1 /* 2 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 * 8 * Vineetg: Oct 2009 9 * No need for ARC specific thread_info allocator (kmalloc/free). This is 10 * anyways one page allocation, thus slab alloc can be short-circuited and 11 * the generic version (get_free_page) would be loads better. 12 * 13 * Sameer Dhavale: Codito Technologies 2004 14 */ 15 16 #ifndef _ASM_THREAD_INFO_H 17 #define _ASM_THREAD_INFO_H 18 19 #ifdef __KERNEL__ 20 21 #include <asm/page.h> 22 23 #ifdef CONFIG_16KSTACKS 24 #define THREAD_SIZE_ORDER 1 25 #else 26 #define THREAD_SIZE_ORDER 0 27 #endif 28 29 #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER) 30 31 #ifndef __ASSEMBLY__ 32 33 #include <linux/thread_info.h> 34 #include <asm/segment.h> 35 36 /* 37 * low level task data that entry.S needs immediate access to 38 * - this struct should fit entirely inside of one cache line 39 * - this struct shares the supervisor stack pages 40 * - if the contents of this structure are changed, the assembly constants 41 * must also be changed 42 */ 43 struct thread_info { 44 unsigned long flags; /* low level flags */ 45 int preempt_count; /* 0 => preemptable, <0 => BUG */ 46 struct task_struct *task; /* main task structure */ 47 mm_segment_t addr_limit; /* thread address space */ 48 struct exec_domain *exec_domain;/* execution domain */ 49 __u32 cpu; /* current CPU */ 50 unsigned long thr_ptr; /* TLS ptr */ 51 struct restart_block restart_block; 52 }; 53 54 /* 55 * macros/functions for gaining access to the thread information structure 56 * 57 * preempt_count needs to be 1 initially, until the scheduler is functional. 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 .restart_block = { \ 68 .fn = do_no_restart_syscall, \ 69 }, \ 70 } 71 72 #define init_thread_info (init_thread_union.thread_info) 73 #define init_stack (init_thread_union.stack) 74 75 static inline __attribute_const__ struct thread_info *current_thread_info(void) 76 { 77 register unsigned long sp asm("sp"); 78 return (struct thread_info *)(sp & ~(THREAD_SIZE - 1)); 79 } 80 81 #endif /* !__ASSEMBLY__ */ 82 83 /* 84 * thread information flags 85 * - these are process state flags that various assembly files may need to 86 * access 87 * - pending work-to-be-done flags are in LSW 88 * - other flags in MSW 89 */ 90 #define TIF_RESTORE_SIGMASK 0 /* restore sig mask in do_signal() */ 91 #define TIF_NOTIFY_RESUME 1 /* resumption notification requested */ 92 #define TIF_SIGPENDING 2 /* signal pending */ 93 #define TIF_NEED_RESCHED 3 /* rescheduling necessary */ 94 #define TIF_SYSCALL_AUDIT 4 /* syscall auditing active */ 95 #define TIF_SYSCALL_TRACE 15 /* syscall trace active */ 96 97 /* true if poll_idle() is polling TIF_NEED_RESCHED */ 98 #define TIF_MEMDIE 16 99 100 #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) 101 #define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME) 102 #define _TIF_SIGPENDING (1<<TIF_SIGPENDING) 103 #define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED) 104 #define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT) 105 #define _TIF_MEMDIE (1<<TIF_MEMDIE) 106 107 /* work to do on interrupt/exception return */ 108 #define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \ 109 _TIF_NOTIFY_RESUME) 110 111 /* 112 * _TIF_ALLWORK_MASK includes SYSCALL_TRACE, but we don't need it. 113 * SYSCALL_TRACE is anways seperately/unconditionally tested right after a 114 * syscall, so all that reamins to be tested is _TIF_WORK_MASK 115 */ 116 117 #endif /* __KERNEL__ */ 118 119 #endif /* _ASM_THREAD_INFO_H */ 120