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 struct restart_block restart_block; 45 46 __u8 supervisor_stack[0]; 47 }; 48 49 #else /* !__ASSEMBLY__ */ 50 51 #include <asm/asm-offsets.h> 52 53 #endif 54 55 #define PREEMPT_ACTIVE 0x10000000 56 57 /* 58 * macros/functions for gaining access to the thread information structure 59 * 60 * preempt_count needs to be 1 initially, until the scheduler is functional. 61 */ 62 #ifndef __ASSEMBLY__ 63 64 #define INIT_THREAD_INFO(tsk) \ 65 { \ 66 .task = &tsk, \ 67 .exec_domain = &default_exec_domain, \ 68 .flags = 0, \ 69 .cpu = 0, \ 70 .preempt_count = 1, \ 71 .addr_limit = KERNEL_DS, \ 72 .restart_block = { \ 73 .fn = do_no_restart_syscall, \ 74 }, \ 75 } 76 77 #define init_thread_info (init_thread_union.thread_info) 78 #define init_stack (init_thread_union.stack) 79 80 /* how to get the thread information struct from C */ 81 register struct thread_info *__current_thread_info asm("gr15"); 82 83 #define current_thread_info() ({ __current_thread_info; }) 84 85 #define __HAVE_ARCH_THREAD_INFO_ALLOCATOR 86 87 /* thread information allocation */ 88 #ifdef CONFIG_DEBUG_STACK_USAGE 89 #define alloc_thread_info(tsk) \ 90 ({ \ 91 struct thread_info *ret; \ 92 \ 93 ret = kzalloc(THREAD_SIZE, GFP_KERNEL); \ 94 \ 95 ret; \ 96 }) 97 #else 98 #define alloc_thread_info(tsk) kmalloc(THREAD_SIZE, GFP_KERNEL) 99 #endif 100 101 #define free_thread_info(info) kfree(info) 102 103 #endif /* __ASSEMBLY__ */ 104 105 /* 106 * thread information flags 107 * - these are process state flags that various assembly files may need to access 108 * - pending work-to-be-done flags are in LSW 109 * - other flags in MSW 110 */ 111 #define TIF_SYSCALL_TRACE 0 /* syscall trace active */ 112 #define TIF_SIGPENDING 1 /* signal pending */ 113 #define TIF_NEED_RESCHED 2 /* rescheduling necessary */ 114 #define TIF_SINGLESTEP 3 /* restore singlestep on return to user mode */ 115 #define TIF_IRET 4 /* return with iret */ 116 #define TIF_RESTORE_SIGMASK 5 /* restore signal mask in do_signal() */ 117 #define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */ 118 #define TIF_MEMDIE 17 /* OOM killer killed process */ 119 #define TIF_FREEZE 18 /* freezing for suspend */ 120 121 #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) 122 #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) 123 #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) 124 #define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP) 125 #define _TIF_IRET (1 << TIF_IRET) 126 #define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK) 127 #define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG) 128 #define _TIF_FREEZE (1 << TIF_FREEZE) 129 130 #define _TIF_WORK_MASK 0x0000FFFE /* work to do on interrupt/exception return */ 131 #define _TIF_ALLWORK_MASK 0x0000FFFF /* work to do on any return to u-space */ 132 133 /* 134 * Thread-synchronous status. 135 * 136 * This is different from the flags in that nobody else 137 * ever touches our thread-synchronous status, so we don't 138 * have to worry about atomic accesses. 139 */ 140 #define TS_USEDFPM 0x0001 /* FPU/Media was used by this task this quantum (SMP) */ 141 142 #endif /* __KERNEL__ */ 143 144 #endif /* _ASM_THREAD_INFO_H */ 145