root/include/asm-mn10300/thread_info.h

INCLUDED FROM

DEFINITIONS

1. current_thread_info
2. current_stack_pointer

/* MN10300 Low-level thread information
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */

#ifndef _ASM_THREAD_INFO_H
#define _ASM_THREAD_INFO_H

#ifdef __KERNEL__

#include <asm/page.h>

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

#define PREEMPT_ACTIVE          0x10000000

#ifdef CONFIG_4KSTACKS
#define THREAD_SIZE             (4096)
#else
#define THREAD_SIZE             (8192)
#endif

#define STACK_WARN              (THREAD_SIZE / 8)

/*
 * 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 */
        __u32                   cpu;            /* current CPU */
        __s32                   preempt_count;  /* 0 => preemptable, <0 => BUG */

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

        __u8                    supervisor_stack[0];
};

#else /* !__ASSEMBLY__ */

#ifndef __ASM_OFFSETS_H__
#include <asm/asm-offsets.h>
#endif

#endif

/*
 * macros/functions for gaining access to the thread information structure
 *
 * preempt_count needs to be 1 initially, until the scheduler is functional.
 */
#ifndef __ASSEMBLY__

#define INIT_THREAD_INFO(tsk)                   \
{                                               \
        .task           = &tsk,                 \
        .exec_domain    = &default_exec_domain, \
        .flags          = 0,                    \
        .cpu            = 0,                    \
        .preempt_count  = 1,                    \
        .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)
#define init_uregs                                                      \
        ((struct pt_regs *)                                             \
         ((unsigned long) init_stack + THREAD_SIZE - sizeof(struct pt_regs)))

extern struct thread_info *__current_ti;

/* how to get the thread information struct from C */
static inline __attribute__((const))
struct thread_info *current_thread_info(void)
{
        struct thread_info *ti;
        asm("mov sp,%0\n"
            "and %1,%0\n"
            : "=d" (ti)
            : "i" (~(THREAD_SIZE - 1))
            : "cc");
        return ti;
}

/* how to get the current stack pointer from C */
static inline unsigned long current_stack_pointer(void)
{
        unsigned long sp;
        asm("mov sp,%0; ":"=r" (sp));
        return sp;
}

#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR

/* thread information allocation */
#ifdef CONFIG_DEBUG_STACK_USAGE
#define alloc_thread_info(tsk) kzalloc(THREAD_SIZE, GFP_KERNEL)
#else
#define alloc_thread_info(tsk) kmalloc(THREAD_SIZE, GFP_KERNEL)
#endif

#define free_thread_info(ti)    kfree((ti))
#define get_thread_info(ti)     get_task_struct((ti)->task)
#define put_thread_info(ti)     put_task_struct((ti)->task)

#else /* !__ASSEMBLY__ */

#ifndef __VMLINUX_LDS__
/* how to get the thread information struct from ASM */
.macro GET_THREAD_INFO reg
        mov     sp,\reg
        and     -THREAD_SIZE,\reg
.endm
#endif
#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_NOTIFY_RESUME       1       /* resumption notification requested */
#define TIF_SIGPENDING          2       /* signal pending */
#define TIF_NEED_RESCHED        3       /* rescheduling necessary */
#define TIF_SINGLESTEP          4       /* restore singlestep on return to user mode */
#define TIF_RESTORE_SIGMASK     5       /* restore signal mask in do_signal() */
#define TIF_POLLING_NRFLAG      16      /* true if poll_idle() is polling TIF_NEED_RESCHED */
#define TIF_MEMDIE              17      /* OOM killer killed process */
#define TIF_FREEZE              18      /* freezing for suspend */

#define _TIF_SYSCALL_TRACE      +(1 << TIF_SYSCALL_TRACE)
#define _TIF_NOTIFY_RESUME      +(1 << TIF_NOTIFY_RESUME)
#define _TIF_SIGPENDING         +(1 << TIF_SIGPENDING)
#define _TIF_NEED_RESCHED       +(1 << TIF_NEED_RESCHED)
#define _TIF_SINGLESTEP         +(1 << TIF_SINGLESTEP)
#define _TIF_RESTORE_SIGMASK    +(1 << TIF_RESTORE_SIGMASK)
#define _TIF_POLLING_NRFLAG     +(1 << TIF_POLLING_NRFLAG)
#define _TIF_FREEZE             +(1 << TIF_FREEZE)

#define _TIF_WORK_MASK          0x0000FFFE      /* work to do on interrupt/exception return */
#define _TIF_ALLWORK_MASK       0x0000FFFF      /* work to do on any return to u-space */

#endif /* __KERNEL__ */

#endif /* _ASM_THREAD_INFO_H */