xref: /linux/drivers/nvdimm/dimm_devs.c (revision 666ed8bfd1de3b091cf32ca03b651757dd86cfff)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
4  */
5 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
6 #include <linux/moduleparam.h>
7 #include <linux/vmalloc.h>
8 #include <linux/device.h>
9 #include <linux/ndctl.h>
10 #include <linux/slab.h>
11 #include <linux/io.h>
12 #include <linux/fs.h>
13 #include <linux/mm.h>
14 #include "nd-core.h"
15 #include "label.h"
16 #include "pmem.h"
17 #include "nd.h"
18 
19 static DEFINE_IDA(dimm_ida);
20 
21 static bool noblk;
22 module_param(noblk, bool, 0444);
23 MODULE_PARM_DESC(noblk, "force disable BLK / local alias support");
24 
25 /*
26  * Retrieve bus and dimm handle and return if this bus supports
27  * get_config_data commands
28  */
29 int nvdimm_check_config_data(struct device *dev)
30 {
31 	struct nvdimm *nvdimm = to_nvdimm(dev);
32 
33 	if (!nvdimm->cmd_mask ||
34 	    !test_bit(ND_CMD_GET_CONFIG_DATA, &nvdimm->cmd_mask)) {
35 		if (test_bit(NDD_LABELING, &nvdimm->flags))
36 			return -ENXIO;
37 		else
38 			return -ENOTTY;
39 	}
40 
41 	return 0;
42 }
43 
44 static int validate_dimm(struct nvdimm_drvdata *ndd)
45 {
46 	int rc;
47 
48 	if (!ndd)
49 		return -EINVAL;
50 
51 	rc = nvdimm_check_config_data(ndd->dev);
52 	if (rc)
53 		dev_dbg(ndd->dev, "%ps: %s error: %d\n",
54 				__builtin_return_address(0), __func__, rc);
55 	return rc;
56 }
57 
58 /**
59  * nvdimm_init_nsarea - determine the geometry of a dimm's namespace area
60  * @nvdimm: dimm to initialize
61  */
62 int nvdimm_init_nsarea(struct nvdimm_drvdata *ndd)
63 {
64 	struct nd_cmd_get_config_size *cmd = &ndd->nsarea;
65 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(ndd->dev);
66 	struct nvdimm_bus_descriptor *nd_desc;
67 	int rc = validate_dimm(ndd);
68 	int cmd_rc = 0;
69 
70 	if (rc)
71 		return rc;
72 
73 	if (cmd->config_size)
74 		return 0; /* already valid */
75 
76 	memset(cmd, 0, sizeof(*cmd));
77 	nd_desc = nvdimm_bus->nd_desc;
78 	rc = nd_desc->ndctl(nd_desc, to_nvdimm(ndd->dev),
79 			ND_CMD_GET_CONFIG_SIZE, cmd, sizeof(*cmd), &cmd_rc);
80 	if (rc < 0)
81 		return rc;
82 	return cmd_rc;
83 }
84 
85 int nvdimm_get_config_data(struct nvdimm_drvdata *ndd, void *buf,
86 			   size_t offset, size_t len)
87 {
88 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(ndd->dev);
89 	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
90 	int rc = validate_dimm(ndd), cmd_rc = 0;
91 	struct nd_cmd_get_config_data_hdr *cmd;
92 	size_t max_cmd_size, buf_offset;
93 
94 	if (rc)
95 		return rc;
96 
97 	if (offset + len > ndd->nsarea.config_size)
98 		return -ENXIO;
99 
100 	max_cmd_size = min_t(u32, len, ndd->nsarea.max_xfer);
101 	cmd = kvzalloc(max_cmd_size + sizeof(*cmd), GFP_KERNEL);
102 	if (!cmd)
103 		return -ENOMEM;
104 
105 	for (buf_offset = 0; len;
106 	     len -= cmd->in_length, buf_offset += cmd->in_length) {
107 		size_t cmd_size;
108 
109 		cmd->in_offset = offset + buf_offset;
110 		cmd->in_length = min(max_cmd_size, len);
111 
112 		cmd_size = sizeof(*cmd) + cmd->in_length;
113 
114 		rc = nd_desc->ndctl(nd_desc, to_nvdimm(ndd->dev),
115 				ND_CMD_GET_CONFIG_DATA, cmd, cmd_size, &cmd_rc);
116 		if (rc < 0)
117 			break;
118 		if (cmd_rc < 0) {
119 			rc = cmd_rc;
120 			break;
121 		}
122 
123 		/* out_buf should be valid, copy it into our output buffer */
124 		memcpy(buf + buf_offset, cmd->out_buf, cmd->in_length);
125 	}
126 	kvfree(cmd);
127 
128 	return rc;
129 }
130 
131 int nvdimm_set_config_data(struct nvdimm_drvdata *ndd, size_t offset,
132 		void *buf, size_t len)
133 {
134 	size_t max_cmd_size, buf_offset;
135 	struct nd_cmd_set_config_hdr *cmd;
136 	int rc = validate_dimm(ndd), cmd_rc = 0;
137 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(ndd->dev);
138 	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
139 
140 	if (rc)
141 		return rc;
142 
143 	if (offset + len > ndd->nsarea.config_size)
144 		return -ENXIO;
145 
146 	max_cmd_size = min_t(u32, len, ndd->nsarea.max_xfer);
147 	cmd = kvzalloc(max_cmd_size + sizeof(*cmd) + sizeof(u32), GFP_KERNEL);
148 	if (!cmd)
149 		return -ENOMEM;
150 
151 	for (buf_offset = 0; len; len -= cmd->in_length,
152 			buf_offset += cmd->in_length) {
153 		size_t cmd_size;
154 
155 		cmd->in_offset = offset + buf_offset;
156 		cmd->in_length = min(max_cmd_size, len);
157 		memcpy(cmd->in_buf, buf + buf_offset, cmd->in_length);
158 
159 		/* status is output in the last 4-bytes of the command buffer */
160 		cmd_size = sizeof(*cmd) + cmd->in_length + sizeof(u32);
161 
162 		rc = nd_desc->ndctl(nd_desc, to_nvdimm(ndd->dev),
163 				ND_CMD_SET_CONFIG_DATA, cmd, cmd_size, &cmd_rc);
164 		if (rc < 0)
165 			break;
166 		if (cmd_rc < 0) {
167 			rc = cmd_rc;
168 			break;
169 		}
170 	}
171 	kvfree(cmd);
172 
173 	return rc;
174 }
175 
176 void nvdimm_set_labeling(struct device *dev)
177 {
178 	struct nvdimm *nvdimm = to_nvdimm(dev);
179 
180 	set_bit(NDD_LABELING, &nvdimm->flags);
181 }
182 
183 void nvdimm_set_locked(struct device *dev)
184 {
185 	struct nvdimm *nvdimm = to_nvdimm(dev);
186 
187 	set_bit(NDD_LOCKED, &nvdimm->flags);
188 }
189 
190 void nvdimm_clear_locked(struct device *dev)
191 {
192 	struct nvdimm *nvdimm = to_nvdimm(dev);
193 
194 	clear_bit(NDD_LOCKED, &nvdimm->flags);
195 }
196 
197 static void nvdimm_release(struct device *dev)
198 {
199 	struct nvdimm *nvdimm = to_nvdimm(dev);
200 
201 	ida_simple_remove(&dimm_ida, nvdimm->id);
202 	kfree(nvdimm);
203 }
204 
205 struct nvdimm *to_nvdimm(struct device *dev)
206 {
207 	struct nvdimm *nvdimm = container_of(dev, struct nvdimm, dev);
208 
209 	WARN_ON(!is_nvdimm(dev));
210 	return nvdimm;
211 }
212 EXPORT_SYMBOL_GPL(to_nvdimm);
213 
214 struct nvdimm *nd_blk_region_to_dimm(struct nd_blk_region *ndbr)
215 {
216 	struct nd_region *nd_region = &ndbr->nd_region;
217 	struct nd_mapping *nd_mapping = &nd_region->mapping[0];
218 
219 	return nd_mapping->nvdimm;
220 }
221 EXPORT_SYMBOL_GPL(nd_blk_region_to_dimm);
222 
223 unsigned long nd_blk_memremap_flags(struct nd_blk_region *ndbr)
224 {
225 	/* pmem mapping properties are private to libnvdimm */
226 	return ARCH_MEMREMAP_PMEM;
227 }
228 EXPORT_SYMBOL_GPL(nd_blk_memremap_flags);
229 
230 struct nvdimm_drvdata *to_ndd(struct nd_mapping *nd_mapping)
231 {
232 	struct nvdimm *nvdimm = nd_mapping->nvdimm;
233 
234 	WARN_ON_ONCE(!is_nvdimm_bus_locked(&nvdimm->dev));
235 
236 	return dev_get_drvdata(&nvdimm->dev);
237 }
238 EXPORT_SYMBOL(to_ndd);
239 
240 void nvdimm_drvdata_release(struct kref *kref)
241 {
242 	struct nvdimm_drvdata *ndd = container_of(kref, typeof(*ndd), kref);
243 	struct device *dev = ndd->dev;
244 	struct resource *res, *_r;
245 
246 	dev_dbg(dev, "trace\n");
247 	nvdimm_bus_lock(dev);
248 	for_each_dpa_resource_safe(ndd, res, _r)
249 		nvdimm_free_dpa(ndd, res);
250 	nvdimm_bus_unlock(dev);
251 
252 	kvfree(ndd->data);
253 	kfree(ndd);
254 	put_device(dev);
255 }
256 
257 void get_ndd(struct nvdimm_drvdata *ndd)
258 {
259 	kref_get(&ndd->kref);
260 }
261 
262 void put_ndd(struct nvdimm_drvdata *ndd)
263 {
264 	if (ndd)
265 		kref_put(&ndd->kref, nvdimm_drvdata_release);
266 }
267 
268 const char *nvdimm_name(struct nvdimm *nvdimm)
269 {
270 	return dev_name(&nvdimm->dev);
271 }
272 EXPORT_SYMBOL_GPL(nvdimm_name);
273 
274 struct kobject *nvdimm_kobj(struct nvdimm *nvdimm)
275 {
276 	return &nvdimm->dev.kobj;
277 }
278 EXPORT_SYMBOL_GPL(nvdimm_kobj);
279 
280 unsigned long nvdimm_cmd_mask(struct nvdimm *nvdimm)
281 {
282 	return nvdimm->cmd_mask;
283 }
284 EXPORT_SYMBOL_GPL(nvdimm_cmd_mask);
285 
286 void *nvdimm_provider_data(struct nvdimm *nvdimm)
287 {
288 	if (nvdimm)
289 		return nvdimm->provider_data;
290 	return NULL;
291 }
292 EXPORT_SYMBOL_GPL(nvdimm_provider_data);
293 
294 static ssize_t commands_show(struct device *dev,
295 		struct device_attribute *attr, char *buf)
296 {
297 	struct nvdimm *nvdimm = to_nvdimm(dev);
298 	int cmd, len = 0;
299 
300 	if (!nvdimm->cmd_mask)
301 		return sprintf(buf, "\n");
302 
303 	for_each_set_bit(cmd, &nvdimm->cmd_mask, BITS_PER_LONG)
304 		len += sprintf(buf + len, "%s ", nvdimm_cmd_name(cmd));
305 	len += sprintf(buf + len, "\n");
306 	return len;
307 }
308 static DEVICE_ATTR_RO(commands);
309 
310 static ssize_t flags_show(struct device *dev,
311 		struct device_attribute *attr, char *buf)
312 {
313 	struct nvdimm *nvdimm = to_nvdimm(dev);
314 
315 	return sprintf(buf, "%s%s%s\n",
316 			test_bit(NDD_ALIASING, &nvdimm->flags) ? "alias " : "",
317 			test_bit(NDD_LABELING, &nvdimm->flags) ? "label " : "",
318 			test_bit(NDD_LOCKED, &nvdimm->flags) ? "lock " : "");
319 }
320 static DEVICE_ATTR_RO(flags);
321 
322 static ssize_t state_show(struct device *dev, struct device_attribute *attr,
323 		char *buf)
324 {
325 	struct nvdimm *nvdimm = to_nvdimm(dev);
326 
327 	/*
328 	 * The state may be in the process of changing, userspace should
329 	 * quiesce probing if it wants a static answer
330 	 */
331 	nvdimm_bus_lock(dev);
332 	nvdimm_bus_unlock(dev);
333 	return sprintf(buf, "%s\n", atomic_read(&nvdimm->busy)
334 			? "active" : "idle");
335 }
336 static DEVICE_ATTR_RO(state);
337 
338 static ssize_t available_slots_show(struct device *dev,
339 		struct device_attribute *attr, char *buf)
340 {
341 	struct nvdimm_drvdata *ndd = dev_get_drvdata(dev);
342 	ssize_t rc;
343 	u32 nfree;
344 
345 	if (!ndd)
346 		return -ENXIO;
347 
348 	nvdimm_bus_lock(dev);
349 	nfree = nd_label_nfree(ndd);
350 	if (nfree - 1 > nfree) {
351 		dev_WARN_ONCE(dev, 1, "we ate our last label?\n");
352 		nfree = 0;
353 	} else
354 		nfree--;
355 	rc = sprintf(buf, "%d\n", nfree);
356 	nvdimm_bus_unlock(dev);
357 	return rc;
358 }
359 static DEVICE_ATTR_RO(available_slots);
360 
361 __weak ssize_t security_show(struct device *dev,
362 		struct device_attribute *attr, char *buf)
363 {
364 	struct nvdimm *nvdimm = to_nvdimm(dev);
365 
366 	if (test_bit(NVDIMM_SECURITY_DISABLED, &nvdimm->sec.flags))
367 		return sprintf(buf, "disabled\n");
368 	if (test_bit(NVDIMM_SECURITY_UNLOCKED, &nvdimm->sec.flags))
369 		return sprintf(buf, "unlocked\n");
370 	if (test_bit(NVDIMM_SECURITY_LOCKED, &nvdimm->sec.flags))
371 		return sprintf(buf, "locked\n");
372 	if (test_bit(NVDIMM_SECURITY_OVERWRITE, &nvdimm->sec.flags))
373 		return sprintf(buf, "overwrite\n");
374 	return -ENOTTY;
375 }
376 
377 static ssize_t frozen_show(struct device *dev,
378 		struct device_attribute *attr, char *buf)
379 {
380 	struct nvdimm *nvdimm = to_nvdimm(dev);
381 
382 	return sprintf(buf, "%d\n", test_bit(NVDIMM_SECURITY_FROZEN,
383 				&nvdimm->sec.flags));
384 }
385 static DEVICE_ATTR_RO(frozen);
386 
387 static ssize_t security_store(struct device *dev,
388 		struct device_attribute *attr, const char *buf, size_t len)
389 
390 {
391 	ssize_t rc;
392 
393 	/*
394 	 * Require all userspace triggered security management to be
395 	 * done while probing is idle and the DIMM is not in active use
396 	 * in any region.
397 	 */
398 	nd_device_lock(dev);
399 	nvdimm_bus_lock(dev);
400 	wait_nvdimm_bus_probe_idle(dev);
401 	rc = nvdimm_security_store(dev, buf, len);
402 	nvdimm_bus_unlock(dev);
403 	nd_device_unlock(dev);
404 
405 	return rc;
406 }
407 static DEVICE_ATTR_RW(security);
408 
409 static struct attribute *nvdimm_attributes[] = {
410 	&dev_attr_state.attr,
411 	&dev_attr_flags.attr,
412 	&dev_attr_commands.attr,
413 	&dev_attr_available_slots.attr,
414 	&dev_attr_security.attr,
415 	&dev_attr_frozen.attr,
416 	NULL,
417 };
418 
419 static umode_t nvdimm_visible(struct kobject *kobj, struct attribute *a, int n)
420 {
421 	struct device *dev = container_of(kobj, typeof(*dev), kobj);
422 	struct nvdimm *nvdimm = to_nvdimm(dev);
423 
424 	if (a != &dev_attr_security.attr && a != &dev_attr_frozen.attr)
425 		return a->mode;
426 	if (!nvdimm->sec.flags)
427 		return 0;
428 
429 	if (a == &dev_attr_security.attr) {
430 		/* Are there any state mutation ops (make writable)? */
431 		if (nvdimm->sec.ops->freeze || nvdimm->sec.ops->disable
432 				|| nvdimm->sec.ops->change_key
433 				|| nvdimm->sec.ops->erase
434 				|| nvdimm->sec.ops->overwrite)
435 			return a->mode;
436 		return 0444;
437 	}
438 
439 	if (nvdimm->sec.ops->freeze)
440 		return a->mode;
441 	return 0;
442 }
443 
444 static const struct attribute_group nvdimm_attribute_group = {
445 	.attrs = nvdimm_attributes,
446 	.is_visible = nvdimm_visible,
447 };
448 
449 static const struct attribute_group *nvdimm_attribute_groups[] = {
450 	&nd_device_attribute_group,
451 	&nvdimm_attribute_group,
452 	NULL,
453 };
454 
455 static const struct device_type nvdimm_device_type = {
456 	.name = "nvdimm",
457 	.release = nvdimm_release,
458 	.groups = nvdimm_attribute_groups,
459 };
460 
461 bool is_nvdimm(struct device *dev)
462 {
463 	return dev->type == &nvdimm_device_type;
464 }
465 
466 struct nvdimm *__nvdimm_create(struct nvdimm_bus *nvdimm_bus,
467 		void *provider_data, const struct attribute_group **groups,
468 		unsigned long flags, unsigned long cmd_mask, int num_flush,
469 		struct resource *flush_wpq, const char *dimm_id,
470 		const struct nvdimm_security_ops *sec_ops)
471 {
472 	struct nvdimm *nvdimm = kzalloc(sizeof(*nvdimm), GFP_KERNEL);
473 	struct device *dev;
474 
475 	if (!nvdimm)
476 		return NULL;
477 
478 	nvdimm->id = ida_simple_get(&dimm_ida, 0, 0, GFP_KERNEL);
479 	if (nvdimm->id < 0) {
480 		kfree(nvdimm);
481 		return NULL;
482 	}
483 
484 	nvdimm->dimm_id = dimm_id;
485 	nvdimm->provider_data = provider_data;
486 	if (noblk)
487 		flags |= 1 << NDD_NOBLK;
488 	nvdimm->flags = flags;
489 	nvdimm->cmd_mask = cmd_mask;
490 	nvdimm->num_flush = num_flush;
491 	nvdimm->flush_wpq = flush_wpq;
492 	atomic_set(&nvdimm->busy, 0);
493 	dev = &nvdimm->dev;
494 	dev_set_name(dev, "nmem%d", nvdimm->id);
495 	dev->parent = &nvdimm_bus->dev;
496 	dev->type = &nvdimm_device_type;
497 	dev->devt = MKDEV(nvdimm_major, nvdimm->id);
498 	dev->groups = groups;
499 	nvdimm->sec.ops = sec_ops;
500 	nvdimm->sec.overwrite_tmo = 0;
501 	INIT_DELAYED_WORK(&nvdimm->dwork, nvdimm_security_overwrite_query);
502 	/*
503 	 * Security state must be initialized before device_add() for
504 	 * attribute visibility.
505 	 */
506 	/* get security state and extended (master) state */
507 	nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER);
508 	nvdimm->sec.ext_flags = nvdimm_security_flags(nvdimm, NVDIMM_MASTER);
509 	nd_device_register(dev);
510 
511 	return nvdimm;
512 }
513 EXPORT_SYMBOL_GPL(__nvdimm_create);
514 
515 static void shutdown_security_notify(void *data)
516 {
517 	struct nvdimm *nvdimm = data;
518 
519 	sysfs_put(nvdimm->sec.overwrite_state);
520 }
521 
522 int nvdimm_security_setup_events(struct device *dev)
523 {
524 	struct nvdimm *nvdimm = to_nvdimm(dev);
525 
526 	if (!nvdimm->sec.flags || !nvdimm->sec.ops
527 			|| !nvdimm->sec.ops->overwrite)
528 		return 0;
529 	nvdimm->sec.overwrite_state = sysfs_get_dirent(dev->kobj.sd, "security");
530 	if (!nvdimm->sec.overwrite_state)
531 		return -ENOMEM;
532 
533 	return devm_add_action_or_reset(dev, shutdown_security_notify, nvdimm);
534 }
535 EXPORT_SYMBOL_GPL(nvdimm_security_setup_events);
536 
537 int nvdimm_in_overwrite(struct nvdimm *nvdimm)
538 {
539 	return test_bit(NDD_SECURITY_OVERWRITE, &nvdimm->flags);
540 }
541 EXPORT_SYMBOL_GPL(nvdimm_in_overwrite);
542 
543 int nvdimm_security_freeze(struct nvdimm *nvdimm)
544 {
545 	int rc;
546 
547 	WARN_ON_ONCE(!is_nvdimm_bus_locked(&nvdimm->dev));
548 
549 	if (!nvdimm->sec.ops || !nvdimm->sec.ops->freeze)
550 		return -EOPNOTSUPP;
551 
552 	if (!nvdimm->sec.flags)
553 		return -EIO;
554 
555 	if (test_bit(NDD_SECURITY_OVERWRITE, &nvdimm->flags)) {
556 		dev_warn(&nvdimm->dev, "Overwrite operation in progress.\n");
557 		return -EBUSY;
558 	}
559 
560 	rc = nvdimm->sec.ops->freeze(nvdimm);
561 	nvdimm->sec.flags = nvdimm_security_flags(nvdimm, NVDIMM_USER);
562 
563 	return rc;
564 }
565 
566 static unsigned long dpa_align(struct nd_region *nd_region)
567 {
568 	struct device *dev = &nd_region->dev;
569 
570 	if (dev_WARN_ONCE(dev, !is_nvdimm_bus_locked(dev),
571 				"bus lock required for capacity provision\n"))
572 		return 0;
573 	if (dev_WARN_ONCE(dev, !nd_region->ndr_mappings || nd_region->align
574 				% nd_region->ndr_mappings,
575 				"invalid region align %#lx mappings: %d\n",
576 				nd_region->align, nd_region->ndr_mappings))
577 		return 0;
578 	return nd_region->align / nd_region->ndr_mappings;
579 }
580 
581 int alias_dpa_busy(struct device *dev, void *data)
582 {
583 	resource_size_t map_end, blk_start, new;
584 	struct blk_alloc_info *info = data;
585 	struct nd_mapping *nd_mapping;
586 	struct nd_region *nd_region;
587 	struct nvdimm_drvdata *ndd;
588 	struct resource *res;
589 	unsigned long align;
590 	int i;
591 
592 	if (!is_memory(dev))
593 		return 0;
594 
595 	nd_region = to_nd_region(dev);
596 	for (i = 0; i < nd_region->ndr_mappings; i++) {
597 		nd_mapping  = &nd_region->mapping[i];
598 		if (nd_mapping->nvdimm == info->nd_mapping->nvdimm)
599 			break;
600 	}
601 
602 	if (i >= nd_region->ndr_mappings)
603 		return 0;
604 
605 	ndd = to_ndd(nd_mapping);
606 	map_end = nd_mapping->start + nd_mapping->size - 1;
607 	blk_start = nd_mapping->start;
608 
609 	/*
610 	 * In the allocation case ->res is set to free space that we are
611 	 * looking to validate against PMEM aliasing collision rules
612 	 * (i.e. BLK is allocated after all aliased PMEM).
613 	 */
614 	if (info->res) {
615 		if (info->res->start >= nd_mapping->start
616 				&& info->res->start < map_end)
617 			/* pass */;
618 		else
619 			return 0;
620 	}
621 
622  retry:
623 	/*
624 	 * Find the free dpa from the end of the last pmem allocation to
625 	 * the end of the interleave-set mapping.
626 	 */
627 	align = dpa_align(nd_region);
628 	if (!align)
629 		return 0;
630 
631 	for_each_dpa_resource(ndd, res) {
632 		resource_size_t start, end;
633 
634 		if (strncmp(res->name, "pmem", 4) != 0)
635 			continue;
636 
637 		start = ALIGN_DOWN(res->start, align);
638 		end = ALIGN(res->end + 1, align) - 1;
639 		if ((start >= blk_start && start < map_end)
640 				|| (end >= blk_start && end <= map_end)) {
641 			new = max(blk_start, min(map_end, end) + 1);
642 			if (new != blk_start) {
643 				blk_start = new;
644 				goto retry;
645 			}
646 		}
647 	}
648 
649 	/* update the free space range with the probed blk_start */
650 	if (info->res && blk_start > info->res->start) {
651 		info->res->start = max(info->res->start, blk_start);
652 		if (info->res->start > info->res->end)
653 			info->res->end = info->res->start - 1;
654 		return 1;
655 	}
656 
657 	info->available -= blk_start - nd_mapping->start;
658 
659 	return 0;
660 }
661 
662 /**
663  * nd_blk_available_dpa - account the unused dpa of BLK region
664  * @nd_mapping: container of dpa-resource-root + labels
665  *
666  * Unlike PMEM, BLK namespaces can occupy discontiguous DPA ranges, but
667  * we arrange for them to never start at an lower dpa than the last
668  * PMEM allocation in an aliased region.
669  */
670 resource_size_t nd_blk_available_dpa(struct nd_region *nd_region)
671 {
672 	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
673 	struct nd_mapping *nd_mapping = &nd_region->mapping[0];
674 	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
675 	struct blk_alloc_info info = {
676 		.nd_mapping = nd_mapping,
677 		.available = nd_mapping->size,
678 		.res = NULL,
679 	};
680 	struct resource *res;
681 	unsigned long align;
682 
683 	if (!ndd)
684 		return 0;
685 
686 	device_for_each_child(&nvdimm_bus->dev, &info, alias_dpa_busy);
687 
688 	/* now account for busy blk allocations in unaliased dpa */
689 	align = dpa_align(nd_region);
690 	if (!align)
691 		return 0;
692 	for_each_dpa_resource(ndd, res) {
693 		resource_size_t start, end, size;
694 
695 		if (strncmp(res->name, "blk", 3) != 0)
696 			continue;
697 		start = ALIGN_DOWN(res->start, align);
698 		end = ALIGN(res->end + 1, align) - 1;
699 		size = end - start + 1;
700 		if (size >= info.available)
701 			return 0;
702 		info.available -= size;
703 	}
704 
705 	return info.available;
706 }
707 
708 /**
709  * nd_pmem_max_contiguous_dpa - For the given dimm+region, return the max
710  *			   contiguous unallocated dpa range.
711  * @nd_region: constrain available space check to this reference region
712  * @nd_mapping: container of dpa-resource-root + labels
713  */
714 resource_size_t nd_pmem_max_contiguous_dpa(struct nd_region *nd_region,
715 					   struct nd_mapping *nd_mapping)
716 {
717 	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
718 	struct nvdimm_bus *nvdimm_bus;
719 	resource_size_t max = 0;
720 	struct resource *res;
721 	unsigned long align;
722 
723 	/* if a dimm is disabled the available capacity is zero */
724 	if (!ndd)
725 		return 0;
726 
727 	align = dpa_align(nd_region);
728 	if (!align)
729 		return 0;
730 
731 	nvdimm_bus = walk_to_nvdimm_bus(ndd->dev);
732 	if (__reserve_free_pmem(&nd_region->dev, nd_mapping->nvdimm))
733 		return 0;
734 	for_each_dpa_resource(ndd, res) {
735 		resource_size_t start, end;
736 
737 		if (strcmp(res->name, "pmem-reserve") != 0)
738 			continue;
739 		/* trim free space relative to current alignment setting */
740 		start = ALIGN(res->start, align);
741 		end = ALIGN_DOWN(res->end + 1, align) - 1;
742 		if (end < start)
743 			continue;
744 		if (end - start + 1 > max)
745 			max = end - start + 1;
746 	}
747 	release_free_pmem(nvdimm_bus, nd_mapping);
748 	return max;
749 }
750 
751 /**
752  * nd_pmem_available_dpa - for the given dimm+region account unallocated dpa
753  * @nd_mapping: container of dpa-resource-root + labels
754  * @nd_region: constrain available space check to this reference region
755  * @overlap: calculate available space assuming this level of overlap
756  *
757  * Validate that a PMEM label, if present, aligns with the start of an
758  * interleave set and truncate the available size at the lowest BLK
759  * overlap point.
760  *
761  * The expectation is that this routine is called multiple times as it
762  * probes for the largest BLK encroachment for any single member DIMM of
763  * the interleave set.  Once that value is determined the PMEM-limit for
764  * the set can be established.
765  */
766 resource_size_t nd_pmem_available_dpa(struct nd_region *nd_region,
767 		struct nd_mapping *nd_mapping, resource_size_t *overlap)
768 {
769 	resource_size_t map_start, map_end, busy = 0, available, blk_start;
770 	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
771 	struct resource *res;
772 	const char *reason;
773 	unsigned long align;
774 
775 	if (!ndd)
776 		return 0;
777 
778 	align = dpa_align(nd_region);
779 	if (!align)
780 		return 0;
781 
782 	map_start = nd_mapping->start;
783 	map_end = map_start + nd_mapping->size - 1;
784 	blk_start = max(map_start, map_end + 1 - *overlap);
785 	for_each_dpa_resource(ndd, res) {
786 		resource_size_t start, end;
787 
788 		start = ALIGN_DOWN(res->start, align);
789 		end = ALIGN(res->end + 1, align) - 1;
790 		if (start >= map_start && start < map_end) {
791 			if (strncmp(res->name, "blk", 3) == 0)
792 				blk_start = min(blk_start,
793 						max(map_start, start));
794 			else if (end > map_end) {
795 				reason = "misaligned to iset";
796 				goto err;
797 			} else
798 				busy += end - start + 1;
799 		} else if (end >= map_start && end <= map_end) {
800 			if (strncmp(res->name, "blk", 3) == 0) {
801 				/*
802 				 * If a BLK allocation overlaps the start of
803 				 * PMEM the entire interleave set may now only
804 				 * be used for BLK.
805 				 */
806 				blk_start = map_start;
807 			} else
808 				busy += end - start + 1;
809 		} else if (map_start > start && map_start < end) {
810 			/* total eclipse of the mapping */
811 			busy += nd_mapping->size;
812 			blk_start = map_start;
813 		}
814 	}
815 
816 	*overlap = map_end + 1 - blk_start;
817 	available = blk_start - map_start;
818 	if (busy < available)
819 		return ALIGN_DOWN(available - busy, align);
820 	return 0;
821 
822  err:
823 	nd_dbg_dpa(nd_region, ndd, res, "%s\n", reason);
824 	return 0;
825 }
826 
827 void nvdimm_free_dpa(struct nvdimm_drvdata *ndd, struct resource *res)
828 {
829 	WARN_ON_ONCE(!is_nvdimm_bus_locked(ndd->dev));
830 	kfree(res->name);
831 	__release_region(&ndd->dpa, res->start, resource_size(res));
832 }
833 
834 struct resource *nvdimm_allocate_dpa(struct nvdimm_drvdata *ndd,
835 		struct nd_label_id *label_id, resource_size_t start,
836 		resource_size_t n)
837 {
838 	char *name = kmemdup(label_id, sizeof(*label_id), GFP_KERNEL);
839 	struct resource *res;
840 
841 	if (!name)
842 		return NULL;
843 
844 	WARN_ON_ONCE(!is_nvdimm_bus_locked(ndd->dev));
845 	res = __request_region(&ndd->dpa, start, n, name, 0);
846 	if (!res)
847 		kfree(name);
848 	return res;
849 }
850 
851 /**
852  * nvdimm_allocated_dpa - sum up the dpa currently allocated to this label_id
853  * @nvdimm: container of dpa-resource-root + labels
854  * @label_id: dpa resource name of the form {pmem|blk}-<human readable uuid>
855  */
856 resource_size_t nvdimm_allocated_dpa(struct nvdimm_drvdata *ndd,
857 		struct nd_label_id *label_id)
858 {
859 	resource_size_t allocated = 0;
860 	struct resource *res;
861 
862 	for_each_dpa_resource(ndd, res)
863 		if (strcmp(res->name, label_id->id) == 0)
864 			allocated += resource_size(res);
865 
866 	return allocated;
867 }
868 
869 static int count_dimms(struct device *dev, void *c)
870 {
871 	int *count = c;
872 
873 	if (is_nvdimm(dev))
874 		(*count)++;
875 	return 0;
876 }
877 
878 int nvdimm_bus_check_dimm_count(struct nvdimm_bus *nvdimm_bus, int dimm_count)
879 {
880 	int count = 0;
881 	/* Flush any possible dimm registration failures */
882 	nd_synchronize();
883 
884 	device_for_each_child(&nvdimm_bus->dev, &count, count_dimms);
885 	dev_dbg(&nvdimm_bus->dev, "count: %d\n", count);
886 	if (count != dimm_count)
887 		return -ENXIO;
888 	return 0;
889 }
890 EXPORT_SYMBOL_GPL(nvdimm_bus_check_dimm_count);
891 
892 void __exit nvdimm_devs_exit(void)
893 {
894 	ida_destroy(&dimm_ida);
895 }
896