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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* thread_info.h: i386 low-level thread information
2 *
3 * Copyright (C) 2002 David Howells (dhowells@redhat.com)
4 * - Incorporating suggestions made by Linus Torvalds and Dave Miller
5 */
6
7#ifndef _ASM_THREAD_INFO_H
8#define _ASM_THREAD_INFO_H
9
10#ifdef __KERNEL__
11
12#include <linux/config.h>
13#include <linux/compiler.h>
14#include <asm/page.h>
15
16#ifndef __ASSEMBLY__
17#include <asm/processor.h>
18#endif
19
20/*
21 * low level task data that entry.S needs immediate access to
22 * - this struct should fit entirely inside of one cache line
23 * - this struct shares the supervisor stack pages
24 * - if the contents of this structure are changed, the assembly constants must also be changed
25 */
26#ifndef __ASSEMBLY__
27
28struct thread_info {
29 struct task_struct *task; /* main task structure */
30 struct exec_domain *exec_domain; /* execution domain */
31 unsigned long flags; /* low level flags */
32 unsigned long status; /* thread-synchronous flags */
33 __u32 cpu; /* current CPU */
Jesper Juhldcd497f2005-06-23 00:09:07 -070034 int preempt_count; /* 0 => preemptable, <0 => BUG */
Linus Torvalds1da177e2005-04-16 15:20:36 -070035
36
37 mm_segment_t addr_limit; /* thread address space:
38 0-0xBFFFFFFF for user-thead
39 0-0xFFFFFFFF for kernel-thread
40 */
41 struct restart_block restart_block;
42
43 unsigned long previous_esp; /* ESP of the previous stack in case
44 of nested (IRQ) stacks
45 */
46 __u8 supervisor_stack[0];
47};
48
49#else /* !__ASSEMBLY__ */
50
Sam Ravnborg86feeaa2005-09-09 19:28:28 +020051#include <asm/asm-offsets.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070052
53#endif
54
55#define PREEMPT_ACTIVE 0x10000000
56#ifdef CONFIG_4KSTACKS
57#define THREAD_SIZE (4096)
58#else
59#define THREAD_SIZE (8192)
60#endif
61
62#define STACK_WARN (THREAD_SIZE/8)
63/*
64 * macros/functions for gaining access to the thread information structure
65 *
66 * preempt_count needs to be 1 initially, until the scheduler is functional.
67 */
68#ifndef __ASSEMBLY__
69
70#define INIT_THREAD_INFO(tsk) \
71{ \
72 .task = &tsk, \
73 .exec_domain = &default_exec_domain, \
74 .flags = 0, \
75 .cpu = 0, \
76 .preempt_count = 1, \
77 .addr_limit = KERNEL_DS, \
78 .restart_block = { \
79 .fn = do_no_restart_syscall, \
80 }, \
81}
82
83#define init_thread_info (init_thread_union.thread_info)
84#define init_stack (init_thread_union.stack)
85
86
87/* how to get the thread information struct from C */
88static inline struct thread_info *current_thread_info(void)
89{
90 struct thread_info *ti;
91 __asm__("andl %%esp,%0; ":"=r" (ti) : "0" (~(THREAD_SIZE - 1)));
92 return ti;
93}
94
95/* how to get the current stack pointer from C */
96register unsigned long current_stack_pointer asm("esp") __attribute_used__;
97
98/* thread information allocation */
99#ifdef CONFIG_DEBUG_STACK_USAGE
100#define alloc_thread_info(tsk) \
101 ({ \
102 struct thread_info *ret; \
103 \
104 ret = kmalloc(THREAD_SIZE, GFP_KERNEL); \
105 if (ret) \
106 memset(ret, 0, THREAD_SIZE); \
107 ret; \
108 })
109#else
110#define alloc_thread_info(tsk) kmalloc(THREAD_SIZE, GFP_KERNEL)
111#endif
112
113#define free_thread_info(info) kfree(info)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114
115#else /* !__ASSEMBLY__ */
116
117/* how to get the thread information struct from ASM */
118#define GET_THREAD_INFO(reg) \
119 movl $-THREAD_SIZE, reg; \
120 andl %esp, reg
121
122/* use this one if reg already contains %esp */
123#define GET_THREAD_INFO_WITH_ESP(reg) \
124 andl $-THREAD_SIZE, reg
125
126#endif
127
128/*
129 * thread information flags
130 * - these are process state flags that various assembly files may need to access
131 * - pending work-to-be-done flags are in LSW
132 * - other flags in MSW
133 */
134#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
135#define TIF_NOTIFY_RESUME 1 /* resumption notification requested */
136#define TIF_SIGPENDING 2 /* signal pending */
137#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
138#define TIF_SINGLESTEP 4 /* restore singlestep on return to user mode */
139#define TIF_IRET 5 /* return with iret */
Laurent Viviered75e8d2005-09-03 15:57:18 -0700140#define TIF_SYSCALL_EMU 6 /* syscall emulation active */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141#define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */
142#define TIF_SECCOMP 8 /* secure computing */
David Howells283828f2006-01-18 17:44:00 -0800143#define TIF_RESTORE_SIGMASK 9 /* restore signal mask in do_signal() */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144#define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
145#define TIF_MEMDIE 17
146
147#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
148#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
149#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
150#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
151#define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP)
152#define _TIF_IRET (1<<TIF_IRET)
Laurent Viviered75e8d2005-09-03 15:57:18 -0700153#define _TIF_SYSCALL_EMU (1<<TIF_SYSCALL_EMU)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
155#define _TIF_SECCOMP (1<<TIF_SECCOMP)
David Howells283828f2006-01-18 17:44:00 -0800156#define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
158
159/* work to do on interrupt/exception return */
160#define _TIF_WORK_MASK \
Laurent Viviered75e8d2005-09-03 15:57:18 -0700161 (0x0000FFFF & ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP|\
162 _TIF_SECCOMP|_TIF_SYSCALL_EMU))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163/* work to do on any return to u-space */
164#define _TIF_ALLWORK_MASK (0x0000FFFF & ~_TIF_SECCOMP)
165
166/*
167 * Thread-synchronous status.
168 *
169 * This is different from the flags in that nobody else
170 * ever touches our thread-synchronous status, so we don't
171 * have to worry about atomic accesses.
172 */
173#define TS_USEDFPU 0x0001 /* FPU was used by this task this quantum (SMP) */
174
175#endif /* __KERNEL__ */
176
177#endif /* _ASM_THREAD_INFO_H */