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1/* thread_info.h: MIPS low-level thread information
2 *
3 * Copyright (C) 2002 David Howells (dhowells@redhat.com)
4 * - Incorporating suggestions made by Linus Torvalds and Dave Miller
5 */
6
7#ifndef _ASM_THREAD_INFO_H
8#define _ASM_THREAD_INFO_H
9
10#ifdef __KERNEL__
11
12#include <linux/config.h>
13
14#ifndef __ASSEMBLY__
15
16#include <asm/processor.h>
17
18/*
19 * low level task data that entry.S needs immediate access to
20 * - this struct should fit entirely inside of one cache line
21 * - this struct shares the supervisor stack pages
22 * - if the contents of this structure are changed, the assembly constants
23 * must also be changed
24 */
25struct thread_info {
26 struct task_struct *task; /* main task structure */
27 struct exec_domain *exec_domain; /* execution domain */
28 unsigned long flags; /* low level flags */
29 __u32 cpu; /* current CPU */
30 int preempt_count; /* 0 => preemptable, <0 => BUG */
31
32 mm_segment_t addr_limit; /* thread address space:
33 0-0xBFFFFFFF for user-thead
34 0-0xFFFFFFFF for kernel-thread
35 */
36 struct restart_block restart_block;
37};
38
39/*
40 * macros/functions for gaining access to the thread information structure
41 *
42 * preempt_count needs to be 1 initially, until the scheduler is functional.
43 */
44#define INIT_THREAD_INFO(tsk) \
45{ \
46 .task = &tsk, \
47 .exec_domain = &default_exec_domain, \
48 .flags = 0, \
49 .cpu = 0, \
50 .preempt_count = 1, \
51 .addr_limit = KERNEL_DS, \
52 .restart_block = { \
53 .fn = do_no_restart_syscall, \
54 }, \
55}
56
57#define init_thread_info (init_thread_union.thread_info)
58#define init_stack (init_thread_union.stack)
59
60/* How to get the thread information struct from C. */
61register struct thread_info *__current_thread_info __asm__("$28");
62#define current_thread_info() __current_thread_info
63
64/* thread information allocation */
65#if defined(CONFIG_PAGE_SIZE_4KB) && defined(CONFIG_MIPS32)
66#define THREAD_SIZE_ORDER (1)
67#endif
68#if defined(CONFIG_PAGE_SIZE_4KB) && defined(CONFIG_MIPS64)
69#define THREAD_SIZE_ORDER (2)
70#endif
71#ifdef CONFIG_PAGE_SIZE_8KB
72#define THREAD_SIZE_ORDER (1)
73#endif
74#ifdef CONFIG_PAGE_SIZE_16KB
75#define THREAD_SIZE_ORDER (0)
76#endif
77#ifdef CONFIG_PAGE_SIZE_64KB
78#define THREAD_SIZE_ORDER (0)
79#endif
80
81#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
82#define THREAD_MASK (THREAD_SIZE - 1UL)
83
84#ifdef CONFIG_DEBUG_STACK_USAGE
85#define alloc_thread_info(tsk) \
86({ \
87 struct thread_info *ret; \
88 \
89 ret = kmalloc(THREAD_SIZE, GFP_KERNEL); \
90 if (ret) \
91 memset(ret, 0, THREAD_SIZE); \
92 ret; \
93})
94#else
95#define alloc_thread_info(tsk) kmalloc(THREAD_SIZE, GFP_KERNEL)
96#endif
97
98#define free_thread_info(info) kfree(info)
99#define get_thread_info(ti) get_task_struct((ti)->task)
100#define put_thread_info(ti) put_task_struct((ti)->task)
101
102#endif /* !__ASSEMBLY__ */
103
104#define PREEMPT_ACTIVE 0x10000000
105
106/*
107 * thread information flags
108 * - these are process state flags that various assembly files may need to
109 * access
110 * - pending work-to-be-done flags are in LSW
111 * - other flags in MSW
112 */
113#define TIF_NOTIFY_RESUME 1 /* resumption notification requested */
114#define TIF_SIGPENDING 2 /* signal pending */
115#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
116#define TIF_SYSCALL_AUDIT 4 /* syscall auditing active */
117#define TIF_USEDFPU 16 /* FPU was used by this task this quantum (SMP) */
118#define TIF_POLLING_NRFLAG 17 /* true if poll_idle() is polling TIF_NEED_RESCHED */
119#define TIF_MEMDIE 18
120#define TIF_SYSCALL_TRACE 31 /* syscall trace active */
121
122#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
123#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
124#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
125#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
126#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
127#define _TIF_USEDFPU (1<<TIF_USEDFPU)
128#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
129
130#define _TIF_WORK_MASK 0x0000ffef /* work to do on
131 interrupt/exception return */
132#define _TIF_ALLWORK_MASK 0x8000ffff /* work to do on any return to
133 u-space */
134
135#endif /* __KERNEL__ */
136
137#endif /* _ASM_THREAD_INFO_H */