xref: /linux/drivers/nvdimm/pmem.c (revision 110e6f26af80dfd90b6e5c645b1aed7228aa580d)
1 /*
2  * Persistent Memory Driver
3  *
4  * Copyright (c) 2014-2015, Intel Corporation.
5  * Copyright (c) 2015, Christoph Hellwig <hch@lst.de>.
6  * Copyright (c) 2015, Boaz Harrosh <boaz@plexistor.com>.
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms and conditions of the GNU General Public License,
10  * version 2, as published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope it will be useful, but WITHOUT
13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
15  * more details.
16  */
17 
18 #include <asm/cacheflush.h>
19 #include <linux/blkdev.h>
20 #include <linux/hdreg.h>
21 #include <linux/init.h>
22 #include <linux/platform_device.h>
23 #include <linux/module.h>
24 #include <linux/moduleparam.h>
25 #include <linux/badblocks.h>
26 #include <linux/memremap.h>
27 #include <linux/vmalloc.h>
28 #include <linux/pfn_t.h>
29 #include <linux/slab.h>
30 #include <linux/pmem.h>
31 #include <linux/nd.h>
32 #include "pfn.h"
33 #include "nd.h"
34 
35 struct pmem_device {
36 	struct request_queue	*pmem_queue;
37 	struct gendisk		*pmem_disk;
38 	struct nd_namespace_common *ndns;
39 
40 	/* One contiguous memory region per device */
41 	phys_addr_t		phys_addr;
42 	/* when non-zero this device is hosting a 'pfn' instance */
43 	phys_addr_t		data_offset;
44 	u64			pfn_flags;
45 	void __pmem		*virt_addr;
46 	/* immutable base size of the namespace */
47 	size_t			size;
48 	/* trim size when namespace capacity has been section aligned */
49 	u32			pfn_pad;
50 	struct badblocks	bb;
51 };
52 
53 static bool is_bad_pmem(struct badblocks *bb, sector_t sector, unsigned int len)
54 {
55 	if (bb->count) {
56 		sector_t first_bad;
57 		int num_bad;
58 
59 		return !!badblocks_check(bb, sector, len / 512, &first_bad,
60 				&num_bad);
61 	}
62 
63 	return false;
64 }
65 
66 static void pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset,
67 		unsigned int len)
68 {
69 	struct device *dev = disk_to_dev(pmem->pmem_disk);
70 	sector_t sector;
71 	long cleared;
72 
73 	sector = (offset - pmem->data_offset) / 512;
74 	cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len);
75 
76 	if (cleared > 0 && cleared / 512) {
77 		dev_dbg(dev, "%s: %llx clear %ld sector%s\n",
78 				__func__, (unsigned long long) sector,
79 				cleared / 512, cleared / 512 > 1 ? "s" : "");
80 		badblocks_clear(&pmem->bb, sector, cleared / 512);
81 	}
82 	invalidate_pmem(pmem->virt_addr + offset, len);
83 }
84 
85 static int pmem_do_bvec(struct pmem_device *pmem, struct page *page,
86 			unsigned int len, unsigned int off, int rw,
87 			sector_t sector)
88 {
89 	int rc = 0;
90 	bool bad_pmem = false;
91 	void *mem = kmap_atomic(page);
92 	phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
93 	void __pmem *pmem_addr = pmem->virt_addr + pmem_off;
94 
95 	if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
96 		bad_pmem = true;
97 
98 	if (rw == READ) {
99 		if (unlikely(bad_pmem))
100 			rc = -EIO;
101 		else {
102 			rc = memcpy_from_pmem(mem + off, pmem_addr, len);
103 			flush_dcache_page(page);
104 		}
105 	} else {
106 		flush_dcache_page(page);
107 		memcpy_to_pmem(pmem_addr, mem + off, len);
108 		if (unlikely(bad_pmem)) {
109 			pmem_clear_poison(pmem, pmem_off, len);
110 			memcpy_to_pmem(pmem_addr, mem + off, len);
111 		}
112 	}
113 
114 	kunmap_atomic(mem);
115 	return rc;
116 }
117 
118 static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
119 {
120 	int rc = 0;
121 	bool do_acct;
122 	unsigned long start;
123 	struct bio_vec bvec;
124 	struct bvec_iter iter;
125 	struct block_device *bdev = bio->bi_bdev;
126 	struct pmem_device *pmem = bdev->bd_disk->private_data;
127 
128 	do_acct = nd_iostat_start(bio, &start);
129 	bio_for_each_segment(bvec, bio, iter) {
130 		rc = pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len,
131 				bvec.bv_offset, bio_data_dir(bio),
132 				iter.bi_sector);
133 		if (rc) {
134 			bio->bi_error = rc;
135 			break;
136 		}
137 	}
138 	if (do_acct)
139 		nd_iostat_end(bio, start);
140 
141 	if (bio_data_dir(bio))
142 		wmb_pmem();
143 
144 	bio_endio(bio);
145 	return BLK_QC_T_NONE;
146 }
147 
148 static int pmem_rw_page(struct block_device *bdev, sector_t sector,
149 		       struct page *page, int rw)
150 {
151 	struct pmem_device *pmem = bdev->bd_disk->private_data;
152 	int rc;
153 
154 	rc = pmem_do_bvec(pmem, page, PAGE_SIZE, 0, rw, sector);
155 	if (rw & WRITE)
156 		wmb_pmem();
157 
158 	/*
159 	 * The ->rw_page interface is subtle and tricky.  The core
160 	 * retries on any error, so we can only invoke page_endio() in
161 	 * the successful completion case.  Otherwise, we'll see crashes
162 	 * caused by double completion.
163 	 */
164 	if (rc == 0)
165 		page_endio(page, rw & WRITE, 0);
166 
167 	return rc;
168 }
169 
170 static long pmem_direct_access(struct block_device *bdev, sector_t sector,
171 		      void __pmem **kaddr, pfn_t *pfn)
172 {
173 	struct pmem_device *pmem = bdev->bd_disk->private_data;
174 	resource_size_t offset = sector * 512 + pmem->data_offset;
175 
176 	*kaddr = pmem->virt_addr + offset;
177 	*pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
178 
179 	return pmem->size - pmem->pfn_pad - offset;
180 }
181 
182 static const struct block_device_operations pmem_fops = {
183 	.owner =		THIS_MODULE,
184 	.rw_page =		pmem_rw_page,
185 	.direct_access =	pmem_direct_access,
186 	.revalidate_disk =	nvdimm_revalidate_disk,
187 };
188 
189 static struct pmem_device *pmem_alloc(struct device *dev,
190 		struct resource *res, int id)
191 {
192 	struct pmem_device *pmem;
193 	struct request_queue *q;
194 
195 	pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
196 	if (!pmem)
197 		return ERR_PTR(-ENOMEM);
198 
199 	pmem->phys_addr = res->start;
200 	pmem->size = resource_size(res);
201 	if (!arch_has_wmb_pmem())
202 		dev_warn(dev, "unable to guarantee persistence of writes\n");
203 
204 	if (!devm_request_mem_region(dev, pmem->phys_addr, pmem->size,
205 			dev_name(dev))) {
206 		dev_warn(dev, "could not reserve region [0x%pa:0x%zx]\n",
207 				&pmem->phys_addr, pmem->size);
208 		return ERR_PTR(-EBUSY);
209 	}
210 
211 	q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev));
212 	if (!q)
213 		return ERR_PTR(-ENOMEM);
214 
215 	pmem->pfn_flags = PFN_DEV;
216 	if (pmem_should_map_pages(dev)) {
217 		pmem->virt_addr = (void __pmem *) devm_memremap_pages(dev, res,
218 				&q->q_usage_counter, NULL);
219 		pmem->pfn_flags |= PFN_MAP;
220 	} else
221 		pmem->virt_addr = (void __pmem *) devm_memremap(dev,
222 				pmem->phys_addr, pmem->size,
223 				ARCH_MEMREMAP_PMEM);
224 
225 	if (IS_ERR(pmem->virt_addr)) {
226 		blk_cleanup_queue(q);
227 		return (void __force *) pmem->virt_addr;
228 	}
229 
230 	pmem->pmem_queue = q;
231 	return pmem;
232 }
233 
234 static void pmem_detach_disk(struct pmem_device *pmem)
235 {
236 	if (!pmem->pmem_disk)
237 		return;
238 
239 	del_gendisk(pmem->pmem_disk);
240 	put_disk(pmem->pmem_disk);
241 	blk_cleanup_queue(pmem->pmem_queue);
242 }
243 
244 static int pmem_attach_disk(struct device *dev,
245 		struct nd_namespace_common *ndns, struct pmem_device *pmem)
246 {
247 	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
248 	int nid = dev_to_node(dev);
249 	struct resource bb_res;
250 	struct gendisk *disk;
251 
252 	blk_queue_make_request(pmem->pmem_queue, pmem_make_request);
253 	blk_queue_physical_block_size(pmem->pmem_queue, PAGE_SIZE);
254 	blk_queue_max_hw_sectors(pmem->pmem_queue, UINT_MAX);
255 	blk_queue_bounce_limit(pmem->pmem_queue, BLK_BOUNCE_ANY);
256 	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, pmem->pmem_queue);
257 
258 	disk = alloc_disk_node(0, nid);
259 	if (!disk) {
260 		blk_cleanup_queue(pmem->pmem_queue);
261 		return -ENOMEM;
262 	}
263 
264 	disk->fops		= &pmem_fops;
265 	disk->private_data	= pmem;
266 	disk->queue		= pmem->pmem_queue;
267 	disk->flags		= GENHD_FL_EXT_DEVT;
268 	nvdimm_namespace_disk_name(ndns, disk->disk_name);
269 	disk->driverfs_dev = dev;
270 	set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
271 			/ 512);
272 	pmem->pmem_disk = disk;
273 	devm_exit_badblocks(dev, &pmem->bb);
274 	if (devm_init_badblocks(dev, &pmem->bb))
275 		return -ENOMEM;
276 	bb_res.start = nsio->res.start + pmem->data_offset;
277 	bb_res.end = nsio->res.end;
278 	if (is_nd_pfn(dev)) {
279 		struct nd_pfn *nd_pfn = to_nd_pfn(dev);
280 		struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
281 
282 		bb_res.start += __le32_to_cpu(pfn_sb->start_pad);
283 		bb_res.end -= __le32_to_cpu(pfn_sb->end_trunc);
284 	}
285 	nvdimm_badblocks_populate(to_nd_region(dev->parent), &pmem->bb,
286 			&bb_res);
287 	disk->bb = &pmem->bb;
288 	add_disk(disk);
289 	revalidate_disk(disk);
290 
291 	return 0;
292 }
293 
294 static int pmem_rw_bytes(struct nd_namespace_common *ndns,
295 		resource_size_t offset, void *buf, size_t size, int rw)
296 {
297 	struct pmem_device *pmem = dev_get_drvdata(ndns->claim);
298 
299 	if (unlikely(offset + size > pmem->size)) {
300 		dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
301 		return -EFAULT;
302 	}
303 
304 	if (rw == READ) {
305 		unsigned int sz_align = ALIGN(size + (offset & (512 - 1)), 512);
306 
307 		if (unlikely(is_bad_pmem(&pmem->bb, offset / 512, sz_align)))
308 			return -EIO;
309 		return memcpy_from_pmem(buf, pmem->virt_addr + offset, size);
310 	} else {
311 		memcpy_to_pmem(pmem->virt_addr + offset, buf, size);
312 		wmb_pmem();
313 	}
314 
315 	return 0;
316 }
317 
318 static int nd_pfn_init(struct nd_pfn *nd_pfn)
319 {
320 	struct nd_pfn_sb *pfn_sb = kzalloc(sizeof(*pfn_sb), GFP_KERNEL);
321 	struct pmem_device *pmem = dev_get_drvdata(&nd_pfn->dev);
322 	struct nd_namespace_common *ndns = nd_pfn->ndns;
323 	u32 start_pad = 0, end_trunc = 0;
324 	resource_size_t start, size;
325 	struct nd_namespace_io *nsio;
326 	struct nd_region *nd_region;
327 	unsigned long npfns;
328 	phys_addr_t offset;
329 	u64 checksum;
330 	int rc;
331 
332 	if (!pfn_sb)
333 		return -ENOMEM;
334 
335 	nd_pfn->pfn_sb = pfn_sb;
336 	rc = nd_pfn_validate(nd_pfn);
337 	if (rc == -ENODEV)
338 		/* no info block, do init */;
339 	else
340 		return rc;
341 
342 	nd_region = to_nd_region(nd_pfn->dev.parent);
343 	if (nd_region->ro) {
344 		dev_info(&nd_pfn->dev,
345 				"%s is read-only, unable to init metadata\n",
346 				dev_name(&nd_region->dev));
347 		goto err;
348 	}
349 
350 	memset(pfn_sb, 0, sizeof(*pfn_sb));
351 
352 	/*
353 	 * Check if pmem collides with 'System RAM' when section aligned and
354 	 * trim it accordingly
355 	 */
356 	nsio = to_nd_namespace_io(&ndns->dev);
357 	start = PHYS_SECTION_ALIGN_DOWN(nsio->res.start);
358 	size = resource_size(&nsio->res);
359 	if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
360 				IORES_DESC_NONE) == REGION_MIXED) {
361 
362 		start = nsio->res.start;
363 		start_pad = PHYS_SECTION_ALIGN_UP(start) - start;
364 	}
365 
366 	start = nsio->res.start;
367 	size = PHYS_SECTION_ALIGN_UP(start + size) - start;
368 	if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
369 				IORES_DESC_NONE) == REGION_MIXED) {
370 		size = resource_size(&nsio->res);
371 		end_trunc = start + size - PHYS_SECTION_ALIGN_DOWN(start + size);
372 	}
373 
374 	if (start_pad + end_trunc)
375 		dev_info(&nd_pfn->dev, "%s section collision, truncate %d bytes\n",
376 				dev_name(&ndns->dev), start_pad + end_trunc);
377 
378 	/*
379 	 * Note, we use 64 here for the standard size of struct page,
380 	 * debugging options may cause it to be larger in which case the
381 	 * implementation will limit the pfns advertised through
382 	 * ->direct_access() to those that are included in the memmap.
383 	 */
384 	start += start_pad;
385 	npfns = (pmem->size - start_pad - end_trunc - SZ_8K) / SZ_4K;
386 	if (nd_pfn->mode == PFN_MODE_PMEM)
387 		offset = ALIGN(start + SZ_8K + 64 * npfns, nd_pfn->align)
388 			- start;
389 	else if (nd_pfn->mode == PFN_MODE_RAM)
390 		offset = ALIGN(start + SZ_8K, nd_pfn->align) - start;
391 	else
392 		goto err;
393 
394 	if (offset + start_pad + end_trunc >= pmem->size) {
395 		dev_err(&nd_pfn->dev, "%s unable to satisfy requested alignment\n",
396 				dev_name(&ndns->dev));
397 		goto err;
398 	}
399 
400 	npfns = (pmem->size - offset - start_pad - end_trunc) / SZ_4K;
401 	pfn_sb->mode = cpu_to_le32(nd_pfn->mode);
402 	pfn_sb->dataoff = cpu_to_le64(offset);
403 	pfn_sb->npfns = cpu_to_le64(npfns);
404 	memcpy(pfn_sb->signature, PFN_SIG, PFN_SIG_LEN);
405 	memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
406 	memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16);
407 	pfn_sb->version_major = cpu_to_le16(1);
408 	pfn_sb->version_minor = cpu_to_le16(1);
409 	pfn_sb->start_pad = cpu_to_le32(start_pad);
410 	pfn_sb->end_trunc = cpu_to_le32(end_trunc);
411 	checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
412 	pfn_sb->checksum = cpu_to_le64(checksum);
413 
414 	rc = nvdimm_write_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb));
415 	if (rc)
416 		goto err;
417 
418 	return 0;
419  err:
420 	nd_pfn->pfn_sb = NULL;
421 	kfree(pfn_sb);
422 	return -ENXIO;
423 }
424 
425 static int nvdimm_namespace_detach_pfn(struct nd_namespace_common *ndns)
426 {
427 	struct nd_pfn *nd_pfn = to_nd_pfn(ndns->claim);
428 	struct pmem_device *pmem;
429 
430 	/* free pmem disk */
431 	pmem = dev_get_drvdata(&nd_pfn->dev);
432 	pmem_detach_disk(pmem);
433 
434 	/* release nd_pfn resources */
435 	kfree(nd_pfn->pfn_sb);
436 	nd_pfn->pfn_sb = NULL;
437 
438 	return 0;
439 }
440 
441 /*
442  * We hotplug memory at section granularity, pad the reserved area from
443  * the previous section base to the namespace base address.
444  */
445 static unsigned long init_altmap_base(resource_size_t base)
446 {
447 	unsigned long base_pfn = PHYS_PFN(base);
448 
449 	return PFN_SECTION_ALIGN_DOWN(base_pfn);
450 }
451 
452 static unsigned long init_altmap_reserve(resource_size_t base)
453 {
454 	unsigned long reserve = PHYS_PFN(SZ_8K);
455 	unsigned long base_pfn = PHYS_PFN(base);
456 
457 	reserve += base_pfn - PFN_SECTION_ALIGN_DOWN(base_pfn);
458 	return reserve;
459 }
460 
461 static int __nvdimm_namespace_attach_pfn(struct nd_pfn *nd_pfn)
462 {
463 	int rc;
464 	struct resource res;
465 	struct request_queue *q;
466 	struct pmem_device *pmem;
467 	struct vmem_altmap *altmap;
468 	struct device *dev = &nd_pfn->dev;
469 	struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
470 	struct nd_namespace_common *ndns = nd_pfn->ndns;
471 	u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
472 	u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
473 	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
474 	resource_size_t base = nsio->res.start + start_pad;
475 	struct vmem_altmap __altmap = {
476 		.base_pfn = init_altmap_base(base),
477 		.reserve = init_altmap_reserve(base),
478 	};
479 
480 	pmem = dev_get_drvdata(dev);
481 	pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
482 	pmem->pfn_pad = start_pad + end_trunc;
483 	nd_pfn->mode = le32_to_cpu(nd_pfn->pfn_sb->mode);
484 	if (nd_pfn->mode == PFN_MODE_RAM) {
485 		if (pmem->data_offset < SZ_8K)
486 			return -EINVAL;
487 		nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns);
488 		altmap = NULL;
489 	} else if (nd_pfn->mode == PFN_MODE_PMEM) {
490 		nd_pfn->npfns = (pmem->size - pmem->pfn_pad - pmem->data_offset)
491 			/ PAGE_SIZE;
492 		if (le64_to_cpu(nd_pfn->pfn_sb->npfns) > nd_pfn->npfns)
493 			dev_info(&nd_pfn->dev,
494 					"number of pfns truncated from %lld to %ld\n",
495 					le64_to_cpu(nd_pfn->pfn_sb->npfns),
496 					nd_pfn->npfns);
497 		altmap = & __altmap;
498 		altmap->free = PHYS_PFN(pmem->data_offset - SZ_8K);
499 		altmap->alloc = 0;
500 	} else {
501 		rc = -ENXIO;
502 		goto err;
503 	}
504 
505 	/* establish pfn range for lookup, and switch to direct map */
506 	q = pmem->pmem_queue;
507 	memcpy(&res, &nsio->res, sizeof(res));
508 	res.start += start_pad;
509 	res.end -= end_trunc;
510 	devm_memunmap(dev, (void __force *) pmem->virt_addr);
511 	pmem->virt_addr = (void __pmem *) devm_memremap_pages(dev, &res,
512 			&q->q_usage_counter, altmap);
513 	pmem->pfn_flags |= PFN_MAP;
514 	if (IS_ERR(pmem->virt_addr)) {
515 		rc = PTR_ERR(pmem->virt_addr);
516 		goto err;
517 	}
518 
519 	/* attach pmem disk in "pfn-mode" */
520 	rc = pmem_attach_disk(dev, ndns, pmem);
521 	if (rc)
522 		goto err;
523 
524 	return rc;
525  err:
526 	nvdimm_namespace_detach_pfn(ndns);
527 	return rc;
528 
529 }
530 
531 static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
532 {
533 	struct nd_pfn *nd_pfn = to_nd_pfn(ndns->claim);
534 	int rc;
535 
536 	if (!nd_pfn->uuid || !nd_pfn->ndns)
537 		return -ENODEV;
538 
539 	rc = nd_pfn_init(nd_pfn);
540 	if (rc)
541 		return rc;
542 	/* we need a valid pfn_sb before we can init a vmem_altmap */
543 	return __nvdimm_namespace_attach_pfn(nd_pfn);
544 }
545 
546 static int nd_pmem_probe(struct device *dev)
547 {
548 	struct nd_region *nd_region = to_nd_region(dev->parent);
549 	struct nd_namespace_common *ndns;
550 	struct nd_namespace_io *nsio;
551 	struct pmem_device *pmem;
552 
553 	ndns = nvdimm_namespace_common_probe(dev);
554 	if (IS_ERR(ndns))
555 		return PTR_ERR(ndns);
556 
557 	nsio = to_nd_namespace_io(&ndns->dev);
558 	pmem = pmem_alloc(dev, &nsio->res, nd_region->id);
559 	if (IS_ERR(pmem))
560 		return PTR_ERR(pmem);
561 
562 	pmem->ndns = ndns;
563 	dev_set_drvdata(dev, pmem);
564 	ndns->rw_bytes = pmem_rw_bytes;
565 	if (devm_init_badblocks(dev, &pmem->bb))
566 		return -ENOMEM;
567 	nvdimm_badblocks_populate(nd_region, &pmem->bb, &nsio->res);
568 
569 	if (is_nd_btt(dev)) {
570 		/* btt allocates its own request_queue */
571 		blk_cleanup_queue(pmem->pmem_queue);
572 		pmem->pmem_queue = NULL;
573 		return nvdimm_namespace_attach_btt(ndns);
574 	}
575 
576 	if (is_nd_pfn(dev))
577 		return nvdimm_namespace_attach_pfn(ndns);
578 
579 	if (nd_btt_probe(ndns, pmem) == 0 || nd_pfn_probe(ndns, pmem) == 0) {
580 		/*
581 		 * We'll come back as either btt-pmem, or pfn-pmem, so
582 		 * drop the queue allocation for now.
583 		 */
584 		blk_cleanup_queue(pmem->pmem_queue);
585 		return -ENXIO;
586 	}
587 
588 	return pmem_attach_disk(dev, ndns, pmem);
589 }
590 
591 static int nd_pmem_remove(struct device *dev)
592 {
593 	struct pmem_device *pmem = dev_get_drvdata(dev);
594 
595 	if (is_nd_btt(dev))
596 		nvdimm_namespace_detach_btt(pmem->ndns);
597 	else if (is_nd_pfn(dev))
598 		nvdimm_namespace_detach_pfn(pmem->ndns);
599 	else
600 		pmem_detach_disk(pmem);
601 
602 	return 0;
603 }
604 
605 static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
606 {
607 	struct pmem_device *pmem = dev_get_drvdata(dev);
608 	struct nd_namespace_common *ndns = pmem->ndns;
609 	struct nd_region *nd_region = to_nd_region(dev->parent);
610 	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
611 	struct resource res = {
612 		.start = nsio->res.start + pmem->data_offset,
613 		.end = nsio->res.end,
614 	};
615 
616 	if (event != NVDIMM_REVALIDATE_POISON)
617 		return;
618 
619 	if (is_nd_pfn(dev)) {
620 		struct nd_pfn *nd_pfn = to_nd_pfn(dev);
621 		struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
622 
623 		res.start += __le32_to_cpu(pfn_sb->start_pad);
624 		res.end -= __le32_to_cpu(pfn_sb->end_trunc);
625 	}
626 
627 	nvdimm_badblocks_populate(nd_region, &pmem->bb, &res);
628 }
629 
630 MODULE_ALIAS("pmem");
631 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO);
632 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM);
633 static struct nd_device_driver nd_pmem_driver = {
634 	.probe = nd_pmem_probe,
635 	.remove = nd_pmem_remove,
636 	.notify = nd_pmem_notify,
637 	.drv = {
638 		.name = "nd_pmem",
639 	},
640 	.type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
641 };
642 
643 static int __init pmem_init(void)
644 {
645 	return nd_driver_register(&nd_pmem_driver);
646 }
647 module_init(pmem_init);
648 
649 static void pmem_exit(void)
650 {
651 	driver_unregister(&nd_pmem_driver.drv);
652 }
653 module_exit(pmem_exit);
654 
655 MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
656 MODULE_LICENSE("GPL v2");
657