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#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 */
  43struct 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
  75static 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 */
 122