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_VMEMMAP)
50 
51 /* memmap is virtually contigious.  */
52 #define __pfn_to_page(pfn)	(vmemmap + (pfn))
53 #define __page_to_pfn(page)	((page) - vmemmap)
54 
55 #elif defined(CONFIG_SPARSEMEM)
56 /*
57  * Note: section's mem_map is encorded to reflect its start_pfn.
58  * section[i].section_mem_map == mem_map's address - start_pfn;
59  */
60 #define __page_to_pfn(pg)					\
61 ({	struct page *__pg = (pg);				\
62 	int __sec = page_to_section(__pg);			\
63 	(unsigned long)(__pg - __section_mem_map_addr(__nr_to_section(__sec)));	\
64 })
65 
66 #define __pfn_to_page(pfn)				\
67 ({	unsigned long __pfn = (pfn);			\
68 	struct mem_section *__sec = __pfn_to_section(__pfn);	\
69 	__section_mem_map_addr(__sec) + __pfn;		\
70 })
71 #endif /* CONFIG_FLATMEM/DISCONTIGMEM/SPARSEMEM */
72 
73 #ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
74 struct page;
75 /* this is useful when inlined pfn_to_page is too big */
76 extern struct page *pfn_to_page(unsigned long pfn);
77 extern unsigned long page_to_pfn(struct page *page);
78 #else
79 #define page_to_pfn __page_to_pfn
80 #define pfn_to_page __pfn_to_page
81 #endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */
82 
83 #endif /* __ASSEMBLY__ */
84 #endif /* __KERNEL__ */
85 
86 #endif
87