thread_info.h

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#ifndef _ASM_M32R_THREAD_INFO_H
#define _ASM_M32R_THREAD_INFO_H

/* thread_info.h: m32r low-level thread information
 *
 * Copyright (C) 2002  David Howells ([email protected])
 * - Incorporating suggestions made by Linus Torvalds and Dave Miller
 * Copyright (C) 2004  Hirokazu Takata <takata at linux-m32r.org>
 */

#ifdef __KERNEL__

#ifndef __ASSEMBLY__
#include <asm/processor.h>
#endif

/*
 * 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
 */
#ifndef __ASSEMBLY__

struct thread_info {
    struct task_struct  *task;      /* main task structure */
    struct exec_domain  *exec_domain;   /* execution domain */
    unsigned long       flags;      /* low level flags */
    unsigned long       status;     /* thread-synchronous flags */
    __u32           cpu;        /* current CPU */
    int         preempt_count;  /* 0 => preemptable, <0 => BUG */

    mm_segment_t        addr_limit; /* thread address space:
                           0-0xBFFFFFFF for user-thread
                           0-0xFFFFFFFF for kernel-thread
                        */
    struct restart_block    restart_block;

    __u8            supervisor_stack[0];
};

#else /* !__ASSEMBLY__ */

/* offsets into the thread_info struct for assembly code access */
#define TI_TASK     0x00000000
#define TI_EXEC_DOMAIN  0x00000004
#define TI_FLAGS    0x00000008
#define TI_STATUS   0x0000000C
#define TI_CPU      0x00000010
#define TI_PRE_COUNT    0x00000014
#define TI_ADDR_LIMIT   0x00000018
#define TI_RESTART_BLOCK 0x000001C

#endif

#define PREEMPT_ACTIVE      0x10000000

#define THREAD_SIZE     (PAGE_SIZE << 1)
#define THREAD_SIZE_ORDER   1
/*
 * macros/functions for gaining access to the thread information structure
 */
#ifndef __ASSEMBLY__

#define INIT_THREAD_INFO(tsk)           \
{                       \
    .task       = &tsk,         \
    .exec_domain    = &default_exec_domain, \
    .flags      = 0,            \
    .cpu        = 0,            \
    .preempt_count  = INIT_PREEMPT_COUNT,   \
    .addr_limit = KERNEL_DS,        \
    .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)
{
    struct thread_info *ti;

    __asm__ __volatile__ (
        "ldi    %0, #%1         \n\t"
        "and    %0, sp          \n\t"
        : "=r" (ti) : "i" (~(THREAD_SIZE - 1))
    );

    return ti;
}

#define TI_FLAG_FAULT_CODE_SHIFT    28

static inline void set_thread_fault_code(unsigned int val)
{
    struct thread_info *ti = current_thread_info();
    ti->flags = (ti->flags & (~0 >> (32 - TI_FLAG_FAULT_CODE_SHIFT)))
        | (val << TI_FLAG_FAULT_CODE_SHIFT);
}

static inline unsigned int get_thread_fault_code(void)
{
    struct thread_info *ti = current_thread_info();
    return ti->flags >> TI_FLAG_FAULT_CODE_SHIFT;
}

#endif

/*
 * thread information flags
 * - these are process state flags that various assembly files may need to access
 * - pending work-to-be-done flags are in LSW
 * - other flags in MSW
 */
#define TIF_SYSCALL_TRACE   0   /* syscall trace active */
#define TIF_SIGPENDING      1   /* signal pending */
#define TIF_NEED_RESCHED    2   /* rescheduling necessary */
#define TIF_SINGLESTEP      3   /* restore singlestep on return to user mode */
#define TIF_NOTIFY_RESUME   5   /* callback before returning to user */
#define TIF_RESTORE_SIGMASK 8   /* restore signal mask in do_signal() */
#define TIF_USEDFPU     16  /* FPU was used by this task this quantum (SMP) */
#define TIF_MEMDIE      18  /* is terminating due to OOM killer */

#define _TIF_SYSCALL_TRACE  (1<<TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING     (1<<TIF_SIGPENDING)
#define _TIF_NEED_RESCHED   (1<<TIF_NEED_RESCHED)
#define _TIF_SINGLESTEP     (1<<TIF_SINGLESTEP)
#define _TIF_NOTIFY_RESUME  (1<<TIF_NOTIFY_RESUME)
#define _TIF_USEDFPU        (1<<TIF_USEDFPU)

#define _TIF_WORK_MASK      (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_NOTIFY_RESUME)
#define _TIF_ALLWORK_MASK   (_TIF_WORK_MASK | _TIF_SYSCALL_TRACE)

/*
 * Thread-synchronous status.
 *
 * This is different from the flags in that nobody else
 * ever touches our thread-synchronous status, so we don't
 * have to worry about atomic accesses.
 */
#define TS_USEDFPU      0x0001  /* FPU was used by this task this quantum (SMP) */

#endif /* __KERNEL__ */

#endif /* _ASM_M32R_THREAD_INFO_H */