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