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 32 struct 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 */ 71 register 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