1/* thread_info.h: m68knommu low-level thread information
2 * adapted from the i386 and PPC versions by Greg Ungerer (gerg@snapgear.com)
3 *
4 * Copyright (C) 2002  David Howells (dhowells@redhat.com)
5 * - Incorporating suggestions made by Linus Torvalds and Dave Miller
6 */
7
8#ifndef _ASM_THREAD_INFO_H
9#define _ASM_THREAD_INFO_H
10
11#include <asm/page.h>
12
13#ifdef __KERNEL__
14
15#ifndef __ASSEMBLY__
16
17/*
18 * Size of kernel stack for each process. This must be a power of 2...
19 */
20#ifdef CONFIG_4KSTACKS
21#define THREAD_SIZE_ORDER (0)
22#else
23#define THREAD_SIZE_ORDER (1)
24#endif
25
26/*
27 * for asm files, THREAD_SIZE is now generated by asm-offsets.c
28 */
29#define THREAD_SIZE (PAGE_SIZE<<THREAD_SIZE_ORDER)
30
31/*
32 * low level task data.
33 */
34struct thread_info {
35	struct task_struct *task;		/* main task structure */
36	struct exec_domain *exec_domain;	/* execution domain */
37	unsigned long	   flags;		/* low level flags */
38	int		   cpu;			/* cpu we're on */
39	int		   preempt_count;	/* 0 => preemptable, <0 => BUG */
40	struct restart_block restart_block;
41};
42
43/*
44 * macros/functions for gaining access to the thread information structure
45 */
46#define INIT_THREAD_INFO(tsk)			\
47{						\
48	.task		= &tsk,			\
49	.exec_domain	= &default_exec_domain,	\
50	.flags		= 0,			\
51	.cpu		= 0,			\
52	.restart_block	= {			\
53		.fn = do_no_restart_syscall,	\
54	},					\
55}
56
57#define init_thread_info	(init_thread_union.thread_info)
58#define init_stack		(init_thread_union.stack)
59
60
61/* how to get the thread information struct from C */
62static inline struct thread_info *current_thread_info(void)
63{
64	struct thread_info *ti;
65	__asm__(
66		"move.l	%%sp, %0 \n\t"
67		"and.l	%1, %0"
68		: "=&d"(ti)
69		: "di" (~(THREAD_SIZE-1))
70		);
71	return ti;
72}
73
74/* thread information allocation */
75#define alloc_thread_info(tsk) ((struct thread_info *) \
76				__get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER))
77#define free_thread_info(ti)	free_pages((unsigned long) (ti), THREAD_SIZE_ORDER)
78#endif /* __ASSEMBLY__ */
79
80#define	PREEMPT_ACTIVE	0x4000000
81
82/*
83 * thread information flag bit numbers
84 */
85#define TIF_SYSCALL_TRACE	0	/* syscall trace active */
86#define TIF_NOTIFY_RESUME	1	/* resumption notification requested */
87#define TIF_SIGPENDING		2	/* signal pending */
88#define TIF_NEED_RESCHED	3	/* rescheduling necessary */
89#define TIF_POLLING_NRFLAG	4	/* true if poll_idle() is polling
90					   TIF_NEED_RESCHED */
91#define TIF_MEMDIE		5
92
93/* as above, but as bit values */
94#define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
95#define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
96#define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
97#define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
98#define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
99
100#define _TIF_WORK_MASK		0x0000FFFE	/* work to do on interrupt/exception return */
101
102#endif /* __KERNEL__ */
103
104#endif /* _ASM_THREAD_INFO_H */
105