page.h

来自「自己做的交叉编译工具！gcc-3.4.5,glibc-2.3.6在ubuntu8」· C头文件 代码 · 共 31 行

/*
 *  linux/include/asm-arm/page.h
 *
 *  Copyright (C) 1995-2003 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#ifndef _ASMARM_PAGE_H
#define _ASMARM_PAGE_H

#include <unistd.h>

#define PAGE_SIZE (getpagesize())
static __inline__ int getpageshift()
{
    int pagesize = getpagesize();
#if (__GNUC__ >= 4) || ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 4))
    return (__builtin_clz(pagesize) ^ 31);
#else
    register int pageshift = -1;
    while (pagesize) { pagesize >>= 1; pageshift++; }
    return pageshift;
#endif
}
#define PAGE_SHIFT (getpageshift())
#define PAGE_MASK    (~(PAGE_SIZE-1))

#endif