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/module.h> 24 #include <linux/moduleparam.h> 25 #include <linux/badblocks.h> 26 #include <linux/memremap.h> 27 #include <linux/vmalloc.h> 28 #include <linux/blk-mq.h> 29 #include <linux/pfn_t.h> 30 #include <linux/slab.h> 31 #include <linux/uio.h> 32 #include <linux/dax.h> 33 #include <linux/nd.h> 34 #include "pmem.h" 35 #include "pfn.h" 36 #include "nd.h" 37 38 static struct device *to_dev(struct pmem_device *pmem) 39 { 40 /* 41 * nvdimm bus services need a 'dev' parameter, and we record the device 42 * at init in bb.dev. 43 */ 44 return pmem->bb.dev; 45 } 46 47 static struct nd_region *to_region(struct pmem_device *pmem) 48 { 49 return to_nd_region(to_dev(pmem)->parent); 50 } 51 52 static blk_status_t pmem_clear_poison(struct pmem_device *pmem, 53 phys_addr_t offset, unsigned int len) 54 { 55 struct device *dev = to_dev(pmem); 56 sector_t sector; 57 long cleared; 58 blk_status_t rc = BLK_STS_OK; 59 60 sector = (offset - pmem->data_offset) / 512; 61 62 cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len); 63 if (cleared < len) 64 rc = BLK_STS_IOERR; 65 if (cleared > 0 && cleared / 512) { 66 cleared /= 512; 67 dev_dbg(dev, "%s: %#llx clear %ld sector%s\n", __func__, 68 (unsigned long long) sector, cleared, 69 cleared > 1 ? "s" : ""); 70 badblocks_clear(&pmem->bb, sector, cleared); 71 if (pmem->bb_state) 72 sysfs_notify_dirent(pmem->bb_state); 73 } 74 75 arch_invalidate_pmem(pmem->virt_addr + offset, len); 76 77 return rc; 78 } 79 80 static void write_pmem(void *pmem_addr, struct page *page, 81 unsigned int off, unsigned int len) 82 { 83 unsigned int chunk; 84 void *mem; 85 86 while (len) { 87 mem = kmap_atomic(page); 88 chunk = min_t(unsigned int, len, PAGE_SIZE); 89 memcpy_flushcache(pmem_addr, mem + off, chunk); 90 kunmap_atomic(mem); 91 len -= chunk; 92 off = 0; 93 page++; 94 pmem_addr += PAGE_SIZE; 95 } 96 } 97 98 static blk_status_t read_pmem(struct page *page, unsigned int off, 99 void *pmem_addr, unsigned int len) 100 { 101 unsigned int chunk; 102 int rc; 103 void *mem; 104 105 while (len) { 106 mem = kmap_atomic(page); 107 chunk = min_t(unsigned int, len, PAGE_SIZE); 108 rc = memcpy_mcsafe(mem + off, pmem_addr, chunk); 109 kunmap_atomic(mem); 110 if (rc) 111 return BLK_STS_IOERR; 112 len -= chunk; 113 off = 0; 114 page++; 115 pmem_addr += PAGE_SIZE; 116 } 117 return BLK_STS_OK; 118 } 119 120 static blk_status_t pmem_do_bvec(struct pmem_device *pmem, struct page *page, 121 unsigned int len, unsigned int off, bool is_write, 122 sector_t sector) 123 { 124 blk_status_t rc = BLK_STS_OK; 125 bool bad_pmem = false; 126 phys_addr_t pmem_off = sector * 512 + pmem->data_offset; 127 void *pmem_addr = pmem->virt_addr + pmem_off; 128 129 if (unlikely(is_bad_pmem(&pmem->bb, sector, len))) 130 bad_pmem = true; 131 132 if (!is_write) { 133 if (unlikely(bad_pmem)) 134 rc = BLK_STS_IOERR; 135 else { 136 rc = read_pmem(page, off, pmem_addr, len); 137 flush_dcache_page(page); 138 } 139 } else { 140 /* 141 * Note that we write the data both before and after 142 * clearing poison. The write before clear poison 143 * handles situations where the latest written data is 144 * preserved and the clear poison operation simply marks 145 * the address range as valid without changing the data. 146 * In this case application software can assume that an 147 * interrupted write will either return the new good 148 * data or an error. 149 * 150 * However, if pmem_clear_poison() leaves the data in an 151 * indeterminate state we need to perform the write 152 * after clear poison. 153 */ 154 flush_dcache_page(page); 155 write_pmem(pmem_addr, page, off, len); 156 if (unlikely(bad_pmem)) { 157 rc = pmem_clear_poison(pmem, pmem_off, len); 158 write_pmem(pmem_addr, page, off, len); 159 } 160 } 161 162 return rc; 163 } 164 165 /* account for REQ_FLUSH rename, replace with REQ_PREFLUSH after v4.8-rc1 */ 166 #ifndef REQ_FLUSH 167 #define REQ_FLUSH REQ_PREFLUSH 168 #endif 169 170 static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio) 171 { 172 blk_status_t rc = 0; 173 bool do_acct; 174 unsigned long start; 175 struct bio_vec bvec; 176 struct bvec_iter iter; 177 struct pmem_device *pmem = q->queuedata; 178 struct nd_region *nd_region = to_region(pmem); 179 180 if (bio->bi_opf & REQ_FLUSH) 181 nvdimm_flush(nd_region); 182 183 do_acct = nd_iostat_start(bio, &start); 184 bio_for_each_segment(bvec, bio, iter) { 185 rc = pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len, 186 bvec.bv_offset, op_is_write(bio_op(bio)), 187 iter.bi_sector); 188 if (rc) { 189 bio->bi_status = rc; 190 break; 191 } 192 } 193 if (do_acct) 194 nd_iostat_end(bio, start); 195 196 if (bio->bi_opf & REQ_FUA) 197 nvdimm_flush(nd_region); 198 199 bio_endio(bio); 200 return BLK_QC_T_NONE; 201 } 202 203 static int pmem_rw_page(struct block_device *bdev, sector_t sector, 204 struct page *page, bool is_write) 205 { 206 struct pmem_device *pmem = bdev->bd_queue->queuedata; 207 blk_status_t rc; 208 209 rc = pmem_do_bvec(pmem, page, hpage_nr_pages(page) * PAGE_SIZE, 210 0, is_write, sector); 211 212 /* 213 * The ->rw_page interface is subtle and tricky. The core 214 * retries on any error, so we can only invoke page_endio() in 215 * the successful completion case. Otherwise, we'll see crashes 216 * caused by double completion. 217 */ 218 if (rc == 0) 219 page_endio(page, is_write, 0); 220 221 return blk_status_to_errno(rc); 222 } 223 224 /* see "strong" declaration in tools/testing/nvdimm/pmem-dax.c */ 225 __weak long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff, 226 long nr_pages, void **kaddr, pfn_t *pfn) 227 { 228 resource_size_t offset = PFN_PHYS(pgoff) + pmem->data_offset; 229 230 if (unlikely(is_bad_pmem(&pmem->bb, PFN_PHYS(pgoff) / 512, 231 PFN_PHYS(nr_pages)))) 232 return -EIO; 233 *kaddr = pmem->virt_addr + offset; 234 *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags); 235 236 /* 237 * If badblocks are present, limit known good range to the 238 * requested range. 239 */ 240 if (unlikely(pmem->bb.count)) 241 return nr_pages; 242 return PHYS_PFN(pmem->size - pmem->pfn_pad - offset); 243 } 244 245 static const struct block_device_operations pmem_fops = { 246 .owner = THIS_MODULE, 247 .rw_page = pmem_rw_page, 248 .revalidate_disk = nvdimm_revalidate_disk, 249 }; 250 251 static long pmem_dax_direct_access(struct dax_device *dax_dev, 252 pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn) 253 { 254 struct pmem_device *pmem = dax_get_private(dax_dev); 255 256 return __pmem_direct_access(pmem, pgoff, nr_pages, kaddr, pfn); 257 } 258 259 static size_t pmem_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, 260 void *addr, size_t bytes, struct iov_iter *i) 261 { 262 return copy_from_iter_flushcache(addr, bytes, i); 263 } 264 265 static void pmem_dax_flush(struct dax_device *dax_dev, pgoff_t pgoff, 266 void *addr, size_t size) 267 { 268 arch_wb_cache_pmem(addr, size); 269 } 270 271 static const struct dax_operations pmem_dax_ops = { 272 .direct_access = pmem_dax_direct_access, 273 .copy_from_iter = pmem_copy_from_iter, 274 .flush = pmem_dax_flush, 275 }; 276 277 static const struct attribute_group *pmem_attribute_groups[] = { 278 &dax_attribute_group, 279 NULL, 280 }; 281 282 static void pmem_release_queue(void *q) 283 { 284 blk_cleanup_queue(q); 285 } 286 287 static void pmem_freeze_queue(void *q) 288 { 289 blk_freeze_queue_start(q); 290 } 291 292 static void pmem_release_disk(void *__pmem) 293 { 294 struct pmem_device *pmem = __pmem; 295 296 kill_dax(pmem->dax_dev); 297 put_dax(pmem->dax_dev); 298 del_gendisk(pmem->disk); 299 put_disk(pmem->disk); 300 } 301 302 static int pmem_attach_disk(struct device *dev, 303 struct nd_namespace_common *ndns) 304 { 305 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev); 306 struct nd_region *nd_region = to_nd_region(dev->parent); 307 struct vmem_altmap __altmap, *altmap = NULL; 308 int nid = dev_to_node(dev), fua, wbc; 309 struct resource *res = &nsio->res; 310 struct nd_pfn *nd_pfn = NULL; 311 struct dax_device *dax_dev; 312 struct nd_pfn_sb *pfn_sb; 313 struct pmem_device *pmem; 314 struct resource pfn_res; 315 struct request_queue *q; 316 struct device *gendev; 317 struct gendisk *disk; 318 void *addr; 319 320 /* while nsio_rw_bytes is active, parse a pfn info block if present */ 321 if (is_nd_pfn(dev)) { 322 nd_pfn = to_nd_pfn(dev); 323 altmap = nvdimm_setup_pfn(nd_pfn, &pfn_res, &__altmap); 324 if (IS_ERR(altmap)) 325 return PTR_ERR(altmap); 326 } 327 328 /* we're attaching a block device, disable raw namespace access */ 329 devm_nsio_disable(dev, nsio); 330 331 pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL); 332 if (!pmem) 333 return -ENOMEM; 334 335 dev_set_drvdata(dev, pmem); 336 pmem->phys_addr = res->start; 337 pmem->size = resource_size(res); 338 fua = nvdimm_has_flush(nd_region); 339 if (!IS_ENABLED(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) || fua < 0) { 340 dev_warn(dev, "unable to guarantee persistence of writes\n"); 341 fua = 0; 342 } 343 wbc = nvdimm_has_cache(nd_region); 344 345 if (!devm_request_mem_region(dev, res->start, resource_size(res), 346 dev_name(&ndns->dev))) { 347 dev_warn(dev, "could not reserve region %pR\n", res); 348 return -EBUSY; 349 } 350 351 q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev)); 352 if (!q) 353 return -ENOMEM; 354 355 if (devm_add_action_or_reset(dev, pmem_release_queue, q)) 356 return -ENOMEM; 357 358 pmem->pfn_flags = PFN_DEV; 359 if (is_nd_pfn(dev)) { 360 addr = devm_memremap_pages(dev, &pfn_res, &q->q_usage_counter, 361 altmap); 362 pfn_sb = nd_pfn->pfn_sb; 363 pmem->data_offset = le64_to_cpu(pfn_sb->dataoff); 364 pmem->pfn_pad = resource_size(res) - resource_size(&pfn_res); 365 pmem->pfn_flags |= PFN_MAP; 366 res = &pfn_res; /* for badblocks populate */ 367 res->start += pmem->data_offset; 368 } else if (pmem_should_map_pages(dev)) { 369 addr = devm_memremap_pages(dev, &nsio->res, 370 &q->q_usage_counter, NULL); 371 pmem->pfn_flags |= PFN_MAP; 372 } else 373 addr = devm_memremap(dev, pmem->phys_addr, 374 pmem->size, ARCH_MEMREMAP_PMEM); 375 376 /* 377 * At release time the queue must be frozen before 378 * devm_memremap_pages is unwound 379 */ 380 if (devm_add_action_or_reset(dev, pmem_freeze_queue, q)) 381 return -ENOMEM; 382 383 if (IS_ERR(addr)) 384 return PTR_ERR(addr); 385 pmem->virt_addr = addr; 386 387 blk_queue_write_cache(q, wbc, fua); 388 blk_queue_make_request(q, pmem_make_request); 389 blk_queue_physical_block_size(q, PAGE_SIZE); 390 blk_queue_logical_block_size(q, pmem_sector_size(ndns)); 391 blk_queue_max_hw_sectors(q, UINT_MAX); 392 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q); 393 queue_flag_set_unlocked(QUEUE_FLAG_DAX, q); 394 q->queuedata = pmem; 395 396 disk = alloc_disk_node(0, nid); 397 if (!disk) 398 return -ENOMEM; 399 pmem->disk = disk; 400 401 disk->fops = &pmem_fops; 402 disk->queue = q; 403 disk->flags = GENHD_FL_EXT_DEVT; 404 nvdimm_namespace_disk_name(ndns, disk->disk_name); 405 set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset) 406 / 512); 407 if (devm_init_badblocks(dev, &pmem->bb)) 408 return -ENOMEM; 409 nvdimm_badblocks_populate(nd_region, &pmem->bb, res); 410 disk->bb = &pmem->bb; 411 412 dax_dev = alloc_dax(pmem, disk->disk_name, &pmem_dax_ops); 413 if (!dax_dev) { 414 put_disk(disk); 415 return -ENOMEM; 416 } 417 dax_write_cache(dax_dev, wbc); 418 pmem->dax_dev = dax_dev; 419 420 gendev = disk_to_dev(disk); 421 gendev->groups = pmem_attribute_groups; 422 423 device_add_disk(dev, disk); 424 if (devm_add_action_or_reset(dev, pmem_release_disk, pmem)) 425 return -ENOMEM; 426 427 revalidate_disk(disk); 428 429 pmem->bb_state = sysfs_get_dirent(disk_to_dev(disk)->kobj.sd, 430 "badblocks"); 431 if (!pmem->bb_state) 432 dev_warn(dev, "'badblocks' notification disabled\n"); 433 434 return 0; 435 } 436 437 static int nd_pmem_probe(struct device *dev) 438 { 439 struct nd_namespace_common *ndns; 440 441 ndns = nvdimm_namespace_common_probe(dev); 442 if (IS_ERR(ndns)) 443 return PTR_ERR(ndns); 444 445 if (devm_nsio_enable(dev, to_nd_namespace_io(&ndns->dev))) 446 return -ENXIO; 447 448 if (is_nd_btt(dev)) 449 return nvdimm_namespace_attach_btt(ndns); 450 451 if (is_nd_pfn(dev)) 452 return pmem_attach_disk(dev, ndns); 453 454 /* if we find a valid info-block we'll come back as that personality */ 455 if (nd_btt_probe(dev, ndns) == 0 || nd_pfn_probe(dev, ndns) == 0 456 || nd_dax_probe(dev, ndns) == 0) 457 return -ENXIO; 458 459 /* ...otherwise we're just a raw pmem device */ 460 return pmem_attach_disk(dev, ndns); 461 } 462 463 static int nd_pmem_remove(struct device *dev) 464 { 465 struct pmem_device *pmem = dev_get_drvdata(dev); 466 467 if (is_nd_btt(dev)) 468 nvdimm_namespace_detach_btt(to_nd_btt(dev)); 469 else { 470 /* 471 * Note, this assumes device_lock() context to not race 472 * nd_pmem_notify() 473 */ 474 sysfs_put(pmem->bb_state); 475 pmem->bb_state = NULL; 476 } 477 nvdimm_flush(to_nd_region(dev->parent)); 478 479 return 0; 480 } 481 482 static void nd_pmem_shutdown(struct device *dev) 483 { 484 nvdimm_flush(to_nd_region(dev->parent)); 485 } 486 487 static void nd_pmem_notify(struct device *dev, enum nvdimm_event event) 488 { 489 struct nd_region *nd_region; 490 resource_size_t offset = 0, end_trunc = 0; 491 struct nd_namespace_common *ndns; 492 struct nd_namespace_io *nsio; 493 struct resource res; 494 struct badblocks *bb; 495 struct kernfs_node *bb_state; 496 497 if (event != NVDIMM_REVALIDATE_POISON) 498 return; 499 500 if (is_nd_btt(dev)) { 501 struct nd_btt *nd_btt = to_nd_btt(dev); 502 503 ndns = nd_btt->ndns; 504 nd_region = to_nd_region(ndns->dev.parent); 505 nsio = to_nd_namespace_io(&ndns->dev); 506 bb = &nsio->bb; 507 bb_state = NULL; 508 } else { 509 struct pmem_device *pmem = dev_get_drvdata(dev); 510 511 nd_region = to_region(pmem); 512 bb = &pmem->bb; 513 bb_state = pmem->bb_state; 514 515 if (is_nd_pfn(dev)) { 516 struct nd_pfn *nd_pfn = to_nd_pfn(dev); 517 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb; 518 519 ndns = nd_pfn->ndns; 520 offset = pmem->data_offset + 521 __le32_to_cpu(pfn_sb->start_pad); 522 end_trunc = __le32_to_cpu(pfn_sb->end_trunc); 523 } else { 524 ndns = to_ndns(dev); 525 } 526 527 nsio = to_nd_namespace_io(&ndns->dev); 528 } 529 530 res.start = nsio->res.start + offset; 531 res.end = nsio->res.end - end_trunc; 532 nvdimm_badblocks_populate(nd_region, bb, &res); 533 if (bb_state) 534 sysfs_notify_dirent(bb_state); 535 } 536 537 MODULE_ALIAS("pmem"); 538 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO); 539 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM); 540 static struct nd_device_driver nd_pmem_driver = { 541 .probe = nd_pmem_probe, 542 .remove = nd_pmem_remove, 543 .notify = nd_pmem_notify, 544 .shutdown = nd_pmem_shutdown, 545 .drv = { 546 .name = "nd_pmem", 547 }, 548 .type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM, 549 }; 550 551 static int __init pmem_init(void) 552 { 553 return nd_driver_register(&nd_pmem_driver); 554 } 555 module_init(pmem_init); 556 557 static void pmem_exit(void) 558 { 559 driver_unregister(&nd_pmem_driver.drv); 560 } 561 module_exit(pmem_exit); 562 563 MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>"); 564 MODULE_LICENSE("GPL v2"); 565