1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __ASM_MEMORY_MODEL_H
3#define __ASM_MEMORY_MODEL_H
4
5#include <linux/pfn.h>
6
7#ifndef __ASSEMBLY__
8
9#if defined(CONFIG_FLATMEM)
10
11#ifndef ARCH_PFN_OFFSET
12#define ARCH_PFN_OFFSET (0UL)
13#endif
14
15#elif defined(CONFIG_DISCONTIGMEM)
16
17#ifndef arch_pfn_to_nid
18#define arch_pfn_to_nid(pfn) pfn_to_nid(pfn)
19#endif
20
21#ifndef arch_local_page_offset
22#define arch_local_page_offset(pfn, nid) \
23 ((pfn) - NODE_DATA(nid)->node_start_pfn)
24#endif
25
26#endif /* CONFIG_DISCONTIGMEM */
27
28/*
29 * supports 3 memory models.
30 */
31#if defined(CONFIG_FLATMEM)
32
33#define __pfn_to_page(pfn) (mem_map + ((pfn) - ARCH_PFN_OFFSET))
34#define __page_to_pfn(page) ((unsigned long)((page) - mem_map) + \
35 ARCH_PFN_OFFSET)
36#elif defined(CONFIG_DISCONTIGMEM)
37
38#define __pfn_to_page(pfn) \
39({ unsigned long __pfn = (pfn); \
40 unsigned long __nid = arch_pfn_to_nid(__pfn); \
41 NODE_DATA(__nid)->node_mem_map + arch_local_page_offset(__pfn, __nid);\
42})
43
44#define __page_to_pfn(pg) \
45({ const struct page *__pg = (pg); \
46 struct pglist_data *__pgdat = NODE_DATA(page_to_nid(__pg)); \
47 (unsigned long)(__pg - __pgdat->node_mem_map) + \
48 __pgdat->node_start_pfn; \
49})
50
51#elif defined(CONFIG_SPARSEMEM_VMEMMAP)
52
53/* memmap is virtually contiguous. */
54#define __pfn_to_page(pfn) (vmemmap + (pfn))
55#define __page_to_pfn(page) (unsigned long)((page) - vmemmap)
56
57#elif defined(CONFIG_SPARSEMEM)
58/*
59 * Note: section's mem_map is encoded to reflect its start_pfn.
60 * section[i].section_mem_map == mem_map's address - start_pfn;
61 */
62#define __page_to_pfn(pg) \
63({ const struct page *__pg = (pg); \
64 int __sec = page_to_section(__pg); \
65 (unsigned long)(__pg - __section_mem_map_addr(__nr_to_section(__sec))); \
66})
67
68#define __pfn_to_page(pfn) \
69({ unsigned long __pfn = (pfn); \
70 struct mem_section *__sec = __pfn_to_section(__pfn); \
71 __section_mem_map_addr(__sec) + __pfn; \
72})
73#endif /* CONFIG_FLATMEM/DISCONTIGMEM/SPARSEMEM */
74
75/*
76 * Convert a physical address to a Page Frame Number and back
77 */
78#define __phys_to_pfn(paddr) PHYS_PFN(paddr)
79#define __pfn_to_phys(pfn) PFN_PHYS(pfn)
80
81#define page_to_pfn __page_to_pfn
82#define pfn_to_page __pfn_to_page
83
84#endif /* __ASSEMBLY__ */
85
86#endif
87