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()
174 	for (section_nr = next_present_section_nr(start-1);	\
175 	     section_nr != -1;								\
180 	return next_present_section_nr(-1);  in first_present_section_nr()
188 	int end = subsection_map_index(pfn + nr_pages - 1);  in subsection_mask_set()
190 	bitmap_set(map, idx, end - idx + 1);  in subsection_mask_set()
195 	int end_sec_nr = pfn_to_section_nr(pfn + nr_pages - 1);  in subsection_map_init()
199 		struct mem_section *ms;  in subsection_map_init()  local
204 		ms = __nr_to_section(nr);  in subsection_map_init()
205 		subsection_mask_set(ms->usage->subsection_map, pfn, pfns);  in subsection_map_init()
209 				subsection_map_index(pfn + pfns - 1));  in subsection_map_init()
230 		struct mem_section *ms;  in memory_present()  local
235 		ms = __nr_to_section(section_nr);  in memory_present()
236 		if (!ms->section_mem_map) {  in memory_present()
237 			ms->section_mem_map = sparse_encode_early_nid(nid) |  in memory_present()
239 			__section_mark_present(ms, section_nr);  in memory_present()
259 		align = 1 << (INTERNODE_CACHE_SHIFT);  in memblocks_present()
294 static void __meminit sparse_init_one_section(struct mem_section *ms,  in sparse_init_one_section()  argument
298 	ms->section_mem_map &= ~SECTION_MAP_MASK;  in sparse_init_one_section()
299 	ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum)  in sparse_init_one_section()
301 	ms->usage = usage;  in sparse_init_one_section()
343 	limit = goal + (1UL << PA_SECTION_SHIFT);  in sparse_early_usemaps_alloc_pgdat_section()
542 		struct mem_section *ms;  in sparse_init_nid()  local
546 		ms = __nr_to_section(pnum);  in sparse_init_nid()
547 		ms->section_mem_map = 0;  in sparse_init_nid()
557 	unsigned long pnum_end, pnum_begin, map_count = 1;  in sparse_init()
570 	for_each_present_section_nr(pnum_begin + 1, pnum_end) {  in sparse_init()
581 		map_count = 1;  in sparse_init()
597 		struct mem_section *ms;  in online_mem_sections()  local
603 		ms = __nr_to_section(section_nr);  in online_mem_sections()
604 		ms->section_mem_map |= SECTION_IS_ONLINE;  in online_mem_sections()
615 		struct mem_section *ms;  in offline_mem_sections()  local
624 		ms = __nr_to_section(section_nr);  in offline_mem_sections()
625 		ms->section_mem_map &= ~SECTION_IS_ONLINE;  in offline_mem_sections()
643 	memmap_pages_add(-1L * (DIV_ROUND_UP(end - start, PAGE_SIZE)));  in depopulate_section_memmap()
658 	struct mem_section *ms = __pfn_to_section(pfn);  in clear_subsection_map()  local
659 	unsigned long *subsection_map = ms->usage  in clear_subsection_map()
660 		? &ms->usage->subsection_map[0] : NULL;  in clear_subsection_map()
675 static bool is_subsection_map_empty(struct mem_section *ms)  in is_subsection_map_empty()  argument
677 	return bitmap_empty(&ms->usage->subsection_map[0],  in is_subsection_map_empty()
683 	struct mem_section *ms = __pfn_to_section(pfn);  in fill_subsection_map()  local
690 	subsection_map = &ms->usage->subsection_map[0];  in fill_subsection_map()
752 static bool is_subsection_map_empty(struct mem_section *ms)  in is_subsection_map_empty()  argument
767  * 1. deactivation of a partial hot-added section (only possible in
774  * For 1, when subsection_map does not empty we will not be freeing the
782 	struct mem_section *ms = __pfn_to_section(pfn);  in section_deactivate()  local
783 	bool section_is_early = early_section(ms);  in section_deactivate()
790 	empty = is_subsection_map_empty(ms);  in section_deactivate()
797 		 * ms->usage array.  in section_deactivate()
799 		ms->section_mem_map &= ~SECTION_HAS_MEM_MAP;  in section_deactivate()
808 		if (!PageReserved(virt_to_page(ms->usage))) {  in section_deactivate()
809 			kfree_rcu(ms->usage, rcu);  in section_deactivate()
810 			WRITE_ONCE(ms->usage, NULL);  in section_deactivate()
812 		memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);  in section_deactivate()
825 		ms->section_mem_map = (unsigned long)NULL;  in section_deactivate()
832 	struct mem_section *ms = __pfn_to_section(pfn);  in section_activate()  local
837 	if (!ms->usage) {  in section_activate()
841 		ms->usage = usage;  in section_activate()
847 			ms->usage = NULL;  in section_activate()
859 	if (nr_pages < PAGES_PER_SECTION && early_section(ms))  in section_activate()
895 	struct mem_section *ms;  in sparse_add_section()  local
914 	ms = __nr_to_section(section_nr);  in sparse_add_section()
916 	__section_mark_present(ms, section_nr);  in sparse_add_section()
921 	sparse_init_one_section(ms, section_nr, memmap, ms->usage, 0);  in sparse_add_section()
929 	struct mem_section *ms = __pfn_to_section(pfn);  in sparse_remove_section()  local
931 	if (WARN_ON_ONCE(!valid_section(ms)))  in sparse_remove_section()