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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 = 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 = pfn_to_section_nr(pfn + nr_pages - 1);
196 unsigned long nr, start_sec = pfn_to_section_nr(pfn);
197
198 if (!nr_pages)
199 return;
200
201 for (nr = start_sec; nr <= end_sec; nr++) {
202 struct mem_section *ms;
203 unsigned long pfns;
204
205 pfns = min(nr_pages, PAGES_PER_SECTION
206 - (pfn & ~PAGE_SECTION_MASK));
207 ms = __nr_to_section(nr);
208 subsection_mask_set(ms->usage->subsection_map, pfn, pfns);
209
210 pr_debug("%s: sec: %lu pfns: %lu set(%d, %d)\n", __func__, nr,
211 pfns, subsection_map_index(pfn),
212 subsection_map_index(pfn + pfns - 1));
213
214 pfn += pfns;
215 nr_pages -= pfns;
216 }
217}
218#else
219void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages)
220{
221}
222#endif
223
224/* Record a memory area against a node. */
225static void __init memory_present(int nid, unsigned long start, unsigned long end)
226{
227 unsigned long pfn;
228
229#ifdef CONFIG_SPARSEMEM_EXTREME
230 if (unlikely(!mem_section)) {
231 unsigned long size, align;
232
233 size = sizeof(struct mem_section *) * NR_SECTION_ROOTS;
234 align = 1 << (INTERNODE_CACHE_SHIFT);
235 mem_section = memblock_alloc(size, align);
236 if (!mem_section)
237 panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
238 __func__, size, align);
239 }
240#endif
241
242 start &= PAGE_SECTION_MASK;
243 mminit_validate_memmodel_limits(&start, &end);
244 for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
245 unsigned long section = pfn_to_section_nr(pfn);
246 struct mem_section *ms;
247
248 sparse_index_init(section, nid);
249 set_section_nid(section, nid);
250
251 ms = __nr_to_section(section);
252 if (!ms->section_mem_map) {
253 ms->section_mem_map = sparse_encode_early_nid(nid) |
254 SECTION_IS_ONLINE;
255 __section_mark_present(ms, section);
256 }
257 }
258}
259
260/*
261 * Mark all memblocks as present using memory_present().
262 * This is a convenience function that is useful to mark all of the systems
263 * memory as present during initialization.
264 */
265static void __init memblocks_present(void)
266{
267 unsigned long start, end;
268 int i, nid;
269
270 for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid)
271 memory_present(nid, start, end);
272}
273
274/*
275 * Subtle, we encode the real pfn into the mem_map such that
276 * the identity pfn - section_mem_map will return the actual
277 * physical page frame number.
278 */
279static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long pnum)
280{
281 unsigned long coded_mem_map =
282 (unsigned long)(mem_map - (section_nr_to_pfn(pnum)));
283 BUILD_BUG_ON(SECTION_MAP_LAST_BIT > PFN_SECTION_SHIFT);
284 BUG_ON(coded_mem_map & ~SECTION_MAP_MASK);
285 return coded_mem_map;
286}
287
288#ifdef CONFIG_MEMORY_HOTPLUG
289/*
290 * Decode mem_map from the coded memmap
291 */
292struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum)
293{
294 /* mask off the extra low bits of information */
295 coded_mem_map &= SECTION_MAP_MASK;
296 return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum);
297}
298#endif /* CONFIG_MEMORY_HOTPLUG */
299
300static void __meminit sparse_init_one_section(struct mem_section *ms,
301 unsigned long pnum, struct page *mem_map,
302 struct mem_section_usage *usage, unsigned long flags)
303{
304 ms->section_mem_map &= ~SECTION_MAP_MASK;
305 ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum)
306 | SECTION_HAS_MEM_MAP | flags;
307 ms->usage = usage;
308}
309
310static unsigned long usemap_size(void)
311{
312 return BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS) * sizeof(unsigned long);
313}
314
315size_t mem_section_usage_size(void)
316{
317 return sizeof(struct mem_section_usage) + usemap_size();
318}
319
320#ifdef CONFIG_MEMORY_HOTREMOVE
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
331static struct mem_section_usage * __init
332sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
333 unsigned long size)
334{
335 struct mem_section_usage *usage;
336 unsigned long goal, limit;
337 int nid;
338 /*
339 * A page may contain usemaps for other sections preventing the
340 * page being freed and making a section unremovable while
341 * other sections referencing the usemap remain active. Similarly,
342 * a pgdat can prevent a section being removed. If section A
343 * contains a pgdat and section B contains the usemap, both
344 * sections become inter-dependent. This allocates usemaps
345 * from the same section as the pgdat where possible to avoid
346 * this problem.
347 */
348 goal = pgdat_to_phys(pgdat) & (PAGE_SECTION_MASK << PAGE_SHIFT);
349 limit = goal + (1UL << PA_SECTION_SHIFT);
350 nid = early_pfn_to_nid(goal >> PAGE_SHIFT);
351again:
352 usage = memblock_alloc_try_nid(size, SMP_CACHE_BYTES, goal, limit, nid);
353 if (!usage && limit) {
354 limit = 0;
355 goto again;
356 }
357 return usage;
358}
359
360static void __init check_usemap_section_nr(int nid,
361 struct mem_section_usage *usage)
362{
363 unsigned long usemap_snr, pgdat_snr;
364 static unsigned long old_usemap_snr;
365 static unsigned long old_pgdat_snr;
366 struct pglist_data *pgdat = NODE_DATA(nid);
367 int usemap_nid;
368
369 /* First call */
370 if (!old_usemap_snr) {
371 old_usemap_snr = NR_MEM_SECTIONS;
372 old_pgdat_snr = NR_MEM_SECTIONS;
373 }
374
375 usemap_snr = pfn_to_section_nr(__pa(usage) >> PAGE_SHIFT);
376 pgdat_snr = pfn_to_section_nr(pgdat_to_phys(pgdat) >> PAGE_SHIFT);
377 if (usemap_snr == pgdat_snr)
378 return;
379
380 if (old_usemap_snr == usemap_snr && old_pgdat_snr == pgdat_snr)
381 /* skip redundant message */
382 return;
383
384 old_usemap_snr = usemap_snr;
385 old_pgdat_snr = pgdat_snr;
386
387 usemap_nid = sparse_early_nid(__nr_to_section(usemap_snr));
388 if (usemap_nid != nid) {
389 pr_info("node %d must be removed before remove section %ld\n",
390 nid, usemap_snr);
391 return;
392 }
393 /*
394 * There is a circular dependency.
395 * Some platforms allow un-removable section because they will just
396 * gather other removable sections for dynamic partitioning.
397 * Just notify un-removable section's number here.
398 */
399 pr_info("Section %ld and %ld (node %d) have a circular dependency on usemap and pgdat allocations\n",
400 usemap_snr, pgdat_snr, nid);
401}
402#else
403static struct mem_section_usage * __init
404sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
405 unsigned long size)
406{
407 return memblock_alloc_node(size, SMP_CACHE_BYTES, pgdat->node_id);
408}
409
410static void __init check_usemap_section_nr(int nid,
411 struct mem_section_usage *usage)
412{
413}
414#endif /* CONFIG_MEMORY_HOTREMOVE */
415
416#ifdef CONFIG_SPARSEMEM_VMEMMAP
417static unsigned long __init section_map_size(void)
418{
419 return ALIGN(sizeof(struct page) * PAGES_PER_SECTION, PMD_SIZE);
420}
421
422#else
423static unsigned long __init section_map_size(void)
424{
425 return PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
426}
427
428struct page __init *__populate_section_memmap(unsigned long pfn,
429 unsigned long nr_pages, int nid, struct vmem_altmap *altmap,
430 struct dev_pagemap *pgmap)
431{
432 unsigned long size = section_map_size();
433 struct page *map = sparse_buffer_alloc(size);
434 phys_addr_t addr = __pa(MAX_DMA_ADDRESS);
435
436 if (map)
437 return map;
438
439 map = memmap_alloc(size, size, addr, nid, false);
440 if (!map)
441 panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d from=%pa\n",
442 __func__, size, PAGE_SIZE, nid, &addr);
443
444 return map;
445}
446#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
447
448static void *sparsemap_buf __meminitdata;
449static void *sparsemap_buf_end __meminitdata;
450
451static inline void __meminit sparse_buffer_free(unsigned long size)
452{
453 WARN_ON(!sparsemap_buf || size == 0);
454 memblock_free(sparsemap_buf, size);
455}
456
457static void __init sparse_buffer_init(unsigned long size, int nid)
458{
459 phys_addr_t addr = __pa(MAX_DMA_ADDRESS);
460 WARN_ON(sparsemap_buf); /* forgot to call sparse_buffer_fini()? */
461 /*
462 * Pre-allocated buffer is mainly used by __populate_section_memmap
463 * and we want it to be properly aligned to the section size - this is
464 * especially the case for VMEMMAP which maps memmap to PMDs
465 */
466 sparsemap_buf = memmap_alloc(size, section_map_size(), addr, nid, true);
467 sparsemap_buf_end = sparsemap_buf + size;
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 memblocks_present();
564
565 pnum_begin = first_present_section_nr();
566 nid_begin = sparse_early_nid(__nr_to_section(pnum_begin));
567
568 /* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */
569 set_pageblock_order();
570
571 for_each_present_section_nr(pnum_begin + 1, pnum_end) {
572 int nid = sparse_early_nid(__nr_to_section(pnum_end));
573
574 if (nid == nid_begin) {
575 map_count++;
576 continue;
577 }
578 /* Init node with sections in range [pnum_begin, pnum_end) */
579 sparse_init_nid(nid_begin, pnum_begin, pnum_end, map_count);
580 nid_begin = nid;
581 pnum_begin = pnum_end;
582 map_count = 1;
583 }
584 /* cover the last node */
585 sparse_init_nid(nid_begin, pnum_begin, pnum_end, map_count);
586 vmemmap_populate_print_last();
587}
588
589#ifdef CONFIG_MEMORY_HOTPLUG
590
591/* Mark all memory sections within the pfn range as online */
592void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
593{
594 unsigned long pfn;
595
596 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
597 unsigned long section_nr = pfn_to_section_nr(pfn);
598 struct mem_section *ms;
599
600 /* onlining code should never touch invalid ranges */
601 if (WARN_ON(!valid_section_nr(section_nr)))
602 continue;
603
604 ms = __nr_to_section(section_nr);
605 ms->section_mem_map |= SECTION_IS_ONLINE;
606 }
607}
608
609/* Mark all memory sections within the pfn range as offline */
610void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
611{
612 unsigned long pfn;
613
614 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
615 unsigned long section_nr = pfn_to_section_nr(pfn);
616 struct mem_section *ms;
617
618 /*
619 * TODO this needs some double checking. Offlining code makes
620 * sure to check pfn_valid but those checks might be just bogus
621 */
622 if (WARN_ON(!valid_section_nr(section_nr)))
623 continue;
624
625 ms = __nr_to_section(section_nr);
626 ms->section_mem_map &= ~SECTION_IS_ONLINE;
627 }
628}
629
630#ifdef CONFIG_SPARSEMEM_VMEMMAP
631static struct page * __meminit populate_section_memmap(unsigned long pfn,
632 unsigned long nr_pages, int nid, struct vmem_altmap *altmap,
633 struct dev_pagemap *pgmap)
634{
635 return __populate_section_memmap(pfn, nr_pages, nid, altmap, pgmap);
636}
637
638static void depopulate_section_memmap(unsigned long pfn, unsigned long nr_pages,
639 struct vmem_altmap *altmap)
640{
641 unsigned long start = (unsigned long) pfn_to_page(pfn);
642 unsigned long end = start + nr_pages * sizeof(struct page);
643
644 vmemmap_free(start, end, altmap);
645}
646static void free_map_bootmem(struct page *memmap)
647{
648 unsigned long start = (unsigned long)memmap;
649 unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION);
650
651 vmemmap_free(start, end, NULL);
652}
653
654static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages)
655{
656 DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
657 DECLARE_BITMAP(tmp, SUBSECTIONS_PER_SECTION) = { 0 };
658 struct mem_section *ms = __pfn_to_section(pfn);
659 unsigned long *subsection_map = ms->usage
660 ? &ms->usage->subsection_map[0] : NULL;
661
662 subsection_mask_set(map, pfn, nr_pages);
663 if (subsection_map)
664 bitmap_and(tmp, map, subsection_map, SUBSECTIONS_PER_SECTION);
665
666 if (WARN(!subsection_map || !bitmap_equal(tmp, map, SUBSECTIONS_PER_SECTION),
667 "section already deactivated (%#lx + %ld)\n",
668 pfn, nr_pages))
669 return -EINVAL;
670
671 bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION);
672 return 0;
673}
674
675static bool is_subsection_map_empty(struct mem_section *ms)
676{
677 return bitmap_empty(&ms->usage->subsection_map[0],
678 SUBSECTIONS_PER_SECTION);
679}
680
681static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages)
682{
683 struct mem_section *ms = __pfn_to_section(pfn);
684 DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
685 unsigned long *subsection_map;
686 int rc = 0;
687
688 subsection_mask_set(map, pfn, nr_pages);
689
690 subsection_map = &ms->usage->subsection_map[0];
691
692 if (bitmap_empty(map, SUBSECTIONS_PER_SECTION))
693 rc = -EINVAL;
694 else if (bitmap_intersects(map, subsection_map, SUBSECTIONS_PER_SECTION))
695 rc = -EEXIST;
696 else
697 bitmap_or(subsection_map, map, subsection_map,
698 SUBSECTIONS_PER_SECTION);
699
700 return rc;
701}
702#else
703static struct page * __meminit populate_section_memmap(unsigned long pfn,
704 unsigned long nr_pages, int nid, struct vmem_altmap *altmap,
705 struct dev_pagemap *pgmap)
706{
707 return kvmalloc_node(array_size(sizeof(struct page),
708 PAGES_PER_SECTION), GFP_KERNEL, nid);
709}
710
711static void depopulate_section_memmap(unsigned long pfn, unsigned long nr_pages,
712 struct vmem_altmap *altmap)
713{
714 kvfree(pfn_to_page(pfn));
715}
716
717static void free_map_bootmem(struct page *memmap)
718{
719 unsigned long maps_section_nr, removing_section_nr, i;
720 unsigned long magic, nr_pages;
721 struct page *page = virt_to_page(memmap);
722
723 nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
724 >> PAGE_SHIFT;
725
726 for (i = 0; i < nr_pages; i++, page++) {
727 magic = page->index;
728
729 BUG_ON(magic == NODE_INFO);
730
731 maps_section_nr = pfn_to_section_nr(page_to_pfn(page));
732 removing_section_nr = page_private(page);
733
734 /*
735 * When this function is called, the removing section is
736 * logical offlined state. This means all pages are isolated
737 * from page allocator. If removing section's memmap is placed
738 * on the same section, it must not be freed.
739 * If it is freed, page allocator may allocate it which will
740 * be removed physically soon.
741 */
742 if (maps_section_nr != removing_section_nr)
743 put_page_bootmem(page);
744 }
745}
746
747static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages)
748{
749 return 0;
750}
751
752static bool is_subsection_map_empty(struct mem_section *ms)
753{
754 return true;
755}
756
757static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages)
758{
759 return 0;
760}
761#endif /* CONFIG_SPARSEMEM_VMEMMAP */
762
763/*
764 * To deactivate a memory region, there are 3 cases to handle across
765 * two configurations (SPARSEMEM_VMEMMAP={y,n}):
766 *
767 * 1. deactivation of a partial hot-added section (only possible in
768 * the SPARSEMEM_VMEMMAP=y case).
769 * a) section was present at memory init.
770 * b) section was hot-added post memory init.
771 * 2. deactivation of a complete hot-added section.
772 * 3. deactivation of a complete section from memory init.
773 *
774 * For 1, when subsection_map does not empty we will not be freeing the
775 * usage map, but still need to free the vmemmap range.
776 *
777 * For 2 and 3, the SPARSEMEM_VMEMMAP={y,n} cases are unified
778 */
779static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
780 struct vmem_altmap *altmap)
781{
782 struct mem_section *ms = __pfn_to_section(pfn);
783 bool section_is_early = early_section(ms);
784 struct page *memmap = NULL;
785 bool empty;
786
787 if (clear_subsection_map(pfn, nr_pages))
788 return;
789
790 empty = is_subsection_map_empty(ms);
791 if (empty) {
792 unsigned long section_nr = pfn_to_section_nr(pfn);
793
794 /*
795 * Mark the section invalid so that valid_section()
796 * return false. This prevents code from dereferencing
797 * ms->usage array.
798 */
799 ms->section_mem_map &= ~SECTION_HAS_MEM_MAP;
800
801 /*
802 * When removing an early section, the usage map is kept (as the
803 * usage maps of other sections fall into the same page). It
804 * will be re-used when re-adding the section - which is then no
805 * longer an early section. If the usage map is PageReserved, it
806 * was allocated during boot.
807 */
808 if (!PageReserved(virt_to_page(ms->usage))) {
809 kfree_rcu(ms->usage, rcu);
810 WRITE_ONCE(ms->usage, NULL);
811 }
812 memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr);
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;
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(unsigned long pfn, unsigned long nr_pages,
926 struct vmem_altmap *altmap)
927{
928 struct mem_section *ms = __pfn_to_section(pfn);
929
930 if (WARN_ON_ONCE(!valid_section(ms)))
931 return;
932
933 section_deactivate(pfn, nr_pages, altmap);
934}
935#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/highmem.h>
9#include <linux/export.h>
10#include <linux/spinlock.h>
11#include <linux/vmalloc.h>
12#include "internal.h"
13#include <asm/dma.h>
14#include <asm/pgalloc.h>
15#include <asm/pgtable.h>
16
17/*
18 * Permanent SPARSEMEM data:
19 *
20 * 1) mem_section - memory sections, mem_map's for valid memory
21 */
22#ifdef CONFIG_SPARSEMEM_EXTREME
23struct mem_section *mem_section[NR_SECTION_ROOTS]
24 ____cacheline_internodealigned_in_smp;
25#else
26struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]
27 ____cacheline_internodealigned_in_smp;
28#endif
29EXPORT_SYMBOL(mem_section);
30
31#ifdef NODE_NOT_IN_PAGE_FLAGS
32/*
33 * If we did not store the node number in the page then we have to
34 * do a lookup in the section_to_node_table in order to find which
35 * node the page belongs to.
36 */
37#if MAX_NUMNODES <= 256
38static u8 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
39#else
40static u16 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
41#endif
42
43int page_to_nid(const struct page *page)
44{
45 return section_to_node_table[page_to_section(page)];
46}
47EXPORT_SYMBOL(page_to_nid);
48
49static void set_section_nid(unsigned long section_nr, int nid)
50{
51 section_to_node_table[section_nr] = nid;
52}
53#else /* !NODE_NOT_IN_PAGE_FLAGS */
54static inline void set_section_nid(unsigned long section_nr, int nid)
55{
56}
57#endif
58
59#ifdef CONFIG_SPARSEMEM_EXTREME
60static struct mem_section noinline __init_refok *sparse_index_alloc(int nid)
61{
62 struct mem_section *section = NULL;
63 unsigned long array_size = SECTIONS_PER_ROOT *
64 sizeof(struct mem_section);
65
66 if (slab_is_available()) {
67 if (node_state(nid, N_HIGH_MEMORY))
68 section = kmalloc_node(array_size, GFP_KERNEL, nid);
69 else
70 section = kmalloc(array_size, GFP_KERNEL);
71 } else
72 section = alloc_bootmem_node(NODE_DATA(nid), array_size);
73
74 if (section)
75 memset(section, 0, array_size);
76
77 return section;
78}
79
80static int __meminit sparse_index_init(unsigned long section_nr, int nid)
81{
82 static DEFINE_SPINLOCK(index_init_lock);
83 unsigned long root = SECTION_NR_TO_ROOT(section_nr);
84 struct mem_section *section;
85 int ret = 0;
86
87 if (mem_section[root])
88 return -EEXIST;
89
90 section = sparse_index_alloc(nid);
91 if (!section)
92 return -ENOMEM;
93 /*
94 * This lock keeps two different sections from
95 * reallocating for the same index
96 */
97 spin_lock(&index_init_lock);
98
99 if (mem_section[root]) {
100 ret = -EEXIST;
101 goto out;
102 }
103
104 mem_section[root] = section;
105out:
106 spin_unlock(&index_init_lock);
107 return ret;
108}
109#else /* !SPARSEMEM_EXTREME */
110static inline int sparse_index_init(unsigned long section_nr, int nid)
111{
112 return 0;
113}
114#endif
115
116/*
117 * Although written for the SPARSEMEM_EXTREME case, this happens
118 * to also work for the flat array case because
119 * NR_SECTION_ROOTS==NR_MEM_SECTIONS.
120 */
121int __section_nr(struct mem_section* ms)
122{
123 unsigned long root_nr;
124 struct mem_section* root;
125
126 for (root_nr = 0; root_nr < NR_SECTION_ROOTS; root_nr++) {
127 root = __nr_to_section(root_nr * SECTIONS_PER_ROOT);
128 if (!root)
129 continue;
130
131 if ((ms >= root) && (ms < (root + SECTIONS_PER_ROOT)))
132 break;
133 }
134
135 return (root_nr * SECTIONS_PER_ROOT) + (ms - root);
136}
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/* Record a memory area against a node. */
181void __init memory_present(int nid, unsigned long start, unsigned long end)
182{
183 unsigned long pfn;
184
185 start &= PAGE_SECTION_MASK;
186 mminit_validate_memmodel_limits(&start, &end);
187 for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
188 unsigned long section = pfn_to_section_nr(pfn);
189 struct mem_section *ms;
190
191 sparse_index_init(section, nid);
192 set_section_nid(section, nid);
193
194 ms = __nr_to_section(section);
195 if (!ms->section_mem_map)
196 ms->section_mem_map = sparse_encode_early_nid(nid) |
197 SECTION_MARKED_PRESENT;
198 }
199}
200
201/*
202 * Only used by the i386 NUMA architecures, but relatively
203 * generic code.
204 */
205unsigned long __init node_memmap_size_bytes(int nid, unsigned long start_pfn,
206 unsigned long end_pfn)
207{
208 unsigned long pfn;
209 unsigned long nr_pages = 0;
210
211 mminit_validate_memmodel_limits(&start_pfn, &end_pfn);
212 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
213 if (nid != early_pfn_to_nid(pfn))
214 continue;
215
216 if (pfn_present(pfn))
217 nr_pages += PAGES_PER_SECTION;
218 }
219
220 return nr_pages * sizeof(struct page);
221}
222
223/*
224 * Subtle, we encode the real pfn into the mem_map such that
225 * the identity pfn - section_mem_map will return the actual
226 * physical page frame number.
227 */
228static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long pnum)
229{
230 return (unsigned long)(mem_map - (section_nr_to_pfn(pnum)));
231}
232
233/*
234 * Decode mem_map from the coded memmap
235 */
236struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum)
237{
238 /* mask off the extra low bits of information */
239 coded_mem_map &= SECTION_MAP_MASK;
240 return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum);
241}
242
243static int __meminit sparse_init_one_section(struct mem_section *ms,
244 unsigned long pnum, struct page *mem_map,
245 unsigned long *pageblock_bitmap)
246{
247 if (!present_section(ms))
248 return -EINVAL;
249
250 ms->section_mem_map &= ~SECTION_MAP_MASK;
251 ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) |
252 SECTION_HAS_MEM_MAP;
253 ms->pageblock_flags = pageblock_bitmap;
254
255 return 1;
256}
257
258unsigned long usemap_size(void)
259{
260 unsigned long size_bytes;
261 size_bytes = roundup(SECTION_BLOCKFLAGS_BITS, 8) / 8;
262 size_bytes = roundup(size_bytes, sizeof(unsigned long));
263 return size_bytes;
264}
265
266#ifdef CONFIG_MEMORY_HOTPLUG
267static unsigned long *__kmalloc_section_usemap(void)
268{
269 return kmalloc(usemap_size(), GFP_KERNEL);
270}
271#endif /* CONFIG_MEMORY_HOTPLUG */
272
273#ifdef CONFIG_MEMORY_HOTREMOVE
274static unsigned long * __init
275sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
276 unsigned long size)
277{
278 unsigned long goal, limit;
279 unsigned long *p;
280 int nid;
281 /*
282 * A page may contain usemaps for other sections preventing the
283 * page being freed and making a section unremovable while
284 * other sections referencing the usemap retmain active. Similarly,
285 * a pgdat can prevent a section being removed. If section A
286 * contains a pgdat and section B contains the usemap, both
287 * sections become inter-dependent. This allocates usemaps
288 * from the same section as the pgdat where possible to avoid
289 * this problem.
290 */
291 goal = __pa(pgdat) & (PAGE_SECTION_MASK << PAGE_SHIFT);
292 limit = goal + (1UL << PA_SECTION_SHIFT);
293 nid = early_pfn_to_nid(goal >> PAGE_SHIFT);
294again:
295 p = ___alloc_bootmem_node_nopanic(NODE_DATA(nid), size,
296 SMP_CACHE_BYTES, goal, limit);
297 if (!p && limit) {
298 limit = 0;
299 goto again;
300 }
301 return p;
302}
303
304static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
305{
306 unsigned long usemap_snr, pgdat_snr;
307 static unsigned long old_usemap_snr = NR_MEM_SECTIONS;
308 static unsigned long old_pgdat_snr = NR_MEM_SECTIONS;
309 struct pglist_data *pgdat = NODE_DATA(nid);
310 int usemap_nid;
311
312 usemap_snr = pfn_to_section_nr(__pa(usemap) >> PAGE_SHIFT);
313 pgdat_snr = pfn_to_section_nr(__pa(pgdat) >> PAGE_SHIFT);
314 if (usemap_snr == pgdat_snr)
315 return;
316
317 if (old_usemap_snr == usemap_snr && old_pgdat_snr == pgdat_snr)
318 /* skip redundant message */
319 return;
320
321 old_usemap_snr = usemap_snr;
322 old_pgdat_snr = pgdat_snr;
323
324 usemap_nid = sparse_early_nid(__nr_to_section(usemap_snr));
325 if (usemap_nid != nid) {
326 printk(KERN_INFO
327 "node %d must be removed before remove section %ld\n",
328 nid, usemap_snr);
329 return;
330 }
331 /*
332 * There is a circular dependency.
333 * Some platforms allow un-removable section because they will just
334 * gather other removable sections for dynamic partitioning.
335 * Just notify un-removable section's number here.
336 */
337 printk(KERN_INFO "Section %ld and %ld (node %d)", usemap_snr,
338 pgdat_snr, nid);
339 printk(KERN_CONT
340 " have a circular dependency on usemap and pgdat allocations\n");
341}
342#else
343static unsigned long * __init
344sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
345 unsigned long size)
346{
347 return alloc_bootmem_node_nopanic(pgdat, size);
348}
349
350static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
351{
352}
353#endif /* CONFIG_MEMORY_HOTREMOVE */
354
355static void __init sparse_early_usemaps_alloc_node(unsigned long**usemap_map,
356 unsigned long pnum_begin,
357 unsigned long pnum_end,
358 unsigned long usemap_count, int nodeid)
359{
360 void *usemap;
361 unsigned long pnum;
362 int size = usemap_size();
363
364 usemap = sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nodeid),
365 size * usemap_count);
366 if (!usemap) {
367 printk(KERN_WARNING "%s: allocation failed\n", __func__);
368 return;
369 }
370
371 for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
372 if (!present_section_nr(pnum))
373 continue;
374 usemap_map[pnum] = usemap;
375 usemap += size;
376 check_usemap_section_nr(nodeid, usemap_map[pnum]);
377 }
378}
379
380#ifndef CONFIG_SPARSEMEM_VMEMMAP
381struct page __init *sparse_mem_map_populate(unsigned long pnum, int nid)
382{
383 struct page *map;
384 unsigned long size;
385
386 map = alloc_remap(nid, sizeof(struct page) * PAGES_PER_SECTION);
387 if (map)
388 return map;
389
390 size = PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
391 map = __alloc_bootmem_node_high(NODE_DATA(nid), size,
392 PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
393 return map;
394}
395void __init sparse_mem_maps_populate_node(struct page **map_map,
396 unsigned long pnum_begin,
397 unsigned long pnum_end,
398 unsigned long map_count, int nodeid)
399{
400 void *map;
401 unsigned long pnum;
402 unsigned long size = sizeof(struct page) * PAGES_PER_SECTION;
403
404 map = alloc_remap(nodeid, size * map_count);
405 if (map) {
406 for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
407 if (!present_section_nr(pnum))
408 continue;
409 map_map[pnum] = map;
410 map += size;
411 }
412 return;
413 }
414
415 size = PAGE_ALIGN(size);
416 map = __alloc_bootmem_node_high(NODE_DATA(nodeid), size * map_count,
417 PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
418 if (map) {
419 for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
420 if (!present_section_nr(pnum))
421 continue;
422 map_map[pnum] = map;
423 map += size;
424 }
425 return;
426 }
427
428 /* fallback */
429 for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
430 struct mem_section *ms;
431
432 if (!present_section_nr(pnum))
433 continue;
434 map_map[pnum] = sparse_mem_map_populate(pnum, nodeid);
435 if (map_map[pnum])
436 continue;
437 ms = __nr_to_section(pnum);
438 printk(KERN_ERR "%s: sparsemem memory map backing failed "
439 "some memory will not be available.\n", __func__);
440 ms->section_mem_map = 0;
441 }
442}
443#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
444
445#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
446static void __init sparse_early_mem_maps_alloc_node(struct page **map_map,
447 unsigned long pnum_begin,
448 unsigned long pnum_end,
449 unsigned long map_count, int nodeid)
450{
451 sparse_mem_maps_populate_node(map_map, pnum_begin, pnum_end,
452 map_count, nodeid);
453}
454#else
455static struct page __init *sparse_early_mem_map_alloc(unsigned long pnum)
456{
457 struct page *map;
458 struct mem_section *ms = __nr_to_section(pnum);
459 int nid = sparse_early_nid(ms);
460
461 map = sparse_mem_map_populate(pnum, nid);
462 if (map)
463 return map;
464
465 printk(KERN_ERR "%s: sparsemem memory map backing failed "
466 "some memory will not be available.\n", __func__);
467 ms->section_mem_map = 0;
468 return NULL;
469}
470#endif
471
472void __attribute__((weak)) __meminit vmemmap_populate_print_last(void)
473{
474}
475
476/*
477 * Allocate the accumulated non-linear sections, allocate a mem_map
478 * for each and record the physical to section mapping.
479 */
480void __init sparse_init(void)
481{
482 unsigned long pnum;
483 struct page *map;
484 unsigned long *usemap;
485 unsigned long **usemap_map;
486 int size;
487 int nodeid_begin = 0;
488 unsigned long pnum_begin = 0;
489 unsigned long usemap_count;
490#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
491 unsigned long map_count;
492 int size2;
493 struct page **map_map;
494#endif
495
496 /* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */
497 set_pageblock_order();
498
499 /*
500 * map is using big page (aka 2M in x86 64 bit)
501 * usemap is less one page (aka 24 bytes)
502 * so alloc 2M (with 2M align) and 24 bytes in turn will
503 * make next 2M slip to one more 2M later.
504 * then in big system, the memory will have a lot of holes...
505 * here try to allocate 2M pages continuously.
506 *
507 * powerpc need to call sparse_init_one_section right after each
508 * sparse_early_mem_map_alloc, so allocate usemap_map at first.
509 */
510 size = sizeof(unsigned long *) * NR_MEM_SECTIONS;
511 usemap_map = alloc_bootmem(size);
512 if (!usemap_map)
513 panic("can not allocate usemap_map\n");
514
515 for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
516 struct mem_section *ms;
517
518 if (!present_section_nr(pnum))
519 continue;
520 ms = __nr_to_section(pnum);
521 nodeid_begin = sparse_early_nid(ms);
522 pnum_begin = pnum;
523 break;
524 }
525 usemap_count = 1;
526 for (pnum = pnum_begin + 1; pnum < NR_MEM_SECTIONS; pnum++) {
527 struct mem_section *ms;
528 int nodeid;
529
530 if (!present_section_nr(pnum))
531 continue;
532 ms = __nr_to_section(pnum);
533 nodeid = sparse_early_nid(ms);
534 if (nodeid == nodeid_begin) {
535 usemap_count++;
536 continue;
537 }
538 /* ok, we need to take cake of from pnum_begin to pnum - 1*/
539 sparse_early_usemaps_alloc_node(usemap_map, pnum_begin, pnum,
540 usemap_count, nodeid_begin);
541 /* new start, update count etc*/
542 nodeid_begin = nodeid;
543 pnum_begin = pnum;
544 usemap_count = 1;
545 }
546 /* ok, last chunk */
547 sparse_early_usemaps_alloc_node(usemap_map, pnum_begin, NR_MEM_SECTIONS,
548 usemap_count, nodeid_begin);
549
550#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
551 size2 = sizeof(struct page *) * NR_MEM_SECTIONS;
552 map_map = alloc_bootmem(size2);
553 if (!map_map)
554 panic("can not allocate map_map\n");
555
556 for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
557 struct mem_section *ms;
558
559 if (!present_section_nr(pnum))
560 continue;
561 ms = __nr_to_section(pnum);
562 nodeid_begin = sparse_early_nid(ms);
563 pnum_begin = pnum;
564 break;
565 }
566 map_count = 1;
567 for (pnum = pnum_begin + 1; pnum < NR_MEM_SECTIONS; pnum++) {
568 struct mem_section *ms;
569 int nodeid;
570
571 if (!present_section_nr(pnum))
572 continue;
573 ms = __nr_to_section(pnum);
574 nodeid = sparse_early_nid(ms);
575 if (nodeid == nodeid_begin) {
576 map_count++;
577 continue;
578 }
579 /* ok, we need to take cake of from pnum_begin to pnum - 1*/
580 sparse_early_mem_maps_alloc_node(map_map, pnum_begin, pnum,
581 map_count, nodeid_begin);
582 /* new start, update count etc*/
583 nodeid_begin = nodeid;
584 pnum_begin = pnum;
585 map_count = 1;
586 }
587 /* ok, last chunk */
588 sparse_early_mem_maps_alloc_node(map_map, pnum_begin, NR_MEM_SECTIONS,
589 map_count, nodeid_begin);
590#endif
591
592 for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
593 if (!present_section_nr(pnum))
594 continue;
595
596 usemap = usemap_map[pnum];
597 if (!usemap)
598 continue;
599
600#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
601 map = map_map[pnum];
602#else
603 map = sparse_early_mem_map_alloc(pnum);
604#endif
605 if (!map)
606 continue;
607
608 sparse_init_one_section(__nr_to_section(pnum), pnum, map,
609 usemap);
610 }
611
612 vmemmap_populate_print_last();
613
614#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
615 free_bootmem(__pa(map_map), size2);
616#endif
617 free_bootmem(__pa(usemap_map), size);
618}
619
620#ifdef CONFIG_MEMORY_HOTPLUG
621#ifdef CONFIG_SPARSEMEM_VMEMMAP
622static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
623 unsigned long nr_pages)
624{
625 /* This will make the necessary allocations eventually. */
626 return sparse_mem_map_populate(pnum, nid);
627}
628static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
629{
630 return; /* XXX: Not implemented yet */
631}
632static void free_map_bootmem(struct page *page, unsigned long nr_pages)
633{
634}
635#else
636static struct page *__kmalloc_section_memmap(unsigned long nr_pages)
637{
638 struct page *page, *ret;
639 unsigned long memmap_size = sizeof(struct page) * nr_pages;
640
641 page = alloc_pages(GFP_KERNEL|__GFP_NOWARN, get_order(memmap_size));
642 if (page)
643 goto got_map_page;
644
645 ret = vmalloc(memmap_size);
646 if (ret)
647 goto got_map_ptr;
648
649 return NULL;
650got_map_page:
651 ret = (struct page *)pfn_to_kaddr(page_to_pfn(page));
652got_map_ptr:
653 memset(ret, 0, memmap_size);
654
655 return ret;
656}
657
658static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
659 unsigned long nr_pages)
660{
661 return __kmalloc_section_memmap(nr_pages);
662}
663
664static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
665{
666 if (is_vmalloc_addr(memmap))
667 vfree(memmap);
668 else
669 free_pages((unsigned long)memmap,
670 get_order(sizeof(struct page) * nr_pages));
671}
672
673static void free_map_bootmem(struct page *page, unsigned long nr_pages)
674{
675 unsigned long maps_section_nr, removing_section_nr, i;
676 unsigned long magic;
677
678 for (i = 0; i < nr_pages; i++, page++) {
679 magic = (unsigned long) page->lru.next;
680
681 BUG_ON(magic == NODE_INFO);
682
683 maps_section_nr = pfn_to_section_nr(page_to_pfn(page));
684 removing_section_nr = page->private;
685
686 /*
687 * When this function is called, the removing section is
688 * logical offlined state. This means all pages are isolated
689 * from page allocator. If removing section's memmap is placed
690 * on the same section, it must not be freed.
691 * If it is freed, page allocator may allocate it which will
692 * be removed physically soon.
693 */
694 if (maps_section_nr != removing_section_nr)
695 put_page_bootmem(page);
696 }
697}
698#endif /* CONFIG_SPARSEMEM_VMEMMAP */
699
700static void free_section_usemap(struct page *memmap, unsigned long *usemap)
701{
702 struct page *usemap_page;
703 unsigned long nr_pages;
704
705 if (!usemap)
706 return;
707
708 usemap_page = virt_to_page(usemap);
709 /*
710 * Check to see if allocation came from hot-plug-add
711 */
712 if (PageSlab(usemap_page)) {
713 kfree(usemap);
714 if (memmap)
715 __kfree_section_memmap(memmap, PAGES_PER_SECTION);
716 return;
717 }
718
719 /*
720 * The usemap came from bootmem. This is packed with other usemaps
721 * on the section which has pgdat at boot time. Just keep it as is now.
722 */
723
724 if (memmap) {
725 struct page *memmap_page;
726 memmap_page = virt_to_page(memmap);
727
728 nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
729 >> PAGE_SHIFT;
730
731 free_map_bootmem(memmap_page, nr_pages);
732 }
733}
734
735/*
736 * returns the number of sections whose mem_maps were properly
737 * set. If this is <=0, then that means that the passed-in
738 * map was not consumed and must be freed.
739 */
740int __meminit sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
741 int nr_pages)
742{
743 unsigned long section_nr = pfn_to_section_nr(start_pfn);
744 struct pglist_data *pgdat = zone->zone_pgdat;
745 struct mem_section *ms;
746 struct page *memmap;
747 unsigned long *usemap;
748 unsigned long flags;
749 int ret;
750
751 /*
752 * no locking for this, because it does its own
753 * plus, it does a kmalloc
754 */
755 ret = sparse_index_init(section_nr, pgdat->node_id);
756 if (ret < 0 && ret != -EEXIST)
757 return ret;
758 memmap = kmalloc_section_memmap(section_nr, pgdat->node_id, nr_pages);
759 if (!memmap)
760 return -ENOMEM;
761 usemap = __kmalloc_section_usemap();
762 if (!usemap) {
763 __kfree_section_memmap(memmap, nr_pages);
764 return -ENOMEM;
765 }
766
767 pgdat_resize_lock(pgdat, &flags);
768
769 ms = __pfn_to_section(start_pfn);
770 if (ms->section_mem_map & SECTION_MARKED_PRESENT) {
771 ret = -EEXIST;
772 goto out;
773 }
774
775 ms->section_mem_map |= SECTION_MARKED_PRESENT;
776
777 ret = sparse_init_one_section(ms, section_nr, memmap, usemap);
778
779out:
780 pgdat_resize_unlock(pgdat, &flags);
781 if (ret <= 0) {
782 kfree(usemap);
783 __kfree_section_memmap(memmap, nr_pages);
784 }
785 return ret;
786}
787
788void sparse_remove_one_section(struct zone *zone, struct mem_section *ms)
789{
790 struct page *memmap = NULL;
791 unsigned long *usemap = NULL;
792
793 if (ms->section_mem_map) {
794 usemap = ms->pageblock_flags;
795 memmap = sparse_decode_mem_map(ms->section_mem_map,
796 __section_nr(ms));
797 ms->section_mem_map = 0;
798 ms->pageblock_flags = NULL;
799 }
800
801 free_section_usemap(memmap, usemap);
802}
803#endif