arch/c6x/include/asm/thread_info.h

   1 /*
   2  *  Port on Texas Instruments TMS320C6x architecture
   3  *
   4  *  Copyright (C) 2004, 2009, 2010, 2011 Texas Instruments Incorporated
   5  *  Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
   6  *
   7  *  Updated for 2.6.3x: Mark Salter <msalter@redhat.com>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License version 2 as
  11  *  published by the Free Software Foundation.
  12  */
  13 #ifndef _ASM_C6X_THREAD_INFO_H
  14 #define _ASM_C6X_THREAD_INFO_H
  15
  16 #ifdef __KERNEL__
  17
  18 #include <asm/page.h>
  19
  20 #ifdef CONFIG_4KSTACKS
  21 #define THREAD_SIZE             4096
  22 #define THREAD_SHIFT            12
  23 #define THREAD_SIZE_ORDER       0
  24 #else
  25 #define THREAD_SIZE             8192
  26 #define THREAD_SHIFT            13
  27 #define THREAD_SIZE_ORDER       1
  28 #endif
  29
  30 #define THREAD_START_SP         (THREAD_SIZE - 8)
  31
  32 #ifndef __ASSEMBLY__
  33
  34 typedef struct {
  35         unsigned long seg;
  36 } mm_segment_t;
  37
  38 /*
  39  * low level task data.
  40  */
  41 struct thread_info {
  42         struct task_struct      *task;          /* main task structure */
  43         unsigned long           flags;          /* low level flags */
  44         int                     cpu;            /* cpu we're on */
  45         int                     preempt_count;  /* 0 = preemptable, <0 = BUG */
  46         mm_segment_t            addr_limit;     /* thread address space */
  47 };
  48
  49 /*
  50  * macros/functions for gaining access to the thread information structure
  51  *
  52  * preempt_count needs to be 1 initially, until the scheduler is functional.
  53  */
  54 #define INIT_THREAD_INFO(tsk)                   \
  55 {                                               \
  56         .task           = &tsk,                 \
  57         .flags          = 0,                    \
  58         .cpu            = 0,                    \
  59         .preempt_count  = INIT_PREEMPT_COUNT,   \
  60         .addr_limit     = KERNEL_DS,            \
  61 }
  62
  63 #define init_thread_info        (init_thread_union.thread_info)
  64 #define init_stack              (init_thread_union.stack)
  65
  66 /* get the thread information struct of current task */
  67 static inline __attribute__((const))
  68 struct thread_info *current_thread_info(void)
  69 {
  70         struct thread_info *ti;
  71         asm volatile (" clr   .s2 B15,0,%1,%0\n"
  72                       : "=b" (ti)
  73                       : "Iu5" (THREAD_SHIFT - 1));
  74         return ti;
  75 }
  76
  77 #define get_thread_info(ti)     get_task_struct((ti)->task)
  78 #define put_thread_info(ti)     put_task_struct((ti)->task)
  79 #endif /* __ASSEMBLY__ */
  80
  81 /*
  82  * thread information flag bit numbers
  83  * - pending work-to-be-done flags are in LSW
  84  * - other flags in MSW
  85  */
  86 #define TIF_SYSCALL_TRACE       0       /* syscall trace active */
  87 #define TIF_NOTIFY_RESUME       1       /* resumption notification requested */
  88 #define TIF_SIGPENDING          2       /* signal pending */
  89 #define TIF_NEED_RESCHED        3       /* rescheduling necessary */
  90 #define TIF_RESTORE_SIGMASK     4       /* restore signal mask in do_signal() */
  91
  92 #define TIF_MEMDIE              17      /* OOM killer killed process */
  93
  94 #define TIF_WORK_MASK           0x00007FFE /* work on irq/exception return */
  95 #define TIF_ALLWORK_MASK        0x00007FFF /* work on any return to u-space */
  96
  97 #endif /* __KERNEL__ */
  98
  99 #endif /* _ASM_C6X_THREAD_INFO_H */