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/pfn_t.h> 29 #include <linux/slab.h> 30 #include <linux/pmem.h> 31 #include <linux/nd.h> 32 #include "pmem.h" 33 #include "pfn.h" 34 #include "nd.h" 35 36 static struct device *to_dev(struct pmem_device *pmem) 37 { 38 /* 39 * nvdimm bus services need a 'dev' parameter, and we record the device 40 * at init in bb.dev. 41 */ 42 return pmem->bb.dev; 43 } 44 45 static struct nd_region *to_region(struct pmem_device *pmem) 46 { 47 return to_nd_region(to_dev(pmem)->parent); 48 } 49 50 static int pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset, 51 unsigned int len) 52 { 53 struct device *dev = to_dev(pmem); 54 sector_t sector; 55 long cleared; 56 57 sector = (offset - pmem->data_offset) / 512; 58 cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len); 59 60 if (cleared > 0 && cleared / 512) { 61 dev_dbg(dev, "%s: %#llx clear %ld sector%s\n", 62 __func__, (unsigned long long) sector, 63 cleared / 512, cleared / 512 > 1 ? "s" : ""); 64 badblocks_clear(&pmem->bb, sector, cleared / 512); 65 } else { 66 return -EIO; 67 } 68 69 invalidate_pmem(pmem->virt_addr + offset, len); 70 return 0; 71 } 72 73 static void write_pmem(void *pmem_addr, struct page *page, 74 unsigned int off, unsigned int len) 75 { 76 void *mem = kmap_atomic(page); 77 78 memcpy_to_pmem(pmem_addr, mem + off, len); 79 kunmap_atomic(mem); 80 } 81 82 static int read_pmem(struct page *page, unsigned int off, 83 void *pmem_addr, unsigned int len) 84 { 85 int rc; 86 void *mem = kmap_atomic(page); 87 88 rc = memcpy_from_pmem(mem + off, pmem_addr, len); 89 kunmap_atomic(mem); 90 return rc; 91 } 92 93 static int pmem_do_bvec(struct pmem_device *pmem, struct page *page, 94 unsigned int len, unsigned int off, bool is_write, 95 sector_t sector) 96 { 97 int rc = 0; 98 bool bad_pmem = false; 99 phys_addr_t pmem_off = sector * 512 + pmem->data_offset; 100 void *pmem_addr = pmem->virt_addr + pmem_off; 101 102 if (unlikely(is_bad_pmem(&pmem->bb, sector, len))) 103 bad_pmem = true; 104 105 if (!is_write) { 106 if (unlikely(bad_pmem)) 107 rc = -EIO; 108 else { 109 rc = read_pmem(page, off, pmem_addr, len); 110 flush_dcache_page(page); 111 } 112 } else { 113 /* 114 * Note that we write the data both before and after 115 * clearing poison. The write before clear poison 116 * handles situations where the latest written data is 117 * preserved and the clear poison operation simply marks 118 * the address range as valid without changing the data. 119 * In this case application software can assume that an 120 * interrupted write will either return the new good 121 * data or an error. 122 * 123 * However, if pmem_clear_poison() leaves the data in an 124 * indeterminate state we need to perform the write 125 * after clear poison. 126 */ 127 flush_dcache_page(page); 128 write_pmem(pmem_addr, page, off, len); 129 if (unlikely(bad_pmem)) { 130 rc = pmem_clear_poison(pmem, pmem_off, len); 131 write_pmem(pmem_addr, page, off, len); 132 } 133 } 134 135 return rc; 136 } 137 138 /* account for REQ_FLUSH rename, replace with REQ_PREFLUSH after v4.8-rc1 */ 139 #ifndef REQ_FLUSH 140 #define REQ_FLUSH REQ_PREFLUSH 141 #endif 142 143 static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio) 144 { 145 int rc = 0; 146 bool do_acct; 147 unsigned long start; 148 struct bio_vec bvec; 149 struct bvec_iter iter; 150 struct pmem_device *pmem = q->queuedata; 151 struct nd_region *nd_region = to_region(pmem); 152 153 if (bio->bi_opf & REQ_FLUSH) 154 nvdimm_flush(nd_region); 155 156 do_acct = nd_iostat_start(bio, &start); 157 bio_for_each_segment(bvec, bio, iter) { 158 rc = pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len, 159 bvec.bv_offset, op_is_write(bio_op(bio)), 160 iter.bi_sector); 161 if (rc) { 162 bio->bi_error = rc; 163 break; 164 } 165 } 166 if (do_acct) 167 nd_iostat_end(bio, start); 168 169 if (bio->bi_opf & REQ_FUA) 170 nvdimm_flush(nd_region); 171 172 bio_endio(bio); 173 return BLK_QC_T_NONE; 174 } 175 176 static int pmem_rw_page(struct block_device *bdev, sector_t sector, 177 struct page *page, bool is_write) 178 { 179 struct pmem_device *pmem = bdev->bd_queue->queuedata; 180 int rc; 181 182 rc = pmem_do_bvec(pmem, page, PAGE_SIZE, 0, is_write, sector); 183 184 /* 185 * The ->rw_page interface is subtle and tricky. The core 186 * retries on any error, so we can only invoke page_endio() in 187 * the successful completion case. Otherwise, we'll see crashes 188 * caused by double completion. 189 */ 190 if (rc == 0) 191 page_endio(page, is_write, 0); 192 193 return rc; 194 } 195 196 /* see "strong" declaration in tools/testing/nvdimm/pmem-dax.c */ 197 __weak long pmem_direct_access(struct block_device *bdev, sector_t sector, 198 void **kaddr, pfn_t *pfn, long size) 199 { 200 struct pmem_device *pmem = bdev->bd_queue->queuedata; 201 resource_size_t offset = sector * 512 + pmem->data_offset; 202 203 if (unlikely(is_bad_pmem(&pmem->bb, sector, size))) 204 return -EIO; 205 *kaddr = pmem->virt_addr + offset; 206 *pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags); 207 208 /* 209 * If badblocks are present, limit known good range to the 210 * requested range. 211 */ 212 if (unlikely(pmem->bb.count)) 213 return size; 214 return pmem->size - pmem->pfn_pad - offset; 215 } 216 217 static const struct block_device_operations pmem_fops = { 218 .owner = THIS_MODULE, 219 .rw_page = pmem_rw_page, 220 .direct_access = pmem_direct_access, 221 .revalidate_disk = nvdimm_revalidate_disk, 222 }; 223 224 static void pmem_release_queue(void *q) 225 { 226 blk_cleanup_queue(q); 227 } 228 229 static void pmem_release_disk(void *disk) 230 { 231 del_gendisk(disk); 232 put_disk(disk); 233 } 234 235 static int pmem_attach_disk(struct device *dev, 236 struct nd_namespace_common *ndns) 237 { 238 struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev); 239 struct nd_region *nd_region = to_nd_region(dev->parent); 240 struct vmem_altmap __altmap, *altmap = NULL; 241 struct resource *res = &nsio->res; 242 struct nd_pfn *nd_pfn = NULL; 243 int nid = dev_to_node(dev); 244 struct nd_pfn_sb *pfn_sb; 245 struct pmem_device *pmem; 246 struct resource pfn_res; 247 struct request_queue *q; 248 struct gendisk *disk; 249 void *addr; 250 251 /* while nsio_rw_bytes is active, parse a pfn info block if present */ 252 if (is_nd_pfn(dev)) { 253 nd_pfn = to_nd_pfn(dev); 254 altmap = nvdimm_setup_pfn(nd_pfn, &pfn_res, &__altmap); 255 if (IS_ERR(altmap)) 256 return PTR_ERR(altmap); 257 } 258 259 /* we're attaching a block device, disable raw namespace access */ 260 devm_nsio_disable(dev, nsio); 261 262 pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL); 263 if (!pmem) 264 return -ENOMEM; 265 266 dev_set_drvdata(dev, pmem); 267 pmem->phys_addr = res->start; 268 pmem->size = resource_size(res); 269 if (nvdimm_has_flush(nd_region) < 0) 270 dev_warn(dev, "unable to guarantee persistence of writes\n"); 271 272 if (!devm_request_mem_region(dev, res->start, resource_size(res), 273 dev_name(dev))) { 274 dev_warn(dev, "could not reserve region %pR\n", res); 275 return -EBUSY; 276 } 277 278 q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev)); 279 if (!q) 280 return -ENOMEM; 281 282 pmem->pfn_flags = PFN_DEV; 283 if (is_nd_pfn(dev)) { 284 addr = devm_memremap_pages(dev, &pfn_res, &q->q_usage_counter, 285 altmap); 286 pfn_sb = nd_pfn->pfn_sb; 287 pmem->data_offset = le64_to_cpu(pfn_sb->dataoff); 288 pmem->pfn_pad = resource_size(res) - resource_size(&pfn_res); 289 pmem->pfn_flags |= PFN_MAP; 290 res = &pfn_res; /* for badblocks populate */ 291 res->start += pmem->data_offset; 292 } else if (pmem_should_map_pages(dev)) { 293 addr = devm_memremap_pages(dev, &nsio->res, 294 &q->q_usage_counter, NULL); 295 pmem->pfn_flags |= PFN_MAP; 296 } else 297 addr = devm_memremap(dev, pmem->phys_addr, 298 pmem->size, ARCH_MEMREMAP_PMEM); 299 300 /* 301 * At release time the queue must be dead before 302 * devm_memremap_pages is unwound 303 */ 304 if (devm_add_action_or_reset(dev, pmem_release_queue, q)) 305 return -ENOMEM; 306 307 if (IS_ERR(addr)) 308 return PTR_ERR(addr); 309 pmem->virt_addr = addr; 310 311 blk_queue_write_cache(q, true, true); 312 blk_queue_make_request(q, pmem_make_request); 313 blk_queue_physical_block_size(q, PAGE_SIZE); 314 blk_queue_max_hw_sectors(q, UINT_MAX); 315 blk_queue_bounce_limit(q, BLK_BOUNCE_ANY); 316 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q); 317 queue_flag_set_unlocked(QUEUE_FLAG_DAX, q); 318 q->queuedata = pmem; 319 320 disk = alloc_disk_node(0, nid); 321 if (!disk) 322 return -ENOMEM; 323 324 disk->fops = &pmem_fops; 325 disk->queue = q; 326 disk->flags = GENHD_FL_EXT_DEVT; 327 nvdimm_namespace_disk_name(ndns, disk->disk_name); 328 set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset) 329 / 512); 330 if (devm_init_badblocks(dev, &pmem->bb)) 331 return -ENOMEM; 332 nvdimm_badblocks_populate(nd_region, &pmem->bb, res); 333 disk->bb = &pmem->bb; 334 device_add_disk(dev, disk); 335 336 if (devm_add_action_or_reset(dev, pmem_release_disk, disk)) 337 return -ENOMEM; 338 339 revalidate_disk(disk); 340 341 return 0; 342 } 343 344 static int nd_pmem_probe(struct device *dev) 345 { 346 struct nd_namespace_common *ndns; 347 348 ndns = nvdimm_namespace_common_probe(dev); 349 if (IS_ERR(ndns)) 350 return PTR_ERR(ndns); 351 352 if (devm_nsio_enable(dev, to_nd_namespace_io(&ndns->dev))) 353 return -ENXIO; 354 355 if (is_nd_btt(dev)) 356 return nvdimm_namespace_attach_btt(ndns); 357 358 if (is_nd_pfn(dev)) 359 return pmem_attach_disk(dev, ndns); 360 361 /* if we find a valid info-block we'll come back as that personality */ 362 if (nd_btt_probe(dev, ndns) == 0 || nd_pfn_probe(dev, ndns) == 0 363 || nd_dax_probe(dev, ndns) == 0) 364 return -ENXIO; 365 366 /* ...otherwise we're just a raw pmem device */ 367 return pmem_attach_disk(dev, ndns); 368 } 369 370 static int nd_pmem_remove(struct device *dev) 371 { 372 if (is_nd_btt(dev)) 373 nvdimm_namespace_detach_btt(to_nd_btt(dev)); 374 nvdimm_flush(to_nd_region(dev->parent)); 375 376 return 0; 377 } 378 379 static void nd_pmem_shutdown(struct device *dev) 380 { 381 nvdimm_flush(to_nd_region(dev->parent)); 382 } 383 384 static void nd_pmem_notify(struct device *dev, enum nvdimm_event event) 385 { 386 struct pmem_device *pmem = dev_get_drvdata(dev); 387 struct nd_region *nd_region = to_region(pmem); 388 resource_size_t offset = 0, end_trunc = 0; 389 struct nd_namespace_common *ndns; 390 struct nd_namespace_io *nsio; 391 struct resource res; 392 393 if (event != NVDIMM_REVALIDATE_POISON) 394 return; 395 396 if (is_nd_btt(dev)) { 397 struct nd_btt *nd_btt = to_nd_btt(dev); 398 399 ndns = nd_btt->ndns; 400 } else if (is_nd_pfn(dev)) { 401 struct nd_pfn *nd_pfn = to_nd_pfn(dev); 402 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb; 403 404 ndns = nd_pfn->ndns; 405 offset = pmem->data_offset + __le32_to_cpu(pfn_sb->start_pad); 406 end_trunc = __le32_to_cpu(pfn_sb->end_trunc); 407 } else 408 ndns = to_ndns(dev); 409 410 nsio = to_nd_namespace_io(&ndns->dev); 411 res.start = nsio->res.start + offset; 412 res.end = nsio->res.end - end_trunc; 413 nvdimm_badblocks_populate(nd_region, &pmem->bb, &res); 414 } 415 416 MODULE_ALIAS("pmem"); 417 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO); 418 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM); 419 static struct nd_device_driver nd_pmem_driver = { 420 .probe = nd_pmem_probe, 421 .remove = nd_pmem_remove, 422 .notify = nd_pmem_notify, 423 .shutdown = nd_pmem_shutdown, 424 .drv = { 425 .name = "nd_pmem", 426 }, 427 .type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM, 428 }; 429 430 static int __init pmem_init(void) 431 { 432 return nd_driver_register(&nd_pmem_driver); 433 } 434 module_init(pmem_init); 435 436 static void pmem_exit(void) 437 { 438 driver_unregister(&nd_pmem_driver.drv); 439 } 440 module_exit(pmem_exit); 441 442 MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>"); 443 MODULE_LICENSE("GPL v2"); 444