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1 /*
2  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
3  * Bugreports.to..: <Linux390@de.ibm.com>
4  * Copyright IBM Corp. 1999, 2009
5  */
6 
7 #define KMSG_COMPONENT "dasd-fba"
8 
9 #include <linux/stddef.h>
10 #include <linux/kernel.h>
11 #include <asm/debug.h>
12 
13 #include <linux/slab.h>
14 #include <linux/hdreg.h>	/* HDIO_GETGEO			    */
15 #include <linux/bio.h>
16 #include <linux/module.h>
17 #include <linux/init.h>
18 
19 #include <asm/idals.h>
20 #include <asm/ebcdic.h>
21 #include <asm/io.h>
22 #include <asm/ccwdev.h>
23 
24 #include "dasd_int.h"
25 #include "dasd_fba.h"
26 
27 #ifdef PRINTK_HEADER
28 #undef PRINTK_HEADER
29 #endif				/* PRINTK_HEADER */
30 #define PRINTK_HEADER "dasd(fba):"
31 
32 #define FBA_DEFAULT_RETRIES 32
33 
34 #define DASD_FBA_CCW_WRITE 0x41
35 #define DASD_FBA_CCW_READ 0x42
36 #define DASD_FBA_CCW_LOCATE 0x43
37 #define DASD_FBA_CCW_DEFINE_EXTENT 0x63
38 
39 MODULE_LICENSE("GPL");
40 
41 static struct dasd_discipline dasd_fba_discipline;
42 
43 struct dasd_fba_private {
44 	struct dasd_fba_characteristics rdc_data;
45 };
46 
47 static struct ccw_device_id dasd_fba_ids[] = {
48 	{ CCW_DEVICE_DEVTYPE (0x6310, 0, 0x9336, 0), .driver_info = 0x1},
49 	{ CCW_DEVICE_DEVTYPE (0x3880, 0, 0x3370, 0), .driver_info = 0x2},
50 	{ /* end of list */ },
51 };
52 
53 MODULE_DEVICE_TABLE(ccw, dasd_fba_ids);
54 
55 static struct ccw_driver dasd_fba_driver; /* see below */
56 static int
dasd_fba_probe(struct ccw_device * cdev)57 dasd_fba_probe(struct ccw_device *cdev)
58 {
59 	return dasd_generic_probe(cdev, &dasd_fba_discipline);
60 }
61 
62 static int
dasd_fba_set_online(struct ccw_device * cdev)63 dasd_fba_set_online(struct ccw_device *cdev)
64 {
65 	return dasd_generic_set_online(cdev, &dasd_fba_discipline);
66 }
67 
68 static struct ccw_driver dasd_fba_driver = {
69 	.driver = {
70 		.name	= "dasd-fba",
71 		.owner	= THIS_MODULE,
72 	},
73 	.ids         = dasd_fba_ids,
74 	.probe       = dasd_fba_probe,
75 	.remove      = dasd_generic_remove,
76 	.set_offline = dasd_generic_set_offline,
77 	.set_online  = dasd_fba_set_online,
78 	.notify      = dasd_generic_notify,
79 	.path_event  = dasd_generic_path_event,
80 	.freeze      = dasd_generic_pm_freeze,
81 	.thaw	     = dasd_generic_restore_device,
82 	.restore     = dasd_generic_restore_device,
83 	.int_class   = IRQIO_DAS,
84 };
85 
86 static void
define_extent(struct ccw1 * ccw,struct DE_fba_data * data,int rw,int blksize,int beg,int nr)87 define_extent(struct ccw1 * ccw, struct DE_fba_data *data, int rw,
88 	      int blksize, int beg, int nr)
89 {
90 	ccw->cmd_code = DASD_FBA_CCW_DEFINE_EXTENT;
91 	ccw->flags = 0;
92 	ccw->count = 16;
93 	ccw->cda = (__u32) __pa(data);
94 	memset(data, 0, sizeof (struct DE_fba_data));
95 	if (rw == WRITE)
96 		(data->mask).perm = 0x0;
97 	else if (rw == READ)
98 		(data->mask).perm = 0x1;
99 	else
100 		data->mask.perm = 0x2;
101 	data->blk_size = blksize;
102 	data->ext_loc = beg;
103 	data->ext_end = nr - 1;
104 }
105 
106 static void
locate_record(struct ccw1 * ccw,struct LO_fba_data * data,int rw,int block_nr,int block_ct)107 locate_record(struct ccw1 * ccw, struct LO_fba_data *data, int rw,
108 	      int block_nr, int block_ct)
109 {
110 	ccw->cmd_code = DASD_FBA_CCW_LOCATE;
111 	ccw->flags = 0;
112 	ccw->count = 8;
113 	ccw->cda = (__u32) __pa(data);
114 	memset(data, 0, sizeof (struct LO_fba_data));
115 	if (rw == WRITE)
116 		data->operation.cmd = 0x5;
117 	else if (rw == READ)
118 		data->operation.cmd = 0x6;
119 	else
120 		data->operation.cmd = 0x8;
121 	data->blk_nr = block_nr;
122 	data->blk_ct = block_ct;
123 }
124 
125 static int
dasd_fba_check_characteristics(struct dasd_device * device)126 dasd_fba_check_characteristics(struct dasd_device *device)
127 {
128 	struct dasd_fba_private *private = device->private;
129 	struct ccw_device *cdev = device->cdev;
130 	struct dasd_block *block;
131 	int readonly, rc;
132 
133 	if (!private) {
134 		private = kzalloc(sizeof(*private), GFP_KERNEL | GFP_DMA);
135 		if (!private) {
136 			dev_warn(&device->cdev->dev,
137 				 "Allocating memory for private DASD "
138 				 "data failed\n");
139 			return -ENOMEM;
140 		}
141 		device->private = private;
142 	} else {
143 		memset(private, 0, sizeof(*private));
144 	}
145 	block = dasd_alloc_block();
146 	if (IS_ERR(block)) {
147 		DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s", "could not allocate "
148 				"dasd block structure");
149 		device->private = NULL;
150 		kfree(private);
151 		return PTR_ERR(block);
152 	}
153 	device->block = block;
154 	block->base = device;
155 
156 	/* Read Device Characteristics */
157 	rc = dasd_generic_read_dev_chars(device, DASD_FBA_MAGIC,
158 					 &private->rdc_data, 32);
159 	if (rc) {
160 		DBF_EVENT_DEVID(DBF_WARNING, cdev, "Read device "
161 				"characteristics returned error %d", rc);
162 		device->block = NULL;
163 		dasd_free_block(block);
164 		device->private = NULL;
165 		kfree(private);
166 		return rc;
167 	}
168 
169 	device->default_expires = DASD_EXPIRES;
170 	device->default_retries = FBA_DEFAULT_RETRIES;
171 	device->path_data.opm = LPM_ANYPATH;
172 
173 	readonly = dasd_device_is_ro(device);
174 	if (readonly)
175 		set_bit(DASD_FLAG_DEVICE_RO, &device->flags);
176 
177 	dev_info(&device->cdev->dev,
178 		 "New FBA DASD %04X/%02X (CU %04X/%02X) with %d MB "
179 		 "and %d B/blk%s\n",
180 		 cdev->id.dev_type,
181 		 cdev->id.dev_model,
182 		 cdev->id.cu_type,
183 		 cdev->id.cu_model,
184 		 ((private->rdc_data.blk_bdsa *
185 		   (private->rdc_data.blk_size >> 9)) >> 11),
186 		 private->rdc_data.blk_size,
187 		 readonly ? ", read-only device" : "");
188 	return 0;
189 }
190 
dasd_fba_do_analysis(struct dasd_block * block)191 static int dasd_fba_do_analysis(struct dasd_block *block)
192 {
193 	struct dasd_fba_private *private = block->base->private;
194 	int sb, rc;
195 
196 	rc = dasd_check_blocksize(private->rdc_data.blk_size);
197 	if (rc) {
198 		DBF_DEV_EVENT(DBF_WARNING, block->base, "unknown blocksize %d",
199 			    private->rdc_data.blk_size);
200 		return rc;
201 	}
202 	block->blocks = private->rdc_data.blk_bdsa;
203 	block->bp_block = private->rdc_data.blk_size;
204 	block->s2b_shift = 0;	/* bits to shift 512 to get a block */
205 	for (sb = 512; sb < private->rdc_data.blk_size; sb = sb << 1)
206 		block->s2b_shift++;
207 	return 0;
208 }
209 
dasd_fba_fill_geometry(struct dasd_block * block,struct hd_geometry * geo)210 static int dasd_fba_fill_geometry(struct dasd_block *block,
211 				  struct hd_geometry *geo)
212 {
213 	if (dasd_check_blocksize(block->bp_block) != 0)
214 		return -EINVAL;
215 	geo->cylinders = (block->blocks << block->s2b_shift) >> 10;
216 	geo->heads = 16;
217 	geo->sectors = 128 >> block->s2b_shift;
218 	return 0;
219 }
220 
221 static dasd_erp_fn_t
dasd_fba_erp_action(struct dasd_ccw_req * cqr)222 dasd_fba_erp_action(struct dasd_ccw_req * cqr)
223 {
224 	return dasd_default_erp_action;
225 }
226 
227 static dasd_erp_fn_t
dasd_fba_erp_postaction(struct dasd_ccw_req * cqr)228 dasd_fba_erp_postaction(struct dasd_ccw_req * cqr)
229 {
230 	if (cqr->function == dasd_default_erp_action)
231 		return dasd_default_erp_postaction;
232 
233 	DBF_DEV_EVENT(DBF_WARNING, cqr->startdev, "unknown ERP action %p",
234 		    cqr->function);
235 	return NULL;
236 }
237 
dasd_fba_check_for_device_change(struct dasd_device * device,struct dasd_ccw_req * cqr,struct irb * irb)238 static void dasd_fba_check_for_device_change(struct dasd_device *device,
239 					     struct dasd_ccw_req *cqr,
240 					     struct irb *irb)
241 {
242 	char mask;
243 
244 	/* first of all check for state change pending interrupt */
245 	mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
246 	if ((irb->scsw.cmd.dstat & mask) == mask)
247 		dasd_generic_handle_state_change(device);
248 };
249 
dasd_fba_build_cp(struct dasd_device * memdev,struct dasd_block * block,struct request * req)250 static struct dasd_ccw_req *dasd_fba_build_cp(struct dasd_device * memdev,
251 					      struct dasd_block *block,
252 					      struct request *req)
253 {
254 	struct dasd_fba_private *private = block->base->private;
255 	unsigned long *idaws;
256 	struct LO_fba_data *LO_data;
257 	struct dasd_ccw_req *cqr;
258 	struct ccw1 *ccw;
259 	struct req_iterator iter;
260 	struct bio_vec bv;
261 	char *dst;
262 	int count, cidaw, cplength, datasize;
263 	sector_t recid, first_rec, last_rec;
264 	unsigned int blksize, off;
265 	unsigned char cmd;
266 
267 	if (rq_data_dir(req) == READ) {
268 		cmd = DASD_FBA_CCW_READ;
269 	} else if (rq_data_dir(req) == WRITE) {
270 		cmd = DASD_FBA_CCW_WRITE;
271 	} else
272 		return ERR_PTR(-EINVAL);
273 	blksize = block->bp_block;
274 	/* Calculate record id of first and last block. */
275 	first_rec = blk_rq_pos(req) >> block->s2b_shift;
276 	last_rec =
277 		(blk_rq_pos(req) + blk_rq_sectors(req) - 1) >> block->s2b_shift;
278 	/* Check struct bio and count the number of blocks for the request. */
279 	count = 0;
280 	cidaw = 0;
281 	rq_for_each_segment(bv, req, iter) {
282 		if (bv.bv_len & (blksize - 1))
283 			/* Fba can only do full blocks. */
284 			return ERR_PTR(-EINVAL);
285 		count += bv.bv_len >> (block->s2b_shift + 9);
286 		if (idal_is_needed (page_address(bv.bv_page), bv.bv_len))
287 			cidaw += bv.bv_len / blksize;
288 	}
289 	/* Paranoia. */
290 	if (count != last_rec - first_rec + 1)
291 		return ERR_PTR(-EINVAL);
292 	/* 1x define extent + 1x locate record + number of blocks */
293 	cplength = 2 + count;
294 	/* 1x define extent + 1x locate record */
295 	datasize = sizeof(struct DE_fba_data) + sizeof(struct LO_fba_data) +
296 		cidaw * sizeof(unsigned long);
297 	/*
298 	 * Find out number of additional locate record ccws if the device
299 	 * can't do data chaining.
300 	 */
301 	if (private->rdc_data.mode.bits.data_chain == 0) {
302 		cplength += count - 1;
303 		datasize += (count - 1)*sizeof(struct LO_fba_data);
304 	}
305 	/* Allocate the ccw request. */
306 	cqr = dasd_smalloc_request(DASD_FBA_MAGIC, cplength, datasize, memdev);
307 	if (IS_ERR(cqr))
308 		return cqr;
309 	ccw = cqr->cpaddr;
310 	/* First ccw is define extent. */
311 	define_extent(ccw++, cqr->data, rq_data_dir(req),
312 		      block->bp_block, blk_rq_pos(req), blk_rq_sectors(req));
313 	/* Build locate_record + read/write ccws. */
314 	idaws = (unsigned long *) (cqr->data + sizeof(struct DE_fba_data));
315 	LO_data = (struct LO_fba_data *) (idaws + cidaw);
316 	/* Locate record for all blocks for smart devices. */
317 	if (private->rdc_data.mode.bits.data_chain != 0) {
318 		ccw[-1].flags |= CCW_FLAG_CC;
319 		locate_record(ccw++, LO_data++, rq_data_dir(req), 0, count);
320 	}
321 	recid = first_rec;
322 	rq_for_each_segment(bv, req, iter) {
323 		dst = page_address(bv.bv_page) + bv.bv_offset;
324 		if (dasd_page_cache) {
325 			char *copy = kmem_cache_alloc(dasd_page_cache,
326 						      GFP_DMA | __GFP_NOWARN);
327 			if (copy && rq_data_dir(req) == WRITE)
328 				memcpy(copy + bv.bv_offset, dst, bv.bv_len);
329 			if (copy)
330 				dst = copy + bv.bv_offset;
331 		}
332 		for (off = 0; off < bv.bv_len; off += blksize) {
333 			/* Locate record for stupid devices. */
334 			if (private->rdc_data.mode.bits.data_chain == 0) {
335 				ccw[-1].flags |= CCW_FLAG_CC;
336 				locate_record(ccw, LO_data++,
337 					      rq_data_dir(req),
338 					      recid - first_rec, 1);
339 				ccw->flags = CCW_FLAG_CC;
340 				ccw++;
341 			} else {
342 				if (recid > first_rec)
343 					ccw[-1].flags |= CCW_FLAG_DC;
344 				else
345 					ccw[-1].flags |= CCW_FLAG_CC;
346 			}
347 			ccw->cmd_code = cmd;
348 			ccw->count = block->bp_block;
349 			if (idal_is_needed(dst, blksize)) {
350 				ccw->cda = (__u32)(addr_t) idaws;
351 				ccw->flags = CCW_FLAG_IDA;
352 				idaws = idal_create_words(idaws, dst, blksize);
353 			} else {
354 				ccw->cda = (__u32)(addr_t) dst;
355 				ccw->flags = 0;
356 			}
357 			ccw++;
358 			dst += blksize;
359 			recid++;
360 		}
361 	}
362 	if (blk_noretry_request(req) ||
363 	    block->base->features & DASD_FEATURE_FAILFAST)
364 		set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
365 	cqr->startdev = memdev;
366 	cqr->memdev = memdev;
367 	cqr->block = block;
368 	cqr->expires = memdev->default_expires * HZ;	/* default 5 minutes */
369 	cqr->retries = memdev->default_retries;
370 	cqr->buildclk = get_tod_clock();
371 	cqr->status = DASD_CQR_FILLED;
372 	return cqr;
373 }
374 
375 static int
dasd_fba_free_cp(struct dasd_ccw_req * cqr,struct request * req)376 dasd_fba_free_cp(struct dasd_ccw_req *cqr, struct request *req)
377 {
378 	struct dasd_fba_private *private = cqr->block->base->private;
379 	struct ccw1 *ccw;
380 	struct req_iterator iter;
381 	struct bio_vec bv;
382 	char *dst, *cda;
383 	unsigned int blksize, off;
384 	int status;
385 
386 	if (!dasd_page_cache)
387 		goto out;
388 	blksize = cqr->block->bp_block;
389 	ccw = cqr->cpaddr;
390 	/* Skip over define extent & locate record. */
391 	ccw++;
392 	if (private->rdc_data.mode.bits.data_chain != 0)
393 		ccw++;
394 	rq_for_each_segment(bv, req, iter) {
395 		dst = page_address(bv.bv_page) + bv.bv_offset;
396 		for (off = 0; off < bv.bv_len; off += blksize) {
397 			/* Skip locate record. */
398 			if (private->rdc_data.mode.bits.data_chain == 0)
399 				ccw++;
400 			if (dst) {
401 				if (ccw->flags & CCW_FLAG_IDA)
402 					cda = *((char **)((addr_t) ccw->cda));
403 				else
404 					cda = (char *)((addr_t) ccw->cda);
405 				if (dst != cda) {
406 					if (rq_data_dir(req) == READ)
407 						memcpy(dst, cda, bv.bv_len);
408 					kmem_cache_free(dasd_page_cache,
409 					    (void *)((addr_t)cda & PAGE_MASK));
410 				}
411 				dst = NULL;
412 			}
413 			ccw++;
414 		}
415 	}
416 out:
417 	status = cqr->status == DASD_CQR_DONE;
418 	dasd_sfree_request(cqr, cqr->memdev);
419 	return status;
420 }
421 
dasd_fba_handle_terminated_request(struct dasd_ccw_req * cqr)422 static void dasd_fba_handle_terminated_request(struct dasd_ccw_req *cqr)
423 {
424 	if (cqr->retries < 0)
425 		cqr->status = DASD_CQR_FAILED;
426 	else
427 		cqr->status = DASD_CQR_FILLED;
428 };
429 
430 static int
dasd_fba_fill_info(struct dasd_device * device,struct dasd_information2_t * info)431 dasd_fba_fill_info(struct dasd_device * device,
432 		   struct dasd_information2_t * info)
433 {
434 	struct dasd_fba_private *private = device->private;
435 
436 	info->label_block = 1;
437 	info->FBA_layout = 1;
438 	info->format = DASD_FORMAT_LDL;
439 	info->characteristics_size = sizeof(private->rdc_data);
440 	memcpy(info->characteristics, &private->rdc_data,
441 	       sizeof(private->rdc_data));
442 	info->confdata_size = 0;
443 	return 0;
444 }
445 
446 static void
dasd_fba_dump_sense_dbf(struct dasd_device * device,struct irb * irb,char * reason)447 dasd_fba_dump_sense_dbf(struct dasd_device *device, struct irb *irb,
448 			char *reason)
449 {
450 	u64 *sense;
451 
452 	sense = (u64 *) dasd_get_sense(irb);
453 	if (sense) {
454 		DBF_DEV_EVENT(DBF_EMERG, device,
455 			      "%s: %s %02x%02x%02x %016llx %016llx %016llx "
456 			      "%016llx", reason,
457 			      scsw_is_tm(&irb->scsw) ? "t" : "c",
458 			      scsw_cc(&irb->scsw), scsw_cstat(&irb->scsw),
459 			      scsw_dstat(&irb->scsw), sense[0], sense[1],
460 			      sense[2], sense[3]);
461 	} else {
462 		DBF_DEV_EVENT(DBF_EMERG, device, "%s",
463 			      "SORRY - NO VALID SENSE AVAILABLE\n");
464 	}
465 }
466 
467 
468 static void
dasd_fba_dump_sense(struct dasd_device * device,struct dasd_ccw_req * req,struct irb * irb)469 dasd_fba_dump_sense(struct dasd_device *device, struct dasd_ccw_req * req,
470 		    struct irb *irb)
471 {
472 	char *page;
473 	struct ccw1 *act, *end, *last;
474 	int len, sl, sct, count;
475 
476 	page = (char *) get_zeroed_page(GFP_ATOMIC);
477 	if (page == NULL) {
478 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
479 			    "No memory to dump sense data");
480 		return;
481 	}
482 	len = sprintf(page, PRINTK_HEADER
483 		      " I/O status report for device %s:\n",
484 		      dev_name(&device->cdev->dev));
485 	len += sprintf(page + len, PRINTK_HEADER
486 		       " in req: %p CS: 0x%02X DS: 0x%02X\n", req,
487 		       irb->scsw.cmd.cstat, irb->scsw.cmd.dstat);
488 	len += sprintf(page + len, PRINTK_HEADER
489 		       " device %s: Failing CCW: %p\n",
490 		       dev_name(&device->cdev->dev),
491 		       (void *) (addr_t) irb->scsw.cmd.cpa);
492 	if (irb->esw.esw0.erw.cons) {
493 		for (sl = 0; sl < 4; sl++) {
494 			len += sprintf(page + len, PRINTK_HEADER
495 				       " Sense(hex) %2d-%2d:",
496 				       (8 * sl), ((8 * sl) + 7));
497 
498 			for (sct = 0; sct < 8; sct++) {
499 				len += sprintf(page + len, " %02x",
500 					       irb->ecw[8 * sl + sct]);
501 			}
502 			len += sprintf(page + len, "\n");
503 		}
504 	} else {
505 		len += sprintf(page + len, PRINTK_HEADER
506 			       " SORRY - NO VALID SENSE AVAILABLE\n");
507 	}
508 	printk(KERN_ERR "%s", page);
509 
510 	/* dump the Channel Program */
511 	/* print first CCWs (maximum 8) */
512 	act = req->cpaddr;
513         for (last = act; last->flags & (CCW_FLAG_CC | CCW_FLAG_DC); last++);
514 	end = min(act + 8, last);
515 	len = sprintf(page, PRINTK_HEADER " Related CP in req: %p\n", req);
516 	while (act <= end) {
517 		len += sprintf(page + len, PRINTK_HEADER
518 			       " CCW %p: %08X %08X DAT:",
519 			       act, ((int *) act)[0], ((int *) act)[1]);
520 		for (count = 0; count < 32 && count < act->count;
521 		     count += sizeof(int))
522 			len += sprintf(page + len, " %08X",
523 				       ((int *) (addr_t) act->cda)
524 				       [(count>>2)]);
525 		len += sprintf(page + len, "\n");
526 		act++;
527 	}
528 	printk(KERN_ERR "%s", page);
529 
530 
531 	/* print failing CCW area */
532 	len = 0;
533 	if (act <  ((struct ccw1 *)(addr_t) irb->scsw.cmd.cpa) - 2) {
534 		act = ((struct ccw1 *)(addr_t) irb->scsw.cmd.cpa) - 2;
535 		len += sprintf(page + len, PRINTK_HEADER "......\n");
536 	}
537 	end = min((struct ccw1 *)(addr_t) irb->scsw.cmd.cpa + 2, last);
538 	while (act <= end) {
539 		len += sprintf(page + len, PRINTK_HEADER
540 			       " CCW %p: %08X %08X DAT:",
541 			       act, ((int *) act)[0], ((int *) act)[1]);
542 		for (count = 0; count < 32 && count < act->count;
543 		     count += sizeof(int))
544 			len += sprintf(page + len, " %08X",
545 				       ((int *) (addr_t) act->cda)
546 				       [(count>>2)]);
547 		len += sprintf(page + len, "\n");
548 		act++;
549 	}
550 
551 	/* print last CCWs */
552 	if (act <  last - 2) {
553 		act = last - 2;
554 		len += sprintf(page + len, PRINTK_HEADER "......\n");
555 	}
556 	while (act <= last) {
557 		len += sprintf(page + len, PRINTK_HEADER
558 			       " CCW %p: %08X %08X DAT:",
559 			       act, ((int *) act)[0], ((int *) act)[1]);
560 		for (count = 0; count < 32 && count < act->count;
561 		     count += sizeof(int))
562 			len += sprintf(page + len, " %08X",
563 				       ((int *) (addr_t) act->cda)
564 				       [(count>>2)]);
565 		len += sprintf(page + len, "\n");
566 		act++;
567 	}
568 	if (len > 0)
569 		printk(KERN_ERR "%s", page);
570 	free_page((unsigned long) page);
571 }
572 
573 /*
574  * max_blocks is dependent on the amount of storage that is available
575  * in the static io buffer for each device. Currently each device has
576  * 8192 bytes (=2 pages). For 64 bit one dasd_mchunkt_t structure has
577  * 24 bytes, the struct dasd_ccw_req has 136 bytes and each block can use
578  * up to 16 bytes (8 for the ccw and 8 for the idal pointer). In
579  * addition we have one define extent ccw + 16 bytes of data and a
580  * locate record ccw for each block (stupid devices!) + 16 bytes of data.
581  * That makes:
582  * (8192 - 24 - 136 - 8 - 16) / 40 = 200.2 blocks at maximum.
583  * We want to fit two into the available memory so that we can immediately
584  * start the next request if one finishes off. That makes 100.1 blocks
585  * for one request. Give a little safety and the result is 96.
586  */
587 static struct dasd_discipline dasd_fba_discipline = {
588 	.owner = THIS_MODULE,
589 	.name = "FBA ",
590 	.ebcname = "FBA ",
591 	.max_blocks = 96,
592 	.check_device = dasd_fba_check_characteristics,
593 	.do_analysis = dasd_fba_do_analysis,
594 	.verify_path = dasd_generic_verify_path,
595 	.fill_geometry = dasd_fba_fill_geometry,
596 	.start_IO = dasd_start_IO,
597 	.term_IO = dasd_term_IO,
598 	.handle_terminated_request = dasd_fba_handle_terminated_request,
599 	.erp_action = dasd_fba_erp_action,
600 	.erp_postaction = dasd_fba_erp_postaction,
601 	.check_for_device_change = dasd_fba_check_for_device_change,
602 	.build_cp = dasd_fba_build_cp,
603 	.free_cp = dasd_fba_free_cp,
604 	.dump_sense = dasd_fba_dump_sense,
605 	.dump_sense_dbf = dasd_fba_dump_sense_dbf,
606 	.fill_info = dasd_fba_fill_info,
607 };
608 
609 static int __init
dasd_fba_init(void)610 dasd_fba_init(void)
611 {
612 	int ret;
613 
614 	ASCEBC(dasd_fba_discipline.ebcname, 4);
615 	ret = ccw_driver_register(&dasd_fba_driver);
616 	if (!ret)
617 		wait_for_device_probe();
618 
619 	return ret;
620 }
621 
622 static void __exit
dasd_fba_cleanup(void)623 dasd_fba_cleanup(void)
624 {
625 	ccw_driver_unregister(&dasd_fba_driver);
626 }
627 
628 module_init(dasd_fba_init);
629 module_exit(dasd_fba_cleanup);
630