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1/* thread_info.h: x86_64 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 <asm/page.h>
13#include <asm/types.h>
14#include <asm/pda.h>
15
16/*
17 * low level task data that entry.S needs immediate access to
18 * - this struct should fit entirely inside of one cache line
19 * - this struct shares the supervisor stack pages
20 */
21#ifndef __ASSEMBLY__
22struct task_struct;
23struct exec_domain;
24#include <asm/mmsegment.h>
25
26struct thread_info {
27 struct task_struct *task; /* main task structure */
28 struct exec_domain *exec_domain; /* execution domain */
29 __u32 flags; /* low level flags */
30 __u32 status; /* thread synchronous flags */
31 __u32 cpu; /* current CPU */
32 int preempt_count; /* 0 => preemptable, <0 => BUG */
33
34 mm_segment_t addr_limit;
35 struct restart_block restart_block;
36};
37#endif
38
39/*
40 * macros/functions for gaining access to the thread information structure
41 * preempt_count needs to be 1 initially, until the scheduler is functional.
42 */
43#ifndef __ASSEMBLY__
44#define INIT_THREAD_INFO(tsk) \
45{ \
46 .task = &tsk, \
47 .exec_domain = &default_exec_domain, \
48 .flags = 0, \
49 .cpu = 0, \
50 .preempt_count = 1, \
51 .addr_limit = KERNEL_DS, \
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
60static inline struct thread_info *current_thread_info(void)
61{
62 struct thread_info *ti;
63 ti = (void *)(read_pda(kernelstack) + PDA_STACKOFFSET - THREAD_SIZE);
64 return ti;
65}
66
67/* do not use in interrupt context */
68static inline struct thread_info *stack_thread_info(void)
69{
70 struct thread_info *ti;
71 __asm__("andq %%rsp,%0; ":"=r" (ti) : "0" (~(THREAD_SIZE - 1)));
72 return ti;
73}
74
75/* thread information allocation */
76#define alloc_thread_info(tsk) \
77 ((struct thread_info *) __get_free_pages(GFP_KERNEL,THREAD_ORDER))
78#define free_thread_info(ti) free_pages((unsigned long) (ti), THREAD_ORDER)
79
80#else /* !__ASSEMBLY__ */
81
82/* how to get the thread information struct from ASM */
83#define GET_THREAD_INFO(reg) \
84 movq %gs:pda_kernelstack,reg ; \
85 subq $(THREAD_SIZE-PDA_STACKOFFSET),reg
86
87#endif
88
89/*
90 * thread information flags
91 * - these are process state flags that various assembly files may need to access
92 * - pending work-to-be-done flags are in LSW
93 * - other flags in MSW
94 * Warning: layout of LSW is hardcoded in entry.S
95 */
96#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
97#define TIF_NOTIFY_RESUME 1 /* resumption notification requested */
98#define TIF_SIGPENDING 2 /* signal pending */
99#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
100#define TIF_SINGLESTEP 4 /* reenable singlestep on user return*/
101#define TIF_IRET 5 /* force IRET */
102#define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */
103#define TIF_SECCOMP 8 /* secure computing */
104#define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
105#define TIF_IA32 17 /* 32bit process */
106#define TIF_FORK 18 /* ret_from_fork */
107#define TIF_ABI_PENDING 19
108#define TIF_MEMDIE 20
109
110#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
111#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
112#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
113#define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP)
114#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
115#define _TIF_IRET (1<<TIF_IRET)
116#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
117#define _TIF_SECCOMP (1<<TIF_SECCOMP)
118#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
119#define _TIF_IA32 (1<<TIF_IA32)
120#define _TIF_FORK (1<<TIF_FORK)
121#define _TIF_ABI_PENDING (1<<TIF_ABI_PENDING)
122
123/* work to do on interrupt/exception return */
124#define _TIF_WORK_MASK \
125 (0x0000FFFF & ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP|_TIF_SECCOMP))
126/* work to do on any return to user space */
127#define _TIF_ALLWORK_MASK (0x0000FFFF & ~_TIF_SECCOMP)
128
129#define PREEMPT_ACTIVE 0x10000000
130
131/*
132 * Thread-synchronous status.
133 *
134 * This is different from the flags in that nobody else
135 * ever touches our thread-synchronous status, so we don't
136 * have to worry about atomic accesses.
137 */
138#define TS_USEDFPU 0x0001 /* FPU was used by this task this quantum (SMP) */
139#define TS_COMPAT 0x0002 /* 32bit syscall active */
140
141#endif /* __KERNEL__ */
142
143#endif /* _ASM_THREAD_INFO_H */