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 
29 typedef 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  */
40 struct 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 */
70 static 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