Merge tag '9p-for-5.3' of git://github.com/martinetd/linux
[linux-2.6-microblaze.git] / drivers / nvdimm / pmem.c
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 <asm/cacheflush.h>
11 #include <linux/blkdev.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/vmalloc.h>
21 #include <linux/blk-mq.h>
22 #include <linux/pfn_t.h>
23 #include <linux/slab.h>
24 #include <linux/uio.h>
25 #include <linux/dax.h>
26 #include <linux/nd.h>
27 #include <linux/backing-dev.h>
28 #include "pmem.h"
29 #include "pfn.h"
30 #include "nd.h"
31 #include "nd-core.h"
32
33 static 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
42 static struct nd_region *to_region(struct pmem_device *pmem)
43 {
44         return to_nd_region(to_dev(pmem)->parent);
45 }
46
47 static 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
71 static 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
100 static 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
118 static 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
140 static blk_status_t pmem_do_bvec(struct pmem_device *pmem, struct page *page,
141                         unsigned int len, unsigned int off, unsigned int op,
142                         sector_t sector)
143 {
144         blk_status_t rc = BLK_STS_OK;
145         bool bad_pmem = false;
146         phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
147         void *pmem_addr = pmem->virt_addr + pmem_off;
148
149         if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
150                 bad_pmem = true;
151
152         if (!op_is_write(op)) {
153                 if (unlikely(bad_pmem))
154                         rc = BLK_STS_IOERR;
155                 else {
156                         rc = read_pmem(page, off, pmem_addr, len);
157                         flush_dcache_page(page);
158                 }
159         } else {
160                 /*
161                  * Note that we write the data both before and after
162                  * clearing poison.  The write before clear poison
163                  * handles situations where the latest written data is
164                  * preserved and the clear poison operation simply marks
165                  * the address range as valid without changing the data.
166                  * In this case application software can assume that an
167                  * interrupted write will either return the new good
168                  * data or an error.
169                  *
170                  * However, if pmem_clear_poison() leaves the data in an
171                  * indeterminate state we need to perform the write
172                  * after clear poison.
173                  */
174                 flush_dcache_page(page);
175                 write_pmem(pmem_addr, page, off, len);
176                 if (unlikely(bad_pmem)) {
177                         rc = pmem_clear_poison(pmem, pmem_off, len);
178                         write_pmem(pmem_addr, page, off, len);
179                 }
180         }
181
182         return rc;
183 }
184
185 static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
186 {
187         blk_status_t rc = 0;
188         bool do_acct;
189         unsigned long start;
190         struct bio_vec bvec;
191         struct bvec_iter iter;
192         struct pmem_device *pmem = q->queuedata;
193         struct nd_region *nd_region = to_region(pmem);
194
195         if (bio->bi_opf & REQ_PREFLUSH)
196                 nvdimm_flush(nd_region);
197
198         do_acct = nd_iostat_start(bio, &start);
199         bio_for_each_segment(bvec, bio, iter) {
200                 rc = pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len,
201                                 bvec.bv_offset, bio_op(bio), iter.bi_sector);
202                 if (rc) {
203                         bio->bi_status = rc;
204                         break;
205                 }
206         }
207         if (do_acct)
208                 nd_iostat_end(bio, start);
209
210         if (bio->bi_opf & REQ_FUA)
211                 nvdimm_flush(nd_region);
212
213         bio_endio(bio);
214         return BLK_QC_T_NONE;
215 }
216
217 static int pmem_rw_page(struct block_device *bdev, sector_t sector,
218                        struct page *page, unsigned int op)
219 {
220         struct pmem_device *pmem = bdev->bd_queue->queuedata;
221         blk_status_t rc;
222
223         rc = pmem_do_bvec(pmem, page, hpage_nr_pages(page) * PAGE_SIZE,
224                           0, op, sector);
225
226         /*
227          * The ->rw_page interface is subtle and tricky.  The core
228          * retries on any error, so we can only invoke page_endio() in
229          * the successful completion case.  Otherwise, we'll see crashes
230          * caused by double completion.
231          */
232         if (rc == 0)
233                 page_endio(page, op_is_write(op), 0);
234
235         return blk_status_to_errno(rc);
236 }
237
238 /* see "strong" declaration in tools/testing/nvdimm/pmem-dax.c */
239 __weak long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
240                 long nr_pages, void **kaddr, pfn_t *pfn)
241 {
242         resource_size_t offset = PFN_PHYS(pgoff) + pmem->data_offset;
243
244         if (unlikely(is_bad_pmem(&pmem->bb, PFN_PHYS(pgoff) / 512,
245                                         PFN_PHYS(nr_pages))))
246                 return -EIO;
247
248         if (kaddr)
249                 *kaddr = pmem->virt_addr + offset;
250         if (pfn)
251                 *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
252
253         /*
254          * If badblocks are present, limit known good range to the
255          * requested range.
256          */
257         if (unlikely(pmem->bb.count))
258                 return nr_pages;
259         return PHYS_PFN(pmem->size - pmem->pfn_pad - offset);
260 }
261
262 static const struct block_device_operations pmem_fops = {
263         .owner =                THIS_MODULE,
264         .rw_page =              pmem_rw_page,
265         .revalidate_disk =      nvdimm_revalidate_disk,
266 };
267
268 static long pmem_dax_direct_access(struct dax_device *dax_dev,
269                 pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn)
270 {
271         struct pmem_device *pmem = dax_get_private(dax_dev);
272
273         return __pmem_direct_access(pmem, pgoff, nr_pages, kaddr, pfn);
274 }
275
276 /*
277  * Use the 'no check' versions of copy_from_iter_flushcache() and
278  * copy_to_iter_mcsafe() to bypass HARDENED_USERCOPY overhead. Bounds
279  * checking, both file offset and device offset, is handled by
280  * dax_iomap_actor()
281  */
282 static size_t pmem_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
283                 void *addr, size_t bytes, struct iov_iter *i)
284 {
285         return _copy_from_iter_flushcache(addr, bytes, i);
286 }
287
288 static size_t pmem_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff,
289                 void *addr, size_t bytes, struct iov_iter *i)
290 {
291         return _copy_to_iter_mcsafe(addr, bytes, i);
292 }
293
294 static const struct dax_operations pmem_dax_ops = {
295         .direct_access = pmem_dax_direct_access,
296         .dax_supported = generic_fsdax_supported,
297         .copy_from_iter = pmem_copy_from_iter,
298         .copy_to_iter = pmem_copy_to_iter,
299 };
300
301 static const struct attribute_group *pmem_attribute_groups[] = {
302         &dax_attribute_group,
303         NULL,
304 };
305
306 static void __pmem_release_queue(struct percpu_ref *ref)
307 {
308         struct request_queue *q;
309
310         q = container_of(ref, typeof(*q), q_usage_counter);
311         blk_cleanup_queue(q);
312 }
313
314 static void pmem_release_queue(void *ref)
315 {
316         __pmem_release_queue(ref);
317 }
318
319 static void pmem_freeze_queue(struct percpu_ref *ref)
320 {
321         struct request_queue *q;
322
323         q = container_of(ref, typeof(*q), q_usage_counter);
324         blk_freeze_queue_start(q);
325 }
326
327 static void pmem_release_disk(void *__pmem)
328 {
329         struct pmem_device *pmem = __pmem;
330
331         kill_dax(pmem->dax_dev);
332         put_dax(pmem->dax_dev);
333         del_gendisk(pmem->disk);
334         put_disk(pmem->disk);
335 }
336
337 static void pmem_release_pgmap_ops(void *__pgmap)
338 {
339         dev_pagemap_put_ops();
340 }
341
342 static void fsdax_pagefree(struct page *page, void *data)
343 {
344         wake_up_var(&page->_refcount);
345 }
346
347 static int setup_pagemap_fsdax(struct device *dev, struct dev_pagemap *pgmap)
348 {
349         dev_pagemap_get_ops();
350         if (devm_add_action_or_reset(dev, pmem_release_pgmap_ops, pgmap))
351                 return -ENOMEM;
352         pgmap->type = MEMORY_DEVICE_FS_DAX;
353         pgmap->page_free = fsdax_pagefree;
354
355         return 0;
356 }
357
358 static int pmem_attach_disk(struct device *dev,
359                 struct nd_namespace_common *ndns)
360 {
361         struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
362         struct nd_region *nd_region = to_nd_region(dev->parent);
363         int nid = dev_to_node(dev), fua;
364         struct resource *res = &nsio->res;
365         struct resource bb_res;
366         struct nd_pfn *nd_pfn = NULL;
367         struct dax_device *dax_dev;
368         struct nd_pfn_sb *pfn_sb;
369         struct pmem_device *pmem;
370         struct request_queue *q;
371         struct device *gendev;
372         struct gendisk *disk;
373         void *addr;
374         int rc;
375
376         pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
377         if (!pmem)
378                 return -ENOMEM;
379
380         /* while nsio_rw_bytes is active, parse a pfn info block if present */
381         if (is_nd_pfn(dev)) {
382                 nd_pfn = to_nd_pfn(dev);
383                 rc = nvdimm_setup_pfn(nd_pfn, &pmem->pgmap);
384                 if (rc)
385                         return rc;
386         }
387
388         /* we're attaching a block device, disable raw namespace access */
389         devm_nsio_disable(dev, nsio);
390
391         dev_set_drvdata(dev, pmem);
392         pmem->phys_addr = res->start;
393         pmem->size = resource_size(res);
394         fua = nvdimm_has_flush(nd_region);
395         if (!IS_ENABLED(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) || fua < 0) {
396                 dev_warn(dev, "unable to guarantee persistence of writes\n");
397                 fua = 0;
398         }
399
400         if (!devm_request_mem_region(dev, res->start, resource_size(res),
401                                 dev_name(&ndns->dev))) {
402                 dev_warn(dev, "could not reserve region %pR\n", res);
403                 return -EBUSY;
404         }
405
406         q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev));
407         if (!q)
408                 return -ENOMEM;
409
410         pmem->pfn_flags = PFN_DEV;
411         pmem->pgmap.ref = &q->q_usage_counter;
412         pmem->pgmap.kill = pmem_freeze_queue;
413         pmem->pgmap.cleanup = __pmem_release_queue;
414         if (is_nd_pfn(dev)) {
415                 if (setup_pagemap_fsdax(dev, &pmem->pgmap))
416                         return -ENOMEM;
417                 addr = devm_memremap_pages(dev, &pmem->pgmap);
418                 pfn_sb = nd_pfn->pfn_sb;
419                 pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
420                 pmem->pfn_pad = resource_size(res) -
421                         resource_size(&pmem->pgmap.res);
422                 pmem->pfn_flags |= PFN_MAP;
423                 memcpy(&bb_res, &pmem->pgmap.res, sizeof(bb_res));
424                 bb_res.start += pmem->data_offset;
425         } else if (pmem_should_map_pages(dev)) {
426                 memcpy(&pmem->pgmap.res, &nsio->res, sizeof(pmem->pgmap.res));
427                 pmem->pgmap.altmap_valid = false;
428                 if (setup_pagemap_fsdax(dev, &pmem->pgmap))
429                         return -ENOMEM;
430                 addr = devm_memremap_pages(dev, &pmem->pgmap);
431                 pmem->pfn_flags |= PFN_MAP;
432                 memcpy(&bb_res, &pmem->pgmap.res, sizeof(bb_res));
433         } else {
434                 if (devm_add_action_or_reset(dev, pmem_release_queue,
435                                         &q->q_usage_counter))
436                         return -ENOMEM;
437                 addr = devm_memremap(dev, pmem->phys_addr,
438                                 pmem->size, ARCH_MEMREMAP_PMEM);
439                 memcpy(&bb_res, &nsio->res, sizeof(bb_res));
440         }
441
442         if (IS_ERR(addr))
443                 return PTR_ERR(addr);
444         pmem->virt_addr = addr;
445
446         blk_queue_write_cache(q, true, fua);
447         blk_queue_make_request(q, pmem_make_request);
448         blk_queue_physical_block_size(q, PAGE_SIZE);
449         blk_queue_logical_block_size(q, pmem_sector_size(ndns));
450         blk_queue_max_hw_sectors(q, UINT_MAX);
451         blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
452         if (pmem->pfn_flags & PFN_MAP)
453                 blk_queue_flag_set(QUEUE_FLAG_DAX, q);
454         q->queuedata = pmem;
455
456         disk = alloc_disk_node(0, nid);
457         if (!disk)
458                 return -ENOMEM;
459         pmem->disk = disk;
460
461         disk->fops              = &pmem_fops;
462         disk->queue             = q;
463         disk->flags             = GENHD_FL_EXT_DEVT;
464         disk->queue->backing_dev_info->capabilities |= BDI_CAP_SYNCHRONOUS_IO;
465         nvdimm_namespace_disk_name(ndns, disk->disk_name);
466         set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
467                         / 512);
468         if (devm_init_badblocks(dev, &pmem->bb))
469                 return -ENOMEM;
470         nvdimm_badblocks_populate(nd_region, &pmem->bb, &bb_res);
471         disk->bb = &pmem->bb;
472
473         dax_dev = alloc_dax(pmem, disk->disk_name, &pmem_dax_ops);
474         if (!dax_dev) {
475                 put_disk(disk);
476                 return -ENOMEM;
477         }
478         dax_write_cache(dax_dev, nvdimm_has_cache(nd_region));
479         pmem->dax_dev = dax_dev;
480
481         gendev = disk_to_dev(disk);
482         gendev->groups = pmem_attribute_groups;
483
484         device_add_disk(dev, disk, NULL);
485         if (devm_add_action_or_reset(dev, pmem_release_disk, pmem))
486                 return -ENOMEM;
487
488         revalidate_disk(disk);
489
490         pmem->bb_state = sysfs_get_dirent(disk_to_dev(disk)->kobj.sd,
491                                           "badblocks");
492         if (!pmem->bb_state)
493                 dev_warn(dev, "'badblocks' notification disabled\n");
494
495         return 0;
496 }
497
498 static int nd_pmem_probe(struct device *dev)
499 {
500         struct nd_namespace_common *ndns;
501
502         ndns = nvdimm_namespace_common_probe(dev);
503         if (IS_ERR(ndns))
504                 return PTR_ERR(ndns);
505
506         if (devm_nsio_enable(dev, to_nd_namespace_io(&ndns->dev)))
507                 return -ENXIO;
508
509         if (is_nd_btt(dev))
510                 return nvdimm_namespace_attach_btt(ndns);
511
512         if (is_nd_pfn(dev))
513                 return pmem_attach_disk(dev, ndns);
514
515         /* if we find a valid info-block we'll come back as that personality */
516         if (nd_btt_probe(dev, ndns) == 0 || nd_pfn_probe(dev, ndns) == 0
517                         || nd_dax_probe(dev, ndns) == 0)
518                 return -ENXIO;
519
520         /* ...otherwise we're just a raw pmem device */
521         return pmem_attach_disk(dev, ndns);
522 }
523
524 static int nd_pmem_remove(struct device *dev)
525 {
526         struct pmem_device *pmem = dev_get_drvdata(dev);
527
528         if (is_nd_btt(dev))
529                 nvdimm_namespace_detach_btt(to_nd_btt(dev));
530         else {
531                 /*
532                  * Note, this assumes device_lock() context to not race
533                  * nd_pmem_notify()
534                  */
535                 sysfs_put(pmem->bb_state);
536                 pmem->bb_state = NULL;
537         }
538         nvdimm_flush(to_nd_region(dev->parent));
539
540         return 0;
541 }
542
543 static void nd_pmem_shutdown(struct device *dev)
544 {
545         nvdimm_flush(to_nd_region(dev->parent));
546 }
547
548 static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
549 {
550         struct nd_region *nd_region;
551         resource_size_t offset = 0, end_trunc = 0;
552         struct nd_namespace_common *ndns;
553         struct nd_namespace_io *nsio;
554         struct resource res;
555         struct badblocks *bb;
556         struct kernfs_node *bb_state;
557
558         if (event != NVDIMM_REVALIDATE_POISON)
559                 return;
560
561         if (is_nd_btt(dev)) {
562                 struct nd_btt *nd_btt = to_nd_btt(dev);
563
564                 ndns = nd_btt->ndns;
565                 nd_region = to_nd_region(ndns->dev.parent);
566                 nsio = to_nd_namespace_io(&ndns->dev);
567                 bb = &nsio->bb;
568                 bb_state = NULL;
569         } else {
570                 struct pmem_device *pmem = dev_get_drvdata(dev);
571
572                 nd_region = to_region(pmem);
573                 bb = &pmem->bb;
574                 bb_state = pmem->bb_state;
575
576                 if (is_nd_pfn(dev)) {
577                         struct nd_pfn *nd_pfn = to_nd_pfn(dev);
578                         struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
579
580                         ndns = nd_pfn->ndns;
581                         offset = pmem->data_offset +
582                                         __le32_to_cpu(pfn_sb->start_pad);
583                         end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
584                 } else {
585                         ndns = to_ndns(dev);
586                 }
587
588                 nsio = to_nd_namespace_io(&ndns->dev);
589         }
590
591         res.start = nsio->res.start + offset;
592         res.end = nsio->res.end - end_trunc;
593         nvdimm_badblocks_populate(nd_region, bb, &res);
594         if (bb_state)
595                 sysfs_notify_dirent(bb_state);
596 }
597
598 MODULE_ALIAS("pmem");
599 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO);
600 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM);
601 static struct nd_device_driver nd_pmem_driver = {
602         .probe = nd_pmem_probe,
603         .remove = nd_pmem_remove,
604         .notify = nd_pmem_notify,
605         .shutdown = nd_pmem_shutdown,
606         .drv = {
607                 .name = "nd_pmem",
608         },
609         .type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
610 };
611
612 module_nd_driver(nd_pmem_driver);
613
614 MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
615 MODULE_LICENSE("GPL v2");