8b1fd7f1a224eedebf08cddfe2258949c50a6bcf
[linux-2.6-microblaze.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 #include "nd-core.h"
39
40 static struct device *to_dev(struct pmem_device *pmem)
41 {
42         /*
43          * nvdimm bus services need a 'dev' parameter, and we record the device
44          * at init in bb.dev.
45          */
46         return pmem->bb.dev;
47 }
48
49 static struct nd_region *to_region(struct pmem_device *pmem)
50 {
51         return to_nd_region(to_dev(pmem)->parent);
52 }
53
54 static blk_status_t pmem_clear_poison(struct pmem_device *pmem,
55                 phys_addr_t offset, unsigned int len)
56 {
57         struct device *dev = to_dev(pmem);
58         sector_t sector;
59         long cleared;
60         blk_status_t rc = BLK_STS_OK;
61
62         sector = (offset - pmem->data_offset) / 512;
63
64         cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len);
65         if (cleared < len)
66                 rc = BLK_STS_IOERR;
67         if (cleared > 0 && cleared / 512) {
68                 cleared /= 512;
69                 dev_dbg(dev, "%#llx clear %ld sector%s\n",
70                                 (unsigned long long) sector, cleared,
71                                 cleared > 1 ? "s" : "");
72                 badblocks_clear(&pmem->bb, sector, cleared);
73                 if (pmem->bb_state)
74                         sysfs_notify_dirent(pmem->bb_state);
75         }
76
77         arch_invalidate_pmem(pmem->virt_addr + offset, len);
78
79         return rc;
80 }
81
82 static void write_pmem(void *pmem_addr, struct page *page,
83                 unsigned int off, unsigned int len)
84 {
85         unsigned int chunk;
86         void *mem;
87
88         while (len) {
89                 mem = kmap_atomic(page);
90                 chunk = min_t(unsigned int, len, PAGE_SIZE);
91                 memcpy_flushcache(pmem_addr, mem + off, chunk);
92                 kunmap_atomic(mem);
93                 len -= chunk;
94                 off = 0;
95                 page++;
96                 pmem_addr += PAGE_SIZE;
97         }
98 }
99
100 static blk_status_t read_pmem(struct page *page, unsigned int off,
101                 void *pmem_addr, unsigned int len)
102 {
103         unsigned int chunk;
104         unsigned long rem;
105         void *mem;
106
107         while (len) {
108                 mem = kmap_atomic(page);
109                 chunk = min_t(unsigned int, len, PAGE_SIZE);
110                 rem = memcpy_mcsafe(mem + off, pmem_addr, chunk);
111                 kunmap_atomic(mem);
112                 if (rem)
113                         return BLK_STS_IOERR;
114                 len -= chunk;
115                 off = 0;
116                 page++;
117                 pmem_addr += PAGE_SIZE;
118         }
119         return BLK_STS_OK;
120 }
121
122 static blk_status_t pmem_do_bvec(struct pmem_device *pmem, struct page *page,
123                         unsigned int len, unsigned int off, bool is_write,
124                         sector_t sector)
125 {
126         blk_status_t rc = BLK_STS_OK;
127         bool bad_pmem = false;
128         phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
129         void *pmem_addr = pmem->virt_addr + pmem_off;
130
131         if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
132                 bad_pmem = true;
133
134         if (!is_write) {
135                 if (unlikely(bad_pmem))
136                         rc = BLK_STS_IOERR;
137                 else {
138                         rc = read_pmem(page, off, pmem_addr, len);
139                         flush_dcache_page(page);
140                 }
141         } else {
142                 /*
143                  * Note that we write the data both before and after
144                  * clearing poison.  The write before clear poison
145                  * handles situations where the latest written data is
146                  * preserved and the clear poison operation simply marks
147                  * the address range as valid without changing the data.
148                  * In this case application software can assume that an
149                  * interrupted write will either return the new good
150                  * data or an error.
151                  *
152                  * However, if pmem_clear_poison() leaves the data in an
153                  * indeterminate state we need to perform the write
154                  * after clear poison.
155                  */
156                 flush_dcache_page(page);
157                 write_pmem(pmem_addr, page, off, len);
158                 if (unlikely(bad_pmem)) {
159                         rc = pmem_clear_poison(pmem, pmem_off, len);
160                         write_pmem(pmem_addr, page, off, len);
161                 }
162         }
163
164         return rc;
165 }
166
167 static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
168 {
169         blk_status_t rc = 0;
170         bool do_acct;
171         unsigned long start;
172         struct bio_vec bvec;
173         struct bvec_iter iter;
174         struct pmem_device *pmem = q->queuedata;
175         struct nd_region *nd_region = to_region(pmem);
176
177         if (bio->bi_opf & REQ_PREFLUSH)
178                 nvdimm_flush(nd_region);
179
180         do_acct = nd_iostat_start(bio, &start);
181         bio_for_each_segment(bvec, bio, iter) {
182                 rc = pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len,
183                                 bvec.bv_offset, op_is_write(bio_op(bio)),
184                                 iter.bi_sector);
185                 if (rc) {
186                         bio->bi_status = rc;
187                         break;
188                 }
189         }
190         if (do_acct)
191                 nd_iostat_end(bio, start);
192
193         if (bio->bi_opf & REQ_FUA)
194                 nvdimm_flush(nd_region);
195
196         bio_endio(bio);
197         return BLK_QC_T_NONE;
198 }
199
200 static int pmem_rw_page(struct block_device *bdev, sector_t sector,
201                        struct page *page, bool is_write)
202 {
203         struct pmem_device *pmem = bdev->bd_queue->queuedata;
204         blk_status_t rc;
205
206         rc = pmem_do_bvec(pmem, page, hpage_nr_pages(page) * PAGE_SIZE,
207                           0, is_write, sector);
208
209         /*
210          * The ->rw_page interface is subtle and tricky.  The core
211          * retries on any error, so we can only invoke page_endio() in
212          * the successful completion case.  Otherwise, we'll see crashes
213          * caused by double completion.
214          */
215         if (rc == 0)
216                 page_endio(page, is_write, 0);
217
218         return blk_status_to_errno(rc);
219 }
220
221 /* see "strong" declaration in tools/testing/nvdimm/pmem-dax.c */
222 __weak long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
223                 long nr_pages, void **kaddr, pfn_t *pfn)
224 {
225         resource_size_t offset = PFN_PHYS(pgoff) + pmem->data_offset;
226
227         if (unlikely(is_bad_pmem(&pmem->bb, PFN_PHYS(pgoff) / 512,
228                                         PFN_PHYS(nr_pages))))
229                 return -EIO;
230         *kaddr = pmem->virt_addr + offset;
231         *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
232
233         /*
234          * If badblocks are present, limit known good range to the
235          * requested range.
236          */
237         if (unlikely(pmem->bb.count))
238                 return nr_pages;
239         return PHYS_PFN(pmem->size - pmem->pfn_pad - offset);
240 }
241
242 static const struct block_device_operations pmem_fops = {
243         .owner =                THIS_MODULE,
244         .rw_page =              pmem_rw_page,
245         .revalidate_disk =      nvdimm_revalidate_disk,
246 };
247
248 static long pmem_dax_direct_access(struct dax_device *dax_dev,
249                 pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn)
250 {
251         struct pmem_device *pmem = dax_get_private(dax_dev);
252
253         return __pmem_direct_access(pmem, pgoff, nr_pages, kaddr, pfn);
254 }
255
256 static size_t pmem_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
257                 void *addr, size_t bytes, struct iov_iter *i)
258 {
259         return copy_from_iter_flushcache(addr, bytes, i);
260 }
261
262 static size_t pmem_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff,
263                 void *addr, size_t bytes, struct iov_iter *i)
264 {
265         return copy_to_iter_mcsafe(addr, bytes, i);
266 }
267
268 static const struct dax_operations pmem_dax_ops = {
269         .direct_access = pmem_dax_direct_access,
270         .copy_from_iter = pmem_copy_from_iter,
271         .copy_to_iter = pmem_copy_to_iter,
272 };
273
274 static const struct attribute_group *pmem_attribute_groups[] = {
275         &dax_attribute_group,
276         NULL,
277 };
278
279 static void pmem_release_queue(void *q)
280 {
281         blk_cleanup_queue(q);
282 }
283
284 static void pmem_freeze_queue(void *q)
285 {
286         blk_freeze_queue_start(q);
287 }
288
289 static void pmem_release_disk(void *__pmem)
290 {
291         struct pmem_device *pmem = __pmem;
292
293         kill_dax(pmem->dax_dev);
294         put_dax(pmem->dax_dev);
295         del_gendisk(pmem->disk);
296         put_disk(pmem->disk);
297 }
298
299 static void pmem_release_pgmap_ops(void *__pgmap)
300 {
301         dev_pagemap_put_ops();
302 }
303
304 static void fsdax_pagefree(struct page *page, void *data)
305 {
306         wake_up_var(&page->_refcount);
307 }
308
309 static int setup_pagemap_fsdax(struct device *dev, struct dev_pagemap *pgmap)
310 {
311         dev_pagemap_get_ops();
312         if (devm_add_action_or_reset(dev, pmem_release_pgmap_ops, pgmap))
313                 return -ENOMEM;
314         pgmap->type = MEMORY_DEVICE_FS_DAX;
315         pgmap->page_free = fsdax_pagefree;
316
317         return 0;
318 }
319
320 static int pmem_attach_disk(struct device *dev,
321                 struct nd_namespace_common *ndns)
322 {
323         struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
324         struct nd_region *nd_region = to_nd_region(dev->parent);
325         int nid = dev_to_node(dev), fua;
326         struct resource *res = &nsio->res;
327         struct resource bb_res;
328         struct nd_pfn *nd_pfn = NULL;
329         struct dax_device *dax_dev;
330         struct nd_pfn_sb *pfn_sb;
331         struct pmem_device *pmem;
332         struct request_queue *q;
333         struct device *gendev;
334         struct gendisk *disk;
335         void *addr;
336         int rc;
337
338         pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
339         if (!pmem)
340                 return -ENOMEM;
341
342         /* while nsio_rw_bytes is active, parse a pfn info block if present */
343         if (is_nd_pfn(dev)) {
344                 nd_pfn = to_nd_pfn(dev);
345                 rc = nvdimm_setup_pfn(nd_pfn, &pmem->pgmap);
346                 if (rc)
347                         return rc;
348         }
349
350         /* we're attaching a block device, disable raw namespace access */
351         devm_nsio_disable(dev, nsio);
352
353         dev_set_drvdata(dev, pmem);
354         pmem->phys_addr = res->start;
355         pmem->size = resource_size(res);
356         fua = nvdimm_has_flush(nd_region);
357         if (!IS_ENABLED(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) || fua < 0) {
358                 dev_warn(dev, "unable to guarantee persistence of writes\n");
359                 fua = 0;
360         }
361
362         if (!devm_request_mem_region(dev, res->start, resource_size(res),
363                                 dev_name(&ndns->dev))) {
364                 dev_warn(dev, "could not reserve region %pR\n", res);
365                 return -EBUSY;
366         }
367
368         q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev), NULL);
369         if (!q)
370                 return -ENOMEM;
371
372         if (devm_add_action_or_reset(dev, pmem_release_queue, q))
373                 return -ENOMEM;
374
375         pmem->pfn_flags = PFN_DEV;
376         pmem->pgmap.ref = &q->q_usage_counter;
377         if (is_nd_pfn(dev)) {
378                 if (setup_pagemap_fsdax(dev, &pmem->pgmap))
379                         return -ENOMEM;
380                 addr = devm_memremap_pages(dev, &pmem->pgmap);
381                 pfn_sb = nd_pfn->pfn_sb;
382                 pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
383                 pmem->pfn_pad = resource_size(res) -
384                         resource_size(&pmem->pgmap.res);
385                 pmem->pfn_flags |= PFN_MAP;
386                 memcpy(&bb_res, &pmem->pgmap.res, sizeof(bb_res));
387                 bb_res.start += pmem->data_offset;
388         } else if (pmem_should_map_pages(dev)) {
389                 memcpy(&pmem->pgmap.res, &nsio->res, sizeof(pmem->pgmap.res));
390                 pmem->pgmap.altmap_valid = false;
391                 if (setup_pagemap_fsdax(dev, &pmem->pgmap))
392                         return -ENOMEM;
393                 addr = devm_memremap_pages(dev, &pmem->pgmap);
394                 pmem->pfn_flags |= PFN_MAP;
395                 memcpy(&bb_res, &pmem->pgmap.res, sizeof(bb_res));
396         } else
397                 addr = devm_memremap(dev, pmem->phys_addr,
398                                 pmem->size, ARCH_MEMREMAP_PMEM);
399
400         /*
401          * At release time the queue must be frozen before
402          * devm_memremap_pages is unwound
403          */
404         if (devm_add_action_or_reset(dev, pmem_freeze_queue, q))
405                 return -ENOMEM;
406
407         if (IS_ERR(addr))
408                 return PTR_ERR(addr);
409         pmem->virt_addr = addr;
410
411         blk_queue_write_cache(q, true, fua);
412         blk_queue_make_request(q, pmem_make_request);
413         blk_queue_physical_block_size(q, PAGE_SIZE);
414         blk_queue_logical_block_size(q, pmem_sector_size(ndns));
415         blk_queue_max_hw_sectors(q, UINT_MAX);
416         blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
417         if (pmem->pfn_flags & PFN_MAP)
418                 blk_queue_flag_set(QUEUE_FLAG_DAX, q);
419         q->queuedata = pmem;
420
421         disk = alloc_disk_node(0, nid);
422         if (!disk)
423                 return -ENOMEM;
424         pmem->disk = disk;
425
426         disk->fops              = &pmem_fops;
427         disk->queue             = q;
428         disk->flags             = GENHD_FL_EXT_DEVT;
429         disk->queue->backing_dev_info->capabilities |= BDI_CAP_SYNCHRONOUS_IO;
430         nvdimm_namespace_disk_name(ndns, disk->disk_name);
431         set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
432                         / 512);
433         if (devm_init_badblocks(dev, &pmem->bb))
434                 return -ENOMEM;
435         nvdimm_badblocks_populate(nd_region, &pmem->bb, &bb_res);
436         disk->bb = &pmem->bb;
437
438         dax_dev = alloc_dax(pmem, disk->disk_name, &pmem_dax_ops);
439         if (!dax_dev) {
440                 put_disk(disk);
441                 return -ENOMEM;
442         }
443         dax_write_cache(dax_dev, nvdimm_has_cache(nd_region));
444         pmem->dax_dev = dax_dev;
445
446         gendev = disk_to_dev(disk);
447         gendev->groups = pmem_attribute_groups;
448
449         device_add_disk(dev, disk);
450         if (devm_add_action_or_reset(dev, pmem_release_disk, pmem))
451                 return -ENOMEM;
452
453         revalidate_disk(disk);
454
455         pmem->bb_state = sysfs_get_dirent(disk_to_dev(disk)->kobj.sd,
456                                           "badblocks");
457         if (!pmem->bb_state)
458                 dev_warn(dev, "'badblocks' notification disabled\n");
459
460         return 0;
461 }
462
463 static int nd_pmem_probe(struct device *dev)
464 {
465         struct nd_namespace_common *ndns;
466
467         ndns = nvdimm_namespace_common_probe(dev);
468         if (IS_ERR(ndns))
469                 return PTR_ERR(ndns);
470
471         if (devm_nsio_enable(dev, to_nd_namespace_io(&ndns->dev)))
472                 return -ENXIO;
473
474         if (is_nd_btt(dev))
475                 return nvdimm_namespace_attach_btt(ndns);
476
477         if (is_nd_pfn(dev))
478                 return pmem_attach_disk(dev, ndns);
479
480         /* if we find a valid info-block we'll come back as that personality */
481         if (nd_btt_probe(dev, ndns) == 0 || nd_pfn_probe(dev, ndns) == 0
482                         || nd_dax_probe(dev, ndns) == 0)
483                 return -ENXIO;
484
485         /* ...otherwise we're just a raw pmem device */
486         return pmem_attach_disk(dev, ndns);
487 }
488
489 static int nd_pmem_remove(struct device *dev)
490 {
491         struct pmem_device *pmem = dev_get_drvdata(dev);
492
493         if (is_nd_btt(dev))
494                 nvdimm_namespace_detach_btt(to_nd_btt(dev));
495         else {
496                 /*
497                  * Note, this assumes device_lock() context to not race
498                  * nd_pmem_notify()
499                  */
500                 sysfs_put(pmem->bb_state);
501                 pmem->bb_state = NULL;
502         }
503         nvdimm_flush(to_nd_region(dev->parent));
504
505         return 0;
506 }
507
508 static void nd_pmem_shutdown(struct device *dev)
509 {
510         nvdimm_flush(to_nd_region(dev->parent));
511 }
512
513 static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
514 {
515         struct nd_region *nd_region;
516         resource_size_t offset = 0, end_trunc = 0;
517         struct nd_namespace_common *ndns;
518         struct nd_namespace_io *nsio;
519         struct resource res;
520         struct badblocks *bb;
521         struct kernfs_node *bb_state;
522
523         if (event != NVDIMM_REVALIDATE_POISON)
524                 return;
525
526         if (is_nd_btt(dev)) {
527                 struct nd_btt *nd_btt = to_nd_btt(dev);
528
529                 ndns = nd_btt->ndns;
530                 nd_region = to_nd_region(ndns->dev.parent);
531                 nsio = to_nd_namespace_io(&ndns->dev);
532                 bb = &nsio->bb;
533                 bb_state = NULL;
534         } else {
535                 struct pmem_device *pmem = dev_get_drvdata(dev);
536
537                 nd_region = to_region(pmem);
538                 bb = &pmem->bb;
539                 bb_state = pmem->bb_state;
540
541                 if (is_nd_pfn(dev)) {
542                         struct nd_pfn *nd_pfn = to_nd_pfn(dev);
543                         struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
544
545                         ndns = nd_pfn->ndns;
546                         offset = pmem->data_offset +
547                                         __le32_to_cpu(pfn_sb->start_pad);
548                         end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
549                 } else {
550                         ndns = to_ndns(dev);
551                 }
552
553                 nsio = to_nd_namespace_io(&ndns->dev);
554         }
555
556         res.start = nsio->res.start + offset;
557         res.end = nsio->res.end - end_trunc;
558         nvdimm_badblocks_populate(nd_region, bb, &res);
559         if (bb_state)
560                 sysfs_notify_dirent(bb_state);
561 }
562
563 MODULE_ALIAS("pmem");
564 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO);
565 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM);
566 static struct nd_device_driver nd_pmem_driver = {
567         .probe = nd_pmem_probe,
568         .remove = nd_pmem_remove,
569         .notify = nd_pmem_notify,
570         .shutdown = nd_pmem_shutdown,
571         .drv = {
572                 .name = "nd_pmem",
573         },
574         .type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
575 };
576
577 module_nd_driver(nd_pmem_driver);
578
579 MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
580 MODULE_LICENSE("GPL v2");