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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
23 struct mem_section *mem_section[NR_SECTION_ROOTS]
24 ____cacheline_internodealigned_in_smp;
25 #else
26 struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]
27 ____cacheline_internodealigned_in_smp;
28 #endif
29 EXPORT_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
38 static u8 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
39 #else
40 static u16 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
41 #endif
42
43 int page_to_nid(const struct page *page)
44 {
45 return section_to_node_table[page_to_section(page)];
46 }
47 EXPORT_SYMBOL(page_to_nid);
48
49 static 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 */
54 static inline void set_section_nid(unsigned long section_nr, int nid)
55 {
56 }
57 #endif
58
59 #ifdef CONFIG_SPARSEMEM_EXTREME
60 static 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
80 static 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;
105 out:
106 spin_unlock(&index_init_lock);
107 return ret;
108 }
109 #else /* !SPARSEMEM_EXTREME */
110 static 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 */
121 int __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 */
144 static inline unsigned long sparse_encode_early_nid(int nid)
145 {
146 return (nid << SECTION_NID_SHIFT);
147 }
148
149 static 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 */
155 void __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. */
181 void __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 */
205 unsigned 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 */
228 static 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 */
236 struct 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
243 static 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
258 unsigned 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
267 static 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
274 static unsigned long * __init
275 sparse_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);
294 again:
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
304 static 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
343 static unsigned long * __init
344 sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
345 unsigned long size)
346 {
347 return alloc_bootmem_node_nopanic(pgdat, size);
348 }
349
350 static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
351 {
352 }
353 #endif /* CONFIG_MEMORY_HOTREMOVE */
354
355 static 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
381 struct 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 }
395 void __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
446 static 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
455 static 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
472 void __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 */
480 void __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 /*
497 * map is using big page (aka 2M in x86 64 bit)
498 * usemap is less one page (aka 24 bytes)
499 * so alloc 2M (with 2M align) and 24 bytes in turn will
500 * make next 2M slip to one more 2M later.
501 * then in big system, the memory will have a lot of holes...
502 * here try to allocate 2M pages continuously.
503 *
504 * powerpc need to call sparse_init_one_section right after each
505 * sparse_early_mem_map_alloc, so allocate usemap_map at first.
506 */
507 size = sizeof(unsigned long *) * NR_MEM_SECTIONS;
508 usemap_map = alloc_bootmem(size);
509 if (!usemap_map)
510 panic("can not allocate usemap_map\n");
511
512 for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
513 struct mem_section *ms;
514
515 if (!present_section_nr(pnum))
516 continue;
517 ms = __nr_to_section(pnum);
518 nodeid_begin = sparse_early_nid(ms);
519 pnum_begin = pnum;
520 break;
521 }
522 usemap_count = 1;
523 for (pnum = pnum_begin + 1; pnum < NR_MEM_SECTIONS; pnum++) {
524 struct mem_section *ms;
525 int nodeid;
526
527 if (!present_section_nr(pnum))
528 continue;
529 ms = __nr_to_section(pnum);
530 nodeid = sparse_early_nid(ms);
531 if (nodeid == nodeid_begin) {
532 usemap_count++;
533 continue;
534 }
535 /* ok, we need to take cake of from pnum_begin to pnum - 1*/
536 sparse_early_usemaps_alloc_node(usemap_map, pnum_begin, pnum,
537 usemap_count, nodeid_begin);
538 /* new start, update count etc*/
539 nodeid_begin = nodeid;
540 pnum_begin = pnum;
541 usemap_count = 1;
542 }
543 /* ok, last chunk */
544 sparse_early_usemaps_alloc_node(usemap_map, pnum_begin, NR_MEM_SECTIONS,
545 usemap_count, nodeid_begin);
546
547 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
548 size2 = sizeof(struct page *) * NR_MEM_SECTIONS;
549 map_map = alloc_bootmem(size2);
550 if (!map_map)
551 panic("can not allocate map_map\n");
552
553 for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
554 struct mem_section *ms;
555
556 if (!present_section_nr(pnum))
557 continue;
558 ms = __nr_to_section(pnum);
559 nodeid_begin = sparse_early_nid(ms);
560 pnum_begin = pnum;
561 break;
562 }
563 map_count = 1;
564 for (pnum = pnum_begin + 1; pnum < NR_MEM_SECTIONS; pnum++) {
565 struct mem_section *ms;
566 int nodeid;
567
568 if (!present_section_nr(pnum))
569 continue;
570 ms = __nr_to_section(pnum);
571 nodeid = sparse_early_nid(ms);
572 if (nodeid == nodeid_begin) {
573 map_count++;
574 continue;
575 }
576 /* ok, we need to take cake of from pnum_begin to pnum - 1*/
577 sparse_early_mem_maps_alloc_node(map_map, pnum_begin, pnum,
578 map_count, nodeid_begin);
579 /* new start, update count etc*/
580 nodeid_begin = nodeid;
581 pnum_begin = pnum;
582 map_count = 1;
583 }
584 /* ok, last chunk */
585 sparse_early_mem_maps_alloc_node(map_map, pnum_begin, NR_MEM_SECTIONS,
586 map_count, nodeid_begin);
587 #endif
588
589 for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
590 if (!present_section_nr(pnum))
591 continue;
592
593 usemap = usemap_map[pnum];
594 if (!usemap)
595 continue;
596
597 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
598 map = map_map[pnum];
599 #else
600 map = sparse_early_mem_map_alloc(pnum);
601 #endif
602 if (!map)
603 continue;
604
605 sparse_init_one_section(__nr_to_section(pnum), pnum, map,
606 usemap);
607 }
608
609 vmemmap_populate_print_last();
610
611 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
612 free_bootmem(__pa(map_map), size2);
613 #endif
614 free_bootmem(__pa(usemap_map), size);
615 }
616
617 #ifdef CONFIG_MEMORY_HOTPLUG
618 #ifdef CONFIG_SPARSEMEM_VMEMMAP
619 static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
620 unsigned long nr_pages)
621 {
622 /* This will make the necessary allocations eventually. */
623 return sparse_mem_map_populate(pnum, nid);
624 }
625 static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
626 {
627 return; /* XXX: Not implemented yet */
628 }
629 static void free_map_bootmem(struct page *page, unsigned long nr_pages)
630 {
631 }
632 #else
633 static struct page *__kmalloc_section_memmap(unsigned long nr_pages)
634 {
635 struct page *page, *ret;
636 unsigned long memmap_size = sizeof(struct page) * nr_pages;
637
638 page = alloc_pages(GFP_KERNEL|__GFP_NOWARN, get_order(memmap_size));
639 if (page)
640 goto got_map_page;
641
642 ret = vmalloc(memmap_size);
643 if (ret)
644 goto got_map_ptr;
645
646 return NULL;
647 got_map_page:
648 ret = (struct page *)pfn_to_kaddr(page_to_pfn(page));
649 got_map_ptr:
650 memset(ret, 0, memmap_size);
651
652 return ret;
653 }
654
655 static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
656 unsigned long nr_pages)
657 {
658 return __kmalloc_section_memmap(nr_pages);
659 }
660
661 static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
662 {
663 if (is_vmalloc_addr(memmap))
664 vfree(memmap);
665 else
666 free_pages((unsigned long)memmap,
667 get_order(sizeof(struct page) * nr_pages));
668 }
669
670 static void free_map_bootmem(struct page *page, unsigned long nr_pages)
671 {
672 unsigned long maps_section_nr, removing_section_nr, i;
673 unsigned long magic;
674
675 for (i = 0; i < nr_pages; i++, page++) {
676 magic = (unsigned long) page->lru.next;
677
678 BUG_ON(magic == NODE_INFO);
679
680 maps_section_nr = pfn_to_section_nr(page_to_pfn(page));
681 removing_section_nr = page->private;
682
683 /*
684 * When this function is called, the removing section is
685 * logical offlined state. This means all pages are isolated
686 * from page allocator. If removing section's memmap is placed
687 * on the same section, it must not be freed.
688 * If it is freed, page allocator may allocate it which will
689 * be removed physically soon.
690 */
691 if (maps_section_nr != removing_section_nr)
692 put_page_bootmem(page);
693 }
694 }
695 #endif /* CONFIG_SPARSEMEM_VMEMMAP */
696
697 static void free_section_usemap(struct page *memmap, unsigned long *usemap)
698 {
699 struct page *usemap_page;
700 unsigned long nr_pages;
701
702 if (!usemap)
703 return;
704
705 usemap_page = virt_to_page(usemap);
706 /*
707 * Check to see if allocation came from hot-plug-add
708 */
709 if (PageSlab(usemap_page)) {
710 kfree(usemap);
711 if (memmap)
712 __kfree_section_memmap(memmap, PAGES_PER_SECTION);
713 return;
714 }
715
716 /*
717 * The usemap came from bootmem. This is packed with other usemaps
718 * on the section which has pgdat at boot time. Just keep it as is now.
719 */
720
721 if (memmap) {
722 struct page *memmap_page;
723 memmap_page = virt_to_page(memmap);
724
725 nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
726 >> PAGE_SHIFT;
727
728 free_map_bootmem(memmap_page, nr_pages);
729 }
730 }
731
732 /*
733 * returns the number of sections whose mem_maps were properly
734 * set. If this is <=0, then that means that the passed-in
735 * map was not consumed and must be freed.
736 */
737 int __meminit sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
738 int nr_pages)
739 {
740 unsigned long section_nr = pfn_to_section_nr(start_pfn);
741 struct pglist_data *pgdat = zone->zone_pgdat;
742 struct mem_section *ms;
743 struct page *memmap;
744 unsigned long *usemap;
745 unsigned long flags;
746 int ret;
747
748 /*
749 * no locking for this, because it does its own
750 * plus, it does a kmalloc
751 */
752 ret = sparse_index_init(section_nr, pgdat->node_id);
753 if (ret < 0 && ret != -EEXIST)
754 return ret;
755 memmap = kmalloc_section_memmap(section_nr, pgdat->node_id, nr_pages);
756 if (!memmap)
757 return -ENOMEM;
758 usemap = __kmalloc_section_usemap();
759 if (!usemap) {
760 __kfree_section_memmap(memmap, nr_pages);
761 return -ENOMEM;
762 }
763
764 pgdat_resize_lock(pgdat, &flags);
765
766 ms = __pfn_to_section(start_pfn);
767 if (ms->section_mem_map & SECTION_MARKED_PRESENT) {
768 ret = -EEXIST;
769 goto out;
770 }
771
772 ms->section_mem_map |= SECTION_MARKED_PRESENT;
773
774 ret = sparse_init_one_section(ms, section_nr, memmap, usemap);
775
776 out:
777 pgdat_resize_unlock(pgdat, &flags);
778 if (ret <= 0) {
779 kfree(usemap);
780 __kfree_section_memmap(memmap, nr_pages);
781 }
782 return ret;
783 }
784
785 void sparse_remove_one_section(struct zone *zone, struct mem_section *ms)
786 {
787 struct page *memmap = NULL;
788 unsigned long *usemap = NULL;
789
790 if (ms->section_mem_map) {
791 usemap = ms->pageblock_flags;
792 memmap = sparse_decode_mem_map(ms->section_mem_map,
793 __section_nr(ms));
794 ms->section_mem_map = 0;
795 ms->pageblock_flags = NULL;
796 }
797
798 free_section_usemap(memmap, usemap);
799 }
800 #endif