1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
4  *
5  * Vineetg: Oct 2009
6  *  No need for ARC specific thread_info allocator (kmalloc/free). This is
7  *  anyways one page allocation, thus slab alloc can be short-circuited and
8  *  the generic version (get_free_page) would be loads better.
9  *
10  * Sameer Dhavale: Codito Technologies 2004
11  */
12 
13 #ifndef _ASM_THREAD_INFO_H
14 #define _ASM_THREAD_INFO_H
15 
16 #include <asm/page.h>
17 
18 #ifdef CONFIG_16KSTACKS
19 #define THREAD_SIZE_ORDER 1
20 #else
21 #define THREAD_SIZE_ORDER 0
22 #endif
23 
24 #define THREAD_SIZE     (PAGE_SIZE << THREAD_SIZE_ORDER)
25 #define THREAD_SHIFT	(PAGE_SHIFT << THREAD_SIZE_ORDER)
26 
27 #ifndef __ASSEMBLY__
28 
29 #include <linux/thread_info.h>
30 #include <asm/segment.h>
31 
32 /*
33  * low level task data that entry.S needs immediate access to
34  * - this struct should fit entirely inside of one cache line
35  * - this struct shares the supervisor stack pages
36  * - if the contents of this structure are changed, the assembly constants
37  *   must also be changed
38  */
39 struct thread_info {
40 	unsigned long flags;		/* low level flags */
41 	int preempt_count;		/* 0 => preemptable, <0 => BUG */
42 	struct task_struct *task;	/* main task structure */
43 	mm_segment_t addr_limit;	/* thread address space */
44 	__u32 cpu;			/* current CPU */
45 	unsigned long thr_ptr;		/* TLS ptr */
46 };
47 
48 /*
49  * macros/functions for gaining access to the thread information structure
50  *
51  * preempt_count needs to be 1 initially, until the scheduler is functional.
52  */
53 #define INIT_THREAD_INFO(tsk)			\
54 {						\
55 	.task       = &tsk,			\
56 	.flags      = 0,			\
57 	.cpu        = 0,			\
58 	.preempt_count  = INIT_PREEMPT_COUNT,	\
59 	.addr_limit = KERNEL_DS,		\
60 }
61 
current_thread_info(void)62 static inline __attribute_const__ struct thread_info *current_thread_info(void)
63 {
64 	register unsigned long sp asm("sp");
65 	return (struct thread_info *)(sp & ~(THREAD_SIZE - 1));
66 }
67 
68 #endif /* !__ASSEMBLY__ */
69 
70 /*
71  * thread information flags
72  * - these are process state flags that various assembly files may need to
73  *   access
74  * - pending work-to-be-done flags are in LSW
75  * - other flags in MSW
76  */
77 #define TIF_RESTORE_SIGMASK	0	/* restore sig mask in do_signal() */
78 #define TIF_NOTIFY_RESUME	1	/* resumption notification requested */
79 #define TIF_SIGPENDING		2	/* signal pending */
80 #define TIF_NEED_RESCHED	3	/* rescheduling necessary */
81 #define TIF_SYSCALL_AUDIT	4	/* syscall auditing active */
82 #define TIF_NOTIFY_SIGNAL	5	/* signal notifications exist */
83 #define TIF_SYSCALL_TRACE	15	/* syscall trace active */
84 
85 /* true if poll_idle() is polling TIF_NEED_RESCHED */
86 #define TIF_MEMDIE		16
87 
88 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
89 #define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
90 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
91 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
92 #define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)
93 #define _TIF_NOTIFY_SIGNAL	(1<<TIF_NOTIFY_SIGNAL)
94 #define _TIF_MEMDIE		(1<<TIF_MEMDIE)
95 
96 /* work to do on interrupt/exception return */
97 #define _TIF_WORK_MASK		(_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
98 				 _TIF_NOTIFY_RESUME | _TIF_NOTIFY_SIGNAL)
99 
100 /*
101  * _TIF_ALLWORK_MASK includes SYSCALL_TRACE, but we don't need it.
102  * SYSCALL_TRACE is anyway seperately/unconditionally tested right after a
103  * syscall, so all that reamins to be tested is _TIF_WORK_MASK
104  */
105 
106 #endif /* _ASM_THREAD_INFO_H */
107