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
|
/* $Id: process.c,v 1.4 2000/01/16 01:34:01 ralf Exp $
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1994 - 1999 by Ralf Baechle and others.
* Copyright (C) 1999 Silicon Graphics, Inc.
*/
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/malloc.h>
#include <linux/mman.h>
#include <linux/sys.h>
#include <linux/user.h>
#include <linux/a.out.h>
#include <asm/bootinfo.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/mipsregs.h>
#include <asm/processor.h>
#include <asm/stackframe.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/elf.h>
asmlinkage int cpu_idle(void)
{
/* endless idle loop with no priority at all */
init_idle();
current->priority = 0;
current->counter = -100;
while (1) {
while (!current->need_resched)
if (wait_available)
__asm__("wait");
schedule();
check_pgt_cache();
}
}
struct task_struct *last_task_used_math = NULL;
asmlinkage void ret_from_fork(void);
void exit_thread(void)
{
/* Forget lazy fpu state */
if (last_task_used_math == current) {
set_cp0_status(ST0_CU1, ST0_CU1);
__asm__ __volatile__("cfc1\t$0,$31");
last_task_used_math = NULL;
}
}
void flush_thread(void)
{
/* Forget lazy fpu state */
if (last_task_used_math == current) {
set_cp0_status(ST0_CU1, ST0_CU1);
__asm__ __volatile__("cfc1\t$0,$31");
last_task_used_math = NULL;
}
}
int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
struct task_struct * p, struct pt_regs * regs)
{
struct pt_regs * childregs;
long childksp;
childksp = (unsigned long)p + KERNEL_STACK_SIZE - 32;
if (last_task_used_math == current) {
set_cp0_status(ST0_CU1, ST0_CU1);
save_fp(p);
}
/* set up new TSS. */
childregs = (struct pt_regs *) childksp - 1;
*childregs = *regs;
childregs->regs[7] = 0; /* Clear error flag */
if (current->personality == PER_LINUX) {
childregs->regs[2] = 0; /* Child gets zero as return value */
regs->regs[2] = p->pid;
} else {
/* Under IRIX things are a little different. */
childregs->regs[2] = 0;
childregs->regs[3] = 1;
regs->regs[2] = p->pid;
regs->regs[3] = 0;
}
if (childregs->cp0_status & ST0_CU0) {
childregs->regs[28] = (unsigned long) p;
childregs->regs[29] = childksp;
p->thread.current_ds = KERNEL_DS;
} else {
childregs->regs[29] = usp;
p->thread.current_ds = USER_DS;
}
p->thread.reg29 = (unsigned long) childregs;
p->thread.reg31 = (unsigned long) ret_from_fork;
/*
* New tasks loose permission to use the fpu. This accelerates context
* switching for most programs since they don't use the fpu.
*/
p->thread.cp0_status = read_32bit_cp0_register(CP0_STATUS) &
~(ST0_CU3|ST0_CU2|ST0_CU1|ST0_KSU);
childregs->cp0_status &= ~(ST0_CU3|ST0_CU2|ST0_CU1);
return 0;
}
/* Fill in the fpu structure for a core dump.. */
int dump_fpu(struct pt_regs *regs, elf_fpregset_t *r)
{
/* We actually store the FPU info in the task->thread
* area.
*/
if(regs->cp0_status & ST0_CU1) {
memcpy(r, ¤t->thread.fpu, sizeof(current->thread.fpu));
return 1;
}
return 0; /* Task didn't use the fpu at all. */
}
/* Fill in the user structure for a core dump.. */
void dump_thread(struct pt_regs *regs, struct user *dump)
{
dump->magic = CMAGIC;
dump->start_code = current->mm->start_code;
dump->start_data = current->mm->start_data;
dump->start_stack = regs->regs[29] & ~(PAGE_SIZE - 1);
dump->u_tsize = (current->mm->end_code - dump->start_code)
>> PAGE_SHIFT;
dump->u_dsize = (current->mm->brk + (PAGE_SIZE - 1) - dump->start_data)
>> PAGE_SHIFT;
dump->u_ssize = (current->mm->start_stack - dump->start_stack +
PAGE_SIZE - 1) >> PAGE_SHIFT;
memcpy(&dump->regs[0], regs, sizeof(struct pt_regs));
memcpy(&dump->regs[EF_SIZE/4], ¤t->thread.fpu,
sizeof(current->thread.fpu));
}
/*
* Create a kernel thread
*/
int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
{
int retval;
__asm__ __volatile__(
"move\t$6, $sp\n\t"
"move\t$4, %5\n\t"
"li\t$2, %1\n\t"
"syscall\n\t"
"beq\t$6, $sp, 1f\n\t"
"move\t$4, %3\n\t"
"jalr\t%4\n\t"
"move\t$4, $2\n\t"
"li\t$2, %2\n\t"
"syscall\n"
"1:\tmove\t%0, $2"
:"=r" (retval)
:"i" (__NR_clone), "i" (__NR_exit), "r" (arg), "r" (fn),
"r" (flags | CLONE_VM)
/* The called subroutine might have destroyed any of the
* at, result, argument or temporary registers ... */
:"$1", "$2", "$3", "$4", "$5", "$6", "$7", "$8",
"$9","$10","$11","$12","$13","$14","$15","$24","$25");
return retval;
}
/*
* These bracket the sleeping functions..
*/
extern void scheduling_functions_start_here(void);
extern void scheduling_functions_end_here(void);
#define first_sched ((unsigned long) scheduling_functions_start_here)
#define last_sched ((unsigned long) scheduling_functions_end_here)
unsigned long get_wchan(struct task_struct *p)
{
unsigned long schedule_frame;
unsigned long pc;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
pc = thread_saved_pc(&p->thread);
if (pc == (unsigned long) interruptible_sleep_on
|| pc == (unsigned long) sleep_on) {
schedule_frame = ((unsigned long *)p->thread.reg30)[9];
return ((unsigned long *)schedule_frame)[15];
}
if (pc == (unsigned long) interruptible_sleep_on_timeout
|| pc == (unsigned long) sleep_on_timeout) {
schedule_frame = ((unsigned long *)p->thread.reg30)[9];
return ((unsigned long *)schedule_frame)[16];
}
if (pc >= first_sched && pc < last_sched) {
printk(KERN_DEBUG "Bug in %s\n", __FUNCTION__);
}
return pc;
}
|
