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