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1 /* thread_info.h: MIPS low-level thread information
2  *
3  * Copyright (C) 2002  David Howells (dhowells@redhat.com)
4  * - Incorporating suggestions made by Linus Torvalds and Dave Miller
5  */
6 
7 #ifndef _ASM_THREAD_INFO_H
8 #define _ASM_THREAD_INFO_H
9 
10 #ifdef __KERNEL__
11 
12 
13 #ifndef __ASSEMBLY__
14 
15 #include <asm/processor.h>
16 
17 /*
18  * low level task data that entry.S needs immediate access to
19  * - this struct should fit entirely inside of one cache line
20  * - this struct shares the supervisor stack pages
21  * - if the contents of this structure are changed, the assembly constants
22  *   must also be changed
23  */
24 struct thread_info {
25 	struct task_struct	*task;		/* main task structure */
26 	struct exec_domain	*exec_domain;	/* execution domain */
27 	unsigned long		flags;		/* low level flags */
28 	unsigned long           local_flags;    /* low level flags, no locking access */
29 	unsigned long		tp_value;	/* thread pointer */
30 	__u32			cpu;		/* current CPU */
31 	int			preempt_count;	/* 0 => preemptable, <0 => BUG */
32 
33 	mm_segment_t		addr_limit;	/*
34 						 * thread address space limit:
35 						 * 0x7fffffff for user-thead
36 						 * 0xffffffff for kernel-thread
37 						 */
38 	unsigned long           vdso_offset;
39 	struct page             *vdso_page;
40 	struct restart_block	restart_block;
41 	struct pt_regs		*regs;
42 };
43 
44 /*
45  * macros/functions for gaining access to the thread information structure
46  */
47 #define INIT_THREAD_INFO(tsk)			\
48 {						\
49 	.task		= &tsk,			\
50 	.exec_domain	= &default_exec_domain, \
51 	.flags		= _TIF_FIXADE,		\
52 	.local_flags    = 0,                    \
53 	.cpu		= 0,			\
54 	.preempt_count	= INIT_PREEMPT_COUNT,	\
55 	.addr_limit	= KERNEL_DS,		\
56 	.vdso_page      = NULL,                 \
57 	.restart_block	= {			\
58 		.fn = do_no_restart_syscall,	\
59 	},					\
60 }
61 
62 #define init_thread_info	(init_thread_union.thread_info)
63 #define init_stack		(init_thread_union.stack)
64 
65 /* How to get the thread information struct from C.  */
current_thread_info(void)66 static inline struct thread_info *current_thread_info(void)
67 {
68 	register struct thread_info *__current_thread_info __asm__("$28");
69 
70 	return __current_thread_info;
71 }
72 
73 #endif /* !__ASSEMBLY__ */
74 
75 /* thread information allocation */
76 #if defined(CONFIG_PAGE_SIZE_4KB) && defined(CONFIG_32BIT)
77 #define THREAD_SIZE_ORDER (1)
78 #endif
79 #if defined(CONFIG_PAGE_SIZE_4KB) && defined(CONFIG_64BIT)
80 #define THREAD_SIZE_ORDER (2)
81 #endif
82 #ifdef CONFIG_PAGE_SIZE_8KB
83 #define THREAD_SIZE_ORDER (1)
84 #endif
85 #ifdef CONFIG_PAGE_SIZE_16KB
86 #define THREAD_SIZE_ORDER (0)
87 #endif
88 #ifdef CONFIG_PAGE_SIZE_32KB
89 #define THREAD_SIZE_ORDER (0)
90 #endif
91 #ifdef CONFIG_PAGE_SIZE_64KB
92 #define THREAD_SIZE_ORDER (0)
93 #endif
94 
95 #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
96 #define THREAD_MASK (THREAD_SIZE - 1UL)
97 
98 #define STACK_WARN	(THREAD_SIZE / 8)
99 
100 #define PREEMPT_ACTIVE		0x10000000
101 
102 /*
103  * thread information flags
104  * - these are process state flags that various assembly files may need to
105  *   access
106  * - pending work-to-be-done flags are in LSW
107  * - other flags in MSW
108  */
109 #define TIF_FPU_LOSE_REQUEST    0       /* request to lose FPU from IPI call */
110 #define TIF_SIGPENDING		1	/* signal pending */
111 #define TIF_NEED_RESCHED	2	/* rescheduling necessary */
112 #define TIF_SYSCALL_AUDIT	3	/* syscall auditing active */
113 #define TIF_SECCOMP		4	/* secure computing */
114 #define TIF_NOTIFY_RESUME	5	/* callback before returning to user */
115 #define TIF_RESTORE_SIGMASK	9	/* restore signal mask in do_signal() */
116 #define TIF_USEDFPU		16	/* FPU was used by this task this quantum (SMP) */
117 #define TIF_MEMDIE		18	/* is terminating due to OOM killer */
118 #define TIF_NOHZ		19	/* in adaptive nohz mode */
119 #define TIF_FIXADE		20	/* Fix address errors in software */
120 #define TIF_LOGADE		21	/* Log address errors to syslog */
121 #define TIF_32BIT_REGS		22	/* also implies 16/32 fprs */
122 #define TIF_32BIT_ADDR		23	/* 32-bit address space (o32/n32) */
123 #define TIF_FPUBOUND		24	/* thread bound to FPU-full CPU set */
124 #define TIF_LOAD_WATCH		25	/* If set, load watch registers */
125 #define TIF_SYSCALL_TRACEPOINT	26	/* syscall tracepoint instrumentation */
126 #define TIF_USEDMSA		29	/* MSA has been used this quantum */
127 #define TIF_MSA_CTX_LIVE	30	/* MSA context must be preserved */
128 #define TIF_SYSCALL_TRACE	31	/* syscall trace active */
129 
130 #define _TIF_FPU_LOSE_REQUEST   (1<<TIF_FPU_LOSE_REQUEST)
131 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
132 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
133 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
134 #define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)
135 #define _TIF_SECCOMP		(1<<TIF_SECCOMP)
136 #define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
137 #define _TIF_USEDFPU		(1<<TIF_USEDFPU)
138 #define _TIF_NOHZ		(1<<TIF_NOHZ)
139 #define _TIF_FIXADE		(1<<TIF_FIXADE)
140 #define _TIF_LOGADE		(1<<TIF_LOGADE)
141 #define _TIF_32BIT_REGS		(1<<TIF_32BIT_REGS)
142 #define _TIF_32BIT_ADDR		(1<<TIF_32BIT_ADDR)
143 #define _TIF_FPUBOUND		(1<<TIF_FPUBOUND)
144 #define _TIF_LOAD_WATCH		(1<<TIF_LOAD_WATCH)
145 #define _TIF_USEDMSA		(1<<TIF_USEDMSA)
146 #define _TIF_MSA_CTX_LIVE	(1<<TIF_MSA_CTX_LIVE)
147 #define _TIF_SYSCALL_TRACEPOINT	(1<<TIF_SYSCALL_TRACEPOINT)
148 
149 #define _TIF_WORK_SYSCALL_ENTRY	(_TIF_NOHZ | _TIF_SYSCALL_TRACE |	\
150 				 _TIF_SYSCALL_AUDIT | \
151 				 _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP)
152 
153 /* work to do in syscall_trace_leave() */
154 #define _TIF_WORK_SYSCALL_EXIT	(_TIF_NOHZ | _TIF_SYSCALL_TRACE |	\
155 				 _TIF_SYSCALL_AUDIT | _TIF_SYSCALL_TRACEPOINT)
156 
157 /* work to do on interrupt/exception return */
158 #define _TIF_WORK_MASK		\
159 	(_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_NOTIFY_RESUME)
160 /* work to do on any return to u-space */
161 #define _TIF_ALLWORK_MASK	(_TIF_NOHZ | _TIF_WORK_MASK |		\
162 				 _TIF_WORK_SYSCALL_EXIT |		\
163 				 _TIF_SYSCALL_TRACEPOINT)
164 
165 /* local thread information flags, update only from thread itself = no locking */
166 #define LTIF_FPU_FR             0x00000001   /* Status.FR bit state for this thread */
167 #define LTIF_FPU_FRE            0x00000002   /* Mixed FPU mode emulation */
168 
169 #ifndef __ASSEMBLY__
set_thread_local_flags(unsigned long x)170 static inline void set_thread_local_flags(unsigned long x)
171 {
172 	current_thread_info()->local_flags |= x;
173 }
174 
clear_thread_local_flags(unsigned long x)175 static inline void clear_thread_local_flags(unsigned long x)
176 {
177 	current_thread_info()->local_flags &= ~x;
178 }
179 
change_thread_local_flags(unsigned long x,unsigned long f)180 static inline void change_thread_local_flags(unsigned long x, unsigned long f)
181 {
182 	current_thread_info()->local_flags =
183 		 (current_thread_info()->local_flags & ~x) | f;
184 }
185 
test_thread_local_flags(unsigned long x)186 static inline int test_thread_local_flags(unsigned long x)
187 {
188 	return ((current_thread_info()->local_flags & x)? 1 : 0);
189 }
190 #endif
191 
192 #endif /* __KERNEL__ */
193 
194 #endif /* _ASM_THREAD_INFO_H */
195