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 #ifndef __ASSEMBLY__
20 #include <asm/processor.h>
21 #endif
22
23 #define PREEMPT_ACTIVE 0x10000000
24
25 #ifdef CONFIG_4KSTACKS
26 #define THREAD_SIZE (4096)
27 #else
28 #define THREAD_SIZE (8192)
29 #endif
30
31 #define STACK_WARN (THREAD_SIZE / 8)
32
33 /*
34 * low level task data that entry.S needs immediate access to
35 * - this struct should fit entirely inside of one cache line
36 * - this struct shares the supervisor stack pages
37 * - if the contents of this structure are changed, the assembly constants
38 * must also be changed
39 */
40 #ifndef __ASSEMBLY__
41
42 struct thread_info {
43 struct task_struct *task; /* main task structure */
44 struct exec_domain *exec_domain; /* execution domain */
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 #else /* !__ASSEMBLY__ */
59
60 #ifndef __ASM_OFFSETS_H__
61 #include <asm/asm-offsets.h>
62 #endif
63
64 #endif
65
66 /*
67 * macros/functions for gaining access to the thread information structure
68 *
69 * preempt_count needs to be 1 initially, until the scheduler is functional.
70 */
71 #ifndef __ASSEMBLY__
72
73 #define INIT_THREAD_INFO(tsk) \
74 { \
75 .task = &tsk, \
76 .exec_domain = &default_exec_domain, \
77 .flags = 0, \
78 .cpu = 0, \
79 .preempt_count = 1, \
80 .addr_limit = KERNEL_DS, \
81 .restart_block = { \
82 .fn = do_no_restart_syscall, \
83 }, \
84 }
85
86 #define init_thread_info (init_thread_union.thread_info)
87 #define init_stack (init_thread_union.stack)
88 #define init_uregs \
89 ((struct pt_regs *) \
90 ((unsigned long) init_stack + THREAD_SIZE - sizeof(struct pt_regs)))
91
92 extern struct thread_info *__current_ti;
93
94 /* how to get the thread information struct from C */
95 static inline __attribute__((const))
current_thread_info(void)96 struct thread_info *current_thread_info(void)
97 {
98 struct thread_info *ti;
99 asm("mov sp,%0\n"
100 "and %1,%0\n"
101 : "=d" (ti)
102 : "i" (~(THREAD_SIZE - 1))
103 : "cc");
104 return ti;
105 }
106
107 /* how to get the current stack pointer from C */
current_stack_pointer(void)108 static inline unsigned long current_stack_pointer(void)
109 {
110 unsigned long sp;
111 asm("mov sp,%0; ":"=r" (sp));
112 return sp;
113 }
114
115 #define __HAVE_ARCH_THREAD_INFO_ALLOCATOR
116
117 /* thread information allocation */
118 #ifdef CONFIG_DEBUG_STACK_USAGE
119 #define alloc_thread_info(tsk) kzalloc(THREAD_SIZE, GFP_KERNEL)
120 #else
121 #define alloc_thread_info(tsk) kmalloc(THREAD_SIZE, GFP_KERNEL)
122 #endif
123
124 #define free_thread_info(ti) kfree((ti))
125 #define get_thread_info(ti) get_task_struct((ti)->task)
126 #define put_thread_info(ti) put_task_struct((ti)->task)
127
128 #else /* !__ASSEMBLY__ */
129
130 #ifndef __VMLINUX_LDS__
131 /* how to get the thread information struct from ASM */
132 .macro GET_THREAD_INFO reg
133 mov sp,\reg
134 and -THREAD_SIZE,\reg
135 .endm
136 #endif
137 #endif
138
139 /*
140 * thread information flags
141 * - these are process state flags that various assembly files may need to
142 * access
143 * - pending work-to-be-done flags are in LSW
144 * - other flags in MSW
145 */
146 #define TIF_SYSCALL_TRACE 0 /* syscall trace active */
147 #define TIF_NOTIFY_RESUME 1 /* resumption notification requested */
148 #define TIF_SIGPENDING 2 /* signal pending */
149 #define TIF_NEED_RESCHED 3 /* rescheduling necessary */
150 #define TIF_SINGLESTEP 4 /* restore singlestep on return to user mode */
151 #define TIF_RESTORE_SIGMASK 5 /* restore signal mask in do_signal() */
152 #define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
153 #define TIF_MEMDIE 17 /* OOM killer killed process */
154 #define TIF_FREEZE 18 /* freezing for suspend */
155
156 #define _TIF_SYSCALL_TRACE +(1 << TIF_SYSCALL_TRACE)
157 #define _TIF_NOTIFY_RESUME +(1 << TIF_NOTIFY_RESUME)
158 #define _TIF_SIGPENDING +(1 << TIF_SIGPENDING)
159 #define _TIF_NEED_RESCHED +(1 << TIF_NEED_RESCHED)
160 #define _TIF_SINGLESTEP +(1 << TIF_SINGLESTEP)
161 #define _TIF_RESTORE_SIGMASK +(1 << TIF_RESTORE_SIGMASK)
162 #define _TIF_POLLING_NRFLAG +(1 << TIF_POLLING_NRFLAG)
163 #define _TIF_FREEZE +(1 << TIF_FREEZE)
164
165 #define _TIF_WORK_MASK 0x0000FFFE /* work to do on interrupt/exception return */
166 #define _TIF_ALLWORK_MASK 0x0000FFFF /* work to do on any return to u-space */
167
168 #endif /* __KERNEL__ */
169
170 #endif /* _ASM_THREAD_INFO_H */
171