1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
4 * Based on.......: linux/drivers/s390/block/mdisk.c
5 * ...............: by Hartmunt Penner <hpenner@de.ibm.com>
6 * Bugreports.to..: <Linux390@de.ibm.com>
7 * Copyright IBM Corp. 1999, 2000
8 *
9 */
10
11#define KMSG_COMPONENT "dasd"
12
13#include <linux/kernel_stat.h>
14#include <linux/stddef.h>
15#include <linux/kernel.h>
16#include <linux/slab.h>
17#include <linux/hdreg.h>
18#include <linux/bio.h>
19#include <linux/module.h>
20#include <linux/init.h>
21#include <linux/jiffies.h>
22#include <asm/asm-extable.h>
23#include <asm/dasd.h>
24#include <asm/debug.h>
25#include <asm/diag.h>
26#include <asm/ebcdic.h>
27#include <linux/io.h>
28#include <asm/irq.h>
29#include <asm/vtoc.h>
30
31#include "dasd_int.h"
32#include "dasd_diag.h"
33
34#define PRINTK_HEADER "dasd(diag):"
35
36MODULE_LICENSE("GPL");
37
38/* The maximum number of blocks per request (max_blocks) is dependent on the
39 * amount of storage that is available in the static I/O buffer for each
40 * device. Currently each device gets 2 pages. We want to fit two requests
41 * into the available memory so that we can immediately start the next if one
42 * finishes. */
43#define DIAG_MAX_BLOCKS (((2 * PAGE_SIZE - sizeof(struct dasd_ccw_req) - \
44 sizeof(struct dasd_diag_req)) / \
45 sizeof(struct dasd_diag_bio)) / 2)
46#define DIAG_MAX_RETRIES 32
47#define DIAG_TIMEOUT 50
48
49static struct dasd_discipline dasd_diag_discipline;
50
51struct dasd_diag_private {
52 struct dasd_diag_characteristics rdc_data;
53 struct dasd_diag_rw_io iob;
54 struct dasd_diag_init_io iib;
55 blocknum_t pt_block;
56 struct ccw_dev_id dev_id;
57};
58
59struct dasd_diag_req {
60 unsigned int block_count;
61 struct dasd_diag_bio bio[];
62};
63
64static const u8 DASD_DIAG_CMS1[] = { 0xc3, 0xd4, 0xe2, 0xf1 };/* EBCDIC CMS1 */
65
66/* Perform DIAG250 call with block I/O parameter list iob (input and output)
67 * and function code cmd.
68 * In case of an exception return 3. Otherwise return result of bitwise OR of
69 * resulting condition code and DIAG return code. */
70static inline int __dia250(void *iob, int cmd)
71{
72 union register_pair rx = { .even = (unsigned long)iob, };
73 typedef union {
74 struct dasd_diag_init_io init_io;
75 struct dasd_diag_rw_io rw_io;
76 } addr_type;
77 int cc;
78
79 cc = 3;
80 asm volatile(
81 " diag %[rx],%[cmd],0x250\n"
82 "0: ipm %[cc]\n"
83 " srl %[cc],28\n"
84 "1:\n"
85 EX_TABLE(0b,1b)
86 : [cc] "+&d" (cc), [rx] "+&d" (rx.pair), "+m" (*(addr_type *)iob)
87 : [cmd] "d" (cmd)
88 : "cc");
89 return cc | rx.odd;
90}
91
92static inline int dia250(void *iob, int cmd)
93{
94 diag_stat_inc(DIAG_STAT_X250);
95 return __dia250(iob, cmd);
96}
97
98/* Initialize block I/O to DIAG device using the specified blocksize and
99 * block offset. On success, return zero and set end_block to contain the
100 * number of blocks on the device minus the specified offset. Return non-zero
101 * otherwise. */
102static inline int
103mdsk_init_io(struct dasd_device *device, unsigned int blocksize,
104 blocknum_t offset, blocknum_t *end_block)
105{
106 struct dasd_diag_private *private = device->private;
107 struct dasd_diag_init_io *iib = &private->iib;
108 int rc;
109
110 memset(iib, 0, sizeof (struct dasd_diag_init_io));
111
112 iib->dev_nr = private->dev_id.devno;
113 iib->block_size = blocksize;
114 iib->offset = offset;
115 iib->flaga = DASD_DIAG_FLAGA_DEFAULT;
116
117 rc = dia250(iob: iib, INIT_BIO);
118
119 if ((rc & 3) == 0 && end_block)
120 *end_block = iib->end_block;
121
122 return rc;
123}
124
125/* Remove block I/O environment for device. Return zero on success, non-zero
126 * otherwise. */
127static inline int
128mdsk_term_io(struct dasd_device * device)
129{
130 struct dasd_diag_private *private = device->private;
131 struct dasd_diag_init_io *iib = &private->iib;
132 int rc;
133
134 memset(iib, 0, sizeof (struct dasd_diag_init_io));
135 iib->dev_nr = private->dev_id.devno;
136 rc = dia250(iob: iib, TERM_BIO);
137 return rc;
138}
139
140/* Error recovery for failed DIAG requests - try to reestablish the DIAG
141 * environment. */
142static void
143dasd_diag_erp(struct dasd_device *device)
144{
145 int rc;
146
147 mdsk_term_io(device);
148 rc = mdsk_init_io(device, blocksize: device->block->bp_block, offset: 0, NULL);
149 if (rc == 4) {
150 if (!(test_and_set_bit(DASD_FLAG_DEVICE_RO, addr: &device->flags)))
151 pr_warn("%s: The access mode of a DIAG device changed to read-only\n",
152 dev_name(&device->cdev->dev));
153 rc = 0;
154 }
155 if (rc)
156 pr_warn("%s: DIAG ERP failed with rc=%d\n",
157 dev_name(&device->cdev->dev), rc);
158}
159
160/* Start a given request at the device. Return zero on success, non-zero
161 * otherwise. */
162static int
163dasd_start_diag(struct dasd_ccw_req * cqr)
164{
165 struct dasd_device *device;
166 struct dasd_diag_private *private;
167 struct dasd_diag_req *dreq;
168 int rc;
169
170 device = cqr->startdev;
171 if (cqr->retries < 0) {
172 DBF_DEV_EVENT(DBF_ERR, device, "DIAG start_IO: request %p "
173 "- no retry left)", cqr);
174 cqr->status = DASD_CQR_ERROR;
175 return -EIO;
176 }
177 private = device->private;
178 dreq = cqr->data;
179
180 private->iob.dev_nr = private->dev_id.devno;
181 private->iob.key = 0;
182 private->iob.flags = DASD_DIAG_RWFLAG_ASYNC;
183 private->iob.block_count = dreq->block_count;
184 private->iob.interrupt_params = (addr_t) cqr;
185 private->iob.bio_list = dreq->bio;
186 private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;
187
188 cqr->startclk = get_tod_clock();
189 cqr->starttime = jiffies;
190 cqr->retries--;
191
192 rc = dia250(iob: &private->iob, RW_BIO);
193 switch (rc) {
194 case 0: /* Synchronous I/O finished successfully */
195 cqr->stopclk = get_tod_clock();
196 cqr->status = DASD_CQR_SUCCESS;
197 /* Indicate to calling function that only a dasd_schedule_bh()
198 and no timer is needed */
199 rc = -EACCES;
200 break;
201 case 8: /* Asynchronous I/O was started */
202 cqr->status = DASD_CQR_IN_IO;
203 rc = 0;
204 break;
205 default: /* Error condition */
206 cqr->status = DASD_CQR_QUEUED;
207 DBF_DEV_EVENT(DBF_WARNING, device, "dia250 returned rc=%d", rc);
208 dasd_diag_erp(device);
209 rc = -EIO;
210 break;
211 }
212 cqr->intrc = rc;
213 return rc;
214}
215
216/* Terminate given request at the device. */
217static int
218dasd_diag_term_IO(struct dasd_ccw_req * cqr)
219{
220 struct dasd_device *device;
221
222 device = cqr->startdev;
223 mdsk_term_io(device);
224 mdsk_init_io(device, blocksize: device->block->bp_block, offset: 0, NULL);
225 cqr->status = DASD_CQR_CLEAR_PENDING;
226 cqr->stopclk = get_tod_clock();
227 dasd_schedule_device_bh(device);
228 return 0;
229}
230
231/* Handle external interruption. */
232static void dasd_ext_handler(struct ext_code ext_code,
233 unsigned int param32, unsigned long param64)
234{
235 struct dasd_ccw_req *cqr, *next;
236 struct dasd_device *device;
237 unsigned long expires;
238 unsigned long flags;
239 addr_t ip;
240 int rc;
241
242 switch (ext_code.subcode >> 8) {
243 case DASD_DIAG_CODE_31BIT:
244 ip = (addr_t) param32;
245 break;
246 case DASD_DIAG_CODE_64BIT:
247 ip = (addr_t) param64;
248 break;
249 default:
250 return;
251 }
252 inc_irq_stat(IRQEXT_DSD);
253 if (!ip) { /* no intparm: unsolicited interrupt */
254 DBF_EVENT(DBF_NOTICE, "%s", "caught unsolicited "
255 "interrupt");
256 return;
257 }
258 cqr = (struct dasd_ccw_req *) ip;
259 device = (struct dasd_device *) cqr->startdev;
260 if (strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
261 DBF_DEV_EVENT(DBF_WARNING, device,
262 " magic number of dasd_ccw_req 0x%08X doesn't"
263 " match discipline 0x%08X",
264 cqr->magic, *(int *) (&device->discipline->name));
265 return;
266 }
267
268 /* get irq lock to modify request queue */
269 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
270
271 /* Check for a pending clear operation */
272 if (cqr->status == DASD_CQR_CLEAR_PENDING) {
273 cqr->status = DASD_CQR_CLEARED;
274 dasd_device_clear_timer(device);
275 dasd_schedule_device_bh(device);
276 spin_unlock_irqrestore(lock: get_ccwdev_lock(device->cdev), flags);
277 return;
278 }
279
280 cqr->stopclk = get_tod_clock();
281
282 expires = 0;
283 if ((ext_code.subcode & 0xff) == 0) {
284 cqr->status = DASD_CQR_SUCCESS;
285 /* Start first request on queue if possible -> fast_io. */
286 if (!list_empty(head: &device->ccw_queue)) {
287 next = list_entry(device->ccw_queue.next,
288 struct dasd_ccw_req, devlist);
289 if (next->status == DASD_CQR_QUEUED) {
290 rc = dasd_start_diag(cqr: next);
291 if (rc == 0)
292 expires = next->expires;
293 }
294 }
295 } else {
296 cqr->status = DASD_CQR_QUEUED;
297 DBF_DEV_EVENT(DBF_DEBUG, device, "interrupt status for "
298 "request %p was %d (%d retries left)", cqr,
299 ext_code.subcode & 0xff, cqr->retries);
300 dasd_diag_erp(device);
301 }
302
303 if (expires != 0)
304 dasd_device_set_timer(device, expires);
305 else
306 dasd_device_clear_timer(device);
307 dasd_schedule_device_bh(device);
308
309 spin_unlock_irqrestore(lock: get_ccwdev_lock(device->cdev), flags);
310}
311
312/* Check whether device can be controlled by DIAG discipline. Return zero on
313 * success, non-zero otherwise. */
314static int
315dasd_diag_check_device(struct dasd_device *device)
316{
317 struct dasd_diag_private *private = device->private;
318 struct dasd_diag_characteristics *rdc_data;
319 struct vtoc_cms_label *label;
320 struct dasd_block *block;
321 struct dasd_diag_bio *bio;
322 unsigned int sb, bsize;
323 blocknum_t end_block;
324 int rc;
325
326 if (private == NULL) {
327 private = kzalloc(size: sizeof(*private), GFP_KERNEL);
328 if (private == NULL) {
329 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
330 "Allocating memory for private DASD data "
331 "failed\n");
332 return -ENOMEM;
333 }
334 ccw_device_get_id(device->cdev, &private->dev_id);
335 device->private = private;
336 }
337 block = dasd_alloc_block();
338 if (IS_ERR(ptr: block)) {
339 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
340 "could not allocate dasd block structure");
341 device->private = NULL;
342 kfree(objp: private);
343 return PTR_ERR(ptr: block);
344 }
345 device->block = block;
346 block->base = device;
347
348 /* Read Device Characteristics */
349 rdc_data = &private->rdc_data;
350 rdc_data->dev_nr = private->dev_id.devno;
351 rdc_data->rdc_len = sizeof (struct dasd_diag_characteristics);
352
353 rc = diag210((struct diag210 *) rdc_data);
354 if (rc) {
355 DBF_DEV_EVENT(DBF_WARNING, device, "failed to retrieve device "
356 "information (rc=%d)", rc);
357 rc = -EOPNOTSUPP;
358 goto out;
359 }
360
361 device->default_expires = DIAG_TIMEOUT;
362 device->default_retries = DIAG_MAX_RETRIES;
363
364 /* Figure out position of label block */
365 switch (private->rdc_data.vdev_class) {
366 case DEV_CLASS_FBA:
367 private->pt_block = 1;
368 break;
369 case DEV_CLASS_ECKD:
370 private->pt_block = 2;
371 break;
372 default:
373 pr_warn("%s: Device type %d is not supported in DIAG mode\n",
374 dev_name(&device->cdev->dev),
375 private->rdc_data.vdev_class);
376 rc = -EOPNOTSUPP;
377 goto out;
378 }
379
380 DBF_DEV_EVENT(DBF_INFO, device,
381 "%04X: %04X on real %04X/%02X",
382 rdc_data->dev_nr,
383 rdc_data->vdev_type,
384 rdc_data->rdev_type, rdc_data->rdev_model);
385
386 /* terminate all outstanding operations */
387 mdsk_term_io(device);
388
389 /* figure out blocksize of device */
390 label = (struct vtoc_cms_label *) get_zeroed_page(GFP_KERNEL);
391 if (label == NULL) {
392 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
393 "No memory to allocate initialization request");
394 rc = -ENOMEM;
395 goto out;
396 }
397 bio = kzalloc(size: sizeof(*bio), GFP_KERNEL);
398 if (bio == NULL) {
399 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
400 "No memory to allocate initialization bio");
401 rc = -ENOMEM;
402 goto out_label;
403 }
404 rc = 0;
405 end_block = 0;
406 /* try all sizes - needed for ECKD devices */
407 for (bsize = 512; bsize <= PAGE_SIZE; bsize <<= 1) {
408 mdsk_init_io(device, blocksize: bsize, offset: 0, end_block: &end_block);
409 memset(bio, 0, sizeof(*bio));
410 bio->type = MDSK_READ_REQ;
411 bio->block_number = private->pt_block + 1;
412 bio->buffer = label;
413 memset(&private->iob, 0, sizeof (struct dasd_diag_rw_io));
414 private->iob.dev_nr = rdc_data->dev_nr;
415 private->iob.key = 0;
416 private->iob.flags = 0; /* do synchronous io */
417 private->iob.block_count = 1;
418 private->iob.interrupt_params = 0;
419 private->iob.bio_list = bio;
420 private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;
421 rc = dia250(iob: &private->iob, RW_BIO);
422 if (rc == 3) {
423 pr_warn("%s: A 64-bit DIAG call failed\n",
424 dev_name(&device->cdev->dev));
425 rc = -EOPNOTSUPP;
426 goto out_bio;
427 }
428 mdsk_term_io(device);
429 if (rc == 0)
430 break;
431 }
432 if (bsize > PAGE_SIZE) {
433 pr_warn("%s: Accessing the DASD failed because of an incorrect format (rc=%d)\n",
434 dev_name(&device->cdev->dev), rc);
435 rc = -EIO;
436 goto out_bio;
437 }
438 /* check for label block */
439 if (memcmp(label->label_id, DASD_DIAG_CMS1,
440 sizeof(DASD_DIAG_CMS1)) == 0) {
441 /* get formatted blocksize from label block */
442 bsize = (unsigned int) label->block_size;
443 block->blocks = (unsigned long) label->block_count;
444 } else
445 block->blocks = end_block;
446 block->bp_block = bsize;
447 block->s2b_shift = 0; /* bits to shift 512 to get a block */
448 for (sb = 512; sb < bsize; sb = sb << 1)
449 block->s2b_shift++;
450 rc = mdsk_init_io(device, blocksize: block->bp_block, offset: 0, NULL);
451 if (rc && (rc != 4)) {
452 pr_warn("%s: DIAG initialization failed with rc=%d\n",
453 dev_name(&device->cdev->dev), rc);
454 rc = -EIO;
455 } else {
456 if (rc == 4)
457 set_bit(DASD_FLAG_DEVICE_RO, addr: &device->flags);
458 pr_info("%s: New DASD with %ld byte/block, total size %ld "
459 "KB%s\n", dev_name(&device->cdev->dev),
460 (unsigned long) block->bp_block,
461 (unsigned long) (block->blocks <<
462 block->s2b_shift) >> 1,
463 (rc == 4) ? ", read-only device" : "");
464 rc = 0;
465 }
466out_bio:
467 kfree(objp: bio);
468out_label:
469 free_page((long) label);
470out:
471 if (rc) {
472 device->block = NULL;
473 dasd_free_block(block);
474 device->private = NULL;
475 kfree(objp: private);
476 }
477 return rc;
478}
479
480/* Fill in virtual disk geometry for device. Return zero on success, non-zero
481 * otherwise. */
482static int
483dasd_diag_fill_geometry(struct dasd_block *block, struct hd_geometry *geo)
484{
485 if (dasd_check_blocksize(bsize: block->bp_block) != 0)
486 return -EINVAL;
487 geo->cylinders = (block->blocks << block->s2b_shift) >> 10;
488 geo->heads = 16;
489 geo->sectors = 128 >> block->s2b_shift;
490 return 0;
491}
492
493static dasd_erp_fn_t
494dasd_diag_erp_action(struct dasd_ccw_req * cqr)
495{
496 return dasd_default_erp_action;
497}
498
499static dasd_erp_fn_t
500dasd_diag_erp_postaction(struct dasd_ccw_req * cqr)
501{
502 return dasd_default_erp_postaction;
503}
504
505/* Create DASD request from block device request. Return pointer to new
506 * request on success, ERR_PTR otherwise. */
507static struct dasd_ccw_req *dasd_diag_build_cp(struct dasd_device *memdev,
508 struct dasd_block *block,
509 struct request *req)
510{
511 struct dasd_ccw_req *cqr;
512 struct dasd_diag_req *dreq;
513 struct dasd_diag_bio *dbio;
514 struct req_iterator iter;
515 struct bio_vec bv;
516 char *dst;
517 unsigned int count;
518 sector_t recid, first_rec, last_rec;
519 unsigned int blksize, off;
520 unsigned char rw_cmd;
521
522 if (rq_data_dir(req) == READ)
523 rw_cmd = MDSK_READ_REQ;
524 else if (rq_data_dir(req) == WRITE)
525 rw_cmd = MDSK_WRITE_REQ;
526 else
527 return ERR_PTR(error: -EINVAL);
528 blksize = block->bp_block;
529 /* Calculate record id of first and last block. */
530 first_rec = blk_rq_pos(rq: req) >> block->s2b_shift;
531 last_rec =
532 (blk_rq_pos(rq: req) + blk_rq_sectors(rq: req) - 1) >> block->s2b_shift;
533 /* Check struct bio and count the number of blocks for the request. */
534 count = 0;
535 rq_for_each_segment(bv, req, iter) {
536 if (bv.bv_len & (blksize - 1))
537 /* Fba can only do full blocks. */
538 return ERR_PTR(error: -EINVAL);
539 count += bv.bv_len >> (block->s2b_shift + 9);
540 }
541 /* Paranoia. */
542 if (count != last_rec - first_rec + 1)
543 return ERR_PTR(error: -EINVAL);
544 /* Build the request */
545 cqr = dasd_smalloc_request(DASD_DIAG_MAGIC, 0, struct_size(dreq, bio, count),
546 memdev, blk_mq_rq_to_pdu(rq: req));
547 if (IS_ERR(ptr: cqr))
548 return cqr;
549
550 dreq = (struct dasd_diag_req *) cqr->data;
551 dreq->block_count = count;
552 dbio = dreq->bio;
553 recid = first_rec;
554 rq_for_each_segment(bv, req, iter) {
555 dst = bvec_virt(bvec: &bv);
556 for (off = 0; off < bv.bv_len; off += blksize) {
557 memset(dbio, 0, sizeof (struct dasd_diag_bio));
558 dbio->type = rw_cmd;
559 dbio->block_number = recid + 1;
560 dbio->buffer = dst;
561 dbio++;
562 dst += blksize;
563 recid++;
564 }
565 }
566 cqr->retries = memdev->default_retries;
567 cqr->buildclk = get_tod_clock();
568 if (blk_noretry_request(req) ||
569 block->base->features & DASD_FEATURE_FAILFAST)
570 set_bit(DASD_CQR_FLAGS_FAILFAST, addr: &cqr->flags);
571 cqr->startdev = memdev;
572 cqr->memdev = memdev;
573 cqr->block = block;
574 cqr->expires = memdev->default_expires * HZ;
575 cqr->status = DASD_CQR_FILLED;
576 return cqr;
577}
578
579/* Release DASD request. Return non-zero if request was successful, zero
580 * otherwise. */
581static int
582dasd_diag_free_cp(struct dasd_ccw_req *cqr, struct request *req)
583{
584 int status;
585
586 status = cqr->status == DASD_CQR_DONE;
587 dasd_sfree_request(cqr, cqr->memdev);
588 return status;
589}
590
591static void dasd_diag_handle_terminated_request(struct dasd_ccw_req *cqr)
592{
593 if (cqr->retries < 0)
594 cqr->status = DASD_CQR_FAILED;
595 else
596 cqr->status = DASD_CQR_FILLED;
597};
598
599/* Fill in IOCTL data for device. */
600static int
601dasd_diag_fill_info(struct dasd_device * device,
602 struct dasd_information2_t * info)
603{
604 struct dasd_diag_private *private = device->private;
605
606 info->label_block = (unsigned int) private->pt_block;
607 info->FBA_layout = 1;
608 info->format = DASD_FORMAT_LDL;
609 info->characteristics_size = sizeof(private->rdc_data);
610 memcpy(info->characteristics, &private->rdc_data,
611 sizeof(private->rdc_data));
612 info->confdata_size = 0;
613 return 0;
614}
615
616static void
617dasd_diag_dump_sense(struct dasd_device *device, struct dasd_ccw_req * req,
618 struct irb *stat)
619{
620 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
621 "dump sense not available for DIAG data");
622}
623
624/*
625 * Initialize block layer request queue.
626 */
627static void dasd_diag_setup_blk_queue(struct dasd_block *block)
628{
629 unsigned int logical_block_size = block->bp_block;
630 struct request_queue *q = block->gdp->queue;
631 int max;
632
633 max = DIAG_MAX_BLOCKS << block->s2b_shift;
634 blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
635 q->limits.max_dev_sectors = max;
636 blk_queue_logical_block_size(q, logical_block_size);
637 blk_queue_max_hw_sectors(q, max);
638 blk_queue_max_segments(q, USHRT_MAX);
639 /* With page sized segments each segment can be translated into one idaw/tidaw */
640 blk_queue_max_segment_size(q, PAGE_SIZE);
641 blk_queue_segment_boundary(q, PAGE_SIZE - 1);
642 blk_queue_dma_alignment(q, PAGE_SIZE - 1);
643}
644
645static int dasd_diag_pe_handler(struct dasd_device *device,
646 __u8 tbvpm, __u8 fcsecpm)
647{
648 return dasd_generic_verify_path(device, tbvpm);
649}
650
651static struct dasd_discipline dasd_diag_discipline = {
652 .owner = THIS_MODULE,
653 .name = "DIAG",
654 .ebcname = "DIAG",
655 .check_device = dasd_diag_check_device,
656 .pe_handler = dasd_diag_pe_handler,
657 .fill_geometry = dasd_diag_fill_geometry,
658 .setup_blk_queue = dasd_diag_setup_blk_queue,
659 .start_IO = dasd_start_diag,
660 .term_IO = dasd_diag_term_IO,
661 .handle_terminated_request = dasd_diag_handle_terminated_request,
662 .erp_action = dasd_diag_erp_action,
663 .erp_postaction = dasd_diag_erp_postaction,
664 .build_cp = dasd_diag_build_cp,
665 .free_cp = dasd_diag_free_cp,
666 .dump_sense = dasd_diag_dump_sense,
667 .fill_info = dasd_diag_fill_info,
668};
669
670static int __init
671dasd_diag_init(void)
672{
673 if (!MACHINE_IS_VM) {
674 pr_info("Discipline %s cannot be used without z/VM\n",
675 dasd_diag_discipline.name);
676 return -ENODEV;
677 }
678 ASCEBC(dasd_diag_discipline.ebcname, 4);
679
680 irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL);
681 register_external_irq(EXT_IRQ_CP_SERVICE, dasd_ext_handler);
682 dasd_diag_discipline_pointer = &dasd_diag_discipline;
683 return 0;
684}
685
686static void __exit
687dasd_diag_cleanup(void)
688{
689 unregister_external_irq(EXT_IRQ_CP_SERVICE, dasd_ext_handler);
690 irq_subclass_unregister(IRQ_SUBCLASS_SERVICE_SIGNAL);
691 dasd_diag_discipline_pointer = NULL;
692}
693
694module_init(dasd_diag_init);
695module_exit(dasd_diag_cleanup);
696

source code of linux/drivers/s390/block/dasd_diag.c