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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/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
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 = 1UL << (MAX_PHYSMEM_BITS-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 <= __highest_present_section_nr)); \
177 section_nr = next_present_section_nr(section_nr))
178
179static inline unsigned long first_present_section_nr(void)
180{
181 return next_present_section_nr(-1);
182}
183
184#ifdef CONFIG_SPARSEMEM_VMEMMAP
185static void subsection_mask_set(unsigned long *map, unsigned long pfn,
186 unsigned long nr_pages)
187{
188 int idx = subsection_map_index(pfn);
189 int end = subsection_map_index(pfn + nr_pages - 1);
190
191 bitmap_set(map, idx, end - idx + 1);
192}
193
194void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages)
195{
196 int end_sec = pfn_to_section_nr(pfn + nr_pages - 1);
197 unsigned long nr, start_sec = pfn_to_section_nr(pfn);
198
199 if (!nr_pages)
200 return;
201
202 for (nr = start_sec; nr <= end_sec; nr++) {
203 struct mem_section *ms;
204 unsigned long pfns;
205
206 pfns = min(nr_pages, PAGES_PER_SECTION
207 - (pfn & ~PAGE_SECTION_MASK));
208 ms = __nr_to_section(nr);
209 subsection_mask_set(ms->usage->subsection_map, pfn, pfns);
210
211 pr_debug("%s: sec: %lu pfns: %lu set(%d, %d)\n", __func__, nr,
212 pfns, subsection_map_index(pfn),
213 subsection_map_index(pfn + pfns - 1));
214
215 pfn += pfns;
216 nr_pages -= pfns;
217 }
218}
219#else
220void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages)
221{
222}
223#endif
224
225/* Record a memory area against a node. */
226static void __init memory_present(int nid, unsigned long start, unsigned long end)
227{
228 unsigned long pfn;
229
230#ifdef CONFIG_SPARSEMEM_EXTREME
231 if (unlikely(!mem_section)) {
232 unsigned long size, align;
233
234 size = sizeof(struct mem_section *) * NR_SECTION_ROOTS;
235 align = 1 << (INTERNODE_CACHE_SHIFT);
236 mem_section = memblock_alloc(size, align);
237 if (!mem_section)
238 panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
239 __func__, size, align);
240 }
241#endif
242
243 start &= PAGE_SECTION_MASK;
244 mminit_validate_memmodel_limits(&start, &end);
245 for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
246 unsigned long section = pfn_to_section_nr(pfn);
247 struct mem_section *ms;
248
249 sparse_index_init(section, nid);
250 set_section_nid(section, nid);
251
252 ms = __nr_to_section(section);
253 if (!ms->section_mem_map) {
254 ms->section_mem_map = sparse_encode_early_nid(nid) |
255 SECTION_IS_ONLINE;
256 __section_mark_present(ms, section);
257 }
258 }
259}
260
261/*
262 * Mark all memblocks as present using memory_present().
263 * This is a convenience function that is useful to mark all of the systems
264 * memory as present during initialization.
265 */
266static void __init memblocks_present(void)
267{
268 unsigned long start, end;
269 int i, nid;
270
271 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid)
272 memory_present(nid, start, end);
273}
274
275/*
276 * Subtle, we encode the real pfn into the mem_map such that
277 * the identity pfn - section_mem_map will return the actual
278 * physical page frame number.
279 */
280static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long pnum)
281{
282 unsigned long coded_mem_map =
283 (unsigned long)(mem_map - (section_nr_to_pfn(pnum)));
284 BUILD_BUG_ON(SECTION_MAP_LAST_BIT > PFN_SECTION_SHIFT);
285 BUG_ON(coded_mem_map & ~SECTION_MAP_MASK);
286 return coded_mem_map;
287}
288
289#ifdef CONFIG_MEMORY_HOTPLUG
290/*
291 * Decode mem_map from the coded memmap
292 */
293struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum)
294{
295 /* mask off the extra low bits of information */
296 coded_mem_map &= SECTION_MAP_MASK;
297 return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum);
298}
299#endif /* CONFIG_MEMORY_HOTPLUG */
300
301static void __meminit sparse_init_one_section(struct mem_section *ms,
302 unsigned long pnum, struct page *mem_map,
303 struct mem_section_usage *usage, unsigned long flags)
304{
305 ms->section_mem_map &= ~SECTION_MAP_MASK;
306 ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum)
307 | SECTION_HAS_MEM_MAP | flags;
308 ms->usage = usage;
309}
310
311static unsigned long usemap_size(void)
312{
313 return BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS) * sizeof(unsigned long);
314}
315
316size_t mem_section_usage_size(void)
317{
318 return sizeof(struct mem_section_usage) + usemap_size();
319}
320
321static inline phys_addr_t pgdat_to_phys(struct pglist_data *pgdat)
322{
323#ifndef CONFIG_NUMA
324 VM_BUG_ON(pgdat != &contig_page_data);
325 return __pa_symbol(&contig_page_data);
326#else
327 return __pa(pgdat);
328#endif
329}
330
331#ifdef CONFIG_MEMORY_HOTREMOVE
332static struct mem_section_usage * __init
333sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
334 unsigned long size)
335{
336 struct mem_section_usage *usage;
337 unsigned long goal, limit;
338 int nid;
339 /*
340 * A page may contain usemaps for other sections preventing the
341 * page being freed and making a section unremovable while
342 * other sections referencing the usemap remain active. Similarly,
343 * a pgdat can prevent a section being removed. If section A
344 * contains a pgdat and section B contains the usemap, both
345 * sections become inter-dependent. This allocates usemaps
346 * from the same section as the pgdat where possible to avoid
347 * this problem.
348 */
349 goal = pgdat_to_phys(pgdat) & (PAGE_SECTION_MASK << PAGE_SHIFT);
350 limit = goal + (1UL << PA_SECTION_SHIFT);
351 nid = early_pfn_to_nid(goal >> PAGE_SHIFT);
352again:
353 usage = memblock_alloc_try_nid(size, SMP_CACHE_BYTES, goal, limit, nid);
354 if (!usage && limit) {
355 limit = 0;
356 goto again;
357 }
358 return usage;
359}
360
361static void __init check_usemap_section_nr(int nid,
362 struct mem_section_usage *usage)
363{
364 unsigned long usemap_snr, pgdat_snr;
365 static unsigned long old_usemap_snr;
366 static unsigned long old_pgdat_snr;
367 struct pglist_data *pgdat = NODE_DATA(nid);
368 int usemap_nid;
369
370 /* First call */
371 if (!old_usemap_snr) {
372 old_usemap_snr = NR_MEM_SECTIONS;
373 old_pgdat_snr = NR_MEM_SECTIONS;
374 }
375
376 usemap_snr = pfn_to_section_nr(__pa(usage) >> PAGE_SHIFT);
377 pgdat_snr = pfn_to_section_nr(pgdat_to_phys(pgdat) >> PAGE_SHIFT);
378 if (usemap_snr == pgdat_snr)
379 return;
380
381 if (old_usemap_snr == usemap_snr && old_pgdat_snr == pgdat_snr)
382 /* skip redundant message */
383 return;
384
385 old_usemap_snr = usemap_snr;
386 old_pgdat_snr = pgdat_snr;
387
388 usemap_nid = sparse_early_nid(__nr_to_section(usemap_snr));
389 if (usemap_nid != nid) {
390 pr_info("node %d must be removed before remove section %ld\n",
391 nid, usemap_snr);
392 return;
393 }
394 /*
395 * There is a circular dependency.
396 * Some platforms allow un-removable section because they will just
397 * gather other removable sections for dynamic partitioning.
398 * Just notify un-removable section's number here.
399 */
400 pr_info("Section %ld and %ld (node %d) have a circular dependency on usemap and pgdat allocations\n",
401 usemap_snr, pgdat_snr, nid);
402}
403#else
404static struct mem_section_usage * __init
405sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
406 unsigned long size)
407{
408 return memblock_alloc_node(size, SMP_CACHE_BYTES, pgdat->node_id);
409}
410
411static void __init check_usemap_section_nr(int nid,
412 struct mem_section_usage *usage)
413{
414}
415#endif /* CONFIG_MEMORY_HOTREMOVE */
416
417#ifdef CONFIG_SPARSEMEM_VMEMMAP
418static unsigned long __init section_map_size(void)
419{
420 return ALIGN(sizeof(struct page) * PAGES_PER_SECTION, PMD_SIZE);
421}
422
423#else
424static unsigned long __init section_map_size(void)
425{
426 return PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
427}
428
429struct page __init *__populate_section_memmap(unsigned long pfn,
430 unsigned long nr_pages, int nid, struct vmem_altmap *altmap,
431 struct dev_pagemap *pgmap)
432{
433 unsigned long size = section_map_size();
434 struct page *map = sparse_buffer_alloc(size);
435 phys_addr_t addr = __pa(MAX_DMA_ADDRESS);
436
437 if (map)
438 return map;
439
440 map = memmap_alloc(size, size, addr, nid, false);
441 if (!map)
442 panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d from=%pa\n",
443 __func__, size, PAGE_SIZE, nid, &addr);
444
445 return map;
446}
447#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
448
449static void *sparsemap_buf __meminitdata;
450static void *sparsemap_buf_end __meminitdata;
451
452static inline void __meminit sparse_buffer_free(unsigned long size)
453{
454 WARN_ON(!sparsemap_buf || size == 0);
455 memblock_free(sparsemap_buf, size);
456}
457
458static void __init sparse_buffer_init(unsigned long size, int nid)
459{
460 phys_addr_t addr = __pa(MAX_DMA_ADDRESS);
461 WARN_ON(sparsemap_buf); /* forgot to call sparse_buffer_fini()? */
462 /*
463 * Pre-allocated buffer is mainly used by __populate_section_memmap
464 * and we want it to be properly aligned to the section size - this is
465 * especially the case for VMEMMAP which maps memmap to PMDs
466 */
467 sparsemap_buf = memmap_alloc(size, section_map_size(), addr, nid, true);
468 sparsemap_buf_end = sparsemap_buf + size;
469}
470
471static void __init sparse_buffer_fini(void)
472{
473 unsigned long size = sparsemap_buf_end - sparsemap_buf;
474
475 if (sparsemap_buf && size > 0)
476 sparse_buffer_free(size);
477 sparsemap_buf = NULL;
478}
479
480void * __meminit sparse_buffer_alloc(unsigned long size)
481{
482 void *ptr = NULL;
483
484 if (sparsemap_buf) {
485 ptr = (void *) roundup((unsigned long)sparsemap_buf, size);
486 if (ptr + size > sparsemap_buf_end)
487 ptr = NULL;
488 else {
489 /* Free redundant aligned space */
490 if ((unsigned long)(ptr - sparsemap_buf) > 0)
491 sparse_buffer_free((unsigned long)(ptr - sparsemap_buf));
492 sparsemap_buf = ptr + size;
493 }
494 }
495 return ptr;
496}
497
498void __weak __meminit vmemmap_populate_print_last(void)
499{
500}
501
502/*
503 * Initialize sparse on a specific node. The node spans [pnum_begin, pnum_end)
504 * And number of present sections in this node is map_count.
505 */
506static void __init sparse_init_nid(int nid, unsigned long pnum_begin,
507 unsigned long pnum_end,
508 unsigned long map_count)
509{
510 struct mem_section_usage *usage;
511 unsigned long pnum;
512 struct page *map;
513
514 usage = sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nid),
515 mem_section_usage_size() * map_count);
516 if (!usage) {
517 pr_err("%s: node[%d] usemap allocation failed", __func__, nid);
518 goto failed;
519 }
520 sparse_buffer_init(map_count * section_map_size(), nid);
521 for_each_present_section_nr(pnum_begin, pnum) {
522 unsigned long pfn = section_nr_to_pfn(pnum);
523
524 if (pnum >= pnum_end)
525 break;
526
527 map = __populate_section_memmap(pfn, PAGES_PER_SECTION,
528 nid, NULL, NULL);
529 if (!map) {
530 pr_err("%s: node[%d] memory map backing failed. Some memory will not be available.",
531 __func__, nid);
532 pnum_begin = pnum;
533 sparse_buffer_fini();
534 goto failed;
535 }
536 check_usemap_section_nr(nid, usage);
537 sparse_init_one_section(__nr_to_section(pnum), pnum, map, usage,
538 SECTION_IS_EARLY);
539 usage = (void *) usage + mem_section_usage_size();
540 }
541 sparse_buffer_fini();
542 return;
543failed:
544 /* We failed to allocate, mark all the following pnums as not present */
545 for_each_present_section_nr(pnum_begin, pnum) {
546 struct mem_section *ms;
547
548 if (pnum >= pnum_end)
549 break;
550 ms = __nr_to_section(pnum);
551 ms->section_mem_map = 0;
552 }
553}
554
555/*
556 * Allocate the accumulated non-linear sections, allocate a mem_map
557 * for each and record the physical to section mapping.
558 */
559void __init sparse_init(void)
560{
561 unsigned long pnum_end, pnum_begin, map_count = 1;
562 int nid_begin;
563
564 memblocks_present();
565
566 pnum_begin = first_present_section_nr();
567 nid_begin = sparse_early_nid(__nr_to_section(pnum_begin));
568
569 /* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */
570 set_pageblock_order();
571
572 for_each_present_section_nr(pnum_begin + 1, pnum_end) {
573 int nid = sparse_early_nid(__nr_to_section(pnum_end));
574
575 if (nid == nid_begin) {
576 map_count++;
577 continue;
578 }
579 /* Init node with sections in range [pnum_begin, pnum_end) */
580 sparse_init_nid(nid_begin, pnum_begin, pnum_end, map_count);
581 nid_begin = nid;
582 pnum_begin = pnum_end;
583 map_count = 1;
584 }
585 /* cover the last node */
586 sparse_init_nid(nid_begin, pnum_begin, pnum_end, map_count);
587 vmemmap_populate_print_last();
588}
589
590#ifdef CONFIG_MEMORY_HOTPLUG
591
592/* Mark all memory sections within the pfn range as online */
593void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
594{
595 unsigned long pfn;
596
597 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
598 unsigned long section_nr = pfn_to_section_nr(pfn);
599 struct mem_section *ms;
600
601 /* onlining code should never touch invalid ranges */
602 if (WARN_ON(!valid_section_nr(section_nr)))
603 continue;
604
605 ms = __nr_to_section(section_nr);
606 ms->section_mem_map |= SECTION_IS_ONLINE;
607 }
608}
609
610/* Mark all memory sections within the pfn range as offline */
611void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
612{
613 unsigned long pfn;
614
615 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
616 unsigned long section_nr = pfn_to_section_nr(pfn);
617 struct mem_section *ms;
618
619 /*
620 * TODO this needs some double checking. Offlining code makes
621 * sure to check pfn_valid but those checks might be just bogus
622 */
623 if (WARN_ON(!valid_section_nr(section_nr)))
624 continue;
625
626 ms = __nr_to_section(section_nr);
627 ms->section_mem_map &= ~SECTION_IS_ONLINE;
628 }
629}
630
631#ifdef CONFIG_SPARSEMEM_VMEMMAP
632static struct page * __meminit populate_section_memmap(unsigned long pfn,
633 unsigned long nr_pages, int nid, struct vmem_altmap *altmap,
634 struct dev_pagemap *pgmap)
635{
636 return __populate_section_memmap(pfn, nr_pages, nid, altmap, pgmap);
637}
638
639static void depopulate_section_memmap(unsigned long pfn, unsigned long nr_pages,
640 struct vmem_altmap *altmap)
641{
642 unsigned long start = (unsigned long) pfn_to_page(pfn);
643 unsigned long end = start + nr_pages * sizeof(struct page);
644
645 vmemmap_free(start, end, altmap);
646}
647static void free_map_bootmem(struct page *memmap)
648{
649 unsigned long start = (unsigned long)memmap;
650 unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION);
651
652 vmemmap_free(start, end, NULL);
653}
654
655static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages)
656{
657 DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
658 DECLARE_BITMAP(tmp, SUBSECTIONS_PER_SECTION) = { 0 };
659 struct mem_section *ms = __pfn_to_section(pfn);
660 unsigned long *subsection_map = ms->usage
661 ? &ms->usage->subsection_map[0] : NULL;
662
663 subsection_mask_set(map, pfn, nr_pages);
664 if (subsection_map)
665 bitmap_and(tmp, map, subsection_map, SUBSECTIONS_PER_SECTION);
666
667 if (WARN(!subsection_map || !bitmap_equal(tmp, map, SUBSECTIONS_PER_SECTION),
668 "section already deactivated (%#lx + %ld)\n",
669 pfn, nr_pages))
670 return -EINVAL;
671
672 bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION);
673 return 0;
674}
675
676static bool is_subsection_map_empty(struct mem_section *ms)
677{
678 return bitmap_empty(&ms->usage->subsection_map[0],
679 SUBSECTIONS_PER_SECTION);
680}
681
682static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages)
683{
684 struct mem_section *ms = __pfn_to_section(pfn);
685 DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
686 unsigned long *subsection_map;
687 int rc = 0;
688
689 subsection_mask_set(map, pfn, nr_pages);
690
691 subsection_map = &ms->usage->subsection_map[0];
692
693 if (bitmap_empty(map, SUBSECTIONS_PER_SECTION))
694 rc = -EINVAL;
695 else if (bitmap_intersects(map, subsection_map, SUBSECTIONS_PER_SECTION))
696 rc = -EEXIST;
697 else
698 bitmap_or(subsection_map, map, subsection_map,
699 SUBSECTIONS_PER_SECTION);
700
701 return rc;
702}
703#else
704struct page * __meminit populate_section_memmap(unsigned long pfn,
705 unsigned long nr_pages, int nid, struct vmem_altmap *altmap,
706 struct dev_pagemap *pgmap)
707{
708 return kvmalloc_node(array_size(sizeof(struct page),
709 PAGES_PER_SECTION), GFP_KERNEL, nid);
710}
711
712static void depopulate_section_memmap(unsigned long pfn, unsigned long nr_pages,
713 struct vmem_altmap *altmap)
714{
715 kvfree(pfn_to_page(pfn));
716}
717
718static void free_map_bootmem(struct page *memmap)
719{
720 unsigned long maps_section_nr, removing_section_nr, i;
721 unsigned long magic, nr_pages;
722 struct page *page = virt_to_page(memmap);
723
724 nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
725 >> PAGE_SHIFT;
726
727 for (i = 0; i < nr_pages; i++, page++) {
728 magic = page->index;
729
730 BUG_ON(magic == NODE_INFO);
731
732 maps_section_nr = pfn_to_section_nr(page_to_pfn(page));
733 removing_section_nr = page_private(page);
734
735 /*
736 * When this function is called, the removing section is
737 * logical offlined state. This means all pages are isolated
738 * from page allocator. If removing section's memmap is placed
739 * on the same section, it must not be freed.
740 * If it is freed, page allocator may allocate it which will
741 * be removed physically soon.
742 */
743 if (maps_section_nr != removing_section_nr)
744 put_page_bootmem(page);
745 }
746}
747
748static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages)
749{
750 return 0;
751}
752
753static bool is_subsection_map_empty(struct mem_section *ms)
754{
755 return true;
756}
757
758static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages)
759{
760 return 0;
761}
762#endif /* CONFIG_SPARSEMEM_VMEMMAP */
763
764/*
765 * To deactivate a memory region, there are 3 cases to handle across
766 * two configurations (SPARSEMEM_VMEMMAP={y,n}):
767 *
768 * 1. deactivation of a partial hot-added section (only possible in
769 * the SPARSEMEM_VMEMMAP=y case).
770 * a) section was present at memory init.
771 * b) section was hot-added post memory init.
772 * 2. deactivation of a complete hot-added section.
773 * 3. deactivation of a complete section from memory init.
774 *
775 * For 1, when subsection_map does not empty we will not be freeing the
776 * usage map, but still need to free the vmemmap range.
777 *
778 * For 2 and 3, the SPARSEMEM_VMEMMAP={y,n} cases are unified
779 */
780static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
781 struct vmem_altmap *altmap)
782{
783 struct mem_section *ms = __pfn_to_section(pfn);
784 bool section_is_early = early_section(ms);
785 struct page *memmap = NULL;
786 bool empty;
787
788 if (clear_subsection_map(pfn, nr_pages))
789 return;
790
791 empty = is_subsection_map_empty(ms);
792 if (empty) {
793 unsigned long section_nr = pfn_to_section_nr(pfn);
794
795 /*
796 * When removing an early section, the usage map is kept (as the
797 * usage maps of other sections fall into the same page). It
798 * will be re-used when re-adding the section - which is then no
799 * longer an early section. If the usage map is PageReserved, it
800 * was allocated during boot.
801 */
802 if (!PageReserved(virt_to_page(ms->usage))) {
803 kfree(ms->usage);
804 ms->usage = NULL;
805 }
806 memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
807 /*
808 * Mark the section invalid so that valid_section()
809 * return false. This prevents code from dereferencing
810 * ms->usage array.
811 */
812 ms->section_mem_map &= ~SECTION_HAS_MEM_MAP;
813 }
814
815 /*
816 * The memmap of early sections is always fully populated. See
817 * section_activate() and pfn_valid() .
818 */
819 if (!section_is_early)
820 depopulate_section_memmap(pfn, nr_pages, altmap);
821 else if (memmap)
822 free_map_bootmem(memmap);
823
824 if (empty)
825 ms->section_mem_map = (unsigned long)NULL;
826}
827
828static struct page * __meminit section_activate(int nid, unsigned long pfn,
829 unsigned long nr_pages, struct vmem_altmap *altmap,
830 struct dev_pagemap *pgmap)
831{
832 struct mem_section *ms = __pfn_to_section(pfn);
833 struct mem_section_usage *usage = NULL;
834 struct page *memmap;
835 int rc = 0;
836
837 if (!ms->usage) {
838 usage = kzalloc(mem_section_usage_size(), GFP_KERNEL);
839 if (!usage)
840 return ERR_PTR(-ENOMEM);
841 ms->usage = usage;
842 }
843
844 rc = fill_subsection_map(pfn, nr_pages);
845 if (rc) {
846 if (usage)
847 ms->usage = NULL;
848 kfree(usage);
849 return ERR_PTR(rc);
850 }
851
852 /*
853 * The early init code does not consider partially populated
854 * initial sections, it simply assumes that memory will never be
855 * referenced. If we hot-add memory into such a section then we
856 * do not need to populate the memmap and can simply reuse what
857 * is already there.
858 */
859 if (nr_pages < PAGES_PER_SECTION && early_section(ms))
860 return pfn_to_page(pfn);
861
862 memmap = populate_section_memmap(pfn, nr_pages, nid, altmap, pgmap);
863 if (!memmap) {
864 section_deactivate(pfn, nr_pages, altmap);
865 return ERR_PTR(-ENOMEM);
866 }
867
868 return memmap;
869}
870
871/**
872 * sparse_add_section - add a memory section, or populate an existing one
873 * @nid: The node to add section on
874 * @start_pfn: start pfn of the memory range
875 * @nr_pages: number of pfns to add in the section
876 * @altmap: alternate pfns to allocate the memmap backing store
877 * @pgmap: alternate compound page geometry for devmap mappings
878 *
879 * This is only intended for hotplug.
880 *
881 * Note that only VMEMMAP supports sub-section aligned hotplug,
882 * the proper alignment and size are gated by check_pfn_span().
883 *
884 *
885 * Return:
886 * * 0 - On success.
887 * * -EEXIST - Section has been present.
888 * * -ENOMEM - Out of memory.
889 */
890int __meminit sparse_add_section(int nid, unsigned long start_pfn,
891 unsigned long nr_pages, struct vmem_altmap *altmap,
892 struct dev_pagemap *pgmap)
893{
894 unsigned long section_nr = pfn_to_section_nr(start_pfn);
895 struct mem_section *ms;
896 struct page *memmap;
897 int ret;
898
899 ret = sparse_index_init(section_nr, nid);
900 if (ret < 0)
901 return ret;
902
903 memmap = section_activate(nid, start_pfn, nr_pages, altmap, pgmap);
904 if (IS_ERR(memmap))
905 return PTR_ERR(memmap);
906
907 /*
908 * Poison uninitialized struct pages in order to catch invalid flags
909 * combinations.
910 */
911 page_init_poison(memmap, sizeof(struct page) * nr_pages);
912
913 ms = __nr_to_section(section_nr);
914 set_section_nid(section_nr, nid);
915 __section_mark_present(ms, section_nr);
916
917 /* Align memmap to section boundary in the subsection case */
918 if (section_nr_to_pfn(section_nr) != start_pfn)
919 memmap = pfn_to_page(section_nr_to_pfn(section_nr));
920 sparse_init_one_section(ms, section_nr, memmap, ms->usage, 0);
921
922 return 0;
923}
924
925void sparse_remove_section(struct mem_section *ms, unsigned long pfn,
926 unsigned long nr_pages, unsigned long map_offset,
927 struct vmem_altmap *altmap)
928{
929 section_deactivate(pfn, nr_pages, altmap);
930}
931#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 */