drivers/nvdimm/blk.c

   1 /*
   2  * NVDIMM Block Window Driver
   3  * Copyright (c) 2014, Intel Corporation.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  */
  14
  15 #include <linux/blkdev.h>
  16 #include <linux/fs.h>
  17 #include <linux/genhd.h>
  18 #include <linux/module.h>
  19 #include <linux/moduleparam.h>
  20 #include <linux/nd.h>
  21 #include <linux/sizes.h>
  22 #include "nd.h"
  23
  24 struct nd_blk_device {
  25         struct nd_namespace_blk *nsblk;
  26         struct nd_blk_region *ndbr;
  27         size_t disk_size;
  28         u32 sector_size;
  29         u32 internal_lbasize;
  30 };
  31
  32 static u32 nd_blk_meta_size(struct nd_blk_device *blk_dev)
  33 {
  34         return blk_dev->nsblk->lbasize - blk_dev->sector_size;
  35 }
  36
  37 static resource_size_t to_dev_offset(struct nd_namespace_blk *nsblk,
  38                                 resource_size_t ns_offset, unsigned int len)
  39 {
  40         int i;
  41
  42         for (i = 0; i < nsblk->num_resources; i++) {
  43                 if (ns_offset < resource_size(nsblk->res[i])) {
  44                         if (ns_offset + len > resource_size(nsblk->res[i])) {
  45                                 dev_WARN_ONCE(&nsblk->common.dev, 1,
  46                                         "illegal request\n");
  47                                 return SIZE_MAX;
  48                         }
  49                         return nsblk->res[i]->start + ns_offset;
  50                 }
  51                 ns_offset -= resource_size(nsblk->res[i]);
  52         }
  53
  54         dev_WARN_ONCE(&nsblk->common.dev, 1, "request out of range\n");
  55         return SIZE_MAX;
  56 }
  57
  58 #ifdef CONFIG_BLK_DEV_INTEGRITY
  59 static int nd_blk_rw_integrity(struct nd_blk_device *blk_dev,
  60                                 struct bio_integrity_payload *bip, u64 lba,
  61                                 int rw)
  62 {
  63         unsigned int len = nd_blk_meta_size(blk_dev);
  64         resource_size_t dev_offset, ns_offset;
  65         struct nd_namespace_blk *nsblk;
  66         struct nd_blk_region *ndbr;
  67         int err = 0;
  68
  69         nsblk = blk_dev->nsblk;
  70         ndbr = blk_dev->ndbr;
  71         ns_offset = lba * blk_dev->internal_lbasize + blk_dev->sector_size;
  72         dev_offset = to_dev_offset(nsblk, ns_offset, len);
  73         if (dev_offset == SIZE_MAX)
  74                 return -EIO;
  75
  76         while (len) {
  77                 unsigned int cur_len;
  78                 struct bio_vec bv;
  79                 void *iobuf;
  80
  81                 bv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter);
  82                 /*
  83                  * The 'bv' obtained from bvec_iter_bvec has its .bv_len and
  84                  * .bv_offset already adjusted for iter->bi_bvec_done, and we
  85                  * can use those directly
  86                  */
  87
  88                 cur_len = min(len, bv.bv_len);
  89                 iobuf = kmap_atomic(bv.bv_page);
  90                 err = ndbr->do_io(ndbr, dev_offset, iobuf + bv.bv_offset,
  91                                 cur_len, rw);
  92                 kunmap_atomic(iobuf);
  93                 if (err)
  94                         return err;
  95
  96                 len -= cur_len;
  97                 dev_offset += cur_len;
  98                 bvec_iter_advance(bip->bip_vec, &bip->bip_iter, cur_len);
  99         }
 100
 101         return err;
 102 }
 103
 104 #else /* CONFIG_BLK_DEV_INTEGRITY */
 105 static int nd_blk_rw_integrity(struct nd_blk_device *blk_dev,
 106                                 struct bio_integrity_payload *bip, u64 lba,
 107                                 int rw)
 108 {
 109         return 0;
 110 }
 111 #endif
 112
 113 static int nd_blk_do_bvec(struct nd_blk_device *blk_dev,
 114                         struct bio_integrity_payload *bip, struct page *page,
 115                         unsigned int len, unsigned int off, int rw,
 116                         sector_t sector)
 117 {
 118         struct nd_blk_region *ndbr = blk_dev->ndbr;
 119         resource_size_t dev_offset, ns_offset;
 120         int err = 0;
 121         void *iobuf;
 122         u64 lba;
 123
 124         while (len) {
 125                 unsigned int cur_len;
 126
 127                 /*
 128                  * If we don't have an integrity payload, we don't have to
 129                  * split the bvec into sectors, as this would cause unnecessary
 130                  * Block Window setup/move steps. the do_io routine is capable
 131                  * of handling len <= PAGE_SIZE.
 132                  */
 133                 cur_len = bip ? min(len, blk_dev->sector_size) : len;
 134
 135                 lba = div_u64(sector << SECTOR_SHIFT, blk_dev->sector_size);
 136                 ns_offset = lba * blk_dev->internal_lbasize;
 137                 dev_offset = to_dev_offset(blk_dev->nsblk, ns_offset, cur_len);
 138                 if (dev_offset == SIZE_MAX)
 139                         return -EIO;
 140
 141                 iobuf = kmap_atomic(page);
 142                 err = ndbr->do_io(ndbr, dev_offset, iobuf + off, cur_len, rw);
 143                 kunmap_atomic(iobuf);
 144                 if (err)
 145                         return err;
 146
 147                 if (bip) {
 148                         err = nd_blk_rw_integrity(blk_dev, bip, lba, rw);
 149                         if (err)
 150                                 return err;
 151                 }
 152                 len -= cur_len;
 153                 off += cur_len;
 154                 sector += blk_dev->sector_size >> SECTOR_SHIFT;
 155         }
 156
 157         return err;
 158 }
 159
 160 static blk_qc_t nd_blk_make_request(struct request_queue *q, struct bio *bio)
 161 {
 162         struct bio_integrity_payload *bip;
 163         struct nd_blk_device *blk_dev;
 164         struct bvec_iter iter;
 165         unsigned long start;
 166         struct bio_vec bvec;
 167         int err = 0, rw;
 168         bool do_acct;
 169
 170         /*
 171          * bio_integrity_enabled also checks if the bio already has an
 172          * integrity payload attached. If it does, we *don't* do a
 173          * bio_integrity_prep here - the payload has been generated by
 174          * another kernel subsystem, and we just pass it through.
 175          */
 176         if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
 177                 bio->bi_error = -EIO;
 178                 goto out;
 179         }
 180
 181         bip = bio_integrity(bio);
 182         blk_dev = q->queuedata;
 183         rw = bio_data_dir(bio);
 184         do_acct = nd_iostat_start(bio, &start);
 185         bio_for_each_segment(bvec, bio, iter) {
 186                 unsigned int len = bvec.bv_len;
 187
 188                 BUG_ON(len > PAGE_SIZE);
 189                 err = nd_blk_do_bvec(blk_dev, bip, bvec.bv_page, len,
 190                                         bvec.bv_offset, rw, iter.bi_sector);
 191                 if (err) {
 192                         dev_dbg(&blk_dev->nsblk->common.dev,
 193                                         "io error in %s sector %lld, len %d,\n",
 194                                         (rw == READ) ? "READ" : "WRITE",
 195                                         (unsigned long long) iter.bi_sector, len);
 196                         bio->bi_error = err;
 197                         break;
 198                 }
 199         }
 200         if (do_acct)
 201                 nd_iostat_end(bio, start);
 202
 203  out:
 204         bio_endio(bio);
 205         return BLK_QC_T_NONE;
 206 }
 207
 208 static int nd_blk_rw_bytes(struct nd_namespace_common *ndns,
 209                 resource_size_t offset, void *iobuf, size_t n, int rw)
 210 {
 211         struct nd_blk_device *blk_dev = dev_get_drvdata(ndns->claim);
 212         struct nd_namespace_blk *nsblk = blk_dev->nsblk;
 213         struct nd_blk_region *ndbr = blk_dev->ndbr;
 214         resource_size_t dev_offset;
 215
 216         dev_offset = to_dev_offset(nsblk, offset, n);
 217
 218         if (unlikely(offset + n > blk_dev->disk_size)) {
 219                 dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
 220                 return -EFAULT;
 221         }
 222
 223         if (dev_offset == SIZE_MAX)
 224                 return -EIO;
 225
 226         return ndbr->do_io(ndbr, dev_offset, iobuf, n, rw);
 227 }
 228
 229 static const struct block_device_operations nd_blk_fops = {
 230         .owner = THIS_MODULE,
 231         .revalidate_disk = nvdimm_revalidate_disk,
 232 };
 233
 234 static void nd_blk_release_queue(void *q)
 235 {
 236         blk_cleanup_queue(q);
 237 }
 238
 239 static void nd_blk_release_disk(void *disk)
 240 {
 241         del_gendisk(disk);
 242         put_disk(disk);
 243 }
 244
 245 static int nd_blk_attach_disk(struct device *dev,
 246                 struct nd_namespace_common *ndns, struct nd_blk_device *blk_dev)
 247 {
 248         resource_size_t available_disk_size;
 249         struct request_queue *q;
 250         struct gendisk *disk;
 251         u64 internal_nlba;
 252
 253         internal_nlba = div_u64(blk_dev->disk_size, blk_dev->internal_lbasize);
 254         available_disk_size = internal_nlba * blk_dev->sector_size;
 255
 256         q = blk_alloc_queue(GFP_KERNEL);
 257         if (!q)
 258                 return -ENOMEM;
 259         if (devm_add_action(dev, nd_blk_release_queue, q)) {
 260                 blk_cleanup_queue(q);
 261                 return -ENOMEM;
 262         }
 263
 264         blk_queue_make_request(q, nd_blk_make_request);
 265         blk_queue_max_hw_sectors(q, UINT_MAX);
 266         blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
 267         blk_queue_logical_block_size(q, blk_dev->sector_size);
 268         queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
 269         q->queuedata = blk_dev;
 270
 271         disk = alloc_disk(0);
 272         if (!disk)
 273                 return -ENOMEM;
 274         if (devm_add_action(dev, nd_blk_release_disk, disk)) {
 275                 put_disk(disk);
 276                 return -ENOMEM;
 277         }
 278
 279         disk->driverfs_dev      = &ndns->dev;
 280         disk->first_minor       = 0;
 281         disk->fops              = &nd_blk_fops;
 282         disk->queue             = q;
 283         disk->flags             = GENHD_FL_EXT_DEVT;
 284         nvdimm_namespace_disk_name(ndns, disk->disk_name);
 285         set_capacity(disk, 0);
 286         add_disk(disk);
 287
 288         if (nd_blk_meta_size(blk_dev)) {
 289                 int rc = nd_integrity_init(disk, nd_blk_meta_size(blk_dev));
 290
 291                 if (rc)
 292                         return rc;
 293         }
 294
 295         set_capacity(disk, available_disk_size >> SECTOR_SHIFT);
 296         revalidate_disk(disk);
 297         return 0;
 298 }
 299
 300 static int nd_blk_probe(struct device *dev)
 301 {
 302         struct nd_namespace_common *ndns;
 303         struct nd_namespace_blk *nsblk;
 304         struct nd_blk_device *blk_dev;
 305
 306         ndns = nvdimm_namespace_common_probe(dev);
 307         if (IS_ERR(ndns))
 308                 return PTR_ERR(ndns);
 309
 310         blk_dev = devm_kzalloc(dev, sizeof(*blk_dev), GFP_KERNEL);
 311         if (!blk_dev)
 312                 return -ENOMEM;
 313
 314         nsblk = to_nd_namespace_blk(&ndns->dev);
 315         blk_dev->disk_size = nvdimm_namespace_capacity(ndns);
 316         blk_dev->ndbr = to_nd_blk_region(dev->parent);
 317         blk_dev->nsblk = to_nd_namespace_blk(&ndns->dev);
 318         blk_dev->internal_lbasize = roundup(nsblk->lbasize,
 319                                                 INT_LBASIZE_ALIGNMENT);
 320         blk_dev->sector_size = ((nsblk->lbasize >= 4096) ? 4096 : 512);
 321         dev_set_drvdata(dev, blk_dev);
 322
 323         ndns->rw_bytes = nd_blk_rw_bytes;
 324         if (is_nd_btt(dev))
 325                 return nvdimm_namespace_attach_btt(ndns);
 326         else if (nd_btt_probe(dev, ndns, blk_dev) == 0) {
 327                 /* we'll come back as btt-blk */
 328                 return -ENXIO;
 329         } else
 330                 return nd_blk_attach_disk(dev, ndns, blk_dev);
 331 }
 332
 333 static int nd_blk_remove(struct device *dev)
 334 {
 335         if (is_nd_btt(dev))
 336                 nvdimm_namespace_detach_btt(to_nd_btt(dev));
 337         return 0;
 338 }
 339
 340 static struct nd_device_driver nd_blk_driver = {
 341         .probe = nd_blk_probe,
 342         .remove = nd_blk_remove,
 343         .drv = {
 344                 .name = "nd_blk",
 345         },
 346         .type = ND_DRIVER_NAMESPACE_BLK,
 347 };
 348
 349 static int __init nd_blk_init(void)
 350 {
 351         return nd_driver_register(&nd_blk_driver);
 352 }
 353
 354 static void __exit nd_blk_exit(void)
 355 {
 356         driver_unregister(&nd_blk_driver.drv);
 357 }
 358
 359 MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
 360 MODULE_LICENSE("GPL v2");
 361 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_BLK);
 362 module_init(nd_blk_init);
 363 module_exit(nd_blk_exit);