1/*
2 * Copyright 2004-2010 Analog Devices Inc.
3 *
4 * Licensed under the GPL-2 or later.
5 */
6
7#ifndef _ASM_THREAD_INFO_H
8#define _ASM_THREAD_INFO_H
9
10#include <asm/page.h>
11#include <asm/entry.h>
12#include <asm/l1layout.h>
13#include <linux/compiler.h>
14
15#ifdef __KERNEL__
16
17/* Thread Align Mask to reach to the top of the stack
18 * for any process
19 */
20#define ALIGN_PAGE_MASK		0xffffe000
21
22/*
23 * Size of kernel stack for each process. This must be a power of 2...
24 */
25#define THREAD_SIZE_ORDER	1
26#define THREAD_SIZE		8192	/* 2 pages */
27#define STACK_WARN		(THREAD_SIZE/8)
28
29#ifndef __ASSEMBLY__
30
31typedef unsigned long mm_segment_t;
32
33/*
34 * low level task data.
35 * If you change this, change the TI_* offsets below to match.
36 */
37
38struct thread_info {
39	struct task_struct *task;	/* main task structure */
40	struct exec_domain *exec_domain;	/* execution domain */
41	unsigned long flags;	/* low level flags */
42	int cpu;		/* cpu we're on */
43	int preempt_count;	/* 0 => preemptable, <0 => BUG */
44	mm_segment_t addr_limit;	/* address limit */
45	struct restart_block restart_block;
46#ifndef CONFIG_SMP
47	struct l1_scratch_task_info l1_task_info;
48#endif
49};
50
51/*
52 * macros/functions for gaining access to the thread information structure
53 */
54#define INIT_THREAD_INFO(tsk)			\
55{						\
56	.task		= &tsk,			\
57	.exec_domain	= &default_exec_domain,	\
58	.flags		= 0,			\
59	.cpu		= 0,			\
60	.preempt_count	= INIT_PREEMPT_COUNT,	\
61	.restart_block	= {			\
62		.fn = do_no_restart_syscall,	\
63	},					\
64}
65#define init_thread_info	(init_thread_union.thread_info)
66#define init_stack		(init_thread_union.stack)
67
68/* Given a task stack pointer, you can find its corresponding
69 * thread_info structure just by masking it to the THREAD_SIZE
70 * boundary (currently 8K as you can see above).
71 */
72__attribute_const__
73static inline struct thread_info *current_thread_info(void)
74{
75	struct thread_info *ti;
76	__asm__("%0 = sp;" : "=da"(ti));
77	return (struct thread_info *)((long)ti & ~((long)THREAD_SIZE-1));
78}
79
80#endif				/* __ASSEMBLY__ */
81
82/*
83 * Offsets in thread_info structure, used in assembly code
84 */
85#define TI_TASK		0
86#define TI_EXECDOMAIN	4
87#define TI_FLAGS	8
88#define TI_CPU		12
89#define TI_PREEMPT	16
90
91#define	PREEMPT_ACTIVE	0x4000000
92
93/*
94 * thread information flag bit numbers
95 */
96#define TIF_SYSCALL_TRACE	0	/* syscall trace active */
97#define TIF_SIGPENDING		1	/* signal pending */
98#define TIF_NEED_RESCHED	2	/* rescheduling necessary */
99#define TIF_POLLING_NRFLAG	3	/* true if poll_idle() is polling
100					   TIF_NEED_RESCHED */
101#define TIF_MEMDIE		4	/* is terminating due to OOM killer */
102#define TIF_RESTORE_SIGMASK	5	/* restore signal mask in do_signal() */
103#define TIF_FREEZE		6	/* is freezing for suspend */
104#define TIF_IRQ_SYNC		7	/* sync pipeline stage */
105#define TIF_NOTIFY_RESUME	8	/* callback before returning to user */
106#define TIF_SINGLESTEP		9
107
108/* as above, but as bit values */
109#define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
110#define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
111#define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
112#define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
113#define _TIF_RESTORE_SIGMASK	(1<<TIF_RESTORE_SIGMASK)
114#define _TIF_FREEZE		(1<<TIF_FREEZE)
115#define _TIF_IRQ_SYNC		(1<<TIF_IRQ_SYNC)
116#define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
117#define _TIF_SINGLESTEP		(1<<TIF_SINGLESTEP)
118
119#define _TIF_WORK_MASK		0x0000FFFE	/* work to do on interrupt/exception return */
120
121#endif				/* __KERNEL__ */
122
123#endif				/* _ASM_THREAD_INFO_H */
124