1/*
2 * NiosII low-level thread information
3 *
4 * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
5 * Copyright (C) 2004 Microtronix Datacom Ltd.
6 *
7 * Based on asm/thread_info_no.h from m68k which is:
8 *
9 * Copyright (C) 2002 David Howells <dhowells@redhat.com>
10 *
11 * This file is subject to the terms and conditions of the GNU General Public
12 * License.  See the file "COPYING" in the main directory of this archive
13 * for more details.
14 */
15
16#ifndef _ASM_NIOS2_THREAD_INFO_H
17#define _ASM_NIOS2_THREAD_INFO_H
18
19#ifdef __KERNEL__
20
21/*
22 * Size of the kernel stack for each process.
23 */
24#define THREAD_SIZE_ORDER	1
25#define THREAD_SIZE		8192 /* 2 * PAGE_SIZE */
26
27#ifndef __ASSEMBLY__
28
29typedef struct {
30	unsigned long seg;
31} mm_segment_t;
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 */
40struct thread_info {
41	struct task_struct	*task;		/* main task structure */
42	unsigned long		flags;		/* low level flags */
43	__u32			cpu;		/* current CPU */
44	int			preempt_count;	/* 0 => preemptable,<0 => BUG */
45	mm_segment_t		addr_limit;	/* thread address space:
46						  0-0x7FFFFFFF for user-thead
47						  0-0xFFFFFFFF for kernel-thread
48						*/
49	struct pt_regs		*regs;
50};
51
52/*
53 * macros/functions for gaining access to the thread information structure
54 *
55 * preempt_count needs to be 1 initially, until the scheduler is functional.
56 */
57#define INIT_THREAD_INFO(tsk)			\
58{						\
59	.task		= &tsk,			\
60	.flags		= 0,			\
61	.cpu		= 0,			\
62	.preempt_count	= INIT_PREEMPT_COUNT,	\
63	.addr_limit	= KERNEL_DS,		\
64}
65
66#define init_thread_info	(init_thread_union.thread_info)
67#define init_stack		(init_thread_union.stack)
68
69/* how to get the thread information struct from C */
70static inline struct thread_info *current_thread_info(void)
71{
72	register unsigned long sp asm("sp");
73
74	return (struct thread_info *)(sp & ~(THREAD_SIZE - 1));
75}
76#endif /* !__ASSEMBLY__ */
77
78/*
79 * thread information flags
80 * - these are process state flags that various assembly files may need to
81 *   access
82 * - pending work-to-be-done flags are in LSW
83 * - other flags in MSW
84 */
85#define TIF_SYSCALL_TRACE	0	/* syscall trace active */
86#define TIF_NOTIFY_RESUME	1	/* resumption notification requested */
87#define TIF_SIGPENDING		2	/* signal pending */
88#define TIF_NEED_RESCHED	3	/* rescheduling necessary */
89#define TIF_MEMDIE		4	/* is terminating due to OOM killer */
90#define TIF_SECCOMP		5	/* secure computing */
91#define TIF_SYSCALL_AUDIT	6	/* syscall auditing active */
92#define TIF_RESTORE_SIGMASK	9	/* restore signal mask in do_signal() */
93
94#define TIF_POLLING_NRFLAG	16	/* true if poll_idle() is polling
95					   TIF_NEED_RESCHED */
96
97#define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
98#define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
99#define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
100#define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
101#define _TIF_SECCOMP		(1 << TIF_SECCOMP)
102#define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)
103#define _TIF_RESTORE_SIGMASK	(1 << TIF_RESTORE_SIGMASK)
104#define _TIF_POLLING_NRFLAG	(1 << TIF_POLLING_NRFLAG)
105
106/* work to do on interrupt/exception return */
107#define _TIF_WORK_MASK		0x0000FFFE
108
109/* work to do on any return to u-space */
110# define _TIF_ALLWORK_MASK	0x0000FFFF
111
112#endif /* __KERNEL__ */
113
114#endif /* _ASM_NIOS2_THREAD_INFO_H */
115