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 #ifdef __KERNEL__
20
21 #include <asm/page.h>
22
23 #ifdef CONFIG_16KSTACKS
24 #define THREAD_SIZE_ORDER 1
25 #else
26 #define THREAD_SIZE_ORDER 0
27 #endif
28
29 #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
30
31 #ifndef __ASSEMBLY__
32
33 #include <linux/thread_info.h>
34 #include <asm/segment.h>
35
36 /*
37 * low level task data that entry.S needs immediate access to
38 * - this struct should fit entirely inside of one cache line
39 * - this struct shares the supervisor stack pages
40 * - if the contents of this structure are changed, the assembly constants
41 * must also be changed
42 */
43 struct thread_info {
44 unsigned long flags; /* low level flags */
45 int preempt_count; /* 0 => preemptable, <0 => BUG */
46 struct task_struct *task; /* main task structure */
47 mm_segment_t addr_limit; /* thread address space */
48 struct exec_domain *exec_domain;/* execution domain */
49 __u32 cpu; /* current CPU */
50 unsigned long thr_ptr; /* TLS ptr */
51 struct restart_block restart_block;
52 };
53
54 /*
55 * macros/functions for gaining access to the thread information structure
56 *
57 * preempt_count needs to be 1 initially, until the scheduler is functional.
58 */
59 #define INIT_THREAD_INFO(tsk) \
60 { \
61 .task = &tsk, \
62 .exec_domain = &default_exec_domain, \
63 .flags = 0, \
64 .cpu = 0, \
65 .preempt_count = INIT_PREEMPT_COUNT, \
66 .addr_limit = KERNEL_DS, \
67 .restart_block = { \
68 .fn = do_no_restart_syscall, \
69 }, \
70 }
71
72 #define init_thread_info (init_thread_union.thread_info)
73 #define init_stack (init_thread_union.stack)
74
current_thread_info(void)75 static inline __attribute_const__ struct thread_info *current_thread_info(void)
76 {
77 register unsigned long sp asm("sp");
78 return (struct thread_info *)(sp & ~(THREAD_SIZE - 1));
79 }
80
81 #endif /* !__ASSEMBLY__ */
82
83 #define PREEMPT_ACTIVE 0x10000000
84
85 /*
86 * thread information flags
87 * - these are process state flags that various assembly files may need to
88 * access
89 * - pending work-to-be-done flags are in LSW
90 * - other flags in MSW
91 */
92 #define TIF_RESTORE_SIGMASK 0 /* restore sig mask in do_signal() */
93 #define TIF_NOTIFY_RESUME 1 /* resumption notification requested */
94 #define TIF_SIGPENDING 2 /* signal pending */
95 #define TIF_NEED_RESCHED 3 /* rescheduling necessary */
96 #define TIF_SYSCALL_AUDIT 4 /* syscall auditing active */
97 #define TIF_SYSCALL_TRACE 15 /* syscall trace active */
98
99 /* true if poll_idle() is polling TIF_NEED_RESCHED */
100 #define TIF_MEMDIE 16
101
102 #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
103 #define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
104 #define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
105 #define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
106 #define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
107 #define _TIF_MEMDIE (1<<TIF_MEMDIE)
108
109 /* work to do on interrupt/exception return */
110 #define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
111 _TIF_NOTIFY_RESUME)
112
113 /*
114 * _TIF_ALLWORK_MASK includes SYSCALL_TRACE, but we don't need it.
115 * SYSCALL_TRACE is anways seperately/unconditionally tested right after a
116 * syscall, so all that reamins to be tested is _TIF_WORK_MASK
117 */
118
119 #endif /* __KERNEL__ */
120
121 #endif /* _ASM_THREAD_INFO_H */
122