arch/arc/include/asm/thread_info.h

   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 #define PREEMPT_ACTIVE      0x10000000
  84
  85 /*
  86  * thread information flags
  87  * - these are process state flags that various assembly files may need to
  88  *   access
  89  * - pending work-to-be-done flags are in LSW
  90  * - other flags in MSW
  91  */
  92 #define TIF_RESTORE_SIGMASK     0       /* restore sig mask in do_signal() */
  93 #define TIF_NOTIFY_RESUME       1       /* resumption notification requested */
  94 #define TIF_SIGPENDING          2       /* signal pending */
  95 #define TIF_NEED_RESCHED        3       /* rescheduling necessary */
  96 #define TIF_SYSCALL_AUDIT       4       /* syscall auditing active */
  97 #define TIF_SYSCALL_TRACE       15      /* syscall trace active */
  98
  99 /* true if poll_idle() is polling TIF_NEED_RESCHED */
 100 #define TIF_MEMDIE              16
 101
 102 #define _TIF_SYSCALL_TRACE      (1<<TIF_SYSCALL_TRACE)
 103 #define _TIF_NOTIFY_RESUME      (1<<TIF_NOTIFY_RESUME)
 104 #define _TIF_SIGPENDING         (1<<TIF_SIGPENDING)
 105 #define _TIF_NEED_RESCHED       (1<<TIF_NEED_RESCHED)
 106 #define _TIF_SYSCALL_AUDIT      (1<<TIF_SYSCALL_AUDIT)
 107 #define _TIF_MEMDIE             (1<<TIF_MEMDIE)
 108
 109 /* work to do on interrupt/exception return */
 110 #define _TIF_WORK_MASK          (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
 111                                  _TIF_NOTIFY_RESUME)
 112
 113 /*
 114  * _TIF_ALLWORK_MASK includes SYSCALL_TRACE, but we don't need it.
 115  * SYSCALL_TRACE is anways seperately/unconditionally tested right after a
 116  * syscall, so all that reamins to be tested is _TIF_WORK_MASK
 117  */
 118
 119 #endif /* __KERNEL__ */
 120
 121 #endif /* _ASM_THREAD_INFO_H */