page.h

来自「鼎力推荐！本程序是基于嵌入式LUNUX系统开发的源程序代码」· C头文件 代码 · 共 32 行

#ifndef _CRIS_ARCH_PAGE_H
#define _CRIS_ARCH_PAGE_H

#include <linux/config.h>

#ifdef __KERNEL__

/* This handles the memory map.. */
#ifdef CONFIG_CRIS_LOW_MAP
#define PAGE_OFFSET		KSEG_6   /* kseg_6 is mapped to physical ram */
#else
#define PAGE_OFFSET		KSEG_C   /* kseg_c is mapped to physical ram */
#endif

/* macros to convert between really physical and virtual addresses
 * by stripping a selected bit, we can convert between KSEG_x and 0x40000000 where
 * the DRAM really resides
 */

#ifdef CONFIG_CRIS_LOW_MAP
/* we have DRAM virtually at 0x6 */
#define __pa(x)                 ((unsigned long)(x) & 0xdfffffff)
#define __va(x)                 ((void *)((unsigned long)(x) | 0x20000000))
#else
/* we have DRAM virtually at 0xc */
#define __pa(x)                 ((unsigned long)(x) & 0x7fffffff)
#define __va(x)                 ((void *)((unsigned long)(x) | 0x80000000))
#endif

#endif
#endif