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 #define THREAD_SHIFT (PAGE_SHIFT << THREAD_SIZE_ORDER)
29
30 #ifndef __ASSEMBLY__
31
32 #include <linux/thread_info.h>
33 #include <asm/segment.h>
34
35 /*
36 * low level task data that entry.S needs immediate access to
37 * - this struct should fit entirely inside of one cache line
38 * - this struct shares the supervisor stack pages
39 * - if the contents of this structure are changed, the assembly constants
40 * must also be changed
41 */
42 struct thread_info {
43 unsigned long flags; /* low level flags */
44 int preempt_count; /* 0 => preemptable, <0 => BUG */
45 struct task_struct *task; /* main task structure */
46 mm_segment_t addr_limit; /* thread address space */
47 __u32 cpu; /* current CPU */
48 unsigned long thr_ptr; /* TLS ptr */
49 };
50
51 /*
52 * macros/functions for gaining access to the thread information structure
53 *
54 * preempt_count needs to be 1 initially, until the scheduler is functional.
55 */
56 #define INIT_THREAD_INFO(tsk) \
57 { \
58 .task = &tsk, \
59 .flags = 0, \
60 .cpu = 0, \
61 .preempt_count = INIT_PREEMPT_COUNT, \
62 .addr_limit = KERNEL_DS, \
63 }
64
65 #define init_thread_info (init_thread_union.thread_info)
66 #define init_stack (init_thread_union.stack)
67
current_thread_info(void)68 static inline __attribute_const__ struct thread_info *current_thread_info(void)
69 {
70 register unsigned long sp asm("sp");
71 return (struct thread_info *)(sp & ~(THREAD_SIZE - 1));
72 }
73
74 #endif /* !__ASSEMBLY__ */
75
76 /*
77 * thread information flags
78 * - these are process state flags that various assembly files may need to
79 * access
80 * - pending work-to-be-done flags are in LSW
81 * - other flags in MSW
82 */
83 #define TIF_RESTORE_SIGMASK 0 /* restore sig mask in do_signal() */
84 #define TIF_NOTIFY_RESUME 1 /* resumption notification requested */
85 #define TIF_SIGPENDING 2 /* signal pending */
86 #define TIF_NEED_RESCHED 3 /* rescheduling necessary */
87 #define TIF_SYSCALL_AUDIT 4 /* syscall auditing active */
88 #define TIF_SYSCALL_TRACE 15 /* syscall trace active */
89
90 /* true if poll_idle() is polling TIF_NEED_RESCHED */
91 #define TIF_MEMDIE 16
92
93 #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
94 #define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
95 #define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
96 #define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
97 #define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
98 #define _TIF_MEMDIE (1<<TIF_MEMDIE)
99
100 /* work to do on interrupt/exception return */
101 #define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
102 _TIF_NOTIFY_RESUME)
103
104 /*
105 * _TIF_ALLWORK_MASK includes SYSCALL_TRACE, but we don't need it.
106 * SYSCALL_TRACE is anways seperately/unconditionally tested right after a
107 * syscall, so all that reamins to be tested is _TIF_WORK_MASK
108 */
109
110 #endif /* _ASM_THREAD_INFO_H */
111