24  * 1) mem_section	- memory sections, mem_map's for valid memory
132 	unsigned long max_sparsemem_pfn = (DIRECT_MAP_PHYSMEM_END + 1) >> PAGE_SHIFT;  in mminit_validate_memmodel_limits()
142 		WARN_ON_ONCE(1);  in mminit_validate_memmodel_limits()
149 		WARN_ON_ONCE(1);  in mminit_validate_memmodel_limits()
164 static void __section_mark_present(struct mem_section *ms,  in __section_mark_present()  argument
170 	ms->section_mem_map |= SECTION_MARKED_PRESENT;  in __section_mark_present()
175 	return next_present_section_nr(-1);  in first_present_section_nr()
183 	int end = subsection_map_index(pfn + nr_pages - 1);  in subsection_mask_set()
185 	bitmap_set(map, idx, end - idx + 1);  in subsection_mask_set()
190 	int end_sec_nr = pfn_to_section_nr(pfn + nr_pages - 1);  in subsection_map_init()
194 		struct mem_section *ms;  in subsection_map_init()  local
199 		ms = __nr_to_section(nr);  in subsection_map_init()
200 		subsection_mask_set(ms->usage->subsection_map, pfn, pfns);  in subsection_map_init()
204 				subsection_map_index(pfn + pfns - 1));  in subsection_map_init()
225 		struct mem_section *ms;  in memory_present()  local
230 		ms = __nr_to_section(section_nr);  in memory_present()
231 		if (!ms->section_mem_map) {  in memory_present()
232 			ms->section_mem_map = sparse_encode_early_nid(nid) |  in memory_present()
234 			__section_mark_present(ms, section_nr);  in memory_present()
254 		align = 1 << (INTERNODE_CACHE_SHIFT);  in memblocks_present()
289 static void __meminit sparse_init_one_section(struct mem_section *ms,  in sparse_init_one_section()  argument
293 	ms->section_mem_map &= ~SECTION_MAP_MASK;  in sparse_init_one_section()
294 	ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum)  in sparse_init_one_section()
296 	ms->usage = usage;  in sparse_init_one_section()
338 	limit = goal + (1UL << PA_SECTION_SHIFT);  in sparse_early_usemaps_alloc_pgdat_section()
541 	struct mem_section *ms;  in sparse_init_nid()  local
558 		ms = __nr_to_section(pnum);  in sparse_init_nid()
559 		if (!preinited_vmemmap_section(ms)) {  in sparse_init_nid()
584 		ms = __nr_to_section(pnum);  in sparse_init_nid()
585 		if (!preinited_vmemmap_section(ms))  in sparse_init_nid()
586 			ms->section_mem_map = 0;  in sparse_init_nid()
587 		ms->section_mem_map = 0;  in sparse_init_nid()
597 	unsigned long pnum_end, pnum_begin, map_count = 1;  in sparse_init()
610 	for_each_present_section_nr(pnum_begin + 1, pnum_end) {  in sparse_init()
621 		map_count = 1;  in sparse_init()
637 		struct mem_section *ms;  in online_mem_sections()  local
643 		ms = __nr_to_section(section_nr);  in online_mem_sections()
644 		ms->section_mem_map |= SECTION_IS_ONLINE;  in online_mem_sections()
655 		struct mem_section *ms;  in offline_mem_sections()  local
664 		ms = __nr_to_section(section_nr);  in offline_mem_sections()
665 		ms->section_mem_map &= ~SECTION_IS_ONLINE;  in offline_mem_sections()
683 	memmap_pages_add(-1L * (DIV_ROUND_UP(end - start, PAGE_SIZE)));  in depopulate_section_memmap()
698 	struct mem_section *ms = __pfn_to_section(pfn);  in clear_subsection_map()  local
699 	unsigned long *subsection_map = ms->usage  in clear_subsection_map()
700 		? &ms->usage->subsection_map[0] : NULL;  in clear_subsection_map()
715 static bool is_subsection_map_empty(struct mem_section *ms)  in is_subsection_map_empty()  argument
717 	return bitmap_empty(&ms->usage->subsection_map[0],  in is_subsection_map_empty()
723 	struct mem_section *ms = __pfn_to_section(pfn);  in fill_subsection_map()  local
730 	subsection_map = &ms->usage->subsection_map[0];  in fill_subsection_map()
792 static bool is_subsection_map_empty(struct mem_section *ms)  in is_subsection_map_empty()  argument
807  * 1. deactivation of a partial hot-added section (only possible in
814  * For 1, when subsection_map does not empty we will not be freeing the
822 	struct mem_section *ms = __pfn_to_section(pfn);  in section_deactivate()  local
823 	bool section_is_early = early_section(ms);  in section_deactivate()
830 	empty = is_subsection_map_empty(ms);  in section_deactivate()
837 		 * ms->usage array.  in section_deactivate()
839 		ms->section_mem_map &= ~SECTION_HAS_MEM_MAP;  in section_deactivate()
848 		if (!PageReserved(virt_to_page(ms->usage))) {  in section_deactivate()
849 			kfree_rcu(ms->usage, rcu);  in section_deactivate()
850 			WRITE_ONCE(ms->usage, NULL);  in section_deactivate()
852 		memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);  in section_deactivate()
865 		ms->section_mem_map = (unsigned long)NULL;  in section_deactivate()
872 	struct mem_section *ms = __pfn_to_section(pfn);  in section_activate()  local
877 	if (!ms->usage) {  in section_activate()
881 		ms->usage = usage;  in section_activate()
887 			ms->usage = NULL;  in section_activate()
899 	if (nr_pages < PAGES_PER_SECTION && early_section(ms))  in section_activate()
935 	struct mem_section *ms;  in sparse_add_section()  local
954 	ms = __nr_to_section(section_nr);  in sparse_add_section()
956 	__section_mark_present(ms, section_nr);  in sparse_add_section()
961 	sparse_init_one_section(ms, section_nr, memmap, ms->usage, 0);  in sparse_add_section()
969 	struct mem_section *ms = __pfn_to_section(pfn);  in sparse_remove_section()  local
971 	if (WARN_ON_ONCE(!valid_section(ms)))  in sparse_remove_section()