include/asm-blackfin/thread_info.h

   1 /*
   2  * File:         include/asm-blackfin/thread_info.h
   3  * Based on:     include/asm-m68knommu/thread_info.h
   4  * Author:       LG Soft India
   5  *               Copyright (C) 2004-2005 Analog Devices Inc.
   6  * Created:      Tue Sep 21 2004
   7  * Description:  Blackfin low-level thread information
   8  * Modified:
   9  * Bugs:         Enter bugs at http://blackfin.uclinux.org/
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2, or (at your option)
  14  * any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; see the file COPYING.
  23  * If not, write to the Free Software Foundation,
  24  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  25  */
  26
  27 #ifndef _ASM_THREAD_INFO_H
  28 #define _ASM_THREAD_INFO_H
  29
  30 #include <asm/page.h>
  31 #include <asm/entry.h>
  32 #include <asm/l1layout.h>
  33 #include <linux/compiler.h>
  34
  35 #ifdef __KERNEL__
  36
  37 /* Thread Align Mask to reach to the top of the stack
  38  * for any process
  39  */
  40 #define ALIGN_PAGE_MASK         0xffffe000
  41
  42 /*
  43  * Size of kernel stack for each process. This must be a power of 2...
  44  */
  45 #define THREAD_SIZE             8192    /* 2 pages */
  46
  47 #ifndef __ASSEMBLY__
  48
  49 typedef unsigned long mm_segment_t;
  50
  51 /*
  52  * low level task data.
  53  * If you change this, change the TI_* offsets below to match.
  54  */
  55
  56 struct thread_info {
  57         struct task_struct *task;       /* main task structure */
  58         struct exec_domain *exec_domain;        /* execution domain */
  59         unsigned long flags;    /* low level flags */
  60         int cpu;                /* cpu we're on */
  61         int preempt_count;      /* 0 => preemptable, <0 => BUG */
  62         mm_segment_t addr_limit;        /* address limit */
  63         struct restart_block restart_block;
  64         struct l1_scratch_task_info l1_task_info;
  65 };
  66
  67 /*
  68  * macros/functions for gaining access to the thread information structure
  69  */
  70 #define INIT_THREAD_INFO(tsk)                   \
  71 {                                               \
  72         .task           = &tsk,                 \
  73         .exec_domain    = &default_exec_domain, \
  74         .flags          = 0,                    \
  75         .cpu            = 0,                    \
  76         .preempt_count  = 1,                    \
  77         .restart_block  = {                     \
  78                 .fn = do_no_restart_syscall,    \
  79         },                                      \
  80 }
  81 #define init_thread_info        (init_thread_union.thread_info)
  82 #define init_stack              (init_thread_union.stack)
  83
  84 /* How to get the thread information struct from C */
  85
  86 static inline struct thread_info *current_thread_info(void)
  87     __attribute__ ((__const__));
  88
  89 /* Given a task stack pointer, you can find it's task structure
  90  * just by masking it to the 8K boundary.
  91  */
  92 static inline struct thread_info *current_thread_info(void)
  93 {
  94         struct thread_info *ti;
  95       __asm__("%0 = sp;": "=&d"(ti):
  96         );
  97         return (struct thread_info *)((long)ti & ~((long)THREAD_SIZE-1));
  98 }
  99
 100 /* thread information allocation */
 101 #define alloc_thread_info(tsk) ((struct thread_info *) \
 102                                 __get_free_pages(GFP_KERNEL, 1))
 103 #define free_thread_info(ti)    free_pages((unsigned long) (ti), 1)
 104 #endif                          /* __ASSEMBLY__ */
 105
 106 /*
 107  * Offsets in thread_info structure, used in assembly code
 108  */
 109 #define TI_TASK         0
 110 #define TI_EXECDOMAIN   4
 111 #define TI_FLAGS        8
 112 #define TI_CPU          12
 113 #define TI_PREEMPT      16
 114
 115 #define PREEMPT_ACTIVE  0x4000000
 116
 117 /*
 118  * thread information flag bit numbers
 119  */
 120 #define TIF_SYSCALL_TRACE       0       /* syscall trace active */
 121 #define TIF_SIGPENDING          1       /* signal pending */
 122 #define TIF_NEED_RESCHED        2       /* rescheduling necessary */
 123 #define TIF_POLLING_NRFLAG      3       /* true if poll_idle() is polling
 124                                            TIF_NEED_RESCHED */
 125 #define TIF_MEMDIE              4
 126 #define TIF_RESTORE_SIGMASK     5       /* restore signal mask in do_signal() */
 127 #define TIF_FREEZE              6       /* is freezing for suspend */
 128
 129 /* as above, but as bit values */
 130 #define _TIF_SYSCALL_TRACE      (1<<TIF_SYSCALL_TRACE)
 131 #define _TIF_SIGPENDING         (1<<TIF_SIGPENDING)
 132 #define _TIF_NEED_RESCHED       (1<<TIF_NEED_RESCHED)
 133 #define _TIF_POLLING_NRFLAG     (1<<TIF_POLLING_NRFLAG)
 134 #define _TIF_RESTORE_SIGMASK    (1<<TIF_RESTORE_SIGMASK)
 135 #define _TIF_FREEZE             (1<<TIF_FREEZE)
 136
 137 #define _TIF_WORK_MASK          0x0000FFFE      /* work to do on interrupt/exception return */
 138
 139 #endif                          /* __KERNEL__ */
 140
 141 #endif                          /* _ASM_THREAD_INFO_H */