libnvdimm: register nvdimm_bus devices with an nd_bus driver
[cascardo/linux.git] / drivers / nvdimm / core.c
1 /*
2  * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of version 2 of the GNU General Public License as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful, but
9  * WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * General Public License for more details.
12  */
13 #include <linux/libnvdimm.h>
14 #include <linux/badblocks.h>
15 #include <linux/export.h>
16 #include <linux/module.h>
17 #include <linux/blkdev.h>
18 #include <linux/device.h>
19 #include <linux/ctype.h>
20 #include <linux/ndctl.h>
21 #include <linux/mutex.h>
22 #include <linux/slab.h>
23 #include <linux/io.h>
24 #include "nd-core.h"
25 #include "nd.h"
26
27 LIST_HEAD(nvdimm_bus_list);
28 DEFINE_MUTEX(nvdimm_bus_list_mutex);
29
30 void nvdimm_bus_lock(struct device *dev)
31 {
32         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
33
34         if (!nvdimm_bus)
35                 return;
36         mutex_lock(&nvdimm_bus->reconfig_mutex);
37 }
38 EXPORT_SYMBOL(nvdimm_bus_lock);
39
40 void nvdimm_bus_unlock(struct device *dev)
41 {
42         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
43
44         if (!nvdimm_bus)
45                 return;
46         mutex_unlock(&nvdimm_bus->reconfig_mutex);
47 }
48 EXPORT_SYMBOL(nvdimm_bus_unlock);
49
50 bool is_nvdimm_bus_locked(struct device *dev)
51 {
52         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
53
54         if (!nvdimm_bus)
55                 return false;
56         return mutex_is_locked(&nvdimm_bus->reconfig_mutex);
57 }
58 EXPORT_SYMBOL(is_nvdimm_bus_locked);
59
60 struct nvdimm_map {
61         struct nvdimm_bus *nvdimm_bus;
62         struct list_head list;
63         resource_size_t offset;
64         unsigned long flags;
65         size_t size;
66         union {
67                 void *mem;
68                 void __iomem *iomem;
69         };
70         struct kref kref;
71 };
72
73 static struct nvdimm_map *find_nvdimm_map(struct device *dev,
74                 resource_size_t offset)
75 {
76         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
77         struct nvdimm_map *nvdimm_map;
78
79         list_for_each_entry(nvdimm_map, &nvdimm_bus->mapping_list, list)
80                 if (nvdimm_map->offset == offset)
81                         return nvdimm_map;
82         return NULL;
83 }
84
85 static struct nvdimm_map *alloc_nvdimm_map(struct device *dev,
86                 resource_size_t offset, size_t size, unsigned long flags)
87 {
88         struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
89         struct nvdimm_map *nvdimm_map;
90
91         nvdimm_map = kzalloc(sizeof(*nvdimm_map), GFP_KERNEL);
92         if (!nvdimm_map)
93                 return NULL;
94
95         INIT_LIST_HEAD(&nvdimm_map->list);
96         nvdimm_map->nvdimm_bus = nvdimm_bus;
97         nvdimm_map->offset = offset;
98         nvdimm_map->flags = flags;
99         nvdimm_map->size = size;
100         kref_init(&nvdimm_map->kref);
101
102         if (!request_mem_region(offset, size, dev_name(&nvdimm_bus->dev)))
103                 goto err_request_region;
104
105         if (flags)
106                 nvdimm_map->mem = memremap(offset, size, flags);
107         else
108                 nvdimm_map->iomem = ioremap(offset, size);
109
110         if (!nvdimm_map->mem)
111                 goto err_map;
112
113         dev_WARN_ONCE(dev, !is_nvdimm_bus_locked(dev), "%s: bus unlocked!",
114                         __func__);
115         list_add(&nvdimm_map->list, &nvdimm_bus->mapping_list);
116
117         return nvdimm_map;
118
119  err_map:
120         release_mem_region(offset, size);
121  err_request_region:
122         kfree(nvdimm_map);
123         return NULL;
124 }
125
126 static void nvdimm_map_release(struct kref *kref)
127 {
128         struct nvdimm_bus *nvdimm_bus;
129         struct nvdimm_map *nvdimm_map;
130
131         nvdimm_map = container_of(kref, struct nvdimm_map, kref);
132         nvdimm_bus = nvdimm_map->nvdimm_bus;
133
134         dev_dbg(&nvdimm_bus->dev, "%s: %pa\n", __func__, &nvdimm_map->offset);
135         list_del(&nvdimm_map->list);
136         if (nvdimm_map->flags)
137                 memunmap(nvdimm_map->mem);
138         else
139                 iounmap(nvdimm_map->iomem);
140         release_mem_region(nvdimm_map->offset, nvdimm_map->size);
141         kfree(nvdimm_map);
142 }
143
144 static void nvdimm_map_put(void *data)
145 {
146         struct nvdimm_map *nvdimm_map = data;
147         struct nvdimm_bus *nvdimm_bus = nvdimm_map->nvdimm_bus;
148
149         nvdimm_bus_lock(&nvdimm_bus->dev);
150         kref_put(&nvdimm_map->kref, nvdimm_map_release);
151         nvdimm_bus_unlock(&nvdimm_bus->dev);
152 }
153
154 /**
155  * devm_nvdimm_memremap - map a resource that is shared across regions
156  * @dev: device that will own a reference to the shared mapping
157  * @offset: physical base address of the mapping
158  * @size: mapping size
159  * @flags: memremap flags, or, if zero, perform an ioremap instead
160  */
161 void *devm_nvdimm_memremap(struct device *dev, resource_size_t offset,
162                 size_t size, unsigned long flags)
163 {
164         struct nvdimm_map *nvdimm_map;
165
166         nvdimm_bus_lock(dev);
167         nvdimm_map = find_nvdimm_map(dev, offset);
168         if (!nvdimm_map)
169                 nvdimm_map = alloc_nvdimm_map(dev, offset, size, flags);
170         else
171                 kref_get(&nvdimm_map->kref);
172         nvdimm_bus_unlock(dev);
173
174         if (devm_add_action_or_reset(dev, nvdimm_map_put, nvdimm_map))
175                 return NULL;
176
177         return nvdimm_map->mem;
178 }
179 EXPORT_SYMBOL_GPL(devm_nvdimm_memremap);
180
181 u64 nd_fletcher64(void *addr, size_t len, bool le)
182 {
183         u32 *buf = addr;
184         u32 lo32 = 0;
185         u64 hi32 = 0;
186         int i;
187
188         for (i = 0; i < len / sizeof(u32); i++) {
189                 lo32 += le ? le32_to_cpu((__le32) buf[i]) : buf[i];
190                 hi32 += lo32;
191         }
192
193         return hi32 << 32 | lo32;
194 }
195 EXPORT_SYMBOL_GPL(nd_fletcher64);
196
197 struct nvdimm_bus_descriptor *to_nd_desc(struct nvdimm_bus *nvdimm_bus)
198 {
199         /* struct nvdimm_bus definition is private to libnvdimm */
200         return nvdimm_bus->nd_desc;
201 }
202 EXPORT_SYMBOL_GPL(to_nd_desc);
203
204 static bool is_uuid_sep(char sep)
205 {
206         if (sep == '\n' || sep == '-' || sep == ':' || sep == '\0')
207                 return true;
208         return false;
209 }
210
211 static int nd_uuid_parse(struct device *dev, u8 *uuid_out, const char *buf,
212                 size_t len)
213 {
214         const char *str = buf;
215         u8 uuid[16];
216         int i;
217
218         for (i = 0; i < 16; i++) {
219                 if (!isxdigit(str[0]) || !isxdigit(str[1])) {
220                         dev_dbg(dev, "%s: pos: %d buf[%zd]: %c buf[%zd]: %c\n",
221                                         __func__, i, str - buf, str[0],
222                                         str + 1 - buf, str[1]);
223                         return -EINVAL;
224                 }
225
226                 uuid[i] = (hex_to_bin(str[0]) << 4) | hex_to_bin(str[1]);
227                 str += 2;
228                 if (is_uuid_sep(*str))
229                         str++;
230         }
231
232         memcpy(uuid_out, uuid, sizeof(uuid));
233         return 0;
234 }
235
236 /**
237  * nd_uuid_store: common implementation for writing 'uuid' sysfs attributes
238  * @dev: container device for the uuid property
239  * @uuid_out: uuid buffer to replace
240  * @buf: raw sysfs buffer to parse
241  *
242  * Enforce that uuids can only be changed while the device is disabled
243  * (driver detached)
244  * LOCKING: expects device_lock() is held on entry
245  */
246 int nd_uuid_store(struct device *dev, u8 **uuid_out, const char *buf,
247                 size_t len)
248 {
249         u8 uuid[16];
250         int rc;
251
252         if (dev->driver)
253                 return -EBUSY;
254
255         rc = nd_uuid_parse(dev, uuid, buf, len);
256         if (rc)
257                 return rc;
258
259         kfree(*uuid_out);
260         *uuid_out = kmemdup(uuid, sizeof(uuid), GFP_KERNEL);
261         if (!(*uuid_out))
262                 return -ENOMEM;
263
264         return 0;
265 }
266
267 ssize_t nd_sector_size_show(unsigned long current_lbasize,
268                 const unsigned long *supported, char *buf)
269 {
270         ssize_t len = 0;
271         int i;
272
273         for (i = 0; supported[i]; i++)
274                 if (current_lbasize == supported[i])
275                         len += sprintf(buf + len, "[%ld] ", supported[i]);
276                 else
277                         len += sprintf(buf + len, "%ld ", supported[i]);
278         len += sprintf(buf + len, "\n");
279         return len;
280 }
281
282 ssize_t nd_sector_size_store(struct device *dev, const char *buf,
283                 unsigned long *current_lbasize, const unsigned long *supported)
284 {
285         unsigned long lbasize;
286         int rc, i;
287
288         if (dev->driver)
289                 return -EBUSY;
290
291         rc = kstrtoul(buf, 0, &lbasize);
292         if (rc)
293                 return rc;
294
295         for (i = 0; supported[i]; i++)
296                 if (lbasize == supported[i])
297                         break;
298
299         if (supported[i]) {
300                 *current_lbasize = lbasize;
301                 return 0;
302         } else {
303                 return -EINVAL;
304         }
305 }
306
307 void __nd_iostat_start(struct bio *bio, unsigned long *start)
308 {
309         struct gendisk *disk = bio->bi_bdev->bd_disk;
310         const int rw = bio_data_dir(bio);
311         int cpu = part_stat_lock();
312
313         *start = jiffies;
314         part_round_stats(cpu, &disk->part0);
315         part_stat_inc(cpu, &disk->part0, ios[rw]);
316         part_stat_add(cpu, &disk->part0, sectors[rw], bio_sectors(bio));
317         part_inc_in_flight(&disk->part0, rw);
318         part_stat_unlock();
319 }
320 EXPORT_SYMBOL(__nd_iostat_start);
321
322 void nd_iostat_end(struct bio *bio, unsigned long start)
323 {
324         struct gendisk *disk = bio->bi_bdev->bd_disk;
325         unsigned long duration = jiffies - start;
326         const int rw = bio_data_dir(bio);
327         int cpu = part_stat_lock();
328
329         part_stat_add(cpu, &disk->part0, ticks[rw], duration);
330         part_round_stats(cpu, &disk->part0);
331         part_dec_in_flight(&disk->part0, rw);
332         part_stat_unlock();
333 }
334 EXPORT_SYMBOL(nd_iostat_end);
335
336 static ssize_t commands_show(struct device *dev,
337                 struct device_attribute *attr, char *buf)
338 {
339         int cmd, len = 0;
340         struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
341         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
342
343         for_each_set_bit(cmd, &nd_desc->cmd_mask, BITS_PER_LONG)
344                 len += sprintf(buf + len, "%s ", nvdimm_bus_cmd_name(cmd));
345         len += sprintf(buf + len, "\n");
346         return len;
347 }
348 static DEVICE_ATTR_RO(commands);
349
350 static const char *nvdimm_bus_provider(struct nvdimm_bus *nvdimm_bus)
351 {
352         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
353         struct device *parent = nvdimm_bus->dev.parent;
354
355         if (nd_desc->provider_name)
356                 return nd_desc->provider_name;
357         else if (parent)
358                 return dev_name(parent);
359         else
360                 return "unknown";
361 }
362
363 static ssize_t provider_show(struct device *dev,
364                 struct device_attribute *attr, char *buf)
365 {
366         struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
367
368         return sprintf(buf, "%s\n", nvdimm_bus_provider(nvdimm_bus));
369 }
370 static DEVICE_ATTR_RO(provider);
371
372 static int flush_namespaces(struct device *dev, void *data)
373 {
374         device_lock(dev);
375         device_unlock(dev);
376         return 0;
377 }
378
379 static int flush_regions_dimms(struct device *dev, void *data)
380 {
381         device_lock(dev);
382         device_unlock(dev);
383         device_for_each_child(dev, NULL, flush_namespaces);
384         return 0;
385 }
386
387 static ssize_t wait_probe_show(struct device *dev,
388                 struct device_attribute *attr, char *buf)
389 {
390         struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
391         struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
392         int rc;
393
394         if (nd_desc->flush_probe) {
395                 rc = nd_desc->flush_probe(nd_desc);
396                 if (rc)
397                         return rc;
398         }
399         nd_synchronize();
400         device_for_each_child(dev, NULL, flush_regions_dimms);
401         return sprintf(buf, "1\n");
402 }
403 static DEVICE_ATTR_RO(wait_probe);
404
405 static struct attribute *nvdimm_bus_attributes[] = {
406         &dev_attr_commands.attr,
407         &dev_attr_wait_probe.attr,
408         &dev_attr_provider.attr,
409         NULL,
410 };
411
412 struct attribute_group nvdimm_bus_attribute_group = {
413         .attrs = nvdimm_bus_attributes,
414 };
415 EXPORT_SYMBOL_GPL(nvdimm_bus_attribute_group);
416
417 static void set_badblock(struct badblocks *bb, sector_t s, int num)
418 {
419         dev_dbg(bb->dev, "Found a poison range (0x%llx, 0x%llx)\n",
420                         (u64) s * 512, (u64) num * 512);
421         /* this isn't an error as the hardware will still throw an exception */
422         if (badblocks_set(bb, s, num, 1))
423                 dev_info_once(bb->dev, "%s: failed for sector %llx\n",
424                                 __func__, (u64) s);
425 }
426
427 /**
428  * __add_badblock_range() - Convert a physical address range to bad sectors
429  * @bb:         badblocks instance to populate
430  * @ns_offset:  namespace offset where the error range begins (in bytes)
431  * @len:        number of bytes of poison to be added
432  *
433  * This assumes that the range provided with (ns_offset, len) is within
434  * the bounds of physical addresses for this namespace, i.e. lies in the
435  * interval [ns_start, ns_start + ns_size)
436  */
437 static void __add_badblock_range(struct badblocks *bb, u64 ns_offset, u64 len)
438 {
439         const unsigned int sector_size = 512;
440         sector_t start_sector;
441         u64 num_sectors;
442         u32 rem;
443
444         start_sector = div_u64(ns_offset, sector_size);
445         num_sectors = div_u64_rem(len, sector_size, &rem);
446         if (rem)
447                 num_sectors++;
448
449         if (unlikely(num_sectors > (u64)INT_MAX)) {
450                 u64 remaining = num_sectors;
451                 sector_t s = start_sector;
452
453                 while (remaining) {
454                         int done = min_t(u64, remaining, INT_MAX);
455
456                         set_badblock(bb, s, done);
457                         remaining -= done;
458                         s += done;
459                 }
460         } else
461                 set_badblock(bb, start_sector, num_sectors);
462 }
463
464 static void badblocks_populate(struct list_head *poison_list,
465                 struct badblocks *bb, const struct resource *res)
466 {
467         struct nd_poison *pl;
468
469         if (list_empty(poison_list))
470                 return;
471
472         list_for_each_entry(pl, poison_list, list) {
473                 u64 pl_end = pl->start + pl->length - 1;
474
475                 /* Discard intervals with no intersection */
476                 if (pl_end < res->start)
477                         continue;
478                 if (pl->start >  res->end)
479                         continue;
480                 /* Deal with any overlap after start of the namespace */
481                 if (pl->start >= res->start) {
482                         u64 start = pl->start;
483                         u64 len;
484
485                         if (pl_end <= res->end)
486                                 len = pl->length;
487                         else
488                                 len = res->start + resource_size(res)
489                                         - pl->start;
490                         __add_badblock_range(bb, start - res->start, len);
491                         continue;
492                 }
493                 /* Deal with overlap for poison starting before the namespace */
494                 if (pl->start < res->start) {
495                         u64 len;
496
497                         if (pl_end < res->end)
498                                 len = pl->start + pl->length - res->start;
499                         else
500                                 len = resource_size(res);
501                         __add_badblock_range(bb, 0, len);
502                 }
503         }
504 }
505
506 /**
507  * nvdimm_badblocks_populate() - Convert a list of poison ranges to badblocks
508  * @region: parent region of the range to interrogate
509  * @bb: badblocks instance to populate
510  * @res: resource range to consider
511  *
512  * The poison list generated during bus initialization may contain
513  * multiple, possibly overlapping physical address ranges.  Compare each
514  * of these ranges to the resource range currently being initialized,
515  * and add badblocks entries for all matching sub-ranges
516  */
517 void nvdimm_badblocks_populate(struct nd_region *nd_region,
518                 struct badblocks *bb, const struct resource *res)
519 {
520         struct nvdimm_bus *nvdimm_bus;
521         struct list_head *poison_list;
522
523         if (!is_nd_pmem(&nd_region->dev)) {
524                 dev_WARN_ONCE(&nd_region->dev, 1,
525                                 "%s only valid for pmem regions\n", __func__);
526                 return;
527         }
528         nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
529         poison_list = &nvdimm_bus->poison_list;
530
531         nvdimm_bus_lock(&nvdimm_bus->dev);
532         badblocks_populate(poison_list, bb, res);
533         nvdimm_bus_unlock(&nvdimm_bus->dev);
534 }
535 EXPORT_SYMBOL_GPL(nvdimm_badblocks_populate);
536
537 static int add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
538 {
539         struct nd_poison *pl;
540
541         pl = kzalloc(sizeof(*pl), GFP_KERNEL);
542         if (!pl)
543                 return -ENOMEM;
544
545         pl->start = addr;
546         pl->length = length;
547         list_add_tail(&pl->list, &nvdimm_bus->poison_list);
548
549         return 0;
550 }
551
552 static int bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
553 {
554         struct nd_poison *pl;
555
556         if (list_empty(&nvdimm_bus->poison_list))
557                 return add_poison(nvdimm_bus, addr, length);
558
559         /*
560          * There is a chance this is a duplicate, check for those first.
561          * This will be the common case as ARS_STATUS returns all known
562          * errors in the SPA space, and we can't query it per region
563          */
564         list_for_each_entry(pl, &nvdimm_bus->poison_list, list)
565                 if (pl->start == addr) {
566                         /* If length has changed, update this list entry */
567                         if (pl->length != length)
568                                 pl->length = length;
569                         return 0;
570                 }
571
572         /*
573          * If not a duplicate or a simple length update, add the entry as is,
574          * as any overlapping ranges will get resolved when the list is consumed
575          * and converted to badblocks
576          */
577         return add_poison(nvdimm_bus, addr, length);
578 }
579
580 int nvdimm_bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
581 {
582         int rc;
583
584         nvdimm_bus_lock(&nvdimm_bus->dev);
585         rc = bus_add_poison(nvdimm_bus, addr, length);
586         nvdimm_bus_unlock(&nvdimm_bus->dev);
587
588         return rc;
589 }
590 EXPORT_SYMBOL_GPL(nvdimm_bus_add_poison);
591
592 #ifdef CONFIG_BLK_DEV_INTEGRITY
593 int nd_integrity_init(struct gendisk *disk, unsigned long meta_size)
594 {
595         struct blk_integrity bi;
596
597         if (meta_size == 0)
598                 return 0;
599
600         memset(&bi, 0, sizeof(bi));
601
602         bi.tuple_size = meta_size;
603         bi.tag_size = meta_size;
604
605         blk_integrity_register(disk, &bi);
606         blk_queue_max_integrity_segments(disk->queue, 1);
607
608         return 0;
609 }
610 EXPORT_SYMBOL(nd_integrity_init);
611
612 #else /* CONFIG_BLK_DEV_INTEGRITY */
613 int nd_integrity_init(struct gendisk *disk, unsigned long meta_size)
614 {
615         return 0;
616 }
617 EXPORT_SYMBOL(nd_integrity_init);
618
619 #endif
620
621 static __init int libnvdimm_init(void)
622 {
623         int rc;
624
625         rc = nvdimm_bus_init();
626         if (rc)
627                 return rc;
628         rc = nvdimm_init();
629         if (rc)
630                 goto err_dimm;
631         rc = nd_region_init();
632         if (rc)
633                 goto err_region;
634         return 0;
635  err_region:
636         nvdimm_exit();
637  err_dimm:
638         nvdimm_bus_exit();
639         return rc;
640 }
641
642 static __exit void libnvdimm_exit(void)
643 {
644         WARN_ON(!list_empty(&nvdimm_bus_list));
645         nd_region_exit();
646         nvdimm_exit();
647         nvdimm_bus_exit();
648         nd_region_devs_exit();
649         nvdimm_devs_exit();
650 }
651
652 MODULE_LICENSE("GPL v2");
653 MODULE_AUTHOR("Intel Corporation");
654 subsys_initcall(libnvdimm_init);
655 module_exit(libnvdimm_exit);