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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#include <scsi/scsi_dbg.h>
32#include <scsi/scsi_device.h>
33#include <scsi/scsi_driver.h>
34#include <scsi/scsi_host.h>
35#include <scsi/scsi_eh.h>
36
37#include "sd.h"
38#include "scsi_priv.h"
39
40enum zbc_zone_type {
41 ZBC_ZONE_TYPE_CONV = 0x1,
42 ZBC_ZONE_TYPE_SEQWRITE_REQ,
43 ZBC_ZONE_TYPE_SEQWRITE_PREF,
44 ZBC_ZONE_TYPE_RESERVED,
45};
46
47enum zbc_zone_cond {
48 ZBC_ZONE_COND_NO_WP,
49 ZBC_ZONE_COND_EMPTY,
50 ZBC_ZONE_COND_IMP_OPEN,
51 ZBC_ZONE_COND_EXP_OPEN,
52 ZBC_ZONE_COND_CLOSED,
53 ZBC_ZONE_COND_READONLY = 0xd,
54 ZBC_ZONE_COND_FULL,
55 ZBC_ZONE_COND_OFFLINE,
56};
57
58/**
59 * Convert a zone descriptor to a zone struct.
60 */
61static void sd_zbc_parse_report(struct scsi_disk *sdkp,
62 u8 *buf,
63 struct blk_zone *zone)
64{
65 struct scsi_device *sdp = sdkp->device;
66
67 memset(zone, 0, sizeof(struct blk_zone));
68
69 zone->type = buf[0] & 0x0f;
70 zone->cond = (buf[1] >> 4) & 0xf;
71 if (buf[1] & 0x01)
72 zone->reset = 1;
73 if (buf[1] & 0x02)
74 zone->non_seq = 1;
75
76 zone->len = logical_to_sectors(sdp, get_unaligned_be64(&buf[8]));
77 zone->start = logical_to_sectors(sdp, get_unaligned_be64(&buf[16]));
78 zone->wp = logical_to_sectors(sdp, get_unaligned_be64(&buf[24]));
79 if (zone->type != ZBC_ZONE_TYPE_CONV &&
80 zone->cond == ZBC_ZONE_COND_FULL)
81 zone->wp = zone->start + zone->len;
82}
83
84/**
85 * Issue a REPORT ZONES scsi command.
86 */
87static int sd_zbc_report_zones(struct scsi_disk *sdkp, unsigned char *buf,
88 unsigned int buflen, sector_t lba)
89{
90 struct scsi_device *sdp = sdkp->device;
91 const int timeout = sdp->request_queue->rq_timeout;
92 struct scsi_sense_hdr sshdr;
93 unsigned char cmd[16];
94 unsigned int rep_len;
95 int result;
96
97 memset(cmd, 0, 16);
98 cmd[0] = ZBC_IN;
99 cmd[1] = ZI_REPORT_ZONES;
100 put_unaligned_be64(lba, &cmd[2]);
101 put_unaligned_be32(buflen, &cmd[10]);
102 memset(buf, 0, buflen);
103
104 result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
105 buf, buflen, &sshdr,
106 timeout, SD_MAX_RETRIES, NULL);
107 if (result) {
108 sd_printk(KERN_ERR, sdkp,
109 "REPORT ZONES lba %llu failed with %d/%d\n",
110 (unsigned long long)lba,
111 host_byte(result), driver_byte(result));
112 return -EIO;
113 }
114
115 rep_len = get_unaligned_be32(&buf[0]);
116 if (rep_len < 64) {
117 sd_printk(KERN_ERR, sdkp,
118 "REPORT ZONES report invalid length %u\n",
119 rep_len);
120 return -EIO;
121 }
122
123 return 0;
124}
125
126int sd_zbc_setup_report_cmnd(struct scsi_cmnd *cmd)
127{
128 struct request *rq = cmd->request;
129 struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
130 sector_t lba, sector = blk_rq_pos(rq);
131 unsigned int nr_bytes = blk_rq_bytes(rq);
132 int ret;
133
134 WARN_ON(nr_bytes == 0);
135
136 if (!sd_is_zoned(sdkp))
137 /* Not a zoned device */
138 return BLKPREP_KILL;
139
140 ret = scsi_init_io(cmd);
141 if (ret != BLKPREP_OK)
142 return ret;
143
144 cmd->cmd_len = 16;
145 memset(cmd->cmnd, 0, cmd->cmd_len);
146 cmd->cmnd[0] = ZBC_IN;
147 cmd->cmnd[1] = ZI_REPORT_ZONES;
148 lba = sectors_to_logical(sdkp->device, sector);
149 put_unaligned_be64(lba, &cmd->cmnd[2]);
150 put_unaligned_be32(nr_bytes, &cmd->cmnd[10]);
151 /* Do partial report for speeding things up */
152 cmd->cmnd[14] = ZBC_REPORT_ZONE_PARTIAL;
153
154 cmd->sc_data_direction = DMA_FROM_DEVICE;
155 cmd->sdb.length = nr_bytes;
156 cmd->transfersize = sdkp->device->sector_size;
157 cmd->allowed = 0;
158
159 /*
160 * Report may return less bytes than requested. Make sure
161 * to report completion on the entire initial request.
162 */
163 rq->__data_len = nr_bytes;
164
165 return BLKPREP_OK;
166}
167
168static 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
223static inline sector_t sd_zbc_zone_sectors(struct scsi_disk *sdkp)
224{
225 return logical_to_sectors(sdkp->device, sdkp->zone_blocks);
226}
227
228static inline unsigned int sd_zbc_zone_no(struct scsi_disk *sdkp,
229 sector_t sector)
230{
231 return sectors_to_logical(sdkp->device, sector) >> sdkp->zone_shift;
232}
233
234int sd_zbc_setup_reset_cmnd(struct scsi_cmnd *cmd)
235{
236 struct request *rq = cmd->request;
237 struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
238 sector_t sector = blk_rq_pos(rq);
239 sector_t block = sectors_to_logical(sdkp->device, sector);
240 unsigned int zno = block >> sdkp->zone_shift;
241
242 if (!sd_is_zoned(sdkp))
243 /* Not a zoned device */
244 return BLKPREP_KILL;
245
246 if (sdkp->device->changed)
247 return BLKPREP_KILL;
248
249 if (sector & (sd_zbc_zone_sectors(sdkp) - 1))
250 /* Unaligned request */
251 return BLKPREP_KILL;
252
253 /* Do not allow concurrent reset and writes */
254 if (sdkp->zones_wlock &&
255 test_and_set_bit(zno, sdkp->zones_wlock))
256 return BLKPREP_DEFER;
257
258 cmd->cmd_len = 16;
259 memset(cmd->cmnd, 0, cmd->cmd_len);
260 cmd->cmnd[0] = ZBC_OUT;
261 cmd->cmnd[1] = ZO_RESET_WRITE_POINTER;
262 put_unaligned_be64(block, &cmd->cmnd[2]);
263
264 rq->timeout = SD_TIMEOUT;
265 cmd->sc_data_direction = DMA_NONE;
266 cmd->transfersize = 0;
267 cmd->allowed = 0;
268
269 return BLKPREP_OK;
270}
271
272int sd_zbc_setup_write_cmnd(struct scsi_cmnd *cmd)
273{
274 struct request *rq = cmd->request;
275 struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
276 sector_t sector = blk_rq_pos(rq);
277 sector_t zone_sectors = sd_zbc_zone_sectors(sdkp);
278 unsigned int zno = sd_zbc_zone_no(sdkp, sector);
279
280 /*
281 * Note: Checks of the alignment of the write command on
282 * logical blocks is done in sd.c
283 */
284
285 /* Do not allow zone boundaries crossing on host-managed drives */
286 if (blk_queue_zoned_model(sdkp->disk->queue) == BLK_ZONED_HM &&
287 (sector & (zone_sectors - 1)) + blk_rq_sectors(rq) > zone_sectors)
288 return BLKPREP_KILL;
289
290 /*
291 * Do not issue more than one write at a time per
292 * zone. This solves write ordering problems due to
293 * the unlocking of the request queue in the dispatch
294 * path in the non scsi-mq case. For scsi-mq, this
295 * also avoids potential write reordering when multiple
296 * threads running on different CPUs write to the same
297 * zone (with a synchronized sequential pattern).
298 */
299 if (sdkp->zones_wlock &&
300 test_and_set_bit(zno, sdkp->zones_wlock))
301 return BLKPREP_DEFER;
302
303 return BLKPREP_OK;
304}
305
306static void sd_zbc_unlock_zone(struct request *rq)
307{
308 struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
309
310 if (sdkp->zones_wlock) {
311 unsigned int zno = sd_zbc_zone_no(sdkp, blk_rq_pos(rq));
312 WARN_ON_ONCE(!test_bit(zno, sdkp->zones_wlock));
313 clear_bit_unlock(zno, sdkp->zones_wlock);
314 smp_mb__after_atomic();
315 }
316}
317
318void sd_zbc_cancel_write_cmnd(struct scsi_cmnd *cmd)
319{
320 sd_zbc_unlock_zone(cmd->request);
321}
322
323void sd_zbc_complete(struct scsi_cmnd *cmd,
324 unsigned int good_bytes,
325 struct scsi_sense_hdr *sshdr)
326{
327 int result = cmd->result;
328 struct request *rq = cmd->request;
329
330 switch (req_op(rq)) {
331 case REQ_OP_WRITE:
332 case REQ_OP_WRITE_SAME:
333 case REQ_OP_ZONE_RESET:
334
335 /* Unlock the zone */
336 sd_zbc_unlock_zone(rq);
337
338 if (!result ||
339 sshdr->sense_key != ILLEGAL_REQUEST)
340 break;
341
342 switch (sshdr->asc) {
343 case 0x24:
344 /*
345 * INVALID FIELD IN CDB error: For a zone reset,
346 * this means that a reset of a conventional
347 * zone was attempted. Nothing to worry about in
348 * this case, so be quiet about the error.
349 */
350 if (req_op(rq) == REQ_OP_ZONE_RESET)
351 rq->rq_flags |= RQF_QUIET;
352 break;
353 case 0x21:
354 /*
355 * INVALID ADDRESS FOR WRITE error: It is unlikely that
356 * retrying write requests failed with any kind of
357 * alignement error will result in success. So don't.
358 */
359 cmd->allowed = 0;
360 break;
361 }
362
363 break;
364
365 case REQ_OP_ZONE_REPORT:
366
367 if (!result)
368 sd_zbc_report_zones_complete(cmd, good_bytes);
369 break;
370
371 }
372}
373
374/**
375 * Read zoned block device characteristics (VPD page B6).
376 */
377static int sd_zbc_read_zoned_characteristics(struct scsi_disk *sdkp,
378 unsigned char *buf)
379{
380
381 if (scsi_get_vpd_page(sdkp->device, 0xb6, buf, 64)) {
382 sd_printk(KERN_NOTICE, sdkp,
383 "Unconstrained-read check failed\n");
384 return -ENODEV;
385 }
386
387 if (sdkp->device->type != TYPE_ZBC) {
388 /* Host-aware */
389 sdkp->urswrz = 1;
390 sdkp->zones_optimal_open = get_unaligned_be64(&buf[8]);
391 sdkp->zones_optimal_nonseq = get_unaligned_be64(&buf[12]);
392 sdkp->zones_max_open = 0;
393 } else {
394 /* Host-managed */
395 sdkp->urswrz = buf[4] & 1;
396 sdkp->zones_optimal_open = 0;
397 sdkp->zones_optimal_nonseq = 0;
398 sdkp->zones_max_open = get_unaligned_be64(&buf[16]);
399 }
400
401 return 0;
402}
403
404/**
405 * Check reported capacity.
406 */
407static int sd_zbc_check_capacity(struct scsi_disk *sdkp,
408 unsigned char *buf)
409{
410 sector_t lba;
411 int ret;
412
413 if (sdkp->rc_basis != 0)
414 return 0;
415
416 /* Do a report zone to get the maximum LBA to check capacity */
417 ret = sd_zbc_report_zones(sdkp, buf, SD_BUF_SIZE, 0);
418 if (ret)
419 return ret;
420
421 /* The max_lba field is the capacity of this device */
422 lba = get_unaligned_be64(&buf[8]);
423 if (lba + 1 == sdkp->capacity)
424 return 0;
425
426 if (sdkp->first_scan)
427 sd_printk(KERN_WARNING, sdkp,
428 "Changing capacity from %llu to max LBA+1 %llu\n",
429 (unsigned long long)sdkp->capacity,
430 (unsigned long long)lba + 1);
431 sdkp->capacity = lba + 1;
432
433 return 0;
434}
435
436#define SD_ZBC_BUF_SIZE 131072
437
438static int sd_zbc_check_zone_size(struct scsi_disk *sdkp)
439{
440 u64 zone_blocks;
441 sector_t block = 0;
442 unsigned char *buf;
443 unsigned char *rec;
444 unsigned int buf_len;
445 unsigned int list_length;
446 int ret;
447 u8 same;
448
449 sdkp->zone_blocks = 0;
450
451 /* Get a buffer */
452 buf = kmalloc(SD_ZBC_BUF_SIZE, GFP_KERNEL);
453 if (!buf)
454 return -ENOMEM;
455
456 /* Do a report zone to get the same field */
457 ret = sd_zbc_report_zones(sdkp, buf, SD_ZBC_BUF_SIZE, 0);
458 if (ret) {
459 zone_blocks = 0;
460 goto out;
461 }
462
463 same = buf[4] & 0x0f;
464 if (same > 0) {
465 rec = &buf[64];
466 zone_blocks = get_unaligned_be64(&rec[8]);
467 goto out;
468 }
469
470 /*
471 * Check the size of all zones: all zones must be of
472 * equal size, except the last zone which can be smaller
473 * than other zones.
474 */
475 do {
476
477 /* Parse REPORT ZONES header */
478 list_length = get_unaligned_be32(&buf[0]) + 64;
479 rec = buf + 64;
480 if (list_length < SD_ZBC_BUF_SIZE)
481 buf_len = list_length;
482 else
483 buf_len = SD_ZBC_BUF_SIZE;
484
485 /* Parse zone descriptors */
486 while (rec < buf + buf_len) {
487 zone_blocks = get_unaligned_be64(&rec[8]);
488 if (sdkp->zone_blocks == 0) {
489 sdkp->zone_blocks = zone_blocks;
490 } else if (zone_blocks != sdkp->zone_blocks &&
491 (block + zone_blocks < sdkp->capacity
492 || zone_blocks > sdkp->zone_blocks)) {
493 zone_blocks = 0;
494 goto out;
495 }
496 block += zone_blocks;
497 rec += 64;
498 }
499
500 if (block < sdkp->capacity) {
501 ret = sd_zbc_report_zones(sdkp, buf,
502 SD_ZBC_BUF_SIZE, block);
503 if (ret)
504 return ret;
505 }
506
507 } while (block < sdkp->capacity);
508
509 zone_blocks = sdkp->zone_blocks;
510
511out:
512 kfree(buf);
513
514 if (!zone_blocks) {
515 if (sdkp->first_scan)
516 sd_printk(KERN_NOTICE, sdkp,
517 "Devices with non constant zone "
518 "size are not supported\n");
519 return -ENODEV;
520 }
521
522 if (!is_power_of_2(zone_blocks)) {
523 if (sdkp->first_scan)
524 sd_printk(KERN_NOTICE, sdkp,
525 "Devices with non power of 2 zone "
526 "size are not supported\n");
527 return -ENODEV;
528 }
529
530 if (logical_to_sectors(sdkp->device, zone_blocks) > UINT_MAX) {
531 if (sdkp->first_scan)
532 sd_printk(KERN_NOTICE, sdkp,
533 "Zone size too large\n");
534 return -ENODEV;
535 }
536
537 sdkp->zone_blocks = zone_blocks;
538
539 return 0;
540}
541
542static int sd_zbc_setup(struct scsi_disk *sdkp)
543{
544
545 /* chunk_sectors indicates the zone size */
546 blk_queue_chunk_sectors(sdkp->disk->queue,
547 logical_to_sectors(sdkp->device, sdkp->zone_blocks));
548 sdkp->zone_shift = ilog2(sdkp->zone_blocks);
549 sdkp->nr_zones = sdkp->capacity >> sdkp->zone_shift;
550 if (sdkp->capacity & (sdkp->zone_blocks - 1))
551 sdkp->nr_zones++;
552
553 if (!sdkp->zones_wlock) {
554 sdkp->zones_wlock = kcalloc(BITS_TO_LONGS(sdkp->nr_zones),
555 sizeof(unsigned long),
556 GFP_KERNEL);
557 if (!sdkp->zones_wlock)
558 return -ENOMEM;
559 }
560
561 return 0;
562}
563
564int sd_zbc_read_zones(struct scsi_disk *sdkp,
565 unsigned char *buf)
566{
567 sector_t capacity;
568 int ret = 0;
569
570 if (!sd_is_zoned(sdkp))
571 /*
572 * Device managed or normal SCSI disk,
573 * no special handling required
574 */
575 return 0;
576
577
578 /* Get zoned block device characteristics */
579 ret = sd_zbc_read_zoned_characteristics(sdkp, buf);
580 if (ret)
581 goto err;
582
583 /*
584 * Check for unconstrained reads: host-managed devices with
585 * constrained reads (drives failing read after write pointer)
586 * are not supported.
587 */
588 if (!sdkp->urswrz) {
589 if (sdkp->first_scan)
590 sd_printk(KERN_NOTICE, sdkp,
591 "constrained reads devices are not supported\n");
592 ret = -ENODEV;
593 goto err;
594 }
595
596 /* Check capacity */
597 ret = sd_zbc_check_capacity(sdkp, buf);
598 if (ret)
599 goto err;
600 capacity = logical_to_sectors(sdkp->device, sdkp->capacity);
601
602 /*
603 * Check zone size: only devices with a constant zone size (except
604 * an eventual last runt zone) that is a power of 2 are supported.
605 */
606 ret = sd_zbc_check_zone_size(sdkp);
607 if (ret)
608 goto err;
609
610 /* The drive satisfies the kernel restrictions: set it up */
611 ret = sd_zbc_setup(sdkp);
612 if (ret)
613 goto err;
614
615 /* READ16/WRITE16 is mandatory for ZBC disks */
616 sdkp->device->use_16_for_rw = 1;
617 sdkp->device->use_10_for_rw = 0;
618
619 return 0;
620
621err:
622 sdkp->capacity = 0;
623
624 return ret;
625}
626
627void sd_zbc_remove(struct scsi_disk *sdkp)
628{
629 kfree(sdkp->zones_wlock);
630 sdkp->zones_wlock = NULL;
631}
632
633void sd_zbc_print_zones(struct scsi_disk *sdkp)
634{
635 if (!sd_is_zoned(sdkp) || !sdkp->capacity)
636 return;
637
638 if (sdkp->capacity & (sdkp->zone_blocks - 1))
639 sd_printk(KERN_NOTICE, sdkp,
640 "%u zones of %u logical blocks + 1 runt zone\n",
641 sdkp->nr_zones - 1,
642 sdkp->zone_blocks);
643 else
644 sd_printk(KERN_NOTICE, sdkp,
645 "%u zones of %u logical blocks\n",
646 sdkp->nr_zones,
647 sdkp->zone_blocks);
648}