linux/drivers/scsi/sd_zbc.c
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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
  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 */
  42static 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 */
  73static 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 */
 118int 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 */
 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
 223/**
 224 * sd_zbc_zone_sectors - Get the device zone size in number of 512B sectors.
 225 * @sdkp: The target disk
 226 */
 227static 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 */
 238int 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 */
 279void 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 */
 320static 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 */
 357static 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 number of blocks upon success or an error code
 395 * upon failure.
 396 */
 397static s64 sd_zbc_check_zone_size(struct scsi_disk *sdkp)
 398{
 399        u64 zone_blocks = 0;
 400        sector_t block = 0;
 401        unsigned char *buf;
 402        unsigned char *rec;
 403        unsigned int buf_len;
 404        unsigned int list_length;
 405        s64 ret;
 406        u8 same;
 407
 408        /* Get a buffer */
 409        buf = kmalloc(SD_ZBC_BUF_SIZE, GFP_KERNEL);
 410        if (!buf)
 411                return -ENOMEM;
 412
 413        /* Do a report zone to get the same field */
 414        ret = sd_zbc_report_zones(sdkp, buf, SD_ZBC_BUF_SIZE, 0);
 415        if (ret)
 416                goto out_free;
 417
 418        same = buf[4] & 0x0f;
 419        if (same > 0) {
 420                rec = &buf[64];
 421                zone_blocks = get_unaligned_be64(&rec[8]);
 422                goto out;
 423        }
 424
 425        /*
 426         * Check the size of all zones: all zones must be of
 427         * equal size, except the last zone which can be smaller
 428         * than other zones.
 429         */
 430        do {
 431
 432                /* Parse REPORT ZONES header */
 433                list_length = get_unaligned_be32(&buf[0]) + 64;
 434                rec = buf + 64;
 435                buf_len = min(list_length, SD_ZBC_BUF_SIZE);
 436
 437                /* Parse zone descriptors */
 438                while (rec < buf + buf_len) {
 439                        u64 this_zone_blocks = get_unaligned_be64(&rec[8]);
 440
 441                        if (zone_blocks == 0) {
 442                                zone_blocks = this_zone_blocks;
 443                        } else if (this_zone_blocks != zone_blocks &&
 444                                   (block + this_zone_blocks < sdkp->capacity
 445                                    || this_zone_blocks > zone_blocks)) {
 446                                zone_blocks = 0;
 447                                goto out;
 448                        }
 449                        block += this_zone_blocks;
 450                        rec += 64;
 451                }
 452
 453                if (block < sdkp->capacity) {
 454                        ret = sd_zbc_report_zones(sdkp, buf,
 455                                                  SD_ZBC_BUF_SIZE, block);
 456                        if (ret)
 457                                goto out_free;
 458                }
 459
 460        } while (block < sdkp->capacity);
 461
 462out:
 463        if (!zone_blocks) {
 464                if (sdkp->first_scan)
 465                        sd_printk(KERN_NOTICE, sdkp,
 466                                  "Devices with non constant zone "
 467                                  "size are not supported\n");
 468                ret = -ENODEV;
 469        } else if (!is_power_of_2(zone_blocks)) {
 470                if (sdkp->first_scan)
 471                        sd_printk(KERN_NOTICE, sdkp,
 472                                  "Devices with non power of 2 zone "
 473                                  "size are not supported\n");
 474                ret = -ENODEV;
 475        } else if (logical_to_sectors(sdkp->device, zone_blocks) > UINT_MAX) {
 476                if (sdkp->first_scan)
 477                        sd_printk(KERN_NOTICE, sdkp,
 478                                  "Zone size too large\n");
 479                ret = -ENODEV;
 480        } else {
 481                ret = zone_blocks;
 482        }
 483
 484out_free:
 485        kfree(buf);
 486
 487        return ret;
 488}
 489
 490/**
 491 * sd_zbc_alloc_zone_bitmap - Allocate a zone bitmap (one bit per zone).
 492 * @nr_zones: Number of zones to allocate space for.
 493 * @numa_node: NUMA node to allocate the memory from.
 494 */
 495static inline unsigned long *
 496sd_zbc_alloc_zone_bitmap(u32 nr_zones, int numa_node)
 497{
 498        return kcalloc_node(BITS_TO_LONGS(nr_zones), sizeof(unsigned long),
 499                            GFP_KERNEL, numa_node);
 500}
 501
 502/**
 503 * sd_zbc_get_seq_zones - Parse report zones reply to identify sequential zones
 504 * @sdkp: disk used
 505 * @buf: report reply buffer
 506 * @buflen: length of @buf
 507 * @zone_shift: logarithm base 2 of the number of blocks in a zone
 508 * @seq_zones_bitmap: bitmap of sequential zones to set
 509 *
 510 * Parse reported zone descriptors in @buf to identify sequential zones and
 511 * set the reported zone bit in @seq_zones_bitmap accordingly.
 512 * Since read-only and offline zones cannot be written, do not
 513 * mark them as sequential in the bitmap.
 514 * Return the LBA after the last zone reported.
 515 */
 516static sector_t sd_zbc_get_seq_zones(struct scsi_disk *sdkp, unsigned char *buf,
 517                                     unsigned int buflen, u32 zone_shift,
 518                                     unsigned long *seq_zones_bitmap)
 519{
 520        sector_t lba, next_lba = sdkp->capacity;
 521        unsigned int buf_len, list_length;
 522        unsigned char *rec;
 523        u8 type, cond;
 524
 525        list_length = get_unaligned_be32(&buf[0]) + 64;
 526        buf_len = min(list_length, buflen);
 527        rec = buf + 64;
 528
 529        while (rec < buf + buf_len) {
 530                type = rec[0] & 0x0f;
 531                cond = (rec[1] >> 4) & 0xf;
 532                lba = get_unaligned_be64(&rec[16]);
 533                if (type != ZBC_ZONE_TYPE_CONV &&
 534                    cond != ZBC_ZONE_COND_READONLY &&
 535                    cond != ZBC_ZONE_COND_OFFLINE)
 536                        set_bit(lba >> zone_shift, seq_zones_bitmap);
 537                next_lba = lba + get_unaligned_be64(&rec[8]);
 538                rec += 64;
 539        }
 540
 541        return next_lba;
 542}
 543
 544/**
 545 * sd_zbc_setup_seq_zones_bitmap - Initialize a seq zone bitmap.
 546 * @sdkp: target disk
 547 * @zone_shift: logarithm base 2 of the number of blocks in a zone
 548 * @nr_zones: number of zones to set up a seq zone bitmap for
 549 *
 550 * Allocate a zone bitmap and initialize it by identifying sequential zones.
 551 */
 552static unsigned long *
 553sd_zbc_setup_seq_zones_bitmap(struct scsi_disk *sdkp, u32 zone_shift,
 554                              u32 nr_zones)
 555{
 556        struct request_queue *q = sdkp->disk->queue;
 557        unsigned long *seq_zones_bitmap;
 558        sector_t lba = 0;
 559        unsigned char *buf;
 560        int ret = -ENOMEM;
 561
 562        seq_zones_bitmap = sd_zbc_alloc_zone_bitmap(nr_zones, q->node);
 563        if (!seq_zones_bitmap)
 564                return ERR_PTR(-ENOMEM);
 565
 566        buf = kmalloc(SD_ZBC_BUF_SIZE, GFP_KERNEL);
 567        if (!buf)
 568                goto out;
 569
 570        while (lba < sdkp->capacity) {
 571                ret = sd_zbc_report_zones(sdkp, buf, SD_ZBC_BUF_SIZE, lba);
 572                if (ret)
 573                        goto out;
 574                lba = sd_zbc_get_seq_zones(sdkp, buf, SD_ZBC_BUF_SIZE,
 575                                           zone_shift, seq_zones_bitmap);
 576        }
 577
 578        if (lba != sdkp->capacity) {
 579                /* Something went wrong */
 580                ret = -EIO;
 581        }
 582
 583out:
 584        kfree(buf);
 585        if (ret) {
 586                kfree(seq_zones_bitmap);
 587                return ERR_PTR(ret);
 588        }
 589        return seq_zones_bitmap;
 590}
 591
 592static void sd_zbc_cleanup(struct scsi_disk *sdkp)
 593{
 594        struct request_queue *q = sdkp->disk->queue;
 595
 596        kfree(q->seq_zones_bitmap);
 597        q->seq_zones_bitmap = NULL;
 598
 599        kfree(q->seq_zones_wlock);
 600        q->seq_zones_wlock = NULL;
 601
 602        q->nr_zones = 0;
 603}
 604
 605static int sd_zbc_setup(struct scsi_disk *sdkp, u32 zone_blocks)
 606{
 607        struct request_queue *q = sdkp->disk->queue;
 608        u32 zone_shift = ilog2(zone_blocks);
 609        u32 nr_zones;
 610        int ret;
 611
 612        /* chunk_sectors indicates the zone size */
 613        blk_queue_chunk_sectors(q,
 614                        logical_to_sectors(sdkp->device, zone_blocks));
 615        nr_zones = round_up(sdkp->capacity, zone_blocks) >> zone_shift;
 616
 617        /*
 618         * Initialize the device request queue information if the number
 619         * of zones changed.
 620         */
 621        if (nr_zones != sdkp->nr_zones || nr_zones != q->nr_zones) {
 622                unsigned long *seq_zones_wlock = NULL, *seq_zones_bitmap = NULL;
 623                size_t zone_bitmap_size;
 624
 625                if (nr_zones) {
 626                        seq_zones_wlock = sd_zbc_alloc_zone_bitmap(nr_zones,
 627                                                                   q->node);
 628                        if (!seq_zones_wlock) {
 629                                ret = -ENOMEM;
 630                                goto err;
 631                        }
 632
 633                        seq_zones_bitmap = sd_zbc_setup_seq_zones_bitmap(sdkp,
 634                                                        zone_shift, nr_zones);
 635                        if (IS_ERR(seq_zones_bitmap)) {
 636                                ret = PTR_ERR(seq_zones_bitmap);
 637                                kfree(seq_zones_wlock);
 638                                goto err;
 639                        }
 640                }
 641                zone_bitmap_size = BITS_TO_LONGS(nr_zones) *
 642                        sizeof(unsigned long);
 643                blk_mq_freeze_queue(q);
 644                if (q->nr_zones != nr_zones) {
 645                        /* READ16/WRITE16 is mandatory for ZBC disks */
 646                        sdkp->device->use_16_for_rw = 1;
 647                        sdkp->device->use_10_for_rw = 0;
 648
 649                        sdkp->zone_blocks = zone_blocks;
 650                        sdkp->zone_shift = zone_shift;
 651                        sdkp->nr_zones = nr_zones;
 652                        q->nr_zones = nr_zones;
 653                        swap(q->seq_zones_wlock, seq_zones_wlock);
 654                        swap(q->seq_zones_bitmap, seq_zones_bitmap);
 655                } else if (memcmp(q->seq_zones_bitmap, seq_zones_bitmap,
 656                                  zone_bitmap_size) != 0) {
 657                        memcpy(q->seq_zones_bitmap, seq_zones_bitmap,
 658                               zone_bitmap_size);
 659                }
 660                blk_mq_unfreeze_queue(q);
 661                kfree(seq_zones_wlock);
 662                kfree(seq_zones_bitmap);
 663        }
 664
 665        return 0;
 666
 667err:
 668        sd_zbc_cleanup(sdkp);
 669        return ret;
 670}
 671
 672int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buf)
 673{
 674        int64_t zone_blocks;
 675        int ret;
 676
 677        if (!sd_is_zoned(sdkp))
 678                /*
 679                 * Device managed or normal SCSI disk,
 680                 * no special handling required
 681                 */
 682                return 0;
 683
 684        /* Get zoned block device characteristics */
 685        ret = sd_zbc_read_zoned_characteristics(sdkp, buf);
 686        if (ret)
 687                goto err;
 688
 689        /*
 690         * Check for unconstrained reads: host-managed devices with
 691         * constrained reads (drives failing read after write pointer)
 692         * are not supported.
 693         */
 694        if (!sdkp->urswrz) {
 695                if (sdkp->first_scan)
 696                        sd_printk(KERN_NOTICE, sdkp,
 697                          "constrained reads devices are not supported\n");
 698                ret = -ENODEV;
 699                goto err;
 700        }
 701
 702        /* Check capacity */
 703        ret = sd_zbc_check_capacity(sdkp, buf);
 704        if (ret)
 705                goto err;
 706
 707        /*
 708         * Check zone size: only devices with a constant zone size (except
 709         * an eventual last runt zone) that is a power of 2 are supported.
 710         */
 711        zone_blocks = sd_zbc_check_zone_size(sdkp);
 712        ret = -EFBIG;
 713        if (zone_blocks != (u32)zone_blocks)
 714                goto err;
 715        ret = zone_blocks;
 716        if (ret < 0)
 717                goto err;
 718
 719        /* The drive satisfies the kernel restrictions: set it up */
 720        ret = sd_zbc_setup(sdkp, zone_blocks);
 721        if (ret)
 722                goto err;
 723
 724        return 0;
 725
 726err:
 727        sdkp->capacity = 0;
 728        sd_zbc_cleanup(sdkp);
 729
 730        return ret;
 731}
 732
 733void sd_zbc_remove(struct scsi_disk *sdkp)
 734{
 735        sd_zbc_cleanup(sdkp);
 736}
 737
 738void sd_zbc_print_zones(struct scsi_disk *sdkp)
 739{
 740        if (!sd_is_zoned(sdkp) || !sdkp->capacity)
 741                return;
 742
 743        if (sdkp->capacity & (sdkp->zone_blocks - 1))
 744                sd_printk(KERN_NOTICE, sdkp,
 745                          "%u zones of %u logical blocks + 1 runt zone\n",
 746                          sdkp->nr_zones - 1,
 747                          sdkp->zone_blocks);
 748        else
 749                sd_printk(KERN_NOTICE, sdkp,
 750                          "%u zones of %u logical blocks\n",
 751                          sdkp->nr_zones,
 752                          sdkp->zone_blocks);
 753}
 754