Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 747 insertions, 0 deletions

diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
new file mode 100644
index 000000000..412c1787d
--- /dev/null
+++ b/drivers/scsi/sd_zbc.c
@@ -0,0 +1,747 @@
+/*
+ * SCSI Zoned Block commands
+ *
+ * Copyright (C) 2014-2015 SUSE Linux GmbH
+ * Written by: Hannes Reinecke <hare@suse.de>
+ * Modified by: Damien Le Moal <damien.lemoal@hgst.com>
+ * Modified by: Shaun Tancheff <shaun.tancheff@seagate.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
+ * USA.
+ *
+ */
+
+#include <linux/blkdev.h>
+
+#include <asm/unaligned.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+
+#include "sd.h"
+
+/**
+ * sd_zbc_parse_report - Convert a zone descriptor to a struct blk_zone,
+ * @sdkp: The disk the report originated from
+ * @buf: Address of the report zone descriptor
+ * @zone: the destination zone structure
+ *
+ * All LBA sized values are converted to 512B sectors unit.
+ */
+static void sd_zbc_parse_report(struct scsi_disk *sdkp, u8 *buf,
+				struct blk_zone *zone)
+{
+	struct scsi_device *sdp = sdkp->device;
+
+	memset(zone, 0, sizeof(struct blk_zone));
+
+	zone->type = buf[0] & 0x0f;
+	zone->cond = (buf[1] >> 4) & 0xf;
+	if (buf[1] & 0x01)
+		zone->reset = 1;
+	if (buf[1] & 0x02)
+		zone->non_seq = 1;
+
+	zone->len = logical_to_sectors(sdp, get_unaligned_be64(&buf[8]));
+	zone->start = logical_to_sectors(sdp, get_unaligned_be64(&buf[16]));
+	zone->wp = logical_to_sectors(sdp, get_unaligned_be64(&buf[24]));
+	if (zone->type != ZBC_ZONE_TYPE_CONV &&
+	    zone->cond == ZBC_ZONE_COND_FULL)
+		zone->wp = zone->start + zone->len;
+}
+
+/**
+ * sd_zbc_report_zones - Issue a REPORT ZONES scsi command.
+ * @sdkp: The target disk
+ * @buf: Buffer to use for the reply
+ * @buflen: the buffer size
+ * @lba: Start LBA of the report
+ *
+ * For internal use during device validation.
+ */
+static int sd_zbc_report_zones(struct scsi_disk *sdkp, unsigned char *buf,
+			       unsigned int buflen, sector_t lba)
+{
+	struct scsi_device *sdp = sdkp->device;
+	const int timeout = sdp->request_queue->rq_timeout;
+	struct scsi_sense_hdr sshdr;
+	unsigned char cmd[16];
+	unsigned int rep_len;
+	int result;
+
+	memset(cmd, 0, 16);
+	cmd[0] = ZBC_IN;
+	cmd[1] = ZI_REPORT_ZONES;
+	put_unaligned_be64(lba, &cmd[2]);
+	put_unaligned_be32(buflen, &cmd[10]);
+	memset(buf, 0, buflen);
+
+	result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
+				  buf, buflen, &sshdr,
+				  timeout, SD_MAX_RETRIES, NULL);
+	if (result) {
+		sd_printk(KERN_ERR, sdkp,
+			  "REPORT ZONES lba %llu failed with %d/%d\n",
+			  (unsigned long long)lba,
+			  host_byte(result), driver_byte(result));
+		return -EIO;
+	}
+
+	rep_len = get_unaligned_be32(&buf[0]);
+	if (rep_len < 64) {
+		sd_printk(KERN_ERR, sdkp,
+			  "REPORT ZONES report invalid length %u\n",
+			  rep_len);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+/**
+ * sd_zbc_setup_report_cmnd - Prepare a REPORT ZONES scsi command
+ * @cmd: The command to setup
+ *
+ * Call in sd_init_command() for a REQ_OP_ZONE_REPORT request.
+ */
+int sd_zbc_setup_report_cmnd(struct scsi_cmnd *cmd)
+{
+	struct request *rq = cmd->request;
+	struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
+	sector_t lba, sector = blk_rq_pos(rq);
+	unsigned int nr_bytes = blk_rq_bytes(rq);
+	int ret;
+
+	WARN_ON(nr_bytes == 0);
+
+	if (!sd_is_zoned(sdkp))
+		/* Not a zoned device */
+		return BLKPREP_KILL;
+
+	ret = scsi_init_io(cmd);
+	if (ret != BLKPREP_OK)
+		return ret;
+
+	cmd->cmd_len = 16;
+	memset(cmd->cmnd, 0, cmd->cmd_len);
+	cmd->cmnd[0] = ZBC_IN;
+	cmd->cmnd[1] = ZI_REPORT_ZONES;
+	lba = sectors_to_logical(sdkp->device, sector);
+	put_unaligned_be64(lba, &cmd->cmnd[2]);
+	put_unaligned_be32(nr_bytes, &cmd->cmnd[10]);
+	/* Do partial report for speeding things up */
+	cmd->cmnd[14] = ZBC_REPORT_ZONE_PARTIAL;
+
+	cmd->sc_data_direction = DMA_FROM_DEVICE;
+	cmd->sdb.length = nr_bytes;
+	cmd->transfersize = sdkp->device->sector_size;
+	cmd->allowed = 0;
+
+	return BLKPREP_OK;
+}
+
+/**
+ * sd_zbc_report_zones_complete - Process a REPORT ZONES scsi command reply.
+ * @scmd: The completed report zones command
+ * @good_bytes: reply size in bytes
+ *
+ * Convert all reported zone descriptors to struct blk_zone. The conversion
+ * is done in-place, directly in the request specified sg buffer.
+ */
+static void sd_zbc_report_zones_complete(struct scsi_cmnd *scmd,
+					 unsigned int good_bytes)
+{
+	struct request *rq = scmd->request;
+	struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
+	struct sg_mapping_iter miter;
+	struct blk_zone_report_hdr hdr;
+	struct blk_zone zone;
+	unsigned int offset, bytes = 0;
+	unsigned long flags;
+	u8 *buf;
+
+	if (good_bytes < 64)
+		return;
+
+	memset(&hdr, 0, sizeof(struct blk_zone_report_hdr));
+
+	sg_miter_start(&miter, scsi_sglist(scmd), scsi_sg_count(scmd),
+		       SG_MITER_TO_SG | SG_MITER_ATOMIC);
+
+	local_irq_save(flags);
+	while (sg_miter_next(&miter) && bytes < good_bytes) {
+
+		buf = miter.addr;
+		offset = 0;
+
+		if (bytes == 0) {
+			/* Set the report header */
+			hdr.nr_zones = min_t(unsigned int,
+					 (good_bytes - 64) / 64,
+					 get_unaligned_be32(&buf[0]) / 64);
+			memcpy(buf, &hdr, sizeof(struct blk_zone_report_hdr));
+			offset += 64;
+			bytes += 64;
+		}
+
+		/* Parse zone descriptors */
+		while (offset < miter.length && hdr.nr_zones) {
+			WARN_ON(offset > miter.length);
+			buf = miter.addr + offset;
+			sd_zbc_parse_report(sdkp, buf, &zone);
+			memcpy(buf, &zone, sizeof(struct blk_zone));
+			offset += 64;
+			bytes += 64;
+			hdr.nr_zones--;
+		}
+
+		if (!hdr.nr_zones)
+			break;
+
+	}
+	sg_miter_stop(&miter);
+	local_irq_restore(flags);
+}
+
+/**
+ * sd_zbc_zone_sectors - Get the device zone size in number of 512B sectors.
+ * @sdkp: The target disk
+ */
+static inline sector_t sd_zbc_zone_sectors(struct scsi_disk *sdkp)
+{
+	return logical_to_sectors(sdkp->device, sdkp->zone_blocks);
+}
+
+/**
+ * sd_zbc_setup_reset_cmnd - Prepare a RESET WRITE POINTER scsi command.
+ * @cmd: the command to setup
+ *
+ * Called from sd_init_command() for a REQ_OP_ZONE_RESET request.
+ */
+int sd_zbc_setup_reset_cmnd(struct scsi_cmnd *cmd)
+{
+	struct request *rq = cmd->request;
+	struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
+	sector_t sector = blk_rq_pos(rq);
+	sector_t block = sectors_to_logical(sdkp->device, sector);
+
+	if (!sd_is_zoned(sdkp))
+		/* Not a zoned device */
+		return BLKPREP_KILL;
+
+	if (sdkp->device->changed)
+		return BLKPREP_KILL;
+
+	if (sector & (sd_zbc_zone_sectors(sdkp) - 1))
+		/* Unaligned request */
+		return BLKPREP_KILL;
+
+	cmd->cmd_len = 16;
+	memset(cmd->cmnd, 0, cmd->cmd_len);
+	cmd->cmnd[0] = ZBC_OUT;
+	cmd->cmnd[1] = ZO_RESET_WRITE_POINTER;
+	put_unaligned_be64(block, &cmd->cmnd[2]);
+
+	rq->timeout = SD_TIMEOUT;
+	cmd->sc_data_direction = DMA_NONE;
+	cmd->transfersize = 0;
+	cmd->allowed = 0;
+
+	return BLKPREP_OK;
+}
+
+/**
+ * sd_zbc_complete - ZBC command post processing.
+ * @cmd: Completed command
+ * @good_bytes: Command reply bytes
+ * @sshdr: command sense header
+ *
+ * Called from sd_done(). Process report zones reply and handle reset zone
+ * and write commands errors.
+ */
+void sd_zbc_complete(struct scsi_cmnd *cmd, unsigned int good_bytes,
+		     struct scsi_sense_hdr *sshdr)
+{
+	int result = cmd->result;
+	struct request *rq = cmd->request;
+
+	switch (req_op(rq)) {
+	case REQ_OP_ZONE_RESET:
+
+		if (result &&
+		    sshdr->sense_key == ILLEGAL_REQUEST &&
+		    sshdr->asc == 0x24)
+			/*
+			 * INVALID FIELD IN CDB error: reset of a conventional
+			 * zone was attempted. Nothing to worry about, so be
+			 * quiet about the error.
+			 */
+			rq->rq_flags |= RQF_QUIET;
+		break;
+
+	case REQ_OP_WRITE:
+	case REQ_OP_WRITE_ZEROES:
+	case REQ_OP_WRITE_SAME:
+		break;
+
+	case REQ_OP_ZONE_REPORT:
+
+		if (!result)
+			sd_zbc_report_zones_complete(cmd, good_bytes);
+		break;
+
+	}
+}
+
+/**
+ * sd_zbc_read_zoned_characteristics - Read zoned block device characteristics
+ * @sdkp: Target disk
+ * @buf: Buffer where to store the VPD page data
+ *
+ * Read VPD page B6.
+ */
+static int sd_zbc_read_zoned_characteristics(struct scsi_disk *sdkp,
+					     unsigned char *buf)
+{
+
+	if (scsi_get_vpd_page(sdkp->device, 0xb6, buf, 64)) {
+		sd_printk(KERN_NOTICE, sdkp,
+			  "Unconstrained-read check failed\n");
+		return -ENODEV;
+	}
+
+	if (sdkp->device->type != TYPE_ZBC) {
+		/* Host-aware */
+		sdkp->urswrz = 1;
+		sdkp->zones_optimal_open = get_unaligned_be32(&buf[8]);
+		sdkp->zones_optimal_nonseq = get_unaligned_be32(&buf[12]);
+		sdkp->zones_max_open = 0;
+	} else {
+		/* Host-managed */
+		sdkp->urswrz = buf[4] & 1;
+		sdkp->zones_optimal_open = 0;
+		sdkp->zones_optimal_nonseq = 0;
+		sdkp->zones_max_open = get_unaligned_be32(&buf[16]);
+	}
+
+	return 0;
+}
+
+/**
+ * sd_zbc_check_capacity - Check reported capacity.
+ * @sdkp: Target disk
+ * @buf: Buffer to use for commands
+ *
+ * ZBC drive may report only the capacity of the first conventional zones at
+ * LBA 0. This is indicated by the RC_BASIS field of the read capacity reply.
+ * Check this here. If the disk reported only its conventional zones capacity,
+ * get the total capacity by doing a report zones.
+ */
+static int sd_zbc_check_capacity(struct scsi_disk *sdkp, unsigned char *buf)
+{
+	sector_t lba;
+	int ret;
+
+	if (sdkp->rc_basis != 0)
+		return 0;
+
+	/* Do a report zone to get the maximum LBA to check capacity */
+	ret = sd_zbc_report_zones(sdkp, buf, SD_BUF_SIZE, 0);
+	if (ret)
+		return ret;
+
+	/* The max_lba field is the capacity of this device */
+	lba = get_unaligned_be64(&buf[8]);
+	if (lba + 1 == sdkp->capacity)
+		return 0;
+
+	if (sdkp->first_scan)
+		sd_printk(KERN_WARNING, sdkp,
+			  "Changing capacity from %llu to max LBA+1 %llu\n",
+			  (unsigned long long)sdkp->capacity,
+			  (unsigned long long)lba + 1);
+	sdkp->capacity = lba + 1;
+
+	return 0;
+}
+
+#define SD_ZBC_BUF_SIZE 131072U
+
+/**
+ * sd_zbc_check_zone_size - Check the device zone sizes
+ * @sdkp: Target disk
+ *
+ * Check that all zones of the device are equal. The last zone can however
+ * be smaller. The zone size must also be a power of two number of LBAs.
+ *
+ * Returns the zone size in number of blocks upon success or an error code
+ * upon failure.
+ */
+static s64 sd_zbc_check_zone_size(struct scsi_disk *sdkp)
+{
+	u64 zone_blocks = 0;
+	sector_t block = 0;
+	unsigned char *buf;
+	unsigned char *rec;
+	unsigned int buf_len;
+	unsigned int list_length;
+	s64 ret;
+	u8 same;
+
+	/* Get a buffer */
+	buf = kmalloc(SD_ZBC_BUF_SIZE, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	/* Do a report zone to get the same field */
+	ret = sd_zbc_report_zones(sdkp, buf, SD_ZBC_BUF_SIZE, 0);
+	if (ret)
+		goto out_free;
+
+	same = buf[4] & 0x0f;
+	if (same > 0) {
+		rec = &buf[64];
+		zone_blocks = get_unaligned_be64(&rec[8]);
+		goto out;
+	}
+
+	/*
+	 * Check the size of all zones: all zones must be of
+	 * equal size, except the last zone which can be smaller
+	 * than other zones.
+	 */
+	do {
+
+		/* Parse REPORT ZONES header */
+		list_length = get_unaligned_be32(&buf[0]) + 64;
+		rec = buf + 64;
+		buf_len = min(list_length, SD_ZBC_BUF_SIZE);
+
+		/* Parse zone descriptors */
+		while (rec < buf + buf_len) {
+			u64 this_zone_blocks = get_unaligned_be64(&rec[8]);
+
+			if (zone_blocks == 0) {
+				zone_blocks = this_zone_blocks;
+			} else if (this_zone_blocks != zone_blocks &&
+				   (block + this_zone_blocks < sdkp->capacity
+				    || this_zone_blocks > zone_blocks)) {
+				zone_blocks = 0;
+				goto out;
+			}
+			block += this_zone_blocks;
+			rec += 64;
+		}
+
+		if (block < sdkp->capacity) {
+			ret = sd_zbc_report_zones(sdkp, buf,
+						  SD_ZBC_BUF_SIZE, block);
+			if (ret)
+				goto out_free;
+		}
+
+	} while (block < sdkp->capacity);
+
+out:
+	if (!zone_blocks) {
+		if (sdkp->first_scan)
+			sd_printk(KERN_NOTICE, sdkp,
+				  "Devices with non constant zone "
+				  "size are not supported\n");
+		ret = -ENODEV;
+	} else if (!is_power_of_2(zone_blocks)) {
+		if (sdkp->first_scan)
+			sd_printk(KERN_NOTICE, sdkp,
+				  "Devices with non power of 2 zone "
+				  "size are not supported\n");
+		ret = -ENODEV;
+	} else if (logical_to_sectors(sdkp->device, zone_blocks) > UINT_MAX) {
+		if (sdkp->first_scan)
+			sd_printk(KERN_NOTICE, sdkp,
+				  "Zone size too large\n");
+		ret = -ENODEV;
+	} else {
+		ret = zone_blocks;
+	}
+
+out_free:
+	kfree(buf);
+
+	return ret;
+}
+
+/**
+ * sd_zbc_alloc_zone_bitmap - Allocate a zone bitmap (one bit per zone).
+ * @nr_zones: Number of zones to allocate space for.
+ * @numa_node: NUMA node to allocate the memory from.
+ */
+static inline unsigned long *
+sd_zbc_alloc_zone_bitmap(u32 nr_zones, int numa_node)
+{
+	return kcalloc_node(BITS_TO_LONGS(nr_zones), sizeof(unsigned long),
+			    GFP_KERNEL, numa_node);
+}
+
+/**
+ * sd_zbc_get_seq_zones - Parse report zones reply to identify sequential zones
+ * @sdkp: disk used
+ * @buf: report reply buffer
+ * @buflen: length of @buf
+ * @zone_shift: logarithm base 2 of the number of blocks in a zone
+ * @seq_zones_bitmap: bitmap of sequential zones to set
+ *
+ * Parse reported zone descriptors in @buf to identify sequential zones and
+ * set the reported zone bit in @seq_zones_bitmap accordingly.
+ * Since read-only and offline zones cannot be written, do not
+ * mark them as sequential in the bitmap.
+ * Return the LBA after the last zone reported.
+ */
+static sector_t sd_zbc_get_seq_zones(struct scsi_disk *sdkp, unsigned char *buf,
+				     unsigned int buflen, u32 zone_shift,
+				     unsigned long *seq_zones_bitmap)
+{
+	sector_t lba, next_lba = sdkp->capacity;
+	unsigned int buf_len, list_length;
+	unsigned char *rec;
+	u8 type, cond;
+
+	list_length = get_unaligned_be32(&buf[0]) + 64;
+	buf_len = min(list_length, buflen);
+	rec = buf + 64;
+
+	while (rec < buf + buf_len) {
+		type = rec[0] & 0x0f;
+		cond = (rec[1] >> 4) & 0xf;
+		lba = get_unaligned_be64(&rec[16]);
+		if (type != ZBC_ZONE_TYPE_CONV &&
+		    cond != ZBC_ZONE_COND_READONLY &&
+		    cond != ZBC_ZONE_COND_OFFLINE)
+			set_bit(lba >> zone_shift, seq_zones_bitmap);
+		next_lba = lba + get_unaligned_be64(&rec[8]);
+		rec += 64;
+	}
+
+	return next_lba;
+}
+
+/**
+ * sd_zbc_setup_seq_zones_bitmap - Initialize a seq zone bitmap.
+ * @sdkp: target disk
+ * @zone_shift: logarithm base 2 of the number of blocks in a zone
+ * @nr_zones: number of zones to set up a seq zone bitmap for
+ *
+ * Allocate a zone bitmap and initialize it by identifying sequential zones.
+ */
+static unsigned long *
+sd_zbc_setup_seq_zones_bitmap(struct scsi_disk *sdkp, u32 zone_shift,
+			      u32 nr_zones)
+{
+	struct request_queue *q = sdkp->disk->queue;
+	unsigned long *seq_zones_bitmap;
+	sector_t lba = 0;
+	unsigned char *buf;
+	int ret = -ENOMEM;
+
+	seq_zones_bitmap = sd_zbc_alloc_zone_bitmap(nr_zones, q->node);
+	if (!seq_zones_bitmap)
+		return ERR_PTR(-ENOMEM);
+
+	buf = kmalloc(SD_ZBC_BUF_SIZE, GFP_KERNEL);
+	if (!buf)
+		goto out;
+
+	while (lba < sdkp->capacity) {
+		ret = sd_zbc_report_zones(sdkp, buf, SD_ZBC_BUF_SIZE, lba);
+		if (ret)
+			goto out;
+		lba = sd_zbc_get_seq_zones(sdkp, buf, SD_ZBC_BUF_SIZE,
+					   zone_shift, seq_zones_bitmap);
+	}
+
+	if (lba != sdkp->capacity) {
+		/* Something went wrong */
+		ret = -EIO;
+	}
+
+out:
+	kfree(buf);
+	if (ret) {
+		kfree(seq_zones_bitmap);
+		return ERR_PTR(ret);
+	}
+	return seq_zones_bitmap;
+}
+
+static void sd_zbc_cleanup(struct scsi_disk *sdkp)
+{
+	struct request_queue *q = sdkp->disk->queue;
+
+	kfree(q->seq_zones_bitmap);
+	q->seq_zones_bitmap = NULL;
+
+	kfree(q->seq_zones_wlock);
+	q->seq_zones_wlock = NULL;
+
+	q->nr_zones = 0;
+}
+
+static int sd_zbc_setup(struct scsi_disk *sdkp, u32 zone_blocks)
+{
+	struct request_queue *q = sdkp->disk->queue;
+	u32 zone_shift = ilog2(zone_blocks);
+	u32 nr_zones;
+	int ret;
+
+	/* chunk_sectors indicates the zone size */
+	blk_queue_chunk_sectors(q,
+			logical_to_sectors(sdkp->device, zone_blocks));
+	nr_zones = round_up(sdkp->capacity, zone_blocks) >> zone_shift;
+
+	/*
+	 * Initialize the device request queue information if the number
+	 * of zones changed.
+	 */
+	if (nr_zones != sdkp->nr_zones || nr_zones != q->nr_zones) {
+		unsigned long *seq_zones_wlock = NULL, *seq_zones_bitmap = NULL;
+		size_t zone_bitmap_size;
+
+		if (nr_zones) {
+			seq_zones_wlock = sd_zbc_alloc_zone_bitmap(nr_zones,
+								   q->node);
+			if (!seq_zones_wlock) {
+				ret = -ENOMEM;
+				goto err;
+			}
+
+			seq_zones_bitmap = sd_zbc_setup_seq_zones_bitmap(sdkp,
+							zone_shift, nr_zones);
+			if (IS_ERR(seq_zones_bitmap)) {
+				ret = PTR_ERR(seq_zones_bitmap);
+				kfree(seq_zones_wlock);
+				goto err;
+			}
+		}
+		zone_bitmap_size = BITS_TO_LONGS(nr_zones) *
+			sizeof(unsigned long);
+		blk_mq_freeze_queue(q);
+		if (q->nr_zones != nr_zones) {
+			/* READ16/WRITE16 is mandatory for ZBC disks */
+			sdkp->device->use_16_for_rw = 1;
+			sdkp->device->use_10_for_rw = 0;
+
+			sdkp->zone_blocks = zone_blocks;
+			sdkp->zone_shift = zone_shift;
+			sdkp->nr_zones = nr_zones;
+			q->nr_zones = nr_zones;
+			swap(q->seq_zones_wlock, seq_zones_wlock);
+			swap(q->seq_zones_bitmap, seq_zones_bitmap);
+		} else if (memcmp(q->seq_zones_bitmap, seq_zones_bitmap,
+				  zone_bitmap_size) != 0) {
+			memcpy(q->seq_zones_bitmap, seq_zones_bitmap,
+			       zone_bitmap_size);
+		}
+		blk_mq_unfreeze_queue(q);
+		kfree(seq_zones_wlock);
+		kfree(seq_zones_bitmap);
+	}
+
+	return 0;
+
+err:
+	sd_zbc_cleanup(sdkp);
+	return ret;
+}
+
+int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buf)
+{
+	int64_t zone_blocks;
+	int ret;
+
+	if (!sd_is_zoned(sdkp))
+		/*
+		 * Device managed or normal SCSI disk,
+		 * no special handling required
+		 */
+		return 0;
+
+	/* Get zoned block device characteristics */
+	ret = sd_zbc_read_zoned_characteristics(sdkp, buf);
+	if (ret)
+		goto err;
+
+	/*
+	 * Check for unconstrained reads: host-managed devices with
+	 * constrained reads (drives failing read after write pointer)
+	 * are not supported.
+	 */
+	if (!sdkp->urswrz) {
+		if (sdkp->first_scan)
+			sd_printk(KERN_NOTICE, sdkp,
+			  "constrained reads devices are not supported\n");
+		ret = -ENODEV;
+		goto err;
+	}
+
+	/* Check capacity */
+	ret = sd_zbc_check_capacity(sdkp, buf);
+	if (ret)
+		goto err;
+
+	/*
+	 * Check zone size: only devices with a constant zone size (except
+	 * an eventual last runt zone) that is a power of 2 are supported.
+	 */
+	zone_blocks = sd_zbc_check_zone_size(sdkp);
+	ret = -EFBIG;
+	if (zone_blocks != (u32)zone_blocks)
+		goto err;
+	ret = zone_blocks;
+	if (ret < 0)
+		goto err;
+
+	/* The drive satisfies the kernel restrictions: set it up */
+	ret = sd_zbc_setup(sdkp, zone_blocks);
+	if (ret)
+		goto err;
+
+	return 0;
+
+err:
+	sdkp->capacity = 0;
+	sd_zbc_cleanup(sdkp);
+
+	return ret;
+}
+
+void sd_zbc_remove(struct scsi_disk *sdkp)
+{
+	sd_zbc_cleanup(sdkp);
+}
+
+void sd_zbc_print_zones(struct scsi_disk *sdkp)
+{
+	if (!sd_is_zoned(sdkp) || !sdkp->capacity)
+		return;
+
+	if (sdkp->capacity & (sdkp->zone_blocks - 1))
+		sd_printk(KERN_NOTICE, sdkp,
+			  "%u zones of %u logical blocks + 1 runt zone\n",
+			  sdkp->nr_zones - 1,
+			  sdkp->zone_blocks);
+	else
+		sd_printk(KERN_NOTICE, sdkp,
+			  "%u zones of %u logical blocks\n",
+			  sdkp->nr_zones,
+			  sdkp->zone_blocks);
+}