1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
4 */
5#ifndef __ND_H__
6#define __ND_H__
7#include <linux/libnvdimm.h>
8#include <linux/badblocks.h>
9#include <linux/blkdev.h>
10#include <linux/device.h>
11#include <linux/mutex.h>
12#include <linux/ndctl.h>
13#include <linux/types.h>
14#include <linux/nd.h>
15#include "label.h"
16
17enum {
18 /*
19 * Limits the maximum number of block apertures a dimm can
20 * support and is an input to the geometry/on-disk-format of a
21 * BTT instance
22 */
23 ND_MAX_LANES = 256,
24 INT_LBASIZE_ALIGNMENT = 64,
25 NVDIMM_IO_ATOMIC = 1,
26};
27
28struct nvdimm_drvdata {
29 struct device *dev;
30 int nslabel_size;
31 struct nd_cmd_get_config_size nsarea;
32 void *data;
33 bool cxl;
34 int ns_current, ns_next;
35 struct resource dpa;
36 struct kref kref;
37};
38
39static inline const u8 *nsl_ref_name(struct nvdimm_drvdata *ndd,
40 struct nd_namespace_label *nd_label)
41{
42 if (ndd->cxl)
43 return nd_label->cxl.name;
44 return nd_label->efi.name;
45}
46
47static inline u8 *nsl_get_name(struct nvdimm_drvdata *ndd,
48 struct nd_namespace_label *nd_label, u8 *name)
49{
50 if (ndd->cxl)
51 return memcpy(name, nd_label->cxl.name, NSLABEL_NAME_LEN);
52 return memcpy(name, nd_label->efi.name, NSLABEL_NAME_LEN);
53}
54
55static inline u8 *nsl_set_name(struct nvdimm_drvdata *ndd,
56 struct nd_namespace_label *nd_label, u8 *name)
57{
58 if (!name)
59 return NULL;
60 if (ndd->cxl)
61 return memcpy(nd_label->cxl.name, name, NSLABEL_NAME_LEN);
62 return memcpy(nd_label->efi.name, name, NSLABEL_NAME_LEN);
63}
64
65static inline u32 nsl_get_slot(struct nvdimm_drvdata *ndd,
66 struct nd_namespace_label *nd_label)
67{
68 if (ndd->cxl)
69 return __le32_to_cpu(nd_label->cxl.slot);
70 return __le32_to_cpu(nd_label->efi.slot);
71}
72
73static inline void nsl_set_slot(struct nvdimm_drvdata *ndd,
74 struct nd_namespace_label *nd_label, u32 slot)
75{
76 if (ndd->cxl)
77 nd_label->cxl.slot = __cpu_to_le32(slot);
78 else
79 nd_label->efi.slot = __cpu_to_le32(slot);
80}
81
82static inline u64 nsl_get_checksum(struct nvdimm_drvdata *ndd,
83 struct nd_namespace_label *nd_label)
84{
85 if (ndd->cxl)
86 return __le64_to_cpu(nd_label->cxl.checksum);
87 return __le64_to_cpu(nd_label->efi.checksum);
88}
89
90static inline void nsl_set_checksum(struct nvdimm_drvdata *ndd,
91 struct nd_namespace_label *nd_label,
92 u64 checksum)
93{
94 if (ndd->cxl)
95 nd_label->cxl.checksum = __cpu_to_le64(checksum);
96 else
97 nd_label->efi.checksum = __cpu_to_le64(checksum);
98}
99
100static inline u32 nsl_get_flags(struct nvdimm_drvdata *ndd,
101 struct nd_namespace_label *nd_label)
102{
103 if (ndd->cxl)
104 return __le32_to_cpu(nd_label->cxl.flags);
105 return __le32_to_cpu(nd_label->efi.flags);
106}
107
108static inline void nsl_set_flags(struct nvdimm_drvdata *ndd,
109 struct nd_namespace_label *nd_label, u32 flags)
110{
111 if (ndd->cxl)
112 nd_label->cxl.flags = __cpu_to_le32(flags);
113 else
114 nd_label->efi.flags = __cpu_to_le32(flags);
115}
116
117static inline u64 nsl_get_dpa(struct nvdimm_drvdata *ndd,
118 struct nd_namespace_label *nd_label)
119{
120 if (ndd->cxl)
121 return __le64_to_cpu(nd_label->cxl.dpa);
122 return __le64_to_cpu(nd_label->efi.dpa);
123}
124
125static inline void nsl_set_dpa(struct nvdimm_drvdata *ndd,
126 struct nd_namespace_label *nd_label, u64 dpa)
127{
128 if (ndd->cxl)
129 nd_label->cxl.dpa = __cpu_to_le64(dpa);
130 else
131 nd_label->efi.dpa = __cpu_to_le64(dpa);
132}
133
134static inline u64 nsl_get_rawsize(struct nvdimm_drvdata *ndd,
135 struct nd_namespace_label *nd_label)
136{
137 if (ndd->cxl)
138 return __le64_to_cpu(nd_label->cxl.rawsize);
139 return __le64_to_cpu(nd_label->efi.rawsize);
140}
141
142static inline void nsl_set_rawsize(struct nvdimm_drvdata *ndd,
143 struct nd_namespace_label *nd_label,
144 u64 rawsize)
145{
146 if (ndd->cxl)
147 nd_label->cxl.rawsize = __cpu_to_le64(rawsize);
148 else
149 nd_label->efi.rawsize = __cpu_to_le64(rawsize);
150}
151
152static inline u64 nsl_get_isetcookie(struct nvdimm_drvdata *ndd,
153 struct nd_namespace_label *nd_label)
154{
155 /* WARN future refactor attempts that break this assumption */
156 if (dev_WARN_ONCE(ndd->dev, ndd->cxl,
157 "CXL labels do not use the isetcookie concept\n"))
158 return 0;
159 return __le64_to_cpu(nd_label->efi.isetcookie);
160}
161
162static inline void nsl_set_isetcookie(struct nvdimm_drvdata *ndd,
163 struct nd_namespace_label *nd_label,
164 u64 isetcookie)
165{
166 if (!ndd->cxl)
167 nd_label->efi.isetcookie = __cpu_to_le64(isetcookie);
168}
169
170static inline bool nsl_validate_isetcookie(struct nvdimm_drvdata *ndd,
171 struct nd_namespace_label *nd_label,
172 u64 cookie)
173{
174 /*
175 * Let the EFI and CXL validation comingle, where fields that
176 * don't matter to CXL always validate.
177 */
178 if (ndd->cxl)
179 return true;
180 return cookie == __le64_to_cpu(nd_label->efi.isetcookie);
181}
182
183static inline u16 nsl_get_position(struct nvdimm_drvdata *ndd,
184 struct nd_namespace_label *nd_label)
185{
186 if (ndd->cxl)
187 return __le16_to_cpu(nd_label->cxl.position);
188 return __le16_to_cpu(nd_label->efi.position);
189}
190
191static inline void nsl_set_position(struct nvdimm_drvdata *ndd,
192 struct nd_namespace_label *nd_label,
193 u16 position)
194{
195 if (ndd->cxl)
196 nd_label->cxl.position = __cpu_to_le16(position);
197 else
198 nd_label->efi.position = __cpu_to_le16(position);
199}
200
201static inline u16 nsl_get_nlabel(struct nvdimm_drvdata *ndd,
202 struct nd_namespace_label *nd_label)
203{
204 if (ndd->cxl)
205 return 0;
206 return __le16_to_cpu(nd_label->efi.nlabel);
207}
208
209static inline void nsl_set_nlabel(struct nvdimm_drvdata *ndd,
210 struct nd_namespace_label *nd_label,
211 u16 nlabel)
212{
213 if (!ndd->cxl)
214 nd_label->efi.nlabel = __cpu_to_le16(nlabel);
215}
216
217static inline u16 nsl_get_nrange(struct nvdimm_drvdata *ndd,
218 struct nd_namespace_label *nd_label)
219{
220 if (ndd->cxl)
221 return __le16_to_cpu(nd_label->cxl.nrange);
222 return 1;
223}
224
225static inline void nsl_set_nrange(struct nvdimm_drvdata *ndd,
226 struct nd_namespace_label *nd_label,
227 u16 nrange)
228{
229 if (ndd->cxl)
230 nd_label->cxl.nrange = __cpu_to_le16(nrange);
231}
232
233static inline u64 nsl_get_lbasize(struct nvdimm_drvdata *ndd,
234 struct nd_namespace_label *nd_label)
235{
236 /*
237 * Yes, for some reason the EFI labels convey a massive 64-bit
238 * lbasize, that got fixed for CXL.
239 */
240 if (ndd->cxl)
241 return __le16_to_cpu(nd_label->cxl.lbasize);
242 return __le64_to_cpu(nd_label->efi.lbasize);
243}
244
245static inline void nsl_set_lbasize(struct nvdimm_drvdata *ndd,
246 struct nd_namespace_label *nd_label,
247 u64 lbasize)
248{
249 if (ndd->cxl)
250 nd_label->cxl.lbasize = __cpu_to_le16(lbasize);
251 else
252 nd_label->efi.lbasize = __cpu_to_le64(lbasize);
253}
254
255static inline const uuid_t *nsl_get_uuid(struct nvdimm_drvdata *ndd,
256 struct nd_namespace_label *nd_label,
257 uuid_t *uuid)
258{
259 if (ndd->cxl)
260 import_uuid(dst: uuid, src: nd_label->cxl.uuid);
261 else
262 import_uuid(dst: uuid, src: nd_label->efi.uuid);
263 return uuid;
264}
265
266static inline const uuid_t *nsl_set_uuid(struct nvdimm_drvdata *ndd,
267 struct nd_namespace_label *nd_label,
268 const uuid_t *uuid)
269{
270 if (ndd->cxl)
271 export_uuid(dst: nd_label->cxl.uuid, src: uuid);
272 else
273 export_uuid(dst: nd_label->efi.uuid, src: uuid);
274 return uuid;
275}
276
277static inline bool nsl_uuid_equal(struct nvdimm_drvdata *ndd,
278 struct nd_namespace_label *nd_label,
279 const uuid_t *uuid)
280{
281 uuid_t tmp;
282
283 if (ndd->cxl)
284 import_uuid(dst: &tmp, src: nd_label->cxl.uuid);
285 else
286 import_uuid(dst: &tmp, src: nd_label->efi.uuid);
287 return uuid_equal(u1: &tmp, u2: uuid);
288}
289
290static inline const u8 *nsl_uuid_raw(struct nvdimm_drvdata *ndd,
291 struct nd_namespace_label *nd_label)
292{
293 if (ndd->cxl)
294 return nd_label->cxl.uuid;
295 return nd_label->efi.uuid;
296}
297
298bool nsl_validate_type_guid(struct nvdimm_drvdata *ndd,
299 struct nd_namespace_label *nd_label, guid_t *guid);
300enum nvdimm_claim_class nsl_get_claim_class(struct nvdimm_drvdata *ndd,
301 struct nd_namespace_label *nd_label);
302
303struct nd_region_data {
304 int ns_count;
305 int ns_active;
306 unsigned int hints_shift;
307 void __iomem *flush_wpq[];
308};
309
310static inline void __iomem *ndrd_get_flush_wpq(struct nd_region_data *ndrd,
311 int dimm, int hint)
312{
313 unsigned int num = 1 << ndrd->hints_shift;
314 unsigned int mask = num - 1;
315
316 return ndrd->flush_wpq[dimm * num + (hint & mask)];
317}
318
319static inline void ndrd_set_flush_wpq(struct nd_region_data *ndrd, int dimm,
320 int hint, void __iomem *flush)
321{
322 unsigned int num = 1 << ndrd->hints_shift;
323 unsigned int mask = num - 1;
324
325 ndrd->flush_wpq[dimm * num + (hint & mask)] = flush;
326}
327
328static inline struct nd_namespace_index *to_namespace_index(
329 struct nvdimm_drvdata *ndd, int i)
330{
331 if (i < 0)
332 return NULL;
333
334 return ndd->data + sizeof_namespace_index(ndd) * i;
335}
336
337static inline struct nd_namespace_index *to_current_namespace_index(
338 struct nvdimm_drvdata *ndd)
339{
340 return to_namespace_index(ndd, i: ndd->ns_current);
341}
342
343static inline struct nd_namespace_index *to_next_namespace_index(
344 struct nvdimm_drvdata *ndd)
345{
346 return to_namespace_index(ndd, i: ndd->ns_next);
347}
348
349unsigned sizeof_namespace_label(struct nvdimm_drvdata *ndd);
350
351#define efi_namespace_label_has(ndd, field) \
352 (!ndd->cxl && offsetof(struct nvdimm_efi_label, field) \
353 < sizeof_namespace_label(ndd))
354
355#define nd_dbg_dpa(r, d, res, fmt, arg...) \
356 dev_dbg((r) ? &(r)->dev : (d)->dev, "%s: %.13s: %#llx @ %#llx " fmt, \
357 (r) ? dev_name((d)->dev) : "", res ? res->name : "null", \
358 (unsigned long long) (res ? resource_size(res) : 0), \
359 (unsigned long long) (res ? res->start : 0), ##arg)
360
361#define for_each_dpa_resource(ndd, res) \
362 for (res = (ndd)->dpa.child; res; res = res->sibling)
363
364#define for_each_dpa_resource_safe(ndd, res, next) \
365 for (res = (ndd)->dpa.child, next = res ? res->sibling : NULL; \
366 res; res = next, next = next ? next->sibling : NULL)
367
368struct nd_percpu_lane {
369 int count;
370 spinlock_t lock;
371};
372
373enum nd_label_flags {
374 ND_LABEL_REAP,
375};
376struct nd_label_ent {
377 struct list_head list;
378 unsigned long flags;
379 struct nd_namespace_label *label;
380};
381
382enum nd_mapping_lock_class {
383 ND_MAPPING_CLASS0,
384 ND_MAPPING_UUID_SCAN,
385};
386
387struct nd_mapping {
388 struct nvdimm *nvdimm;
389 u64 start;
390 u64 size;
391 int position;
392 struct list_head labels;
393 struct mutex lock;
394 /*
395 * @ndd is for private use at region enable / disable time for
396 * get_ndd() + put_ndd(), all other nd_mapping to ndd
397 * conversions use to_ndd() which respects enabled state of the
398 * nvdimm.
399 */
400 struct nvdimm_drvdata *ndd;
401};
402
403struct nd_region {
404 struct device dev;
405 struct ida ns_ida;
406 struct ida btt_ida;
407 struct ida pfn_ida;
408 struct ida dax_ida;
409 unsigned long flags;
410 struct device *ns_seed;
411 struct device *btt_seed;
412 struct device *pfn_seed;
413 struct device *dax_seed;
414 unsigned long align;
415 u16 ndr_mappings;
416 u64 ndr_size;
417 u64 ndr_start;
418 int id, num_lanes, ro, numa_node, target_node;
419 void *provider_data;
420 struct kernfs_node *bb_state;
421 struct badblocks bb;
422 struct nd_interleave_set *nd_set;
423 struct nd_percpu_lane __percpu *lane;
424 int (*flush)(struct nd_region *nd_region, struct bio *bio);
425 struct nd_mapping mapping[] __counted_by(ndr_mappings);
426};
427
428static inline bool nsl_validate_nlabel(struct nd_region *nd_region,
429 struct nvdimm_drvdata *ndd,
430 struct nd_namespace_label *nd_label)
431{
432 if (ndd->cxl)
433 return true;
434 return nsl_get_nlabel(ndd, nd_label) == nd_region->ndr_mappings;
435}
436
437/*
438 * Lookup next in the repeating sequence of 01, 10, and 11.
439 */
440static inline unsigned nd_inc_seq(unsigned seq)
441{
442 static const unsigned next[] = { 0, 2, 3, 1 };
443
444 return next[seq & 3];
445}
446
447struct btt;
448struct nd_btt {
449 struct device dev;
450 struct nd_namespace_common *ndns;
451 struct btt *btt;
452 unsigned long lbasize;
453 u64 size;
454 uuid_t *uuid;
455 int id;
456 int initial_offset;
457 u16 version_major;
458 u16 version_minor;
459};
460
461enum nd_pfn_mode {
462 PFN_MODE_NONE,
463 PFN_MODE_RAM,
464 PFN_MODE_PMEM,
465};
466
467struct nd_pfn {
468 int id;
469 uuid_t *uuid;
470 struct device dev;
471 unsigned long align;
472 unsigned long npfns;
473 enum nd_pfn_mode mode;
474 struct nd_pfn_sb *pfn_sb;
475 struct nd_namespace_common *ndns;
476};
477
478struct nd_dax {
479 struct nd_pfn nd_pfn;
480};
481
482static inline u32 nd_info_block_reserve(void)
483{
484 return ALIGN(SZ_8K, PAGE_SIZE);
485}
486
487enum nd_async_mode {
488 ND_SYNC,
489 ND_ASYNC,
490};
491
492int nd_integrity_init(struct gendisk *disk, unsigned long meta_size);
493void wait_nvdimm_bus_probe_idle(struct device *dev);
494void nd_device_register(struct device *dev);
495void nd_device_unregister(struct device *dev, enum nd_async_mode mode);
496void nd_device_notify(struct device *dev, enum nvdimm_event event);
497int nd_uuid_store(struct device *dev, uuid_t **uuid_out, const char *buf,
498 size_t len);
499ssize_t nd_size_select_show(unsigned long current_size,
500 const unsigned long *supported, char *buf);
501ssize_t nd_size_select_store(struct device *dev, const char *buf,
502 unsigned long *current_size, const unsigned long *supported);
503int __init nvdimm_init(void);
504int __init nd_region_init(void);
505int __init nd_label_init(void);
506void nvdimm_exit(void);
507void nd_region_exit(void);
508struct nvdimm;
509extern const struct attribute_group nd_device_attribute_group;
510extern const struct attribute_group nd_numa_attribute_group;
511extern const struct attribute_group *nvdimm_bus_attribute_groups[];
512struct nvdimm_drvdata *to_ndd(struct nd_mapping *nd_mapping);
513int nvdimm_check_config_data(struct device *dev);
514int nvdimm_init_nsarea(struct nvdimm_drvdata *ndd);
515int nvdimm_init_config_data(struct nvdimm_drvdata *ndd);
516int nvdimm_get_config_data(struct nvdimm_drvdata *ndd, void *buf,
517 size_t offset, size_t len);
518int nvdimm_set_config_data(struct nvdimm_drvdata *ndd, size_t offset,
519 void *buf, size_t len);
520long nvdimm_clear_poison(struct device *dev, phys_addr_t phys,
521 unsigned int len);
522void nvdimm_set_labeling(struct device *dev);
523void nvdimm_set_locked(struct device *dev);
524void nvdimm_clear_locked(struct device *dev);
525int nvdimm_security_setup_events(struct device *dev);
526#if IS_ENABLED(CONFIG_NVDIMM_KEYS)
527int nvdimm_security_unlock(struct device *dev);
528#else
529static inline int nvdimm_security_unlock(struct device *dev)
530{
531 return 0;
532}
533#endif
534struct nd_btt *to_nd_btt(struct device *dev);
535
536struct nd_gen_sb {
537 char reserved[SZ_4K - 8];
538 __le64 checksum;
539};
540
541u64 nd_sb_checksum(struct nd_gen_sb *sb);
542#if IS_ENABLED(CONFIG_BTT)
543int nd_btt_probe(struct device *dev, struct nd_namespace_common *ndns);
544bool is_nd_btt(struct device *dev);
545struct device *nd_btt_create(struct nd_region *nd_region);
546#else
547static inline int nd_btt_probe(struct device *dev,
548 struct nd_namespace_common *ndns)
549{
550 return -ENODEV;
551}
552
553static inline bool is_nd_btt(struct device *dev)
554{
555 return false;
556}
557
558static inline struct device *nd_btt_create(struct nd_region *nd_region)
559{
560 return NULL;
561}
562#endif
563
564struct nd_pfn *to_nd_pfn(struct device *dev);
565#if IS_ENABLED(CONFIG_NVDIMM_PFN)
566
567#define MAX_NVDIMM_ALIGN 4
568
569int nd_pfn_probe(struct device *dev, struct nd_namespace_common *ndns);
570bool is_nd_pfn(struct device *dev);
571struct device *nd_pfn_create(struct nd_region *nd_region);
572struct device *nd_pfn_devinit(struct nd_pfn *nd_pfn,
573 struct nd_namespace_common *ndns);
574int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig);
575extern const struct attribute_group *nd_pfn_attribute_groups[];
576#else
577static inline int nd_pfn_probe(struct device *dev,
578 struct nd_namespace_common *ndns)
579{
580 return -ENODEV;
581}
582
583static inline bool is_nd_pfn(struct device *dev)
584{
585 return false;
586}
587
588static inline struct device *nd_pfn_create(struct nd_region *nd_region)
589{
590 return NULL;
591}
592
593static inline int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
594{
595 return -ENODEV;
596}
597#endif
598
599struct nd_dax *to_nd_dax(struct device *dev);
600#if IS_ENABLED(CONFIG_NVDIMM_DAX)
601int nd_dax_probe(struct device *dev, struct nd_namespace_common *ndns);
602bool is_nd_dax(const struct device *dev);
603struct device *nd_dax_create(struct nd_region *nd_region);
604#else
605static inline int nd_dax_probe(struct device *dev,
606 struct nd_namespace_common *ndns)
607{
608 return -ENODEV;
609}
610
611static inline bool is_nd_dax(const struct device *dev)
612{
613 return false;
614}
615
616static inline struct device *nd_dax_create(struct nd_region *nd_region)
617{
618 return NULL;
619}
620#endif
621
622int nd_region_to_nstype(struct nd_region *nd_region);
623int nd_region_register_namespaces(struct nd_region *nd_region, int *err);
624u64 nd_region_interleave_set_cookie(struct nd_region *nd_region,
625 struct nd_namespace_index *nsindex);
626u64 nd_region_interleave_set_altcookie(struct nd_region *nd_region);
627void nvdimm_bus_lock(struct device *dev);
628void nvdimm_bus_unlock(struct device *dev);
629bool is_nvdimm_bus_locked(struct device *dev);
630void nvdimm_check_and_set_ro(struct gendisk *disk);
631void nvdimm_drvdata_release(struct kref *kref);
632void put_ndd(struct nvdimm_drvdata *ndd);
633int nd_label_reserve_dpa(struct nvdimm_drvdata *ndd);
634void nvdimm_free_dpa(struct nvdimm_drvdata *ndd, struct resource *res);
635struct resource *nvdimm_allocate_dpa(struct nvdimm_drvdata *ndd,
636 struct nd_label_id *label_id, resource_size_t start,
637 resource_size_t n);
638resource_size_t nvdimm_namespace_capacity(struct nd_namespace_common *ndns);
639bool nvdimm_namespace_locked(struct nd_namespace_common *ndns);
640struct nd_namespace_common *nvdimm_namespace_common_probe(struct device *dev);
641int nvdimm_namespace_attach_btt(struct nd_namespace_common *ndns);
642int nvdimm_namespace_detach_btt(struct nd_btt *nd_btt);
643const char *nvdimm_namespace_disk_name(struct nd_namespace_common *ndns,
644 char *name);
645unsigned int pmem_sector_size(struct nd_namespace_common *ndns);
646struct range;
647void nvdimm_badblocks_populate(struct nd_region *nd_region,
648 struct badblocks *bb, const struct range *range);
649int devm_namespace_enable(struct device *dev, struct nd_namespace_common *ndns,
650 resource_size_t size);
651void devm_namespace_disable(struct device *dev,
652 struct nd_namespace_common *ndns);
653#if IS_ENABLED(CONFIG_ND_CLAIM)
654/* max struct page size independent of kernel config */
655#define MAX_STRUCT_PAGE_SIZE 64
656int nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap);
657#else
658static inline int nvdimm_setup_pfn(struct nd_pfn *nd_pfn,
659 struct dev_pagemap *pgmap)
660{
661 return -ENXIO;
662}
663#endif
664int nd_region_activate(struct nd_region *nd_region);
665static inline bool is_bad_pmem(struct badblocks *bb, sector_t sector,
666 unsigned int len)
667{
668 if (bb->count) {
669 sector_t first_bad;
670 int num_bad;
671
672 return !!badblocks_check(bb, s: sector, sectors: len / 512, first_bad: &first_bad,
673 bad_sectors: &num_bad);
674 }
675
676 return false;
677}
678const uuid_t *nd_dev_to_uuid(struct device *dev);
679bool pmem_should_map_pages(struct device *dev);
680#endif /* __ND_H__ */
681

source code of linux/drivers/nvdimm/nd.h