summaryrefslogtreecommitdiffstats
path: root/drivers/nvdimm/pmem.c
blob: f9f76f6ba07b1ba3283d1d48e6eebcf631e0acc5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Persistent Memory Driver
 *
 * Copyright (c) 2014-2015, Intel Corporation.
 * Copyright (c) 2015, Christoph Hellwig <hch@lst.de>.
 * Copyright (c) 2015, Boaz Harrosh <boaz@plexistor.com>.
 */

#include <asm/cacheflush.h>
#include <linux/blkdev.h>
#include <linux/hdreg.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/set_memory.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/badblocks.h>
#include <linux/memremap.h>
#include <linux/vmalloc.h>
#include <linux/blk-mq.h>
#include <linux/pfn_t.h>
#include <linux/slab.h>
#include <linux/uio.h>
#include <linux/dax.h>
#include <linux/nd.h>
#include <linux/backing-dev.h>
#include "pmem.h"
#include "pfn.h"
#include "nd.h"
#include "nd-core.h"

static struct device *to_dev(struct pmem_device *pmem)
{
	/*
	 * nvdimm bus services need a 'dev' parameter, and we record the device
	 * at init in bb.dev.
	 */
	return pmem->bb.dev;
}

static struct nd_region *to_region(struct pmem_device *pmem)
{
	return to_nd_region(to_dev(pmem)->parent);
}

static void hwpoison_clear(struct pmem_device *pmem,
		phys_addr_t phys, unsigned int len)
{
	unsigned long pfn_start, pfn_end, pfn;

	/* only pmem in the linear map supports HWPoison */
	if (is_vmalloc_addr(pmem->virt_addr))
		return;

	pfn_start = PHYS_PFN(phys);
	pfn_end = pfn_start + PHYS_PFN(len);
	for (pfn = pfn_start; pfn < pfn_end; pfn++) {
		struct page *page = pfn_to_page(pfn);

		/*
		 * Note, no need to hold a get_dev_pagemap() reference
		 * here since we're in the driver I/O path and
		 * outstanding I/O requests pin the dev_pagemap.
		 */
		if (test_and_clear_pmem_poison(page))
			clear_mce_nospec(pfn);
	}
}

static blk_status_t pmem_clear_poison(struct pmem_device *pmem,
		phys_addr_t offset, unsigned int len)
{
	struct device *dev = to_dev(pmem);
	sector_t sector;
	long cleared;
	blk_status_t rc = BLK_STS_OK;

	sector = (offset - pmem->data_offset) / 512;

	cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len);
	if (cleared < len)
		rc = BLK_STS_IOERR;
	if (cleared > 0 && cleared / 512) {
		hwpoison_clear(pmem, pmem->phys_addr + offset, cleared);
		cleared /= 512;
		dev_dbg(dev, "%#llx clear %ld sector%s\n",
				(unsigned long long) sector, cleared,
				cleared > 1 ? "s" : "");
		badblocks_clear(&pmem->bb, sector, cleared);
		if (pmem->bb_state)
			sysfs_notify_dirent(pmem->bb_state);
	}

	arch_invalidate_pmem(pmem->virt_addr + offset, len);

	return rc;
}

static void write_pmem(void *pmem_addr, struct page *page,
		unsigned int off, unsigned int len)
{
	unsigned int chunk;
	void *mem;

	while (len) {
		mem = kmap_atomic(page);
		chunk = min_t(unsigned int, len, PAGE_SIZE - off);
		memcpy_flushcache(pmem_addr, mem + off, chunk);
		kunmap_atomic(mem);
		len -= chunk;
		off = 0;
		page++;
		pmem_addr += chunk;
	}
}

static blk_status_t read_pmem(struct page *page, unsigned int off,
		void *pmem_addr, unsigned int len)
{
	unsigned int chunk;
	unsigned long rem;
	void *mem;

	while (len) {
		mem = kmap_atomic(page);
		chunk = min_t(unsigned int, len, PAGE_SIZE - off);
		rem = memcpy_mcsafe(mem + off, pmem_addr, chunk);
		kunmap_atomic(mem);
		if (rem)
			return BLK_STS_IOERR;
		len -= chunk;
		off = 0;
		page++;
		pmem_addr += chunk;
	}
	return BLK_STS_OK;
}

static blk_status_t pmem_do_bvec(struct pmem_device *pmem, struct page *page,
			unsigned int len, unsigned int off, unsigned int op,
			sector_t sector)
{
	blk_status_t rc = BLK_STS_OK;
	bool bad_pmem = false;
	phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
	void *pmem_addr = pmem->virt_addr + pmem_off;

	if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
		bad_pmem = true;

	if (!op_is_write(op)) {
		if (unlikely(bad_pmem))
			rc = BLK_STS_IOERR;
		else {
			rc = read_pmem(page, off, pmem_addr, len);
			flush_dcache_page(page);
		}
	} else {
		/*
		 * Note that we write the data both before and after
		 * clearing poison.  The write before clear poison
		 * handles situations where the latest written data is
		 * preserved and the clear poison operation simply marks
		 * the address range as valid without changing the data.
		 * In this case application software can assume that an
		 * interrupted write will either return the new good
		 * data or an error.
		 *
		 * However, if pmem_clear_poison() leaves the data in an
		 * indeterminate state we need to perform the write
		 * after clear poison.
		 */
		flush_dcache_page(page);
		write_pmem(pmem_addr, page, off, len);
		if (unlikely(bad_pmem)) {
			rc = pmem_clear_poison(pmem, pmem_off, len);
			write_pmem(pmem_addr, page, off, len);
		}
	}

	return rc;
}

static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
{
	int ret = 0;
	blk_status_t rc = 0;
	bool do_acct;
	unsigned long start;
	struct bio_vec bvec;
	struct bvec_iter iter;
	struct pmem_device *pmem = q->queuedata;
	struct nd_region *nd_region = to_region(pmem);

	if (bio->bi_opf & REQ_PREFLUSH)
		ret = nvdimm_flush(nd_region, bio);

	do_acct = nd_iostat_start(bio, &start);
	bio_for_each_segment(bvec, bio, iter) {
		rc = pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len,
				bvec.bv_offset, bio_op(bio), iter.bi_sector);
		if (rc) {
			bio->bi_status = rc;
			break;
		}
	}
	if (do_acct)
		nd_iostat_end(bio, start);

	if (bio->bi_opf & REQ_FUA)
		ret = nvdimm_flush(nd_region, bio);

	if (ret)
		bio->bi_status = errno_to_blk_status(ret);

	bio_endio(bio);
	return BLK_QC_T_NONE;
}

static int pmem_rw_page(struct block_device *bdev, sector_t sector,
		       struct page *page, unsigned int op)
{
	struct pmem_device *pmem = bdev->bd_queue->queuedata;
	blk_status_t rc;

	rc = pmem_do_bvec(pmem, page, hpage_nr_pages(page) * PAGE_SIZE,
			  0, op, sector);

	/*
	 * The ->rw_page interface is subtle and tricky.  The core
	 * retries on any error, so we can only invoke page_endio() in
	 * the successful completion case.  Otherwise, we'll see crashes
	 * caused by double completion.
	 */
	if (rc == 0)
		page_endio(page, op_is_write(op), 0);

	return blk_status_to_errno(rc);
}

/* see "strong" declaration in tools/testing/nvdimm/pmem-dax.c */
__weak long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
		long nr_pages, void **kaddr, pfn_t *pfn)
{
	resource_size_t offset = PFN_PHYS(pgoff) + pmem->data_offset;

	if (unlikely(is_bad_pmem(&pmem->bb, PFN_PHYS(pgoff) / 512,
					PFN_PHYS(nr_pages))))
		return -EIO;

	if (kaddr)
		*kaddr = pmem->virt_addr + offset;
	if (pfn)
		*pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);

	/*
	 * If badblocks are present, limit known good range to the
	 * requested range.
	 */
	if (unlikely(pmem->bb.count))
		return nr_pages;
	return PHYS_PFN(pmem->size - pmem->pfn_pad - offset);
}

static const struct block_device_operations pmem_fops = {
	.owner =		THIS_MODULE,
	.rw_page =		pmem_rw_page,
	.revalidate_disk =	nvdimm_revalidate_disk,
};

static long pmem_dax_direct_access(struct dax_device *dax_dev,
		pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn)
{
	struct pmem_device *pmem = dax_get_private(dax_dev);

	return __pmem_direct_access(pmem, pgoff, nr_pages, kaddr, pfn);
}

/*
 * Use the 'no check' versions of copy_from_iter_flushcache() and
 * copy_to_iter_mcsafe() to bypass HARDENED_USERCOPY overhead. Bounds
 * checking, both file offset and device offset, is handled by
 * dax_iomap_actor()
 */
static size_t pmem_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
		void *addr, size_t bytes, struct iov_iter *i)
{
	return _copy_from_iter_flushcache(addr, bytes, i);
}

static size_t pmem_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff,
		void *addr, size_t bytes, struct iov_iter *i)
{
	return _copy_to_iter_mcsafe(addr, bytes, i);
}

static const struct dax_operations pmem_dax_ops = {
	.direct_access = pmem_dax_direct_access,
	.dax_supported = generic_fsdax_supported,
	.copy_from_iter = pmem_copy_from_iter,
	.copy_to_iter = pmem_copy_to_iter,
};

static const struct attribute_group *pmem_attribute_groups[] = {
	&dax_attribute_group,
	NULL,
};

static void pmem_pagemap_cleanup(struct dev_pagemap *pgmap)
{
	struct request_queue *q =
		container_of(pgmap->ref, struct request_queue, q_usage_counter);

	blk_cleanup_queue(q);
}

static void pmem_release_queue(void *pgmap)
{
	pmem_pagemap_cleanup(pgmap);
}

static void pmem_pagemap_kill(struct dev_pagemap *pgmap)
{
	struct request_queue *q =
		container_of(pgmap->ref, struct request_queue, q_usage_counter);

	blk_freeze_queue_start(q);
}

static void pmem_release_disk(void *__pmem)
{
	struct pmem_device *pmem = __pmem;

	kill_dax(pmem->dax_dev);
	put_dax(pmem->dax_dev);
	del_gendisk(pmem->disk);
	put_disk(pmem->disk);
}

static void pmem_pagemap_page_free(struct page *page)
{
	wake_up_var(&page->_refcount);
}

static const struct dev_pagemap_ops fsdax_pagemap_ops = {
	.page_free		= pmem_pagemap_page_free,
	.kill			= pmem_pagemap_kill,
	.cleanup		= pmem_pagemap_cleanup,
};

static int pmem_attach_disk(struct device *dev,
		struct nd_namespace_common *ndns)
{
	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
	struct nd_region *nd_region = to_nd_region(dev->parent);
	int nid = dev_to_node(dev), fua;
	struct resource *res = &nsio->res;
	struct resource bb_res;
	struct nd_pfn *nd_pfn = NULL;
	struct dax_device *dax_dev;
	struct nd_pfn_sb *pfn_sb;
	struct pmem_device *pmem;
	struct request_queue *q;
	struct device *gendev;
	struct gendisk *disk;
	void *addr;
	int rc;
	unsigned long flags = 0UL;

	pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
	if (!pmem)
		return -ENOMEM;

	/* while nsio_rw_bytes is active, parse a pfn info block if present */
	if (is_nd_pfn(dev)) {
		nd_pfn = to_nd_pfn(dev);
		rc = nvdimm_setup_pfn(nd_pfn, &pmem->pgmap);
		if (rc)
			return rc;
	}

	/* we're attaching a block device, disable raw namespace access */
	devm_nsio_disable(dev, nsio);

	dev_set_drvdata(dev, pmem);
	pmem->phys_addr = res->start;
	pmem->size = resource_size(res);
	fua = nvdimm_has_flush(nd_region);
	if (!IS_ENABLED(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) || fua < 0) {
		dev_warn(dev, "unable to guarantee persistence of writes\n");
		fua = 0;
	}

	if (!devm_request_mem_region(dev, res->start, resource_size(res),
				dev_name(&ndns->dev))) {
		dev_warn(dev, "could not reserve region %pR\n", res);
		return -EBUSY;
	}

	q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev));
	if (!q)
		return -ENOMEM;

	pmem->pfn_flags = PFN_DEV;
	pmem->pgmap.ref = &q->q_usage_counter;
	if (is_nd_pfn(dev)) {
		pmem->pgmap.type = MEMORY_DEVICE_FS_DAX;
		pmem->pgmap.ops = &fsdax_pagemap_ops;
		addr = devm_memremap_pages(dev, &pmem->pgmap);
		pfn_sb = nd_pfn->pfn_sb;
		pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
		pmem->pfn_pad = resource_size(res) -
			resource_size(&pmem->pgmap.res);
		pmem->pfn_flags |= PFN_MAP;
		memcpy(&bb_res, &pmem->pgmap.res, sizeof(bb_res));
		bb_res.start += pmem->data_offset;
	} else if (pmem_should_map_pages(dev)) {
		memcpy(&pmem->pgmap.res, &nsio->res, sizeof(pmem->pgmap.res));
		pmem->pgmap.type = MEMORY_DEVICE_FS_DAX;
		pmem->pgmap.ops = &fsdax_pagemap_ops;
		addr = devm_memremap_pages(dev, &pmem->pgmap);
		pmem->pfn_flags |= PFN_MAP;
		memcpy(&bb_res, &pmem->pgmap.res, sizeof(bb_res));
	} else {
		if (devm_add_action_or_reset(dev, pmem_release_queue,
					&pmem->pgmap))
			return -ENOMEM;
		addr = devm_memremap(dev, pmem->phys_addr,
				pmem->size, ARCH_MEMREMAP_PMEM);
		memcpy(&bb_res, &nsio->res, sizeof(bb_res));
	}

	if (IS_ERR(addr))
		return PTR_ERR(addr);
	pmem->virt_addr = addr;

	blk_queue_write_cache(q, true, fua);
	blk_queue_make_request(q, pmem_make_request);
	blk_queue_physical_block_size(q, PAGE_SIZE);
	blk_queue_logical_block_size(q, pmem_sector_size(ndns));
	blk_queue_max_hw_sectors(q, UINT_MAX);
	blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
	if (pmem->pfn_flags & PFN_MAP)
		blk_queue_flag_set(QUEUE_FLAG_DAX, q);
	q->queuedata = pmem;

	disk = alloc_disk_node(0, nid);
	if (!disk)
		return -ENOMEM;
	pmem->disk = disk;

	disk->fops		= &pmem_fops;
	disk->queue		= q;
	disk->flags		= GENHD_FL_EXT_DEVT;
	disk->queue->backing_dev_info->capabilities |= BDI_CAP_SYNCHRONOUS_IO;
	nvdimm_namespace_disk_name(ndns, disk->disk_name);
	set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
			/ 512);
	if (devm_init_badblocks(dev, &pmem->bb))
		return -ENOMEM;
	nvdimm_badblocks_populate(nd_region, &pmem->bb, &bb_res);
	disk->bb = &pmem->bb;

	if (is_nvdimm_sync(nd_region))
		flags = DAXDEV_F_SYNC;
	dax_dev = alloc_dax(pmem, disk->disk_name, &pmem_dax_ops, flags);
	if (!dax_dev) {
		put_disk(disk);
		return -ENOMEM;
	}
	dax_write_cache(dax_dev, nvdimm_has_cache(nd_region));
	pmem->dax_dev = dax_dev;
	gendev = disk_to_dev(disk);
	gendev->groups = pmem_attribute_groups;

	device_add_disk(dev, disk, NULL);
	if (devm_add_action_or_reset(dev, pmem_release_disk, pmem))
		return -ENOMEM;

	revalidate_disk(disk);

	pmem->bb_state = sysfs_get_dirent(disk_to_dev(disk)->kobj.sd,
					  "badblocks");
	if (!pmem->bb_state)
		dev_warn(dev, "'badblocks' notification disabled\n");

	return 0;
}

static int nd_pmem_probe(struct device *dev)
{
	int ret;
	struct nd_namespace_common *ndns;

	ndns = nvdimm_namespace_common_probe(dev);
	if (IS_ERR(ndns))
		return PTR_ERR(ndns);

	if (devm_nsio_enable(dev, to_nd_namespace_io(&ndns->dev)))
		return -ENXIO;

	if (is_nd_btt(dev))
		return nvdimm_namespace_attach_btt(ndns);

	if (is_nd_pfn(dev))
		return pmem_attach_disk(dev, ndns);

	ret = nd_btt_probe(dev, ndns);
	if (ret == 0)
		return -ENXIO;

	/*
	 * We have two failure conditions here, there is no
	 * info reserver block or we found a valid info reserve block
	 * but failed to initialize the pfn superblock.
	 *
	 * For the first case consider namespace as a raw pmem namespace
	 * and attach a disk.
	 *
	 * For the latter, consider this a success and advance the namespace
	 * seed.
	 */
	ret = nd_pfn_probe(dev, ndns);
	if (ret == 0)
		return -ENXIO;
	else if (ret == -EOPNOTSUPP)
		return ret;

	ret = nd_dax_probe(dev, ndns);
	if (ret == 0)
		return -ENXIO;
	else if (ret == -EOPNOTSUPP)
		return ret;
	return pmem_attach_disk(dev, ndns);
}

static int nd_pmem_remove(struct device *dev)
{
	struct pmem_device *pmem = dev_get_drvdata(dev);

	if (is_nd_btt(dev))
		nvdimm_namespace_detach_btt(to_nd_btt(dev));
	else {
		/*
		 * Note, this assumes nd_device_lock() context to not
		 * race nd_pmem_notify()
		 */
		sysfs_put(pmem->bb_state);
		pmem->bb_state = NULL;
	}
	nvdimm_flush(to_nd_region(dev->parent), NULL);

	return 0;
}

static void nd_pmem_shutdown(struct device *dev)
{
	nvdimm_flush(to_nd_region(dev->parent), NULL);
}

static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
{
	struct nd_region *nd_region;
	resource_size_t offset = 0, end_trunc = 0;
	struct nd_namespace_common *ndns;
	struct nd_namespace_io *nsio;
	struct resource res;
	struct badblocks *bb;
	struct kernfs_node *bb_state;

	if (event != NVDIMM_REVALIDATE_POISON)
		return;

	if (is_nd_btt(dev)) {
		struct nd_btt *nd_btt = to_nd_btt(dev);

		ndns = nd_btt->ndns;
		nd_region = to_nd_region(ndns->dev.parent);
		nsio = to_nd_namespace_io(&ndns->dev);
		bb = &nsio->bb;
		bb_state = NULL;
	} else {
		struct pmem_device *pmem = dev_get_drvdata(dev);

		nd_region = to_region(pmem);
		bb = &pmem->bb;
		bb_state = pmem->bb_state;

		if (is_nd_pfn(dev)) {
			struct nd_pfn *nd_pfn = to_nd_pfn(dev);
			struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;

			ndns = nd_pfn->ndns;
			offset = pmem->data_offset +
					__le32_to_cpu(pfn_sb->start_pad);
			end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
		} else {
			ndns = to_ndns(dev);
		}

		nsio = to_nd_namespace_io(&ndns->dev);
	}

	res.start = nsio->res.start + offset;
	res.end = nsio->res.end - end_trunc;
	nvdimm_badblocks_populate(nd_region, bb, &res);
	if (bb_state)
		sysfs_notify_dirent(bb_state);
}

MODULE_ALIAS("pmem");
MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO);
MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM);
static struct nd_device_driver nd_pmem_driver = {
	.probe = nd_pmem_probe,
	.remove = nd_pmem_remove,
	.notify = nd_pmem_notify,
	.shutdown = nd_pmem_shutdown,
	.drv = {
		.name = "nd_pmem",
	},
	.type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
};

module_nd_driver(nd_pmem_driver);

MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
MODULE_LICENSE("GPL v2");