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