1 /* thread_info.h: description
3 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 * Derived from include/asm-i386/thread_info.h
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
13 #ifndef _ASM_THREAD_INFO_H
14 #define _ASM_THREAD_INFO_H
19 #include <asm/processor.h>
23 * low level task data that entry.S needs immediate access to
24 * - this struct should fit entirely inside of one cache line
25 * - this struct shares the supervisor stack pages
26 * - if the contents of this structure are changed, the assembly constants must also be changed
31 struct task_struct *task; /* main task structure */
32 struct exec_domain *exec_domain; /* execution domain */
33 unsigned long flags; /* low level flags */
34 unsigned long status; /* thread-synchronous flags */
35 __u32 cpu; /* current CPU */
36 int preempt_count; /* 0 => preemptable, <0 => BUG */
38 mm_segment_t addr_limit; /* thread address space:
39 0-0xBFFFFFFF for user-thead
40 0-0xFFFFFFFF for kernel-thread
42 struct restart_block restart_block;
44 __u8 supervisor_stack[0];
47 #else /* !__ASSEMBLY__ */
49 /* offsets into the thread_info struct for assembly code access */
50 #define TI_TASK 0x00000000
51 #define TI_EXEC_DOMAIN 0x00000004
52 #define TI_FLAGS 0x00000008
53 #define TI_STATUS 0x0000000C
54 #define TI_CPU 0x00000010
55 #define TI_PRE_COUNT 0x00000014
56 #define TI_ADDR_LIMIT 0x00000018
57 #define TI_RESTART_BLOCK 0x0000001C
61 #define PREEMPT_ACTIVE 0x10000000
64 * macros/functions for gaining access to the thread information structure
66 * preempt_count needs to be 1 initially, until the scheduler is functional.
70 #define INIT_THREAD_INFO(tsk) \
73 .exec_domain = &default_exec_domain, \
77 .addr_limit = KERNEL_DS, \
79 .fn = do_no_restart_syscall, \
83 #define init_thread_info (init_thread_union.thread_info)
84 #define init_stack (init_thread_union.stack)
86 #ifdef CONFIG_SMALL_TASKS
87 #define THREAD_SIZE 4096
89 #define THREAD_SIZE 8192
92 /* how to get the thread information struct from C */
93 register struct thread_info *__current_thread_info asm("gr15");
95 #define current_thread_info() ({ __current_thread_info; })
97 /* thread information allocation */
98 #ifdef CONFIG_DEBUG_STACK_USAGE
99 #define alloc_thread_info(tsk) \
101 struct thread_info *ret; \
103 ret = kmalloc(THREAD_SIZE, GFP_KERNEL); \
105 memset(ret, 0, THREAD_SIZE); \
109 #define alloc_thread_info(tsk) kmalloc(THREAD_SIZE, GFP_KERNEL)
112 #define free_thread_info(info) kfree(info)
113 #define get_thread_info(ti) get_task_struct((ti)->task)
114 #define put_thread_info(ti) put_task_struct((ti)->task)
116 #else /* !__ASSEMBLY__ */
118 #define THREAD_SIZE 8192
123 * thread information flags
124 * - these are process state flags that various assembly files may need to access
125 * - pending work-to-be-done flags are in LSW
126 * - other flags in MSW
128 #define TIF_SYSCALL_TRACE 0 /* syscall trace active */
129 #define TIF_NOTIFY_RESUME 1 /* resumption notification requested */
130 #define TIF_SIGPENDING 2 /* signal pending */
131 #define TIF_NEED_RESCHED 3 /* rescheduling necessary */
132 #define TIF_SINGLESTEP 4 /* restore singlestep on return to user mode */
133 #define TIF_IRET 5 /* return with iret */
134 #define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
135 #define TIF_MEMDIE 17 /* OOM killer killed process */
137 #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
138 #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
139 #define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
140 #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
141 #define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
142 #define _TIF_IRET (1 << TIF_IRET)
143 #define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
145 #define _TIF_WORK_MASK 0x0000FFFE /* work to do on interrupt/exception return */
146 #define _TIF_ALLWORK_MASK 0x0000FFFF /* work to do on any return to u-space */
149 * Thread-synchronous status.
151 * This is different from the flags in that nobody else
152 * ever touches our thread-synchronous status, so we don't
153 * have to worry about atomic accesses.
155 #define TS_USEDFPM 0x0001 /* FPU/Media was used by this task this quantum (SMP) */
157 #endif /* __KERNEL__ */
159 #endif /* _ASM_THREAD_INFO_H */