1/*
2 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * Vineetg: Oct 2009
9 *  No need for ARC specific thread_info allocator (kmalloc/free). This is
10 *  anyways one page allocation, thus slab alloc can be short-circuited and
11 *  the generic version (get_free_page) would be loads better.
12 *
13 * Sameer Dhavale: Codito Technologies 2004
14 */
15
16#ifndef _ASM_THREAD_INFO_H
17#define _ASM_THREAD_INFO_H
18
19#include <asm/page.h>
20
21#ifdef CONFIG_16KSTACKS
22#define THREAD_SIZE_ORDER 1
23#else
24#define THREAD_SIZE_ORDER 0
25#endif
26
27#define THREAD_SIZE     (PAGE_SIZE << THREAD_SIZE_ORDER)
28
29#ifndef __ASSEMBLY__
30
31#include <linux/thread_info.h>
32#include <asm/segment.h>
33
34/*
35 * low level task data that entry.S needs immediate access to
36 * - this struct should fit entirely inside of one cache line
37 * - this struct shares the supervisor stack pages
38 * - if the contents of this structure are changed, the assembly constants
39 *   must also be changed
40 */
41struct thread_info {
42	unsigned long flags;		/* low level flags */
43	int preempt_count;		/* 0 => preemptable, <0 => BUG */
44	struct task_struct *task;	/* main task structure */
45	mm_segment_t addr_limit;	/* thread address space */
46	__u32 cpu;			/* current CPU */
47	unsigned long thr_ptr;		/* TLS ptr */
48};
49
50/*
51 * macros/functions for gaining access to the thread information structure
52 *
53 * preempt_count needs to be 1 initially, until the scheduler is functional.
54 */
55#define INIT_THREAD_INFO(tsk)			\
56{						\
57	.task       = &tsk,			\
58	.flags      = 0,			\
59	.cpu        = 0,			\
60	.preempt_count  = INIT_PREEMPT_COUNT,	\
61	.addr_limit = KERNEL_DS,		\
62}
63
64#define init_thread_info    (init_thread_union.thread_info)
65#define init_stack          (init_thread_union.stack)
66
67static inline __attribute_const__ struct thread_info *current_thread_info(void)
68{
69	register unsigned long sp asm("sp");
70	return (struct thread_info *)(sp & ~(THREAD_SIZE - 1));
71}
72
73#endif /* !__ASSEMBLY__ */
74
75/*
76 * thread information flags
77 * - these are process state flags that various assembly files may need to
78 *   access
79 * - pending work-to-be-done flags are in LSW
80 * - other flags in MSW
81 */
82#define TIF_RESTORE_SIGMASK	0	/* restore sig mask in do_signal() */
83#define TIF_NOTIFY_RESUME	1	/* resumption notification requested */
84#define TIF_SIGPENDING		2	/* signal pending */
85#define TIF_NEED_RESCHED	3	/* rescheduling necessary */
86#define TIF_SYSCALL_AUDIT	4	/* syscall auditing active */
87#define TIF_SYSCALL_TRACE	15	/* syscall trace active */
88
89/* true if poll_idle() is polling TIF_NEED_RESCHED */
90#define TIF_MEMDIE		16
91
92#define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
93#define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
94#define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
95#define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
96#define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)
97#define _TIF_MEMDIE		(1<<TIF_MEMDIE)
98
99/* work to do on interrupt/exception return */
100#define _TIF_WORK_MASK		(_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
101				 _TIF_NOTIFY_RESUME)
102
103/*
104 * _TIF_ALLWORK_MASK includes SYSCALL_TRACE, but we don't need it.
105 * SYSCALL_TRACE is anways seperately/unconditionally tested right after a
106 * syscall, so all that reamins to be tested is _TIF_WORK_MASK
107 */
108
109#endif /* _ASM_THREAD_INFO_H */
110