xref: /linux/drivers/nvdimm/label.c (revision f9aec1648df09d55436a0e3a94acff1df507751f)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
4  */
5 #include <linux/device.h>
6 #include <linux/ndctl.h>
7 #include <linux/uuid.h>
8 #include <linux/slab.h>
9 #include <linux/io.h>
10 #include <linux/nd.h>
11 #include "nd-core.h"
12 #include "label.h"
13 #include "nd.h"
14 
15 static guid_t nvdimm_btt_guid;
16 static guid_t nvdimm_btt2_guid;
17 static guid_t nvdimm_pfn_guid;
18 static guid_t nvdimm_dax_guid;
19 
20 static const char NSINDEX_SIGNATURE[] = "NAMESPACE_INDEX\0";
21 
22 static u32 best_seq(u32 a, u32 b)
23 {
24 	a &= NSINDEX_SEQ_MASK;
25 	b &= NSINDEX_SEQ_MASK;
26 
27 	if (a == 0 || a == b)
28 		return b;
29 	else if (b == 0)
30 		return a;
31 	else if (nd_inc_seq(a) == b)
32 		return b;
33 	else
34 		return a;
35 }
36 
37 unsigned sizeof_namespace_label(struct nvdimm_drvdata *ndd)
38 {
39 	return ndd->nslabel_size;
40 }
41 
42 static size_t __sizeof_namespace_index(u32 nslot)
43 {
44 	return ALIGN(sizeof(struct nd_namespace_index) + DIV_ROUND_UP(nslot, 8),
45 			NSINDEX_ALIGN);
46 }
47 
48 static int __nvdimm_num_label_slots(struct nvdimm_drvdata *ndd,
49 		size_t index_size)
50 {
51 	return (ndd->nsarea.config_size - index_size * 2) /
52 			sizeof_namespace_label(ndd);
53 }
54 
55 int nvdimm_num_label_slots(struct nvdimm_drvdata *ndd)
56 {
57 	u32 tmp_nslot, n;
58 
59 	tmp_nslot = ndd->nsarea.config_size / sizeof_namespace_label(ndd);
60 	n = __sizeof_namespace_index(tmp_nslot) / NSINDEX_ALIGN;
61 
62 	return __nvdimm_num_label_slots(ndd, NSINDEX_ALIGN * n);
63 }
64 
65 size_t sizeof_namespace_index(struct nvdimm_drvdata *ndd)
66 {
67 	u32 nslot, space, size;
68 
69 	/*
70 	 * Per UEFI 2.7, the minimum size of the Label Storage Area is large
71 	 * enough to hold 2 index blocks and 2 labels.  The minimum index
72 	 * block size is 256 bytes. The label size is 128 for namespaces
73 	 * prior to version 1.2 and at minimum 256 for version 1.2 and later.
74 	 */
75 	nslot = nvdimm_num_label_slots(ndd);
76 	space = ndd->nsarea.config_size - nslot * sizeof_namespace_label(ndd);
77 	size = __sizeof_namespace_index(nslot) * 2;
78 	if (size <= space && nslot >= 2)
79 		return size / 2;
80 
81 	dev_err(ndd->dev, "label area (%d) too small to host (%d byte) labels\n",
82 			ndd->nsarea.config_size, sizeof_namespace_label(ndd));
83 	return 0;
84 }
85 
86 static int __nd_label_validate(struct nvdimm_drvdata *ndd)
87 {
88 	/*
89 	 * On media label format consists of two index blocks followed
90 	 * by an array of labels.  None of these structures are ever
91 	 * updated in place.  A sequence number tracks the current
92 	 * active index and the next one to write, while labels are
93 	 * written to free slots.
94 	 *
95 	 *     +------------+
96 	 *     |            |
97 	 *     |  nsindex0  |
98 	 *     |            |
99 	 *     +------------+
100 	 *     |            |
101 	 *     |  nsindex1  |
102 	 *     |            |
103 	 *     +------------+
104 	 *     |   label0   |
105 	 *     +------------+
106 	 *     |   label1   |
107 	 *     +------------+
108 	 *     |            |
109 	 *      ....nslot...
110 	 *     |            |
111 	 *     +------------+
112 	 *     |   labelN   |
113 	 *     +------------+
114 	 */
115 	struct nd_namespace_index *nsindex[] = {
116 		to_namespace_index(ndd, 0),
117 		to_namespace_index(ndd, 1),
118 	};
119 	const int num_index = ARRAY_SIZE(nsindex);
120 	struct device *dev = ndd->dev;
121 	bool valid[2] = { 0 };
122 	int i, num_valid = 0;
123 	u32 seq;
124 
125 	for (i = 0; i < num_index; i++) {
126 		u32 nslot;
127 		u8 sig[NSINDEX_SIG_LEN];
128 		u64 sum_save, sum, size;
129 		unsigned int version, labelsize;
130 
131 		memcpy(sig, nsindex[i]->sig, NSINDEX_SIG_LEN);
132 		if (memcmp(sig, NSINDEX_SIGNATURE, NSINDEX_SIG_LEN) != 0) {
133 			dev_dbg(dev, "nsindex%d signature invalid\n", i);
134 			continue;
135 		}
136 
137 		/* label sizes larger than 128 arrived with v1.2 */
138 		version = __le16_to_cpu(nsindex[i]->major) * 100
139 			+ __le16_to_cpu(nsindex[i]->minor);
140 		if (version >= 102)
141 			labelsize = 1 << (7 + nsindex[i]->labelsize);
142 		else
143 			labelsize = 128;
144 
145 		if (labelsize != sizeof_namespace_label(ndd)) {
146 			dev_dbg(dev, "nsindex%d labelsize %d invalid\n",
147 					i, nsindex[i]->labelsize);
148 			continue;
149 		}
150 
151 		sum_save = __le64_to_cpu(nsindex[i]->checksum);
152 		nsindex[i]->checksum = __cpu_to_le64(0);
153 		sum = nd_fletcher64(nsindex[i], sizeof_namespace_index(ndd), 1);
154 		nsindex[i]->checksum = __cpu_to_le64(sum_save);
155 		if (sum != sum_save) {
156 			dev_dbg(dev, "nsindex%d checksum invalid\n", i);
157 			continue;
158 		}
159 
160 		seq = __le32_to_cpu(nsindex[i]->seq);
161 		if ((seq & NSINDEX_SEQ_MASK) == 0) {
162 			dev_dbg(dev, "nsindex%d sequence: %#x invalid\n", i, seq);
163 			continue;
164 		}
165 
166 		/* sanity check the index against expected values */
167 		if (__le64_to_cpu(nsindex[i]->myoff)
168 				!= i * sizeof_namespace_index(ndd)) {
169 			dev_dbg(dev, "nsindex%d myoff: %#llx invalid\n",
170 					i, (unsigned long long)
171 					__le64_to_cpu(nsindex[i]->myoff));
172 			continue;
173 		}
174 		if (__le64_to_cpu(nsindex[i]->otheroff)
175 				!= (!i) * sizeof_namespace_index(ndd)) {
176 			dev_dbg(dev, "nsindex%d otheroff: %#llx invalid\n",
177 					i, (unsigned long long)
178 					__le64_to_cpu(nsindex[i]->otheroff));
179 			continue;
180 		}
181 		if (__le64_to_cpu(nsindex[i]->labeloff)
182 				!= 2 * sizeof_namespace_index(ndd)) {
183 			dev_dbg(dev, "nsindex%d labeloff: %#llx invalid\n",
184 					i, (unsigned long long)
185 					__le64_to_cpu(nsindex[i]->labeloff));
186 			continue;
187 		}
188 
189 		size = __le64_to_cpu(nsindex[i]->mysize);
190 		if (size > sizeof_namespace_index(ndd)
191 				|| size < sizeof(struct nd_namespace_index)) {
192 			dev_dbg(dev, "nsindex%d mysize: %#llx invalid\n", i, size);
193 			continue;
194 		}
195 
196 		nslot = __le32_to_cpu(nsindex[i]->nslot);
197 		if (nslot * sizeof_namespace_label(ndd)
198 				+ 2 * sizeof_namespace_index(ndd)
199 				> ndd->nsarea.config_size) {
200 			dev_dbg(dev, "nsindex%d nslot: %u invalid, config_size: %#x\n",
201 					i, nslot, ndd->nsarea.config_size);
202 			continue;
203 		}
204 		valid[i] = true;
205 		num_valid++;
206 	}
207 
208 	switch (num_valid) {
209 	case 0:
210 		break;
211 	case 1:
212 		for (i = 0; i < num_index; i++)
213 			if (valid[i])
214 				return i;
215 		/* can't have num_valid > 0 but valid[] = { false, false } */
216 		WARN_ON(1);
217 		break;
218 	default:
219 		/* pick the best index... */
220 		seq = best_seq(__le32_to_cpu(nsindex[0]->seq),
221 				__le32_to_cpu(nsindex[1]->seq));
222 		if (seq == (__le32_to_cpu(nsindex[1]->seq) & NSINDEX_SEQ_MASK))
223 			return 1;
224 		else
225 			return 0;
226 		break;
227 	}
228 
229 	return -1;
230 }
231 
232 static int nd_label_validate(struct nvdimm_drvdata *ndd)
233 {
234 	/*
235 	 * In order to probe for and validate namespace index blocks we
236 	 * need to know the size of the labels, and we can't trust the
237 	 * size of the labels until we validate the index blocks.
238 	 * Resolve this dependency loop by probing for known label
239 	 * sizes, but default to v1.2 256-byte namespace labels if
240 	 * discovery fails.
241 	 */
242 	int label_size[] = { 128, 256 };
243 	int i, rc;
244 
245 	for (i = 0; i < ARRAY_SIZE(label_size); i++) {
246 		ndd->nslabel_size = label_size[i];
247 		rc = __nd_label_validate(ndd);
248 		if (rc >= 0)
249 			return rc;
250 	}
251 
252 	return -1;
253 }
254 
255 static void nd_label_copy(struct nvdimm_drvdata *ndd,
256 			  struct nd_namespace_index *dst,
257 			  struct nd_namespace_index *src)
258 {
259 	/* just exit if either destination or source is NULL */
260 	if (!dst || !src)
261 		return;
262 
263 	memcpy(dst, src, sizeof_namespace_index(ndd));
264 }
265 
266 static struct nd_namespace_label *nd_label_base(struct nvdimm_drvdata *ndd)
267 {
268 	void *base = to_namespace_index(ndd, 0);
269 
270 	return base + 2 * sizeof_namespace_index(ndd);
271 }
272 
273 static int to_slot(struct nvdimm_drvdata *ndd,
274 		struct nd_namespace_label *nd_label)
275 {
276 	unsigned long label, base;
277 
278 	label = (unsigned long) nd_label;
279 	base = (unsigned long) nd_label_base(ndd);
280 
281 	return (label - base) / sizeof_namespace_label(ndd);
282 }
283 
284 static struct nd_namespace_label *to_label(struct nvdimm_drvdata *ndd, int slot)
285 {
286 	unsigned long label, base;
287 
288 	base = (unsigned long) nd_label_base(ndd);
289 	label = base + sizeof_namespace_label(ndd) * slot;
290 
291 	return (struct nd_namespace_label *) label;
292 }
293 
294 #define for_each_clear_bit_le(bit, addr, size) \
295 	for ((bit) = find_next_zero_bit_le((addr), (size), 0);  \
296 	     (bit) < (size);                                    \
297 	     (bit) = find_next_zero_bit_le((addr), (size), (bit) + 1))
298 
299 /**
300  * preamble_index - common variable initialization for nd_label_* routines
301  * @ndd: dimm container for the relevant label set
302  * @idx: namespace_index index
303  * @nsindex_out: on return set to the currently active namespace index
304  * @free: on return set to the free label bitmap in the index
305  * @nslot: on return set to the number of slots in the label space
306  */
307 static bool preamble_index(struct nvdimm_drvdata *ndd, int idx,
308 		struct nd_namespace_index **nsindex_out,
309 		unsigned long **free, u32 *nslot)
310 {
311 	struct nd_namespace_index *nsindex;
312 
313 	nsindex = to_namespace_index(ndd, idx);
314 	if (nsindex == NULL)
315 		return false;
316 
317 	*free = (unsigned long *) nsindex->free;
318 	*nslot = __le32_to_cpu(nsindex->nslot);
319 	*nsindex_out = nsindex;
320 
321 	return true;
322 }
323 
324 char *nd_label_gen_id(struct nd_label_id *label_id, u8 *uuid, u32 flags)
325 {
326 	if (!label_id || !uuid)
327 		return NULL;
328 	snprintf(label_id->id, ND_LABEL_ID_SIZE, "%s-%pUb",
329 			flags & NSLABEL_FLAG_LOCAL ? "blk" : "pmem", uuid);
330 	return label_id->id;
331 }
332 
333 static bool preamble_current(struct nvdimm_drvdata *ndd,
334 		struct nd_namespace_index **nsindex,
335 		unsigned long **free, u32 *nslot)
336 {
337 	return preamble_index(ndd, ndd->ns_current, nsindex,
338 			free, nslot);
339 }
340 
341 static bool preamble_next(struct nvdimm_drvdata *ndd,
342 		struct nd_namespace_index **nsindex,
343 		unsigned long **free, u32 *nslot)
344 {
345 	return preamble_index(ndd, ndd->ns_next, nsindex,
346 			free, nslot);
347 }
348 
349 static bool nsl_validate_checksum(struct nvdimm_drvdata *ndd,
350 				  struct nd_namespace_label *nd_label)
351 {
352 	u64 sum, sum_save;
353 
354 	if (!namespace_label_has(ndd, checksum))
355 		return true;
356 
357 	sum_save = nsl_get_checksum(ndd, nd_label);
358 	nsl_set_checksum(ndd, nd_label, 0);
359 	sum = nd_fletcher64(nd_label, sizeof_namespace_label(ndd), 1);
360 	nsl_set_checksum(ndd, nd_label, sum_save);
361 	return sum == sum_save;
362 }
363 
364 static void nsl_calculate_checksum(struct nvdimm_drvdata *ndd,
365 				   struct nd_namespace_label *nd_label)
366 {
367 	u64 sum;
368 
369 	if (!namespace_label_has(ndd, checksum))
370 		return;
371 	nsl_set_checksum(ndd, nd_label, 0);
372 	sum = nd_fletcher64(nd_label, sizeof_namespace_label(ndd), 1);
373 	nsl_set_checksum(ndd, nd_label, sum);
374 }
375 
376 static bool slot_valid(struct nvdimm_drvdata *ndd,
377 		struct nd_namespace_label *nd_label, u32 slot)
378 {
379 	bool valid;
380 
381 	/* check that we are written where we expect to be written */
382 	if (slot != nsl_get_slot(ndd, nd_label))
383 		return false;
384 	valid = nsl_validate_checksum(ndd, nd_label);
385 	if (!valid)
386 		dev_dbg(ndd->dev, "fail checksum. slot: %d\n", slot);
387 	return valid;
388 }
389 
390 int nd_label_reserve_dpa(struct nvdimm_drvdata *ndd)
391 {
392 	struct nd_namespace_index *nsindex;
393 	unsigned long *free;
394 	u32 nslot, slot;
395 
396 	if (!preamble_current(ndd, &nsindex, &free, &nslot))
397 		return 0; /* no label, nothing to reserve */
398 
399 	for_each_clear_bit_le(slot, free, nslot) {
400 		struct nvdimm *nvdimm = to_nvdimm(ndd->dev);
401 		struct nd_namespace_label *nd_label;
402 		struct nd_region *nd_region = NULL;
403 		u8 label_uuid[NSLABEL_UUID_LEN];
404 		struct nd_label_id label_id;
405 		struct resource *res;
406 		u32 flags;
407 
408 		nd_label = to_label(ndd, slot);
409 
410 		if (!slot_valid(ndd, nd_label, slot))
411 			continue;
412 
413 		memcpy(label_uuid, nd_label->uuid, NSLABEL_UUID_LEN);
414 		flags = nsl_get_flags(ndd, nd_label);
415 		if (test_bit(NDD_NOBLK, &nvdimm->flags))
416 			flags &= ~NSLABEL_FLAG_LOCAL;
417 		nd_label_gen_id(&label_id, label_uuid, flags);
418 		res = nvdimm_allocate_dpa(ndd, &label_id,
419 					  nsl_get_dpa(ndd, nd_label),
420 					  nsl_get_rawsize(ndd, nd_label));
421 		nd_dbg_dpa(nd_region, ndd, res, "reserve\n");
422 		if (!res)
423 			return -EBUSY;
424 	}
425 
426 	return 0;
427 }
428 
429 int nd_label_data_init(struct nvdimm_drvdata *ndd)
430 {
431 	size_t config_size, read_size, max_xfer, offset;
432 	struct nd_namespace_index *nsindex;
433 	unsigned int i;
434 	int rc = 0;
435 	u32 nslot;
436 
437 	if (ndd->data)
438 		return 0;
439 
440 	if (ndd->nsarea.status || ndd->nsarea.max_xfer == 0) {
441 		dev_dbg(ndd->dev, "failed to init config data area: (%u:%u)\n",
442 			ndd->nsarea.max_xfer, ndd->nsarea.config_size);
443 		return -ENXIO;
444 	}
445 
446 	/*
447 	 * We need to determine the maximum index area as this is the section
448 	 * we must read and validate before we can start processing labels.
449 	 *
450 	 * If the area is too small to contain the two indexes and 2 labels
451 	 * then we abort.
452 	 *
453 	 * Start at a label size of 128 as this should result in the largest
454 	 * possible namespace index size.
455 	 */
456 	ndd->nslabel_size = 128;
457 	read_size = sizeof_namespace_index(ndd) * 2;
458 	if (!read_size)
459 		return -ENXIO;
460 
461 	/* Allocate config data */
462 	config_size = ndd->nsarea.config_size;
463 	ndd->data = kvzalloc(config_size, GFP_KERNEL);
464 	if (!ndd->data)
465 		return -ENOMEM;
466 
467 	/*
468 	 * We want to guarantee as few reads as possible while conserving
469 	 * memory. To do that we figure out how much unused space will be left
470 	 * in the last read, divide that by the total number of reads it is
471 	 * going to take given our maximum transfer size, and then reduce our
472 	 * maximum transfer size based on that result.
473 	 */
474 	max_xfer = min_t(size_t, ndd->nsarea.max_xfer, config_size);
475 	if (read_size < max_xfer) {
476 		/* trim waste */
477 		max_xfer -= ((max_xfer - 1) - (config_size - 1) % max_xfer) /
478 			    DIV_ROUND_UP(config_size, max_xfer);
479 		/* make certain we read indexes in exactly 1 read */
480 		if (max_xfer < read_size)
481 			max_xfer = read_size;
482 	}
483 
484 	/* Make our initial read size a multiple of max_xfer size */
485 	read_size = min(DIV_ROUND_UP(read_size, max_xfer) * max_xfer,
486 			config_size);
487 
488 	/* Read the index data */
489 	rc = nvdimm_get_config_data(ndd, ndd->data, 0, read_size);
490 	if (rc)
491 		goto out_err;
492 
493 	/* Validate index data, if not valid assume all labels are invalid */
494 	ndd->ns_current = nd_label_validate(ndd);
495 	if (ndd->ns_current < 0)
496 		return 0;
497 
498 	/* Record our index values */
499 	ndd->ns_next = nd_label_next_nsindex(ndd->ns_current);
500 
501 	/* Copy "current" index on top of the "next" index */
502 	nsindex = to_current_namespace_index(ndd);
503 	nd_label_copy(ndd, to_next_namespace_index(ndd), nsindex);
504 
505 	/* Determine starting offset for label data */
506 	offset = __le64_to_cpu(nsindex->labeloff);
507 	nslot = __le32_to_cpu(nsindex->nslot);
508 
509 	/* Loop through the free list pulling in any active labels */
510 	for (i = 0; i < nslot; i++, offset += ndd->nslabel_size) {
511 		size_t label_read_size;
512 
513 		/* zero out the unused labels */
514 		if (test_bit_le(i, nsindex->free)) {
515 			memset(ndd->data + offset, 0, ndd->nslabel_size);
516 			continue;
517 		}
518 
519 		/* if we already read past here then just continue */
520 		if (offset + ndd->nslabel_size <= read_size)
521 			continue;
522 
523 		/* if we haven't read in a while reset our read_size offset */
524 		if (read_size < offset)
525 			read_size = offset;
526 
527 		/* determine how much more will be read after this next call. */
528 		label_read_size = offset + ndd->nslabel_size - read_size;
529 		label_read_size = DIV_ROUND_UP(label_read_size, max_xfer) *
530 				  max_xfer;
531 
532 		/* truncate last read if needed */
533 		if (read_size + label_read_size > config_size)
534 			label_read_size = config_size - read_size;
535 
536 		/* Read the label data */
537 		rc = nvdimm_get_config_data(ndd, ndd->data + read_size,
538 					    read_size, label_read_size);
539 		if (rc)
540 			goto out_err;
541 
542 		/* push read_size to next read offset */
543 		read_size += label_read_size;
544 	}
545 
546 	dev_dbg(ndd->dev, "len: %zu rc: %d\n", offset, rc);
547 out_err:
548 	return rc;
549 }
550 
551 int nd_label_active_count(struct nvdimm_drvdata *ndd)
552 {
553 	struct nd_namespace_index *nsindex;
554 	unsigned long *free;
555 	u32 nslot, slot;
556 	int count = 0;
557 
558 	if (!preamble_current(ndd, &nsindex, &free, &nslot))
559 		return 0;
560 
561 	for_each_clear_bit_le(slot, free, nslot) {
562 		struct nd_namespace_label *nd_label;
563 
564 		nd_label = to_label(ndd, slot);
565 
566 		if (!slot_valid(ndd, nd_label, slot)) {
567 			u32 label_slot = nsl_get_slot(ndd, nd_label);
568 			u64 size = nsl_get_rawsize(ndd, nd_label);
569 			u64 dpa = nsl_get_dpa(ndd, nd_label);
570 
571 			dev_dbg(ndd->dev,
572 				"slot%d invalid slot: %d dpa: %llx size: %llx\n",
573 					slot, label_slot, dpa, size);
574 			continue;
575 		}
576 		count++;
577 	}
578 	return count;
579 }
580 
581 struct nd_namespace_label *nd_label_active(struct nvdimm_drvdata *ndd, int n)
582 {
583 	struct nd_namespace_index *nsindex;
584 	unsigned long *free;
585 	u32 nslot, slot;
586 
587 	if (!preamble_current(ndd, &nsindex, &free, &nslot))
588 		return NULL;
589 
590 	for_each_clear_bit_le(slot, free, nslot) {
591 		struct nd_namespace_label *nd_label;
592 
593 		nd_label = to_label(ndd, slot);
594 		if (!slot_valid(ndd, nd_label, slot))
595 			continue;
596 
597 		if (n-- == 0)
598 			return to_label(ndd, slot);
599 	}
600 
601 	return NULL;
602 }
603 
604 u32 nd_label_alloc_slot(struct nvdimm_drvdata *ndd)
605 {
606 	struct nd_namespace_index *nsindex;
607 	unsigned long *free;
608 	u32 nslot, slot;
609 
610 	if (!preamble_next(ndd, &nsindex, &free, &nslot))
611 		return UINT_MAX;
612 
613 	WARN_ON(!is_nvdimm_bus_locked(ndd->dev));
614 
615 	slot = find_next_bit_le(free, nslot, 0);
616 	if (slot == nslot)
617 		return UINT_MAX;
618 
619 	clear_bit_le(slot, free);
620 
621 	return slot;
622 }
623 
624 bool nd_label_free_slot(struct nvdimm_drvdata *ndd, u32 slot)
625 {
626 	struct nd_namespace_index *nsindex;
627 	unsigned long *free;
628 	u32 nslot;
629 
630 	if (!preamble_next(ndd, &nsindex, &free, &nslot))
631 		return false;
632 
633 	WARN_ON(!is_nvdimm_bus_locked(ndd->dev));
634 
635 	if (slot < nslot)
636 		return !test_and_set_bit_le(slot, free);
637 	return false;
638 }
639 
640 u32 nd_label_nfree(struct nvdimm_drvdata *ndd)
641 {
642 	struct nd_namespace_index *nsindex;
643 	unsigned long *free;
644 	u32 nslot;
645 
646 	WARN_ON(!is_nvdimm_bus_locked(ndd->dev));
647 
648 	if (!preamble_next(ndd, &nsindex, &free, &nslot))
649 		return nvdimm_num_label_slots(ndd);
650 
651 	return bitmap_weight(free, nslot);
652 }
653 
654 static int nd_label_write_index(struct nvdimm_drvdata *ndd, int index, u32 seq,
655 		unsigned long flags)
656 {
657 	struct nd_namespace_index *nsindex;
658 	unsigned long offset;
659 	u64 checksum;
660 	u32 nslot;
661 	int rc;
662 
663 	nsindex = to_namespace_index(ndd, index);
664 	if (flags & ND_NSINDEX_INIT)
665 		nslot = nvdimm_num_label_slots(ndd);
666 	else
667 		nslot = __le32_to_cpu(nsindex->nslot);
668 
669 	memcpy(nsindex->sig, NSINDEX_SIGNATURE, NSINDEX_SIG_LEN);
670 	memset(&nsindex->flags, 0, 3);
671 	nsindex->labelsize = sizeof_namespace_label(ndd) >> 8;
672 	nsindex->seq = __cpu_to_le32(seq);
673 	offset = (unsigned long) nsindex
674 		- (unsigned long) to_namespace_index(ndd, 0);
675 	nsindex->myoff = __cpu_to_le64(offset);
676 	nsindex->mysize = __cpu_to_le64(sizeof_namespace_index(ndd));
677 	offset = (unsigned long) to_namespace_index(ndd,
678 			nd_label_next_nsindex(index))
679 		- (unsigned long) to_namespace_index(ndd, 0);
680 	nsindex->otheroff = __cpu_to_le64(offset);
681 	offset = (unsigned long) nd_label_base(ndd)
682 		- (unsigned long) to_namespace_index(ndd, 0);
683 	nsindex->labeloff = __cpu_to_le64(offset);
684 	nsindex->nslot = __cpu_to_le32(nslot);
685 	nsindex->major = __cpu_to_le16(1);
686 	if (sizeof_namespace_label(ndd) < 256)
687 		nsindex->minor = __cpu_to_le16(1);
688 	else
689 		nsindex->minor = __cpu_to_le16(2);
690 	nsindex->checksum = __cpu_to_le64(0);
691 	if (flags & ND_NSINDEX_INIT) {
692 		unsigned long *free = (unsigned long *) nsindex->free;
693 		u32 nfree = ALIGN(nslot, BITS_PER_LONG);
694 		int last_bits, i;
695 
696 		memset(nsindex->free, 0xff, nfree / 8);
697 		for (i = 0, last_bits = nfree - nslot; i < last_bits; i++)
698 			clear_bit_le(nslot + i, free);
699 	}
700 	checksum = nd_fletcher64(nsindex, sizeof_namespace_index(ndd), 1);
701 	nsindex->checksum = __cpu_to_le64(checksum);
702 	rc = nvdimm_set_config_data(ndd, __le64_to_cpu(nsindex->myoff),
703 			nsindex, sizeof_namespace_index(ndd));
704 	if (rc < 0)
705 		return rc;
706 
707 	if (flags & ND_NSINDEX_INIT)
708 		return 0;
709 
710 	/* copy the index we just wrote to the new 'next' */
711 	WARN_ON(index != ndd->ns_next);
712 	nd_label_copy(ndd, to_current_namespace_index(ndd), nsindex);
713 	ndd->ns_current = nd_label_next_nsindex(ndd->ns_current);
714 	ndd->ns_next = nd_label_next_nsindex(ndd->ns_next);
715 	WARN_ON(ndd->ns_current == ndd->ns_next);
716 
717 	return 0;
718 }
719 
720 static unsigned long nd_label_offset(struct nvdimm_drvdata *ndd,
721 		struct nd_namespace_label *nd_label)
722 {
723 	return (unsigned long) nd_label
724 		- (unsigned long) to_namespace_index(ndd, 0);
725 }
726 
727 static enum nvdimm_claim_class to_nvdimm_cclass(guid_t *guid)
728 {
729 	if (guid_equal(guid, &nvdimm_btt_guid))
730 		return NVDIMM_CCLASS_BTT;
731 	else if (guid_equal(guid, &nvdimm_btt2_guid))
732 		return NVDIMM_CCLASS_BTT2;
733 	else if (guid_equal(guid, &nvdimm_pfn_guid))
734 		return NVDIMM_CCLASS_PFN;
735 	else if (guid_equal(guid, &nvdimm_dax_guid))
736 		return NVDIMM_CCLASS_DAX;
737 	else if (guid_equal(guid, &guid_null))
738 		return NVDIMM_CCLASS_NONE;
739 
740 	return NVDIMM_CCLASS_UNKNOWN;
741 }
742 
743 static const guid_t *to_abstraction_guid(enum nvdimm_claim_class claim_class,
744 	guid_t *target)
745 {
746 	if (claim_class == NVDIMM_CCLASS_BTT)
747 		return &nvdimm_btt_guid;
748 	else if (claim_class == NVDIMM_CCLASS_BTT2)
749 		return &nvdimm_btt2_guid;
750 	else if (claim_class == NVDIMM_CCLASS_PFN)
751 		return &nvdimm_pfn_guid;
752 	else if (claim_class == NVDIMM_CCLASS_DAX)
753 		return &nvdimm_dax_guid;
754 	else if (claim_class == NVDIMM_CCLASS_UNKNOWN) {
755 		/*
756 		 * If we're modifying a namespace for which we don't
757 		 * know the claim_class, don't touch the existing guid.
758 		 */
759 		return target;
760 	} else
761 		return &guid_null;
762 }
763 
764 static void reap_victim(struct nd_mapping *nd_mapping,
765 		struct nd_label_ent *victim)
766 {
767 	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
768 	u32 slot = to_slot(ndd, victim->label);
769 
770 	dev_dbg(ndd->dev, "free: %d\n", slot);
771 	nd_label_free_slot(ndd, slot);
772 	victim->label = NULL;
773 }
774 
775 static void nsl_set_type_guid(struct nvdimm_drvdata *ndd,
776 			      struct nd_namespace_label *nd_label, guid_t *guid)
777 {
778 	if (namespace_label_has(ndd, type_guid))
779 		guid_copy(&nd_label->type_guid, guid);
780 }
781 
782 bool nsl_validate_type_guid(struct nvdimm_drvdata *ndd,
783 			    struct nd_namespace_label *nd_label, guid_t *guid)
784 {
785 	if (!namespace_label_has(ndd, type_guid))
786 		return true;
787 	if (!guid_equal(&nd_label->type_guid, guid)) {
788 		dev_dbg(ndd->dev, "expect type_guid %pUb got %pUb\n", guid,
789 			&nd_label->type_guid);
790 		return false;
791 	}
792 	return true;
793 }
794 
795 static void nsl_set_claim_class(struct nvdimm_drvdata *ndd,
796 				struct nd_namespace_label *nd_label,
797 				enum nvdimm_claim_class claim_class)
798 {
799 	if (!namespace_label_has(ndd, abstraction_guid))
800 		return;
801 	guid_copy(&nd_label->abstraction_guid,
802 		  to_abstraction_guid(claim_class,
803 				      &nd_label->abstraction_guid));
804 }
805 
806 enum nvdimm_claim_class nsl_get_claim_class(struct nvdimm_drvdata *ndd,
807 					    struct nd_namespace_label *nd_label)
808 {
809 	if (!namespace_label_has(ndd, abstraction_guid))
810 		return NVDIMM_CCLASS_NONE;
811 	return to_nvdimm_cclass(&nd_label->abstraction_guid);
812 }
813 
814 static int __pmem_label_update(struct nd_region *nd_region,
815 		struct nd_mapping *nd_mapping, struct nd_namespace_pmem *nspm,
816 		int pos, unsigned long flags)
817 {
818 	struct nd_namespace_common *ndns = &nspm->nsio.common;
819 	struct nd_interleave_set *nd_set = nd_region->nd_set;
820 	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
821 	struct nd_namespace_label *nd_label;
822 	struct nd_namespace_index *nsindex;
823 	struct nd_label_ent *label_ent;
824 	struct nd_label_id label_id;
825 	struct resource *res;
826 	unsigned long *free;
827 	u32 nslot, slot;
828 	size_t offset;
829 	u64 cookie;
830 	int rc;
831 
832 	if (!preamble_next(ndd, &nsindex, &free, &nslot))
833 		return -ENXIO;
834 
835 	cookie = nd_region_interleave_set_cookie(nd_region, nsindex);
836 	nd_label_gen_id(&label_id, nspm->uuid, 0);
837 	for_each_dpa_resource(ndd, res)
838 		if (strcmp(res->name, label_id.id) == 0)
839 			break;
840 
841 	if (!res) {
842 		WARN_ON_ONCE(1);
843 		return -ENXIO;
844 	}
845 
846 	/* allocate and write the label to the staging (next) index */
847 	slot = nd_label_alloc_slot(ndd);
848 	if (slot == UINT_MAX)
849 		return -ENXIO;
850 	dev_dbg(ndd->dev, "allocated: %d\n", slot);
851 
852 	nd_label = to_label(ndd, slot);
853 	memset(nd_label, 0, sizeof_namespace_label(ndd));
854 	memcpy(nd_label->uuid, nspm->uuid, NSLABEL_UUID_LEN);
855 	nsl_set_name(ndd, nd_label, nspm->alt_name);
856 	nsl_set_flags(ndd, nd_label, flags);
857 	nsl_set_nlabel(ndd, nd_label, nd_region->ndr_mappings);
858 	nsl_set_position(ndd, nd_label, pos);
859 	nsl_set_isetcookie(ndd, nd_label, cookie);
860 	nsl_set_rawsize(ndd, nd_label, resource_size(res));
861 	nsl_set_lbasize(ndd, nd_label, nspm->lbasize);
862 	nsl_set_dpa(ndd, nd_label, res->start);
863 	nsl_set_slot(ndd, nd_label, slot);
864 	nsl_set_type_guid(ndd, nd_label, &nd_set->type_guid);
865 	nsl_set_claim_class(ndd, nd_label, ndns->claim_class);
866 	nsl_calculate_checksum(ndd, nd_label);
867 	nd_dbg_dpa(nd_region, ndd, res, "\n");
868 
869 	/* update label */
870 	offset = nd_label_offset(ndd, nd_label);
871 	rc = nvdimm_set_config_data(ndd, offset, nd_label,
872 			sizeof_namespace_label(ndd));
873 	if (rc < 0)
874 		return rc;
875 
876 	/* Garbage collect the previous label */
877 	mutex_lock(&nd_mapping->lock);
878 	list_for_each_entry(label_ent, &nd_mapping->labels, list) {
879 		if (!label_ent->label)
880 			continue;
881 		if (test_and_clear_bit(ND_LABEL_REAP, &label_ent->flags)
882 				|| memcmp(nspm->uuid, label_ent->label->uuid,
883 					NSLABEL_UUID_LEN) == 0)
884 			reap_victim(nd_mapping, label_ent);
885 	}
886 
887 	/* update index */
888 	rc = nd_label_write_index(ndd, ndd->ns_next,
889 			nd_inc_seq(__le32_to_cpu(nsindex->seq)), 0);
890 	if (rc == 0) {
891 		list_for_each_entry(label_ent, &nd_mapping->labels, list)
892 			if (!label_ent->label) {
893 				label_ent->label = nd_label;
894 				nd_label = NULL;
895 				break;
896 			}
897 		dev_WARN_ONCE(&nspm->nsio.common.dev, nd_label,
898 				"failed to track label: %d\n",
899 				to_slot(ndd, nd_label));
900 		if (nd_label)
901 			rc = -ENXIO;
902 	}
903 	mutex_unlock(&nd_mapping->lock);
904 
905 	return rc;
906 }
907 
908 static bool is_old_resource(struct resource *res, struct resource **list, int n)
909 {
910 	int i;
911 
912 	if (res->flags & DPA_RESOURCE_ADJUSTED)
913 		return false;
914 	for (i = 0; i < n; i++)
915 		if (res == list[i])
916 			return true;
917 	return false;
918 }
919 
920 static struct resource *to_resource(struct nvdimm_drvdata *ndd,
921 		struct nd_namespace_label *nd_label)
922 {
923 	struct resource *res;
924 
925 	for_each_dpa_resource(ndd, res) {
926 		if (res->start != nsl_get_dpa(ndd, nd_label))
927 			continue;
928 		if (resource_size(res) != nsl_get_rawsize(ndd, nd_label))
929 			continue;
930 		return res;
931 	}
932 
933 	return NULL;
934 }
935 
936 /*
937  * Use the presence of the type_guid as a flag to determine isetcookie
938  * usage and nlabel + position policy for blk-aperture namespaces.
939  */
940 static void nsl_set_blk_isetcookie(struct nvdimm_drvdata *ndd,
941 				   struct nd_namespace_label *nd_label,
942 				   u64 isetcookie)
943 {
944 	if (namespace_label_has(ndd, type_guid)) {
945 		nsl_set_isetcookie(ndd, nd_label, isetcookie);
946 		return;
947 	}
948 	nsl_set_isetcookie(ndd, nd_label, 0); /* N/A */
949 }
950 
951 bool nsl_validate_blk_isetcookie(struct nvdimm_drvdata *ndd,
952 				 struct nd_namespace_label *nd_label,
953 				 u64 isetcookie)
954 {
955 	if (!namespace_label_has(ndd, type_guid))
956 		return true;
957 
958 	if (nsl_get_isetcookie(ndd, nd_label) != isetcookie) {
959 		dev_dbg(ndd->dev, "expect cookie %#llx got %#llx\n", isetcookie,
960 			nsl_get_isetcookie(ndd, nd_label));
961 		return false;
962 	}
963 
964 	return true;
965 }
966 
967 static void nsl_set_blk_nlabel(struct nvdimm_drvdata *ndd,
968 			       struct nd_namespace_label *nd_label, int nlabel,
969 			       bool first)
970 {
971 	if (!namespace_label_has(ndd, type_guid)) {
972 		nsl_set_nlabel(ndd, nd_label, 0); /* N/A */
973 		return;
974 	}
975 	nsl_set_nlabel(ndd, nd_label, first ? nlabel : 0xffff);
976 }
977 
978 static void nsl_set_blk_position(struct nvdimm_drvdata *ndd,
979 				 struct nd_namespace_label *nd_label,
980 				 bool first)
981 {
982 	if (!namespace_label_has(ndd, type_guid)) {
983 		nsl_set_position(ndd, nd_label, 0);
984 		return;
985 	}
986 	nsl_set_position(ndd, nd_label, first ? 0 : 0xffff);
987 }
988 
989 /*
990  * 1/ Account all the labels that can be freed after this update
991  * 2/ Allocate and write the label to the staging (next) index
992  * 3/ Record the resources in the namespace device
993  */
994 static int __blk_label_update(struct nd_region *nd_region,
995 		struct nd_mapping *nd_mapping, struct nd_namespace_blk *nsblk,
996 		int num_labels)
997 {
998 	int i, alloc, victims, nfree, old_num_resources, nlabel, rc = -ENXIO;
999 	struct nd_interleave_set *nd_set = nd_region->nd_set;
1000 	struct nd_namespace_common *ndns = &nsblk->common;
1001 	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
1002 	struct nd_namespace_label *nd_label;
1003 	struct nd_label_ent *label_ent, *e;
1004 	struct nd_namespace_index *nsindex;
1005 	unsigned long *free, *victim_map = NULL;
1006 	struct resource *res, **old_res_list;
1007 	struct nd_label_id label_id;
1008 	u8 uuid[NSLABEL_UUID_LEN];
1009 	int min_dpa_idx = 0;
1010 	LIST_HEAD(list);
1011 	u32 nslot, slot;
1012 
1013 	if (!preamble_next(ndd, &nsindex, &free, &nslot))
1014 		return -ENXIO;
1015 
1016 	old_res_list = nsblk->res;
1017 	nfree = nd_label_nfree(ndd);
1018 	old_num_resources = nsblk->num_resources;
1019 	nd_label_gen_id(&label_id, nsblk->uuid, NSLABEL_FLAG_LOCAL);
1020 
1021 	/*
1022 	 * We need to loop over the old resources a few times, which seems a
1023 	 * bit inefficient, but we need to know that we have the label
1024 	 * space before we start mutating the tracking structures.
1025 	 * Otherwise the recovery method of last resort for userspace is
1026 	 * disable and re-enable the parent region.
1027 	 */
1028 	alloc = 0;
1029 	for_each_dpa_resource(ndd, res) {
1030 		if (strcmp(res->name, label_id.id) != 0)
1031 			continue;
1032 		if (!is_old_resource(res, old_res_list, old_num_resources))
1033 			alloc++;
1034 	}
1035 
1036 	victims = 0;
1037 	if (old_num_resources) {
1038 		/* convert old local-label-map to dimm-slot victim-map */
1039 		victim_map = bitmap_zalloc(nslot, GFP_KERNEL);
1040 		if (!victim_map)
1041 			return -ENOMEM;
1042 
1043 		/* mark unused labels for garbage collection */
1044 		for_each_clear_bit_le(slot, free, nslot) {
1045 			nd_label = to_label(ndd, slot);
1046 			memcpy(uuid, nd_label->uuid, NSLABEL_UUID_LEN);
1047 			if (memcmp(uuid, nsblk->uuid, NSLABEL_UUID_LEN) != 0)
1048 				continue;
1049 			res = to_resource(ndd, nd_label);
1050 			if (res && is_old_resource(res, old_res_list,
1051 						old_num_resources))
1052 				continue;
1053 			slot = to_slot(ndd, nd_label);
1054 			set_bit(slot, victim_map);
1055 			victims++;
1056 		}
1057 	}
1058 
1059 	/* don't allow updates that consume the last label */
1060 	if (nfree - alloc < 0 || nfree - alloc + victims < 1) {
1061 		dev_info(&nsblk->common.dev, "insufficient label space\n");
1062 		bitmap_free(victim_map);
1063 		return -ENOSPC;
1064 	}
1065 	/* from here on we need to abort on error */
1066 
1067 
1068 	/* assign all resources to the namespace before writing the labels */
1069 	nsblk->res = NULL;
1070 	nsblk->num_resources = 0;
1071 	for_each_dpa_resource(ndd, res) {
1072 		if (strcmp(res->name, label_id.id) != 0)
1073 			continue;
1074 		if (!nsblk_add_resource(nd_region, ndd, nsblk, res->start)) {
1075 			rc = -ENOMEM;
1076 			goto abort;
1077 		}
1078 	}
1079 
1080 	/* release slots associated with any invalidated UUIDs */
1081 	mutex_lock(&nd_mapping->lock);
1082 	list_for_each_entry_safe(label_ent, e, &nd_mapping->labels, list)
1083 		if (test_and_clear_bit(ND_LABEL_REAP, &label_ent->flags)) {
1084 			reap_victim(nd_mapping, label_ent);
1085 			list_move(&label_ent->list, &list);
1086 		}
1087 	mutex_unlock(&nd_mapping->lock);
1088 
1089 	/*
1090 	 * Find the resource associated with the first label in the set
1091 	 * per the v1.2 namespace specification.
1092 	 */
1093 	for (i = 0; i < nsblk->num_resources; i++) {
1094 		struct resource *min = nsblk->res[min_dpa_idx];
1095 
1096 		res = nsblk->res[i];
1097 		if (res->start < min->start)
1098 			min_dpa_idx = i;
1099 	}
1100 
1101 	for (i = 0; i < nsblk->num_resources; i++) {
1102 		size_t offset;
1103 
1104 		res = nsblk->res[i];
1105 		if (is_old_resource(res, old_res_list, old_num_resources))
1106 			continue; /* carry-over */
1107 		slot = nd_label_alloc_slot(ndd);
1108 		if (slot == UINT_MAX) {
1109 			rc = -ENXIO;
1110 			goto abort;
1111 		}
1112 		dev_dbg(ndd->dev, "allocated: %d\n", slot);
1113 
1114 		nd_label = to_label(ndd, slot);
1115 		memset(nd_label, 0, sizeof_namespace_label(ndd));
1116 		memcpy(nd_label->uuid, nsblk->uuid, NSLABEL_UUID_LEN);
1117 		nsl_set_name(ndd, nd_label, nsblk->alt_name);
1118 		nsl_set_flags(ndd, nd_label, NSLABEL_FLAG_LOCAL);
1119 
1120 		nsl_set_blk_nlabel(ndd, nd_label, nsblk->num_resources,
1121 				   i == min_dpa_idx);
1122 		nsl_set_blk_position(ndd, nd_label, i == min_dpa_idx);
1123 		nsl_set_blk_isetcookie(ndd, nd_label, nd_set->cookie2);
1124 
1125 		nsl_set_dpa(ndd, nd_label, res->start);
1126 		nsl_set_rawsize(ndd, nd_label, resource_size(res));
1127 		nsl_set_lbasize(ndd, nd_label, nsblk->lbasize);
1128 		nsl_set_slot(ndd, nd_label, slot);
1129 		nsl_set_type_guid(ndd, nd_label, &nd_set->type_guid);
1130 		nsl_set_claim_class(ndd, nd_label, ndns->claim_class);
1131 		nsl_calculate_checksum(ndd, nd_label);
1132 
1133 		/* update label */
1134 		offset = nd_label_offset(ndd, nd_label);
1135 		rc = nvdimm_set_config_data(ndd, offset, nd_label,
1136 				sizeof_namespace_label(ndd));
1137 		if (rc < 0)
1138 			goto abort;
1139 	}
1140 
1141 	/* free up now unused slots in the new index */
1142 	for_each_set_bit(slot, victim_map, victim_map ? nslot : 0) {
1143 		dev_dbg(ndd->dev, "free: %d\n", slot);
1144 		nd_label_free_slot(ndd, slot);
1145 	}
1146 
1147 	/* update index */
1148 	rc = nd_label_write_index(ndd, ndd->ns_next,
1149 			nd_inc_seq(__le32_to_cpu(nsindex->seq)), 0);
1150 	if (rc)
1151 		goto abort;
1152 
1153 	/*
1154 	 * Now that the on-dimm labels are up to date, fix up the tracking
1155 	 * entries in nd_mapping->labels
1156 	 */
1157 	nlabel = 0;
1158 	mutex_lock(&nd_mapping->lock);
1159 	list_for_each_entry_safe(label_ent, e, &nd_mapping->labels, list) {
1160 		nd_label = label_ent->label;
1161 		if (!nd_label)
1162 			continue;
1163 		nlabel++;
1164 		memcpy(uuid, nd_label->uuid, NSLABEL_UUID_LEN);
1165 		if (memcmp(uuid, nsblk->uuid, NSLABEL_UUID_LEN) != 0)
1166 			continue;
1167 		nlabel--;
1168 		list_move(&label_ent->list, &list);
1169 		label_ent->label = NULL;
1170 	}
1171 	list_splice_tail_init(&list, &nd_mapping->labels);
1172 	mutex_unlock(&nd_mapping->lock);
1173 
1174 	if (nlabel + nsblk->num_resources > num_labels) {
1175 		/*
1176 		 * Bug, we can't end up with more resources than
1177 		 * available labels
1178 		 */
1179 		WARN_ON_ONCE(1);
1180 		rc = -ENXIO;
1181 		goto out;
1182 	}
1183 
1184 	mutex_lock(&nd_mapping->lock);
1185 	label_ent = list_first_entry_or_null(&nd_mapping->labels,
1186 			typeof(*label_ent), list);
1187 	if (!label_ent) {
1188 		WARN_ON(1);
1189 		mutex_unlock(&nd_mapping->lock);
1190 		rc = -ENXIO;
1191 		goto out;
1192 	}
1193 	for_each_clear_bit_le(slot, free, nslot) {
1194 		nd_label = to_label(ndd, slot);
1195 		memcpy(uuid, nd_label->uuid, NSLABEL_UUID_LEN);
1196 		if (memcmp(uuid, nsblk->uuid, NSLABEL_UUID_LEN) != 0)
1197 			continue;
1198 		res = to_resource(ndd, nd_label);
1199 		res->flags &= ~DPA_RESOURCE_ADJUSTED;
1200 		dev_vdbg(&nsblk->common.dev, "assign label slot: %d\n", slot);
1201 		list_for_each_entry_from(label_ent, &nd_mapping->labels, list) {
1202 			if (label_ent->label)
1203 				continue;
1204 			label_ent->label = nd_label;
1205 			nd_label = NULL;
1206 			break;
1207 		}
1208 		if (nd_label)
1209 			dev_WARN(&nsblk->common.dev,
1210 					"failed to track label slot%d\n", slot);
1211 	}
1212 	mutex_unlock(&nd_mapping->lock);
1213 
1214  out:
1215 	kfree(old_res_list);
1216 	bitmap_free(victim_map);
1217 	return rc;
1218 
1219  abort:
1220 	/*
1221 	 * 1/ repair the allocated label bitmap in the index
1222 	 * 2/ restore the resource list
1223 	 */
1224 	nd_label_copy(ndd, nsindex, to_current_namespace_index(ndd));
1225 	kfree(nsblk->res);
1226 	nsblk->res = old_res_list;
1227 	nsblk->num_resources = old_num_resources;
1228 	old_res_list = NULL;
1229 	goto out;
1230 }
1231 
1232 static int init_labels(struct nd_mapping *nd_mapping, int num_labels)
1233 {
1234 	int i, old_num_labels = 0;
1235 	struct nd_label_ent *label_ent;
1236 	struct nd_namespace_index *nsindex;
1237 	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
1238 
1239 	mutex_lock(&nd_mapping->lock);
1240 	list_for_each_entry(label_ent, &nd_mapping->labels, list)
1241 		old_num_labels++;
1242 	mutex_unlock(&nd_mapping->lock);
1243 
1244 	/*
1245 	 * We need to preserve all the old labels for the mapping so
1246 	 * they can be garbage collected after writing the new labels.
1247 	 */
1248 	for (i = old_num_labels; i < num_labels; i++) {
1249 		label_ent = kzalloc(sizeof(*label_ent), GFP_KERNEL);
1250 		if (!label_ent)
1251 			return -ENOMEM;
1252 		mutex_lock(&nd_mapping->lock);
1253 		list_add_tail(&label_ent->list, &nd_mapping->labels);
1254 		mutex_unlock(&nd_mapping->lock);
1255 	}
1256 
1257 	if (ndd->ns_current == -1 || ndd->ns_next == -1)
1258 		/* pass */;
1259 	else
1260 		return max(num_labels, old_num_labels);
1261 
1262 	nsindex = to_namespace_index(ndd, 0);
1263 	memset(nsindex, 0, ndd->nsarea.config_size);
1264 	for (i = 0; i < 2; i++) {
1265 		int rc = nd_label_write_index(ndd, i, 3 - i, ND_NSINDEX_INIT);
1266 
1267 		if (rc)
1268 			return rc;
1269 	}
1270 	ndd->ns_next = 1;
1271 	ndd->ns_current = 0;
1272 
1273 	return max(num_labels, old_num_labels);
1274 }
1275 
1276 static int del_labels(struct nd_mapping *nd_mapping, u8 *uuid)
1277 {
1278 	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
1279 	struct nd_label_ent *label_ent, *e;
1280 	struct nd_namespace_index *nsindex;
1281 	u8 label_uuid[NSLABEL_UUID_LEN];
1282 	unsigned long *free;
1283 	LIST_HEAD(list);
1284 	u32 nslot, slot;
1285 	int active = 0;
1286 
1287 	if (!uuid)
1288 		return 0;
1289 
1290 	/* no index || no labels == nothing to delete */
1291 	if (!preamble_next(ndd, &nsindex, &free, &nslot))
1292 		return 0;
1293 
1294 	mutex_lock(&nd_mapping->lock);
1295 	list_for_each_entry_safe(label_ent, e, &nd_mapping->labels, list) {
1296 		struct nd_namespace_label *nd_label = label_ent->label;
1297 
1298 		if (!nd_label)
1299 			continue;
1300 		active++;
1301 		memcpy(label_uuid, nd_label->uuid, NSLABEL_UUID_LEN);
1302 		if (memcmp(label_uuid, uuid, NSLABEL_UUID_LEN) != 0)
1303 			continue;
1304 		active--;
1305 		slot = to_slot(ndd, nd_label);
1306 		nd_label_free_slot(ndd, slot);
1307 		dev_dbg(ndd->dev, "free: %d\n", slot);
1308 		list_move_tail(&label_ent->list, &list);
1309 		label_ent->label = NULL;
1310 	}
1311 	list_splice_tail_init(&list, &nd_mapping->labels);
1312 
1313 	if (active == 0) {
1314 		nd_mapping_free_labels(nd_mapping);
1315 		dev_dbg(ndd->dev, "no more active labels\n");
1316 	}
1317 	mutex_unlock(&nd_mapping->lock);
1318 
1319 	return nd_label_write_index(ndd, ndd->ns_next,
1320 			nd_inc_seq(__le32_to_cpu(nsindex->seq)), 0);
1321 }
1322 
1323 int nd_pmem_namespace_label_update(struct nd_region *nd_region,
1324 		struct nd_namespace_pmem *nspm, resource_size_t size)
1325 {
1326 	int i, rc;
1327 
1328 	for (i = 0; i < nd_region->ndr_mappings; i++) {
1329 		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
1330 		struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
1331 		struct resource *res;
1332 		int count = 0;
1333 
1334 		if (size == 0) {
1335 			rc = del_labels(nd_mapping, nspm->uuid);
1336 			if (rc)
1337 				return rc;
1338 			continue;
1339 		}
1340 
1341 		for_each_dpa_resource(ndd, res)
1342 			if (strncmp(res->name, "pmem", 4) == 0)
1343 				count++;
1344 		WARN_ON_ONCE(!count);
1345 
1346 		rc = init_labels(nd_mapping, count);
1347 		if (rc < 0)
1348 			return rc;
1349 
1350 		rc = __pmem_label_update(nd_region, nd_mapping, nspm, i,
1351 				NSLABEL_FLAG_UPDATING);
1352 		if (rc)
1353 			return rc;
1354 	}
1355 
1356 	if (size == 0)
1357 		return 0;
1358 
1359 	/* Clear the UPDATING flag per UEFI 2.7 expectations */
1360 	for (i = 0; i < nd_region->ndr_mappings; i++) {
1361 		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
1362 
1363 		rc = __pmem_label_update(nd_region, nd_mapping, nspm, i, 0);
1364 		if (rc)
1365 			return rc;
1366 	}
1367 
1368 	return 0;
1369 }
1370 
1371 int nd_blk_namespace_label_update(struct nd_region *nd_region,
1372 		struct nd_namespace_blk *nsblk, resource_size_t size)
1373 {
1374 	struct nd_mapping *nd_mapping = &nd_region->mapping[0];
1375 	struct resource *res;
1376 	int count = 0;
1377 
1378 	if (size == 0)
1379 		return del_labels(nd_mapping, nsblk->uuid);
1380 
1381 	for_each_dpa_resource(to_ndd(nd_mapping), res)
1382 		count++;
1383 
1384 	count = init_labels(nd_mapping, count);
1385 	if (count < 0)
1386 		return count;
1387 
1388 	return __blk_label_update(nd_region, nd_mapping, nsblk, count);
1389 }
1390 
1391 int __init nd_label_init(void)
1392 {
1393 	WARN_ON(guid_parse(NVDIMM_BTT_GUID, &nvdimm_btt_guid));
1394 	WARN_ON(guid_parse(NVDIMM_BTT2_GUID, &nvdimm_btt2_guid));
1395 	WARN_ON(guid_parse(NVDIMM_PFN_GUID, &nvdimm_pfn_guid));
1396 	WARN_ON(guid_parse(NVDIMM_DAX_GUID, &nvdimm_dax_guid));
1397 
1398 	return 0;
1399 }
1400