GNU Linux-libre 4.19.211-gnu1
[releases.git] / include / asm-generic / memory_model.h
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