gpxe/src/drivers/block/scsi.c

   1 /*
   2  * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation; either version 2 of the
   7  * License, or any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17  */
  18
  19 FILE_LICENCE ( GPL2_OR_LATER );
  20
  21 #include <stddef.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <byteswap.h>
  25 #include <errno.h>
  26 #include <gpxe/blockdev.h>
  27 #include <gpxe/process.h>
  28 #include <gpxe/scsi.h>
  29
  30 /** @file
  31  *
  32  * SCSI block device
  33  *
  34  */
  35
  36 /** Maximum number of dummy "read capacity (10)" operations
  37  *
  38  * These are issued at connection setup to draw out various useless
  39  * power-on messages.
  40  */
  41 #define SCSI_MAX_DUMMY_READ_CAP 10
  42
  43 static inline __attribute__ (( always_inline )) struct scsi_device *
  44 block_to_scsi ( struct block_device *blockdev ) {
  45         return container_of ( blockdev, struct scsi_device, blockdev );
  46 }
  47
  48 /**
  49  * Handle SCSI command with no backing device
  50  *
  51  * @v scsi              SCSI device
  52  * @v command           SCSI command
  53  * @ret rc              Return status code
  54  */
  55 int scsi_detached_command ( struct scsi_device *scsi __unused,
  56                             struct scsi_command *command __unused ) {
  57         return -ENODEV;
  58 }
  59
  60 /**
  61  * Issue SCSI command
  62  *
  63  * @v scsi              SCSI device
  64  * @v command           SCSI command
  65  * @ret rc              Return status code
  66  */
  67 static int scsi_command ( struct scsi_device *scsi,
  68                           struct scsi_command *command ) {
  69         int rc;
  70
  71         DBGC2 ( scsi, "SCSI %p " SCSI_CDB_FORMAT "\n",
  72                 scsi, SCSI_CDB_DATA ( command->cdb ) );
  73
  74         /* Clear sense response code before issuing command */
  75         command->sense_response = 0;
  76
  77         /* Flag command as in-progress */
  78         command->rc = -EINPROGRESS;
  79
  80         /* Issue SCSI command */
  81         if ( ( rc = scsi->command ( scsi, command ) ) != 0 ) {
  82                 /* Something went wrong with the issuing mechanism */
  83                 DBGC ( scsi, "SCSI %p " SCSI_CDB_FORMAT " err %s\n",
  84                        scsi, SCSI_CDB_DATA ( command->cdb ), strerror ( rc ) );
  85                 return rc;
  86         }
  87
  88         /* Wait for command to complete */
  89         while ( command->rc == -EINPROGRESS )
  90                 step();
  91         if ( ( rc = command->rc ) != 0 ) {
  92                 /* Something went wrong with the command execution */
  93                 DBGC ( scsi, "SCSI %p " SCSI_CDB_FORMAT " err %s\n",
  94                        scsi, SCSI_CDB_DATA ( command->cdb ), strerror ( rc ) );
  95                 return rc;
  96         }
  97
  98         /* Check for SCSI errors */
  99         if ( command->status != 0 ) {
 100                 DBGC ( scsi, "SCSI %p " SCSI_CDB_FORMAT " status %02x sense "
 101                        "%02x\n", scsi, SCSI_CDB_DATA ( command->cdb ),
 102                        command->status, command->sense_response );
 103                 return -EIO;
 104         }
 105
 106         return 0;
 107 }
 108
 109 /**
 110  * Read block from SCSI device using READ (10)
 111  *
 112  * @v blockdev          Block device
 113  * @v block             LBA block number
 114  * @v count             Block count
 115  * @v buffer            Data buffer
 116  * @ret rc              Return status code
 117  */
 118 static int scsi_read_10 ( struct block_device *blockdev, uint64_t block,
 119                           unsigned long count, userptr_t buffer ) {
 120         struct scsi_device *scsi = block_to_scsi ( blockdev );
 121         struct scsi_command command;
 122         struct scsi_cdb_read_10 *cdb = &command.cdb.read10;
 123
 124         /* Issue READ (10) */
 125         memset ( &command, 0, sizeof ( command ) );
 126         cdb->opcode = SCSI_OPCODE_READ_10;
 127         cdb->lba = cpu_to_be32 ( block );
 128         cdb->len = cpu_to_be16 ( count );
 129         command.data_in = buffer;
 130         command.data_in_len = ( count * blockdev->blksize );
 131         return scsi_command ( scsi, &command );
 132 }
 133
 134 /**
 135  * Read block from SCSI device using READ (16)
 136  *
 137  * @v blockdev          Block device
 138  * @v block             LBA block number
 139  * @v count             Block count
 140  * @v buffer            Data buffer
 141  * @ret rc              Return status code
 142  */
 143 static int scsi_read_16 ( struct block_device *blockdev, uint64_t block,
 144                           unsigned long count, userptr_t buffer ) {
 145         struct scsi_device *scsi = block_to_scsi ( blockdev );
 146         struct scsi_command command;
 147         struct scsi_cdb_read_16 *cdb = &command.cdb.read16;
 148
 149         /* Issue READ (16) */
 150         memset ( &command, 0, sizeof ( command ) );
 151         cdb->opcode = SCSI_OPCODE_READ_16;
 152         cdb->lba = cpu_to_be64 ( block );
 153         cdb->len = cpu_to_be32 ( count );
 154         command.data_in = buffer;
 155         command.data_in_len = ( count * blockdev->blksize );
 156         return scsi_command ( scsi, &command );
 157 }
 158
 159 /**
 160  * Write block to SCSI device using WRITE (10)
 161  *
 162  * @v blockdev          Block device
 163  * @v block             LBA block number
 164  * @v count             Block count
 165  * @v buffer            Data buffer
 166  * @ret rc              Return status code
 167  */
 168 static int scsi_write_10 ( struct block_device *blockdev, uint64_t block,
 169                            unsigned long count, userptr_t buffer ) {
 170         struct scsi_device *scsi = block_to_scsi ( blockdev );
 171         struct scsi_command command;
 172         struct scsi_cdb_write_10 *cdb = &command.cdb.write10;
 173
 174         /* Issue WRITE (10) */
 175         memset ( &command, 0, sizeof ( command ) );
 176         cdb->opcode = SCSI_OPCODE_WRITE_10;
 177         cdb->lba = cpu_to_be32 ( block );
 178         cdb->len = cpu_to_be16 ( count );
 179         command.data_out = buffer;
 180         command.data_out_len = ( count * blockdev->blksize );
 181         return scsi_command ( scsi, &command );
 182 }
 183
 184 /**
 185  * Write block to SCSI device using WRITE (16)
 186  *
 187  * @v blockdev          Block device
 188  * @v block             LBA block number
 189  * @v count             Block count
 190  * @v buffer            Data buffer
 191  * @ret rc              Return status code
 192  */
 193 static int scsi_write_16 ( struct block_device *blockdev, uint64_t block,
 194                            unsigned long count, userptr_t buffer ) {
 195         struct scsi_device *scsi = block_to_scsi ( blockdev );
 196         struct scsi_command command;
 197         struct scsi_cdb_write_16 *cdb = &command.cdb.write16;
 198
 199         /* Issue WRITE (16) */
 200         memset ( &command, 0, sizeof ( command ) );
 201         cdb->opcode = SCSI_OPCODE_WRITE_16;
 202         cdb->lba = cpu_to_be64 ( block );
 203         cdb->len = cpu_to_be32 ( count );
 204         command.data_out = buffer;
 205         command.data_out_len = ( count * blockdev->blksize );
 206         return scsi_command ( scsi, &command );
 207 }
 208
 209 /**
 210  * Read capacity of SCSI device via READ CAPACITY (10)
 211  *
 212  * @v blockdev          Block device
 213  * @ret rc              Return status code
 214  */
 215 static int scsi_read_capacity_10 ( struct block_device *blockdev ) {
 216         struct scsi_device *scsi = block_to_scsi ( blockdev );
 217         struct scsi_command command;
 218         struct scsi_cdb_read_capacity_10 *cdb = &command.cdb.readcap10;
 219         struct scsi_capacity_10 capacity;
 220         int rc;
 221
 222         /* Issue READ CAPACITY (10) */
 223         memset ( &command, 0, sizeof ( command ) );
 224         cdb->opcode = SCSI_OPCODE_READ_CAPACITY_10;
 225         command.data_in = virt_to_user ( &capacity );
 226         command.data_in_len = sizeof ( capacity );
 227
 228         if ( ( rc = scsi_command ( scsi, &command ) ) != 0 )
 229                 return rc;
 230
 231         /* Fill in block device fields */
 232         blockdev->blksize = be32_to_cpu ( capacity.blksize );
 233         blockdev->blocks = ( be32_to_cpu ( capacity.lba ) + 1 );
 234
 235         return 0;
 236 }
 237
 238 /**
 239  * Read capacity of SCSI device via READ CAPACITY (16)
 240  *
 241  * @v blockdev          Block device
 242  * @ret rc              Return status code
 243  */
 244 static int scsi_read_capacity_16 ( struct block_device *blockdev ) {
 245         struct scsi_device *scsi = block_to_scsi ( blockdev );
 246         struct scsi_command command;
 247         struct scsi_cdb_read_capacity_16 *cdb = &command.cdb.readcap16;
 248         struct scsi_capacity_16 capacity;
 249         int rc;
 250
 251         /* Issue READ CAPACITY (16) */
 252         memset ( &command, 0, sizeof ( command ) );
 253         cdb->opcode = SCSI_OPCODE_SERVICE_ACTION_IN;
 254         cdb->service_action = SCSI_SERVICE_ACTION_READ_CAPACITY_16;
 255         cdb->len = cpu_to_be32 ( sizeof ( capacity ) );
 256         command.data_in = virt_to_user ( &capacity );
 257         command.data_in_len = sizeof ( capacity );
 258
 259         if ( ( rc = scsi_command ( scsi, &command ) ) != 0 )
 260                 return rc;
 261
 262         /* Fill in block device fields */
 263         blockdev->blksize = be32_to_cpu ( capacity.blksize );
 264         blockdev->blocks = ( be64_to_cpu ( capacity.lba ) + 1 );
 265         return 0;
 266 }
 267
 268 static struct block_device_operations scsi_operations_16 = {
 269         .read   = scsi_read_16,
 270         .write  = scsi_write_16,
 271 };
 272
 273 static struct block_device_operations scsi_operations_10 = {
 274         .read   = scsi_read_10,
 275         .write  = scsi_write_10,
 276 };
 277
 278 /**
 279  * Initialise SCSI device
 280  *
 281  * @v scsi              SCSI device
 282  * @ret rc              Return status code
 283  *
 284  * Initialises a SCSI device.  The scsi_device::command and
 285  * scsi_device::lun fields must already be filled in.  This function
 286  * will configure scsi_device::blockdev, including issuing a READ
 287  * CAPACITY call to determine the block size and total device size.
 288  */
 289 int init_scsidev ( struct scsi_device *scsi ) {
 290         unsigned int i;
 291         int rc;
 292
 293         /* Issue some theoretically extraneous READ CAPACITY (10)
 294          * commands, solely in order to draw out the "CHECK CONDITION
 295          * (power-on occurred)", "CHECK CONDITION (reported LUNs data
 296          * has changed)" etc. that some dumb targets insist on sending
 297          * as an error at start of day.  The precise command that we
 298          * use is unimportant; we just need to provide the target with
 299          * an opportunity to send its responses.
 300          */
 301         for ( i = 0 ; i < SCSI_MAX_DUMMY_READ_CAP ; i++ ) {
 302                 if ( ( rc = scsi_read_capacity_10 ( &scsi->blockdev ) ) == 0 )
 303                         break;
 304                 DBGC ( scsi, "SCSI %p ignoring start-of-day error (#%d)\n",
 305                        scsi, ( i + 1 ) );
 306         }
 307
 308         /* Try READ CAPACITY (10), which is a mandatory command, first. */
 309         scsi->blockdev.op = &scsi_operations_10;
 310         if ( ( rc = scsi_read_capacity_10 ( &scsi->blockdev ) ) != 0 ) {
 311                 DBGC ( scsi, "SCSI %p could not READ CAPACITY (10): %s\n",
 312                        scsi, strerror ( rc ) );
 313                 return rc;
 314         }
 315
 316         /* If capacity range was exceeded (i.e. capacity.lba was
 317          * 0xffffffff, meaning that blockdev->blocks is now zero), use
 318          * READ CAPACITY (16) instead.  READ CAPACITY (16) is not
 319          * mandatory, so we can't just use it straight off.
 320          */
 321         if ( scsi->blockdev.blocks == 0 ) {
 322                 scsi->blockdev.op = &scsi_operations_16;
 323                 if ( ( rc = scsi_read_capacity_16 ( &scsi->blockdev ) ) != 0 ){
 324                         DBGC ( scsi, "SCSI %p could not READ CAPACITY (16): "
 325                                "%s\n", scsi, strerror ( rc ) );
 326                         return rc;
 327                 }
 328         }
 329
 330         DBGC ( scsi, "SCSI %p using READ/WRITE (%d) commands\n", scsi,
 331                ( ( scsi->blockdev.op == &scsi_operations_10 ) ? 10 : 16 ) );
 332         DBGC ( scsi, "SCSI %p capacity is %ld MB (%#llx blocks)\n", scsi,
 333                ( ( unsigned long ) ( scsi->blockdev.blocks >> 11 ) ),
 334                scsi->blockdev.blocks );
 335
 336         return 0;
 337 }
 338
 339 /**
 340  * Parse SCSI LUN
 341  *
 342  * @v lun_string        LUN string representation
 343  * @v lun               LUN to fill in
 344  * @ret rc              Return status code
 345  */
 346 int scsi_parse_lun ( const char *lun_string, struct scsi_lun *lun ) {
 347         char *p;
 348         int i;
 349
 350         memset ( lun, 0, sizeof ( *lun ) );
 351         if ( lun_string ) {
 352                 p = ( char * ) lun_string;
 353                 for ( i = 0 ; i < 4 ; i++ ) {
 354                         lun->u16[i] = htons ( strtoul ( p, &p, 16 ) );
 355                         if ( *p == '\0' )
 356                                 break;
 357                         if ( *p != '-' )
 358                                 return -EINVAL;
 359                         p++;
 360                 }
 361                 if ( *p )
 362                         return -EINVAL;
 363         }
 364
 365         return 0;
 366 }