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