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v5.9
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Persistent Memory Driver
  4 *
  5 * Copyright (c) 2014-2015, Intel Corporation.
  6 * Copyright (c) 2015, Christoph Hellwig <hch@lst.de>.
  7 * Copyright (c) 2015, Boaz Harrosh <boaz@plexistor.com>.
  8 */
  9
 10#include <linux/blkdev.h>
 
 11#include <linux/hdreg.h>
 12#include <linux/init.h>
 13#include <linux/platform_device.h>
 14#include <linux/set_memory.h>
 15#include <linux/module.h>
 16#include <linux/moduleparam.h>
 17#include <linux/badblocks.h>
 18#include <linux/memremap.h>
 
 19#include <linux/vmalloc.h>
 20#include <linux/blk-mq.h>
 21#include <linux/pfn_t.h>
 22#include <linux/slab.h>
 23#include <linux/uio.h>
 24#include <linux/dax.h>
 25#include <linux/nd.h>
 26#include <linux/backing-dev.h>
 27#include <linux/mm.h>
 28#include <asm/cacheflush.h>
 29#include "pmem.h"
 
 30#include "pfn.h"
 31#include "nd.h"
 32
 33static struct device *to_dev(struct pmem_device *pmem)
 34{
 35	/*
 36	 * nvdimm bus services need a 'dev' parameter, and we record the device
 37	 * at init in bb.dev.
 38	 */
 39	return pmem->bb.dev;
 40}
 41
 42static struct nd_region *to_region(struct pmem_device *pmem)
 43{
 44	return to_nd_region(to_dev(pmem)->parent);
 45}
 46
 47static void hwpoison_clear(struct pmem_device *pmem,
 48		phys_addr_t phys, unsigned int len)
 49{
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 50	unsigned long pfn_start, pfn_end, pfn;
 51
 52	/* only pmem in the linear map supports HWPoison */
 53	if (is_vmalloc_addr(pmem->virt_addr))
 54		return;
 55
 56	pfn_start = PHYS_PFN(phys);
 57	pfn_end = pfn_start + PHYS_PFN(len);
 58	for (pfn = pfn_start; pfn < pfn_end; pfn++) {
 59		struct page *page = pfn_to_page(pfn);
 60
 61		/*
 62		 * Note, no need to hold a get_dev_pagemap() reference
 63		 * here since we're in the driver I/O path and
 64		 * outstanding I/O requests pin the dev_pagemap.
 65		 */
 66		if (test_and_clear_pmem_poison(page))
 67			clear_mce_nospec(pfn);
 68	}
 69}
 70
 71static blk_status_t pmem_clear_poison(struct pmem_device *pmem,
 72		phys_addr_t offset, unsigned int len)
 73{
 74	struct device *dev = to_dev(pmem);
 75	sector_t sector;
 76	long cleared;
 77	blk_status_t rc = BLK_STS_OK;
 
 
 78
 79	sector = (offset - pmem->data_offset) / 512;
 
 
 
 
 80
 81	cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len);
 82	if (cleared < len)
 83		rc = BLK_STS_IOERR;
 84	if (cleared > 0 && cleared / 512) {
 85		hwpoison_clear(pmem, pmem->phys_addr + offset, cleared);
 86		cleared /= 512;
 87		dev_dbg(dev, "%#llx clear %ld sector%s\n",
 88				(unsigned long long) sector, cleared,
 89				cleared > 1 ? "s" : "");
 90		badblocks_clear(&pmem->bb, sector, cleared);
 91		if (pmem->bb_state)
 92			sysfs_notify_dirent(pmem->bb_state);
 93	}
 
 
 
 
 
 
 
 94
 95	arch_invalidate_pmem(pmem->virt_addr + offset, len);
 
 96
 97	return rc;
 
 
 
 98}
 99
100static void write_pmem(void *pmem_addr, struct page *page,
101		unsigned int off, unsigned int len)
102{
103	unsigned int chunk;
104	void *mem;
105
106	while (len) {
107		mem = kmap_atomic(page);
108		chunk = min_t(unsigned int, len, PAGE_SIZE - off);
109		memcpy_flushcache(pmem_addr, mem + off, chunk);
110		kunmap_atomic(mem);
111		len -= chunk;
112		off = 0;
113		page++;
114		pmem_addr += chunk;
115	}
116}
117
118static blk_status_t read_pmem(struct page *page, unsigned int off,
119		void *pmem_addr, unsigned int len)
120{
121	unsigned int chunk;
122	unsigned long rem;
123	void *mem;
124
125	while (len) {
126		mem = kmap_atomic(page);
127		chunk = min_t(unsigned int, len, PAGE_SIZE - off);
128		rem = memcpy_mcsafe(mem + off, pmem_addr, chunk);
129		kunmap_atomic(mem);
130		if (rem)
131			return BLK_STS_IOERR;
132		len -= chunk;
133		off = 0;
134		page++;
135		pmem_addr += chunk;
136	}
137	return BLK_STS_OK;
138}
139
140static blk_status_t pmem_do_read(struct pmem_device *pmem,
141			struct page *page, unsigned int page_off,
142			sector_t sector, unsigned int len)
143{
144	blk_status_t rc;
145	phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
146	void *pmem_addr = pmem->virt_addr + pmem_off;
147
148	if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
149		return BLK_STS_IOERR;
150
151	rc = read_pmem(page, page_off, pmem_addr, len);
152	flush_dcache_page(page);
153	return rc;
154}
155
156static blk_status_t pmem_do_write(struct pmem_device *pmem,
157			struct page *page, unsigned int page_off,
158			sector_t sector, unsigned int len)
159{
160	blk_status_t rc = BLK_STS_OK;
161	bool bad_pmem = false;
162	phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
163	void *pmem_addr = pmem->virt_addr + pmem_off;
164
165	if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
166		bad_pmem = true;
 
 
 
 
167
168	/*
169	 * Note that we write the data both before and after
170	 * clearing poison.  The write before clear poison
171	 * handles situations where the latest written data is
172	 * preserved and the clear poison operation simply marks
173	 * the address range as valid without changing the data.
174	 * In this case application software can assume that an
175	 * interrupted write will either return the new good
176	 * data or an error.
177	 *
178	 * However, if pmem_clear_poison() leaves the data in an
179	 * indeterminate state we need to perform the write
180	 * after clear poison.
181	 */
182	flush_dcache_page(page);
183	write_pmem(pmem_addr, page, page_off, len);
184	if (unlikely(bad_pmem)) {
185		rc = pmem_clear_poison(pmem, pmem_off, len);
186		write_pmem(pmem_addr, page, page_off, len);
187	}
188
189	return rc;
190}
191
192static blk_qc_t pmem_submit_bio(struct bio *bio)
193{
194	int ret = 0;
195	blk_status_t rc = 0;
196	bool do_acct;
197	unsigned long start;
198	struct bio_vec bvec;
199	struct bvec_iter iter;
200	struct pmem_device *pmem = bio->bi_disk->private_data;
201	struct nd_region *nd_region = to_region(pmem);
202
203	if (bio->bi_opf & REQ_PREFLUSH)
204		ret = nvdimm_flush(nd_region, bio);
205
206	do_acct = blk_queue_io_stat(bio->bi_disk->queue);
207	if (do_acct)
208		start = bio_start_io_acct(bio);
209	bio_for_each_segment(bvec, bio, iter) {
210		if (op_is_write(bio_op(bio)))
211			rc = pmem_do_write(pmem, bvec.bv_page, bvec.bv_offset,
212				iter.bi_sector, bvec.bv_len);
213		else
214			rc = pmem_do_read(pmem, bvec.bv_page, bvec.bv_offset,
215				iter.bi_sector, bvec.bv_len);
216		if (rc) {
217			bio->bi_status = rc;
218			break;
219		}
220	}
221	if (do_acct)
222		bio_end_io_acct(bio, start);
223
224	if (bio->bi_opf & REQ_FUA)
225		ret = nvdimm_flush(nd_region, bio);
226
227	if (ret)
228		bio->bi_status = errno_to_blk_status(ret);
229
230	bio_endio(bio);
231	return BLK_QC_T_NONE;
232}
233
234static int pmem_rw_page(struct block_device *bdev, sector_t sector,
235		       struct page *page, unsigned int op)
236{
237	struct pmem_device *pmem = bdev->bd_disk->private_data;
238	blk_status_t rc;
239
240	if (op_is_write(op))
241		rc = pmem_do_write(pmem, page, 0, sector, thp_size(page));
242	else
243		rc = pmem_do_read(pmem, page, 0, sector, thp_size(page));
244	/*
245	 * The ->rw_page interface is subtle and tricky.  The core
246	 * retries on any error, so we can only invoke page_endio() in
247	 * the successful completion case.  Otherwise, we'll see crashes
248	 * caused by double completion.
249	 */
250	if (rc == 0)
251		page_endio(page, op_is_write(op), 0);
252
253	return blk_status_to_errno(rc);
254}
255
256/* see "strong" declaration in tools/testing/nvdimm/pmem-dax.c */
257__weak long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
258		long nr_pages, void **kaddr, pfn_t *pfn)
 
259{
260	resource_size_t offset = PFN_PHYS(pgoff) + pmem->data_offset;
261
262	if (unlikely(is_bad_pmem(&pmem->bb, PFN_PHYS(pgoff) / 512,
263					PFN_PHYS(nr_pages))))
264		return -EIO;
 
265
266	if (kaddr)
267		*kaddr = pmem->virt_addr + offset;
268	if (pfn)
269		*pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
270
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
271	/*
272	 * If badblocks are present, limit known good range to the
273	 * requested range.
274	 */
275	if (unlikely(pmem->bb.count))
276		return nr_pages;
277	return PHYS_PFN(pmem->size - pmem->pfn_pad - offset);
278}
279
280static const struct block_device_operations pmem_fops = {
281	.owner =		THIS_MODULE,
282	.submit_bio =		pmem_submit_bio,
283	.rw_page =		pmem_rw_page,
284	.revalidate_disk =	nvdimm_revalidate_disk,
285};
286
287static int pmem_dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff,
288				    size_t nr_pages)
289{
290	struct pmem_device *pmem = dax_get_private(dax_dev);
291
292	return blk_status_to_errno(pmem_do_write(pmem, ZERO_PAGE(0), 0,
293				   PFN_PHYS(pgoff) >> SECTOR_SHIFT,
294				   PAGE_SIZE));
295}
296
297static long pmem_dax_direct_access(struct dax_device *dax_dev,
298		pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn)
 
299{
300	struct pmem_device *pmem = dax_get_private(dax_dev);
301
302	return __pmem_direct_access(pmem, pgoff, nr_pages, kaddr, pfn);
303}
304
305/*
306 * Use the 'no check' versions of copy_from_iter_flushcache() and
307 * copy_to_iter_mcsafe() to bypass HARDENED_USERCOPY overhead. Bounds
308 * checking, both file offset and device offset, is handled by
309 * dax_iomap_actor()
 
 
 
 
 
 
 
310 */
311static size_t pmem_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
312		void *addr, size_t bytes, struct iov_iter *i)
313{
314	return _copy_from_iter_flushcache(addr, bytes, i);
315}
 
 
 
316
317static size_t pmem_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff,
318		void *addr, size_t bytes, struct iov_iter *i)
319{
320	return _copy_to_iter_mcsafe(addr, bytes, i);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
321}
322
323static const struct dax_operations pmem_dax_ops = {
324	.direct_access = pmem_dax_direct_access,
325	.dax_supported = generic_fsdax_supported,
326	.copy_from_iter = pmem_copy_from_iter,
327	.copy_to_iter = pmem_copy_to_iter,
328	.zero_page_range = pmem_dax_zero_page_range,
 
329};
330
331static const struct attribute_group *pmem_attribute_groups[] = {
332	&dax_attribute_group,
333	NULL,
334};
335
336static void pmem_pagemap_cleanup(struct dev_pagemap *pgmap)
337{
338	struct request_queue *q =
339		container_of(pgmap->ref, struct request_queue, q_usage_counter);
340
341	blk_cleanup_queue(q);
342}
343
344static void pmem_release_queue(void *pgmap)
 
345{
346	pmem_pagemap_cleanup(pgmap);
 
 
 
 
 
 
 
 
347}
 
348
349static void pmem_pagemap_kill(struct dev_pagemap *pgmap)
350{
351	struct request_queue *q =
352		container_of(pgmap->ref, struct request_queue, q_usage_counter);
353
354	blk_freeze_queue_start(q);
 
355}
356
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
357static void pmem_release_disk(void *__pmem)
358{
359	struct pmem_device *pmem = __pmem;
360
 
361	kill_dax(pmem->dax_dev);
362	put_dax(pmem->dax_dev);
363	del_gendisk(pmem->disk);
 
364	put_disk(pmem->disk);
365}
366
 
 
 
 
 
 
 
 
 
 
 
367static const struct dev_pagemap_ops fsdax_pagemap_ops = {
368	.kill			= pmem_pagemap_kill,
369	.cleanup		= pmem_pagemap_cleanup,
370};
371
372static int pmem_attach_disk(struct device *dev,
373		struct nd_namespace_common *ndns)
374{
375	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
376	struct nd_region *nd_region = to_nd_region(dev->parent);
377	int nid = dev_to_node(dev), fua;
378	struct resource *res = &nsio->res;
379	struct resource bb_res;
380	struct nd_pfn *nd_pfn = NULL;
381	struct dax_device *dax_dev;
382	struct nd_pfn_sb *pfn_sb;
383	struct pmem_device *pmem;
384	struct request_queue *q;
385	struct device *gendev;
386	struct gendisk *disk;
387	void *addr;
388	int rc;
389	unsigned long flags = 0UL;
390
391	pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
392	if (!pmem)
393		return -ENOMEM;
394
395	rc = devm_namespace_enable(dev, ndns, nd_info_block_reserve());
396	if (rc)
397		return rc;
398
399	/* while nsio_rw_bytes is active, parse a pfn info block if present */
400	if (is_nd_pfn(dev)) {
401		nd_pfn = to_nd_pfn(dev);
402		rc = nvdimm_setup_pfn(nd_pfn, &pmem->pgmap);
403		if (rc)
404			return rc;
405	}
406
407	/* we're attaching a block device, disable raw namespace access */
408	devm_namespace_disable(dev, ndns);
409
410	dev_set_drvdata(dev, pmem);
411	pmem->phys_addr = res->start;
412	pmem->size = resource_size(res);
413	fua = nvdimm_has_flush(nd_region);
414	if (!IS_ENABLED(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) || fua < 0) {
415		dev_warn(dev, "unable to guarantee persistence of writes\n");
416		fua = 0;
417	}
418
419	if (!devm_request_mem_region(dev, res->start, resource_size(res),
420				dev_name(&ndns->dev))) {
421		dev_warn(dev, "could not reserve region %pR\n", res);
422		return -EBUSY;
423	}
424
425	q = blk_alloc_queue(dev_to_node(dev));
426	if (!q)
427		return -ENOMEM;
 
428
 
 
429	pmem->pfn_flags = PFN_DEV;
430	pmem->pgmap.ref = &q->q_usage_counter;
431	if (is_nd_pfn(dev)) {
432		pmem->pgmap.type = MEMORY_DEVICE_FS_DAX;
433		pmem->pgmap.ops = &fsdax_pagemap_ops;
434		addr = devm_memremap_pages(dev, &pmem->pgmap);
435		pfn_sb = nd_pfn->pfn_sb;
436		pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
437		pmem->pfn_pad = resource_size(res) -
438			resource_size(&pmem->pgmap.res);
439		pmem->pfn_flags |= PFN_MAP;
440		memcpy(&bb_res, &pmem->pgmap.res, sizeof(bb_res));
441		bb_res.start += pmem->data_offset;
442	} else if (pmem_should_map_pages(dev)) {
443		memcpy(&pmem->pgmap.res, &nsio->res, sizeof(pmem->pgmap.res));
 
 
444		pmem->pgmap.type = MEMORY_DEVICE_FS_DAX;
445		pmem->pgmap.ops = &fsdax_pagemap_ops;
446		addr = devm_memremap_pages(dev, &pmem->pgmap);
447		pmem->pfn_flags |= PFN_MAP;
448		memcpy(&bb_res, &pmem->pgmap.res, sizeof(bb_res));
449	} else {
450		if (devm_add_action_or_reset(dev, pmem_release_queue,
451					&pmem->pgmap))
452			return -ENOMEM;
453		addr = devm_memremap(dev, pmem->phys_addr,
454				pmem->size, ARCH_MEMREMAP_PMEM);
455		memcpy(&bb_res, &nsio->res, sizeof(bb_res));
 
456	}
457
458	if (IS_ERR(addr))
459		return PTR_ERR(addr);
 
 
460	pmem->virt_addr = addr;
461
462	blk_queue_write_cache(q, true, fua);
463	blk_queue_physical_block_size(q, PAGE_SIZE);
464	blk_queue_logical_block_size(q, pmem_sector_size(ndns));
465	blk_queue_max_hw_sectors(q, UINT_MAX);
466	blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
 
467	if (pmem->pfn_flags & PFN_MAP)
468		blk_queue_flag_set(QUEUE_FLAG_DAX, q);
469
470	disk = alloc_disk_node(0, nid);
471	if (!disk)
472		return -ENOMEM;
473	pmem->disk = disk;
474
475	disk->fops		= &pmem_fops;
476	disk->queue		= q;
477	disk->flags		= GENHD_FL_EXT_DEVT;
478	disk->private_data	= pmem;
479	disk->queue->backing_dev_info->capabilities |= BDI_CAP_SYNCHRONOUS_IO;
480	nvdimm_namespace_disk_name(ndns, disk->disk_name);
481	set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
482			/ 512);
483	if (devm_init_badblocks(dev, &pmem->bb))
484		return -ENOMEM;
485	nvdimm_badblocks_populate(nd_region, &pmem->bb, &bb_res);
486	disk->bb = &pmem->bb;
487
488	if (is_nvdimm_sync(nd_region))
489		flags = DAXDEV_F_SYNC;
490	dax_dev = alloc_dax(pmem, disk->disk_name, &pmem_dax_ops, flags);
491	if (IS_ERR(dax_dev)) {
492		put_disk(disk);
493		return PTR_ERR(dax_dev);
494	}
 
 
 
 
 
 
 
495	dax_write_cache(dax_dev, nvdimm_has_cache(nd_region));
496	pmem->dax_dev = dax_dev;
497	gendev = disk_to_dev(disk);
498	gendev->groups = pmem_attribute_groups;
499
500	device_add_disk(dev, disk, NULL);
 
 
501	if (devm_add_action_or_reset(dev, pmem_release_disk, pmem))
502		return -ENOMEM;
503
504	revalidate_disk(disk);
505
506	pmem->bb_state = sysfs_get_dirent(disk_to_dev(disk)->kobj.sd,
507					  "badblocks");
508	if (!pmem->bb_state)
509		dev_warn(dev, "'badblocks' notification disabled\n");
510
511	return 0;
 
 
 
 
 
 
 
 
 
512}
513
514static int nd_pmem_probe(struct device *dev)
515{
516	int ret;
517	struct nd_namespace_common *ndns;
518
519	ndns = nvdimm_namespace_common_probe(dev);
520	if (IS_ERR(ndns))
521		return PTR_ERR(ndns);
522
523	if (is_nd_btt(dev))
524		return nvdimm_namespace_attach_btt(ndns);
525
526	if (is_nd_pfn(dev))
527		return pmem_attach_disk(dev, ndns);
528
529	ret = devm_namespace_enable(dev, ndns, nd_info_block_reserve());
530	if (ret)
531		return ret;
532
533	ret = nd_btt_probe(dev, ndns);
534	if (ret == 0)
535		return -ENXIO;
536
537	/*
538	 * We have two failure conditions here, there is no
539	 * info reserver block or we found a valid info reserve block
540	 * but failed to initialize the pfn superblock.
541	 *
542	 * For the first case consider namespace as a raw pmem namespace
543	 * and attach a disk.
544	 *
545	 * For the latter, consider this a success and advance the namespace
546	 * seed.
547	 */
548	ret = nd_pfn_probe(dev, ndns);
549	if (ret == 0)
550		return -ENXIO;
551	else if (ret == -EOPNOTSUPP)
552		return ret;
553
554	ret = nd_dax_probe(dev, ndns);
555	if (ret == 0)
556		return -ENXIO;
557	else if (ret == -EOPNOTSUPP)
558		return ret;
559
560	/* probe complete, attach handles namespace enabling */
561	devm_namespace_disable(dev, ndns);
562
563	return pmem_attach_disk(dev, ndns);
564}
565
566static int nd_pmem_remove(struct device *dev)
567{
568	struct pmem_device *pmem = dev_get_drvdata(dev);
569
570	if (is_nd_btt(dev))
571		nvdimm_namespace_detach_btt(to_nd_btt(dev));
572	else {
573		/*
574		 * Note, this assumes nd_device_lock() context to not
575		 * race nd_pmem_notify()
576		 */
577		sysfs_put(pmem->bb_state);
578		pmem->bb_state = NULL;
579	}
580	nvdimm_flush(to_nd_region(dev->parent), NULL);
581
582	return 0;
583}
584
585static void nd_pmem_shutdown(struct device *dev)
586{
587	nvdimm_flush(to_nd_region(dev->parent), NULL);
588}
589
590static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
591{
592	struct nd_region *nd_region;
593	resource_size_t offset = 0, end_trunc = 0;
594	struct nd_namespace_common *ndns;
595	struct nd_namespace_io *nsio;
596	struct resource res;
597	struct badblocks *bb;
 
598	struct kernfs_node *bb_state;
599
600	if (event != NVDIMM_REVALIDATE_POISON)
601		return;
602
603	if (is_nd_btt(dev)) {
604		struct nd_btt *nd_btt = to_nd_btt(dev);
605
606		ndns = nd_btt->ndns;
607		nd_region = to_nd_region(ndns->dev.parent);
608		nsio = to_nd_namespace_io(&ndns->dev);
609		bb = &nsio->bb;
610		bb_state = NULL;
611	} else {
612		struct pmem_device *pmem = dev_get_drvdata(dev);
613
614		nd_region = to_region(pmem);
615		bb = &pmem->bb;
616		bb_state = pmem->bb_state;
617
618		if (is_nd_pfn(dev)) {
619			struct nd_pfn *nd_pfn = to_nd_pfn(dev);
620			struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
621
622			ndns = nd_pfn->ndns;
623			offset = pmem->data_offset +
624					__le32_to_cpu(pfn_sb->start_pad);
625			end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
626		} else {
627			ndns = to_ndns(dev);
628		}
629
630		nsio = to_nd_namespace_io(&ndns->dev);
631	}
632
633	res.start = nsio->res.start + offset;
634	res.end = nsio->res.end - end_trunc;
635	nvdimm_badblocks_populate(nd_region, bb, &res);
636	if (bb_state)
637		sysfs_notify_dirent(bb_state);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
638}
639
640MODULE_ALIAS("pmem");
641MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO);
642MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM);
643static struct nd_device_driver nd_pmem_driver = {
644	.probe = nd_pmem_probe,
645	.remove = nd_pmem_remove,
646	.notify = nd_pmem_notify,
647	.shutdown = nd_pmem_shutdown,
648	.drv = {
649		.name = "nd_pmem",
650	},
651	.type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
652};
653
654module_nd_driver(nd_pmem_driver);
655
656MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
657MODULE_LICENSE("GPL v2");
v6.8
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Persistent Memory Driver
  4 *
  5 * Copyright (c) 2014-2015, Intel Corporation.
  6 * Copyright (c) 2015, Christoph Hellwig <hch@lst.de>.
  7 * Copyright (c) 2015, Boaz Harrosh <boaz@plexistor.com>.
  8 */
  9
 10#include <linux/blkdev.h>
 11#include <linux/pagemap.h>
 12#include <linux/hdreg.h>
 13#include <linux/init.h>
 14#include <linux/platform_device.h>
 15#include <linux/set_memory.h>
 16#include <linux/module.h>
 17#include <linux/moduleparam.h>
 18#include <linux/badblocks.h>
 19#include <linux/memremap.h>
 20#include <linux/kstrtox.h>
 21#include <linux/vmalloc.h>
 22#include <linux/blk-mq.h>
 23#include <linux/pfn_t.h>
 24#include <linux/slab.h>
 25#include <linux/uio.h>
 26#include <linux/dax.h>
 27#include <linux/nd.h>
 
 28#include <linux/mm.h>
 29#include <asm/cacheflush.h>
 30#include "pmem.h"
 31#include "btt.h"
 32#include "pfn.h"
 33#include "nd.h"
 34
 35static struct device *to_dev(struct pmem_device *pmem)
 36{
 37	/*
 38	 * nvdimm bus services need a 'dev' parameter, and we record the device
 39	 * at init in bb.dev.
 40	 */
 41	return pmem->bb.dev;
 42}
 43
 44static struct nd_region *to_region(struct pmem_device *pmem)
 45{
 46	return to_nd_region(to_dev(pmem)->parent);
 47}
 48
 49static phys_addr_t pmem_to_phys(struct pmem_device *pmem, phys_addr_t offset)
 
 50{
 51	return pmem->phys_addr + offset;
 52}
 53
 54static sector_t to_sect(struct pmem_device *pmem, phys_addr_t offset)
 55{
 56	return (offset - pmem->data_offset) >> SECTOR_SHIFT;
 57}
 58
 59static phys_addr_t to_offset(struct pmem_device *pmem, sector_t sector)
 60{
 61	return (sector << SECTOR_SHIFT) + pmem->data_offset;
 62}
 63
 64static void pmem_mkpage_present(struct pmem_device *pmem, phys_addr_t offset,
 65		unsigned int len)
 66{
 67	phys_addr_t phys = pmem_to_phys(pmem, offset);
 68	unsigned long pfn_start, pfn_end, pfn;
 69
 70	/* only pmem in the linear map supports HWPoison */
 71	if (is_vmalloc_addr(pmem->virt_addr))
 72		return;
 73
 74	pfn_start = PHYS_PFN(phys);
 75	pfn_end = pfn_start + PHYS_PFN(len);
 76	for (pfn = pfn_start; pfn < pfn_end; pfn++) {
 77		struct page *page = pfn_to_page(pfn);
 78
 79		/*
 80		 * Note, no need to hold a get_dev_pagemap() reference
 81		 * here since we're in the driver I/O path and
 82		 * outstanding I/O requests pin the dev_pagemap.
 83		 */
 84		if (test_and_clear_pmem_poison(page))
 85			clear_mce_nospec(pfn);
 86	}
 87}
 88
 89static void pmem_clear_bb(struct pmem_device *pmem, sector_t sector, long blks)
 
 90{
 91	if (blks == 0)
 92		return;
 93	badblocks_clear(&pmem->bb, sector, blks);
 94	if (pmem->bb_state)
 95		sysfs_notify_dirent(pmem->bb_state);
 96}
 97
 98static long __pmem_clear_poison(struct pmem_device *pmem,
 99		phys_addr_t offset, unsigned int len)
100{
101	phys_addr_t phys = pmem_to_phys(pmem, offset);
102	long cleared = nvdimm_clear_poison(to_dev(pmem), phys, len);
103
104	if (cleared > 0) {
105		pmem_mkpage_present(pmem, offset, cleared);
106		arch_invalidate_pmem(pmem->virt_addr + offset, len);
 
 
 
 
 
 
 
 
 
107	}
108	return cleared;
109}
110
111static blk_status_t pmem_clear_poison(struct pmem_device *pmem,
112		phys_addr_t offset, unsigned int len)
113{
114	long cleared = __pmem_clear_poison(pmem, offset, len);
115
116	if (cleared < 0)
117		return BLK_STS_IOERR;
118
119	pmem_clear_bb(pmem, to_sect(pmem, offset), cleared >> SECTOR_SHIFT);
120	if (cleared < len)
121		return BLK_STS_IOERR;
122	return BLK_STS_OK;
123}
124
125static void write_pmem(void *pmem_addr, struct page *page,
126		unsigned int off, unsigned int len)
127{
128	unsigned int chunk;
129	void *mem;
130
131	while (len) {
132		mem = kmap_atomic(page);
133		chunk = min_t(unsigned int, len, PAGE_SIZE - off);
134		memcpy_flushcache(pmem_addr, mem + off, chunk);
135		kunmap_atomic(mem);
136		len -= chunk;
137		off = 0;
138		page++;
139		pmem_addr += chunk;
140	}
141}
142
143static blk_status_t read_pmem(struct page *page, unsigned int off,
144		void *pmem_addr, unsigned int len)
145{
146	unsigned int chunk;
147	unsigned long rem;
148	void *mem;
149
150	while (len) {
151		mem = kmap_atomic(page);
152		chunk = min_t(unsigned int, len, PAGE_SIZE - off);
153		rem = copy_mc_to_kernel(mem + off, pmem_addr, chunk);
154		kunmap_atomic(mem);
155		if (rem)
156			return BLK_STS_IOERR;
157		len -= chunk;
158		off = 0;
159		page++;
160		pmem_addr += chunk;
161	}
162	return BLK_STS_OK;
163}
164
165static blk_status_t pmem_do_read(struct pmem_device *pmem,
166			struct page *page, unsigned int page_off,
167			sector_t sector, unsigned int len)
168{
169	blk_status_t rc;
170	phys_addr_t pmem_off = to_offset(pmem, sector);
171	void *pmem_addr = pmem->virt_addr + pmem_off;
172
173	if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
174		return BLK_STS_IOERR;
175
176	rc = read_pmem(page, page_off, pmem_addr, len);
177	flush_dcache_page(page);
178	return rc;
179}
180
181static blk_status_t pmem_do_write(struct pmem_device *pmem,
182			struct page *page, unsigned int page_off,
183			sector_t sector, unsigned int len)
184{
185	phys_addr_t pmem_off = to_offset(pmem, sector);
 
 
186	void *pmem_addr = pmem->virt_addr + pmem_off;
187
188	if (unlikely(is_bad_pmem(&pmem->bb, sector, len))) {
189		blk_status_t rc = pmem_clear_poison(pmem, pmem_off, len);
190
191		if (rc != BLK_STS_OK)
192			return rc;
193	}
194
 
 
 
 
 
 
 
 
 
 
 
 
 
 
195	flush_dcache_page(page);
196	write_pmem(pmem_addr, page, page_off, len);
 
 
 
 
197
198	return BLK_STS_OK;
199}
200
201static void pmem_submit_bio(struct bio *bio)
202{
203	int ret = 0;
204	blk_status_t rc = 0;
205	bool do_acct;
206	unsigned long start;
207	struct bio_vec bvec;
208	struct bvec_iter iter;
209	struct pmem_device *pmem = bio->bi_bdev->bd_disk->private_data;
210	struct nd_region *nd_region = to_region(pmem);
211
212	if (bio->bi_opf & REQ_PREFLUSH)
213		ret = nvdimm_flush(nd_region, bio);
214
215	do_acct = blk_queue_io_stat(bio->bi_bdev->bd_disk->queue);
216	if (do_acct)
217		start = bio_start_io_acct(bio);
218	bio_for_each_segment(bvec, bio, iter) {
219		if (op_is_write(bio_op(bio)))
220			rc = pmem_do_write(pmem, bvec.bv_page, bvec.bv_offset,
221				iter.bi_sector, bvec.bv_len);
222		else
223			rc = pmem_do_read(pmem, bvec.bv_page, bvec.bv_offset,
224				iter.bi_sector, bvec.bv_len);
225		if (rc) {
226			bio->bi_status = rc;
227			break;
228		}
229	}
230	if (do_acct)
231		bio_end_io_acct(bio, start);
232
233	if (bio->bi_opf & REQ_FUA)
234		ret = nvdimm_flush(nd_region, bio);
235
236	if (ret)
237		bio->bi_status = errno_to_blk_status(ret);
238
239	bio_endio(bio);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
240}
241
242/* see "strong" declaration in tools/testing/nvdimm/pmem-dax.c */
243__weak long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
244		long nr_pages, enum dax_access_mode mode, void **kaddr,
245		pfn_t *pfn)
246{
247	resource_size_t offset = PFN_PHYS(pgoff) + pmem->data_offset;
248	sector_t sector = PFN_PHYS(pgoff) >> SECTOR_SHIFT;
249	unsigned int num = PFN_PHYS(nr_pages) >> SECTOR_SHIFT;
250	struct badblocks *bb = &pmem->bb;
251	sector_t first_bad;
252	int num_bad;
253
254	if (kaddr)
255		*kaddr = pmem->virt_addr + offset;
256	if (pfn)
257		*pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
258
259	if (bb->count &&
260	    badblocks_check(bb, sector, num, &first_bad, &num_bad)) {
261		long actual_nr;
262
263		if (mode != DAX_RECOVERY_WRITE)
264			return -EHWPOISON;
265
266		/*
267		 * Set the recovery stride is set to kernel page size because
268		 * the underlying driver and firmware clear poison functions
269		 * don't appear to handle large chunk(such as 2MiB) reliably.
270		 */
271		actual_nr = PHYS_PFN(
272			PAGE_ALIGN((first_bad - sector) << SECTOR_SHIFT));
273		dev_dbg(pmem->bb.dev, "start sector(%llu), nr_pages(%ld), first_bad(%llu), actual_nr(%ld)\n",
274				sector, nr_pages, first_bad, actual_nr);
275		if (actual_nr)
276			return actual_nr;
277		return 1;
278	}
279
280	/*
281	 * If badblocks are present but not in the range, limit known good range
282	 * to the requested range.
283	 */
284	if (bb->count)
285		return nr_pages;
286	return PHYS_PFN(pmem->size - pmem->pfn_pad - offset);
287}
288
289static const struct block_device_operations pmem_fops = {
290	.owner =		THIS_MODULE,
291	.submit_bio =		pmem_submit_bio,
 
 
292};
293
294static int pmem_dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff,
295				    size_t nr_pages)
296{
297	struct pmem_device *pmem = dax_get_private(dax_dev);
298
299	return blk_status_to_errno(pmem_do_write(pmem, ZERO_PAGE(0), 0,
300				   PFN_PHYS(pgoff) >> SECTOR_SHIFT,
301				   PAGE_SIZE));
302}
303
304static long pmem_dax_direct_access(struct dax_device *dax_dev,
305		pgoff_t pgoff, long nr_pages, enum dax_access_mode mode,
306		void **kaddr, pfn_t *pfn)
307{
308	struct pmem_device *pmem = dax_get_private(dax_dev);
309
310	return __pmem_direct_access(pmem, pgoff, nr_pages, mode, kaddr, pfn);
311}
312
313/*
314 * The recovery write thread started out as a normal pwrite thread and
315 * when the filesystem was told about potential media error in the
316 * range, filesystem turns the normal pwrite to a dax_recovery_write.
317 *
318 * The recovery write consists of clearing media poison, clearing page
319 * HWPoison bit, reenable page-wide read-write permission, flush the
320 * caches and finally write.  A competing pread thread will be held
321 * off during the recovery process since data read back might not be
322 * valid, and this is achieved by clearing the badblock records after
323 * the recovery write is complete. Competing recovery write threads
324 * are already serialized by writer lock held by dax_iomap_rw().
325 */
326static size_t pmem_recovery_write(struct dax_device *dax_dev, pgoff_t pgoff,
327		void *addr, size_t bytes, struct iov_iter *i)
328{
329	struct pmem_device *pmem = dax_get_private(dax_dev);
330	size_t olen, len, off;
331	phys_addr_t pmem_off;
332	struct device *dev = pmem->bb.dev;
333	long cleared;
334
335	off = offset_in_page(addr);
336	len = PFN_PHYS(PFN_UP(off + bytes));
337	if (!is_bad_pmem(&pmem->bb, PFN_PHYS(pgoff) >> SECTOR_SHIFT, len))
338		return _copy_from_iter_flushcache(addr, bytes, i);
339
340	/*
341	 * Not page-aligned range cannot be recovered. This should not
342	 * happen unless something else went wrong.
343	 */
344	if (off || !PAGE_ALIGNED(bytes)) {
345		dev_dbg(dev, "Found poison, but addr(%p) or bytes(%#zx) not page aligned\n",
346			addr, bytes);
347		return 0;
348	}
349
350	pmem_off = PFN_PHYS(pgoff) + pmem->data_offset;
351	cleared = __pmem_clear_poison(pmem, pmem_off, len);
352	if (cleared > 0 && cleared < len) {
353		dev_dbg(dev, "poison cleared only %ld out of %zu bytes\n",
354			cleared, len);
355		return 0;
356	}
357	if (cleared < 0) {
358		dev_dbg(dev, "poison clear failed: %ld\n", cleared);
359		return 0;
360	}
361
362	olen = _copy_from_iter_flushcache(addr, bytes, i);
363	pmem_clear_bb(pmem, to_sect(pmem, pmem_off), cleared >> SECTOR_SHIFT);
364
365	return olen;
366}
367
368static const struct dax_operations pmem_dax_ops = {
369	.direct_access = pmem_dax_direct_access,
 
 
 
370	.zero_page_range = pmem_dax_zero_page_range,
371	.recovery_write = pmem_recovery_write,
372};
373
374static ssize_t write_cache_show(struct device *dev,
375		struct device_attribute *attr, char *buf)
 
 
 
 
376{
377	struct pmem_device *pmem = dev_to_disk(dev)->private_data;
 
378
379	return sprintf(buf, "%d\n", !!dax_write_cache_enabled(pmem->dax_dev));
380}
381
382static ssize_t write_cache_store(struct device *dev,
383		struct device_attribute *attr, const char *buf, size_t len)
384{
385	struct pmem_device *pmem = dev_to_disk(dev)->private_data;
386	bool write_cache;
387	int rc;
388
389	rc = kstrtobool(buf, &write_cache);
390	if (rc)
391		return rc;
392	dax_write_cache(pmem->dax_dev, write_cache);
393	return len;
394}
395static DEVICE_ATTR_RW(write_cache);
396
397static umode_t dax_visible(struct kobject *kobj, struct attribute *a, int n)
398{
399#ifndef CONFIG_ARCH_HAS_PMEM_API
400	if (a == &dev_attr_write_cache.attr)
401		return 0;
402#endif
403	return a->mode;
404}
405
406static struct attribute *dax_attributes[] = {
407	&dev_attr_write_cache.attr,
408	NULL,
409};
410
411static const struct attribute_group dax_attribute_group = {
412	.name		= "dax",
413	.attrs		= dax_attributes,
414	.is_visible	= dax_visible,
415};
416
417static const struct attribute_group *pmem_attribute_groups[] = {
418	&dax_attribute_group,
419	NULL,
420};
421
422static void pmem_release_disk(void *__pmem)
423{
424	struct pmem_device *pmem = __pmem;
425
426	dax_remove_host(pmem->disk);
427	kill_dax(pmem->dax_dev);
428	put_dax(pmem->dax_dev);
429	del_gendisk(pmem->disk);
430
431	put_disk(pmem->disk);
432}
433
434static int pmem_pagemap_memory_failure(struct dev_pagemap *pgmap,
435		unsigned long pfn, unsigned long nr_pages, int mf_flags)
436{
437	struct pmem_device *pmem =
438			container_of(pgmap, struct pmem_device, pgmap);
439	u64 offset = PFN_PHYS(pfn) - pmem->phys_addr - pmem->data_offset;
440	u64 len = nr_pages << PAGE_SHIFT;
441
442	return dax_holder_notify_failure(pmem->dax_dev, offset, len, mf_flags);
443}
444
445static const struct dev_pagemap_ops fsdax_pagemap_ops = {
446	.memory_failure		= pmem_pagemap_memory_failure,
 
447};
448
449static int pmem_attach_disk(struct device *dev,
450		struct nd_namespace_common *ndns)
451{
452	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
453	struct nd_region *nd_region = to_nd_region(dev->parent);
454	int nid = dev_to_node(dev), fua;
455	struct resource *res = &nsio->res;
456	struct range bb_range;
457	struct nd_pfn *nd_pfn = NULL;
458	struct dax_device *dax_dev;
459	struct nd_pfn_sb *pfn_sb;
460	struct pmem_device *pmem;
461	struct request_queue *q;
 
462	struct gendisk *disk;
463	void *addr;
464	int rc;
 
465
466	pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
467	if (!pmem)
468		return -ENOMEM;
469
470	rc = devm_namespace_enable(dev, ndns, nd_info_block_reserve());
471	if (rc)
472		return rc;
473
474	/* while nsio_rw_bytes is active, parse a pfn info block if present */
475	if (is_nd_pfn(dev)) {
476		nd_pfn = to_nd_pfn(dev);
477		rc = nvdimm_setup_pfn(nd_pfn, &pmem->pgmap);
478		if (rc)
479			return rc;
480	}
481
482	/* we're attaching a block device, disable raw namespace access */
483	devm_namespace_disable(dev, ndns);
484
485	dev_set_drvdata(dev, pmem);
486	pmem->phys_addr = res->start;
487	pmem->size = resource_size(res);
488	fua = nvdimm_has_flush(nd_region);
489	if (!IS_ENABLED(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) || fua < 0) {
490		dev_warn(dev, "unable to guarantee persistence of writes\n");
491		fua = 0;
492	}
493
494	if (!devm_request_mem_region(dev, res->start, resource_size(res),
495				dev_name(&ndns->dev))) {
496		dev_warn(dev, "could not reserve region %pR\n", res);
497		return -EBUSY;
498	}
499
500	disk = blk_alloc_disk(nid);
501	if (!disk)
502		return -ENOMEM;
503	q = disk->queue;
504
505	pmem->disk = disk;
506	pmem->pgmap.owner = pmem;
507	pmem->pfn_flags = PFN_DEV;
 
508	if (is_nd_pfn(dev)) {
509		pmem->pgmap.type = MEMORY_DEVICE_FS_DAX;
510		pmem->pgmap.ops = &fsdax_pagemap_ops;
511		addr = devm_memremap_pages(dev, &pmem->pgmap);
512		pfn_sb = nd_pfn->pfn_sb;
513		pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
514		pmem->pfn_pad = resource_size(res) -
515			range_len(&pmem->pgmap.range);
516		pmem->pfn_flags |= PFN_MAP;
517		bb_range = pmem->pgmap.range;
518		bb_range.start += pmem->data_offset;
519	} else if (pmem_should_map_pages(dev)) {
520		pmem->pgmap.range.start = res->start;
521		pmem->pgmap.range.end = res->end;
522		pmem->pgmap.nr_range = 1;
523		pmem->pgmap.type = MEMORY_DEVICE_FS_DAX;
524		pmem->pgmap.ops = &fsdax_pagemap_ops;
525		addr = devm_memremap_pages(dev, &pmem->pgmap);
526		pmem->pfn_flags |= PFN_MAP;
527		bb_range = pmem->pgmap.range;
528	} else {
 
 
 
529		addr = devm_memremap(dev, pmem->phys_addr,
530				pmem->size, ARCH_MEMREMAP_PMEM);
531		bb_range.start =  res->start;
532		bb_range.end = res->end;
533	}
534
535	if (IS_ERR(addr)) {
536		rc = PTR_ERR(addr);
537		goto out;
538	}
539	pmem->virt_addr = addr;
540
541	blk_queue_write_cache(q, true, fua);
542	blk_queue_physical_block_size(q, PAGE_SIZE);
543	blk_queue_logical_block_size(q, pmem_sector_size(ndns));
544	blk_queue_max_hw_sectors(q, UINT_MAX);
545	blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
546	blk_queue_flag_set(QUEUE_FLAG_SYNCHRONOUS, q);
547	if (pmem->pfn_flags & PFN_MAP)
548		blk_queue_flag_set(QUEUE_FLAG_DAX, q);
549
 
 
 
 
 
550	disk->fops		= &pmem_fops;
 
 
551	disk->private_data	= pmem;
 
552	nvdimm_namespace_disk_name(ndns, disk->disk_name);
553	set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
554			/ 512);
555	if (devm_init_badblocks(dev, &pmem->bb))
556		return -ENOMEM;
557	nvdimm_badblocks_populate(nd_region, &pmem->bb, &bb_range);
558	disk->bb = &pmem->bb;
559
560	dax_dev = alloc_dax(pmem, &pmem_dax_ops);
 
 
561	if (IS_ERR(dax_dev)) {
562		rc = PTR_ERR(dax_dev);
563		goto out;
564	}
565	set_dax_nocache(dax_dev);
566	set_dax_nomc(dax_dev);
567	if (is_nvdimm_sync(nd_region))
568		set_dax_synchronous(dax_dev);
569	rc = dax_add_host(dax_dev, disk);
570	if (rc)
571		goto out_cleanup_dax;
572	dax_write_cache(dax_dev, nvdimm_has_cache(nd_region));
573	pmem->dax_dev = dax_dev;
 
 
574
575	rc = device_add_disk(dev, disk, pmem_attribute_groups);
576	if (rc)
577		goto out_remove_host;
578	if (devm_add_action_or_reset(dev, pmem_release_disk, pmem))
579		return -ENOMEM;
580
581	nvdimm_check_and_set_ro(disk);
582
583	pmem->bb_state = sysfs_get_dirent(disk_to_dev(disk)->kobj.sd,
584					  "badblocks");
585	if (!pmem->bb_state)
586		dev_warn(dev, "'badblocks' notification disabled\n");
 
587	return 0;
588
589out_remove_host:
590	dax_remove_host(pmem->disk);
591out_cleanup_dax:
592	kill_dax(pmem->dax_dev);
593	put_dax(pmem->dax_dev);
594out:
595	put_disk(pmem->disk);
596	return rc;
597}
598
599static int nd_pmem_probe(struct device *dev)
600{
601	int ret;
602	struct nd_namespace_common *ndns;
603
604	ndns = nvdimm_namespace_common_probe(dev);
605	if (IS_ERR(ndns))
606		return PTR_ERR(ndns);
607
608	if (is_nd_btt(dev))
609		return nvdimm_namespace_attach_btt(ndns);
610
611	if (is_nd_pfn(dev))
612		return pmem_attach_disk(dev, ndns);
613
614	ret = devm_namespace_enable(dev, ndns, nd_info_block_reserve());
615	if (ret)
616		return ret;
617
618	ret = nd_btt_probe(dev, ndns);
619	if (ret == 0)
620		return -ENXIO;
621
622	/*
623	 * We have two failure conditions here, there is no
624	 * info reserver block or we found a valid info reserve block
625	 * but failed to initialize the pfn superblock.
626	 *
627	 * For the first case consider namespace as a raw pmem namespace
628	 * and attach a disk.
629	 *
630	 * For the latter, consider this a success and advance the namespace
631	 * seed.
632	 */
633	ret = nd_pfn_probe(dev, ndns);
634	if (ret == 0)
635		return -ENXIO;
636	else if (ret == -EOPNOTSUPP)
637		return ret;
638
639	ret = nd_dax_probe(dev, ndns);
640	if (ret == 0)
641		return -ENXIO;
642	else if (ret == -EOPNOTSUPP)
643		return ret;
644
645	/* probe complete, attach handles namespace enabling */
646	devm_namespace_disable(dev, ndns);
647
648	return pmem_attach_disk(dev, ndns);
649}
650
651static void nd_pmem_remove(struct device *dev)
652{
653	struct pmem_device *pmem = dev_get_drvdata(dev);
654
655	if (is_nd_btt(dev))
656		nvdimm_namespace_detach_btt(to_nd_btt(dev));
657	else {
658		/*
659		 * Note, this assumes device_lock() context to not
660		 * race nd_pmem_notify()
661		 */
662		sysfs_put(pmem->bb_state);
663		pmem->bb_state = NULL;
664	}
665	nvdimm_flush(to_nd_region(dev->parent), NULL);
 
 
666}
667
668static void nd_pmem_shutdown(struct device *dev)
669{
670	nvdimm_flush(to_nd_region(dev->parent), NULL);
671}
672
673static void pmem_revalidate_poison(struct device *dev)
674{
675	struct nd_region *nd_region;
676	resource_size_t offset = 0, end_trunc = 0;
677	struct nd_namespace_common *ndns;
678	struct nd_namespace_io *nsio;
 
679	struct badblocks *bb;
680	struct range range;
681	struct kernfs_node *bb_state;
682
 
 
 
683	if (is_nd_btt(dev)) {
684		struct nd_btt *nd_btt = to_nd_btt(dev);
685
686		ndns = nd_btt->ndns;
687		nd_region = to_nd_region(ndns->dev.parent);
688		nsio = to_nd_namespace_io(&ndns->dev);
689		bb = &nsio->bb;
690		bb_state = NULL;
691	} else {
692		struct pmem_device *pmem = dev_get_drvdata(dev);
693
694		nd_region = to_region(pmem);
695		bb = &pmem->bb;
696		bb_state = pmem->bb_state;
697
698		if (is_nd_pfn(dev)) {
699			struct nd_pfn *nd_pfn = to_nd_pfn(dev);
700			struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
701
702			ndns = nd_pfn->ndns;
703			offset = pmem->data_offset +
704					__le32_to_cpu(pfn_sb->start_pad);
705			end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
706		} else {
707			ndns = to_ndns(dev);
708		}
709
710		nsio = to_nd_namespace_io(&ndns->dev);
711	}
712
713	range.start = nsio->res.start + offset;
714	range.end = nsio->res.end - end_trunc;
715	nvdimm_badblocks_populate(nd_region, bb, &range);
716	if (bb_state)
717		sysfs_notify_dirent(bb_state);
718}
719
720static void pmem_revalidate_region(struct device *dev)
721{
722	struct pmem_device *pmem;
723
724	if (is_nd_btt(dev)) {
725		struct nd_btt *nd_btt = to_nd_btt(dev);
726		struct btt *btt = nd_btt->btt;
727
728		nvdimm_check_and_set_ro(btt->btt_disk);
729		return;
730	}
731
732	pmem = dev_get_drvdata(dev);
733	nvdimm_check_and_set_ro(pmem->disk);
734}
735
736static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
737{
738	switch (event) {
739	case NVDIMM_REVALIDATE_POISON:
740		pmem_revalidate_poison(dev);
741		break;
742	case NVDIMM_REVALIDATE_REGION:
743		pmem_revalidate_region(dev);
744		break;
745	default:
746		dev_WARN_ONCE(dev, 1, "notify: unknown event: %d\n", event);
747		break;
748	}
749}
750
751MODULE_ALIAS("pmem");
752MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO);
753MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM);
754static struct nd_device_driver nd_pmem_driver = {
755	.probe = nd_pmem_probe,
756	.remove = nd_pmem_remove,
757	.notify = nd_pmem_notify,
758	.shutdown = nd_pmem_shutdown,
759	.drv = {
760		.name = "nd_pmem",
761	},
762	.type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
763};
764
765module_nd_driver(nd_pmem_driver);
766
767MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
768MODULE_LICENSE("GPL v2");