[SCSI] add ability to deny binding to SPI transport class
[linux-2.6.git] / drivers / scsi / scsi_transport_spi.c
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 14        /* 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_hold_mcs(starget) = 0;
235         spi_dv_pending(starget) = 0;
236         spi_initial_dv(starget) = 0;
237         init_MUTEX(&spi_dv_sem(starget));
238
239         return 0;
240 }
241
242 #define spi_transport_show_simple(field, format_string)                 \
243                                                                         \
244 static ssize_t                                                          \
245 show_spi_transport_##field(struct class_device *cdev, char *buf)        \
246 {                                                                       \
247         struct scsi_target *starget = transport_class_to_starget(cdev); \
248         struct spi_transport_attrs *tp;                                 \
249                                                                         \
250         tp = (struct spi_transport_attrs *)&starget->starget_data;      \
251         return snprintf(buf, 20, format_string, tp->field);             \
252 }
253
254 #define spi_transport_store_simple(field, format_string)                \
255                                                                         \
256 static ssize_t                                                          \
257 store_spi_transport_##field(struct class_device *cdev, const char *buf, \
258                             size_t count)                               \
259 {                                                                       \
260         int val;                                                        \
261         struct scsi_target *starget = transport_class_to_starget(cdev); \
262         struct spi_transport_attrs *tp;                                 \
263                                                                         \
264         tp = (struct spi_transport_attrs *)&starget->starget_data;      \
265         val = simple_strtoul(buf, NULL, 0);                             \
266         tp->field = val;                                                \
267         return count;                                                   \
268 }
269
270 #define spi_transport_show_function(field, format_string)               \
271                                                                         \
272 static ssize_t                                                          \
273 show_spi_transport_##field(struct class_device *cdev, char *buf)        \
274 {                                                                       \
275         struct scsi_target *starget = transport_class_to_starget(cdev); \
276         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);    \
277         struct spi_transport_attrs *tp;                                 \
278         struct spi_internal *i = to_spi_internal(shost->transportt);    \
279         tp = (struct spi_transport_attrs *)&starget->starget_data;      \
280         if (i->f->get_##field)                                          \
281                 i->f->get_##field(starget);                             \
282         return snprintf(buf, 20, format_string, tp->field);             \
283 }
284
285 #define spi_transport_store_function(field, format_string)              \
286 static ssize_t                                                          \
287 store_spi_transport_##field(struct class_device *cdev, const char *buf, \
288                             size_t count)                               \
289 {                                                                       \
290         int val;                                                        \
291         struct scsi_target *starget = transport_class_to_starget(cdev); \
292         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);    \
293         struct spi_internal *i = to_spi_internal(shost->transportt);    \
294                                                                         \
295         val = simple_strtoul(buf, NULL, 0);                             \
296         i->f->set_##field(starget, val);                        \
297         return count;                                                   \
298 }
299
300 #define spi_transport_store_max(field, format_string)                   \
301 static ssize_t                                                          \
302 store_spi_transport_##field(struct class_device *cdev, const char *buf, \
303                             size_t count)                               \
304 {                                                                       \
305         int val;                                                        \
306         struct scsi_target *starget = transport_class_to_starget(cdev); \
307         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);    \
308         struct spi_internal *i = to_spi_internal(shost->transportt);    \
309         struct spi_transport_attrs *tp                                  \
310                 = (struct spi_transport_attrs *)&starget->starget_data; \
311                                                                         \
312         val = simple_strtoul(buf, NULL, 0);                             \
313         if (val > tp->max_##field)                                      \
314                 val = tp->max_##field;                                  \
315         i->f->set_##field(starget, val);                                \
316         return count;                                                   \
317 }
318
319 #define spi_transport_rd_attr(field, format_string)                     \
320         spi_transport_show_function(field, format_string)               \
321         spi_transport_store_function(field, format_string)              \
322 static CLASS_DEVICE_ATTR(field, S_IRUGO | S_IWUSR,                      \
323                          show_spi_transport_##field,                    \
324                          store_spi_transport_##field);
325
326 #define spi_transport_simple_attr(field, format_string)                 \
327         spi_transport_show_simple(field, format_string)                 \
328         spi_transport_store_simple(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_max_attr(field, format_string)                    \
334         spi_transport_show_function(field, format_string)               \
335         spi_transport_store_max(field, format_string)                   \
336         spi_transport_simple_attr(max_##field, format_string)           \
337 static CLASS_DEVICE_ATTR(field, S_IRUGO | S_IWUSR,                      \
338                          show_spi_transport_##field,                    \
339                          store_spi_transport_##field);
340
341 /* The Parallel SCSI Tranport Attributes: */
342 spi_transport_max_attr(offset, "%d\n");
343 spi_transport_max_attr(width, "%d\n");
344 spi_transport_rd_attr(iu, "%d\n");
345 spi_transport_rd_attr(dt, "%d\n");
346 spi_transport_rd_attr(qas, "%d\n");
347 spi_transport_rd_attr(wr_flow, "%d\n");
348 spi_transport_rd_attr(rd_strm, "%d\n");
349 spi_transport_rd_attr(rti, "%d\n");
350 spi_transport_rd_attr(pcomp_en, "%d\n");
351 spi_transport_rd_attr(hold_mcs, "%d\n");
352
353 /* we only care about the first child device so we return 1 */
354 static int child_iter(struct device *dev, void *data)
355 {
356         struct scsi_device *sdev = to_scsi_device(dev);
357
358         spi_dv_device(sdev);
359         return 1;
360 }
361
362 static ssize_t
363 store_spi_revalidate(struct class_device *cdev, const char *buf, size_t count)
364 {
365         struct scsi_target *starget = transport_class_to_starget(cdev);
366
367         device_for_each_child(&starget->dev, NULL, child_iter);
368         return count;
369 }
370 static CLASS_DEVICE_ATTR(revalidate, S_IWUSR, NULL, store_spi_revalidate);
371
372 /* Translate the period into ns according to the current spec
373  * for SDTR/PPR messages */
374 static ssize_t
375 show_spi_transport_period_helper(struct class_device *cdev, char *buf,
376                                  int period)
377 {
378         int len, picosec;
379
380         if (period < 0 || period > 0xff) {
381                 picosec = -1;
382         } else if (period <= SPI_STATIC_PPR) {
383                 picosec = ppr_to_ps[period];
384         } else {
385                 picosec = period * 4000;
386         }
387
388         if (picosec == -1) {
389                 len = sprintf(buf, "reserved");
390         } else {
391                 len = sprint_frac(buf, picosec, 1000);
392         }
393
394         buf[len++] = '\n';
395         buf[len] = '\0';
396         return len;
397 }
398
399 static ssize_t
400 store_spi_transport_period_helper(struct class_device *cdev, const char *buf,
401                                   size_t count, int *periodp)
402 {
403         int j, picosec, period = -1;
404         char *endp;
405
406         picosec = simple_strtoul(buf, &endp, 10) * 1000;
407         if (*endp == '.') {
408                 int mult = 100;
409                 do {
410                         endp++;
411                         if (!isdigit(*endp))
412                                 break;
413                         picosec += (*endp - '0') * mult;
414                         mult /= 10;
415                 } while (mult > 0);
416         }
417
418         for (j = 0; j <= SPI_STATIC_PPR; j++) {
419                 if (ppr_to_ps[j] < picosec)
420                         continue;
421                 period = j;
422                 break;
423         }
424
425         if (period == -1)
426                 period = picosec / 4000;
427
428         if (period > 0xff)
429                 period = 0xff;
430
431         *periodp = period;
432
433         return count;
434 }
435
436 static ssize_t
437 show_spi_transport_period(struct class_device *cdev, char *buf)
438 {
439         struct scsi_target *starget = transport_class_to_starget(cdev);
440         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
441         struct spi_internal *i = to_spi_internal(shost->transportt);
442         struct spi_transport_attrs *tp =
443                 (struct spi_transport_attrs *)&starget->starget_data;
444
445         if (i->f->get_period)
446                 i->f->get_period(starget);
447
448         return show_spi_transport_period_helper(cdev, buf, tp->period);
449 }
450
451 static ssize_t
452 store_spi_transport_period(struct class_device *cdev, const char *buf,
453                             size_t count)
454 {
455         struct scsi_target *starget = transport_class_to_starget(cdev);
456         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
457         struct spi_internal *i = to_spi_internal(shost->transportt);
458         struct spi_transport_attrs *tp =
459                 (struct spi_transport_attrs *)&starget->starget_data;
460         int period, retval;
461
462         retval = store_spi_transport_period_helper(cdev, buf, count, &period);
463
464         if (period < tp->min_period)
465                 period = tp->min_period;
466
467         i->f->set_period(starget, period);
468
469         return retval;
470 }
471
472 static CLASS_DEVICE_ATTR(period, S_IRUGO | S_IWUSR, 
473                          show_spi_transport_period,
474                          store_spi_transport_period);
475
476 static ssize_t
477 show_spi_transport_min_period(struct class_device *cdev, char *buf)
478 {
479         struct scsi_target *starget = transport_class_to_starget(cdev);
480         struct spi_transport_attrs *tp =
481                 (struct spi_transport_attrs *)&starget->starget_data;
482
483         return show_spi_transport_period_helper(cdev, buf, tp->min_period);
484 }
485
486 static ssize_t
487 store_spi_transport_min_period(struct class_device *cdev, const char *buf,
488                             size_t count)
489 {
490         struct scsi_target *starget = transport_class_to_starget(cdev);
491         struct spi_transport_attrs *tp =
492                 (struct spi_transport_attrs *)&starget->starget_data;
493
494         return store_spi_transport_period_helper(cdev, buf, count,
495                                                  &tp->min_period);
496 }
497
498
499 static CLASS_DEVICE_ATTR(min_period, S_IRUGO | S_IWUSR, 
500                          show_spi_transport_min_period,
501                          store_spi_transport_min_period);
502
503
504 static ssize_t show_spi_host_signalling(struct class_device *cdev, char *buf)
505 {
506         struct Scsi_Host *shost = transport_class_to_shost(cdev);
507         struct spi_internal *i = to_spi_internal(shost->transportt);
508
509         if (i->f->get_signalling)
510                 i->f->get_signalling(shost);
511
512         return sprintf(buf, "%s\n", spi_signal_to_string(spi_signalling(shost)));
513 }
514 static ssize_t store_spi_host_signalling(struct class_device *cdev,
515                                          const char *buf, size_t count)
516 {
517         struct Scsi_Host *shost = transport_class_to_shost(cdev);
518         struct spi_internal *i = to_spi_internal(shost->transportt);
519         enum spi_signal_type type = spi_signal_to_value(buf);
520
521         if (type != SPI_SIGNAL_UNKNOWN)
522                 i->f->set_signalling(shost, type);
523
524         return count;
525 }
526 static CLASS_DEVICE_ATTR(signalling, S_IRUGO | S_IWUSR,
527                          show_spi_host_signalling,
528                          store_spi_host_signalling);
529
530 #define DV_SET(x, y)                    \
531         if(i->f->set_##x)               \
532                 i->f->set_##x(sdev->sdev_target, y)
533
534 enum spi_compare_returns {
535         SPI_COMPARE_SUCCESS,
536         SPI_COMPARE_FAILURE,
537         SPI_COMPARE_SKIP_TEST,
538 };
539
540
541 /* This is for read/write Domain Validation:  If the device supports
542  * an echo buffer, we do read/write tests to it */
543 static enum spi_compare_returns
544 spi_dv_device_echo_buffer(struct scsi_request *sreq, u8 *buffer,
545                           u8 *ptr, const int retries)
546 {
547         struct scsi_device *sdev = sreq->sr_device;
548         int len = ptr - buffer;
549         int j, k, r;
550         unsigned int pattern = 0x0000ffff;
551
552         const char spi_write_buffer[] = {
553                 WRITE_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
554         };
555         const char spi_read_buffer[] = {
556                 READ_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
557         };
558
559         /* set up the pattern buffer.  Doesn't matter if we spill
560          * slightly beyond since that's where the read buffer is */
561         for (j = 0; j < len; ) {
562
563                 /* fill the buffer with counting (test a) */
564                 for ( ; j < min(len, 32); j++)
565                         buffer[j] = j;
566                 k = j;
567                 /* fill the buffer with alternating words of 0x0 and
568                  * 0xffff (test b) */
569                 for ( ; j < min(len, k + 32); j += 2) {
570                         u16 *word = (u16 *)&buffer[j];
571                         
572                         *word = (j & 0x02) ? 0x0000 : 0xffff;
573                 }
574                 k = j;
575                 /* fill with crosstalk (alternating 0x5555 0xaaa)
576                  * (test c) */
577                 for ( ; j < min(len, k + 32); j += 2) {
578                         u16 *word = (u16 *)&buffer[j];
579
580                         *word = (j & 0x02) ? 0x5555 : 0xaaaa;
581                 }
582                 k = j;
583                 /* fill with shifting bits (test d) */
584                 for ( ; j < min(len, k + 32); j += 4) {
585                         u32 *word = (unsigned int *)&buffer[j];
586                         u32 roll = (pattern & 0x80000000) ? 1 : 0;
587                         
588                         *word = pattern;
589                         pattern = (pattern << 1) | roll;
590                 }
591                 /* don't bother with random data (test e) */
592         }
593
594         for (r = 0; r < retries; r++) {
595                 sreq->sr_cmd_len = 0;   /* wait_req to fill in */
596                 sreq->sr_data_direction = DMA_TO_DEVICE;
597                 spi_wait_req(sreq, spi_write_buffer, buffer, len);
598                 if(sreq->sr_result || !scsi_device_online(sdev)) {
599                         struct scsi_sense_hdr sshdr;
600
601                         scsi_device_set_state(sdev, SDEV_QUIESCE);
602                         if (scsi_request_normalize_sense(sreq, &sshdr)
603                             && sshdr.sense_key == ILLEGAL_REQUEST
604                             /* INVALID FIELD IN CDB */
605                             && sshdr.asc == 0x24 && sshdr.ascq == 0x00)
606                                 /* This would mean that the drive lied
607                                  * to us about supporting an echo
608                                  * buffer (unfortunately some Western
609                                  * Digital drives do precisely this)
610                                  */
611                                 return SPI_COMPARE_SKIP_TEST;
612
613
614                         SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Write Buffer failure %x\n", sreq->sr_result);
615                         return SPI_COMPARE_FAILURE;
616                 }
617
618                 memset(ptr, 0, len);
619                 sreq->sr_cmd_len = 0;   /* wait_req to fill in */
620                 sreq->sr_data_direction = DMA_FROM_DEVICE;
621                 spi_wait_req(sreq, spi_read_buffer, ptr, len);
622                 scsi_device_set_state(sdev, SDEV_QUIESCE);
623
624                 if (memcmp(buffer, ptr, len) != 0)
625                         return SPI_COMPARE_FAILURE;
626         }
627         return SPI_COMPARE_SUCCESS;
628 }
629
630 /* This is for the simplest form of Domain Validation: a read test
631  * on the inquiry data from the device */
632 static enum spi_compare_returns
633 spi_dv_device_compare_inquiry(struct scsi_request *sreq, u8 *buffer,
634                               u8 *ptr, const int retries)
635 {
636         int r;
637         const int len = sreq->sr_device->inquiry_len;
638         struct scsi_device *sdev = sreq->sr_device;
639         const char spi_inquiry[] = {
640                 INQUIRY, 0, 0, 0, len, 0
641         };
642
643         for (r = 0; r < retries; r++) {
644                 sreq->sr_cmd_len = 0;   /* wait_req to fill in */
645                 sreq->sr_data_direction = DMA_FROM_DEVICE;
646
647                 memset(ptr, 0, len);
648
649                 spi_wait_req(sreq, spi_inquiry, ptr, len);
650                 
651                 if(sreq->sr_result || !scsi_device_online(sdev)) {
652                         scsi_device_set_state(sdev, SDEV_QUIESCE);
653                         return SPI_COMPARE_FAILURE;
654                 }
655
656                 /* If we don't have the inquiry data already, the
657                  * first read gets it */
658                 if (ptr == buffer) {
659                         ptr += len;
660                         --r;
661                         continue;
662                 }
663
664                 if (memcmp(buffer, ptr, len) != 0)
665                         /* failure */
666                         return SPI_COMPARE_FAILURE;
667         }
668         return SPI_COMPARE_SUCCESS;
669 }
670
671 static enum spi_compare_returns
672 spi_dv_retrain(struct scsi_request *sreq, u8 *buffer, u8 *ptr,
673                enum spi_compare_returns 
674                (*compare_fn)(struct scsi_request *, u8 *, u8 *, int))
675 {
676         struct spi_internal *i = to_spi_internal(sreq->sr_host->transportt);
677         struct scsi_device *sdev = sreq->sr_device;
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(sreq, 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                         SPI_PRINTK(starget, KERN_ERR, "Domain Validation Disabing Information Units\n");
704                         DV_SET(iu, 0);
705                 } else if (i->f->set_qas && spi_qas(starget)) {
706                         SPI_PRINTK(starget, KERN_ERR, "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                                 SPI_PRINTK(starget, KERN_ERR, "Domain Validation Failure, dropping back to Asynchronous\n");
719                                 DV_SET(offset, 0);
720                                 return SPI_COMPARE_FAILURE;
721                         }
722                         SPI_PRINTK(starget, KERN_ERR, "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_request *sreq, u8 *buffer)
732 {
733         int l;
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         sreq->sr_cmd_len = 0;
750         sreq->sr_data_direction = DMA_NONE;
751
752         /* We send a set of three TURs to clear any outstanding 
753          * unit attention conditions if they exist (Otherwise the
754          * buffer tests won't be happy).  If the TUR still fails
755          * (reservation conflict, device not ready, etc) just
756          * skip the write tests */
757         for (l = 0; ; l++) {
758                 spi_wait_req(sreq, spi_test_unit_ready, NULL, 0);
759
760                 if(sreq->sr_result) {
761                         if(l >= 3)
762                                 return 0;
763                 } else {
764                         /* TUR succeeded */
765                         break;
766                 }
767         }
768
769         sreq->sr_cmd_len = 0;
770         sreq->sr_data_direction = DMA_FROM_DEVICE;
771
772         spi_wait_req(sreq, spi_read_buffer_descriptor, buffer, 4);
773
774         if (sreq->sr_result)
775                 /* Device has no echo buffer */
776                 return 0;
777
778         return buffer[3] + ((buffer[2] & 0x1f) << 8);
779 }
780
781 static void
782 spi_dv_device_internal(struct scsi_request *sreq, u8 *buffer)
783 {
784         struct spi_internal *i = to_spi_internal(sreq->sr_host->transportt);
785         struct scsi_device *sdev = sreq->sr_device;
786         struct scsi_target *starget = sdev->sdev_target;
787         int len = sdev->inquiry_len;
788         /* first set us up for narrow async */
789         DV_SET(offset, 0);
790         DV_SET(width, 0);
791         
792         if (spi_dv_device_compare_inquiry(sreq, buffer, buffer, DV_LOOPS)
793             != SPI_COMPARE_SUCCESS) {
794                 SPI_PRINTK(starget, KERN_ERR, "Domain Validation Initial Inquiry Failed\n");
795                 /* FIXME: should probably offline the device here? */
796                 return;
797         }
798
799         /* test width */
800         if (i->f->set_width && spi_max_width(starget) &&
801             scsi_device_wide(sdev)) {
802                 i->f->set_width(starget, 1);
803
804                 if (spi_dv_device_compare_inquiry(sreq, buffer,
805                                                    buffer + len,
806                                                    DV_LOOPS)
807                     != SPI_COMPARE_SUCCESS) {
808                         SPI_PRINTK(starget, KERN_ERR, "Wide Transfers Fail\n");
809                         i->f->set_width(starget, 0);
810                 }
811         }
812
813         if (!i->f->set_period)
814                 return;
815
816         /* device can't handle synchronous */
817         if (!scsi_device_sync(sdev) && !scsi_device_dt(sdev))
818                 return;
819
820         /* see if the device has an echo buffer.  If it does we can
821          * do the SPI pattern write tests */
822
823         len = 0;
824         if (scsi_device_dt(sdev))
825                 len = spi_dv_device_get_echo_buffer(sreq, buffer);
826
827  retry:
828
829         /* now set up to the maximum */
830         DV_SET(offset, spi_max_offset(starget));
831         DV_SET(period, spi_min_period(starget));
832         /* try QAS requests; this should be harmless to set if the
833          * target supports it */
834         if (scsi_device_qas(sdev))
835                 DV_SET(qas, 1);
836         /* Also try IU transfers */
837         if (scsi_device_ius(sdev))
838                 DV_SET(iu, 1);
839         if (spi_min_period(starget) < 9) {
840                 /* This u320 (or u640). Ignore the coupled parameters
841                  * like DT and IU, but set the optional ones */
842                 DV_SET(rd_strm, 1);
843                 DV_SET(wr_flow, 1);
844                 DV_SET(rti, 1);
845                 if (spi_min_period(starget) == 8)
846                         DV_SET(pcomp_en, 1);
847         }
848
849         if (len == 0) {
850                 SPI_PRINTK(starget, KERN_INFO, "Domain Validation skipping write tests\n");
851                 spi_dv_retrain(sreq, buffer, buffer + len,
852                                spi_dv_device_compare_inquiry);
853                 return;
854         }
855
856         if (len > SPI_MAX_ECHO_BUFFER_SIZE) {
857                 SPI_PRINTK(starget, KERN_WARNING, "Echo buffer size %d is too big, trimming to %d\n", len, SPI_MAX_ECHO_BUFFER_SIZE);
858                 len = SPI_MAX_ECHO_BUFFER_SIZE;
859         }
860
861         if (spi_dv_retrain(sreq, buffer, buffer + len,
862                            spi_dv_device_echo_buffer)
863             == SPI_COMPARE_SKIP_TEST) {
864                 /* OK, the stupid drive can't do a write echo buffer
865                  * test after all, fall back to the read tests */
866                 len = 0;
867                 goto retry;
868         }
869 }
870
871
872 /**     spi_dv_device - Do Domain Validation on the device
873  *      @sdev:          scsi device to validate
874  *
875  *      Performs the domain validation on the given device in the
876  *      current execution thread.  Since DV operations may sleep,
877  *      the current thread must have user context.  Also no SCSI
878  *      related locks that would deadlock I/O issued by the DV may
879  *      be held.
880  */
881 void
882 spi_dv_device(struct scsi_device *sdev)
883 {
884         struct scsi_request *sreq = scsi_allocate_request(sdev, GFP_KERNEL);
885         struct scsi_target *starget = sdev->sdev_target;
886         u8 *buffer;
887         const int len = SPI_MAX_ECHO_BUFFER_SIZE*2;
888
889         if (unlikely(!sreq))
890                 return;
891
892         if (unlikely(scsi_device_get(sdev)))
893                 goto out_free_req;
894
895         buffer = kmalloc(len, GFP_KERNEL);
896
897         if (unlikely(!buffer))
898                 goto out_put;
899
900         memset(buffer, 0, len);
901
902         /* We need to verify that the actual device will quiesce; the
903          * later target quiesce is just a nice to have */
904         if (unlikely(scsi_device_quiesce(sdev)))
905                 goto out_free;
906
907         scsi_target_quiesce(starget);
908
909         spi_dv_pending(starget) = 1;
910         down(&spi_dv_sem(starget));
911
912         SPI_PRINTK(starget, KERN_INFO, "Beginning Domain Validation\n");
913
914         spi_dv_device_internal(sreq, buffer);
915
916         SPI_PRINTK(starget, KERN_INFO, "Ending Domain Validation\n");
917
918         up(&spi_dv_sem(starget));
919         spi_dv_pending(starget) = 0;
920
921         scsi_target_resume(starget);
922
923         spi_initial_dv(starget) = 1;
924
925  out_free:
926         kfree(buffer);
927  out_put:
928         scsi_device_put(sdev);
929  out_free_req:
930         scsi_release_request(sreq);
931 }
932 EXPORT_SYMBOL(spi_dv_device);
933
934 struct work_queue_wrapper {
935         struct work_struct      work;
936         struct scsi_device      *sdev;
937 };
938
939 static void
940 spi_dv_device_work_wrapper(void *data)
941 {
942         struct work_queue_wrapper *wqw = (struct work_queue_wrapper *)data;
943         struct scsi_device *sdev = wqw->sdev;
944
945         kfree(wqw);
946         spi_dv_device(sdev);
947         spi_dv_pending(sdev->sdev_target) = 0;
948         scsi_device_put(sdev);
949 }
950
951
952 /**
953  *      spi_schedule_dv_device - schedule domain validation to occur on the device
954  *      @sdev:  The device to validate
955  *
956  *      Identical to spi_dv_device() above, except that the DV will be
957  *      scheduled to occur in a workqueue later.  All memory allocations
958  *      are atomic, so may be called from any context including those holding
959  *      SCSI locks.
960  */
961 void
962 spi_schedule_dv_device(struct scsi_device *sdev)
963 {
964         struct work_queue_wrapper *wqw =
965                 kmalloc(sizeof(struct work_queue_wrapper), GFP_ATOMIC);
966
967         if (unlikely(!wqw))
968                 return;
969
970         if (unlikely(spi_dv_pending(sdev->sdev_target))) {
971                 kfree(wqw);
972                 return;
973         }
974         /* Set pending early (dv_device doesn't check it, only sets it) */
975         spi_dv_pending(sdev->sdev_target) = 1;
976         if (unlikely(scsi_device_get(sdev))) {
977                 kfree(wqw);
978                 spi_dv_pending(sdev->sdev_target) = 0;
979                 return;
980         }
981
982         INIT_WORK(&wqw->work, spi_dv_device_work_wrapper, wqw);
983         wqw->sdev = sdev;
984
985         schedule_work(&wqw->work);
986 }
987 EXPORT_SYMBOL(spi_schedule_dv_device);
988
989 /**
990  * spi_display_xfer_agreement - Print the current target transfer agreement
991  * @starget: The target for which to display the agreement
992  *
993  * Each SPI port is required to maintain a transfer agreement for each
994  * other port on the bus.  This function prints a one-line summary of
995  * the current agreement; more detailed information is available in sysfs.
996  */
997 void spi_display_xfer_agreement(struct scsi_target *starget)
998 {
999         struct spi_transport_attrs *tp;
1000         tp = (struct spi_transport_attrs *)&starget->starget_data;
1001
1002         if (tp->offset > 0 && tp->period > 0) {
1003                 unsigned int picosec, kb100;
1004                 char *scsi = "FAST-?";
1005                 char tmp[8];
1006
1007                 if (tp->period <= SPI_STATIC_PPR) {
1008                         picosec = ppr_to_ps[tp->period];
1009                         switch (tp->period) {
1010                                 case  7: scsi = "FAST-320"; break;
1011                                 case  8: scsi = "FAST-160"; break;
1012                                 case  9: scsi = "FAST-80"; break;
1013                                 case 10:
1014                                 case 11: scsi = "FAST-40"; break;
1015                                 case 12: scsi = "FAST-20"; break;
1016                         }
1017                 } else {
1018                         picosec = tp->period * 4000;
1019                         if (tp->period < 25)
1020                                 scsi = "FAST-20";
1021                         else if (tp->period < 50)
1022                                 scsi = "FAST-10";
1023                         else
1024                                 scsi = "FAST-5";
1025                 }
1026
1027                 kb100 = (10000000 + picosec / 2) / picosec;
1028                 if (tp->width)
1029                         kb100 *= 2;
1030                 sprint_frac(tmp, picosec, 1000);
1031
1032                 dev_info(&starget->dev,
1033                          "%s %sSCSI %d.%d MB/s %s%s%s%s%s%s%s%s (%s ns, offset %d)\n",
1034                          scsi, tp->width ? "WIDE " : "", kb100/10, kb100 % 10,
1035                          tp->dt ? "DT" : "ST",
1036                          tp->iu ? " IU" : "",
1037                          tp->qas  ? " QAS" : "",
1038                          tp->rd_strm ? " RDSTRM" : "",
1039                          tp->rti ? " RTI" : "",
1040                          tp->wr_flow ? " WRFLOW" : "",
1041                          tp->pcomp_en ? " PCOMP" : "",
1042                          tp->hold_mcs ? " HMCS" : "",
1043                          tmp, tp->offset);
1044         } else {
1045                 dev_info(&starget->dev, "%sasynchronous.\n",
1046                                 tp->width ? "wide " : "");
1047         }
1048 }
1049 EXPORT_SYMBOL(spi_display_xfer_agreement);
1050
1051 #define SETUP_ATTRIBUTE(field)                                          \
1052         i->private_attrs[count] = class_device_attr_##field;            \
1053         if (!i->f->set_##field) {                                       \
1054                 i->private_attrs[count].attr.mode = S_IRUGO;            \
1055                 i->private_attrs[count].store = NULL;                   \
1056         }                                                               \
1057         i->attrs[count] = &i->private_attrs[count];                     \
1058         if (i->f->show_##field)                                         \
1059                 count++
1060
1061 #define SETUP_RELATED_ATTRIBUTE(field, rel_field)                       \
1062         i->private_attrs[count] = class_device_attr_##field;            \
1063         if (!i->f->set_##rel_field) {                                   \
1064                 i->private_attrs[count].attr.mode = S_IRUGO;            \
1065                 i->private_attrs[count].store = NULL;                   \
1066         }                                                               \
1067         i->attrs[count] = &i->private_attrs[count];                     \
1068         if (i->f->show_##rel_field)                                     \
1069                 count++
1070
1071 #define SETUP_HOST_ATTRIBUTE(field)                                     \
1072         i->private_host_attrs[count] = class_device_attr_##field;       \
1073         if (!i->f->set_##field) {                                       \
1074                 i->private_host_attrs[count].attr.mode = S_IRUGO;       \
1075                 i->private_host_attrs[count].store = NULL;              \
1076         }                                                               \
1077         i->host_attrs[count] = &i->private_host_attrs[count];           \
1078         count++
1079
1080 static int spi_device_match(struct attribute_container *cont,
1081                             struct device *dev)
1082 {
1083         struct scsi_device *sdev;
1084         struct Scsi_Host *shost;
1085         struct spi_internal *i;
1086
1087         if (!scsi_is_sdev_device(dev))
1088                 return 0;
1089
1090         sdev = to_scsi_device(dev);
1091         shost = sdev->host;
1092         if (!shost->transportt  || shost->transportt->host_attrs.ac.class
1093             != &spi_host_class.class)
1094                 return 0;
1095         /* Note: this class has no device attributes, so it has
1096          * no per-HBA allocation and thus we don't need to distinguish
1097          * the attribute containers for the device */
1098         i = to_spi_internal(shost->transportt);
1099         if (i->f->deny_binding && i->f->deny_binding(sdev->sdev_target))
1100                 return 0;
1101         return 1;
1102 }
1103
1104 static int spi_target_match(struct attribute_container *cont,
1105                             struct device *dev)
1106 {
1107         struct Scsi_Host *shost;
1108         struct scsi_target *starget;
1109         struct spi_internal *i;
1110
1111         if (!scsi_is_target_device(dev))
1112                 return 0;
1113
1114         shost = dev_to_shost(dev->parent);
1115         if (!shost->transportt  || shost->transportt->host_attrs.ac.class
1116             != &spi_host_class.class)
1117                 return 0;
1118
1119         i = to_spi_internal(shost->transportt);
1120         starget = to_scsi_target(dev);
1121
1122         if (i->f->deny_binding && i->f->deny_binding(starget))
1123                 return 0;
1124
1125         return &i->t.target_attrs.ac == cont;
1126 }
1127
1128 static DECLARE_TRANSPORT_CLASS(spi_transport_class,
1129                                "spi_transport",
1130                                spi_setup_transport_attrs,
1131                                NULL,
1132                                NULL);
1133
1134 static DECLARE_ANON_TRANSPORT_CLASS(spi_device_class,
1135                                     spi_device_match,
1136                                     spi_device_configure);
1137
1138 struct scsi_transport_template *
1139 spi_attach_transport(struct spi_function_template *ft)
1140 {
1141         struct spi_internal *i = kmalloc(sizeof(struct spi_internal),
1142                                          GFP_KERNEL);
1143         int count = 0;
1144         if (unlikely(!i))
1145                 return NULL;
1146
1147         memset(i, 0, sizeof(struct spi_internal));
1148
1149
1150         i->t.target_attrs.ac.class = &spi_transport_class.class;
1151         i->t.target_attrs.ac.attrs = &i->attrs[0];
1152         i->t.target_attrs.ac.match = spi_target_match;
1153         transport_container_register(&i->t.target_attrs);
1154         i->t.target_size = sizeof(struct spi_transport_attrs);
1155         i->t.host_attrs.ac.class = &spi_host_class.class;
1156         i->t.host_attrs.ac.attrs = &i->host_attrs[0];
1157         i->t.host_attrs.ac.match = spi_host_match;
1158         transport_container_register(&i->t.host_attrs);
1159         i->t.host_size = sizeof(struct spi_host_attrs);
1160         i->f = ft;
1161
1162         SETUP_ATTRIBUTE(period);
1163         SETUP_RELATED_ATTRIBUTE(min_period, period);
1164         SETUP_ATTRIBUTE(offset);
1165         SETUP_RELATED_ATTRIBUTE(max_offset, offset);
1166         SETUP_ATTRIBUTE(width);
1167         SETUP_RELATED_ATTRIBUTE(max_width, width);
1168         SETUP_ATTRIBUTE(iu);
1169         SETUP_ATTRIBUTE(dt);
1170         SETUP_ATTRIBUTE(qas);
1171         SETUP_ATTRIBUTE(wr_flow);
1172         SETUP_ATTRIBUTE(rd_strm);
1173         SETUP_ATTRIBUTE(rti);
1174         SETUP_ATTRIBUTE(pcomp_en);
1175         SETUP_ATTRIBUTE(hold_mcs);
1176
1177         /* if you add an attribute but forget to increase SPI_NUM_ATTRS
1178          * this bug will trigger */
1179         BUG_ON(count > SPI_NUM_ATTRS);
1180
1181         i->attrs[count++] = &class_device_attr_revalidate;
1182
1183         i->attrs[count] = NULL;
1184
1185         count = 0;
1186         SETUP_HOST_ATTRIBUTE(signalling);
1187
1188         BUG_ON(count > SPI_HOST_ATTRS);
1189
1190         i->host_attrs[count] = NULL;
1191
1192         return &i->t;
1193 }
1194 EXPORT_SYMBOL(spi_attach_transport);
1195
1196 void spi_release_transport(struct scsi_transport_template *t)
1197 {
1198         struct spi_internal *i = to_spi_internal(t);
1199
1200         transport_container_unregister(&i->t.target_attrs);
1201         transport_container_unregister(&i->t.host_attrs);
1202
1203         kfree(i);
1204 }
1205 EXPORT_SYMBOL(spi_release_transport);
1206
1207 static __init int spi_transport_init(void)
1208 {
1209         int error = transport_class_register(&spi_transport_class);
1210         if (error)
1211                 return error;
1212         error = anon_transport_class_register(&spi_device_class);
1213         return transport_class_register(&spi_host_class);
1214 }
1215
1216 static void __exit spi_transport_exit(void)
1217 {
1218         transport_class_unregister(&spi_transport_class);
1219         anon_transport_class_unregister(&spi_device_class);
1220         transport_class_unregister(&spi_host_class);
1221 }
1222
1223 MODULE_AUTHOR("Martin Hicks");
1224 MODULE_DESCRIPTION("SPI Transport Attributes");
1225 MODULE_LICENSE("GPL");
1226
1227 module_init(spi_transport_init);
1228 module_exit(spi_transport_exit);