xref: /linux/drivers/scsi/scsi_transport_spi.c (revision 36ca1195ad7f760a6af3814cb002bd3a3d4b4db1)
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_request.h>
32 #include <scsi/scsi_eh.h>
33 #include <scsi/scsi_transport.h>
34 #include <scsi/scsi_transport_spi.h>
35 
36 #define SPI_PRINTK(x, l, f, a...)	dev_printk(l, &(x)->dev, f , ##a)
37 
38 #define SPI_NUM_ATTRS 13	/* increase this if you add attributes */
39 #define SPI_OTHER_ATTRS 1	/* Increase this if you add "always
40 				 * on" attributes */
41 #define SPI_HOST_ATTRS	1
42 
43 #define SPI_MAX_ECHO_BUFFER_SIZE	4096
44 
45 #define DV_LOOPS	3
46 #define DV_TIMEOUT	(10*HZ)
47 #define DV_RETRIES	3	/* should only need at most
48 				 * two cc/ua clears */
49 
50 /* Private data accessors (keep these out of the header file) */
51 #define spi_dv_pending(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_pending)
52 #define spi_dv_sem(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_sem)
53 
54 struct spi_internal {
55 	struct scsi_transport_template t;
56 	struct spi_function_template *f;
57 	/* The actual attributes */
58 	struct class_device_attribute private_attrs[SPI_NUM_ATTRS];
59 	/* The array of null terminated pointers to attributes
60 	 * needed by scsi_sysfs.c */
61 	struct class_device_attribute *attrs[SPI_NUM_ATTRS + SPI_OTHER_ATTRS + 1];
62 	struct class_device_attribute private_host_attrs[SPI_HOST_ATTRS];
63 	struct class_device_attribute *host_attrs[SPI_HOST_ATTRS + 1];
64 };
65 
66 #define to_spi_internal(tmpl)	container_of(tmpl, struct spi_internal, t)
67 
68 static const int ppr_to_ps[] = {
69 	/* The PPR values 0-6 are reserved, fill them in when
70 	 * the committee defines them */
71 	-1,			/* 0x00 */
72 	-1,			/* 0x01 */
73 	-1,			/* 0x02 */
74 	-1,			/* 0x03 */
75 	-1,			/* 0x04 */
76 	-1,			/* 0x05 */
77 	-1,			/* 0x06 */
78 	 3125,			/* 0x07 */
79 	 6250,			/* 0x08 */
80 	12500,			/* 0x09 */
81 	25000,			/* 0x0a */
82 	30300,			/* 0x0b */
83 	50000,			/* 0x0c */
84 };
85 /* The PPR values at which you calculate the period in ns by multiplying
86  * by 4 */
87 #define SPI_STATIC_PPR	0x0c
88 
89 static int sprint_frac(char *dest, int value, int denom)
90 {
91 	int frac = value % denom;
92 	int result = sprintf(dest, "%d", value / denom);
93 
94 	if (frac == 0)
95 		return result;
96 	dest[result++] = '.';
97 
98 	do {
99 		denom /= 10;
100 		sprintf(dest + result, "%d", frac / denom);
101 		result++;
102 		frac %= denom;
103 	} while (frac);
104 
105 	dest[result++] = '\0';
106 	return result;
107 }
108 
109 /* Modification of scsi_wait_req that will clear UNIT ATTENTION conditions
110  * resulting from (likely) bus and device resets */
111 static void spi_wait_req(struct scsi_request *sreq, const void *cmd,
112 			 void *buffer, unsigned bufflen)
113 {
114 	int i;
115 
116 	for(i = 0; i < DV_RETRIES; i++) {
117 		sreq->sr_request->flags |= REQ_FAILFAST;
118 
119 		scsi_wait_req(sreq, cmd, buffer, bufflen,
120 			      DV_TIMEOUT, /* retries */ 1);
121 		if (sreq->sr_result & DRIVER_SENSE) {
122 			struct scsi_sense_hdr sshdr;
123 
124 			if (scsi_request_normalize_sense(sreq, &sshdr)
125 			    && sshdr.sense_key == UNIT_ATTENTION)
126 				continue;
127 		}
128 		break;
129 	}
130 }
131 
132 static struct {
133 	enum spi_signal_type	value;
134 	char			*name;
135 } signal_types[] = {
136 	{ SPI_SIGNAL_UNKNOWN, "unknown" },
137 	{ SPI_SIGNAL_SE, "SE" },
138 	{ SPI_SIGNAL_LVD, "LVD" },
139 	{ SPI_SIGNAL_HVD, "HVD" },
140 };
141 
142 static inline const char *spi_signal_to_string(enum spi_signal_type type)
143 {
144 	int i;
145 
146 	for (i = 0; i < sizeof(signal_types)/sizeof(signal_types[0]); i++) {
147 		if (type == signal_types[i].value)
148 			return signal_types[i].name;
149 	}
150 	return NULL;
151 }
152 static inline enum spi_signal_type spi_signal_to_value(const char *name)
153 {
154 	int i, len;
155 
156 	for (i = 0; i < sizeof(signal_types)/sizeof(signal_types[0]); i++) {
157 		len =  strlen(signal_types[i].name);
158 		if (strncmp(name, signal_types[i].name, len) == 0 &&
159 		    (name[len] == '\n' || name[len] == '\0'))
160 			return signal_types[i].value;
161 	}
162 	return SPI_SIGNAL_UNKNOWN;
163 }
164 
165 static int spi_host_setup(struct device *dev)
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 DECLARE_TRANSPORT_CLASS(spi_host_class,
175 			       "spi_host",
176 			       spi_host_setup,
177 			       NULL,
178 			       NULL);
179 
180 static int spi_host_match(struct attribute_container *cont,
181 			  struct device *dev)
182 {
183 	struct Scsi_Host *shost;
184 	struct spi_internal *i;
185 
186 	if (!scsi_is_host_device(dev))
187 		return 0;
188 
189 	shost = dev_to_shost(dev);
190 	if (!shost->transportt  || shost->transportt->host_attrs.ac.class
191 	    != &spi_host_class.class)
192 		return 0;
193 
194 	i = to_spi_internal(shost->transportt);
195 
196 	return &i->t.host_attrs.ac == cont;
197 }
198 
199 static int spi_device_configure(struct device *dev)
200 {
201 	struct scsi_device *sdev = to_scsi_device(dev);
202 	struct scsi_target *starget = sdev->sdev_target;
203 
204 	/* Populate the target capability fields with the values
205 	 * gleaned from the device inquiry */
206 
207 	spi_support_sync(starget) = scsi_device_sync(sdev);
208 	spi_support_wide(starget) = scsi_device_wide(sdev);
209 	spi_support_dt(starget) = scsi_device_dt(sdev);
210 	spi_support_dt_only(starget) = scsi_device_dt_only(sdev);
211 	spi_support_ius(starget) = scsi_device_ius(sdev);
212 	spi_support_qas(starget) = scsi_device_qas(sdev);
213 
214 	return 0;
215 }
216 
217 static int spi_setup_transport_attrs(struct device *dev)
218 {
219 	struct scsi_target *starget = to_scsi_target(dev);
220 
221 	spi_period(starget) = -1;	/* illegal value */
222 	spi_min_period(starget) = 0;
223 	spi_offset(starget) = 0;	/* async */
224 	spi_max_offset(starget) = 255;
225 	spi_width(starget) = 0;	/* narrow */
226 	spi_max_width(starget) = 1;
227 	spi_iu(starget) = 0;	/* no IU */
228 	spi_dt(starget) = 0;	/* ST */
229 	spi_qas(starget) = 0;
230 	spi_wr_flow(starget) = 0;
231 	spi_rd_strm(starget) = 0;
232 	spi_rti(starget) = 0;
233 	spi_pcomp_en(starget) = 0;
234 	spi_dv_pending(starget) = 0;
235 	spi_initial_dv(starget) = 0;
236 	init_MUTEX(&spi_dv_sem(starget));
237 
238 	return 0;
239 }
240 
241 #define spi_transport_show_simple(field, format_string)			\
242 									\
243 static ssize_t								\
244 show_spi_transport_##field(struct class_device *cdev, char *buf)	\
245 {									\
246 	struct scsi_target *starget = transport_class_to_starget(cdev);	\
247 	struct spi_transport_attrs *tp;					\
248 									\
249 	tp = (struct spi_transport_attrs *)&starget->starget_data;	\
250 	return snprintf(buf, 20, format_string, tp->field);		\
251 }
252 
253 #define spi_transport_store_simple(field, format_string)		\
254 									\
255 static ssize_t								\
256 store_spi_transport_##field(struct class_device *cdev, const char *buf, \
257 			    size_t count)				\
258 {									\
259 	int val;							\
260 	struct scsi_target *starget = transport_class_to_starget(cdev);	\
261 	struct spi_transport_attrs *tp;					\
262 									\
263 	tp = (struct spi_transport_attrs *)&starget->starget_data;	\
264 	val = simple_strtoul(buf, NULL, 0);				\
265 	tp->field = val;						\
266 	return count;							\
267 }
268 
269 #define spi_transport_show_function(field, format_string)		\
270 									\
271 static ssize_t								\
272 show_spi_transport_##field(struct class_device *cdev, char *buf)	\
273 {									\
274 	struct scsi_target *starget = transport_class_to_starget(cdev);	\
275 	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);	\
276 	struct spi_transport_attrs *tp;					\
277 	struct spi_internal *i = to_spi_internal(shost->transportt);	\
278 	tp = (struct spi_transport_attrs *)&starget->starget_data;	\
279 	if (i->f->get_##field)						\
280 		i->f->get_##field(starget);				\
281 	return snprintf(buf, 20, format_string, tp->field);		\
282 }
283 
284 #define spi_transport_store_function(field, format_string)		\
285 static ssize_t								\
286 store_spi_transport_##field(struct class_device *cdev, const char *buf, \
287 			    size_t count)				\
288 {									\
289 	int val;							\
290 	struct scsi_target *starget = transport_class_to_starget(cdev);	\
291 	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);	\
292 	struct spi_internal *i = to_spi_internal(shost->transportt);	\
293 									\
294 	val = simple_strtoul(buf, NULL, 0);				\
295 	i->f->set_##field(starget, val);			\
296 	return count;							\
297 }
298 
299 #define spi_transport_store_max(field, format_string)			\
300 static ssize_t								\
301 store_spi_transport_##field(struct class_device *cdev, const char *buf, \
302 			    size_t count)				\
303 {									\
304 	int val;							\
305 	struct scsi_target *starget = transport_class_to_starget(cdev);	\
306 	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);	\
307 	struct spi_internal *i = to_spi_internal(shost->transportt);	\
308 	struct spi_transport_attrs *tp					\
309 		= (struct spi_transport_attrs *)&starget->starget_data;	\
310 									\
311 	val = simple_strtoul(buf, NULL, 0);				\
312 	if (val > tp->max_##field)					\
313 		val = tp->max_##field;					\
314 	i->f->set_##field(starget, val);				\
315 	return count;							\
316 }
317 
318 #define spi_transport_rd_attr(field, format_string)			\
319 	spi_transport_show_function(field, format_string)		\
320 	spi_transport_store_function(field, format_string)		\
321 static CLASS_DEVICE_ATTR(field, S_IRUGO | S_IWUSR,			\
322 			 show_spi_transport_##field,			\
323 			 store_spi_transport_##field);
324 
325 #define spi_transport_simple_attr(field, format_string)			\
326 	spi_transport_show_simple(field, format_string)			\
327 	spi_transport_store_simple(field, format_string)		\
328 static CLASS_DEVICE_ATTR(field, S_IRUGO | S_IWUSR,			\
329 			 show_spi_transport_##field,			\
330 			 store_spi_transport_##field);
331 
332 #define spi_transport_max_attr(field, format_string)			\
333 	spi_transport_show_function(field, format_string)		\
334 	spi_transport_store_max(field, format_string)			\
335 	spi_transport_simple_attr(max_##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 /* The Parallel SCSI Tranport Attributes: */
341 spi_transport_max_attr(offset, "%d\n");
342 spi_transport_max_attr(width, "%d\n");
343 spi_transport_rd_attr(iu, "%d\n");
344 spi_transport_rd_attr(dt, "%d\n");
345 spi_transport_rd_attr(qas, "%d\n");
346 spi_transport_rd_attr(wr_flow, "%d\n");
347 spi_transport_rd_attr(rd_strm, "%d\n");
348 spi_transport_rd_attr(rti, "%d\n");
349 spi_transport_rd_attr(pcomp_en, "%d\n");
350 
351 static ssize_t
352 store_spi_revalidate(struct class_device *cdev, const char *buf, size_t count)
353 {
354 	struct scsi_target *starget = transport_class_to_starget(cdev);
355 
356 	/* FIXME: we're relying on an awful lot of device internals
357 	 * here.  We really need a function to get the first available
358 	 * child */
359 	struct device *dev = container_of(starget->dev.children.next, struct device, node);
360 	struct scsi_device *sdev = to_scsi_device(dev);
361 	spi_dv_device(sdev);
362 	return count;
363 }
364 static CLASS_DEVICE_ATTR(revalidate, S_IWUSR, NULL, store_spi_revalidate);
365 
366 /* Translate the period into ns according to the current spec
367  * for SDTR/PPR messages */
368 static ssize_t
369 show_spi_transport_period_helper(struct class_device *cdev, char *buf,
370 				 int period)
371 {
372 	int len, picosec;
373 
374 	if (period < 0 || period > 0xff) {
375 		picosec = -1;
376 	} else if (period <= SPI_STATIC_PPR) {
377 		picosec = ppr_to_ps[period];
378 	} else {
379 		picosec = period * 4000;
380 	}
381 
382 	if (picosec == -1) {
383 		len = sprintf(buf, "reserved");
384 	} else {
385 		len = sprint_frac(buf, picosec, 1000);
386 	}
387 
388 	buf[len++] = '\n';
389 	buf[len] = '\0';
390 	return len;
391 }
392 
393 static ssize_t
394 store_spi_transport_period_helper(struct class_device *cdev, const char *buf,
395 				  size_t count, int *periodp)
396 {
397 	int j, picosec, period = -1;
398 	char *endp;
399 
400 	picosec = simple_strtoul(buf, &endp, 10) * 1000;
401 	if (*endp == '.') {
402 		int mult = 100;
403 		do {
404 			endp++;
405 			if (!isdigit(*endp))
406 				break;
407 			picosec += (*endp - '0') * mult;
408 			mult /= 10;
409 		} while (mult > 0);
410 	}
411 
412 	for (j = 0; j <= SPI_STATIC_PPR; j++) {
413 		if (ppr_to_ps[j] < picosec)
414 			continue;
415 		period = j;
416 		break;
417 	}
418 
419 	if (period == -1)
420 		period = picosec / 4000;
421 
422 	if (period > 0xff)
423 		period = 0xff;
424 
425 	*periodp = period;
426 
427 	return count;
428 }
429 
430 static ssize_t
431 show_spi_transport_period(struct class_device *cdev, char *buf)
432 {
433 	struct scsi_target *starget = transport_class_to_starget(cdev);
434 	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
435 	struct spi_internal *i = to_spi_internal(shost->transportt);
436 	struct spi_transport_attrs *tp =
437 		(struct spi_transport_attrs *)&starget->starget_data;
438 
439 	if (i->f->get_period)
440 		i->f->get_period(starget);
441 
442 	return show_spi_transport_period_helper(cdev, buf, tp->period);
443 }
444 
445 static ssize_t
446 store_spi_transport_period(struct class_device *cdev, const char *buf,
447 			    size_t count)
448 {
449 	struct scsi_target *starget = transport_class_to_starget(cdev);
450 	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
451 	struct spi_internal *i = to_spi_internal(shost->transportt);
452 	struct spi_transport_attrs *tp =
453 		(struct spi_transport_attrs *)&starget->starget_data;
454 	int period, retval;
455 
456 	retval = store_spi_transport_period_helper(cdev, buf, count, &period);
457 
458 	if (period < tp->min_period)
459 		period = tp->min_period;
460 
461 	i->f->set_period(starget, period);
462 
463 	return retval;
464 }
465 
466 static CLASS_DEVICE_ATTR(period, S_IRUGO | S_IWUSR,
467 			 show_spi_transport_period,
468 			 store_spi_transport_period);
469 
470 static ssize_t
471 show_spi_transport_min_period(struct class_device *cdev, char *buf)
472 {
473 	struct scsi_target *starget = transport_class_to_starget(cdev);
474 	struct spi_transport_attrs *tp =
475 		(struct spi_transport_attrs *)&starget->starget_data;
476 
477 	return show_spi_transport_period_helper(cdev, buf, tp->min_period);
478 }
479 
480 static ssize_t
481 store_spi_transport_min_period(struct class_device *cdev, const char *buf,
482 			    size_t count)
483 {
484 	struct scsi_target *starget = transport_class_to_starget(cdev);
485 	struct spi_transport_attrs *tp =
486 		(struct spi_transport_attrs *)&starget->starget_data;
487 
488 	return store_spi_transport_period_helper(cdev, buf, count,
489 						 &tp->min_period);
490 }
491 
492 
493 static CLASS_DEVICE_ATTR(min_period, S_IRUGO | S_IWUSR,
494 			 show_spi_transport_min_period,
495 			 store_spi_transport_min_period);
496 
497 
498 static ssize_t show_spi_host_signalling(struct class_device *cdev, char *buf)
499 {
500 	struct Scsi_Host *shost = transport_class_to_shost(cdev);
501 	struct spi_internal *i = to_spi_internal(shost->transportt);
502 
503 	if (i->f->get_signalling)
504 		i->f->get_signalling(shost);
505 
506 	return sprintf(buf, "%s\n", spi_signal_to_string(spi_signalling(shost)));
507 }
508 static ssize_t store_spi_host_signalling(struct class_device *cdev,
509 					 const char *buf, size_t count)
510 {
511 	struct Scsi_Host *shost = transport_class_to_shost(cdev);
512 	struct spi_internal *i = to_spi_internal(shost->transportt);
513 	enum spi_signal_type type = spi_signal_to_value(buf);
514 
515 	if (type != SPI_SIGNAL_UNKNOWN)
516 		i->f->set_signalling(shost, type);
517 
518 	return count;
519 }
520 static CLASS_DEVICE_ATTR(signalling, S_IRUGO | S_IWUSR,
521 			 show_spi_host_signalling,
522 			 store_spi_host_signalling);
523 
524 #define DV_SET(x, y)			\
525 	if(i->f->set_##x)		\
526 		i->f->set_##x(sdev->sdev_target, y)
527 
528 enum spi_compare_returns {
529 	SPI_COMPARE_SUCCESS,
530 	SPI_COMPARE_FAILURE,
531 	SPI_COMPARE_SKIP_TEST,
532 };
533 
534 
535 /* This is for read/write Domain Validation:  If the device supports
536  * an echo buffer, we do read/write tests to it */
537 static enum spi_compare_returns
538 spi_dv_device_echo_buffer(struct scsi_request *sreq, u8 *buffer,
539 			  u8 *ptr, const int retries)
540 {
541 	struct scsi_device *sdev = sreq->sr_device;
542 	int len = ptr - buffer;
543 	int j, k, r;
544 	unsigned int pattern = 0x0000ffff;
545 
546 	const char spi_write_buffer[] = {
547 		WRITE_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
548 	};
549 	const char spi_read_buffer[] = {
550 		READ_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
551 	};
552 
553 	/* set up the pattern buffer.  Doesn't matter if we spill
554 	 * slightly beyond since that's where the read buffer is */
555 	for (j = 0; j < len; ) {
556 
557 		/* fill the buffer with counting (test a) */
558 		for ( ; j < min(len, 32); j++)
559 			buffer[j] = j;
560 		k = j;
561 		/* fill the buffer with alternating words of 0x0 and
562 		 * 0xffff (test b) */
563 		for ( ; j < min(len, k + 32); j += 2) {
564 			u16 *word = (u16 *)&buffer[j];
565 
566 			*word = (j & 0x02) ? 0x0000 : 0xffff;
567 		}
568 		k = j;
569 		/* fill with crosstalk (alternating 0x5555 0xaaa)
570                  * (test c) */
571 		for ( ; j < min(len, k + 32); j += 2) {
572 			u16 *word = (u16 *)&buffer[j];
573 
574 			*word = (j & 0x02) ? 0x5555 : 0xaaaa;
575 		}
576 		k = j;
577 		/* fill with shifting bits (test d) */
578 		for ( ; j < min(len, k + 32); j += 4) {
579 			u32 *word = (unsigned int *)&buffer[j];
580 			u32 roll = (pattern & 0x80000000) ? 1 : 0;
581 
582 			*word = pattern;
583 			pattern = (pattern << 1) | roll;
584 		}
585 		/* don't bother with random data (test e) */
586 	}
587 
588 	for (r = 0; r < retries; r++) {
589 		sreq->sr_cmd_len = 0;	/* wait_req to fill in */
590 		sreq->sr_data_direction = DMA_TO_DEVICE;
591 		spi_wait_req(sreq, spi_write_buffer, buffer, len);
592 		if(sreq->sr_result || !scsi_device_online(sdev)) {
593 			struct scsi_sense_hdr sshdr;
594 
595 			scsi_device_set_state(sdev, SDEV_QUIESCE);
596 			if (scsi_request_normalize_sense(sreq, &sshdr)
597 			    && sshdr.sense_key == ILLEGAL_REQUEST
598 			    /* INVALID FIELD IN CDB */
599 			    && sshdr.asc == 0x24 && sshdr.ascq == 0x00)
600 				/* This would mean that the drive lied
601 				 * to us about supporting an echo
602 				 * buffer (unfortunately some Western
603 				 * Digital drives do precisely this)
604 				 */
605 				return SPI_COMPARE_SKIP_TEST;
606 
607 
608 			SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Write Buffer failure %x\n", sreq->sr_result);
609 			return SPI_COMPARE_FAILURE;
610 		}
611 
612 		memset(ptr, 0, len);
613 		sreq->sr_cmd_len = 0;	/* wait_req to fill in */
614 		sreq->sr_data_direction = DMA_FROM_DEVICE;
615 		spi_wait_req(sreq, spi_read_buffer, ptr, len);
616 		scsi_device_set_state(sdev, SDEV_QUIESCE);
617 
618 		if (memcmp(buffer, ptr, len) != 0)
619 			return SPI_COMPARE_FAILURE;
620 	}
621 	return SPI_COMPARE_SUCCESS;
622 }
623 
624 /* This is for the simplest form of Domain Validation: a read test
625  * on the inquiry data from the device */
626 static enum spi_compare_returns
627 spi_dv_device_compare_inquiry(struct scsi_request *sreq, u8 *buffer,
628 			      u8 *ptr, const int retries)
629 {
630 	int r;
631 	const int len = sreq->sr_device->inquiry_len;
632 	struct scsi_device *sdev = sreq->sr_device;
633 	const char spi_inquiry[] = {
634 		INQUIRY, 0, 0, 0, len, 0
635 	};
636 
637 	for (r = 0; r < retries; r++) {
638 		sreq->sr_cmd_len = 0;	/* wait_req to fill in */
639 		sreq->sr_data_direction = DMA_FROM_DEVICE;
640 
641 		memset(ptr, 0, len);
642 
643 		spi_wait_req(sreq, spi_inquiry, ptr, len);
644 
645 		if(sreq->sr_result || !scsi_device_online(sdev)) {
646 			scsi_device_set_state(sdev, SDEV_QUIESCE);
647 			return SPI_COMPARE_FAILURE;
648 		}
649 
650 		/* If we don't have the inquiry data already, the
651 		 * first read gets it */
652 		if (ptr == buffer) {
653 			ptr += len;
654 			--r;
655 			continue;
656 		}
657 
658 		if (memcmp(buffer, ptr, len) != 0)
659 			/* failure */
660 			return SPI_COMPARE_FAILURE;
661 	}
662 	return SPI_COMPARE_SUCCESS;
663 }
664 
665 static enum spi_compare_returns
666 spi_dv_retrain(struct scsi_request *sreq, u8 *buffer, u8 *ptr,
667 	       enum spi_compare_returns
668 	       (*compare_fn)(struct scsi_request *, u8 *, u8 *, int))
669 {
670 	struct spi_internal *i = to_spi_internal(sreq->sr_host->transportt);
671 	struct scsi_device *sdev = sreq->sr_device;
672 	int period = 0, prevperiod = 0;
673 	enum spi_compare_returns retval;
674 
675 
676 	for (;;) {
677 		int newperiod;
678 		retval = compare_fn(sreq, buffer, ptr, DV_LOOPS);
679 
680 		if (retval == SPI_COMPARE_SUCCESS
681 		    || retval == SPI_COMPARE_SKIP_TEST)
682 			break;
683 
684 		/* OK, retrain, fallback */
685 		if (i->f->get_period)
686 			i->f->get_period(sdev->sdev_target);
687 		newperiod = spi_period(sdev->sdev_target);
688 		period = newperiod > period ? newperiod : period;
689 		if (period < 0x0d)
690 			period++;
691 		else
692 			period += period >> 1;
693 
694 		if (unlikely(period > 0xff || period == prevperiod)) {
695 			/* Total failure; set to async and return */
696 			SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Domain Validation Failure, dropping back to Asynchronous\n");
697 			DV_SET(offset, 0);
698 			return SPI_COMPARE_FAILURE;
699 		}
700 		SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Domain Validation detected failure, dropping back\n");
701 		DV_SET(period, period);
702 		prevperiod = period;
703 	}
704 	return retval;
705 }
706 
707 static int
708 spi_dv_device_get_echo_buffer(struct scsi_request *sreq, u8 *buffer)
709 {
710 	int l;
711 
712 	/* first off do a test unit ready.  This can error out
713 	 * because of reservations or some other reason.  If it
714 	 * fails, the device won't let us write to the echo buffer
715 	 * so just return failure */
716 
717 	const char spi_test_unit_ready[] = {
718 		TEST_UNIT_READY, 0, 0, 0, 0, 0
719 	};
720 
721 	const char spi_read_buffer_descriptor[] = {
722 		READ_BUFFER, 0x0b, 0, 0, 0, 0, 0, 0, 4, 0
723 	};
724 
725 
726 	sreq->sr_cmd_len = 0;
727 	sreq->sr_data_direction = DMA_NONE;
728 
729 	/* We send a set of three TURs to clear any outstanding
730 	 * unit attention conditions if they exist (Otherwise the
731 	 * buffer tests won't be happy).  If the TUR still fails
732 	 * (reservation conflict, device not ready, etc) just
733 	 * skip the write tests */
734 	for (l = 0; ; l++) {
735 		spi_wait_req(sreq, spi_test_unit_ready, NULL, 0);
736 
737 		if(sreq->sr_result) {
738 			if(l >= 3)
739 				return 0;
740 		} else {
741 			/* TUR succeeded */
742 			break;
743 		}
744 	}
745 
746 	sreq->sr_cmd_len = 0;
747 	sreq->sr_data_direction = DMA_FROM_DEVICE;
748 
749 	spi_wait_req(sreq, spi_read_buffer_descriptor, buffer, 4);
750 
751 	if (sreq->sr_result)
752 		/* Device has no echo buffer */
753 		return 0;
754 
755 	return buffer[3] + ((buffer[2] & 0x1f) << 8);
756 }
757 
758 static void
759 spi_dv_device_internal(struct scsi_request *sreq, u8 *buffer)
760 {
761 	struct spi_internal *i = to_spi_internal(sreq->sr_host->transportt);
762 	struct scsi_device *sdev = sreq->sr_device;
763 	struct scsi_target *starget = sdev->sdev_target;
764 	int len = sdev->inquiry_len;
765 	/* first set us up for narrow async */
766 	DV_SET(offset, 0);
767 	DV_SET(width, 0);
768 
769 	if (spi_dv_device_compare_inquiry(sreq, buffer, buffer, DV_LOOPS)
770 	    != SPI_COMPARE_SUCCESS) {
771 		SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Domain Validation Initial Inquiry Failed\n");
772 		/* FIXME: should probably offline the device here? */
773 		return;
774 	}
775 
776 	/* test width */
777 	if (i->f->set_width && spi_max_width(starget) && sdev->wdtr) {
778 		i->f->set_width(sdev->sdev_target, 1);
779 
780 		printk("WIDTH IS %d\n", spi_max_width(starget));
781 
782 		if (spi_dv_device_compare_inquiry(sreq, buffer,
783 						   buffer + len,
784 						   DV_LOOPS)
785 		    != SPI_COMPARE_SUCCESS) {
786 			SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Wide Transfers Fail\n");
787 			i->f->set_width(sdev->sdev_target, 0);
788 		}
789 	}
790 
791 	if (!i->f->set_period)
792 		return;
793 
794 	/* device can't handle synchronous */
795 	if(!sdev->ppr && !sdev->sdtr)
796 		return;
797 
798 	/* see if the device has an echo buffer.  If it does we can
799 	 * do the SPI pattern write tests */
800 
801 	len = 0;
802 	if (sdev->ppr)
803 		len = spi_dv_device_get_echo_buffer(sreq, buffer);
804 
805  retry:
806 
807 	/* now set up to the maximum */
808 	DV_SET(offset, spi_max_offset(starget));
809 	DV_SET(period, spi_min_period(starget));
810 
811 	if (len == 0) {
812 		SPI_PRINTK(sdev->sdev_target, KERN_INFO, "Domain Validation skipping write tests\n");
813 		spi_dv_retrain(sreq, buffer, buffer + len,
814 			       spi_dv_device_compare_inquiry);
815 		return;
816 	}
817 
818 	if (len > SPI_MAX_ECHO_BUFFER_SIZE) {
819 		SPI_PRINTK(sdev->sdev_target, KERN_WARNING, "Echo buffer size %d is too big, trimming to %d\n", len, SPI_MAX_ECHO_BUFFER_SIZE);
820 		len = SPI_MAX_ECHO_BUFFER_SIZE;
821 	}
822 
823 	if (spi_dv_retrain(sreq, buffer, buffer + len,
824 			   spi_dv_device_echo_buffer)
825 	    == SPI_COMPARE_SKIP_TEST) {
826 		/* OK, the stupid drive can't do a write echo buffer
827 		 * test after all, fall back to the read tests */
828 		len = 0;
829 		goto retry;
830 	}
831 }
832 
833 
834 /**	spi_dv_device - Do Domain Validation on the device
835  *	@sdev:		scsi device to validate
836  *
837  *	Performs the domain validation on the given device in the
838  *	current execution thread.  Since DV operations may sleep,
839  *	the current thread must have user context.  Also no SCSI
840  *	related locks that would deadlock I/O issued by the DV may
841  *	be held.
842  */
843 void
844 spi_dv_device(struct scsi_device *sdev)
845 {
846 	struct scsi_request *sreq = scsi_allocate_request(sdev, GFP_KERNEL);
847 	struct scsi_target *starget = sdev->sdev_target;
848 	u8 *buffer;
849 	const int len = SPI_MAX_ECHO_BUFFER_SIZE*2;
850 
851 	if (unlikely(!sreq))
852 		return;
853 
854 	if (unlikely(scsi_device_get(sdev)))
855 		goto out_free_req;
856 
857 	buffer = kmalloc(len, GFP_KERNEL);
858 
859 	if (unlikely(!buffer))
860 		goto out_put;
861 
862 	memset(buffer, 0, len);
863 
864 	/* We need to verify that the actual device will quiesce; the
865 	 * later target quiesce is just a nice to have */
866 	if (unlikely(scsi_device_quiesce(sdev)))
867 		goto out_free;
868 
869 	scsi_target_quiesce(starget);
870 
871 	spi_dv_pending(starget) = 1;
872 	down(&spi_dv_sem(starget));
873 
874 	SPI_PRINTK(starget, KERN_INFO, "Beginning Domain Validation\n");
875 
876 	spi_dv_device_internal(sreq, buffer);
877 
878 	SPI_PRINTK(starget, KERN_INFO, "Ending Domain Validation\n");
879 
880 	up(&spi_dv_sem(starget));
881 	spi_dv_pending(starget) = 0;
882 
883 	scsi_target_resume(starget);
884 
885 	spi_initial_dv(starget) = 1;
886 
887  out_free:
888 	kfree(buffer);
889  out_put:
890 	scsi_device_put(sdev);
891  out_free_req:
892 	scsi_release_request(sreq);
893 }
894 EXPORT_SYMBOL(spi_dv_device);
895 
896 struct work_queue_wrapper {
897 	struct work_struct	work;
898 	struct scsi_device	*sdev;
899 };
900 
901 static void
902 spi_dv_device_work_wrapper(void *data)
903 {
904 	struct work_queue_wrapper *wqw = (struct work_queue_wrapper *)data;
905 	struct scsi_device *sdev = wqw->sdev;
906 
907 	kfree(wqw);
908 	spi_dv_device(sdev);
909 	spi_dv_pending(sdev->sdev_target) = 0;
910 	scsi_device_put(sdev);
911 }
912 
913 
914 /**
915  *	spi_schedule_dv_device - schedule domain validation to occur on the device
916  *	@sdev:	The device to validate
917  *
918  *	Identical to spi_dv_device() above, except that the DV will be
919  *	scheduled to occur in a workqueue later.  All memory allocations
920  *	are atomic, so may be called from any context including those holding
921  *	SCSI locks.
922  */
923 void
924 spi_schedule_dv_device(struct scsi_device *sdev)
925 {
926 	struct work_queue_wrapper *wqw =
927 		kmalloc(sizeof(struct work_queue_wrapper), GFP_ATOMIC);
928 
929 	if (unlikely(!wqw))
930 		return;
931 
932 	if (unlikely(spi_dv_pending(sdev->sdev_target))) {
933 		kfree(wqw);
934 		return;
935 	}
936 	/* Set pending early (dv_device doesn't check it, only sets it) */
937 	spi_dv_pending(sdev->sdev_target) = 1;
938 	if (unlikely(scsi_device_get(sdev))) {
939 		kfree(wqw);
940 		spi_dv_pending(sdev->sdev_target) = 0;
941 		return;
942 	}
943 
944 	INIT_WORK(&wqw->work, spi_dv_device_work_wrapper, wqw);
945 	wqw->sdev = sdev;
946 
947 	schedule_work(&wqw->work);
948 }
949 EXPORT_SYMBOL(spi_schedule_dv_device);
950 
951 /**
952  * spi_display_xfer_agreement - Print the current target transfer agreement
953  * @starget: The target for which to display the agreement
954  *
955  * Each SPI port is required to maintain a transfer agreement for each
956  * other port on the bus.  This function prints a one-line summary of
957  * the current agreement; more detailed information is available in sysfs.
958  */
959 void spi_display_xfer_agreement(struct scsi_target *starget)
960 {
961 	struct spi_transport_attrs *tp;
962 	tp = (struct spi_transport_attrs *)&starget->starget_data;
963 
964 	if (tp->offset > 0 && tp->period > 0) {
965 		unsigned int picosec, kb100;
966 		char *scsi = "FAST-?";
967 		char tmp[8];
968 
969 		if (tp->period <= SPI_STATIC_PPR) {
970 			picosec = ppr_to_ps[tp->period];
971 			switch (tp->period) {
972 				case  7: scsi = "FAST-320"; break;
973 				case  8: scsi = "FAST-160"; break;
974 				case  9: scsi = "FAST-80"; break;
975 				case 10:
976 				case 11: scsi = "FAST-40"; break;
977 				case 12: scsi = "FAST-20"; break;
978 			}
979 		} else {
980 			picosec = tp->period * 4000;
981 			if (tp->period < 25)
982 				scsi = "FAST-20";
983 			else if (tp->period < 50)
984 				scsi = "FAST-10";
985 			else
986 				scsi = "FAST-5";
987 		}
988 
989 		kb100 = (10000000 + picosec / 2) / picosec;
990 		if (tp->width)
991 			kb100 *= 2;
992 		sprint_frac(tmp, picosec, 1000);
993 
994 		dev_info(&starget->dev,
995 			"%s %sSCSI %d.%d MB/s %s%s%s (%s ns, offset %d)\n",
996 			scsi, tp->width ? "WIDE " : "", kb100/10, kb100 % 10,
997 			tp->dt ? "DT" : "ST", tp->iu ? " IU" : "",
998 			tp->qas  ? " QAS" : "", tmp, tp->offset);
999 	} else {
1000 		dev_info(&starget->dev, "%sasynchronous.\n",
1001 				tp->width ? "wide " : "");
1002 	}
1003 }
1004 EXPORT_SYMBOL(spi_display_xfer_agreement);
1005 
1006 #define SETUP_ATTRIBUTE(field)						\
1007 	i->private_attrs[count] = class_device_attr_##field;		\
1008 	if (!i->f->set_##field) {					\
1009 		i->private_attrs[count].attr.mode = S_IRUGO;		\
1010 		i->private_attrs[count].store = NULL;			\
1011 	}								\
1012 	i->attrs[count] = &i->private_attrs[count];			\
1013 	if (i->f->show_##field)						\
1014 		count++
1015 
1016 #define SETUP_RELATED_ATTRIBUTE(field, rel_field)			\
1017 	i->private_attrs[count] = class_device_attr_##field;		\
1018 	if (!i->f->set_##rel_field) {					\
1019 		i->private_attrs[count].attr.mode = S_IRUGO;		\
1020 		i->private_attrs[count].store = NULL;			\
1021 	}								\
1022 	i->attrs[count] = &i->private_attrs[count];			\
1023 	if (i->f->show_##rel_field)					\
1024 		count++
1025 
1026 #define SETUP_HOST_ATTRIBUTE(field)					\
1027 	i->private_host_attrs[count] = class_device_attr_##field;	\
1028 	if (!i->f->set_##field) {					\
1029 		i->private_host_attrs[count].attr.mode = S_IRUGO;	\
1030 		i->private_host_attrs[count].store = NULL;		\
1031 	}								\
1032 	i->host_attrs[count] = &i->private_host_attrs[count];		\
1033 	count++
1034 
1035 static int spi_device_match(struct attribute_container *cont,
1036 			    struct device *dev)
1037 {
1038 	struct scsi_device *sdev;
1039 	struct Scsi_Host *shost;
1040 
1041 	if (!scsi_is_sdev_device(dev))
1042 		return 0;
1043 
1044 	sdev = to_scsi_device(dev);
1045 	shost = sdev->host;
1046 	if (!shost->transportt  || shost->transportt->host_attrs.ac.class
1047 	    != &spi_host_class.class)
1048 		return 0;
1049 	/* Note: this class has no device attributes, so it has
1050 	 * no per-HBA allocation and thus we don't need to distinguish
1051 	 * the attribute containers for the device */
1052 	return 1;
1053 }
1054 
1055 static int spi_target_match(struct attribute_container *cont,
1056 			    struct device *dev)
1057 {
1058 	struct Scsi_Host *shost;
1059 	struct spi_internal *i;
1060 
1061 	if (!scsi_is_target_device(dev))
1062 		return 0;
1063 
1064 	shost = dev_to_shost(dev->parent);
1065 	if (!shost->transportt  || shost->transportt->host_attrs.ac.class
1066 	    != &spi_host_class.class)
1067 		return 0;
1068 
1069 	i = to_spi_internal(shost->transportt);
1070 
1071 	return &i->t.target_attrs.ac == cont;
1072 }
1073 
1074 static DECLARE_TRANSPORT_CLASS(spi_transport_class,
1075 			       "spi_transport",
1076 			       spi_setup_transport_attrs,
1077 			       NULL,
1078 			       NULL);
1079 
1080 static DECLARE_ANON_TRANSPORT_CLASS(spi_device_class,
1081 				    spi_device_match,
1082 				    spi_device_configure);
1083 
1084 struct scsi_transport_template *
1085 spi_attach_transport(struct spi_function_template *ft)
1086 {
1087 	struct spi_internal *i = kmalloc(sizeof(struct spi_internal),
1088 					 GFP_KERNEL);
1089 	int count = 0;
1090 	if (unlikely(!i))
1091 		return NULL;
1092 
1093 	memset(i, 0, sizeof(struct spi_internal));
1094 
1095 
1096 	i->t.target_attrs.ac.class = &spi_transport_class.class;
1097 	i->t.target_attrs.ac.attrs = &i->attrs[0];
1098 	i->t.target_attrs.ac.match = spi_target_match;
1099 	transport_container_register(&i->t.target_attrs);
1100 	i->t.target_size = sizeof(struct spi_transport_attrs);
1101 	i->t.host_attrs.ac.class = &spi_host_class.class;
1102 	i->t.host_attrs.ac.attrs = &i->host_attrs[0];
1103 	i->t.host_attrs.ac.match = spi_host_match;
1104 	transport_container_register(&i->t.host_attrs);
1105 	i->t.host_size = sizeof(struct spi_host_attrs);
1106 	i->f = ft;
1107 
1108 	SETUP_ATTRIBUTE(period);
1109 	SETUP_RELATED_ATTRIBUTE(min_period, period);
1110 	SETUP_ATTRIBUTE(offset);
1111 	SETUP_RELATED_ATTRIBUTE(max_offset, offset);
1112 	SETUP_ATTRIBUTE(width);
1113 	SETUP_RELATED_ATTRIBUTE(max_width, width);
1114 	SETUP_ATTRIBUTE(iu);
1115 	SETUP_ATTRIBUTE(dt);
1116 	SETUP_ATTRIBUTE(qas);
1117 	SETUP_ATTRIBUTE(wr_flow);
1118 	SETUP_ATTRIBUTE(rd_strm);
1119 	SETUP_ATTRIBUTE(rti);
1120 	SETUP_ATTRIBUTE(pcomp_en);
1121 
1122 	/* if you add an attribute but forget to increase SPI_NUM_ATTRS
1123 	 * this bug will trigger */
1124 	BUG_ON(count > SPI_NUM_ATTRS);
1125 
1126 	i->attrs[count++] = &class_device_attr_revalidate;
1127 
1128 	i->attrs[count] = NULL;
1129 
1130 	count = 0;
1131 	SETUP_HOST_ATTRIBUTE(signalling);
1132 
1133 	BUG_ON(count > SPI_HOST_ATTRS);
1134 
1135 	i->host_attrs[count] = NULL;
1136 
1137 	return &i->t;
1138 }
1139 EXPORT_SYMBOL(spi_attach_transport);
1140 
1141 void spi_release_transport(struct scsi_transport_template *t)
1142 {
1143 	struct spi_internal *i = to_spi_internal(t);
1144 
1145 	transport_container_unregister(&i->t.target_attrs);
1146 	transport_container_unregister(&i->t.host_attrs);
1147 
1148 	kfree(i);
1149 }
1150 EXPORT_SYMBOL(spi_release_transport);
1151 
1152 static __init int spi_transport_init(void)
1153 {
1154 	int error = transport_class_register(&spi_transport_class);
1155 	if (error)
1156 		return error;
1157 	error = anon_transport_class_register(&spi_device_class);
1158 	return transport_class_register(&spi_host_class);
1159 }
1160 
1161 static void __exit spi_transport_exit(void)
1162 {
1163 	transport_class_unregister(&spi_transport_class);
1164 	anon_transport_class_unregister(&spi_device_class);
1165 	transport_class_unregister(&spi_host_class);
1166 }
1167 
1168 MODULE_AUTHOR("Martin Hicks");
1169 MODULE_DESCRIPTION("SPI Transport Attributes");
1170 MODULE_LICENSE("GPL");
1171 
1172 module_init(spi_transport_init);
1173 module_exit(spi_transport_exit);
1174