1 /* MN10300 Low-level thread information
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
10 */
11
12 #ifndef _ASM_THREAD_INFO_H
13 #define _ASM_THREAD_INFO_H
14
15 #ifdef __KERNEL__
16
17 #include <asm/page.h>
18
19 #ifdef CONFIG_4KSTACKS
20 #define THREAD_SIZE (4096)
21 #define THREAD_SIZE_ORDER (0)
22 #else
23 #define THREAD_SIZE (8192)
24 #define THREAD_SIZE_ORDER (1)
25 #endif
26
27 #define STACK_WARN (THREAD_SIZE / 8)
28
29 /*
30 * low level task data that entry.S needs immediate access to
31 * - this struct should fit entirely inside of one cache line
32 * - this struct shares the supervisor stack pages
33 * - if the contents of this structure are changed, the assembly constants
34 * must also be changed
35 */
36 #ifndef __ASSEMBLY__
37 typedef struct {
38 unsigned long seg;
39 } mm_segment_t;
40
41 struct thread_info {
42 struct task_struct *task; /* main task structure */
43 struct exec_domain *exec_domain; /* execution domain */
44 struct pt_regs *frame; /* current exception frame */
45 unsigned long flags; /* low level flags */
46 __u32 cpu; /* current CPU */
47 __s32 preempt_count; /* 0 => preemptable, <0 => BUG */
48
49 mm_segment_t addr_limit; /* thread address space:
50 0-0xBFFFFFFF for user-thead
51 0-0xFFFFFFFF for kernel-thread
52 */
53
54 __u8 supervisor_stack[0];
55 };
56
57 #define thread_info_to_uregs(ti) \
58 ((struct pt_regs *) \
59 ((unsigned long)ti + THREAD_SIZE - sizeof(struct pt_regs)))
60
61 #else /* !__ASSEMBLY__ */
62
63 #ifndef __ASM_OFFSETS_H__
64 #include <asm/asm-offsets.h>
65 #endif
66
67 #endif
68
69 /*
70 * macros/functions for gaining access to the thread information structure
71 */
72 #ifndef __ASSEMBLY__
73
74 #define INIT_THREAD_INFO(tsk) \
75 { \
76 .task = &tsk, \
77 .exec_domain = &default_exec_domain, \
78 .flags = 0, \
79 .cpu = 0, \
80 .preempt_count = INIT_PREEMPT_COUNT, \
81 .addr_limit = KERNEL_DS, \
82 }
83
84 #define init_thread_info (init_thread_union.thread_info)
85 #define init_stack (init_thread_union.stack)
86 #define init_uregs \
87 ((struct pt_regs *) \
88 ((unsigned long) init_stack + THREAD_SIZE - sizeof(struct pt_regs)))
89
90 extern struct thread_info *__current_ti;
91
92 /* how to get the thread information struct from C */
93 static inline __attribute__((const))
current_thread_info(void)94 struct thread_info *current_thread_info(void)
95 {
96 struct thread_info *ti;
97 asm("mov sp,%0\n"
98 "and %1,%0\n"
99 : "=d" (ti)
100 : "i" (~(THREAD_SIZE - 1))
101 : "cc");
102 return ti;
103 }
104
105 static inline __attribute__((const))
current_frame(void)106 struct pt_regs *current_frame(void)
107 {
108 return current_thread_info()->frame;
109 }
110
111 /* how to get the current stack pointer from C */
current_stack_pointer(void)112 static inline unsigned long current_stack_pointer(void)
113 {
114 unsigned long sp;
115 asm("mov sp,%0; ":"=r" (sp));
116 return sp;
117 }
118
119 #ifndef CONFIG_KGDB
120 void arch_release_thread_info(struct thread_info *ti);
121 #endif
122 #define get_thread_info(ti) get_task_struct((ti)->task)
123 #define put_thread_info(ti) put_task_struct((ti)->task)
124
125 #else /* !__ASSEMBLY__ */
126
127 #ifndef __VMLINUX_LDS__
128 /* how to get the thread information struct from ASM */
129 .macro GET_THREAD_INFO reg
130 mov sp,\reg
131 and -THREAD_SIZE,\reg
132 .endm
133 #endif
134 #endif
135
136 /*
137 * thread information flags
138 * - these are process state flags that various assembly files may need to
139 * access
140 * - pending work-to-be-done flags are in LSW
141 * - other flags in MSW
142 */
143 #define TIF_SYSCALL_TRACE 0 /* syscall trace active */
144 #define TIF_NOTIFY_RESUME 1 /* resumption notification requested */
145 #define TIF_SIGPENDING 2 /* signal pending */
146 #define TIF_NEED_RESCHED 3 /* rescheduling necessary */
147 #define TIF_SINGLESTEP 4 /* restore singlestep on return to user mode */
148 #define TIF_RESTORE_SIGMASK 5 /* restore signal mask in do_signal() */
149 #define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
150 #define TIF_MEMDIE 17 /* is terminating due to OOM killer */
151
152 #define _TIF_SYSCALL_TRACE +(1 << TIF_SYSCALL_TRACE)
153 #define _TIF_NOTIFY_RESUME +(1 << TIF_NOTIFY_RESUME)
154 #define _TIF_SIGPENDING +(1 << TIF_SIGPENDING)
155 #define _TIF_NEED_RESCHED +(1 << TIF_NEED_RESCHED)
156 #define _TIF_SINGLESTEP +(1 << TIF_SINGLESTEP)
157 #define _TIF_POLLING_NRFLAG +(1 << TIF_POLLING_NRFLAG)
158
159 #define _TIF_WORK_MASK 0x0000FFFE /* work to do on interrupt/exception return */
160 #define _TIF_ALLWORK_MASK 0x0000FFFF /* work to do on any return to u-space */
161
162 #endif /* __KERNEL__ */
163
164 #endif /* _ASM_THREAD_INFO_H */
165