1#ifndef __ASM_MEMORY_MODEL_H
2#define __ASM_MEMORY_MODEL_H
3
4#ifdef __KERNEL__
5#ifndef __ASSEMBLY__
6
7#if defined(CONFIG_FLATMEM)
8
9#ifndef ARCH_PFN_OFFSET
10#define ARCH_PFN_OFFSET		(0UL)
11#endif
12
13#elif defined(CONFIG_DISCONTIGMEM)
14
15#ifndef arch_pfn_to_nid
16#define arch_pfn_to_nid(pfn)	pfn_to_nid(pfn)
17#endif
18
19#ifndef arch_local_page_offset
20#define arch_local_page_offset(pfn, nid)	\
21	((pfn) - NODE_DATA(nid)->node_start_pfn)
22#endif
23
24#endif /* CONFIG_DISCONTIGMEM */
25
26/*
27 * supports 3 memory models.
28 */
29#if defined(CONFIG_FLATMEM)
30
31#define __pfn_to_page(pfn)	(mem_map + ((pfn) - ARCH_PFN_OFFSET))
32#define __page_to_pfn(page)	((unsigned long)((page) - mem_map) + \
33				 ARCH_PFN_OFFSET)
34#elif defined(CONFIG_DISCONTIGMEM)
35
36#define __pfn_to_page(pfn)			\
37({	unsigned long __pfn = (pfn);		\
38	unsigned long __nid = arch_pfn_to_nid(pfn);  \
39	NODE_DATA(__nid)->node_mem_map + arch_local_page_offset(__pfn, __nid);\
40})
41
42#define __page_to_pfn(pg)						\
43({	struct page *__pg = (pg);					\
44	struct pglist_data *__pgdat = NODE_DATA(page_to_nid(__pg));	\
45	(unsigned long)(__pg - __pgdat->node_mem_map) +			\
46	 __pgdat->node_start_pfn;					\
47})
48
49#elif defined(CONFIG_SPARSEMEM)
50/*
51 * Note: section's mem_map is encorded to reflect its start_pfn.
52 * section[i].section_mem_map == mem_map's address - start_pfn;
53 */
54#define __page_to_pfn(pg)					\
55({	struct page *__pg = (pg);				\
56	int __sec = page_to_section(__pg);			\
57	(unsigned long)(__pg - __section_mem_map_addr(__nr_to_section(__sec)));	\
58})
59
60#define __pfn_to_page(pfn)				\
61({	unsigned long __pfn = (pfn);			\
62	struct mem_section *__sec = __pfn_to_section(__pfn);	\
63	__section_mem_map_addr(__sec) + __pfn;		\
64})
65#endif /* CONFIG_FLATMEM/DISCONTIGMEM/SPARSEMEM */
66
67#ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
68struct page;
69/* this is useful when inlined pfn_to_page is too big */
70extern struct page *pfn_to_page(unsigned long pfn);
71extern unsigned long page_to_pfn(struct page *page);
72#else
73#define page_to_pfn __page_to_pfn
74#define pfn_to_page __pfn_to_page
75#endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */
76
77#endif /* __ASSEMBLY__ */
78#endif /* __KERNEL__ */
79
80#endif
81