xref: /openbmc/linux/drivers/scsi/scsi_transport_spi.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
1 /*
2  *  Parallel SCSI (SPI) transport specific attributes exported to sysfs.
3  *
4  *  Copyright (c) 2003 Silicon Graphics, Inc.  All rights reserved.
5  *  Copyright (c) 2004, 2005 James Bottomley <James.Bottomley@SteelEye.com>
6  *
7  *  This program is free software; you can redistribute it and/or modify
8  *  it under the terms of the GNU General Public License as published by
9  *  the Free Software Foundation; either version 2 of the License, or
10  *  (at your option) any later version.
11  *
12  *  This program is distributed in the hope that it will be useful,
13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  *  GNU General Public License for more details.
16  *
17  *  You should have received a copy of the GNU General Public License
18  *  along with this program; if not, write to the Free Software
19  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
20  */
21 #include <linux/ctype.h>
22 #include <linux/init.h>
23 #include <linux/module.h>
24 #include <linux/workqueue.h>
25 #include <linux/blkdev.h>
26 #include <linux/mutex.h>
27 #include <linux/sysfs.h>
28 #include <scsi/scsi.h>
29 #include "scsi_priv.h"
30 #include <scsi/scsi_device.h>
31 #include <scsi/scsi_host.h>
32 #include <scsi/scsi_cmnd.h>
33 #include <scsi/scsi_eh.h>
34 #include <scsi/scsi_transport.h>
35 #include <scsi/scsi_transport_spi.h>
36 
37 #define SPI_NUM_ATTRS 14	/* increase this if you add attributes */
38 #define SPI_OTHER_ATTRS 1	/* Increase this if you add "always
39 				 * on" attributes */
40 #define SPI_HOST_ATTRS	1
41 
42 #define SPI_MAX_ECHO_BUFFER_SIZE	4096
43 
44 #define DV_LOOPS	3
45 #define DV_TIMEOUT	(10*HZ)
46 #define DV_RETRIES	3	/* should only need at most
47 				 * two cc/ua clears */
48 
49 /* Private data accessors (keep these out of the header file) */
50 #define spi_dv_in_progress(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_in_progress)
51 #define spi_dv_mutex(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_mutex)
52 
53 struct spi_internal {
54 	struct scsi_transport_template t;
55 	struct spi_function_template *f;
56 };
57 
58 #define to_spi_internal(tmpl)	container_of(tmpl, struct spi_internal, t)
59 
60 static const int ppr_to_ps[] = {
61 	/* The PPR values 0-6 are reserved, fill them in when
62 	 * the committee defines them */
63 	-1,			/* 0x00 */
64 	-1,			/* 0x01 */
65 	-1,			/* 0x02 */
66 	-1,			/* 0x03 */
67 	-1,			/* 0x04 */
68 	-1,			/* 0x05 */
69 	-1,			/* 0x06 */
70 	 3125,			/* 0x07 */
71 	 6250,			/* 0x08 */
72 	12500,			/* 0x09 */
73 	25000,			/* 0x0a */
74 	30300,			/* 0x0b */
75 	50000,			/* 0x0c */
76 };
77 /* The PPR values at which you calculate the period in ns by multiplying
78  * by 4 */
79 #define SPI_STATIC_PPR	0x0c
80 
81 static int sprint_frac(char *dest, int value, int denom)
82 {
83 	int frac = value % denom;
84 	int result = sprintf(dest, "%d", value / denom);
85 
86 	if (frac == 0)
87 		return result;
88 	dest[result++] = '.';
89 
90 	do {
91 		denom /= 10;
92 		sprintf(dest + result, "%d", frac / denom);
93 		result++;
94 		frac %= denom;
95 	} while (frac);
96 
97 	dest[result++] = '\0';
98 	return result;
99 }
100 
101 static int spi_execute(struct scsi_device *sdev, const void *cmd,
102 		       enum dma_data_direction dir,
103 		       void *buffer, unsigned bufflen,
104 		       struct scsi_sense_hdr *sshdr)
105 {
106 	int i, result;
107 	unsigned char sense[SCSI_SENSE_BUFFERSIZE];
108 
109 	for(i = 0; i < DV_RETRIES; i++) {
110 		result = scsi_execute(sdev, cmd, dir, buffer, bufflen,
111 				      sense, DV_TIMEOUT, /* retries */ 1,
112 				      REQ_FAILFAST_DEV |
113 				      REQ_FAILFAST_TRANSPORT |
114 				      REQ_FAILFAST_DRIVER,
115 				      NULL);
116 		if (driver_byte(result) & DRIVER_SENSE) {
117 			struct scsi_sense_hdr sshdr_tmp;
118 			if (!sshdr)
119 				sshdr = &sshdr_tmp;
120 
121 			if (scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE,
122 						 sshdr)
123 			    && sshdr->sense_key == UNIT_ATTENTION)
124 				continue;
125 		}
126 		break;
127 	}
128 	return result;
129 }
130 
131 static struct {
132 	enum spi_signal_type	value;
133 	char			*name;
134 } signal_types[] = {
135 	{ SPI_SIGNAL_UNKNOWN, "unknown" },
136 	{ SPI_SIGNAL_SE, "SE" },
137 	{ SPI_SIGNAL_LVD, "LVD" },
138 	{ SPI_SIGNAL_HVD, "HVD" },
139 };
140 
141 static inline const char *spi_signal_to_string(enum spi_signal_type type)
142 {
143 	int i;
144 
145 	for (i = 0; i < ARRAY_SIZE(signal_types); i++) {
146 		if (type == signal_types[i].value)
147 			return signal_types[i].name;
148 	}
149 	return NULL;
150 }
151 static inline enum spi_signal_type spi_signal_to_value(const char *name)
152 {
153 	int i, len;
154 
155 	for (i = 0; i < ARRAY_SIZE(signal_types); i++) {
156 		len =  strlen(signal_types[i].name);
157 		if (strncmp(name, signal_types[i].name, len) == 0 &&
158 		    (name[len] == '\n' || name[len] == '\0'))
159 			return signal_types[i].value;
160 	}
161 	return SPI_SIGNAL_UNKNOWN;
162 }
163 
164 static int spi_host_setup(struct transport_container *tc, struct device *dev,
165 			  struct device *cdev)
166 {
167 	struct Scsi_Host *shost = dev_to_shost(dev);
168 
169 	spi_signalling(shost) = SPI_SIGNAL_UNKNOWN;
170 
171 	return 0;
172 }
173 
174 static int spi_host_configure(struct transport_container *tc,
175 			      struct device *dev,
176 			      struct device *cdev);
177 
178 static DECLARE_TRANSPORT_CLASS(spi_host_class,
179 			       "spi_host",
180 			       spi_host_setup,
181 			       NULL,
182 			       spi_host_configure);
183 
184 static int spi_host_match(struct attribute_container *cont,
185 			  struct device *dev)
186 {
187 	struct Scsi_Host *shost;
188 
189 	if (!scsi_is_host_device(dev))
190 		return 0;
191 
192 	shost = dev_to_shost(dev);
193 	if (!shost->transportt  || shost->transportt->host_attrs.ac.class
194 	    != &spi_host_class.class)
195 		return 0;
196 
197 	return &shost->transportt->host_attrs.ac == cont;
198 }
199 
200 static int spi_target_configure(struct transport_container *tc,
201 				struct device *dev,
202 				struct device *cdev);
203 
204 static int spi_device_configure(struct transport_container *tc,
205 				struct device *dev,
206 				struct device *cdev)
207 {
208 	struct scsi_device *sdev = to_scsi_device(dev);
209 	struct scsi_target *starget = sdev->sdev_target;
210 
211 	/* Populate the target capability fields with the values
212 	 * gleaned from the device inquiry */
213 
214 	spi_support_sync(starget) = scsi_device_sync(sdev);
215 	spi_support_wide(starget) = scsi_device_wide(sdev);
216 	spi_support_dt(starget) = scsi_device_dt(sdev);
217 	spi_support_dt_only(starget) = scsi_device_dt_only(sdev);
218 	spi_support_ius(starget) = scsi_device_ius(sdev);
219 	spi_support_qas(starget) = scsi_device_qas(sdev);
220 
221 	return 0;
222 }
223 
224 static int spi_setup_transport_attrs(struct transport_container *tc,
225 				     struct device *dev,
226 				     struct device *cdev)
227 {
228 	struct scsi_target *starget = to_scsi_target(dev);
229 
230 	spi_period(starget) = -1;	/* illegal value */
231 	spi_min_period(starget) = 0;
232 	spi_offset(starget) = 0;	/* async */
233 	spi_max_offset(starget) = 255;
234 	spi_width(starget) = 0;	/* narrow */
235 	spi_max_width(starget) = 1;
236 	spi_iu(starget) = 0;	/* no IU */
237 	spi_dt(starget) = 0;	/* ST */
238 	spi_qas(starget) = 0;
239 	spi_wr_flow(starget) = 0;
240 	spi_rd_strm(starget) = 0;
241 	spi_rti(starget) = 0;
242 	spi_pcomp_en(starget) = 0;
243 	spi_hold_mcs(starget) = 0;
244 	spi_dv_pending(starget) = 0;
245 	spi_dv_in_progress(starget) = 0;
246 	spi_initial_dv(starget) = 0;
247 	mutex_init(&spi_dv_mutex(starget));
248 
249 	return 0;
250 }
251 
252 #define spi_transport_show_simple(field, format_string)			\
253 									\
254 static ssize_t								\
255 show_spi_transport_##field(struct device *dev, 			\
256 			   struct device_attribute *attr, char *buf)	\
257 {									\
258 	struct scsi_target *starget = transport_class_to_starget(dev);	\
259 	struct spi_transport_attrs *tp;					\
260 									\
261 	tp = (struct spi_transport_attrs *)&starget->starget_data;	\
262 	return snprintf(buf, 20, format_string, tp->field);		\
263 }
264 
265 #define spi_transport_store_simple(field, format_string)		\
266 									\
267 static ssize_t								\
268 store_spi_transport_##field(struct device *dev, 			\
269 			    struct device_attribute *attr, 		\
270 			    const char *buf, size_t count)		\
271 {									\
272 	int val;							\
273 	struct scsi_target *starget = transport_class_to_starget(dev);	\
274 	struct spi_transport_attrs *tp;					\
275 									\
276 	tp = (struct spi_transport_attrs *)&starget->starget_data;	\
277 	val = simple_strtoul(buf, NULL, 0);				\
278 	tp->field = val;						\
279 	return count;							\
280 }
281 
282 #define spi_transport_show_function(field, format_string)		\
283 									\
284 static ssize_t								\
285 show_spi_transport_##field(struct device *dev, 			\
286 			   struct device_attribute *attr, char *buf)	\
287 {									\
288 	struct scsi_target *starget = transport_class_to_starget(dev);	\
289 	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);	\
290 	struct spi_transport_attrs *tp;					\
291 	struct spi_internal *i = to_spi_internal(shost->transportt);	\
292 	tp = (struct spi_transport_attrs *)&starget->starget_data;	\
293 	if (i->f->get_##field)						\
294 		i->f->get_##field(starget);				\
295 	return snprintf(buf, 20, format_string, tp->field);		\
296 }
297 
298 #define spi_transport_store_function(field, format_string)		\
299 static ssize_t								\
300 store_spi_transport_##field(struct device *dev, 			\
301 			    struct device_attribute *attr,		\
302 			    const char *buf, size_t count)		\
303 {									\
304 	int val;							\
305 	struct scsi_target *starget = transport_class_to_starget(dev);	\
306 	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);	\
307 	struct spi_internal *i = to_spi_internal(shost->transportt);	\
308 									\
309 	if (!i->f->set_##field)						\
310 		return -EINVAL;						\
311 	val = simple_strtoul(buf, NULL, 0);				\
312 	i->f->set_##field(starget, val);				\
313 	return count;							\
314 }
315 
316 #define spi_transport_store_max(field, format_string)			\
317 static ssize_t								\
318 store_spi_transport_##field(struct device *dev, 			\
319 			    struct device_attribute *attr,		\
320 			    const char *buf, size_t count)		\
321 {									\
322 	int val;							\
323 	struct scsi_target *starget = transport_class_to_starget(dev);	\
324 	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);	\
325 	struct spi_internal *i = to_spi_internal(shost->transportt);	\
326 	struct spi_transport_attrs *tp					\
327 		= (struct spi_transport_attrs *)&starget->starget_data;	\
328 									\
329 	if (i->f->set_##field)						\
330 		return -EINVAL;						\
331 	val = simple_strtoul(buf, NULL, 0);				\
332 	if (val > tp->max_##field)					\
333 		val = tp->max_##field;					\
334 	i->f->set_##field(starget, val);				\
335 	return count;							\
336 }
337 
338 #define spi_transport_rd_attr(field, format_string)			\
339 	spi_transport_show_function(field, format_string)		\
340 	spi_transport_store_function(field, format_string)		\
341 static DEVICE_ATTR(field, S_IRUGO,				\
342 		   show_spi_transport_##field,			\
343 		   store_spi_transport_##field);
344 
345 #define spi_transport_simple_attr(field, format_string)			\
346 	spi_transport_show_simple(field, format_string)			\
347 	spi_transport_store_simple(field, format_string)		\
348 static DEVICE_ATTR(field, S_IRUGO,				\
349 		   show_spi_transport_##field,			\
350 		   store_spi_transport_##field);
351 
352 #define spi_transport_max_attr(field, format_string)			\
353 	spi_transport_show_function(field, format_string)		\
354 	spi_transport_store_max(field, format_string)			\
355 	spi_transport_simple_attr(max_##field, format_string)		\
356 static DEVICE_ATTR(field, S_IRUGO,				\
357 		   show_spi_transport_##field,			\
358 		   store_spi_transport_##field);
359 
360 /* The Parallel SCSI Tranport Attributes: */
361 spi_transport_max_attr(offset, "%d\n");
362 spi_transport_max_attr(width, "%d\n");
363 spi_transport_rd_attr(iu, "%d\n");
364 spi_transport_rd_attr(dt, "%d\n");
365 spi_transport_rd_attr(qas, "%d\n");
366 spi_transport_rd_attr(wr_flow, "%d\n");
367 spi_transport_rd_attr(rd_strm, "%d\n");
368 spi_transport_rd_attr(rti, "%d\n");
369 spi_transport_rd_attr(pcomp_en, "%d\n");
370 spi_transport_rd_attr(hold_mcs, "%d\n");
371 
372 /* we only care about the first child device that's a real SCSI device
373  * so we return 1 to terminate the iteration when we find it */
374 static int child_iter(struct device *dev, void *data)
375 {
376 	if (!scsi_is_sdev_device(dev))
377 		return 0;
378 
379 	spi_dv_device(to_scsi_device(dev));
380 	return 1;
381 }
382 
383 static ssize_t
384 store_spi_revalidate(struct device *dev, struct device_attribute *attr,
385 		     const char *buf, size_t count)
386 {
387 	struct scsi_target *starget = transport_class_to_starget(dev);
388 
389 	device_for_each_child(&starget->dev, NULL, child_iter);
390 	return count;
391 }
392 static DEVICE_ATTR(revalidate, S_IWUSR, NULL, store_spi_revalidate);
393 
394 /* Translate the period into ns according to the current spec
395  * for SDTR/PPR messages */
396 static int period_to_str(char *buf, int period)
397 {
398 	int len, picosec;
399 
400 	if (period < 0 || period > 0xff) {
401 		picosec = -1;
402 	} else if (period <= SPI_STATIC_PPR) {
403 		picosec = ppr_to_ps[period];
404 	} else {
405 		picosec = period * 4000;
406 	}
407 
408 	if (picosec == -1) {
409 		len = sprintf(buf, "reserved");
410 	} else {
411 		len = sprint_frac(buf, picosec, 1000);
412 	}
413 
414 	return len;
415 }
416 
417 static ssize_t
418 show_spi_transport_period_helper(char *buf, int period)
419 {
420 	int len = period_to_str(buf, period);
421 	buf[len++] = '\n';
422 	buf[len] = '\0';
423 	return len;
424 }
425 
426 static ssize_t
427 store_spi_transport_period_helper(struct device *dev, const char *buf,
428 				  size_t count, int *periodp)
429 {
430 	int j, picosec, period = -1;
431 	char *endp;
432 
433 	picosec = simple_strtoul(buf, &endp, 10) * 1000;
434 	if (*endp == '.') {
435 		int mult = 100;
436 		do {
437 			endp++;
438 			if (!isdigit(*endp))
439 				break;
440 			picosec += (*endp - '0') * mult;
441 			mult /= 10;
442 		} while (mult > 0);
443 	}
444 
445 	for (j = 0; j <= SPI_STATIC_PPR; j++) {
446 		if (ppr_to_ps[j] < picosec)
447 			continue;
448 		period = j;
449 		break;
450 	}
451 
452 	if (period == -1)
453 		period = picosec / 4000;
454 
455 	if (period > 0xff)
456 		period = 0xff;
457 
458 	*periodp = period;
459 
460 	return count;
461 }
462 
463 static ssize_t
464 show_spi_transport_period(struct device *dev,
465 			  struct device_attribute *attr, char *buf)
466 {
467 	struct scsi_target *starget = transport_class_to_starget(dev);
468 	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
469 	struct spi_internal *i = to_spi_internal(shost->transportt);
470 	struct spi_transport_attrs *tp =
471 		(struct spi_transport_attrs *)&starget->starget_data;
472 
473 	if (i->f->get_period)
474 		i->f->get_period(starget);
475 
476 	return show_spi_transport_period_helper(buf, tp->period);
477 }
478 
479 static ssize_t
480 store_spi_transport_period(struct device *cdev, struct device_attribute *attr,
481 			   const char *buf, size_t count)
482 {
483 	struct scsi_target *starget = transport_class_to_starget(cdev);
484 	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
485 	struct spi_internal *i = to_spi_internal(shost->transportt);
486 	struct spi_transport_attrs *tp =
487 		(struct spi_transport_attrs *)&starget->starget_data;
488 	int period, retval;
489 
490 	if (!i->f->set_period)
491 		return -EINVAL;
492 
493 	retval = store_spi_transport_period_helper(cdev, buf, count, &period);
494 
495 	if (period < tp->min_period)
496 		period = tp->min_period;
497 
498 	i->f->set_period(starget, period);
499 
500 	return retval;
501 }
502 
503 static DEVICE_ATTR(period, S_IRUGO,
504 		   show_spi_transport_period,
505 		   store_spi_transport_period);
506 
507 static ssize_t
508 show_spi_transport_min_period(struct device *cdev,
509 			      struct device_attribute *attr, char *buf)
510 {
511 	struct scsi_target *starget = transport_class_to_starget(cdev);
512 	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
513 	struct spi_internal *i = to_spi_internal(shost->transportt);
514 	struct spi_transport_attrs *tp =
515 		(struct spi_transport_attrs *)&starget->starget_data;
516 
517 	if (!i->f->set_period)
518 		return -EINVAL;
519 
520 	return show_spi_transport_period_helper(buf, tp->min_period);
521 }
522 
523 static ssize_t
524 store_spi_transport_min_period(struct device *cdev,
525 			       struct device_attribute *attr,
526 			       const char *buf, size_t count)
527 {
528 	struct scsi_target *starget = transport_class_to_starget(cdev);
529 	struct spi_transport_attrs *tp =
530 		(struct spi_transport_attrs *)&starget->starget_data;
531 
532 	return store_spi_transport_period_helper(cdev, buf, count,
533 						 &tp->min_period);
534 }
535 
536 
537 static DEVICE_ATTR(min_period, S_IRUGO,
538 		   show_spi_transport_min_period,
539 		   store_spi_transport_min_period);
540 
541 
542 static ssize_t show_spi_host_signalling(struct device *cdev,
543 					struct device_attribute *attr,
544 					char *buf)
545 {
546 	struct Scsi_Host *shost = transport_class_to_shost(cdev);
547 	struct spi_internal *i = to_spi_internal(shost->transportt);
548 
549 	if (i->f->get_signalling)
550 		i->f->get_signalling(shost);
551 
552 	return sprintf(buf, "%s\n", spi_signal_to_string(spi_signalling(shost)));
553 }
554 static ssize_t store_spi_host_signalling(struct device *dev,
555 					 struct device_attribute *attr,
556 					 const char *buf, size_t count)
557 {
558 	struct Scsi_Host *shost = transport_class_to_shost(dev);
559 	struct spi_internal *i = to_spi_internal(shost->transportt);
560 	enum spi_signal_type type = spi_signal_to_value(buf);
561 
562 	if (!i->f->set_signalling)
563 		return -EINVAL;
564 
565 	if (type != SPI_SIGNAL_UNKNOWN)
566 		i->f->set_signalling(shost, type);
567 
568 	return count;
569 }
570 static DEVICE_ATTR(signalling, S_IRUGO,
571 		   show_spi_host_signalling,
572 		   store_spi_host_signalling);
573 
574 #define DV_SET(x, y)			\
575 	if(i->f->set_##x)		\
576 		i->f->set_##x(sdev->sdev_target, y)
577 
578 enum spi_compare_returns {
579 	SPI_COMPARE_SUCCESS,
580 	SPI_COMPARE_FAILURE,
581 	SPI_COMPARE_SKIP_TEST,
582 };
583 
584 
585 /* This is for read/write Domain Validation:  If the device supports
586  * an echo buffer, we do read/write tests to it */
587 static enum spi_compare_returns
588 spi_dv_device_echo_buffer(struct scsi_device *sdev, u8 *buffer,
589 			  u8 *ptr, const int retries)
590 {
591 	int len = ptr - buffer;
592 	int j, k, r, result;
593 	unsigned int pattern = 0x0000ffff;
594 	struct scsi_sense_hdr sshdr;
595 
596 	const char spi_write_buffer[] = {
597 		WRITE_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
598 	};
599 	const char spi_read_buffer[] = {
600 		READ_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
601 	};
602 
603 	/* set up the pattern buffer.  Doesn't matter if we spill
604 	 * slightly beyond since that's where the read buffer is */
605 	for (j = 0; j < len; ) {
606 
607 		/* fill the buffer with counting (test a) */
608 		for ( ; j < min(len, 32); j++)
609 			buffer[j] = j;
610 		k = j;
611 		/* fill the buffer with alternating words of 0x0 and
612 		 * 0xffff (test b) */
613 		for ( ; j < min(len, k + 32); j += 2) {
614 			u16 *word = (u16 *)&buffer[j];
615 
616 			*word = (j & 0x02) ? 0x0000 : 0xffff;
617 		}
618 		k = j;
619 		/* fill with crosstalk (alternating 0x5555 0xaaa)
620                  * (test c) */
621 		for ( ; j < min(len, k + 32); j += 2) {
622 			u16 *word = (u16 *)&buffer[j];
623 
624 			*word = (j & 0x02) ? 0x5555 : 0xaaaa;
625 		}
626 		k = j;
627 		/* fill with shifting bits (test d) */
628 		for ( ; j < min(len, k + 32); j += 4) {
629 			u32 *word = (unsigned int *)&buffer[j];
630 			u32 roll = (pattern & 0x80000000) ? 1 : 0;
631 
632 			*word = pattern;
633 			pattern = (pattern << 1) | roll;
634 		}
635 		/* don't bother with random data (test e) */
636 	}
637 
638 	for (r = 0; r < retries; r++) {
639 		result = spi_execute(sdev, spi_write_buffer, DMA_TO_DEVICE,
640 				     buffer, len, &sshdr);
641 		if(result || !scsi_device_online(sdev)) {
642 
643 			scsi_device_set_state(sdev, SDEV_QUIESCE);
644 			if (scsi_sense_valid(&sshdr)
645 			    && sshdr.sense_key == ILLEGAL_REQUEST
646 			    /* INVALID FIELD IN CDB */
647 			    && sshdr.asc == 0x24 && sshdr.ascq == 0x00)
648 				/* This would mean that the drive lied
649 				 * to us about supporting an echo
650 				 * buffer (unfortunately some Western
651 				 * Digital drives do precisely this)
652 				 */
653 				return SPI_COMPARE_SKIP_TEST;
654 
655 
656 			sdev_printk(KERN_ERR, sdev, "Write Buffer failure %x\n", result);
657 			return SPI_COMPARE_FAILURE;
658 		}
659 
660 		memset(ptr, 0, len);
661 		spi_execute(sdev, spi_read_buffer, DMA_FROM_DEVICE,
662 			    ptr, len, NULL);
663 		scsi_device_set_state(sdev, SDEV_QUIESCE);
664 
665 		if (memcmp(buffer, ptr, len) != 0)
666 			return SPI_COMPARE_FAILURE;
667 	}
668 	return SPI_COMPARE_SUCCESS;
669 }
670 
671 /* This is for the simplest form of Domain Validation: a read test
672  * on the inquiry data from the device */
673 static enum spi_compare_returns
674 spi_dv_device_compare_inquiry(struct scsi_device *sdev, u8 *buffer,
675 			      u8 *ptr, const int retries)
676 {
677 	int r, result;
678 	const int len = sdev->inquiry_len;
679 	const char spi_inquiry[] = {
680 		INQUIRY, 0, 0, 0, len, 0
681 	};
682 
683 	for (r = 0; r < retries; r++) {
684 		memset(ptr, 0, len);
685 
686 		result = spi_execute(sdev, spi_inquiry, DMA_FROM_DEVICE,
687 				     ptr, len, NULL);
688 
689 		if(result || !scsi_device_online(sdev)) {
690 			scsi_device_set_state(sdev, SDEV_QUIESCE);
691 			return SPI_COMPARE_FAILURE;
692 		}
693 
694 		/* If we don't have the inquiry data already, the
695 		 * first read gets it */
696 		if (ptr == buffer) {
697 			ptr += len;
698 			--r;
699 			continue;
700 		}
701 
702 		if (memcmp(buffer, ptr, len) != 0)
703 			/* failure */
704 			return SPI_COMPARE_FAILURE;
705 	}
706 	return SPI_COMPARE_SUCCESS;
707 }
708 
709 static enum spi_compare_returns
710 spi_dv_retrain(struct scsi_device *sdev, u8 *buffer, u8 *ptr,
711 	       enum spi_compare_returns
712 	       (*compare_fn)(struct scsi_device *, u8 *, u8 *, int))
713 {
714 	struct spi_internal *i = to_spi_internal(sdev->host->transportt);
715 	struct scsi_target *starget = sdev->sdev_target;
716 	int period = 0, prevperiod = 0;
717 	enum spi_compare_returns retval;
718 
719 
720 	for (;;) {
721 		int newperiod;
722 		retval = compare_fn(sdev, buffer, ptr, DV_LOOPS);
723 
724 		if (retval == SPI_COMPARE_SUCCESS
725 		    || retval == SPI_COMPARE_SKIP_TEST)
726 			break;
727 
728 		/* OK, retrain, fallback */
729 		if (i->f->get_iu)
730 			i->f->get_iu(starget);
731 		if (i->f->get_qas)
732 			i->f->get_qas(starget);
733 		if (i->f->get_period)
734 			i->f->get_period(sdev->sdev_target);
735 
736 		/* Here's the fallback sequence; first try turning off
737 		 * IU, then QAS (if we can control them), then finally
738 		 * fall down the periods */
739 		if (i->f->set_iu && spi_iu(starget)) {
740 			starget_printk(KERN_ERR, starget, "Domain Validation Disabing Information Units\n");
741 			DV_SET(iu, 0);
742 		} else if (i->f->set_qas && spi_qas(starget)) {
743 			starget_printk(KERN_ERR, starget, "Domain Validation Disabing Quick Arbitration and Selection\n");
744 			DV_SET(qas, 0);
745 		} else {
746 			newperiod = spi_period(starget);
747 			period = newperiod > period ? newperiod : period;
748 			if (period < 0x0d)
749 				period++;
750 			else
751 				period += period >> 1;
752 
753 			if (unlikely(period > 0xff || period == prevperiod)) {
754 				/* Total failure; set to async and return */
755 				starget_printk(KERN_ERR, starget, "Domain Validation Failure, dropping back to Asynchronous\n");
756 				DV_SET(offset, 0);
757 				return SPI_COMPARE_FAILURE;
758 			}
759 			starget_printk(KERN_ERR, starget, "Domain Validation detected failure, dropping back\n");
760 			DV_SET(period, period);
761 			prevperiod = period;
762 		}
763 	}
764 	return retval;
765 }
766 
767 static int
768 spi_dv_device_get_echo_buffer(struct scsi_device *sdev, u8 *buffer)
769 {
770 	int l, result;
771 
772 	/* first off do a test unit ready.  This can error out
773 	 * because of reservations or some other reason.  If it
774 	 * fails, the device won't let us write to the echo buffer
775 	 * so just return failure */
776 
777 	const char spi_test_unit_ready[] = {
778 		TEST_UNIT_READY, 0, 0, 0, 0, 0
779 	};
780 
781 	const char spi_read_buffer_descriptor[] = {
782 		READ_BUFFER, 0x0b, 0, 0, 0, 0, 0, 0, 4, 0
783 	};
784 
785 
786 	/* We send a set of three TURs to clear any outstanding
787 	 * unit attention conditions if they exist (Otherwise the
788 	 * buffer tests won't be happy).  If the TUR still fails
789 	 * (reservation conflict, device not ready, etc) just
790 	 * skip the write tests */
791 	for (l = 0; ; l++) {
792 		result = spi_execute(sdev, spi_test_unit_ready, DMA_NONE,
793 				     NULL, 0, NULL);
794 
795 		if(result) {
796 			if(l >= 3)
797 				return 0;
798 		} else {
799 			/* TUR succeeded */
800 			break;
801 		}
802 	}
803 
804 	result = spi_execute(sdev, spi_read_buffer_descriptor,
805 			     DMA_FROM_DEVICE, buffer, 4, NULL);
806 
807 	if (result)
808 		/* Device has no echo buffer */
809 		return 0;
810 
811 	return buffer[3] + ((buffer[2] & 0x1f) << 8);
812 }
813 
814 static void
815 spi_dv_device_internal(struct scsi_device *sdev, u8 *buffer)
816 {
817 	struct spi_internal *i = to_spi_internal(sdev->host->transportt);
818 	struct scsi_target *starget = sdev->sdev_target;
819 	struct Scsi_Host *shost = sdev->host;
820 	int len = sdev->inquiry_len;
821 	int min_period = spi_min_period(starget);
822 	int max_width = spi_max_width(starget);
823 	/* first set us up for narrow async */
824 	DV_SET(offset, 0);
825 	DV_SET(width, 0);
826 
827 	if (spi_dv_device_compare_inquiry(sdev, buffer, buffer, DV_LOOPS)
828 	    != SPI_COMPARE_SUCCESS) {
829 		starget_printk(KERN_ERR, starget, "Domain Validation Initial Inquiry Failed\n");
830 		/* FIXME: should probably offline the device here? */
831 		return;
832 	}
833 
834 	if (!scsi_device_wide(sdev)) {
835 		spi_max_width(starget) = 0;
836 		max_width = 0;
837 	}
838 
839 	/* test width */
840 	if (i->f->set_width && max_width) {
841 		i->f->set_width(starget, 1);
842 
843 		if (spi_dv_device_compare_inquiry(sdev, buffer,
844 						   buffer + len,
845 						   DV_LOOPS)
846 		    != SPI_COMPARE_SUCCESS) {
847 			starget_printk(KERN_ERR, starget, "Wide Transfers Fail\n");
848 			i->f->set_width(starget, 0);
849 			/* Make sure we don't force wide back on by asking
850 			 * for a transfer period that requires it */
851 			max_width = 0;
852 			if (min_period < 10)
853 				min_period = 10;
854 		}
855 	}
856 
857 	if (!i->f->set_period)
858 		return;
859 
860 	/* device can't handle synchronous */
861 	if (!scsi_device_sync(sdev) && !scsi_device_dt(sdev))
862 		return;
863 
864 	/* len == -1 is the signal that we need to ascertain the
865 	 * presence of an echo buffer before trying to use it.  len ==
866 	 * 0 means we don't have an echo buffer */
867 	len = -1;
868 
869  retry:
870 
871 	/* now set up to the maximum */
872 	DV_SET(offset, spi_max_offset(starget));
873 	DV_SET(period, min_period);
874 
875 	/* try QAS requests; this should be harmless to set if the
876 	 * target supports it */
877 	if (scsi_device_qas(sdev)) {
878 		DV_SET(qas, 1);
879 	} else {
880 		DV_SET(qas, 0);
881 	}
882 
883 	if (scsi_device_ius(sdev) && min_period < 9) {
884 		/* This u320 (or u640). Set IU transfers */
885 		DV_SET(iu, 1);
886 		/* Then set the optional parameters */
887 		DV_SET(rd_strm, 1);
888 		DV_SET(wr_flow, 1);
889 		DV_SET(rti, 1);
890 		if (min_period == 8)
891 			DV_SET(pcomp_en, 1);
892 	} else {
893 		DV_SET(iu, 0);
894 	}
895 
896 	/* now that we've done all this, actually check the bus
897 	 * signal type (if known).  Some devices are stupid on
898 	 * a SE bus and still claim they can try LVD only settings */
899 	if (i->f->get_signalling)
900 		i->f->get_signalling(shost);
901 	if (spi_signalling(shost) == SPI_SIGNAL_SE ||
902 	    spi_signalling(shost) == SPI_SIGNAL_HVD ||
903 	    !scsi_device_dt(sdev)) {
904 		DV_SET(dt, 0);
905 	} else {
906 		DV_SET(dt, 1);
907 	}
908 	/* set width last because it will pull all the other
909 	 * parameters down to required values */
910 	DV_SET(width, max_width);
911 
912 	/* Do the read only INQUIRY tests */
913 	spi_dv_retrain(sdev, buffer, buffer + sdev->inquiry_len,
914 		       spi_dv_device_compare_inquiry);
915 	/* See if we actually managed to negotiate and sustain DT */
916 	if (i->f->get_dt)
917 		i->f->get_dt(starget);
918 
919 	/* see if the device has an echo buffer.  If it does we can do
920 	 * the SPI pattern write tests.  Because of some broken
921 	 * devices, we *only* try this on a device that has actually
922 	 * negotiated DT */
923 
924 	if (len == -1 && spi_dt(starget))
925 		len = spi_dv_device_get_echo_buffer(sdev, buffer);
926 
927 	if (len <= 0) {
928 		starget_printk(KERN_INFO, starget, "Domain Validation skipping write tests\n");
929 		return;
930 	}
931 
932 	if (len > SPI_MAX_ECHO_BUFFER_SIZE) {
933 		starget_printk(KERN_WARNING, starget, "Echo buffer size %d is too big, trimming to %d\n", len, SPI_MAX_ECHO_BUFFER_SIZE);
934 		len = SPI_MAX_ECHO_BUFFER_SIZE;
935 	}
936 
937 	if (spi_dv_retrain(sdev, buffer, buffer + len,
938 			   spi_dv_device_echo_buffer)
939 	    == SPI_COMPARE_SKIP_TEST) {
940 		/* OK, the stupid drive can't do a write echo buffer
941 		 * test after all, fall back to the read tests */
942 		len = 0;
943 		goto retry;
944 	}
945 }
946 
947 
948 /**	spi_dv_device - Do Domain Validation on the device
949  *	@sdev:		scsi device to validate
950  *
951  *	Performs the domain validation on the given device in the
952  *	current execution thread.  Since DV operations may sleep,
953  *	the current thread must have user context.  Also no SCSI
954  *	related locks that would deadlock I/O issued by the DV may
955  *	be held.
956  */
957 void
958 spi_dv_device(struct scsi_device *sdev)
959 {
960 	struct scsi_target *starget = sdev->sdev_target;
961 	u8 *buffer;
962 	const int len = SPI_MAX_ECHO_BUFFER_SIZE*2;
963 
964 	if (unlikely(scsi_device_get(sdev)))
965 		return;
966 
967 	if (unlikely(spi_dv_in_progress(starget)))
968 		return;
969 	spi_dv_in_progress(starget) = 1;
970 
971 	buffer = kzalloc(len, GFP_KERNEL);
972 
973 	if (unlikely(!buffer))
974 		goto out_put;
975 
976 	/* We need to verify that the actual device will quiesce; the
977 	 * later target quiesce is just a nice to have */
978 	if (unlikely(scsi_device_quiesce(sdev)))
979 		goto out_free;
980 
981 	scsi_target_quiesce(starget);
982 
983 	spi_dv_pending(starget) = 1;
984 	mutex_lock(&spi_dv_mutex(starget));
985 
986 	starget_printk(KERN_INFO, starget, "Beginning Domain Validation\n");
987 
988 	spi_dv_device_internal(sdev, buffer);
989 
990 	starget_printk(KERN_INFO, starget, "Ending Domain Validation\n");
991 
992 	mutex_unlock(&spi_dv_mutex(starget));
993 	spi_dv_pending(starget) = 0;
994 
995 	scsi_target_resume(starget);
996 
997 	spi_initial_dv(starget) = 1;
998 
999  out_free:
1000 	kfree(buffer);
1001  out_put:
1002 	spi_dv_in_progress(starget) = 0;
1003 	scsi_device_put(sdev);
1004 }
1005 EXPORT_SYMBOL(spi_dv_device);
1006 
1007 struct work_queue_wrapper {
1008 	struct work_struct	work;
1009 	struct scsi_device	*sdev;
1010 };
1011 
1012 static void
1013 spi_dv_device_work_wrapper(struct work_struct *work)
1014 {
1015 	struct work_queue_wrapper *wqw =
1016 		container_of(work, struct work_queue_wrapper, work);
1017 	struct scsi_device *sdev = wqw->sdev;
1018 
1019 	kfree(wqw);
1020 	spi_dv_device(sdev);
1021 	spi_dv_pending(sdev->sdev_target) = 0;
1022 	scsi_device_put(sdev);
1023 }
1024 
1025 
1026 /**
1027  *	spi_schedule_dv_device - schedule domain validation to occur on the device
1028  *	@sdev:	The device to validate
1029  *
1030  *	Identical to spi_dv_device() above, except that the DV will be
1031  *	scheduled to occur in a workqueue later.  All memory allocations
1032  *	are atomic, so may be called from any context including those holding
1033  *	SCSI locks.
1034  */
1035 void
1036 spi_schedule_dv_device(struct scsi_device *sdev)
1037 {
1038 	struct work_queue_wrapper *wqw =
1039 		kmalloc(sizeof(struct work_queue_wrapper), GFP_ATOMIC);
1040 
1041 	if (unlikely(!wqw))
1042 		return;
1043 
1044 	if (unlikely(spi_dv_pending(sdev->sdev_target))) {
1045 		kfree(wqw);
1046 		return;
1047 	}
1048 	/* Set pending early (dv_device doesn't check it, only sets it) */
1049 	spi_dv_pending(sdev->sdev_target) = 1;
1050 	if (unlikely(scsi_device_get(sdev))) {
1051 		kfree(wqw);
1052 		spi_dv_pending(sdev->sdev_target) = 0;
1053 		return;
1054 	}
1055 
1056 	INIT_WORK(&wqw->work, spi_dv_device_work_wrapper);
1057 	wqw->sdev = sdev;
1058 
1059 	schedule_work(&wqw->work);
1060 }
1061 EXPORT_SYMBOL(spi_schedule_dv_device);
1062 
1063 /**
1064  * spi_display_xfer_agreement - Print the current target transfer agreement
1065  * @starget: The target for which to display the agreement
1066  *
1067  * Each SPI port is required to maintain a transfer agreement for each
1068  * other port on the bus.  This function prints a one-line summary of
1069  * the current agreement; more detailed information is available in sysfs.
1070  */
1071 void spi_display_xfer_agreement(struct scsi_target *starget)
1072 {
1073 	struct spi_transport_attrs *tp;
1074 	tp = (struct spi_transport_attrs *)&starget->starget_data;
1075 
1076 	if (tp->offset > 0 && tp->period > 0) {
1077 		unsigned int picosec, kb100;
1078 		char *scsi = "FAST-?";
1079 		char tmp[8];
1080 
1081 		if (tp->period <= SPI_STATIC_PPR) {
1082 			picosec = ppr_to_ps[tp->period];
1083 			switch (tp->period) {
1084 				case  7: scsi = "FAST-320"; break;
1085 				case  8: scsi = "FAST-160"; break;
1086 				case  9: scsi = "FAST-80"; break;
1087 				case 10:
1088 				case 11: scsi = "FAST-40"; break;
1089 				case 12: scsi = "FAST-20"; break;
1090 			}
1091 		} else {
1092 			picosec = tp->period * 4000;
1093 			if (tp->period < 25)
1094 				scsi = "FAST-20";
1095 			else if (tp->period < 50)
1096 				scsi = "FAST-10";
1097 			else
1098 				scsi = "FAST-5";
1099 		}
1100 
1101 		kb100 = (10000000 + picosec / 2) / picosec;
1102 		if (tp->width)
1103 			kb100 *= 2;
1104 		sprint_frac(tmp, picosec, 1000);
1105 
1106 		dev_info(&starget->dev,
1107 			 "%s %sSCSI %d.%d MB/s %s%s%s%s%s%s%s%s (%s ns, offset %d)\n",
1108 			 scsi, tp->width ? "WIDE " : "", kb100/10, kb100 % 10,
1109 			 tp->dt ? "DT" : "ST",
1110 			 tp->iu ? " IU" : "",
1111 			 tp->qas  ? " QAS" : "",
1112 			 tp->rd_strm ? " RDSTRM" : "",
1113 			 tp->rti ? " RTI" : "",
1114 			 tp->wr_flow ? " WRFLOW" : "",
1115 			 tp->pcomp_en ? " PCOMP" : "",
1116 			 tp->hold_mcs ? " HMCS" : "",
1117 			 tmp, tp->offset);
1118 	} else {
1119 		dev_info(&starget->dev, "%sasynchronous\n",
1120 				tp->width ? "wide " : "");
1121 	}
1122 }
1123 EXPORT_SYMBOL(spi_display_xfer_agreement);
1124 
1125 int spi_populate_width_msg(unsigned char *msg, int width)
1126 {
1127 	msg[0] = EXTENDED_MESSAGE;
1128 	msg[1] = 2;
1129 	msg[2] = EXTENDED_WDTR;
1130 	msg[3] = width;
1131 	return 4;
1132 }
1133 EXPORT_SYMBOL_GPL(spi_populate_width_msg);
1134 
1135 int spi_populate_sync_msg(unsigned char *msg, int period, int offset)
1136 {
1137 	msg[0] = EXTENDED_MESSAGE;
1138 	msg[1] = 3;
1139 	msg[2] = EXTENDED_SDTR;
1140 	msg[3] = period;
1141 	msg[4] = offset;
1142 	return 5;
1143 }
1144 EXPORT_SYMBOL_GPL(spi_populate_sync_msg);
1145 
1146 int spi_populate_ppr_msg(unsigned char *msg, int period, int offset,
1147 		int width, int options)
1148 {
1149 	msg[0] = EXTENDED_MESSAGE;
1150 	msg[1] = 6;
1151 	msg[2] = EXTENDED_PPR;
1152 	msg[3] = period;
1153 	msg[4] = 0;
1154 	msg[5] = offset;
1155 	msg[6] = width;
1156 	msg[7] = options;
1157 	return 8;
1158 }
1159 EXPORT_SYMBOL_GPL(spi_populate_ppr_msg);
1160 
1161 #ifdef CONFIG_SCSI_CONSTANTS
1162 static const char * const one_byte_msgs[] = {
1163 /* 0x00 */ "Task Complete", NULL /* Extended Message */, "Save Pointers",
1164 /* 0x03 */ "Restore Pointers", "Disconnect", "Initiator Error",
1165 /* 0x06 */ "Abort Task Set", "Message Reject", "Nop", "Message Parity Error",
1166 /* 0x0a */ "Linked Command Complete", "Linked Command Complete w/flag",
1167 /* 0x0c */ "Target Reset", "Abort Task", "Clear Task Set",
1168 /* 0x0f */ "Initiate Recovery", "Release Recovery",
1169 /* 0x11 */ "Terminate Process", "Continue Task", "Target Transfer Disable",
1170 /* 0x14 */ NULL, NULL, "Clear ACA", "LUN Reset"
1171 };
1172 
1173 static const char * const two_byte_msgs[] = {
1174 /* 0x20 */ "Simple Queue Tag", "Head of Queue Tag", "Ordered Queue Tag",
1175 /* 0x23 */ "Ignore Wide Residue", "ACA"
1176 };
1177 
1178 static const char * const extended_msgs[] = {
1179 /* 0x00 */ "Modify Data Pointer", "Synchronous Data Transfer Request",
1180 /* 0x02 */ "SCSI-I Extended Identify", "Wide Data Transfer Request",
1181 /* 0x04 */ "Parallel Protocol Request", "Modify Bidirectional Data Pointer"
1182 };
1183 
1184 static void print_nego(const unsigned char *msg, int per, int off, int width)
1185 {
1186 	if (per) {
1187 		char buf[20];
1188 		period_to_str(buf, msg[per]);
1189 		printk("period = %s ns ", buf);
1190 	}
1191 
1192 	if (off)
1193 		printk("offset = %d ", msg[off]);
1194 	if (width)
1195 		printk("width = %d ", 8 << msg[width]);
1196 }
1197 
1198 static void print_ptr(const unsigned char *msg, int msb, const char *desc)
1199 {
1200 	int ptr = (msg[msb] << 24) | (msg[msb+1] << 16) | (msg[msb+2] << 8) |
1201 			msg[msb+3];
1202 	printk("%s = %d ", desc, ptr);
1203 }
1204 
1205 int spi_print_msg(const unsigned char *msg)
1206 {
1207 	int len = 1, i;
1208 	if (msg[0] == EXTENDED_MESSAGE) {
1209 		len = 2 + msg[1];
1210 		if (len == 2)
1211 			len += 256;
1212 		if (msg[2] < ARRAY_SIZE(extended_msgs))
1213 			printk ("%s ", extended_msgs[msg[2]]);
1214 		else
1215 			printk ("Extended Message, reserved code (0x%02x) ",
1216 				(int) msg[2]);
1217 		switch (msg[2]) {
1218 		case EXTENDED_MODIFY_DATA_POINTER:
1219 			print_ptr(msg, 3, "pointer");
1220 			break;
1221 		case EXTENDED_SDTR:
1222 			print_nego(msg, 3, 4, 0);
1223 			break;
1224 		case EXTENDED_WDTR:
1225 			print_nego(msg, 0, 0, 3);
1226 			break;
1227 		case EXTENDED_PPR:
1228 			print_nego(msg, 3, 5, 6);
1229 			break;
1230 		case EXTENDED_MODIFY_BIDI_DATA_PTR:
1231 			print_ptr(msg, 3, "out");
1232 			print_ptr(msg, 7, "in");
1233 			break;
1234 		default:
1235 		for (i = 2; i < len; ++i)
1236 			printk("%02x ", msg[i]);
1237 		}
1238 	/* Identify */
1239 	} else if (msg[0] & 0x80) {
1240 		printk("Identify disconnect %sallowed %s %d ",
1241 			(msg[0] & 0x40) ? "" : "not ",
1242 			(msg[0] & 0x20) ? "target routine" : "lun",
1243 			msg[0] & 0x7);
1244 	/* Normal One byte */
1245 	} else if (msg[0] < 0x1f) {
1246 		if (msg[0] < ARRAY_SIZE(one_byte_msgs) && one_byte_msgs[msg[0]])
1247 			printk("%s ", one_byte_msgs[msg[0]]);
1248 		else
1249 			printk("reserved (%02x) ", msg[0]);
1250 	} else if (msg[0] == 0x55) {
1251 		printk("QAS Request ");
1252 	/* Two byte */
1253 	} else if (msg[0] <= 0x2f) {
1254 		if ((msg[0] - 0x20) < ARRAY_SIZE(two_byte_msgs))
1255 			printk("%s %02x ", two_byte_msgs[msg[0] - 0x20],
1256 				msg[1]);
1257 		else
1258 			printk("reserved two byte (%02x %02x) ",
1259 				msg[0], msg[1]);
1260 		len = 2;
1261 	} else
1262 		printk("reserved ");
1263 	return len;
1264 }
1265 EXPORT_SYMBOL(spi_print_msg);
1266 
1267 #else  /* ifndef CONFIG_SCSI_CONSTANTS */
1268 
1269 int spi_print_msg(const unsigned char *msg)
1270 {
1271 	int len = 1, i;
1272 
1273 	if (msg[0] == EXTENDED_MESSAGE) {
1274 		len = 2 + msg[1];
1275 		if (len == 2)
1276 			len += 256;
1277 		for (i = 0; i < len; ++i)
1278 			printk("%02x ", msg[i]);
1279 	/* Identify */
1280 	} else if (msg[0] & 0x80) {
1281 		printk("%02x ", msg[0]);
1282 	/* Normal One byte */
1283 	} else if ((msg[0] < 0x1f) || (msg[0] == 0x55)) {
1284 		printk("%02x ", msg[0]);
1285 	/* Two byte */
1286 	} else if (msg[0] <= 0x2f) {
1287 		printk("%02x %02x", msg[0], msg[1]);
1288 		len = 2;
1289 	} else
1290 		printk("%02x ", msg[0]);
1291 	return len;
1292 }
1293 EXPORT_SYMBOL(spi_print_msg);
1294 #endif /* ! CONFIG_SCSI_CONSTANTS */
1295 
1296 static int spi_device_match(struct attribute_container *cont,
1297 			    struct device *dev)
1298 {
1299 	struct scsi_device *sdev;
1300 	struct Scsi_Host *shost;
1301 	struct spi_internal *i;
1302 
1303 	if (!scsi_is_sdev_device(dev))
1304 		return 0;
1305 
1306 	sdev = to_scsi_device(dev);
1307 	shost = sdev->host;
1308 	if (!shost->transportt  || shost->transportt->host_attrs.ac.class
1309 	    != &spi_host_class.class)
1310 		return 0;
1311 	/* Note: this class has no device attributes, so it has
1312 	 * no per-HBA allocation and thus we don't need to distinguish
1313 	 * the attribute containers for the device */
1314 	i = to_spi_internal(shost->transportt);
1315 	if (i->f->deny_binding && i->f->deny_binding(sdev->sdev_target))
1316 		return 0;
1317 	return 1;
1318 }
1319 
1320 static int spi_target_match(struct attribute_container *cont,
1321 			    struct device *dev)
1322 {
1323 	struct Scsi_Host *shost;
1324 	struct scsi_target *starget;
1325 	struct spi_internal *i;
1326 
1327 	if (!scsi_is_target_device(dev))
1328 		return 0;
1329 
1330 	shost = dev_to_shost(dev->parent);
1331 	if (!shost->transportt  || shost->transportt->host_attrs.ac.class
1332 	    != &spi_host_class.class)
1333 		return 0;
1334 
1335 	i = to_spi_internal(shost->transportt);
1336 	starget = to_scsi_target(dev);
1337 
1338 	if (i->f->deny_binding && i->f->deny_binding(starget))
1339 		return 0;
1340 
1341 	return &i->t.target_attrs.ac == cont;
1342 }
1343 
1344 static DECLARE_TRANSPORT_CLASS(spi_transport_class,
1345 			       "spi_transport",
1346 			       spi_setup_transport_attrs,
1347 			       NULL,
1348 			       spi_target_configure);
1349 
1350 static DECLARE_ANON_TRANSPORT_CLASS(spi_device_class,
1351 				    spi_device_match,
1352 				    spi_device_configure);
1353 
1354 static struct attribute *host_attributes[] = {
1355 	&dev_attr_signalling.attr,
1356 	NULL
1357 };
1358 
1359 static struct attribute_group host_attribute_group = {
1360 	.attrs = host_attributes,
1361 };
1362 
1363 static int spi_host_configure(struct transport_container *tc,
1364 			      struct device *dev,
1365 			      struct device *cdev)
1366 {
1367 	struct kobject *kobj = &cdev->kobj;
1368 	struct Scsi_Host *shost = transport_class_to_shost(cdev);
1369 	struct spi_internal *si = to_spi_internal(shost->transportt);
1370 	struct attribute *attr = &dev_attr_signalling.attr;
1371 	int rc = 0;
1372 
1373 	if (si->f->set_signalling)
1374 		rc = sysfs_chmod_file(kobj, attr, attr->mode | S_IWUSR);
1375 
1376 	return rc;
1377 }
1378 
1379 /* returns true if we should be showing the variable.  Also
1380  * overloads the return by setting 1<<1 if the attribute should
1381  * be writeable */
1382 #define TARGET_ATTRIBUTE_HELPER(name) \
1383 	(si->f->show_##name ? S_IRUGO : 0) | \
1384 	(si->f->set_##name ? S_IWUSR : 0)
1385 
1386 static mode_t target_attribute_is_visible(struct kobject *kobj,
1387 					  struct attribute *attr, int i)
1388 {
1389 	struct device *cdev = container_of(kobj, struct device, kobj);
1390 	struct scsi_target *starget = transport_class_to_starget(cdev);
1391 	struct Scsi_Host *shost = transport_class_to_shost(cdev);
1392 	struct spi_internal *si = to_spi_internal(shost->transportt);
1393 
1394 	if (attr == &dev_attr_period.attr &&
1395 	    spi_support_sync(starget))
1396 		return TARGET_ATTRIBUTE_HELPER(period);
1397 	else if (attr == &dev_attr_min_period.attr &&
1398 		 spi_support_sync(starget))
1399 		return TARGET_ATTRIBUTE_HELPER(period);
1400 	else if (attr == &dev_attr_offset.attr &&
1401 		 spi_support_sync(starget))
1402 		return TARGET_ATTRIBUTE_HELPER(offset);
1403 	else if (attr == &dev_attr_max_offset.attr &&
1404 		 spi_support_sync(starget))
1405 		return TARGET_ATTRIBUTE_HELPER(offset);
1406 	else if (attr == &dev_attr_width.attr &&
1407 		 spi_support_wide(starget))
1408 		return TARGET_ATTRIBUTE_HELPER(width);
1409 	else if (attr == &dev_attr_max_width.attr &&
1410 		 spi_support_wide(starget))
1411 		return TARGET_ATTRIBUTE_HELPER(width);
1412 	else if (attr == &dev_attr_iu.attr &&
1413 		 spi_support_ius(starget))
1414 		return TARGET_ATTRIBUTE_HELPER(iu);
1415 	else if (attr == &dev_attr_dt.attr &&
1416 		 spi_support_dt(starget))
1417 		return TARGET_ATTRIBUTE_HELPER(dt);
1418 	else if (attr == &dev_attr_qas.attr &&
1419 		 spi_support_qas(starget))
1420 		return TARGET_ATTRIBUTE_HELPER(qas);
1421 	else if (attr == &dev_attr_wr_flow.attr &&
1422 		 spi_support_ius(starget))
1423 		return TARGET_ATTRIBUTE_HELPER(wr_flow);
1424 	else if (attr == &dev_attr_rd_strm.attr &&
1425 		 spi_support_ius(starget))
1426 		return TARGET_ATTRIBUTE_HELPER(rd_strm);
1427 	else if (attr == &dev_attr_rti.attr &&
1428 		 spi_support_ius(starget))
1429 		return TARGET_ATTRIBUTE_HELPER(rti);
1430 	else if (attr == &dev_attr_pcomp_en.attr &&
1431 		 spi_support_ius(starget))
1432 		return TARGET_ATTRIBUTE_HELPER(pcomp_en);
1433 	else if (attr == &dev_attr_hold_mcs.attr &&
1434 		 spi_support_ius(starget))
1435 		return TARGET_ATTRIBUTE_HELPER(hold_mcs);
1436 	else if (attr == &dev_attr_revalidate.attr)
1437 		return S_IWUSR;
1438 
1439 	return 0;
1440 }
1441 
1442 static struct attribute *target_attributes[] = {
1443 	&dev_attr_period.attr,
1444 	&dev_attr_min_period.attr,
1445 	&dev_attr_offset.attr,
1446 	&dev_attr_max_offset.attr,
1447 	&dev_attr_width.attr,
1448 	&dev_attr_max_width.attr,
1449 	&dev_attr_iu.attr,
1450 	&dev_attr_dt.attr,
1451 	&dev_attr_qas.attr,
1452 	&dev_attr_wr_flow.attr,
1453 	&dev_attr_rd_strm.attr,
1454 	&dev_attr_rti.attr,
1455 	&dev_attr_pcomp_en.attr,
1456 	&dev_attr_hold_mcs.attr,
1457 	&dev_attr_revalidate.attr,
1458 	NULL
1459 };
1460 
1461 static struct attribute_group target_attribute_group = {
1462 	.attrs = target_attributes,
1463 	.is_visible = target_attribute_is_visible,
1464 };
1465 
1466 static int spi_target_configure(struct transport_container *tc,
1467 				struct device *dev,
1468 				struct device *cdev)
1469 {
1470 	struct kobject *kobj = &cdev->kobj;
1471 
1472 	/* force an update based on parameters read from the device */
1473 	sysfs_update_group(kobj, &target_attribute_group);
1474 
1475 	return 0;
1476 }
1477 
1478 struct scsi_transport_template *
1479 spi_attach_transport(struct spi_function_template *ft)
1480 {
1481 	struct spi_internal *i = kzalloc(sizeof(struct spi_internal),
1482 					 GFP_KERNEL);
1483 
1484 	if (unlikely(!i))
1485 		return NULL;
1486 
1487 	i->t.target_attrs.ac.class = &spi_transport_class.class;
1488 	i->t.target_attrs.ac.grp = &target_attribute_group;
1489 	i->t.target_attrs.ac.match = spi_target_match;
1490 	transport_container_register(&i->t.target_attrs);
1491 	i->t.target_size = sizeof(struct spi_transport_attrs);
1492 	i->t.host_attrs.ac.class = &spi_host_class.class;
1493 	i->t.host_attrs.ac.grp = &host_attribute_group;
1494 	i->t.host_attrs.ac.match = spi_host_match;
1495 	transport_container_register(&i->t.host_attrs);
1496 	i->t.host_size = sizeof(struct spi_host_attrs);
1497 	i->f = ft;
1498 
1499 	return &i->t;
1500 }
1501 EXPORT_SYMBOL(spi_attach_transport);
1502 
1503 void spi_release_transport(struct scsi_transport_template *t)
1504 {
1505 	struct spi_internal *i = to_spi_internal(t);
1506 
1507 	transport_container_unregister(&i->t.target_attrs);
1508 	transport_container_unregister(&i->t.host_attrs);
1509 
1510 	kfree(i);
1511 }
1512 EXPORT_SYMBOL(spi_release_transport);
1513 
1514 static __init int spi_transport_init(void)
1515 {
1516 	int error = transport_class_register(&spi_transport_class);
1517 	if (error)
1518 		return error;
1519 	error = anon_transport_class_register(&spi_device_class);
1520 	return transport_class_register(&spi_host_class);
1521 }
1522 
1523 static void __exit spi_transport_exit(void)
1524 {
1525 	transport_class_unregister(&spi_transport_class);
1526 	anon_transport_class_unregister(&spi_device_class);
1527 	transport_class_unregister(&spi_host_class);
1528 }
1529 
1530 MODULE_AUTHOR("Martin Hicks");
1531 MODULE_DESCRIPTION("SPI Transport Attributes");
1532 MODULE_LICENSE("GPL");
1533 
1534 module_init(spi_transport_init);
1535 module_exit(spi_transport_exit);
1536