Linux kernel mirror (for testing)
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linux
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#ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
27struct page;
28/* this is useful when inlined pfn_to_page is too big */
29extern struct page *pfn_to_page(unsigned long pfn);
30extern unsigned long page_to_pfn(struct page *page);
31#else
32/*
33 * supports 3 memory models.
34 */
35#if defined(CONFIG_FLATMEM)
36
37#define pfn_to_page(pfn) (mem_map + ((pfn) - ARCH_PFN_OFFSET))
38#define page_to_pfn(page) ((unsigned long)((page) - mem_map) + \
39 ARCH_PFN_OFFSET)
40#elif defined(CONFIG_DISCONTIGMEM)
41
42#define pfn_to_page(pfn) \
43({ unsigned long __pfn = (pfn); \
44 unsigned long __nid = arch_pfn_to_nid(pfn); \
45 NODE_DATA(__nid)->node_mem_map + arch_local_page_offset(__pfn, __nid);\
46})
47
48#define page_to_pfn(pg) \
49({ struct page *__pg = (pg); \
50 struct pglist_data *__pgdat = NODE_DATA(page_to_nid(__pg)); \
51 (unsigned long)(__pg - __pgdat->node_mem_map) + \
52 __pgdat->node_start_pfn; \
53})
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 __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#endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */
73
74#endif /* __ASSEMBLY__ */
75#endif /* __KERNEL__ */
76
77#endif