Introduce rq_for_each_segment replacing rq_for_each_bio
[linux-2.6.git] / drivers / s390 / block / dasd_diag.c
1 /*
2  * File...........: linux/drivers/s390/block/dasd_diag.c
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  * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000
8  *
9  */
10
11 #include <linux/stddef.h>
12 #include <linux/kernel.h>
13 #include <linux/slab.h>
14 #include <linux/hdreg.h>
15 #include <linux/bio.h>
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/jiffies.h>
19
20 #include <asm/dasd.h>
21 #include <asm/debug.h>
22 #include <asm/ebcdic.h>
23 #include <asm/io.h>
24 #include <asm/s390_ext.h>
25 #include <asm/todclk.h>
26 #include <asm/vtoc.h>
27 #include <asm/diag.h>
28
29 #include "dasd_int.h"
30 #include "dasd_diag.h"
31
32 #define PRINTK_HEADER "dasd(diag):"
33
34 MODULE_LICENSE("GPL");
35
36 /* The maximum number of blocks per request (max_blocks) is dependent on the
37  * amount of storage that is available in the static I/O buffer for each
38  * device. Currently each device gets 2 pages. We want to fit two requests
39  * into the available memory so that we can immediately start the next if one
40  * finishes. */
41 #define DIAG_MAX_BLOCKS (((2 * PAGE_SIZE - sizeof(struct dasd_ccw_req) - \
42                            sizeof(struct dasd_diag_req)) / \
43                            sizeof(struct dasd_diag_bio)) / 2)
44 #define DIAG_MAX_RETRIES        32
45 #define DIAG_TIMEOUT            50 * HZ
46
47 static struct dasd_discipline dasd_diag_discipline;
48
49 struct dasd_diag_private {
50         struct dasd_diag_characteristics rdc_data;
51         struct dasd_diag_rw_io iob;
52         struct dasd_diag_init_io iib;
53         blocknum_t pt_block;
54         struct ccw_dev_id dev_id;
55 };
56
57 struct dasd_diag_req {
58         unsigned int block_count;
59         struct dasd_diag_bio bio[0];
60 };
61
62 static const u8 DASD_DIAG_CMS1[] = { 0xc3, 0xd4, 0xe2, 0xf1 };/* EBCDIC CMS1 */
63
64 /* Perform DIAG250 call with block I/O parameter list iob (input and output)
65  * and function code cmd.
66  * In case of an exception return 3. Otherwise return result of bitwise OR of
67  * resulting condition code and DIAG return code. */
68 static inline int dia250(void *iob, int cmd)
69 {
70         register unsigned long reg2 asm ("2") = (unsigned long) iob;
71         typedef union {
72                 struct dasd_diag_init_io init_io;
73                 struct dasd_diag_rw_io rw_io;
74         } addr_type;
75         int rc;
76
77         rc = 3;
78         asm volatile(
79                 "       diag    2,%2,0x250\n"
80                 "0:     ipm     %0\n"
81                 "       srl     %0,28\n"
82                 "       or      %0,3\n"
83                 "1:\n"
84                 EX_TABLE(0b,1b)
85                 : "+d" (rc), "=m" (*(addr_type *) iob)
86                 : "d" (cmd), "d" (reg2), "m" (*(addr_type *) iob)
87                 : "3", "cc");
88         return rc;
89 }
90
91 /* Initialize block I/O to DIAG device using the specified blocksize and
92  * block offset. On success, return zero and set end_block to contain the
93  * number of blocks on the device minus the specified offset. Return non-zero
94  * otherwise. */
95 static inline int
96 mdsk_init_io(struct dasd_device *device, unsigned int blocksize,
97              blocknum_t offset, blocknum_t *end_block)
98 {
99         struct dasd_diag_private *private;
100         struct dasd_diag_init_io *iib;
101         int rc;
102
103         private = (struct dasd_diag_private *) device->private;
104         iib = &private->iib;
105         memset(iib, 0, sizeof (struct dasd_diag_init_io));
106
107         iib->dev_nr = private->dev_id.devno;
108         iib->block_size = blocksize;
109         iib->offset = offset;
110         iib->flaga = DASD_DIAG_FLAGA_DEFAULT;
111
112         rc = dia250(iib, INIT_BIO);
113
114         if ((rc & 3) == 0 && end_block)
115                 *end_block = iib->end_block;
116
117         return rc;
118 }
119
120 /* Remove block I/O environment for device. Return zero on success, non-zero
121  * otherwise. */
122 static inline int
123 mdsk_term_io(struct dasd_device * device)
124 {
125         struct dasd_diag_private *private;
126         struct dasd_diag_init_io *iib;
127         int rc;
128
129         private = (struct dasd_diag_private *) device->private;
130         iib = &private->iib;
131         memset(iib, 0, sizeof (struct dasd_diag_init_io));
132         iib->dev_nr = private->dev_id.devno;
133         rc = dia250(iib, TERM_BIO);
134         return rc;
135 }
136
137 /* Error recovery for failed DIAG requests - try to reestablish the DIAG
138  * environment. */
139 static void
140 dasd_diag_erp(struct dasd_device *device)
141 {
142         int rc;
143
144         mdsk_term_io(device);
145         rc = mdsk_init_io(device, device->bp_block, 0, NULL);
146         if (rc)
147                 DEV_MESSAGE(KERN_WARNING, device, "DIAG ERP unsuccessful, "
148                             "rc=%d", rc);
149 }
150
151 /* Start a given request at the device. Return zero on success, non-zero
152  * otherwise. */
153 static int
154 dasd_start_diag(struct dasd_ccw_req * cqr)
155 {
156         struct dasd_device *device;
157         struct dasd_diag_private *private;
158         struct dasd_diag_req *dreq;
159         int rc;
160
161         device = cqr->device;
162         if (cqr->retries < 0) {
163                 DEV_MESSAGE(KERN_WARNING, device, "DIAG start_IO: request %p "
164                             "- no retry left)", cqr);
165                 cqr->status = DASD_CQR_FAILED;
166                 return -EIO;
167         }
168         private = (struct dasd_diag_private *) device->private;
169         dreq = (struct dasd_diag_req *) cqr->data;
170
171         private->iob.dev_nr = private->dev_id.devno;
172         private->iob.key = 0;
173         private->iob.flags = DASD_DIAG_RWFLAG_ASYNC;
174         private->iob.block_count = dreq->block_count;
175         private->iob.interrupt_params = (addr_t) cqr;
176         private->iob.bio_list = dreq->bio;
177         private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;
178
179         cqr->startclk = get_clock();
180         cqr->starttime = jiffies;
181         cqr->retries--;
182
183         rc = dia250(&private->iob, RW_BIO);
184         switch (rc) {
185         case 0: /* Synchronous I/O finished successfully */
186                 cqr->stopclk = get_clock();
187                 cqr->status = DASD_CQR_DONE;
188                 /* Indicate to calling function that only a dasd_schedule_bh()
189                    and no timer is needed */
190                 rc = -EACCES;
191                 break;
192         case 8: /* Asynchronous I/O was started */
193                 cqr->status = DASD_CQR_IN_IO;
194                 rc = 0;
195                 break;
196         default: /* Error condition */
197                 cqr->status = DASD_CQR_QUEUED;
198                 DEV_MESSAGE(KERN_WARNING, device, "dia250 returned rc=%d", rc);
199                 dasd_diag_erp(device);
200                 rc = -EIO;
201                 break;
202         }
203         return rc;
204 }
205
206 /* Terminate given request at the device. */
207 static int
208 dasd_diag_term_IO(struct dasd_ccw_req * cqr)
209 {
210         struct dasd_device *device;
211
212         device = cqr->device;
213         mdsk_term_io(device);
214         mdsk_init_io(device, device->bp_block, 0, NULL);
215         cqr->status = DASD_CQR_CLEAR;
216         cqr->stopclk = get_clock();
217         dasd_schedule_bh(device);
218         return 0;
219 }
220
221 /* Handle external interruption. */
222 static void
223 dasd_ext_handler(__u16 code)
224 {
225         struct dasd_ccw_req *cqr, *next;
226         struct dasd_device *device;
227         unsigned long long expires;
228         unsigned long flags;
229         u8 int_code, status;
230         addr_t ip;
231         int rc;
232
233         int_code = *((u8 *) DASD_DIAG_LC_INT_CODE);
234         status = *((u8 *) DASD_DIAG_LC_INT_STATUS);
235         switch (int_code) {
236         case DASD_DIAG_CODE_31BIT:
237                 ip = (addr_t) *((u32 *) DASD_DIAG_LC_INT_PARM_31BIT);
238                 break;
239         case DASD_DIAG_CODE_64BIT:
240                 ip = (addr_t) *((u64 *) DASD_DIAG_LC_INT_PARM_64BIT);
241                 break;
242         default:
243                 return;
244         }
245         if (!ip) {              /* no intparm: unsolicited interrupt */
246                 MESSAGE(KERN_DEBUG, "%s", "caught unsolicited interrupt");
247                 return;
248         }
249         cqr = (struct dasd_ccw_req *) ip;
250         device = (struct dasd_device *) cqr->device;
251         if (strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
252                 DEV_MESSAGE(KERN_WARNING, device,
253                             " magic number of dasd_ccw_req 0x%08X doesn't"
254                             " match discipline 0x%08X",
255                             cqr->magic, *(int *) (&device->discipline->name));
256                 return;
257         }
258
259         /* get irq lock to modify request queue */
260         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
261
262         /* Check for a pending clear operation */
263         if (cqr->status == DASD_CQR_CLEAR) {
264                 cqr->status = DASD_CQR_QUEUED;
265                 dasd_clear_timer(device);
266                 dasd_schedule_bh(device);
267                 spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
268                 return;
269         }
270
271         cqr->stopclk = get_clock();
272
273         expires = 0;
274         if (status == 0) {
275                 cqr->status = DASD_CQR_DONE;
276                 /* Start first request on queue if possible -> fast_io. */
277                 if (!list_empty(&device->ccw_queue)) {
278                         next = list_entry(device->ccw_queue.next,
279                                           struct dasd_ccw_req, list);
280                         if (next->status == DASD_CQR_QUEUED) {
281                                 rc = dasd_start_diag(next);
282                                 if (rc == 0)
283                                         expires = next->expires;
284                                 else if (rc != -EACCES)
285                                         DEV_MESSAGE(KERN_WARNING, device, "%s",
286                                                     "Interrupt fastpath "
287                                                     "failed!");
288                         }
289                 }
290         } else {
291                 cqr->status = DASD_CQR_QUEUED;
292                 DEV_MESSAGE(KERN_WARNING, device, "interrupt status for "
293                             "request %p was %d (%d retries left)", cqr, status,
294                             cqr->retries);
295                 dasd_diag_erp(device);
296         }
297
298         if (expires != 0)
299                 dasd_set_timer(device, expires);
300         else
301                 dasd_clear_timer(device);
302         dasd_schedule_bh(device);
303
304         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
305 }
306
307 /* Check whether device can be controlled by DIAG discipline. Return zero on
308  * success, non-zero otherwise. */
309 static int
310 dasd_diag_check_device(struct dasd_device *device)
311 {
312         struct dasd_diag_private *private;
313         struct dasd_diag_characteristics *rdc_data;
314         struct dasd_diag_bio bio;
315         struct vtoc_cms_label *label;
316         blocknum_t end_block;
317         unsigned int sb, bsize;
318         int rc;
319
320         private = (struct dasd_diag_private *) device->private;
321         if (private == NULL) {
322                 private = kzalloc(sizeof(struct dasd_diag_private),GFP_KERNEL);
323                 if (private == NULL) {
324                         DEV_MESSAGE(KERN_WARNING, device, "%s",
325                                 "memory allocation failed for private data");
326                         return -ENOMEM;
327                 }
328                 ccw_device_get_id(device->cdev, &private->dev_id);
329                 device->private = (void *) private;
330         }
331         /* Read Device Characteristics */
332         rdc_data = (void *) &(private->rdc_data);
333         rdc_data->dev_nr = private->dev_id.devno;
334         rdc_data->rdc_len = sizeof (struct dasd_diag_characteristics);
335
336         rc = diag210((struct diag210 *) rdc_data);
337         if (rc) {
338                 DEV_MESSAGE(KERN_WARNING, device, "failed to retrieve device "
339                             "information (rc=%d)", rc);
340                 return -ENOTSUPP;
341         }
342
343         /* Figure out position of label block */
344         switch (private->rdc_data.vdev_class) {
345         case DEV_CLASS_FBA:
346                 private->pt_block = 1;
347                 break;
348         case DEV_CLASS_ECKD:
349                 private->pt_block = 2;
350                 break;
351         default:
352                 DEV_MESSAGE(KERN_WARNING, device, "unsupported device class "
353                             "(class=%d)", private->rdc_data.vdev_class);
354                 return -ENOTSUPP;
355         }
356
357         DBF_DEV_EVENT(DBF_INFO, device,
358                       "%04X: %04X on real %04X/%02X",
359                       rdc_data->dev_nr,
360                       rdc_data->vdev_type,
361                       rdc_data->rdev_type, rdc_data->rdev_model);
362
363         /* terminate all outstanding operations */
364         mdsk_term_io(device);
365
366         /* figure out blocksize of device */
367         label = (struct vtoc_cms_label *) get_zeroed_page(GFP_KERNEL);
368         if (label == NULL)  {
369                 DEV_MESSAGE(KERN_WARNING, device, "%s",
370                             "No memory to allocate initialization request");
371                 return -ENOMEM;
372         }
373         rc = 0;
374         end_block = 0;
375         /* try all sizes - needed for ECKD devices */
376         for (bsize = 512; bsize <= PAGE_SIZE; bsize <<= 1) {
377                 mdsk_init_io(device, bsize, 0, &end_block);
378                 memset(&bio, 0, sizeof (struct dasd_diag_bio));
379                 bio.type = MDSK_READ_REQ;
380                 bio.block_number = private->pt_block + 1;
381                 bio.buffer = label;
382                 memset(&private->iob, 0, sizeof (struct dasd_diag_rw_io));
383                 private->iob.dev_nr = rdc_data->dev_nr;
384                 private->iob.key = 0;
385                 private->iob.flags = 0; /* do synchronous io */
386                 private->iob.block_count = 1;
387                 private->iob.interrupt_params = 0;
388                 private->iob.bio_list = &bio;
389                 private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;
390                 rc = dia250(&private->iob, RW_BIO);
391                 if (rc == 3) {
392                         DEV_MESSAGE(KERN_WARNING, device, "%s",
393                                 "DIAG call failed");
394                         rc = -EOPNOTSUPP;
395                         goto out;
396                 }
397                 mdsk_term_io(device);
398                 if (rc == 0)
399                         break;
400         }
401         if (bsize > PAGE_SIZE) {
402                 DEV_MESSAGE(KERN_WARNING, device, "device access failed "
403                             "(rc=%d)", rc);
404                 rc = -EIO;
405                 goto out;
406         }
407         /* check for label block */
408         if (memcmp(label->label_id, DASD_DIAG_CMS1,
409                   sizeof(DASD_DIAG_CMS1)) == 0) {
410                 /* get formatted blocksize from label block */
411                 bsize = (unsigned int) label->block_size;
412                 device->blocks = (unsigned long) label->block_count;
413         } else
414                 device->blocks = end_block;
415         device->bp_block = bsize;
416         device->s2b_shift = 0;  /* bits to shift 512 to get a block */
417         for (sb = 512; sb < bsize; sb = sb << 1)
418                 device->s2b_shift++;
419         rc = mdsk_init_io(device, device->bp_block, 0, NULL);
420         if (rc) {
421                 DEV_MESSAGE(KERN_WARNING, device, "DIAG initialization "
422                         "failed (rc=%d)", rc);
423                 rc = -EIO;
424         } else {
425                 DEV_MESSAGE(KERN_INFO, device,
426                             "(%ld B/blk): %ldkB",
427                             (unsigned long) device->bp_block,
428                             (unsigned long) (device->blocks <<
429                                 device->s2b_shift) >> 1);
430         }
431 out:
432         free_page((long) label);
433         return rc;
434 }
435
436 /* Fill in virtual disk geometry for device. Return zero on success, non-zero
437  * otherwise. */
438 static int
439 dasd_diag_fill_geometry(struct dasd_device *device, struct hd_geometry *geo)
440 {
441         if (dasd_check_blocksize(device->bp_block) != 0)
442                 return -EINVAL;
443         geo->cylinders = (device->blocks << device->s2b_shift) >> 10;
444         geo->heads = 16;
445         geo->sectors = 128 >> device->s2b_shift;
446         return 0;
447 }
448
449 static dasd_era_t
450 dasd_diag_examine_error(struct dasd_ccw_req * cqr, struct irb * stat)
451 {
452         return dasd_era_fatal;
453 }
454
455 static dasd_erp_fn_t
456 dasd_diag_erp_action(struct dasd_ccw_req * cqr)
457 {
458         return dasd_default_erp_action;
459 }
460
461 static dasd_erp_fn_t
462 dasd_diag_erp_postaction(struct dasd_ccw_req * cqr)
463 {
464         return dasd_default_erp_postaction;
465 }
466
467 /* Create DASD request from block device request. Return pointer to new
468  * request on success, ERR_PTR otherwise. */
469 static struct dasd_ccw_req *
470 dasd_diag_build_cp(struct dasd_device * device, struct request *req)
471 {
472         struct dasd_ccw_req *cqr;
473         struct dasd_diag_req *dreq;
474         struct dasd_diag_bio *dbio;
475         struct req_iterator iter;
476         struct bio_vec *bv;
477         char *dst;
478         unsigned int count, datasize;
479         sector_t recid, first_rec, last_rec;
480         unsigned int blksize, off;
481         unsigned char rw_cmd;
482
483         if (rq_data_dir(req) == READ)
484                 rw_cmd = MDSK_READ_REQ;
485         else if (rq_data_dir(req) == WRITE)
486                 rw_cmd = MDSK_WRITE_REQ;
487         else
488                 return ERR_PTR(-EINVAL);
489         blksize = device->bp_block;
490         /* Calculate record id of first and last block. */
491         first_rec = req->sector >> device->s2b_shift;
492         last_rec = (req->sector + req->nr_sectors - 1) >> device->s2b_shift;
493         /* Check struct bio and count the number of blocks for the request. */
494         count = 0;
495         rq_for_each_segment(bv, req, iter) {
496                         if (bv->bv_len & (blksize - 1))
497                                 /* Fba can only do full blocks. */
498                                 return ERR_PTR(-EINVAL);
499                         count += bv->bv_len >> (device->s2b_shift + 9);
500         }
501         /* Paranoia. */
502         if (count != last_rec - first_rec + 1)
503                 return ERR_PTR(-EINVAL);
504         /* Build the request */
505         datasize = sizeof(struct dasd_diag_req) +
506                 count*sizeof(struct dasd_diag_bio);
507         cqr = dasd_smalloc_request(dasd_diag_discipline.name, 0,
508                                    datasize, device);
509         if (IS_ERR(cqr))
510                 return cqr;
511
512         dreq = (struct dasd_diag_req *) cqr->data;
513         dreq->block_count = count;
514         dbio = dreq->bio;
515         recid = first_rec;
516         rq_for_each_segment(bv, req, iter) {
517                         dst = page_address(bv->bv_page) + bv->bv_offset;
518                         for (off = 0; off < bv->bv_len; off += blksize) {
519                                 memset(dbio, 0, sizeof (struct dasd_diag_bio));
520                                 dbio->type = rw_cmd;
521                                 dbio->block_number = recid + 1;
522                                 dbio->buffer = dst;
523                                 dbio++;
524                                 dst += blksize;
525                                 recid++;
526                         }
527         }
528         cqr->retries = DIAG_MAX_RETRIES;
529         cqr->buildclk = get_clock();
530         if (req->cmd_flags & REQ_FAILFAST)
531                 set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
532         cqr->device = device;
533         cqr->expires = DIAG_TIMEOUT;
534         cqr->status = DASD_CQR_FILLED;
535         return cqr;
536 }
537
538 /* Release DASD request. Return non-zero if request was successful, zero
539  * otherwise. */
540 static int
541 dasd_diag_free_cp(struct dasd_ccw_req *cqr, struct request *req)
542 {
543         int status;
544
545         status = cqr->status == DASD_CQR_DONE;
546         dasd_sfree_request(cqr, cqr->device);
547         return status;
548 }
549
550 /* Fill in IOCTL data for device. */
551 static int
552 dasd_diag_fill_info(struct dasd_device * device,
553                     struct dasd_information2_t * info)
554 {
555         struct dasd_diag_private *private;
556
557         private = (struct dasd_diag_private *) device->private;
558         info->label_block = (unsigned int) private->pt_block;
559         info->FBA_layout = 1;
560         info->format = DASD_FORMAT_LDL;
561         info->characteristics_size = sizeof (struct dasd_diag_characteristics);
562         memcpy(info->characteristics,
563                &((struct dasd_diag_private *) device->private)->rdc_data,
564                sizeof (struct dasd_diag_characteristics));
565         info->confdata_size = 0;
566         return 0;
567 }
568
569 static void
570 dasd_diag_dump_sense(struct dasd_device *device, struct dasd_ccw_req * req,
571                      struct irb *stat)
572 {
573         DEV_MESSAGE(KERN_ERR, device, "%s",
574                     "dump sense not available for DIAG data");
575 }
576
577 static struct dasd_discipline dasd_diag_discipline = {
578         .owner = THIS_MODULE,
579         .name = "DIAG",
580         .ebcname = "DIAG",
581         .max_blocks = DIAG_MAX_BLOCKS,
582         .check_device = dasd_diag_check_device,
583         .fill_geometry = dasd_diag_fill_geometry,
584         .start_IO = dasd_start_diag,
585         .term_IO = dasd_diag_term_IO,
586         .examine_error = dasd_diag_examine_error,
587         .erp_action = dasd_diag_erp_action,
588         .erp_postaction = dasd_diag_erp_postaction,
589         .build_cp = dasd_diag_build_cp,
590         .free_cp = dasd_diag_free_cp,
591         .dump_sense = dasd_diag_dump_sense,
592         .fill_info = dasd_diag_fill_info,
593 };
594
595 static int __init
596 dasd_diag_init(void)
597 {
598         if (!MACHINE_IS_VM) {
599                 MESSAGE_LOG(KERN_INFO,
600                             "Machine is not VM: %s "
601                             "discipline not initializing",
602                             dasd_diag_discipline.name);
603                 return -ENODEV;
604         }
605         ASCEBC(dasd_diag_discipline.ebcname, 4);
606
607         ctl_set_bit(0, 9);
608         register_external_interrupt(0x2603, dasd_ext_handler);
609         dasd_diag_discipline_pointer = &dasd_diag_discipline;
610         return 0;
611 }
612
613 static void __exit
614 dasd_diag_cleanup(void)
615 {
616         unregister_external_interrupt(0x2603, dasd_ext_handler);
617         ctl_clear_bit(0, 9);
618         dasd_diag_discipline_pointer = NULL;
619 }
620
621 module_init(dasd_diag_init);
622 module_exit(dasd_diag_cleanup);