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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* 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 */
Jesper Juhldcd497f2005-06-23 00:09:07 -070039 int preempt_count; /* 0 => preemptable, <0 => BUG */
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 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)
Linus Torvalds1da177e2005-04-16 15:20:36 -070078#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 */