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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/compiler.h>
9 #include <linux/highmem.h>
10 #include <linux/export.h>
11 #include <linux/spinlock.h>
12 #include <linux/vmalloc.h>
13 
14 #include "internal.h"
15 #include <asm/dma.h>
16 #include <asm/pgalloc.h>
17 #include <asm/pgtable.h>
18 
19 /*
20  * Permanent SPARSEMEM data:
21  *
22  * 1) mem_section	- memory sections, mem_map's for valid memory
23  */
24 #ifdef CONFIG_SPARSEMEM_EXTREME
25 struct mem_section *mem_section[NR_SECTION_ROOTS]
26 	____cacheline_internodealigned_in_smp;
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 
page_to_nid(const struct page * page)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 
set_section_nid(unsigned long section_nr,int nid)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 */
set_section_nid(unsigned long section_nr,int nid)56 static inline void set_section_nid(unsigned long section_nr, int nid)
57 {
58 }
59 #endif
60 
61 #ifdef CONFIG_SPARSEMEM_EXTREME
sparse_index_alloc(int nid)62 static struct mem_section noinline __init_refok *sparse_index_alloc(int nid)
63 {
64 	struct mem_section *section = NULL;
65 	unsigned long array_size = SECTIONS_PER_ROOT *
66 				   sizeof(struct mem_section);
67 
68 	if (slab_is_available()) {
69 		if (node_state(nid, N_HIGH_MEMORY))
70 			section = kzalloc_node(array_size, GFP_KERNEL, nid);
71 		else
72 			section = kzalloc(array_size, GFP_KERNEL);
73 	} else {
74 		section = memblock_virt_alloc_node(array_size, nid);
75 	}
76 
77 	return section;
78 }
79 
sparse_index_init(unsigned long section_nr,int nid)80 static int __meminit sparse_index_init(unsigned long section_nr, int nid)
81 {
82 	unsigned long root = SECTION_NR_TO_ROOT(section_nr);
83 	struct mem_section *section;
84 
85 	if (mem_section[root])
86 		return -EEXIST;
87 
88 	section = sparse_index_alloc(nid);
89 	if (!section)
90 		return -ENOMEM;
91 
92 	mem_section[root] = section;
93 
94 	return 0;
95 }
96 #else /* !SPARSEMEM_EXTREME */
sparse_index_init(unsigned long section_nr,int nid)97 static inline int sparse_index_init(unsigned long section_nr, int nid)
98 {
99 	return 0;
100 }
101 #endif
102 
103 /*
104  * Although written for the SPARSEMEM_EXTREME case, this happens
105  * to also work for the flat array case because
106  * NR_SECTION_ROOTS==NR_MEM_SECTIONS.
107  */
__section_nr(struct mem_section * ms)108 int __section_nr(struct mem_section* ms)
109 {
110 	unsigned long root_nr;
111 	struct mem_section* root;
112 
113 	for (root_nr = 0; root_nr < NR_SECTION_ROOTS; root_nr++) {
114 		root = __nr_to_section(root_nr * SECTIONS_PER_ROOT);
115 		if (!root)
116 			continue;
117 
118 		if ((ms >= root) && (ms < (root + SECTIONS_PER_ROOT)))
119 		     break;
120 	}
121 
122 	VM_BUG_ON(root_nr == NR_SECTION_ROOTS);
123 
124 	return (root_nr * SECTIONS_PER_ROOT) + (ms - root);
125 }
126 
127 /*
128  * During early boot, before section_mem_map is used for an actual
129  * mem_map, we use section_mem_map to store the section's NUMA
130  * node.  This keeps us from having to use another data structure.  The
131  * node information is cleared just before we store the real mem_map.
132  */
sparse_encode_early_nid(int nid)133 static inline unsigned long sparse_encode_early_nid(int nid)
134 {
135 	return (nid << SECTION_NID_SHIFT);
136 }
137 
sparse_early_nid(struct mem_section * section)138 static inline int sparse_early_nid(struct mem_section *section)
139 {
140 	return (section->section_mem_map >> SECTION_NID_SHIFT);
141 }
142 
143 /* Validate the physical addressing limitations of the model */
mminit_validate_memmodel_limits(unsigned long * start_pfn,unsigned long * end_pfn)144 void __meminit mminit_validate_memmodel_limits(unsigned long *start_pfn,
145 						unsigned long *end_pfn)
146 {
147 	unsigned long max_sparsemem_pfn = 1UL << (MAX_PHYSMEM_BITS-PAGE_SHIFT);
148 
149 	/*
150 	 * Sanity checks - do not allow an architecture to pass
151 	 * in larger pfns than the maximum scope of sparsemem:
152 	 */
153 	if (*start_pfn > max_sparsemem_pfn) {
154 		mminit_dprintk(MMINIT_WARNING, "pfnvalidation",
155 			"Start of range %lu -> %lu exceeds SPARSEMEM max %lu\n",
156 			*start_pfn, *end_pfn, max_sparsemem_pfn);
157 		WARN_ON_ONCE(1);
158 		*start_pfn = max_sparsemem_pfn;
159 		*end_pfn = max_sparsemem_pfn;
160 	} else if (*end_pfn > max_sparsemem_pfn) {
161 		mminit_dprintk(MMINIT_WARNING, "pfnvalidation",
162 			"End of range %lu -> %lu exceeds SPARSEMEM max %lu\n",
163 			*start_pfn, *end_pfn, max_sparsemem_pfn);
164 		WARN_ON_ONCE(1);
165 		*end_pfn = max_sparsemem_pfn;
166 	}
167 }
168 
169 /* Record a memory area against a node. */
memory_present(int nid,unsigned long start,unsigned long end)170 void __init memory_present(int nid, unsigned long start, unsigned long end)
171 {
172 	unsigned long pfn;
173 
174 	start &= PAGE_SECTION_MASK;
175 	mminit_validate_memmodel_limits(&start, &end);
176 	for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
177 		unsigned long section = pfn_to_section_nr(pfn);
178 		struct mem_section *ms;
179 
180 		sparse_index_init(section, nid);
181 		set_section_nid(section, nid);
182 
183 		ms = __nr_to_section(section);
184 		if (!ms->section_mem_map)
185 			ms->section_mem_map = sparse_encode_early_nid(nid) |
186 							SECTION_MARKED_PRESENT;
187 	}
188 }
189 
190 /*
191  * Only used by the i386 NUMA architecures, but relatively
192  * generic code.
193  */
node_memmap_size_bytes(int nid,unsigned long start_pfn,unsigned long end_pfn)194 unsigned long __init node_memmap_size_bytes(int nid, unsigned long start_pfn,
195 						     unsigned long end_pfn)
196 {
197 	unsigned long pfn;
198 	unsigned long nr_pages = 0;
199 
200 	mminit_validate_memmodel_limits(&start_pfn, &end_pfn);
201 	for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
202 		if (nid != early_pfn_to_nid(pfn))
203 			continue;
204 
205 		if (pfn_present(pfn))
206 			nr_pages += PAGES_PER_SECTION;
207 	}
208 
209 	return nr_pages * sizeof(struct page);
210 }
211 
212 /*
213  * Subtle, we encode the real pfn into the mem_map such that
214  * the identity pfn - section_mem_map will return the actual
215  * physical page frame number.
216  */
sparse_encode_mem_map(struct page * mem_map,unsigned long pnum)217 static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long pnum)
218 {
219 	return (unsigned long)(mem_map - (section_nr_to_pfn(pnum)));
220 }
221 
222 /*
223  * Decode mem_map from the coded memmap
224  */
sparse_decode_mem_map(unsigned long coded_mem_map,unsigned long pnum)225 struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum)
226 {
227 	/* mask off the extra low bits of information */
228 	coded_mem_map &= SECTION_MAP_MASK;
229 	return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum);
230 }
231 
sparse_init_one_section(struct mem_section * ms,unsigned long pnum,struct page * mem_map,unsigned long * pageblock_bitmap)232 static int __meminit sparse_init_one_section(struct mem_section *ms,
233 		unsigned long pnum, struct page *mem_map,
234 		unsigned long *pageblock_bitmap)
235 {
236 	if (!present_section(ms))
237 		return -EINVAL;
238 
239 	ms->section_mem_map &= ~SECTION_MAP_MASK;
240 	ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) |
241 							SECTION_HAS_MEM_MAP;
242  	ms->pageblock_flags = pageblock_bitmap;
243 
244 	return 1;
245 }
246 
usemap_size(void)247 unsigned long usemap_size(void)
248 {
249 	unsigned long size_bytes;
250 	size_bytes = roundup(SECTION_BLOCKFLAGS_BITS, 8) / 8;
251 	size_bytes = roundup(size_bytes, sizeof(unsigned long));
252 	return size_bytes;
253 }
254 
255 #ifdef CONFIG_MEMORY_HOTPLUG
__kmalloc_section_usemap(void)256 static unsigned long *__kmalloc_section_usemap(void)
257 {
258 	return kmalloc(usemap_size(), GFP_KERNEL);
259 }
260 #endif /* CONFIG_MEMORY_HOTPLUG */
261 
262 #ifdef CONFIG_MEMORY_HOTREMOVE
263 static unsigned long * __init
sparse_early_usemaps_alloc_pgdat_section(struct pglist_data * pgdat,unsigned long size)264 sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
265 					 unsigned long size)
266 {
267 	unsigned long goal, limit;
268 	unsigned long *p;
269 	int nid;
270 	/*
271 	 * A page may contain usemaps for other sections preventing the
272 	 * page being freed and making a section unremovable while
273 	 * other sections referencing the usemap remain active. Similarly,
274 	 * a pgdat can prevent a section being removed. If section A
275 	 * contains a pgdat and section B contains the usemap, both
276 	 * sections become inter-dependent. This allocates usemaps
277 	 * from the same section as the pgdat where possible to avoid
278 	 * this problem.
279 	 */
280 	goal = __pa(pgdat) & (PAGE_SECTION_MASK << PAGE_SHIFT);
281 	limit = goal + (1UL << PA_SECTION_SHIFT);
282 	nid = early_pfn_to_nid(goal >> PAGE_SHIFT);
283 again:
284 	p = memblock_virt_alloc_try_nid_nopanic(size,
285 						SMP_CACHE_BYTES, goal, limit,
286 						nid);
287 	if (!p && limit) {
288 		limit = 0;
289 		goto again;
290 	}
291 	return p;
292 }
293 
check_usemap_section_nr(int nid,unsigned long * usemap)294 static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
295 {
296 	unsigned long usemap_snr, pgdat_snr;
297 	static unsigned long old_usemap_snr = NR_MEM_SECTIONS;
298 	static unsigned long old_pgdat_snr = NR_MEM_SECTIONS;
299 	struct pglist_data *pgdat = NODE_DATA(nid);
300 	int usemap_nid;
301 
302 	usemap_snr = pfn_to_section_nr(__pa(usemap) >> PAGE_SHIFT);
303 	pgdat_snr = pfn_to_section_nr(__pa(pgdat) >> PAGE_SHIFT);
304 	if (usemap_snr == pgdat_snr)
305 		return;
306 
307 	if (old_usemap_snr == usemap_snr && old_pgdat_snr == pgdat_snr)
308 		/* skip redundant message */
309 		return;
310 
311 	old_usemap_snr = usemap_snr;
312 	old_pgdat_snr = pgdat_snr;
313 
314 	usemap_nid = sparse_early_nid(__nr_to_section(usemap_snr));
315 	if (usemap_nid != nid) {
316 		printk(KERN_INFO
317 		       "node %d must be removed before remove section %ld\n",
318 		       nid, usemap_snr);
319 		return;
320 	}
321 	/*
322 	 * There is a circular dependency.
323 	 * Some platforms allow un-removable section because they will just
324 	 * gather other removable sections for dynamic partitioning.
325 	 * Just notify un-removable section's number here.
326 	 */
327 	printk(KERN_INFO "Section %ld and %ld (node %d)", usemap_snr,
328 	       pgdat_snr, nid);
329 	printk(KERN_CONT
330 	       " have a circular dependency on usemap and pgdat allocations\n");
331 }
332 #else
333 static unsigned long * __init
sparse_early_usemaps_alloc_pgdat_section(struct pglist_data * pgdat,unsigned long size)334 sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
335 					 unsigned long size)
336 {
337 	return memblock_virt_alloc_node_nopanic(size, pgdat->node_id);
338 }
339 
check_usemap_section_nr(int nid,unsigned long * usemap)340 static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
341 {
342 }
343 #endif /* CONFIG_MEMORY_HOTREMOVE */
344 
sparse_early_usemaps_alloc_node(void * data,unsigned long pnum_begin,unsigned long pnum_end,unsigned long usemap_count,int nodeid)345 static void __init sparse_early_usemaps_alloc_node(void *data,
346 				 unsigned long pnum_begin,
347 				 unsigned long pnum_end,
348 				 unsigned long usemap_count, int nodeid)
349 {
350 	void *usemap;
351 	unsigned long pnum;
352 	unsigned long **usemap_map = (unsigned long **)data;
353 	int size = usemap_size();
354 
355 	usemap = sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nodeid),
356 							  size * usemap_count);
357 	if (!usemap) {
358 		printk(KERN_WARNING "%s: allocation failed\n", __func__);
359 		return;
360 	}
361 
362 	for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
363 		if (!present_section_nr(pnum))
364 			continue;
365 		usemap_map[pnum] = usemap;
366 		usemap += size;
367 		check_usemap_section_nr(nodeid, usemap_map[pnum]);
368 	}
369 }
370 
371 #ifndef CONFIG_SPARSEMEM_VMEMMAP
sparse_mem_map_populate(unsigned long pnum,int nid)372 struct page __init *sparse_mem_map_populate(unsigned long pnum, int nid)
373 {
374 	struct page *map;
375 	unsigned long size;
376 
377 	map = alloc_remap(nid, sizeof(struct page) * PAGES_PER_SECTION);
378 	if (map)
379 		return map;
380 
381 	size = PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
382 	map = memblock_virt_alloc_try_nid(size,
383 					  PAGE_SIZE, __pa(MAX_DMA_ADDRESS),
384 					  BOOTMEM_ALLOC_ACCESSIBLE, nid);
385 	return map;
386 }
sparse_mem_maps_populate_node(struct page ** map_map,unsigned long pnum_begin,unsigned long pnum_end,unsigned long map_count,int nodeid)387 void __init sparse_mem_maps_populate_node(struct page **map_map,
388 					  unsigned long pnum_begin,
389 					  unsigned long pnum_end,
390 					  unsigned long map_count, int nodeid)
391 {
392 	void *map;
393 	unsigned long pnum;
394 	unsigned long size = sizeof(struct page) * PAGES_PER_SECTION;
395 
396 	map = alloc_remap(nodeid, size * map_count);
397 	if (map) {
398 		for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
399 			if (!present_section_nr(pnum))
400 				continue;
401 			map_map[pnum] = map;
402 			map += size;
403 		}
404 		return;
405 	}
406 
407 	size = PAGE_ALIGN(size);
408 	map = memblock_virt_alloc_try_nid(size * map_count,
409 					  PAGE_SIZE, __pa(MAX_DMA_ADDRESS),
410 					  BOOTMEM_ALLOC_ACCESSIBLE, nodeid);
411 	if (map) {
412 		for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
413 			if (!present_section_nr(pnum))
414 				continue;
415 			map_map[pnum] = map;
416 			map += size;
417 		}
418 		return;
419 	}
420 
421 	/* fallback */
422 	for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
423 		struct mem_section *ms;
424 
425 		if (!present_section_nr(pnum))
426 			continue;
427 		map_map[pnum] = sparse_mem_map_populate(pnum, nodeid);
428 		if (map_map[pnum])
429 			continue;
430 		ms = __nr_to_section(pnum);
431 		printk(KERN_ERR "%s: sparsemem memory map backing failed some memory will not be available.\n",
432 		       __func__);
433 		ms->section_mem_map = 0;
434 	}
435 }
436 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
437 
438 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
sparse_early_mem_maps_alloc_node(void * data,unsigned long pnum_begin,unsigned long pnum_end,unsigned long map_count,int nodeid)439 static void __init sparse_early_mem_maps_alloc_node(void *data,
440 				 unsigned long pnum_begin,
441 				 unsigned long pnum_end,
442 				 unsigned long map_count, int nodeid)
443 {
444 	struct page **map_map = (struct page **)data;
445 	sparse_mem_maps_populate_node(map_map, pnum_begin, pnum_end,
446 					 map_count, nodeid);
447 }
448 #else
sparse_early_mem_map_alloc(unsigned long pnum)449 static struct page __init *sparse_early_mem_map_alloc(unsigned long pnum)
450 {
451 	struct page *map;
452 	struct mem_section *ms = __nr_to_section(pnum);
453 	int nid = sparse_early_nid(ms);
454 
455 	map = sparse_mem_map_populate(pnum, nid);
456 	if (map)
457 		return map;
458 
459 	printk(KERN_ERR "%s: sparsemem memory map backing failed some memory will not be available.\n",
460 	       __func__);
461 	ms->section_mem_map = 0;
462 	return NULL;
463 }
464 #endif
465 
vmemmap_populate_print_last(void)466 void __weak __meminit vmemmap_populate_print_last(void)
467 {
468 }
469 
470 /**
471  *  alloc_usemap_and_memmap - memory alloction for pageblock flags and vmemmap
472  *  @map: usemap_map for pageblock flags or mmap_map for vmemmap
473  */
alloc_usemap_and_memmap(void (* alloc_func)(void *,unsigned long,unsigned long,unsigned long,int),void * data)474 static void __init alloc_usemap_and_memmap(void (*alloc_func)
475 					(void *, unsigned long, unsigned long,
476 					unsigned long, int), void *data)
477 {
478 	unsigned long pnum;
479 	unsigned long map_count;
480 	int nodeid_begin = 0;
481 	unsigned long pnum_begin = 0;
482 
483 	for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
484 		struct mem_section *ms;
485 
486 		if (!present_section_nr(pnum))
487 			continue;
488 		ms = __nr_to_section(pnum);
489 		nodeid_begin = sparse_early_nid(ms);
490 		pnum_begin = pnum;
491 		break;
492 	}
493 	map_count = 1;
494 	for (pnum = pnum_begin + 1; pnum < NR_MEM_SECTIONS; pnum++) {
495 		struct mem_section *ms;
496 		int nodeid;
497 
498 		if (!present_section_nr(pnum))
499 			continue;
500 		ms = __nr_to_section(pnum);
501 		nodeid = sparse_early_nid(ms);
502 		if (nodeid == nodeid_begin) {
503 			map_count++;
504 			continue;
505 		}
506 		/* ok, we need to take cake of from pnum_begin to pnum - 1*/
507 		alloc_func(data, pnum_begin, pnum,
508 						map_count, nodeid_begin);
509 		/* new start, update count etc*/
510 		nodeid_begin = nodeid;
511 		pnum_begin = pnum;
512 		map_count = 1;
513 	}
514 	/* ok, last chunk */
515 	alloc_func(data, pnum_begin, NR_MEM_SECTIONS,
516 						map_count, nodeid_begin);
517 }
518 
519 /*
520  * Allocate the accumulated non-linear sections, allocate a mem_map
521  * for each and record the physical to section mapping.
522  */
sparse_init(void)523 void __init sparse_init(void)
524 {
525 	unsigned long pnum;
526 	struct page *map;
527 	unsigned long *usemap;
528 	unsigned long **usemap_map;
529 	int size;
530 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
531 	int size2;
532 	struct page **map_map;
533 #endif
534 
535 	/* see include/linux/mmzone.h 'struct mem_section' definition */
536 	BUILD_BUG_ON(!is_power_of_2(sizeof(struct mem_section)));
537 
538 	/* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */
539 	set_pageblock_order();
540 
541 	/*
542 	 * map is using big page (aka 2M in x86 64 bit)
543 	 * usemap is less one page (aka 24 bytes)
544 	 * so alloc 2M (with 2M align) and 24 bytes in turn will
545 	 * make next 2M slip to one more 2M later.
546 	 * then in big system, the memory will have a lot of holes...
547 	 * here try to allocate 2M pages continuously.
548 	 *
549 	 * powerpc need to call sparse_init_one_section right after each
550 	 * sparse_early_mem_map_alloc, so allocate usemap_map at first.
551 	 */
552 	size = sizeof(unsigned long *) * NR_MEM_SECTIONS;
553 	usemap_map = memblock_virt_alloc(size, 0);
554 	if (!usemap_map)
555 		panic("can not allocate usemap_map\n");
556 	alloc_usemap_and_memmap(sparse_early_usemaps_alloc_node,
557 							(void *)usemap_map);
558 
559 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
560 	size2 = sizeof(struct page *) * NR_MEM_SECTIONS;
561 	map_map = memblock_virt_alloc(size2, 0);
562 	if (!map_map)
563 		panic("can not allocate map_map\n");
564 	alloc_usemap_and_memmap(sparse_early_mem_maps_alloc_node,
565 							(void *)map_map);
566 #endif
567 
568 	for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
569 		if (!present_section_nr(pnum))
570 			continue;
571 
572 		usemap = usemap_map[pnum];
573 		if (!usemap)
574 			continue;
575 
576 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
577 		map = map_map[pnum];
578 #else
579 		map = sparse_early_mem_map_alloc(pnum);
580 #endif
581 		if (!map)
582 			continue;
583 
584 		sparse_init_one_section(__nr_to_section(pnum), pnum, map,
585 								usemap);
586 	}
587 
588 	vmemmap_populate_print_last();
589 
590 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
591 	memblock_free_early(__pa(map_map), size2);
592 #endif
593 	memblock_free_early(__pa(usemap_map), size);
594 }
595 
596 #ifdef CONFIG_MEMORY_HOTPLUG
597 #ifdef CONFIG_SPARSEMEM_VMEMMAP
kmalloc_section_memmap(unsigned long pnum,int nid)598 static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid)
599 {
600 	/* This will make the necessary allocations eventually. */
601 	return sparse_mem_map_populate(pnum, nid);
602 }
__kfree_section_memmap(struct page * memmap)603 static void __kfree_section_memmap(struct page *memmap)
604 {
605 	unsigned long start = (unsigned long)memmap;
606 	unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION);
607 
608 	vmemmap_free(start, end);
609 }
610 #ifdef CONFIG_MEMORY_HOTREMOVE
free_map_bootmem(struct page * memmap)611 static void free_map_bootmem(struct page *memmap)
612 {
613 	unsigned long start = (unsigned long)memmap;
614 	unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION);
615 
616 	vmemmap_free(start, end);
617 }
618 #endif /* CONFIG_MEMORY_HOTREMOVE */
619 #else
__kmalloc_section_memmap(void)620 static struct page *__kmalloc_section_memmap(void)
621 {
622 	struct page *page, *ret;
623 	unsigned long memmap_size = sizeof(struct page) * PAGES_PER_SECTION;
624 
625 	page = alloc_pages(GFP_KERNEL|__GFP_NOWARN, get_order(memmap_size));
626 	if (page)
627 		goto got_map_page;
628 
629 	ret = vmalloc(memmap_size);
630 	if (ret)
631 		goto got_map_ptr;
632 
633 	return NULL;
634 got_map_page:
635 	ret = (struct page *)pfn_to_kaddr(page_to_pfn(page));
636 got_map_ptr:
637 
638 	return ret;
639 }
640 
kmalloc_section_memmap(unsigned long pnum,int nid)641 static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid)
642 {
643 	return __kmalloc_section_memmap();
644 }
645 
__kfree_section_memmap(struct page * memmap)646 static void __kfree_section_memmap(struct page *memmap)
647 {
648 	if (is_vmalloc_addr(memmap))
649 		vfree(memmap);
650 	else
651 		free_pages((unsigned long)memmap,
652 			   get_order(sizeof(struct page) * PAGES_PER_SECTION));
653 }
654 
655 #ifdef CONFIG_MEMORY_HOTREMOVE
free_map_bootmem(struct page * memmap)656 static void free_map_bootmem(struct page *memmap)
657 {
658 	unsigned long maps_section_nr, removing_section_nr, i;
659 	unsigned long magic, nr_pages;
660 	struct page *page = virt_to_page(memmap);
661 
662 	nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
663 		>> PAGE_SHIFT;
664 
665 	for (i = 0; i < nr_pages; i++, page++) {
666 		magic = (unsigned long) page->lru.next;
667 
668 		BUG_ON(magic == NODE_INFO);
669 
670 		maps_section_nr = pfn_to_section_nr(page_to_pfn(page));
671 		removing_section_nr = page->private;
672 
673 		/*
674 		 * When this function is called, the removing section is
675 		 * logical offlined state. This means all pages are isolated
676 		 * from page allocator. If removing section's memmap is placed
677 		 * on the same section, it must not be freed.
678 		 * If it is freed, page allocator may allocate it which will
679 		 * be removed physically soon.
680 		 */
681 		if (maps_section_nr != removing_section_nr)
682 			put_page_bootmem(page);
683 	}
684 }
685 #endif /* CONFIG_MEMORY_HOTREMOVE */
686 #endif /* CONFIG_SPARSEMEM_VMEMMAP */
687 
688 /*
689  * returns the number of sections whose mem_maps were properly
690  * set.  If this is <=0, then that means that the passed-in
691  * map was not consumed and must be freed.
692  */
sparse_add_one_section(struct zone * zone,unsigned long start_pfn)693 int __meminit sparse_add_one_section(struct zone *zone, unsigned long start_pfn)
694 {
695 	unsigned long section_nr = pfn_to_section_nr(start_pfn);
696 	struct pglist_data *pgdat = zone->zone_pgdat;
697 	struct mem_section *ms;
698 	struct page *memmap;
699 	unsigned long *usemap;
700 	unsigned long flags;
701 	int ret;
702 
703 	/*
704 	 * no locking for this, because it does its own
705 	 * plus, it does a kmalloc
706 	 */
707 	ret = sparse_index_init(section_nr, pgdat->node_id);
708 	if (ret < 0 && ret != -EEXIST)
709 		return ret;
710 	memmap = kmalloc_section_memmap(section_nr, pgdat->node_id);
711 	if (!memmap)
712 		return -ENOMEM;
713 	usemap = __kmalloc_section_usemap();
714 	if (!usemap) {
715 		__kfree_section_memmap(memmap);
716 		return -ENOMEM;
717 	}
718 
719 	pgdat_resize_lock(pgdat, &flags);
720 
721 	ms = __pfn_to_section(start_pfn);
722 	if (ms->section_mem_map & SECTION_MARKED_PRESENT) {
723 		ret = -EEXIST;
724 		goto out;
725 	}
726 
727 	memset(memmap, 0, sizeof(struct page) * PAGES_PER_SECTION);
728 
729 	ms->section_mem_map |= SECTION_MARKED_PRESENT;
730 
731 	ret = sparse_init_one_section(ms, section_nr, memmap, usemap);
732 
733 out:
734 	pgdat_resize_unlock(pgdat, &flags);
735 	if (ret <= 0) {
736 		kfree(usemap);
737 		__kfree_section_memmap(memmap);
738 	}
739 	return ret;
740 }
741 
742 #ifdef CONFIG_MEMORY_HOTREMOVE
743 #ifdef CONFIG_MEMORY_FAILURE
clear_hwpoisoned_pages(struct page * memmap,int nr_pages)744 static void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
745 {
746 	int i;
747 
748 	if (!memmap)
749 		return;
750 
751 	for (i = 0; i < PAGES_PER_SECTION; i++) {
752 		if (PageHWPoison(&memmap[i])) {
753 			atomic_long_sub(1, &num_poisoned_pages);
754 			ClearPageHWPoison(&memmap[i]);
755 		}
756 	}
757 }
758 #else
clear_hwpoisoned_pages(struct page * memmap,int nr_pages)759 static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
760 {
761 }
762 #endif
763 
free_section_usemap(struct page * memmap,unsigned long * usemap)764 static void free_section_usemap(struct page *memmap, unsigned long *usemap)
765 {
766 	struct page *usemap_page;
767 
768 	if (!usemap)
769 		return;
770 
771 	usemap_page = virt_to_page(usemap);
772 	/*
773 	 * Check to see if allocation came from hot-plug-add
774 	 */
775 	if (PageSlab(usemap_page) || PageCompound(usemap_page)) {
776 		kfree(usemap);
777 		if (memmap)
778 			__kfree_section_memmap(memmap);
779 		return;
780 	}
781 
782 	/*
783 	 * The usemap came from bootmem. This is packed with other usemaps
784 	 * on the section which has pgdat at boot time. Just keep it as is now.
785 	 */
786 
787 	if (memmap)
788 		free_map_bootmem(memmap);
789 }
790 
sparse_remove_one_section(struct zone * zone,struct mem_section * ms)791 void sparse_remove_one_section(struct zone *zone, struct mem_section *ms)
792 {
793 	struct page *memmap = NULL;
794 	unsigned long *usemap = NULL, flags;
795 	struct pglist_data *pgdat = zone->zone_pgdat;
796 
797 	pgdat_resize_lock(pgdat, &flags);
798 	if (ms->section_mem_map) {
799 		usemap = ms->pageblock_flags;
800 		memmap = sparse_decode_mem_map(ms->section_mem_map,
801 						__section_nr(ms));
802 		ms->section_mem_map = 0;
803 		ms->pageblock_flags = NULL;
804 	}
805 	pgdat_resize_unlock(pgdat, &flags);
806 
807 	clear_hwpoisoned_pages(memmap, PAGES_PER_SECTION);
808 	free_section_usemap(memmap, usemap);
809 }
810 #endif /* CONFIG_MEMORY_HOTREMOVE */
811 #endif /* CONFIG_MEMORY_HOTPLUG */
812