Linux Kernel  3.7.1
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memory_model.h
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1 #ifndef __ASM_MEMORY_MODEL_H
2 #define __ASM_MEMORY_MODEL_H
3 
4 #ifndef __ASSEMBLY__
5 
6 #if defined(CONFIG_FLATMEM)
7 
8 #ifndef ARCH_PFN_OFFSET
9 #define ARCH_PFN_OFFSET (0UL)
10 #endif
11 
12 #elif defined(CONFIG_DISCONTIGMEM)
13 
14 #ifndef arch_pfn_to_nid
15 #define arch_pfn_to_nid(pfn) pfn_to_nid(pfn)
16 #endif
17 
18 #ifndef arch_local_page_offset
19 #define arch_local_page_offset(pfn, nid) \
20  ((pfn) - NODE_DATA(nid)->node_start_pfn)
21 #endif
22 
23 #endif /* CONFIG_DISCONTIGMEM */
24 
25 /*
26  * supports 3 memory models.
27  */
28 #if defined(CONFIG_FLATMEM)
29 
30 #define __pfn_to_page(pfn) (mem_map + ((pfn) - ARCH_PFN_OFFSET))
31 #define __page_to_pfn(page) ((unsigned long)((page) - mem_map) + \
32  ARCH_PFN_OFFSET)
33 #elif defined(CONFIG_DISCONTIGMEM)
34 
35 #define __pfn_to_page(pfn) \
36 ({ unsigned long __pfn = (pfn); \
37  unsigned long __nid = arch_pfn_to_nid(__pfn); \
38  NODE_DATA(__nid)->node_mem_map + arch_local_page_offset(__pfn, __nid);\
39 })
40 
41 #define __page_to_pfn(pg) \
42 ({ const struct page *__pg = (pg); \
43  struct pglist_data *__pgdat = NODE_DATA(page_to_nid(__pg)); \
44  (unsigned long)(__pg - __pgdat->node_mem_map) + \
45  __pgdat->node_start_pfn; \
46 })
47 
48 #elif defined(CONFIG_SPARSEMEM_VMEMMAP)
49 
50 /* memmap is virtually contiguous. */
51 #define __pfn_to_page(pfn) (vmemmap + (pfn))
52 #define __page_to_pfn(page) (unsigned long)((page) - vmemmap)
53 
54 #elif defined(CONFIG_SPARSEMEM)
55 /*
56  * Note: section's mem_map is encorded to reflect its start_pfn.
57  * section[i].section_mem_map == mem_map's address - start_pfn;
58  */
59 #define __page_to_pfn(pg) \
60 ({ const struct page *__pg = (pg); \
61  int __sec = page_to_section(__pg); \
62  (unsigned long)(__pg - __section_mem_map_addr(__nr_to_section(__sec))); \
63 })
64 
65 #define __pfn_to_page(pfn) \
66 ({ unsigned long __pfn = (pfn); \
67  struct mem_section *__sec = __pfn_to_section(__pfn); \
68  __section_mem_map_addr(__sec) + __pfn; \
69 })
70 #endif /* CONFIG_FLATMEM/DISCONTIGMEM/SPARSEMEM */
71 
72 #define page_to_pfn __page_to_pfn
73 #define pfn_to_page __pfn_to_page
74 
75 #endif /* __ASSEMBLY__ */
76 
77 #endif