Merge branch 'for-linus' of git://git.infradead.org/~dedekind/ubi-2.6
[linux-2.6] / 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->block->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->startdev;
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_ERROR;
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_SUCCESS;
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->startdev;
213         mdsk_term_io(device);
214         mdsk_init_io(device, device->block->bp_block, 0, NULL);
215         cqr->status = DASD_CQR_CLEAR_PENDING;
216         cqr->stopclk = get_clock();
217         dasd_schedule_device_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->startdev;
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_PENDING) {
264                 cqr->status = DASD_CQR_CLEARED;
265                 dasd_device_clear_timer(device);
266                 dasd_schedule_device_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_SUCCESS;
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, devlist);
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_device_set_timer(device, expires);
300         else
301                 dasd_device_clear_timer(device);
302         dasd_schedule_device_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_block *block;
313         struct dasd_diag_private *private;
314         struct dasd_diag_characteristics *rdc_data;
315         struct dasd_diag_bio bio;
316         struct vtoc_cms_label *label;
317         blocknum_t end_block;
318         unsigned int sb, bsize;
319         int rc;
320
321         private = (struct dasd_diag_private *) device->private;
322         if (private == NULL) {
323                 private = kzalloc(sizeof(struct dasd_diag_private),GFP_KERNEL);
324                 if (private == NULL) {
325                         DEV_MESSAGE(KERN_WARNING, device, "%s",
326                                 "memory allocation failed for private data");
327                         return -ENOMEM;
328                 }
329                 ccw_device_get_id(device->cdev, &private->dev_id);
330                 device->private = (void *) private;
331         }
332         block = dasd_alloc_block();
333         if (IS_ERR(block)) {
334                 DEV_MESSAGE(KERN_WARNING, device, "%s",
335                             "could not allocate dasd block structure");
336                 kfree(device->private);
337                 return PTR_ERR(block);
338         }
339         device->block = block;
340         block->base = device;
341
342         /* Read Device Characteristics */
343         rdc_data = (void *) &(private->rdc_data);
344         rdc_data->dev_nr = private->dev_id.devno;
345         rdc_data->rdc_len = sizeof (struct dasd_diag_characteristics);
346
347         rc = diag210((struct diag210 *) rdc_data);
348         if (rc) {
349                 DEV_MESSAGE(KERN_WARNING, device, "failed to retrieve device "
350                             "information (rc=%d)", rc);
351                 return -ENOTSUPP;
352         }
353
354         /* Figure out position of label block */
355         switch (private->rdc_data.vdev_class) {
356         case DEV_CLASS_FBA:
357                 private->pt_block = 1;
358                 break;
359         case DEV_CLASS_ECKD:
360                 private->pt_block = 2;
361                 break;
362         default:
363                 DEV_MESSAGE(KERN_WARNING, device, "unsupported device class "
364                             "(class=%d)", private->rdc_data.vdev_class);
365                 return -ENOTSUPP;
366         }
367
368         DBF_DEV_EVENT(DBF_INFO, device,
369                       "%04X: %04X on real %04X/%02X",
370                       rdc_data->dev_nr,
371                       rdc_data->vdev_type,
372                       rdc_data->rdev_type, rdc_data->rdev_model);
373
374         /* terminate all outstanding operations */
375         mdsk_term_io(device);
376
377         /* figure out blocksize of device */
378         label = (struct vtoc_cms_label *) get_zeroed_page(GFP_KERNEL);
379         if (label == NULL)  {
380                 DEV_MESSAGE(KERN_WARNING, device, "%s",
381                             "No memory to allocate initialization request");
382                 return -ENOMEM;
383         }
384         rc = 0;
385         end_block = 0;
386         /* try all sizes - needed for ECKD devices */
387         for (bsize = 512; bsize <= PAGE_SIZE; bsize <<= 1) {
388                 mdsk_init_io(device, bsize, 0, &end_block);
389                 memset(&bio, 0, sizeof (struct dasd_diag_bio));
390                 bio.type = MDSK_READ_REQ;
391                 bio.block_number = private->pt_block + 1;
392                 bio.buffer = label;
393                 memset(&private->iob, 0, sizeof (struct dasd_diag_rw_io));
394                 private->iob.dev_nr = rdc_data->dev_nr;
395                 private->iob.key = 0;
396                 private->iob.flags = 0; /* do synchronous io */
397                 private->iob.block_count = 1;
398                 private->iob.interrupt_params = 0;
399                 private->iob.bio_list = &bio;
400                 private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;
401                 rc = dia250(&private->iob, RW_BIO);
402                 if (rc == 3) {
403                         DEV_MESSAGE(KERN_WARNING, device, "%s",
404                                 "DIAG call failed");
405                         rc = -EOPNOTSUPP;
406                         goto out;
407                 }
408                 mdsk_term_io(device);
409                 if (rc == 0)
410                         break;
411         }
412         if (bsize > PAGE_SIZE) {
413                 DEV_MESSAGE(KERN_WARNING, device, "device access failed "
414                             "(rc=%d)", rc);
415                 rc = -EIO;
416                 goto out;
417         }
418         /* check for label block */
419         if (memcmp(label->label_id, DASD_DIAG_CMS1,
420                   sizeof(DASD_DIAG_CMS1)) == 0) {
421                 /* get formatted blocksize from label block */
422                 bsize = (unsigned int) label->block_size;
423                 block->blocks = (unsigned long) label->block_count;
424         } else
425                 block->blocks = end_block;
426         block->bp_block = bsize;
427         block->s2b_shift = 0;   /* bits to shift 512 to get a block */
428         for (sb = 512; sb < bsize; sb = sb << 1)
429                 block->s2b_shift++;
430         rc = mdsk_init_io(device, block->bp_block, 0, NULL);
431         if (rc) {
432                 DEV_MESSAGE(KERN_WARNING, device, "DIAG initialization "
433                         "failed (rc=%d)", rc);
434                 rc = -EIO;
435         } else {
436                 DEV_MESSAGE(KERN_INFO, device,
437                             "(%ld B/blk): %ldkB",
438                             (unsigned long) block->bp_block,
439                             (unsigned long) (block->blocks <<
440                                 block->s2b_shift) >> 1);
441         }
442 out:
443         free_page((long) label);
444         return rc;
445 }
446
447 /* Fill in virtual disk geometry for device. Return zero on success, non-zero
448  * otherwise. */
449 static int
450 dasd_diag_fill_geometry(struct dasd_block *block, struct hd_geometry *geo)
451 {
452         if (dasd_check_blocksize(block->bp_block) != 0)
453                 return -EINVAL;
454         geo->cylinders = (block->blocks << block->s2b_shift) >> 10;
455         geo->heads = 16;
456         geo->sectors = 128 >> block->s2b_shift;
457         return 0;
458 }
459
460 static dasd_erp_fn_t
461 dasd_diag_erp_action(struct dasd_ccw_req * cqr)
462 {
463         return dasd_default_erp_action;
464 }
465
466 static dasd_erp_fn_t
467 dasd_diag_erp_postaction(struct dasd_ccw_req * cqr)
468 {
469         return dasd_default_erp_postaction;
470 }
471
472 /* Create DASD request from block device request. Return pointer to new
473  * request on success, ERR_PTR otherwise. */
474 static struct dasd_ccw_req *dasd_diag_build_cp(struct dasd_device *memdev,
475                                                struct dasd_block *block,
476                                                struct request *req)
477 {
478         struct dasd_ccw_req *cqr;
479         struct dasd_diag_req *dreq;
480         struct dasd_diag_bio *dbio;
481         struct req_iterator iter;
482         struct bio_vec *bv;
483         char *dst;
484         unsigned int count, datasize;
485         sector_t recid, first_rec, last_rec;
486         unsigned int blksize, off;
487         unsigned char rw_cmd;
488
489         if (rq_data_dir(req) == READ)
490                 rw_cmd = MDSK_READ_REQ;
491         else if (rq_data_dir(req) == WRITE)
492                 rw_cmd = MDSK_WRITE_REQ;
493         else
494                 return ERR_PTR(-EINVAL);
495         blksize = block->bp_block;
496         /* Calculate record id of first and last block. */
497         first_rec = req->sector >> block->s2b_shift;
498         last_rec = (req->sector + req->nr_sectors - 1) >> block->s2b_shift;
499         /* Check struct bio and count the number of blocks for the request. */
500         count = 0;
501         rq_for_each_segment(bv, req, iter) {
502                 if (bv->bv_len & (blksize - 1))
503                         /* Fba can only do full blocks. */
504                         return ERR_PTR(-EINVAL);
505                 count += bv->bv_len >> (block->s2b_shift + 9);
506         }
507         /* Paranoia. */
508         if (count != last_rec - first_rec + 1)
509                 return ERR_PTR(-EINVAL);
510         /* Build the request */
511         datasize = sizeof(struct dasd_diag_req) +
512                 count*sizeof(struct dasd_diag_bio);
513         cqr = dasd_smalloc_request(dasd_diag_discipline.name, 0,
514                                    datasize, memdev);
515         if (IS_ERR(cqr))
516                 return cqr;
517
518         dreq = (struct dasd_diag_req *) cqr->data;
519         dreq->block_count = count;
520         dbio = dreq->bio;
521         recid = first_rec;
522         rq_for_each_segment(bv, req, iter) {
523                 dst = page_address(bv->bv_page) + bv->bv_offset;
524                 for (off = 0; off < bv->bv_len; off += blksize) {
525                         memset(dbio, 0, sizeof (struct dasd_diag_bio));
526                         dbio->type = rw_cmd;
527                         dbio->block_number = recid + 1;
528                         dbio->buffer = dst;
529                         dbio++;
530                         dst += blksize;
531                         recid++;
532                 }
533         }
534         cqr->retries = DIAG_MAX_RETRIES;
535         cqr->buildclk = get_clock();
536         if (req->cmd_flags & REQ_FAILFAST)
537                 set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
538         cqr->startdev = memdev;
539         cqr->memdev = memdev;
540         cqr->block = block;
541         cqr->expires = DIAG_TIMEOUT;
542         cqr->status = DASD_CQR_FILLED;
543         return cqr;
544 }
545
546 /* Release DASD request. Return non-zero if request was successful, zero
547  * otherwise. */
548 static int
549 dasd_diag_free_cp(struct dasd_ccw_req *cqr, struct request *req)
550 {
551         int status;
552
553         status = cqr->status == DASD_CQR_DONE;
554         dasd_sfree_request(cqr, cqr->memdev);
555         return status;
556 }
557
558 static void dasd_diag_handle_terminated_request(struct dasd_ccw_req *cqr)
559 {
560         cqr->status = DASD_CQR_FILLED;
561 };
562
563 /* Fill in IOCTL data for device. */
564 static int
565 dasd_diag_fill_info(struct dasd_device * device,
566                     struct dasd_information2_t * info)
567 {
568         struct dasd_diag_private *private;
569
570         private = (struct dasd_diag_private *) device->private;
571         info->label_block = (unsigned int) private->pt_block;
572         info->FBA_layout = 1;
573         info->format = DASD_FORMAT_LDL;
574         info->characteristics_size = sizeof (struct dasd_diag_characteristics);
575         memcpy(info->characteristics,
576                &((struct dasd_diag_private *) device->private)->rdc_data,
577                sizeof (struct dasd_diag_characteristics));
578         info->confdata_size = 0;
579         return 0;
580 }
581
582 static void
583 dasd_diag_dump_sense(struct dasd_device *device, struct dasd_ccw_req * req,
584                      struct irb *stat)
585 {
586         DEV_MESSAGE(KERN_ERR, device, "%s",
587                     "dump sense not available for DIAG data");
588 }
589
590 static struct dasd_discipline dasd_diag_discipline = {
591         .owner = THIS_MODULE,
592         .name = "DIAG",
593         .ebcname = "DIAG",
594         .max_blocks = DIAG_MAX_BLOCKS,
595         .check_device = dasd_diag_check_device,
596         .fill_geometry = dasd_diag_fill_geometry,
597         .start_IO = dasd_start_diag,
598         .term_IO = dasd_diag_term_IO,
599         .handle_terminated_request = dasd_diag_handle_terminated_request,
600         .erp_action = dasd_diag_erp_action,
601         .erp_postaction = dasd_diag_erp_postaction,
602         .build_cp = dasd_diag_build_cp,
603         .free_cp = dasd_diag_free_cp,
604         .dump_sense = dasd_diag_dump_sense,
605         .fill_info = dasd_diag_fill_info,
606 };
607
608 static int __init
609 dasd_diag_init(void)
610 {
611         if (!MACHINE_IS_VM) {
612                 MESSAGE_LOG(KERN_INFO,
613                             "Machine is not VM: %s "
614                             "discipline not initializing",
615                             dasd_diag_discipline.name);
616                 return -ENODEV;
617         }
618         ASCEBC(dasd_diag_discipline.ebcname, 4);
619
620         ctl_set_bit(0, 9);
621         register_external_interrupt(0x2603, dasd_ext_handler);
622         dasd_diag_discipline_pointer = &dasd_diag_discipline;
623         return 0;
624 }
625
626 static void __exit
627 dasd_diag_cleanup(void)
628 {
629         unregister_external_interrupt(0x2603, dasd_ext_handler);
630         ctl_clear_bit(0, 9);
631         dasd_diag_discipline_pointer = NULL;
632 }
633
634 module_init(dasd_diag_init);
635 module_exit(dasd_diag_cleanup);