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