1/* thread_info.h: description 2 * 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 6 * 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. 11 */ 12 13#ifndef _ASM_THREAD_INFO_H 14#define _ASM_THREAD_INFO_H 15 16#ifdef __KERNEL__ 17 18#ifndef __ASSEMBLY__ 19#include <asm/processor.h> 20#endif 21 22#define THREAD_SIZE 8192 23 24/* 25 * low level task data that entry.S needs immediate access to 26 * - this struct should fit entirely inside of one cache line 27 * - this struct shares the supervisor stack pages 28 * - if the contents of this structure are changed, the assembly constants must also be changed 29 */ 30#ifndef __ASSEMBLY__ 31 32struct thread_info { 33 struct task_struct *task; /* main task structure */ 34 unsigned long flags; /* low level flags */ 35 unsigned long status; /* thread-synchronous flags */ 36 __u32 cpu; /* current CPU */ 37 int preempt_count; /* 0 => preemptable, <0 => BUG */ 38 39 mm_segment_t addr_limit; /* thread address space: 40 * 0-0xBFFFFFFF for user-thead 41 * 0-0xFFFFFFFF for kernel-thread 42 */ 43 44 __u8 supervisor_stack[0]; 45}; 46 47#else /* !__ASSEMBLY__ */ 48 49#include <asm/asm-offsets.h> 50 51#endif 52 53/* 54 * macros/functions for gaining access to the thread information structure 55 */ 56#ifndef __ASSEMBLY__ 57 58#define INIT_THREAD_INFO(tsk) \ 59{ \ 60 .task = &tsk, \ 61 .flags = 0, \ 62 .cpu = 0, \ 63 .preempt_count = INIT_PREEMPT_COUNT, \ 64 .addr_limit = KERNEL_DS, \ 65} 66 67#define init_thread_info (init_thread_union.thread_info) 68#define init_stack (init_thread_union.stack) 69 70/* how to get the thread information struct from C */ 71register struct thread_info *__current_thread_info asm("gr15"); 72 73#define current_thread_info() ({ __current_thread_info; }) 74 75#endif /* __ASSEMBLY__ */ 76 77/* 78 * thread information flags 79 * - these are process state flags that various assembly files may need to access 80 * - pending work-to-be-done flags are in LSW 81 * - other flags in MSW 82 */ 83#define TIF_SYSCALL_TRACE 0 /* syscall trace active */ 84#define TIF_NOTIFY_RESUME 1 /* callback before returning to user */ 85#define TIF_SIGPENDING 2 /* signal pending */ 86#define TIF_NEED_RESCHED 3 /* rescheduling necessary */ 87#define TIF_SINGLESTEP 4 /* restore singlestep on return to user mode */ 88#define TIF_RESTORE_SIGMASK 5 /* restore signal mask in do_signal() */ 89#define TIF_MEMDIE 7 /* is terminating due to OOM killer */ 90 91#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) 92#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) 93#define _TIF_SIGPENDING (1 << TIF_SIGPENDING) 94#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) 95#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP) 96 97/* work to do on interrupt/exception return */ 98#define _TIF_WORK_MASK \ 99 (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_SINGLESTEP) 100 101/* work to do on any return to u-space */ 102#define _TIF_ALLWORK_MASK (_TIF_WORK_MASK | _TIF_SYSCALL_TRACE) 103 104#if _TIF_ALLWORK_MASK >= 0x2000 105#error "_TIF_ALLWORK_MASK won't fit in an ANDI now (see entry.S)" 106#endif 107 108/* 109 * Thread-synchronous status. 110 * 111 * This is different from the flags in that nobody else 112 * ever touches our thread-synchronous status, so we don't 113 * have to worry about atomic accesses. 114 */ 115#define TS_USEDFPM 0x0001 /* FPU/Media was used by this task this quantum (SMP) */ 116 117#endif /* __KERNEL__ */ 118 119#endif /* _ASM_THREAD_INFO_H */ 120