aboutsummaryrefslogtreecommitdiffstats
path: root/include/asm-x86_64/thread_info.h
blob: beae2bfb62cacdc7aa6705be207a59b11edea1ae (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
/* thread_info.h: x86_64 low-level thread information
 *
 * Copyright (C) 2002  David Howells (dhowells@redhat.com)
 * - Incorporating suggestions made by Linus Torvalds and Dave Miller
 */

#ifndef _ASM_THREAD_INFO_H
#define _ASM_THREAD_INFO_H

#ifdef __KERNEL__

#include <asm/page.h>
#include <asm/types.h>
#include <asm/pda.h>

/*
 * low level task data that entry.S needs immediate access to
 * - this struct should fit entirely inside of one cache line
 * - this struct shares the supervisor stack pages
 */
#ifndef __ASSEMBLY__
struct task_struct;
struct exec_domain;
#include <asm/mmsegment.h>

struct thread_info {
	struct task_struct	*task;		/* main task structure */
	struct exec_domain	*exec_domain;	/* execution domain */
	__u32			flags;		/* low level flags */
	__u32			status;		/* thread synchronous flags */
	__u32			cpu;		/* current CPU */
	int 			preempt_count;	/* 0 => preemptable, <0 => BUG */

	mm_segment_t		addr_limit;	
	struct restart_block    restart_block;
};
#endif

/*
 * macros/functions for gaining access to the thread information structure
 * preempt_count needs to be 1 initially, until the scheduler is functional.
 */
#ifndef __ASSEMBLY__
#define INIT_THREAD_INFO(tsk)			\
{						\
	.task	       = &tsk,			\
	.exec_domain   = &default_exec_domain,	\
	.flags	       = 0,			\
	.cpu	       = 0,			\
	.preempt_count = 1,			\
	.addr_limit     = KERNEL_DS,		\
	.restart_block = {			\
		.fn = do_no_restart_syscall,	\
	},					\
}

#define init_thread_info	(init_thread_union.thread_info)
#define init_stack		(init_thread_union.stack)

static inline struct thread_info *current_thread_info(void)
{ 
	struct thread_info *ti;
	ti = (void *)(read_pda(kernelstack) + PDA_STACKOFFSET - THREAD_SIZE);
	return ti; 
}

/* do not use in interrupt context */
static inline struct thread_info *stack_thread_info(void)
{
	struct thread_info *ti;
	__asm__("andq %%rsp,%0; ":"=r" (ti) : "0" (~(THREAD_SIZE - 1)));
	return ti;
}

/* thread information allocation */
#ifdef CONFIG_DEBUG_STACK_USAGE
#define alloc_thread_info(tsk)					\
    ({								\
	struct thread_info *ret;				\
								\
	ret = ((struct thread_info *) __get_free_pages(GFP_KERNEL,THREAD_ORDER)); \
	if (ret)						\
		memset(ret, 0, THREAD_SIZE);			\
	ret;							\
    })
#else
#define alloc_thread_info(tsk) \
	((struct thread_info *) __get_free_pages(GFP_KERNEL,THREAD_ORDER))
#endif

#define free_thread_info(ti) free_pages((unsigned long) (ti), THREAD_ORDER)

#else /* !__ASSEMBLY__ */

/* how to get the thread information struct from ASM */
#define GET_THREAD_INFO(reg) \
	movq %gs:pda_kernelstack,reg ; \
	subq $(THREAD_SIZE-PDA_STACKOFFSET),reg

#endif

/*
 * thread information flags
 * - these are process state flags that various assembly files may need to access
 * - pending work-to-be-done flags are in LSW
 * - other flags in MSW
 * Warning: layout of LSW is hardcoded in entry.S
 */
#define TIF_SYSCALL_TRACE	0	/* syscall trace active */
#define TIF_SIGPENDING		2	/* signal pending */
#define TIF_NEED_RESCHED	3	/* rescheduling necessary */
#define TIF_SINGLESTEP		4	/* reenable singlestep on user return*/
#define TIF_IRET		5	/* force IRET */
#define TIF_SYSCALL_AUDIT	7	/* syscall auditing active */
#define TIF_SECCOMP		8	/* secure computing */
#define TIF_RESTORE_SIGMASK	9	/* restore signal mask in do_signal */
#define TIF_MCE_NOTIFY		10	/* notify userspace of an MCE */
/* 16 free */
#define TIF_IA32		17	/* 32bit process */ 
#define TIF_FORK		18	/* ret_from_fork */
#define TIF_ABI_PENDING		19
#define TIF_MEMDIE		20
#define TIF_DEBUG		21	/* uses debug registers */
#define TIF_IO_BITMAP		22	/* uses I/O bitmap */
#define TIF_FREEZE		23	/* is freezing for suspend */

#define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
#define _TIF_SINGLESTEP		(1<<TIF_SINGLESTEP)
#define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
#define _TIF_IRET		(1<<TIF_IRET)
#define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)
#define _TIF_SECCOMP		(1<<TIF_SECCOMP)
#define _TIF_RESTORE_SIGMASK	(1<<TIF_RESTORE_SIGMASK)
#define _TIF_MCE_NOTIFY		(1<<TIF_MCE_NOTIFY)
#define _TIF_IA32		(1<<TIF_IA32)
#define _TIF_FORK		(1<<TIF_FORK)
#define _TIF_ABI_PENDING	(1<<TIF_ABI_PENDING)
#define _TIF_DEBUG		(1<<TIF_DEBUG)
#define _TIF_IO_BITMAP		(1<<TIF_IO_BITMAP)
#define _TIF_FREEZE		(1<<TIF_FREEZE)

/* work to do on interrupt/exception return */
#define _TIF_WORK_MASK \
  (0x0000FFFF & ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP|_TIF_SECCOMP))
/* work to do on any return to user space */
#define _TIF_ALLWORK_MASK (0x0000FFFF & ~_TIF_SECCOMP)

/* flags to check in __switch_to() */
#define _TIF_WORK_CTXSW (_TIF_DEBUG|_TIF_IO_BITMAP)

#define PREEMPT_ACTIVE     0x10000000

/*
 * Thread-synchronous status.
 *
 * This is different from the flags in that nobody else
 * ever touches our thread-synchronous status, so we don't
 * have to worry about atomic accesses.
 */
#define TS_USEDFPU		0x0001	/* FPU was used by this task this quantum (SMP) */
#define TS_COMPAT		0x0002	/* 32bit syscall active */
#define TS_POLLING		0x0004	/* true if in idle loop and not sleeping */

#define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)

#endif /* __KERNEL__ */

#endif /* _ASM_THREAD_INFO_H */