1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* thread_info.h: MIPS low-level thread information
3  *
4  * Copyright (C) 2002  David Howells (dhowells@redhat.com)
5  * - Incorporating suggestions made by Linus Torvalds and Dave Miller
6  */
7 
8 #ifndef _ASM_THREAD_INFO_H
9 #define _ASM_THREAD_INFO_H
10 
11 #ifdef __KERNEL__
12 
13 
14 #ifndef __ASSEMBLY__
15 
16 #include <asm/processor.h>
17 
18 /*
19  * low level task data that entry.S needs immediate access to
20  * - this struct should fit entirely inside of one cache line
21  * - this struct shares the supervisor stack pages
22  * - if the contents of this structure are changed, the assembly constants
23  *   must also be changed
24  */
25 struct thread_info {
26 	struct task_struct	*task;		/* main task structure */
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 	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 /* How to get the thread information struct from C.  */
53 register struct thread_info *__current_thread_info __asm__("$28");
54 
55 static inline struct thread_info *current_thread_info(void)
56 {
57 	return __current_thread_info;
58 }
59 
60 #endif /* !__ASSEMBLY__ */
61 
62 /* thread information allocation */
63 #if defined(CONFIG_PAGE_SIZE_4KB) && defined(CONFIG_32BIT)
64 #define THREAD_SIZE_ORDER (1)
65 #endif
66 #if defined(CONFIG_PAGE_SIZE_4KB) && defined(CONFIG_64BIT)
67 #define THREAD_SIZE_ORDER (2)
68 #endif
69 #ifdef CONFIG_PAGE_SIZE_8KB
70 #define THREAD_SIZE_ORDER (1)
71 #endif
72 #ifdef CONFIG_PAGE_SIZE_16KB
73 #define THREAD_SIZE_ORDER (0)
74 #endif
75 #ifdef CONFIG_PAGE_SIZE_32KB
76 #define THREAD_SIZE_ORDER (0)
77 #endif
78 #ifdef CONFIG_PAGE_SIZE_64KB
79 #define THREAD_SIZE_ORDER (0)
80 #endif
81 
82 #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
83 #define THREAD_MASK (THREAD_SIZE - 1UL)
84 
85 #define STACK_WARN	(THREAD_SIZE / 8)
86 
87 /*
88  * thread information flags
89  * - these are process state flags that various assembly files may need to
90  *   access
91  * - pending work-to-be-done flags are in LSW
92  * - other flags in MSW
93  */
94 #define TIF_SIGPENDING		1	/* signal pending */
95 #define TIF_NEED_RESCHED	2	/* rescheduling necessary */
96 #define TIF_SYSCALL_AUDIT	3	/* syscall auditing active */
97 #define TIF_SECCOMP		4	/* secure computing */
98 #define TIF_NOTIFY_RESUME	5	/* callback before returning to user */
99 #define TIF_UPROBE		6	/* breakpointed or singlestepping */
100 #define TIF_RESTORE_SIGMASK	9	/* restore signal mask in do_signal() */
101 #define TIF_USEDFPU		16	/* FPU was used by this task this quantum (SMP) */
102 #define TIF_MEMDIE		18	/* is terminating due to OOM killer */
103 #define TIF_NOHZ		19	/* in adaptive nohz mode */
104 #define TIF_FIXADE		20	/* Fix address errors in software */
105 #define TIF_LOGADE		21	/* Log address errors to syslog */
106 #define TIF_32BIT_REGS		22	/* 32-bit general purpose registers */
107 #define TIF_32BIT_ADDR		23	/* 32-bit address space (o32/n32) */
108 #define TIF_FPUBOUND		24	/* thread bound to FPU-full CPU set */
109 #define TIF_LOAD_WATCH		25	/* If set, load watch registers */
110 #define TIF_SYSCALL_TRACEPOINT	26	/* syscall tracepoint instrumentation */
111 #define TIF_32BIT_FPREGS	27	/* 32-bit floating point registers */
112 #define TIF_HYBRID_FPREGS	28	/* 64b FP registers, odd singles in bits 63:32 of even doubles */
113 #define TIF_USEDMSA		29	/* MSA has been used this quantum */
114 #define TIF_MSA_CTX_LIVE	30	/* MSA context must be preserved */
115 #define TIF_SYSCALL_TRACE	31	/* syscall trace active */
116 
117 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
118 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
119 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
120 #define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)
121 #define _TIF_SECCOMP		(1<<TIF_SECCOMP)
122 #define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
123 #define _TIF_UPROBE		(1<<TIF_UPROBE)
124 #define _TIF_USEDFPU		(1<<TIF_USEDFPU)
125 #define _TIF_NOHZ		(1<<TIF_NOHZ)
126 #define _TIF_FIXADE		(1<<TIF_FIXADE)
127 #define _TIF_LOGADE		(1<<TIF_LOGADE)
128 #define _TIF_32BIT_REGS		(1<<TIF_32BIT_REGS)
129 #define _TIF_32BIT_ADDR		(1<<TIF_32BIT_ADDR)
130 #define _TIF_FPUBOUND		(1<<TIF_FPUBOUND)
131 #define _TIF_LOAD_WATCH		(1<<TIF_LOAD_WATCH)
132 #define _TIF_32BIT_FPREGS	(1<<TIF_32BIT_FPREGS)
133 #define _TIF_HYBRID_FPREGS	(1<<TIF_HYBRID_FPREGS)
134 #define _TIF_USEDMSA		(1<<TIF_USEDMSA)
135 #define _TIF_MSA_CTX_LIVE	(1<<TIF_MSA_CTX_LIVE)
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 | \
140 				 _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP)
141 
142 /* work to do in syscall_trace_leave() */
143 #define _TIF_WORK_SYSCALL_EXIT	(_TIF_NOHZ | _TIF_SYSCALL_TRACE |	\
144 				 _TIF_SYSCALL_AUDIT | _TIF_SYSCALL_TRACEPOINT)
145 
146 /* work to do on interrupt/exception return */
147 #define _TIF_WORK_MASK		\
148 	(_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_NOTIFY_RESUME |	\
149 	 _TIF_UPROBE)
150 /* work to do on any return to u-space */
151 #define _TIF_ALLWORK_MASK	(_TIF_NOHZ | _TIF_WORK_MASK |		\
152 				 _TIF_WORK_SYSCALL_EXIT |		\
153 				 _TIF_SYSCALL_TRACEPOINT)
154 
155 /*
156  * We stash processor id into a COP0 register to retrieve it fast
157  * at kernel exception entry.
158  */
159 #if   defined(CONFIG_MIPS_PGD_C0_CONTEXT)
160 #define SMP_CPUID_REG		20, 0	/* XCONTEXT */
161 #define ASM_SMP_CPUID_REG	$20
162 #define SMP_CPUID_PTRSHIFT	48
163 #else
164 #define SMP_CPUID_REG		4, 0	/* CONTEXT */
165 #define ASM_SMP_CPUID_REG	$4
166 #define SMP_CPUID_PTRSHIFT	23
167 #endif
168 
169 #ifdef CONFIG_64BIT
170 #define SMP_CPUID_REGSHIFT	(SMP_CPUID_PTRSHIFT + 3)
171 #else
172 #define SMP_CPUID_REGSHIFT	(SMP_CPUID_PTRSHIFT + 2)
173 #endif
174 
175 #define ASM_CPUID_MFC0		MFC0
176 #define UASM_i_CPUID_MFC0	UASM_i_MFC0
177 
178 #endif /* __KERNEL__ */
179 #endif /* _ASM_THREAD_INFO_H */
180