virtconvert.h

来自「linux 内核源代码」· C头文件 代码 · 共 55 行

#ifndef __VIRT_CONVERT__
#define __VIRT_CONVERT__

/*
 * Macros used for converting between virtual and physical mappings.
 */

#ifdef __KERNEL__

#include <linux/compiler.h>
#include <linux/mmzone.h>
#include <asm/setup.h>
#include <asm/page.h>

/*
 * Change virtual addresses to physical addresses and vv.
 */
static inline unsigned long virt_to_phys(void *address)
{
	return __pa(address);
}

static inline void *phys_to_virt(unsigned long address)
{
	return __va(address);
}

/* Permanent address of a page. */
#ifdef CONFIG_SINGLE_MEMORY_CHUNK
#define page_to_phys(page) \
	__pa(PAGE_OFFSET + (((page) - pg_data_map[0].node_mem_map) << PAGE_SHIFT))
#else
#define page_to_phys(_page) ({						\
	struct page *__page = _page;					\
	struct pglist_data *pgdat;					\
	pgdat = pg_data_table[page_to_nid(__page)];			\
	page_to_pfn(__page) << PAGE_SHIFT;				\
})
#endif

/*
 * IO bus memory addresses are 1:1 with the physical address,
 * except on the PCI bus of the Hades.
 */
#ifdef CONFIG_HADES
#define virt_to_bus(a) (virt_to_phys(a) + (MACH_IS_HADES ? 0x80000000 : 0))
#define bus_to_virt(a) (phys_to_virt((a) - (MACH_IS_HADES ? 0x80000000 : 0)))
#else
#define virt_to_bus virt_to_phys
#define bus_to_virt phys_to_virt
#endif

#endif
#endif