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 pt_regs *frame; /* current exception frame */
44 unsigned long flags; /* low level flags */
45 __u32 cpu; /* current CPU */
46 __s32 preempt_count; /* 0 => preemptable, <0 => BUG */
47
48 mm_segment_t addr_limit; /* thread address space:
49 0-0xBFFFFFFF for user-thead
50 0-0xFFFFFFFF for kernel-thread
51 */
52
53 __u8 supervisor_stack[0];
54 };
55
56 #define thread_info_to_uregs(ti) \
57 ((struct pt_regs *) \
58 ((unsigned long)ti + THREAD_SIZE - sizeof(struct pt_regs)))
59
60 #else /* !__ASSEMBLY__ */
61
62 #ifndef __ASM_OFFSETS_H__
63 #include <asm/asm-offsets.h>
64 #endif
65
66 #endif
67
68 /*
69 * macros/functions for gaining access to the thread information structure
70 */
71 #ifndef __ASSEMBLY__
72
73 #define INIT_THREAD_INFO(tsk) \
74 { \
75 .task = &tsk, \
76 .flags = 0, \
77 .cpu = 0, \
78 .preempt_count = INIT_PREEMPT_COUNT, \
79 .addr_limit = KERNEL_DS, \
80 }
81
82 #define init_thread_info (init_thread_union.thread_info)
83 #define init_stack (init_thread_union.stack)
84 #define init_uregs \
85 ((struct pt_regs *) \
86 ((unsigned long) init_stack + THREAD_SIZE - sizeof(struct pt_regs)))
87
88 extern struct thread_info *__current_ti;
89
90 /* how to get the thread information struct from C */
91 static inline __attribute__((const))
current_thread_info(void)92 struct thread_info *current_thread_info(void)
93 {
94 struct thread_info *ti;
95 asm("mov sp,%0\n"
96 "and %1,%0\n"
97 : "=d" (ti)
98 : "i" (~(THREAD_SIZE - 1))
99 : "cc");
100 return ti;
101 }
102
103 static inline __attribute__((const))
current_frame(void)104 struct pt_regs *current_frame(void)
105 {
106 return current_thread_info()->frame;
107 }
108
109 /* how to get the current stack pointer from C */
current_stack_pointer(void)110 static inline unsigned long current_stack_pointer(void)
111 {
112 unsigned long sp;
113 asm("mov sp,%0; ":"=r" (sp));
114 return sp;
115 }
116
117 #ifndef CONFIG_KGDB
118 void arch_release_thread_stack(unsigned long *stack);
119 #endif
120 #define get_thread_info(ti) get_task_struct((ti)->task)
121 #define put_thread_info(ti) put_task_struct((ti)->task)
122
123 #else /* !__ASSEMBLY__ */
124
125 #ifndef __VMLINUX_LDS__
126 /* how to get the thread information struct from ASM */
127 .macro GET_THREAD_INFO reg
128 mov sp,\reg
129 and -THREAD_SIZE,\reg
130 .endm
131 #endif
132 #endif
133
134 /*
135 * thread information flags
136 * - these are process state flags that various assembly files may need to
137 * access
138 * - pending work-to-be-done flags are in LSW
139 * - other flags in MSW
140 */
141 #define TIF_SYSCALL_TRACE 0 /* syscall trace active */
142 #define TIF_NOTIFY_RESUME 1 /* resumption notification requested */
143 #define TIF_SIGPENDING 2 /* signal pending */
144 #define TIF_NEED_RESCHED 3 /* rescheduling necessary */
145 #define TIF_SINGLESTEP 4 /* restore singlestep on return to user mode */
146 #define TIF_RESTORE_SIGMASK 5 /* restore signal mask in do_signal() */
147 #define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
148 #define TIF_MEMDIE 17 /* is terminating due to OOM killer */
149
150 #define _TIF_SYSCALL_TRACE +(1 << TIF_SYSCALL_TRACE)
151 #define _TIF_NOTIFY_RESUME +(1 << TIF_NOTIFY_RESUME)
152 #define _TIF_SIGPENDING +(1 << TIF_SIGPENDING)
153 #define _TIF_NEED_RESCHED +(1 << TIF_NEED_RESCHED)
154 #define _TIF_SINGLESTEP +(1 << TIF_SINGLESTEP)
155 #define _TIF_POLLING_NRFLAG +(1 << TIF_POLLING_NRFLAG)
156
157 #define _TIF_WORK_MASK 0x0000FFFE /* work to do on interrupt/exception return */
158 #define _TIF_ALLWORK_MASK 0x0000FFFF /* work to do on any return to u-space */
159
160 #endif /* __KERNEL__ */
161
162 #endif /* _ASM_THREAD_INFO_H */
163