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 static int sd_zbc_parse_report(struct scsi_disk *sdkp, u8 *buf,
  23                                unsigned int idx, report_zones_cb cb, void *data)
  24 {
  25         struct scsi_device *sdp = sdkp->device;
  26         struct blk_zone zone = { 0 };
  27
  28         zone.type = buf[0] & 0x0f;
  29         zone.cond = (buf[1] >> 4) & 0xf;
  30         if (buf[1] & 0x01)
  31                 zone.reset = 1;
  32         if (buf[1] & 0x02)
  33                 zone.non_seq = 1;
  34
  35         zone.len = logical_to_sectors(sdp, get_unaligned_be64(&buf[8]));
  36         zone.start = logical_to_sectors(sdp, get_unaligned_be64(&buf[16]));
  37         zone.wp = logical_to_sectors(sdp, get_unaligned_be64(&buf[24]));
  38         if (zone.type != ZBC_ZONE_TYPE_CONV &&
  39             zone.cond == ZBC_ZONE_COND_FULL)
  40                 zone.wp = zone.start + zone.len;
  41
  42         return cb(&zone, idx, data);
  43 }
  44
  45 /**
  46  * sd_zbc_do_report_zones - Issue a REPORT ZONES scsi command.
  47  * @sdkp: The target disk
  48  * @buf: vmalloc-ed buffer to use for the reply
  49  * @buflen: the buffer size
  50  * @lba: Start LBA of the report
  51  * @partial: Do partial report
  52  *
  53  * For internal use during device validation.
  54  * Using partial=true can significantly speed up execution of a report zones
  55  * command because the disk does not have to count all possible report matching
  56  * zones and will only report the count of zones fitting in the command reply
  57  * buffer.
  58  */
  59 static int sd_zbc_do_report_zones(struct scsi_disk *sdkp, unsigned char *buf,
  60                                   unsigned int buflen, sector_t lba,
  61                                   bool partial)
  62 {
  63         struct scsi_device *sdp = sdkp->device;
  64         const int timeout = sdp->request_queue->rq_timeout;
  65         struct scsi_sense_hdr sshdr;
  66         unsigned char cmd[16];
  67         unsigned int rep_len;
  68         int result;
  69
  70         memset(cmd, 0, 16);
  71         cmd[0] = ZBC_IN;
  72         cmd[1] = ZI_REPORT_ZONES;
  73         put_unaligned_be64(lba, &cmd[2]);
  74         put_unaligned_be32(buflen, &cmd[10]);
  75         if (partial)
  76                 cmd[14] = ZBC_REPORT_ZONE_PARTIAL;
  77
  78         result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
  79                                   buf, buflen, &sshdr,
  80                                   timeout, SD_MAX_RETRIES, NULL);
  81         if (result) {
  82                 sd_printk(KERN_ERR, sdkp,
  83                           "REPORT ZONES lba %llu failed with %d/%d\n",
  84                           (unsigned long long)lba,
  85                           host_byte(result), driver_byte(result));
  86                 return -EIO;
  87         }
  88
  89         rep_len = get_unaligned_be32(&buf[0]);
  90         if (rep_len < 64) {
  91                 sd_printk(KERN_ERR, sdkp,
  92                           "REPORT ZONES report invalid length %u\n",
  93                           rep_len);
  94                 return -EIO;
  95         }
  96
  97         return 0;
  98 }
  99
 100 /**
 101  * Allocate a buffer for report zones reply.
 102  * @sdkp: The target disk
 103  * @nr_zones: Maximum number of zones to report
 104  * @buflen: Size of the buffer allocated
 105  *
 106  * Try to allocate a reply buffer for the number of requested zones.
 107  * The size of the buffer allocated may be smaller than requested to
 108  * satify the device constraint (max_hw_sectors, max_segments, etc).
 109  *
 110  * Return the address of the allocated buffer and update @buflen with
 111  * the size of the allocated buffer.
 112  */
 113 static void *sd_zbc_alloc_report_buffer(struct scsi_disk *sdkp,
 114                                         unsigned int nr_zones, size_t *buflen)
 115 {
 116         struct request_queue *q = sdkp->disk->queue;
 117         size_t bufsize;
 118         void *buf;
 119
 120         /*
 121          * Report zone buffer size should be at most 64B times the number of
 122          * zones requested plus the 64B reply header, but should be at least
 123          * SECTOR_SIZE for ATA devices.
 124          * Make sure that this size does not exceed the hardware capabilities.
 125          * Furthermore, since the report zone command cannot be split, make
 126          * sure that the allocated buffer can always be mapped by limiting the
 127          * number of pages allocated to the HBA max segments limit.
 128          */
 129         nr_zones = min(nr_zones, sdkp->nr_zones);
 130         bufsize = roundup((nr_zones + 1) * 64, SECTOR_SIZE);
 131         bufsize = min_t(size_t, bufsize,
 132                         queue_max_hw_sectors(q) << SECTOR_SHIFT);
 133         bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT);
 134
 135         while (bufsize >= SECTOR_SIZE) {
 136                 buf = __vmalloc(bufsize,
 137                                 GFP_KERNEL | __GFP_ZERO | __GFP_NORETRY,
 138                                 PAGE_KERNEL);
 139                 if (buf) {
 140                         *buflen = bufsize;
 141                         return buf;
 142                 }
 143                 bufsize >>= 1;
 144         }
 145
 146         return NULL;
 147 }
 148
 149 /**
 150  * sd_zbc_zone_sectors - Get the device zone size in number of 512B sectors.
 151  * @sdkp: The target disk
 152  */
 153 static inline sector_t sd_zbc_zone_sectors(struct scsi_disk *sdkp)
 154 {
 155         return logical_to_sectors(sdkp->device, sdkp->zone_blocks);
 156 }
 157
 158 int sd_zbc_report_zones(struct gendisk *disk, sector_t sector,
 159                         unsigned int nr_zones, report_zones_cb cb, void *data)
 160 {
 161         struct scsi_disk *sdkp = scsi_disk(disk);
 162         unsigned int nr, i;
 163         unsigned char *buf;
 164         size_t offset, buflen = 0;
 165         int zone_idx = 0;
 166         int ret;
 167
 168         if (!sd_is_zoned(sdkp))
 169                 /* Not a zoned device */
 170                 return -EOPNOTSUPP;
 171
 172         buf = sd_zbc_alloc_report_buffer(sdkp, nr_zones, &buflen);
 173         if (!buf)
 174                 return -ENOMEM;
 175
 176         while (zone_idx < nr_zones && sector < get_capacity(disk)) {
 177                 ret = sd_zbc_do_report_zones(sdkp, buf, buflen,
 178                                 sectors_to_logical(sdkp->device, sector), true);
 179                 if (ret)
 180                         goto out;
 181
 182                 offset = 0;
 183                 nr = min(nr_zones, get_unaligned_be32(&buf[0]) / 64);
 184                 if (!nr)
 185                         break;
 186
 187                 for (i = 0; i < nr && zone_idx < nr_zones; i++) {
 188                         offset += 64;
 189                         ret = sd_zbc_parse_report(sdkp, buf + offset, zone_idx,
 190                                                   cb, data);
 191                         if (ret)
 192                                 goto out;
 193                         zone_idx++;
 194                 }
 195
 196                 sector += sd_zbc_zone_sectors(sdkp) * i;
 197         }
 198
 199         ret = zone_idx;
 200 out:
 201         kvfree(buf);
 202         return ret;
 203 }
 204
 205 /**
 206  * sd_zbc_setup_zone_mgmt_cmnd - Prepare a zone ZBC_OUT command. The operations
 207  *                      can be RESET WRITE POINTER, OPEN, CLOSE or FINISH.
 208  * @cmd: the command to setup
 209  * @op: Operation to be performed
 210  * @all: All zones control
 211  *
 212  * Called from sd_init_command() for REQ_OP_ZONE_RESET, REQ_OP_ZONE_RESET_ALL,
 213  * REQ_OP_ZONE_OPEN, REQ_OP_ZONE_CLOSE or REQ_OP_ZONE_FINISH requests.
 214  */
 215 blk_status_t sd_zbc_setup_zone_mgmt_cmnd(struct scsi_cmnd *cmd,
 216                                          unsigned char op, bool all)
 217 {
 218         struct request *rq = cmd->request;
 219         struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
 220         sector_t sector = blk_rq_pos(rq);
 221         sector_t block = sectors_to_logical(sdkp->device, sector);
 222
 223         if (!sd_is_zoned(sdkp))
 224                 /* Not a zoned device */
 225                 return BLK_STS_IOERR;
 226
 227         if (sdkp->device->changed)
 228                 return BLK_STS_IOERR;
 229
 230         if (sector & (sd_zbc_zone_sectors(sdkp) - 1))
 231                 /* Unaligned request */
 232                 return BLK_STS_IOERR;
 233
 234         cmd->cmd_len = 16;
 235         memset(cmd->cmnd, 0, cmd->cmd_len);
 236         cmd->cmnd[0] = ZBC_OUT;
 237         cmd->cmnd[1] = op;
 238         if (all)
 239                 cmd->cmnd[14] = 0x1;
 240         else
 241                 put_unaligned_be64(block, &cmd->cmnd[2]);
 242
 243         rq->timeout = SD_TIMEOUT;
 244         cmd->sc_data_direction = DMA_NONE;
 245         cmd->transfersize = 0;
 246         cmd->allowed = 0;
 247
 248         return BLK_STS_OK;
 249 }
 250
 251 /**
 252  * sd_zbc_complete - ZBC command post processing.
 253  * @cmd: Completed command
 254  * @good_bytes: Command reply bytes
 255  * @sshdr: command sense header
 256  *
 257  * Called from sd_done(). Process report zones reply and handle reset zone
 258  * and write commands errors.
 259  */
 260 void sd_zbc_complete(struct scsi_cmnd *cmd, unsigned int good_bytes,
 261                      struct scsi_sense_hdr *sshdr)
 262 {
 263         int result = cmd->result;
 264         struct request *rq = cmd->request;
 265
 266         if (op_is_zone_mgmt(req_op(rq)) &&
 267             result &&
 268             sshdr->sense_key == ILLEGAL_REQUEST &&
 269             sshdr->asc == 0x24) {
 270                 /*
 271                  * INVALID FIELD IN CDB error: a zone management command was
 272                  * attempted on a conventional zone. Nothing to worry about,
 273                  * so be quiet about the error.
 274                  */
 275                 rq->rq_flags |= RQF_QUIET;
 276         }
 277 }
 278
 279 /**
 280  * sd_zbc_check_zoned_characteristics - Check zoned block device characteristics
 281  * @sdkp: Target disk
 282  * @buf: Buffer where to store the VPD page data
 283  *
 284  * Read VPD page B6, get information and check that reads are unconstrained.
 285  */
 286 static int sd_zbc_check_zoned_characteristics(struct scsi_disk *sdkp,
 287                                               unsigned char *buf)
 288 {
 289
 290         if (scsi_get_vpd_page(sdkp->device, 0xb6, buf, 64)) {
 291                 sd_printk(KERN_NOTICE, sdkp,
 292                           "Read zoned characteristics VPD page failed\n");
 293                 return -ENODEV;
 294         }
 295
 296         if (sdkp->device->type != TYPE_ZBC) {
 297                 /* Host-aware */
 298                 sdkp->urswrz = 1;
 299                 sdkp->zones_optimal_open = get_unaligned_be32(&buf[8]);
 300                 sdkp->zones_optimal_nonseq = get_unaligned_be32(&buf[12]);
 301                 sdkp->zones_max_open = 0;
 302         } else {
 303                 /* Host-managed */
 304                 sdkp->urswrz = buf[4] & 1;
 305                 sdkp->zones_optimal_open = 0;
 306                 sdkp->zones_optimal_nonseq = 0;
 307                 sdkp->zones_max_open = get_unaligned_be32(&buf[16]);
 308         }
 309
 310         /*
 311          * Check for unconstrained reads: host-managed devices with
 312          * constrained reads (drives failing read after write pointer)
 313          * are not supported.
 314          */
 315         if (!sdkp->urswrz) {
 316                 if (sdkp->first_scan)
 317                         sd_printk(KERN_NOTICE, sdkp,
 318                           "constrained reads devices are not supported\n");
 319                 return -ENODEV;
 320         }
 321
 322         return 0;
 323 }
 324
 325 /**
 326  * sd_zbc_check_zones - Check the device capacity and zone sizes
 327  * @sdkp: Target disk
 328  *
 329  * Check that the device capacity as reported by READ CAPACITY matches the
 330  * max_lba value (plus one)of the report zones command reply. Also check that
 331  * all zones of the device have an equal size, only allowing the last zone of
 332  * the disk to have a smaller size (runt zone). The zone size must also be a
 333  * power of two.
 334  *
 335  * Returns the zone size in number of blocks upon success or an error code
 336  * upon failure.
 337  */
 338 static int sd_zbc_check_zones(struct scsi_disk *sdkp, unsigned char *buf,
 339                               u32 *zblocks)
 340 {
 341         u64 zone_blocks = 0;
 342         sector_t max_lba;
 343         unsigned char *rec;
 344         int ret;
 345
 346         /* Do a report zone to get max_lba and the size of the first zone */
 347         ret = sd_zbc_do_report_zones(sdkp, buf, SD_BUF_SIZE, 0, false);
 348         if (ret)
 349                 return ret;
 350
 351         if (sdkp->rc_basis == 0) {
 352                 /* The max_lba field is the capacity of this device */
 353                 max_lba = get_unaligned_be64(&buf[8]);
 354                 if (sdkp->capacity != max_lba + 1) {
 355                         if (sdkp->first_scan)
 356                                 sd_printk(KERN_WARNING, sdkp,
 357                                         "Changing capacity from %llu to max LBA+1 %llu\n",
 358                                         (unsigned long long)sdkp->capacity,
 359                                         (unsigned long long)max_lba + 1);
 360                         sdkp->capacity = max_lba + 1;
 361                 }
 362         }
 363
 364         /* Parse REPORT ZONES header */
 365         rec = buf + 64;
 366         zone_blocks = get_unaligned_be64(&rec[8]);
 367         if (!zone_blocks || !is_power_of_2(zone_blocks)) {
 368                 if (sdkp->first_scan)
 369                         sd_printk(KERN_NOTICE, sdkp,
 370                                   "Devices with non power of 2 zone "
 371                                   "size are not supported\n");
 372                 return -ENODEV;
 373         }
 374
 375         if (logical_to_sectors(sdkp->device, zone_blocks) > UINT_MAX) {
 376                 if (sdkp->first_scan)
 377                         sd_printk(KERN_NOTICE, sdkp,
 378                                   "Zone size too large\n");
 379                 return -EFBIG;
 380         }
 381
 382         *zblocks = zone_blocks;
 383
 384         return 0;
 385 }
 386
 387 int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buf)
 388 {
 389         struct gendisk *disk = sdkp->disk;
 390         unsigned int nr_zones;
 391         u32 zone_blocks = 0;
 392         int ret;
 393
 394         if (!sd_is_zoned(sdkp))
 395                 /*
 396                  * Device managed or normal SCSI disk,
 397                  * no special handling required
 398                  */
 399                 return 0;
 400
 401         /* Check zoned block device characteristics (unconstrained reads) */
 402         ret = sd_zbc_check_zoned_characteristics(sdkp, buf);
 403         if (ret)
 404                 goto err;
 405
 406         /*
 407          * Check zone size: only devices with a constant zone size (except
 408          * an eventual last runt zone) that is a power of 2 are supported.
 409          */
 410         ret = sd_zbc_check_zones(sdkp, buf, &zone_blocks);
 411         if (ret != 0)
 412                 goto err;
 413
 414         /* The drive satisfies the kernel restrictions: set it up */
 415         blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, sdkp->disk->queue);
 416         blk_queue_required_elevator_features(sdkp->disk->queue,
 417                                              ELEVATOR_F_ZBD_SEQ_WRITE);
 418         nr_zones = round_up(sdkp->capacity, zone_blocks) >> ilog2(zone_blocks);
 419
 420         /* READ16/WRITE16 is mandatory for ZBC disks */
 421         sdkp->device->use_16_for_rw = 1;
 422         sdkp->device->use_10_for_rw = 0;
 423
 424         /*
 425          * Revalidate the disk zone bitmaps once the block device capacity is
 426          * set on the second revalidate execution during disk scan and if
 427          * something changed when executing a normal revalidate.
 428          */
 429         if (sdkp->first_scan) {
 430                 sdkp->zone_blocks = zone_blocks;
 431                 sdkp->nr_zones = nr_zones;
 432                 return 0;
 433         }
 434
 435         if (sdkp->zone_blocks != zone_blocks ||
 436             sdkp->nr_zones != nr_zones ||
 437             disk->queue->nr_zones != nr_zones) {
 438                 ret = blk_revalidate_disk_zones(disk);
 439                 if (ret != 0)
 440                         goto err;
 441                 sdkp->zone_blocks = zone_blocks;
 442                 sdkp->nr_zones = nr_zones;
 443         }
 444
 445         return 0;
 446
 447 err:
 448         sdkp->capacity = 0;
 449
 450         return ret;
 451 }
 452
 453 void sd_zbc_print_zones(struct scsi_disk *sdkp)
 454 {
 455         if (!sd_is_zoned(sdkp) || !sdkp->capacity)
 456                 return;
 457
 458         if (sdkp->capacity & (sdkp->zone_blocks - 1))
 459                 sd_printk(KERN_NOTICE, sdkp,
 460                           "%u zones of %u logical blocks + 1 runt zone\n",
 461                           sdkp->nr_zones - 1,
 462                           sdkp->zone_blocks);
 463         else
 464                 sd_printk(KERN_NOTICE, sdkp,
 465                           "%u zones of %u logical blocks\n",
 466                           sdkp->nr_zones,
 467                           sdkp->zone_blocks);
 468 }