sched: Fix schedule_tail() to disable preemption
[linux/fpc-iii.git] / drivers / s390 / block / dasd_diag.c
blobc062f1620c58d419514af3ce7b81da8952e11546
1 /*
2 * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
3 * Based on.......: linux/drivers/s390/block/mdisk.c
4 * ...............: by Hartmunt Penner <hpenner@de.ibm.com>
5 * Bugreports.to..: <Linux390@de.ibm.com>
6 * Copyright IBM Corp. 1999, 2000
8 */
10 #define KMSG_COMPONENT "dasd"
12 #include <linux/kernel_stat.h>
13 #include <linux/stddef.h>
14 #include <linux/kernel.h>
15 #include <linux/slab.h>
16 #include <linux/hdreg.h>
17 #include <linux/bio.h>
18 #include <linux/module.h>
19 #include <linux/init.h>
20 #include <linux/jiffies.h>
22 #include <asm/dasd.h>
23 #include <asm/debug.h>
24 #include <asm/ebcdic.h>
25 #include <asm/io.h>
26 #include <asm/irq.h>
27 #include <asm/vtoc.h>
28 #include <asm/diag.h>
30 #include "dasd_int.h"
31 #include "dasd_diag.h"
33 #define PRINTK_HEADER "dasd(diag):"
35 MODULE_LICENSE("GPL");
37 /* The maximum number of blocks per request (max_blocks) is dependent on the
38 * amount of storage that is available in the static I/O buffer for each
39 * device. Currently each device gets 2 pages. We want to fit two requests
40 * into the available memory so that we can immediately start the next if one
41 * finishes. */
42 #define DIAG_MAX_BLOCKS (((2 * PAGE_SIZE - sizeof(struct dasd_ccw_req) - \
43 sizeof(struct dasd_diag_req)) / \
44 sizeof(struct dasd_diag_bio)) / 2)
45 #define DIAG_MAX_RETRIES 32
46 #define DIAG_TIMEOUT 50
48 static struct dasd_discipline dasd_diag_discipline;
50 struct dasd_diag_private {
51 struct dasd_diag_characteristics rdc_data;
52 struct dasd_diag_rw_io iob;
53 struct dasd_diag_init_io iib;
54 blocknum_t pt_block;
55 struct ccw_dev_id dev_id;
58 struct dasd_diag_req {
59 unsigned int block_count;
60 struct dasd_diag_bio bio[0];
63 static const u8 DASD_DIAG_CMS1[] = { 0xc3, 0xd4, 0xe2, 0xf1 };/* EBCDIC CMS1 */
65 /* Perform DIAG250 call with block I/O parameter list iob (input and output)
66 * and function code cmd.
67 * In case of an exception return 3. Otherwise return result of bitwise OR of
68 * resulting condition code and DIAG return code. */
69 static inline int dia250(void *iob, int cmd)
71 register unsigned long reg2 asm ("2") = (unsigned long) iob;
72 typedef union {
73 struct dasd_diag_init_io init_io;
74 struct dasd_diag_rw_io rw_io;
75 } addr_type;
76 int rc;
78 rc = 3;
79 asm volatile(
80 " diag 2,%2,0x250\n"
81 "0: ipm %0\n"
82 " srl %0,28\n"
83 " or %0,3\n"
84 "1:\n"
85 EX_TABLE(0b,1b)
86 : "+d" (rc), "=m" (*(addr_type *) iob)
87 : "d" (cmd), "d" (reg2), "m" (*(addr_type *) iob)
88 : "3", "cc");
89 return rc;
92 /* Initialize block I/O to DIAG device using the specified blocksize and
93 * block offset. On success, return zero and set end_block to contain the
94 * number of blocks on the device minus the specified offset. Return non-zero
95 * otherwise. */
96 static inline int
97 mdsk_init_io(struct dasd_device *device, unsigned int blocksize,
98 blocknum_t offset, blocknum_t *end_block)
100 struct dasd_diag_private *private;
101 struct dasd_diag_init_io *iib;
102 int rc;
104 private = (struct dasd_diag_private *) device->private;
105 iib = &private->iib;
106 memset(iib, 0, sizeof (struct dasd_diag_init_io));
108 iib->dev_nr = private->dev_id.devno;
109 iib->block_size = blocksize;
110 iib->offset = offset;
111 iib->flaga = DASD_DIAG_FLAGA_DEFAULT;
113 rc = dia250(iib, INIT_BIO);
115 if ((rc & 3) == 0 && end_block)
116 *end_block = iib->end_block;
118 return rc;
121 /* Remove block I/O environment for device. Return zero on success, non-zero
122 * otherwise. */
123 static inline int
124 mdsk_term_io(struct dasd_device * device)
126 struct dasd_diag_private *private;
127 struct dasd_diag_init_io *iib;
128 int rc;
130 private = (struct dasd_diag_private *) device->private;
131 iib = &private->iib;
132 memset(iib, 0, sizeof (struct dasd_diag_init_io));
133 iib->dev_nr = private->dev_id.devno;
134 rc = dia250(iib, TERM_BIO);
135 return rc;
138 /* Error recovery for failed DIAG requests - try to reestablish the DIAG
139 * environment. */
140 static void
141 dasd_diag_erp(struct dasd_device *device)
143 int rc;
145 mdsk_term_io(device);
146 rc = mdsk_init_io(device, device->block->bp_block, 0, NULL);
147 if (rc == 4) {
148 if (!(test_and_set_bit(DASD_FLAG_DEVICE_RO, &device->flags)))
149 pr_warning("%s: The access mode of a DIAG device "
150 "changed to read-only\n",
151 dev_name(&device->cdev->dev));
152 rc = 0;
154 if (rc)
155 pr_warning("%s: DIAG ERP failed with "
156 "rc=%d\n", dev_name(&device->cdev->dev), rc);
159 /* Start a given request at the device. Return zero on success, non-zero
160 * otherwise. */
161 static int
162 dasd_start_diag(struct dasd_ccw_req * cqr)
164 struct dasd_device *device;
165 struct dasd_diag_private *private;
166 struct dasd_diag_req *dreq;
167 int rc;
169 device = cqr->startdev;
170 if (cqr->retries < 0) {
171 DBF_DEV_EVENT(DBF_ERR, device, "DIAG start_IO: request %p "
172 "- no retry left)", cqr);
173 cqr->status = DASD_CQR_ERROR;
174 return -EIO;
176 private = (struct dasd_diag_private *) device->private;
177 dreq = (struct dasd_diag_req *) cqr->data;
179 private->iob.dev_nr = private->dev_id.devno;
180 private->iob.key = 0;
181 private->iob.flags = DASD_DIAG_RWFLAG_ASYNC;
182 private->iob.block_count = dreq->block_count;
183 private->iob.interrupt_params = (addr_t) cqr;
184 private->iob.bio_list = dreq->bio;
185 private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;
187 cqr->startclk = get_tod_clock();
188 cqr->starttime = jiffies;
189 cqr->retries--;
191 rc = dia250(&private->iob, RW_BIO);
192 switch (rc) {
193 case 0: /* Synchronous I/O finished successfully */
194 cqr->stopclk = get_tod_clock();
195 cqr->status = DASD_CQR_SUCCESS;
196 /* Indicate to calling function that only a dasd_schedule_bh()
197 and no timer is needed */
198 rc = -EACCES;
199 break;
200 case 8: /* Asynchronous I/O was started */
201 cqr->status = DASD_CQR_IN_IO;
202 rc = 0;
203 break;
204 default: /* Error condition */
205 cqr->status = DASD_CQR_QUEUED;
206 DBF_DEV_EVENT(DBF_WARNING, device, "dia250 returned rc=%d", rc);
207 dasd_diag_erp(device);
208 rc = -EIO;
209 break;
211 cqr->intrc = rc;
212 return rc;
215 /* Terminate given request at the device. */
216 static int
217 dasd_diag_term_IO(struct dasd_ccw_req * cqr)
219 struct dasd_device *device;
221 device = cqr->startdev;
222 mdsk_term_io(device);
223 mdsk_init_io(device, device->block->bp_block, 0, NULL);
224 cqr->status = DASD_CQR_CLEAR_PENDING;
225 cqr->stopclk = get_tod_clock();
226 dasd_schedule_device_bh(device);
227 return 0;
230 /* Handle external interruption. */
231 static void dasd_ext_handler(struct ext_code ext_code,
232 unsigned int param32, unsigned long param64)
234 struct dasd_ccw_req *cqr, *next;
235 struct dasd_device *device;
236 unsigned long long expires;
237 unsigned long flags;
238 addr_t ip;
239 int rc;
241 switch (ext_code.subcode >> 8) {
242 case DASD_DIAG_CODE_31BIT:
243 ip = (addr_t) param32;
244 break;
245 case DASD_DIAG_CODE_64BIT:
246 ip = (addr_t) param64;
247 break;
248 default:
249 return;
251 inc_irq_stat(IRQEXT_DSD);
252 if (!ip) { /* no intparm: unsolicited interrupt */
253 DBF_EVENT(DBF_NOTICE, "%s", "caught unsolicited "
254 "interrupt");
255 return;
257 cqr = (struct dasd_ccw_req *) ip;
258 device = (struct dasd_device *) cqr->startdev;
259 if (strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
260 DBF_DEV_EVENT(DBF_WARNING, device,
261 " magic number of dasd_ccw_req 0x%08X doesn't"
262 " match discipline 0x%08X",
263 cqr->magic, *(int *) (&device->discipline->name));
264 return;
267 /* get irq lock to modify request queue */
268 spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
270 /* Check for a pending clear operation */
271 if (cqr->status == DASD_CQR_CLEAR_PENDING) {
272 cqr->status = DASD_CQR_CLEARED;
273 dasd_device_clear_timer(device);
274 dasd_schedule_device_bh(device);
275 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
276 return;
279 cqr->stopclk = get_tod_clock();
281 expires = 0;
282 if ((ext_code.subcode & 0xff) == 0) {
283 cqr->status = DASD_CQR_SUCCESS;
284 /* Start first request on queue if possible -> fast_io. */
285 if (!list_empty(&device->ccw_queue)) {
286 next = list_entry(device->ccw_queue.next,
287 struct dasd_ccw_req, devlist);
288 if (next->status == DASD_CQR_QUEUED) {
289 rc = dasd_start_diag(next);
290 if (rc == 0)
291 expires = next->expires;
294 } else {
295 cqr->status = DASD_CQR_QUEUED;
296 DBF_DEV_EVENT(DBF_DEBUG, device, "interrupt status for "
297 "request %p was %d (%d retries left)", cqr,
298 ext_code.subcode & 0xff, cqr->retries);
299 dasd_diag_erp(device);
302 if (expires != 0)
303 dasd_device_set_timer(device, expires);
304 else
305 dasd_device_clear_timer(device);
306 dasd_schedule_device_bh(device);
308 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
311 /* Check whether device can be controlled by DIAG discipline. Return zero on
312 * success, non-zero otherwise. */
313 static int
314 dasd_diag_check_device(struct dasd_device *device)
316 struct dasd_block *block;
317 struct dasd_diag_private *private;
318 struct dasd_diag_characteristics *rdc_data;
319 struct dasd_diag_bio bio;
320 struct vtoc_cms_label *label;
321 blocknum_t end_block;
322 unsigned int sb, bsize;
323 int rc;
325 private = (struct dasd_diag_private *) device->private;
326 if (private == NULL) {
327 private = kzalloc(sizeof(struct dasd_diag_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;
334 ccw_device_get_id(device->cdev, &private->dev_id);
335 device->private = (void *) private;
337 block = dasd_alloc_block();
338 if (IS_ERR(block)) {
339 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
340 "could not allocate dasd block structure");
341 device->private = NULL;
342 kfree(private);
343 return PTR_ERR(block);
345 device->block = block;
346 block->base = device;
348 /* Read Device Characteristics */
349 rdc_data = (void *) &(private->rdc_data);
350 rdc_data->dev_nr = private->dev_id.devno;
351 rdc_data->rdc_len = sizeof (struct dasd_diag_characteristics);
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;
361 device->default_expires = DIAG_TIMEOUT;
362 device->default_retries = DIAG_MAX_RETRIES;
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_warning("%s: Device type %d is not supported "
374 "in DIAG mode\n", dev_name(&device->cdev->dev),
375 private->rdc_data.vdev_class);
376 rc = -EOPNOTSUPP;
377 goto out;
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);
386 /* terminate all outstanding operations */
387 mdsk_term_io(device);
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;
397 rc = 0;
398 end_block = 0;
399 /* try all sizes - needed for ECKD devices */
400 for (bsize = 512; bsize <= PAGE_SIZE; bsize <<= 1) {
401 mdsk_init_io(device, bsize, 0, &end_block);
402 memset(&bio, 0, sizeof (struct dasd_diag_bio));
403 bio.type = MDSK_READ_REQ;
404 bio.block_number = private->pt_block + 1;
405 bio.buffer = label;
406 memset(&private->iob, 0, sizeof (struct dasd_diag_rw_io));
407 private->iob.dev_nr = rdc_data->dev_nr;
408 private->iob.key = 0;
409 private->iob.flags = 0; /* do synchronous io */
410 private->iob.block_count = 1;
411 private->iob.interrupt_params = 0;
412 private->iob.bio_list = &bio;
413 private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;
414 rc = dia250(&private->iob, RW_BIO);
415 if (rc == 3) {
416 pr_warning("%s: A 64-bit DIAG call failed\n",
417 dev_name(&device->cdev->dev));
418 rc = -EOPNOTSUPP;
419 goto out_label;
421 mdsk_term_io(device);
422 if (rc == 0)
423 break;
425 if (bsize > PAGE_SIZE) {
426 pr_warning("%s: Accessing the DASD failed because of an "
427 "incorrect format (rc=%d)\n",
428 dev_name(&device->cdev->dev), rc);
429 rc = -EIO;
430 goto out_label;
432 /* check for label block */
433 if (memcmp(label->label_id, DASD_DIAG_CMS1,
434 sizeof(DASD_DIAG_CMS1)) == 0) {
435 /* get formatted blocksize from label block */
436 bsize = (unsigned int) label->block_size;
437 block->blocks = (unsigned long) label->block_count;
438 } else
439 block->blocks = end_block;
440 block->bp_block = bsize;
441 block->s2b_shift = 0; /* bits to shift 512 to get a block */
442 for (sb = 512; sb < bsize; sb = sb << 1)
443 block->s2b_shift++;
444 rc = mdsk_init_io(device, block->bp_block, 0, NULL);
445 if (rc && (rc != 4)) {
446 pr_warning("%s: DIAG initialization failed with rc=%d\n",
447 dev_name(&device->cdev->dev), rc);
448 rc = -EIO;
449 } else {
450 if (rc == 4)
451 set_bit(DASD_FLAG_DEVICE_RO, &device->flags);
452 pr_info("%s: New DASD with %ld byte/block, total size %ld "
453 "KB%s\n", dev_name(&device->cdev->dev),
454 (unsigned long) block->bp_block,
455 (unsigned long) (block->blocks <<
456 block->s2b_shift) >> 1,
457 (rc == 4) ? ", read-only device" : "");
458 rc = 0;
460 out_label:
461 free_page((long) label);
462 out:
463 if (rc) {
464 device->block = NULL;
465 dasd_free_block(block);
466 device->private = NULL;
467 kfree(private);
469 return rc;
472 /* Fill in virtual disk geometry for device. Return zero on success, non-zero
473 * otherwise. */
474 static int
475 dasd_diag_fill_geometry(struct dasd_block *block, struct hd_geometry *geo)
477 if (dasd_check_blocksize(block->bp_block) != 0)
478 return -EINVAL;
479 geo->cylinders = (block->blocks << block->s2b_shift) >> 10;
480 geo->heads = 16;
481 geo->sectors = 128 >> block->s2b_shift;
482 return 0;
485 static dasd_erp_fn_t
486 dasd_diag_erp_action(struct dasd_ccw_req * cqr)
488 return dasd_default_erp_action;
491 static dasd_erp_fn_t
492 dasd_diag_erp_postaction(struct dasd_ccw_req * cqr)
494 return dasd_default_erp_postaction;
497 /* Create DASD request from block device request. Return pointer to new
498 * request on success, ERR_PTR otherwise. */
499 static struct dasd_ccw_req *dasd_diag_build_cp(struct dasd_device *memdev,
500 struct dasd_block *block,
501 struct request *req)
503 struct dasd_ccw_req *cqr;
504 struct dasd_diag_req *dreq;
505 struct dasd_diag_bio *dbio;
506 struct req_iterator iter;
507 struct bio_vec bv;
508 char *dst;
509 unsigned int count, datasize;
510 sector_t recid, first_rec, last_rec;
511 unsigned int blksize, off;
512 unsigned char rw_cmd;
514 if (rq_data_dir(req) == READ)
515 rw_cmd = MDSK_READ_REQ;
516 else if (rq_data_dir(req) == WRITE)
517 rw_cmd = MDSK_WRITE_REQ;
518 else
519 return ERR_PTR(-EINVAL);
520 blksize = block->bp_block;
521 /* Calculate record id of first and last block. */
522 first_rec = blk_rq_pos(req) >> block->s2b_shift;
523 last_rec =
524 (blk_rq_pos(req) + blk_rq_sectors(req) - 1) >> block->s2b_shift;
525 /* Check struct bio and count the number of blocks for the request. */
526 count = 0;
527 rq_for_each_segment(bv, req, iter) {
528 if (bv.bv_len & (blksize - 1))
529 /* Fba can only do full blocks. */
530 return ERR_PTR(-EINVAL);
531 count += bv.bv_len >> (block->s2b_shift + 9);
533 /* Paranoia. */
534 if (count != last_rec - first_rec + 1)
535 return ERR_PTR(-EINVAL);
536 /* Build the request */
537 datasize = sizeof(struct dasd_diag_req) +
538 count*sizeof(struct dasd_diag_bio);
539 cqr = dasd_smalloc_request(DASD_DIAG_MAGIC, 0, datasize, memdev);
540 if (IS_ERR(cqr))
541 return cqr;
543 dreq = (struct dasd_diag_req *) cqr->data;
544 dreq->block_count = count;
545 dbio = dreq->bio;
546 recid = first_rec;
547 rq_for_each_segment(bv, req, iter) {
548 dst = page_address(bv.bv_page) + bv.bv_offset;
549 for (off = 0; off < bv.bv_len; off += blksize) {
550 memset(dbio, 0, sizeof (struct dasd_diag_bio));
551 dbio->type = rw_cmd;
552 dbio->block_number = recid + 1;
553 dbio->buffer = dst;
554 dbio++;
555 dst += blksize;
556 recid++;
559 cqr->retries = memdev->default_retries;
560 cqr->buildclk = get_tod_clock();
561 if (blk_noretry_request(req) ||
562 block->base->features & DASD_FEATURE_FAILFAST)
563 set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
564 cqr->startdev = memdev;
565 cqr->memdev = memdev;
566 cqr->block = block;
567 cqr->expires = memdev->default_expires * HZ;
568 cqr->status = DASD_CQR_FILLED;
569 return cqr;
572 /* Release DASD request. Return non-zero if request was successful, zero
573 * otherwise. */
574 static int
575 dasd_diag_free_cp(struct dasd_ccw_req *cqr, struct request *req)
577 int status;
579 status = cqr->status == DASD_CQR_DONE;
580 dasd_sfree_request(cqr, cqr->memdev);
581 return status;
584 static void dasd_diag_handle_terminated_request(struct dasd_ccw_req *cqr)
586 if (cqr->retries < 0)
587 cqr->status = DASD_CQR_FAILED;
588 else
589 cqr->status = DASD_CQR_FILLED;
592 /* Fill in IOCTL data for device. */
593 static int
594 dasd_diag_fill_info(struct dasd_device * device,
595 struct dasd_information2_t * info)
597 struct dasd_diag_private *private;
599 private = (struct dasd_diag_private *) device->private;
600 info->label_block = (unsigned int) private->pt_block;
601 info->FBA_layout = 1;
602 info->format = DASD_FORMAT_LDL;
603 info->characteristics_size = sizeof (struct dasd_diag_characteristics);
604 memcpy(info->characteristics,
605 &((struct dasd_diag_private *) device->private)->rdc_data,
606 sizeof (struct dasd_diag_characteristics));
607 info->confdata_size = 0;
608 return 0;
611 static void
612 dasd_diag_dump_sense(struct dasd_device *device, struct dasd_ccw_req * req,
613 struct irb *stat)
615 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
616 "dump sense not available for DIAG data");
619 static struct dasd_discipline dasd_diag_discipline = {
620 .owner = THIS_MODULE,
621 .name = "DIAG",
622 .ebcname = "DIAG",
623 .max_blocks = DIAG_MAX_BLOCKS,
624 .check_device = dasd_diag_check_device,
625 .verify_path = dasd_generic_verify_path,
626 .fill_geometry = dasd_diag_fill_geometry,
627 .start_IO = dasd_start_diag,
628 .term_IO = dasd_diag_term_IO,
629 .handle_terminated_request = dasd_diag_handle_terminated_request,
630 .erp_action = dasd_diag_erp_action,
631 .erp_postaction = dasd_diag_erp_postaction,
632 .build_cp = dasd_diag_build_cp,
633 .free_cp = dasd_diag_free_cp,
634 .dump_sense = dasd_diag_dump_sense,
635 .fill_info = dasd_diag_fill_info,
638 static int __init
639 dasd_diag_init(void)
641 if (!MACHINE_IS_VM) {
642 pr_info("Discipline %s cannot be used without z/VM\n",
643 dasd_diag_discipline.name);
644 return -ENODEV;
646 ASCEBC(dasd_diag_discipline.ebcname, 4);
648 irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL);
649 register_external_irq(EXT_IRQ_CP_SERVICE, dasd_ext_handler);
650 dasd_diag_discipline_pointer = &dasd_diag_discipline;
651 return 0;
654 static void __exit
655 dasd_diag_cleanup(void)
657 unregister_external_irq(EXT_IRQ_CP_SERVICE, dasd_ext_handler);
658 irq_subclass_unregister(IRQ_SUBCLASS_SERVICE_SIGNAL);
659 dasd_diag_discipline_pointer = NULL;
662 module_init(dasd_diag_init);
663 module_exit(dasd_diag_cleanup);