xref: /linux/drivers/scsi/scsi_transport_spi.c (revision 9ce7677cfd7cd871adb457c80bea3b581b839641)
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 <asm/semaphore.h>
27 #include <scsi/scsi.h>
28 #include "scsi_priv.h"
29 #include <scsi/scsi_device.h>
30 #include <scsi/scsi_host.h>
31 #include <scsi/scsi_cmnd.h>
32 #include <scsi/scsi_eh.h>
33 #include <scsi/scsi_transport.h>
34 #include <scsi/scsi_transport_spi.h>
35 
36 #define SPI_NUM_ATTRS 14	/* increase this if you add attributes */
37 #define SPI_OTHER_ATTRS 1	/* Increase this if you add "always
38 				 * on" attributes */
39 #define SPI_HOST_ATTRS	1
40 
41 #define SPI_MAX_ECHO_BUFFER_SIZE	4096
42 
43 #define DV_LOOPS	3
44 #define DV_TIMEOUT	(10*HZ)
45 #define DV_RETRIES	3	/* should only need at most
46 				 * two cc/ua clears */
47 
48 /* Private data accessors (keep these out of the header file) */
49 #define spi_dv_pending(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_pending)
50 #define spi_dv_sem(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_sem)
51 
52 struct spi_internal {
53 	struct scsi_transport_template t;
54 	struct spi_function_template *f;
55 	/* The actual attributes */
56 	struct class_device_attribute private_attrs[SPI_NUM_ATTRS];
57 	/* The array of null terminated pointers to attributes
58 	 * needed by scsi_sysfs.c */
59 	struct class_device_attribute *attrs[SPI_NUM_ATTRS + SPI_OTHER_ATTRS + 1];
60 	struct class_device_attribute private_host_attrs[SPI_HOST_ATTRS];
61 	struct class_device_attribute *host_attrs[SPI_HOST_ATTRS + 1];
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 dma_data_direction dir,
109 		       void *buffer, unsigned bufflen,
110 		       struct scsi_sense_hdr *sshdr)
111 {
112 	int i, result;
113 	unsigned char sense[SCSI_SENSE_BUFFERSIZE];
114 
115 	for(i = 0; i < DV_RETRIES; i++) {
116 		result = scsi_execute(sdev, cmd, dir, buffer, bufflen,
117 				      sense, DV_TIMEOUT, /* retries */ 1,
118 				      REQ_FAILFAST);
119 		if (result & DRIVER_SENSE) {
120 			struct scsi_sense_hdr sshdr_tmp;
121 			if (!sshdr)
122 				sshdr = &sshdr_tmp;
123 
124 			if (scsi_normalize_sense(sense, sizeof(*sense),
125 						 sshdr)
126 			    && sshdr->sense_key == UNIT_ATTENTION)
127 				continue;
128 		}
129 		break;
130 	}
131 	return result;
132 }
133 
134 static struct {
135 	enum spi_signal_type	value;
136 	char			*name;
137 } signal_types[] = {
138 	{ SPI_SIGNAL_UNKNOWN, "unknown" },
139 	{ SPI_SIGNAL_SE, "SE" },
140 	{ SPI_SIGNAL_LVD, "LVD" },
141 	{ SPI_SIGNAL_HVD, "HVD" },
142 };
143 
144 static inline const char *spi_signal_to_string(enum spi_signal_type type)
145 {
146 	int i;
147 
148 	for (i = 0; i < sizeof(signal_types)/sizeof(signal_types[0]); i++) {
149 		if (type == signal_types[i].value)
150 			return signal_types[i].name;
151 	}
152 	return NULL;
153 }
154 static inline enum spi_signal_type spi_signal_to_value(const char *name)
155 {
156 	int i, len;
157 
158 	for (i = 0; i < sizeof(signal_types)/sizeof(signal_types[0]); i++) {
159 		len =  strlen(signal_types[i].name);
160 		if (strncmp(name, signal_types[i].name, len) == 0 &&
161 		    (name[len] == '\n' || name[len] == '\0'))
162 			return signal_types[i].value;
163 	}
164 	return SPI_SIGNAL_UNKNOWN;
165 }
166 
167 static int spi_host_setup(struct transport_container *tc, struct device *dev,
168 			  struct class_device *cdev)
169 {
170 	struct Scsi_Host *shost = dev_to_shost(dev);
171 
172 	spi_signalling(shost) = SPI_SIGNAL_UNKNOWN;
173 
174 	return 0;
175 }
176 
177 static DECLARE_TRANSPORT_CLASS(spi_host_class,
178 			       "spi_host",
179 			       spi_host_setup,
180 			       NULL,
181 			       NULL);
182 
183 static int spi_host_match(struct attribute_container *cont,
184 			  struct device *dev)
185 {
186 	struct Scsi_Host *shost;
187 	struct spi_internal *i;
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 	i = to_spi_internal(shost->transportt);
198 
199 	return &i->t.host_attrs.ac == cont;
200 }
201 
202 static int spi_device_configure(struct transport_container *tc,
203 				struct device *dev,
204 				struct class_device *cdev)
205 {
206 	struct scsi_device *sdev = to_scsi_device(dev);
207 	struct scsi_target *starget = sdev->sdev_target;
208 
209 	/* Populate the target capability fields with the values
210 	 * gleaned from the device inquiry */
211 
212 	spi_support_sync(starget) = scsi_device_sync(sdev);
213 	spi_support_wide(starget) = scsi_device_wide(sdev);
214 	spi_support_dt(starget) = scsi_device_dt(sdev);
215 	spi_support_dt_only(starget) = scsi_device_dt_only(sdev);
216 	spi_support_ius(starget) = scsi_device_ius(sdev);
217 	spi_support_qas(starget) = scsi_device_qas(sdev);
218 
219 	return 0;
220 }
221 
222 static int spi_setup_transport_attrs(struct transport_container *tc,
223 				     struct device *dev,
224 				     struct class_device *cdev)
225 {
226 	struct scsi_target *starget = to_scsi_target(dev);
227 
228 	spi_period(starget) = -1;	/* illegal value */
229 	spi_min_period(starget) = 0;
230 	spi_offset(starget) = 0;	/* async */
231 	spi_max_offset(starget) = 255;
232 	spi_width(starget) = 0;	/* narrow */
233 	spi_max_width(starget) = 1;
234 	spi_iu(starget) = 0;	/* no IU */
235 	spi_dt(starget) = 0;	/* ST */
236 	spi_qas(starget) = 0;
237 	spi_wr_flow(starget) = 0;
238 	spi_rd_strm(starget) = 0;
239 	spi_rti(starget) = 0;
240 	spi_pcomp_en(starget) = 0;
241 	spi_hold_mcs(starget) = 0;
242 	spi_dv_pending(starget) = 0;
243 	spi_initial_dv(starget) = 0;
244 	init_MUTEX(&spi_dv_sem(starget));
245 
246 	return 0;
247 }
248 
249 #define spi_transport_show_simple(field, format_string)			\
250 									\
251 static ssize_t								\
252 show_spi_transport_##field(struct class_device *cdev, char *buf)	\
253 {									\
254 	struct scsi_target *starget = transport_class_to_starget(cdev);	\
255 	struct spi_transport_attrs *tp;					\
256 									\
257 	tp = (struct spi_transport_attrs *)&starget->starget_data;	\
258 	return snprintf(buf, 20, format_string, tp->field);		\
259 }
260 
261 #define spi_transport_store_simple(field, format_string)		\
262 									\
263 static ssize_t								\
264 store_spi_transport_##field(struct class_device *cdev, const char *buf, \
265 			    size_t count)				\
266 {									\
267 	int val;							\
268 	struct scsi_target *starget = transport_class_to_starget(cdev);	\
269 	struct spi_transport_attrs *tp;					\
270 									\
271 	tp = (struct spi_transport_attrs *)&starget->starget_data;	\
272 	val = simple_strtoul(buf, NULL, 0);				\
273 	tp->field = val;						\
274 	return count;							\
275 }
276 
277 #define spi_transport_show_function(field, format_string)		\
278 									\
279 static ssize_t								\
280 show_spi_transport_##field(struct class_device *cdev, char *buf)	\
281 {									\
282 	struct scsi_target *starget = transport_class_to_starget(cdev);	\
283 	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);	\
284 	struct spi_transport_attrs *tp;					\
285 	struct spi_internal *i = to_spi_internal(shost->transportt);	\
286 	tp = (struct spi_transport_attrs *)&starget->starget_data;	\
287 	if (i->f->get_##field)						\
288 		i->f->get_##field(starget);				\
289 	return snprintf(buf, 20, format_string, tp->field);		\
290 }
291 
292 #define spi_transport_store_function(field, format_string)		\
293 static ssize_t								\
294 store_spi_transport_##field(struct class_device *cdev, const char *buf, \
295 			    size_t count)				\
296 {									\
297 	int val;							\
298 	struct scsi_target *starget = transport_class_to_starget(cdev);	\
299 	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);	\
300 	struct spi_internal *i = to_spi_internal(shost->transportt);	\
301 									\
302 	val = simple_strtoul(buf, NULL, 0);				\
303 	i->f->set_##field(starget, val);			\
304 	return count;							\
305 }
306 
307 #define spi_transport_store_max(field, format_string)			\
308 static ssize_t								\
309 store_spi_transport_##field(struct class_device *cdev, const char *buf, \
310 			    size_t count)				\
311 {									\
312 	int val;							\
313 	struct scsi_target *starget = transport_class_to_starget(cdev);	\
314 	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);	\
315 	struct spi_internal *i = to_spi_internal(shost->transportt);	\
316 	struct spi_transport_attrs *tp					\
317 		= (struct spi_transport_attrs *)&starget->starget_data;	\
318 									\
319 	val = simple_strtoul(buf, NULL, 0);				\
320 	if (val > tp->max_##field)					\
321 		val = tp->max_##field;					\
322 	i->f->set_##field(starget, val);				\
323 	return count;							\
324 }
325 
326 #define spi_transport_rd_attr(field, format_string)			\
327 	spi_transport_show_function(field, format_string)		\
328 	spi_transport_store_function(field, format_string)		\
329 static CLASS_DEVICE_ATTR(field, S_IRUGO | S_IWUSR,			\
330 			 show_spi_transport_##field,			\
331 			 store_spi_transport_##field);
332 
333 #define spi_transport_simple_attr(field, format_string)			\
334 	spi_transport_show_simple(field, format_string)			\
335 	spi_transport_store_simple(field, format_string)		\
336 static CLASS_DEVICE_ATTR(field, S_IRUGO | S_IWUSR,			\
337 			 show_spi_transport_##field,			\
338 			 store_spi_transport_##field);
339 
340 #define spi_transport_max_attr(field, format_string)			\
341 	spi_transport_show_function(field, format_string)		\
342 	spi_transport_store_max(field, format_string)			\
343 	spi_transport_simple_attr(max_##field, format_string)		\
344 static CLASS_DEVICE_ATTR(field, S_IRUGO | S_IWUSR,			\
345 			 show_spi_transport_##field,			\
346 			 store_spi_transport_##field);
347 
348 /* The Parallel SCSI Tranport Attributes: */
349 spi_transport_max_attr(offset, "%d\n");
350 spi_transport_max_attr(width, "%d\n");
351 spi_transport_rd_attr(iu, "%d\n");
352 spi_transport_rd_attr(dt, "%d\n");
353 spi_transport_rd_attr(qas, "%d\n");
354 spi_transport_rd_attr(wr_flow, "%d\n");
355 spi_transport_rd_attr(rd_strm, "%d\n");
356 spi_transport_rd_attr(rti, "%d\n");
357 spi_transport_rd_attr(pcomp_en, "%d\n");
358 spi_transport_rd_attr(hold_mcs, "%d\n");
359 
360 /* we only care about the first child device so we return 1 */
361 static int child_iter(struct device *dev, void *data)
362 {
363 	struct scsi_device *sdev = to_scsi_device(dev);
364 
365 	spi_dv_device(sdev);
366 	return 1;
367 }
368 
369 static ssize_t
370 store_spi_revalidate(struct class_device *cdev, const char *buf, size_t count)
371 {
372 	struct scsi_target *starget = transport_class_to_starget(cdev);
373 
374 	device_for_each_child(&starget->dev, NULL, child_iter);
375 	return count;
376 }
377 static CLASS_DEVICE_ATTR(revalidate, S_IWUSR, NULL, store_spi_revalidate);
378 
379 /* Translate the period into ns according to the current spec
380  * for SDTR/PPR messages */
381 static ssize_t
382 show_spi_transport_period_helper(struct class_device *cdev, char *buf,
383 				 int period)
384 {
385 	int len, picosec;
386 
387 	if (period < 0 || period > 0xff) {
388 		picosec = -1;
389 	} else if (period <= SPI_STATIC_PPR) {
390 		picosec = ppr_to_ps[period];
391 	} else {
392 		picosec = period * 4000;
393 	}
394 
395 	if (picosec == -1) {
396 		len = sprintf(buf, "reserved");
397 	} else {
398 		len = sprint_frac(buf, picosec, 1000);
399 	}
400 
401 	buf[len++] = '\n';
402 	buf[len] = '\0';
403 	return len;
404 }
405 
406 static ssize_t
407 store_spi_transport_period_helper(struct class_device *cdev, const char *buf,
408 				  size_t count, int *periodp)
409 {
410 	int j, picosec, period = -1;
411 	char *endp;
412 
413 	picosec = simple_strtoul(buf, &endp, 10) * 1000;
414 	if (*endp == '.') {
415 		int mult = 100;
416 		do {
417 			endp++;
418 			if (!isdigit(*endp))
419 				break;
420 			picosec += (*endp - '0') * mult;
421 			mult /= 10;
422 		} while (mult > 0);
423 	}
424 
425 	for (j = 0; j <= SPI_STATIC_PPR; j++) {
426 		if (ppr_to_ps[j] < picosec)
427 			continue;
428 		period = j;
429 		break;
430 	}
431 
432 	if (period == -1)
433 		period = picosec / 4000;
434 
435 	if (period > 0xff)
436 		period = 0xff;
437 
438 	*periodp = period;
439 
440 	return count;
441 }
442 
443 static ssize_t
444 show_spi_transport_period(struct class_device *cdev, char *buf)
445 {
446 	struct scsi_target *starget = transport_class_to_starget(cdev);
447 	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
448 	struct spi_internal *i = to_spi_internal(shost->transportt);
449 	struct spi_transport_attrs *tp =
450 		(struct spi_transport_attrs *)&starget->starget_data;
451 
452 	if (i->f->get_period)
453 		i->f->get_period(starget);
454 
455 	return show_spi_transport_period_helper(cdev, buf, tp->period);
456 }
457 
458 static ssize_t
459 store_spi_transport_period(struct class_device *cdev, const char *buf,
460 			    size_t count)
461 {
462 	struct scsi_target *starget = transport_class_to_starget(cdev);
463 	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
464 	struct spi_internal *i = to_spi_internal(shost->transportt);
465 	struct spi_transport_attrs *tp =
466 		(struct spi_transport_attrs *)&starget->starget_data;
467 	int period, retval;
468 
469 	retval = store_spi_transport_period_helper(cdev, buf, count, &period);
470 
471 	if (period < tp->min_period)
472 		period = tp->min_period;
473 
474 	i->f->set_period(starget, period);
475 
476 	return retval;
477 }
478 
479 static CLASS_DEVICE_ATTR(period, S_IRUGO | S_IWUSR,
480 			 show_spi_transport_period,
481 			 store_spi_transport_period);
482 
483 static ssize_t
484 show_spi_transport_min_period(struct class_device *cdev, char *buf)
485 {
486 	struct scsi_target *starget = transport_class_to_starget(cdev);
487 	struct spi_transport_attrs *tp =
488 		(struct spi_transport_attrs *)&starget->starget_data;
489 
490 	return show_spi_transport_period_helper(cdev, buf, tp->min_period);
491 }
492 
493 static ssize_t
494 store_spi_transport_min_period(struct class_device *cdev, const char *buf,
495 			    size_t count)
496 {
497 	struct scsi_target *starget = transport_class_to_starget(cdev);
498 	struct spi_transport_attrs *tp =
499 		(struct spi_transport_attrs *)&starget->starget_data;
500 
501 	return store_spi_transport_period_helper(cdev, buf, count,
502 						 &tp->min_period);
503 }
504 
505 
506 static CLASS_DEVICE_ATTR(min_period, S_IRUGO | S_IWUSR,
507 			 show_spi_transport_min_period,
508 			 store_spi_transport_min_period);
509 
510 
511 static ssize_t show_spi_host_signalling(struct class_device *cdev, char *buf)
512 {
513 	struct Scsi_Host *shost = transport_class_to_shost(cdev);
514 	struct spi_internal *i = to_spi_internal(shost->transportt);
515 
516 	if (i->f->get_signalling)
517 		i->f->get_signalling(shost);
518 
519 	return sprintf(buf, "%s\n", spi_signal_to_string(spi_signalling(shost)));
520 }
521 static ssize_t store_spi_host_signalling(struct class_device *cdev,
522 					 const char *buf, size_t count)
523 {
524 	struct Scsi_Host *shost = transport_class_to_shost(cdev);
525 	struct spi_internal *i = to_spi_internal(shost->transportt);
526 	enum spi_signal_type type = spi_signal_to_value(buf);
527 
528 	if (type != SPI_SIGNAL_UNKNOWN)
529 		i->f->set_signalling(shost, type);
530 
531 	return count;
532 }
533 static CLASS_DEVICE_ATTR(signalling, S_IRUGO | S_IWUSR,
534 			 show_spi_host_signalling,
535 			 store_spi_host_signalling);
536 
537 #define DV_SET(x, y)			\
538 	if(i->f->set_##x)		\
539 		i->f->set_##x(sdev->sdev_target, y)
540 
541 enum spi_compare_returns {
542 	SPI_COMPARE_SUCCESS,
543 	SPI_COMPARE_FAILURE,
544 	SPI_COMPARE_SKIP_TEST,
545 };
546 
547 
548 /* This is for read/write Domain Validation:  If the device supports
549  * an echo buffer, we do read/write tests to it */
550 static enum spi_compare_returns
551 spi_dv_device_echo_buffer(struct scsi_device *sdev, u8 *buffer,
552 			  u8 *ptr, const int retries)
553 {
554 	int len = ptr - buffer;
555 	int j, k, r, result;
556 	unsigned int pattern = 0x0000ffff;
557 	struct scsi_sense_hdr sshdr;
558 
559 	const char spi_write_buffer[] = {
560 		WRITE_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
561 	};
562 	const char spi_read_buffer[] = {
563 		READ_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
564 	};
565 
566 	/* set up the pattern buffer.  Doesn't matter if we spill
567 	 * slightly beyond since that's where the read buffer is */
568 	for (j = 0; j < len; ) {
569 
570 		/* fill the buffer with counting (test a) */
571 		for ( ; j < min(len, 32); j++)
572 			buffer[j] = j;
573 		k = j;
574 		/* fill the buffer with alternating words of 0x0 and
575 		 * 0xffff (test b) */
576 		for ( ; j < min(len, k + 32); j += 2) {
577 			u16 *word = (u16 *)&buffer[j];
578 
579 			*word = (j & 0x02) ? 0x0000 : 0xffff;
580 		}
581 		k = j;
582 		/* fill with crosstalk (alternating 0x5555 0xaaa)
583                  * (test c) */
584 		for ( ; j < min(len, k + 32); j += 2) {
585 			u16 *word = (u16 *)&buffer[j];
586 
587 			*word = (j & 0x02) ? 0x5555 : 0xaaaa;
588 		}
589 		k = j;
590 		/* fill with shifting bits (test d) */
591 		for ( ; j < min(len, k + 32); j += 4) {
592 			u32 *word = (unsigned int *)&buffer[j];
593 			u32 roll = (pattern & 0x80000000) ? 1 : 0;
594 
595 			*word = pattern;
596 			pattern = (pattern << 1) | roll;
597 		}
598 		/* don't bother with random data (test e) */
599 	}
600 
601 	for (r = 0; r < retries; r++) {
602 		result = spi_execute(sdev, spi_write_buffer, DMA_TO_DEVICE,
603 				     buffer, len, &sshdr);
604 		if(result || !scsi_device_online(sdev)) {
605 
606 			scsi_device_set_state(sdev, SDEV_QUIESCE);
607 			if (scsi_sense_valid(&sshdr)
608 			    && sshdr.sense_key == ILLEGAL_REQUEST
609 			    /* INVALID FIELD IN CDB */
610 			    && sshdr.asc == 0x24 && sshdr.ascq == 0x00)
611 				/* This would mean that the drive lied
612 				 * to us about supporting an echo
613 				 * buffer (unfortunately some Western
614 				 * Digital drives do precisely this)
615 				 */
616 				return SPI_COMPARE_SKIP_TEST;
617 
618 
619 			sdev_printk(KERN_ERR, sdev, "Write Buffer failure %x\n", result);
620 			return SPI_COMPARE_FAILURE;
621 		}
622 
623 		memset(ptr, 0, len);
624 		spi_execute(sdev, spi_read_buffer, DMA_FROM_DEVICE,
625 			    ptr, len, NULL);
626 		scsi_device_set_state(sdev, SDEV_QUIESCE);
627 
628 		if (memcmp(buffer, ptr, len) != 0)
629 			return SPI_COMPARE_FAILURE;
630 	}
631 	return SPI_COMPARE_SUCCESS;
632 }
633 
634 /* This is for the simplest form of Domain Validation: a read test
635  * on the inquiry data from the device */
636 static enum spi_compare_returns
637 spi_dv_device_compare_inquiry(struct scsi_device *sdev, u8 *buffer,
638 			      u8 *ptr, const int retries)
639 {
640 	int r, result;
641 	const int len = sdev->inquiry_len;
642 	const char spi_inquiry[] = {
643 		INQUIRY, 0, 0, 0, len, 0
644 	};
645 
646 	for (r = 0; r < retries; r++) {
647 		memset(ptr, 0, len);
648 
649 		result = spi_execute(sdev, spi_inquiry, DMA_FROM_DEVICE,
650 				     ptr, len, NULL);
651 
652 		if(result || !scsi_device_online(sdev)) {
653 			scsi_device_set_state(sdev, SDEV_QUIESCE);
654 			return SPI_COMPARE_FAILURE;
655 		}
656 
657 		/* If we don't have the inquiry data already, the
658 		 * first read gets it */
659 		if (ptr == buffer) {
660 			ptr += len;
661 			--r;
662 			continue;
663 		}
664 
665 		if (memcmp(buffer, ptr, len) != 0)
666 			/* failure */
667 			return SPI_COMPARE_FAILURE;
668 	}
669 	return SPI_COMPARE_SUCCESS;
670 }
671 
672 static enum spi_compare_returns
673 spi_dv_retrain(struct scsi_device *sdev, u8 *buffer, u8 *ptr,
674 	       enum spi_compare_returns
675 	       (*compare_fn)(struct scsi_device *, u8 *, u8 *, int))
676 {
677 	struct spi_internal *i = to_spi_internal(sdev->host->transportt);
678 	struct scsi_target *starget = sdev->sdev_target;
679 	int period = 0, prevperiod = 0;
680 	enum spi_compare_returns retval;
681 
682 
683 	for (;;) {
684 		int newperiod;
685 		retval = compare_fn(sdev, buffer, ptr, DV_LOOPS);
686 
687 		if (retval == SPI_COMPARE_SUCCESS
688 		    || retval == SPI_COMPARE_SKIP_TEST)
689 			break;
690 
691 		/* OK, retrain, fallback */
692 		if (i->f->get_iu)
693 			i->f->get_iu(starget);
694 		if (i->f->get_qas)
695 			i->f->get_qas(starget);
696 		if (i->f->get_period)
697 			i->f->get_period(sdev->sdev_target);
698 
699 		/* Here's the fallback sequence; first try turning off
700 		 * IU, then QAS (if we can control them), then finally
701 		 * fall down the periods */
702 		if (i->f->set_iu && spi_iu(starget)) {
703 			starget_printk(KERN_ERR, starget, "Domain Validation Disabing Information Units\n");
704 			DV_SET(iu, 0);
705 		} else if (i->f->set_qas && spi_qas(starget)) {
706 			starget_printk(KERN_ERR, starget, "Domain Validation Disabing Quick Arbitration and Selection\n");
707 			DV_SET(qas, 0);
708 		} else {
709 			newperiod = spi_period(starget);
710 			period = newperiod > period ? newperiod : period;
711 			if (period < 0x0d)
712 				period++;
713 			else
714 				period += period >> 1;
715 
716 			if (unlikely(period > 0xff || period == prevperiod)) {
717 				/* Total failure; set to async and return */
718 				starget_printk(KERN_ERR, starget, "Domain Validation Failure, dropping back to Asynchronous\n");
719 				DV_SET(offset, 0);
720 				return SPI_COMPARE_FAILURE;
721 			}
722 			starget_printk(KERN_ERR, starget, "Domain Validation detected failure, dropping back\n");
723 			DV_SET(period, period);
724 			prevperiod = period;
725 		}
726 	}
727 	return retval;
728 }
729 
730 static int
731 spi_dv_device_get_echo_buffer(struct scsi_device *sdev, u8 *buffer)
732 {
733 	int l, result;
734 
735 	/* first off do a test unit ready.  This can error out
736 	 * because of reservations or some other reason.  If it
737 	 * fails, the device won't let us write to the echo buffer
738 	 * so just return failure */
739 
740 	const char spi_test_unit_ready[] = {
741 		TEST_UNIT_READY, 0, 0, 0, 0, 0
742 	};
743 
744 	const char spi_read_buffer_descriptor[] = {
745 		READ_BUFFER, 0x0b, 0, 0, 0, 0, 0, 0, 4, 0
746 	};
747 
748 
749 	/* We send a set of three TURs to clear any outstanding
750 	 * unit attention conditions if they exist (Otherwise the
751 	 * buffer tests won't be happy).  If the TUR still fails
752 	 * (reservation conflict, device not ready, etc) just
753 	 * skip the write tests */
754 	for (l = 0; ; l++) {
755 		result = spi_execute(sdev, spi_test_unit_ready, DMA_NONE,
756 				     NULL, 0, NULL);
757 
758 		if(result) {
759 			if(l >= 3)
760 				return 0;
761 		} else {
762 			/* TUR succeeded */
763 			break;
764 		}
765 	}
766 
767 	result = spi_execute(sdev, spi_read_buffer_descriptor,
768 			     DMA_FROM_DEVICE, buffer, 4, NULL);
769 
770 	if (result)
771 		/* Device has no echo buffer */
772 		return 0;
773 
774 	return buffer[3] + ((buffer[2] & 0x1f) << 8);
775 }
776 
777 static void
778 spi_dv_device_internal(struct scsi_device *sdev, u8 *buffer)
779 {
780 	struct spi_internal *i = to_spi_internal(sdev->host->transportt);
781 	struct scsi_target *starget = sdev->sdev_target;
782 	int len = sdev->inquiry_len;
783 	/* first set us up for narrow async */
784 	DV_SET(offset, 0);
785 	DV_SET(width, 0);
786 
787 	if (spi_dv_device_compare_inquiry(sdev, buffer, buffer, DV_LOOPS)
788 	    != SPI_COMPARE_SUCCESS) {
789 		starget_printk(KERN_ERR, starget, "Domain Validation Initial Inquiry Failed\n");
790 		/* FIXME: should probably offline the device here? */
791 		return;
792 	}
793 
794 	/* test width */
795 	if (i->f->set_width && spi_max_width(starget) &&
796 	    scsi_device_wide(sdev)) {
797 		i->f->set_width(starget, 1);
798 
799 		if (spi_dv_device_compare_inquiry(sdev, buffer,
800 						   buffer + len,
801 						   DV_LOOPS)
802 		    != SPI_COMPARE_SUCCESS) {
803 			starget_printk(KERN_ERR, starget, "Wide Transfers Fail\n");
804 			i->f->set_width(starget, 0);
805 		}
806 	}
807 
808 	if (!i->f->set_period)
809 		return;
810 
811 	/* device can't handle synchronous */
812 	if (!scsi_device_sync(sdev) && !scsi_device_dt(sdev))
813 		return;
814 
815 	/* len == -1 is the signal that we need to ascertain the
816 	 * presence of an echo buffer before trying to use it.  len ==
817 	 * 0 means we don't have an echo buffer */
818 	len = -1;
819 
820  retry:
821 
822 	/* now set up to the maximum */
823 	DV_SET(offset, spi_max_offset(starget));
824 	DV_SET(period, spi_min_period(starget));
825 	/* try QAS requests; this should be harmless to set if the
826 	 * target supports it */
827 	if (scsi_device_qas(sdev))
828 		DV_SET(qas, 1);
829 	/* Also try IU transfers */
830 	if (scsi_device_ius(sdev))
831 		DV_SET(iu, 1);
832 	if (spi_min_period(starget) < 9) {
833 		/* This u320 (or u640). Ignore the coupled parameters
834 		 * like DT and IU, but set the optional ones */
835 		DV_SET(rd_strm, 1);
836 		DV_SET(wr_flow, 1);
837 		DV_SET(rti, 1);
838 		if (spi_min_period(starget) == 8)
839 			DV_SET(pcomp_en, 1);
840 	}
841 	/* Do the read only INQUIRY tests */
842 	spi_dv_retrain(sdev, buffer, buffer + sdev->inquiry_len,
843 		       spi_dv_device_compare_inquiry);
844 	/* See if we actually managed to negotiate and sustain DT */
845 	if (i->f->get_dt)
846 		i->f->get_dt(starget);
847 
848 	/* see if the device has an echo buffer.  If it does we can do
849 	 * the SPI pattern write tests.  Because of some broken
850 	 * devices, we *only* try this on a device that has actually
851 	 * negotiated DT */
852 
853 	if (len == -1 && spi_dt(starget))
854 		len = spi_dv_device_get_echo_buffer(sdev, buffer);
855 
856 	if (len <= 0) {
857 		starget_printk(KERN_INFO, starget, "Domain Validation skipping write tests\n");
858 		return;
859 	}
860 
861 	if (len > SPI_MAX_ECHO_BUFFER_SIZE) {
862 		starget_printk(KERN_WARNING, starget, "Echo buffer size %d is too big, trimming to %d\n", len, SPI_MAX_ECHO_BUFFER_SIZE);
863 		len = SPI_MAX_ECHO_BUFFER_SIZE;
864 	}
865 
866 	if (spi_dv_retrain(sdev, buffer, buffer + len,
867 			   spi_dv_device_echo_buffer)
868 	    == SPI_COMPARE_SKIP_TEST) {
869 		/* OK, the stupid drive can't do a write echo buffer
870 		 * test after all, fall back to the read tests */
871 		len = 0;
872 		goto retry;
873 	}
874 }
875 
876 
877 /**	spi_dv_device - Do Domain Validation on the device
878  *	@sdev:		scsi device to validate
879  *
880  *	Performs the domain validation on the given device in the
881  *	current execution thread.  Since DV operations may sleep,
882  *	the current thread must have user context.  Also no SCSI
883  *	related locks that would deadlock I/O issued by the DV may
884  *	be held.
885  */
886 void
887 spi_dv_device(struct scsi_device *sdev)
888 {
889 	struct scsi_target *starget = sdev->sdev_target;
890 	u8 *buffer;
891 	const int len = SPI_MAX_ECHO_BUFFER_SIZE*2;
892 
893 	if (unlikely(scsi_device_get(sdev)))
894 		return;
895 
896 	buffer = kmalloc(len, GFP_KERNEL);
897 
898 	if (unlikely(!buffer))
899 		goto out_put;
900 
901 	memset(buffer, 0, len);
902 
903 	/* We need to verify that the actual device will quiesce; the
904 	 * later target quiesce is just a nice to have */
905 	if (unlikely(scsi_device_quiesce(sdev)))
906 		goto out_free;
907 
908 	scsi_target_quiesce(starget);
909 
910 	spi_dv_pending(starget) = 1;
911 	down(&spi_dv_sem(starget));
912 
913 	starget_printk(KERN_INFO, starget, "Beginning Domain Validation\n");
914 
915 	spi_dv_device_internal(sdev, buffer);
916 
917 	starget_printk(KERN_INFO, starget, "Ending Domain Validation\n");
918 
919 	up(&spi_dv_sem(starget));
920 	spi_dv_pending(starget) = 0;
921 
922 	scsi_target_resume(starget);
923 
924 	spi_initial_dv(starget) = 1;
925 
926  out_free:
927 	kfree(buffer);
928  out_put:
929 	scsi_device_put(sdev);
930 }
931 EXPORT_SYMBOL(spi_dv_device);
932 
933 struct work_queue_wrapper {
934 	struct work_struct	work;
935 	struct scsi_device	*sdev;
936 };
937 
938 static void
939 spi_dv_device_work_wrapper(void *data)
940 {
941 	struct work_queue_wrapper *wqw = (struct work_queue_wrapper *)data;
942 	struct scsi_device *sdev = wqw->sdev;
943 
944 	kfree(wqw);
945 	spi_dv_device(sdev);
946 	spi_dv_pending(sdev->sdev_target) = 0;
947 	scsi_device_put(sdev);
948 }
949 
950 
951 /**
952  *	spi_schedule_dv_device - schedule domain validation to occur on the device
953  *	@sdev:	The device to validate
954  *
955  *	Identical to spi_dv_device() above, except that the DV will be
956  *	scheduled to occur in a workqueue later.  All memory allocations
957  *	are atomic, so may be called from any context including those holding
958  *	SCSI locks.
959  */
960 void
961 spi_schedule_dv_device(struct scsi_device *sdev)
962 {
963 	struct work_queue_wrapper *wqw =
964 		kmalloc(sizeof(struct work_queue_wrapper), GFP_ATOMIC);
965 
966 	if (unlikely(!wqw))
967 		return;
968 
969 	if (unlikely(spi_dv_pending(sdev->sdev_target))) {
970 		kfree(wqw);
971 		return;
972 	}
973 	/* Set pending early (dv_device doesn't check it, only sets it) */
974 	spi_dv_pending(sdev->sdev_target) = 1;
975 	if (unlikely(scsi_device_get(sdev))) {
976 		kfree(wqw);
977 		spi_dv_pending(sdev->sdev_target) = 0;
978 		return;
979 	}
980 
981 	INIT_WORK(&wqw->work, spi_dv_device_work_wrapper, wqw);
982 	wqw->sdev = sdev;
983 
984 	schedule_work(&wqw->work);
985 }
986 EXPORT_SYMBOL(spi_schedule_dv_device);
987 
988 /**
989  * spi_display_xfer_agreement - Print the current target transfer agreement
990  * @starget: The target for which to display the agreement
991  *
992  * Each SPI port is required to maintain a transfer agreement for each
993  * other port on the bus.  This function prints a one-line summary of
994  * the current agreement; more detailed information is available in sysfs.
995  */
996 void spi_display_xfer_agreement(struct scsi_target *starget)
997 {
998 	struct spi_transport_attrs *tp;
999 	tp = (struct spi_transport_attrs *)&starget->starget_data;
1000 
1001 	if (tp->offset > 0 && tp->period > 0) {
1002 		unsigned int picosec, kb100;
1003 		char *scsi = "FAST-?";
1004 		char tmp[8];
1005 
1006 		if (tp->period <= SPI_STATIC_PPR) {
1007 			picosec = ppr_to_ps[tp->period];
1008 			switch (tp->period) {
1009 				case  7: scsi = "FAST-320"; break;
1010 				case  8: scsi = "FAST-160"; break;
1011 				case  9: scsi = "FAST-80"; break;
1012 				case 10:
1013 				case 11: scsi = "FAST-40"; break;
1014 				case 12: scsi = "FAST-20"; break;
1015 			}
1016 		} else {
1017 			picosec = tp->period * 4000;
1018 			if (tp->period < 25)
1019 				scsi = "FAST-20";
1020 			else if (tp->period < 50)
1021 				scsi = "FAST-10";
1022 			else
1023 				scsi = "FAST-5";
1024 		}
1025 
1026 		kb100 = (10000000 + picosec / 2) / picosec;
1027 		if (tp->width)
1028 			kb100 *= 2;
1029 		sprint_frac(tmp, picosec, 1000);
1030 
1031 		dev_info(&starget->dev,
1032 			 "%s %sSCSI %d.%d MB/s %s%s%s%s%s%s%s%s (%s ns, offset %d)\n",
1033 			 scsi, tp->width ? "WIDE " : "", kb100/10, kb100 % 10,
1034 			 tp->dt ? "DT" : "ST",
1035 			 tp->iu ? " IU" : "",
1036 			 tp->qas  ? " QAS" : "",
1037 			 tp->rd_strm ? " RDSTRM" : "",
1038 			 tp->rti ? " RTI" : "",
1039 			 tp->wr_flow ? " WRFLOW" : "",
1040 			 tp->pcomp_en ? " PCOMP" : "",
1041 			 tp->hold_mcs ? " HMCS" : "",
1042 			 tmp, tp->offset);
1043 	} else {
1044 		dev_info(&starget->dev, "%sasynchronous.\n",
1045 				tp->width ? "wide " : "");
1046 	}
1047 }
1048 EXPORT_SYMBOL(spi_display_xfer_agreement);
1049 
1050 #define SETUP_ATTRIBUTE(field)						\
1051 	i->private_attrs[count] = class_device_attr_##field;		\
1052 	if (!i->f->set_##field) {					\
1053 		i->private_attrs[count].attr.mode = S_IRUGO;		\
1054 		i->private_attrs[count].store = NULL;			\
1055 	}								\
1056 	i->attrs[count] = &i->private_attrs[count];			\
1057 	if (i->f->show_##field)						\
1058 		count++
1059 
1060 #define SETUP_RELATED_ATTRIBUTE(field, rel_field)			\
1061 	i->private_attrs[count] = class_device_attr_##field;		\
1062 	if (!i->f->set_##rel_field) {					\
1063 		i->private_attrs[count].attr.mode = S_IRUGO;		\
1064 		i->private_attrs[count].store = NULL;			\
1065 	}								\
1066 	i->attrs[count] = &i->private_attrs[count];			\
1067 	if (i->f->show_##rel_field)					\
1068 		count++
1069 
1070 #define SETUP_HOST_ATTRIBUTE(field)					\
1071 	i->private_host_attrs[count] = class_device_attr_##field;	\
1072 	if (!i->f->set_##field) {					\
1073 		i->private_host_attrs[count].attr.mode = S_IRUGO;	\
1074 		i->private_host_attrs[count].store = NULL;		\
1075 	}								\
1076 	i->host_attrs[count] = &i->private_host_attrs[count];		\
1077 	count++
1078 
1079 static int spi_device_match(struct attribute_container *cont,
1080 			    struct device *dev)
1081 {
1082 	struct scsi_device *sdev;
1083 	struct Scsi_Host *shost;
1084 	struct spi_internal *i;
1085 
1086 	if (!scsi_is_sdev_device(dev))
1087 		return 0;
1088 
1089 	sdev = to_scsi_device(dev);
1090 	shost = sdev->host;
1091 	if (!shost->transportt  || shost->transportt->host_attrs.ac.class
1092 	    != &spi_host_class.class)
1093 		return 0;
1094 	/* Note: this class has no device attributes, so it has
1095 	 * no per-HBA allocation and thus we don't need to distinguish
1096 	 * the attribute containers for the device */
1097 	i = to_spi_internal(shost->transportt);
1098 	if (i->f->deny_binding && i->f->deny_binding(sdev->sdev_target))
1099 		return 0;
1100 	return 1;
1101 }
1102 
1103 static int spi_target_match(struct attribute_container *cont,
1104 			    struct device *dev)
1105 {
1106 	struct Scsi_Host *shost;
1107 	struct scsi_target *starget;
1108 	struct spi_internal *i;
1109 
1110 	if (!scsi_is_target_device(dev))
1111 		return 0;
1112 
1113 	shost = dev_to_shost(dev->parent);
1114 	if (!shost->transportt  || shost->transportt->host_attrs.ac.class
1115 	    != &spi_host_class.class)
1116 		return 0;
1117 
1118 	i = to_spi_internal(shost->transportt);
1119 	starget = to_scsi_target(dev);
1120 
1121 	if (i->f->deny_binding && i->f->deny_binding(starget))
1122 		return 0;
1123 
1124 	return &i->t.target_attrs.ac == cont;
1125 }
1126 
1127 static DECLARE_TRANSPORT_CLASS(spi_transport_class,
1128 			       "spi_transport",
1129 			       spi_setup_transport_attrs,
1130 			       NULL,
1131 			       NULL);
1132 
1133 static DECLARE_ANON_TRANSPORT_CLASS(spi_device_class,
1134 				    spi_device_match,
1135 				    spi_device_configure);
1136 
1137 struct scsi_transport_template *
1138 spi_attach_transport(struct spi_function_template *ft)
1139 {
1140 	struct spi_internal *i = kmalloc(sizeof(struct spi_internal),
1141 					 GFP_KERNEL);
1142 	int count = 0;
1143 	if (unlikely(!i))
1144 		return NULL;
1145 
1146 	memset(i, 0, sizeof(struct spi_internal));
1147 
1148 
1149 	i->t.target_attrs.ac.class = &spi_transport_class.class;
1150 	i->t.target_attrs.ac.attrs = &i->attrs[0];
1151 	i->t.target_attrs.ac.match = spi_target_match;
1152 	transport_container_register(&i->t.target_attrs);
1153 	i->t.target_size = sizeof(struct spi_transport_attrs);
1154 	i->t.host_attrs.ac.class = &spi_host_class.class;
1155 	i->t.host_attrs.ac.attrs = &i->host_attrs[0];
1156 	i->t.host_attrs.ac.match = spi_host_match;
1157 	transport_container_register(&i->t.host_attrs);
1158 	i->t.host_size = sizeof(struct spi_host_attrs);
1159 	i->f = ft;
1160 
1161 	SETUP_ATTRIBUTE(period);
1162 	SETUP_RELATED_ATTRIBUTE(min_period, period);
1163 	SETUP_ATTRIBUTE(offset);
1164 	SETUP_RELATED_ATTRIBUTE(max_offset, offset);
1165 	SETUP_ATTRIBUTE(width);
1166 	SETUP_RELATED_ATTRIBUTE(max_width, width);
1167 	SETUP_ATTRIBUTE(iu);
1168 	SETUP_ATTRIBUTE(dt);
1169 	SETUP_ATTRIBUTE(qas);
1170 	SETUP_ATTRIBUTE(wr_flow);
1171 	SETUP_ATTRIBUTE(rd_strm);
1172 	SETUP_ATTRIBUTE(rti);
1173 	SETUP_ATTRIBUTE(pcomp_en);
1174 	SETUP_ATTRIBUTE(hold_mcs);
1175 
1176 	/* if you add an attribute but forget to increase SPI_NUM_ATTRS
1177 	 * this bug will trigger */
1178 	BUG_ON(count > SPI_NUM_ATTRS);
1179 
1180 	i->attrs[count++] = &class_device_attr_revalidate;
1181 
1182 	i->attrs[count] = NULL;
1183 
1184 	count = 0;
1185 	SETUP_HOST_ATTRIBUTE(signalling);
1186 
1187 	BUG_ON(count > SPI_HOST_ATTRS);
1188 
1189 	i->host_attrs[count] = NULL;
1190 
1191 	return &i->t;
1192 }
1193 EXPORT_SYMBOL(spi_attach_transport);
1194 
1195 void spi_release_transport(struct scsi_transport_template *t)
1196 {
1197 	struct spi_internal *i = to_spi_internal(t);
1198 
1199 	transport_container_unregister(&i->t.target_attrs);
1200 	transport_container_unregister(&i->t.host_attrs);
1201 
1202 	kfree(i);
1203 }
1204 EXPORT_SYMBOL(spi_release_transport);
1205 
1206 static __init int spi_transport_init(void)
1207 {
1208 	int error = transport_class_register(&spi_transport_class);
1209 	if (error)
1210 		return error;
1211 	error = anon_transport_class_register(&spi_device_class);
1212 	return transport_class_register(&spi_host_class);
1213 }
1214 
1215 static void __exit spi_transport_exit(void)
1216 {
1217 	transport_class_unregister(&spi_transport_class);
1218 	anon_transport_class_unregister(&spi_device_class);
1219 	transport_class_unregister(&spi_host_class);
1220 }
1221 
1222 MODULE_AUTHOR("Martin Hicks");
1223 MODULE_DESCRIPTION("SPI Transport Attributes");
1224 MODULE_LICENSE("GPL");
1225 
1226 module_init(spi_transport_init);
1227 module_exit(spi_transport_exit);
1228