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 #include <asm/page.h>
  20
  21 #ifdef CONFIG_16KSTACKS
  22 #define THREAD_SIZE_ORDER 1
  23 #else
  24 #define THREAD_SIZE_ORDER 0
  25 #endif
  26
  27 #define THREAD_SIZE     (PAGE_SIZE << THREAD_SIZE_ORDER)
  28 #define THREAD_SHIFT    (PAGE_SHIFT << THREAD_SIZE_ORDER)
  29
  30 #ifndef __ASSEMBLY__
  31
  32 #include <linux/thread_info.h>
  33 #include <asm/segment.h>
  34
  35 /*
  36  * low level task data that entry.S needs immediate access to
  37  * - this struct should fit entirely inside of one cache line
  38  * - this struct shares the supervisor stack pages
  39  * - if the contents of this structure are changed, the assembly constants
  40  *   must also be changed
  41  */
  42 struct thread_info {
  43         unsigned long flags;            /* low level flags */
  44         int preempt_count;              /* 0 => preemptable, <0 => BUG */
  45         struct task_struct *task;       /* main task structure */
  46         mm_segment_t addr_limit;        /* thread address space */
  47         __u32 cpu;                      /* current CPU */
  48         unsigned long thr_ptr;          /* TLS ptr */
  49 };
  50
  51 /*
  52  * macros/functions for gaining access to the thread information structure
  53  *
  54  * preempt_count needs to be 1 initially, until the scheduler is functional.
  55  */
  56 #define INIT_THREAD_INFO(tsk)                   \
  57 {                                               \
  58         .task       = &tsk,                     \
  59         .flags      = 0,                        \
  60         .cpu        = 0,                        \
  61         .preempt_count  = INIT_PREEMPT_COUNT,   \
  62         .addr_limit = KERNEL_DS,                \
  63 }
  64
  65 static inline __attribute_const__ struct thread_info *current_thread_info(void)
  66 {
  67         register unsigned long sp asm("sp");
  68         return (struct thread_info *)(sp & ~(THREAD_SIZE - 1));
  69 }
  70
  71 #endif /* !__ASSEMBLY__ */
  72
  73 /*
  74  * thread information flags
  75  * - these are process state flags that various assembly files may need to
  76  *   access
  77  * - pending work-to-be-done flags are in LSW
  78  * - other flags in MSW
  79  */
  80 #define TIF_RESTORE_SIGMASK     0       /* restore sig mask in do_signal() */
  81 #define TIF_NOTIFY_RESUME       1       /* resumption notification requested */
  82 #define TIF_SIGPENDING          2       /* signal pending */
  83 #define TIF_NEED_RESCHED        3       /* rescheduling necessary */
  84 #define TIF_SYSCALL_AUDIT       4       /* syscall auditing active */
  85 #define TIF_SYSCALL_TRACE       15      /* syscall trace active */
  86
  87 /* true if poll_idle() is polling TIF_NEED_RESCHED */
  88 #define TIF_MEMDIE              16
  89
  90 #define _TIF_SYSCALL_TRACE      (1<<TIF_SYSCALL_TRACE)
  91 #define _TIF_NOTIFY_RESUME      (1<<TIF_NOTIFY_RESUME)
  92 #define _TIF_SIGPENDING         (1<<TIF_SIGPENDING)
  93 #define _TIF_NEED_RESCHED       (1<<TIF_NEED_RESCHED)
  94 #define _TIF_SYSCALL_AUDIT      (1<<TIF_SYSCALL_AUDIT)
  95 #define _TIF_MEMDIE             (1<<TIF_MEMDIE)
  96
  97 /* work to do on interrupt/exception return */
  98 #define _TIF_WORK_MASK          (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
  99                                  _TIF_NOTIFY_RESUME)
 100
 101 /*
 102  * _TIF_ALLWORK_MASK includes SYSCALL_TRACE, but we don't need it.
 103  * SYSCALL_TRACE is anyway seperately/unconditionally tested right after a
 104  * syscall, so all that reamins to be tested is _TIF_WORK_MASK
 105  */
 106
 107 #endif /* _ASM_THREAD_INFO_H */