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
|
/*
* linux/arch/cris/kernel/process.c
*
* Copyright (C) 1995 Linus Torvalds
* Copyright (C) 2000-2002 Axis Communications AB
*
* Authors: Bjorn Wesen (bjornw@axis.com)
* Mikael Starvik (starvik@axis.com)
*
* This file handles the architecture-dependent parts of process handling..
*/
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/sched/task.h>
#include <linux/sched/task_stack.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/fs.h>
#include <arch/svinto.h>
#include <linux/init.h>
#include <arch/system.h>
#include <linux/ptrace.h>
#ifdef CONFIG_ETRAX_GPIO
void etrax_gpio_wake_up_check(void); /* drivers/gpio.c */
#endif
/*
* We use this if we don't have any better
* idle routine..
*/
void default_idle(void)
{
#ifdef CONFIG_ETRAX_GPIO
etrax_gpio_wake_up_check();
#endif
local_irq_enable();
}
/* if the watchdog is enabled, we can simply disable interrupts and go
* into an eternal loop, and the watchdog will reset the CPU after 0.1s
* if on the other hand the watchdog wasn't enabled, we just enable it and wait
*/
void hard_reset_now (void)
{
/*
* Don't declare this variable elsewhere. We don't want any other
* code to know about it than the watchdog handler in entry.S and
* this code, implementing hard reset through the watchdog.
*/
#if defined(CONFIG_ETRAX_WATCHDOG)
extern int cause_of_death;
#endif
printk("*** HARD RESET ***\n");
local_irq_disable();
#if defined(CONFIG_ETRAX_WATCHDOG)
cause_of_death = 0xbedead;
#else
/* Since we dont plan to keep on resetting the watchdog,
the key can be arbitrary hence three */
*R_WATCHDOG = IO_FIELD(R_WATCHDOG, key, 3) |
IO_STATE(R_WATCHDOG, enable, start);
#endif
while(1) /* waiting for RETRIBUTION! */ ;
}
/* setup the child's kernel stack with a pt_regs and switch_stack on it.
* it will be un-nested during _resume and _ret_from_sys_call when the
* new thread is scheduled.
*
* also setup the thread switching structure which is used to keep
* thread-specific data during _resumes.
*
*/
asmlinkage void ret_from_fork(void);
asmlinkage void ret_from_kernel_thread(void);
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long arg, struct task_struct *p)
{
struct pt_regs *childregs = task_pt_regs(p);
struct switch_stack *swstack = ((struct switch_stack *)childregs) - 1;
/* put the pt_regs structure at the end of the new kernel stack page and fix it up
* remember that the task_struct doubles as the kernel stack for the task
*/
if (unlikely(p->flags & PF_KTHREAD)) {
memset(swstack, 0,
sizeof(struct switch_stack) + sizeof(struct pt_regs));
swstack->r1 = usp;
swstack->r2 = arg;
childregs->dccr = 1 << I_DCCR_BITNR;
swstack->return_ip = (unsigned long) ret_from_kernel_thread;
p->thread.ksp = (unsigned long) swstack;
p->thread.usp = 0;
return 0;
}
*childregs = *current_pt_regs(); /* struct copy of pt_regs */
childregs->r10 = 0; /* child returns 0 after a fork/clone */
/* put the switch stack right below the pt_regs */
swstack->r9 = 0; /* parameter to ret_from_sys_call, 0 == dont restart the syscall */
/* we want to return into ret_from_sys_call after the _resume */
swstack->return_ip = (unsigned long) ret_from_fork; /* Will call ret_from_sys_call */
/* fix the user-mode stackpointer */
p->thread.usp = usp ?: rdusp();
/* and the kernel-mode one */
p->thread.ksp = (unsigned long) swstack;
#ifdef DEBUG
printk("copy_thread: new regs at 0x%p, as shown below:\n", childregs);
show_registers(childregs);
#endif
return 0;
}
unsigned long get_wchan(struct task_struct *p)
{
#if 0
/* YURGH. TODO. */
unsigned long ebp, esp, eip;
unsigned long stack_page;
int count = 0;
if (!p || p == current || p->state == TASK_RUNNING)
return 0;
stack_page = (unsigned long)p;
esp = p->thread.esp;
if (!stack_page || esp < stack_page || esp > 8188+stack_page)
return 0;
/* include/asm-i386/system.h:switch_to() pushes ebp last. */
ebp = *(unsigned long *) esp;
do {
if (ebp < stack_page || ebp > 8184+stack_page)
return 0;
eip = *(unsigned long *) (ebp+4);
if (!in_sched_functions(eip))
return eip;
ebp = *(unsigned long *) ebp;
} while (count++ < 16);
#endif
return 0;
}
#undef last_sched
#undef first_sched
void show_regs(struct pt_regs * regs)
{
unsigned long usp = rdusp();
show_regs_print_info(KERN_DEFAULT);
printk("IRP: %08lx SRP: %08lx DCCR: %08lx USP: %08lx MOF: %08lx\n",
regs->irp, regs->srp, regs->dccr, usp, regs->mof );
printk(" r0: %08lx r1: %08lx r2: %08lx r3: %08lx\n",
regs->r0, regs->r1, regs->r2, regs->r3);
printk(" r4: %08lx r5: %08lx r6: %08lx r7: %08lx\n",
regs->r4, regs->r5, regs->r6, regs->r7);
printk(" r8: %08lx r9: %08lx r10: %08lx r11: %08lx\n",
regs->r8, regs->r9, regs->r10, regs->r11);
printk("r12: %08lx r13: %08lx oR10: %08lx\n",
regs->r12, regs->r13, regs->orig_r10);
}
|
