drivers/scsi/scsi_transport_spi.c

   1 /*
   2  *  Parallel SCSI (SPI) transport specific attributes exported to sysfs.
   3  *
   4  *  Copyright (c) 2003 Silicon Graphics, Inc.  All rights reserved.
   5  *  Copyright (c) 2004, 2005 James Bottomley <James.Bottomley@SteelEye.com>
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 2 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, write to the Free Software
  19  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21 #include <linux/module.h>
  22 #include <linux/init.h>
  23 #include <linux/smp_lock.h>
  24 #include <linux/list.h>
  25 #include <linux/spinlock.h>
  26 #include <linux/mm.h>
  27 #include <linux/workqueue.h>
  28 #include <asm/scatterlist.h>
  29 #include <asm/io.h>
  30 #include <scsi/scsi.h>
  31 #include "scsi_priv.h"
  32 #include <scsi/scsi_device.h>
  33 #include <scsi/scsi_host.h>
  34 #include <scsi/scsi_request.h>
  35 #include <scsi/scsi_eh.h>
  36 #include <scsi/scsi_transport.h>
  37 #include <scsi/scsi_transport_spi.h>
  38
  39 #define SPI_PRINTK(x, l, f, a...)       dev_printk(l, &(x)->dev, f , ##a)
  40
  41 #define SPI_NUM_ATTRS 10        /* increase this if you add attributes */
  42 #define SPI_OTHER_ATTRS 1       /* Increase this if you add "always
  43                                  * on" attributes */
  44 #define SPI_HOST_ATTRS  1
  45
  46 #define SPI_MAX_ECHO_BUFFER_SIZE        4096
  47
  48 /* Private data accessors (keep these out of the header file) */
  49 #define spi_dv_pending(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_pending)
  50 #define spi_dv_sem(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_sem)
  51
  52 struct spi_internal {
  53         struct scsi_transport_template t;
  54         struct spi_function_template *f;
  55         /* The actual attributes */
  56         struct class_device_attribute private_attrs[SPI_NUM_ATTRS];
  57         /* The array of null terminated pointers to attributes
  58          * needed by scsi_sysfs.c */
  59         struct class_device_attribute *attrs[SPI_NUM_ATTRS + SPI_OTHER_ATTRS + 1];
  60         struct class_device_attribute private_host_attrs[SPI_HOST_ATTRS];
  61         struct class_device_attribute *host_attrs[SPI_HOST_ATTRS + 1];
  62 };
  63
  64 #define to_spi_internal(tmpl)   container_of(tmpl, struct spi_internal, t)
  65
  66 static const char *const ppr_to_ns[] = {
  67         /* The PPR values 0-6 are reserved, fill them in when
  68          * the committee defines them */
  69         NULL,                   /* 0x00 */
  70         NULL,                   /* 0x01 */
  71         NULL,                   /* 0x02 */
  72         NULL,                   /* 0x03 */
  73         NULL,                   /* 0x04 */
  74         NULL,                   /* 0x05 */
  75         NULL,                   /* 0x06 */
  76         "3.125",                /* 0x07 */
  77         "6.25",                 /* 0x08 */
  78         "12.5",                 /* 0x09 */
  79         "25",                   /* 0x0a */
  80         "30.3",                 /* 0x0b */
  81         "50",                   /* 0x0c */
  82 };
  83 /* The PPR values at which you calculate the period in ns by multiplying
  84  * by 4 */
  85 #define SPI_STATIC_PPR  0x0c
  86
  87 static struct {
  88         enum spi_signal_type    value;
  89         char                    *name;
  90 } signal_types[] = {
  91         { SPI_SIGNAL_UNKNOWN, "unknown" },
  92         { SPI_SIGNAL_SE, "SE" },
  93         { SPI_SIGNAL_LVD, "LVD" },
  94         { SPI_SIGNAL_HVD, "HVD" },
  95 };
  96
  97 static inline const char *spi_signal_to_string(enum spi_signal_type type)
  98 {
  99         int i;
 100
 101         for (i = 0; i < sizeof(signal_types)/sizeof(signal_types[0]); i++) {
 102                 if (type == signal_types[i].value)
 103                         return signal_types[i].name;
 104         }
 105         return NULL;
 106 }
 107 static inline enum spi_signal_type spi_signal_to_value(const char *name)
 108 {
 109         int i, len;
 110
 111         for (i = 0; i < sizeof(signal_types)/sizeof(signal_types[0]); i++) {
 112                 len =  strlen(signal_types[i].name);
 113                 if (strncmp(name, signal_types[i].name, len) == 0 &&
 114                     (name[len] == '\n' || name[len] == '\0'))
 115                         return signal_types[i].value;
 116         }
 117         return SPI_SIGNAL_UNKNOWN;
 118 }
 119
 120 static int spi_host_setup(struct device *dev)
 121 {
 122         struct Scsi_Host *shost = dev_to_shost(dev);
 123
 124         spi_signalling(shost) = SPI_SIGNAL_UNKNOWN;
 125
 126         return 0;
 127 }
 128
 129 static DECLARE_TRANSPORT_CLASS(spi_host_class,
 130                                "spi_host",
 131                                spi_host_setup,
 132                                NULL,
 133                                NULL);
 134
 135 static int spi_host_match(struct attribute_container *cont,
 136                           struct device *dev)
 137 {
 138         struct Scsi_Host *shost;
 139         struct spi_internal *i;
 140
 141         if (!scsi_is_host_device(dev))
 142                 return 0;
 143
 144         shost = dev_to_shost(dev);
 145         if (!shost->transportt  || shost->transportt->host_attrs.class
 146             != &spi_host_class.class)
 147                 return 0;
 148
 149         i = to_spi_internal(shost->transportt);
 150
 151         return &i->t.host_attrs == cont;
 152 }
 153
 154 static int spi_device_configure(struct device *dev)
 155 {
 156         struct scsi_device *sdev = to_scsi_device(dev);
 157         struct scsi_target *starget = sdev->sdev_target;
 158
 159         /* Populate the target capability fields with the values
 160          * gleaned from the device inquiry */
 161
 162         spi_support_sync(starget) = scsi_device_sync(sdev);
 163         spi_support_wide(starget) = scsi_device_wide(sdev);
 164         spi_support_dt(starget) = scsi_device_dt(sdev);
 165         spi_support_dt_only(starget) = scsi_device_dt_only(sdev);
 166         spi_support_ius(starget) = scsi_device_ius(sdev);
 167         spi_support_qas(starget) = scsi_device_qas(sdev);
 168
 169         return 0;
 170 }
 171
 172 static int spi_setup_transport_attrs(struct device *dev)
 173 {
 174         struct scsi_target *starget = to_scsi_target(dev);
 175
 176         spi_period(starget) = -1;       /* illegal value */
 177         spi_offset(starget) = 0;        /* async */
 178         spi_width(starget) = 0; /* narrow */
 179         spi_iu(starget) = 0;    /* no IU */
 180         spi_dt(starget) = 0;    /* ST */
 181         spi_qas(starget) = 0;
 182         spi_wr_flow(starget) = 0;
 183         spi_rd_strm(starget) = 0;
 184         spi_rti(starget) = 0;
 185         spi_pcomp_en(starget) = 0;
 186         spi_dv_pending(starget) = 0;
 187         spi_initial_dv(starget) = 0;
 188         init_MUTEX(&spi_dv_sem(starget));
 189
 190         return 0;
 191 }
 192
 193 #define spi_transport_show_function(field, format_string)               \
 194                                                                         \
 195 static ssize_t                                                          \
 196 show_spi_transport_##field(struct class_device *cdev, char *buf)        \
 197 {                                                                       \
 198         struct scsi_target *starget = transport_class_to_starget(cdev); \
 199         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);    \
 200         struct spi_transport_attrs *tp;                                 \
 201         struct spi_internal *i = to_spi_internal(shost->transportt);    \
 202         tp = (struct spi_transport_attrs *)&starget->starget_data;      \
 203         if (i->f->get_##field)                                          \
 204                 i->f->get_##field(starget);                             \
 205         return snprintf(buf, 20, format_string, tp->field);             \
 206 }
 207
 208 #define spi_transport_store_function(field, format_string)              \
 209 static ssize_t                                                          \
 210 store_spi_transport_##field(struct class_device *cdev, const char *buf, \
 211                             size_t count)                               \
 212 {                                                                       \
 213         int val;                                                        \
 214         struct scsi_target *starget = transport_class_to_starget(cdev); \
 215         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);    \
 216         struct spi_internal *i = to_spi_internal(shost->transportt);    \
 217                                                                         \
 218         val = simple_strtoul(buf, NULL, 0);                             \
 219         i->f->set_##field(starget, val);                                \
 220         return count;                                                   \
 221 }
 222
 223 #define spi_transport_rd_attr(field, format_string)                     \
 224         spi_transport_show_function(field, format_string)               \
 225         spi_transport_store_function(field, format_string)              \
 226 static CLASS_DEVICE_ATTR(field, S_IRUGO | S_IWUSR,                      \
 227                          show_spi_transport_##field,                    \
 228                          store_spi_transport_##field);
 229
 230 /* The Parallel SCSI Tranport Attributes: */
 231 spi_transport_rd_attr(offset, "%d\n");
 232 spi_transport_rd_attr(width, "%d\n");
 233 spi_transport_rd_attr(iu, "%d\n");
 234 spi_transport_rd_attr(dt, "%d\n");
 235 spi_transport_rd_attr(qas, "%d\n");
 236 spi_transport_rd_attr(wr_flow, "%d\n");
 237 spi_transport_rd_attr(rd_strm, "%d\n");
 238 spi_transport_rd_attr(rti, "%d\n");
 239 spi_transport_rd_attr(pcomp_en, "%d\n");
 240
 241 static ssize_t
 242 store_spi_revalidate(struct class_device *cdev, const char *buf, size_t count)
 243 {
 244         struct scsi_target *starget = transport_class_to_starget(cdev);
 245
 246         /* FIXME: we're relying on an awful lot of device internals
 247          * here.  We really need a function to get the first available
 248          * child */
 249         struct device *dev = container_of(starget->dev.children.next, struct device, node);
 250         struct scsi_device *sdev = to_scsi_device(dev);
 251         spi_dv_device(sdev);
 252         return count;
 253 }
 254 static CLASS_DEVICE_ATTR(revalidate, S_IWUSR, NULL, store_spi_revalidate);
 255
 256 /* Translate the period into ns according to the current spec
 257  * for SDTR/PPR messages */
 258 static ssize_t show_spi_transport_period(struct class_device *cdev, char *buf)
 259
 260 {
 261         struct scsi_target *starget = transport_class_to_starget(cdev);
 262         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
 263         struct spi_transport_attrs *tp;
 264         const char *str;
 265         struct spi_internal *i = to_spi_internal(shost->transportt);
 266
 267         tp = (struct spi_transport_attrs *)&starget->starget_data;
 268
 269         if (i->f->get_period)
 270                 i->f->get_period(starget);
 271
 272         switch(tp->period) {
 273
 274         case 0x07 ... SPI_STATIC_PPR:
 275                 str = ppr_to_ns[tp->period];
 276                 if(!str)
 277                         str = "reserved";
 278                 break;
 279
 280
 281         case (SPI_STATIC_PPR+1) ... 0xff:
 282                 return sprintf(buf, "%d\n", tp->period * 4);
 283
 284         default:
 285                 str = "unknown";
 286         }
 287         return sprintf(buf, "%s\n", str);
 288 }
 289
 290 static ssize_t
 291 store_spi_transport_period(struct class_device *cdev, const char *buf,
 292                             size_t count)
 293 {
 294         struct scsi_target *starget = transport_class_to_starget(cdev);
 295         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
 296         struct spi_internal *i = to_spi_internal(shost->transportt);
 297         int j, period = -1;
 298
 299         for (j = 0; j < SPI_STATIC_PPR; j++) {
 300                 int len;
 301
 302                 if(ppr_to_ns[j] == NULL)
 303                         continue;
 304
 305                 len = strlen(ppr_to_ns[j]);
 306
 307                 if(strncmp(ppr_to_ns[j], buf, len) != 0)
 308                         continue;
 309
 310                 if(buf[len] != '\n')
 311                         continue;
 312
 313                 period = j;
 314                 break;
 315         }
 316
 317         if (period == -1) {
 318                 int val = simple_strtoul(buf, NULL, 0);
 319
 320
 321                 /* Should probably check limits here, but this
 322                  * gets reasonably close to OK for most things */
 323                 period = val/4;
 324         }
 325
 326         if (period > 0xff)
 327                 period = 0xff;
 328
 329         i->f->set_period(starget, period);
 330
 331         return count;
 332 }
 333
 334 static CLASS_DEVICE_ATTR(period, S_IRUGO | S_IWUSR,
 335                          show_spi_transport_period,
 336                          store_spi_transport_period);
 337
 338 static ssize_t show_spi_host_signalling(struct class_device *cdev, char *buf)
 339 {
 340         struct Scsi_Host *shost = transport_class_to_shost(cdev);
 341         struct spi_internal *i = to_spi_internal(shost->transportt);
 342
 343         if (i->f->get_signalling)
 344                 i->f->get_signalling(shost);
 345
 346         return sprintf(buf, "%s\n", spi_signal_to_string(spi_signalling(shost)));
 347 }
 348 static ssize_t store_spi_host_signalling(struct class_device *cdev,
 349                                          const char *buf, size_t count)
 350 {
 351         struct Scsi_Host *shost = transport_class_to_shost(cdev);
 352         struct spi_internal *i = to_spi_internal(shost->transportt);
 353         enum spi_signal_type type = spi_signal_to_value(buf);
 354
 355         if (type != SPI_SIGNAL_UNKNOWN)
 356                 i->f->set_signalling(shost, type);
 357
 358         return count;
 359 }
 360 static CLASS_DEVICE_ATTR(signalling, S_IRUGO | S_IWUSR,
 361                          show_spi_host_signalling,
 362                          store_spi_host_signalling);
 363
 364 #define DV_SET(x, y)                    \
 365         if(i->f->set_##x)               \
 366                 i->f->set_##x(sdev->sdev_target, y)
 367
 368 #define DV_LOOPS        3
 369 #define DV_TIMEOUT      (10*HZ)
 370 #define DV_RETRIES      3       /* should only need at most
 371                                  * two cc/ua clears */
 372
 373 enum spi_compare_returns {
 374         SPI_COMPARE_SUCCESS,
 375         SPI_COMPARE_FAILURE,
 376         SPI_COMPARE_SKIP_TEST,
 377 };
 378
 379
 380 /* This is for read/write Domain Validation:  If the device supports
 381  * an echo buffer, we do read/write tests to it */
 382 static enum spi_compare_returns
 383 spi_dv_device_echo_buffer(struct scsi_request *sreq, u8 *buffer,
 384                           u8 *ptr, const int retries)
 385 {
 386         struct scsi_device *sdev = sreq->sr_device;
 387         int len = ptr - buffer;
 388         int j, k, r;
 389         unsigned int pattern = 0x0000ffff;
 390
 391         const char spi_write_buffer[] = {
 392                 WRITE_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
 393         };
 394         const char spi_read_buffer[] = {
 395                 READ_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
 396         };
 397
 398         /* set up the pattern buffer.  Doesn't matter if we spill
 399          * slightly beyond since that's where the read buffer is */
 400         for (j = 0; j < len; ) {
 401
 402                 /* fill the buffer with counting (test a) */
 403                 for ( ; j < min(len, 32); j++)
 404                         buffer[j] = j;
 405                 k = j;
 406                 /* fill the buffer with alternating words of 0x0 and
 407                  * 0xffff (test b) */
 408                 for ( ; j < min(len, k + 32); j += 2) {
 409                         u16 *word = (u16 *)&buffer[j];
 410
 411                         *word = (j & 0x02) ? 0x0000 : 0xffff;
 412                 }
 413                 k = j;
 414                 /* fill with crosstalk (alternating 0x5555 0xaaa)
 415                  * (test c) */
 416                 for ( ; j < min(len, k + 32); j += 2) {
 417                         u16 *word = (u16 *)&buffer[j];
 418
 419                         *word = (j & 0x02) ? 0x5555 : 0xaaaa;
 420                 }
 421                 k = j;
 422                 /* fill with shifting bits (test d) */
 423                 for ( ; j < min(len, k + 32); j += 4) {
 424                         u32 *word = (unsigned int *)&buffer[j];
 425                         u32 roll = (pattern & 0x80000000) ? 1 : 0;
 426
 427                         *word = pattern;
 428                         pattern = (pattern << 1) | roll;
 429                 }
 430                 /* don't bother with random data (test e) */
 431         }
 432
 433         for (r = 0; r < retries; r++) {
 434                 sreq->sr_cmd_len = 0;   /* wait_req to fill in */
 435                 sreq->sr_data_direction = DMA_TO_DEVICE;
 436                 scsi_wait_req(sreq, spi_write_buffer, buffer, len,
 437                               DV_TIMEOUT, DV_RETRIES);
 438                 if(sreq->sr_result || !scsi_device_online(sdev)) {
 439                         struct scsi_sense_hdr sshdr;
 440
 441                         scsi_device_set_state(sdev, SDEV_QUIESCE);
 442                         if (scsi_request_normalize_sense(sreq, &sshdr)
 443                             && sshdr.sense_key == ILLEGAL_REQUEST
 444                             /* INVALID FIELD IN CDB */
 445                             && sshdr.asc == 0x24 && sshdr.ascq == 0x00)
 446                                 /* This would mean that the drive lied
 447                                  * to us about supporting an echo
 448                                  * buffer (unfortunately some Western
 449                                  * Digital drives do precisely this)
 450                                  */
 451                                 return SPI_COMPARE_SKIP_TEST;
 452
 453
 454                         SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Write Buffer failure %x\n", sreq->sr_result);
 455                         return SPI_COMPARE_FAILURE;
 456                 }
 457
 458                 memset(ptr, 0, len);
 459                 sreq->sr_cmd_len = 0;   /* wait_req to fill in */
 460                 sreq->sr_data_direction = DMA_FROM_DEVICE;
 461                 scsi_wait_req(sreq, spi_read_buffer, ptr, len,
 462                               DV_TIMEOUT, DV_RETRIES);
 463                 scsi_device_set_state(sdev, SDEV_QUIESCE);
 464
 465                 if (memcmp(buffer, ptr, len) != 0)
 466                         return SPI_COMPARE_FAILURE;
 467         }
 468         return SPI_COMPARE_SUCCESS;
 469 }
 470
 471 /* This is for the simplest form of Domain Validation: a read test
 472  * on the inquiry data from the device */
 473 static enum spi_compare_returns
 474 spi_dv_device_compare_inquiry(struct scsi_request *sreq, u8 *buffer,
 475                               u8 *ptr, const int retries)
 476 {
 477         int r;
 478         const int len = sreq->sr_device->inquiry_len;
 479         struct scsi_device *sdev = sreq->sr_device;
 480         const char spi_inquiry[] = {
 481                 INQUIRY, 0, 0, 0, len, 0
 482         };
 483
 484         for (r = 0; r < retries; r++) {
 485                 sreq->sr_cmd_len = 0;   /* wait_req to fill in */
 486                 sreq->sr_data_direction = DMA_FROM_DEVICE;
 487
 488                 memset(ptr, 0, len);
 489
 490                 scsi_wait_req(sreq, spi_inquiry, ptr, len,
 491                               DV_TIMEOUT, DV_RETRIES);
 492
 493                 if(sreq->sr_result || !scsi_device_online(sdev)) {
 494                         scsi_device_set_state(sdev, SDEV_QUIESCE);
 495                         return SPI_COMPARE_FAILURE;
 496                 }
 497
 498                 /* If we don't have the inquiry data already, the
 499                  * first read gets it */
 500                 if (ptr == buffer) {
 501                         ptr += len;
 502                         --r;
 503                         continue;
 504                 }
 505
 506                 if (memcmp(buffer, ptr, len) != 0)
 507                         /* failure */
 508                         return SPI_COMPARE_FAILURE;
 509         }
 510         return SPI_COMPARE_SUCCESS;
 511 }
 512
 513 static enum spi_compare_returns
 514 spi_dv_retrain(struct scsi_request *sreq, u8 *buffer, u8 *ptr,
 515                enum spi_compare_returns
 516                (*compare_fn)(struct scsi_request *, u8 *, u8 *, int))
 517 {
 518         struct spi_internal *i = to_spi_internal(sreq->sr_host->transportt);
 519         struct scsi_device *sdev = sreq->sr_device;
 520         int period = 0, prevperiod = 0;
 521         enum spi_compare_returns retval;
 522
 523
 524         for (;;) {
 525                 int newperiod;
 526                 retval = compare_fn(sreq, buffer, ptr, DV_LOOPS);
 527
 528                 if (retval == SPI_COMPARE_SUCCESS
 529                     || retval == SPI_COMPARE_SKIP_TEST)
 530                         break;
 531
 532                 /* OK, retrain, fallback */
 533                 if (i->f->get_period)
 534                         i->f->get_period(sdev->sdev_target);
 535                 newperiod = spi_period(sdev->sdev_target);
 536                 period = newperiod > period ? newperiod : period;
 537                 if (period < 0x0d)
 538                         period++;
 539                 else
 540                         period += period >> 1;
 541
 542                 if (unlikely(period > 0xff || period == prevperiod)) {
 543                         /* Total failure; set to async and return */
 544                         SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Domain Validation Failure, dropping back to Asynchronous\n");
 545                         DV_SET(offset, 0);
 546                         return SPI_COMPARE_FAILURE;
 547                 }
 548                 SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Domain Validation detected failure, dropping back\n");
 549                 DV_SET(period, period);
 550                 prevperiod = period;
 551         }
 552         return retval;
 553 }
 554
 555 static int
 556 spi_dv_device_get_echo_buffer(struct scsi_request *sreq, u8 *buffer)
 557 {
 558         int l;
 559
 560         /* first off do a test unit ready.  This can error out
 561          * because of reservations or some other reason.  If it
 562          * fails, the device won't let us write to the echo buffer
 563          * so just return failure */
 564
 565         const char spi_test_unit_ready[] = {
 566                 TEST_UNIT_READY, 0, 0, 0, 0, 0
 567         };
 568
 569         const char spi_read_buffer_descriptor[] = {
 570                 READ_BUFFER, 0x0b, 0, 0, 0, 0, 0, 0, 4, 0
 571         };
 572
 573
 574         sreq->sr_cmd_len = 0;
 575         sreq->sr_data_direction = DMA_NONE;
 576
 577         /* We send a set of three TURs to clear any outstanding
 578          * unit attention conditions if they exist (Otherwise the
 579          * buffer tests won't be happy).  If the TUR still fails
 580          * (reservation conflict, device not ready, etc) just
 581          * skip the write tests */
 582         for (l = 0; ; l++) {
 583                 scsi_wait_req(sreq, spi_test_unit_ready, NULL, 0,
 584                               DV_TIMEOUT, DV_RETRIES);
 585
 586                 if(sreq->sr_result) {
 587                         if(l >= 3)
 588                                 return 0;
 589                 } else {
 590                         /* TUR succeeded */
 591                         break;
 592                 }
 593         }
 594
 595         sreq->sr_cmd_len = 0;
 596         sreq->sr_data_direction = DMA_FROM_DEVICE;
 597
 598         scsi_wait_req(sreq, spi_read_buffer_descriptor, buffer, 4,
 599                       DV_TIMEOUT, DV_RETRIES);
 600
 601         if (sreq->sr_result)
 602                 /* Device has no echo buffer */
 603                 return 0;
 604
 605         return buffer[3] + ((buffer[2] & 0x1f) << 8);
 606 }
 607
 608 static void
 609 spi_dv_device_internal(struct scsi_request *sreq, u8 *buffer)
 610 {
 611         struct spi_internal *i = to_spi_internal(sreq->sr_host->transportt);
 612         struct scsi_device *sdev = sreq->sr_device;
 613         int len = sdev->inquiry_len;
 614         /* first set us up for narrow async */
 615         DV_SET(offset, 0);
 616         DV_SET(width, 0);
 617
 618         if (spi_dv_device_compare_inquiry(sreq, buffer, buffer, DV_LOOPS)
 619             != SPI_COMPARE_SUCCESS) {
 620                 SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Domain Validation Initial Inquiry Failed\n");
 621                 /* FIXME: should probably offline the device here? */
 622                 return;
 623         }
 624
 625         /* test width */
 626         if (i->f->set_width && sdev->wdtr) {
 627                 i->f->set_width(sdev->sdev_target, 1);
 628
 629                 if (spi_dv_device_compare_inquiry(sreq, buffer,
 630                                                    buffer + len,
 631                                                    DV_LOOPS)
 632                     != SPI_COMPARE_SUCCESS) {
 633                         SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Wide Transfers Fail\n");
 634                         i->f->set_width(sdev->sdev_target, 0);
 635                 }
 636         }
 637
 638         if (!i->f->set_period)
 639                 return;
 640
 641         /* device can't handle synchronous */
 642         if(!sdev->ppr && !sdev->sdtr)
 643                 return;
 644
 645         /* see if the device has an echo buffer.  If it does we can
 646          * do the SPI pattern write tests */
 647
 648         len = 0;
 649         if (sdev->ppr)
 650                 len = spi_dv_device_get_echo_buffer(sreq, buffer);
 651
 652  retry:
 653
 654         /* now set up to the maximum */
 655         DV_SET(offset, 255);
 656         DV_SET(period, 1);
 657
 658         if (len == 0) {
 659                 SPI_PRINTK(sdev->sdev_target, KERN_INFO, "Domain Validation skipping write tests\n");
 660                 spi_dv_retrain(sreq, buffer, buffer + len,
 661                                spi_dv_device_compare_inquiry);
 662                 return;
 663         }
 664
 665         if (len > SPI_MAX_ECHO_BUFFER_SIZE) {
 666                 SPI_PRINTK(sdev->sdev_target, KERN_WARNING, "Echo buffer size %d is too big, trimming to %d\n", len, SPI_MAX_ECHO_BUFFER_SIZE);
 667                 len = SPI_MAX_ECHO_BUFFER_SIZE;
 668         }
 669
 670         if (spi_dv_retrain(sreq, buffer, buffer + len,
 671                            spi_dv_device_echo_buffer)
 672             == SPI_COMPARE_SKIP_TEST) {
 673                 /* OK, the stupid drive can't do a write echo buffer
 674                  * test after all, fall back to the read tests */
 675                 len = 0;
 676                 goto retry;
 677         }
 678 }
 679
 680
 681 /**     spi_dv_device - Do Domain Validation on the device
 682  *      @sdev:          scsi device to validate
 683  *
 684  *      Performs the domain validation on the given device in the
 685  *      current execution thread.  Since DV operations may sleep,
 686  *      the current thread must have user context.  Also no SCSI
 687  *      related locks that would deadlock I/O issued by the DV may
 688  *      be held.
 689  */
 690 void
 691 spi_dv_device(struct scsi_device *sdev)
 692 {
 693         struct scsi_request *sreq = scsi_allocate_request(sdev, GFP_KERNEL);
 694         struct scsi_target *starget = sdev->sdev_target;
 695         u8 *buffer;
 696         const int len = SPI_MAX_ECHO_BUFFER_SIZE*2;
 697
 698         if (unlikely(!sreq))
 699                 return;
 700
 701         if (unlikely(scsi_device_get(sdev)))
 702                 goto out_free_req;
 703
 704         buffer = kmalloc(len, GFP_KERNEL);
 705
 706         if (unlikely(!buffer))
 707                 goto out_put;
 708
 709         memset(buffer, 0, len);
 710
 711         /* We need to verify that the actual device will quiesce; the
 712          * later target quiesce is just a nice to have */
 713         if (unlikely(scsi_device_quiesce(sdev)))
 714                 goto out_free;
 715
 716         scsi_target_quiesce(starget);
 717
 718         spi_dv_pending(starget) = 1;
 719         down(&spi_dv_sem(starget));
 720
 721         SPI_PRINTK(starget, KERN_INFO, "Beginning Domain Validation\n");
 722
 723         spi_dv_device_internal(sreq, buffer);
 724
 725         SPI_PRINTK(starget, KERN_INFO, "Ending Domain Validation\n");
 726
 727         up(&spi_dv_sem(starget));
 728         spi_dv_pending(starget) = 0;
 729
 730         scsi_target_resume(starget);
 731
 732         spi_initial_dv(starget) = 1;
 733
 734  out_free:
 735         kfree(buffer);
 736  out_put:
 737         scsi_device_put(sdev);
 738  out_free_req:
 739         scsi_release_request(sreq);
 740 }
 741 EXPORT_SYMBOL(spi_dv_device);
 742
 743 struct work_queue_wrapper {
 744         struct work_struct      work;
 745         struct scsi_device      *sdev;
 746 };
 747
 748 static void
 749 spi_dv_device_work_wrapper(void *data)
 750 {
 751         struct work_queue_wrapper *wqw = (struct work_queue_wrapper *)data;
 752         struct scsi_device *sdev = wqw->sdev;
 753
 754         kfree(wqw);
 755         spi_dv_device(sdev);
 756         spi_dv_pending(sdev->sdev_target) = 0;
 757         scsi_device_put(sdev);
 758 }
 759
 760
 761 /**
 762  *      spi_schedule_dv_device - schedule domain validation to occur on the device
 763  *      @sdev:  The device to validate
 764  *
 765  *      Identical to spi_dv_device() above, except that the DV will be
 766  *      scheduled to occur in a workqueue later.  All memory allocations
 767  *      are atomic, so may be called from any context including those holding
 768  *      SCSI locks.
 769  */
 770 void
 771 spi_schedule_dv_device(struct scsi_device *sdev)
 772 {
 773         struct work_queue_wrapper *wqw =
 774                 kmalloc(sizeof(struct work_queue_wrapper), GFP_ATOMIC);
 775
 776         if (unlikely(!wqw))
 777                 return;
 778
 779         if (unlikely(spi_dv_pending(sdev->sdev_target))) {
 780                 kfree(wqw);
 781                 return;
 782         }
 783         /* Set pending early (dv_device doesn't check it, only sets it) */
 784         spi_dv_pending(sdev->sdev_target) = 1;
 785         if (unlikely(scsi_device_get(sdev))) {
 786                 kfree(wqw);
 787                 spi_dv_pending(sdev->sdev_target) = 0;
 788                 return;
 789         }
 790
 791         INIT_WORK(&wqw->work, spi_dv_device_work_wrapper, wqw);
 792         wqw->sdev = sdev;
 793
 794         schedule_work(&wqw->work);
 795 }
 796 EXPORT_SYMBOL(spi_schedule_dv_device);
 797
 798 #define SETUP_ATTRIBUTE(field)                                          \
 799         i->private_attrs[count] = class_device_attr_##field;            \
 800         if (!i->f->set_##field) {                                       \
 801                 i->private_attrs[count].attr.mode = S_IRUGO;            \
 802                 i->private_attrs[count].store = NULL;                   \
 803         }                                                               \
 804         i->attrs[count] = &i->private_attrs[count];                     \
 805         if (i->f->show_##field)                                         \
 806                 count++
 807
 808 #define SETUP_HOST_ATTRIBUTE(field)                                     \
 809         i->private_host_attrs[count] = class_device_attr_##field;       \
 810         if (!i->f->set_##field) {                                       \
 811                 i->private_host_attrs[count].attr.mode = S_IRUGO;       \
 812                 i->private_host_attrs[count].store = NULL;              \
 813         }                                                               \
 814         i->host_attrs[count] = &i->private_host_attrs[count];           \
 815         count++
 816
 817 static int spi_device_match(struct attribute_container *cont,
 818                             struct device *dev)
 819 {
 820         struct scsi_device *sdev;
 821         struct Scsi_Host *shost;
 822
 823         if (!scsi_is_sdev_device(dev))
 824                 return 0;
 825
 826         sdev = to_scsi_device(dev);
 827         shost = sdev->host;
 828         if (!shost->transportt  || shost->transportt->host_attrs.class
 829             != &spi_host_class.class)
 830                 return 0;
 831         /* Note: this class has no device attributes, so it has
 832          * no per-HBA allocation and thus we don't need to distinguish
 833          * the attribute containers for the device */
 834         return 1;
 835 }
 836
 837 static int spi_target_match(struct attribute_container *cont,
 838                             struct device *dev)
 839 {
 840         struct Scsi_Host *shost;
 841         struct spi_internal *i;
 842
 843         if (!scsi_is_target_device(dev))
 844                 return 0;
 845
 846         shost = dev_to_shost(dev->parent);
 847         if (!shost->transportt  || shost->transportt->host_attrs.class
 848             != &spi_host_class.class)
 849                 return 0;
 850
 851         i = to_spi_internal(shost->transportt);
 852
 853         return &i->t.target_attrs == cont;
 854 }
 855
 856 static DECLARE_TRANSPORT_CLASS(spi_transport_class,
 857                                "spi_transport",
 858                                spi_setup_transport_attrs,
 859                                NULL,
 860                                NULL);
 861
 862 static DECLARE_ANON_TRANSPORT_CLASS(spi_device_class,
 863                                     spi_device_match,
 864                                     spi_device_configure);
 865
 866 struct scsi_transport_template *
 867 spi_attach_transport(struct spi_function_template *ft)
 868 {
 869         struct spi_internal *i = kmalloc(sizeof(struct spi_internal),
 870                                          GFP_KERNEL);
 871         int count = 0;
 872         if (unlikely(!i))
 873                 return NULL;
 874
 875         memset(i, 0, sizeof(struct spi_internal));
 876
 877
 878         i->t.target_attrs.class = &spi_transport_class.class;
 879         i->t.target_attrs.attrs = &i->attrs[0];
 880         i->t.target_attrs.match = spi_target_match;
 881         attribute_container_register(&i->t.target_attrs);
 882         i->t.target_size = sizeof(struct spi_transport_attrs);
 883         i->t.host_attrs.class = &spi_host_class.class;
 884         i->t.host_attrs.attrs = &i->host_attrs[0];
 885         i->t.host_attrs.match = spi_host_match;
 886         attribute_container_register(&i->t.host_attrs);
 887         i->t.host_size = sizeof(struct spi_host_attrs);
 888         i->f = ft;
 889
 890         SETUP_ATTRIBUTE(period);
 891         SETUP_ATTRIBUTE(offset);
 892         SETUP_ATTRIBUTE(width);
 893         SETUP_ATTRIBUTE(iu);
 894         SETUP_ATTRIBUTE(dt);
 895         SETUP_ATTRIBUTE(qas);
 896         SETUP_ATTRIBUTE(wr_flow);
 897         SETUP_ATTRIBUTE(rd_strm);
 898         SETUP_ATTRIBUTE(rti);
 899         SETUP_ATTRIBUTE(pcomp_en);
 900
 901         /* if you add an attribute but forget to increase SPI_NUM_ATTRS
 902          * this bug will trigger */
 903         BUG_ON(count > SPI_NUM_ATTRS);
 904
 905         i->attrs[count++] = &class_device_attr_revalidate;
 906
 907         i->attrs[count] = NULL;
 908
 909         count = 0;
 910         SETUP_HOST_ATTRIBUTE(signalling);
 911
 912         BUG_ON(count > SPI_HOST_ATTRS);
 913
 914         i->host_attrs[count] = NULL;
 915
 916         return &i->t;
 917 }
 918 EXPORT_SYMBOL(spi_attach_transport);
 919
 920 void spi_release_transport(struct scsi_transport_template *t)
 921 {
 922         struct spi_internal *i = to_spi_internal(t);
 923
 924         attribute_container_unregister(&i->t.target_attrs);
 925         attribute_container_unregister(&i->t.host_attrs);
 926
 927         kfree(i);
 928 }
 929 EXPORT_SYMBOL(spi_release_transport);
 930
 931 static __init int spi_transport_init(void)
 932 {
 933         int error = transport_class_register(&spi_transport_class);
 934         if (error)
 935                 return error;
 936         error = anon_transport_class_register(&spi_device_class);
 937         return transport_class_register(&spi_host_class);
 938 }
 939
 940 static void __exit spi_transport_exit(void)
 941 {
 942         transport_class_unregister(&spi_transport_class);
 943         anon_transport_class_unregister(&spi_device_class);
 944         transport_class_unregister(&spi_host_class);
 945 }
 946
 947 MODULE_AUTHOR("Martin Hicks");
 948 MODULE_DESCRIPTION("SPI Transport Attributes");
 949 MODULE_LICENSE("GPL");
 950
 951 module_init(spi_transport_init);
 952 module_exit(spi_transport_exit);