thread_info.h

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/* thread_info.h: h8300 low-level thread information
 * adapted from the i386 and PPC versions by Yoshinori Sato <[email protected]>
 *
 * Copyright (C) 2002  David Howells ([email protected])
 * - Incorporating suggestions made by Linus Torvalds and Dave Miller
 */

#ifndef _ASM_THREAD_INFO_H
#define _ASM_THREAD_INFO_H

#include <asm/page.h>

#ifdef __KERNEL__

#ifndef __ASSEMBLY__

/*
 * low level task data.
 * If you change this, change the TI_* offsets below to match.
 */
struct thread_info {
    struct task_struct *task;       /* main task structure */
    struct exec_domain *exec_domain;    /* execution domain */
    unsigned long      flags;       /* low level flags */
    int        cpu;         /* cpu we're on */
    int        preempt_count;   /* 0 => preemptable, <0 => BUG */
    struct restart_block restart_block;
};

/*
 * macros/functions for gaining access to the thread information structure
 */
#define INIT_THREAD_INFO(tsk)           \
{                       \
    .task =     &tsk,           \
    .exec_domain =  &default_exec_domain,   \
    .flags =    0,          \
    .cpu =      0,          \
    .preempt_count = INIT_PREEMPT_COUNT,    \
    .restart_block  = {         \
        .fn = do_no_restart_syscall,    \
    },                  \
}

#define init_thread_info    (init_thread_union.thread_info)
#define init_stack      (init_thread_union.stack)


/*
 * Size of kernel stack for each process. This must be a power of 2...
 */
#define THREAD_SIZE_ORDER   1
#define THREAD_SIZE     8192    /* 2 pages */


/* how to get the thread information struct from C */
static inline struct thread_info *current_thread_info(void)
{
    struct thread_info *ti;
    __asm__(
        "mov.l  sp, %0 \n\t"
        "and.l  %1, %0"
        : "=&r"(ti)
        : "i" (~(THREAD_SIZE-1))
        );
    return ti;
}

#endif /* __ASSEMBLY__ */

/*
 * Offsets in thread_info structure, used in assembly code
 */
#define TI_TASK     0
#define TI_EXECDOMAIN   4
#define TI_FLAGS    8
#define TI_CPU      12
#define TI_PRE_COUNT    16

#define PREEMPT_ACTIVE  0x4000000

/*
 * thread information flag bit numbers
 */
#define TIF_SYSCALL_TRACE   0   /* syscall trace active */
#define TIF_SIGPENDING      1   /* signal pending */
#define TIF_NEED_RESCHED    2   /* rescheduling necessary */
#define TIF_MEMDIE      4   /* is terminating due to OOM killer */
#define TIF_RESTORE_SIGMASK 5   /* restore signal mask in do_signal() */
#define TIF_NOTIFY_RESUME   6   /* callback before returning to user */

/* as above, but as bit values */
#define _TIF_SYSCALL_TRACE  (1<<TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING     (1<<TIF_SIGPENDING)
#define _TIF_NEED_RESCHED   (1<<TIF_NEED_RESCHED)
#define _TIF_NOTIFY_RESUME  (1 << TIF_NOTIFY_RESUME)

#define _TIF_WORK_MASK      (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
                 _TIF_NOTIFY_RESUME)

#endif /* __KERNEL__ */

#endif /* _ASM_THREAD_INFO_H */