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libnvdimm/pfn: fix fsdax-mode namespace info-block zero-fields
[thirdparty/kernel/stable.git] / drivers / nvdimm / pfn_devs.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright(c) 2013-2016 Intel Corporation. All rights reserved.
4 */
5 #include <linux/memremap.h>
6 #include <linux/blkdev.h>
7 #include <linux/device.h>
8 #include <linux/genhd.h>
9 #include <linux/sizes.h>
10 #include <linux/slab.h>
11 #include <linux/fs.h>
12 #include <linux/mm.h>
13 #include "nd-core.h"
14 #include "pfn.h"
15 #include "nd.h"
16
17 static void nd_pfn_release(struct device *dev)
18 {
19 struct nd_region *nd_region = to_nd_region(dev->parent);
20 struct nd_pfn *nd_pfn = to_nd_pfn(dev);
21
22 dev_dbg(dev, "trace\n");
23 nd_detach_ndns(&nd_pfn->dev, &nd_pfn->ndns);
24 ida_simple_remove(&nd_region->pfn_ida, nd_pfn->id);
25 kfree(nd_pfn->uuid);
26 kfree(nd_pfn);
27 }
28
29 static struct device_type nd_pfn_device_type = {
30 .name = "nd_pfn",
31 .release = nd_pfn_release,
32 };
33
34 bool is_nd_pfn(struct device *dev)
35 {
36 return dev ? dev->type == &nd_pfn_device_type : false;
37 }
38 EXPORT_SYMBOL(is_nd_pfn);
39
40 struct nd_pfn *to_nd_pfn(struct device *dev)
41 {
42 struct nd_pfn *nd_pfn = container_of(dev, struct nd_pfn, dev);
43
44 WARN_ON(!is_nd_pfn(dev));
45 return nd_pfn;
46 }
47 EXPORT_SYMBOL(to_nd_pfn);
48
49 static ssize_t mode_show(struct device *dev,
50 struct device_attribute *attr, char *buf)
51 {
52 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
53
54 switch (nd_pfn->mode) {
55 case PFN_MODE_RAM:
56 return sprintf(buf, "ram\n");
57 case PFN_MODE_PMEM:
58 return sprintf(buf, "pmem\n");
59 default:
60 return sprintf(buf, "none\n");
61 }
62 }
63
64 static ssize_t mode_store(struct device *dev,
65 struct device_attribute *attr, const char *buf, size_t len)
66 {
67 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
68 ssize_t rc = 0;
69
70 device_lock(dev);
71 nvdimm_bus_lock(dev);
72 if (dev->driver)
73 rc = -EBUSY;
74 else {
75 size_t n = len - 1;
76
77 if (strncmp(buf, "pmem\n", n) == 0
78 || strncmp(buf, "pmem", n) == 0) {
79 nd_pfn->mode = PFN_MODE_PMEM;
80 } else if (strncmp(buf, "ram\n", n) == 0
81 || strncmp(buf, "ram", n) == 0)
82 nd_pfn->mode = PFN_MODE_RAM;
83 else if (strncmp(buf, "none\n", n) == 0
84 || strncmp(buf, "none", n) == 0)
85 nd_pfn->mode = PFN_MODE_NONE;
86 else
87 rc = -EINVAL;
88 }
89 dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
90 buf[len - 1] == '\n' ? "" : "\n");
91 nvdimm_bus_unlock(dev);
92 device_unlock(dev);
93
94 return rc ? rc : len;
95 }
96 static DEVICE_ATTR_RW(mode);
97
98 static ssize_t align_show(struct device *dev,
99 struct device_attribute *attr, char *buf)
100 {
101 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
102
103 return sprintf(buf, "%ld\n", nd_pfn->align);
104 }
105
106 static const unsigned long *nd_pfn_supported_alignments(void)
107 {
108 /*
109 * This needs to be a non-static variable because the *_SIZE
110 * macros aren't always constants.
111 */
112 const unsigned long supported_alignments[] = {
113 PAGE_SIZE,
114 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
115 HPAGE_PMD_SIZE,
116 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
117 HPAGE_PUD_SIZE,
118 #endif
119 #endif
120 0,
121 };
122 static unsigned long data[ARRAY_SIZE(supported_alignments)];
123
124 memcpy(data, supported_alignments, sizeof(data));
125
126 return data;
127 }
128
129 static ssize_t align_store(struct device *dev,
130 struct device_attribute *attr, const char *buf, size_t len)
131 {
132 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
133 ssize_t rc;
134
135 device_lock(dev);
136 nvdimm_bus_lock(dev);
137 rc = nd_size_select_store(dev, buf, &nd_pfn->align,
138 nd_pfn_supported_alignments());
139 dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
140 buf[len - 1] == '\n' ? "" : "\n");
141 nvdimm_bus_unlock(dev);
142 device_unlock(dev);
143
144 return rc ? rc : len;
145 }
146 static DEVICE_ATTR_RW(align);
147
148 static ssize_t uuid_show(struct device *dev,
149 struct device_attribute *attr, char *buf)
150 {
151 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
152
153 if (nd_pfn->uuid)
154 return sprintf(buf, "%pUb\n", nd_pfn->uuid);
155 return sprintf(buf, "\n");
156 }
157
158 static ssize_t uuid_store(struct device *dev,
159 struct device_attribute *attr, const char *buf, size_t len)
160 {
161 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
162 ssize_t rc;
163
164 device_lock(dev);
165 rc = nd_uuid_store(dev, &nd_pfn->uuid, buf, len);
166 dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
167 buf[len - 1] == '\n' ? "" : "\n");
168 device_unlock(dev);
169
170 return rc ? rc : len;
171 }
172 static DEVICE_ATTR_RW(uuid);
173
174 static ssize_t namespace_show(struct device *dev,
175 struct device_attribute *attr, char *buf)
176 {
177 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
178 ssize_t rc;
179
180 nvdimm_bus_lock(dev);
181 rc = sprintf(buf, "%s\n", nd_pfn->ndns
182 ? dev_name(&nd_pfn->ndns->dev) : "");
183 nvdimm_bus_unlock(dev);
184 return rc;
185 }
186
187 static ssize_t namespace_store(struct device *dev,
188 struct device_attribute *attr, const char *buf, size_t len)
189 {
190 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
191 ssize_t rc;
192
193 device_lock(dev);
194 nvdimm_bus_lock(dev);
195 rc = nd_namespace_store(dev, &nd_pfn->ndns, buf, len);
196 dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
197 buf[len - 1] == '\n' ? "" : "\n");
198 nvdimm_bus_unlock(dev);
199 device_unlock(dev);
200
201 return rc;
202 }
203 static DEVICE_ATTR_RW(namespace);
204
205 static ssize_t resource_show(struct device *dev,
206 struct device_attribute *attr, char *buf)
207 {
208 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
209 ssize_t rc;
210
211 device_lock(dev);
212 if (dev->driver) {
213 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
214 u64 offset = __le64_to_cpu(pfn_sb->dataoff);
215 struct nd_namespace_common *ndns = nd_pfn->ndns;
216 u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
217 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
218
219 rc = sprintf(buf, "%#llx\n", (unsigned long long) nsio->res.start
220 + start_pad + offset);
221 } else {
222 /* no address to convey if the pfn instance is disabled */
223 rc = -ENXIO;
224 }
225 device_unlock(dev);
226
227 return rc;
228 }
229 static DEVICE_ATTR_RO(resource);
230
231 static ssize_t size_show(struct device *dev,
232 struct device_attribute *attr, char *buf)
233 {
234 struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
235 ssize_t rc;
236
237 device_lock(dev);
238 if (dev->driver) {
239 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
240 u64 offset = __le64_to_cpu(pfn_sb->dataoff);
241 struct nd_namespace_common *ndns = nd_pfn->ndns;
242 u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
243 u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
244 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
245
246 rc = sprintf(buf, "%llu\n", (unsigned long long)
247 resource_size(&nsio->res) - start_pad
248 - end_trunc - offset);
249 } else {
250 /* no size to convey if the pfn instance is disabled */
251 rc = -ENXIO;
252 }
253 device_unlock(dev);
254
255 return rc;
256 }
257 static DEVICE_ATTR_RO(size);
258
259 static ssize_t supported_alignments_show(struct device *dev,
260 struct device_attribute *attr, char *buf)
261 {
262 return nd_size_select_show(0, nd_pfn_supported_alignments(), buf);
263 }
264 static DEVICE_ATTR_RO(supported_alignments);
265
266 static struct attribute *nd_pfn_attributes[] = {
267 &dev_attr_mode.attr,
268 &dev_attr_namespace.attr,
269 &dev_attr_uuid.attr,
270 &dev_attr_align.attr,
271 &dev_attr_resource.attr,
272 &dev_attr_size.attr,
273 &dev_attr_supported_alignments.attr,
274 NULL,
275 };
276
277 static umode_t pfn_visible(struct kobject *kobj, struct attribute *a, int n)
278 {
279 if (a == &dev_attr_resource.attr)
280 return 0400;
281 return a->mode;
282 }
283
284 struct attribute_group nd_pfn_attribute_group = {
285 .attrs = nd_pfn_attributes,
286 .is_visible = pfn_visible,
287 };
288
289 static const struct attribute_group *nd_pfn_attribute_groups[] = {
290 &nd_pfn_attribute_group,
291 &nd_device_attribute_group,
292 &nd_numa_attribute_group,
293 NULL,
294 };
295
296 struct device *nd_pfn_devinit(struct nd_pfn *nd_pfn,
297 struct nd_namespace_common *ndns)
298 {
299 struct device *dev;
300
301 if (!nd_pfn)
302 return NULL;
303
304 nd_pfn->mode = PFN_MODE_NONE;
305 nd_pfn->align = PFN_DEFAULT_ALIGNMENT;
306 dev = &nd_pfn->dev;
307 device_initialize(&nd_pfn->dev);
308 if (ndns && !__nd_attach_ndns(&nd_pfn->dev, ndns, &nd_pfn->ndns)) {
309 dev_dbg(&ndns->dev, "failed, already claimed by %s\n",
310 dev_name(ndns->claim));
311 put_device(dev);
312 return NULL;
313 }
314 return dev;
315 }
316
317 static struct nd_pfn *nd_pfn_alloc(struct nd_region *nd_region)
318 {
319 struct nd_pfn *nd_pfn;
320 struct device *dev;
321
322 nd_pfn = kzalloc(sizeof(*nd_pfn), GFP_KERNEL);
323 if (!nd_pfn)
324 return NULL;
325
326 nd_pfn->id = ida_simple_get(&nd_region->pfn_ida, 0, 0, GFP_KERNEL);
327 if (nd_pfn->id < 0) {
328 kfree(nd_pfn);
329 return NULL;
330 }
331
332 dev = &nd_pfn->dev;
333 dev_set_name(dev, "pfn%d.%d", nd_region->id, nd_pfn->id);
334 dev->groups = nd_pfn_attribute_groups;
335 dev->type = &nd_pfn_device_type;
336 dev->parent = &nd_region->dev;
337
338 return nd_pfn;
339 }
340
341 struct device *nd_pfn_create(struct nd_region *nd_region)
342 {
343 struct nd_pfn *nd_pfn;
344 struct device *dev;
345
346 if (!is_memory(&nd_region->dev))
347 return NULL;
348
349 nd_pfn = nd_pfn_alloc(nd_region);
350 dev = nd_pfn_devinit(nd_pfn, NULL);
351
352 __nd_device_register(dev);
353 return dev;
354 }
355
356 /*
357 * nd_pfn_clear_memmap_errors() clears any errors in the volatile memmap
358 * space associated with the namespace. If the memmap is set to DRAM, then
359 * this is a no-op. Since the memmap area is freshly initialized during
360 * probe, we have an opportunity to clear any badblocks in this area.
361 */
362 static int nd_pfn_clear_memmap_errors(struct nd_pfn *nd_pfn)
363 {
364 struct nd_region *nd_region = to_nd_region(nd_pfn->dev.parent);
365 struct nd_namespace_common *ndns = nd_pfn->ndns;
366 void *zero_page = page_address(ZERO_PAGE(0));
367 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
368 int num_bad, meta_num, rc, bb_present;
369 sector_t first_bad, meta_start;
370 struct nd_namespace_io *nsio;
371
372 if (nd_pfn->mode != PFN_MODE_PMEM)
373 return 0;
374
375 nsio = to_nd_namespace_io(&ndns->dev);
376 meta_start = (SZ_4K + sizeof(*pfn_sb)) >> 9;
377 meta_num = (le64_to_cpu(pfn_sb->dataoff) >> 9) - meta_start;
378
379 do {
380 unsigned long zero_len;
381 u64 nsoff;
382
383 bb_present = badblocks_check(&nd_region->bb, meta_start,
384 meta_num, &first_bad, &num_bad);
385 if (bb_present) {
386 dev_dbg(&nd_pfn->dev, "meta: %x badblocks at %llx\n",
387 num_bad, first_bad);
388 nsoff = ALIGN_DOWN((nd_region->ndr_start
389 + (first_bad << 9)) - nsio->res.start,
390 PAGE_SIZE);
391 zero_len = ALIGN(num_bad << 9, PAGE_SIZE);
392 while (zero_len) {
393 unsigned long chunk = min(zero_len, PAGE_SIZE);
394
395 rc = nvdimm_write_bytes(ndns, nsoff, zero_page,
396 chunk, 0);
397 if (rc)
398 break;
399
400 zero_len -= chunk;
401 nsoff += chunk;
402 }
403 if (rc) {
404 dev_err(&nd_pfn->dev,
405 "error clearing %x badblocks at %llx\n",
406 num_bad, first_bad);
407 return rc;
408 }
409 }
410 } while (bb_present);
411
412 return 0;
413 }
414
415 /**
416 * nd_pfn_validate - read and validate info-block
417 * @nd_pfn: fsdax namespace runtime state / properties
418 * @sig: 'devdax' or 'fsdax' signature
419 *
420 * Upon return the info-block buffer contents (->pfn_sb) are
421 * indeterminate when validation fails, and a coherent info-block
422 * otherwise.
423 */
424 int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
425 {
426 u64 checksum, offset;
427 enum nd_pfn_mode mode;
428 struct nd_namespace_io *nsio;
429 unsigned long align, start_pad;
430 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
431 struct nd_namespace_common *ndns = nd_pfn->ndns;
432 const u8 *parent_uuid = nd_dev_to_uuid(&ndns->dev);
433
434 if (!pfn_sb || !ndns)
435 return -ENODEV;
436
437 if (!is_memory(nd_pfn->dev.parent))
438 return -ENODEV;
439
440 if (nvdimm_read_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb), 0))
441 return -ENXIO;
442
443 if (memcmp(pfn_sb->signature, sig, PFN_SIG_LEN) != 0)
444 return -ENODEV;
445
446 checksum = le64_to_cpu(pfn_sb->checksum);
447 pfn_sb->checksum = 0;
448 if (checksum != nd_sb_checksum((struct nd_gen_sb *) pfn_sb))
449 return -ENODEV;
450 pfn_sb->checksum = cpu_to_le64(checksum);
451
452 if (memcmp(pfn_sb->parent_uuid, parent_uuid, 16) != 0)
453 return -ENODEV;
454
455 if (__le16_to_cpu(pfn_sb->version_minor) < 1) {
456 pfn_sb->start_pad = 0;
457 pfn_sb->end_trunc = 0;
458 }
459
460 if (__le16_to_cpu(pfn_sb->version_minor) < 2)
461 pfn_sb->align = 0;
462
463 switch (le32_to_cpu(pfn_sb->mode)) {
464 case PFN_MODE_RAM:
465 case PFN_MODE_PMEM:
466 break;
467 default:
468 return -ENXIO;
469 }
470
471 align = le32_to_cpu(pfn_sb->align);
472 offset = le64_to_cpu(pfn_sb->dataoff);
473 start_pad = le32_to_cpu(pfn_sb->start_pad);
474 if (align == 0)
475 align = 1UL << ilog2(offset);
476 mode = le32_to_cpu(pfn_sb->mode);
477
478 if (!nd_pfn->uuid) {
479 /*
480 * When probing a namepace via nd_pfn_probe() the uuid
481 * is NULL (see: nd_pfn_devinit()) we init settings from
482 * pfn_sb
483 */
484 nd_pfn->uuid = kmemdup(pfn_sb->uuid, 16, GFP_KERNEL);
485 if (!nd_pfn->uuid)
486 return -ENOMEM;
487 nd_pfn->align = align;
488 nd_pfn->mode = mode;
489 } else {
490 /*
491 * When probing a pfn / dax instance we validate the
492 * live settings against the pfn_sb
493 */
494 if (memcmp(nd_pfn->uuid, pfn_sb->uuid, 16) != 0)
495 return -ENODEV;
496
497 /*
498 * If the uuid validates, but other settings mismatch
499 * return EINVAL because userspace has managed to change
500 * the configuration without specifying new
501 * identification.
502 */
503 if (nd_pfn->align != align || nd_pfn->mode != mode) {
504 dev_err(&nd_pfn->dev,
505 "init failed, settings mismatch\n");
506 dev_dbg(&nd_pfn->dev, "align: %lx:%lx mode: %d:%d\n",
507 nd_pfn->align, align, nd_pfn->mode,
508 mode);
509 return -EINVAL;
510 }
511 }
512
513 if (align > nvdimm_namespace_capacity(ndns)) {
514 dev_err(&nd_pfn->dev, "alignment: %lx exceeds capacity %llx\n",
515 align, nvdimm_namespace_capacity(ndns));
516 return -EINVAL;
517 }
518
519 /*
520 * These warnings are verbose because they can only trigger in
521 * the case where the physical address alignment of the
522 * namespace has changed since the pfn superblock was
523 * established.
524 */
525 nsio = to_nd_namespace_io(&ndns->dev);
526 if (offset >= resource_size(&nsio->res)) {
527 dev_err(&nd_pfn->dev, "pfn array size exceeds capacity of %s\n",
528 dev_name(&ndns->dev));
529 return -EBUSY;
530 }
531
532 if ((align && !IS_ALIGNED(nsio->res.start + offset + start_pad, align))
533 || !IS_ALIGNED(offset, PAGE_SIZE)) {
534 dev_err(&nd_pfn->dev,
535 "bad offset: %#llx dax disabled align: %#lx\n",
536 offset, align);
537 return -ENXIO;
538 }
539
540 return nd_pfn_clear_memmap_errors(nd_pfn);
541 }
542 EXPORT_SYMBOL(nd_pfn_validate);
543
544 int nd_pfn_probe(struct device *dev, struct nd_namespace_common *ndns)
545 {
546 int rc;
547 struct nd_pfn *nd_pfn;
548 struct device *pfn_dev;
549 struct nd_pfn_sb *pfn_sb;
550 struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
551
552 if (ndns->force_raw)
553 return -ENODEV;
554
555 switch (ndns->claim_class) {
556 case NVDIMM_CCLASS_NONE:
557 case NVDIMM_CCLASS_PFN:
558 break;
559 default:
560 return -ENODEV;
561 }
562
563 nvdimm_bus_lock(&ndns->dev);
564 nd_pfn = nd_pfn_alloc(nd_region);
565 pfn_dev = nd_pfn_devinit(nd_pfn, ndns);
566 nvdimm_bus_unlock(&ndns->dev);
567 if (!pfn_dev)
568 return -ENOMEM;
569 pfn_sb = devm_kmalloc(dev, sizeof(*pfn_sb), GFP_KERNEL);
570 nd_pfn = to_nd_pfn(pfn_dev);
571 nd_pfn->pfn_sb = pfn_sb;
572 rc = nd_pfn_validate(nd_pfn, PFN_SIG);
573 dev_dbg(dev, "pfn: %s\n", rc == 0 ? dev_name(pfn_dev) : "<none>");
574 if (rc < 0) {
575 nd_detach_ndns(pfn_dev, &nd_pfn->ndns);
576 put_device(pfn_dev);
577 } else
578 __nd_device_register(pfn_dev);
579
580 return rc;
581 }
582 EXPORT_SYMBOL(nd_pfn_probe);
583
584 static u32 info_block_reserve(void)
585 {
586 return ALIGN(SZ_8K, PAGE_SIZE);
587 }
588
589 /*
590 * We hotplug memory at section granularity, pad the reserved area from
591 * the previous section base to the namespace base address.
592 */
593 static unsigned long init_altmap_base(resource_size_t base)
594 {
595 unsigned long base_pfn = PHYS_PFN(base);
596
597 return PFN_SECTION_ALIGN_DOWN(base_pfn);
598 }
599
600 static unsigned long init_altmap_reserve(resource_size_t base)
601 {
602 unsigned long reserve = info_block_reserve() >> PAGE_SHIFT;
603 unsigned long base_pfn = PHYS_PFN(base);
604
605 reserve += base_pfn - PFN_SECTION_ALIGN_DOWN(base_pfn);
606 return reserve;
607 }
608
609 static int __nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap)
610 {
611 struct resource *res = &pgmap->res;
612 struct vmem_altmap *altmap = &pgmap->altmap;
613 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
614 u64 offset = le64_to_cpu(pfn_sb->dataoff);
615 u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
616 u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
617 u32 reserve = info_block_reserve();
618 struct nd_namespace_common *ndns = nd_pfn->ndns;
619 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
620 resource_size_t base = nsio->res.start + start_pad;
621 struct vmem_altmap __altmap = {
622 .base_pfn = init_altmap_base(base),
623 .reserve = init_altmap_reserve(base),
624 };
625
626 memcpy(res, &nsio->res, sizeof(*res));
627 res->start += start_pad;
628 res->end -= end_trunc;
629
630 if (nd_pfn->mode == PFN_MODE_RAM) {
631 if (offset < reserve)
632 return -EINVAL;
633 nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns);
634 } else if (nd_pfn->mode == PFN_MODE_PMEM) {
635 nd_pfn->npfns = PFN_SECTION_ALIGN_UP((resource_size(res)
636 - offset) / PAGE_SIZE);
637 if (le64_to_cpu(nd_pfn->pfn_sb->npfns) > nd_pfn->npfns)
638 dev_info(&nd_pfn->dev,
639 "number of pfns truncated from %lld to %ld\n",
640 le64_to_cpu(nd_pfn->pfn_sb->npfns),
641 nd_pfn->npfns);
642 memcpy(altmap, &__altmap, sizeof(*altmap));
643 altmap->free = PHYS_PFN(offset - reserve);
644 altmap->alloc = 0;
645 pgmap->flags |= PGMAP_ALTMAP_VALID;
646 } else
647 return -ENXIO;
648
649 return 0;
650 }
651
652 static u64 phys_pmem_align_down(struct nd_pfn *nd_pfn, u64 phys)
653 {
654 return min_t(u64, PHYS_SECTION_ALIGN_DOWN(phys),
655 ALIGN_DOWN(phys, nd_pfn->align));
656 }
657
658 /*
659 * Check if pmem collides with 'System RAM', or other regions when
660 * section aligned. Trim it accordingly.
661 */
662 static void trim_pfn_device(struct nd_pfn *nd_pfn, u32 *start_pad, u32 *end_trunc)
663 {
664 struct nd_namespace_common *ndns = nd_pfn->ndns;
665 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
666 struct nd_region *nd_region = to_nd_region(nd_pfn->dev.parent);
667 const resource_size_t start = nsio->res.start;
668 const resource_size_t end = start + resource_size(&nsio->res);
669 resource_size_t adjust, size;
670
671 *start_pad = 0;
672 *end_trunc = 0;
673
674 adjust = start - PHYS_SECTION_ALIGN_DOWN(start);
675 size = resource_size(&nsio->res) + adjust;
676 if (region_intersects(start - adjust, size, IORESOURCE_SYSTEM_RAM,
677 IORES_DESC_NONE) == REGION_MIXED
678 || nd_region_conflict(nd_region, start - adjust, size))
679 *start_pad = PHYS_SECTION_ALIGN_UP(start) - start;
680
681 /* Now check that end of the range does not collide. */
682 adjust = PHYS_SECTION_ALIGN_UP(end) - end;
683 size = resource_size(&nsio->res) + adjust;
684 if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
685 IORES_DESC_NONE) == REGION_MIXED
686 || !IS_ALIGNED(end, nd_pfn->align)
687 || nd_region_conflict(nd_region, start, size))
688 *end_trunc = end - phys_pmem_align_down(nd_pfn, end);
689 }
690
691 static int nd_pfn_init(struct nd_pfn *nd_pfn)
692 {
693 struct nd_namespace_common *ndns = nd_pfn->ndns;
694 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
695 u32 start_pad, end_trunc, reserve = info_block_reserve();
696 resource_size_t start, size;
697 struct nd_region *nd_region;
698 struct nd_pfn_sb *pfn_sb;
699 unsigned long npfns;
700 phys_addr_t offset;
701 const char *sig;
702 u64 checksum;
703 int rc;
704
705 pfn_sb = devm_kmalloc(&nd_pfn->dev, sizeof(*pfn_sb), GFP_KERNEL);
706 if (!pfn_sb)
707 return -ENOMEM;
708
709 nd_pfn->pfn_sb = pfn_sb;
710 if (is_nd_dax(&nd_pfn->dev))
711 sig = DAX_SIG;
712 else
713 sig = PFN_SIG;
714
715 rc = nd_pfn_validate(nd_pfn, sig);
716 if (rc != -ENODEV)
717 return rc;
718
719 /* no info block, do init */;
720 memset(pfn_sb, 0, sizeof(*pfn_sb));
721
722 nd_region = to_nd_region(nd_pfn->dev.parent);
723 if (nd_region->ro) {
724 dev_info(&nd_pfn->dev,
725 "%s is read-only, unable to init metadata\n",
726 dev_name(&nd_region->dev));
727 return -ENXIO;
728 }
729
730 memset(pfn_sb, 0, sizeof(*pfn_sb));
731
732 trim_pfn_device(nd_pfn, &start_pad, &end_trunc);
733 if (start_pad + end_trunc)
734 dev_info(&nd_pfn->dev, "%s alignment collision, truncate %d bytes\n",
735 dev_name(&ndns->dev), start_pad + end_trunc);
736
737 /*
738 * Note, we use 64 here for the standard size of struct page,
739 * debugging options may cause it to be larger in which case the
740 * implementation will limit the pfns advertised through
741 * ->direct_access() to those that are included in the memmap.
742 */
743 start = nsio->res.start + start_pad;
744 size = resource_size(&nsio->res);
745 npfns = PFN_SECTION_ALIGN_UP((size - start_pad - end_trunc - reserve)
746 / PAGE_SIZE);
747 if (nd_pfn->mode == PFN_MODE_PMEM) {
748 /*
749 * The altmap should be padded out to the block size used
750 * when populating the vmemmap. This *should* be equal to
751 * PMD_SIZE for most architectures.
752 */
753 offset = ALIGN(start + reserve + 64 * npfns,
754 max(nd_pfn->align, PMD_SIZE)) - start;
755 } else if (nd_pfn->mode == PFN_MODE_RAM)
756 offset = ALIGN(start + reserve, nd_pfn->align) - start;
757 else
758 return -ENXIO;
759
760 if (offset + start_pad + end_trunc >= size) {
761 dev_err(&nd_pfn->dev, "%s unable to satisfy requested alignment\n",
762 dev_name(&ndns->dev));
763 return -ENXIO;
764 }
765
766 npfns = (size - offset - start_pad - end_trunc) / SZ_4K;
767 pfn_sb->mode = cpu_to_le32(nd_pfn->mode);
768 pfn_sb->dataoff = cpu_to_le64(offset);
769 pfn_sb->npfns = cpu_to_le64(npfns);
770 memcpy(pfn_sb->signature, sig, PFN_SIG_LEN);
771 memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
772 memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16);
773 pfn_sb->version_major = cpu_to_le16(1);
774 pfn_sb->version_minor = cpu_to_le16(3);
775 pfn_sb->start_pad = cpu_to_le32(start_pad);
776 pfn_sb->end_trunc = cpu_to_le32(end_trunc);
777 pfn_sb->align = cpu_to_le32(nd_pfn->align);
778 checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
779 pfn_sb->checksum = cpu_to_le64(checksum);
780
781 return nvdimm_write_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb), 0);
782 }
783
784 /*
785 * Determine the effective resource range and vmem_altmap from an nd_pfn
786 * instance.
787 */
788 int nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap)
789 {
790 int rc;
791
792 if (!nd_pfn->uuid || !nd_pfn->ndns)
793 return -ENODEV;
794
795 rc = nd_pfn_init(nd_pfn);
796 if (rc)
797 return rc;
798
799 /* we need a valid pfn_sb before we can init a dev_pagemap */
800 return __nvdimm_setup_pfn(nd_pfn, pgmap);
801 }
802 EXPORT_SYMBOL_GPL(nvdimm_setup_pfn);