drivers/scsi/sd_zbc.c

   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
  15 #include <asm/unaligned.h>
  16
  17 #include <scsi/scsi.h>
  18 #include <scsi/scsi_cmnd.h>
  19
  20 #include "sd.h"
  21
  22 /**
  23  * sd_zbc_parse_report - Convert a zone descriptor to a struct blk_zone,
  24  * @sdkp: The disk the report originated from
  25  * @buf: Address of the report zone descriptor
  26  * @zone: the destination zone structure
  27  *
  28  * All LBA sized values are converted to 512B sectors unit.
  29  */
  30 static void sd_zbc_parse_report(struct scsi_disk *sdkp, u8 *buf,
  31                                 struct blk_zone *zone)
  32 {
  33         struct scsi_device *sdp = sdkp->device;
  34
  35         memset(zone, 0, sizeof(struct blk_zone));
  36
  37         zone->type = buf[0] & 0x0f;
  38         zone->cond = (buf[1] >> 4) & 0xf;
  39         if (buf[1] & 0x01)
  40                 zone->reset = 1;
  41         if (buf[1] & 0x02)
  42                 zone->non_seq = 1;
  43
  44         zone->len = logical_to_sectors(sdp, get_unaligned_be64(&buf[8]));
  45         zone->start = logical_to_sectors(sdp, get_unaligned_be64(&buf[16]));
  46         zone->wp = logical_to_sectors(sdp, get_unaligned_be64(&buf[24]));
  47         if (zone->type != ZBC_ZONE_TYPE_CONV &&
  48             zone->cond == ZBC_ZONE_COND_FULL)
  49                 zone->wp = zone->start + zone->len;
  50 }
  51
  52 /**
  53  * sd_zbc_do_report_zones - Issue a REPORT ZONES scsi command.
  54  * @sdkp: The target disk
  55  * @buf: vmalloc-ed buffer to use for the reply
  56  * @buflen: the buffer size
  57  * @lba: Start LBA of the report
  58  * @partial: Do partial report
  59  *
  60  * For internal use during device validation.
  61  * Using partial=true can significantly speed up execution of a report zones
  62  * command because the disk does not have to count all possible report matching
  63  * zones and will only report the count of zones fitting in the command reply
  64  * buffer.
  65  */
  66 static int sd_zbc_do_report_zones(struct scsi_disk *sdkp, unsigned char *buf,
  67                                   unsigned int buflen, sector_t lba,
  68                                   bool partial)
  69 {
  70         struct scsi_device *sdp = sdkp->device;
  71         const int timeout = sdp->request_queue->rq_timeout;
  72         struct scsi_sense_hdr sshdr;
  73         unsigned char cmd[16];
  74         unsigned int rep_len;
  75         int result;
  76
  77         memset(cmd, 0, 16);
  78         cmd[0] = ZBC_IN;
  79         cmd[1] = ZI_REPORT_ZONES;
  80         put_unaligned_be64(lba, &cmd[2]);
  81         put_unaligned_be32(buflen, &cmd[10]);
  82         if (partial)
  83                 cmd[14] = ZBC_REPORT_ZONE_PARTIAL;
  84
  85         result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
  86                                   buf, buflen, &sshdr,
  87                                   timeout, SD_MAX_RETRIES, NULL);
  88         if (result) {
  89                 sd_printk(KERN_ERR, sdkp,
  90                           "REPORT ZONES lba %llu failed with %d/%d\n",
  91                           (unsigned long long)lba,
  92                           host_byte(result), driver_byte(result));
  93                 return -EIO;
  94         }
  95
  96         rep_len = get_unaligned_be32(&buf[0]);
  97         if (rep_len < 64) {
  98                 sd_printk(KERN_ERR, sdkp,
  99                           "REPORT ZONES report invalid length %u\n",
 100                           rep_len);
 101                 return -EIO;
 102         }
 103
 104         return 0;
 105 }
 106
 107 /*
 108  * Maximum number of zones to get with one report zones command.
 109  */
 110 #define SD_ZBC_REPORT_MAX_ZONES         8192U
 111
 112 /**
 113  * Allocate a buffer for report zones reply.
 114  * @sdkp: The target disk
 115  * @nr_zones: Maximum number of zones to report
 116  * @buflen: Size of the buffer allocated
 117  *
 118  * Try to allocate a reply buffer for the number of requested zones.
 119  * The size of the buffer allocated may be smaller than requested to
 120  * satify the device constraint (max_hw_sectors, max_segments, etc).
 121  *
 122  * Return the address of the allocated buffer and update @buflen with
 123  * the size of the allocated buffer.
 124  */
 125 static void *sd_zbc_alloc_report_buffer(struct scsi_disk *sdkp,
 126                                         unsigned int nr_zones, size_t *buflen)
 127 {
 128         struct request_queue *q = sdkp->disk->queue;
 129         size_t bufsize;
 130         void *buf;
 131
 132         /*
 133          * Report zone buffer size should be at most 64B times the number of
 134          * zones requested plus the 64B reply header, but should be at least
 135          * SECTOR_SIZE for ATA devices.
 136          * Make sure that this size does not exceed the hardware capabilities.
 137          * Furthermore, since the report zone command cannot be split, make
 138          * sure that the allocated buffer can always be mapped by limiting the
 139          * number of pages allocated to the HBA max segments limit.
 140          */
 141         nr_zones = min(nr_zones, SD_ZBC_REPORT_MAX_ZONES);
 142         bufsize = roundup((nr_zones + 1) * 64, 512);
 143         bufsize = min_t(size_t, bufsize,
 144                         queue_max_hw_sectors(q) << SECTOR_SHIFT);
 145         bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT);
 146
 147         buf = vzalloc(bufsize);
 148         if (buf)
 149                 *buflen = bufsize;
 150
 151         return buf;
 152 }
 153
 154 /**
 155  * sd_zbc_report_zones - Disk report zones operation.
 156  * @disk: The target disk
 157  * @sector: Start 512B sector of the report
 158  * @zones: Array of zone descriptors
 159  * @nr_zones: Number of descriptors in the array
 160  *
 161  * Execute a report zones command on the target disk.
 162  */
 163 int sd_zbc_report_zones(struct gendisk *disk, sector_t sector,
 164                         struct blk_zone *zones, unsigned int *nr_zones)
 165 {
 166         struct scsi_disk *sdkp = scsi_disk(disk);
 167         unsigned int i, nrz = *nr_zones;
 168         unsigned char *buf;
 169         size_t buflen = 0, offset = 0;
 170         int ret = 0;
 171
 172         if (!sd_is_zoned(sdkp))
 173                 /* Not a zoned device */
 174                 return -EOPNOTSUPP;
 175
 176         buf = sd_zbc_alloc_report_buffer(sdkp, nrz, &buflen);
 177         if (!buf)
 178                 return -ENOMEM;
 179
 180         ret = sd_zbc_do_report_zones(sdkp, buf, buflen,
 181                         sectors_to_logical(sdkp->device, sector), true);
 182         if (ret)
 183                 goto out;
 184
 185         nrz = min(nrz, get_unaligned_be32(&buf[0]) / 64);
 186         for (i = 0; i < nrz; i++) {
 187                 offset += 64;
 188                 sd_zbc_parse_report(sdkp, buf + offset, zones);
 189                 zones++;
 190         }
 191
 192         *nr_zones = nrz;
 193
 194 out:
 195         kvfree(buf);
 196
 197         return ret;
 198 }
 199
 200 /**
 201  * sd_zbc_zone_sectors - Get the device zone size in number of 512B sectors.
 202  * @sdkp: The target disk
 203  */
 204 static inline sector_t sd_zbc_zone_sectors(struct scsi_disk *sdkp)
 205 {
 206         return logical_to_sectors(sdkp->device, sdkp->zone_blocks);
 207 }
 208
 209 /**
 210  * sd_zbc_setup_reset_cmnd - Prepare a RESET WRITE POINTER scsi command.
 211  * @cmd: the command to setup
 212  *
 213  * Called from sd_init_command() for a REQ_OP_ZONE_RESET request.
 214  */
 215 blk_status_t sd_zbc_setup_reset_cmnd(struct scsi_cmnd *cmd)
 216 {
 217         struct request *rq = cmd->request;
 218         struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
 219         sector_t sector = blk_rq_pos(rq);
 220         sector_t block = sectors_to_logical(sdkp->device, sector);
 221
 222         if (!sd_is_zoned(sdkp))
 223                 /* Not a zoned device */
 224                 return BLK_STS_IOERR;
 225
 226         if (sdkp->device->changed)
 227                 return BLK_STS_IOERR;
 228
 229         if (sector & (sd_zbc_zone_sectors(sdkp) - 1))
 230                 /* Unaligned request */
 231                 return BLK_STS_IOERR;
 232
 233         cmd->cmd_len = 16;
 234         memset(cmd->cmnd, 0, cmd->cmd_len);
 235         cmd->cmnd[0] = ZBC_OUT;
 236         cmd->cmnd[1] = ZO_RESET_WRITE_POINTER;
 237         put_unaligned_be64(block, &cmd->cmnd[2]);
 238
 239         rq->timeout = SD_TIMEOUT;
 240         cmd->sc_data_direction = DMA_NONE;
 241         cmd->transfersize = 0;
 242         cmd->allowed = 0;
 243
 244         return BLK_STS_OK;
 245 }
 246
 247 /**
 248  * sd_zbc_complete - ZBC command post processing.
 249  * @cmd: Completed command
 250  * @good_bytes: Command reply bytes
 251  * @sshdr: command sense header
 252  *
 253  * Called from sd_done(). Process report zones reply and handle reset zone
 254  * and write commands errors.
 255  */
 256 void sd_zbc_complete(struct scsi_cmnd *cmd, unsigned int good_bytes,
 257                      struct scsi_sense_hdr *sshdr)
 258 {
 259         int result = cmd->result;
 260         struct request *rq = cmd->request;
 261
 262         switch (req_op(rq)) {
 263         case REQ_OP_ZONE_RESET:
 264
 265                 if (result &&
 266                     sshdr->sense_key == ILLEGAL_REQUEST &&
 267                     sshdr->asc == 0x24)
 268                         /*
 269                          * INVALID FIELD IN CDB error: reset of a conventional
 270                          * zone was attempted. Nothing to worry about, so be
 271                          * quiet about the error.
 272                          */
 273                         rq->rq_flags |= RQF_QUIET;
 274                 break;
 275
 276         case REQ_OP_WRITE:
 277         case REQ_OP_WRITE_ZEROES:
 278         case REQ_OP_WRITE_SAME:
 279                 break;
 280         }
 281 }
 282
 283 /**
 284  * sd_zbc_check_zoned_characteristics - Check zoned block device characteristics
 285  * @sdkp: Target disk
 286  * @buf: Buffer where to store the VPD page data
 287  *
 288  * Read VPD page B6, get information and check that reads are unconstrained.
 289  */
 290 static int sd_zbc_check_zoned_characteristics(struct scsi_disk *sdkp,
 291                                               unsigned char *buf)
 292 {
 293
 294         if (scsi_get_vpd_page(sdkp->device, 0xb6, buf, 64)) {
 295                 sd_printk(KERN_NOTICE, sdkp,
 296                           "Read zoned characteristics VPD page failed\n");
 297                 return -ENODEV;
 298         }
 299
 300         if (sdkp->device->type != TYPE_ZBC) {
 301                 /* Host-aware */
 302                 sdkp->urswrz = 1;
 303                 sdkp->zones_optimal_open = get_unaligned_be32(&buf[8]);
 304                 sdkp->zones_optimal_nonseq = get_unaligned_be32(&buf[12]);
 305                 sdkp->zones_max_open = 0;
 306         } else {
 307                 /* Host-managed */
 308                 sdkp->urswrz = buf[4] & 1;
 309                 sdkp->zones_optimal_open = 0;
 310                 sdkp->zones_optimal_nonseq = 0;
 311                 sdkp->zones_max_open = get_unaligned_be32(&buf[16]);
 312         }
 313
 314         /*
 315          * Check for unconstrained reads: host-managed devices with
 316          * constrained reads (drives failing read after write pointer)
 317          * are not supported.
 318          */
 319         if (!sdkp->urswrz) {
 320                 if (sdkp->first_scan)
 321                         sd_printk(KERN_NOTICE, sdkp,
 322                           "constrained reads devices are not supported\n");
 323                 return -ENODEV;
 324         }
 325
 326         return 0;
 327 }
 328
 329 /**
 330  * sd_zbc_check_zones - Check the device capacity and zone sizes
 331  * @sdkp: Target disk
 332  *
 333  * Check that the device capacity as reported by READ CAPACITY matches the
 334  * max_lba value (plus one)of the report zones command reply. Also check that
 335  * all zones of the device have an equal size, only allowing the last zone of
 336  * the disk to have a smaller size (runt zone). The zone size must also be a
 337  * power of two.
 338  *
 339  * Returns the zone size in number of blocks upon success or an error code
 340  * upon failure.
 341  */
 342 static int sd_zbc_check_zones(struct scsi_disk *sdkp, u32 *zblocks)
 343 {
 344         size_t bufsize, buflen;
 345         unsigned int noio_flag;
 346         u64 zone_blocks = 0;
 347         sector_t max_lba, block = 0;
 348         unsigned char *buf;
 349         unsigned char *rec;
 350         int ret;
 351         u8 same;
 352
 353         /* Do all memory allocations as if GFP_NOIO was specified */
 354         noio_flag = memalloc_noio_save();
 355
 356         /* Get a buffer */
 357         buf = sd_zbc_alloc_report_buffer(sdkp, SD_ZBC_REPORT_MAX_ZONES,
 358                                          &bufsize);
 359         if (!buf) {
 360                 ret = -ENOMEM;
 361                 goto out;
 362         }
 363
 364         /* Do a report zone to get max_lba and the same field */
 365         ret = sd_zbc_do_report_zones(sdkp, buf, bufsize, 0, false);
 366         if (ret)
 367                 goto out_free;
 368
 369         if (sdkp->rc_basis == 0) {
 370                 /* The max_lba field is the capacity of this device */
 371                 max_lba = get_unaligned_be64(&buf[8]);
 372                 if (sdkp->capacity != max_lba + 1) {
 373                         if (sdkp->first_scan)
 374                                 sd_printk(KERN_WARNING, sdkp,
 375                                         "Changing capacity from %llu to max LBA+1 %llu\n",
 376                                         (unsigned long long)sdkp->capacity,
 377                                         (unsigned long long)max_lba + 1);
 378                         sdkp->capacity = max_lba + 1;
 379                 }
 380         }
 381
 382         /*
 383          * Check same field: for any value other than 0, we know that all zones
 384          * have the same size.
 385          */
 386         same = buf[4] & 0x0f;
 387         if (same > 0) {
 388                 rec = &buf[64];
 389                 zone_blocks = get_unaligned_be64(&rec[8]);
 390                 goto out;
 391         }
 392
 393         /*
 394          * Check the size of all zones: all zones must be of
 395          * equal size, except the last zone which can be smaller
 396          * than other zones.
 397          */
 398         do {
 399
 400                 /* Parse REPORT ZONES header */
 401                 buflen = min_t(size_t, get_unaligned_be32(&buf[0]) + 64,
 402                                bufsize);
 403                 rec = buf + 64;
 404
 405                 /* Parse zone descriptors */
 406                 while (rec < buf + buflen) {
 407                         u64 this_zone_blocks = get_unaligned_be64(&rec[8]);
 408
 409                         if (zone_blocks == 0) {
 410                                 zone_blocks = this_zone_blocks;
 411                         } else if (this_zone_blocks != zone_blocks &&
 412                                    (block + this_zone_blocks < sdkp->capacity
 413                                     || this_zone_blocks > zone_blocks)) {
 414                                 zone_blocks = 0;
 415                                 goto out;
 416                         }
 417                         block += this_zone_blocks;
 418                         rec += 64;
 419                 }
 420
 421                 if (block < sdkp->capacity) {
 422                         ret = sd_zbc_do_report_zones(sdkp, buf, bufsize, block,
 423                                                      true);
 424                         if (ret)
 425                                 goto out_free;
 426                 }
 427
 428         } while (block < sdkp->capacity);
 429
 430 out:
 431         if (!zone_blocks) {
 432                 if (sdkp->first_scan)
 433                         sd_printk(KERN_NOTICE, sdkp,
 434                                   "Devices with non constant zone "
 435                                   "size are not supported\n");
 436                 ret = -ENODEV;
 437         } else if (!is_power_of_2(zone_blocks)) {
 438                 if (sdkp->first_scan)
 439                         sd_printk(KERN_NOTICE, sdkp,
 440                                   "Devices with non power of 2 zone "
 441                                   "size are not supported\n");
 442                 ret = -ENODEV;
 443         } else if (logical_to_sectors(sdkp->device, zone_blocks) > UINT_MAX) {
 444                 if (sdkp->first_scan)
 445                         sd_printk(KERN_NOTICE, sdkp,
 446                                   "Zone size too large\n");
 447                 ret = -EFBIG;
 448         } else {
 449                 *zblocks = zone_blocks;
 450                 ret = 0;
 451         }
 452
 453 out_free:
 454         memalloc_noio_restore(noio_flag);
 455         kvfree(buf);
 456
 457         return ret;
 458 }
 459
 460 int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buf)
 461 {
 462         struct gendisk *disk = sdkp->disk;
 463         unsigned int nr_zones;
 464         u32 zone_blocks = 0;
 465         int ret;
 466
 467         if (!sd_is_zoned(sdkp))
 468                 /*
 469                  * Device managed or normal SCSI disk,
 470                  * no special handling required
 471                  */
 472                 return 0;
 473
 474         /* Check zoned block device characteristics (unconstrained reads) */
 475         ret = sd_zbc_check_zoned_characteristics(sdkp, buf);
 476         if (ret)
 477                 goto err;
 478
 479         /*
 480          * Check zone size: only devices with a constant zone size (except
 481          * an eventual last runt zone) that is a power of 2 are supported.
 482          */
 483         ret = sd_zbc_check_zones(sdkp, &zone_blocks);
 484         if (ret != 0)
 485                 goto err;
 486
 487         /* The drive satisfies the kernel restrictions: set it up */
 488         blk_queue_chunk_sectors(sdkp->disk->queue,
 489                         logical_to_sectors(sdkp->device, zone_blocks));
 490         nr_zones = round_up(sdkp->capacity, zone_blocks) >> ilog2(zone_blocks);
 491
 492         /* READ16/WRITE16 is mandatory for ZBC disks */
 493         sdkp->device->use_16_for_rw = 1;
 494         sdkp->device->use_10_for_rw = 0;
 495
 496         /*
 497          * Revalidate the disk zone bitmaps once the block device capacity is
 498          * set on the second revalidate execution during disk scan and if
 499          * something changed when executing a normal revalidate.
 500          */
 501         if (sdkp->first_scan) {
 502                 sdkp->zone_blocks = zone_blocks;
 503                 sdkp->nr_zones = nr_zones;
 504                 return 0;
 505         }
 506
 507         if (sdkp->zone_blocks != zone_blocks ||
 508             sdkp->nr_zones != nr_zones ||
 509             disk->queue->nr_zones != nr_zones) {
 510                 ret = blk_revalidate_disk_zones(disk);
 511                 if (ret != 0)
 512                         goto err;
 513                 sdkp->zone_blocks = zone_blocks;
 514                 sdkp->nr_zones = nr_zones;
 515         }
 516
 517         return 0;
 518
 519 err:
 520         sdkp->capacity = 0;
 521
 522         return ret;
 523 }
 524
 525 void sd_zbc_print_zones(struct scsi_disk *sdkp)
 526 {
 527         if (!sd_is_zoned(sdkp) || !sdkp->capacity)
 528                 return;
 529
 530         if (sdkp->capacity & (sdkp->zone_blocks - 1))
 531                 sd_printk(KERN_NOTICE, sdkp,
 532                           "%u zones of %u logical blocks + 1 runt zone\n",
 533                           sdkp->nr_zones - 1,
 534                           sdkp->zone_blocks);
 535         else
 536                 sd_printk(KERN_NOTICE, sdkp,
 537                           "%u zones of %u logical blocks\n",
 538                           sdkp->nr_zones,
 539                           sdkp->zone_blocks);
 540 }