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__
37typedef struct {
38	unsigned long	seg;
39} mm_segment_t;
40
41struct 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
88extern struct thread_info *__current_ti;
89
90/* how to get the thread information struct from C */
91static inline __attribute__((const))
92struct 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
103static inline __attribute__((const))
104struct pt_regs *current_frame(void)
105{
106	return current_thread_info()->frame;
107}
108
109/* how to get the current stack pointer from C */
110static 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
118void arch_release_thread_info(struct thread_info *ti);
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