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 	unsigned long		flags;		/* low level flags */
27 	unsigned long		tp_value;	/* thread pointer */
28 	__u32			cpu;		/* current CPU */
29 	int			preempt_count;	/* 0 => preemptable, <0 => BUG */
30 	int			r2_emul_return; /* 1 => Returning from R2 emulator */
31 	mm_segment_t		addr_limit;	/*
32 						 * thread address space limit:
33 						 * 0x7fffffff for user-thead
34 						 * 0xffffffff for kernel-thread
35 						 */
36 	struct pt_regs		*regs;
37 	long			syscall;	/* syscall number */
38 };
39 
40 /*
41  * macros/functions for gaining access to the thread information structure
42  */
43 #define INIT_THREAD_INFO(tsk)			\
44 {						\
45 	.task		= &tsk,			\
46 	.flags		= _TIF_FIXADE,		\
47 	.cpu		= 0,			\
48 	.preempt_count	= INIT_PREEMPT_COUNT,	\
49 	.addr_limit	= KERNEL_DS,		\
50 }
51 
52 #define init_thread_info	(init_thread_union.thread_info)
53 #define init_stack		(init_thread_union.stack)
54 
55 /* How to get the thread information struct from C.  */
56 register struct thread_info *__current_thread_info __asm__("$28");
57 
58 static inline struct thread_info *current_thread_info(void)
59 {
60 	return __current_thread_info;
61 }
62 
63 #endif /* !__ASSEMBLY__ */
64 
65 /* thread information allocation */
66 #if defined(CONFIG_PAGE_SIZE_4KB) && defined(CONFIG_32BIT)
67 #define THREAD_SIZE_ORDER (1)
68 #endif
69 #if defined(CONFIG_PAGE_SIZE_4KB) && defined(CONFIG_64BIT)
70 #define THREAD_SIZE_ORDER (2)
71 #endif
72 #ifdef CONFIG_PAGE_SIZE_8KB
73 #define THREAD_SIZE_ORDER (1)
74 #endif
75 #ifdef CONFIG_PAGE_SIZE_16KB
76 #define THREAD_SIZE_ORDER (0)
77 #endif
78 #ifdef CONFIG_PAGE_SIZE_32KB
79 #define THREAD_SIZE_ORDER (0)
80 #endif
81 #ifdef CONFIG_PAGE_SIZE_64KB
82 #define THREAD_SIZE_ORDER (0)
83 #endif
84 
85 #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
86 #define THREAD_MASK (THREAD_SIZE - 1UL)
87 
88 #define STACK_WARN	(THREAD_SIZE / 8)
89 
90 /*
91  * thread information flags
92  * - these are process state flags that various assembly files may need to
93  *   access
94  * - pending work-to-be-done flags are in LSW
95  * - other flags in MSW
96  */
97 #define TIF_SIGPENDING		1	/* signal pending */
98 #define TIF_NEED_RESCHED	2	/* rescheduling necessary */
99 #define TIF_SYSCALL_AUDIT	3	/* syscall auditing active */
100 #define TIF_SECCOMP		4	/* secure computing */
101 #define TIF_NOTIFY_RESUME	5	/* callback before returning to user */
102 #define TIF_UPROBE		6	/* breakpointed or singlestepping */
103 #define TIF_RESTORE_SIGMASK	9	/* restore signal mask in do_signal() */
104 #define TIF_USEDFPU		16	/* FPU was used by this task this quantum (SMP) */
105 #define TIF_MEMDIE		18	/* is terminating due to OOM killer */
106 #define TIF_NOHZ		19	/* in adaptive nohz mode */
107 #define TIF_FIXADE		20	/* Fix address errors in software */
108 #define TIF_LOGADE		21	/* Log address errors to syslog */
109 #define TIF_32BIT_REGS		22	/* 32-bit general purpose registers */
110 #define TIF_32BIT_ADDR		23	/* 32-bit address space (o32/n32) */
111 #define TIF_FPUBOUND		24	/* thread bound to FPU-full CPU set */
112 #define TIF_LOAD_WATCH		25	/* If set, load watch registers */
113 #define TIF_SYSCALL_TRACEPOINT	26	/* syscall tracepoint instrumentation */
114 #define TIF_32BIT_FPREGS	27	/* 32-bit floating point registers */
115 #define TIF_HYBRID_FPREGS	28	/* 64b FP registers, odd singles in bits 63:32 of even doubles */
116 #define TIF_USEDMSA		29	/* MSA has been used this quantum */
117 #define TIF_MSA_CTX_LIVE	30	/* MSA context must be preserved */
118 #define TIF_SYSCALL_TRACE	31	/* syscall trace active */
119 
120 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
121 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
122 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
123 #define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)
124 #define _TIF_SECCOMP		(1<<TIF_SECCOMP)
125 #define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
126 #define _TIF_UPROBE		(1<<TIF_UPROBE)
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_HYBRID_FPREGS	(1<<TIF_HYBRID_FPREGS)
137 #define _TIF_USEDMSA		(1<<TIF_USEDMSA)
138 #define _TIF_MSA_CTX_LIVE	(1<<TIF_MSA_CTX_LIVE)
139 #define _TIF_SYSCALL_TRACEPOINT	(1<<TIF_SYSCALL_TRACEPOINT)
140 
141 #define _TIF_WORK_SYSCALL_ENTRY	(_TIF_NOHZ | _TIF_SYSCALL_TRACE |	\
142 				 _TIF_SYSCALL_AUDIT | \
143 				 _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP)
144 
145 /* work to do in syscall_trace_leave() */
146 #define _TIF_WORK_SYSCALL_EXIT	(_TIF_NOHZ | _TIF_SYSCALL_TRACE |	\
147 				 _TIF_SYSCALL_AUDIT | _TIF_SYSCALL_TRACEPOINT)
148 
149 /* work to do on interrupt/exception return */
150 #define _TIF_WORK_MASK		\
151 	(_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_NOTIFY_RESUME |	\
152 	 _TIF_UPROBE)
153 /* work to do on any return to u-space */
154 #define _TIF_ALLWORK_MASK	(_TIF_NOHZ | _TIF_WORK_MASK |		\
155 				 _TIF_WORK_SYSCALL_EXIT |		\
156 				 _TIF_SYSCALL_TRACEPOINT)
157 
158 /*
159  * We stash processor id into a COP0 register to retrieve it fast
160  * at kernel exception entry.
161  */
162 #if   defined(CONFIG_MIPS_PGD_C0_CONTEXT)
163 #define SMP_CPUID_REG		20, 0	/* XCONTEXT */
164 #define ASM_SMP_CPUID_REG	$20
165 #define SMP_CPUID_PTRSHIFT	48
166 #else
167 #define SMP_CPUID_REG		4, 0	/* CONTEXT */
168 #define ASM_SMP_CPUID_REG	$4
169 #define SMP_CPUID_PTRSHIFT	23
170 #endif
171 
172 #ifdef CONFIG_64BIT
173 #define SMP_CPUID_REGSHIFT	(SMP_CPUID_PTRSHIFT + 3)
174 #else
175 #define SMP_CPUID_REGSHIFT	(SMP_CPUID_PTRSHIFT + 2)
176 #endif
177 
178 #define ASM_CPUID_MFC0		MFC0
179 #define UASM_i_CPUID_MFC0	UASM_i_MFC0
180 
181 #endif /* __KERNEL__ */
182 #endif /* _ASM_THREAD_INFO_H */
183