1. 根目录:
2. arch
3. unicore32
4. include
5. asm
6. memory.h

/*
 * linux/arch/unicore32/include/asm/memory.h
 *
 * Code specific to PKUnity SoC and UniCore ISA
 *
 * Copyright (C) 2001-2010 GUAN Xue-tao
 *
 * 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.
 *
 *  Note: this file should not be included by non-asm/.h files
 */
#ifndef __UNICORE_MEMORY_H__
#define __UNICORE_MEMORY_H__

#include <linux/compiler.h>
#include <linux/const.h>
#include <asm/sizes.h>
#include <mach/memory.h>

/*
 * Allow for constants defined here to be used from assembly code
 * by prepending the UL suffix only with actual C code compilation.
 */
#define UL(x) _AC(x, UL)

/*
 * PAGE_OFFSET - the virtual address of the start of the kernel image
 * TASK_SIZE - the maximum size of a user space task.
 * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area
 */
#define PAGE_OFFSET		UL(0xC0000000)
#define TASK_SIZE		(PAGE_OFFSET - UL(0x41000000))
#define TASK_UNMAPPED_BASE	(PAGE_OFFSET / 3)

/*
 * The module space lives between the addresses given by TASK_SIZE
 * and PAGE_OFFSET - it must be within 32MB of the kernel text.
 */
#define MODULES_VADDR		(PAGE_OFFSET - 16*1024*1024)
#if TASK_SIZE > MODULES_VADDR
#error Top of user space clashes with start of module space
#endif

#define MODULES_END		(PAGE_OFFSET)

/*
 * Allow 16MB-aligned ioremap pages
 */
#define IOREMAP_MAX_ORDER	24

/*
 * Physical vs virtual RAM address space conversion.  These are
 * private definitions which should NOT be used outside memory.h
 * files.  Use virt_to_phys/phys_to_virt/__pa/__va instead.
 */
#ifndef __virt_to_phys
#define __virt_to_phys(x)	((x) - PAGE_OFFSET + PHYS_OFFSET)
#define __phys_to_virt(x)	((x) - PHYS_OFFSET + PAGE_OFFSET)
#endif

/*
 * Convert a physical address to a Page Frame Number and back
 */
#define	__phys_to_pfn(paddr)	((paddr) >> PAGE_SHIFT)
#define	__pfn_to_phys(pfn)	((pfn) << PAGE_SHIFT)

/*
 * Convert a page to/from a physical address
 */
#define page_to_phys(page)	(__pfn_to_phys(page_to_pfn(page)))
#define phys_to_page(phys)	(pfn_to_page(__phys_to_pfn(phys)))

#ifndef __ASSEMBLY__

#ifndef arch_adjust_zones
#define arch_adjust_zones(size, holes) do { } while (0)
#endif

/*
 * PFNs are used to describe any physical page; this means
 * PFN 0 == physical address 0.
 *
 * This is the PFN of the first RAM page in the kernel
 * direct-mapped view.  We assume this is the first page
 * of RAM in the mem_map as well.
 */
#define PHYS_PFN_OFFSET	(PHYS_OFFSET >> PAGE_SHIFT)

/*
 * Drivers should NOT use these either.
 */
#define __pa(x)			__virt_to_phys((unsigned long)(x))
#define __va(x)			((void *)__phys_to_virt((unsigned long)(x)))
#define pfn_to_kaddr(pfn)	__va((pfn) << PAGE_SHIFT)

/*
 * Conversion between a struct page and a physical address.
 *
 * Note: when converting an unknown physical address to a
 * struct page, the resulting pointer must be validated
 * using VALID_PAGE().  It must return an invalid struct page
 * for any physical address not corresponding to a system
 * RAM address.
 *
 *  page_to_pfn(page)	convert a struct page * to a PFN number
 *  pfn_to_page(pfn)	convert a _valid_ PFN number to struct page *
 *
 *  virt_to_page(k)	convert a _valid_ virtual address to struct page *
 *  virt_addr_valid(k)	indicates whether a virtual address is valid
 */
#define ARCH_PFN_OFFSET		PHYS_PFN_OFFSET

#define virt_to_page(kaddr)	pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
#define virt_addr_valid(kaddr)	((unsigned long)(kaddr) >= PAGE_OFFSET && \
		(unsigned long)(kaddr) < (unsigned long)high_memory)

#endif

#include <asm-generic/memory_model.h>

#endif