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		tp_value;	/* thread pointer */
29 	__u32			cpu;		/* current CPU */
30 	int			preempt_count;	/* 0 => preemptable, <0 => BUG */
31 
32 	mm_segment_t		addr_limit;	/*
33 						 * thread address space limit:
34 						 * 0x7fffffff for user-thead
35 						 * 0xffffffff for kernel-thread
36 						 */
37 	struct restart_block	restart_block;
38 	struct pt_regs		*regs;
39 };
40 
41 /*
42  * macros/functions for gaining access to the thread information structure
43  */
44 #define INIT_THREAD_INFO(tsk)			\
45 {						\
46 	.task		= &tsk,			\
47 	.exec_domain	= &default_exec_domain, \
48 	.flags		= _TIF_FIXADE,		\
49 	.cpu		= 0,			\
50 	.preempt_count	= INIT_PREEMPT_COUNT,	\
51 	.addr_limit	= KERNEL_DS,		\
52 	.restart_block	= {			\
53 		.fn = do_no_restart_syscall,	\
54 	},					\
55 }
56 
57 #define init_thread_info	(init_thread_union.thread_info)
58 #define init_stack		(init_thread_union.stack)
59 
60 /* How to get the thread information struct from C.  */
61 static inline struct thread_info *current_thread_info(void)
62 {
63 	register struct thread_info *__current_thread_info __asm__("$28");
64 
65 	return __current_thread_info;
66 }
67 
68 #endif /* !__ASSEMBLY__ */
69 
70 /* thread information allocation */
71 #if defined(CONFIG_PAGE_SIZE_4KB) && defined(CONFIG_32BIT)
72 #define THREAD_SIZE_ORDER (1)
73 #endif
74 #if defined(CONFIG_PAGE_SIZE_4KB) && defined(CONFIG_64BIT)
75 #define THREAD_SIZE_ORDER (2)
76 #endif
77 #ifdef CONFIG_PAGE_SIZE_8KB
78 #define THREAD_SIZE_ORDER (1)
79 #endif
80 #ifdef CONFIG_PAGE_SIZE_16KB
81 #define THREAD_SIZE_ORDER (0)
82 #endif
83 #ifdef CONFIG_PAGE_SIZE_32KB
84 #define THREAD_SIZE_ORDER (0)
85 #endif
86 #ifdef CONFIG_PAGE_SIZE_64KB
87 #define THREAD_SIZE_ORDER (0)
88 #endif
89 
90 #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
91 #define THREAD_MASK (THREAD_SIZE - 1UL)
92 
93 #define STACK_WARN	(THREAD_SIZE / 8)
94 
95 /*
96  * thread information flags
97  * - these are process state flags that various assembly files may need to
98  *   access
99  * - pending work-to-be-done flags are in LSW
100  * - other flags in MSW
101  */
102 #define TIF_SIGPENDING		1	/* signal pending */
103 #define TIF_NEED_RESCHED	2	/* rescheduling necessary */
104 #define TIF_SYSCALL_AUDIT	3	/* syscall auditing active */
105 #define TIF_SECCOMP		4	/* secure computing */
106 #define TIF_NOTIFY_RESUME	5	/* callback before returning to user */
107 #define TIF_RESTORE_SIGMASK	9	/* restore signal mask in do_signal() */
108 #define TIF_USEDFPU		16	/* FPU was used by this task this quantum (SMP) */
109 #define TIF_MEMDIE		18	/* is terminating due to OOM killer */
110 #define TIF_NOHZ		19	/* in adaptive nohz mode */
111 #define TIF_FIXADE		20	/* Fix address errors in software */
112 #define TIF_LOGADE		21	/* Log address errors to syslog */
113 #define TIF_32BIT_REGS		22	/* 32-bit general purpose registers */
114 #define TIF_32BIT_ADDR		23	/* 32-bit address space (o32/n32) */
115 #define TIF_FPUBOUND		24	/* thread bound to FPU-full CPU set */
116 #define TIF_LOAD_WATCH		25	/* If set, load watch registers */
117 #define TIF_SYSCALL_TRACEPOINT	26	/* syscall tracepoint instrumentation */
118 #define TIF_32BIT_FPREGS	27	/* 32-bit floating point registers */
119 #define TIF_SYSCALL_TRACE	31	/* syscall trace active */
120 
121 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
122 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
123 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
124 #define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)
125 #define _TIF_SECCOMP		(1<<TIF_SECCOMP)
126 #define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
127 #define _TIF_USEDFPU		(1<<TIF_USEDFPU)
128 #define _TIF_NOHZ		(1<<TIF_NOHZ)
129 #define _TIF_FIXADE		(1<<TIF_FIXADE)
130 #define _TIF_LOGADE		(1<<TIF_LOGADE)
131 #define _TIF_32BIT_REGS		(1<<TIF_32BIT_REGS)
132 #define _TIF_32BIT_ADDR		(1<<TIF_32BIT_ADDR)
133 #define _TIF_FPUBOUND		(1<<TIF_FPUBOUND)
134 #define _TIF_LOAD_WATCH		(1<<TIF_LOAD_WATCH)
135 #define _TIF_32BIT_FPREGS	(1<<TIF_32BIT_FPREGS)
136 #define _TIF_SYSCALL_TRACEPOINT	(1<<TIF_SYSCALL_TRACEPOINT)
137 
138 #define _TIF_WORK_SYSCALL_ENTRY	(_TIF_NOHZ | _TIF_SYSCALL_TRACE |	\
139 				 _TIF_SYSCALL_AUDIT | _TIF_SYSCALL_TRACEPOINT)
140 
141 /* work to do in syscall_trace_leave() */
142 #define _TIF_WORK_SYSCALL_EXIT	(_TIF_NOHZ | _TIF_SYSCALL_TRACE |	\
143 				 _TIF_SYSCALL_AUDIT | _TIF_SYSCALL_TRACEPOINT)
144 
145 /* work to do on interrupt/exception return */
146 #define _TIF_WORK_MASK		\
147 	(_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_NOTIFY_RESUME)
148 /* work to do on any return to u-space */
149 #define _TIF_ALLWORK_MASK	(_TIF_NOHZ | _TIF_WORK_MASK |		\
150 				 _TIF_WORK_SYSCALL_EXIT |		\
151 				 _TIF_SYSCALL_TRACEPOINT)
152 
153 /*
154  * We stash processor id into a COP0 register to retrieve it fast
155  * at kernel exception entry.
156  */
157 #if defined(CONFIG_MIPS_MT_SMTC)
158 #define SMP_CPUID_REG		2, 2	/* TCBIND */
159 #define ASM_SMP_CPUID_REG	$2, 2
160 #define SMP_CPUID_PTRSHIFT	19
161 #elif defined(CONFIG_MIPS_PGD_C0_CONTEXT)
162 #define SMP_CPUID_REG		20, 0	/* XCONTEXT */
163 #define ASM_SMP_CPUID_REG	$20
164 #define SMP_CPUID_PTRSHIFT	48
165 #else
166 #define SMP_CPUID_REG		4, 0	/* CONTEXT */
167 #define ASM_SMP_CPUID_REG	$4
168 #define SMP_CPUID_PTRSHIFT	23
169 #endif
170 
171 #ifdef CONFIG_64BIT
172 #define SMP_CPUID_REGSHIFT	(SMP_CPUID_PTRSHIFT + 3)
173 #else
174 #define SMP_CPUID_REGSHIFT	(SMP_CPUID_PTRSHIFT + 2)
175 #endif
176 
177 #ifdef CONFIG_MIPS_MT_SMTC
178 #define ASM_CPUID_MFC0		mfc0
179 #define UASM_i_CPUID_MFC0	uasm_i_mfc0
180 #else
181 #define ASM_CPUID_MFC0		MFC0
182 #define UASM_i_CPUID_MFC0	UASM_i_MFC0
183 #endif
184 
185 #endif /* __KERNEL__ */
186 #endif /* _ASM_THREAD_INFO_H */
187