1 /*
2  * Copyright (C) 2009 Chen Liqin <liqin.chen@sunplusct.com>
3  * Copyright (C) 2012 Regents of the University of California
4  * Copyright (C) 2017 SiFive
5  *
6  *   This program is free software; you can redistribute it and/or
7  *   modify it under the terms of the GNU General Public License
8  *   as published by the Free Software Foundation, version 2.
9  *
10  *   This program is distributed in the hope that it will be useful,
11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  *   GNU General Public License for more details.
14  */
15 
16 #ifndef _ASM_RISCV_THREAD_INFO_H
17 #define _ASM_RISCV_THREAD_INFO_H
18 
19 #include <asm/page.h>
20 #include <linux/const.h>
21 
22 /* thread information allocation */
23 #define THREAD_SIZE_ORDER	(1)
24 #define THREAD_SIZE		(PAGE_SIZE << THREAD_SIZE_ORDER)
25 
26 #ifndef __ASSEMBLY__
27 
28 #include <asm/processor.h>
29 #include <asm/csr.h>
30 
31 typedef unsigned long 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  * - if the members of this struct changes, the assembly constants
37  *   in asm-offsets.c must be updated accordingly
38  * - thread_info is included in task_struct at an offset of 0.  This means that
39  *   tp points to both thread_info and task_struct.
40  */
41 struct thread_info {
42 	unsigned long		flags;		/* low level flags */
43 	int                     preempt_count;  /* 0=>preemptible, <0=>BUG */
44 	mm_segment_t		addr_limit;
45 	/*
46 	 * These stack pointers are overwritten on every system call or
47 	 * exception.  SP is also saved to the stack it can be recovered when
48 	 * overwritten.
49 	 */
50 	long			kernel_sp;	/* Kernel stack pointer */
51 	long			user_sp;	/* User stack pointer */
52 	int			cpu;
53 };
54 
55 /*
56  * macros/functions for gaining access to the thread information structure
57  *
58  * preempt_count needs to be 1 initially, until the scheduler is functional.
59  */
60 #define INIT_THREAD_INFO(tsk)			\
61 {						\
62 	.flags		= 0,			\
63 	.preempt_count	= INIT_PREEMPT_COUNT,	\
64 	.addr_limit	= KERNEL_DS,		\
65 }
66 
67 #endif /* !__ASSEMBLY__ */
68 
69 /*
70  * thread information flags
71  * - these are process state flags that various assembly files may need to
72  *   access
73  * - pending work-to-be-done flags are in lowest half-word
74  * - other flags in upper half-word(s)
75  */
76 #define TIF_SYSCALL_TRACE	0	/* syscall trace active */
77 #define TIF_NOTIFY_RESUME	1	/* callback before returning to user */
78 #define TIF_SIGPENDING		2	/* signal pending */
79 #define TIF_NEED_RESCHED	3	/* rescheduling necessary */
80 #define TIF_RESTORE_SIGMASK	4	/* restore signal mask in do_signal() */
81 #define TIF_MEMDIE		5	/* is terminating due to OOM killer */
82 #define TIF_SYSCALL_TRACEPOINT  6       /* syscall tracepoint instrumentation */
83 
84 #define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
85 #define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
86 #define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
87 #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
88 
89 #define _TIF_WORK_MASK \
90 	(_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | _TIF_NEED_RESCHED)
91 
92 #endif /* _ASM_RISCV_THREAD_INFO_H */
93