| /* |
| * NVDIMM Block Window Driver |
| * Copyright (c) 2014, Intel Corporation. |
| * |
| * This program is free software; you can redistribute it and/or modify it |
| * under the terms and conditions of the GNU General Public License, |
| * version 2, as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| * more details. |
| */ |
| |
| #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; |
| bvec_iter_advance(bip->bip_vec, &bip->bip_iter, cur_len); |
| } |
| |
| 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; |
| |
| /* |
| * bio_integrity_enabled also checks if the bio already has an |
| * integrity payload attached. If it does, we *don't* do a |
| * bio_integrity_prep here - the payload has been generated by |
| * another kernel subsystem, and we just pass it through. |
| */ |
| if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { |
| bio->bi_error = -EIO; |
| goto out; |
| } |
| |
| bip = bio_integrity(bio); |
| nsblk = q->queuedata; |
| rw = bio_data_dir(bio); |
| do_acct = nd_iostat_start(bio, &start); |
| 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_error = err; |
| break; |
| } |
| } |
| if (do_acct) |
| nd_iostat_end(bio, start); |
| |
| out: |
| 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) |
| { |
| 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(GFP_KERNEL); |
| if (!q) |
| return -ENOMEM; |
| if (devm_add_action_or_reset(dev, nd_blk_release_queue, q)) |
| return -ENOMEM; |
| |
| blk_queue_make_request(q, nd_blk_make_request); |
| blk_queue_max_hw_sectors(q, UINT_MAX); |
| blk_queue_bounce_limit(q, BLK_BOUNCE_ANY); |
| blk_queue_logical_block_size(q, nsblk_sector_size(nsblk)); |
| queue_flag_set_unlocked(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); |
| 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); |