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