1 // SPDX-License-Identifier: GPL-2.0
3 * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
4 * Bugreports.to..: <Linux390@de.ibm.com>
5 * Copyright IBM Corp. 1999, 2009
8 #define KMSG_COMPONENT "dasd-fba"
10 #include <linux/stddef.h>
11 #include <linux/kernel.h>
12 #include <asm/debug.h>
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>
20 #include <asm/idals.h>
21 #include <asm/ebcdic.h>
23 #include <asm/ccwdev.h>
30 #endif /* PRINTK_HEADER */
31 #define PRINTK_HEADER "dasd(fba):"
33 #define FBA_DEFAULT_RETRIES 32
35 #define DASD_FBA_CCW_WRITE 0x41
36 #define DASD_FBA_CCW_READ 0x42
37 #define DASD_FBA_CCW_LOCATE 0x43
38 #define DASD_FBA_CCW_DEFINE_EXTENT 0x63
40 MODULE_LICENSE("GPL");
42 static struct dasd_discipline dasd_fba_discipline;
44 struct dasd_fba_private {
45 struct dasd_fba_characteristics rdc_data;
48 static struct ccw_device_id dasd_fba_ids[] = {
49 { CCW_DEVICE_DEVTYPE (0x6310, 0, 0x9336, 0), .driver_info = 0x1},
50 { CCW_DEVICE_DEVTYPE (0x3880, 0, 0x3370, 0), .driver_info = 0x2},
51 { /* end of list */ },
54 MODULE_DEVICE_TABLE(ccw, dasd_fba_ids);
56 static struct ccw_driver dasd_fba_driver; /* see below */
58 dasd_fba_probe(struct ccw_device *cdev)
60 return dasd_generic_probe(cdev, &dasd_fba_discipline);
64 dasd_fba_set_online(struct ccw_device *cdev)
66 return dasd_generic_set_online(cdev, &dasd_fba_discipline);
69 static struct ccw_driver dasd_fba_driver = {
75 .probe = dasd_fba_probe,
76 .remove = dasd_generic_remove,
77 .set_offline = dasd_generic_set_offline,
78 .set_online = dasd_fba_set_online,
79 .notify = dasd_generic_notify,
80 .path_event = dasd_generic_path_event,
81 .freeze = dasd_generic_pm_freeze,
82 .thaw = dasd_generic_restore_device,
83 .restore = dasd_generic_restore_device,
84 .int_class = IRQIO_DAS,
88 define_extent(struct ccw1 * ccw, struct DE_fba_data *data, int rw,
89 int blksize, int beg, int nr)
91 ccw->cmd_code = DASD_FBA_CCW_DEFINE_EXTENT;
94 ccw->cda = (__u32) __pa(data);
95 memset(data, 0, sizeof (struct DE_fba_data));
97 (data->mask).perm = 0x0;
99 (data->mask).perm = 0x1;
101 data->mask.perm = 0x2;
102 data->blk_size = blksize;
104 data->ext_end = nr - 1;
108 locate_record(struct ccw1 * ccw, struct LO_fba_data *data, int rw,
109 int block_nr, int block_ct)
111 ccw->cmd_code = DASD_FBA_CCW_LOCATE;
114 ccw->cda = (__u32) __pa(data);
115 memset(data, 0, sizeof (struct LO_fba_data));
117 data->operation.cmd = 0x5;
119 data->operation.cmd = 0x6;
121 data->operation.cmd = 0x8;
122 data->blk_nr = block_nr;
123 data->blk_ct = block_ct;
127 dasd_fba_check_characteristics(struct dasd_device *device)
129 struct dasd_fba_private *private = device->private;
130 struct ccw_device *cdev = device->cdev;
131 struct dasd_block *block;
135 private = kzalloc(sizeof(*private), GFP_KERNEL | GFP_DMA);
137 dev_warn(&device->cdev->dev,
138 "Allocating memory for private DASD "
142 device->private = private;
144 memset(private, 0, sizeof(*private));
146 block = dasd_alloc_block();
148 DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s", "could not allocate "
149 "dasd block structure");
150 device->private = NULL;
152 return PTR_ERR(block);
154 device->block = block;
155 block->base = device;
157 /* Read Device Characteristics */
158 rc = dasd_generic_read_dev_chars(device, DASD_FBA_MAGIC,
159 &private->rdc_data, 32);
161 DBF_EVENT_DEVID(DBF_WARNING, cdev, "Read device "
162 "characteristics returned error %d", rc);
163 device->block = NULL;
164 dasd_free_block(block);
165 device->private = NULL;
170 device->default_expires = DASD_EXPIRES;
171 device->default_retries = FBA_DEFAULT_RETRIES;
172 dasd_path_set_opm(device, LPM_ANYPATH);
174 readonly = dasd_device_is_ro(device);
176 set_bit(DASD_FLAG_DEVICE_RO, &device->flags);
178 /* FBA supports discard, set the according feature bit */
179 dasd_set_feature(cdev, DASD_FEATURE_DISCARD, 1);
181 dev_info(&device->cdev->dev,
182 "New FBA DASD %04X/%02X (CU %04X/%02X) with %d MB "
188 ((private->rdc_data.blk_bdsa *
189 (private->rdc_data.blk_size >> 9)) >> 11),
190 private->rdc_data.blk_size,
191 readonly ? ", read-only device" : "");
195 static int dasd_fba_do_analysis(struct dasd_block *block)
197 struct dasd_fba_private *private = block->base->private;
200 rc = dasd_check_blocksize(private->rdc_data.blk_size);
202 DBF_DEV_EVENT(DBF_WARNING, block->base, "unknown blocksize %d",
203 private->rdc_data.blk_size);
206 block->blocks = private->rdc_data.blk_bdsa;
207 block->bp_block = private->rdc_data.blk_size;
208 block->s2b_shift = 0; /* bits to shift 512 to get a block */
209 for (sb = 512; sb < private->rdc_data.blk_size; sb = sb << 1)
214 static int dasd_fba_fill_geometry(struct dasd_block *block,
215 struct hd_geometry *geo)
217 if (dasd_check_blocksize(block->bp_block) != 0)
219 geo->cylinders = (block->blocks << block->s2b_shift) >> 10;
221 geo->sectors = 128 >> block->s2b_shift;
226 dasd_fba_erp_action(struct dasd_ccw_req * cqr)
228 return dasd_default_erp_action;
232 dasd_fba_erp_postaction(struct dasd_ccw_req * cqr)
234 if (cqr->function == dasd_default_erp_action)
235 return dasd_default_erp_postaction;
237 DBF_DEV_EVENT(DBF_WARNING, cqr->startdev, "unknown ERP action %p",
242 static void dasd_fba_check_for_device_change(struct dasd_device *device,
243 struct dasd_ccw_req *cqr,
248 /* first of all check for state change pending interrupt */
249 mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
250 if ((irb->scsw.cmd.dstat & mask) == mask)
251 dasd_generic_handle_state_change(device);
256 * Builds a CCW with no data payload
258 static void ccw_write_no_data(struct ccw1 *ccw)
260 ccw->cmd_code = DASD_FBA_CCW_WRITE;
261 ccw->flags |= CCW_FLAG_SLI;
266 * Builds a CCW that writes only zeroes.
268 static void ccw_write_zero(struct ccw1 *ccw, int count)
270 ccw->cmd_code = DASD_FBA_CCW_WRITE;
271 ccw->flags |= CCW_FLAG_SLI;
273 ccw->cda = (__u32) (addr_t) page_to_phys(ZERO_PAGE(0));
277 * Helper function to count the amount of necessary CCWs within a given range
278 * with 4k alignment and command chaining in mind.
280 static int count_ccws(sector_t first_rec, sector_t last_rec,
281 unsigned int blocks_per_page)
283 sector_t wz_stop = 0, d_stop = 0;
287 if (first_rec % blocks_per_page != 0) {
288 wz_stop = first_rec + blocks_per_page -
289 (first_rec % blocks_per_page) - 1;
290 if (wz_stop > last_rec)
292 cur_pos = wz_stop - first_rec + 1;
296 if (last_rec - (first_rec + cur_pos) + 1 >= blocks_per_page) {
297 if ((last_rec - blocks_per_page + 1) % blocks_per_page != 0)
298 d_stop = last_rec - ((last_rec - blocks_per_page + 1) %
303 cur_pos += d_stop - (first_rec + cur_pos) + 1;
307 if (cur_pos == 0 || first_rec + cur_pos - 1 < last_rec)
314 * This function builds a CCW request for block layer discard requests.
315 * Each page in the z/VM hypervisor that represents certain records of an FBA
316 * device will be padded with zeros. This is a special behaviour of the WRITE
317 * command which is triggered when no data payload is added to the CCW.
319 * Note: Due to issues in some z/VM versions, we can't fully utilise this
320 * special behaviour. We have to keep a 4k (or 8 block) alignment in mind to
321 * work around those issues and write actual zeroes to the unaligned parts in
322 * the request. This workaround might be removed in the future.
324 static struct dasd_ccw_req *dasd_fba_build_cp_discard(
325 struct dasd_device *memdev,
326 struct dasd_block *block,
329 struct LO_fba_data *LO_data;
330 struct dasd_ccw_req *cqr;
333 sector_t wz_stop = 0, d_stop = 0;
334 sector_t first_rec, last_rec;
336 unsigned int blksize = block->bp_block;
337 unsigned int blocks_per_page;
340 int cur_pos = 0; /* Current position within the extent */
346 first_rec = blk_rq_pos(req) >> block->s2b_shift;
348 (blk_rq_pos(req) + blk_rq_sectors(req) - 1) >> block->s2b_shift;
349 count = last_rec - first_rec + 1;
351 blocks_per_page = BLOCKS_PER_PAGE(blksize);
352 nr_ccws = count_ccws(first_rec, last_rec, blocks_per_page);
354 /* define extent + nr_ccws * locate record + nr_ccws * single CCW */
355 cplength = 1 + 2 * nr_ccws;
356 datasize = sizeof(struct DE_fba_data) +
357 nr_ccws * (sizeof(struct LO_fba_data) + sizeof(struct ccw1));
359 cqr = dasd_smalloc_request(DASD_FBA_MAGIC, cplength, datasize, memdev,
360 blk_mq_rq_to_pdu(req));
366 define_extent(ccw++, cqr->data, WRITE, blksize, first_rec, count);
367 LO_data = cqr->data + sizeof(struct DE_fba_data);
369 /* First part is not aligned. Calculate range to write zeroes. */
370 if (first_rec % blocks_per_page != 0) {
371 wz_stop = first_rec + blocks_per_page -
372 (first_rec % blocks_per_page) - 1;
373 if (wz_stop > last_rec)
375 wz_count = wz_stop - first_rec + 1;
377 ccw[-1].flags |= CCW_FLAG_CC;
378 locate_record(ccw++, LO_data++, WRITE, cur_pos, wz_count);
380 ccw[-1].flags |= CCW_FLAG_CC;
381 ccw_write_zero(ccw++, wz_count * blksize);
386 /* We can do proper discard when we've got at least blocks_per_page blocks. */
387 if (last_rec - (first_rec + cur_pos) + 1 >= blocks_per_page) {
388 /* is last record at page boundary? */
389 if ((last_rec - blocks_per_page + 1) % blocks_per_page != 0)
390 d_stop = last_rec - ((last_rec - blocks_per_page + 1) %
395 d_count = d_stop - (first_rec + cur_pos) + 1;
397 ccw[-1].flags |= CCW_FLAG_CC;
398 locate_record(ccw++, LO_data++, WRITE, cur_pos, d_count);
400 ccw[-1].flags |= CCW_FLAG_CC;
401 ccw_write_no_data(ccw++);
406 /* We might still have some bits left which need to be zeroed. */
407 if (cur_pos == 0 || first_rec + cur_pos - 1 < last_rec) {
409 wz_count = last_rec - d_stop;
410 else if (wz_stop != 0)
411 wz_count = last_rec - wz_stop;
415 ccw[-1].flags |= CCW_FLAG_CC;
416 locate_record(ccw++, LO_data++, WRITE, cur_pos, wz_count);
418 ccw[-1].flags |= CCW_FLAG_CC;
419 ccw_write_zero(ccw++, wz_count * blksize);
422 if (blk_noretry_request(req) ||
423 block->base->features & DASD_FEATURE_FAILFAST)
424 set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
426 cqr->startdev = memdev;
427 cqr->memdev = memdev;
429 cqr->expires = memdev->default_expires * HZ; /* default 5 minutes */
430 cqr->retries = memdev->default_retries;
431 cqr->buildclk = get_tod_clock();
432 cqr->status = DASD_CQR_FILLED;
437 static struct dasd_ccw_req *dasd_fba_build_cp_regular(
438 struct dasd_device *memdev,
439 struct dasd_block *block,
442 struct dasd_fba_private *private = block->base->private;
443 unsigned long *idaws;
444 struct LO_fba_data *LO_data;
445 struct dasd_ccw_req *cqr;
447 struct req_iterator iter;
450 int count, cidaw, cplength, datasize;
451 sector_t recid, first_rec, last_rec;
452 unsigned int blksize, off;
455 if (rq_data_dir(req) == READ) {
456 cmd = DASD_FBA_CCW_READ;
457 } else if (rq_data_dir(req) == WRITE) {
458 cmd = DASD_FBA_CCW_WRITE;
460 return ERR_PTR(-EINVAL);
461 blksize = block->bp_block;
462 /* Calculate record id of first and last block. */
463 first_rec = blk_rq_pos(req) >> block->s2b_shift;
465 (blk_rq_pos(req) + blk_rq_sectors(req) - 1) >> block->s2b_shift;
466 /* Check struct bio and count the number of blocks for the request. */
469 rq_for_each_segment(bv, req, iter) {
470 if (bv.bv_len & (blksize - 1))
471 /* Fba can only do full blocks. */
472 return ERR_PTR(-EINVAL);
473 count += bv.bv_len >> (block->s2b_shift + 9);
474 if (idal_is_needed (page_address(bv.bv_page), bv.bv_len))
475 cidaw += bv.bv_len / blksize;
478 if (count != last_rec - first_rec + 1)
479 return ERR_PTR(-EINVAL);
480 /* 1x define extent + 1x locate record + number of blocks */
481 cplength = 2 + count;
482 /* 1x define extent + 1x locate record */
483 datasize = sizeof(struct DE_fba_data) + sizeof(struct LO_fba_data) +
484 cidaw * sizeof(unsigned long);
486 * Find out number of additional locate record ccws if the device
487 * can't do data chaining.
489 if (private->rdc_data.mode.bits.data_chain == 0) {
490 cplength += count - 1;
491 datasize += (count - 1)*sizeof(struct LO_fba_data);
493 /* Allocate the ccw request. */
494 cqr = dasd_smalloc_request(DASD_FBA_MAGIC, cplength, datasize, memdev,
495 blk_mq_rq_to_pdu(req));
499 /* First ccw is define extent. */
500 define_extent(ccw++, cqr->data, rq_data_dir(req),
501 block->bp_block, blk_rq_pos(req), blk_rq_sectors(req));
502 /* Build locate_record + read/write ccws. */
503 idaws = (unsigned long *) (cqr->data + sizeof(struct DE_fba_data));
504 LO_data = (struct LO_fba_data *) (idaws + cidaw);
505 /* Locate record for all blocks for smart devices. */
506 if (private->rdc_data.mode.bits.data_chain != 0) {
507 ccw[-1].flags |= CCW_FLAG_CC;
508 locate_record(ccw++, LO_data++, rq_data_dir(req), 0, count);
511 rq_for_each_segment(bv, req, iter) {
512 dst = page_address(bv.bv_page) + bv.bv_offset;
513 if (dasd_page_cache) {
514 char *copy = kmem_cache_alloc(dasd_page_cache,
515 GFP_DMA | __GFP_NOWARN);
516 if (copy && rq_data_dir(req) == WRITE)
517 memcpy(copy + bv.bv_offset, dst, bv.bv_len);
519 dst = copy + bv.bv_offset;
521 for (off = 0; off < bv.bv_len; off += blksize) {
522 /* Locate record for stupid devices. */
523 if (private->rdc_data.mode.bits.data_chain == 0) {
524 ccw[-1].flags |= CCW_FLAG_CC;
525 locate_record(ccw, LO_data++,
527 recid - first_rec, 1);
528 ccw->flags = CCW_FLAG_CC;
531 if (recid > first_rec)
532 ccw[-1].flags |= CCW_FLAG_DC;
534 ccw[-1].flags |= CCW_FLAG_CC;
537 ccw->count = block->bp_block;
538 if (idal_is_needed(dst, blksize)) {
539 ccw->cda = (__u32)(addr_t) idaws;
540 ccw->flags = CCW_FLAG_IDA;
541 idaws = idal_create_words(idaws, dst, blksize);
543 ccw->cda = (__u32)(addr_t) dst;
551 if (blk_noretry_request(req) ||
552 block->base->features & DASD_FEATURE_FAILFAST)
553 set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
554 cqr->startdev = memdev;
555 cqr->memdev = memdev;
557 cqr->expires = memdev->default_expires * HZ; /* default 5 minutes */
558 cqr->retries = memdev->default_retries;
559 cqr->buildclk = get_tod_clock();
560 cqr->status = DASD_CQR_FILLED;
564 static struct dasd_ccw_req *dasd_fba_build_cp(struct dasd_device *memdev,
565 struct dasd_block *block,
568 if (req_op(req) == REQ_OP_DISCARD || req_op(req) == REQ_OP_WRITE_ZEROES)
569 return dasd_fba_build_cp_discard(memdev, block, req);
571 return dasd_fba_build_cp_regular(memdev, block, req);
575 dasd_fba_free_cp(struct dasd_ccw_req *cqr, struct request *req)
577 struct dasd_fba_private *private = cqr->block->base->private;
579 struct req_iterator iter;
582 unsigned int blksize, off;
585 if (!dasd_page_cache)
587 blksize = cqr->block->bp_block;
589 /* Skip over define extent & locate record. */
591 if (private->rdc_data.mode.bits.data_chain != 0)
593 rq_for_each_segment(bv, req, iter) {
594 dst = page_address(bv.bv_page) + bv.bv_offset;
595 for (off = 0; off < bv.bv_len; off += blksize) {
596 /* Skip locate record. */
597 if (private->rdc_data.mode.bits.data_chain == 0)
600 if (ccw->flags & CCW_FLAG_IDA)
601 cda = *((char **)((addr_t) ccw->cda));
603 cda = (char *)((addr_t) ccw->cda);
605 if (rq_data_dir(req) == READ)
606 memcpy(dst, cda, bv.bv_len);
607 kmem_cache_free(dasd_page_cache,
608 (void *)((addr_t)cda & PAGE_MASK));
616 status = cqr->status == DASD_CQR_DONE;
617 dasd_sfree_request(cqr, cqr->memdev);
621 static void dasd_fba_handle_terminated_request(struct dasd_ccw_req *cqr)
623 if (cqr->retries < 0)
624 cqr->status = DASD_CQR_FAILED;
626 cqr->status = DASD_CQR_FILLED;
630 dasd_fba_fill_info(struct dasd_device * device,
631 struct dasd_information2_t * info)
633 struct dasd_fba_private *private = device->private;
635 info->label_block = 1;
636 info->FBA_layout = 1;
637 info->format = DASD_FORMAT_LDL;
638 info->characteristics_size = sizeof(private->rdc_data);
639 memcpy(info->characteristics, &private->rdc_data,
640 sizeof(private->rdc_data));
641 info->confdata_size = 0;
646 dasd_fba_dump_sense_dbf(struct dasd_device *device, struct irb *irb,
651 sense = (u64 *) dasd_get_sense(irb);
653 DBF_DEV_EVENT(DBF_EMERG, device,
654 "%s: %s %02x%02x%02x %016llx %016llx %016llx "
656 scsw_is_tm(&irb->scsw) ? "t" : "c",
657 scsw_cc(&irb->scsw), scsw_cstat(&irb->scsw),
658 scsw_dstat(&irb->scsw), sense[0], sense[1],
661 DBF_DEV_EVENT(DBF_EMERG, device, "%s",
662 "SORRY - NO VALID SENSE AVAILABLE\n");
668 dasd_fba_dump_sense(struct dasd_device *device, struct dasd_ccw_req * req,
672 struct ccw1 *act, *end, *last;
673 int len, sl, sct, count;
675 page = (char *) get_zeroed_page(GFP_ATOMIC);
677 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
678 "No memory to dump sense data");
681 len = sprintf(page, PRINTK_HEADER
682 " I/O status report for device %s:\n",
683 dev_name(&device->cdev->dev));
684 len += sprintf(page + len, PRINTK_HEADER
685 " in req: %p CS: 0x%02X DS: 0x%02X\n", req,
686 irb->scsw.cmd.cstat, irb->scsw.cmd.dstat);
687 len += sprintf(page + len, PRINTK_HEADER
688 " device %s: Failing CCW: %p\n",
689 dev_name(&device->cdev->dev),
690 (void *) (addr_t) irb->scsw.cmd.cpa);
691 if (irb->esw.esw0.erw.cons) {
692 for (sl = 0; sl < 4; sl++) {
693 len += sprintf(page + len, PRINTK_HEADER
694 " Sense(hex) %2d-%2d:",
695 (8 * sl), ((8 * sl) + 7));
697 for (sct = 0; sct < 8; sct++) {
698 len += sprintf(page + len, " %02x",
699 irb->ecw[8 * sl + sct]);
701 len += sprintf(page + len, "\n");
704 len += sprintf(page + len, PRINTK_HEADER
705 " SORRY - NO VALID SENSE AVAILABLE\n");
707 printk(KERN_ERR "%s", page);
709 /* dump the Channel Program */
710 /* print first CCWs (maximum 8) */
712 for (last = act; last->flags & (CCW_FLAG_CC | CCW_FLAG_DC); last++);
713 end = min(act + 8, last);
714 len = sprintf(page, PRINTK_HEADER " Related CP in req: %p\n", req);
716 len += sprintf(page + len, PRINTK_HEADER
717 " CCW %p: %08X %08X DAT:",
718 act, ((int *) act)[0], ((int *) act)[1]);
719 for (count = 0; count < 32 && count < act->count;
720 count += sizeof(int))
721 len += sprintf(page + len, " %08X",
722 ((int *) (addr_t) act->cda)
724 len += sprintf(page + len, "\n");
727 printk(KERN_ERR "%s", page);
730 /* print failing CCW area */
732 if (act < ((struct ccw1 *)(addr_t) irb->scsw.cmd.cpa) - 2) {
733 act = ((struct ccw1 *)(addr_t) irb->scsw.cmd.cpa) - 2;
734 len += sprintf(page + len, PRINTK_HEADER "......\n");
736 end = min((struct ccw1 *)(addr_t) irb->scsw.cmd.cpa + 2, last);
738 len += sprintf(page + len, PRINTK_HEADER
739 " CCW %p: %08X %08X DAT:",
740 act, ((int *) act)[0], ((int *) act)[1]);
741 for (count = 0; count < 32 && count < act->count;
742 count += sizeof(int))
743 len += sprintf(page + len, " %08X",
744 ((int *) (addr_t) act->cda)
746 len += sprintf(page + len, "\n");
750 /* print last CCWs */
751 if (act < last - 2) {
753 len += sprintf(page + len, PRINTK_HEADER "......\n");
755 while (act <= last) {
756 len += sprintf(page + len, PRINTK_HEADER
757 " CCW %p: %08X %08X DAT:",
758 act, ((int *) act)[0], ((int *) act)[1]);
759 for (count = 0; count < 32 && count < act->count;
760 count += sizeof(int))
761 len += sprintf(page + len, " %08X",
762 ((int *) (addr_t) act->cda)
764 len += sprintf(page + len, "\n");
768 printk(KERN_ERR "%s", page);
769 free_page((unsigned long) page);
773 * max_blocks is dependent on the amount of storage that is available
774 * in the static io buffer for each device. Currently each device has
775 * 8192 bytes (=2 pages). For 64 bit one dasd_mchunkt_t structure has
776 * 24 bytes, the struct dasd_ccw_req has 136 bytes and each block can use
777 * up to 16 bytes (8 for the ccw and 8 for the idal pointer). In
778 * addition we have one define extent ccw + 16 bytes of data and a
779 * locate record ccw for each block (stupid devices!) + 16 bytes of data.
781 * (8192 - 24 - 136 - 8 - 16) / 40 = 200.2 blocks at maximum.
782 * We want to fit two into the available memory so that we can immediately
783 * start the next request if one finishes off. That makes 100.1 blocks
784 * for one request. Give a little safety and the result is 96.
786 static struct dasd_discipline dasd_fba_discipline = {
787 .owner = THIS_MODULE,
791 .check_device = dasd_fba_check_characteristics,
792 .do_analysis = dasd_fba_do_analysis,
793 .verify_path = dasd_generic_verify_path,
794 .fill_geometry = dasd_fba_fill_geometry,
795 .start_IO = dasd_start_IO,
796 .term_IO = dasd_term_IO,
797 .handle_terminated_request = dasd_fba_handle_terminated_request,
798 .erp_action = dasd_fba_erp_action,
799 .erp_postaction = dasd_fba_erp_postaction,
800 .check_for_device_change = dasd_fba_check_for_device_change,
801 .build_cp = dasd_fba_build_cp,
802 .free_cp = dasd_fba_free_cp,
803 .dump_sense = dasd_fba_dump_sense,
804 .dump_sense_dbf = dasd_fba_dump_sense_dbf,
805 .fill_info = dasd_fba_fill_info,
813 ASCEBC(dasd_fba_discipline.ebcname, 4);
814 ret = ccw_driver_register(&dasd_fba_driver);
816 wait_for_device_probe();
822 dasd_fba_cleanup(void)
824 ccw_driver_unregister(&dasd_fba_driver);
827 module_init(dasd_fba_init);
828 module_exit(dasd_fba_cleanup);