xref: /linux/arch/um/kernel/skas/process.c (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4  */
5 
6 #include <linux/init.h>
7 #include <linux/sched/mm.h>
8 #include <linux/sched/task_stack.h>
9 #include <linux/sched/task.h>
10 
11 #include <asm/tlbflush.h>
12 
13 #include <as-layout.h>
14 #include <kern.h>
15 #include <os.h>
16 #include <skas.h>
17 #include <kern_util.h>
18 
19 extern void start_kernel(void);
20 
21 static int __init start_kernel_proc(void *unused)
22 {
23 	block_signals_trace();
24 
25 	cpu_tasks[0].task = current;
26 
27 	start_kernel();
28 	return 0;
29 }
30 
31 extern int userspace_pid[];
32 
33 extern char cpu0_irqstack[];
34 
35 int __init start_uml(void)
36 {
37 	stack_protections((unsigned long) &cpu0_irqstack);
38 	set_sigstack(cpu0_irqstack, THREAD_SIZE);
39 
40 	init_new_thread_signals();
41 
42 	init_task.thread.request.u.thread.proc = start_kernel_proc;
43 	init_task.thread.request.u.thread.arg = NULL;
44 	return start_idle_thread(task_stack_page(&init_task),
45 				 &init_task.thread.switch_buf);
46 }
47 
48 unsigned long current_stub_stack(void)
49 {
50 	if (current->mm == NULL)
51 		return 0;
52 
53 	return current->mm->context.id.stack;
54 }
55 
56 struct mm_id *current_mm_id(void)
57 {
58 	if (current->mm == NULL)
59 		return NULL;
60 
61 	return &current->mm->context.id;
62 }
63 
64 void current_mm_sync(void)
65 {
66 	if (current->mm == NULL)
67 		return;
68 
69 	um_tlb_sync(current->mm);
70 }
71