drivers/s390/block/dasd_fba.c

   1 /*
   2  * File...........: linux/drivers/s390/block/dasd_fba.c
   3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   4  * Bugreports.to..: <Linux390@de.ibm.com>
   5  * Copyright IBM Corp. 1999, 2009
   6  */
   7
   8 #define KMSG_COMPONENT "dasd-fba"
   9
  10 #include <linux/stddef.h>
  11 #include <linux/kernel.h>
  12 #include <asm/debug.h>
  13
  14 #include <linux/slab.h>
  15 #include <linux/hdreg.h>        /* HDIO_GETGEO                      */
  16 #include <linux/bio.h>
  17 #include <linux/module.h>
  18 #include <linux/init.h>
  19
  20 #include <asm/idals.h>
  21 #include <asm/ebcdic.h>
  22 #include <asm/io.h>
  23 #include <asm/todclk.h>
  24 #include <asm/ccwdev.h>
  25
  26 #include "dasd_int.h"
  27 #include "dasd_fba.h"
  28
  29 #ifdef PRINTK_HEADER
  30 #undef PRINTK_HEADER
  31 #endif                          /* PRINTK_HEADER */
  32 #define PRINTK_HEADER "dasd(fba):"
  33
  34 #define DASD_FBA_CCW_WRITE 0x41
  35 #define DASD_FBA_CCW_READ 0x42
  36 #define DASD_FBA_CCW_LOCATE 0x43
  37 #define DASD_FBA_CCW_DEFINE_EXTENT 0x63
  38
  39 MODULE_LICENSE("GPL");
  40
  41 static struct dasd_discipline dasd_fba_discipline;
  42
  43 struct dasd_fba_private {
  44         struct dasd_fba_characteristics rdc_data;
  45 };
  46
  47 static struct ccw_device_id dasd_fba_ids[] = {
  48         { CCW_DEVICE_DEVTYPE (0x6310, 0, 0x9336, 0), .driver_info = 0x1},
  49         { CCW_DEVICE_DEVTYPE (0x3880, 0, 0x3370, 0), .driver_info = 0x2},
  50         { /* end of list */ },
  51 };
  52
  53 MODULE_DEVICE_TABLE(ccw, dasd_fba_ids);
  54
  55 static struct ccw_driver dasd_fba_driver; /* see below */
  56 static int
  57 dasd_fba_probe(struct ccw_device *cdev)
  58 {
  59         return dasd_generic_probe(cdev, &dasd_fba_discipline);
  60 }
  61
  62 static int
  63 dasd_fba_set_online(struct ccw_device *cdev)
  64 {
  65         return dasd_generic_set_online(cdev, &dasd_fba_discipline);
  66 }
  67
  68 static struct ccw_driver dasd_fba_driver = {
  69         .name        = "dasd-fba",
  70         .owner       = THIS_MODULE,
  71         .ids         = dasd_fba_ids,
  72         .probe       = dasd_fba_probe,
  73         .remove      = dasd_generic_remove,
  74         .set_offline = dasd_generic_set_offline,
  75         .set_online  = dasd_fba_set_online,
  76         .notify      = dasd_generic_notify,
  77         .freeze      = dasd_generic_pm_freeze,
  78         .thaw        = dasd_generic_restore_device,
  79         .restore     = dasd_generic_restore_device,
  80 };
  81
  82 static void
  83 define_extent(struct ccw1 * ccw, struct DE_fba_data *data, int rw,
  84               int blksize, int beg, int nr)
  85 {
  86         ccw->cmd_code = DASD_FBA_CCW_DEFINE_EXTENT;
  87         ccw->flags = 0;
  88         ccw->count = 16;
  89         ccw->cda = (__u32) __pa(data);
  90         memset(data, 0, sizeof (struct DE_fba_data));
  91         if (rw == WRITE)
  92                 (data->mask).perm = 0x0;
  93         else if (rw == READ)
  94                 (data->mask).perm = 0x1;
  95         else
  96                 data->mask.perm = 0x2;
  97         data->blk_size = blksize;
  98         data->ext_loc = beg;
  99         data->ext_end = nr - 1;
 100 }
 101
 102 static void
 103 locate_record(struct ccw1 * ccw, struct LO_fba_data *data, int rw,
 104               int block_nr, int block_ct)
 105 {
 106         ccw->cmd_code = DASD_FBA_CCW_LOCATE;
 107         ccw->flags = 0;
 108         ccw->count = 8;
 109         ccw->cda = (__u32) __pa(data);
 110         memset(data, 0, sizeof (struct LO_fba_data));
 111         if (rw == WRITE)
 112                 data->operation.cmd = 0x5;
 113         else if (rw == READ)
 114                 data->operation.cmd = 0x6;
 115         else
 116                 data->operation.cmd = 0x8;
 117         data->blk_nr = block_nr;
 118         data->blk_ct = block_ct;
 119 }
 120
 121 static int
 122 dasd_fba_check_characteristics(struct dasd_device *device)
 123 {
 124         struct dasd_block *block;
 125         struct dasd_fba_private *private;
 126         struct ccw_device *cdev = device->cdev;
 127         int rc;
 128
 129         private = (struct dasd_fba_private *) device->private;
 130         if (!private) {
 131                 private = kzalloc(sizeof(*private), GFP_KERNEL | GFP_DMA);
 132                 if (!private) {
 133                         dev_warn(&device->cdev->dev,
 134                                  "Allocating memory for private DASD "
 135                                  "data failed\n");
 136                         return -ENOMEM;
 137                 }
 138                 device->private = (void *) private;
 139         } else {
 140                 memset(private, 0, sizeof(*private));
 141         }
 142         block = dasd_alloc_block();
 143         if (IS_ERR(block)) {
 144                 DBF_EVENT(DBF_WARNING, "could not allocate dasd block "
 145                           "structure for device: %s",
 146                           dev_name(&device->cdev->dev));
 147                 device->private = NULL;
 148                 kfree(private);
 149                 return PTR_ERR(block);
 150         }
 151         device->block = block;
 152         block->base = device;
 153
 154         /* Read Device Characteristics */
 155         rc = dasd_generic_read_dev_chars(device, DASD_FBA_MAGIC,
 156                                          &private->rdc_data, 32);
 157         if (rc) {
 158                 DBF_EVENT(DBF_WARNING, "Read device characteristics returned "
 159                           "error %d for device: %s",
 160                           rc, dev_name(&device->cdev->dev));
 161                 device->block = NULL;
 162                 dasd_free_block(block);
 163                 device->private = NULL;
 164                 kfree(private);
 165                 return rc;
 166         }
 167
 168         dev_info(&device->cdev->dev,
 169                  "New FBA DASD %04X/%02X (CU %04X/%02X) with %d MB "
 170                  "and %d B/blk\n",
 171                  cdev->id.dev_type,
 172                  cdev->id.dev_model,
 173                  cdev->id.cu_type,
 174                  cdev->id.cu_model,
 175                  ((private->rdc_data.blk_bdsa *
 176                    (private->rdc_data.blk_size >> 9)) >> 11),
 177                  private->rdc_data.blk_size);
 178         return 0;
 179 }
 180
 181 static int dasd_fba_do_analysis(struct dasd_block *block)
 182 {
 183         struct dasd_fba_private *private;
 184         int sb, rc;
 185
 186         private = (struct dasd_fba_private *) block->base->private;
 187         rc = dasd_check_blocksize(private->rdc_data.blk_size);
 188         if (rc) {
 189                 DBF_DEV_EVENT(DBF_WARNING, block->base, "unknown blocksize %d",
 190                             private->rdc_data.blk_size);
 191                 return rc;
 192         }
 193         block->blocks = private->rdc_data.blk_bdsa;
 194         block->bp_block = private->rdc_data.blk_size;
 195         block->s2b_shift = 0;   /* bits to shift 512 to get a block */
 196         for (sb = 512; sb < private->rdc_data.blk_size; sb = sb << 1)
 197                 block->s2b_shift++;
 198         return 0;
 199 }
 200
 201 static int dasd_fba_fill_geometry(struct dasd_block *block,
 202                                   struct hd_geometry *geo)
 203 {
 204         if (dasd_check_blocksize(block->bp_block) != 0)
 205                 return -EINVAL;
 206         geo->cylinders = (block->blocks << block->s2b_shift) >> 10;
 207         geo->heads = 16;
 208         geo->sectors = 128 >> block->s2b_shift;
 209         return 0;
 210 }
 211
 212 static dasd_erp_fn_t
 213 dasd_fba_erp_action(struct dasd_ccw_req * cqr)
 214 {
 215         return dasd_default_erp_action;
 216 }
 217
 218 static dasd_erp_fn_t
 219 dasd_fba_erp_postaction(struct dasd_ccw_req * cqr)
 220 {
 221         if (cqr->function == dasd_default_erp_action)
 222                 return dasd_default_erp_postaction;
 223
 224         DBF_DEV_EVENT(DBF_WARNING, cqr->startdev, "unknown ERP action %p",
 225                     cqr->function);
 226         return NULL;
 227 }
 228
 229 static void dasd_fba_handle_unsolicited_interrupt(struct dasd_device *device,
 230                                                    struct irb *irb)
 231 {
 232         char mask;
 233
 234         /* first of all check for state change pending interrupt */
 235         mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
 236         if ((irb->scsw.cmd.dstat & mask) == mask) {
 237                 dasd_generic_handle_state_change(device);
 238                 return;
 239         }
 240
 241         /* check for unsolicited interrupts */
 242         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
 243                     "unsolicited interrupt received");
 244         device->discipline->dump_sense_dbf(device, irb, "unsolicited");
 245         dasd_schedule_device_bh(device);
 246         return;
 247 };
 248
 249 static struct dasd_ccw_req *dasd_fba_build_cp(struct dasd_device * memdev,
 250                                               struct dasd_block *block,
 251                                               struct request *req)
 252 {
 253         struct dasd_fba_private *private;
 254         unsigned long *idaws;
 255         struct LO_fba_data *LO_data;
 256         struct dasd_ccw_req *cqr;
 257         struct ccw1 *ccw;
 258         struct req_iterator iter;
 259         struct bio_vec *bv;
 260         char *dst;
 261         int count, cidaw, cplength, datasize;
 262         sector_t recid, first_rec, last_rec;
 263         unsigned int blksize, off;
 264         unsigned char cmd;
 265
 266         private = (struct dasd_fba_private *) block->base->private;
 267         if (rq_data_dir(req) == READ) {
 268                 cmd = DASD_FBA_CCW_READ;
 269         } else if (rq_data_dir(req) == WRITE) {
 270                 cmd = DASD_FBA_CCW_WRITE;
 271         } else
 272                 return ERR_PTR(-EINVAL);
 273         blksize = block->bp_block;
 274         /* Calculate record id of first and last block. */
 275         first_rec = blk_rq_pos(req) >> block->s2b_shift;
 276         last_rec =
 277                 (blk_rq_pos(req) + blk_rq_sectors(req) - 1) >> block->s2b_shift;
 278         /* Check struct bio and count the number of blocks for the request. */
 279         count = 0;
 280         cidaw = 0;
 281         rq_for_each_segment(bv, req, iter) {
 282                 if (bv->bv_len & (blksize - 1))
 283                         /* Fba can only do full blocks. */
 284                         return ERR_PTR(-EINVAL);
 285                 count += bv->bv_len >> (block->s2b_shift + 9);
 286 #if defined(CONFIG_64BIT)
 287                 if (idal_is_needed (page_address(bv->bv_page), bv->bv_len))
 288                         cidaw += bv->bv_len / blksize;
 289 #endif
 290         }
 291         /* Paranoia. */
 292         if (count != last_rec - first_rec + 1)
 293                 return ERR_PTR(-EINVAL);
 294         /* 1x define extent + 1x locate record + number of blocks */
 295         cplength = 2 + count;
 296         /* 1x define extent + 1x locate record */
 297         datasize = sizeof(struct DE_fba_data) + sizeof(struct LO_fba_data) +
 298                 cidaw * sizeof(unsigned long);
 299         /*
 300          * Find out number of additional locate record ccws if the device
 301          * can't do data chaining.
 302          */
 303         if (private->rdc_data.mode.bits.data_chain == 0) {
 304                 cplength += count - 1;
 305                 datasize += (count - 1)*sizeof(struct LO_fba_data);
 306         }
 307         /* Allocate the ccw request. */
 308         cqr = dasd_smalloc_request(DASD_FBA_MAGIC, cplength, datasize, memdev);
 309         if (IS_ERR(cqr))
 310                 return cqr;
 311         ccw = cqr->cpaddr;
 312         /* First ccw is define extent. */
 313         define_extent(ccw++, cqr->data, rq_data_dir(req),
 314                       block->bp_block, blk_rq_pos(req), blk_rq_sectors(req));
 315         /* Build locate_record + read/write ccws. */
 316         idaws = (unsigned long *) (cqr->data + sizeof(struct DE_fba_data));
 317         LO_data = (struct LO_fba_data *) (idaws + cidaw);
 318         /* Locate record for all blocks for smart devices. */
 319         if (private->rdc_data.mode.bits.data_chain != 0) {
 320                 ccw[-1].flags |= CCW_FLAG_CC;
 321                 locate_record(ccw++, LO_data++, rq_data_dir(req), 0, count);
 322         }
 323         recid = first_rec;
 324         rq_for_each_segment(bv, req, iter) {
 325                 dst = page_address(bv->bv_page) + bv->bv_offset;
 326                 if (dasd_page_cache) {
 327                         char *copy = kmem_cache_alloc(dasd_page_cache,
 328                                                       GFP_DMA | __GFP_NOWARN);
 329                         if (copy && rq_data_dir(req) == WRITE)
 330                                 memcpy(copy + bv->bv_offset, dst, bv->bv_len);
 331                         if (copy)
 332                                 dst = copy + bv->bv_offset;
 333                 }
 334                 for (off = 0; off < bv->bv_len; off += blksize) {
 335                         /* Locate record for stupid devices. */
 336                         if (private->rdc_data.mode.bits.data_chain == 0) {
 337                                 ccw[-1].flags |= CCW_FLAG_CC;
 338                                 locate_record(ccw, LO_data++,
 339                                               rq_data_dir(req),
 340                                               recid - first_rec, 1);
 341                                 ccw->flags = CCW_FLAG_CC;
 342                                 ccw++;
 343                         } else {
 344                                 if (recid > first_rec)
 345                                         ccw[-1].flags |= CCW_FLAG_DC;
 346                                 else
 347                                         ccw[-1].flags |= CCW_FLAG_CC;
 348                         }
 349                         ccw->cmd_code = cmd;
 350                         ccw->count = block->bp_block;
 351                         if (idal_is_needed(dst, blksize)) {
 352                                 ccw->cda = (__u32)(addr_t) idaws;
 353                                 ccw->flags = CCW_FLAG_IDA;
 354                                 idaws = idal_create_words(idaws, dst, blksize);
 355                         } else {
 356                                 ccw->cda = (__u32)(addr_t) dst;
 357                                 ccw->flags = 0;
 358                         }
 359                         ccw++;
 360                         dst += blksize;
 361                         recid++;
 362                 }
 363         }
 364         if (blk_noretry_request(req) ||
 365             block->base->features & DASD_FEATURE_FAILFAST)
 366                 set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
 367         cqr->startdev = memdev;
 368         cqr->memdev = memdev;
 369         cqr->block = block;
 370         cqr->expires = 5 * 60 * HZ;     /* 5 minutes */
 371         cqr->retries = 32;
 372         cqr->buildclk = get_clock();
 373         cqr->status = DASD_CQR_FILLED;
 374         return cqr;
 375 }
 376
 377 static int
 378 dasd_fba_free_cp(struct dasd_ccw_req *cqr, struct request *req)
 379 {
 380         struct dasd_fba_private *private;
 381         struct ccw1 *ccw;
 382         struct req_iterator iter;
 383         struct bio_vec *bv;
 384         char *dst, *cda;
 385         unsigned int blksize, off;
 386         int status;
 387
 388         if (!dasd_page_cache)
 389                 goto out;
 390         private = (struct dasd_fba_private *) cqr->block->base->private;
 391         blksize = cqr->block->bp_block;
 392         ccw = cqr->cpaddr;
 393         /* Skip over define extent & locate record. */
 394         ccw++;
 395         if (private->rdc_data.mode.bits.data_chain != 0)
 396                 ccw++;
 397         rq_for_each_segment(bv, req, iter) {
 398                 dst = page_address(bv->bv_page) + bv->bv_offset;
 399                 for (off = 0; off < bv->bv_len; off += blksize) {
 400                         /* Skip locate record. */
 401                         if (private->rdc_data.mode.bits.data_chain == 0)
 402                                 ccw++;
 403                         if (dst) {
 404                                 if (ccw->flags & CCW_FLAG_IDA)
 405                                         cda = *((char **)((addr_t) ccw->cda));
 406                                 else
 407                                         cda = (char *)((addr_t) ccw->cda);
 408                                 if (dst != cda) {
 409                                         if (rq_data_dir(req) == READ)
 410                                                 memcpy(dst, cda, bv->bv_len);
 411                                         kmem_cache_free(dasd_page_cache,
 412                                             (void *)((addr_t)cda & PAGE_MASK));
 413                                 }
 414                                 dst = NULL;
 415                         }
 416                         ccw++;
 417                 }
 418         }
 419 out:
 420         status = cqr->status == DASD_CQR_DONE;
 421         dasd_sfree_request(cqr, cqr->memdev);
 422         return status;
 423 }
 424
 425 static void dasd_fba_handle_terminated_request(struct dasd_ccw_req *cqr)
 426 {
 427         cqr->status = DASD_CQR_FILLED;
 428 };
 429
 430 static int
 431 dasd_fba_fill_info(struct dasd_device * device,
 432                    struct dasd_information2_t * info)
 433 {
 434         info->label_block = 1;
 435         info->FBA_layout = 1;
 436         info->format = DASD_FORMAT_LDL;
 437         info->characteristics_size = sizeof(struct dasd_fba_characteristics);
 438         memcpy(info->characteristics,
 439                &((struct dasd_fba_private *) device->private)->rdc_data,
 440                sizeof (struct dasd_fba_characteristics));
 441         info->confdata_size = 0;
 442         return 0;
 443 }
 444
 445 static void
 446 dasd_fba_dump_sense_dbf(struct dasd_device *device, struct irb *irb,
 447                         char *reason)
 448 {
 449         u64 *sense;
 450
 451         sense = (u64 *) dasd_get_sense(irb);
 452         if (sense) {
 453                 DBF_DEV_EVENT(DBF_EMERG, device,
 454                               "%s: %s %02x%02x%02x %016llx %016llx %016llx "
 455                               "%016llx", reason,
 456                               scsw_is_tm(&irb->scsw) ? "t" : "c",
 457                               scsw_cc(&irb->scsw), scsw_cstat(&irb->scsw),
 458                               scsw_dstat(&irb->scsw), sense[0], sense[1],
 459                               sense[2], sense[3]);
 460         } else {
 461                 DBF_DEV_EVENT(DBF_EMERG, device, "%s",
 462                               "SORRY - NO VALID SENSE AVAILABLE\n");
 463         }
 464 }
 465
 466
 467 static void
 468 dasd_fba_dump_sense(struct dasd_device *device, struct dasd_ccw_req * req,
 469                     struct irb *irb)
 470 {
 471         char *page;
 472         struct ccw1 *act, *end, *last;
 473         int len, sl, sct, count;
 474
 475         page = (char *) get_zeroed_page(GFP_ATOMIC);
 476         if (page == NULL) {
 477                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
 478                             "No memory to dump sense data");
 479                 return;
 480         }
 481         len = sprintf(page, KERN_ERR PRINTK_HEADER
 482                       " I/O status report for device %s:\n",
 483                       dev_name(&device->cdev->dev));
 484         len += sprintf(page + len, KERN_ERR PRINTK_HEADER
 485                        " in req: %p CS: 0x%02X DS: 0x%02X\n", req,
 486                        irb->scsw.cmd.cstat, irb->scsw.cmd.dstat);
 487         len += sprintf(page + len, KERN_ERR PRINTK_HEADER
 488                        " device %s: Failing CCW: %p\n",
 489                        dev_name(&device->cdev->dev),
 490                        (void *) (addr_t) irb->scsw.cmd.cpa);
 491         if (irb->esw.esw0.erw.cons) {
 492                 for (sl = 0; sl < 4; sl++) {
 493                         len += sprintf(page + len, KERN_ERR PRINTK_HEADER
 494                                        " Sense(hex) %2d-%2d:",
 495                                        (8 * sl), ((8 * sl) + 7));
 496
 497                         for (sct = 0; sct < 8; sct++) {
 498                                 len += sprintf(page + len, " %02x",
 499                                                irb->ecw[8 * sl + sct]);
 500                         }
 501                         len += sprintf(page + len, "\n");
 502                 }
 503         } else {
 504                 len += sprintf(page + len, KERN_ERR PRINTK_HEADER
 505                                " SORRY - NO VALID SENSE AVAILABLE\n");
 506         }
 507         printk(KERN_ERR "%s", page);
 508
 509         /* dump the Channel Program */
 510         /* print first CCWs (maximum 8) */
 511         act = req->cpaddr;
 512         for (last = act; last->flags & (CCW_FLAG_CC | CCW_FLAG_DC); last++);
 513         end = min(act + 8, last);
 514         len = sprintf(page, KERN_ERR PRINTK_HEADER
 515                       " Related CP in req: %p\n", req);
 516         while (act <= end) {
 517                 len += sprintf(page + len, KERN_ERR PRINTK_HEADER
 518                                " CCW %p: %08X %08X DAT:",
 519                                act, ((int *) act)[0], ((int *) act)[1]);
 520                 for (count = 0; count < 32 && count < act->count;
 521                      count += sizeof(int))
 522                         len += sprintf(page + len, " %08X",
 523                                        ((int *) (addr_t) act->cda)
 524                                        [(count>>2)]);
 525                 len += sprintf(page + len, "\n");
 526                 act++;
 527         }
 528         printk(KERN_ERR "%s", page);
 529
 530
 531         /* print failing CCW area */
 532         len = 0;
 533         if (act <  ((struct ccw1 *)(addr_t) irb->scsw.cmd.cpa) - 2) {
 534                 act = ((struct ccw1 *)(addr_t) irb->scsw.cmd.cpa) - 2;
 535                 len += sprintf(page + len, KERN_ERR PRINTK_HEADER "......\n");
 536         }
 537         end = min((struct ccw1 *)(addr_t) irb->scsw.cmd.cpa + 2, last);
 538         while (act <= end) {
 539                 len += sprintf(page + len, KERN_ERR PRINTK_HEADER
 540                                " CCW %p: %08X %08X DAT:",
 541                                act, ((int *) act)[0], ((int *) act)[1]);
 542                 for (count = 0; count < 32 && count < act->count;
 543                      count += sizeof(int))
 544                         len += sprintf(page + len, " %08X",
 545                                        ((int *) (addr_t) act->cda)
 546                                        [(count>>2)]);
 547                 len += sprintf(page + len, "\n");
 548                 act++;
 549         }
 550
 551         /* print last CCWs */
 552         if (act <  last - 2) {
 553                 act = last - 2;
 554                 len += sprintf(page + len, KERN_ERR PRINTK_HEADER "......\n");
 555         }
 556         while (act <= last) {
 557                 len += sprintf(page + len, KERN_ERR PRINTK_HEADER
 558                                " CCW %p: %08X %08X DAT:",
 559                                act, ((int *) act)[0], ((int *) act)[1]);
 560                 for (count = 0; count < 32 && count < act->count;
 561                      count += sizeof(int))
 562                         len += sprintf(page + len, " %08X",
 563                                        ((int *) (addr_t) act->cda)
 564                                        [(count>>2)]);
 565                 len += sprintf(page + len, "\n");
 566                 act++;
 567         }
 568         if (len > 0)
 569                 printk(KERN_ERR "%s", page);
 570         free_page((unsigned long) page);
 571 }
 572
 573 /*
 574  * max_blocks is dependent on the amount of storage that is available
 575  * in the static io buffer for each device. Currently each device has
 576  * 8192 bytes (=2 pages). For 64 bit one dasd_mchunkt_t structure has
 577  * 24 bytes, the struct dasd_ccw_req has 136 bytes and each block can use
 578  * up to 16 bytes (8 for the ccw and 8 for the idal pointer). In
 579  * addition we have one define extent ccw + 16 bytes of data and a
 580  * locate record ccw for each block (stupid devices!) + 16 bytes of data.
 581  * That makes:
 582  * (8192 - 24 - 136 - 8 - 16) / 40 = 200.2 blocks at maximum.
 583  * We want to fit two into the available memory so that we can immediately
 584  * start the next request if one finishes off. That makes 100.1 blocks
 585  * for one request. Give a little safety and the result is 96.
 586  */
 587 static struct dasd_discipline dasd_fba_discipline = {
 588         .owner = THIS_MODULE,
 589         .name = "FBA ",
 590         .ebcname = "FBA ",
 591         .max_blocks = 96,
 592         .check_device = dasd_fba_check_characteristics,
 593         .do_analysis = dasd_fba_do_analysis,
 594         .fill_geometry = dasd_fba_fill_geometry,
 595         .start_IO = dasd_start_IO,
 596         .term_IO = dasd_term_IO,
 597         .handle_terminated_request = dasd_fba_handle_terminated_request,
 598         .erp_action = dasd_fba_erp_action,
 599         .erp_postaction = dasd_fba_erp_postaction,
 600         .handle_unsolicited_interrupt = dasd_fba_handle_unsolicited_interrupt,
 601         .build_cp = dasd_fba_build_cp,
 602         .free_cp = dasd_fba_free_cp,
 603         .dump_sense = dasd_fba_dump_sense,
 604         .dump_sense_dbf = dasd_fba_dump_sense_dbf,
 605         .fill_info = dasd_fba_fill_info,
 606 };
 607
 608 static int __init
 609 dasd_fba_init(void)
 610 {
 611         int ret;
 612
 613         ASCEBC(dasd_fba_discipline.ebcname, 4);
 614         ret = ccw_driver_register(&dasd_fba_driver);
 615         if (!ret)
 616                 wait_for_device_probe();
 617
 618         return ret;
 619 }
 620
 621 static void __exit
 622 dasd_fba_cleanup(void)
 623 {
 624         ccw_driver_unregister(&dasd_fba_driver);
 625 }
 626
 627 module_init(dasd_fba_init);
 628 module_exit(dasd_fba_cleanup);