Merge branch 'for-4.16/dax' into libnvdimm-for-next
[sfrench/cifs-2.6.git] / drivers / nvdimm / pmem.c
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/blk-mq.h>
29 #include <linux/pfn_t.h>
30 #include <linux/slab.h>
31 #include <linux/uio.h>
32 #include <linux/dax.h>
33 #include <linux/nd.h>
34 #include <linux/backing-dev.h>
35 #include "pmem.h"
36 #include "pfn.h"
37 #include "nd.h"
38
39 static struct device *to_dev(struct pmem_device *pmem)
40 {
41         /*
42          * nvdimm bus services need a 'dev' parameter, and we record the device
43          * at init in bb.dev.
44          */
45         return pmem->bb.dev;
46 }
47
48 static struct nd_region *to_region(struct pmem_device *pmem)
49 {
50         return to_nd_region(to_dev(pmem)->parent);
51 }
52
53 static blk_status_t pmem_clear_poison(struct pmem_device *pmem,
54                 phys_addr_t offset, unsigned int len)
55 {
56         struct device *dev = to_dev(pmem);
57         sector_t sector;
58         long cleared;
59         blk_status_t rc = BLK_STS_OK;
60
61         sector = (offset - pmem->data_offset) / 512;
62
63         cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len);
64         if (cleared < len)
65                 rc = BLK_STS_IOERR;
66         if (cleared > 0 && cleared / 512) {
67                 cleared /= 512;
68                 dev_dbg(dev, "%s: %#llx clear %ld sector%s\n", __func__,
69                                 (unsigned long long) sector, cleared,
70                                 cleared > 1 ? "s" : "");
71                 badblocks_clear(&pmem->bb, sector, cleared);
72                 if (pmem->bb_state)
73                         sysfs_notify_dirent(pmem->bb_state);
74         }
75
76         arch_invalidate_pmem(pmem->virt_addr + offset, len);
77
78         return rc;
79 }
80
81 static void write_pmem(void *pmem_addr, struct page *page,
82                 unsigned int off, unsigned int len)
83 {
84         unsigned int chunk;
85         void *mem;
86
87         while (len) {
88                 mem = kmap_atomic(page);
89                 chunk = min_t(unsigned int, len, PAGE_SIZE);
90                 memcpy_flushcache(pmem_addr, mem + off, chunk);
91                 kunmap_atomic(mem);
92                 len -= chunk;
93                 off = 0;
94                 page++;
95                 pmem_addr += PAGE_SIZE;
96         }
97 }
98
99 static blk_status_t read_pmem(struct page *page, unsigned int off,
100                 void *pmem_addr, unsigned int len)
101 {
102         unsigned int chunk;
103         int rc;
104         void *mem;
105
106         while (len) {
107                 mem = kmap_atomic(page);
108                 chunk = min_t(unsigned int, len, PAGE_SIZE);
109                 rc = memcpy_mcsafe(mem + off, pmem_addr, chunk);
110                 kunmap_atomic(mem);
111                 if (rc)
112                         return BLK_STS_IOERR;
113                 len -= chunk;
114                 off = 0;
115                 page++;
116                 pmem_addr += PAGE_SIZE;
117         }
118         return BLK_STS_OK;
119 }
120
121 static blk_status_t pmem_do_bvec(struct pmem_device *pmem, struct page *page,
122                         unsigned int len, unsigned int off, bool is_write,
123                         sector_t sector)
124 {
125         blk_status_t rc = BLK_STS_OK;
126         bool bad_pmem = false;
127         phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
128         void *pmem_addr = pmem->virt_addr + pmem_off;
129
130         if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
131                 bad_pmem = true;
132
133         if (!is_write) {
134                 if (unlikely(bad_pmem))
135                         rc = BLK_STS_IOERR;
136                 else {
137                         rc = read_pmem(page, off, pmem_addr, len);
138                         flush_dcache_page(page);
139                 }
140         } else {
141                 /*
142                  * Note that we write the data both before and after
143                  * clearing poison.  The write before clear poison
144                  * handles situations where the latest written data is
145                  * preserved and the clear poison operation simply marks
146                  * the address range as valid without changing the data.
147                  * In this case application software can assume that an
148                  * interrupted write will either return the new good
149                  * data or an error.
150                  *
151                  * However, if pmem_clear_poison() leaves the data in an
152                  * indeterminate state we need to perform the write
153                  * after clear poison.
154                  */
155                 flush_dcache_page(page);
156                 write_pmem(pmem_addr, page, off, len);
157                 if (unlikely(bad_pmem)) {
158                         rc = pmem_clear_poison(pmem, pmem_off, len);
159                         write_pmem(pmem_addr, page, off, len);
160                 }
161         }
162
163         return rc;
164 }
165
166 /* account for REQ_FLUSH rename, replace with REQ_PREFLUSH after v4.8-rc1 */
167 #ifndef REQ_FLUSH
168 #define REQ_FLUSH REQ_PREFLUSH
169 #endif
170
171 static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
172 {
173         blk_status_t rc = 0;
174         bool do_acct;
175         unsigned long start;
176         struct bio_vec bvec;
177         struct bvec_iter iter;
178         struct pmem_device *pmem = q->queuedata;
179         struct nd_region *nd_region = to_region(pmem);
180
181         if (bio->bi_opf & REQ_FLUSH)
182                 nvdimm_flush(nd_region);
183
184         do_acct = nd_iostat_start(bio, &start);
185         bio_for_each_segment(bvec, bio, iter) {
186                 rc = pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len,
187                                 bvec.bv_offset, op_is_write(bio_op(bio)),
188                                 iter.bi_sector);
189                 if (rc) {
190                         bio->bi_status = rc;
191                         break;
192                 }
193         }
194         if (do_acct)
195                 nd_iostat_end(bio, start);
196
197         if (bio->bi_opf & REQ_FUA)
198                 nvdimm_flush(nd_region);
199
200         bio_endio(bio);
201         return BLK_QC_T_NONE;
202 }
203
204 static int pmem_rw_page(struct block_device *bdev, sector_t sector,
205                        struct page *page, bool is_write)
206 {
207         struct pmem_device *pmem = bdev->bd_queue->queuedata;
208         blk_status_t rc;
209
210         rc = pmem_do_bvec(pmem, page, hpage_nr_pages(page) * PAGE_SIZE,
211                           0, is_write, sector);
212
213         /*
214          * The ->rw_page interface is subtle and tricky.  The core
215          * retries on any error, so we can only invoke page_endio() in
216          * the successful completion case.  Otherwise, we'll see crashes
217          * caused by double completion.
218          */
219         if (rc == 0)
220                 page_endio(page, is_write, 0);
221
222         return blk_status_to_errno(rc);
223 }
224
225 /* see "strong" declaration in tools/testing/nvdimm/pmem-dax.c */
226 __weak long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
227                 long nr_pages, void **kaddr, pfn_t *pfn)
228 {
229         resource_size_t offset = PFN_PHYS(pgoff) + pmem->data_offset;
230
231         if (unlikely(is_bad_pmem(&pmem->bb, PFN_PHYS(pgoff) / 512,
232                                         PFN_PHYS(nr_pages))))
233                 return -EIO;
234         *kaddr = pmem->virt_addr + offset;
235         *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
236
237         /*
238          * If badblocks are present, limit known good range to the
239          * requested range.
240          */
241         if (unlikely(pmem->bb.count))
242                 return nr_pages;
243         return PHYS_PFN(pmem->size - pmem->pfn_pad - offset);
244 }
245
246 static const struct block_device_operations pmem_fops = {
247         .owner =                THIS_MODULE,
248         .rw_page =              pmem_rw_page,
249         .revalidate_disk =      nvdimm_revalidate_disk,
250 };
251
252 static long pmem_dax_direct_access(struct dax_device *dax_dev,
253                 pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn)
254 {
255         struct pmem_device *pmem = dax_get_private(dax_dev);
256
257         return __pmem_direct_access(pmem, pgoff, nr_pages, kaddr, pfn);
258 }
259
260 static size_t pmem_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
261                 void *addr, size_t bytes, struct iov_iter *i)
262 {
263         return copy_from_iter_flushcache(addr, bytes, i);
264 }
265
266 static const struct dax_operations pmem_dax_ops = {
267         .direct_access = pmem_dax_direct_access,
268         .copy_from_iter = pmem_copy_from_iter,
269 };
270
271 static const struct attribute_group *pmem_attribute_groups[] = {
272         &dax_attribute_group,
273         NULL,
274 };
275
276 static void pmem_release_queue(void *q)
277 {
278         blk_cleanup_queue(q);
279 }
280
281 static void pmem_freeze_queue(void *q)
282 {
283         blk_freeze_queue_start(q);
284 }
285
286 static void pmem_release_disk(void *__pmem)
287 {
288         struct pmem_device *pmem = __pmem;
289
290         kill_dax(pmem->dax_dev);
291         put_dax(pmem->dax_dev);
292         del_gendisk(pmem->disk);
293         put_disk(pmem->disk);
294 }
295
296 static int pmem_attach_disk(struct device *dev,
297                 struct nd_namespace_common *ndns)
298 {
299         struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
300         struct nd_region *nd_region = to_nd_region(dev->parent);
301         int nid = dev_to_node(dev), fua, wbc;
302         struct resource *res = &nsio->res;
303         struct resource bb_res;
304         struct nd_pfn *nd_pfn = NULL;
305         struct dax_device *dax_dev;
306         struct nd_pfn_sb *pfn_sb;
307         struct pmem_device *pmem;
308         struct request_queue *q;
309         struct device *gendev;
310         struct gendisk *disk;
311         void *addr;
312         int rc;
313
314         pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
315         if (!pmem)
316                 return -ENOMEM;
317
318         /* while nsio_rw_bytes is active, parse a pfn info block if present */
319         if (is_nd_pfn(dev)) {
320                 nd_pfn = to_nd_pfn(dev);
321                 rc = nvdimm_setup_pfn(nd_pfn, &pmem->pgmap);
322                 if (rc)
323                         return rc;
324         }
325
326         /* we're attaching a block device, disable raw namespace access */
327         devm_nsio_disable(dev, nsio);
328
329         dev_set_drvdata(dev, pmem);
330         pmem->phys_addr = res->start;
331         pmem->size = resource_size(res);
332         fua = nvdimm_has_flush(nd_region);
333         if (!IS_ENABLED(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) || fua < 0) {
334                 dev_warn(dev, "unable to guarantee persistence of writes\n");
335                 fua = 0;
336         }
337         wbc = nvdimm_has_cache(nd_region);
338
339         if (!devm_request_mem_region(dev, res->start, resource_size(res),
340                                 dev_name(&ndns->dev))) {
341                 dev_warn(dev, "could not reserve region %pR\n", res);
342                 return -EBUSY;
343         }
344
345         q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev));
346         if (!q)
347                 return -ENOMEM;
348
349         if (devm_add_action_or_reset(dev, pmem_release_queue, q))
350                 return -ENOMEM;
351
352         pmem->pfn_flags = PFN_DEV;
353         pmem->pgmap.ref = &q->q_usage_counter;
354         if (is_nd_pfn(dev)) {
355                 addr = devm_memremap_pages(dev, &pmem->pgmap);
356                 pfn_sb = nd_pfn->pfn_sb;
357                 pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
358                 pmem->pfn_pad = resource_size(res) -
359                         resource_size(&pmem->pgmap.res);
360                 pmem->pfn_flags |= PFN_MAP;
361                 memcpy(&bb_res, &pmem->pgmap.res, sizeof(bb_res));
362                 bb_res.start += pmem->data_offset;
363         } else if (pmem_should_map_pages(dev)) {
364                 memcpy(&pmem->pgmap.res, &nsio->res, sizeof(pmem->pgmap.res));
365                 pmem->pgmap.altmap_valid = false;
366                 addr = devm_memremap_pages(dev, &pmem->pgmap);
367                 pmem->pfn_flags |= PFN_MAP;
368                 memcpy(&bb_res, &pmem->pgmap.res, sizeof(bb_res));
369         } else
370                 addr = devm_memremap(dev, pmem->phys_addr,
371                                 pmem->size, ARCH_MEMREMAP_PMEM);
372
373         /*
374          * At release time the queue must be frozen before
375          * devm_memremap_pages is unwound
376          */
377         if (devm_add_action_or_reset(dev, pmem_freeze_queue, q))
378                 return -ENOMEM;
379
380         if (IS_ERR(addr))
381                 return PTR_ERR(addr);
382         pmem->virt_addr = addr;
383
384         blk_queue_write_cache(q, wbc, fua);
385         blk_queue_make_request(q, pmem_make_request);
386         blk_queue_physical_block_size(q, PAGE_SIZE);
387         blk_queue_logical_block_size(q, pmem_sector_size(ndns));
388         blk_queue_max_hw_sectors(q, UINT_MAX);
389         queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
390         queue_flag_set_unlocked(QUEUE_FLAG_DAX, q);
391         q->queuedata = pmem;
392
393         disk = alloc_disk_node(0, nid);
394         if (!disk)
395                 return -ENOMEM;
396         pmem->disk = disk;
397
398         disk->fops              = &pmem_fops;
399         disk->queue             = q;
400         disk->flags             = GENHD_FL_EXT_DEVT;
401         disk->queue->backing_dev_info->capabilities |= BDI_CAP_SYNCHRONOUS_IO;
402         nvdimm_namespace_disk_name(ndns, disk->disk_name);
403         set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
404                         / 512);
405         if (devm_init_badblocks(dev, &pmem->bb))
406                 return -ENOMEM;
407         nvdimm_badblocks_populate(nd_region, &pmem->bb, &bb_res);
408         disk->bb = &pmem->bb;
409
410         dax_dev = alloc_dax(pmem, disk->disk_name, &pmem_dax_ops);
411         if (!dax_dev) {
412                 put_disk(disk);
413                 return -ENOMEM;
414         }
415         dax_write_cache(dax_dev, wbc);
416         pmem->dax_dev = dax_dev;
417
418         gendev = disk_to_dev(disk);
419         gendev->groups = pmem_attribute_groups;
420
421         device_add_disk(dev, disk);
422         if (devm_add_action_or_reset(dev, pmem_release_disk, pmem))
423                 return -ENOMEM;
424
425         revalidate_disk(disk);
426
427         pmem->bb_state = sysfs_get_dirent(disk_to_dev(disk)->kobj.sd,
428                                           "badblocks");
429         if (!pmem->bb_state)
430                 dev_warn(dev, "'badblocks' notification disabled\n");
431
432         return 0;
433 }
434
435 static int nd_pmem_probe(struct device *dev)
436 {
437         struct nd_namespace_common *ndns;
438
439         ndns = nvdimm_namespace_common_probe(dev);
440         if (IS_ERR(ndns))
441                 return PTR_ERR(ndns);
442
443         if (devm_nsio_enable(dev, to_nd_namespace_io(&ndns->dev)))
444                 return -ENXIO;
445
446         if (is_nd_btt(dev))
447                 return nvdimm_namespace_attach_btt(ndns);
448
449         if (is_nd_pfn(dev))
450                 return pmem_attach_disk(dev, ndns);
451
452         /* if we find a valid info-block we'll come back as that personality */
453         if (nd_btt_probe(dev, ndns) == 0 || nd_pfn_probe(dev, ndns) == 0
454                         || nd_dax_probe(dev, ndns) == 0)
455                 return -ENXIO;
456
457         /* ...otherwise we're just a raw pmem device */
458         return pmem_attach_disk(dev, ndns);
459 }
460
461 static int nd_pmem_remove(struct device *dev)
462 {
463         struct pmem_device *pmem = dev_get_drvdata(dev);
464
465         if (is_nd_btt(dev))
466                 nvdimm_namespace_detach_btt(to_nd_btt(dev));
467         else {
468                 /*
469                  * Note, this assumes device_lock() context to not race
470                  * nd_pmem_notify()
471                  */
472                 sysfs_put(pmem->bb_state);
473                 pmem->bb_state = NULL;
474         }
475         nvdimm_flush(to_nd_region(dev->parent));
476
477         return 0;
478 }
479
480 static void nd_pmem_shutdown(struct device *dev)
481 {
482         nvdimm_flush(to_nd_region(dev->parent));
483 }
484
485 static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
486 {
487         struct nd_region *nd_region;
488         resource_size_t offset = 0, end_trunc = 0;
489         struct nd_namespace_common *ndns;
490         struct nd_namespace_io *nsio;
491         struct resource res;
492         struct badblocks *bb;
493         struct kernfs_node *bb_state;
494
495         if (event != NVDIMM_REVALIDATE_POISON)
496                 return;
497
498         if (is_nd_btt(dev)) {
499                 struct nd_btt *nd_btt = to_nd_btt(dev);
500
501                 ndns = nd_btt->ndns;
502                 nd_region = to_nd_region(ndns->dev.parent);
503                 nsio = to_nd_namespace_io(&ndns->dev);
504                 bb = &nsio->bb;
505                 bb_state = NULL;
506         } else {
507                 struct pmem_device *pmem = dev_get_drvdata(dev);
508
509                 nd_region = to_region(pmem);
510                 bb = &pmem->bb;
511                 bb_state = pmem->bb_state;
512
513                 if (is_nd_pfn(dev)) {
514                         struct nd_pfn *nd_pfn = to_nd_pfn(dev);
515                         struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
516
517                         ndns = nd_pfn->ndns;
518                         offset = pmem->data_offset +
519                                         __le32_to_cpu(pfn_sb->start_pad);
520                         end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
521                 } else {
522                         ndns = to_ndns(dev);
523                 }
524
525                 nsio = to_nd_namespace_io(&ndns->dev);
526         }
527
528         res.start = nsio->res.start + offset;
529         res.end = nsio->res.end - end_trunc;
530         nvdimm_badblocks_populate(nd_region, bb, &res);
531         if (bb_state)
532                 sysfs_notify_dirent(bb_state);
533 }
534
535 MODULE_ALIAS("pmem");
536 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO);
537 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM);
538 static struct nd_device_driver nd_pmem_driver = {
539         .probe = nd_pmem_probe,
540         .remove = nd_pmem_remove,
541         .notify = nd_pmem_notify,
542         .shutdown = nd_pmem_shutdown,
543         .drv = {
544                 .name = "nd_pmem",
545         },
546         .type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
547 };
548
549 static int __init pmem_init(void)
550 {
551         return nd_driver_register(&nd_pmem_driver);
552 }
553 module_init(pmem_init);
554
555 static void pmem_exit(void)
556 {
557         driver_unregister(&nd_pmem_driver.drv);
558 }
559 module_exit(pmem_exit);
560
561 MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
562 MODULE_LICENSE("GPL v2");