xref: /linux/arch/arm64/include/asm/thread_info.h (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
1 /*
2  * Based on arch/arm/include/asm/thread_info.h
3  *
4  * Copyright (C) 2002 Russell King.
5  * Copyright (C) 2012 ARM Ltd.
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19 #ifndef __ASM_THREAD_INFO_H
20 #define __ASM_THREAD_INFO_H
21 
22 #ifdef __KERNEL__
23 
24 #include <linux/compiler.h>
25 
26 #ifndef CONFIG_ARM64_64K_PAGES
27 #define THREAD_SIZE_ORDER	1
28 #endif
29 
30 #define THREAD_SIZE		8192
31 #define THREAD_START_SP		(THREAD_SIZE - 16)
32 
33 #ifndef __ASSEMBLY__
34 
35 struct task_struct;
36 struct exec_domain;
37 
38 #include <asm/types.h>
39 
40 typedef unsigned long mm_segment_t;
41 
42 /*
43  * low level task data that entry.S needs immediate access to.
44  * __switch_to() assumes cpu_context follows immediately after cpu_domain.
45  */
46 struct thread_info {
47 	unsigned long		flags;		/* low level flags */
48 	mm_segment_t		addr_limit;	/* address limit */
49 	struct task_struct	*task;		/* main task structure */
50 	struct exec_domain	*exec_domain;	/* execution domain */
51 	struct restart_block	restart_block;
52 	int			preempt_count;	/* 0 => preemptable, <0 => bug */
53 	int			cpu;		/* cpu */
54 };
55 
56 #define INIT_THREAD_INFO(tsk)						\
57 {									\
58 	.task		= &tsk,						\
59 	.exec_domain	= &default_exec_domain,				\
60 	.flags		= 0,						\
61 	.preempt_count	= INIT_PREEMPT_COUNT,				\
62 	.addr_limit	= KERNEL_DS,					\
63 	.restart_block	= {						\
64 		.fn	= do_no_restart_syscall,			\
65 	},								\
66 }
67 
68 #define init_thread_info	(init_thread_union.thread_info)
69 #define init_stack		(init_thread_union.stack)
70 
71 /*
72  * how to get the thread information struct from C
73  */
74 static inline struct thread_info *current_thread_info(void) __attribute_const__;
75 
76 static inline struct thread_info *current_thread_info(void)
77 {
78 	register unsigned long sp asm ("sp");
79 	return (struct thread_info *)(sp & ~(THREAD_SIZE - 1));
80 }
81 
82 #define thread_saved_pc(tsk)	\
83 	((unsigned long)(tsk->thread.cpu_context.pc))
84 #define thread_saved_sp(tsk)	\
85 	((unsigned long)(tsk->thread.cpu_context.sp))
86 #define thread_saved_fp(tsk)	\
87 	((unsigned long)(tsk->thread.cpu_context.fp))
88 
89 #endif
90 
91 /*
92  * We use bit 30 of the preempt_count to indicate that kernel
93  * preemption is occurring.  See <asm/hardirq.h>.
94  */
95 #define PREEMPT_ACTIVE	0x40000000
96 
97 /*
98  * thread information flags:
99  *  TIF_SYSCALL_TRACE	- syscall trace active
100  *  TIF_SIGPENDING	- signal pending
101  *  TIF_NEED_RESCHED	- rescheduling necessary
102  *  TIF_NOTIFY_RESUME	- callback before returning to user
103  *  TIF_USEDFPU		- FPU was used by this task this quantum (SMP)
104  *  TIF_POLLING_NRFLAG	- true if poll_idle() is polling TIF_NEED_RESCHED
105  */
106 #define TIF_SIGPENDING		0
107 #define TIF_NEED_RESCHED	1
108 #define TIF_NOTIFY_RESUME	2	/* callback before returning to user */
109 #define TIF_SYSCALL_TRACE	8
110 #define TIF_POLLING_NRFLAG	16
111 #define TIF_MEMDIE		18	/* is terminating due to OOM killer */
112 #define TIF_FREEZE		19
113 #define TIF_RESTORE_SIGMASK	20
114 #define TIF_SINGLESTEP		21
115 #define TIF_32BIT		22	/* 32bit process */
116 #define TIF_SWITCH_MM		23	/* deferred switch_mm */
117 
118 #define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
119 #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
120 #define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
121 #define _TIF_32BIT		(1 << TIF_32BIT)
122 
123 #define _TIF_WORK_MASK		(_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
124 				 _TIF_NOTIFY_RESUME)
125 
126 #endif /* __KERNEL__ */
127 #endif /* __ASM_THREAD_INFO_H */
128