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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#ifdef CONFIG_SPARSEMEM_EXTREME
113unsigned long __section_nr(struct mem_section *ms)
114{
115 unsigned long root_nr;
116 struct mem_section *root = NULL;
117
118 for (root_nr = 0; root_nr < NR_SECTION_ROOTS; root_nr++) {
119 root = __nr_to_section(root_nr * SECTIONS_PER_ROOT);
120 if (!root)
121 continue;
122
123 if ((ms >= root) && (ms < (root + SECTIONS_PER_ROOT)))
124 break;
125 }
126
127 VM_BUG_ON(!root);
128
129 return (root_nr * SECTIONS_PER_ROOT) + (ms - root);
130}
131#else
132unsigned long __section_nr(struct mem_section *ms)
133{
134 return (unsigned long)(ms - mem_section[0]);
135}
136#endif
137
138/*
139 * During early boot, before section_mem_map is used for an actual
140 * mem_map, we use section_mem_map to store the section's NUMA
141 * node. This keeps us from having to use another data structure. The
142 * node information is cleared just before we store the real mem_map.
143 */
144static inline unsigned long sparse_encode_early_nid(int nid)
145{
146 return (nid << SECTION_NID_SHIFT);
147}
148
149static inline int sparse_early_nid(struct mem_section *section)
150{
151 return (section->section_mem_map >> SECTION_NID_SHIFT);
152}
153
154/* Validate the physical addressing limitations of the model */
155void __meminit mminit_validate_memmodel_limits(unsigned long *start_pfn,
156 unsigned long *end_pfn)
157{
158 unsigned long max_sparsemem_pfn = 1UL << (MAX_PHYSMEM_BITS-PAGE_SHIFT);
159
160 /*
161 * Sanity checks - do not allow an architecture to pass
162 * in larger pfns than the maximum scope of sparsemem:
163 */
164 if (*start_pfn > max_sparsemem_pfn) {
165 mminit_dprintk(MMINIT_WARNING, "pfnvalidation",
166 "Start of range %lu -> %lu exceeds SPARSEMEM max %lu\n",
167 *start_pfn, *end_pfn, max_sparsemem_pfn);
168 WARN_ON_ONCE(1);
169 *start_pfn = max_sparsemem_pfn;
170 *end_pfn = max_sparsemem_pfn;
171 } else if (*end_pfn > max_sparsemem_pfn) {
172 mminit_dprintk(MMINIT_WARNING, "pfnvalidation",
173 "End of range %lu -> %lu exceeds SPARSEMEM max %lu\n",
174 *start_pfn, *end_pfn, max_sparsemem_pfn);
175 WARN_ON_ONCE(1);
176 *end_pfn = max_sparsemem_pfn;
177 }
178}
179
180/*
181 * There are a number of times that we loop over NR_MEM_SECTIONS,
182 * looking for section_present() on each. But, when we have very
183 * large physical address spaces, NR_MEM_SECTIONS can also be
184 * very large which makes the loops quite long.
185 *
186 * Keeping track of this gives us an easy way to break out of
187 * those loops early.
188 */
189unsigned long __highest_present_section_nr;
190static void section_mark_present(struct mem_section *ms)
191{
192 unsigned long section_nr = __section_nr(ms);
193
194 if (section_nr > __highest_present_section_nr)
195 __highest_present_section_nr = section_nr;
196
197 ms->section_mem_map |= SECTION_MARKED_PRESENT;
198}
199
200#define for_each_present_section_nr(start, section_nr) \
201 for (section_nr = next_present_section_nr(start-1); \
202 ((section_nr != -1) && \
203 (section_nr <= __highest_present_section_nr)); \
204 section_nr = next_present_section_nr(section_nr))
205
206static inline unsigned long first_present_section_nr(void)
207{
208 return next_present_section_nr(-1);
209}
210
211#ifdef CONFIG_SPARSEMEM_VMEMMAP
212static void subsection_mask_set(unsigned long *map, unsigned long pfn,
213 unsigned long nr_pages)
214{
215 int idx = subsection_map_index(pfn);
216 int end = subsection_map_index(pfn + nr_pages - 1);
217
218 bitmap_set(map, idx, end - idx + 1);
219}
220
221void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages)
222{
223 int end_sec = pfn_to_section_nr(pfn + nr_pages - 1);
224 unsigned long nr, start_sec = pfn_to_section_nr(pfn);
225
226 if (!nr_pages)
227 return;
228
229 for (nr = start_sec; nr <= end_sec; nr++) {
230 struct mem_section *ms;
231 unsigned long pfns;
232
233 pfns = min(nr_pages, PAGES_PER_SECTION
234 - (pfn & ~PAGE_SECTION_MASK));
235 ms = __nr_to_section(nr);
236 subsection_mask_set(ms->usage->subsection_map, pfn, pfns);
237
238 pr_debug("%s: sec: %lu pfns: %lu set(%d, %d)\n", __func__, nr,
239 pfns, subsection_map_index(pfn),
240 subsection_map_index(pfn + pfns - 1));
241
242 pfn += pfns;
243 nr_pages -= pfns;
244 }
245}
246#else
247void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages)
248{
249}
250#endif
251
252/* Record a memory area against a node. */
253static void __init memory_present(int nid, unsigned long start, unsigned long end)
254{
255 unsigned long pfn;
256
257#ifdef CONFIG_SPARSEMEM_EXTREME
258 if (unlikely(!mem_section)) {
259 unsigned long size, align;
260
261 size = sizeof(struct mem_section *) * NR_SECTION_ROOTS;
262 align = 1 << (INTERNODE_CACHE_SHIFT);
263 mem_section = memblock_alloc(size, align);
264 if (!mem_section)
265 panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
266 __func__, size, align);
267 }
268#endif
269
270 start &= PAGE_SECTION_MASK;
271 mminit_validate_memmodel_limits(&start, &end);
272 for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
273 unsigned long section = pfn_to_section_nr(pfn);
274 struct mem_section *ms;
275
276 sparse_index_init(section, nid);
277 set_section_nid(section, nid);
278
279 ms = __nr_to_section(section);
280 if (!ms->section_mem_map) {
281 ms->section_mem_map = sparse_encode_early_nid(nid) |
282 SECTION_IS_ONLINE;
283 section_mark_present(ms);
284 }
285 }
286}
287
288/*
289 * Mark all memblocks as present using memory_present().
290 * This is a convenience function that is useful to mark all of the systems
291 * memory as present during initialization.
292 */
293static void __init memblocks_present(void)
294{
295 unsigned long start, end;
296 int i, nid;
297
298 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid)
299 memory_present(nid, start, end);
300}
301
302/*
303 * Subtle, we encode the real pfn into the mem_map such that
304 * the identity pfn - section_mem_map will return the actual
305 * physical page frame number.
306 */
307static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long pnum)
308{
309 unsigned long coded_mem_map =
310 (unsigned long)(mem_map - (section_nr_to_pfn(pnum)));
311 BUILD_BUG_ON(SECTION_MAP_LAST_BIT > (1UL<<PFN_SECTION_SHIFT));
312 BUG_ON(coded_mem_map & ~SECTION_MAP_MASK);
313 return coded_mem_map;
314}
315
316#ifdef CONFIG_MEMORY_HOTPLUG
317/*
318 * Decode mem_map from the coded memmap
319 */
320struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum)
321{
322 /* mask off the extra low bits of information */
323 coded_mem_map &= SECTION_MAP_MASK;
324 return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum);
325}
326#endif /* CONFIG_MEMORY_HOTPLUG */
327
328static void __meminit sparse_init_one_section(struct mem_section *ms,
329 unsigned long pnum, struct page *mem_map,
330 struct mem_section_usage *usage, unsigned long flags)
331{
332 ms->section_mem_map &= ~SECTION_MAP_MASK;
333 ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum)
334 | SECTION_HAS_MEM_MAP | flags;
335 ms->usage = usage;
336}
337
338static unsigned long usemap_size(void)
339{
340 return BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS) * sizeof(unsigned long);
341}
342
343size_t mem_section_usage_size(void)
344{
345 return sizeof(struct mem_section_usage) + usemap_size();
346}
347
348static inline phys_addr_t pgdat_to_phys(struct pglist_data *pgdat)
349{
350#ifndef CONFIG_NUMA
351 return __pa_symbol(pgdat);
352#else
353 return __pa(pgdat);
354#endif
355}
356
357#ifdef CONFIG_MEMORY_HOTREMOVE
358static struct mem_section_usage * __init
359sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
360 unsigned long size)
361{
362 struct mem_section_usage *usage;
363 unsigned long goal, limit;
364 int nid;
365 /*
366 * A page may contain usemaps for other sections preventing the
367 * page being freed and making a section unremovable while
368 * other sections referencing the usemap remain active. Similarly,
369 * a pgdat can prevent a section being removed. If section A
370 * contains a pgdat and section B contains the usemap, both
371 * sections become inter-dependent. This allocates usemaps
372 * from the same section as the pgdat where possible to avoid
373 * this problem.
374 */
375 goal = pgdat_to_phys(pgdat) & (PAGE_SECTION_MASK << PAGE_SHIFT);
376 limit = goal + (1UL << PA_SECTION_SHIFT);
377 nid = early_pfn_to_nid(goal >> PAGE_SHIFT);
378again:
379 usage = memblock_alloc_try_nid(size, SMP_CACHE_BYTES, goal, limit, nid);
380 if (!usage && limit) {
381 limit = 0;
382 goto again;
383 }
384 return usage;
385}
386
387static void __init check_usemap_section_nr(int nid,
388 struct mem_section_usage *usage)
389{
390 unsigned long usemap_snr, pgdat_snr;
391 static unsigned long old_usemap_snr;
392 static unsigned long old_pgdat_snr;
393 struct pglist_data *pgdat = NODE_DATA(nid);
394 int usemap_nid;
395
396 /* First call */
397 if (!old_usemap_snr) {
398 old_usemap_snr = NR_MEM_SECTIONS;
399 old_pgdat_snr = NR_MEM_SECTIONS;
400 }
401
402 usemap_snr = pfn_to_section_nr(__pa(usage) >> PAGE_SHIFT);
403 pgdat_snr = pfn_to_section_nr(pgdat_to_phys(pgdat) >> PAGE_SHIFT);
404 if (usemap_snr == pgdat_snr)
405 return;
406
407 if (old_usemap_snr == usemap_snr && old_pgdat_snr == pgdat_snr)
408 /* skip redundant message */
409 return;
410
411 old_usemap_snr = usemap_snr;
412 old_pgdat_snr = pgdat_snr;
413
414 usemap_nid = sparse_early_nid(__nr_to_section(usemap_snr));
415 if (usemap_nid != nid) {
416 pr_info("node %d must be removed before remove section %ld\n",
417 nid, usemap_snr);
418 return;
419 }
420 /*
421 * There is a circular dependency.
422 * Some platforms allow un-removable section because they will just
423 * gather other removable sections for dynamic partitioning.
424 * Just notify un-removable section's number here.
425 */
426 pr_info("Section %ld and %ld (node %d) have a circular dependency on usemap and pgdat allocations\n",
427 usemap_snr, pgdat_snr, nid);
428}
429#else
430static struct mem_section_usage * __init
431sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
432 unsigned long size)
433{
434 return memblock_alloc_node(size, SMP_CACHE_BYTES, pgdat->node_id);
435}
436
437static void __init check_usemap_section_nr(int nid,
438 struct mem_section_usage *usage)
439{
440}
441#endif /* CONFIG_MEMORY_HOTREMOVE */
442
443#ifdef CONFIG_SPARSEMEM_VMEMMAP
444static unsigned long __init section_map_size(void)
445{
446 return ALIGN(sizeof(struct page) * PAGES_PER_SECTION, PMD_SIZE);
447}
448
449#else
450static unsigned long __init section_map_size(void)
451{
452 return PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
453}
454
455struct page __init *__populate_section_memmap(unsigned long pfn,
456 unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
457{
458 unsigned long size = section_map_size();
459 struct page *map = sparse_buffer_alloc(size);
460 phys_addr_t addr = __pa(MAX_DMA_ADDRESS);
461
462 if (map)
463 return map;
464
465 map = memblock_alloc_try_nid_raw(size, size, addr,
466 MEMBLOCK_ALLOC_ACCESSIBLE, nid);
467 if (!map)
468 panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d from=%pa\n",
469 __func__, size, PAGE_SIZE, nid, &addr);
470
471 return map;
472}
473#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
474
475static void *sparsemap_buf __meminitdata;
476static void *sparsemap_buf_end __meminitdata;
477
478static inline void __meminit sparse_buffer_free(unsigned long size)
479{
480 WARN_ON(!sparsemap_buf || size == 0);
481 memblock_free_early(__pa(sparsemap_buf), size);
482}
483
484static void __init sparse_buffer_init(unsigned long size, int nid)
485{
486 phys_addr_t addr = __pa(MAX_DMA_ADDRESS);
487 WARN_ON(sparsemap_buf); /* forgot to call sparse_buffer_fini()? */
488 /*
489 * Pre-allocated buffer is mainly used by __populate_section_memmap
490 * and we want it to be properly aligned to the section size - this is
491 * especially the case for VMEMMAP which maps memmap to PMDs
492 */
493 sparsemap_buf = memblock_alloc_exact_nid_raw(size, section_map_size(),
494 addr, MEMBLOCK_ALLOC_ACCESSIBLE, nid);
495 sparsemap_buf_end = sparsemap_buf + size;
496}
497
498static void __init sparse_buffer_fini(void)
499{
500 unsigned long size = sparsemap_buf_end - sparsemap_buf;
501
502 if (sparsemap_buf && size > 0)
503 sparse_buffer_free(size);
504 sparsemap_buf = NULL;
505}
506
507void * __meminit sparse_buffer_alloc(unsigned long size)
508{
509 void *ptr = NULL;
510
511 if (sparsemap_buf) {
512 ptr = (void *) roundup((unsigned long)sparsemap_buf, size);
513 if (ptr + size > sparsemap_buf_end)
514 ptr = NULL;
515 else {
516 /* Free redundant aligned space */
517 if ((unsigned long)(ptr - sparsemap_buf) > 0)
518 sparse_buffer_free((unsigned long)(ptr - sparsemap_buf));
519 sparsemap_buf = ptr + size;
520 }
521 }
522 return ptr;
523}
524
525void __weak __meminit vmemmap_populate_print_last(void)
526{
527}
528
529/*
530 * Initialize sparse on a specific node. The node spans [pnum_begin, pnum_end)
531 * And number of present sections in this node is map_count.
532 */
533static void __init sparse_init_nid(int nid, unsigned long pnum_begin,
534 unsigned long pnum_end,
535 unsigned long map_count)
536{
537 struct mem_section_usage *usage;
538 unsigned long pnum;
539 struct page *map;
540
541 usage = sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nid),
542 mem_section_usage_size() * map_count);
543 if (!usage) {
544 pr_err("%s: node[%d] usemap allocation failed", __func__, nid);
545 goto failed;
546 }
547 sparse_buffer_init(map_count * section_map_size(), nid);
548 for_each_present_section_nr(pnum_begin, pnum) {
549 unsigned long pfn = section_nr_to_pfn(pnum);
550
551 if (pnum >= pnum_end)
552 break;
553
554 map = __populate_section_memmap(pfn, PAGES_PER_SECTION,
555 nid, NULL);
556 if (!map) {
557 pr_err("%s: node[%d] memory map backing failed. Some memory will not be available.",
558 __func__, nid);
559 pnum_begin = pnum;
560 sparse_buffer_fini();
561 goto failed;
562 }
563 check_usemap_section_nr(nid, usage);
564 sparse_init_one_section(__nr_to_section(pnum), pnum, map, usage,
565 SECTION_IS_EARLY);
566 usage = (void *) usage + mem_section_usage_size();
567 }
568 sparse_buffer_fini();
569 return;
570failed:
571 /* We failed to allocate, mark all the following pnums as not present */
572 for_each_present_section_nr(pnum_begin, pnum) {
573 struct mem_section *ms;
574
575 if (pnum >= pnum_end)
576 break;
577 ms = __nr_to_section(pnum);
578 ms->section_mem_map = 0;
579 }
580}
581
582/*
583 * Allocate the accumulated non-linear sections, allocate a mem_map
584 * for each and record the physical to section mapping.
585 */
586void __init sparse_init(void)
587{
588 unsigned long pnum_end, pnum_begin, map_count = 1;
589 int nid_begin;
590
591 memblocks_present();
592
593 pnum_begin = first_present_section_nr();
594 nid_begin = sparse_early_nid(__nr_to_section(pnum_begin));
595
596 /* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */
597 set_pageblock_order();
598
599 for_each_present_section_nr(pnum_begin + 1, pnum_end) {
600 int nid = sparse_early_nid(__nr_to_section(pnum_end));
601
602 if (nid == nid_begin) {
603 map_count++;
604 continue;
605 }
606 /* Init node with sections in range [pnum_begin, pnum_end) */
607 sparse_init_nid(nid_begin, pnum_begin, pnum_end, map_count);
608 nid_begin = nid;
609 pnum_begin = pnum_end;
610 map_count = 1;
611 }
612 /* cover the last node */
613 sparse_init_nid(nid_begin, pnum_begin, pnum_end, map_count);
614 vmemmap_populate_print_last();
615}
616
617#ifdef CONFIG_MEMORY_HOTPLUG
618
619/* Mark all memory sections within the pfn range as online */
620void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
621{
622 unsigned long pfn;
623
624 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
625 unsigned long section_nr = pfn_to_section_nr(pfn);
626 struct mem_section *ms;
627
628 /* onlining code should never touch invalid ranges */
629 if (WARN_ON(!valid_section_nr(section_nr)))
630 continue;
631
632 ms = __nr_to_section(section_nr);
633 ms->section_mem_map |= SECTION_IS_ONLINE;
634 }
635}
636
637/* Mark all memory sections within the pfn range as offline */
638void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
639{
640 unsigned long pfn;
641
642 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
643 unsigned long section_nr = pfn_to_section_nr(pfn);
644 struct mem_section *ms;
645
646 /*
647 * TODO this needs some double checking. Offlining code makes
648 * sure to check pfn_valid but those checks might be just bogus
649 */
650 if (WARN_ON(!valid_section_nr(section_nr)))
651 continue;
652
653 ms = __nr_to_section(section_nr);
654 ms->section_mem_map &= ~SECTION_IS_ONLINE;
655 }
656}
657
658#ifdef CONFIG_SPARSEMEM_VMEMMAP
659static struct page * __meminit populate_section_memmap(unsigned long pfn,
660 unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
661{
662 return __populate_section_memmap(pfn, nr_pages, nid, altmap);
663}
664
665static void depopulate_section_memmap(unsigned long pfn, unsigned long nr_pages,
666 struct vmem_altmap *altmap)
667{
668 unsigned long start = (unsigned long) pfn_to_page(pfn);
669 unsigned long end = start + nr_pages * sizeof(struct page);
670
671 vmemmap_free(start, end, altmap);
672}
673static void free_map_bootmem(struct page *memmap)
674{
675 unsigned long start = (unsigned long)memmap;
676 unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION);
677
678 vmemmap_free(start, end, NULL);
679}
680
681static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages)
682{
683 DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
684 DECLARE_BITMAP(tmp, SUBSECTIONS_PER_SECTION) = { 0 };
685 struct mem_section *ms = __pfn_to_section(pfn);
686 unsigned long *subsection_map = ms->usage
687 ? &ms->usage->subsection_map[0] : NULL;
688
689 subsection_mask_set(map, pfn, nr_pages);
690 if (subsection_map)
691 bitmap_and(tmp, map, subsection_map, SUBSECTIONS_PER_SECTION);
692
693 if (WARN(!subsection_map || !bitmap_equal(tmp, map, SUBSECTIONS_PER_SECTION),
694 "section already deactivated (%#lx + %ld)\n",
695 pfn, nr_pages))
696 return -EINVAL;
697
698 bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION);
699 return 0;
700}
701
702static bool is_subsection_map_empty(struct mem_section *ms)
703{
704 return bitmap_empty(&ms->usage->subsection_map[0],
705 SUBSECTIONS_PER_SECTION);
706}
707
708static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages)
709{
710 struct mem_section *ms = __pfn_to_section(pfn);
711 DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
712 unsigned long *subsection_map;
713 int rc = 0;
714
715 subsection_mask_set(map, pfn, nr_pages);
716
717 subsection_map = &ms->usage->subsection_map[0];
718
719 if (bitmap_empty(map, SUBSECTIONS_PER_SECTION))
720 rc = -EINVAL;
721 else if (bitmap_intersects(map, subsection_map, SUBSECTIONS_PER_SECTION))
722 rc = -EEXIST;
723 else
724 bitmap_or(subsection_map, map, subsection_map,
725 SUBSECTIONS_PER_SECTION);
726
727 return rc;
728}
729#else
730struct page * __meminit populate_section_memmap(unsigned long pfn,
731 unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
732{
733 return kvmalloc_node(array_size(sizeof(struct page),
734 PAGES_PER_SECTION), GFP_KERNEL, nid);
735}
736
737static void depopulate_section_memmap(unsigned long pfn, unsigned long nr_pages,
738 struct vmem_altmap *altmap)
739{
740 kvfree(pfn_to_page(pfn));
741}
742
743static void free_map_bootmem(struct page *memmap)
744{
745 unsigned long maps_section_nr, removing_section_nr, i;
746 unsigned long magic, nr_pages;
747 struct page *page = virt_to_page(memmap);
748
749 nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
750 >> PAGE_SHIFT;
751
752 for (i = 0; i < nr_pages; i++, page++) {
753 magic = (unsigned long) page->freelist;
754
755 BUG_ON(magic == NODE_INFO);
756
757 maps_section_nr = pfn_to_section_nr(page_to_pfn(page));
758 removing_section_nr = page_private(page);
759
760 /*
761 * When this function is called, the removing section is
762 * logical offlined state. This means all pages are isolated
763 * from page allocator. If removing section's memmap is placed
764 * on the same section, it must not be freed.
765 * If it is freed, page allocator may allocate it which will
766 * be removed physically soon.
767 */
768 if (maps_section_nr != removing_section_nr)
769 put_page_bootmem(page);
770 }
771}
772
773static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages)
774{
775 return 0;
776}
777
778static bool is_subsection_map_empty(struct mem_section *ms)
779{
780 return true;
781}
782
783static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages)
784{
785 return 0;
786}
787#endif /* CONFIG_SPARSEMEM_VMEMMAP */
788
789/*
790 * To deactivate a memory region, there are 3 cases to handle across
791 * two configurations (SPARSEMEM_VMEMMAP={y,n}):
792 *
793 * 1. deactivation of a partial hot-added section (only possible in
794 * the SPARSEMEM_VMEMMAP=y case).
795 * a) section was present at memory init.
796 * b) section was hot-added post memory init.
797 * 2. deactivation of a complete hot-added section.
798 * 3. deactivation of a complete section from memory init.
799 *
800 * For 1, when subsection_map does not empty we will not be freeing the
801 * usage map, but still need to free the vmemmap range.
802 *
803 * For 2 and 3, the SPARSEMEM_VMEMMAP={y,n} cases are unified
804 */
805static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
806 struct vmem_altmap *altmap)
807{
808 struct mem_section *ms = __pfn_to_section(pfn);
809 bool section_is_early = early_section(ms);
810 struct page *memmap = NULL;
811 bool empty;
812
813 if (clear_subsection_map(pfn, nr_pages))
814 return;
815
816 empty = is_subsection_map_empty(ms);
817 if (empty) {
818 unsigned long section_nr = pfn_to_section_nr(pfn);
819
820 /*
821 * When removing an early section, the usage map is kept (as the
822 * usage maps of other sections fall into the same page). It
823 * will be re-used when re-adding the section - which is then no
824 * longer an early section. If the usage map is PageReserved, it
825 * was allocated during boot.
826 */
827 if (!PageReserved(virt_to_page(ms->usage))) {
828 kfree(ms->usage);
829 ms->usage = NULL;
830 }
831 memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
832 /*
833 * Mark the section invalid so that valid_section()
834 * return false. This prevents code from dereferencing
835 * ms->usage array.
836 */
837 ms->section_mem_map &= ~SECTION_HAS_MEM_MAP;
838 }
839
840 /*
841 * The memmap of early sections is always fully populated. See
842 * section_activate() and pfn_valid() .
843 */
844 if (!section_is_early)
845 depopulate_section_memmap(pfn, nr_pages, altmap);
846 else if (memmap)
847 free_map_bootmem(memmap);
848
849 if (empty)
850 ms->section_mem_map = (unsigned long)NULL;
851}
852
853static struct page * __meminit section_activate(int nid, unsigned long pfn,
854 unsigned long nr_pages, struct vmem_altmap *altmap)
855{
856 struct mem_section *ms = __pfn_to_section(pfn);
857 struct mem_section_usage *usage = NULL;
858 struct page *memmap;
859 int rc = 0;
860
861 if (!ms->usage) {
862 usage = kzalloc(mem_section_usage_size(), GFP_KERNEL);
863 if (!usage)
864 return ERR_PTR(-ENOMEM);
865 ms->usage = usage;
866 }
867
868 rc = fill_subsection_map(pfn, nr_pages);
869 if (rc) {
870 if (usage)
871 ms->usage = NULL;
872 kfree(usage);
873 return ERR_PTR(rc);
874 }
875
876 /*
877 * The early init code does not consider partially populated
878 * initial sections, it simply assumes that memory will never be
879 * referenced. If we hot-add memory into such a section then we
880 * do not need to populate the memmap and can simply reuse what
881 * is already there.
882 */
883 if (nr_pages < PAGES_PER_SECTION && early_section(ms))
884 return pfn_to_page(pfn);
885
886 memmap = populate_section_memmap(pfn, nr_pages, nid, altmap);
887 if (!memmap) {
888 section_deactivate(pfn, nr_pages, altmap);
889 return ERR_PTR(-ENOMEM);
890 }
891
892 return memmap;
893}
894
895/**
896 * sparse_add_section - add a memory section, or populate an existing one
897 * @nid: The node to add section on
898 * @start_pfn: start pfn of the memory range
899 * @nr_pages: number of pfns to add in the section
900 * @altmap: device page map
901 *
902 * This is only intended for hotplug.
903 *
904 * Note that only VMEMMAP supports sub-section aligned hotplug,
905 * the proper alignment and size are gated by check_pfn_span().
906 *
907 *
908 * Return:
909 * * 0 - On success.
910 * * -EEXIST - Section has been present.
911 * * -ENOMEM - Out of memory.
912 */
913int __meminit sparse_add_section(int nid, unsigned long start_pfn,
914 unsigned long nr_pages, struct vmem_altmap *altmap)
915{
916 unsigned long section_nr = pfn_to_section_nr(start_pfn);
917 struct mem_section *ms;
918 struct page *memmap;
919 int ret;
920
921 ret = sparse_index_init(section_nr, nid);
922 if (ret < 0)
923 return ret;
924
925 memmap = section_activate(nid, start_pfn, nr_pages, altmap);
926 if (IS_ERR(memmap))
927 return PTR_ERR(memmap);
928
929 /*
930 * Poison uninitialized struct pages in order to catch invalid flags
931 * combinations.
932 */
933 page_init_poison(memmap, sizeof(struct page) * nr_pages);
934
935 ms = __nr_to_section(section_nr);
936 set_section_nid(section_nr, nid);
937 section_mark_present(ms);
938
939 /* Align memmap to section boundary in the subsection case */
940 if (section_nr_to_pfn(section_nr) != start_pfn)
941 memmap = pfn_to_page(section_nr_to_pfn(section_nr));
942 sparse_init_one_section(ms, section_nr, memmap, ms->usage, 0);
943
944 return 0;
945}
946
947#ifdef CONFIG_MEMORY_FAILURE
948static void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
949{
950 int i;
951
952 /*
953 * A further optimization is to have per section refcounted
954 * num_poisoned_pages. But that would need more space per memmap, so
955 * for now just do a quick global check to speed up this routine in the
956 * absence of bad pages.
957 */
958 if (atomic_long_read(&num_poisoned_pages) == 0)
959 return;
960
961 for (i = 0; i < nr_pages; i++) {
962 if (PageHWPoison(&memmap[i])) {
963 num_poisoned_pages_dec();
964 ClearPageHWPoison(&memmap[i]);
965 }
966 }
967}
968#else
969static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
970{
971}
972#endif
973
974void sparse_remove_section(struct mem_section *ms, unsigned long pfn,
975 unsigned long nr_pages, unsigned long map_offset,
976 struct vmem_altmap *altmap)
977{
978 clear_hwpoisoned_pages(pfn_to_page(pfn) + map_offset,
979 nr_pages - map_offset);
980 section_deactivate(pfn, nr_pages, altmap);
981}
982#endif /* CONFIG_MEMORY_HOTPLUG */
1/*
2 * sparse memory mappings.
3 */
4#include <linux/mm.h>
5#include <linux/slab.h>
6#include <linux/mmzone.h>
7#include <linux/bootmem.h>
8#include <linux/compiler.h>
9#include <linux/highmem.h>
10#include <linux/export.h>
11#include <linux/spinlock.h>
12#include <linux/vmalloc.h>
13
14#include "internal.h"
15#include <asm/dma.h>
16#include <asm/pgalloc.h>
17#include <asm/pgtable.h>
18
19/*
20 * Permanent SPARSEMEM data:
21 *
22 * 1) mem_section - memory sections, mem_map's for valid memory
23 */
24#ifdef CONFIG_SPARSEMEM_EXTREME
25struct mem_section *mem_section[NR_SECTION_ROOTS]
26 ____cacheline_internodealigned_in_smp;
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 if (node_state(nid, N_HIGH_MEMORY))
70 section = kzalloc_node(array_size, GFP_KERNEL, nid);
71 else
72 section = kzalloc(array_size, GFP_KERNEL);
73 } else {
74 section = memblock_virt_alloc_node(array_size, nid);
75 }
76
77 return section;
78}
79
80static int __meminit sparse_index_init(unsigned long section_nr, int nid)
81{
82 unsigned long root = SECTION_NR_TO_ROOT(section_nr);
83 struct mem_section *section;
84
85 if (mem_section[root])
86 return -EEXIST;
87
88 section = sparse_index_alloc(nid);
89 if (!section)
90 return -ENOMEM;
91
92 mem_section[root] = section;
93
94 return 0;
95}
96#else /* !SPARSEMEM_EXTREME */
97static inline int sparse_index_init(unsigned long section_nr, int nid)
98{
99 return 0;
100}
101#endif
102
103#ifdef CONFIG_SPARSEMEM_EXTREME
104int __section_nr(struct mem_section* ms)
105{
106 unsigned long root_nr;
107 struct mem_section* root;
108
109 for (root_nr = 0; root_nr < NR_SECTION_ROOTS; root_nr++) {
110 root = __nr_to_section(root_nr * SECTIONS_PER_ROOT);
111 if (!root)
112 continue;
113
114 if ((ms >= root) && (ms < (root + SECTIONS_PER_ROOT)))
115 break;
116 }
117
118 VM_BUG_ON(root_nr == NR_SECTION_ROOTS);
119
120 return (root_nr * SECTIONS_PER_ROOT) + (ms - root);
121}
122#else
123int __section_nr(struct mem_section* ms)
124{
125 return (int)(ms - mem_section[0]);
126}
127#endif
128
129/*
130 * During early boot, before section_mem_map is used for an actual
131 * mem_map, we use section_mem_map to store the section's NUMA
132 * node. This keeps us from having to use another data structure. The
133 * node information is cleared just before we store the real mem_map.
134 */
135static inline unsigned long sparse_encode_early_nid(int nid)
136{
137 return (nid << SECTION_NID_SHIFT);
138}
139
140static inline int sparse_early_nid(struct mem_section *section)
141{
142 return (section->section_mem_map >> SECTION_NID_SHIFT);
143}
144
145/* Validate the physical addressing limitations of the model */
146void __meminit mminit_validate_memmodel_limits(unsigned long *start_pfn,
147 unsigned long *end_pfn)
148{
149 unsigned long max_sparsemem_pfn = 1UL << (MAX_PHYSMEM_BITS-PAGE_SHIFT);
150
151 /*
152 * Sanity checks - do not allow an architecture to pass
153 * in larger pfns than the maximum scope of sparsemem:
154 */
155 if (*start_pfn > max_sparsemem_pfn) {
156 mminit_dprintk(MMINIT_WARNING, "pfnvalidation",
157 "Start of range %lu -> %lu exceeds SPARSEMEM max %lu\n",
158 *start_pfn, *end_pfn, max_sparsemem_pfn);
159 WARN_ON_ONCE(1);
160 *start_pfn = max_sparsemem_pfn;
161 *end_pfn = max_sparsemem_pfn;
162 } else if (*end_pfn > max_sparsemem_pfn) {
163 mminit_dprintk(MMINIT_WARNING, "pfnvalidation",
164 "End of range %lu -> %lu exceeds SPARSEMEM max %lu\n",
165 *start_pfn, *end_pfn, max_sparsemem_pfn);
166 WARN_ON_ONCE(1);
167 *end_pfn = max_sparsemem_pfn;
168 }
169}
170
171/* Record a memory area against a node. */
172void __init memory_present(int nid, unsigned long start, unsigned long end)
173{
174 unsigned long pfn;
175
176 start &= PAGE_SECTION_MASK;
177 mminit_validate_memmodel_limits(&start, &end);
178 for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
179 unsigned long section = pfn_to_section_nr(pfn);
180 struct mem_section *ms;
181
182 sparse_index_init(section, nid);
183 set_section_nid(section, nid);
184
185 ms = __nr_to_section(section);
186 if (!ms->section_mem_map)
187 ms->section_mem_map = sparse_encode_early_nid(nid) |
188 SECTION_MARKED_PRESENT;
189 }
190}
191
192/*
193 * Only used by the i386 NUMA architecures, but relatively
194 * generic code.
195 */
196unsigned long __init node_memmap_size_bytes(int nid, unsigned long start_pfn,
197 unsigned long end_pfn)
198{
199 unsigned long pfn;
200 unsigned long nr_pages = 0;
201
202 mminit_validate_memmodel_limits(&start_pfn, &end_pfn);
203 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
204 if (nid != early_pfn_to_nid(pfn))
205 continue;
206
207 if (pfn_present(pfn))
208 nr_pages += PAGES_PER_SECTION;
209 }
210
211 return nr_pages * sizeof(struct page);
212}
213
214/*
215 * Subtle, we encode the real pfn into the mem_map such that
216 * the identity pfn - section_mem_map will return the actual
217 * physical page frame number.
218 */
219static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long pnum)
220{
221 return (unsigned long)(mem_map - (section_nr_to_pfn(pnum)));
222}
223
224/*
225 * Decode mem_map from the coded memmap
226 */
227struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum)
228{
229 /* mask off the extra low bits of information */
230 coded_mem_map &= SECTION_MAP_MASK;
231 return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum);
232}
233
234static int __meminit sparse_init_one_section(struct mem_section *ms,
235 unsigned long pnum, struct page *mem_map,
236 unsigned long *pageblock_bitmap)
237{
238 if (!present_section(ms))
239 return -EINVAL;
240
241 ms->section_mem_map &= ~SECTION_MAP_MASK;
242 ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) |
243 SECTION_HAS_MEM_MAP;
244 ms->pageblock_flags = pageblock_bitmap;
245
246 return 1;
247}
248
249unsigned long usemap_size(void)
250{
251 unsigned long size_bytes;
252 size_bytes = roundup(SECTION_BLOCKFLAGS_BITS, 8) / 8;
253 size_bytes = roundup(size_bytes, sizeof(unsigned long));
254 return size_bytes;
255}
256
257#ifdef CONFIG_MEMORY_HOTPLUG
258static unsigned long *__kmalloc_section_usemap(void)
259{
260 return kmalloc(usemap_size(), GFP_KERNEL);
261}
262#endif /* CONFIG_MEMORY_HOTPLUG */
263
264#ifdef CONFIG_MEMORY_HOTREMOVE
265static unsigned long * __init
266sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
267 unsigned long size)
268{
269 unsigned long goal, limit;
270 unsigned long *p;
271 int nid;
272 /*
273 * A page may contain usemaps for other sections preventing the
274 * page being freed and making a section unremovable while
275 * other sections referencing the usemap remain active. Similarly,
276 * a pgdat can prevent a section being removed. If section A
277 * contains a pgdat and section B contains the usemap, both
278 * sections become inter-dependent. This allocates usemaps
279 * from the same section as the pgdat where possible to avoid
280 * this problem.
281 */
282 goal = __pa(pgdat) & (PAGE_SECTION_MASK << PAGE_SHIFT);
283 limit = goal + (1UL << PA_SECTION_SHIFT);
284 nid = early_pfn_to_nid(goal >> PAGE_SHIFT);
285again:
286 p = memblock_virt_alloc_try_nid_nopanic(size,
287 SMP_CACHE_BYTES, goal, limit,
288 nid);
289 if (!p && limit) {
290 limit = 0;
291 goto again;
292 }
293 return p;
294}
295
296static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
297{
298 unsigned long usemap_snr, pgdat_snr;
299 static unsigned long old_usemap_snr = NR_MEM_SECTIONS;
300 static unsigned long old_pgdat_snr = NR_MEM_SECTIONS;
301 struct pglist_data *pgdat = NODE_DATA(nid);
302 int usemap_nid;
303
304 usemap_snr = pfn_to_section_nr(__pa(usemap) >> PAGE_SHIFT);
305 pgdat_snr = pfn_to_section_nr(__pa(pgdat) >> PAGE_SHIFT);
306 if (usemap_snr == pgdat_snr)
307 return;
308
309 if (old_usemap_snr == usemap_snr && old_pgdat_snr == pgdat_snr)
310 /* skip redundant message */
311 return;
312
313 old_usemap_snr = usemap_snr;
314 old_pgdat_snr = pgdat_snr;
315
316 usemap_nid = sparse_early_nid(__nr_to_section(usemap_snr));
317 if (usemap_nid != nid) {
318 pr_info("node %d must be removed before remove section %ld\n",
319 nid, usemap_snr);
320 return;
321 }
322 /*
323 * There is a circular dependency.
324 * Some platforms allow un-removable section because they will just
325 * gather other removable sections for dynamic partitioning.
326 * Just notify un-removable section's number here.
327 */
328 pr_info("Section %ld and %ld (node %d) have a circular dependency on usemap and pgdat allocations\n",
329 usemap_snr, pgdat_snr, nid);
330}
331#else
332static unsigned long * __init
333sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
334 unsigned long size)
335{
336 return memblock_virt_alloc_node_nopanic(size, pgdat->node_id);
337}
338
339static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
340{
341}
342#endif /* CONFIG_MEMORY_HOTREMOVE */
343
344static void __init sparse_early_usemaps_alloc_node(void *data,
345 unsigned long pnum_begin,
346 unsigned long pnum_end,
347 unsigned long usemap_count, int nodeid)
348{
349 void *usemap;
350 unsigned long pnum;
351 unsigned long **usemap_map = (unsigned long **)data;
352 int size = usemap_size();
353
354 usemap = sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nodeid),
355 size * usemap_count);
356 if (!usemap) {
357 pr_warn("%s: allocation failed\n", __func__);
358 return;
359 }
360
361 for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
362 if (!present_section_nr(pnum))
363 continue;
364 usemap_map[pnum] = usemap;
365 usemap += size;
366 check_usemap_section_nr(nodeid, usemap_map[pnum]);
367 }
368}
369
370#ifndef CONFIG_SPARSEMEM_VMEMMAP
371struct page __init *sparse_mem_map_populate(unsigned long pnum, int nid)
372{
373 struct page *map;
374 unsigned long size;
375
376 map = alloc_remap(nid, sizeof(struct page) * PAGES_PER_SECTION);
377 if (map)
378 return map;
379
380 size = PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
381 map = memblock_virt_alloc_try_nid(size,
382 PAGE_SIZE, __pa(MAX_DMA_ADDRESS),
383 BOOTMEM_ALLOC_ACCESSIBLE, nid);
384 return map;
385}
386void __init sparse_mem_maps_populate_node(struct page **map_map,
387 unsigned long pnum_begin,
388 unsigned long pnum_end,
389 unsigned long map_count, int nodeid)
390{
391 void *map;
392 unsigned long pnum;
393 unsigned long size = sizeof(struct page) * PAGES_PER_SECTION;
394
395 map = alloc_remap(nodeid, size * map_count);
396 if (map) {
397 for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
398 if (!present_section_nr(pnum))
399 continue;
400 map_map[pnum] = map;
401 map += size;
402 }
403 return;
404 }
405
406 size = PAGE_ALIGN(size);
407 map = memblock_virt_alloc_try_nid(size * map_count,
408 PAGE_SIZE, __pa(MAX_DMA_ADDRESS),
409 BOOTMEM_ALLOC_ACCESSIBLE, nodeid);
410 if (map) {
411 for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
412 if (!present_section_nr(pnum))
413 continue;
414 map_map[pnum] = map;
415 map += size;
416 }
417 return;
418 }
419
420 /* fallback */
421 for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
422 struct mem_section *ms;
423
424 if (!present_section_nr(pnum))
425 continue;
426 map_map[pnum] = sparse_mem_map_populate(pnum, nodeid);
427 if (map_map[pnum])
428 continue;
429 ms = __nr_to_section(pnum);
430 pr_err("%s: sparsemem memory map backing failed some memory will not be available\n",
431 __func__);
432 ms->section_mem_map = 0;
433 }
434}
435#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
436
437#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
438static void __init sparse_early_mem_maps_alloc_node(void *data,
439 unsigned long pnum_begin,
440 unsigned long pnum_end,
441 unsigned long map_count, int nodeid)
442{
443 struct page **map_map = (struct page **)data;
444 sparse_mem_maps_populate_node(map_map, pnum_begin, pnum_end,
445 map_count, nodeid);
446}
447#else
448static struct page __init *sparse_early_mem_map_alloc(unsigned long pnum)
449{
450 struct page *map;
451 struct mem_section *ms = __nr_to_section(pnum);
452 int nid = sparse_early_nid(ms);
453
454 map = sparse_mem_map_populate(pnum, nid);
455 if (map)
456 return map;
457
458 pr_err("%s: sparsemem memory map backing failed some memory will not be available\n",
459 __func__);
460 ms->section_mem_map = 0;
461 return NULL;
462}
463#endif
464
465void __weak __meminit vmemmap_populate_print_last(void)
466{
467}
468
469/**
470 * alloc_usemap_and_memmap - memory alloction for pageblock flags and vmemmap
471 * @map: usemap_map for pageblock flags or mmap_map for vmemmap
472 */
473static void __init alloc_usemap_and_memmap(void (*alloc_func)
474 (void *, unsigned long, unsigned long,
475 unsigned long, int), void *data)
476{
477 unsigned long pnum;
478 unsigned long map_count;
479 int nodeid_begin = 0;
480 unsigned long pnum_begin = 0;
481
482 for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
483 struct mem_section *ms;
484
485 if (!present_section_nr(pnum))
486 continue;
487 ms = __nr_to_section(pnum);
488 nodeid_begin = sparse_early_nid(ms);
489 pnum_begin = pnum;
490 break;
491 }
492 map_count = 1;
493 for (pnum = pnum_begin + 1; pnum < NR_MEM_SECTIONS; pnum++) {
494 struct mem_section *ms;
495 int nodeid;
496
497 if (!present_section_nr(pnum))
498 continue;
499 ms = __nr_to_section(pnum);
500 nodeid = sparse_early_nid(ms);
501 if (nodeid == nodeid_begin) {
502 map_count++;
503 continue;
504 }
505 /* ok, we need to take cake of from pnum_begin to pnum - 1*/
506 alloc_func(data, pnum_begin, pnum,
507 map_count, nodeid_begin);
508 /* new start, update count etc*/
509 nodeid_begin = nodeid;
510 pnum_begin = pnum;
511 map_count = 1;
512 }
513 /* ok, last chunk */
514 alloc_func(data, pnum_begin, NR_MEM_SECTIONS,
515 map_count, nodeid_begin);
516}
517
518/*
519 * Allocate the accumulated non-linear sections, allocate a mem_map
520 * for each and record the physical to section mapping.
521 */
522void __init sparse_init(void)
523{
524 unsigned long pnum;
525 struct page *map;
526 unsigned long *usemap;
527 unsigned long **usemap_map;
528 int size;
529#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
530 int size2;
531 struct page **map_map;
532#endif
533
534 /* see include/linux/mmzone.h 'struct mem_section' definition */
535 BUILD_BUG_ON(!is_power_of_2(sizeof(struct mem_section)));
536
537 /* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */
538 set_pageblock_order();
539
540 /*
541 * map is using big page (aka 2M in x86 64 bit)
542 * usemap is less one page (aka 24 bytes)
543 * so alloc 2M (with 2M align) and 24 bytes in turn will
544 * make next 2M slip to one more 2M later.
545 * then in big system, the memory will have a lot of holes...
546 * here try to allocate 2M pages continuously.
547 *
548 * powerpc need to call sparse_init_one_section right after each
549 * sparse_early_mem_map_alloc, so allocate usemap_map at first.
550 */
551 size = sizeof(unsigned long *) * NR_MEM_SECTIONS;
552 usemap_map = memblock_virt_alloc(size, 0);
553 if (!usemap_map)
554 panic("can not allocate usemap_map\n");
555 alloc_usemap_and_memmap(sparse_early_usemaps_alloc_node,
556 (void *)usemap_map);
557
558#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
559 size2 = sizeof(struct page *) * NR_MEM_SECTIONS;
560 map_map = memblock_virt_alloc(size2, 0);
561 if (!map_map)
562 panic("can not allocate map_map\n");
563 alloc_usemap_and_memmap(sparse_early_mem_maps_alloc_node,
564 (void *)map_map);
565#endif
566
567 for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
568 if (!present_section_nr(pnum))
569 continue;
570
571 usemap = usemap_map[pnum];
572 if (!usemap)
573 continue;
574
575#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
576 map = map_map[pnum];
577#else
578 map = sparse_early_mem_map_alloc(pnum);
579#endif
580 if (!map)
581 continue;
582
583 sparse_init_one_section(__nr_to_section(pnum), pnum, map,
584 usemap);
585 }
586
587 vmemmap_populate_print_last();
588
589#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
590 memblock_free_early(__pa(map_map), size2);
591#endif
592 memblock_free_early(__pa(usemap_map), size);
593}
594
595#ifdef CONFIG_MEMORY_HOTPLUG
596#ifdef CONFIG_SPARSEMEM_VMEMMAP
597static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid)
598{
599 /* This will make the necessary allocations eventually. */
600 return sparse_mem_map_populate(pnum, nid);
601}
602static void __kfree_section_memmap(struct page *memmap)
603{
604 unsigned long start = (unsigned long)memmap;
605 unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION);
606
607 vmemmap_free(start, end);
608}
609#ifdef CONFIG_MEMORY_HOTREMOVE
610static void free_map_bootmem(struct page *memmap)
611{
612 unsigned long start = (unsigned long)memmap;
613 unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION);
614
615 vmemmap_free(start, end);
616}
617#endif /* CONFIG_MEMORY_HOTREMOVE */
618#else
619static struct page *__kmalloc_section_memmap(void)
620{
621 struct page *page, *ret;
622 unsigned long memmap_size = sizeof(struct page) * PAGES_PER_SECTION;
623
624 page = alloc_pages(GFP_KERNEL|__GFP_NOWARN, get_order(memmap_size));
625 if (page)
626 goto got_map_page;
627
628 ret = vmalloc(memmap_size);
629 if (ret)
630 goto got_map_ptr;
631
632 return NULL;
633got_map_page:
634 ret = (struct page *)pfn_to_kaddr(page_to_pfn(page));
635got_map_ptr:
636
637 return ret;
638}
639
640static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid)
641{
642 return __kmalloc_section_memmap();
643}
644
645static void __kfree_section_memmap(struct page *memmap)
646{
647 if (is_vmalloc_addr(memmap))
648 vfree(memmap);
649 else
650 free_pages((unsigned long)memmap,
651 get_order(sizeof(struct page) * PAGES_PER_SECTION));
652}
653
654#ifdef CONFIG_MEMORY_HOTREMOVE
655static void free_map_bootmem(struct page *memmap)
656{
657 unsigned long maps_section_nr, removing_section_nr, i;
658 unsigned long magic, nr_pages;
659 struct page *page = virt_to_page(memmap);
660
661 nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
662 >> PAGE_SHIFT;
663
664 for (i = 0; i < nr_pages; i++, page++) {
665 magic = (unsigned long) page->lru.next;
666
667 BUG_ON(magic == NODE_INFO);
668
669 maps_section_nr = pfn_to_section_nr(page_to_pfn(page));
670 removing_section_nr = page->private;
671
672 /*
673 * When this function is called, the removing section is
674 * logical offlined state. This means all pages are isolated
675 * from page allocator. If removing section's memmap is placed
676 * on the same section, it must not be freed.
677 * If it is freed, page allocator may allocate it which will
678 * be removed physically soon.
679 */
680 if (maps_section_nr != removing_section_nr)
681 put_page_bootmem(page);
682 }
683}
684#endif /* CONFIG_MEMORY_HOTREMOVE */
685#endif /* CONFIG_SPARSEMEM_VMEMMAP */
686
687/*
688 * returns the number of sections whose mem_maps were properly
689 * set. If this is <=0, then that means that the passed-in
690 * map was not consumed and must be freed.
691 */
692int __meminit sparse_add_one_section(struct zone *zone, unsigned long start_pfn)
693{
694 unsigned long section_nr = pfn_to_section_nr(start_pfn);
695 struct pglist_data *pgdat = zone->zone_pgdat;
696 struct mem_section *ms;
697 struct page *memmap;
698 unsigned long *usemap;
699 unsigned long flags;
700 int ret;
701
702 /*
703 * no locking for this, because it does its own
704 * plus, it does a kmalloc
705 */
706 ret = sparse_index_init(section_nr, pgdat->node_id);
707 if (ret < 0 && ret != -EEXIST)
708 return ret;
709 memmap = kmalloc_section_memmap(section_nr, pgdat->node_id);
710 if (!memmap)
711 return -ENOMEM;
712 usemap = __kmalloc_section_usemap();
713 if (!usemap) {
714 __kfree_section_memmap(memmap);
715 return -ENOMEM;
716 }
717
718 pgdat_resize_lock(pgdat, &flags);
719
720 ms = __pfn_to_section(start_pfn);
721 if (ms->section_mem_map & SECTION_MARKED_PRESENT) {
722 ret = -EEXIST;
723 goto out;
724 }
725
726 memset(memmap, 0, sizeof(struct page) * PAGES_PER_SECTION);
727
728 ms->section_mem_map |= SECTION_MARKED_PRESENT;
729
730 ret = sparse_init_one_section(ms, section_nr, memmap, usemap);
731
732out:
733 pgdat_resize_unlock(pgdat, &flags);
734 if (ret <= 0) {
735 kfree(usemap);
736 __kfree_section_memmap(memmap);
737 }
738 return ret;
739}
740
741#ifdef CONFIG_MEMORY_HOTREMOVE
742#ifdef CONFIG_MEMORY_FAILURE
743static void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
744{
745 int i;
746
747 if (!memmap)
748 return;
749
750 for (i = 0; i < nr_pages; i++) {
751 if (PageHWPoison(&memmap[i])) {
752 atomic_long_sub(1, &num_poisoned_pages);
753 ClearPageHWPoison(&memmap[i]);
754 }
755 }
756}
757#else
758static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
759{
760}
761#endif
762
763static void free_section_usemap(struct page *memmap, unsigned long *usemap)
764{
765 struct page *usemap_page;
766
767 if (!usemap)
768 return;
769
770 usemap_page = virt_to_page(usemap);
771 /*
772 * Check to see if allocation came from hot-plug-add
773 */
774 if (PageSlab(usemap_page) || PageCompound(usemap_page)) {
775 kfree(usemap);
776 if (memmap)
777 __kfree_section_memmap(memmap);
778 return;
779 }
780
781 /*
782 * The usemap came from bootmem. This is packed with other usemaps
783 * on the section which has pgdat at boot time. Just keep it as is now.
784 */
785
786 if (memmap)
787 free_map_bootmem(memmap);
788}
789
790void sparse_remove_one_section(struct zone *zone, struct mem_section *ms,
791 unsigned long map_offset)
792{
793 struct page *memmap = NULL;
794 unsigned long *usemap = NULL, flags;
795 struct pglist_data *pgdat = zone->zone_pgdat;
796
797 pgdat_resize_lock(pgdat, &flags);
798 if (ms->section_mem_map) {
799 usemap = ms->pageblock_flags;
800 memmap = sparse_decode_mem_map(ms->section_mem_map,
801 __section_nr(ms));
802 ms->section_mem_map = 0;
803 ms->pageblock_flags = NULL;
804 }
805 pgdat_resize_unlock(pgdat, &flags);
806
807 clear_hwpoisoned_pages(memmap + map_offset,
808 PAGES_PER_SECTION - map_offset);
809 free_section_usemap(memmap, usemap);
810}
811#endif /* CONFIG_MEMORY_HOTREMOVE */
812#endif /* CONFIG_MEMORY_HOTPLUG */