summaryrefslogtreecommitdiffstats
path: root/arch/um/kernel/skas/process_kern.c
blob: 5d096ea63b97a696be392daa08d92536a6375c9c (plain)
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
/* 
 * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
 * Licensed under the GPL
 */

#include "linux/sched.h"
#include "linux/slab.h"
#include "linux/ptrace.h"
#include "linux/proc_fs.h"
#include "linux/file.h"
#include "linux/errno.h"
#include "linux/init.h"
#include "asm/uaccess.h"
#include "asm/atomic.h"
#include "kern_util.h"
#include "time_user.h"
#include "signal_user.h"
#include "skas.h"
#include "os.h"
#include "user_util.h"
#include "tlb.h"
#include "kern.h"
#include "mode.h"
#include "proc_mm.h"
#include "registers.h"

void *switch_to_skas(void *prev, void *next)
{
	struct task_struct *from, *to;

	from = prev;
	to = next;

	/* XXX need to check runqueues[cpu].idle */
	if(current->pid == 0)
		switch_timers(0);

	to->thread.prev_sched = from;
	set_current(to);

	switch_threads(&from->thread.mode.skas.switch_buf, 
		       to->thread.mode.skas.switch_buf);

	if(current->pid == 0)
		switch_timers(1);

	return(current->thread.prev_sched);
}

extern void schedule_tail(struct task_struct *prev);

void new_thread_handler(int sig)
{
	int (*fn)(void *), n;
	void *arg;

	fn = current->thread.request.u.thread.proc;
	arg = current->thread.request.u.thread.arg;
	change_sig(SIGUSR1, 1);
	thread_wait(&current->thread.mode.skas.switch_buf, 
		    current->thread.mode.skas.fork_buf);

	if(current->thread.prev_sched != NULL)
		schedule_tail(current->thread.prev_sched);
	current->thread.prev_sched = NULL;

	/* The return value is 1 if the kernel thread execs a process,
	 * 0 if it just exits
	 */
	n = run_kernel_thread(fn, arg, &current->thread.exec_buf);
	if(n == 1)
		userspace(&current->thread.regs.regs);
	else do_exit(0);
}

void new_thread_proc(void *stack, void (*handler)(int sig))
{
	init_new_thread_stack(stack, handler);
	os_usr1_process(os_getpid());
}

void release_thread_skas(struct task_struct *task)
{
}

void exit_thread_skas(void)
{
}

void fork_handler(int sig)
{
        change_sig(SIGUSR1, 1);
 	thread_wait(&current->thread.mode.skas.switch_buf, 
		    current->thread.mode.skas.fork_buf);
  	
	force_flush_all();
	if(current->thread.prev_sched == NULL)
		panic("blech");

	schedule_tail(current->thread.prev_sched);
	current->thread.prev_sched = NULL;

	userspace(&current->thread.regs.regs);
}

int copy_thread_skas(int nr, unsigned long clone_flags, unsigned long sp,
		     unsigned long stack_top, struct task_struct * p, 
		     struct pt_regs *regs)
{
  	void (*handler)(int);

	if(current->thread.forking){
	  	memcpy(&p->thread.regs.regs.skas, 
		       &current->thread.regs.regs.skas, 
		       sizeof(p->thread.regs.regs.skas));
		REGS_SET_SYSCALL_RETURN(p->thread.regs.regs.skas.regs, 0);
		if(sp != 0) REGS_SP(p->thread.regs.regs.skas.regs) = sp;

		handler = fork_handler;
	}
	else {
		init_thread_registers(&p->thread.regs.regs);
                p->thread.request.u.thread = current->thread.request.u.thread;
		handler = new_thread_handler;
	}

	new_thread(p->thread_info, &p->thread.mode.skas.switch_buf,
		   &p->thread.mode.skas.fork_buf, handler);
	return(0);
}

int new_mm(int from)
{
	struct proc_mm_op copy;
	int n, fd;

	fd = os_open_file("/proc/mm", of_cloexec(of_write(OPENFLAGS())), 0);
	if(fd < 0)
		return(fd);

	if(from != -1){
		copy = ((struct proc_mm_op) { .op 	= MM_COPY_SEGMENTS,
					      .u 	=
					      { .copy_segments	= from } } );
		n = os_write_file(fd, &copy, sizeof(copy));
		if(n != sizeof(copy))
			printk("new_mm : /proc/mm copy_segments failed, "
			       "err = %d\n", -n);
	}

	return(fd);
}

void init_idle_skas(void)
{
	cpu_tasks[current_thread->cpu].pid = os_getpid();
	default_idle();
}

extern void start_kernel(void);

static int start_kernel_proc(void *unused)
{
	int pid;

	block_signals();
	pid = os_getpid();

	cpu_tasks[0].pid = pid;
	cpu_tasks[0].task = current;
#ifdef CONFIG_SMP
 	cpu_online_map = cpumask_of_cpu(0);
#endif
	start_kernel();
	return(0);
}

int start_uml_skas(void)
{
	start_userspace(0);

	init_new_thread_signals(1);
	uml_idle_timer();

	init_task.thread.request.u.thread.proc = start_kernel_proc;
	init_task.thread.request.u.thread.arg = NULL;
	return(start_idle_thread(init_task.thread_info,
				 &init_task.thread.mode.skas.switch_buf,
				 &init_task.thread.mode.skas.fork_buf));
}

int external_pid_skas(struct task_struct *task)
{
#warning Need to look up userspace_pid by cpu
	return(userspace_pid[0]);
}

int thread_pid_skas(struct task_struct *task)
{
#warning Need to look up userspace_pid by cpu
	return(userspace_pid[0]);
}

/*
 * Overrides for Emacs so that we follow Linus's tabbing style.
 * Emacs will notice this stuff at the end of the file and automatically
 * adjust the settings for this buffer only.  This must remain at the end
 * of the file.
 * ---------------------------------------------------------------------------
 * Local variables:
 * c-file-style: "linux"
 * End:
 */