git.oblomov.eu Git - linux-2.6/blob - 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/ctype.h>
  22 #include <linux/init.h>
  23 #include <linux/module.h>
  24 #include <linux/workqueue.h>
  25 #include <linux/blkdev.h>
  26 #include <asm/semaphore.h>
  27 #include <scsi/scsi.h>
  28 #include "scsi_priv.h"
  29 #include <scsi/scsi_device.h>
  30 #include <scsi/scsi_host.h>
  31 #include <scsi/scsi_request.h>
  32 #include <scsi/scsi_eh.h>
  33 #include <scsi/scsi_transport.h>
  34 #include <scsi/scsi_transport_spi.h>
  35
  36 #define SPI_PRINTK(x, l, f, a...)       dev_printk(l, &(x)->dev, f , ##a)
  37
  38 #define SPI_NUM_ATTRS 10        /* increase this if you add attributes */
  39 #define SPI_OTHER_ATTRS 1       /* Increase this if you add "always
  40                                  * on" attributes */
  41 #define SPI_HOST_ATTRS  1
  42
  43 #define SPI_MAX_ECHO_BUFFER_SIZE        4096
  44
  45 #define DV_LOOPS        3
  46 #define DV_TIMEOUT      (10*HZ)
  47 #define DV_RETRIES      3       /* should only need at most
  48                                  * two cc/ua clears */
  49
  50 /* Private data accessors (keep these out of the header file) */
  51 #define spi_dv_pending(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_pending)
  52 #define spi_dv_sem(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_sem)
  53
  54 struct spi_internal {
  55         struct scsi_transport_template t;
  56         struct spi_function_template *f;
  57         /* The actual attributes */
  58         struct class_device_attribute private_attrs[SPI_NUM_ATTRS];
  59         /* The array of null terminated pointers to attributes
  60          * needed by scsi_sysfs.c */
  61         struct class_device_attribute *attrs[SPI_NUM_ATTRS + SPI_OTHER_ATTRS + 1];
  62         struct class_device_attribute private_host_attrs[SPI_HOST_ATTRS];
  63         struct class_device_attribute *host_attrs[SPI_HOST_ATTRS + 1];
  64 };
  65
  66 #define to_spi_internal(tmpl)   container_of(tmpl, struct spi_internal, t)
  67
  68 static const int ppr_to_ps[] = {
  69         /* The PPR values 0-6 are reserved, fill them in when
  70          * the committee defines them */
  71         -1,                     /* 0x00 */
  72         -1,                     /* 0x01 */
  73         -1,                     /* 0x02 */
  74         -1,                     /* 0x03 */
  75         -1,                     /* 0x04 */
  76         -1,                     /* 0x05 */
  77         -1,                     /* 0x06 */
  78          3125,                  /* 0x07 */
  79          6250,                  /* 0x08 */
  80         12500,                  /* 0x09 */
  81         25000,                  /* 0x0a */
  82         30300,                  /* 0x0b */
  83         50000,                  /* 0x0c */
  84 };
  85 /* The PPR values at which you calculate the period in ns by multiplying
  86  * by 4 */
  87 #define SPI_STATIC_PPR  0x0c
  88
  89 static int sprint_frac(char *dest, int value, int denom)
  90 {
  91         int frac = value % denom;
  92         int result = sprintf(dest, "%d", value / denom);
  93
  94         if (frac == 0)
  95                 return result;
  96         dest[result++] = '.';
  97
  98         do {
  99                 denom /= 10;
 100                 sprintf(dest + result, "%d", frac / denom);
 101                 result++;
 102                 frac %= denom;
 103         } while (frac);
 104
 105         dest[result++] = '\0';
 106         return result;
 107 }
 108
 109 /* Modification of scsi_wait_req that will clear UNIT ATTENTION conditions
 110  * resulting from (likely) bus and device resets */
 111 static void spi_wait_req(struct scsi_request *sreq, const void *cmd,
 112                          void *buffer, unsigned bufflen)
 113 {
 114         int i;
 115
 116         for(i = 0; i < DV_RETRIES; i++) {
 117                 sreq->sr_request->flags |= REQ_FAILFAST;
 118
 119                 scsi_wait_req(sreq, cmd, buffer, bufflen,
 120                               DV_TIMEOUT, /* retries */ 1);
 121                 if (sreq->sr_result & DRIVER_SENSE) {
 122                         struct scsi_sense_hdr sshdr;
 123
 124                         if (scsi_request_normalize_sense(sreq, &sshdr)
 125                             && sshdr.sense_key == UNIT_ATTENTION)
 126                                 continue;
 127                 }
 128                 break;
 129         }
 130 }
 131
 132 static struct {
 133         enum spi_signal_type    value;
 134         char                    *name;
 135 } signal_types[] = {
 136         { SPI_SIGNAL_UNKNOWN, "unknown" },
 137         { SPI_SIGNAL_SE, "SE" },
 138         { SPI_SIGNAL_LVD, "LVD" },
 139         { SPI_SIGNAL_HVD, "HVD" },
 140 };
 141
 142 static inline const char *spi_signal_to_string(enum spi_signal_type type)
 143 {
 144         int i;
 145
 146         for (i = 0; i < sizeof(signal_types)/sizeof(signal_types[0]); i++) {
 147                 if (type == signal_types[i].value)
 148                         return signal_types[i].name;
 149         }
 150         return NULL;
 151 }
 152 static inline enum spi_signal_type spi_signal_to_value(const char *name)
 153 {
 154         int i, len;
 155
 156         for (i = 0; i < sizeof(signal_types)/sizeof(signal_types[0]); i++) {
 157                 len =  strlen(signal_types[i].name);
 158                 if (strncmp(name, signal_types[i].name, len) == 0 &&
 159                     (name[len] == '\n' || name[len] == '\0'))
 160                         return signal_types[i].value;
 161         }
 162         return SPI_SIGNAL_UNKNOWN;
 163 }
 164
 165 static int spi_host_setup(struct device *dev)
 166 {
 167         struct Scsi_Host *shost = dev_to_shost(dev);
 168
 169         spi_signalling(shost) = SPI_SIGNAL_UNKNOWN;
 170
 171         return 0;
 172 }
 173
 174 static DECLARE_TRANSPORT_CLASS(spi_host_class,
 175                                "spi_host",
 176                                spi_host_setup,
 177                                NULL,
 178                                NULL);
 179
 180 static int spi_host_match(struct attribute_container *cont,
 181                           struct device *dev)
 182 {
 183         struct Scsi_Host *shost;
 184         struct spi_internal *i;
 185
 186         if (!scsi_is_host_device(dev))
 187                 return 0;
 188
 189         shost = dev_to_shost(dev);
 190         if (!shost->transportt  || shost->transportt->host_attrs.ac.class
 191             != &spi_host_class.class)
 192                 return 0;
 193
 194         i = to_spi_internal(shost->transportt);
 195
 196         return &i->t.host_attrs.ac == cont;
 197 }
 198
 199 static int spi_device_configure(struct device *dev)
 200 {
 201         struct scsi_device *sdev = to_scsi_device(dev);
 202         struct scsi_target *starget = sdev->sdev_target;
 203
 204         /* Populate the target capability fields with the values
 205          * gleaned from the device inquiry */
 206
 207         spi_support_sync(starget) = scsi_device_sync(sdev);
 208         spi_support_wide(starget) = scsi_device_wide(sdev);
 209         spi_support_dt(starget) = scsi_device_dt(sdev);
 210         spi_support_dt_only(starget) = scsi_device_dt_only(sdev);
 211         spi_support_ius(starget) = scsi_device_ius(sdev);
 212         spi_support_qas(starget) = scsi_device_qas(sdev);
 213
 214         return 0;
 215 }
 216
 217 static int spi_setup_transport_attrs(struct device *dev)
 218 {
 219         struct scsi_target *starget = to_scsi_target(dev);
 220
 221         spi_period(starget) = -1;       /* illegal value */
 222         spi_offset(starget) = 0;        /* async */
 223         spi_width(starget) = 0; /* narrow */
 224         spi_iu(starget) = 0;    /* no IU */
 225         spi_dt(starget) = 0;    /* ST */
 226         spi_qas(starget) = 0;
 227         spi_wr_flow(starget) = 0;
 228         spi_rd_strm(starget) = 0;
 229         spi_rti(starget) = 0;
 230         spi_pcomp_en(starget) = 0;
 231         spi_dv_pending(starget) = 0;
 232         spi_initial_dv(starget) = 0;
 233         init_MUTEX(&spi_dv_sem(starget));
 234
 235         return 0;
 236 }
 237
 238 #define spi_transport_show_function(field, format_string)               \
 239                                                                         \
 240 static ssize_t                                                          \
 241 show_spi_transport_##field(struct class_device *cdev, char *buf)        \
 242 {                                                                       \
 243         struct scsi_target *starget = transport_class_to_starget(cdev); \
 244         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);    \
 245         struct spi_transport_attrs *tp;                                 \
 246         struct spi_internal *i = to_spi_internal(shost->transportt);    \
 247         tp = (struct spi_transport_attrs *)&starget->starget_data;      \
 248         if (i->f->get_##field)                                          \
 249                 i->f->get_##field(starget);                             \
 250         return snprintf(buf, 20, format_string, tp->field);             \
 251 }
 252
 253 #define spi_transport_store_function(field, format_string)              \
 254 static ssize_t                                                          \
 255 store_spi_transport_##field(struct class_device *cdev, const char *buf, \
 256                             size_t count)                               \
 257 {                                                                       \
 258         int val;                                                        \
 259         struct scsi_target *starget = transport_class_to_starget(cdev); \
 260         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);    \
 261         struct spi_internal *i = to_spi_internal(shost->transportt);    \
 262                                                                         \
 263         val = simple_strtoul(buf, NULL, 0);                             \
 264         i->f->set_##field(starget, val);                                \
 265         return count;                                                   \
 266 }
 267
 268 #define spi_transport_rd_attr(field, format_string)                     \
 269         spi_transport_show_function(field, format_string)               \
 270         spi_transport_store_function(field, format_string)              \
 271 static CLASS_DEVICE_ATTR(field, S_IRUGO | S_IWUSR,                      \
 272                          show_spi_transport_##field,                    \
 273                          store_spi_transport_##field);
 274
 275 /* The Parallel SCSI Tranport Attributes: */
 276 spi_transport_rd_attr(offset, "%d\n");
 277 spi_transport_rd_attr(width, "%d\n");
 278 spi_transport_rd_attr(iu, "%d\n");
 279 spi_transport_rd_attr(dt, "%d\n");
 280 spi_transport_rd_attr(qas, "%d\n");
 281 spi_transport_rd_attr(wr_flow, "%d\n");
 282 spi_transport_rd_attr(rd_strm, "%d\n");
 283 spi_transport_rd_attr(rti, "%d\n");
 284 spi_transport_rd_attr(pcomp_en, "%d\n");
 285
 286 static ssize_t
 287 store_spi_revalidate(struct class_device *cdev, const char *buf, size_t count)
 288 {
 289         struct scsi_target *starget = transport_class_to_starget(cdev);
 290
 291         /* FIXME: we're relying on an awful lot of device internals
 292          * here.  We really need a function to get the first available
 293          * child */
 294         struct device *dev = container_of(starget->dev.children.next, struct device, node);
 295         struct scsi_device *sdev = to_scsi_device(dev);
 296         spi_dv_device(sdev);
 297         return count;
 298 }
 299 static CLASS_DEVICE_ATTR(revalidate, S_IWUSR, NULL, store_spi_revalidate);
 300
 301 /* Translate the period into ns according to the current spec
 302  * for SDTR/PPR messages */
 303 static ssize_t show_spi_transport_period(struct class_device *cdev, char *buf)
 304
 305 {
 306         struct scsi_target *starget = transport_class_to_starget(cdev);
 307         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
 308         struct spi_transport_attrs *tp;
 309         int len, picosec;
 310         struct spi_internal *i = to_spi_internal(shost->transportt);
 311
 312         tp = (struct spi_transport_attrs *)&starget->starget_data;
 313
 314         if (i->f->get_period)
 315                 i->f->get_period(starget);
 316
 317         if (tp->period < 0 || tp->period > 0xff) {
 318                 picosec = -1;
 319         } else if (tp->period <= SPI_STATIC_PPR) {
 320                 picosec = ppr_to_ps[tp->period];
 321         } else {
 322                 picosec = tp->period * 4000;
 323         }
 324
 325         if (picosec == -1) {
 326                 len = sprintf(buf, "reserved");
 327         } else {
 328                 len = sprint_frac(buf, picosec, 1000);
 329         }
 330
 331         buf[len++] = '\n';
 332         buf[len] = '\0';
 333         return len;
 334 }
 335
 336 static ssize_t
 337 store_spi_transport_period(struct class_device *cdev, const char *buf,
 338                             size_t count)
 339 {
 340         struct scsi_target *starget = transport_class_to_starget(cdev);
 341         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
 342         struct spi_internal *i = to_spi_internal(shost->transportt);
 343         int j, picosec, period = -1;
 344         char *endp;
 345
 346         picosec = simple_strtoul(buf, &endp, 10) * 1000;
 347         if (*endp == '.') {
 348                 int mult = 100;
 349                 do {
 350                         endp++;
 351                         if (!isdigit(*endp))
 352                                 break;
 353                         picosec += (*endp - '0') * mult;
 354                         mult /= 10;
 355                 } while (mult > 0);
 356         }
 357
 358         for (j = 0; j <= SPI_STATIC_PPR; j++) {
 359                 if (ppr_to_ps[j] < picosec)
 360                         continue;
 361                 period = j;
 362                 break;
 363         }
 364
 365         if (period == -1)
 366                 period = picosec / 4000;
 367
 368         if (period > 0xff)
 369                 period = 0xff;
 370
 371         i->f->set_period(starget, period);
 372
 373         return count;
 374 }
 375
 376 static CLASS_DEVICE_ATTR(period, S_IRUGO | S_IWUSR,
 377                          show_spi_transport_period,
 378                          store_spi_transport_period);
 379
 380 static ssize_t show_spi_host_signalling(struct class_device *cdev, char *buf)
 381 {
 382         struct Scsi_Host *shost = transport_class_to_shost(cdev);
 383         struct spi_internal *i = to_spi_internal(shost->transportt);
 384
 385         if (i->f->get_signalling)
 386                 i->f->get_signalling(shost);
 387
 388         return sprintf(buf, "%s\n", spi_signal_to_string(spi_signalling(shost)));
 389 }
 390 static ssize_t store_spi_host_signalling(struct class_device *cdev,
 391                                          const char *buf, size_t count)
 392 {
 393         struct Scsi_Host *shost = transport_class_to_shost(cdev);
 394         struct spi_internal *i = to_spi_internal(shost->transportt);
 395         enum spi_signal_type type = spi_signal_to_value(buf);
 396
 397         if (type != SPI_SIGNAL_UNKNOWN)
 398                 i->f->set_signalling(shost, type);
 399
 400         return count;
 401 }
 402 static CLASS_DEVICE_ATTR(signalling, S_IRUGO | S_IWUSR,
 403                          show_spi_host_signalling,
 404                          store_spi_host_signalling);
 405
 406 #define DV_SET(x, y)                    \
 407         if(i->f->set_##x)               \
 408                 i->f->set_##x(sdev->sdev_target, y)
 409
 410 enum spi_compare_returns {
 411         SPI_COMPARE_SUCCESS,
 412         SPI_COMPARE_FAILURE,
 413         SPI_COMPARE_SKIP_TEST,
 414 };
 415
 416
 417 /* This is for read/write Domain Validation:  If the device supports
 418  * an echo buffer, we do read/write tests to it */
 419 static enum spi_compare_returns
 420 spi_dv_device_echo_buffer(struct scsi_request *sreq, u8 *buffer,
 421                           u8 *ptr, const int retries)
 422 {
 423         struct scsi_device *sdev = sreq->sr_device;
 424         int len = ptr - buffer;
 425         int j, k, r;
 426         unsigned int pattern = 0x0000ffff;
 427
 428         const char spi_write_buffer[] = {
 429                 WRITE_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
 430         };
 431         const char spi_read_buffer[] = {
 432                 READ_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
 433         };
 434
 435         /* set up the pattern buffer.  Doesn't matter if we spill
 436          * slightly beyond since that's where the read buffer is */
 437         for (j = 0; j < len; ) {
 438
 439                 /* fill the buffer with counting (test a) */
 440                 for ( ; j < min(len, 32); j++)
 441                         buffer[j] = j;
 442                 k = j;
 443                 /* fill the buffer with alternating words of 0x0 and
 444                  * 0xffff (test b) */
 445                 for ( ; j < min(len, k + 32); j += 2) {
 446                         u16 *word = (u16 *)&buffer[j];
 447
 448                         *word = (j & 0x02) ? 0x0000 : 0xffff;
 449                 }
 450                 k = j;
 451                 /* fill with crosstalk (alternating 0x5555 0xaaa)
 452                  * (test c) */
 453                 for ( ; j < min(len, k + 32); j += 2) {
 454                         u16 *word = (u16 *)&buffer[j];
 455
 456                         *word = (j & 0x02) ? 0x5555 : 0xaaaa;
 457                 }
 458                 k = j;
 459                 /* fill with shifting bits (test d) */
 460                 for ( ; j < min(len, k + 32); j += 4) {
 461                         u32 *word = (unsigned int *)&buffer[j];
 462                         u32 roll = (pattern & 0x80000000) ? 1 : 0;
 463
 464                         *word = pattern;
 465                         pattern = (pattern << 1) | roll;
 466                 }
 467                 /* don't bother with random data (test e) */
 468         }
 469
 470         for (r = 0; r < retries; r++) {
 471                 sreq->sr_cmd_len = 0;   /* wait_req to fill in */
 472                 sreq->sr_data_direction = DMA_TO_DEVICE;
 473                 spi_wait_req(sreq, spi_write_buffer, buffer, len);
 474                 if(sreq->sr_result || !scsi_device_online(sdev)) {
 475                         struct scsi_sense_hdr sshdr;
 476
 477                         scsi_device_set_state(sdev, SDEV_QUIESCE);
 478                         if (scsi_request_normalize_sense(sreq, &sshdr)
 479                             && sshdr.sense_key == ILLEGAL_REQUEST
 480                             /* INVALID FIELD IN CDB */
 481                             && sshdr.asc == 0x24 && sshdr.ascq == 0x00)
 482                                 /* This would mean that the drive lied
 483                                  * to us about supporting an echo
 484                                  * buffer (unfortunately some Western
 485                                  * Digital drives do precisely this)
 486                                  */
 487                                 return SPI_COMPARE_SKIP_TEST;
 488
 489
 490                         SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Write Buffer failure %x\n", sreq->sr_result);
 491                         return SPI_COMPARE_FAILURE;
 492                 }
 493
 494                 memset(ptr, 0, len);
 495                 sreq->sr_cmd_len = 0;   /* wait_req to fill in */
 496                 sreq->sr_data_direction = DMA_FROM_DEVICE;
 497                 spi_wait_req(sreq, spi_read_buffer, ptr, len);
 498                 scsi_device_set_state(sdev, SDEV_QUIESCE);
 499
 500                 if (memcmp(buffer, ptr, len) != 0)
 501                         return SPI_COMPARE_FAILURE;
 502         }
 503         return SPI_COMPARE_SUCCESS;
 504 }
 505
 506 /* This is for the simplest form of Domain Validation: a read test
 507  * on the inquiry data from the device */
 508 static enum spi_compare_returns
 509 spi_dv_device_compare_inquiry(struct scsi_request *sreq, u8 *buffer,
 510                               u8 *ptr, const int retries)
 511 {
 512         int r;
 513         const int len = sreq->sr_device->inquiry_len;
 514         struct scsi_device *sdev = sreq->sr_device;
 515         const char spi_inquiry[] = {
 516                 INQUIRY, 0, 0, 0, len, 0
 517         };
 518
 519         for (r = 0; r < retries; r++) {
 520                 sreq->sr_cmd_len = 0;   /* wait_req to fill in */
 521                 sreq->sr_data_direction = DMA_FROM_DEVICE;
 522
 523                 memset(ptr, 0, len);
 524
 525                 spi_wait_req(sreq, spi_inquiry, ptr, len);
 526
 527                 if(sreq->sr_result || !scsi_device_online(sdev)) {
 528                         scsi_device_set_state(sdev, SDEV_QUIESCE);
 529                         return SPI_COMPARE_FAILURE;
 530                 }
 531
 532                 /* If we don't have the inquiry data already, the
 533                  * first read gets it */
 534                 if (ptr == buffer) {
 535                         ptr += len;
 536                         --r;
 537                         continue;
 538                 }
 539
 540                 if (memcmp(buffer, ptr, len) != 0)
 541                         /* failure */
 542                         return SPI_COMPARE_FAILURE;
 543         }
 544         return SPI_COMPARE_SUCCESS;
 545 }
 546
 547 static enum spi_compare_returns
 548 spi_dv_retrain(struct scsi_request *sreq, u8 *buffer, u8 *ptr,
 549                enum spi_compare_returns
 550                (*compare_fn)(struct scsi_request *, u8 *, u8 *, int))
 551 {
 552         struct spi_internal *i = to_spi_internal(sreq->sr_host->transportt);
 553         struct scsi_device *sdev = sreq->sr_device;
 554         int period = 0, prevperiod = 0;
 555         enum spi_compare_returns retval;
 556
 557
 558         for (;;) {
 559                 int newperiod;
 560                 retval = compare_fn(sreq, buffer, ptr, DV_LOOPS);
 561
 562                 if (retval == SPI_COMPARE_SUCCESS
 563                     || retval == SPI_COMPARE_SKIP_TEST)
 564                         break;
 565
 566                 /* OK, retrain, fallback */
 567                 if (i->f->get_period)
 568                         i->f->get_period(sdev->sdev_target);
 569                 newperiod = spi_period(sdev->sdev_target);
 570                 period = newperiod > period ? newperiod : period;
 571                 if (period < 0x0d)
 572                         period++;
 573                 else
 574                         period += period >> 1;
 575
 576                 if (unlikely(period > 0xff || period == prevperiod)) {
 577                         /* Total failure; set to async and return */
 578                         SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Domain Validation Failure, dropping back to Asynchronous\n");
 579                         DV_SET(offset, 0);
 580                         return SPI_COMPARE_FAILURE;
 581                 }
 582                 SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Domain Validation detected failure, dropping back\n");
 583                 DV_SET(period, period);
 584                 prevperiod = period;
 585         }
 586         return retval;
 587 }
 588
 589 static int
 590 spi_dv_device_get_echo_buffer(struct scsi_request *sreq, u8 *buffer)
 591 {
 592         int l;
 593
 594         /* first off do a test unit ready.  This can error out
 595          * because of reservations or some other reason.  If it
 596          * fails, the device won't let us write to the echo buffer
 597          * so just return failure */
 598
 599         const char spi_test_unit_ready[] = {
 600                 TEST_UNIT_READY, 0, 0, 0, 0, 0
 601         };
 602
 603         const char spi_read_buffer_descriptor[] = {
 604                 READ_BUFFER, 0x0b, 0, 0, 0, 0, 0, 0, 4, 0
 605         };
 606
 607
 608         sreq->sr_cmd_len = 0;
 609         sreq->sr_data_direction = DMA_NONE;
 610
 611         /* We send a set of three TURs to clear any outstanding
 612          * unit attention conditions if they exist (Otherwise the
 613          * buffer tests won't be happy).  If the TUR still fails
 614          * (reservation conflict, device not ready, etc) just
 615          * skip the write tests */
 616         for (l = 0; ; l++) {
 617                 spi_wait_req(sreq, spi_test_unit_ready, NULL, 0);
 618
 619                 if(sreq->sr_result) {
 620                         if(l >= 3)
 621                                 return 0;
 622                 } else {
 623                         /* TUR succeeded */
 624                         break;
 625                 }
 626         }
 627
 628         sreq->sr_cmd_len = 0;
 629         sreq->sr_data_direction = DMA_FROM_DEVICE;
 630
 631         spi_wait_req(sreq, spi_read_buffer_descriptor, buffer, 4);
 632
 633         if (sreq->sr_result)
 634                 /* Device has no echo buffer */
 635                 return 0;
 636
 637         return buffer[3] + ((buffer[2] & 0x1f) << 8);
 638 }
 639
 640 static void
 641 spi_dv_device_internal(struct scsi_request *sreq, u8 *buffer)
 642 {
 643         struct spi_internal *i = to_spi_internal(sreq->sr_host->transportt);
 644         struct scsi_device *sdev = sreq->sr_device;
 645         int len = sdev->inquiry_len;
 646         /* first set us up for narrow async */
 647         DV_SET(offset, 0);
 648         DV_SET(width, 0);
 649
 650         if (spi_dv_device_compare_inquiry(sreq, buffer, buffer, DV_LOOPS)
 651             != SPI_COMPARE_SUCCESS) {
 652                 SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Domain Validation Initial Inquiry Failed\n");
 653                 /* FIXME: should probably offline the device here? */
 654                 return;
 655         }
 656
 657         /* test width */
 658         if (i->f->set_width && sdev->wdtr) {
 659                 i->f->set_width(sdev->sdev_target, 1);
 660
 661                 if (spi_dv_device_compare_inquiry(sreq, buffer,
 662                                                    buffer + len,
 663                                                    DV_LOOPS)
 664                     != SPI_COMPARE_SUCCESS) {
 665                         SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Wide Transfers Fail\n");
 666                         i->f->set_width(sdev->sdev_target, 0);
 667                 }
 668         }
 669
 670         if (!i->f->set_period)
 671                 return;
 672
 673         /* device can't handle synchronous */
 674         if(!sdev->ppr && !sdev->sdtr)
 675                 return;
 676
 677         /* see if the device has an echo buffer.  If it does we can
 678          * do the SPI pattern write tests */
 679
 680         len = 0;
 681         if (sdev->ppr)
 682                 len = spi_dv_device_get_echo_buffer(sreq, buffer);
 683
 684  retry:
 685
 686         /* now set up to the maximum */
 687         DV_SET(offset, 255);
 688         DV_SET(period, 1);
 689
 690         if (len == 0) {
 691                 SPI_PRINTK(sdev->sdev_target, KERN_INFO, "Domain Validation skipping write tests\n");
 692                 spi_dv_retrain(sreq, buffer, buffer + len,
 693                                spi_dv_device_compare_inquiry);
 694                 return;
 695         }
 696
 697         if (len > SPI_MAX_ECHO_BUFFER_SIZE) {
 698                 SPI_PRINTK(sdev->sdev_target, KERN_WARNING, "Echo buffer size %d is too big, trimming to %d\n", len, SPI_MAX_ECHO_BUFFER_SIZE);
 699                 len = SPI_MAX_ECHO_BUFFER_SIZE;
 700         }
 701
 702         if (spi_dv_retrain(sreq, buffer, buffer + len,
 703                            spi_dv_device_echo_buffer)
 704             == SPI_COMPARE_SKIP_TEST) {
 705                 /* OK, the stupid drive can't do a write echo buffer
 706                  * test after all, fall back to the read tests */
 707                 len = 0;
 708                 goto retry;
 709         }
 710 }
 711
 712
 713 /**     spi_dv_device - Do Domain Validation on the device
 714  *      @sdev:          scsi device to validate
 715  *
 716  *      Performs the domain validation on the given device in the
 717  *      current execution thread.  Since DV operations may sleep,
 718  *      the current thread must have user context.  Also no SCSI
 719  *      related locks that would deadlock I/O issued by the DV may
 720  *      be held.
 721  */
 722 void
 723 spi_dv_device(struct scsi_device *sdev)
 724 {
 725         struct scsi_request *sreq = scsi_allocate_request(sdev, GFP_KERNEL);
 726         struct scsi_target *starget = sdev->sdev_target;
 727         u8 *buffer;
 728         const int len = SPI_MAX_ECHO_BUFFER_SIZE*2;
 729
 730         if (unlikely(!sreq))
 731                 return;
 732
 733         if (unlikely(scsi_device_get(sdev)))
 734                 goto out_free_req;
 735
 736         buffer = kmalloc(len, GFP_KERNEL);
 737
 738         if (unlikely(!buffer))
 739                 goto out_put;
 740
 741         memset(buffer, 0, len);
 742
 743         /* We need to verify that the actual device will quiesce; the
 744          * later target quiesce is just a nice to have */
 745         if (unlikely(scsi_device_quiesce(sdev)))
 746                 goto out_free;
 747
 748         scsi_target_quiesce(starget);
 749
 750         spi_dv_pending(starget) = 1;
 751         down(&spi_dv_sem(starget));
 752
 753         SPI_PRINTK(starget, KERN_INFO, "Beginning Domain Validation\n");
 754
 755         spi_dv_device_internal(sreq, buffer);
 756
 757         SPI_PRINTK(starget, KERN_INFO, "Ending Domain Validation\n");
 758
 759         up(&spi_dv_sem(starget));
 760         spi_dv_pending(starget) = 0;
 761
 762         scsi_target_resume(starget);
 763
 764         spi_initial_dv(starget) = 1;
 765
 766  out_free:
 767         kfree(buffer);
 768  out_put:
 769         scsi_device_put(sdev);
 770  out_free_req:
 771         scsi_release_request(sreq);
 772 }
 773 EXPORT_SYMBOL(spi_dv_device);
 774
 775 struct work_queue_wrapper {
 776         struct work_struct      work;
 777         struct scsi_device      *sdev;
 778 };
 779
 780 static void
 781 spi_dv_device_work_wrapper(void *data)
 782 {
 783         struct work_queue_wrapper *wqw = (struct work_queue_wrapper *)data;
 784         struct scsi_device *sdev = wqw->sdev;
 785
 786         kfree(wqw);
 787         spi_dv_device(sdev);
 788         spi_dv_pending(sdev->sdev_target) = 0;
 789         scsi_device_put(sdev);
 790 }
 791
 792
 793 /**
 794  *      spi_schedule_dv_device - schedule domain validation to occur on the device
 795  *      @sdev:  The device to validate
 796  *
 797  *      Identical to spi_dv_device() above, except that the DV will be
 798  *      scheduled to occur in a workqueue later.  All memory allocations
 799  *      are atomic, so may be called from any context including those holding
 800  *      SCSI locks.
 801  */
 802 void
 803 spi_schedule_dv_device(struct scsi_device *sdev)
 804 {
 805         struct work_queue_wrapper *wqw =
 806                 kmalloc(sizeof(struct work_queue_wrapper), GFP_ATOMIC);
 807
 808         if (unlikely(!wqw))
 809                 return;
 810
 811         if (unlikely(spi_dv_pending(sdev->sdev_target))) {
 812                 kfree(wqw);
 813                 return;
 814         }
 815         /* Set pending early (dv_device doesn't check it, only sets it) */
 816         spi_dv_pending(sdev->sdev_target) = 1;
 817         if (unlikely(scsi_device_get(sdev))) {
 818                 kfree(wqw);
 819                 spi_dv_pending(sdev->sdev_target) = 0;
 820                 return;
 821         }
 822
 823         INIT_WORK(&wqw->work, spi_dv_device_work_wrapper, wqw);
 824         wqw->sdev = sdev;
 825
 826         schedule_work(&wqw->work);
 827 }
 828 EXPORT_SYMBOL(spi_schedule_dv_device);
 829
 830 /**
 831  * spi_display_xfer_agreement - Print the current target transfer agreement
 832  * @starget: The target for which to display the agreement
 833  *
 834  * Each SPI port is required to maintain a transfer agreement for each
 835  * other port on the bus.  This function prints a one-line summary of
 836  * the current agreement; more detailed information is available in sysfs.
 837  */
 838 void spi_display_xfer_agreement(struct scsi_target *starget)
 839 {
 840         struct spi_transport_attrs *tp;
 841         tp = (struct spi_transport_attrs *)&starget->starget_data;
 842
 843         if (tp->offset > 0 && tp->period > 0) {
 844                 unsigned int picosec, kb100;
 845                 char *scsi = "FAST-?";
 846                 char tmp[8];
 847
 848                 if (tp->period <= SPI_STATIC_PPR) {
 849                         picosec = ppr_to_ps[tp->period];
 850                         switch (tp->period) {
 851                                 case  7: scsi = "FAST-320"; break;
 852                                 case  8: scsi = "FAST-160"; break;
 853                                 case  9: scsi = "FAST-80"; break;
 854                                 case 10:
 855                                 case 11: scsi = "FAST-40"; break;
 856                                 case 12: scsi = "FAST-20"; break;
 857                         }
 858                 } else {
 859                         picosec = tp->period * 4000;
 860                         if (tp->period < 25)
 861                                 scsi = "FAST-20";
 862                         else if (tp->period < 50)
 863                                 scsi = "FAST-10";
 864                         else
 865                                 scsi = "FAST-5";
 866                 }
 867
 868                 kb100 = (10000000 + picosec / 2) / picosec;
 869                 if (tp->width)
 870                         kb100 *= 2;
 871                 sprint_frac(tmp, picosec, 1000);
 872
 873                 dev_info(&starget->dev,
 874                         "%s %sSCSI %d.%d MB/s %s%s%s (%s ns, offset %d)\n",
 875                         scsi, tp->width ? "WIDE " : "", kb100/10, kb100 % 10,
 876                         tp->dt ? "DT" : "ST", tp->iu ? " IU" : "",
 877                         tp->qas  ? " QAS" : "", tmp, tp->offset);
 878         } else {
 879                 dev_info(&starget->dev, "%sasynchronous.\n",
 880                                 tp->width ? "wide " : "");
 881         }
 882 }
 883 EXPORT_SYMBOL(spi_display_xfer_agreement);
 884
 885 #define SETUP_ATTRIBUTE(field)                                          \
 886         i->private_attrs[count] = class_device_attr_##field;            \
 887         if (!i->f->set_##field) {                                       \
 888                 i->private_attrs[count].attr.mode = S_IRUGO;            \
 889                 i->private_attrs[count].store = NULL;                   \
 890         }                                                               \
 891         i->attrs[count] = &i->private_attrs[count];                     \
 892         if (i->f->show_##field)                                         \
 893                 count++
 894
 895 #define SETUP_HOST_ATTRIBUTE(field)                                     \
 896         i->private_host_attrs[count] = class_device_attr_##field;       \
 897         if (!i->f->set_##field) {                                       \
 898                 i->private_host_attrs[count].attr.mode = S_IRUGO;       \
 899                 i->private_host_attrs[count].store = NULL;              \
 900         }                                                               \
 901         i->host_attrs[count] = &i->private_host_attrs[count];           \
 902         count++
 903
 904 static int spi_device_match(struct attribute_container *cont,
 905                             struct device *dev)
 906 {
 907         struct scsi_device *sdev;
 908         struct Scsi_Host *shost;
 909
 910         if (!scsi_is_sdev_device(dev))
 911                 return 0;
 912
 913         sdev = to_scsi_device(dev);
 914         shost = sdev->host;
 915         if (!shost->transportt  || shost->transportt->host_attrs.ac.class
 916             != &spi_host_class.class)
 917                 return 0;
 918         /* Note: this class has no device attributes, so it has
 919          * no per-HBA allocation and thus we don't need to distinguish
 920          * the attribute containers for the device */
 921         return 1;
 922 }
 923
 924 static int spi_target_match(struct attribute_container *cont,
 925                             struct device *dev)
 926 {
 927         struct Scsi_Host *shost;
 928         struct spi_internal *i;
 929
 930         if (!scsi_is_target_device(dev))
 931                 return 0;
 932
 933         shost = dev_to_shost(dev->parent);
 934         if (!shost->transportt  || shost->transportt->host_attrs.ac.class
 935             != &spi_host_class.class)
 936                 return 0;
 937
 938         i = to_spi_internal(shost->transportt);
 939
 940         return &i->t.target_attrs.ac == cont;
 941 }
 942
 943 static DECLARE_TRANSPORT_CLASS(spi_transport_class,
 944                                "spi_transport",
 945                                spi_setup_transport_attrs,
 946                                NULL,
 947                                NULL);
 948
 949 static DECLARE_ANON_TRANSPORT_CLASS(spi_device_class,
 950                                     spi_device_match,
 951                                     spi_device_configure);
 952
 953 struct scsi_transport_template *
 954 spi_attach_transport(struct spi_function_template *ft)
 955 {
 956         struct spi_internal *i = kmalloc(sizeof(struct spi_internal),
 957                                          GFP_KERNEL);
 958         int count = 0;
 959         if (unlikely(!i))
 960                 return NULL;
 961
 962         memset(i, 0, sizeof(struct spi_internal));
 963
 964
 965         i->t.target_attrs.ac.class = &spi_transport_class.class;
 966         i->t.target_attrs.ac.attrs = &i->attrs[0];
 967         i->t.target_attrs.ac.match = spi_target_match;
 968         transport_container_register(&i->t.target_attrs);
 969         i->t.target_size = sizeof(struct spi_transport_attrs);
 970         i->t.host_attrs.ac.class = &spi_host_class.class;
 971         i->t.host_attrs.ac.attrs = &i->host_attrs[0];
 972         i->t.host_attrs.ac.match = spi_host_match;
 973         transport_container_register(&i->t.host_attrs);
 974         i->t.host_size = sizeof(struct spi_host_attrs);
 975         i->f = ft;
 976
 977         SETUP_ATTRIBUTE(period);
 978         SETUP_ATTRIBUTE(offset);
 979         SETUP_ATTRIBUTE(width);
 980         SETUP_ATTRIBUTE(iu);
 981         SETUP_ATTRIBUTE(dt);
 982         SETUP_ATTRIBUTE(qas);
 983         SETUP_ATTRIBUTE(wr_flow);
 984         SETUP_ATTRIBUTE(rd_strm);
 985         SETUP_ATTRIBUTE(rti);
 986         SETUP_ATTRIBUTE(pcomp_en);
 987
 988         /* if you add an attribute but forget to increase SPI_NUM_ATTRS
 989          * this bug will trigger */
 990         BUG_ON(count > SPI_NUM_ATTRS);
 991
 992         i->attrs[count++] = &class_device_attr_revalidate;
 993
 994         i->attrs[count] = NULL;
 995
 996         count = 0;
 997         SETUP_HOST_ATTRIBUTE(signalling);
 998
 999         BUG_ON(count > SPI_HOST_ATTRS);
1000
1001         i->host_attrs[count] = NULL;
1002
1003         return &i->t;
1004 }
1005 EXPORT_SYMBOL(spi_attach_transport);
1006
1007 void spi_release_transport(struct scsi_transport_template *t)
1008 {
1009         struct spi_internal *i = to_spi_internal(t);
1010
1011         transport_container_unregister(&i->t.target_attrs);
1012         transport_container_unregister(&i->t.host_attrs);
1013
1014         kfree(i);
1015 }
1016 EXPORT_SYMBOL(spi_release_transport);
1017
1018 static __init int spi_transport_init(void)
1019 {
1020         int error = transport_class_register(&spi_transport_class);
1021         if (error)
1022                 return error;
1023         error = anon_transport_class_register(&spi_device_class);
1024         return transport_class_register(&spi_host_class);
1025 }
1026
1027 static void __exit spi_transport_exit(void)
1028 {
1029         transport_class_unregister(&spi_transport_class);
1030         anon_transport_class_unregister(&spi_device_class);
1031         transport_class_unregister(&spi_host_class);
1032 }
1033
1034 MODULE_AUTHOR("Martin Hicks");
1035 MODULE_DESCRIPTION("SPI Transport Attributes");
1036 MODULE_LICENSE("GPL");
1037
1038 module_init(spi_transport_init);
1039 module_exit(spi_transport_exit);