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 struct exec_domain *exec_domain; /* execution domain */ 35 unsigned long flags; /* low level flags */ 36 unsigned long status; /* thread-synchronous flags */ 37 __u32 cpu; /* current CPU */ 38 int preempt_count; /* 0 => preemptable, <0 => BUG */ 39 40 mm_segment_t addr_limit; /* thread address space: 41 * 0-0xBFFFFFFF for user-thead 42 * 0-0xFFFFFFFF for kernel-thread 43 */ 44 45 __u8 supervisor_stack[0]; 46 }; 47 48 #else /* !__ASSEMBLY__ */ 49 50 #include <asm/asm-offsets.h> 51 52 #endif 53 54 /* 55 * macros/functions for gaining access to the thread information structure 56 */ 57 #ifndef __ASSEMBLY__ 58 59 #define INIT_THREAD_INFO(tsk) \ 60 { \ 61 .task = &tsk, \ 62 .exec_domain = &default_exec_domain, \ 63 .flags = 0, \ 64 .cpu = 0, \ 65 .preempt_count = INIT_PREEMPT_COUNT, \ 66 .addr_limit = KERNEL_DS, \ 67 } 68 69 #define init_thread_info (init_thread_union.thread_info) 70 #define init_stack (init_thread_union.stack) 71 72 /* how to get the thread information struct from C */ 73 register struct thread_info *__current_thread_info asm("gr15"); 74 75 #define current_thread_info() ({ __current_thread_info; }) 76 77 #endif /* __ASSEMBLY__ */ 78 79 /* 80 * thread information flags 81 * - these are process state flags that various assembly files may need to access 82 * - pending work-to-be-done flags are in LSW 83 * - other flags in MSW 84 */ 85 #define TIF_SYSCALL_TRACE 0 /* syscall trace active */ 86 #define TIF_NOTIFY_RESUME 1 /* callback before returning to user */ 87 #define TIF_SIGPENDING 2 /* signal pending */ 88 #define TIF_NEED_RESCHED 3 /* rescheduling necessary */ 89 #define TIF_SINGLESTEP 4 /* restore singlestep on return to user mode */ 90 #define TIF_RESTORE_SIGMASK 5 /* restore signal mask in do_signal() */ 91 #define TIF_MEMDIE 7 /* is terminating due to OOM killer */ 92 93 #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) 94 #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) 95 #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) 96 #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) 97 #define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP) 98 99 /* work to do on interrupt/exception return */ 100 #define _TIF_WORK_MASK \ 101 (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_SINGLESTEP) 102 103 /* work to do on any return to u-space */ 104 #define _TIF_ALLWORK_MASK (_TIF_WORK_MASK | _TIF_SYSCALL_TRACE) 105 106 #if _TIF_ALLWORK_MASK >= 0x2000 107 #error "_TIF_ALLWORK_MASK won't fit in an ANDI now (see entry.S)" 108 #endif 109 110 /* 111 * Thread-synchronous status. 112 * 113 * This is different from the flags in that nobody else 114 * ever touches our thread-synchronous status, so we don't 115 * have to worry about atomic accesses. 116 */ 117 #define TS_USEDFPM 0x0001 /* FPU/Media was used by this task this quantum (SMP) */ 118 119 #endif /* __KERNEL__ */ 120 121 #endif /* _ASM_THREAD_INFO_H */ 122