xref: /linux/drivers/scsi/scsi_transport_spi.c (revision 537c2e91d3549e5d6020bb0576cf9b54a845255f)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Parallel SCSI (SPI) transport specific attributes exported to sysfs.
4  *
5  *  Copyright (c) 2003 Silicon Graphics, Inc.  All rights reserved.
6  *  Copyright (c) 2004, 2005 James Bottomley <James.Bottomley@SteelEye.com>
7  */
8 #include <linux/ctype.h>
9 #include <linux/init.h>
10 #include <linux/module.h>
11 #include <linux/workqueue.h>
12 #include <linux/blkdev.h>
13 #include <linux/mutex.h>
14 #include <linux/sysfs.h>
15 #include <linux/slab.h>
16 #include <linux/suspend.h>
17 #include <scsi/scsi.h>
18 #include "scsi_priv.h"
19 #include <scsi/scsi_device.h>
20 #include <scsi/scsi_host.h>
21 #include <scsi/scsi_cmnd.h>
22 #include <scsi/scsi_eh.h>
23 #include <scsi/scsi_tcq.h>
24 #include <scsi/scsi_transport.h>
25 #include <scsi/scsi_transport_spi.h>
26 
27 #define SPI_NUM_ATTRS 14	/* increase this if you add attributes */
28 #define SPI_OTHER_ATTRS 1	/* Increase this if you add "always
29 				 * on" attributes */
30 #define SPI_HOST_ATTRS	1
31 
32 #define SPI_MAX_ECHO_BUFFER_SIZE	4096
33 
34 #define DV_LOOPS	3
35 #define DV_TIMEOUT	(10*HZ)
36 #define DV_RETRIES	3	/* should only need at most
37 				 * two cc/ua clears */
38 
39 /* Our blacklist flags */
40 enum {
41 	SPI_BLIST_NOIUS = (__force blist_flags_t)0x1,
42 };
43 
44 /* blacklist table, modelled on scsi_devinfo.c */
45 static struct {
46 	char *vendor;
47 	char *model;
48 	blist_flags_t flags;
49 } spi_static_device_list[] __initdata = {
50 	{"HP", "Ultrium 3-SCSI", SPI_BLIST_NOIUS },
51 	{"IBM", "ULTRIUM-TD3", SPI_BLIST_NOIUS },
52 	{NULL, NULL, 0}
53 };
54 
55 /* Private data accessors (keep these out of the header file) */
56 #define spi_dv_in_progress(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_in_progress)
57 #define spi_dv_mutex(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_mutex)
58 
59 struct spi_internal {
60 	struct scsi_transport_template t;
61 	struct spi_function_template *f;
62 };
63 
64 #define to_spi_internal(tmpl)	container_of(tmpl, struct spi_internal, t)
65 
66 static const int ppr_to_ps[] = {
67 	/* The PPR values 0-6 are reserved, fill them in when
68 	 * the committee defines them */
69 	-1,			/* 0x00 */
70 	-1,			/* 0x01 */
71 	-1,			/* 0x02 */
72 	-1,			/* 0x03 */
73 	-1,			/* 0x04 */
74 	-1,			/* 0x05 */
75 	-1,			/* 0x06 */
76 	 3125,			/* 0x07 */
77 	 6250,			/* 0x08 */
78 	12500,			/* 0x09 */
79 	25000,			/* 0x0a */
80 	30300,			/* 0x0b */
81 	50000,			/* 0x0c */
82 };
83 /* The PPR values at which you calculate the period in ns by multiplying
84  * by 4 */
85 #define SPI_STATIC_PPR	0x0c
86 
87 static int sprint_frac(char *dest, int value, int denom)
88 {
89 	int frac = value % denom;
90 	int result = sprintf(dest, "%d", value / denom);
91 
92 	if (frac == 0)
93 		return result;
94 	dest[result++] = '.';
95 
96 	do {
97 		denom /= 10;
98 		sprintf(dest + result, "%d", frac / denom);
99 		result++;
100 		frac %= denom;
101 	} while (frac);
102 
103 	dest[result++] = '\0';
104 	return result;
105 }
106 
107 static int spi_execute(struct scsi_device *sdev, const void *cmd,
108 		       enum req_op op, void *buffer, unsigned int bufflen,
109 		       struct scsi_sense_hdr *sshdr)
110 {
111 	blk_opf_t opf = op | REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
112 			REQ_FAILFAST_DRIVER;
113 	struct scsi_failure failure_defs[] = {
114 		{
115 			.sense = UNIT_ATTENTION,
116 			.asc = SCMD_FAILURE_ASC_ANY,
117 			.ascq = SCMD_FAILURE_ASCQ_ANY,
118 			.allowed = DV_RETRIES,
119 			.result = SAM_STAT_CHECK_CONDITION,
120 		},
121 		{}
122 	};
123 	struct scsi_failures failures = {
124 		.failure_definitions = failure_defs,
125 	};
126 	const struct scsi_exec_args exec_args = {
127 		/* bypass the SDEV_QUIESCE state with BLK_MQ_REQ_PM */
128 		.req_flags = BLK_MQ_REQ_PM,
129 		.sshdr = sshdr,
130 		.failures = &failures,
131 	};
132 
133 	return scsi_execute_cmd(sdev, cmd, opf, buffer, bufflen, DV_TIMEOUT, 1,
134 				&exec_args);
135 }
136 
137 static struct {
138 	enum spi_signal_type	value;
139 	char			*name;
140 } signal_types[] = {
141 	{ SPI_SIGNAL_UNKNOWN, "unknown" },
142 	{ SPI_SIGNAL_SE, "SE" },
143 	{ SPI_SIGNAL_LVD, "LVD" },
144 	{ SPI_SIGNAL_HVD, "HVD" },
145 };
146 
147 static inline const char *spi_signal_to_string(enum spi_signal_type type)
148 {
149 	int i;
150 
151 	for (i = 0; i < ARRAY_SIZE(signal_types); i++) {
152 		if (type == signal_types[i].value)
153 			return signal_types[i].name;
154 	}
155 	return NULL;
156 }
157 static inline enum spi_signal_type spi_signal_to_value(const char *name)
158 {
159 	int i, len;
160 
161 	for (i = 0; i < ARRAY_SIZE(signal_types); i++) {
162 		len =  strlen(signal_types[i].name);
163 		if (strncmp(name, signal_types[i].name, len) == 0 &&
164 		    (name[len] == '\n' || name[len] == '\0'))
165 			return signal_types[i].value;
166 	}
167 	return SPI_SIGNAL_UNKNOWN;
168 }
169 
170 static int spi_host_setup(struct transport_container *tc, struct device *dev,
171 			  struct device *cdev)
172 {
173 	struct Scsi_Host *shost = dev_to_shost(dev);
174 
175 	spi_signalling(shost) = SPI_SIGNAL_UNKNOWN;
176 
177 	return 0;
178 }
179 
180 static int spi_host_configure(struct transport_container *tc,
181 			      struct device *dev,
182 			      struct device *cdev);
183 
184 static DECLARE_TRANSPORT_CLASS(spi_host_class,
185 			       "spi_host",
186 			       spi_host_setup,
187 			       NULL,
188 			       spi_host_configure);
189 
190 static int spi_host_match(struct attribute_container *cont,
191 			  struct device *dev)
192 {
193 	struct Scsi_Host *shost;
194 
195 	if (!scsi_is_host_device(dev))
196 		return 0;
197 
198 	shost = dev_to_shost(dev);
199 	if (!shost->transportt  || shost->transportt->host_attrs.ac.class
200 	    != &spi_host_class.class)
201 		return 0;
202 
203 	return &shost->transportt->host_attrs.ac == cont;
204 }
205 
206 static int spi_target_configure(struct transport_container *tc,
207 				struct device *dev,
208 				struct device *cdev);
209 
210 static int spi_device_configure(struct transport_container *tc,
211 				struct device *dev,
212 				struct device *cdev)
213 {
214 	struct scsi_device *sdev = to_scsi_device(dev);
215 	struct scsi_target *starget = sdev->sdev_target;
216 	blist_flags_t bflags;
217 
218 	bflags = scsi_get_device_flags_keyed(sdev, &sdev->inquiry[8],
219 					     &sdev->inquiry[16],
220 					     SCSI_DEVINFO_SPI);
221 
222 	/* Populate the target capability fields with the values
223 	 * gleaned from the device inquiry */
224 
225 	spi_support_sync(starget) = scsi_device_sync(sdev);
226 	spi_support_wide(starget) = scsi_device_wide(sdev);
227 	spi_support_dt(starget) = scsi_device_dt(sdev);
228 	spi_support_dt_only(starget) = scsi_device_dt_only(sdev);
229 	spi_support_ius(starget) = scsi_device_ius(sdev);
230 	if (bflags & SPI_BLIST_NOIUS) {
231 		dev_info(dev, "Information Units disabled by blacklist\n");
232 		spi_support_ius(starget) = 0;
233 	}
234 	spi_support_qas(starget) = scsi_device_qas(sdev);
235 
236 	return 0;
237 }
238 
239 static int spi_setup_transport_attrs(struct transport_container *tc,
240 				     struct device *dev,
241 				     struct device *cdev)
242 {
243 	struct scsi_target *starget = to_scsi_target(dev);
244 
245 	spi_period(starget) = -1;	/* illegal value */
246 	spi_min_period(starget) = 0;
247 	spi_offset(starget) = 0;	/* async */
248 	spi_max_offset(starget) = 255;
249 	spi_width(starget) = 0;	/* narrow */
250 	spi_max_width(starget) = 1;
251 	spi_iu(starget) = 0;	/* no IU */
252 	spi_max_iu(starget) = 1;
253 	spi_dt(starget) = 0;	/* ST */
254 	spi_qas(starget) = 0;
255 	spi_max_qas(starget) = 1;
256 	spi_wr_flow(starget) = 0;
257 	spi_rd_strm(starget) = 0;
258 	spi_rti(starget) = 0;
259 	spi_pcomp_en(starget) = 0;
260 	spi_hold_mcs(starget) = 0;
261 	spi_dv_pending(starget) = 0;
262 	spi_dv_in_progress(starget) = 0;
263 	spi_initial_dv(starget) = 0;
264 	mutex_init(&spi_dv_mutex(starget));
265 
266 	return 0;
267 }
268 
269 #define spi_transport_show_simple(field, format_string)			\
270 									\
271 static ssize_t								\
272 show_spi_transport_##field(struct device *dev, 			\
273 			   struct device_attribute *attr, char *buf)	\
274 {									\
275 	struct scsi_target *starget = transport_class_to_starget(dev);	\
276 	struct spi_transport_attrs *tp;					\
277 									\
278 	tp = (struct spi_transport_attrs *)&starget->starget_data;	\
279 	return snprintf(buf, 20, format_string, tp->field);		\
280 }
281 
282 #define spi_transport_store_simple(field, format_string)		\
283 									\
284 static ssize_t								\
285 store_spi_transport_##field(struct device *dev, 			\
286 			    struct device_attribute *attr, 		\
287 			    const char *buf, size_t count)		\
288 {									\
289 	int val;							\
290 	struct scsi_target *starget = transport_class_to_starget(dev);	\
291 	struct spi_transport_attrs *tp;					\
292 									\
293 	tp = (struct spi_transport_attrs *)&starget->starget_data;	\
294 	val = simple_strtoul(buf, NULL, 0);				\
295 	tp->field = val;						\
296 	return count;							\
297 }
298 
299 #define spi_transport_show_function(field, format_string)		\
300 									\
301 static ssize_t								\
302 show_spi_transport_##field(struct device *dev, 			\
303 			   struct device_attribute *attr, char *buf)	\
304 {									\
305 	struct scsi_target *starget = transport_class_to_starget(dev);	\
306 	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);	\
307 	struct spi_transport_attrs *tp;					\
308 	struct spi_internal *i = to_spi_internal(shost->transportt);	\
309 	tp = (struct spi_transport_attrs *)&starget->starget_data;	\
310 	if (i->f->get_##field)						\
311 		i->f->get_##field(starget);				\
312 	return snprintf(buf, 20, format_string, tp->field);		\
313 }
314 
315 #define spi_transport_store_function(field, format_string)		\
316 static ssize_t								\
317 store_spi_transport_##field(struct device *dev, 			\
318 			    struct device_attribute *attr,		\
319 			    const char *buf, size_t count)		\
320 {									\
321 	int val;							\
322 	struct scsi_target *starget = transport_class_to_starget(dev);	\
323 	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);	\
324 	struct spi_internal *i = to_spi_internal(shost->transportt);	\
325 									\
326 	if (!i->f->set_##field)						\
327 		return -EINVAL;						\
328 	val = simple_strtoul(buf, NULL, 0);				\
329 	i->f->set_##field(starget, val);				\
330 	return count;							\
331 }
332 
333 #define spi_transport_store_max(field, format_string)			\
334 static ssize_t								\
335 store_spi_transport_##field(struct device *dev, 			\
336 			    struct device_attribute *attr,		\
337 			    const char *buf, size_t count)		\
338 {									\
339 	int val;							\
340 	struct scsi_target *starget = transport_class_to_starget(dev);	\
341 	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);	\
342 	struct spi_internal *i = to_spi_internal(shost->transportt);	\
343 	struct spi_transport_attrs *tp					\
344 		= (struct spi_transport_attrs *)&starget->starget_data;	\
345 									\
346 	if (!i->f->set_##field)						\
347 		return -EINVAL;						\
348 	val = simple_strtoul(buf, NULL, 0);				\
349 	if (val > tp->max_##field)					\
350 		val = tp->max_##field;					\
351 	i->f->set_##field(starget, val);				\
352 	return count;							\
353 }
354 
355 #define spi_transport_rd_attr(field, format_string)			\
356 	spi_transport_show_function(field, format_string)		\
357 	spi_transport_store_function(field, format_string)		\
358 static DEVICE_ATTR(field, S_IRUGO,				\
359 		   show_spi_transport_##field,			\
360 		   store_spi_transport_##field);
361 
362 #define spi_transport_simple_attr(field, format_string)			\
363 	spi_transport_show_simple(field, format_string)			\
364 	spi_transport_store_simple(field, format_string)		\
365 static DEVICE_ATTR(field, S_IRUGO,				\
366 		   show_spi_transport_##field,			\
367 		   store_spi_transport_##field);
368 
369 #define spi_transport_max_attr(field, format_string)			\
370 	spi_transport_show_function(field, format_string)		\
371 	spi_transport_store_max(field, format_string)			\
372 	spi_transport_simple_attr(max_##field, format_string)		\
373 static DEVICE_ATTR(field, S_IRUGO,				\
374 		   show_spi_transport_##field,			\
375 		   store_spi_transport_##field);
376 
377 /* The Parallel SCSI Tranport Attributes: */
378 spi_transport_max_attr(offset, "%d\n");
379 spi_transport_max_attr(width, "%d\n");
380 spi_transport_max_attr(iu, "%d\n");
381 spi_transport_rd_attr(dt, "%d\n");
382 spi_transport_max_attr(qas, "%d\n");
383 spi_transport_rd_attr(wr_flow, "%d\n");
384 spi_transport_rd_attr(rd_strm, "%d\n");
385 spi_transport_rd_attr(rti, "%d\n");
386 spi_transport_rd_attr(pcomp_en, "%d\n");
387 spi_transport_rd_attr(hold_mcs, "%d\n");
388 
389 /* we only care about the first child device that's a real SCSI device
390  * so we return 1 to terminate the iteration when we find it */
391 static int child_iter(struct device *dev, void *data)
392 {
393 	if (!scsi_is_sdev_device(dev))
394 		return 0;
395 
396 	spi_dv_device(to_scsi_device(dev));
397 	return 1;
398 }
399 
400 static ssize_t
401 store_spi_revalidate(struct device *dev, struct device_attribute *attr,
402 		     const char *buf, size_t count)
403 {
404 	struct scsi_target *starget = transport_class_to_starget(dev);
405 
406 	device_for_each_child(&starget->dev, NULL, child_iter);
407 	return count;
408 }
409 static DEVICE_ATTR(revalidate, S_IWUSR, NULL, store_spi_revalidate);
410 
411 /* Translate the period into ns according to the current spec
412  * for SDTR/PPR messages */
413 static int period_to_str(char *buf, int period)
414 {
415 	int len, picosec;
416 
417 	if (period < 0 || period > 0xff) {
418 		picosec = -1;
419 	} else if (period <= SPI_STATIC_PPR) {
420 		picosec = ppr_to_ps[period];
421 	} else {
422 		picosec = period * 4000;
423 	}
424 
425 	if (picosec == -1) {
426 		len = sprintf(buf, "reserved");
427 	} else {
428 		len = sprint_frac(buf, picosec, 1000);
429 	}
430 
431 	return len;
432 }
433 
434 static ssize_t
435 show_spi_transport_period_helper(char *buf, int period)
436 {
437 	int len = period_to_str(buf, period);
438 	buf[len++] = '\n';
439 	buf[len] = '\0';
440 	return len;
441 }
442 
443 static ssize_t
444 store_spi_transport_period_helper(struct device *dev, const char *buf,
445 				  size_t count, int *periodp)
446 {
447 	int j, picosec, period = -1;
448 	char *endp;
449 
450 	picosec = simple_strtoul(buf, &endp, 10) * 1000;
451 	if (*endp == '.') {
452 		int mult = 100;
453 		do {
454 			endp++;
455 			if (!isdigit(*endp))
456 				break;
457 			picosec += (*endp - '0') * mult;
458 			mult /= 10;
459 		} while (mult > 0);
460 	}
461 
462 	for (j = 0; j <= SPI_STATIC_PPR; j++) {
463 		if (ppr_to_ps[j] < picosec)
464 			continue;
465 		period = j;
466 		break;
467 	}
468 
469 	if (period == -1)
470 		period = picosec / 4000;
471 
472 	if (period > 0xff)
473 		period = 0xff;
474 
475 	*periodp = period;
476 
477 	return count;
478 }
479 
480 static ssize_t
481 show_spi_transport_period(struct device *dev,
482 			  struct device_attribute *attr, char *buf)
483 {
484 	struct scsi_target *starget = transport_class_to_starget(dev);
485 	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
486 	struct spi_internal *i = to_spi_internal(shost->transportt);
487 	struct spi_transport_attrs *tp =
488 		(struct spi_transport_attrs *)&starget->starget_data;
489 
490 	if (i->f->get_period)
491 		i->f->get_period(starget);
492 
493 	return show_spi_transport_period_helper(buf, tp->period);
494 }
495 
496 static ssize_t
497 store_spi_transport_period(struct device *cdev, struct device_attribute *attr,
498 			   const char *buf, size_t count)
499 {
500 	struct scsi_target *starget = transport_class_to_starget(cdev);
501 	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
502 	struct spi_internal *i = to_spi_internal(shost->transportt);
503 	struct spi_transport_attrs *tp =
504 		(struct spi_transport_attrs *)&starget->starget_data;
505 	int period, retval;
506 
507 	if (!i->f->set_period)
508 		return -EINVAL;
509 
510 	retval = store_spi_transport_period_helper(cdev, buf, count, &period);
511 
512 	if (period < tp->min_period)
513 		period = tp->min_period;
514 
515 	i->f->set_period(starget, period);
516 
517 	return retval;
518 }
519 
520 static DEVICE_ATTR(period, S_IRUGO,
521 		   show_spi_transport_period,
522 		   store_spi_transport_period);
523 
524 static ssize_t
525 show_spi_transport_min_period(struct device *cdev,
526 			      struct device_attribute *attr, char *buf)
527 {
528 	struct scsi_target *starget = transport_class_to_starget(cdev);
529 	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
530 	struct spi_internal *i = to_spi_internal(shost->transportt);
531 	struct spi_transport_attrs *tp =
532 		(struct spi_transport_attrs *)&starget->starget_data;
533 
534 	if (!i->f->set_period)
535 		return -EINVAL;
536 
537 	return show_spi_transport_period_helper(buf, tp->min_period);
538 }
539 
540 static ssize_t
541 store_spi_transport_min_period(struct device *cdev,
542 			       struct device_attribute *attr,
543 			       const char *buf, size_t count)
544 {
545 	struct scsi_target *starget = transport_class_to_starget(cdev);
546 	struct spi_transport_attrs *tp =
547 		(struct spi_transport_attrs *)&starget->starget_data;
548 
549 	return store_spi_transport_period_helper(cdev, buf, count,
550 						 &tp->min_period);
551 }
552 
553 
554 static DEVICE_ATTR(min_period, S_IRUGO,
555 		   show_spi_transport_min_period,
556 		   store_spi_transport_min_period);
557 
558 
559 static ssize_t show_spi_host_signalling(struct device *cdev,
560 					struct device_attribute *attr,
561 					char *buf)
562 {
563 	struct Scsi_Host *shost = transport_class_to_shost(cdev);
564 	struct spi_internal *i = to_spi_internal(shost->transportt);
565 
566 	if (i->f->get_signalling)
567 		i->f->get_signalling(shost);
568 
569 	return sprintf(buf, "%s\n", spi_signal_to_string(spi_signalling(shost)));
570 }
571 static ssize_t store_spi_host_signalling(struct device *dev,
572 					 struct device_attribute *attr,
573 					 const char *buf, size_t count)
574 {
575 	struct Scsi_Host *shost = transport_class_to_shost(dev);
576 	struct spi_internal *i = to_spi_internal(shost->transportt);
577 	enum spi_signal_type type = spi_signal_to_value(buf);
578 
579 	if (!i->f->set_signalling)
580 		return -EINVAL;
581 
582 	if (type != SPI_SIGNAL_UNKNOWN)
583 		i->f->set_signalling(shost, type);
584 
585 	return count;
586 }
587 static DEVICE_ATTR(signalling, S_IRUGO,
588 		   show_spi_host_signalling,
589 		   store_spi_host_signalling);
590 
591 static ssize_t show_spi_host_width(struct device *cdev,
592 				      struct device_attribute *attr,
593 				      char *buf)
594 {
595 	struct Scsi_Host *shost = transport_class_to_shost(cdev);
596 
597 	return sprintf(buf, "%s\n", shost->max_id == 16 ? "wide" : "narrow");
598 }
599 static DEVICE_ATTR(host_width, S_IRUGO,
600 		   show_spi_host_width, NULL);
601 
602 static ssize_t show_spi_host_hba_id(struct device *cdev,
603 				    struct device_attribute *attr,
604 				    char *buf)
605 {
606 	struct Scsi_Host *shost = transport_class_to_shost(cdev);
607 
608 	return sprintf(buf, "%d\n", shost->this_id);
609 }
610 static DEVICE_ATTR(hba_id, S_IRUGO,
611 		   show_spi_host_hba_id, NULL);
612 
613 #define DV_SET(x, y)			\
614 	if(i->f->set_##x)		\
615 		i->f->set_##x(sdev->sdev_target, y)
616 
617 enum spi_compare_returns {
618 	SPI_COMPARE_SUCCESS,
619 	SPI_COMPARE_FAILURE,
620 	SPI_COMPARE_SKIP_TEST,
621 };
622 
623 
624 /* This is for read/write Domain Validation:  If the device supports
625  * an echo buffer, we do read/write tests to it */
626 static enum spi_compare_returns
627 spi_dv_device_echo_buffer(struct scsi_device *sdev, u8 *buffer,
628 			  u8 *ptr, const int retries)
629 {
630 	int len = ptr - buffer;
631 	int j, k, r, result;
632 	unsigned int pattern = 0x0000ffff;
633 	struct scsi_sense_hdr sshdr;
634 
635 	const char spi_write_buffer[] = {
636 		WRITE_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
637 	};
638 	const char spi_read_buffer[] = {
639 		READ_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
640 	};
641 
642 	/* set up the pattern buffer.  Doesn't matter if we spill
643 	 * slightly beyond since that's where the read buffer is */
644 	for (j = 0; j < len; ) {
645 
646 		/* fill the buffer with counting (test a) */
647 		for ( ; j < min(len, 32); j++)
648 			buffer[j] = j;
649 		k = j;
650 		/* fill the buffer with alternating words of 0x0 and
651 		 * 0xffff (test b) */
652 		for ( ; j < min(len, k + 32); j += 2) {
653 			u16 *word = (u16 *)&buffer[j];
654 
655 			*word = (j & 0x02) ? 0x0000 : 0xffff;
656 		}
657 		k = j;
658 		/* fill with crosstalk (alternating 0x5555 0xaaa)
659                  * (test c) */
660 		for ( ; j < min(len, k + 32); j += 2) {
661 			u16 *word = (u16 *)&buffer[j];
662 
663 			*word = (j & 0x02) ? 0x5555 : 0xaaaa;
664 		}
665 		k = j;
666 		/* fill with shifting bits (test d) */
667 		for ( ; j < min(len, k + 32); j += 4) {
668 			u32 *word = (unsigned int *)&buffer[j];
669 			u32 roll = (pattern & 0x80000000) ? 1 : 0;
670 
671 			*word = pattern;
672 			pattern = (pattern << 1) | roll;
673 		}
674 		/* don't bother with random data (test e) */
675 	}
676 
677 	for (r = 0; r < retries; r++) {
678 		result = spi_execute(sdev, spi_write_buffer, REQ_OP_DRV_OUT,
679 				     buffer, len, &sshdr);
680 		if (result || !scsi_device_online(sdev)) {
681 
682 			scsi_device_set_state(sdev, SDEV_QUIESCE);
683 			if (result > 0 && scsi_sense_valid(&sshdr)
684 			    && sshdr.sense_key == ILLEGAL_REQUEST
685 			    /* INVALID FIELD IN CDB */
686 			    && sshdr.asc == 0x24 && sshdr.ascq == 0x00)
687 				/* This would mean that the drive lied
688 				 * to us about supporting an echo
689 				 * buffer (unfortunately some Western
690 				 * Digital drives do precisely this)
691 				 */
692 				return SPI_COMPARE_SKIP_TEST;
693 
694 
695 			sdev_printk(KERN_ERR, sdev, "Write Buffer failure %x\n", result);
696 			return SPI_COMPARE_FAILURE;
697 		}
698 
699 		memset(ptr, 0, len);
700 		spi_execute(sdev, spi_read_buffer, REQ_OP_DRV_IN,
701 			    ptr, len, NULL);
702 		scsi_device_set_state(sdev, SDEV_QUIESCE);
703 
704 		if (memcmp(buffer, ptr, len) != 0)
705 			return SPI_COMPARE_FAILURE;
706 	}
707 	return SPI_COMPARE_SUCCESS;
708 }
709 
710 /* This is for the simplest form of Domain Validation: a read test
711  * on the inquiry data from the device */
712 static enum spi_compare_returns
713 spi_dv_device_compare_inquiry(struct scsi_device *sdev, u8 *buffer,
714 			      u8 *ptr, const int retries)
715 {
716 	int r, result;
717 	const int len = sdev->inquiry_len;
718 	const char spi_inquiry[] = {
719 		INQUIRY, 0, 0, 0, len, 0
720 	};
721 
722 	for (r = 0; r < retries; r++) {
723 		memset(ptr, 0, len);
724 
725 		result = spi_execute(sdev, spi_inquiry, REQ_OP_DRV_IN,
726 				     ptr, len, NULL);
727 
728 		if(result || !scsi_device_online(sdev)) {
729 			scsi_device_set_state(sdev, SDEV_QUIESCE);
730 			return SPI_COMPARE_FAILURE;
731 		}
732 
733 		/* If we don't have the inquiry data already, the
734 		 * first read gets it */
735 		if (ptr == buffer) {
736 			ptr += len;
737 			--r;
738 			continue;
739 		}
740 
741 		if (memcmp(buffer, ptr, len) != 0)
742 			/* failure */
743 			return SPI_COMPARE_FAILURE;
744 	}
745 	return SPI_COMPARE_SUCCESS;
746 }
747 
748 static enum spi_compare_returns
749 spi_dv_retrain(struct scsi_device *sdev, u8 *buffer, u8 *ptr,
750 	       enum spi_compare_returns
751 	       (*compare_fn)(struct scsi_device *, u8 *, u8 *, int))
752 {
753 	struct spi_internal *i = to_spi_internal(sdev->host->transportt);
754 	struct scsi_target *starget = sdev->sdev_target;
755 	int period = 0, prevperiod = 0;
756 	enum spi_compare_returns retval;
757 
758 
759 	for (;;) {
760 		int newperiod;
761 		retval = compare_fn(sdev, buffer, ptr, DV_LOOPS);
762 
763 		if (retval == SPI_COMPARE_SUCCESS
764 		    || retval == SPI_COMPARE_SKIP_TEST)
765 			break;
766 
767 		/* OK, retrain, fallback */
768 		if (i->f->get_iu)
769 			i->f->get_iu(starget);
770 		if (i->f->get_qas)
771 			i->f->get_qas(starget);
772 		if (i->f->get_period)
773 			i->f->get_period(sdev->sdev_target);
774 
775 		/* Here's the fallback sequence; first try turning off
776 		 * IU, then QAS (if we can control them), then finally
777 		 * fall down the periods */
778 		if (i->f->set_iu && spi_iu(starget)) {
779 			starget_printk(KERN_ERR, starget, "Domain Validation Disabling Information Units\n");
780 			DV_SET(iu, 0);
781 		} else if (i->f->set_qas && spi_qas(starget)) {
782 			starget_printk(KERN_ERR, starget, "Domain Validation Disabling Quick Arbitration and Selection\n");
783 			DV_SET(qas, 0);
784 		} else {
785 			newperiod = spi_period(starget);
786 			period = newperiod > period ? newperiod : period;
787 			if (period < 0x0d)
788 				period++;
789 			else
790 				period += period >> 1;
791 
792 			if (unlikely(period > 0xff || period == prevperiod)) {
793 				/* Total failure; set to async and return */
794 				starget_printk(KERN_ERR, starget, "Domain Validation Failure, dropping back to Asynchronous\n");
795 				DV_SET(offset, 0);
796 				return SPI_COMPARE_FAILURE;
797 			}
798 			starget_printk(KERN_ERR, starget, "Domain Validation detected failure, dropping back\n");
799 			DV_SET(period, period);
800 			prevperiod = period;
801 		}
802 	}
803 	return retval;
804 }
805 
806 static int
807 spi_dv_device_get_echo_buffer(struct scsi_device *sdev, u8 *buffer)
808 {
809 	int l, result;
810 
811 	/* first off do a test unit ready.  This can error out
812 	 * because of reservations or some other reason.  If it
813 	 * fails, the device won't let us write to the echo buffer
814 	 * so just return failure */
815 
816 	static const char spi_test_unit_ready[] = {
817 		TEST_UNIT_READY, 0, 0, 0, 0, 0
818 	};
819 
820 	static const char spi_read_buffer_descriptor[] = {
821 		READ_BUFFER, 0x0b, 0, 0, 0, 0, 0, 0, 4, 0
822 	};
823 
824 
825 	/* We send a set of three TURs to clear any outstanding
826 	 * unit attention conditions if they exist (Otherwise the
827 	 * buffer tests won't be happy).  If the TUR still fails
828 	 * (reservation conflict, device not ready, etc) just
829 	 * skip the write tests */
830 	for (l = 0; ; l++) {
831 		result = spi_execute(sdev, spi_test_unit_ready, REQ_OP_DRV_IN,
832 				     NULL, 0, NULL);
833 
834 		if(result) {
835 			if(l >= 3)
836 				return 0;
837 		} else {
838 			/* TUR succeeded */
839 			break;
840 		}
841 	}
842 
843 	result = spi_execute(sdev, spi_read_buffer_descriptor,
844 			     REQ_OP_DRV_IN, buffer, 4, NULL);
845 
846 	if (result)
847 		/* Device has no echo buffer */
848 		return 0;
849 
850 	return buffer[3] + ((buffer[2] & 0x1f) << 8);
851 }
852 
853 static void
854 spi_dv_device_internal(struct scsi_device *sdev, u8 *buffer)
855 {
856 	struct spi_internal *i = to_spi_internal(sdev->host->transportt);
857 	struct scsi_target *starget = sdev->sdev_target;
858 	struct Scsi_Host *shost = sdev->host;
859 	int len = sdev->inquiry_len;
860 	int min_period = spi_min_period(starget);
861 	int max_width = spi_max_width(starget);
862 	/* first set us up for narrow async */
863 	DV_SET(offset, 0);
864 	DV_SET(width, 0);
865 
866 	if (spi_dv_device_compare_inquiry(sdev, buffer, buffer, DV_LOOPS)
867 	    != SPI_COMPARE_SUCCESS) {
868 		starget_printk(KERN_ERR, starget, "Domain Validation Initial Inquiry Failed\n");
869 		/* FIXME: should probably offline the device here? */
870 		return;
871 	}
872 
873 	if (!spi_support_wide(starget)) {
874 		spi_max_width(starget) = 0;
875 		max_width = 0;
876 	}
877 
878 	/* test width */
879 	if (i->f->set_width && max_width) {
880 		i->f->set_width(starget, 1);
881 
882 		if (spi_dv_device_compare_inquiry(sdev, buffer,
883 						   buffer + len,
884 						   DV_LOOPS)
885 		    != SPI_COMPARE_SUCCESS) {
886 			starget_printk(KERN_ERR, starget, "Wide Transfers Fail\n");
887 			i->f->set_width(starget, 0);
888 			/* Make sure we don't force wide back on by asking
889 			 * for a transfer period that requires it */
890 			max_width = 0;
891 			if (min_period < 10)
892 				min_period = 10;
893 		}
894 	}
895 
896 	if (!i->f->set_period)
897 		return;
898 
899 	/* device can't handle synchronous */
900 	if (!spi_support_sync(starget) && !spi_support_dt(starget))
901 		return;
902 
903 	/* len == -1 is the signal that we need to ascertain the
904 	 * presence of an echo buffer before trying to use it.  len ==
905 	 * 0 means we don't have an echo buffer */
906 	len = -1;
907 
908  retry:
909 
910 	/* now set up to the maximum */
911 	DV_SET(offset, spi_max_offset(starget));
912 	DV_SET(period, min_period);
913 
914 	/* try QAS requests; this should be harmless to set if the
915 	 * target supports it */
916 	if (spi_support_qas(starget) && spi_max_qas(starget)) {
917 		DV_SET(qas, 1);
918 	} else {
919 		DV_SET(qas, 0);
920 	}
921 
922 	if (spi_support_ius(starget) && spi_max_iu(starget) &&
923 	    min_period < 9) {
924 		/* This u320 (or u640). Set IU transfers */
925 		DV_SET(iu, 1);
926 		/* Then set the optional parameters */
927 		DV_SET(rd_strm, 1);
928 		DV_SET(wr_flow, 1);
929 		DV_SET(rti, 1);
930 		if (min_period == 8)
931 			DV_SET(pcomp_en, 1);
932 	} else {
933 		DV_SET(iu, 0);
934 	}
935 
936 	/* now that we've done all this, actually check the bus
937 	 * signal type (if known).  Some devices are stupid on
938 	 * a SE bus and still claim they can try LVD only settings */
939 	if (i->f->get_signalling)
940 		i->f->get_signalling(shost);
941 	if (spi_signalling(shost) == SPI_SIGNAL_SE ||
942 	    spi_signalling(shost) == SPI_SIGNAL_HVD ||
943 	    !spi_support_dt(starget)) {
944 		DV_SET(dt, 0);
945 	} else {
946 		DV_SET(dt, 1);
947 	}
948 	/* set width last because it will pull all the other
949 	 * parameters down to required values */
950 	DV_SET(width, max_width);
951 
952 	/* Do the read only INQUIRY tests */
953 	spi_dv_retrain(sdev, buffer, buffer + sdev->inquiry_len,
954 		       spi_dv_device_compare_inquiry);
955 	/* See if we actually managed to negotiate and sustain DT */
956 	if (i->f->get_dt)
957 		i->f->get_dt(starget);
958 
959 	/* see if the device has an echo buffer.  If it does we can do
960 	 * the SPI pattern write tests.  Because of some broken
961 	 * devices, we *only* try this on a device that has actually
962 	 * negotiated DT */
963 
964 	if (len == -1 && spi_dt(starget))
965 		len = spi_dv_device_get_echo_buffer(sdev, buffer);
966 
967 	if (len <= 0) {
968 		starget_printk(KERN_INFO, starget, "Domain Validation skipping write tests\n");
969 		return;
970 	}
971 
972 	if (len > SPI_MAX_ECHO_BUFFER_SIZE) {
973 		starget_printk(KERN_WARNING, starget, "Echo buffer size %d is too big, trimming to %d\n", len, SPI_MAX_ECHO_BUFFER_SIZE);
974 		len = SPI_MAX_ECHO_BUFFER_SIZE;
975 	}
976 
977 	if (spi_dv_retrain(sdev, buffer, buffer + len,
978 			   spi_dv_device_echo_buffer)
979 	    == SPI_COMPARE_SKIP_TEST) {
980 		/* OK, the stupid drive can't do a write echo buffer
981 		 * test after all, fall back to the read tests */
982 		len = 0;
983 		goto retry;
984 	}
985 }
986 
987 
988 /**	spi_dv_device - Do Domain Validation on the device
989  *	@sdev:		scsi device to validate
990  *
991  *	Performs the domain validation on the given device in the
992  *	current execution thread.  Since DV operations may sleep,
993  *	the current thread must have user context.  Also no SCSI
994  *	related locks that would deadlock I/O issued by the DV may
995  *	be held.
996  */
997 void
998 spi_dv_device(struct scsi_device *sdev)
999 {
1000 	struct scsi_target *starget = sdev->sdev_target;
1001 	const int len = SPI_MAX_ECHO_BUFFER_SIZE*2;
1002 	unsigned int sleep_flags;
1003 	u8 *buffer;
1004 
1005 	/*
1006 	 * Because this function and the power management code both call
1007 	 * scsi_device_quiesce(), it is not safe to perform domain validation
1008 	 * while suspend or resume is in progress. Hence the
1009 	 * lock/unlock_system_sleep() calls.
1010 	 */
1011 	sleep_flags = lock_system_sleep();
1012 
1013 	if (scsi_autopm_get_device(sdev))
1014 		goto unlock_system_sleep;
1015 
1016 	if (unlikely(spi_dv_in_progress(starget)))
1017 		goto put_autopm;
1018 
1019 	if (unlikely(scsi_device_get(sdev)))
1020 		goto put_autopm;
1021 
1022 	spi_dv_in_progress(starget) = 1;
1023 
1024 	buffer = kzalloc(len, GFP_KERNEL);
1025 
1026 	if (unlikely(!buffer))
1027 		goto put_sdev;
1028 
1029 	/* We need to verify that the actual device will quiesce; the
1030 	 * later target quiesce is just a nice to have */
1031 	if (unlikely(scsi_device_quiesce(sdev)))
1032 		goto free_buffer;
1033 
1034 	scsi_target_quiesce(starget);
1035 
1036 	spi_dv_pending(starget) = 1;
1037 	mutex_lock(&spi_dv_mutex(starget));
1038 
1039 	starget_printk(KERN_INFO, starget, "Beginning Domain Validation\n");
1040 
1041 	spi_dv_device_internal(sdev, buffer);
1042 
1043 	starget_printk(KERN_INFO, starget, "Ending Domain Validation\n");
1044 
1045 	mutex_unlock(&spi_dv_mutex(starget));
1046 	spi_dv_pending(starget) = 0;
1047 
1048 	scsi_target_resume(starget);
1049 
1050 	spi_initial_dv(starget) = 1;
1051 
1052 free_buffer:
1053 	kfree(buffer);
1054 
1055 put_sdev:
1056 	spi_dv_in_progress(starget) = 0;
1057 	scsi_device_put(sdev);
1058 put_autopm:
1059 	scsi_autopm_put_device(sdev);
1060 
1061 unlock_system_sleep:
1062 	unlock_system_sleep(sleep_flags);
1063 }
1064 EXPORT_SYMBOL(spi_dv_device);
1065 
1066 struct work_queue_wrapper {
1067 	struct work_struct	work;
1068 	struct scsi_device	*sdev;
1069 };
1070 
1071 static void
1072 spi_dv_device_work_wrapper(struct work_struct *work)
1073 {
1074 	struct work_queue_wrapper *wqw =
1075 		container_of(work, struct work_queue_wrapper, work);
1076 	struct scsi_device *sdev = wqw->sdev;
1077 
1078 	kfree(wqw);
1079 	spi_dv_device(sdev);
1080 	spi_dv_pending(sdev->sdev_target) = 0;
1081 	scsi_device_put(sdev);
1082 }
1083 
1084 
1085 /**
1086  *	spi_schedule_dv_device - schedule domain validation to occur on the device
1087  *	@sdev:	The device to validate
1088  *
1089  *	Identical to spi_dv_device() above, except that the DV will be
1090  *	scheduled to occur in a workqueue later.  All memory allocations
1091  *	are atomic, so may be called from any context including those holding
1092  *	SCSI locks.
1093  */
1094 void
1095 spi_schedule_dv_device(struct scsi_device *sdev)
1096 {
1097 	struct work_queue_wrapper *wqw =
1098 		kmalloc(sizeof(struct work_queue_wrapper), GFP_ATOMIC);
1099 
1100 	if (unlikely(!wqw))
1101 		return;
1102 
1103 	if (unlikely(spi_dv_pending(sdev->sdev_target))) {
1104 		kfree(wqw);
1105 		return;
1106 	}
1107 	/* Set pending early (dv_device doesn't check it, only sets it) */
1108 	spi_dv_pending(sdev->sdev_target) = 1;
1109 	if (unlikely(scsi_device_get(sdev))) {
1110 		kfree(wqw);
1111 		spi_dv_pending(sdev->sdev_target) = 0;
1112 		return;
1113 	}
1114 
1115 	INIT_WORK(&wqw->work, spi_dv_device_work_wrapper);
1116 	wqw->sdev = sdev;
1117 
1118 	schedule_work(&wqw->work);
1119 }
1120 EXPORT_SYMBOL(spi_schedule_dv_device);
1121 
1122 /**
1123  * spi_display_xfer_agreement - Print the current target transfer agreement
1124  * @starget: The target for which to display the agreement
1125  *
1126  * Each SPI port is required to maintain a transfer agreement for each
1127  * other port on the bus.  This function prints a one-line summary of
1128  * the current agreement; more detailed information is available in sysfs.
1129  */
1130 void spi_display_xfer_agreement(struct scsi_target *starget)
1131 {
1132 	struct spi_transport_attrs *tp;
1133 	tp = (struct spi_transport_attrs *)&starget->starget_data;
1134 
1135 	if (tp->offset > 0 && tp->period > 0) {
1136 		unsigned int picosec, kb100;
1137 		char *scsi = "FAST-?";
1138 		char tmp[8];
1139 
1140 		if (tp->period <= SPI_STATIC_PPR) {
1141 			picosec = ppr_to_ps[tp->period];
1142 			switch (tp->period) {
1143 				case  7: scsi = "FAST-320"; break;
1144 				case  8: scsi = "FAST-160"; break;
1145 				case  9: scsi = "FAST-80"; break;
1146 				case 10:
1147 				case 11: scsi = "FAST-40"; break;
1148 				case 12: scsi = "FAST-20"; break;
1149 			}
1150 		} else {
1151 			picosec = tp->period * 4000;
1152 			if (tp->period < 25)
1153 				scsi = "FAST-20";
1154 			else if (tp->period < 50)
1155 				scsi = "FAST-10";
1156 			else
1157 				scsi = "FAST-5";
1158 		}
1159 
1160 		kb100 = (10000000 + picosec / 2) / picosec;
1161 		if (tp->width)
1162 			kb100 *= 2;
1163 		sprint_frac(tmp, picosec, 1000);
1164 
1165 		dev_info(&starget->dev,
1166 			 "%s %sSCSI %d.%d MB/s %s%s%s%s%s%s%s%s (%s ns, offset %d)\n",
1167 			 scsi, tp->width ? "WIDE " : "", kb100/10, kb100 % 10,
1168 			 tp->dt ? "DT" : "ST",
1169 			 tp->iu ? " IU" : "",
1170 			 tp->qas  ? " QAS" : "",
1171 			 tp->rd_strm ? " RDSTRM" : "",
1172 			 tp->rti ? " RTI" : "",
1173 			 tp->wr_flow ? " WRFLOW" : "",
1174 			 tp->pcomp_en ? " PCOMP" : "",
1175 			 tp->hold_mcs ? " HMCS" : "",
1176 			 tmp, tp->offset);
1177 	} else {
1178 		dev_info(&starget->dev, "%sasynchronous\n",
1179 				tp->width ? "wide " : "");
1180 	}
1181 }
1182 EXPORT_SYMBOL(spi_display_xfer_agreement);
1183 
1184 int spi_populate_width_msg(unsigned char *msg, int width)
1185 {
1186 	msg[0] = EXTENDED_MESSAGE;
1187 	msg[1] = 2;
1188 	msg[2] = EXTENDED_WDTR;
1189 	msg[3] = width;
1190 	return 4;
1191 }
1192 EXPORT_SYMBOL_GPL(spi_populate_width_msg);
1193 
1194 int spi_populate_sync_msg(unsigned char *msg, int period, int offset)
1195 {
1196 	msg[0] = EXTENDED_MESSAGE;
1197 	msg[1] = 3;
1198 	msg[2] = EXTENDED_SDTR;
1199 	msg[3] = period;
1200 	msg[4] = offset;
1201 	return 5;
1202 }
1203 EXPORT_SYMBOL_GPL(spi_populate_sync_msg);
1204 
1205 int spi_populate_ppr_msg(unsigned char *msg, int period, int offset,
1206 		int width, int options)
1207 {
1208 	msg[0] = EXTENDED_MESSAGE;
1209 	msg[1] = 6;
1210 	msg[2] = EXTENDED_PPR;
1211 	msg[3] = period;
1212 	msg[4] = 0;
1213 	msg[5] = offset;
1214 	msg[6] = width;
1215 	msg[7] = options;
1216 	return 8;
1217 }
1218 EXPORT_SYMBOL_GPL(spi_populate_ppr_msg);
1219 
1220 /**
1221  * spi_populate_tag_msg - place a tag message in a buffer
1222  * @msg:	pointer to the area to place the tag
1223  * @cmd:	pointer to the scsi command for the tag
1224  *
1225  * Notes:
1226  *	designed to create the correct type of tag message for the
1227  *	particular request.  Returns the size of the tag message.
1228  *	May return 0 if TCQ is disabled for this device.
1229  **/
1230 int spi_populate_tag_msg(unsigned char *msg, struct scsi_cmnd *cmd)
1231 {
1232         if (cmd->flags & SCMD_TAGGED) {
1233 		*msg++ = SIMPLE_QUEUE_TAG;
1234 		*msg++ = scsi_cmd_to_rq(cmd)->tag;
1235         	return 2;
1236 	}
1237 
1238 	return 0;
1239 }
1240 EXPORT_SYMBOL_GPL(spi_populate_tag_msg);
1241 
1242 #ifdef CONFIG_SCSI_CONSTANTS
1243 static const char * const one_byte_msgs[] = {
1244 /* 0x00 */ "Task Complete", NULL /* Extended Message */, "Save Pointers",
1245 /* 0x03 */ "Restore Pointers", "Disconnect", "Initiator Error",
1246 /* 0x06 */ "Abort Task Set", "Message Reject", "Nop", "Message Parity Error",
1247 /* 0x0a */ "Linked Command Complete", "Linked Command Complete w/flag",
1248 /* 0x0c */ "Target Reset", "Abort Task", "Clear Task Set",
1249 /* 0x0f */ "Initiate Recovery", "Release Recovery",
1250 /* 0x11 */ "Terminate Process", "Continue Task", "Target Transfer Disable",
1251 /* 0x14 */ NULL, NULL, "Clear ACA", "LUN Reset"
1252 };
1253 
1254 static const char * const two_byte_msgs[] = {
1255 /* 0x20 */ "Simple Queue Tag", "Head of Queue Tag", "Ordered Queue Tag",
1256 /* 0x23 */ "Ignore Wide Residue", "ACA"
1257 };
1258 
1259 static const char * const extended_msgs[] = {
1260 /* 0x00 */ "Modify Data Pointer", "Synchronous Data Transfer Request",
1261 /* 0x02 */ "SCSI-I Extended Identify", "Wide Data Transfer Request",
1262 /* 0x04 */ "Parallel Protocol Request", "Modify Bidirectional Data Pointer"
1263 };
1264 
1265 static void print_nego(const unsigned char *msg, int per, int off, int width)
1266 {
1267 	if (per) {
1268 		char buf[20];
1269 		period_to_str(buf, msg[per]);
1270 		printk("period = %s ns ", buf);
1271 	}
1272 
1273 	if (off)
1274 		printk("offset = %d ", msg[off]);
1275 	if (width)
1276 		printk("width = %d ", 8 << msg[width]);
1277 }
1278 
1279 static void print_ptr(const unsigned char *msg, int msb, const char *desc)
1280 {
1281 	int ptr = (msg[msb] << 24) | (msg[msb+1] << 16) | (msg[msb+2] << 8) |
1282 			msg[msb+3];
1283 	printk("%s = %d ", desc, ptr);
1284 }
1285 
1286 int spi_print_msg(const unsigned char *msg)
1287 {
1288 	int len = 1, i;
1289 	if (msg[0] == EXTENDED_MESSAGE) {
1290 		len = 2 + msg[1];
1291 		if (len == 2)
1292 			len += 256;
1293 		if (msg[2] < ARRAY_SIZE(extended_msgs))
1294 			printk ("%s ", extended_msgs[msg[2]]);
1295 		else
1296 			printk ("Extended Message, reserved code (0x%02x) ",
1297 				(int) msg[2]);
1298 		switch (msg[2]) {
1299 		case EXTENDED_MODIFY_DATA_POINTER:
1300 			print_ptr(msg, 3, "pointer");
1301 			break;
1302 		case EXTENDED_SDTR:
1303 			print_nego(msg, 3, 4, 0);
1304 			break;
1305 		case EXTENDED_WDTR:
1306 			print_nego(msg, 0, 0, 3);
1307 			break;
1308 		case EXTENDED_PPR:
1309 			print_nego(msg, 3, 5, 6);
1310 			break;
1311 		case EXTENDED_MODIFY_BIDI_DATA_PTR:
1312 			print_ptr(msg, 3, "out");
1313 			print_ptr(msg, 7, "in");
1314 			break;
1315 		default:
1316 		for (i = 2; i < len; ++i)
1317 			printk("%02x ", msg[i]);
1318 		}
1319 	/* Identify */
1320 	} else if (msg[0] & 0x80) {
1321 		printk("Identify disconnect %sallowed %s %d ",
1322 			(msg[0] & 0x40) ? "" : "not ",
1323 			(msg[0] & 0x20) ? "target routine" : "lun",
1324 			msg[0] & 0x7);
1325 	/* Normal One byte */
1326 	} else if (msg[0] < 0x1f) {
1327 		if (msg[0] < ARRAY_SIZE(one_byte_msgs) && one_byte_msgs[msg[0]])
1328 			printk("%s ", one_byte_msgs[msg[0]]);
1329 		else
1330 			printk("reserved (%02x) ", msg[0]);
1331 	} else if (msg[0] == 0x55) {
1332 		printk("QAS Request ");
1333 	/* Two byte */
1334 	} else if (msg[0] <= 0x2f) {
1335 		if ((msg[0] - 0x20) < ARRAY_SIZE(two_byte_msgs))
1336 			printk("%s %02x ", two_byte_msgs[msg[0] - 0x20],
1337 				msg[1]);
1338 		else
1339 			printk("reserved two byte (%02x %02x) ",
1340 				msg[0], msg[1]);
1341 		len = 2;
1342 	} else
1343 		printk("reserved ");
1344 	return len;
1345 }
1346 EXPORT_SYMBOL(spi_print_msg);
1347 
1348 #else  /* ifndef CONFIG_SCSI_CONSTANTS */
1349 
1350 int spi_print_msg(const unsigned char *msg)
1351 {
1352 	int len = 1, i;
1353 
1354 	if (msg[0] == EXTENDED_MESSAGE) {
1355 		len = 2 + msg[1];
1356 		if (len == 2)
1357 			len += 256;
1358 		for (i = 0; i < len; ++i)
1359 			printk("%02x ", msg[i]);
1360 	/* Identify */
1361 	} else if (msg[0] & 0x80) {
1362 		printk("%02x ", msg[0]);
1363 	/* Normal One byte */
1364 	} else if ((msg[0] < 0x1f) || (msg[0] == 0x55)) {
1365 		printk("%02x ", msg[0]);
1366 	/* Two byte */
1367 	} else if (msg[0] <= 0x2f) {
1368 		printk("%02x %02x", msg[0], msg[1]);
1369 		len = 2;
1370 	} else
1371 		printk("%02x ", msg[0]);
1372 	return len;
1373 }
1374 EXPORT_SYMBOL(spi_print_msg);
1375 #endif /* ! CONFIG_SCSI_CONSTANTS */
1376 
1377 static int spi_device_match(struct attribute_container *cont,
1378 			    struct device *dev)
1379 {
1380 	struct scsi_device *sdev;
1381 	struct Scsi_Host *shost;
1382 	struct spi_internal *i;
1383 
1384 	if (!scsi_is_sdev_device(dev))
1385 		return 0;
1386 
1387 	sdev = to_scsi_device(dev);
1388 	shost = sdev->host;
1389 	if (!shost->transportt  || shost->transportt->host_attrs.ac.class
1390 	    != &spi_host_class.class)
1391 		return 0;
1392 	/* Note: this class has no device attributes, so it has
1393 	 * no per-HBA allocation and thus we don't need to distinguish
1394 	 * the attribute containers for the device */
1395 	i = to_spi_internal(shost->transportt);
1396 	if (i->f->deny_binding && i->f->deny_binding(sdev->sdev_target))
1397 		return 0;
1398 	return 1;
1399 }
1400 
1401 static int spi_target_match(struct attribute_container *cont,
1402 			    struct device *dev)
1403 {
1404 	struct Scsi_Host *shost;
1405 	struct scsi_target *starget;
1406 	struct spi_internal *i;
1407 
1408 	if (!scsi_is_target_device(dev))
1409 		return 0;
1410 
1411 	shost = dev_to_shost(dev->parent);
1412 	if (!shost->transportt  || shost->transportt->host_attrs.ac.class
1413 	    != &spi_host_class.class)
1414 		return 0;
1415 
1416 	i = to_spi_internal(shost->transportt);
1417 	starget = to_scsi_target(dev);
1418 
1419 	if (i->f->deny_binding && i->f->deny_binding(starget))
1420 		return 0;
1421 
1422 	return &i->t.target_attrs.ac == cont;
1423 }
1424 
1425 static DECLARE_TRANSPORT_CLASS(spi_transport_class,
1426 			       "spi_transport",
1427 			       spi_setup_transport_attrs,
1428 			       NULL,
1429 			       spi_target_configure);
1430 
1431 static DECLARE_ANON_TRANSPORT_CLASS(spi_device_class,
1432 				    spi_device_match,
1433 				    spi_device_configure);
1434 
1435 static struct attribute *host_attributes[] = {
1436 	&dev_attr_signalling.attr,
1437 	&dev_attr_host_width.attr,
1438 	&dev_attr_hba_id.attr,
1439 	NULL
1440 };
1441 
1442 static struct attribute_group host_attribute_group = {
1443 	.attrs = host_attributes,
1444 };
1445 
1446 static int spi_host_configure(struct transport_container *tc,
1447 			      struct device *dev,
1448 			      struct device *cdev)
1449 {
1450 	struct kobject *kobj = &cdev->kobj;
1451 	struct Scsi_Host *shost = transport_class_to_shost(cdev);
1452 	struct spi_internal *si = to_spi_internal(shost->transportt);
1453 	struct attribute *attr = &dev_attr_signalling.attr;
1454 	int rc = 0;
1455 
1456 	if (si->f->set_signalling)
1457 		rc = sysfs_chmod_file(kobj, attr, attr->mode | S_IWUSR);
1458 
1459 	return rc;
1460 }
1461 
1462 /* returns true if we should be showing the variable.  Also
1463  * overloads the return by setting 1<<1 if the attribute should
1464  * be writeable */
1465 #define TARGET_ATTRIBUTE_HELPER(name) \
1466 	(si->f->show_##name ? S_IRUGO : 0) | \
1467 	(si->f->set_##name ? S_IWUSR : 0)
1468 
1469 static umode_t target_attribute_is_visible(struct kobject *kobj,
1470 					  struct attribute *attr, int i)
1471 {
1472 	struct device *cdev = container_of(kobj, struct device, kobj);
1473 	struct scsi_target *starget = transport_class_to_starget(cdev);
1474 	struct Scsi_Host *shost = transport_class_to_shost(cdev);
1475 	struct spi_internal *si = to_spi_internal(shost->transportt);
1476 
1477 	if (attr == &dev_attr_period.attr &&
1478 	    spi_support_sync(starget))
1479 		return TARGET_ATTRIBUTE_HELPER(period);
1480 	else if (attr == &dev_attr_min_period.attr &&
1481 		 spi_support_sync(starget))
1482 		return TARGET_ATTRIBUTE_HELPER(period);
1483 	else if (attr == &dev_attr_offset.attr &&
1484 		 spi_support_sync(starget))
1485 		return TARGET_ATTRIBUTE_HELPER(offset);
1486 	else if (attr == &dev_attr_max_offset.attr &&
1487 		 spi_support_sync(starget))
1488 		return TARGET_ATTRIBUTE_HELPER(offset);
1489 	else if (attr == &dev_attr_width.attr &&
1490 		 spi_support_wide(starget))
1491 		return TARGET_ATTRIBUTE_HELPER(width);
1492 	else if (attr == &dev_attr_max_width.attr &&
1493 		 spi_support_wide(starget))
1494 		return TARGET_ATTRIBUTE_HELPER(width);
1495 	else if (attr == &dev_attr_iu.attr &&
1496 		 spi_support_ius(starget))
1497 		return TARGET_ATTRIBUTE_HELPER(iu);
1498 	else if (attr == &dev_attr_max_iu.attr &&
1499 		 spi_support_ius(starget))
1500 		return TARGET_ATTRIBUTE_HELPER(iu);
1501 	else if (attr == &dev_attr_dt.attr &&
1502 		 spi_support_dt(starget))
1503 		return TARGET_ATTRIBUTE_HELPER(dt);
1504 	else if (attr == &dev_attr_qas.attr &&
1505 		 spi_support_qas(starget))
1506 		return TARGET_ATTRIBUTE_HELPER(qas);
1507 	else if (attr == &dev_attr_max_qas.attr &&
1508 		 spi_support_qas(starget))
1509 		return TARGET_ATTRIBUTE_HELPER(qas);
1510 	else if (attr == &dev_attr_wr_flow.attr &&
1511 		 spi_support_ius(starget))
1512 		return TARGET_ATTRIBUTE_HELPER(wr_flow);
1513 	else if (attr == &dev_attr_rd_strm.attr &&
1514 		 spi_support_ius(starget))
1515 		return TARGET_ATTRIBUTE_HELPER(rd_strm);
1516 	else if (attr == &dev_attr_rti.attr &&
1517 		 spi_support_ius(starget))
1518 		return TARGET_ATTRIBUTE_HELPER(rti);
1519 	else if (attr == &dev_attr_pcomp_en.attr &&
1520 		 spi_support_ius(starget))
1521 		return TARGET_ATTRIBUTE_HELPER(pcomp_en);
1522 	else if (attr == &dev_attr_hold_mcs.attr &&
1523 		 spi_support_ius(starget))
1524 		return TARGET_ATTRIBUTE_HELPER(hold_mcs);
1525 	else if (attr == &dev_attr_revalidate.attr)
1526 		return S_IWUSR;
1527 
1528 	return 0;
1529 }
1530 
1531 static struct attribute *target_attributes[] = {
1532 	&dev_attr_period.attr,
1533 	&dev_attr_min_period.attr,
1534 	&dev_attr_offset.attr,
1535 	&dev_attr_max_offset.attr,
1536 	&dev_attr_width.attr,
1537 	&dev_attr_max_width.attr,
1538 	&dev_attr_iu.attr,
1539 	&dev_attr_max_iu.attr,
1540 	&dev_attr_dt.attr,
1541 	&dev_attr_qas.attr,
1542 	&dev_attr_max_qas.attr,
1543 	&dev_attr_wr_flow.attr,
1544 	&dev_attr_rd_strm.attr,
1545 	&dev_attr_rti.attr,
1546 	&dev_attr_pcomp_en.attr,
1547 	&dev_attr_hold_mcs.attr,
1548 	&dev_attr_revalidate.attr,
1549 	NULL
1550 };
1551 
1552 static struct attribute_group target_attribute_group = {
1553 	.attrs = target_attributes,
1554 	.is_visible = target_attribute_is_visible,
1555 };
1556 
1557 static int spi_target_configure(struct transport_container *tc,
1558 				struct device *dev,
1559 				struct device *cdev)
1560 {
1561 	struct kobject *kobj = &cdev->kobj;
1562 
1563 	/* force an update based on parameters read from the device */
1564 	sysfs_update_group(kobj, &target_attribute_group);
1565 
1566 	return 0;
1567 }
1568 
1569 struct scsi_transport_template *
1570 spi_attach_transport(struct spi_function_template *ft)
1571 {
1572 	struct spi_internal *i = kzalloc(sizeof(struct spi_internal),
1573 					 GFP_KERNEL);
1574 
1575 	if (unlikely(!i))
1576 		return NULL;
1577 
1578 	i->t.target_attrs.ac.class = &spi_transport_class.class;
1579 	i->t.target_attrs.ac.grp = &target_attribute_group;
1580 	i->t.target_attrs.ac.match = spi_target_match;
1581 	transport_container_register(&i->t.target_attrs);
1582 	i->t.target_size = sizeof(struct spi_transport_attrs);
1583 	i->t.host_attrs.ac.class = &spi_host_class.class;
1584 	i->t.host_attrs.ac.grp = &host_attribute_group;
1585 	i->t.host_attrs.ac.match = spi_host_match;
1586 	transport_container_register(&i->t.host_attrs);
1587 	i->t.host_size = sizeof(struct spi_host_attrs);
1588 	i->f = ft;
1589 
1590 	return &i->t;
1591 }
1592 EXPORT_SYMBOL(spi_attach_transport);
1593 
1594 void spi_release_transport(struct scsi_transport_template *t)
1595 {
1596 	struct spi_internal *i = to_spi_internal(t);
1597 
1598 	transport_container_unregister(&i->t.target_attrs);
1599 	transport_container_unregister(&i->t.host_attrs);
1600 
1601 	kfree(i);
1602 }
1603 EXPORT_SYMBOL(spi_release_transport);
1604 
1605 static __init int spi_transport_init(void)
1606 {
1607 	int error = scsi_dev_info_add_list(SCSI_DEVINFO_SPI,
1608 					   "SCSI Parallel Transport Class");
1609 	if (!error) {
1610 		int i;
1611 
1612 		for (i = 0; spi_static_device_list[i].vendor; i++)
1613 			scsi_dev_info_list_add_keyed(1,	/* compatible */
1614 						     spi_static_device_list[i].vendor,
1615 						     spi_static_device_list[i].model,
1616 						     NULL,
1617 						     spi_static_device_list[i].flags,
1618 						     SCSI_DEVINFO_SPI);
1619 	}
1620 
1621 	error = transport_class_register(&spi_transport_class);
1622 	if (error)
1623 		return error;
1624 	error = anon_transport_class_register(&spi_device_class);
1625 	return transport_class_register(&spi_host_class);
1626 }
1627 
1628 static void __exit spi_transport_exit(void)
1629 {
1630 	transport_class_unregister(&spi_transport_class);
1631 	anon_transport_class_unregister(&spi_device_class);
1632 	transport_class_unregister(&spi_host_class);
1633 	scsi_dev_info_remove_list(SCSI_DEVINFO_SPI);
1634 }
1635 
1636 MODULE_AUTHOR("Martin Hicks");
1637 MODULE_DESCRIPTION("SPI Transport Attributes");
1638 MODULE_LICENSE("GPL");
1639 
1640 module_init(spi_transport_init);
1641 module_exit(spi_transport_exit);
1642