1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_MEMORY_MODEL_H
3 #define __ASM_MEMORY_MODEL_H
10 * supports 3 memory models.
12 #if defined(CONFIG_FLATMEM)
14 #ifndef ARCH_PFN_OFFSET
15 #define ARCH_PFN_OFFSET (0UL)
18 #define __pfn_to_page(pfn) (mem_map + ((pfn) - ARCH_PFN_OFFSET))
19 #define __page_to_pfn(page) ((unsigned long)((page) - mem_map) + \
22 #elif defined(CONFIG_SPARSEMEM_VMEMMAP)
24 /* memmap is virtually contiguous. */
25 #define __pfn_to_page(pfn) (vmemmap + (pfn))
26 #define __page_to_pfn(page) (unsigned long)((page) - vmemmap)
28 #elif defined(CONFIG_SPARSEMEM)
30 * Note: section's mem_map is encoded to reflect its start_pfn.
31 * section[i].section_mem_map == mem_map's address - start_pfn;
33 #define __page_to_pfn(pg) \
34 ({ const struct page *__pg = (pg); \
35 int __sec = page_to_section(__pg); \
36 (unsigned long)(__pg - __section_mem_map_addr(__nr_to_section(__sec))); \
39 #define __pfn_to_page(pfn) \
40 ({ unsigned long __pfn = (pfn); \
41 struct mem_section *__sec = __pfn_to_section(__pfn); \
42 __section_mem_map_addr(__sec) + __pfn; \
44 #endif /* CONFIG_FLATMEM/SPARSEMEM */
47 * Convert a physical address to a Page Frame Number and back
49 #define __phys_to_pfn(paddr) PHYS_PFN(paddr)
50 #define __pfn_to_phys(pfn) PFN_PHYS(pfn)
52 #define page_to_pfn __page_to_pfn
53 #define pfn_to_page __pfn_to_page
55 #endif /* __ASSEMBLY__ */