1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * SCSI Zoned Block commands
4  *
5  * Copyright (C) 2014-2015 SUSE Linux GmbH
6  * Written by: Hannes Reinecke <hare@suse.de>
7  * Modified by: Damien Le Moal <damien.lemoal@hgst.com>
8  * Modified by: Shaun Tancheff <shaun.tancheff@seagate.com>
9  */
10 
11 #include <linux/blkdev.h>
12 #include <linux/vmalloc.h>
13 #include <linux/sched/mm.h>
14 #include <linux/mutex.h>
15 
16 #include <asm/unaligned.h>
17 
18 #include <scsi/scsi.h>
19 #include <scsi/scsi_cmnd.h>
20 
21 #include "sd.h"
22 
sd_zbc_get_zone_wp_offset(struct blk_zone * zone)23 static unsigned int sd_zbc_get_zone_wp_offset(struct blk_zone *zone)
24 {
25 	if (zone->type == ZBC_ZONE_TYPE_CONV)
26 		return 0;
27 
28 	switch (zone->cond) {
29 	case BLK_ZONE_COND_IMP_OPEN:
30 	case BLK_ZONE_COND_EXP_OPEN:
31 	case BLK_ZONE_COND_CLOSED:
32 		return zone->wp - zone->start;
33 	case BLK_ZONE_COND_FULL:
34 		return zone->len;
35 	case BLK_ZONE_COND_EMPTY:
36 	case BLK_ZONE_COND_OFFLINE:
37 	case BLK_ZONE_COND_READONLY:
38 	default:
39 		/*
40 		 * Offline and read-only zones do not have a valid
41 		 * write pointer. Use 0 as for an empty zone.
42 		 */
43 		return 0;
44 	}
45 }
46 
sd_zbc_parse_report(struct scsi_disk * sdkp,u8 * buf,unsigned int idx,report_zones_cb cb,void * data)47 static int sd_zbc_parse_report(struct scsi_disk *sdkp, u8 *buf,
48 			       unsigned int idx, report_zones_cb cb, void *data)
49 {
50 	struct scsi_device *sdp = sdkp->device;
51 	struct blk_zone zone = { 0 };
52 	int ret;
53 
54 	zone.type = buf[0] & 0x0f;
55 	zone.cond = (buf[1] >> 4) & 0xf;
56 	if (buf[1] & 0x01)
57 		zone.reset = 1;
58 	if (buf[1] & 0x02)
59 		zone.non_seq = 1;
60 
61 	zone.len = logical_to_sectors(sdp, get_unaligned_be64(&buf[8]));
62 	zone.capacity = zone.len;
63 	zone.start = logical_to_sectors(sdp, get_unaligned_be64(&buf[16]));
64 	zone.wp = logical_to_sectors(sdp, get_unaligned_be64(&buf[24]));
65 	if (zone.type != ZBC_ZONE_TYPE_CONV &&
66 	    zone.cond == ZBC_ZONE_COND_FULL)
67 		zone.wp = zone.start + zone.len;
68 
69 	ret = cb(&zone, idx, data);
70 	if (ret)
71 		return ret;
72 
73 	if (sdkp->rev_wp_offset)
74 		sdkp->rev_wp_offset[idx] = sd_zbc_get_zone_wp_offset(&zone);
75 
76 	return 0;
77 }
78 
79 /**
80  * sd_zbc_do_report_zones - Issue a REPORT ZONES scsi command.
81  * @sdkp: The target disk
82  * @buf: vmalloc-ed buffer to use for the reply
83  * @buflen: the buffer size
84  * @lba: Start LBA of the report
85  * @partial: Do partial report
86  *
87  * For internal use during device validation.
88  * Using partial=true can significantly speed up execution of a report zones
89  * command because the disk does not have to count all possible report matching
90  * zones and will only report the count of zones fitting in the command reply
91  * buffer.
92  */
sd_zbc_do_report_zones(struct scsi_disk * sdkp,unsigned char * buf,unsigned int buflen,sector_t lba,bool partial)93 static int sd_zbc_do_report_zones(struct scsi_disk *sdkp, unsigned char *buf,
94 				  unsigned int buflen, sector_t lba,
95 				  bool partial)
96 {
97 	struct scsi_device *sdp = sdkp->device;
98 	const int timeout = sdp->request_queue->rq_timeout;
99 	struct scsi_sense_hdr sshdr;
100 	unsigned char cmd[16];
101 	unsigned int rep_len;
102 	int result;
103 
104 	memset(cmd, 0, 16);
105 	cmd[0] = ZBC_IN;
106 	cmd[1] = ZI_REPORT_ZONES;
107 	put_unaligned_be64(lba, &cmd[2]);
108 	put_unaligned_be32(buflen, &cmd[10]);
109 	if (partial)
110 		cmd[14] = ZBC_REPORT_ZONE_PARTIAL;
111 
112 	result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
113 				  buf, buflen, &sshdr,
114 				  timeout, SD_MAX_RETRIES, NULL);
115 	if (result) {
116 		sd_printk(KERN_ERR, sdkp,
117 			  "REPORT ZONES start lba %llu failed\n", lba);
118 		sd_print_result(sdkp, "REPORT ZONES", result);
119 		if (driver_byte(result) == DRIVER_SENSE &&
120 		    scsi_sense_valid(&sshdr))
121 			sd_print_sense_hdr(sdkp, &sshdr);
122 		return -EIO;
123 	}
124 
125 	rep_len = get_unaligned_be32(&buf[0]);
126 	if (rep_len < 64) {
127 		sd_printk(KERN_ERR, sdkp,
128 			  "REPORT ZONES report invalid length %u\n",
129 			  rep_len);
130 		return -EIO;
131 	}
132 
133 	return 0;
134 }
135 
136 /**
137  * Allocate a buffer for report zones reply.
138  * @sdkp: The target disk
139  * @nr_zones: Maximum number of zones to report
140  * @buflen: Size of the buffer allocated
141  *
142  * Try to allocate a reply buffer for the number of requested zones.
143  * The size of the buffer allocated may be smaller than requested to
144  * satify the device constraint (max_hw_sectors, max_segments, etc).
145  *
146  * Return the address of the allocated buffer and update @buflen with
147  * the size of the allocated buffer.
148  */
sd_zbc_alloc_report_buffer(struct scsi_disk * sdkp,unsigned int nr_zones,size_t * buflen)149 static void *sd_zbc_alloc_report_buffer(struct scsi_disk *sdkp,
150 					unsigned int nr_zones, size_t *buflen)
151 {
152 	struct request_queue *q = sdkp->disk->queue;
153 	size_t bufsize;
154 	void *buf;
155 
156 	/*
157 	 * Report zone buffer size should be at most 64B times the number of
158 	 * zones requested plus the 64B reply header, but should be at least
159 	 * SECTOR_SIZE for ATA devices.
160 	 * Make sure that this size does not exceed the hardware capabilities.
161 	 * Furthermore, since the report zone command cannot be split, make
162 	 * sure that the allocated buffer can always be mapped by limiting the
163 	 * number of pages allocated to the HBA max segments limit.
164 	 */
165 	nr_zones = min(nr_zones, sdkp->nr_zones);
166 	bufsize = roundup((nr_zones + 1) * 64, SECTOR_SIZE);
167 	bufsize = min_t(size_t, bufsize,
168 			queue_max_hw_sectors(q) << SECTOR_SHIFT);
169 	bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT);
170 
171 	while (bufsize >= SECTOR_SIZE) {
172 		buf = __vmalloc(bufsize,
173 				GFP_KERNEL | __GFP_ZERO | __GFP_NORETRY);
174 		if (buf) {
175 			*buflen = bufsize;
176 			return buf;
177 		}
178 		bufsize >>= 1;
179 	}
180 
181 	return NULL;
182 }
183 
184 /**
185  * sd_zbc_zone_sectors - Get the device zone size in number of 512B sectors.
186  * @sdkp: The target disk
187  */
sd_zbc_zone_sectors(struct scsi_disk * sdkp)188 static inline sector_t sd_zbc_zone_sectors(struct scsi_disk *sdkp)
189 {
190 	return logical_to_sectors(sdkp->device, sdkp->zone_blocks);
191 }
192 
sd_zbc_report_zones(struct gendisk * disk,sector_t sector,unsigned int nr_zones,report_zones_cb cb,void * data)193 int sd_zbc_report_zones(struct gendisk *disk, sector_t sector,
194 			unsigned int nr_zones, report_zones_cb cb, void *data)
195 {
196 	struct scsi_disk *sdkp = scsi_disk(disk);
197 	sector_t capacity = logical_to_sectors(sdkp->device, sdkp->capacity);
198 	unsigned int nr, i;
199 	unsigned char *buf;
200 	size_t offset, buflen = 0;
201 	int zone_idx = 0;
202 	int ret;
203 
204 	if (!sd_is_zoned(sdkp))
205 		/* Not a zoned device */
206 		return -EOPNOTSUPP;
207 
208 	if (!capacity)
209 		/* Device gone or invalid */
210 		return -ENODEV;
211 
212 	buf = sd_zbc_alloc_report_buffer(sdkp, nr_zones, &buflen);
213 	if (!buf)
214 		return -ENOMEM;
215 
216 	while (zone_idx < nr_zones && sector < capacity) {
217 		ret = sd_zbc_do_report_zones(sdkp, buf, buflen,
218 				sectors_to_logical(sdkp->device, sector), true);
219 		if (ret)
220 			goto out;
221 
222 		offset = 0;
223 		nr = min(nr_zones, get_unaligned_be32(&buf[0]) / 64);
224 		if (!nr)
225 			break;
226 
227 		for (i = 0; i < nr && zone_idx < nr_zones; i++) {
228 			offset += 64;
229 			ret = sd_zbc_parse_report(sdkp, buf + offset, zone_idx,
230 						  cb, data);
231 			if (ret)
232 				goto out;
233 			zone_idx++;
234 		}
235 
236 		sector += sd_zbc_zone_sectors(sdkp) * i;
237 	}
238 
239 	ret = zone_idx;
240 out:
241 	kvfree(buf);
242 	return ret;
243 }
244 
sd_zbc_cmnd_checks(struct scsi_cmnd * cmd)245 static blk_status_t sd_zbc_cmnd_checks(struct scsi_cmnd *cmd)
246 {
247 	struct request *rq = cmd->request;
248 	struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
249 	sector_t sector = blk_rq_pos(rq);
250 
251 	if (!sd_is_zoned(sdkp))
252 		/* Not a zoned device */
253 		return BLK_STS_IOERR;
254 
255 	if (sdkp->device->changed)
256 		return BLK_STS_IOERR;
257 
258 	if (sector & (sd_zbc_zone_sectors(sdkp) - 1))
259 		/* Unaligned request */
260 		return BLK_STS_IOERR;
261 
262 	return BLK_STS_OK;
263 }
264 
265 #define SD_ZBC_INVALID_WP_OFST	(~0u)
266 #define SD_ZBC_UPDATING_WP_OFST	(SD_ZBC_INVALID_WP_OFST - 1)
267 
sd_zbc_update_wp_offset_cb(struct blk_zone * zone,unsigned int idx,void * data)268 static int sd_zbc_update_wp_offset_cb(struct blk_zone *zone, unsigned int idx,
269 				    void *data)
270 {
271 	struct scsi_disk *sdkp = data;
272 
273 	lockdep_assert_held(&sdkp->zones_wp_offset_lock);
274 
275 	sdkp->zones_wp_offset[idx] = sd_zbc_get_zone_wp_offset(zone);
276 
277 	return 0;
278 }
279 
sd_zbc_update_wp_offset_workfn(struct work_struct * work)280 static void sd_zbc_update_wp_offset_workfn(struct work_struct *work)
281 {
282 	struct scsi_disk *sdkp;
283 	unsigned int zno;
284 	int ret;
285 
286 	sdkp = container_of(work, struct scsi_disk, zone_wp_offset_work);
287 
288 	spin_lock_bh(&sdkp->zones_wp_offset_lock);
289 	for (zno = 0; zno < sdkp->nr_zones; zno++) {
290 		if (sdkp->zones_wp_offset[zno] != SD_ZBC_UPDATING_WP_OFST)
291 			continue;
292 
293 		spin_unlock_bh(&sdkp->zones_wp_offset_lock);
294 		ret = sd_zbc_do_report_zones(sdkp, sdkp->zone_wp_update_buf,
295 					     SD_BUF_SIZE,
296 					     zno * sdkp->zone_blocks, true);
297 		spin_lock_bh(&sdkp->zones_wp_offset_lock);
298 		if (!ret)
299 			sd_zbc_parse_report(sdkp, sdkp->zone_wp_update_buf + 64,
300 					    zno, sd_zbc_update_wp_offset_cb,
301 					    sdkp);
302 	}
303 	spin_unlock_bh(&sdkp->zones_wp_offset_lock);
304 
305 	scsi_device_put(sdkp->device);
306 }
307 
308 /**
309  * sd_zbc_prepare_zone_append() - Prepare an emulated ZONE_APPEND command.
310  * @cmd: the command to setup
311  * @lba: the LBA to patch
312  * @nr_blocks: the number of LBAs to be written
313  *
314  * Called from sd_setup_read_write_cmnd() for REQ_OP_ZONE_APPEND.
315  * @sd_zbc_prepare_zone_append() handles the necessary zone wrote locking and
316  * patching of the lba for an emulated ZONE_APPEND command.
317  *
318  * In case the cached write pointer offset is %SD_ZBC_INVALID_WP_OFST it will
319  * schedule a REPORT ZONES command and return BLK_STS_IOERR.
320  */
sd_zbc_prepare_zone_append(struct scsi_cmnd * cmd,sector_t * lba,unsigned int nr_blocks)321 blk_status_t sd_zbc_prepare_zone_append(struct scsi_cmnd *cmd, sector_t *lba,
322 					unsigned int nr_blocks)
323 {
324 	struct request *rq = cmd->request;
325 	struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
326 	unsigned int wp_offset, zno = blk_rq_zone_no(rq);
327 	blk_status_t ret;
328 
329 	ret = sd_zbc_cmnd_checks(cmd);
330 	if (ret != BLK_STS_OK)
331 		return ret;
332 
333 	if (!blk_rq_zone_is_seq(rq))
334 		return BLK_STS_IOERR;
335 
336 	/* Unlock of the write lock will happen in sd_zbc_complete() */
337 	if (!blk_req_zone_write_trylock(rq))
338 		return BLK_STS_ZONE_RESOURCE;
339 
340 	spin_lock_bh(&sdkp->zones_wp_offset_lock);
341 	wp_offset = sdkp->zones_wp_offset[zno];
342 	switch (wp_offset) {
343 	case SD_ZBC_INVALID_WP_OFST:
344 		/*
345 		 * We are about to schedule work to update a zone write pointer
346 		 * offset, which will cause the zone append command to be
347 		 * requeued. So make sure that the scsi device does not go away
348 		 * while the work is being processed.
349 		 */
350 		if (scsi_device_get(sdkp->device)) {
351 			ret = BLK_STS_IOERR;
352 			break;
353 		}
354 		sdkp->zones_wp_offset[zno] = SD_ZBC_UPDATING_WP_OFST;
355 		schedule_work(&sdkp->zone_wp_offset_work);
356 		fallthrough;
357 	case SD_ZBC_UPDATING_WP_OFST:
358 		ret = BLK_STS_DEV_RESOURCE;
359 		break;
360 	default:
361 		wp_offset = sectors_to_logical(sdkp->device, wp_offset);
362 		if (wp_offset + nr_blocks > sdkp->zone_blocks) {
363 			ret = BLK_STS_IOERR;
364 			break;
365 		}
366 
367 		*lba += wp_offset;
368 	}
369 	spin_unlock_bh(&sdkp->zones_wp_offset_lock);
370 	if (ret)
371 		blk_req_zone_write_unlock(rq);
372 	return ret;
373 }
374 
375 /**
376  * sd_zbc_setup_zone_mgmt_cmnd - Prepare a zone ZBC_OUT command. The operations
377  *			can be RESET WRITE POINTER, OPEN, CLOSE or FINISH.
378  * @cmd: the command to setup
379  * @op: Operation to be performed
380  * @all: All zones control
381  *
382  * Called from sd_init_command() for REQ_OP_ZONE_RESET, REQ_OP_ZONE_RESET_ALL,
383  * REQ_OP_ZONE_OPEN, REQ_OP_ZONE_CLOSE or REQ_OP_ZONE_FINISH requests.
384  */
sd_zbc_setup_zone_mgmt_cmnd(struct scsi_cmnd * cmd,unsigned char op,bool all)385 blk_status_t sd_zbc_setup_zone_mgmt_cmnd(struct scsi_cmnd *cmd,
386 					 unsigned char op, bool all)
387 {
388 	struct request *rq = cmd->request;
389 	sector_t sector = blk_rq_pos(rq);
390 	struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
391 	sector_t block = sectors_to_logical(sdkp->device, sector);
392 	blk_status_t ret;
393 
394 	ret = sd_zbc_cmnd_checks(cmd);
395 	if (ret != BLK_STS_OK)
396 		return ret;
397 
398 	cmd->cmd_len = 16;
399 	memset(cmd->cmnd, 0, cmd->cmd_len);
400 	cmd->cmnd[0] = ZBC_OUT;
401 	cmd->cmnd[1] = op;
402 	if (all)
403 		cmd->cmnd[14] = 0x1;
404 	else
405 		put_unaligned_be64(block, &cmd->cmnd[2]);
406 
407 	rq->timeout = SD_TIMEOUT;
408 	cmd->sc_data_direction = DMA_NONE;
409 	cmd->transfersize = 0;
410 	cmd->allowed = 0;
411 
412 	return BLK_STS_OK;
413 }
414 
sd_zbc_need_zone_wp_update(struct request * rq)415 static bool sd_zbc_need_zone_wp_update(struct request *rq)
416 {
417 	switch (req_op(rq)) {
418 	case REQ_OP_ZONE_APPEND:
419 	case REQ_OP_ZONE_FINISH:
420 	case REQ_OP_ZONE_RESET:
421 	case REQ_OP_ZONE_RESET_ALL:
422 		return true;
423 	case REQ_OP_WRITE:
424 	case REQ_OP_WRITE_ZEROES:
425 	case REQ_OP_WRITE_SAME:
426 		return blk_rq_zone_is_seq(rq);
427 	default:
428 		return false;
429 	}
430 }
431 
432 /**
433  * sd_zbc_zone_wp_update - Update cached zone write pointer upon cmd completion
434  * @cmd: Completed command
435  * @good_bytes: Command reply bytes
436  *
437  * Called from sd_zbc_complete() to handle the update of the cached zone write
438  * pointer value in case an update is needed.
439  */
sd_zbc_zone_wp_update(struct scsi_cmnd * cmd,unsigned int good_bytes)440 static unsigned int sd_zbc_zone_wp_update(struct scsi_cmnd *cmd,
441 					  unsigned int good_bytes)
442 {
443 	int result = cmd->result;
444 	struct request *rq = cmd->request;
445 	struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
446 	unsigned int zno = blk_rq_zone_no(rq);
447 	enum req_opf op = req_op(rq);
448 
449 	/*
450 	 * If we got an error for a command that needs updating the write
451 	 * pointer offset cache, we must mark the zone wp offset entry as
452 	 * invalid to force an update from disk the next time a zone append
453 	 * command is issued.
454 	 */
455 	spin_lock_bh(&sdkp->zones_wp_offset_lock);
456 
457 	if (result && op != REQ_OP_ZONE_RESET_ALL) {
458 		if (op == REQ_OP_ZONE_APPEND) {
459 			/* Force complete completion (no retry) */
460 			good_bytes = 0;
461 			scsi_set_resid(cmd, blk_rq_bytes(rq));
462 		}
463 
464 		/*
465 		 * Force an update of the zone write pointer offset on
466 		 * the next zone append access.
467 		 */
468 		if (sdkp->zones_wp_offset[zno] != SD_ZBC_UPDATING_WP_OFST)
469 			sdkp->zones_wp_offset[zno] = SD_ZBC_INVALID_WP_OFST;
470 		goto unlock_wp_offset;
471 	}
472 
473 	switch (op) {
474 	case REQ_OP_ZONE_APPEND:
475 		rq->__sector += sdkp->zones_wp_offset[zno];
476 		fallthrough;
477 	case REQ_OP_WRITE_ZEROES:
478 	case REQ_OP_WRITE_SAME:
479 	case REQ_OP_WRITE:
480 		if (sdkp->zones_wp_offset[zno] < sd_zbc_zone_sectors(sdkp))
481 			sdkp->zones_wp_offset[zno] +=
482 						good_bytes >> SECTOR_SHIFT;
483 		break;
484 	case REQ_OP_ZONE_RESET:
485 		sdkp->zones_wp_offset[zno] = 0;
486 		break;
487 	case REQ_OP_ZONE_FINISH:
488 		sdkp->zones_wp_offset[zno] = sd_zbc_zone_sectors(sdkp);
489 		break;
490 	case REQ_OP_ZONE_RESET_ALL:
491 		memset(sdkp->zones_wp_offset, 0,
492 		       sdkp->nr_zones * sizeof(unsigned int));
493 		break;
494 	default:
495 		break;
496 	}
497 
498 unlock_wp_offset:
499 	spin_unlock_bh(&sdkp->zones_wp_offset_lock);
500 
501 	return good_bytes;
502 }
503 
504 /**
505  * sd_zbc_complete - ZBC command post processing.
506  * @cmd: Completed command
507  * @good_bytes: Command reply bytes
508  * @sshdr: command sense header
509  *
510  * Called from sd_done() to handle zone commands errors and updates to the
511  * device queue zone write pointer offset cahce.
512  */
sd_zbc_complete(struct scsi_cmnd * cmd,unsigned int good_bytes,struct scsi_sense_hdr * sshdr)513 unsigned int sd_zbc_complete(struct scsi_cmnd *cmd, unsigned int good_bytes,
514 		     struct scsi_sense_hdr *sshdr)
515 {
516 	int result = cmd->result;
517 	struct request *rq = cmd->request;
518 
519 	if (op_is_zone_mgmt(req_op(rq)) &&
520 	    result &&
521 	    sshdr->sense_key == ILLEGAL_REQUEST &&
522 	    sshdr->asc == 0x24) {
523 		/*
524 		 * INVALID FIELD IN CDB error: a zone management command was
525 		 * attempted on a conventional zone. Nothing to worry about,
526 		 * so be quiet about the error.
527 		 */
528 		rq->rq_flags |= RQF_QUIET;
529 	} else if (sd_zbc_need_zone_wp_update(rq))
530 		good_bytes = sd_zbc_zone_wp_update(cmd, good_bytes);
531 
532 	if (req_op(rq) == REQ_OP_ZONE_APPEND)
533 		blk_req_zone_write_unlock(rq);
534 
535 	return good_bytes;
536 }
537 
538 /**
539  * sd_zbc_check_zoned_characteristics - Check zoned block device characteristics
540  * @sdkp: Target disk
541  * @buf: Buffer where to store the VPD page data
542  *
543  * Read VPD page B6, get information and check that reads are unconstrained.
544  */
sd_zbc_check_zoned_characteristics(struct scsi_disk * sdkp,unsigned char * buf)545 static int sd_zbc_check_zoned_characteristics(struct scsi_disk *sdkp,
546 					      unsigned char *buf)
547 {
548 
549 	if (scsi_get_vpd_page(sdkp->device, 0xb6, buf, 64)) {
550 		sd_printk(KERN_NOTICE, sdkp,
551 			  "Read zoned characteristics VPD page failed\n");
552 		return -ENODEV;
553 	}
554 
555 	if (sdkp->device->type != TYPE_ZBC) {
556 		/* Host-aware */
557 		sdkp->urswrz = 1;
558 		sdkp->zones_optimal_open = get_unaligned_be32(&buf[8]);
559 		sdkp->zones_optimal_nonseq = get_unaligned_be32(&buf[12]);
560 		sdkp->zones_max_open = 0;
561 	} else {
562 		/* Host-managed */
563 		sdkp->urswrz = buf[4] & 1;
564 		sdkp->zones_optimal_open = 0;
565 		sdkp->zones_optimal_nonseq = 0;
566 		sdkp->zones_max_open = get_unaligned_be32(&buf[16]);
567 	}
568 
569 	/*
570 	 * Check for unconstrained reads: host-managed devices with
571 	 * constrained reads (drives failing read after write pointer)
572 	 * are not supported.
573 	 */
574 	if (!sdkp->urswrz) {
575 		if (sdkp->first_scan)
576 			sd_printk(KERN_NOTICE, sdkp,
577 			  "constrained reads devices are not supported\n");
578 		return -ENODEV;
579 	}
580 
581 	return 0;
582 }
583 
584 /**
585  * sd_zbc_check_capacity - Check the device capacity
586  * @sdkp: Target disk
587  * @buf: command buffer
588  * @zblocks: zone size in number of blocks
589  *
590  * Get the device zone size and check that the device capacity as reported
591  * by READ CAPACITY matches the max_lba value (plus one) of the report zones
592  * command reply for devices with RC_BASIS == 0.
593  *
594  * Returns 0 upon success or an error code upon failure.
595  */
sd_zbc_check_capacity(struct scsi_disk * sdkp,unsigned char * buf,u32 * zblocks)596 static int sd_zbc_check_capacity(struct scsi_disk *sdkp, unsigned char *buf,
597 				 u32 *zblocks)
598 {
599 	u64 zone_blocks;
600 	sector_t max_lba;
601 	unsigned char *rec;
602 	int ret;
603 
604 	/* Do a report zone to get max_lba and the size of the first zone */
605 	ret = sd_zbc_do_report_zones(sdkp, buf, SD_BUF_SIZE, 0, false);
606 	if (ret)
607 		return ret;
608 
609 	if (sdkp->rc_basis == 0) {
610 		/* The max_lba field is the capacity of this device */
611 		max_lba = get_unaligned_be64(&buf[8]);
612 		if (sdkp->capacity != max_lba + 1) {
613 			if (sdkp->first_scan)
614 				sd_printk(KERN_WARNING, sdkp,
615 					"Changing capacity from %llu to max LBA+1 %llu\n",
616 					(unsigned long long)sdkp->capacity,
617 					(unsigned long long)max_lba + 1);
618 			sdkp->capacity = max_lba + 1;
619 		}
620 	}
621 
622 	/* Get the size of the first reported zone */
623 	rec = buf + 64;
624 	zone_blocks = get_unaligned_be64(&rec[8]);
625 	if (logical_to_sectors(sdkp->device, zone_blocks) > UINT_MAX) {
626 		if (sdkp->first_scan)
627 			sd_printk(KERN_NOTICE, sdkp,
628 				  "Zone size too large\n");
629 		return -EFBIG;
630 	}
631 
632 	*zblocks = zone_blocks;
633 
634 	return 0;
635 }
636 
sd_zbc_print_zones(struct scsi_disk * sdkp)637 static void sd_zbc_print_zones(struct scsi_disk *sdkp)
638 {
639 	if (!sd_is_zoned(sdkp) || !sdkp->capacity)
640 		return;
641 
642 	if (sdkp->capacity & (sdkp->zone_blocks - 1))
643 		sd_printk(KERN_NOTICE, sdkp,
644 			  "%u zones of %u logical blocks + 1 runt zone\n",
645 			  sdkp->nr_zones - 1,
646 			  sdkp->zone_blocks);
647 	else
648 		sd_printk(KERN_NOTICE, sdkp,
649 			  "%u zones of %u logical blocks\n",
650 			  sdkp->nr_zones,
651 			  sdkp->zone_blocks);
652 }
653 
sd_zbc_init_disk(struct scsi_disk * sdkp)654 static int sd_zbc_init_disk(struct scsi_disk *sdkp)
655 {
656 	sdkp->zones_wp_offset = NULL;
657 	spin_lock_init(&sdkp->zones_wp_offset_lock);
658 	sdkp->rev_wp_offset = NULL;
659 	mutex_init(&sdkp->rev_mutex);
660 	INIT_WORK(&sdkp->zone_wp_offset_work, sd_zbc_update_wp_offset_workfn);
661 	sdkp->zone_wp_update_buf = kzalloc(SD_BUF_SIZE, GFP_KERNEL);
662 	if (!sdkp->zone_wp_update_buf)
663 		return -ENOMEM;
664 
665 	return 0;
666 }
667 
sd_zbc_release_disk(struct scsi_disk * sdkp)668 void sd_zbc_release_disk(struct scsi_disk *sdkp)
669 {
670 	kvfree(sdkp->zones_wp_offset);
671 	sdkp->zones_wp_offset = NULL;
672 	kfree(sdkp->zone_wp_update_buf);
673 	sdkp->zone_wp_update_buf = NULL;
674 }
675 
sd_zbc_revalidate_zones_cb(struct gendisk * disk)676 static void sd_zbc_revalidate_zones_cb(struct gendisk *disk)
677 {
678 	struct scsi_disk *sdkp = scsi_disk(disk);
679 
680 	swap(sdkp->zones_wp_offset, sdkp->rev_wp_offset);
681 }
682 
sd_zbc_revalidate_zones(struct scsi_disk * sdkp)683 int sd_zbc_revalidate_zones(struct scsi_disk *sdkp)
684 {
685 	struct gendisk *disk = sdkp->disk;
686 	struct request_queue *q = disk->queue;
687 	u32 zone_blocks = sdkp->rev_zone_blocks;
688 	unsigned int nr_zones = sdkp->rev_nr_zones;
689 	u32 max_append;
690 	int ret = 0;
691 
692 	/*
693 	 * For all zoned disks, initialize zone append emulation data if not
694 	 * already done. This is necessary also for host-aware disks used as
695 	 * regular disks due to the presence of partitions as these partitions
696 	 * may be deleted and the disk zoned model changed back from
697 	 * BLK_ZONED_NONE to BLK_ZONED_HA.
698 	 */
699 	if (sd_is_zoned(sdkp) && !sdkp->zone_wp_update_buf) {
700 		ret = sd_zbc_init_disk(sdkp);
701 		if (ret)
702 			return ret;
703 	}
704 
705 	/*
706 	 * There is nothing to do for regular disks, including host-aware disks
707 	 * that have partitions.
708 	 */
709 	if (!blk_queue_is_zoned(q))
710 		return 0;
711 
712 	/*
713 	 * Make sure revalidate zones are serialized to ensure exclusive
714 	 * updates of the scsi disk data.
715 	 */
716 	mutex_lock(&sdkp->rev_mutex);
717 
718 	if (sdkp->zone_blocks == zone_blocks &&
719 	    sdkp->nr_zones == nr_zones &&
720 	    disk->queue->nr_zones == nr_zones)
721 		goto unlock;
722 
723 	sdkp->zone_blocks = zone_blocks;
724 	sdkp->nr_zones = nr_zones;
725 	sdkp->rev_wp_offset = kvcalloc(nr_zones, sizeof(u32), GFP_NOIO);
726 	if (!sdkp->rev_wp_offset) {
727 		ret = -ENOMEM;
728 		goto unlock;
729 	}
730 
731 	ret = blk_revalidate_disk_zones(disk, sd_zbc_revalidate_zones_cb);
732 
733 	kvfree(sdkp->rev_wp_offset);
734 	sdkp->rev_wp_offset = NULL;
735 
736 	if (ret) {
737 		sdkp->zone_blocks = 0;
738 		sdkp->nr_zones = 0;
739 		sdkp->capacity = 0;
740 		goto unlock;
741 	}
742 
743 	max_append = min_t(u32, logical_to_sectors(sdkp->device, zone_blocks),
744 			   q->limits.max_segments << (PAGE_SHIFT - 9));
745 	max_append = min_t(u32, max_append, queue_max_hw_sectors(q));
746 
747 	blk_queue_max_zone_append_sectors(q, max_append);
748 
749 	sd_zbc_print_zones(sdkp);
750 
751 unlock:
752 	mutex_unlock(&sdkp->rev_mutex);
753 
754 	return ret;
755 }
756 
sd_zbc_read_zones(struct scsi_disk * sdkp,unsigned char * buf)757 int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buf)
758 {
759 	struct gendisk *disk = sdkp->disk;
760 	struct request_queue *q = disk->queue;
761 	unsigned int nr_zones;
762 	u32 zone_blocks = 0;
763 	int ret;
764 
765 	if (!sd_is_zoned(sdkp))
766 		/*
767 		 * Device managed or normal SCSI disk,
768 		 * no special handling required
769 		 */
770 		return 0;
771 
772 	/* Check zoned block device characteristics (unconstrained reads) */
773 	ret = sd_zbc_check_zoned_characteristics(sdkp, buf);
774 	if (ret)
775 		goto err;
776 
777 	/* Check the device capacity reported by report zones */
778 	ret = sd_zbc_check_capacity(sdkp, buf, &zone_blocks);
779 	if (ret != 0)
780 		goto err;
781 
782 	/* The drive satisfies the kernel restrictions: set it up */
783 	blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q);
784 	blk_queue_required_elevator_features(q, ELEVATOR_F_ZBD_SEQ_WRITE);
785 	if (sdkp->zones_max_open == U32_MAX)
786 		blk_queue_max_open_zones(q, 0);
787 	else
788 		blk_queue_max_open_zones(q, sdkp->zones_max_open);
789 	blk_queue_max_active_zones(q, 0);
790 	nr_zones = round_up(sdkp->capacity, zone_blocks) >> ilog2(zone_blocks);
791 
792 	/* READ16/WRITE16 is mandatory for ZBC disks */
793 	sdkp->device->use_16_for_rw = 1;
794 	sdkp->device->use_10_for_rw = 0;
795 
796 	sdkp->rev_nr_zones = nr_zones;
797 	sdkp->rev_zone_blocks = zone_blocks;
798 
799 	return 0;
800 
801 err:
802 	sdkp->capacity = 0;
803 
804 	return ret;
805 }
806