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1da177e4 LT |
1 | /* thread_info.h: i386 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 | ||
1da177e4 LT |
12 | #include <linux/compiler.h> |
13 | #include <asm/page.h> | |
14 | ||
15 | #ifndef __ASSEMBLY__ | |
16 | #include <asm/processor.h> | |
17 | #endif | |
18 | ||
19 | /* | |
20 | * low level task data that entry.S needs immediate access to | |
21 | * - this struct should fit entirely inside of one cache line | |
22 | * - this struct shares the supervisor stack pages | |
23 | * - if the contents of this structure are changed, the assembly constants must also be changed | |
24 | */ | |
25 | #ifndef __ASSEMBLY__ | |
26 | ||
27 | struct thread_info { | |
28 | struct task_struct *task; /* main task structure */ | |
29 | struct exec_domain *exec_domain; /* execution domain */ | |
30 | unsigned long flags; /* low level flags */ | |
31 | unsigned long status; /* thread-synchronous flags */ | |
32 | __u32 cpu; /* current CPU */ | |
dcd497f9 | 33 | int preempt_count; /* 0 => preemptable, <0 => BUG */ |
1da177e4 LT |
34 | |
35 | ||
36 | mm_segment_t addr_limit; /* thread address space: | |
37 | 0-0xBFFFFFFF for user-thead | |
38 | 0-0xFFFFFFFF for kernel-thread | |
39 | */ | |
e6e5494c | 40 | void *sysenter_return; |
1da177e4 LT |
41 | struct restart_block restart_block; |
42 | ||
43 | unsigned long previous_esp; /* ESP of the previous stack in case | |
44 | of nested (IRQ) stacks | |
45 | */ | |
46 | __u8 supervisor_stack[0]; | |
47 | }; | |
48 | ||
49 | #else /* !__ASSEMBLY__ */ | |
50 | ||
86feeaa8 | 51 | #include <asm/asm-offsets.h> |
1da177e4 LT |
52 | |
53 | #endif | |
54 | ||
55 | #define PREEMPT_ACTIVE 0x10000000 | |
56 | #ifdef CONFIG_4KSTACKS | |
57 | #define THREAD_SIZE (4096) | |
58 | #else | |
59 | #define THREAD_SIZE (8192) | |
60 | #endif | |
61 | ||
62 | #define STACK_WARN (THREAD_SIZE/8) | |
63 | /* | |
64 | * macros/functions for gaining access to the thread information structure | |
65 | * | |
66 | * preempt_count needs to be 1 initially, until the scheduler is functional. | |
67 | */ | |
68 | #ifndef __ASSEMBLY__ | |
69 | ||
70 | #define INIT_THREAD_INFO(tsk) \ | |
71 | { \ | |
72 | .task = &tsk, \ | |
73 | .exec_domain = &default_exec_domain, \ | |
74 | .flags = 0, \ | |
75 | .cpu = 0, \ | |
76 | .preempt_count = 1, \ | |
77 | .addr_limit = KERNEL_DS, \ | |
78 | .restart_block = { \ | |
79 | .fn = do_no_restart_syscall, \ | |
80 | }, \ | |
81 | } | |
82 | ||
83 | #define init_thread_info (init_thread_union.thread_info) | |
84 | #define init_stack (init_thread_union.stack) | |
85 | ||
86 | ||
c723e084 CE |
87 | /* how to get the current stack pointer from C */ |
88 | register unsigned long current_stack_pointer asm("esp") __attribute_used__; | |
89 | ||
1da177e4 LT |
90 | /* how to get the thread information struct from C */ |
91 | static inline struct thread_info *current_thread_info(void) | |
92 | { | |
c723e084 | 93 | return (struct thread_info *)(current_stack_pointer & ~(THREAD_SIZE - 1)); |
1da177e4 LT |
94 | } |
95 | ||
1da177e4 LT |
96 | /* thread information allocation */ |
97 | #ifdef CONFIG_DEBUG_STACK_USAGE | |
b5637e65 CL |
98 | #define alloc_thread_info(tsk) ((struct thread_info *) \ |
99 | __get_free_pages(GFP_KERNEL| __GFP_ZERO, get_order(THREAD_SIZE))) | |
1da177e4 | 100 | #else |
b5637e65 CL |
101 | #define alloc_thread_info(tsk) ((struct thread_info *) \ |
102 | __get_free_pages(GFP_KERNEL, get_order(THREAD_SIZE))) | |
1da177e4 LT |
103 | #endif |
104 | ||
b5637e65 | 105 | #define free_thread_info(info) free_pages((unsigned long)(info), get_order(THREAD_SIZE)) |
1da177e4 LT |
106 | |
107 | #else /* !__ASSEMBLY__ */ | |
108 | ||
109 | /* how to get the thread information struct from ASM */ | |
110 | #define GET_THREAD_INFO(reg) \ | |
111 | movl $-THREAD_SIZE, reg; \ | |
112 | andl %esp, reg | |
113 | ||
114 | /* use this one if reg already contains %esp */ | |
115 | #define GET_THREAD_INFO_WITH_ESP(reg) \ | |
116 | andl $-THREAD_SIZE, reg | |
117 | ||
118 | #endif | |
119 | ||
120 | /* | |
121 | * thread information flags | |
122 | * - these are process state flags that various assembly files may need to access | |
123 | * - pending work-to-be-done flags are in LSW | |
124 | * - other flags in MSW | |
125 | */ | |
126 | #define TIF_SYSCALL_TRACE 0 /* syscall trace active */ | |
127 | #define TIF_NOTIFY_RESUME 1 /* resumption notification requested */ | |
128 | #define TIF_SIGPENDING 2 /* signal pending */ | |
129 | #define TIF_NEED_RESCHED 3 /* rescheduling necessary */ | |
130 | #define TIF_SINGLESTEP 4 /* restore singlestep on return to user mode */ | |
131 | #define TIF_IRET 5 /* return with iret */ | |
ed75e8d5 | 132 | #define TIF_SYSCALL_EMU 6 /* syscall emulation active */ |
1da177e4 LT |
133 | #define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */ |
134 | #define TIF_SECCOMP 8 /* secure computing */ | |
283828f3 | 135 | #define TIF_RESTORE_SIGMASK 9 /* restore signal mask in do_signal() */ |
495ab9c0 | 136 | #define TIF_MEMDIE 16 |
b3cf2576 SE |
137 | #define TIF_DEBUG 17 /* uses debug registers */ |
138 | #define TIF_IO_BITMAP 18 /* uses I/O bitmap */ | |
8a102eed | 139 | #define TIF_FREEZE 19 /* is freezing for suspend */ |
1da177e4 LT |
140 | |
141 | #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) | |
142 | #define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME) | |
143 | #define _TIF_SIGPENDING (1<<TIF_SIGPENDING) | |
144 | #define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED) | |
145 | #define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP) | |
146 | #define _TIF_IRET (1<<TIF_IRET) | |
ed75e8d5 | 147 | #define _TIF_SYSCALL_EMU (1<<TIF_SYSCALL_EMU) |
1da177e4 LT |
148 | #define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT) |
149 | #define _TIF_SECCOMP (1<<TIF_SECCOMP) | |
283828f3 | 150 | #define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK) |
b3cf2576 SE |
151 | #define _TIF_DEBUG (1<<TIF_DEBUG) |
152 | #define _TIF_IO_BITMAP (1<<TIF_IO_BITMAP) | |
8a102eed | 153 | #define _TIF_FREEZE (1<<TIF_FREEZE) |
1da177e4 LT |
154 | |
155 | /* work to do on interrupt/exception return */ | |
156 | #define _TIF_WORK_MASK \ | |
cfe91f9c CE |
157 | (0x0000FFFF & ~(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \ |
158 | _TIF_SECCOMP | _TIF_SYSCALL_EMU)) | |
1da177e4 LT |
159 | /* work to do on any return to u-space */ |
160 | #define _TIF_ALLWORK_MASK (0x0000FFFF & ~_TIF_SECCOMP) | |
161 | ||
b3cf2576 SE |
162 | /* flags to check in __switch_to() */ |
163 | #define _TIF_WORK_CTXSW (_TIF_DEBUG|_TIF_IO_BITMAP) | |
164 | ||
1da177e4 LT |
165 | /* |
166 | * Thread-synchronous status. | |
167 | * | |
168 | * This is different from the flags in that nobody else | |
169 | * ever touches our thread-synchronous status, so we don't | |
170 | * have to worry about atomic accesses. | |
171 | */ | |
172 | #define TS_USEDFPU 0x0001 /* FPU was used by this task this quantum (SMP) */ | |
495ab9c0 AK |
173 | #define TS_POLLING 0x0002 /* True if in idle loop and not sleeping */ |
174 | ||
175 | #define tsk_is_polling(t) ((t)->thread_info->status & TS_POLLING) | |
1da177e4 LT |
176 | |
177 | #endif /* __KERNEL__ */ | |
178 | ||
179 | #endif /* _ASM_THREAD_INFO_H */ |