LXR linux/arch/arc/include/asm/thread

   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
  29#ifndef __ASSEMBLY__
  30
  31#include <linux/thread_info.h>
  32#include <asm/segment.h>
  33
  34/*
  35 * low level task data that entry.S needs immediate access to
  36 * - this struct should fit entirely inside of one cache line
  37 * - this struct shares the supervisor stack pages
  38 * - if the contents of this structure are changed, the assembly constants
  39 *   must also be changed
  40 */
  41struct thread_info {
  42        unsigned long flags;            /* low level flags */
  43        int preempt_count;              /* 0 => preemptable, <0 => BUG */
  44        struct task_struct *task;       /* main task structure */
  45        mm_segment_t addr_limit;        /* thread address space */
  46        __u32 cpu;                      /* current CPU */
  47        unsigned long thr_ptr;          /* TLS ptr */
  48};
  49
  50/*
  51 * macros/functions for gaining access to the thread information structure
  52 *
  53 * preempt_count needs to be 1 initially, until the scheduler is functional.
  54 */
  55#define INIT_THREAD_INFO(tsk)                   \
  56{                                               \
  57        .task       = &tsk,                     \
  58        .flags      = 0,                        \
  59        .cpu        = 0,                        \
  60        .preempt_count  = INIT_PREEMPT_COUNT,   \
  61        .addr_limit = KERNEL_DS,                \
  62}
  63
  64#define init_thread_info    (init_thread_union.thread_info)
  65#define init_stack          (init_thread_union.stack)
  66
  67static inline __attribute_const__ struct thread_info *current_thread_info(void)
  68{
  69        register unsigned long sp asm("sp");
  70        return (struct thread_info *)(sp & ~(THREAD_SIZE - 1));
  71}
  72
  73#endif /* !__ASSEMBLY__ */
  74
  75/*
  76 * thread information flags
  77 * - these are process state flags that various assembly files may need to
  78 *   access
  79 * - pending work-to-be-done flags are in LSW
  80 * - other flags in MSW
  81 */
  82#define TIF_RESTORE_SIGMASK     0       /* restore sig mask in do_signal() */
  83#define TIF_NOTIFY_RESUME       1       /* resumption notification requested */
  84#define TIF_SIGPENDING          2       /* signal pending */
  85#define TIF_NEED_RESCHED        3       /* rescheduling necessary */
  86#define TIF_SYSCALL_AUDIT       4       /* syscall auditing active */
  87#define TIF_SYSCALL_TRACE       15      /* syscall trace active */
  88
  89/* true if poll_idle() is polling TIF_NEED_RESCHED */
  90#define TIF_MEMDIE              16
  91
  92#define _TIF_SYSCALL_TRACE      (1<<TIF_SYSCALL_TRACE)
  93#define _TIF_NOTIFY_RESUME      (1<<TIF_NOTIFY_RESUME)
  94#define _TIF_SIGPENDING         (1<<TIF_SIGPENDING)
  95#define _TIF_NEED_RESCHED       (1<<TIF_NEED_RESCHED)
  96#define _TIF_SYSCALL_AUDIT      (1<<TIF_SYSCALL_AUDIT)
  97#define _TIF_MEMDIE             (1<<TIF_MEMDIE)
  98
  99/* work to do on interrupt/exception return */
 100#define _TIF_WORK_MASK          (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
 101                                 _TIF_NOTIFY_RESUME)
 102
 103/*
 104 * _TIF_ALLWORK_MASK includes SYSCALL_TRACE, but we don't need it.
 105 * SYSCALL_TRACE is anways seperately/unconditionally tested right after a
 106 * syscall, so all that reamins to be tested is _TIF_WORK_MASK
 107 */
 108
 109#endif /* _ASM_THREAD_INFO_H */
 110