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1/*
2 * Copyright(c) 2013-2016 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/memremap.h>
14#include <linux/blkdev.h>
15#include <linux/device.h>
16#include <linux/genhd.h>
17#include <linux/sizes.h>
18#include <linux/slab.h>
19#include <linux/fs.h>
20#include <linux/mm.h>
21#include "nd-core.h"
22#include "pfn.h"
23#include "nd.h"
24
25static void nd_pfn_release(struct device *dev)
26{
27 struct nd_region *nd_region = to_nd_region(dev->parent);
28 struct nd_pfn *nd_pfn = to_nd_pfn(dev);
29
30 dev_dbg(dev, "%s\n", __func__);
31 nd_detach_ndns(&nd_pfn->dev, &nd_pfn->ndns);
32 ida_simple_remove(&nd_region->pfn_ida, nd_pfn->id);
33 kfree(nd_pfn->uuid);
34 kfree(nd_pfn);
35}
36
37static struct device_type nd_pfn_device_type = {
38 .name = "nd_pfn",
39 .release = nd_pfn_release,
40};
41
42bool is_nd_pfn(struct device *dev)
43{
44 return dev ? dev->type == &nd_pfn_device_type : false;
45}
46EXPORT_SYMBOL(is_nd_pfn);
47
48struct nd_pfn *to_nd_pfn(struct device *dev)
49{
50 struct nd_pfn *nd_pfn = container_of(dev, struct nd_pfn, dev);
51
52 WARN_ON(!is_nd_pfn(dev));
53 return nd_pfn;
54}
55EXPORT_SYMBOL(to_nd_pfn);
56
57static ssize_t mode_show(struct device *dev,
58 struct device_attribute *attr, char *buf)
59{
60 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
61
62 switch (nd_pfn->mode) {
63 case PFN_MODE_RAM:
64 return sprintf(buf, "ram\n");
65 case PFN_MODE_PMEM:
66 return sprintf(buf, "pmem\n");
67 default:
68 return sprintf(buf, "none\n");
69 }
70}
71
72static ssize_t mode_store(struct device *dev,
73 struct device_attribute *attr, const char *buf, size_t len)
74{
75 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
76 ssize_t rc = 0;
77
78 device_lock(dev);
79 nvdimm_bus_lock(dev);
80 if (dev->driver)
81 rc = -EBUSY;
82 else {
83 size_t n = len - 1;
84
85 if (strncmp(buf, "pmem\n", n) == 0
86 || strncmp(buf, "pmem", n) == 0) {
87 nd_pfn->mode = PFN_MODE_PMEM;
88 } else if (strncmp(buf, "ram\n", n) == 0
89 || strncmp(buf, "ram", n) == 0)
90 nd_pfn->mode = PFN_MODE_RAM;
91 else if (strncmp(buf, "none\n", n) == 0
92 || strncmp(buf, "none", n) == 0)
93 nd_pfn->mode = PFN_MODE_NONE;
94 else
95 rc = -EINVAL;
96 }
97 dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
98 rc, buf, buf[len - 1] == '\n' ? "" : "\n");
99 nvdimm_bus_unlock(dev);
100 device_unlock(dev);
101
102 return rc ? rc : len;
103}
104static DEVICE_ATTR_RW(mode);
105
106static ssize_t align_show(struct device *dev,
107 struct device_attribute *attr, char *buf)
108{
109 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
110
111 return sprintf(buf, "%ld\n", nd_pfn->align);
112}
113
114static ssize_t __align_store(struct nd_pfn *nd_pfn, const char *buf)
115{
116 unsigned long val;
117 int rc;
118
119 rc = kstrtoul(buf, 0, &val);
120 if (rc)
121 return rc;
122
123 if (!is_power_of_2(val) || val < PAGE_SIZE || val > SZ_1G)
124 return -EINVAL;
125
126 if (nd_pfn->dev.driver)
127 return -EBUSY;
128 else
129 nd_pfn->align = val;
130
131 return 0;
132}
133
134static ssize_t align_store(struct device *dev,
135 struct device_attribute *attr, const char *buf, size_t len)
136{
137 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
138 ssize_t rc;
139
140 device_lock(dev);
141 nvdimm_bus_lock(dev);
142 rc = __align_store(nd_pfn, buf);
143 dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
144 rc, buf, buf[len - 1] == '\n' ? "" : "\n");
145 nvdimm_bus_unlock(dev);
146 device_unlock(dev);
147
148 return rc ? rc : len;
149}
150static DEVICE_ATTR_RW(align);
151
152static ssize_t uuid_show(struct device *dev,
153 struct device_attribute *attr, char *buf)
154{
155 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
156
157 if (nd_pfn->uuid)
158 return sprintf(buf, "%pUb\n", nd_pfn->uuid);
159 return sprintf(buf, "\n");
160}
161
162static ssize_t uuid_store(struct device *dev,
163 struct device_attribute *attr, const char *buf, size_t len)
164{
165 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
166 ssize_t rc;
167
168 device_lock(dev);
169 rc = nd_uuid_store(dev, &nd_pfn->uuid, buf, len);
170 dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
171 rc, buf, buf[len - 1] == '\n' ? "" : "\n");
172 device_unlock(dev);
173
174 return rc ? rc : len;
175}
176static DEVICE_ATTR_RW(uuid);
177
178static ssize_t namespace_show(struct device *dev,
179 struct device_attribute *attr, char *buf)
180{
181 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
182 ssize_t rc;
183
184 nvdimm_bus_lock(dev);
185 rc = sprintf(buf, "%s\n", nd_pfn->ndns
186 ? dev_name(&nd_pfn->ndns->dev) : "");
187 nvdimm_bus_unlock(dev);
188 return rc;
189}
190
191static ssize_t namespace_store(struct device *dev,
192 struct device_attribute *attr, const char *buf, size_t len)
193{
194 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
195 ssize_t rc;
196
197 device_lock(dev);
198 nvdimm_bus_lock(dev);
199 rc = nd_namespace_store(dev, &nd_pfn->ndns, buf, len);
200 dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
201 rc, buf, buf[len - 1] == '\n' ? "" : "\n");
202 nvdimm_bus_unlock(dev);
203 device_unlock(dev);
204
205 return rc;
206}
207static DEVICE_ATTR_RW(namespace);
208
209static ssize_t resource_show(struct device *dev,
210 struct device_attribute *attr, char *buf)
211{
212 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
213 ssize_t rc;
214
215 device_lock(dev);
216 if (dev->driver) {
217 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
218 u64 offset = __le64_to_cpu(pfn_sb->dataoff);
219 struct nd_namespace_common *ndns = nd_pfn->ndns;
220 u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
221 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
222
223 rc = sprintf(buf, "%#llx\n", (unsigned long long) nsio->res.start
224 + start_pad + offset);
225 } else {
226 /* no address to convey if the pfn instance is disabled */
227 rc = -ENXIO;
228 }
229 device_unlock(dev);
230
231 return rc;
232}
233static DEVICE_ATTR_RO(resource);
234
235static ssize_t size_show(struct device *dev,
236 struct device_attribute *attr, char *buf)
237{
238 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
239 ssize_t rc;
240
241 device_lock(dev);
242 if (dev->driver) {
243 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
244 u64 offset = __le64_to_cpu(pfn_sb->dataoff);
245 struct nd_namespace_common *ndns = nd_pfn->ndns;
246 u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
247 u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
248 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
249
250 rc = sprintf(buf, "%llu\n", (unsigned long long)
251 resource_size(&nsio->res) - start_pad
252 - end_trunc - offset);
253 } else {
254 /* no size to convey if the pfn instance is disabled */
255 rc = -ENXIO;
256 }
257 device_unlock(dev);
258
259 return rc;
260}
261static DEVICE_ATTR_RO(size);
262
263static struct attribute *nd_pfn_attributes[] = {
264 &dev_attr_mode.attr,
265 &dev_attr_namespace.attr,
266 &dev_attr_uuid.attr,
267 &dev_attr_align.attr,
268 &dev_attr_resource.attr,
269 &dev_attr_size.attr,
270 NULL,
271};
272
273struct attribute_group nd_pfn_attribute_group = {
274 .attrs = nd_pfn_attributes,
275};
276
277static const struct attribute_group *nd_pfn_attribute_groups[] = {
278 &nd_pfn_attribute_group,
279 &nd_device_attribute_group,
280 &nd_numa_attribute_group,
281 NULL,
282};
283
284struct device *nd_pfn_devinit(struct nd_pfn *nd_pfn,
285 struct nd_namespace_common *ndns)
286{
287 struct device *dev = &nd_pfn->dev;
288
289 if (!nd_pfn)
290 return NULL;
291
292 nd_pfn->mode = PFN_MODE_NONE;
293 nd_pfn->align = HPAGE_SIZE;
294 dev = &nd_pfn->dev;
295 device_initialize(&nd_pfn->dev);
296 if (ndns && !__nd_attach_ndns(&nd_pfn->dev, ndns, &nd_pfn->ndns)) {
297 dev_dbg(&ndns->dev, "%s failed, already claimed by %s\n",
298 __func__, dev_name(ndns->claim));
299 put_device(dev);
300 return NULL;
301 }
302 return dev;
303}
304
305static struct nd_pfn *nd_pfn_alloc(struct nd_region *nd_region)
306{
307 struct nd_pfn *nd_pfn;
308 struct device *dev;
309
310 nd_pfn = kzalloc(sizeof(*nd_pfn), GFP_KERNEL);
311 if (!nd_pfn)
312 return NULL;
313
314 nd_pfn->id = ida_simple_get(&nd_region->pfn_ida, 0, 0, GFP_KERNEL);
315 if (nd_pfn->id < 0) {
316 kfree(nd_pfn);
317 return NULL;
318 }
319
320 dev = &nd_pfn->dev;
321 dev_set_name(dev, "pfn%d.%d", nd_region->id, nd_pfn->id);
322 dev->groups = nd_pfn_attribute_groups;
323 dev->type = &nd_pfn_device_type;
324 dev->parent = &nd_region->dev;
325
326 return nd_pfn;
327}
328
329struct device *nd_pfn_create(struct nd_region *nd_region)
330{
331 struct nd_pfn *nd_pfn;
332 struct device *dev;
333
334 if (!is_nd_pmem(&nd_region->dev))
335 return NULL;
336
337 nd_pfn = nd_pfn_alloc(nd_region);
338 dev = nd_pfn_devinit(nd_pfn, NULL);
339
340 __nd_device_register(dev);
341 return dev;
342}
343
344int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
345{
346 u64 checksum, offset;
347 unsigned long align;
348 enum nd_pfn_mode mode;
349 struct nd_namespace_io *nsio;
350 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
351 struct nd_namespace_common *ndns = nd_pfn->ndns;
352 const u8 *parent_uuid = nd_dev_to_uuid(&ndns->dev);
353
354 if (!pfn_sb || !ndns)
355 return -ENODEV;
356
357 if (!is_nd_pmem(nd_pfn->dev.parent))
358 return -ENODEV;
359
360 if (nvdimm_read_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb)))
361 return -ENXIO;
362
363 if (memcmp(pfn_sb->signature, sig, PFN_SIG_LEN) != 0)
364 return -ENODEV;
365
366 checksum = le64_to_cpu(pfn_sb->checksum);
367 pfn_sb->checksum = 0;
368 if (checksum != nd_sb_checksum((struct nd_gen_sb *) pfn_sb))
369 return -ENODEV;
370 pfn_sb->checksum = cpu_to_le64(checksum);
371
372 if (memcmp(pfn_sb->parent_uuid, parent_uuid, 16) != 0)
373 return -ENODEV;
374
375 if (__le16_to_cpu(pfn_sb->version_minor) < 1) {
376 pfn_sb->start_pad = 0;
377 pfn_sb->end_trunc = 0;
378 }
379
380 if (__le16_to_cpu(pfn_sb->version_minor) < 2)
381 pfn_sb->align = 0;
382
383 switch (le32_to_cpu(pfn_sb->mode)) {
384 case PFN_MODE_RAM:
385 case PFN_MODE_PMEM:
386 break;
387 default:
388 return -ENXIO;
389 }
390
391 align = le32_to_cpu(pfn_sb->align);
392 offset = le64_to_cpu(pfn_sb->dataoff);
393 if (align == 0)
394 align = 1UL << ilog2(offset);
395 mode = le32_to_cpu(pfn_sb->mode);
396
397 if (!nd_pfn->uuid) {
398 /*
399 * When probing a namepace via nd_pfn_probe() the uuid
400 * is NULL (see: nd_pfn_devinit()) we init settings from
401 * pfn_sb
402 */
403 nd_pfn->uuid = kmemdup(pfn_sb->uuid, 16, GFP_KERNEL);
404 if (!nd_pfn->uuid)
405 return -ENOMEM;
406 nd_pfn->align = align;
407 nd_pfn->mode = mode;
408 } else {
409 /*
410 * When probing a pfn / dax instance we validate the
411 * live settings against the pfn_sb
412 */
413 if (memcmp(nd_pfn->uuid, pfn_sb->uuid, 16) != 0)
414 return -ENODEV;
415
416 /*
417 * If the uuid validates, but other settings mismatch
418 * return EINVAL because userspace has managed to change
419 * the configuration without specifying new
420 * identification.
421 */
422 if (nd_pfn->align != align || nd_pfn->mode != mode) {
423 dev_err(&nd_pfn->dev,
424 "init failed, settings mismatch\n");
425 dev_dbg(&nd_pfn->dev, "align: %lx:%lx mode: %d:%d\n",
426 nd_pfn->align, align, nd_pfn->mode,
427 mode);
428 return -EINVAL;
429 }
430 }
431
432 if (align > nvdimm_namespace_capacity(ndns)) {
433 dev_err(&nd_pfn->dev, "alignment: %lx exceeds capacity %llx\n",
434 align, nvdimm_namespace_capacity(ndns));
435 return -EINVAL;
436 }
437
438 /*
439 * These warnings are verbose because they can only trigger in
440 * the case where the physical address alignment of the
441 * namespace has changed since the pfn superblock was
442 * established.
443 */
444 nsio = to_nd_namespace_io(&ndns->dev);
445 if (offset >= resource_size(&nsio->res)) {
446 dev_err(&nd_pfn->dev, "pfn array size exceeds capacity of %s\n",
447 dev_name(&ndns->dev));
448 return -EBUSY;
449 }
450
451 if ((align && !IS_ALIGNED(offset, align))
452 || !IS_ALIGNED(offset, PAGE_SIZE)) {
453 dev_err(&nd_pfn->dev,
454 "bad offset: %#llx dax disabled align: %#lx\n",
455 offset, align);
456 return -ENXIO;
457 }
458
459 return 0;
460}
461EXPORT_SYMBOL(nd_pfn_validate);
462
463int nd_pfn_probe(struct device *dev, struct nd_namespace_common *ndns)
464{
465 int rc;
466 struct nd_pfn *nd_pfn;
467 struct device *pfn_dev;
468 struct nd_pfn_sb *pfn_sb;
469 struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
470
471 if (ndns->force_raw)
472 return -ENODEV;
473
474 nvdimm_bus_lock(&ndns->dev);
475 nd_pfn = nd_pfn_alloc(nd_region);
476 pfn_dev = nd_pfn_devinit(nd_pfn, ndns);
477 nvdimm_bus_unlock(&ndns->dev);
478 if (!pfn_dev)
479 return -ENOMEM;
480 pfn_sb = devm_kzalloc(dev, sizeof(*pfn_sb), GFP_KERNEL);
481 nd_pfn = to_nd_pfn(pfn_dev);
482 nd_pfn->pfn_sb = pfn_sb;
483 rc = nd_pfn_validate(nd_pfn, PFN_SIG);
484 dev_dbg(dev, "%s: pfn: %s\n", __func__,
485 rc == 0 ? dev_name(pfn_dev) : "<none>");
486 if (rc < 0) {
487 __nd_detach_ndns(pfn_dev, &nd_pfn->ndns);
488 put_device(pfn_dev);
489 } else
490 __nd_device_register(pfn_dev);
491
492 return rc;
493}
494EXPORT_SYMBOL(nd_pfn_probe);
495
496/*
497 * We hotplug memory at section granularity, pad the reserved area from
498 * the previous section base to the namespace base address.
499 */
500static unsigned long init_altmap_base(resource_size_t base)
501{
502 unsigned long base_pfn = PHYS_PFN(base);
503
504 return PFN_SECTION_ALIGN_DOWN(base_pfn);
505}
506
507static unsigned long init_altmap_reserve(resource_size_t base)
508{
509 unsigned long reserve = PHYS_PFN(SZ_8K);
510 unsigned long base_pfn = PHYS_PFN(base);
511
512 reserve += base_pfn - PFN_SECTION_ALIGN_DOWN(base_pfn);
513 return reserve;
514}
515
516static struct vmem_altmap *__nvdimm_setup_pfn(struct nd_pfn *nd_pfn,
517 struct resource *res, struct vmem_altmap *altmap)
518{
519 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
520 u64 offset = le64_to_cpu(pfn_sb->dataoff);
521 u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
522 u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
523 struct nd_namespace_common *ndns = nd_pfn->ndns;
524 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
525 resource_size_t base = nsio->res.start + start_pad;
526 struct vmem_altmap __altmap = {
527 .base_pfn = init_altmap_base(base),
528 .reserve = init_altmap_reserve(base),
529 };
530
531 memcpy(res, &nsio->res, sizeof(*res));
532 res->start += start_pad;
533 res->end -= end_trunc;
534
535 if (nd_pfn->mode == PFN_MODE_RAM) {
536 if (offset < SZ_8K)
537 return ERR_PTR(-EINVAL);
538 nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns);
539 altmap = NULL;
540 } else if (nd_pfn->mode == PFN_MODE_PMEM) {
541 nd_pfn->npfns = (resource_size(res) - offset) / PAGE_SIZE;
542 if (le64_to_cpu(nd_pfn->pfn_sb->npfns) > nd_pfn->npfns)
543 dev_info(&nd_pfn->dev,
544 "number of pfns truncated from %lld to %ld\n",
545 le64_to_cpu(nd_pfn->pfn_sb->npfns),
546 nd_pfn->npfns);
547 memcpy(altmap, &__altmap, sizeof(*altmap));
548 altmap->free = PHYS_PFN(offset - SZ_8K);
549 altmap->alloc = 0;
550 } else
551 return ERR_PTR(-ENXIO);
552
553 return altmap;
554}
555
556static int nd_pfn_init(struct nd_pfn *nd_pfn)
557{
558 u32 dax_label_reserve = is_nd_dax(&nd_pfn->dev) ? SZ_128K : 0;
559 struct nd_namespace_common *ndns = nd_pfn->ndns;
560 u32 start_pad = 0, end_trunc = 0;
561 resource_size_t start, size;
562 struct nd_namespace_io *nsio;
563 struct nd_region *nd_region;
564 struct nd_pfn_sb *pfn_sb;
565 unsigned long npfns;
566 phys_addr_t offset;
567 const char *sig;
568 u64 checksum;
569 int rc;
570
571 pfn_sb = devm_kzalloc(&nd_pfn->dev, sizeof(*pfn_sb), GFP_KERNEL);
572 if (!pfn_sb)
573 return -ENOMEM;
574
575 nd_pfn->pfn_sb = pfn_sb;
576 if (is_nd_dax(&nd_pfn->dev))
577 sig = DAX_SIG;
578 else
579 sig = PFN_SIG;
580 rc = nd_pfn_validate(nd_pfn, sig);
581 if (rc != -ENODEV)
582 return rc;
583
584 /* no info block, do init */;
585 nd_region = to_nd_region(nd_pfn->dev.parent);
586 if (nd_region->ro) {
587 dev_info(&nd_pfn->dev,
588 "%s is read-only, unable to init metadata\n",
589 dev_name(&nd_region->dev));
590 return -ENXIO;
591 }
592
593 memset(pfn_sb, 0, sizeof(*pfn_sb));
594
595 /*
596 * Check if pmem collides with 'System RAM' when section aligned and
597 * trim it accordingly
598 */
599 nsio = to_nd_namespace_io(&ndns->dev);
600 start = PHYS_SECTION_ALIGN_DOWN(nsio->res.start);
601 size = resource_size(&nsio->res);
602 if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
603 IORES_DESC_NONE) == REGION_MIXED) {
604 start = nsio->res.start;
605 start_pad = PHYS_SECTION_ALIGN_UP(start) - start;
606 }
607
608 start = nsio->res.start;
609 size = PHYS_SECTION_ALIGN_UP(start + size) - start;
610 if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
611 IORES_DESC_NONE) == REGION_MIXED) {
612 size = resource_size(&nsio->res);
613 end_trunc = start + size - PHYS_SECTION_ALIGN_DOWN(start + size);
614 }
615
616 if (start_pad + end_trunc)
617 dev_info(&nd_pfn->dev, "%s section collision, truncate %d bytes\n",
618 dev_name(&ndns->dev), start_pad + end_trunc);
619
620 /*
621 * Note, we use 64 here for the standard size of struct page,
622 * debugging options may cause it to be larger in which case the
623 * implementation will limit the pfns advertised through
624 * ->direct_access() to those that are included in the memmap.
625 */
626 start += start_pad;
627 size = resource_size(&nsio->res);
628 npfns = (size - start_pad - end_trunc - SZ_8K) / SZ_4K;
629 if (nd_pfn->mode == PFN_MODE_PMEM) {
630 /*
631 * vmemmap_populate_hugepages() allocates the memmap array in
632 * HPAGE_SIZE chunks.
633 */
634 offset = ALIGN(start + SZ_8K + 64 * npfns + dax_label_reserve,
635 max(nd_pfn->align, HPAGE_SIZE)) - start;
636 } else if (nd_pfn->mode == PFN_MODE_RAM)
637 offset = ALIGN(start + SZ_8K + dax_label_reserve,
638 nd_pfn->align) - start;
639 else
640 return -ENXIO;
641
642 if (offset + start_pad + end_trunc >= size) {
643 dev_err(&nd_pfn->dev, "%s unable to satisfy requested alignment\n",
644 dev_name(&ndns->dev));
645 return -ENXIO;
646 }
647
648 npfns = (size - offset - start_pad - end_trunc) / SZ_4K;
649 pfn_sb->mode = cpu_to_le32(nd_pfn->mode);
650 pfn_sb->dataoff = cpu_to_le64(offset);
651 pfn_sb->npfns = cpu_to_le64(npfns);
652 memcpy(pfn_sb->signature, sig, PFN_SIG_LEN);
653 memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
654 memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16);
655 pfn_sb->version_major = cpu_to_le16(1);
656 pfn_sb->version_minor = cpu_to_le16(2);
657 pfn_sb->start_pad = cpu_to_le32(start_pad);
658 pfn_sb->end_trunc = cpu_to_le32(end_trunc);
659 pfn_sb->align = cpu_to_le32(nd_pfn->align);
660 checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
661 pfn_sb->checksum = cpu_to_le64(checksum);
662
663 return nvdimm_write_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb));
664}
665
666/*
667 * Determine the effective resource range and vmem_altmap from an nd_pfn
668 * instance.
669 */
670struct vmem_altmap *nvdimm_setup_pfn(struct nd_pfn *nd_pfn,
671 struct resource *res, struct vmem_altmap *altmap)
672{
673 int rc;
674
675 if (!nd_pfn->uuid || !nd_pfn->ndns)
676 return ERR_PTR(-ENODEV);
677
678 rc = nd_pfn_init(nd_pfn);
679 if (rc)
680 return ERR_PTR(rc);
681
682 /* we need a valid pfn_sb before we can init a vmem_altmap */
683 return __nvdimm_setup_pfn(nd_pfn, res, altmap);
684}
685EXPORT_SYMBOL_GPL(nvdimm_setup_pfn);