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