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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * sparse memory mappings.
4 */
5#include <linux/mm.h>
6#include <linux/slab.h>
7#include <linux/mmzone.h>
8#include <linux/bootmem.h>
9#include <linux/compiler.h>
10#include <linux/highmem.h>
11#include <linux/export.h>
12#include <linux/spinlock.h>
13#include <linux/vmalloc.h>
14
15#include "internal.h"
16#include <asm/dma.h>
17#include <asm/pgalloc.h>
18#include <asm/pgtable.h>
19
20/*
21 * Permanent SPARSEMEM data:
22 *
23 * 1) mem_section - memory sections, mem_map's for valid memory
24 */
25#ifdef CONFIG_SPARSEMEM_EXTREME
26struct mem_section **mem_section;
27#else
28struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]
29 ____cacheline_internodealigned_in_smp;
30#endif
31EXPORT_SYMBOL(mem_section);
32
33#ifdef NODE_NOT_IN_PAGE_FLAGS
34/*
35 * If we did not store the node number in the page then we have to
36 * do a lookup in the section_to_node_table in order to find which
37 * node the page belongs to.
38 */
39#if MAX_NUMNODES <= 256
40static u8 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
41#else
42static u16 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
43#endif
44
45int page_to_nid(const struct page *page)
46{
47 return section_to_node_table[page_to_section(page)];
48}
49EXPORT_SYMBOL(page_to_nid);
50
51static void set_section_nid(unsigned long section_nr, int nid)
52{
53 section_to_node_table[section_nr] = nid;
54}
55#else /* !NODE_NOT_IN_PAGE_FLAGS */
56static inline void set_section_nid(unsigned long section_nr, int nid)
57{
58}
59#endif
60
61#ifdef CONFIG_SPARSEMEM_EXTREME
62static noinline struct mem_section __ref *sparse_index_alloc(int nid)
63{
64 struct mem_section *section = NULL;
65 unsigned long array_size = SECTIONS_PER_ROOT *
66 sizeof(struct mem_section);
67
68 if (slab_is_available())
69 section = kzalloc_node(array_size, GFP_KERNEL, nid);
70 else
71 section = memblock_virt_alloc_node(array_size, nid);
72
73 return section;
74}
75
76static int __meminit sparse_index_init(unsigned long section_nr, int nid)
77{
78 unsigned long root = SECTION_NR_TO_ROOT(section_nr);
79 struct mem_section *section;
80
81 if (mem_section[root])
82 return -EEXIST;
83
84 section = sparse_index_alloc(nid);
85 if (!section)
86 return -ENOMEM;
87
88 mem_section[root] = section;
89
90 return 0;
91}
92#else /* !SPARSEMEM_EXTREME */
93static inline int sparse_index_init(unsigned long section_nr, int nid)
94{
95 return 0;
96}
97#endif
98
99#ifdef CONFIG_SPARSEMEM_EXTREME
100int __section_nr(struct mem_section* ms)
101{
102 unsigned long root_nr;
103 struct mem_section *root = NULL;
104
105 for (root_nr = 0; root_nr < NR_SECTION_ROOTS; root_nr++) {
106 root = __nr_to_section(root_nr * SECTIONS_PER_ROOT);
107 if (!root)
108 continue;
109
110 if ((ms >= root) && (ms < (root + SECTIONS_PER_ROOT)))
111 break;
112 }
113
114 VM_BUG_ON(!root);
115
116 return (root_nr * SECTIONS_PER_ROOT) + (ms - root);
117}
118#else
119int __section_nr(struct mem_section* ms)
120{
121 return (int)(ms - mem_section[0]);
122}
123#endif
124
125/*
126 * During early boot, before section_mem_map is used for an actual
127 * mem_map, we use section_mem_map to store the section's NUMA
128 * node. This keeps us from having to use another data structure. The
129 * node information is cleared just before we store the real mem_map.
130 */
131static inline unsigned long sparse_encode_early_nid(int nid)
132{
133 return (nid << SECTION_NID_SHIFT);
134}
135
136static inline int sparse_early_nid(struct mem_section *section)
137{
138 return (section->section_mem_map >> SECTION_NID_SHIFT);
139}
140
141/* Validate the physical addressing limitations of the model */
142void __meminit mminit_validate_memmodel_limits(unsigned long *start_pfn,
143 unsigned long *end_pfn)
144{
145 unsigned long max_sparsemem_pfn = 1UL << (MAX_PHYSMEM_BITS-PAGE_SHIFT);
146
147 /*
148 * Sanity checks - do not allow an architecture to pass
149 * in larger pfns than the maximum scope of sparsemem:
150 */
151 if (*start_pfn > max_sparsemem_pfn) {
152 mminit_dprintk(MMINIT_WARNING, "pfnvalidation",
153 "Start of range %lu -> %lu exceeds SPARSEMEM max %lu\n",
154 *start_pfn, *end_pfn, max_sparsemem_pfn);
155 WARN_ON_ONCE(1);
156 *start_pfn = max_sparsemem_pfn;
157 *end_pfn = max_sparsemem_pfn;
158 } else if (*end_pfn > max_sparsemem_pfn) {
159 mminit_dprintk(MMINIT_WARNING, "pfnvalidation",
160 "End of range %lu -> %lu exceeds SPARSEMEM max %lu\n",
161 *start_pfn, *end_pfn, max_sparsemem_pfn);
162 WARN_ON_ONCE(1);
163 *end_pfn = max_sparsemem_pfn;
164 }
165}
166
167/*
168 * There are a number of times that we loop over NR_MEM_SECTIONS,
169 * looking for section_present() on each. But, when we have very
170 * large physical address spaces, NR_MEM_SECTIONS can also be
171 * very large which makes the loops quite long.
172 *
173 * Keeping track of this gives us an easy way to break out of
174 * those loops early.
175 */
176int __highest_present_section_nr;
177static void section_mark_present(struct mem_section *ms)
178{
179 int section_nr = __section_nr(ms);
180
181 if (section_nr > __highest_present_section_nr)
182 __highest_present_section_nr = section_nr;
183
184 ms->section_mem_map |= SECTION_MARKED_PRESENT;
185}
186
187static inline int next_present_section_nr(int section_nr)
188{
189 do {
190 section_nr++;
191 if (present_section_nr(section_nr))
192 return section_nr;
193 } while ((section_nr < NR_MEM_SECTIONS) &&
194 (section_nr <= __highest_present_section_nr));
195
196 return -1;
197}
198#define for_each_present_section_nr(start, section_nr) \
199 for (section_nr = next_present_section_nr(start-1); \
200 ((section_nr >= 0) && \
201 (section_nr < NR_MEM_SECTIONS) && \
202 (section_nr <= __highest_present_section_nr)); \
203 section_nr = next_present_section_nr(section_nr))
204
205/* Record a memory area against a node. */
206void __init memory_present(int nid, unsigned long start, unsigned long end)
207{
208 unsigned long pfn;
209
210#ifdef CONFIG_SPARSEMEM_EXTREME
211 if (unlikely(!mem_section)) {
212 unsigned long size, align;
213
214 size = sizeof(struct mem_section*) * NR_SECTION_ROOTS;
215 align = 1 << (INTERNODE_CACHE_SHIFT);
216 mem_section = memblock_virt_alloc(size, align);
217 }
218#endif
219
220 start &= PAGE_SECTION_MASK;
221 mminit_validate_memmodel_limits(&start, &end);
222 for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
223 unsigned long section = pfn_to_section_nr(pfn);
224 struct mem_section *ms;
225
226 sparse_index_init(section, nid);
227 set_section_nid(section, nid);
228
229 ms = __nr_to_section(section);
230 if (!ms->section_mem_map) {
231 ms->section_mem_map = sparse_encode_early_nid(nid) |
232 SECTION_IS_ONLINE;
233 section_mark_present(ms);
234 }
235 }
236}
237
238/*
239 * Subtle, we encode the real pfn into the mem_map such that
240 * the identity pfn - section_mem_map will return the actual
241 * physical page frame number.
242 */
243static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long pnum)
244{
245 unsigned long coded_mem_map =
246 (unsigned long)(mem_map - (section_nr_to_pfn(pnum)));
247 BUILD_BUG_ON(SECTION_MAP_LAST_BIT > (1UL<<PFN_SECTION_SHIFT));
248 BUG_ON(coded_mem_map & ~SECTION_MAP_MASK);
249 return coded_mem_map;
250}
251
252/*
253 * Decode mem_map from the coded memmap
254 */
255struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum)
256{
257 /* mask off the extra low bits of information */
258 coded_mem_map &= SECTION_MAP_MASK;
259 return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum);
260}
261
262static int __meminit sparse_init_one_section(struct mem_section *ms,
263 unsigned long pnum, struct page *mem_map,
264 unsigned long *pageblock_bitmap)
265{
266 if (!present_section(ms))
267 return -EINVAL;
268
269 ms->section_mem_map &= ~SECTION_MAP_MASK;
270 ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) |
271 SECTION_HAS_MEM_MAP;
272 ms->pageblock_flags = pageblock_bitmap;
273
274 return 1;
275}
276
277unsigned long usemap_size(void)
278{
279 return BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS) * sizeof(unsigned long);
280}
281
282#ifdef CONFIG_MEMORY_HOTPLUG
283static unsigned long *__kmalloc_section_usemap(void)
284{
285 return kmalloc(usemap_size(), GFP_KERNEL);
286}
287#endif /* CONFIG_MEMORY_HOTPLUG */
288
289#ifdef CONFIG_MEMORY_HOTREMOVE
290static unsigned long * __init
291sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
292 unsigned long size)
293{
294 unsigned long goal, limit;
295 unsigned long *p;
296 int nid;
297 /*
298 * A page may contain usemaps for other sections preventing the
299 * page being freed and making a section unremovable while
300 * other sections referencing the usemap remain active. Similarly,
301 * a pgdat can prevent a section being removed. If section A
302 * contains a pgdat and section B contains the usemap, both
303 * sections become inter-dependent. This allocates usemaps
304 * from the same section as the pgdat where possible to avoid
305 * this problem.
306 */
307 goal = __pa(pgdat) & (PAGE_SECTION_MASK << PAGE_SHIFT);
308 limit = goal + (1UL << PA_SECTION_SHIFT);
309 nid = early_pfn_to_nid(goal >> PAGE_SHIFT);
310again:
311 p = memblock_virt_alloc_try_nid_nopanic(size,
312 SMP_CACHE_BYTES, goal, limit,
313 nid);
314 if (!p && limit) {
315 limit = 0;
316 goto again;
317 }
318 return p;
319}
320
321static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
322{
323 unsigned long usemap_snr, pgdat_snr;
324 static unsigned long old_usemap_snr;
325 static unsigned long old_pgdat_snr;
326 struct pglist_data *pgdat = NODE_DATA(nid);
327 int usemap_nid;
328
329 /* First call */
330 if (!old_usemap_snr) {
331 old_usemap_snr = NR_MEM_SECTIONS;
332 old_pgdat_snr = NR_MEM_SECTIONS;
333 }
334
335 usemap_snr = pfn_to_section_nr(__pa(usemap) >> PAGE_SHIFT);
336 pgdat_snr = pfn_to_section_nr(__pa(pgdat) >> PAGE_SHIFT);
337 if (usemap_snr == pgdat_snr)
338 return;
339
340 if (old_usemap_snr == usemap_snr && old_pgdat_snr == pgdat_snr)
341 /* skip redundant message */
342 return;
343
344 old_usemap_snr = usemap_snr;
345 old_pgdat_snr = pgdat_snr;
346
347 usemap_nid = sparse_early_nid(__nr_to_section(usemap_snr));
348 if (usemap_nid != nid) {
349 pr_info("node %d must be removed before remove section %ld\n",
350 nid, usemap_snr);
351 return;
352 }
353 /*
354 * There is a circular dependency.
355 * Some platforms allow un-removable section because they will just
356 * gather other removable sections for dynamic partitioning.
357 * Just notify un-removable section's number here.
358 */
359 pr_info("Section %ld and %ld (node %d) have a circular dependency on usemap and pgdat allocations\n",
360 usemap_snr, pgdat_snr, nid);
361}
362#else
363static unsigned long * __init
364sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
365 unsigned long size)
366{
367 return memblock_virt_alloc_node_nopanic(size, pgdat->node_id);
368}
369
370static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
371{
372}
373#endif /* CONFIG_MEMORY_HOTREMOVE */
374
375static void __init sparse_early_usemaps_alloc_node(void *data,
376 unsigned long pnum_begin,
377 unsigned long pnum_end,
378 unsigned long usemap_count, int nodeid)
379{
380 void *usemap;
381 unsigned long pnum;
382 unsigned long **usemap_map = (unsigned long **)data;
383 int size = usemap_size();
384
385 usemap = sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nodeid),
386 size * usemap_count);
387 if (!usemap) {
388 pr_warn("%s: allocation failed\n", __func__);
389 return;
390 }
391
392 for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
393 if (!present_section_nr(pnum))
394 continue;
395 usemap_map[pnum] = usemap;
396 usemap += size;
397 check_usemap_section_nr(nodeid, usemap_map[pnum]);
398 }
399}
400
401#ifndef CONFIG_SPARSEMEM_VMEMMAP
402struct page __init *sparse_mem_map_populate(unsigned long pnum, int nid,
403 struct vmem_altmap *altmap)
404{
405 struct page *map;
406 unsigned long size;
407
408 size = PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
409 map = memblock_virt_alloc_try_nid(size,
410 PAGE_SIZE, __pa(MAX_DMA_ADDRESS),
411 BOOTMEM_ALLOC_ACCESSIBLE, nid);
412 return map;
413}
414void __init sparse_mem_maps_populate_node(struct page **map_map,
415 unsigned long pnum_begin,
416 unsigned long pnum_end,
417 unsigned long map_count, int nodeid)
418{
419 void *map;
420 unsigned long pnum;
421 unsigned long size = sizeof(struct page) * PAGES_PER_SECTION;
422
423 size = PAGE_ALIGN(size);
424 map = memblock_virt_alloc_try_nid_raw(size * map_count,
425 PAGE_SIZE, __pa(MAX_DMA_ADDRESS),
426 BOOTMEM_ALLOC_ACCESSIBLE, nodeid);
427 if (map) {
428 for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
429 if (!present_section_nr(pnum))
430 continue;
431 map_map[pnum] = map;
432 map += size;
433 }
434 return;
435 }
436
437 /* fallback */
438 for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
439 struct mem_section *ms;
440
441 if (!present_section_nr(pnum))
442 continue;
443 map_map[pnum] = sparse_mem_map_populate(pnum, nodeid, NULL);
444 if (map_map[pnum])
445 continue;
446 ms = __nr_to_section(pnum);
447 pr_err("%s: sparsemem memory map backing failed some memory will not be available\n",
448 __func__);
449 ms->section_mem_map = 0;
450 }
451}
452#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
453
454#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
455static void __init sparse_early_mem_maps_alloc_node(void *data,
456 unsigned long pnum_begin,
457 unsigned long pnum_end,
458 unsigned long map_count, int nodeid)
459{
460 struct page **map_map = (struct page **)data;
461 sparse_mem_maps_populate_node(map_map, pnum_begin, pnum_end,
462 map_count, nodeid);
463}
464#else
465static struct page __init *sparse_early_mem_map_alloc(unsigned long pnum)
466{
467 struct page *map;
468 struct mem_section *ms = __nr_to_section(pnum);
469 int nid = sparse_early_nid(ms);
470
471 map = sparse_mem_map_populate(pnum, nid, NULL);
472 if (map)
473 return map;
474
475 pr_err("%s: sparsemem memory map backing failed some memory will not be available\n",
476 __func__);
477 ms->section_mem_map = 0;
478 return NULL;
479}
480#endif
481
482void __weak __meminit vmemmap_populate_print_last(void)
483{
484}
485
486/**
487 * alloc_usemap_and_memmap - memory alloction for pageblock flags and vmemmap
488 * @map: usemap_map for pageblock flags or mmap_map for vmemmap
489 */
490static void __init alloc_usemap_and_memmap(void (*alloc_func)
491 (void *, unsigned long, unsigned long,
492 unsigned long, int), void *data)
493{
494 unsigned long pnum;
495 unsigned long map_count;
496 int nodeid_begin = 0;
497 unsigned long pnum_begin = 0;
498
499 for_each_present_section_nr(0, pnum) {
500 struct mem_section *ms;
501
502 ms = __nr_to_section(pnum);
503 nodeid_begin = sparse_early_nid(ms);
504 pnum_begin = pnum;
505 break;
506 }
507 map_count = 1;
508 for_each_present_section_nr(pnum_begin + 1, pnum) {
509 struct mem_section *ms;
510 int nodeid;
511
512 ms = __nr_to_section(pnum);
513 nodeid = sparse_early_nid(ms);
514 if (nodeid == nodeid_begin) {
515 map_count++;
516 continue;
517 }
518 /* ok, we need to take cake of from pnum_begin to pnum - 1*/
519 alloc_func(data, pnum_begin, pnum,
520 map_count, nodeid_begin);
521 /* new start, update count etc*/
522 nodeid_begin = nodeid;
523 pnum_begin = pnum;
524 map_count = 1;
525 }
526 /* ok, last chunk */
527 alloc_func(data, pnum_begin, NR_MEM_SECTIONS,
528 map_count, nodeid_begin);
529}
530
531/*
532 * Allocate the accumulated non-linear sections, allocate a mem_map
533 * for each and record the physical to section mapping.
534 */
535void __init sparse_init(void)
536{
537 unsigned long pnum;
538 struct page *map;
539 unsigned long *usemap;
540 unsigned long **usemap_map;
541 int size;
542#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
543 int size2;
544 struct page **map_map;
545#endif
546
547 /* see include/linux/mmzone.h 'struct mem_section' definition */
548 BUILD_BUG_ON(!is_power_of_2(sizeof(struct mem_section)));
549
550 /* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */
551 set_pageblock_order();
552
553 /*
554 * map is using big page (aka 2M in x86 64 bit)
555 * usemap is less one page (aka 24 bytes)
556 * so alloc 2M (with 2M align) and 24 bytes in turn will
557 * make next 2M slip to one more 2M later.
558 * then in big system, the memory will have a lot of holes...
559 * here try to allocate 2M pages continuously.
560 *
561 * powerpc need to call sparse_init_one_section right after each
562 * sparse_early_mem_map_alloc, so allocate usemap_map at first.
563 */
564 size = sizeof(unsigned long *) * NR_MEM_SECTIONS;
565 usemap_map = memblock_virt_alloc(size, 0);
566 if (!usemap_map)
567 panic("can not allocate usemap_map\n");
568 alloc_usemap_and_memmap(sparse_early_usemaps_alloc_node,
569 (void *)usemap_map);
570
571#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
572 size2 = sizeof(struct page *) * NR_MEM_SECTIONS;
573 map_map = memblock_virt_alloc(size2, 0);
574 if (!map_map)
575 panic("can not allocate map_map\n");
576 alloc_usemap_and_memmap(sparse_early_mem_maps_alloc_node,
577 (void *)map_map);
578#endif
579
580 for_each_present_section_nr(0, pnum) {
581 usemap = usemap_map[pnum];
582 if (!usemap)
583 continue;
584
585#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
586 map = map_map[pnum];
587#else
588 map = sparse_early_mem_map_alloc(pnum);
589#endif
590 if (!map)
591 continue;
592
593 sparse_init_one_section(__nr_to_section(pnum), pnum, map,
594 usemap);
595 }
596
597 vmemmap_populate_print_last();
598
599#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
600 memblock_free_early(__pa(map_map), size2);
601#endif
602 memblock_free_early(__pa(usemap_map), size);
603}
604
605#ifdef CONFIG_MEMORY_HOTPLUG
606
607/* Mark all memory sections within the pfn range as online */
608void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
609{
610 unsigned long pfn;
611
612 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
613 unsigned long section_nr = pfn_to_section_nr(pfn);
614 struct mem_section *ms;
615
616 /* onlining code should never touch invalid ranges */
617 if (WARN_ON(!valid_section_nr(section_nr)))
618 continue;
619
620 ms = __nr_to_section(section_nr);
621 ms->section_mem_map |= SECTION_IS_ONLINE;
622 }
623}
624
625#ifdef CONFIG_MEMORY_HOTREMOVE
626/* Mark all memory sections within the pfn range as online */
627void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
628{
629 unsigned long pfn;
630
631 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
632 unsigned long section_nr = pfn_to_section_nr(pfn);
633 struct mem_section *ms;
634
635 /*
636 * TODO this needs some double checking. Offlining code makes
637 * sure to check pfn_valid but those checks might be just bogus
638 */
639 if (WARN_ON(!valid_section_nr(section_nr)))
640 continue;
641
642 ms = __nr_to_section(section_nr);
643 ms->section_mem_map &= ~SECTION_IS_ONLINE;
644 }
645}
646#endif
647
648#ifdef CONFIG_SPARSEMEM_VMEMMAP
649static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
650 struct vmem_altmap *altmap)
651{
652 /* This will make the necessary allocations eventually. */
653 return sparse_mem_map_populate(pnum, nid, altmap);
654}
655static void __kfree_section_memmap(struct page *memmap,
656 struct vmem_altmap *altmap)
657{
658 unsigned long start = (unsigned long)memmap;
659 unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION);
660
661 vmemmap_free(start, end, altmap);
662}
663#ifdef CONFIG_MEMORY_HOTREMOVE
664static void free_map_bootmem(struct page *memmap)
665{
666 unsigned long start = (unsigned long)memmap;
667 unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION);
668
669 vmemmap_free(start, end, NULL);
670}
671#endif /* CONFIG_MEMORY_HOTREMOVE */
672#else
673static struct page *__kmalloc_section_memmap(void)
674{
675 struct page *page, *ret;
676 unsigned long memmap_size = sizeof(struct page) * PAGES_PER_SECTION;
677
678 page = alloc_pages(GFP_KERNEL|__GFP_NOWARN, get_order(memmap_size));
679 if (page)
680 goto got_map_page;
681
682 ret = vmalloc(memmap_size);
683 if (ret)
684 goto got_map_ptr;
685
686 return NULL;
687got_map_page:
688 ret = (struct page *)pfn_to_kaddr(page_to_pfn(page));
689got_map_ptr:
690
691 return ret;
692}
693
694static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
695 struct vmem_altmap *altmap)
696{
697 return __kmalloc_section_memmap();
698}
699
700static void __kfree_section_memmap(struct page *memmap,
701 struct vmem_altmap *altmap)
702{
703 if (is_vmalloc_addr(memmap))
704 vfree(memmap);
705 else
706 free_pages((unsigned long)memmap,
707 get_order(sizeof(struct page) * PAGES_PER_SECTION));
708}
709
710#ifdef CONFIG_MEMORY_HOTREMOVE
711static void free_map_bootmem(struct page *memmap)
712{
713 unsigned long maps_section_nr, removing_section_nr, i;
714 unsigned long magic, nr_pages;
715 struct page *page = virt_to_page(memmap);
716
717 nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
718 >> PAGE_SHIFT;
719
720 for (i = 0; i < nr_pages; i++, page++) {
721 magic = (unsigned long) page->freelist;
722
723 BUG_ON(magic == NODE_INFO);
724
725 maps_section_nr = pfn_to_section_nr(page_to_pfn(page));
726 removing_section_nr = page_private(page);
727
728 /*
729 * When this function is called, the removing section is
730 * logical offlined state. This means all pages are isolated
731 * from page allocator. If removing section's memmap is placed
732 * on the same section, it must not be freed.
733 * If it is freed, page allocator may allocate it which will
734 * be removed physically soon.
735 */
736 if (maps_section_nr != removing_section_nr)
737 put_page_bootmem(page);
738 }
739}
740#endif /* CONFIG_MEMORY_HOTREMOVE */
741#endif /* CONFIG_SPARSEMEM_VMEMMAP */
742
743/*
744 * returns the number of sections whose mem_maps were properly
745 * set. If this is <=0, then that means that the passed-in
746 * map was not consumed and must be freed.
747 */
748int __meminit sparse_add_one_section(struct pglist_data *pgdat,
749 unsigned long start_pfn, struct vmem_altmap *altmap)
750{
751 unsigned long section_nr = pfn_to_section_nr(start_pfn);
752 struct mem_section *ms;
753 struct page *memmap;
754 unsigned long *usemap;
755 unsigned long flags;
756 int ret;
757
758 /*
759 * no locking for this, because it does its own
760 * plus, it does a kmalloc
761 */
762 ret = sparse_index_init(section_nr, pgdat->node_id);
763 if (ret < 0 && ret != -EEXIST)
764 return ret;
765 memmap = kmalloc_section_memmap(section_nr, pgdat->node_id, altmap);
766 if (!memmap)
767 return -ENOMEM;
768 usemap = __kmalloc_section_usemap();
769 if (!usemap) {
770 __kfree_section_memmap(memmap, altmap);
771 return -ENOMEM;
772 }
773
774 pgdat_resize_lock(pgdat, &flags);
775
776 ms = __pfn_to_section(start_pfn);
777 if (ms->section_mem_map & SECTION_MARKED_PRESENT) {
778 ret = -EEXIST;
779 goto out;
780 }
781
782#ifdef CONFIG_DEBUG_VM
783 /*
784 * Poison uninitialized struct pages in order to catch invalid flags
785 * combinations.
786 */
787 memset(memmap, PAGE_POISON_PATTERN, sizeof(struct page) * PAGES_PER_SECTION);
788#endif
789
790 section_mark_present(ms);
791
792 ret = sparse_init_one_section(ms, section_nr, memmap, usemap);
793
794out:
795 pgdat_resize_unlock(pgdat, &flags);
796 if (ret <= 0) {
797 kfree(usemap);
798 __kfree_section_memmap(memmap, altmap);
799 }
800 return ret;
801}
802
803#ifdef CONFIG_MEMORY_HOTREMOVE
804#ifdef CONFIG_MEMORY_FAILURE
805static void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
806{
807 int i;
808
809 if (!memmap)
810 return;
811
812 for (i = 0; i < nr_pages; i++) {
813 if (PageHWPoison(&memmap[i])) {
814 atomic_long_sub(1, &num_poisoned_pages);
815 ClearPageHWPoison(&memmap[i]);
816 }
817 }
818}
819#else
820static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
821{
822}
823#endif
824
825static void free_section_usemap(struct page *memmap, unsigned long *usemap,
826 struct vmem_altmap *altmap)
827{
828 struct page *usemap_page;
829
830 if (!usemap)
831 return;
832
833 usemap_page = virt_to_page(usemap);
834 /*
835 * Check to see if allocation came from hot-plug-add
836 */
837 if (PageSlab(usemap_page) || PageCompound(usemap_page)) {
838 kfree(usemap);
839 if (memmap)
840 __kfree_section_memmap(memmap, altmap);
841 return;
842 }
843
844 /*
845 * The usemap came from bootmem. This is packed with other usemaps
846 * on the section which has pgdat at boot time. Just keep it as is now.
847 */
848
849 if (memmap)
850 free_map_bootmem(memmap);
851}
852
853void sparse_remove_one_section(struct zone *zone, struct mem_section *ms,
854 unsigned long map_offset, struct vmem_altmap *altmap)
855{
856 struct page *memmap = NULL;
857 unsigned long *usemap = NULL, flags;
858 struct pglist_data *pgdat = zone->zone_pgdat;
859
860 pgdat_resize_lock(pgdat, &flags);
861 if (ms->section_mem_map) {
862 usemap = ms->pageblock_flags;
863 memmap = sparse_decode_mem_map(ms->section_mem_map,
864 __section_nr(ms));
865 ms->section_mem_map = 0;
866 ms->pageblock_flags = NULL;
867 }
868 pgdat_resize_unlock(pgdat, &flags);
869
870 clear_hwpoisoned_pages(memmap + map_offset,
871 PAGES_PER_SECTION - map_offset);
872 free_section_usemap(memmap, usemap, altmap);
873}
874#endif /* CONFIG_MEMORY_HOTREMOVE */
875#endif /* CONFIG_MEMORY_HOTPLUG */
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * sparse memory mappings.
4 */
5#include <linux/mm.h>
6#include <linux/slab.h>
7#include <linux/mmzone.h>
8#include <linux/memblock.h>
9#include <linux/compiler.h>
10#include <linux/highmem.h>
11#include <linux/export.h>
12#include <linux/spinlock.h>
13#include <linux/vmalloc.h>
14#include <linux/swap.h>
15#include <linux/swapops.h>
16#include <linux/bootmem_info.h>
17#include <linux/vmstat.h>
18#include "internal.h"
19#include <asm/dma.h>
20
21/*
22 * Permanent SPARSEMEM data:
23 *
24 * 1) mem_section - memory sections, mem_map's for valid memory
25 */
26#ifdef CONFIG_SPARSEMEM_EXTREME
27struct mem_section **mem_section;
28#else
29struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]
30 ____cacheline_internodealigned_in_smp;
31#endif
32EXPORT_SYMBOL(mem_section);
33
34#ifdef NODE_NOT_IN_PAGE_FLAGS
35/*
36 * If we did not store the node number in the page then we have to
37 * do a lookup in the section_to_node_table in order to find which
38 * node the page belongs to.
39 */
40#if MAX_NUMNODES <= 256
41static u8 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
42#else
43static u16 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
44#endif
45
46int page_to_nid(const struct page *page)
47{
48 return section_to_node_table[page_to_section(page)];
49}
50EXPORT_SYMBOL(page_to_nid);
51
52static void set_section_nid(unsigned long section_nr, int nid)
53{
54 section_to_node_table[section_nr] = nid;
55}
56#else /* !NODE_NOT_IN_PAGE_FLAGS */
57static inline void set_section_nid(unsigned long section_nr, int nid)
58{
59}
60#endif
61
62#ifdef CONFIG_SPARSEMEM_EXTREME
63static noinline struct mem_section __ref *sparse_index_alloc(int nid)
64{
65 struct mem_section *section = NULL;
66 unsigned long array_size = SECTIONS_PER_ROOT *
67 sizeof(struct mem_section);
68
69 if (slab_is_available()) {
70 section = kzalloc_node(array_size, GFP_KERNEL, nid);
71 } else {
72 section = memblock_alloc_node(array_size, SMP_CACHE_BYTES,
73 nid);
74 if (!section)
75 panic("%s: Failed to allocate %lu bytes nid=%d\n",
76 __func__, array_size, nid);
77 }
78
79 return section;
80}
81
82static int __meminit sparse_index_init(unsigned long section_nr, int nid)
83{
84 unsigned long root = SECTION_NR_TO_ROOT(section_nr);
85 struct mem_section *section;
86
87 /*
88 * An existing section is possible in the sub-section hotplug
89 * case. First hot-add instantiates, follow-on hot-add reuses
90 * the existing section.
91 *
92 * The mem_hotplug_lock resolves the apparent race below.
93 */
94 if (mem_section[root])
95 return 0;
96
97 section = sparse_index_alloc(nid);
98 if (!section)
99 return -ENOMEM;
100
101 mem_section[root] = section;
102
103 return 0;
104}
105#else /* !SPARSEMEM_EXTREME */
106static inline int sparse_index_init(unsigned long section_nr, int nid)
107{
108 return 0;
109}
110#endif
111
112/*
113 * During early boot, before section_mem_map is used for an actual
114 * mem_map, we use section_mem_map to store the section's NUMA
115 * node. This keeps us from having to use another data structure. The
116 * node information is cleared just before we store the real mem_map.
117 */
118static inline unsigned long sparse_encode_early_nid(int nid)
119{
120 return ((unsigned long)nid << SECTION_NID_SHIFT);
121}
122
123static inline int sparse_early_nid(struct mem_section *section)
124{
125 return (section->section_mem_map >> SECTION_NID_SHIFT);
126}
127
128/* Validate the physical addressing limitations of the model */
129static void __meminit mminit_validate_memmodel_limits(unsigned long *start_pfn,
130 unsigned long *end_pfn)
131{
132 unsigned long max_sparsemem_pfn = (DIRECT_MAP_PHYSMEM_END + 1) >> PAGE_SHIFT;
133
134 /*
135 * Sanity checks - do not allow an architecture to pass
136 * in larger pfns than the maximum scope of sparsemem:
137 */
138 if (*start_pfn > max_sparsemem_pfn) {
139 mminit_dprintk(MMINIT_WARNING, "pfnvalidation",
140 "Start of range %lu -> %lu exceeds SPARSEMEM max %lu\n",
141 *start_pfn, *end_pfn, max_sparsemem_pfn);
142 WARN_ON_ONCE(1);
143 *start_pfn = max_sparsemem_pfn;
144 *end_pfn = max_sparsemem_pfn;
145 } else if (*end_pfn > max_sparsemem_pfn) {
146 mminit_dprintk(MMINIT_WARNING, "pfnvalidation",
147 "End of range %lu -> %lu exceeds SPARSEMEM max %lu\n",
148 *start_pfn, *end_pfn, max_sparsemem_pfn);
149 WARN_ON_ONCE(1);
150 *end_pfn = max_sparsemem_pfn;
151 }
152}
153
154/*
155 * There are a number of times that we loop over NR_MEM_SECTIONS,
156 * looking for section_present() on each. But, when we have very
157 * large physical address spaces, NR_MEM_SECTIONS can also be
158 * very large which makes the loops quite long.
159 *
160 * Keeping track of this gives us an easy way to break out of
161 * those loops early.
162 */
163unsigned long __highest_present_section_nr;
164static void __section_mark_present(struct mem_section *ms,
165 unsigned long section_nr)
166{
167 if (section_nr > __highest_present_section_nr)
168 __highest_present_section_nr = section_nr;
169
170 ms->section_mem_map |= SECTION_MARKED_PRESENT;
171}
172
173#define for_each_present_section_nr(start, section_nr) \
174 for (section_nr = next_present_section_nr(start-1); \
175 section_nr != -1; \
176 section_nr = next_present_section_nr(section_nr))
177
178static inline unsigned long first_present_section_nr(void)
179{
180 return next_present_section_nr(-1);
181}
182
183#ifdef CONFIG_SPARSEMEM_VMEMMAP
184static void subsection_mask_set(unsigned long *map, unsigned long pfn,
185 unsigned long nr_pages)
186{
187 int idx = subsection_map_index(pfn);
188 int end = subsection_map_index(pfn + nr_pages - 1);
189
190 bitmap_set(map, idx, end - idx + 1);
191}
192
193void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages)
194{
195 int end_sec_nr = pfn_to_section_nr(pfn + nr_pages - 1);
196 unsigned long nr, start_sec_nr = pfn_to_section_nr(pfn);
197
198 for (nr = start_sec_nr; nr <= end_sec_nr; nr++) {
199 struct mem_section *ms;
200 unsigned long pfns;
201
202 pfns = min(nr_pages, PAGES_PER_SECTION
203 - (pfn & ~PAGE_SECTION_MASK));
204 ms = __nr_to_section(nr);
205 subsection_mask_set(ms->usage->subsection_map, pfn, pfns);
206
207 pr_debug("%s: sec: %lu pfns: %lu set(%d, %d)\n", __func__, nr,
208 pfns, subsection_map_index(pfn),
209 subsection_map_index(pfn + pfns - 1));
210
211 pfn += pfns;
212 nr_pages -= pfns;
213 }
214}
215#else
216void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages)
217{
218}
219#endif
220
221/* Record a memory area against a node. */
222static void __init memory_present(int nid, unsigned long start, unsigned long end)
223{
224 unsigned long pfn;
225
226 start &= PAGE_SECTION_MASK;
227 mminit_validate_memmodel_limits(&start, &end);
228 for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
229 unsigned long section_nr = pfn_to_section_nr(pfn);
230 struct mem_section *ms;
231
232 sparse_index_init(section_nr, nid);
233 set_section_nid(section_nr, nid);
234
235 ms = __nr_to_section(section_nr);
236 if (!ms->section_mem_map) {
237 ms->section_mem_map = sparse_encode_early_nid(nid) |
238 SECTION_IS_ONLINE;
239 __section_mark_present(ms, section_nr);
240 }
241 }
242}
243
244/*
245 * Mark all memblocks as present using memory_present().
246 * This is a convenience function that is useful to mark all of the systems
247 * memory as present during initialization.
248 */
249static void __init memblocks_present(void)
250{
251 unsigned long start, end;
252 int i, nid;
253
254#ifdef CONFIG_SPARSEMEM_EXTREME
255 if (unlikely(!mem_section)) {
256 unsigned long size, align;
257
258 size = sizeof(struct mem_section *) * NR_SECTION_ROOTS;
259 align = 1 << (INTERNODE_CACHE_SHIFT);
260 mem_section = memblock_alloc(size, align);
261 if (!mem_section)
262 panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
263 __func__, size, align);
264 }
265#endif
266
267 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid)
268 memory_present(nid, start, end);
269}
270
271/*
272 * Subtle, we encode the real pfn into the mem_map such that
273 * the identity pfn - section_mem_map will return the actual
274 * physical page frame number.
275 */
276static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long pnum)
277{
278 unsigned long coded_mem_map =
279 (unsigned long)(mem_map - (section_nr_to_pfn(pnum)));
280 BUILD_BUG_ON(SECTION_MAP_LAST_BIT > PFN_SECTION_SHIFT);
281 BUG_ON(coded_mem_map & ~SECTION_MAP_MASK);
282 return coded_mem_map;
283}
284
285#ifdef CONFIG_MEMORY_HOTPLUG
286/*
287 * Decode mem_map from the coded memmap
288 */
289struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum)
290{
291 /* mask off the extra low bits of information */
292 coded_mem_map &= SECTION_MAP_MASK;
293 return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum);
294}
295#endif /* CONFIG_MEMORY_HOTPLUG */
296
297static void __meminit sparse_init_one_section(struct mem_section *ms,
298 unsigned long pnum, struct page *mem_map,
299 struct mem_section_usage *usage, unsigned long flags)
300{
301 ms->section_mem_map &= ~SECTION_MAP_MASK;
302 ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum)
303 | SECTION_HAS_MEM_MAP | flags;
304 ms->usage = usage;
305}
306
307static unsigned long usemap_size(void)
308{
309 return BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS) * sizeof(unsigned long);
310}
311
312size_t mem_section_usage_size(void)
313{
314 return sizeof(struct mem_section_usage) + usemap_size();
315}
316
317#ifdef CONFIG_MEMORY_HOTREMOVE
318static inline phys_addr_t pgdat_to_phys(struct pglist_data *pgdat)
319{
320#ifndef CONFIG_NUMA
321 VM_BUG_ON(pgdat != &contig_page_data);
322 return __pa_symbol(&contig_page_data);
323#else
324 return __pa(pgdat);
325#endif
326}
327
328static struct mem_section_usage * __init
329sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
330 unsigned long size)
331{
332 struct mem_section_usage *usage;
333 unsigned long goal, limit;
334 int nid;
335 /*
336 * A page may contain usemaps for other sections preventing the
337 * page being freed and making a section unremovable while
338 * other sections referencing the usemap remain active. Similarly,
339 * a pgdat can prevent a section being removed. If section A
340 * contains a pgdat and section B contains the usemap, both
341 * sections become inter-dependent. This allocates usemaps
342 * from the same section as the pgdat where possible to avoid
343 * this problem.
344 */
345 goal = pgdat_to_phys(pgdat) & (PAGE_SECTION_MASK << PAGE_SHIFT);
346 limit = goal + (1UL << PA_SECTION_SHIFT);
347 nid = early_pfn_to_nid(goal >> PAGE_SHIFT);
348again:
349 usage = memblock_alloc_try_nid(size, SMP_CACHE_BYTES, goal, limit, nid);
350 if (!usage && limit) {
351 limit = MEMBLOCK_ALLOC_ACCESSIBLE;
352 goto again;
353 }
354 return usage;
355}
356
357static void __init check_usemap_section_nr(int nid,
358 struct mem_section_usage *usage)
359{
360 unsigned long usemap_snr, pgdat_snr;
361 static unsigned long old_usemap_snr;
362 static unsigned long old_pgdat_snr;
363 struct pglist_data *pgdat = NODE_DATA(nid);
364 int usemap_nid;
365
366 /* First call */
367 if (!old_usemap_snr) {
368 old_usemap_snr = NR_MEM_SECTIONS;
369 old_pgdat_snr = NR_MEM_SECTIONS;
370 }
371
372 usemap_snr = pfn_to_section_nr(__pa(usage) >> PAGE_SHIFT);
373 pgdat_snr = pfn_to_section_nr(pgdat_to_phys(pgdat) >> PAGE_SHIFT);
374 if (usemap_snr == pgdat_snr)
375 return;
376
377 if (old_usemap_snr == usemap_snr && old_pgdat_snr == pgdat_snr)
378 /* skip redundant message */
379 return;
380
381 old_usemap_snr = usemap_snr;
382 old_pgdat_snr = pgdat_snr;
383
384 usemap_nid = sparse_early_nid(__nr_to_section(usemap_snr));
385 if (usemap_nid != nid) {
386 pr_info("node %d must be removed before remove section %ld\n",
387 nid, usemap_snr);
388 return;
389 }
390 /*
391 * There is a circular dependency.
392 * Some platforms allow un-removable section because they will just
393 * gather other removable sections for dynamic partitioning.
394 * Just notify un-removable section's number here.
395 */
396 pr_info("Section %ld and %ld (node %d) have a circular dependency on usemap and pgdat allocations\n",
397 usemap_snr, pgdat_snr, nid);
398}
399#else
400static struct mem_section_usage * __init
401sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
402 unsigned long size)
403{
404 return memblock_alloc_node(size, SMP_CACHE_BYTES, pgdat->node_id);
405}
406
407static void __init check_usemap_section_nr(int nid,
408 struct mem_section_usage *usage)
409{
410}
411#endif /* CONFIG_MEMORY_HOTREMOVE */
412
413#ifdef CONFIG_SPARSEMEM_VMEMMAP
414static unsigned long __init section_map_size(void)
415{
416 return ALIGN(sizeof(struct page) * PAGES_PER_SECTION, PMD_SIZE);
417}
418
419#else
420static unsigned long __init section_map_size(void)
421{
422 return PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
423}
424
425struct page __init *__populate_section_memmap(unsigned long pfn,
426 unsigned long nr_pages, int nid, struct vmem_altmap *altmap,
427 struct dev_pagemap *pgmap)
428{
429 unsigned long size = section_map_size();
430 struct page *map = sparse_buffer_alloc(size);
431 phys_addr_t addr = __pa(MAX_DMA_ADDRESS);
432
433 if (map)
434 return map;
435
436 map = memmap_alloc(size, size, addr, nid, false);
437 if (!map)
438 panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d from=%pa\n",
439 __func__, size, PAGE_SIZE, nid, &addr);
440
441 return map;
442}
443#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
444
445static void *sparsemap_buf __meminitdata;
446static void *sparsemap_buf_end __meminitdata;
447
448static inline void __meminit sparse_buffer_free(unsigned long size)
449{
450 WARN_ON(!sparsemap_buf || size == 0);
451 memblock_free(sparsemap_buf, size);
452}
453
454static void __init sparse_buffer_init(unsigned long size, int nid)
455{
456 phys_addr_t addr = __pa(MAX_DMA_ADDRESS);
457 WARN_ON(sparsemap_buf); /* forgot to call sparse_buffer_fini()? */
458 /*
459 * Pre-allocated buffer is mainly used by __populate_section_memmap
460 * and we want it to be properly aligned to the section size - this is
461 * especially the case for VMEMMAP which maps memmap to PMDs
462 */
463 sparsemap_buf = memmap_alloc(size, section_map_size(), addr, nid, true);
464 sparsemap_buf_end = sparsemap_buf + size;
465#ifndef CONFIG_SPARSEMEM_VMEMMAP
466 memmap_boot_pages_add(DIV_ROUND_UP(size, PAGE_SIZE));
467#endif
468}
469
470static void __init sparse_buffer_fini(void)
471{
472 unsigned long size = sparsemap_buf_end - sparsemap_buf;
473
474 if (sparsemap_buf && size > 0)
475 sparse_buffer_free(size);
476 sparsemap_buf = NULL;
477}
478
479void * __meminit sparse_buffer_alloc(unsigned long size)
480{
481 void *ptr = NULL;
482
483 if (sparsemap_buf) {
484 ptr = (void *) roundup((unsigned long)sparsemap_buf, size);
485 if (ptr + size > sparsemap_buf_end)
486 ptr = NULL;
487 else {
488 /* Free redundant aligned space */
489 if ((unsigned long)(ptr - sparsemap_buf) > 0)
490 sparse_buffer_free((unsigned long)(ptr - sparsemap_buf));
491 sparsemap_buf = ptr + size;
492 }
493 }
494 return ptr;
495}
496
497void __weak __meminit vmemmap_populate_print_last(void)
498{
499}
500
501/*
502 * Initialize sparse on a specific node. The node spans [pnum_begin, pnum_end)
503 * And number of present sections in this node is map_count.
504 */
505static void __init sparse_init_nid(int nid, unsigned long pnum_begin,
506 unsigned long pnum_end,
507 unsigned long map_count)
508{
509 struct mem_section_usage *usage;
510 unsigned long pnum;
511 struct page *map;
512
513 usage = sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nid),
514 mem_section_usage_size() * map_count);
515 if (!usage) {
516 pr_err("%s: node[%d] usemap allocation failed", __func__, nid);
517 goto failed;
518 }
519 sparse_buffer_init(map_count * section_map_size(), nid);
520 for_each_present_section_nr(pnum_begin, pnum) {
521 unsigned long pfn = section_nr_to_pfn(pnum);
522
523 if (pnum >= pnum_end)
524 break;
525
526 map = __populate_section_memmap(pfn, PAGES_PER_SECTION,
527 nid, NULL, NULL);
528 if (!map) {
529 pr_err("%s: node[%d] memory map backing failed. Some memory will not be available.",
530 __func__, nid);
531 pnum_begin = pnum;
532 sparse_buffer_fini();
533 goto failed;
534 }
535 check_usemap_section_nr(nid, usage);
536 sparse_init_one_section(__nr_to_section(pnum), pnum, map, usage,
537 SECTION_IS_EARLY);
538 usage = (void *) usage + mem_section_usage_size();
539 }
540 sparse_buffer_fini();
541 return;
542failed:
543 /* We failed to allocate, mark all the following pnums as not present */
544 for_each_present_section_nr(pnum_begin, pnum) {
545 struct mem_section *ms;
546
547 if (pnum >= pnum_end)
548 break;
549 ms = __nr_to_section(pnum);
550 ms->section_mem_map = 0;
551 }
552}
553
554/*
555 * Allocate the accumulated non-linear sections, allocate a mem_map
556 * for each and record the physical to section mapping.
557 */
558void __init sparse_init(void)
559{
560 unsigned long pnum_end, pnum_begin, map_count = 1;
561 int nid_begin;
562
563 /* see include/linux/mmzone.h 'struct mem_section' definition */
564 BUILD_BUG_ON(!is_power_of_2(sizeof(struct mem_section)));
565 memblocks_present();
566
567 pnum_begin = first_present_section_nr();
568 nid_begin = sparse_early_nid(__nr_to_section(pnum_begin));
569
570 /* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */
571 set_pageblock_order();
572
573 for_each_present_section_nr(pnum_begin + 1, pnum_end) {
574 int nid = sparse_early_nid(__nr_to_section(pnum_end));
575
576 if (nid == nid_begin) {
577 map_count++;
578 continue;
579 }
580 /* Init node with sections in range [pnum_begin, pnum_end) */
581 sparse_init_nid(nid_begin, pnum_begin, pnum_end, map_count);
582 nid_begin = nid;
583 pnum_begin = pnum_end;
584 map_count = 1;
585 }
586 /* cover the last node */
587 sparse_init_nid(nid_begin, pnum_begin, pnum_end, map_count);
588 vmemmap_populate_print_last();
589}
590
591#ifdef CONFIG_MEMORY_HOTPLUG
592
593/* Mark all memory sections within the pfn range as online */
594void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
595{
596 unsigned long pfn;
597
598 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
599 unsigned long section_nr = pfn_to_section_nr(pfn);
600 struct mem_section *ms;
601
602 /* onlining code should never touch invalid ranges */
603 if (WARN_ON(!valid_section_nr(section_nr)))
604 continue;
605
606 ms = __nr_to_section(section_nr);
607 ms->section_mem_map |= SECTION_IS_ONLINE;
608 }
609}
610
611/* Mark all memory sections within the pfn range as offline */
612void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
613{
614 unsigned long pfn;
615
616 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
617 unsigned long section_nr = pfn_to_section_nr(pfn);
618 struct mem_section *ms;
619
620 /*
621 * TODO this needs some double checking. Offlining code makes
622 * sure to check pfn_valid but those checks might be just bogus
623 */
624 if (WARN_ON(!valid_section_nr(section_nr)))
625 continue;
626
627 ms = __nr_to_section(section_nr);
628 ms->section_mem_map &= ~SECTION_IS_ONLINE;
629 }
630}
631
632#ifdef CONFIG_SPARSEMEM_VMEMMAP
633static struct page * __meminit populate_section_memmap(unsigned long pfn,
634 unsigned long nr_pages, int nid, struct vmem_altmap *altmap,
635 struct dev_pagemap *pgmap)
636{
637 return __populate_section_memmap(pfn, nr_pages, nid, altmap, pgmap);
638}
639
640static void depopulate_section_memmap(unsigned long pfn, unsigned long nr_pages,
641 struct vmem_altmap *altmap)
642{
643 unsigned long start = (unsigned long) pfn_to_page(pfn);
644 unsigned long end = start + nr_pages * sizeof(struct page);
645
646 memmap_pages_add(-1L * (DIV_ROUND_UP(end - start, PAGE_SIZE)));
647 vmemmap_free(start, end, altmap);
648}
649static void free_map_bootmem(struct page *memmap)
650{
651 unsigned long start = (unsigned long)memmap;
652 unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION);
653
654 vmemmap_free(start, end, NULL);
655}
656
657static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages)
658{
659 DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
660 DECLARE_BITMAP(tmp, SUBSECTIONS_PER_SECTION) = { 0 };
661 struct mem_section *ms = __pfn_to_section(pfn);
662 unsigned long *subsection_map = ms->usage
663 ? &ms->usage->subsection_map[0] : NULL;
664
665 subsection_mask_set(map, pfn, nr_pages);
666 if (subsection_map)
667 bitmap_and(tmp, map, subsection_map, SUBSECTIONS_PER_SECTION);
668
669 if (WARN(!subsection_map || !bitmap_equal(tmp, map, SUBSECTIONS_PER_SECTION),
670 "section already deactivated (%#lx + %ld)\n",
671 pfn, nr_pages))
672 return -EINVAL;
673
674 bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION);
675 return 0;
676}
677
678static bool is_subsection_map_empty(struct mem_section *ms)
679{
680 return bitmap_empty(&ms->usage->subsection_map[0],
681 SUBSECTIONS_PER_SECTION);
682}
683
684static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages)
685{
686 struct mem_section *ms = __pfn_to_section(pfn);
687 DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
688 unsigned long *subsection_map;
689 int rc = 0;
690
691 subsection_mask_set(map, pfn, nr_pages);
692
693 subsection_map = &ms->usage->subsection_map[0];
694
695 if (bitmap_empty(map, SUBSECTIONS_PER_SECTION))
696 rc = -EINVAL;
697 else if (bitmap_intersects(map, subsection_map, SUBSECTIONS_PER_SECTION))
698 rc = -EEXIST;
699 else
700 bitmap_or(subsection_map, map, subsection_map,
701 SUBSECTIONS_PER_SECTION);
702
703 return rc;
704}
705#else
706static struct page * __meminit populate_section_memmap(unsigned long pfn,
707 unsigned long nr_pages, int nid, struct vmem_altmap *altmap,
708 struct dev_pagemap *pgmap)
709{
710 return kvmalloc_node(array_size(sizeof(struct page),
711 PAGES_PER_SECTION), GFP_KERNEL, nid);
712}
713
714static void depopulate_section_memmap(unsigned long pfn, unsigned long nr_pages,
715 struct vmem_altmap *altmap)
716{
717 kvfree(pfn_to_page(pfn));
718}
719
720static void free_map_bootmem(struct page *memmap)
721{
722 unsigned long maps_section_nr, removing_section_nr, i;
723 unsigned long type, nr_pages;
724 struct page *page = virt_to_page(memmap);
725
726 nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
727 >> PAGE_SHIFT;
728
729 for (i = 0; i < nr_pages; i++, page++) {
730 type = bootmem_type(page);
731
732 BUG_ON(type == NODE_INFO);
733
734 maps_section_nr = pfn_to_section_nr(page_to_pfn(page));
735 removing_section_nr = bootmem_info(page);
736
737 /*
738 * When this function is called, the removing section is
739 * logical offlined state. This means all pages are isolated
740 * from page allocator. If removing section's memmap is placed
741 * on the same section, it must not be freed.
742 * If it is freed, page allocator may allocate it which will
743 * be removed physically soon.
744 */
745 if (maps_section_nr != removing_section_nr)
746 put_page_bootmem(page);
747 }
748}
749
750static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages)
751{
752 return 0;
753}
754
755static bool is_subsection_map_empty(struct mem_section *ms)
756{
757 return true;
758}
759
760static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages)
761{
762 return 0;
763}
764#endif /* CONFIG_SPARSEMEM_VMEMMAP */
765
766/*
767 * To deactivate a memory region, there are 3 cases to handle across
768 * two configurations (SPARSEMEM_VMEMMAP={y,n}):
769 *
770 * 1. deactivation of a partial hot-added section (only possible in
771 * the SPARSEMEM_VMEMMAP=y case).
772 * a) section was present at memory init.
773 * b) section was hot-added post memory init.
774 * 2. deactivation of a complete hot-added section.
775 * 3. deactivation of a complete section from memory init.
776 *
777 * For 1, when subsection_map does not empty we will not be freeing the
778 * usage map, but still need to free the vmemmap range.
779 *
780 * For 2 and 3, the SPARSEMEM_VMEMMAP={y,n} cases are unified
781 */
782static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
783 struct vmem_altmap *altmap)
784{
785 struct mem_section *ms = __pfn_to_section(pfn);
786 bool section_is_early = early_section(ms);
787 struct page *memmap = NULL;
788 bool empty;
789
790 if (clear_subsection_map(pfn, nr_pages))
791 return;
792
793 empty = is_subsection_map_empty(ms);
794 if (empty) {
795 unsigned long section_nr = pfn_to_section_nr(pfn);
796
797 /*
798 * Mark the section invalid so that valid_section()
799 * return false. This prevents code from dereferencing
800 * ms->usage array.
801 */
802 ms->section_mem_map &= ~SECTION_HAS_MEM_MAP;
803
804 /*
805 * When removing an early section, the usage map is kept (as the
806 * usage maps of other sections fall into the same page). It
807 * will be re-used when re-adding the section - which is then no
808 * longer an early section. If the usage map is PageReserved, it
809 * was allocated during boot.
810 */
811 if (!PageReserved(virt_to_page(ms->usage))) {
812 kfree_rcu(ms->usage, rcu);
813 WRITE_ONCE(ms->usage, NULL);
814 }
815 memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
816 }
817
818 /*
819 * The memmap of early sections is always fully populated. See
820 * section_activate() and pfn_valid() .
821 */
822 if (!section_is_early)
823 depopulate_section_memmap(pfn, nr_pages, altmap);
824 else if (memmap)
825 free_map_bootmem(memmap);
826
827 if (empty)
828 ms->section_mem_map = (unsigned long)NULL;
829}
830
831static struct page * __meminit section_activate(int nid, unsigned long pfn,
832 unsigned long nr_pages, struct vmem_altmap *altmap,
833 struct dev_pagemap *pgmap)
834{
835 struct mem_section *ms = __pfn_to_section(pfn);
836 struct mem_section_usage *usage = NULL;
837 struct page *memmap;
838 int rc;
839
840 if (!ms->usage) {
841 usage = kzalloc(mem_section_usage_size(), GFP_KERNEL);
842 if (!usage)
843 return ERR_PTR(-ENOMEM);
844 ms->usage = usage;
845 }
846
847 rc = fill_subsection_map(pfn, nr_pages);
848 if (rc) {
849 if (usage)
850 ms->usage = NULL;
851 kfree(usage);
852 return ERR_PTR(rc);
853 }
854
855 /*
856 * The early init code does not consider partially populated
857 * initial sections, it simply assumes that memory will never be
858 * referenced. If we hot-add memory into such a section then we
859 * do not need to populate the memmap and can simply reuse what
860 * is already there.
861 */
862 if (nr_pages < PAGES_PER_SECTION && early_section(ms))
863 return pfn_to_page(pfn);
864
865 memmap = populate_section_memmap(pfn, nr_pages, nid, altmap, pgmap);
866 if (!memmap) {
867 section_deactivate(pfn, nr_pages, altmap);
868 return ERR_PTR(-ENOMEM);
869 }
870
871 return memmap;
872}
873
874/**
875 * sparse_add_section - add a memory section, or populate an existing one
876 * @nid: The node to add section on
877 * @start_pfn: start pfn of the memory range
878 * @nr_pages: number of pfns to add in the section
879 * @altmap: alternate pfns to allocate the memmap backing store
880 * @pgmap: alternate compound page geometry for devmap mappings
881 *
882 * This is only intended for hotplug.
883 *
884 * Note that only VMEMMAP supports sub-section aligned hotplug,
885 * the proper alignment and size are gated by check_pfn_span().
886 *
887 *
888 * Return:
889 * * 0 - On success.
890 * * -EEXIST - Section has been present.
891 * * -ENOMEM - Out of memory.
892 */
893int __meminit sparse_add_section(int nid, unsigned long start_pfn,
894 unsigned long nr_pages, struct vmem_altmap *altmap,
895 struct dev_pagemap *pgmap)
896{
897 unsigned long section_nr = pfn_to_section_nr(start_pfn);
898 struct mem_section *ms;
899 struct page *memmap;
900 int ret;
901
902 ret = sparse_index_init(section_nr, nid);
903 if (ret < 0)
904 return ret;
905
906 memmap = section_activate(nid, start_pfn, nr_pages, altmap, pgmap);
907 if (IS_ERR(memmap))
908 return PTR_ERR(memmap);
909
910 /*
911 * Poison uninitialized struct pages in order to catch invalid flags
912 * combinations.
913 */
914 if (!altmap || !altmap->inaccessible)
915 page_init_poison(memmap, sizeof(struct page) * nr_pages);
916
917 ms = __nr_to_section(section_nr);
918 set_section_nid(section_nr, nid);
919 __section_mark_present(ms, section_nr);
920
921 /* Align memmap to section boundary in the subsection case */
922 if (section_nr_to_pfn(section_nr) != start_pfn)
923 memmap = pfn_to_page(section_nr_to_pfn(section_nr));
924 sparse_init_one_section(ms, section_nr, memmap, ms->usage, 0);
925
926 return 0;
927}
928
929void sparse_remove_section(unsigned long pfn, unsigned long nr_pages,
930 struct vmem_altmap *altmap)
931{
932 struct mem_section *ms = __pfn_to_section(pfn);
933
934 if (WARN_ON_ONCE(!valid_section(ms)))
935 return;
936
937 section_deactivate(pfn, nr_pages, altmap);
938}
939#endif /* CONFIG_MEMORY_HOTPLUG */