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 16static u32 nsblk_meta_size(struct nd_namespace_blk *nsblk) 17{ 18 return nsblk->lbasize - ((nsblk->lbasize >= 4096) ? 4096 : 512); 19} 20 21static u32 nsblk_internal_lbasize(struct nd_namespace_blk *nsblk) 22{ 23 return roundup(nsblk->lbasize, INT_LBASIZE_ALIGNMENT); 24} 25 26static u32 nsblk_sector_size(struct nd_namespace_blk *nsblk) 27{ 28 return nsblk->lbasize - nsblk_meta_size(nsblk); 29} 30 31static 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 52static 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 63static 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 */ 109static 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 116static 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 165static blk_qc_t nd_blk_submit_bio(struct bio *bio) 166{ 167 struct bio_integrity_payload *bip; 168 struct nd_namespace_blk *nsblk = bio->bi_disk->private_data; 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 rw = bio_data_dir(bio); 180 do_acct = blk_queue_io_stat(bio->bi_disk->queue); 181 if (do_acct) 182 start = bio_start_io_acct(bio); 183 bio_for_each_segment(bvec, bio, iter) { 184 unsigned int len = bvec.bv_len; 185 186 BUG_ON(len > PAGE_SIZE); 187 err = nsblk_do_bvec(nsblk, bip, bvec.bv_page, len, 188 bvec.bv_offset, rw, iter.bi_sector); 189 if (err) { 190 dev_dbg(&nsblk->common.dev, 191 "io error in %s sector %lld, len %d,\n", 192 (rw == READ) ? "READ" : "WRITE", 193 (unsigned long long) iter.bi_sector, len); 194 bio->bi_status = errno_to_blk_status(err); 195 break; 196 } 197 } 198 if (do_acct) 199 bio_end_io_acct(bio, start); 200 201 bio_endio(bio); 202 return BLK_QC_T_NONE; 203} 204 205static int nsblk_rw_bytes(struct nd_namespace_common *ndns, 206 resource_size_t offset, void *iobuf, size_t n, int rw, 207 unsigned long flags) 208{ 209 struct nd_namespace_blk *nsblk = to_nd_namespace_blk(&ndns->dev); 210 struct nd_blk_region *ndbr = to_ndbr(nsblk); 211 resource_size_t dev_offset; 212 213 dev_offset = to_dev_offset(nsblk, offset, n); 214 215 if (unlikely(offset + n > nsblk->size)) { 216 dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n"); 217 return -EFAULT; 218 } 219 220 if (dev_offset == SIZE_MAX) 221 return -EIO; 222 223 return ndbr->do_io(ndbr, dev_offset, iobuf, n, rw); 224} 225 226static const struct block_device_operations nd_blk_fops = { 227 .owner = THIS_MODULE, 228 .submit_bio = nd_blk_submit_bio, 229}; 230 231static void nd_blk_release_queue(void *q) 232{ 233 blk_cleanup_queue(q); 234} 235 236static void nd_blk_release_disk(void *disk) 237{ 238 del_gendisk(disk); 239 put_disk(disk); 240} 241 242static int nsblk_attach_disk(struct nd_namespace_blk *nsblk) 243{ 244 struct device *dev = &nsblk->common.dev; 245 resource_size_t available_disk_size; 246 struct request_queue *q; 247 struct gendisk *disk; 248 u64 internal_nlba; 249 250 internal_nlba = div_u64(nsblk->size, nsblk_internal_lbasize(nsblk)); 251 available_disk_size = internal_nlba * nsblk_sector_size(nsblk); 252 253 q = blk_alloc_queue(NUMA_NO_NODE); 254 if (!q) 255 return -ENOMEM; 256 if (devm_add_action_or_reset(dev, nd_blk_release_queue, q)) 257 return -ENOMEM; 258 259 blk_queue_max_hw_sectors(q, UINT_MAX); 260 blk_queue_logical_block_size(q, nsblk_sector_size(nsblk)); 261 blk_queue_flag_set(QUEUE_FLAG_NONROT, q); 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 disk->private_data = nsblk; 272 nvdimm_namespace_disk_name(&nsblk->common, disk->disk_name); 273 274 if (devm_add_action_or_reset(dev, nd_blk_release_disk, disk)) 275 return -ENOMEM; 276 277 if (nsblk_meta_size(nsblk)) { 278 int rc = nd_integrity_init(disk, nsblk_meta_size(nsblk)); 279 280 if (rc) 281 return rc; 282 } 283 284 set_capacity(disk, available_disk_size >> SECTOR_SHIFT); 285 device_add_disk(dev, disk, NULL); 286 nvdimm_check_and_set_ro(disk); 287 return 0; 288} 289 290static int nd_blk_probe(struct device *dev) 291{ 292 struct nd_namespace_common *ndns; 293 struct nd_namespace_blk *nsblk; 294 295 ndns = nvdimm_namespace_common_probe(dev); 296 if (IS_ERR(ndns)) 297 return PTR_ERR(ndns); 298 299 nsblk = to_nd_namespace_blk(&ndns->dev); 300 nsblk->size = nvdimm_namespace_capacity(ndns); 301 dev_set_drvdata(dev, nsblk); 302 303 ndns->rw_bytes = nsblk_rw_bytes; 304 if (is_nd_btt(dev)) 305 return nvdimm_namespace_attach_btt(ndns); 306 else if (nd_btt_probe(dev, ndns) == 0) { 307 /* we'll come back as btt-blk */ 308 return -ENXIO; 309 } else 310 return nsblk_attach_disk(nsblk); 311} 312 313static int nd_blk_remove(struct device *dev) 314{ 315 if (is_nd_btt(dev)) 316 nvdimm_namespace_detach_btt(to_nd_btt(dev)); 317 return 0; 318} 319 320static struct nd_device_driver nd_blk_driver = { 321 .probe = nd_blk_probe, 322 .remove = nd_blk_remove, 323 .drv = { 324 .name = "nd_blk", 325 }, 326 .type = ND_DRIVER_NAMESPACE_BLK, 327}; 328 329static int __init nd_blk_init(void) 330{ 331 return nd_driver_register(&nd_blk_driver); 332} 333 334static void __exit nd_blk_exit(void) 335{ 336 driver_unregister(&nd_blk_driver.drv); 337} 338 339MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>"); 340MODULE_LICENSE("GPL v2"); 341MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_BLK); 342module_init(nd_blk_init); 343module_exit(nd_blk_exit); 344