBOL(disable_hlt
);
173 void enable_hlt(void)
178 EXPORT_SYMBOL(enable_hlt
);
181 * The following aren't currently used.
183 void (*pm_idle
)(void);
185 extern void default_idle(void);
188 * The idle thread. There's no useful work to be
189 * done, so just try to conserve power and have a
190 * low exit latency (ie sit in a loop waiting for
191 * somebody to say that they'd like to reschedule)
195 /* endless idle loop with no priority at all */
197 while (!need_resched()) {
198 void (*idle
)(void) = pm_idle
;
210 void hard_reset_now (void);
212 void machine_restart(char *cmd
)
218 * Similar to machine_power_off, but don't shut off power. Add code
219 * here to freeze the system for e.g. post-mortem debug purpose when
220 * possible. This halt has nothing to do with the idle halt.
223 void machine_halt(void)
227 /* If or when software power-off is implemented, add code here. */
229 void machine_power_off(void)
234 * When a process does an "exec", machine state like FPU and debug
235 * registers need to be reset. This is a hook function for that.
236 * Currently we don't have any such state to reset, so this is empty.
239 void flush_thread(void)
244 * fill in the user structure for a core dump..
246 void dump_thread(struct pt_regs
* regs
, struct user
* dump
)
251 /* changed the size calculations - should hopefully work better. lbt */
252 dump
->magic
= CMAGIC
;
253 dump
->start_code
= 0;
254 dump
->start_stack
= regs
->esp
& ~(PAGE_SIZE
- 1);
255 dump
->u_tsize
= ((unsigned long) current
->mm
->end_code
) >> PAGE_SHIFT
;
256 dump
->u_dsize
= ((unsigned long) (current
->mm
->brk
+ (PAGE_SIZE
-1))) >> PAGE_SHIFT
;
257 dump
->u_dsize
-= dump
->u_tsize
;
259 for (i
= 0; i
< 8; i
++)
260 dump
->u_debugreg
[i
] = current
->debugreg
[i
];
262 if (dump
->start_stack
< TASK_SIZE
)
263 dump
->u_ssize
= ((unsigned long) (TASK_SIZE
- dump
->start_stack
)) >> PAGE_SHIFT
;
267 dump
->u_fpvalid
= dump_fpu (regs
, &dump
->i387
);
271 /* Fill in the fpu structure for a core dump. */
272 int dump_fpu(struct pt_regs
*regs
, elf_fpregset_t
*fpu
)