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 #define PREEMPT_ACTIVE 0x10000000
20
21 #ifdef CONFIG_4KSTACKS
22 #define THREAD_SIZE (4096)
23 #else
24 #define THREAD_SIZE (8192)
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 struct restart_block restart_block;
54
55 __u8 supervisor_stack[0];
56 };
57
58 #define thread_info_to_uregs(ti) \
59 ((struct pt_regs *) \
60 ((unsigned long)ti + THREAD_SIZE - sizeof(struct pt_regs)))
61
62 #else /* !__ASSEMBLY__ */
63
64 #ifndef __ASM_OFFSETS_H__
65 #include <asm/asm-offsets.h>
66 #endif
67
68 #endif
69
70 /*
71 * macros/functions for gaining access to the thread information structure
72 */
73 #ifndef __ASSEMBLY__
74
75 #define INIT_THREAD_INFO(tsk) \
76 { \
77 .task = &tsk, \
78 .exec_domain = &default_exec_domain, \
79 .flags = 0, \
80 .cpu = 0, \
81 .preempt_count = INIT_PREEMPT_COUNT, \
82 .addr_limit = KERNEL_DS, \
83 .restart_block = { \
84 .fn = do_no_restart_syscall, \
85 }, \
86 }
87
88 #define init_thread_info (init_thread_union.thread_info)
89 #define init_stack (init_thread_union.stack)
90 #define init_uregs \
91 ((struct pt_regs *) \
92 ((unsigned long) init_stack + THREAD_SIZE - sizeof(struct pt_regs)))
93
94 extern struct thread_info *__current_ti;
95
96 /* how to get the thread information struct from C */
97 static inline __attribute__((const))
current_thread_info(void)98 struct thread_info *current_thread_info(void)
99 {
100 struct thread_info *ti;
101 asm("mov sp,%0\n"
102 "and %1,%0\n"
103 : "=d" (ti)
104 : "i" (~(THREAD_SIZE - 1))
105 : "cc");
106 return ti;
107 }
108
109 static inline __attribute__((const))
current_frame(void)110 struct pt_regs *current_frame(void)
111 {
112 return current_thread_info()->frame;
113 }
114
115 /* how to get the current stack pointer from C */
current_stack_pointer(void)116 static inline unsigned long current_stack_pointer(void)
117 {
118 unsigned long sp;
119 asm("mov sp,%0; ":"=r" (sp));
120 return sp;
121 }
122
123 #define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
124
125 /* thread information allocation */
126 #ifdef CONFIG_DEBUG_STACK_USAGE
127 #define alloc_thread_info_node(tsk, node) \
128 kzalloc_node(THREAD_SIZE, GFP_KERNEL, node)
129 #else
130 #define alloc_thread_info_node(tsk, node) \
131 kmalloc_node(THREAD_SIZE, GFP_KERNEL, node)
132 #endif
133
134 #ifndef CONFIG_KGDB
135 #define free_thread_info(ti) kfree((ti))
136 #else
137 extern void free_thread_info(struct thread_info *);
138 #endif
139 #define get_thread_info(ti) get_task_struct((ti)->task)
140 #define put_thread_info(ti) put_task_struct((ti)->task)
141
142 #else /* !__ASSEMBLY__ */
143
144 #ifndef __VMLINUX_LDS__
145 /* how to get the thread information struct from ASM */
146 .macro GET_THREAD_INFO reg
147 mov sp,\reg
148 and -THREAD_SIZE,\reg
149 .endm
150 #endif
151 #endif
152
153 /*
154 * thread information flags
155 * - these are process state flags that various assembly files may need to
156 * access
157 * - pending work-to-be-done flags are in LSW
158 * - other flags in MSW
159 */
160 #define TIF_SYSCALL_TRACE 0 /* syscall trace active */
161 #define TIF_NOTIFY_RESUME 1 /* resumption notification requested */
162 #define TIF_SIGPENDING 2 /* signal pending */
163 #define TIF_NEED_RESCHED 3 /* rescheduling necessary */
164 #define TIF_SINGLESTEP 4 /* restore singlestep on return to user mode */
165 #define TIF_RESTORE_SIGMASK 5 /* restore signal mask in do_signal() */
166 #define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
167 #define TIF_MEMDIE 17 /* is terminating due to OOM killer */
168
169 #define _TIF_SYSCALL_TRACE +(1 << TIF_SYSCALL_TRACE)
170 #define _TIF_NOTIFY_RESUME +(1 << TIF_NOTIFY_RESUME)
171 #define _TIF_SIGPENDING +(1 << TIF_SIGPENDING)
172 #define _TIF_NEED_RESCHED +(1 << TIF_NEED_RESCHED)
173 #define _TIF_SINGLESTEP +(1 << TIF_SINGLESTEP)
174 #define _TIF_RESTORE_SIGMASK +(1 << TIF_RESTORE_SIGMASK)
175 #define _TIF_POLLING_NRFLAG +(1 << TIF_POLLING_NRFLAG)
176
177 #define _TIF_WORK_MASK 0x0000FFFE /* work to do on interrupt/exception return */
178 #define _TIF_ALLWORK_MASK 0x0000FFFF /* work to do on any return to u-space */
179
180 #endif /* __KERNEL__ */
181
182 #endif /* _ASM_THREAD_INFO_H */
183