drivers/nvdimm/blk.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * NVDIMM Block Window Driver
   4  * Copyright (c) 2014, Intel Corporation.
   5  */
   6
   7 #include <linux/blkdev.h>
   8 #include <linux/fs.h>
   9 #include <linux/genhd.h>
  10 #include <linux/module.h>
  11 #include <linux/moduleparam.h>
  12 #include <linux/nd.h>
  13 #include <linux/sizes.h>
  14 #include "nd.h"
  15
  16 static u32 nsblk_meta_size(struct nd_namespace_blk *nsblk)
  17 {
  18         return nsblk->lbasize - ((nsblk->lbasize >= 4096) ? 4096 : 512);
  19 }
  20
  21 static u32 nsblk_internal_lbasize(struct nd_namespace_blk *nsblk)
  22 {
  23         return roundup(nsblk->lbasize, INT_LBASIZE_ALIGNMENT);
  24 }
  25
  26 static u32 nsblk_sector_size(struct nd_namespace_blk *nsblk)
  27 {
  28         return nsblk->lbasize - nsblk_meta_size(nsblk);
  29 }
  30
  31 static resource_size_t to_dev_offset(struct nd_namespace_blk *nsblk,
  32                                 resource_size_t ns_offset, unsigned int len)
  33 {
  34         int i;
  35
  36         for (i = 0; i < nsblk->num_resources; i++) {
  37                 if (ns_offset < resource_size(nsblk->res[i])) {
  38                         if (ns_offset + len > resource_size(nsblk->res[i])) {
  39                                 dev_WARN_ONCE(&nsblk->common.dev, 1,
  40                                         "illegal request\n");
  41                                 return SIZE_MAX;
  42                         }
  43                         return nsblk->res[i]->start + ns_offset;
  44                 }
  45                 ns_offset -= resource_size(nsblk->res[i]);
  46         }
  47
  48         dev_WARN_ONCE(&nsblk->common.dev, 1, "request out of range\n");
  49         return SIZE_MAX;
  50 }
  51
  52 static struct nd_blk_region *to_ndbr(struct nd_namespace_blk *nsblk)
  53 {
  54         struct nd_region *nd_region;
  55         struct device *parent;
  56
  57         parent = nsblk->common.dev.parent;
  58         nd_region = container_of(parent, struct nd_region, dev);
  59         return container_of(nd_region, struct nd_blk_region, nd_region);
  60 }
  61
  62 #ifdef CONFIG_BLK_DEV_INTEGRITY
  63 static int nd_blk_rw_integrity(struct nd_namespace_blk *nsblk,
  64                 struct bio_integrity_payload *bip, u64 lba, int rw)
  65 {
  66         struct nd_blk_region *ndbr = to_ndbr(nsblk);
  67         unsigned int len = nsblk_meta_size(nsblk);
  68         resource_size_t dev_offset, ns_offset;
  69         u32 internal_lbasize, sector_size;
  70         int err = 0;
  71
  72         internal_lbasize = nsblk_internal_lbasize(nsblk);
  73         sector_size = nsblk_sector_size(nsblk);
  74         ns_offset = lba * internal_lbasize + sector_size;
  75         dev_offset = to_dev_offset(nsblk, ns_offset, len);
  76         if (dev_offset == SIZE_MAX)
  77                 return -EIO;
  78
  79         while (len) {
  80                 unsigned int cur_len;
  81                 struct bio_vec bv;
  82                 void *iobuf;
  83
  84                 bv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter);
  85                 /*
  86                  * The 'bv' obtained from bvec_iter_bvec has its .bv_len and
  87                  * .bv_offset already adjusted for iter->bi_bvec_done, and we
  88                  * can use those directly
  89                  */
  90
  91                 cur_len = min(len, bv.bv_len);
  92                 iobuf = kmap_atomic(bv.bv_page);
  93                 err = ndbr->do_io(ndbr, dev_offset, iobuf + bv.bv_offset,
  94                                 cur_len, rw);
  95                 kunmap_atomic(iobuf);
  96                 if (err)
  97                         return err;
  98
  99                 len -= cur_len;
 100                 dev_offset += cur_len;
 101                 if (!bvec_iter_advance(bip->bip_vec, &bip->bip_iter, cur_len))
 102                         return -EIO;
 103         }
 104
 105         return err;
 106 }
 107
 108 #else /* CONFIG_BLK_DEV_INTEGRITY */
 109 static int nd_blk_rw_integrity(struct nd_namespace_blk *nsblk,
 110                 struct bio_integrity_payload *bip, u64 lba, int rw)
 111 {
 112         return 0;
 113 }
 114 #endif
 115
 116 static int nsblk_do_bvec(struct nd_namespace_blk *nsblk,
 117                 struct bio_integrity_payload *bip, struct page *page,
 118                 unsigned int len, unsigned int off, int rw, sector_t sector)
 119 {
 120         struct nd_blk_region *ndbr = to_ndbr(nsblk);
 121         resource_size_t dev_offset, ns_offset;
 122         u32 internal_lbasize, sector_size;
 123         int err = 0;
 124         void *iobuf;
 125         u64 lba;
 126
 127         internal_lbasize = nsblk_internal_lbasize(nsblk);
 128         sector_size = nsblk_sector_size(nsblk);
 129         while (len) {
 130                 unsigned int cur_len;
 131
 132                 /*
 133                  * If we don't have an integrity payload, we don't have to
 134                  * split the bvec into sectors, as this would cause unnecessary
 135                  * Block Window setup/move steps. the do_io routine is capable
 136                  * of handling len <= PAGE_SIZE.
 137                  */
 138                 cur_len = bip ? min(len, sector_size) : len;
 139
 140                 lba = div_u64(sector << SECTOR_SHIFT, sector_size);
 141                 ns_offset = lba * internal_lbasize;
 142                 dev_offset = to_dev_offset(nsblk, ns_offset, cur_len);
 143                 if (dev_offset == SIZE_MAX)
 144                         return -EIO;
 145
 146                 iobuf = kmap_atomic(page);
 147                 err = ndbr->do_io(ndbr, dev_offset, iobuf + off, cur_len, rw);
 148                 kunmap_atomic(iobuf);
 149                 if (err)
 150                         return err;
 151
 152                 if (bip) {
 153                         err = nd_blk_rw_integrity(nsblk, bip, lba, rw);
 154                         if (err)
 155                                 return err;
 156                 }
 157                 len -= cur_len;
 158                 off += cur_len;
 159                 sector += sector_size >> SECTOR_SHIFT;
 160         }
 161
 162         return err;
 163 }
 164
 165 static blk_qc_t nd_blk_make_request(struct request_queue *q, struct bio *bio)
 166 {
 167         struct bio_integrity_payload *bip;
 168         struct nd_namespace_blk *nsblk;
 169         struct bvec_iter iter;
 170         unsigned long start;
 171         struct bio_vec bvec;
 172         int err = 0, rw;
 173         bool do_acct;
 174
 175         if (!bio_integrity_prep(bio))
 176                 return BLK_QC_T_NONE;
 177
 178         bip = bio_integrity(bio);
 179         nsblk = q->queuedata;
 180         rw = bio_data_dir(bio);
 181         do_acct = nd_iostat_start(bio, &start);
 182         bio_for_each_segment(bvec, bio, iter) {
 183                 unsigned int len = bvec.bv_len;
 184
 185                 BUG_ON(len > PAGE_SIZE);
 186                 err = nsblk_do_bvec(nsblk, bip, bvec.bv_page, len,
 187                                 bvec.bv_offset, rw, iter.bi_sector);
 188                 if (err) {
 189                         dev_dbg(&nsblk->common.dev,
 190                                         "io error in %s sector %lld, len %d,\n",
 191                                         (rw == READ) ? "READ" : "WRITE",
 192                                         (unsigned long long) iter.bi_sector, len);
 193                         bio->bi_status = errno_to_blk_status(err);
 194                         break;
 195                 }
 196         }
 197         if (do_acct)
 198                 nd_iostat_end(bio, start);
 199
 200         bio_endio(bio);
 201         return BLK_QC_T_NONE;
 202 }
 203
 204 static int nsblk_rw_bytes(struct nd_namespace_common *ndns,
 205                 resource_size_t offset, void *iobuf, size_t n, int rw,
 206                 unsigned long flags)
 207 {
 208         struct nd_namespace_blk *nsblk = to_nd_namespace_blk(&ndns->dev);
 209         struct nd_blk_region *ndbr = to_ndbr(nsblk);
 210         resource_size_t dev_offset;
 211
 212         dev_offset = to_dev_offset(nsblk, offset, n);
 213
 214         if (unlikely(offset + n > nsblk->size)) {
 215                 dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
 216                 return -EFAULT;
 217         }
 218
 219         if (dev_offset == SIZE_MAX)
 220                 return -EIO;
 221
 222         return ndbr->do_io(ndbr, dev_offset, iobuf, n, rw);
 223 }
 224
 225 static const struct block_device_operations nd_blk_fops = {
 226         .owner = THIS_MODULE,
 227         .revalidate_disk = nvdimm_revalidate_disk,
 228 };
 229
 230 static void nd_blk_release_queue(void *q)
 231 {
 232         blk_cleanup_queue(q);
 233 }
 234
 235 static void nd_blk_release_disk(void *disk)
 236 {
 237         del_gendisk(disk);
 238         put_disk(disk);
 239 }
 240
 241 static int nsblk_attach_disk(struct nd_namespace_blk *nsblk)
 242 {
 243         struct device *dev = &nsblk->common.dev;
 244         resource_size_t available_disk_size;
 245         struct request_queue *q;
 246         struct gendisk *disk;
 247         u64 internal_nlba;
 248
 249         internal_nlba = div_u64(nsblk->size, nsblk_internal_lbasize(nsblk));
 250         available_disk_size = internal_nlba * nsblk_sector_size(nsblk);
 251
 252         q = blk_alloc_queue(nd_blk_make_request, NUMA_NO_NODE);
 253         if (!q)
 254                 return -ENOMEM;
 255         if (devm_add_action_or_reset(dev, nd_blk_release_queue, q))
 256                 return -ENOMEM;
 257
 258         blk_queue_max_hw_sectors(q, UINT_MAX);
 259         blk_queue_logical_block_size(q, nsblk_sector_size(nsblk));
 260         blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
 261         q->queuedata = nsblk;
 262
 263         disk = alloc_disk(0);
 264         if (!disk)
 265                 return -ENOMEM;
 266
 267         disk->first_minor       = 0;
 268         disk->fops              = &nd_blk_fops;
 269         disk->queue             = q;
 270         disk->flags             = GENHD_FL_EXT_DEVT;
 271         nvdimm_namespace_disk_name(&nsblk->common, disk->disk_name);
 272
 273         if (devm_add_action_or_reset(dev, nd_blk_release_disk, disk))
 274                 return -ENOMEM;
 275
 276         if (nsblk_meta_size(nsblk)) {
 277                 int rc = nd_integrity_init(disk, nsblk_meta_size(nsblk));
 278
 279                 if (rc)
 280                         return rc;
 281         }
 282
 283         set_capacity(disk, available_disk_size >> SECTOR_SHIFT);
 284         device_add_disk(dev, disk, NULL);
 285         revalidate_disk(disk);
 286         return 0;
 287 }
 288
 289 static int nd_blk_probe(struct device *dev)
 290 {
 291         struct nd_namespace_common *ndns;
 292         struct nd_namespace_blk *nsblk;
 293
 294         ndns = nvdimm_namespace_common_probe(dev);
 295         if (IS_ERR(ndns))
 296                 return PTR_ERR(ndns);
 297
 298         nsblk = to_nd_namespace_blk(&ndns->dev);
 299         nsblk->size = nvdimm_namespace_capacity(ndns);
 300         dev_set_drvdata(dev, nsblk);
 301
 302         ndns->rw_bytes = nsblk_rw_bytes;
 303         if (is_nd_btt(dev))
 304                 return nvdimm_namespace_attach_btt(ndns);
 305         else if (nd_btt_probe(dev, ndns) == 0) {
 306                 /* we'll come back as btt-blk */
 307                 return -ENXIO;
 308         } else
 309                 return nsblk_attach_disk(nsblk);
 310 }
 311
 312 static int nd_blk_remove(struct device *dev)
 313 {
 314         if (is_nd_btt(dev))
 315                 nvdimm_namespace_detach_btt(to_nd_btt(dev));
 316         return 0;
 317 }
 318
 319 static struct nd_device_driver nd_blk_driver = {
 320         .probe = nd_blk_probe,
 321         .remove = nd_blk_remove,
 322         .drv = {
 323                 .name = "nd_blk",
 324         },
 325         .type = ND_DRIVER_NAMESPACE_BLK,
 326 };
 327
 328 static int __init nd_blk_init(void)
 329 {
 330         return nd_driver_register(&nd_blk_driver);
 331 }
 332
 333 static void __exit nd_blk_exit(void)
 334 {
 335         driver_unregister(&nd_blk_driver.drv);
 336 }
 337
 338 MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
 339 MODULE_LICENSE("GPL v2");
 340 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_BLK);
 341 module_init(nd_blk_init);
 342 module_exit(nd_blk_exit);