// SPDX-License-Identifier: GPL-2.0-only /* * NVDIMM Block Window Driver * Copyright (c) 2014, Intel Corporation. */ #include <linux/blkdev.h> #include <linux/fs.h> #include <linux/genhd.h> #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/nd.h> #include <linux/sizes.h> #include "nd.h" static u32 nsblk_meta_size(struct nd_namespace_blk *nsblk) { return nsblk->lbasize - ((nsblk->lbasize >= 4096) ? 4096 : 512); } static u32 nsblk_internal_lbasize(struct nd_namespace_blk *nsblk) { return roundup(nsblk->lbasize, INT_LBASIZE_ALIGNMENT); } static u32 nsblk_sector_size(struct nd_namespace_blk *nsblk) { return nsblk->lbasize - nsblk_meta_size(nsblk); } static resource_size_t to_dev_offset(struct nd_namespace_blk *nsblk, resource_size_t ns_offset, unsigned int len) { int i; for (i = 0; i < nsblk->num_resources; i++) { if (ns_offset < resource_size(nsblk->res[i])) { if (ns_offset + len > resource_size(nsblk->res[i])) { dev_WARN_ONCE(&nsblk->common.dev, 1, "illegal request\n"); return SIZE_MAX; } return nsblk->res[i]->start + ns_offset; } ns_offset -= resource_size(nsblk->res[i]); } dev_WARN_ONCE(&nsblk->common.dev, 1, "request out of range\n"); return SIZE_MAX; } static struct nd_blk_region *to_ndbr(struct nd_namespace_blk *nsblk) { struct nd_region *nd_region; struct device *parent; parent = nsblk->common.dev.parent; nd_region = container_of(parent, struct nd_region, dev); return container_of(nd_region, struct nd_blk_region, nd_region); } #ifdef CONFIG_BLK_DEV_INTEGRITY static int nd_blk_rw_integrity(struct nd_namespace_blk *nsblk, struct bio_integrity_payload *bip, u64 lba, int rw) { struct nd_blk_region *ndbr = to_ndbr(nsblk); unsigned int len = nsblk_meta_size(nsblk); resource_size_t dev_offset, ns_offset; u32 internal_lbasize, sector_size; int err = 0; internal_lbasize = nsblk_internal_lbasize(nsblk); sector_size = nsblk_sector_size(nsblk); ns_offset = lba * internal_lbasize + sector_size; dev_offset = to_dev_offset(nsblk, ns_offset, len); if (dev_offset == SIZE_MAX) return -EIO; while (len) { unsigned int cur_len; struct bio_vec bv; void *iobuf; bv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter); /* * The 'bv' obtained from bvec_iter_bvec has its .bv_len and * .bv_offset already adjusted for iter->bi_bvec_done, and we * can use those directly */ cur_len = min(len, bv.bv_len); iobuf = kmap_atomic(bv.bv_page); err = ndbr->do_io(ndbr, dev_offset, iobuf + bv.bv_offset, cur_len, rw); kunmap_atomic(iobuf); if (err) return err; len -= cur_len; dev_offset += cur_len; if (!bvec_iter_advance(bip->bip_vec, &bip->bip_iter, cur_len)) return -EIO; } return err; } #else /* CONFIG_BLK_DEV_INTEGRITY */ static int nd_blk_rw_integrity(struct nd_namespace_blk *nsblk, struct bio_integrity_payload *bip, u64 lba, int rw) { return 0; } #endif static int nsblk_do_bvec(struct nd_namespace_blk *nsblk, struct bio_integrity_payload *bip, struct page *page, unsigned int len, unsigned int off, int rw, sector_t sector) { struct nd_blk_region *ndbr = to_ndbr(nsblk); resource_size_t dev_offset, ns_offset; u32 internal_lbasize, sector_size; int err = 0; void *iobuf; u64 lba; internal_lbasize = nsblk_internal_lbasize(nsblk); sector_size = nsblk_sector_size(nsblk); while (len) { unsigned int cur_len; /* * If we don't have an integrity payload, we don't have to * split the bvec into sectors, as this would cause unnecessary * Block Window setup/move steps. the do_io routine is capable * of handling len <= PAGE_SIZE. */ cur_len = bip ? min(len, sector_size) : len; lba = div_u64(sector << SECTOR_SHIFT, sector_size); ns_offset = lba * internal_lbasize; dev_offset = to_dev_offset(nsblk, ns_offset, cur_len); if (dev_offset == SIZE_MAX) return -EIO; iobuf = kmap_atomic(page); err = ndbr->do_io(ndbr, dev_offset, iobuf + off, cur_len, rw); kunmap_atomic(iobuf); if (err) return err; if (bip) { err = nd_blk_rw_integrity(nsblk, bip, lba, rw); if (err) return err; } len -= cur_len; off += cur_len; sector += sector_size >> SECTOR_SHIFT; } return err; } static blk_qc_t nd_blk_make_request(struct request_queue *q, struct bio *bio) { struct bio_integrity_payload *bip; struct nd_namespace_blk *nsblk; struct bvec_iter iter; unsigned long start; struct bio_vec bvec; int err = 0, rw; bool do_acct; if (!bio_integrity_prep(bio)) return BLK_QC_T_NONE; bip = bio_integrity(bio); nsblk = q->queuedata; rw = bio_data_dir(bio); do_acct = blk_queue_io_stat(bio->bi_disk->queue); if (do_acct) start = bio_start_io_acct(bio); bio_for_each_segment(bvec, bio, iter) { unsigned int len = bvec.bv_len; BUG_ON(len > PAGE_SIZE); err = nsblk_do_bvec(nsblk, bip, bvec.bv_page, len, bvec.bv_offset, rw, iter.bi_sector); if (err) { dev_dbg(&nsblk->common.dev, "io error in %s sector %lld, len %d,\n", (rw == READ) ? "READ" : "WRITE", (unsigned long long) iter.bi_sector, len); bio->bi_status = errno_to_blk_status(err); break; } } if (do_acct) bio_end_io_acct(bio, start); bio_endio(bio); return BLK_QC_T_NONE; } static int nsblk_rw_bytes(struct nd_namespace_common *ndns, resource_size_t offset, void *iobuf, size_t n, int rw, unsigned long flags) { struct nd_namespace_blk *nsblk = to_nd_namespace_blk(&ndns->dev); struct nd_blk_region *ndbr = to_ndbr(nsblk); resource_size_t dev_offset; dev_offset = to_dev_offset(nsblk, offset, n); if (unlikely(offset + n > nsblk->size)) { dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n"); return -EFAULT; } if (dev_offset == SIZE_MAX) return -EIO; return ndbr->do_io(ndbr, dev_offset, iobuf, n, rw); } static const struct block_device_operations nd_blk_fops = { .owner = THIS_MODULE, .revalidate_disk = nvdimm_revalidate_disk, }; static void nd_blk_release_queue(void *q) { blk_cleanup_queue(q); } static void nd_blk_release_disk(void *disk) { del_gendisk(disk); put_disk(disk); } static int nsblk_attach_disk(struct nd_namespace_blk *nsblk) { struct device *dev = &nsblk->common.dev; resource_size_t available_disk_size; struct request_queue *q; struct gendisk *disk; u64 internal_nlba; internal_nlba = div_u64(nsblk->size, nsblk_internal_lbasize(nsblk)); available_disk_size = internal_nlba * nsblk_sector_size(nsblk); q = blk_alloc_queue(nd_blk_make_request, NUMA_NO_NODE); if (!q) return -ENOMEM; if (devm_add_action_or_reset(dev, nd_blk_release_queue, q)) return -ENOMEM; blk_queue_max_hw_sectors(q, UINT_MAX); blk_queue_logical_block_size(q, nsblk_sector_size(nsblk)); blk_queue_flag_set(QUEUE_FLAG_NONROT, q); q->queuedata = nsblk; disk = alloc_disk(0); if (!disk) return -ENOMEM; disk->first_minor = 0; disk->fops = &nd_blk_fops; disk->queue = q; disk->flags = GENHD_FL_EXT_DEVT; nvdimm_namespace_disk_name(&nsblk->common, disk->disk_name); if (devm_add_action_or_reset(dev, nd_blk_release_disk, disk)) return -ENOMEM; if (nsblk_meta_size(nsblk)) { int rc = nd_integrity_init(disk, nsblk_meta_size(nsblk)); if (rc) return rc; } set_capacity(disk, available_disk_size >> SECTOR_SHIFT); device_add_disk(dev, disk, NULL); revalidate_disk(disk); return 0; } static int nd_blk_probe(struct device *dev) { struct nd_namespace_common *ndns; struct nd_namespace_blk *nsblk; ndns = nvdimm_namespace_common_probe(dev); if (IS_ERR(ndns)) return PTR_ERR(ndns); nsblk = to_nd_namespace_blk(&ndns->dev); nsblk->size = nvdimm_namespace_capacity(ndns); dev_set_drvdata(dev, nsblk); ndns->rw_bytes = nsblk_rw_bytes; if (is_nd_btt(dev)) return nvdimm_namespace_attach_btt(ndns); else if (nd_btt_probe(dev, ndns) == 0) { /* we'll come back as btt-blk */ return -ENXIO; } else return nsblk_attach_disk(nsblk); } static int nd_blk_remove(struct device *dev) { if (is_nd_btt(dev)) nvdimm_namespace_detach_btt(to_nd_btt(dev)); return 0; } static struct nd_device_driver nd_blk_driver = { .probe = nd_blk_probe, .remove = nd_blk_remove, .drv = { .name = "nd_blk", }, .type = ND_DRIVER_NAMESPACE_BLK, }; static int __init nd_blk_init(void) { return nd_driver_register(&nd_blk_driver); } static void __exit nd_blk_exit(void) { driver_unregister(&nd_blk_driver.drv); } MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_BLK); module_init(nd_blk_init); module_exit(nd_blk_exit);