1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Persistent Memory Driver 4 * 5 * Copyright (c) 2014-2015, Intel Corporation. 6 * Copyright (c) 2015, Christoph Hellwig <hch@lst.de>. 7 * Copyright (c) 2015, Boaz Harrosh <boaz@plexistor.com>. 8 */ 9 10 #include <asm/cacheflush.h> 11 #include <linux/blkdev.h> 12 #include <linux/hdreg.h> 13 #include <linux/init.h> 14 #include <linux/platform_device.h> 15 #include <linux/set_memory.h> 16 #include <linux/module.h> 17 #include <linux/moduleparam.h> 18 #include <linux/badblocks.h> 19 #include <linux/memremap.h> 20 #include <linux/vmalloc.h> 21 #include <linux/blk-mq.h> 22 #include <linux/pfn_t.h> 23 #include <linux/slab.h> 24 #include <linux/uio.h> 25 #include <linux/dax.h> 26 #include <linux/nd.h> 27 #include <linux/backing-dev.h> 28 #include "pmem.h" 29 #include "pfn.h" 30 #include "nd.h" 31 #include "nd-core.h" 32 33 static struct device *to_dev(struct pmem_device *pmem) 34 { 35 /* 36 * nvdimm bus services need a 'dev' parameter, and we record the device 37 * at init in bb.dev. 38 */ 39 return pmem->bb.dev; 40 } 41 42 static struct nd_region *to_region(struct pmem_device *pmem) 43 { 44 return to_nd_region(to_dev(pmem)->parent); 45 } 46 47 static void hwpoison_clear(struct pmem_device *pmem, 48 phys_addr_t phys, unsigned int len) 49 { 50 unsigned long pfn_start, pfn_end, pfn; 51 52 /* only pmem in the linear map supports HWPoison */ 53 if (is_vmalloc_addr(pmem->virt_addr)) 54 return; 55 56 pfn_start = PHYS_PFN(phys); 57 pfn_end = pfn_start + PHYS_PFN(len); 58 for (pfn = pfn_start; pfn < pfn_end; pfn++) { 59 struct page *page = pfn_to_page(pfn); 60 61 /* 62 * Note, no need to hold a get_dev_pagemap() reference 63 * here since we're in the driver I/O path and 64 * outstanding I/O requests pin the dev_pagemap. 65 */ 66 if (test_and_clear_pmem_poison(page)) 67 clear_mce_nospec(pfn); 68 } 69 } 70 71 static blk_status_t pmem_clear_poison(struct pmem_device *pmem, 72 phys_addr_t offset, unsigned int len) 73 { 74 struct device *dev = to_dev(pmem); 75 sector_t sector; 76 long cleared; 77 blk_status_t rc = BLK_STS_OK; 78 79 sector = (offset - pmem->data_offset) / 512; 80 81 cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len); 82 if (cleared < len) 83 rc = BLK_STS_IOERR; 84 if (cleared > 0 && cleared / 512) { 85 hwpoison_clear(pmem, pmem->phys_addr + offset, cleared); 86 cleared /= 512; 87 dev_dbg(dev, "%#llx clear %ld sector%s\n", 88 (unsigned long long) sector, cleared, 89 cleared > 1 ? "s" : ""); 90 badblocks_clear(&pmem->bb, sector, cleared); 91 if (pmem->bb_state) 92 sysfs_notify_dirent(pmem->bb_state); 93 } 94 95 arch_invalidate_pmem(pmem->virt_addr + offset, len); 96 97 return rc; 98 } 99 100 static void write_pmem(void *pmem_addr, struct page *page, 101 unsigned int off, unsigned int len) 102 { 103 unsigned int chunk; 104 void *mem; 105 106 while (len) { 107 mem = kmap_atomic(page); 108 chunk = min_t(unsigned int, len, PAGE_SIZE - off); 109 memcpy_flushcache(pmem_addr, mem + off, chunk); 110 kunmap_atomic(mem); 111 len -= chunk; 112 off = 0; 113 page++; 114 pmem_addr += chunk; 115 } 116 } 117 118 static blk_status_t read_pmem(struct page *page, unsigned int off, 119 void *pmem_addr, unsigned int len) 120 { 121 unsigned int chunk; 122 unsigned long rem; 123 void *mem; 124 125 while (len) { 126 mem = kmap_atomic(page); 127 chunk = min_t(unsigned int, len, PAGE_SIZE - off); 128 rem = memcpy_mcsafe(mem + off, pmem_addr, chunk); 129 kunmap_atomic(mem); 130 if (rem) 131 return BLK_STS_IOERR; 132 len -= chunk; 133 off = 0; 134 page++; 135 pmem_addr += chunk; 136 } 137 return BLK_STS_OK; 138 } 139 140 static blk_status_t pmem_do_bvec(struct pmem_device *pmem, struct page *page, 141 unsigned int len, unsigned int off, unsigned int op, 142 sector_t sector) 143 { 144 blk_status_t rc = BLK_STS_OK; 145 bool bad_pmem = false; 146 phys_addr_t pmem_off = sector * 512 + pmem->data_offset; 147 void *pmem_addr = pmem->virt_addr + pmem_off; 148 149 if (unlikely(is_bad_pmem(&pmem->bb, sector, len))) 150 bad_pmem = true; 151 152 if (!op_is_write(op)) { 153 if (unlikely(bad_pmem)) 154 rc = BLK_STS_IOERR; 155 else { 156 rc = read_pmem(page, off, pmem_addr, len); 157 flush_dcache_page(page); 158 } 159 } else { 160 /* 161 * Note that we write the data both before and after 162 * clearing poison. The write before clear poison 163 * handles situations where the latest written data is 164 * preserved and the clear poison operation simply marks 165 * the address range as valid without changing the data. 166 * In this case application software can assume that an 167 * interrupted write will either return the new good 168 * data or an error. 169 * 170 * However, if pmem_clear_poison() leaves the data in an 171 * indeterminate state we need to perform the write 172 * after clear poison. 173 */ 174 flush_dcache_page(page); 175 write_pmem(pmem_addr, page, off, len); 176 if (unlikely(bad_pmem)) { 177 rc = pmem_clear_poison(pmem, pmem_off, len); 178 write_pmem(pmem_addr, page, off, len); 179 } 180 } 181 182 return rc; 183 } 184 185 static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio) 186 { 187 blk_status_t rc = 0; 188 bool do_acct; 189 unsigned long start; 190 struct bio_vec bvec; 191 struct bvec_iter iter; 192 struct pmem_device *pmem = q->queuedata; 193 struct nd_region *nd_region = to_region(pmem); 194 195 if (bio->bi_opf & REQ_PREFLUSH) 196 nvdimm_flush(nd_region); 197 198 do_acct = nd_iostat_start(bio, &start); 199 bio_for_each_segment(bvec, bio, iter) { 200 rc = pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len, 201 bvec.bv_offset, bio_op(bio), iter.bi_sector); 202 if (rc) { 203 bio->bi_status = rc; 204 break; 205 } 206 } 207 if (do_acct) 208 nd_iostat_end(bio, start); 209 210 if (bio->bi_opf & REQ_FUA) 211 nvdimm_flush(nd_region); 212 213 bio_endio(bio); 214 return BLK_QC_T_NONE; 215 } 216 217 static int pmem_rw_page(struct block_device *bdev, sector_t sector, 218 struct page *page, unsigned int op) 219 { 220 struct pmem_device *pmem = bdev->bd_queue->queuedata; 221 blk_status_t rc; 222 223 rc = pmem_do_bvec(pmem, page, hpage_nr_pages(page) * PAGE_SIZE, 224 0, op, sector); 225 226 /* 227 * The ->rw_page interface is subtle and tricky. The core 228 * retries on any error, so we can only invoke page_endio() in 229 * the successful completion case. Otherwise, we'll see crashes 230 * caused by double completion. 231 */ 232 if (rc == 0) 233 page_endio(page, op_is_write(op), 0); 234 235 return blk_status_to_errno(rc); 236 } 237 238 /* see "strong" declaration in tools/testing/nvdimm/pmem-dax.c */ 239 __weak long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff, 240 long nr_pages, void **kaddr, pfn_t *pfn) 241 { 242 resource_size_t offset = PFN_PHYS(pgoff) + pmem->data_offset; 243 244 if (unlikely(is_bad_pmem(&pmem->bb, PFN_PHYS(pgoff) / 512, 245 PFN_PHYS(nr_pages)))) 246 return -EIO; 247 248 if (kaddr) 249 *kaddr = pmem->virt_addr + offset; 250 if (pfn) 251 *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags); 252 253 /* 254 * If badblocks are present, limit known good range to the 255 * requested range. 256 */ 257 if (unlikely(pmem->bb.count)) 258 return nr_pages; 259 return PHYS_PFN(pmem->size - pmem->pfn_pad - offset); 260 } 261 262 static const struct block_device_operations pmem_fops = { 263 .owner = THIS_MODULE, 264 .rw_page = pmem_rw_page, 265 .revalidate_disk = nvdimm_revalidate_disk, 266 }; 267 268 static long pmem_dax_direct_access(struct dax_device *dax_dev, 269 pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn) 270 { 271 struct pmem_device *pmem = dax_get_private(dax_dev); 272 273 return __pmem_direct_access(pmem, pgoff, nr_pages, kaddr, pfn); 274 } 275 276 /* 277 * Use the 'no check' versions of copy_from_iter_flushcache() and 278 * copy_to_iter_mcsafe() to bypass HARDENED_USERCOPY overhead. Bounds 279 * checking, both file offset and device offset, is handled by 280 * dax_iomap_actor() 281 */ 282 static size_t pmem_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, 283 void *addr, size_t bytes, struct iov_iter *i) 284 { 285 return _copy_from_iter_flushcache(addr, bytes, i); 286 } 287 288 static size_t pmem_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, 289 void *addr, size_t bytes, struct iov_iter *i) 290 { 291 return _copy_to_iter_mcsafe(addr, bytes, i); 292 } 293 294 static const struct dax_operations pmem_dax_ops = { 295 .direct_access = pmem_dax_direct_access, 296 .dax_supported = generic_fsdax_supported, 297 .copy_from_iter = pmem_copy_from_iter, 298 .copy_to_iter = pmem_copy_to_iter, 299 }; 300 301 static const struct attribute_group *pmem_attribute_groups[] = { 302 &dax_attribute_group, 303 NULL, 304 }; 305 306 static void __pmem_release_queue(struct percpu_ref *ref) 307 { 308 struct request_queue *q; 309 310 q = container_of(ref, typeof(*q), q_usage_counter); 311 blk_cleanup_queue(q); 312 } 313 314 static void pmem_release_queue(void *ref) 315 { 316 __pmem_release_queue(ref); 317 } 318 319 static void pmem_freeze_queue(struct percpu_ref *ref) 320 { 321 struct request_queue *q; 322 323 q = container_of(ref, typeof(*q), q_usage_counter); 324 blk_freeze_queue_start(q); 325 } 326 327 static void pmem_release_disk(void *__pmem) 328 { 329 struct pmem_device *pmem = __pmem; 330 331 kill_dax(pmem->dax_dev); 332 put_dax(pmem->dax_dev); 333 del_gendisk(pmem->disk); 334 put_disk(pmem->disk); 335 } 336 337 static void pmem_release_pgmap_ops(void *__pgmap) 338 { 339 dev_pagemap_put_ops(); 340 } 341 342 static void fsdax_pagefree(struct page *page, void *data) 343 { 344 wake_up_var(&page->_refcount); 345 } 346 347 static int setup_pagemap_fsdax(struct device *dev, struct dev_pagemap *pgmap) 348 { 349 dev_pagemap_get_ops(); 350 if (devm_add_action_or_reset(dev, pmem_release_pgmap_ops, pgmap)) 351 return -ENOMEM; 352 pgmap->type = MEMORY_DEVICE_FS_DAX; 353 pgmap->page_free = fsdax_pagefree; 354 355 return 0; 356 } 357 358 static int pmem_attach_disk(struct device *dev, 359 struct nd_namespace_common *ndns) 360 { 361 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev); 362 struct nd_region *nd_region = to_nd_region(dev->parent); 363 int nid = dev_to_node(dev), fua; 364 struct resource *res = &nsio->res; 365 struct resource bb_res; 366 struct nd_pfn *nd_pfn = NULL; 367 struct dax_device *dax_dev; 368 struct nd_pfn_sb *pfn_sb; 369 struct pmem_device *pmem; 370 struct request_queue *q; 371 struct device *gendev; 372 struct gendisk *disk; 373 void *addr; 374 int rc; 375 376 pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL); 377 if (!pmem) 378 return -ENOMEM; 379 380 /* while nsio_rw_bytes is active, parse a pfn info block if present */ 381 if (is_nd_pfn(dev)) { 382 nd_pfn = to_nd_pfn(dev); 383 rc = nvdimm_setup_pfn(nd_pfn, &pmem->pgmap); 384 if (rc) 385 return rc; 386 } 387 388 /* we're attaching a block device, disable raw namespace access */ 389 devm_nsio_disable(dev, nsio); 390 391 dev_set_drvdata(dev, pmem); 392 pmem->phys_addr = res->start; 393 pmem->size = resource_size(res); 394 fua = nvdimm_has_flush(nd_region); 395 if (!IS_ENABLED(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) || fua < 0) { 396 dev_warn(dev, "unable to guarantee persistence of writes\n"); 397 fua = 0; 398 } 399 400 if (!devm_request_mem_region(dev, res->start, resource_size(res), 401 dev_name(&ndns->dev))) { 402 dev_warn(dev, "could not reserve region %pR\n", res); 403 return -EBUSY; 404 } 405 406 q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev)); 407 if (!q) 408 return -ENOMEM; 409 410 pmem->pfn_flags = PFN_DEV; 411 pmem->pgmap.ref = &q->q_usage_counter; 412 pmem->pgmap.kill = pmem_freeze_queue; 413 pmem->pgmap.cleanup = __pmem_release_queue; 414 if (is_nd_pfn(dev)) { 415 if (setup_pagemap_fsdax(dev, &pmem->pgmap)) 416 return -ENOMEM; 417 addr = devm_memremap_pages(dev, &pmem->pgmap); 418 pfn_sb = nd_pfn->pfn_sb; 419 pmem->data_offset = le64_to_cpu(pfn_sb->dataoff); 420 pmem->pfn_pad = resource_size(res) - 421 resource_size(&pmem->pgmap.res); 422 pmem->pfn_flags |= PFN_MAP; 423 memcpy(&bb_res, &pmem->pgmap.res, sizeof(bb_res)); 424 bb_res.start += pmem->data_offset; 425 } else if (pmem_should_map_pages(dev)) { 426 memcpy(&pmem->pgmap.res, &nsio->res, sizeof(pmem->pgmap.res)); 427 pmem->pgmap.altmap_valid = false; 428 if (setup_pagemap_fsdax(dev, &pmem->pgmap)) 429 return -ENOMEM; 430 addr = devm_memremap_pages(dev, &pmem->pgmap); 431 pmem->pfn_flags |= PFN_MAP; 432 memcpy(&bb_res, &pmem->pgmap.res, sizeof(bb_res)); 433 } else { 434 if (devm_add_action_or_reset(dev, pmem_release_queue, 435 &q->q_usage_counter)) 436 return -ENOMEM; 437 addr = devm_memremap(dev, pmem->phys_addr, 438 pmem->size, ARCH_MEMREMAP_PMEM); 439 memcpy(&bb_res, &nsio->res, sizeof(bb_res)); 440 } 441 442 if (IS_ERR(addr)) 443 return PTR_ERR(addr); 444 pmem->virt_addr = addr; 445 446 blk_queue_write_cache(q, true, fua); 447 blk_queue_make_request(q, pmem_make_request); 448 blk_queue_physical_block_size(q, PAGE_SIZE); 449 blk_queue_logical_block_size(q, pmem_sector_size(ndns)); 450 blk_queue_max_hw_sectors(q, UINT_MAX); 451 blk_queue_flag_set(QUEUE_FLAG_NONROT, q); 452 if (pmem->pfn_flags & PFN_MAP) 453 blk_queue_flag_set(QUEUE_FLAG_DAX, q); 454 q->queuedata = pmem; 455 456 disk = alloc_disk_node(0, nid); 457 if (!disk) 458 return -ENOMEM; 459 pmem->disk = disk; 460 461 disk->fops = &pmem_fops; 462 disk->queue = q; 463 disk->flags = GENHD_FL_EXT_DEVT; 464 disk->queue->backing_dev_info->capabilities |= BDI_CAP_SYNCHRONOUS_IO; 465 nvdimm_namespace_disk_name(ndns, disk->disk_name); 466 set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset) 467 / 512); 468 if (devm_init_badblocks(dev, &pmem->bb)) 469 return -ENOMEM; 470 nvdimm_badblocks_populate(nd_region, &pmem->bb, &bb_res); 471 disk->bb = &pmem->bb; 472 473 dax_dev = alloc_dax(pmem, disk->disk_name, &pmem_dax_ops); 474 if (!dax_dev) { 475 put_disk(disk); 476 return -ENOMEM; 477 } 478 dax_write_cache(dax_dev, nvdimm_has_cache(nd_region)); 479 pmem->dax_dev = dax_dev; 480 481 gendev = disk_to_dev(disk); 482 gendev->groups = pmem_attribute_groups; 483 484 device_add_disk(dev, disk, NULL); 485 if (devm_add_action_or_reset(dev, pmem_release_disk, pmem)) 486 return -ENOMEM; 487 488 revalidate_disk(disk); 489 490 pmem->bb_state = sysfs_get_dirent(disk_to_dev(disk)->kobj.sd, 491 "badblocks"); 492 if (!pmem->bb_state) 493 dev_warn(dev, "'badblocks' notification disabled\n"); 494 495 return 0; 496 } 497 498 static int nd_pmem_probe(struct device *dev) 499 { 500 struct nd_namespace_common *ndns; 501 502 ndns = nvdimm_namespace_common_probe(dev); 503 if (IS_ERR(ndns)) 504 return PTR_ERR(ndns); 505 506 if (devm_nsio_enable(dev, to_nd_namespace_io(&ndns->dev))) 507 return -ENXIO; 508 509 if (is_nd_btt(dev)) 510 return nvdimm_namespace_attach_btt(ndns); 511 512 if (is_nd_pfn(dev)) 513 return pmem_attach_disk(dev, ndns); 514 515 /* if we find a valid info-block we'll come back as that personality */ 516 if (nd_btt_probe(dev, ndns) == 0 || nd_pfn_probe(dev, ndns) == 0 517 || nd_dax_probe(dev, ndns) == 0) 518 return -ENXIO; 519 520 /* ...otherwise we're just a raw pmem device */ 521 return pmem_attach_disk(dev, ndns); 522 } 523 524 static int nd_pmem_remove(struct device *dev) 525 { 526 struct pmem_device *pmem = dev_get_drvdata(dev); 527 528 if (is_nd_btt(dev)) 529 nvdimm_namespace_detach_btt(to_nd_btt(dev)); 530 else { 531 /* 532 * Note, this assumes device_lock() context to not race 533 * nd_pmem_notify() 534 */ 535 sysfs_put(pmem->bb_state); 536 pmem->bb_state = NULL; 537 } 538 nvdimm_flush(to_nd_region(dev->parent)); 539 540 return 0; 541 } 542 543 static void nd_pmem_shutdown(struct device *dev) 544 { 545 nvdimm_flush(to_nd_region(dev->parent)); 546 } 547 548 static void nd_pmem_notify(struct device *dev, enum nvdimm_event event) 549 { 550 struct nd_region *nd_region; 551 resource_size_t offset = 0, end_trunc = 0; 552 struct nd_namespace_common *ndns; 553 struct nd_namespace_io *nsio; 554 struct resource res; 555 struct badblocks *bb; 556 struct kernfs_node *bb_state; 557 558 if (event != NVDIMM_REVALIDATE_POISON) 559 return; 560 561 if (is_nd_btt(dev)) { 562 struct nd_btt *nd_btt = to_nd_btt(dev); 563 564 ndns = nd_btt->ndns; 565 nd_region = to_nd_region(ndns->dev.parent); 566 nsio = to_nd_namespace_io(&ndns->dev); 567 bb = &nsio->bb; 568 bb_state = NULL; 569 } else { 570 struct pmem_device *pmem = dev_get_drvdata(dev); 571 572 nd_region = to_region(pmem); 573 bb = &pmem->bb; 574 bb_state = pmem->bb_state; 575 576 if (is_nd_pfn(dev)) { 577 struct nd_pfn *nd_pfn = to_nd_pfn(dev); 578 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb; 579 580 ndns = nd_pfn->ndns; 581 offset = pmem->data_offset + 582 __le32_to_cpu(pfn_sb->start_pad); 583 end_trunc = __le32_to_cpu(pfn_sb->end_trunc); 584 } else { 585 ndns = to_ndns(dev); 586 } 587 588 nsio = to_nd_namespace_io(&ndns->dev); 589 } 590 591 res.start = nsio->res.start + offset; 592 res.end = nsio->res.end - end_trunc; 593 nvdimm_badblocks_populate(nd_region, bb, &res); 594 if (bb_state) 595 sysfs_notify_dirent(bb_state); 596 } 597 598 MODULE_ALIAS("pmem"); 599 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO); 600 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM); 601 static struct nd_device_driver nd_pmem_driver = { 602 .probe = nd_pmem_probe, 603 .remove = nd_pmem_remove, 604 .notify = nd_pmem_notify, 605 .shutdown = nd_pmem_shutdown, 606 .drv = { 607 .name = "nd_pmem", 608 }, 609 .type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM, 610 }; 611 612 module_nd_driver(nd_pmem_driver); 613 614 MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>"); 615 MODULE_LICENSE("GPL v2"); 616