xref: /openbmc/linux/drivers/scsi/sd_zbc.c (revision ba61bb17)
1 /*
2  * SCSI Zoned Block commands
3  *
4  * Copyright (C) 2014-2015 SUSE Linux GmbH
5  * Written by: Hannes Reinecke <hare@suse.de>
6  * Modified by: Damien Le Moal <damien.lemoal@hgst.com>
7  * Modified by: Shaun Tancheff <shaun.tancheff@seagate.com>
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License version
11  * 2 as published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful, but
14  * WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; see the file COPYING.  If not, write to
20  * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
21  * USA.
22  *
23  */
24 
25 #include <linux/blkdev.h>
26 
27 #include <asm/unaligned.h>
28 
29 #include <scsi/scsi.h>
30 #include <scsi/scsi_cmnd.h>
31 
32 #include "sd.h"
33 
34 /**
35  * sd_zbc_parse_report - Convert a zone descriptor to a struct blk_zone,
36  * @sdkp: The disk the report originated from
37  * @buf: Address of the report zone descriptor
38  * @zone: the destination zone structure
39  *
40  * All LBA sized values are converted to 512B sectors unit.
41  */
42 static void sd_zbc_parse_report(struct scsi_disk *sdkp, u8 *buf,
43 				struct blk_zone *zone)
44 {
45 	struct scsi_device *sdp = sdkp->device;
46 
47 	memset(zone, 0, sizeof(struct blk_zone));
48 
49 	zone->type = buf[0] & 0x0f;
50 	zone->cond = (buf[1] >> 4) & 0xf;
51 	if (buf[1] & 0x01)
52 		zone->reset = 1;
53 	if (buf[1] & 0x02)
54 		zone->non_seq = 1;
55 
56 	zone->len = logical_to_sectors(sdp, get_unaligned_be64(&buf[8]));
57 	zone->start = logical_to_sectors(sdp, get_unaligned_be64(&buf[16]));
58 	zone->wp = logical_to_sectors(sdp, get_unaligned_be64(&buf[24]));
59 	if (zone->type != ZBC_ZONE_TYPE_CONV &&
60 	    zone->cond == ZBC_ZONE_COND_FULL)
61 		zone->wp = zone->start + zone->len;
62 }
63 
64 /**
65  * sd_zbc_report_zones - Issue a REPORT ZONES scsi command.
66  * @sdkp: The target disk
67  * @buf: Buffer to use for the reply
68  * @buflen: the buffer size
69  * @lba: Start LBA of the report
70  *
71  * For internal use during device validation.
72  */
73 static int sd_zbc_report_zones(struct scsi_disk *sdkp, unsigned char *buf,
74 			       unsigned int buflen, sector_t lba)
75 {
76 	struct scsi_device *sdp = sdkp->device;
77 	const int timeout = sdp->request_queue->rq_timeout;
78 	struct scsi_sense_hdr sshdr;
79 	unsigned char cmd[16];
80 	unsigned int rep_len;
81 	int result;
82 
83 	memset(cmd, 0, 16);
84 	cmd[0] = ZBC_IN;
85 	cmd[1] = ZI_REPORT_ZONES;
86 	put_unaligned_be64(lba, &cmd[2]);
87 	put_unaligned_be32(buflen, &cmd[10]);
88 	memset(buf, 0, buflen);
89 
90 	result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
91 				  buf, buflen, &sshdr,
92 				  timeout, SD_MAX_RETRIES, NULL);
93 	if (result) {
94 		sd_printk(KERN_ERR, sdkp,
95 			  "REPORT ZONES lba %llu failed with %d/%d\n",
96 			  (unsigned long long)lba,
97 			  host_byte(result), driver_byte(result));
98 		return -EIO;
99 	}
100 
101 	rep_len = get_unaligned_be32(&buf[0]);
102 	if (rep_len < 64) {
103 		sd_printk(KERN_ERR, sdkp,
104 			  "REPORT ZONES report invalid length %u\n",
105 			  rep_len);
106 		return -EIO;
107 	}
108 
109 	return 0;
110 }
111 
112 /**
113  * sd_zbc_setup_report_cmnd - Prepare a REPORT ZONES scsi command
114  * @cmd: The command to setup
115  *
116  * Call in sd_init_command() for a REQ_OP_ZONE_REPORT request.
117  */
118 int sd_zbc_setup_report_cmnd(struct scsi_cmnd *cmd)
119 {
120 	struct request *rq = cmd->request;
121 	struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
122 	sector_t lba, sector = blk_rq_pos(rq);
123 	unsigned int nr_bytes = blk_rq_bytes(rq);
124 	int ret;
125 
126 	WARN_ON(nr_bytes == 0);
127 
128 	if (!sd_is_zoned(sdkp))
129 		/* Not a zoned device */
130 		return BLKPREP_KILL;
131 
132 	ret = scsi_init_io(cmd);
133 	if (ret != BLKPREP_OK)
134 		return ret;
135 
136 	cmd->cmd_len = 16;
137 	memset(cmd->cmnd, 0, cmd->cmd_len);
138 	cmd->cmnd[0] = ZBC_IN;
139 	cmd->cmnd[1] = ZI_REPORT_ZONES;
140 	lba = sectors_to_logical(sdkp->device, sector);
141 	put_unaligned_be64(lba, &cmd->cmnd[2]);
142 	put_unaligned_be32(nr_bytes, &cmd->cmnd[10]);
143 	/* Do partial report for speeding things up */
144 	cmd->cmnd[14] = ZBC_REPORT_ZONE_PARTIAL;
145 
146 	cmd->sc_data_direction = DMA_FROM_DEVICE;
147 	cmd->sdb.length = nr_bytes;
148 	cmd->transfersize = sdkp->device->sector_size;
149 	cmd->allowed = 0;
150 
151 	/*
152 	 * Report may return less bytes than requested. Make sure
153 	 * to report completion on the entire initial request.
154 	 */
155 	rq->__data_len = nr_bytes;
156 
157 	return BLKPREP_OK;
158 }
159 
160 /**
161  * sd_zbc_report_zones_complete - Process a REPORT ZONES scsi command reply.
162  * @scmd: The completed report zones command
163  * @good_bytes: reply size in bytes
164  *
165  * Convert all reported zone descriptors to struct blk_zone. The conversion
166  * is done in-place, directly in the request specified sg buffer.
167  */
168 static void sd_zbc_report_zones_complete(struct scsi_cmnd *scmd,
169 					 unsigned int good_bytes)
170 {
171 	struct request *rq = scmd->request;
172 	struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
173 	struct sg_mapping_iter miter;
174 	struct blk_zone_report_hdr hdr;
175 	struct blk_zone zone;
176 	unsigned int offset, bytes = 0;
177 	unsigned long flags;
178 	u8 *buf;
179 
180 	if (good_bytes < 64)
181 		return;
182 
183 	memset(&hdr, 0, sizeof(struct blk_zone_report_hdr));
184 
185 	sg_miter_start(&miter, scsi_sglist(scmd), scsi_sg_count(scmd),
186 		       SG_MITER_TO_SG | SG_MITER_ATOMIC);
187 
188 	local_irq_save(flags);
189 	while (sg_miter_next(&miter) && bytes < good_bytes) {
190 
191 		buf = miter.addr;
192 		offset = 0;
193 
194 		if (bytes == 0) {
195 			/* Set the report header */
196 			hdr.nr_zones = min_t(unsigned int,
197 					 (good_bytes - 64) / 64,
198 					 get_unaligned_be32(&buf[0]) / 64);
199 			memcpy(buf, &hdr, sizeof(struct blk_zone_report_hdr));
200 			offset += 64;
201 			bytes += 64;
202 		}
203 
204 		/* Parse zone descriptors */
205 		while (offset < miter.length && hdr.nr_zones) {
206 			WARN_ON(offset > miter.length);
207 			buf = miter.addr + offset;
208 			sd_zbc_parse_report(sdkp, buf, &zone);
209 			memcpy(buf, &zone, sizeof(struct blk_zone));
210 			offset += 64;
211 			bytes += 64;
212 			hdr.nr_zones--;
213 		}
214 
215 		if (!hdr.nr_zones)
216 			break;
217 
218 	}
219 	sg_miter_stop(&miter);
220 	local_irq_restore(flags);
221 }
222 
223 /**
224  * sd_zbc_zone_sectors - Get the device zone size in number of 512B sectors.
225  * @sdkp: The target disk
226  */
227 static inline sector_t sd_zbc_zone_sectors(struct scsi_disk *sdkp)
228 {
229 	return logical_to_sectors(sdkp->device, sdkp->zone_blocks);
230 }
231 
232 /**
233  * sd_zbc_setup_reset_cmnd - Prepare a RESET WRITE POINTER scsi command.
234  * @cmd: the command to setup
235  *
236  * Called from sd_init_command() for a REQ_OP_ZONE_RESET request.
237  */
238 int sd_zbc_setup_reset_cmnd(struct scsi_cmnd *cmd)
239 {
240 	struct request *rq = cmd->request;
241 	struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
242 	sector_t sector = blk_rq_pos(rq);
243 	sector_t block = sectors_to_logical(sdkp->device, sector);
244 
245 	if (!sd_is_zoned(sdkp))
246 		/* Not a zoned device */
247 		return BLKPREP_KILL;
248 
249 	if (sdkp->device->changed)
250 		return BLKPREP_KILL;
251 
252 	if (sector & (sd_zbc_zone_sectors(sdkp) - 1))
253 		/* Unaligned request */
254 		return BLKPREP_KILL;
255 
256 	cmd->cmd_len = 16;
257 	memset(cmd->cmnd, 0, cmd->cmd_len);
258 	cmd->cmnd[0] = ZBC_OUT;
259 	cmd->cmnd[1] = ZO_RESET_WRITE_POINTER;
260 	put_unaligned_be64(block, &cmd->cmnd[2]);
261 
262 	rq->timeout = SD_TIMEOUT;
263 	cmd->sc_data_direction = DMA_NONE;
264 	cmd->transfersize = 0;
265 	cmd->allowed = 0;
266 
267 	return BLKPREP_OK;
268 }
269 
270 /**
271  * sd_zbc_complete - ZBC command post processing.
272  * @cmd: Completed command
273  * @good_bytes: Command reply bytes
274  * @sshdr: command sense header
275  *
276  * Called from sd_done(). Process report zones reply and handle reset zone
277  * and write commands errors.
278  */
279 void sd_zbc_complete(struct scsi_cmnd *cmd, unsigned int good_bytes,
280 		     struct scsi_sense_hdr *sshdr)
281 {
282 	int result = cmd->result;
283 	struct request *rq = cmd->request;
284 
285 	switch (req_op(rq)) {
286 	case REQ_OP_ZONE_RESET:
287 
288 		if (result &&
289 		    sshdr->sense_key == ILLEGAL_REQUEST &&
290 		    sshdr->asc == 0x24)
291 			/*
292 			 * INVALID FIELD IN CDB error: reset of a conventional
293 			 * zone was attempted. Nothing to worry about, so be
294 			 * quiet about the error.
295 			 */
296 			rq->rq_flags |= RQF_QUIET;
297 		break;
298 
299 	case REQ_OP_WRITE:
300 	case REQ_OP_WRITE_ZEROES:
301 	case REQ_OP_WRITE_SAME:
302 		break;
303 
304 	case REQ_OP_ZONE_REPORT:
305 
306 		if (!result)
307 			sd_zbc_report_zones_complete(cmd, good_bytes);
308 		break;
309 
310 	}
311 }
312 
313 /**
314  * sd_zbc_read_zoned_characteristics - Read zoned block device characteristics
315  * @sdkp: Target disk
316  * @buf: Buffer where to store the VPD page data
317  *
318  * Read VPD page B6.
319  */
320 static int sd_zbc_read_zoned_characteristics(struct scsi_disk *sdkp,
321 					     unsigned char *buf)
322 {
323 
324 	if (scsi_get_vpd_page(sdkp->device, 0xb6, buf, 64)) {
325 		sd_printk(KERN_NOTICE, sdkp,
326 			  "Unconstrained-read check failed\n");
327 		return -ENODEV;
328 	}
329 
330 	if (sdkp->device->type != TYPE_ZBC) {
331 		/* Host-aware */
332 		sdkp->urswrz = 1;
333 		sdkp->zones_optimal_open = get_unaligned_be32(&buf[8]);
334 		sdkp->zones_optimal_nonseq = get_unaligned_be32(&buf[12]);
335 		sdkp->zones_max_open = 0;
336 	} else {
337 		/* Host-managed */
338 		sdkp->urswrz = buf[4] & 1;
339 		sdkp->zones_optimal_open = 0;
340 		sdkp->zones_optimal_nonseq = 0;
341 		sdkp->zones_max_open = get_unaligned_be32(&buf[16]);
342 	}
343 
344 	return 0;
345 }
346 
347 /**
348  * sd_zbc_check_capacity - Check reported capacity.
349  * @sdkp: Target disk
350  * @buf: Buffer to use for commands
351  *
352  * ZBC drive may report only the capacity of the first conventional zones at
353  * LBA 0. This is indicated by the RC_BASIS field of the read capacity reply.
354  * Check this here. If the disk reported only its conventional zones capacity,
355  * get the total capacity by doing a report zones.
356  */
357 static int sd_zbc_check_capacity(struct scsi_disk *sdkp, unsigned char *buf)
358 {
359 	sector_t lba;
360 	int ret;
361 
362 	if (sdkp->rc_basis != 0)
363 		return 0;
364 
365 	/* Do a report zone to get the maximum LBA to check capacity */
366 	ret = sd_zbc_report_zones(sdkp, buf, SD_BUF_SIZE, 0);
367 	if (ret)
368 		return ret;
369 
370 	/* The max_lba field is the capacity of this device */
371 	lba = get_unaligned_be64(&buf[8]);
372 	if (lba + 1 == sdkp->capacity)
373 		return 0;
374 
375 	if (sdkp->first_scan)
376 		sd_printk(KERN_WARNING, sdkp,
377 			  "Changing capacity from %llu to max LBA+1 %llu\n",
378 			  (unsigned long long)sdkp->capacity,
379 			  (unsigned long long)lba + 1);
380 	sdkp->capacity = lba + 1;
381 
382 	return 0;
383 }
384 
385 #define SD_ZBC_BUF_SIZE 131072U
386 
387 /**
388  * sd_zbc_check_zone_size - Check the device zone sizes
389  * @sdkp: Target disk
390  *
391  * Check that all zones of the device are equal. The last zone can however
392  * be smaller. The zone size must also be a power of two number of LBAs.
393  *
394  * Returns the zone size in bytes upon success or an error code upon failure.
395  */
396 static s64 sd_zbc_check_zone_size(struct scsi_disk *sdkp)
397 {
398 	u64 zone_blocks = 0;
399 	sector_t block = 0;
400 	unsigned char *buf;
401 	unsigned char *rec;
402 	unsigned int buf_len;
403 	unsigned int list_length;
404 	int ret;
405 	u8 same;
406 
407 	/* Get a buffer */
408 	buf = kmalloc(SD_ZBC_BUF_SIZE, GFP_KERNEL);
409 	if (!buf)
410 		return -ENOMEM;
411 
412 	/* Do a report zone to get the same field */
413 	ret = sd_zbc_report_zones(sdkp, buf, SD_ZBC_BUF_SIZE, 0);
414 	if (ret)
415 		goto out_free;
416 
417 	same = buf[4] & 0x0f;
418 	if (same > 0) {
419 		rec = &buf[64];
420 		zone_blocks = get_unaligned_be64(&rec[8]);
421 		goto out;
422 	}
423 
424 	/*
425 	 * Check the size of all zones: all zones must be of
426 	 * equal size, except the last zone which can be smaller
427 	 * than other zones.
428 	 */
429 	do {
430 
431 		/* Parse REPORT ZONES header */
432 		list_length = get_unaligned_be32(&buf[0]) + 64;
433 		rec = buf + 64;
434 		buf_len = min(list_length, SD_ZBC_BUF_SIZE);
435 
436 		/* Parse zone descriptors */
437 		while (rec < buf + buf_len) {
438 			u64 this_zone_blocks = get_unaligned_be64(&rec[8]);
439 
440 			if (zone_blocks == 0) {
441 				zone_blocks = this_zone_blocks;
442 			} else if (this_zone_blocks != zone_blocks &&
443 				   (block + this_zone_blocks < sdkp->capacity
444 				    || this_zone_blocks > zone_blocks)) {
445 				zone_blocks = 0;
446 				goto out;
447 			}
448 			block += this_zone_blocks;
449 			rec += 64;
450 		}
451 
452 		if (block < sdkp->capacity) {
453 			ret = sd_zbc_report_zones(sdkp, buf,
454 						  SD_ZBC_BUF_SIZE, block);
455 			if (ret)
456 				goto out_free;
457 		}
458 
459 	} while (block < sdkp->capacity);
460 
461 out:
462 	if (!zone_blocks) {
463 		if (sdkp->first_scan)
464 			sd_printk(KERN_NOTICE, sdkp,
465 				  "Devices with non constant zone "
466 				  "size are not supported\n");
467 		ret = -ENODEV;
468 	} else if (!is_power_of_2(zone_blocks)) {
469 		if (sdkp->first_scan)
470 			sd_printk(KERN_NOTICE, sdkp,
471 				  "Devices with non power of 2 zone "
472 				  "size are not supported\n");
473 		ret = -ENODEV;
474 	} else if (logical_to_sectors(sdkp->device, zone_blocks) > UINT_MAX) {
475 		if (sdkp->first_scan)
476 			sd_printk(KERN_NOTICE, sdkp,
477 				  "Zone size too large\n");
478 		ret = -ENODEV;
479 	} else {
480 		ret = zone_blocks;
481 	}
482 
483 out_free:
484 	kfree(buf);
485 
486 	return ret;
487 }
488 
489 /**
490  * sd_zbc_alloc_zone_bitmap - Allocate a zone bitmap (one bit per zone).
491  * @nr_zones: Number of zones to allocate space for.
492  * @numa_node: NUMA node to allocate the memory from.
493  */
494 static inline unsigned long *
495 sd_zbc_alloc_zone_bitmap(u32 nr_zones, int numa_node)
496 {
497 	return kcalloc_node(BITS_TO_LONGS(nr_zones), sizeof(unsigned long),
498 			    GFP_KERNEL, numa_node);
499 }
500 
501 /**
502  * sd_zbc_get_seq_zones - Parse report zones reply to identify sequential zones
503  * @sdkp: disk used
504  * @buf: report reply buffer
505  * @buflen: length of @buf
506  * @zone_shift: logarithm base 2 of the number of blocks in a zone
507  * @seq_zones_bitmap: bitmap of sequential zones to set
508  *
509  * Parse reported zone descriptors in @buf to identify sequential zones and
510  * set the reported zone bit in @seq_zones_bitmap accordingly.
511  * Since read-only and offline zones cannot be written, do not
512  * mark them as sequential in the bitmap.
513  * Return the LBA after the last zone reported.
514  */
515 static sector_t sd_zbc_get_seq_zones(struct scsi_disk *sdkp, unsigned char *buf,
516 				     unsigned int buflen, u32 zone_shift,
517 				     unsigned long *seq_zones_bitmap)
518 {
519 	sector_t lba, next_lba = sdkp->capacity;
520 	unsigned int buf_len, list_length;
521 	unsigned char *rec;
522 	u8 type, cond;
523 
524 	list_length = get_unaligned_be32(&buf[0]) + 64;
525 	buf_len = min(list_length, buflen);
526 	rec = buf + 64;
527 
528 	while (rec < buf + buf_len) {
529 		type = rec[0] & 0x0f;
530 		cond = (rec[1] >> 4) & 0xf;
531 		lba = get_unaligned_be64(&rec[16]);
532 		if (type != ZBC_ZONE_TYPE_CONV &&
533 		    cond != ZBC_ZONE_COND_READONLY &&
534 		    cond != ZBC_ZONE_COND_OFFLINE)
535 			set_bit(lba >> zone_shift, seq_zones_bitmap);
536 		next_lba = lba + get_unaligned_be64(&rec[8]);
537 		rec += 64;
538 	}
539 
540 	return next_lba;
541 }
542 
543 /**
544  * sd_zbc_setup_seq_zones_bitmap - Initialize a seq zone bitmap.
545  * @sdkp: target disk
546  * @zone_shift: logarithm base 2 of the number of blocks in a zone
547  * @nr_zones: number of zones to set up a seq zone bitmap for
548  *
549  * Allocate a zone bitmap and initialize it by identifying sequential zones.
550  */
551 static unsigned long *
552 sd_zbc_setup_seq_zones_bitmap(struct scsi_disk *sdkp, u32 zone_shift,
553 			      u32 nr_zones)
554 {
555 	struct request_queue *q = sdkp->disk->queue;
556 	unsigned long *seq_zones_bitmap;
557 	sector_t lba = 0;
558 	unsigned char *buf;
559 	int ret = -ENOMEM;
560 
561 	seq_zones_bitmap = sd_zbc_alloc_zone_bitmap(nr_zones, q->node);
562 	if (!seq_zones_bitmap)
563 		return ERR_PTR(-ENOMEM);
564 
565 	buf = kmalloc(SD_ZBC_BUF_SIZE, GFP_KERNEL);
566 	if (!buf)
567 		goto out;
568 
569 	while (lba < sdkp->capacity) {
570 		ret = sd_zbc_report_zones(sdkp, buf, SD_ZBC_BUF_SIZE, lba);
571 		if (ret)
572 			goto out;
573 		lba = sd_zbc_get_seq_zones(sdkp, buf, SD_ZBC_BUF_SIZE,
574 					   zone_shift, seq_zones_bitmap);
575 	}
576 
577 	if (lba != sdkp->capacity) {
578 		/* Something went wrong */
579 		ret = -EIO;
580 	}
581 
582 out:
583 	kfree(buf);
584 	if (ret) {
585 		kfree(seq_zones_bitmap);
586 		return ERR_PTR(ret);
587 	}
588 	return seq_zones_bitmap;
589 }
590 
591 static void sd_zbc_cleanup(struct scsi_disk *sdkp)
592 {
593 	struct request_queue *q = sdkp->disk->queue;
594 
595 	kfree(q->seq_zones_bitmap);
596 	q->seq_zones_bitmap = NULL;
597 
598 	kfree(q->seq_zones_wlock);
599 	q->seq_zones_wlock = NULL;
600 
601 	q->nr_zones = 0;
602 }
603 
604 static int sd_zbc_setup(struct scsi_disk *sdkp, u32 zone_blocks)
605 {
606 	struct request_queue *q = sdkp->disk->queue;
607 	u32 zone_shift = ilog2(zone_blocks);
608 	u32 nr_zones;
609 	int ret;
610 
611 	/* chunk_sectors indicates the zone size */
612 	blk_queue_chunk_sectors(q,
613 			logical_to_sectors(sdkp->device, zone_blocks));
614 	nr_zones = round_up(sdkp->capacity, zone_blocks) >> zone_shift;
615 
616 	/*
617 	 * Initialize the device request queue information if the number
618 	 * of zones changed.
619 	 */
620 	if (nr_zones != sdkp->nr_zones || nr_zones != q->nr_zones) {
621 		unsigned long *seq_zones_wlock = NULL, *seq_zones_bitmap = NULL;
622 		size_t zone_bitmap_size;
623 
624 		if (nr_zones) {
625 			seq_zones_wlock = sd_zbc_alloc_zone_bitmap(nr_zones,
626 								   q->node);
627 			if (!seq_zones_wlock) {
628 				ret = -ENOMEM;
629 				goto err;
630 			}
631 
632 			seq_zones_bitmap = sd_zbc_setup_seq_zones_bitmap(sdkp,
633 							zone_shift, nr_zones);
634 			if (IS_ERR(seq_zones_bitmap)) {
635 				ret = PTR_ERR(seq_zones_bitmap);
636 				kfree(seq_zones_wlock);
637 				goto err;
638 			}
639 		}
640 		zone_bitmap_size = BITS_TO_LONGS(nr_zones) *
641 			sizeof(unsigned long);
642 		blk_mq_freeze_queue(q);
643 		if (q->nr_zones != nr_zones) {
644 			/* READ16/WRITE16 is mandatory for ZBC disks */
645 			sdkp->device->use_16_for_rw = 1;
646 			sdkp->device->use_10_for_rw = 0;
647 
648 			sdkp->zone_blocks = zone_blocks;
649 			sdkp->zone_shift = zone_shift;
650 			sdkp->nr_zones = nr_zones;
651 			q->nr_zones = nr_zones;
652 			swap(q->seq_zones_wlock, seq_zones_wlock);
653 			swap(q->seq_zones_bitmap, seq_zones_bitmap);
654 		} else if (memcmp(q->seq_zones_bitmap, seq_zones_bitmap,
655 				  zone_bitmap_size) != 0) {
656 			memcpy(q->seq_zones_bitmap, seq_zones_bitmap,
657 			       zone_bitmap_size);
658 		}
659 		blk_mq_unfreeze_queue(q);
660 		kfree(seq_zones_wlock);
661 		kfree(seq_zones_bitmap);
662 	}
663 
664 	return 0;
665 
666 err:
667 	sd_zbc_cleanup(sdkp);
668 	return ret;
669 }
670 
671 int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buf)
672 {
673 	int64_t zone_blocks;
674 	int ret;
675 
676 	if (!sd_is_zoned(sdkp))
677 		/*
678 		 * Device managed or normal SCSI disk,
679 		 * no special handling required
680 		 */
681 		return 0;
682 
683 	/* Get zoned block device characteristics */
684 	ret = sd_zbc_read_zoned_characteristics(sdkp, buf);
685 	if (ret)
686 		goto err;
687 
688 	/*
689 	 * Check for unconstrained reads: host-managed devices with
690 	 * constrained reads (drives failing read after write pointer)
691 	 * are not supported.
692 	 */
693 	if (!sdkp->urswrz) {
694 		if (sdkp->first_scan)
695 			sd_printk(KERN_NOTICE, sdkp,
696 			  "constrained reads devices are not supported\n");
697 		ret = -ENODEV;
698 		goto err;
699 	}
700 
701 	/* Check capacity */
702 	ret = sd_zbc_check_capacity(sdkp, buf);
703 	if (ret)
704 		goto err;
705 
706 	/*
707 	 * Check zone size: only devices with a constant zone size (except
708 	 * an eventual last runt zone) that is a power of 2 are supported.
709 	 */
710 	zone_blocks = sd_zbc_check_zone_size(sdkp);
711 	ret = -EFBIG;
712 	if (zone_blocks != (u32)zone_blocks)
713 		goto err;
714 	ret = zone_blocks;
715 	if (ret < 0)
716 		goto err;
717 
718 	/* The drive satisfies the kernel restrictions: set it up */
719 	ret = sd_zbc_setup(sdkp, zone_blocks);
720 	if (ret)
721 		goto err;
722 
723 	return 0;
724 
725 err:
726 	sdkp->capacity = 0;
727 	sd_zbc_cleanup(sdkp);
728 
729 	return ret;
730 }
731 
732 void sd_zbc_remove(struct scsi_disk *sdkp)
733 {
734 	sd_zbc_cleanup(sdkp);
735 }
736 
737 void sd_zbc_print_zones(struct scsi_disk *sdkp)
738 {
739 	if (!sd_is_zoned(sdkp) || !sdkp->capacity)
740 		return;
741 
742 	if (sdkp->capacity & (sdkp->zone_blocks - 1))
743 		sd_printk(KERN_NOTICE, sdkp,
744 			  "%u zones of %u logical blocks + 1 runt zone\n",
745 			  sdkp->nr_zones - 1,
746 			  sdkp->zone_blocks);
747 	else
748 		sd_printk(KERN_NOTICE, sdkp,
749 			  "%u zones of %u logical blocks\n",
750 			  sdkp->nr_zones,
751 			  sdkp->zone_blocks);
752 }
753