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