1 files changed, 384 insertions, 0 deletions

diff --git a/drivers/nvdimm/blk.c b/drivers/nvdimm/blk.c
new file mode 100644
index 000000000000..4f97b248c236
--- /dev/null
+++ b/drivers/nvdimm/blk.c
@@ -0,0 +1,384 @@
+/*
+ * 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"
+
+struct nd_blk_device {
+        struct request_queue *queue;
+        struct gendisk *disk;
+        struct nd_namespace_blk *nsblk;
+        struct nd_blk_region *ndbr;
+        size_t disk_size;
+        u32 sector_size;
+        u32 internal_lbasize;
+};
+
+static int nd_blk_major;
+
+static u32 nd_blk_meta_size(struct nd_blk_device *blk_dev)
+{
+        return blk_dev->nsblk->lbasize - blk_dev->sector_size;
+}
+
+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;
+}
+
+#ifdef CONFIG_BLK_DEV_INTEGRITY
+static int nd_blk_rw_integrity(struct nd_blk_device *blk_dev,
+                                struct bio_integrity_payload *bip, u64 lba,
+                                int rw)
+{
+        unsigned int len = nd_blk_meta_size(blk_dev);
+        resource_size_t dev_offset, ns_offset;
+        struct nd_namespace_blk *nsblk;
+        struct nd_blk_region *ndbr;
+        int err = 0;
+
+        nsblk = blk_dev->nsblk;
+        ndbr = blk_dev->ndbr;
+        ns_offset = lba * blk_dev->internal_lbasize + blk_dev->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_blk_device *blk_dev,
+                                struct bio_integrity_payload *bip, u64 lba,
+                                int rw)
+{
+        return 0;
+}
+#endif
+
+static int nd_blk_do_bvec(struct nd_blk_device *blk_dev,
+                        struct bio_integrity_payload *bip, struct page *page,
+                        unsigned int len, unsigned int off, int rw,
+                        sector_t sector)
+{
+        struct nd_blk_region *ndbr = blk_dev->ndbr;
+        resource_size_t dev_offset, ns_offset;
+        int err = 0;
+        void *iobuf;
+        u64 lba;
+
+        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, blk_dev->sector_size) : len;
+
+                lba = div_u64(sector << SECTOR_SHIFT, blk_dev->sector_size);
+                ns_offset = lba * blk_dev->internal_lbasize;
+                dev_offset = to_dev_offset(blk_dev->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(blk_dev, bip, lba, rw);
+                        if (err)
+                                return err;
+                }
+                len -= cur_len;
+                off += cur_len;
+                sector += blk_dev->sector_size >> SECTOR_SHIFT;
+        }
+
+        return err;
+}
+
+static void nd_blk_make_request(struct request_queue *q, struct bio *bio)
+{
+        struct block_device *bdev = bio->bi_bdev;
+        struct gendisk *disk = bdev->bd_disk;
+        struct bio_integrity_payload *bip;
+        struct nd_blk_device *blk_dev;
+        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)) {
+                err = -EIO;
+                goto out;
+        }
+
+        bip = bio_integrity(bio);
+        blk_dev = disk->private_data;
+        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 = nd_blk_do_bvec(blk_dev, bip, bvec.bv_page, len,
+                                        bvec.bv_offset, rw, iter.bi_sector);
+                if (err) {
+                        dev_info(&blk_dev->nsblk->common.dev,
+                                        "io error in %s sector %lld, len %d,\n",
+                                        (rw == READ) ? "READ" : "WRITE",
+                                        (unsigned long long) iter.bi_sector, len);
+                        break;
+                }
+        }
+        if (do_acct)
+                nd_iostat_end(bio, start);
+
+ out:
+        bio_endio(bio, err);
+}
+
+static int nd_blk_rw_bytes(struct nd_namespace_common *ndns,
+                resource_size_t offset, void *iobuf, size_t n, int rw)
+{
+        struct nd_blk_device *blk_dev = dev_get_drvdata(ndns->claim);
+        struct nd_namespace_blk *nsblk = blk_dev->nsblk;
+        struct nd_blk_region *ndbr = blk_dev->ndbr;
+        resource_size_t dev_offset;
+
+        dev_offset = to_dev_offset(nsblk, offset, n);
+
+        if (unlikely(offset + n > blk_dev->disk_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 int nd_blk_attach_disk(struct nd_namespace_common *ndns,
+                struct nd_blk_device *blk_dev)
+{
+        resource_size_t available_disk_size;
+        struct gendisk *disk;
+        u64 internal_nlba;
+
+        internal_nlba = div_u64(blk_dev->disk_size, blk_dev->internal_lbasize);
+        available_disk_size = internal_nlba * blk_dev->sector_size;
+
+        blk_dev->queue = blk_alloc_queue(GFP_KERNEL);
+        if (!blk_dev->queue)
+                return -ENOMEM;
+
+        blk_queue_make_request(blk_dev->queue, nd_blk_make_request);
+        blk_queue_max_hw_sectors(blk_dev->queue, UINT_MAX);
+        blk_queue_bounce_limit(blk_dev->queue, BLK_BOUNCE_ANY);
+        blk_queue_logical_block_size(blk_dev->queue, blk_dev->sector_size);
+        queue_flag_set_unlocked(QUEUE_FLAG_NONROT, blk_dev->queue);
+
+        disk = blk_dev->disk = alloc_disk(0);
+        if (!disk) {
+                blk_cleanup_queue(blk_dev->queue);
+                return -ENOMEM;
+        }
+
+        disk->driverfs_dev      = &ndns->dev;
+        disk->major             = nd_blk_major;
+        disk->first_minor       = 0;
+        disk->fops              = &nd_blk_fops;
+        disk->private_data      = blk_dev;
+        disk->queue             = blk_dev->queue;
+        disk->flags             = GENHD_FL_EXT_DEVT;
+        nvdimm_namespace_disk_name(ndns, disk->disk_name);
+        set_capacity(disk, 0);
+        add_disk(disk);
+
+        if (nd_blk_meta_size(blk_dev)) {
+                int rc = nd_integrity_init(disk, nd_blk_meta_size(blk_dev));
+
+                if (rc) {
+                        del_gendisk(disk);
+                        put_disk(disk);
+                        blk_cleanup_queue(blk_dev->queue);
+                        return rc;
+                }
+        }
+
+        set_capacity(disk, available_disk_size >> SECTOR_SHIFT);
+        revalidate_disk(disk);
+        return 0;
+}
+
+static int nd_blk_probe(struct device *dev)
+{
+        struct nd_namespace_common *ndns;
+        struct nd_namespace_blk *nsblk;
+        struct nd_blk_device *blk_dev;
+        int rc;
+
+        ndns = nvdimm_namespace_common_probe(dev);
+        if (IS_ERR(ndns))
+                return PTR_ERR(ndns);
+
+        blk_dev = kzalloc(sizeof(*blk_dev), GFP_KERNEL);
+        if (!blk_dev)
+                return -ENOMEM;
+
+        nsblk = to_nd_namespace_blk(&ndns->dev);
+        blk_dev->disk_size = nvdimm_namespace_capacity(ndns);
+        blk_dev->ndbr = to_nd_blk_region(dev->parent);
+        blk_dev->nsblk = to_nd_namespace_blk(&ndns->dev);
+        blk_dev->internal_lbasize = roundup(nsblk->lbasize,
+                                                INT_LBASIZE_ALIGNMENT);
+        blk_dev->sector_size = ((nsblk->lbasize >= 4096) ? 4096 : 512);
+        dev_set_drvdata(dev, blk_dev);
+
+        ndns->rw_bytes = nd_blk_rw_bytes;
+        if (is_nd_btt(dev))
+                rc = nvdimm_namespace_attach_btt(ndns);
+        else if (nd_btt_probe(ndns, blk_dev) == 0) {
+                /* we'll come back as btt-blk */
+                rc = -ENXIO;
+        } else
+                rc = nd_blk_attach_disk(ndns, blk_dev);
+        if (rc)
+                kfree(blk_dev);
+        return rc;
+}
+
+static void nd_blk_detach_disk(struct nd_blk_device *blk_dev)
+{
+        del_gendisk(blk_dev->disk);
+        put_disk(blk_dev->disk);
+        blk_cleanup_queue(blk_dev->queue);
+}
+
+static int nd_blk_remove(struct device *dev)
+{
+        struct nd_blk_device *blk_dev = dev_get_drvdata(dev);
+
+        if (is_nd_btt(dev))
+                nvdimm_namespace_detach_btt(to_nd_btt(dev)->ndns);
+        else
+                nd_blk_detach_disk(blk_dev);
+        kfree(blk_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)
+{
+        int rc;
+
+        rc = register_blkdev(0, "nd_blk");
+        if (rc < 0)
+                return rc;
+
+        nd_blk_major = rc;
+        rc = nd_driver_register(&nd_blk_driver);
+
+        if (rc < 0)
+                unregister_blkdev(nd_blk_major, "nd_blk");
+
+        return rc;
+}
+
+static void __exit nd_blk_exit(void)
+{
+        driver_unregister(&nd_blk_driver.drv);
+        unregister_blkdev(nd_blk_major, "nd_blk");
+}
+
+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);