thread_info.h

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/*
 *  S390 version
 *    Copyright IBM Corp. 2002, 2006
 *    Author(s): Martin Schwidefsky ([email protected])
 */

#ifndef _ASM_THREAD_INFO_H
#define _ASM_THREAD_INFO_H

/*
 * Size of kernel stack for each process
 */
#ifndef CONFIG_64BIT
#define THREAD_ORDER 1
#define ASYNC_ORDER  1
#else /* CONFIG_64BIT */
#ifndef __SMALL_STACK
#define THREAD_ORDER 2
#define ASYNC_ORDER  2
#else
#define THREAD_ORDER 1
#define ASYNC_ORDER  1
#endif
#endif /* CONFIG_64BIT */

#define THREAD_SIZE (PAGE_SIZE << THREAD_ORDER)
#define ASYNC_SIZE  (PAGE_SIZE << ASYNC_ORDER)

#ifndef __ASSEMBLY__
#include <asm/lowcore.h>
#include <asm/page.h>
#include <asm/processor.h>

/*
 * low level task data that entry.S needs immediate access to
 * - this struct should fit entirely inside of one cache line
 * - this struct shares the supervisor stack pages
 * - if the contents of this structure are changed, the assembly constants must also be changed
 */
struct thread_info {
    struct task_struct  *task;      /* main task structure */
    struct exec_domain  *exec_domain;   /* execution domain */
    unsigned long       flags;      /* low level flags */
    unsigned int        cpu;        /* current CPU */
    int         preempt_count;  /* 0 => preemptable, <0 => BUG */
    struct restart_block    restart_block;
    unsigned int        system_call;
    __u64           user_timer;
    __u64           system_timer;
    unsigned long       last_break; /* last breaking-event-address. */
};

/*
 * 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)

/* how to get the thread information struct from C */
static inline struct thread_info *current_thread_info(void)
{
    return (struct thread_info *) S390_lowcore.thread_info;
}

#define THREAD_SIZE_ORDER THREAD_ORDER

#endif

/*
 * thread information flags bit numbers
 */
#define TIF_SYSCALL     0   /* inside a system call */
#define TIF_NOTIFY_RESUME   1   /* callback before returning to user */
#define TIF_SIGPENDING      2   /* signal pending */
#define TIF_NEED_RESCHED    3   /* rescheduling necessary */
#define TIF_PER_TRAP        6   /* deliver sigtrap on return to user */
#define TIF_MCCK_PENDING    7   /* machine check handling is pending */
#define TIF_SYSCALL_TRACE   8   /* syscall trace active */
#define TIF_SYSCALL_AUDIT   9   /* syscall auditing active */
#define TIF_SECCOMP     10  /* secure computing */
#define TIF_SYSCALL_TRACEPOINT  11  /* syscall tracepoint instrumentation */
#define TIF_31BIT       17  /* 32bit process */
#define TIF_MEMDIE      18  /* is terminating due to OOM killer */
#define TIF_RESTORE_SIGMASK 19  /* restore signal mask in do_signal() */
#define TIF_SINGLE_STEP     20  /* This task is single stepped */

#define _TIF_SYSCALL        (1<<TIF_SYSCALL)
#define _TIF_NOTIFY_RESUME  (1<<TIF_NOTIFY_RESUME)
#define _TIF_SIGPENDING     (1<<TIF_SIGPENDING)
#define _TIF_NEED_RESCHED   (1<<TIF_NEED_RESCHED)
#define _TIF_PER_TRAP       (1<<TIF_PER_TRAP)
#define _TIF_MCCK_PENDING   (1<<TIF_MCCK_PENDING)
#define _TIF_SYSCALL_TRACE  (1<<TIF_SYSCALL_TRACE)
#define _TIF_SYSCALL_AUDIT  (1<<TIF_SYSCALL_AUDIT)
#define _TIF_SECCOMP        (1<<TIF_SECCOMP)
#define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)
#define _TIF_31BIT      (1<<TIF_31BIT)
#define _TIF_SINGLE_STEP    (1<<TIF_SINGLE_STEP)

#ifdef CONFIG_64BIT
#define is_32bit_task()     (test_thread_flag(TIF_31BIT))
#else
#define is_32bit_task()     (1)
#endif

#define PREEMPT_ACTIVE      0x4000000

#endif /* _ASM_THREAD_INFO_H */