1 #ifndef __ASM_MEMORY_MODEL_H
2 #define __ASM_MEMORY_MODEL_H
3 
4 #include <linux/pfn.h>
5 
6 #ifndef __ASSEMBLY__
7 
8 #if defined(CONFIG_FLATMEM)
9 
10 #ifndef ARCH_PFN_OFFSET
11 #define ARCH_PFN_OFFSET		(0UL)
12 #endif
13 
14 #elif defined(CONFIG_DISCONTIGMEM)
15 
16 #ifndef arch_pfn_to_nid
17 #define arch_pfn_to_nid(pfn)	pfn_to_nid(pfn)
18 #endif
19 
20 #ifndef arch_local_page_offset
21 #define arch_local_page_offset(pfn, nid)	\
22 	((pfn) - NODE_DATA(nid)->node_start_pfn)
23 #endif
24 
25 #endif /* CONFIG_DISCONTIGMEM */
26 
27 /*
28  * supports 3 memory models.
29  */
30 #if defined(CONFIG_FLATMEM)
31 
32 #define __pfn_to_page(pfn)	(mem_map + ((pfn) - ARCH_PFN_OFFSET))
33 #define __page_to_pfn(page)	((unsigned long)((page) - mem_map) + \
34 				 ARCH_PFN_OFFSET)
35 #elif defined(CONFIG_DISCONTIGMEM)
36 
37 #define __pfn_to_page(pfn)			\
38 ({	unsigned long __pfn = (pfn);		\
39 	unsigned long __nid = arch_pfn_to_nid(__pfn);  \
40 	NODE_DATA(__nid)->node_mem_map + arch_local_page_offset(__pfn, __nid);\
41 })
42 
43 #define __page_to_pfn(pg)						\
44 ({	const struct page *__pg = (pg);					\
45 	struct pglist_data *__pgdat = NODE_DATA(page_to_nid(__pg));	\
46 	(unsigned long)(__pg - __pgdat->node_mem_map) +			\
47 	 __pgdat->node_start_pfn;					\
48 })
49 
50 #elif defined(CONFIG_SPARSEMEM_VMEMMAP)
51 
52 /* memmap is virtually contiguous.  */
53 #define __pfn_to_page(pfn)	(vmemmap + (pfn))
54 #define __page_to_pfn(page)	(unsigned long)((page) - vmemmap)
55 
56 #elif defined(CONFIG_SPARSEMEM)
57 /*
58  * Note: section's mem_map is encoded to reflect its start_pfn.
59  * section[i].section_mem_map == mem_map's address - start_pfn;
60  */
61 #define __page_to_pfn(pg)					\
62 ({	const struct page *__pg = (pg);				\
63 	int __sec = page_to_section(__pg);			\
64 	(unsigned long)(__pg - __section_mem_map_addr(__nr_to_section(__sec)));	\
65 })
66 
67 #define __pfn_to_page(pfn)				\
68 ({	unsigned long __pfn = (pfn);			\
69 	struct mem_section *__sec = __pfn_to_section(__pfn);	\
70 	__section_mem_map_addr(__sec) + __pfn;		\
71 })
72 #endif /* CONFIG_FLATMEM/DISCONTIGMEM/SPARSEMEM */
73 
74 /*
75  * Convert a physical address to a Page Frame Number and back
76  */
77 #define	__phys_to_pfn(paddr)	PHYS_PFN(paddr)
78 #define	__pfn_to_phys(pfn)	PFN_PHYS(pfn)
79 
80 #define page_to_pfn __page_to_pfn
81 #define pfn_to_page __pfn_to_page
82 
83 #endif /* __ASSEMBLY__ */
84 
85 #endif
86