[SCSI] lpfc: Move a dereference below a NULL test
[linux-2.6] / 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 <linux/mutex.h>
27 #include <linux/sysfs.h>
28 #include <scsi/scsi.h>
29 #include "scsi_priv.h"
30 #include <scsi/scsi_device.h>
31 #include <scsi/scsi_host.h>
32 #include <scsi/scsi_cmnd.h>
33 #include <scsi/scsi_eh.h>
34 #include <scsi/scsi_transport.h>
35 #include <scsi/scsi_transport_spi.h>
36
37 #define SPI_NUM_ATTRS 14        /* increase this if you add attributes */
38 #define SPI_OTHER_ATTRS 1       /* Increase this if you add "always
39                                  * on" attributes */
40 #define SPI_HOST_ATTRS  1
41
42 #define SPI_MAX_ECHO_BUFFER_SIZE        4096
43
44 #define DV_LOOPS        3
45 #define DV_TIMEOUT      (10*HZ)
46 #define DV_RETRIES      3       /* should only need at most 
47                                  * two cc/ua clears */
48
49 /* Private data accessors (keep these out of the header file) */
50 #define spi_dv_in_progress(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_in_progress)
51 #define spi_dv_mutex(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_mutex)
52
53 struct spi_internal {
54         struct scsi_transport_template t;
55         struct spi_function_template *f;
56 };
57
58 #define to_spi_internal(tmpl)   container_of(tmpl, struct spi_internal, t)
59
60 static const int ppr_to_ps[] = {
61         /* The PPR values 0-6 are reserved, fill them in when
62          * the committee defines them */
63         -1,                     /* 0x00 */
64         -1,                     /* 0x01 */
65         -1,                     /* 0x02 */
66         -1,                     /* 0x03 */
67         -1,                     /* 0x04 */
68         -1,                     /* 0x05 */
69         -1,                     /* 0x06 */
70          3125,                  /* 0x07 */
71          6250,                  /* 0x08 */
72         12500,                  /* 0x09 */
73         25000,                  /* 0x0a */
74         30300,                  /* 0x0b */
75         50000,                  /* 0x0c */
76 };
77 /* The PPR values at which you calculate the period in ns by multiplying
78  * by 4 */
79 #define SPI_STATIC_PPR  0x0c
80
81 static int sprint_frac(char *dest, int value, int denom)
82 {
83         int frac = value % denom;
84         int result = sprintf(dest, "%d", value / denom);
85
86         if (frac == 0)
87                 return result;
88         dest[result++] = '.';
89
90         do {
91                 denom /= 10;
92                 sprintf(dest + result, "%d", frac / denom);
93                 result++;
94                 frac %= denom;
95         } while (frac);
96
97         dest[result++] = '\0';
98         return result;
99 }
100
101 static int spi_execute(struct scsi_device *sdev, const void *cmd,
102                        enum dma_data_direction dir,
103                        void *buffer, unsigned bufflen,
104                        struct scsi_sense_hdr *sshdr)
105 {
106         int i, result;
107         unsigned char sense[SCSI_SENSE_BUFFERSIZE];
108
109         for(i = 0; i < DV_RETRIES; i++) {
110                 result = scsi_execute(sdev, cmd, dir, buffer, bufflen,
111                                       sense, DV_TIMEOUT, /* retries */ 1,
112                                       REQ_FAILFAST_DEV |
113                                       REQ_FAILFAST_TRANSPORT |
114                                       REQ_FAILFAST_DRIVER,
115                                       NULL);
116                 if (driver_byte(result) & DRIVER_SENSE) {
117                         struct scsi_sense_hdr sshdr_tmp;
118                         if (!sshdr)
119                                 sshdr = &sshdr_tmp;
120
121                         if (scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE,
122                                                  sshdr)
123                             && sshdr->sense_key == UNIT_ATTENTION)
124                                 continue;
125                 }
126                 break;
127         }
128         return result;
129 }
130
131 static struct {
132         enum spi_signal_type    value;
133         char                    *name;
134 } signal_types[] = {
135         { SPI_SIGNAL_UNKNOWN, "unknown" },
136         { SPI_SIGNAL_SE, "SE" },
137         { SPI_SIGNAL_LVD, "LVD" },
138         { SPI_SIGNAL_HVD, "HVD" },
139 };
140
141 static inline const char *spi_signal_to_string(enum spi_signal_type type)
142 {
143         int i;
144
145         for (i = 0; i < ARRAY_SIZE(signal_types); i++) {
146                 if (type == signal_types[i].value)
147                         return signal_types[i].name;
148         }
149         return NULL;
150 }
151 static inline enum spi_signal_type spi_signal_to_value(const char *name)
152 {
153         int i, len;
154
155         for (i = 0; i < ARRAY_SIZE(signal_types); i++) {
156                 len =  strlen(signal_types[i].name);
157                 if (strncmp(name, signal_types[i].name, len) == 0 &&
158                     (name[len] == '\n' || name[len] == '\0'))
159                         return signal_types[i].value;
160         }
161         return SPI_SIGNAL_UNKNOWN;
162 }
163
164 static int spi_host_setup(struct transport_container *tc, struct device *dev,
165                           struct device *cdev)
166 {
167         struct Scsi_Host *shost = dev_to_shost(dev);
168
169         spi_signalling(shost) = SPI_SIGNAL_UNKNOWN;
170
171         return 0;
172 }
173
174 static int spi_host_configure(struct transport_container *tc,
175                               struct device *dev,
176                               struct device *cdev);
177
178 static DECLARE_TRANSPORT_CLASS(spi_host_class,
179                                "spi_host",
180                                spi_host_setup,
181                                NULL,
182                                spi_host_configure);
183
184 static int spi_host_match(struct attribute_container *cont,
185                           struct device *dev)
186 {
187         struct Scsi_Host *shost;
188
189         if (!scsi_is_host_device(dev))
190                 return 0;
191
192         shost = dev_to_shost(dev);
193         if (!shost->transportt  || shost->transportt->host_attrs.ac.class
194             != &spi_host_class.class)
195                 return 0;
196
197         return &shost->transportt->host_attrs.ac == cont;
198 }
199
200 static int spi_target_configure(struct transport_container *tc,
201                                 struct device *dev,
202                                 struct device *cdev);
203
204 static int spi_device_configure(struct transport_container *tc,
205                                 struct device *dev,
206                                 struct device *cdev)
207 {
208         struct scsi_device *sdev = to_scsi_device(dev);
209         struct scsi_target *starget = sdev->sdev_target;
210
211         /* Populate the target capability fields with the values
212          * gleaned from the device inquiry */
213
214         spi_support_sync(starget) = scsi_device_sync(sdev);
215         spi_support_wide(starget) = scsi_device_wide(sdev);
216         spi_support_dt(starget) = scsi_device_dt(sdev);
217         spi_support_dt_only(starget) = scsi_device_dt_only(sdev);
218         spi_support_ius(starget) = scsi_device_ius(sdev);
219         spi_support_qas(starget) = scsi_device_qas(sdev);
220
221         return 0;
222 }
223
224 static int spi_setup_transport_attrs(struct transport_container *tc,
225                                      struct device *dev,
226                                      struct device *cdev)
227 {
228         struct scsi_target *starget = to_scsi_target(dev);
229
230         spi_period(starget) = -1;       /* illegal value */
231         spi_min_period(starget) = 0;
232         spi_offset(starget) = 0;        /* async */
233         spi_max_offset(starget) = 255;
234         spi_width(starget) = 0; /* narrow */
235         spi_max_width(starget) = 1;
236         spi_iu(starget) = 0;    /* no IU */
237         spi_dt(starget) = 0;    /* ST */
238         spi_qas(starget) = 0;
239         spi_wr_flow(starget) = 0;
240         spi_rd_strm(starget) = 0;
241         spi_rti(starget) = 0;
242         spi_pcomp_en(starget) = 0;
243         spi_hold_mcs(starget) = 0;
244         spi_dv_pending(starget) = 0;
245         spi_dv_in_progress(starget) = 0;
246         spi_initial_dv(starget) = 0;
247         mutex_init(&spi_dv_mutex(starget));
248
249         return 0;
250 }
251
252 #define spi_transport_show_simple(field, format_string)                 \
253                                                                         \
254 static ssize_t                                                          \
255 show_spi_transport_##field(struct device *dev,                  \
256                            struct device_attribute *attr, char *buf)    \
257 {                                                                       \
258         struct scsi_target *starget = transport_class_to_starget(dev);  \
259         struct spi_transport_attrs *tp;                                 \
260                                                                         \
261         tp = (struct spi_transport_attrs *)&starget->starget_data;      \
262         return snprintf(buf, 20, format_string, tp->field);             \
263 }
264
265 #define spi_transport_store_simple(field, format_string)                \
266                                                                         \
267 static ssize_t                                                          \
268 store_spi_transport_##field(struct device *dev,                         \
269                             struct device_attribute *attr,              \
270                             const char *buf, size_t count)              \
271 {                                                                       \
272         int val;                                                        \
273         struct scsi_target *starget = transport_class_to_starget(dev);  \
274         struct spi_transport_attrs *tp;                                 \
275                                                                         \
276         tp = (struct spi_transport_attrs *)&starget->starget_data;      \
277         val = simple_strtoul(buf, NULL, 0);                             \
278         tp->field = val;                                                \
279         return count;                                                   \
280 }
281
282 #define spi_transport_show_function(field, format_string)               \
283                                                                         \
284 static ssize_t                                                          \
285 show_spi_transport_##field(struct device *dev,                  \
286                            struct device_attribute *attr, char *buf)    \
287 {                                                                       \
288         struct scsi_target *starget = transport_class_to_starget(dev);  \
289         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);    \
290         struct spi_transport_attrs *tp;                                 \
291         struct spi_internal *i = to_spi_internal(shost->transportt);    \
292         tp = (struct spi_transport_attrs *)&starget->starget_data;      \
293         if (i->f->get_##field)                                          \
294                 i->f->get_##field(starget);                             \
295         return snprintf(buf, 20, format_string, tp->field);             \
296 }
297
298 #define spi_transport_store_function(field, format_string)              \
299 static ssize_t                                                          \
300 store_spi_transport_##field(struct device *dev,                         \
301                             struct device_attribute *attr,              \
302                             const char *buf, size_t count)              \
303 {                                                                       \
304         int val;                                                        \
305         struct scsi_target *starget = transport_class_to_starget(dev);  \
306         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);    \
307         struct spi_internal *i = to_spi_internal(shost->transportt);    \
308                                                                         \
309         if (!i->f->set_##field)                                         \
310                 return -EINVAL;                                         \
311         val = simple_strtoul(buf, NULL, 0);                             \
312         i->f->set_##field(starget, val);                                \
313         return count;                                                   \
314 }
315
316 #define spi_transport_store_max(field, format_string)                   \
317 static ssize_t                                                          \
318 store_spi_transport_##field(struct device *dev,                         \
319                             struct device_attribute *attr,              \
320                             const char *buf, size_t count)              \
321 {                                                                       \
322         int val;                                                        \
323         struct scsi_target *starget = transport_class_to_starget(dev);  \
324         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);    \
325         struct spi_internal *i = to_spi_internal(shost->transportt);    \
326         struct spi_transport_attrs *tp                                  \
327                 = (struct spi_transport_attrs *)&starget->starget_data; \
328                                                                         \
329         if (i->f->set_##field)                                          \
330                 return -EINVAL;                                         \
331         val = simple_strtoul(buf, NULL, 0);                             \
332         if (val > tp->max_##field)                                      \
333                 val = tp->max_##field;                                  \
334         i->f->set_##field(starget, val);                                \
335         return count;                                                   \
336 }
337
338 #define spi_transport_rd_attr(field, format_string)                     \
339         spi_transport_show_function(field, format_string)               \
340         spi_transport_store_function(field, format_string)              \
341 static DEVICE_ATTR(field, S_IRUGO,                              \
342                    show_spi_transport_##field,                  \
343                    store_spi_transport_##field);
344
345 #define spi_transport_simple_attr(field, format_string)                 \
346         spi_transport_show_simple(field, format_string)                 \
347         spi_transport_store_simple(field, format_string)                \
348 static DEVICE_ATTR(field, S_IRUGO,                              \
349                    show_spi_transport_##field,                  \
350                    store_spi_transport_##field);
351
352 #define spi_transport_max_attr(field, format_string)                    \
353         spi_transport_show_function(field, format_string)               \
354         spi_transport_store_max(field, format_string)                   \
355         spi_transport_simple_attr(max_##field, format_string)           \
356 static DEVICE_ATTR(field, S_IRUGO,                              \
357                    show_spi_transport_##field,                  \
358                    store_spi_transport_##field);
359
360 /* The Parallel SCSI Tranport Attributes: */
361 spi_transport_max_attr(offset, "%d\n");
362 spi_transport_max_attr(width, "%d\n");
363 spi_transport_rd_attr(iu, "%d\n");
364 spi_transport_rd_attr(dt, "%d\n");
365 spi_transport_rd_attr(qas, "%d\n");
366 spi_transport_rd_attr(wr_flow, "%d\n");
367 spi_transport_rd_attr(rd_strm, "%d\n");
368 spi_transport_rd_attr(rti, "%d\n");
369 spi_transport_rd_attr(pcomp_en, "%d\n");
370 spi_transport_rd_attr(hold_mcs, "%d\n");
371
372 /* we only care about the first child device that's a real SCSI device
373  * so we return 1 to terminate the iteration when we find it */
374 static int child_iter(struct device *dev, void *data)
375 {
376         if (!scsi_is_sdev_device(dev))
377                 return 0;
378
379         spi_dv_device(to_scsi_device(dev));
380         return 1;
381 }
382
383 static ssize_t
384 store_spi_revalidate(struct device *dev, struct device_attribute *attr,
385                      const char *buf, size_t count)
386 {
387         struct scsi_target *starget = transport_class_to_starget(dev);
388
389         device_for_each_child(&starget->dev, NULL, child_iter);
390         return count;
391 }
392 static DEVICE_ATTR(revalidate, S_IWUSR, NULL, store_spi_revalidate);
393
394 /* Translate the period into ns according to the current spec
395  * for SDTR/PPR messages */
396 static int period_to_str(char *buf, int period)
397 {
398         int len, picosec;
399
400         if (period < 0 || period > 0xff) {
401                 picosec = -1;
402         } else if (period <= SPI_STATIC_PPR) {
403                 picosec = ppr_to_ps[period];
404         } else {
405                 picosec = period * 4000;
406         }
407
408         if (picosec == -1) {
409                 len = sprintf(buf, "reserved");
410         } else {
411                 len = sprint_frac(buf, picosec, 1000);
412         }
413
414         return len;
415 }
416
417 static ssize_t
418 show_spi_transport_period_helper(char *buf, int period)
419 {
420         int len = period_to_str(buf, period);
421         buf[len++] = '\n';
422         buf[len] = '\0';
423         return len;
424 }
425
426 static ssize_t
427 store_spi_transport_period_helper(struct device *dev, const char *buf,
428                                   size_t count, int *periodp)
429 {
430         int j, picosec, period = -1;
431         char *endp;
432
433         picosec = simple_strtoul(buf, &endp, 10) * 1000;
434         if (*endp == '.') {
435                 int mult = 100;
436                 do {
437                         endp++;
438                         if (!isdigit(*endp))
439                                 break;
440                         picosec += (*endp - '0') * mult;
441                         mult /= 10;
442                 } while (mult > 0);
443         }
444
445         for (j = 0; j <= SPI_STATIC_PPR; j++) {
446                 if (ppr_to_ps[j] < picosec)
447                         continue;
448                 period = j;
449                 break;
450         }
451
452         if (period == -1)
453                 period = picosec / 4000;
454
455         if (period > 0xff)
456                 period = 0xff;
457
458         *periodp = period;
459
460         return count;
461 }
462
463 static ssize_t
464 show_spi_transport_period(struct device *dev,
465                           struct device_attribute *attr, char *buf)
466 {
467         struct scsi_target *starget = transport_class_to_starget(dev);
468         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
469         struct spi_internal *i = to_spi_internal(shost->transportt);
470         struct spi_transport_attrs *tp =
471                 (struct spi_transport_attrs *)&starget->starget_data;
472
473         if (i->f->get_period)
474                 i->f->get_period(starget);
475
476         return show_spi_transport_period_helper(buf, tp->period);
477 }
478
479 static ssize_t
480 store_spi_transport_period(struct device *cdev, struct device_attribute *attr,
481                            const char *buf, size_t count)
482 {
483         struct scsi_target *starget = transport_class_to_starget(cdev);
484         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
485         struct spi_internal *i = to_spi_internal(shost->transportt);
486         struct spi_transport_attrs *tp =
487                 (struct spi_transport_attrs *)&starget->starget_data;
488         int period, retval;
489
490         if (!i->f->set_period)
491                 return -EINVAL;
492
493         retval = store_spi_transport_period_helper(cdev, buf, count, &period);
494
495         if (period < tp->min_period)
496                 period = tp->min_period;
497
498         i->f->set_period(starget, period);
499
500         return retval;
501 }
502
503 static DEVICE_ATTR(period, S_IRUGO,
504                    show_spi_transport_period,
505                    store_spi_transport_period);
506
507 static ssize_t
508 show_spi_transport_min_period(struct device *cdev,
509                               struct device_attribute *attr, char *buf)
510 {
511         struct scsi_target *starget = transport_class_to_starget(cdev);
512         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
513         struct spi_internal *i = to_spi_internal(shost->transportt);
514         struct spi_transport_attrs *tp =
515                 (struct spi_transport_attrs *)&starget->starget_data;
516
517         if (!i->f->set_period)
518                 return -EINVAL;
519
520         return show_spi_transport_period_helper(buf, tp->min_period);
521 }
522
523 static ssize_t
524 store_spi_transport_min_period(struct device *cdev,
525                                struct device_attribute *attr,
526                                const char *buf, size_t count)
527 {
528         struct scsi_target *starget = transport_class_to_starget(cdev);
529         struct spi_transport_attrs *tp =
530                 (struct spi_transport_attrs *)&starget->starget_data;
531
532         return store_spi_transport_period_helper(cdev, buf, count,
533                                                  &tp->min_period);
534 }
535
536
537 static DEVICE_ATTR(min_period, S_IRUGO,
538                    show_spi_transport_min_period,
539                    store_spi_transport_min_period);
540
541
542 static ssize_t show_spi_host_signalling(struct device *cdev,
543                                         struct device_attribute *attr,
544                                         char *buf)
545 {
546         struct Scsi_Host *shost = transport_class_to_shost(cdev);
547         struct spi_internal *i = to_spi_internal(shost->transportt);
548
549         if (i->f->get_signalling)
550                 i->f->get_signalling(shost);
551
552         return sprintf(buf, "%s\n", spi_signal_to_string(spi_signalling(shost)));
553 }
554 static ssize_t store_spi_host_signalling(struct device *dev,
555                                          struct device_attribute *attr,
556                                          const char *buf, size_t count)
557 {
558         struct Scsi_Host *shost = transport_class_to_shost(dev);
559         struct spi_internal *i = to_spi_internal(shost->transportt);
560         enum spi_signal_type type = spi_signal_to_value(buf);
561
562         if (!i->f->set_signalling)
563                 return -EINVAL;
564
565         if (type != SPI_SIGNAL_UNKNOWN)
566                 i->f->set_signalling(shost, type);
567
568         return count;
569 }
570 static DEVICE_ATTR(signalling, S_IRUGO,
571                    show_spi_host_signalling,
572                    store_spi_host_signalling);
573
574 #define DV_SET(x, y)                    \
575         if(i->f->set_##x)               \
576                 i->f->set_##x(sdev->sdev_target, y)
577
578 enum spi_compare_returns {
579         SPI_COMPARE_SUCCESS,
580         SPI_COMPARE_FAILURE,
581         SPI_COMPARE_SKIP_TEST,
582 };
583
584
585 /* This is for read/write Domain Validation:  If the device supports
586  * an echo buffer, we do read/write tests to it */
587 static enum spi_compare_returns
588 spi_dv_device_echo_buffer(struct scsi_device *sdev, u8 *buffer,
589                           u8 *ptr, const int retries)
590 {
591         int len = ptr - buffer;
592         int j, k, r, result;
593         unsigned int pattern = 0x0000ffff;
594         struct scsi_sense_hdr sshdr;
595
596         const char spi_write_buffer[] = {
597                 WRITE_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
598         };
599         const char spi_read_buffer[] = {
600                 READ_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
601         };
602
603         /* set up the pattern buffer.  Doesn't matter if we spill
604          * slightly beyond since that's where the read buffer is */
605         for (j = 0; j < len; ) {
606
607                 /* fill the buffer with counting (test a) */
608                 for ( ; j < min(len, 32); j++)
609                         buffer[j] = j;
610                 k = j;
611                 /* fill the buffer with alternating words of 0x0 and
612                  * 0xffff (test b) */
613                 for ( ; j < min(len, k + 32); j += 2) {
614                         u16 *word = (u16 *)&buffer[j];
615                         
616                         *word = (j & 0x02) ? 0x0000 : 0xffff;
617                 }
618                 k = j;
619                 /* fill with crosstalk (alternating 0x5555 0xaaa)
620                  * (test c) */
621                 for ( ; j < min(len, k + 32); j += 2) {
622                         u16 *word = (u16 *)&buffer[j];
623
624                         *word = (j & 0x02) ? 0x5555 : 0xaaaa;
625                 }
626                 k = j;
627                 /* fill with shifting bits (test d) */
628                 for ( ; j < min(len, k + 32); j += 4) {
629                         u32 *word = (unsigned int *)&buffer[j];
630                         u32 roll = (pattern & 0x80000000) ? 1 : 0;
631                         
632                         *word = pattern;
633                         pattern = (pattern << 1) | roll;
634                 }
635                 /* don't bother with random data (test e) */
636         }
637
638         for (r = 0; r < retries; r++) {
639                 result = spi_execute(sdev, spi_write_buffer, DMA_TO_DEVICE,
640                                      buffer, len, &sshdr);
641                 if(result || !scsi_device_online(sdev)) {
642
643                         scsi_device_set_state(sdev, SDEV_QUIESCE);
644                         if (scsi_sense_valid(&sshdr)
645                             && sshdr.sense_key == ILLEGAL_REQUEST
646                             /* INVALID FIELD IN CDB */
647                             && sshdr.asc == 0x24 && sshdr.ascq == 0x00)
648                                 /* This would mean that the drive lied
649                                  * to us about supporting an echo
650                                  * buffer (unfortunately some Western
651                                  * Digital drives do precisely this)
652                                  */
653                                 return SPI_COMPARE_SKIP_TEST;
654
655
656                         sdev_printk(KERN_ERR, sdev, "Write Buffer failure %x\n", result);
657                         return SPI_COMPARE_FAILURE;
658                 }
659
660                 memset(ptr, 0, len);
661                 spi_execute(sdev, spi_read_buffer, DMA_FROM_DEVICE,
662                             ptr, len, NULL);
663                 scsi_device_set_state(sdev, SDEV_QUIESCE);
664
665                 if (memcmp(buffer, ptr, len) != 0)
666                         return SPI_COMPARE_FAILURE;
667         }
668         return SPI_COMPARE_SUCCESS;
669 }
670
671 /* This is for the simplest form of Domain Validation: a read test
672  * on the inquiry data from the device */
673 static enum spi_compare_returns
674 spi_dv_device_compare_inquiry(struct scsi_device *sdev, u8 *buffer,
675                               u8 *ptr, const int retries)
676 {
677         int r, result;
678         const int len = sdev->inquiry_len;
679         const char spi_inquiry[] = {
680                 INQUIRY, 0, 0, 0, len, 0
681         };
682
683         for (r = 0; r < retries; r++) {
684                 memset(ptr, 0, len);
685
686                 result = spi_execute(sdev, spi_inquiry, DMA_FROM_DEVICE,
687                                      ptr, len, NULL);
688                 
689                 if(result || !scsi_device_online(sdev)) {
690                         scsi_device_set_state(sdev, SDEV_QUIESCE);
691                         return SPI_COMPARE_FAILURE;
692                 }
693
694                 /* If we don't have the inquiry data already, the
695                  * first read gets it */
696                 if (ptr == buffer) {
697                         ptr += len;
698                         --r;
699                         continue;
700                 }
701
702                 if (memcmp(buffer, ptr, len) != 0)
703                         /* failure */
704                         return SPI_COMPARE_FAILURE;
705         }
706         return SPI_COMPARE_SUCCESS;
707 }
708
709 static enum spi_compare_returns
710 spi_dv_retrain(struct scsi_device *sdev, u8 *buffer, u8 *ptr,
711                enum spi_compare_returns 
712                (*compare_fn)(struct scsi_device *, u8 *, u8 *, int))
713 {
714         struct spi_internal *i = to_spi_internal(sdev->host->transportt);
715         struct scsi_target *starget = sdev->sdev_target;
716         int period = 0, prevperiod = 0; 
717         enum spi_compare_returns retval;
718
719
720         for (;;) {
721                 int newperiod;
722                 retval = compare_fn(sdev, buffer, ptr, DV_LOOPS);
723
724                 if (retval == SPI_COMPARE_SUCCESS
725                     || retval == SPI_COMPARE_SKIP_TEST)
726                         break;
727
728                 /* OK, retrain, fallback */
729                 if (i->f->get_iu)
730                         i->f->get_iu(starget);
731                 if (i->f->get_qas)
732                         i->f->get_qas(starget);
733                 if (i->f->get_period)
734                         i->f->get_period(sdev->sdev_target);
735
736                 /* Here's the fallback sequence; first try turning off
737                  * IU, then QAS (if we can control them), then finally
738                  * fall down the periods */
739                 if (i->f->set_iu && spi_iu(starget)) {
740                         starget_printk(KERN_ERR, starget, "Domain Validation Disabing Information Units\n");
741                         DV_SET(iu, 0);
742                 } else if (i->f->set_qas && spi_qas(starget)) {
743                         starget_printk(KERN_ERR, starget, "Domain Validation Disabing Quick Arbitration and Selection\n");
744                         DV_SET(qas, 0);
745                 } else {
746                         newperiod = spi_period(starget);
747                         period = newperiod > period ? newperiod : period;
748                         if (period < 0x0d)
749                                 period++;
750                         else
751                                 period += period >> 1;
752
753                         if (unlikely(period > 0xff || period == prevperiod)) {
754                                 /* Total failure; set to async and return */
755                                 starget_printk(KERN_ERR, starget, "Domain Validation Failure, dropping back to Asynchronous\n");
756                                 DV_SET(offset, 0);
757                                 return SPI_COMPARE_FAILURE;
758                         }
759                         starget_printk(KERN_ERR, starget, "Domain Validation detected failure, dropping back\n");
760                         DV_SET(period, period);
761                         prevperiod = period;
762                 }
763         }
764         return retval;
765 }
766
767 static int
768 spi_dv_device_get_echo_buffer(struct scsi_device *sdev, u8 *buffer)
769 {
770         int l, result;
771
772         /* first off do a test unit ready.  This can error out 
773          * because of reservations or some other reason.  If it
774          * fails, the device won't let us write to the echo buffer
775          * so just return failure */
776         
777         const char spi_test_unit_ready[] = {
778                 TEST_UNIT_READY, 0, 0, 0, 0, 0
779         };
780
781         const char spi_read_buffer_descriptor[] = {
782                 READ_BUFFER, 0x0b, 0, 0, 0, 0, 0, 0, 4, 0
783         };
784
785         
786         /* We send a set of three TURs to clear any outstanding 
787          * unit attention conditions if they exist (Otherwise the
788          * buffer tests won't be happy).  If the TUR still fails
789          * (reservation conflict, device not ready, etc) just
790          * skip the write tests */
791         for (l = 0; ; l++) {
792                 result = spi_execute(sdev, spi_test_unit_ready, DMA_NONE, 
793                                      NULL, 0, NULL);
794
795                 if(result) {
796                         if(l >= 3)
797                                 return 0;
798                 } else {
799                         /* TUR succeeded */
800                         break;
801                 }
802         }
803
804         result = spi_execute(sdev, spi_read_buffer_descriptor, 
805                              DMA_FROM_DEVICE, buffer, 4, NULL);
806
807         if (result)
808                 /* Device has no echo buffer */
809                 return 0;
810
811         return buffer[3] + ((buffer[2] & 0x1f) << 8);
812 }
813
814 static void
815 spi_dv_device_internal(struct scsi_device *sdev, u8 *buffer)
816 {
817         struct spi_internal *i = to_spi_internal(sdev->host->transportt);
818         struct scsi_target *starget = sdev->sdev_target;
819         struct Scsi_Host *shost = sdev->host;
820         int len = sdev->inquiry_len;
821         int min_period = spi_min_period(starget);
822         int max_width = spi_max_width(starget);
823         /* first set us up for narrow async */
824         DV_SET(offset, 0);
825         DV_SET(width, 0);
826
827         if (spi_dv_device_compare_inquiry(sdev, buffer, buffer, DV_LOOPS)
828             != SPI_COMPARE_SUCCESS) {
829                 starget_printk(KERN_ERR, starget, "Domain Validation Initial Inquiry Failed\n");
830                 /* FIXME: should probably offline the device here? */
831                 return;
832         }
833
834         if (!scsi_device_wide(sdev)) {
835                 spi_max_width(starget) = 0;
836                 max_width = 0;
837         }
838
839         /* test width */
840         if (i->f->set_width && max_width) {
841                 i->f->set_width(starget, 1);
842
843                 if (spi_dv_device_compare_inquiry(sdev, buffer,
844                                                    buffer + len,
845                                                    DV_LOOPS)
846                     != SPI_COMPARE_SUCCESS) {
847                         starget_printk(KERN_ERR, starget, "Wide Transfers Fail\n");
848                         i->f->set_width(starget, 0);
849                         /* Make sure we don't force wide back on by asking
850                          * for a transfer period that requires it */
851                         max_width = 0;
852                         if (min_period < 10)
853                                 min_period = 10;
854                 }
855         }
856
857         if (!i->f->set_period)
858                 return;
859
860         /* device can't handle synchronous */
861         if (!scsi_device_sync(sdev) && !scsi_device_dt(sdev))
862                 return;
863
864         /* len == -1 is the signal that we need to ascertain the
865          * presence of an echo buffer before trying to use it.  len ==
866          * 0 means we don't have an echo buffer */
867         len = -1;
868
869  retry:
870
871         /* now set up to the maximum */
872         DV_SET(offset, spi_max_offset(starget));
873         DV_SET(period, min_period);
874
875         /* try QAS requests; this should be harmless to set if the
876          * target supports it */
877         if (scsi_device_qas(sdev)) {
878                 DV_SET(qas, 1);
879         } else {
880                 DV_SET(qas, 0);
881         }
882
883         if (scsi_device_ius(sdev) && min_period < 9) {
884                 /* This u320 (or u640). Set IU transfers */
885                 DV_SET(iu, 1);
886                 /* Then set the optional parameters */
887                 DV_SET(rd_strm, 1);
888                 DV_SET(wr_flow, 1);
889                 DV_SET(rti, 1);
890                 if (min_period == 8)
891                         DV_SET(pcomp_en, 1);
892         } else {
893                 DV_SET(iu, 0);
894         }
895
896         /* now that we've done all this, actually check the bus
897          * signal type (if known).  Some devices are stupid on
898          * a SE bus and still claim they can try LVD only settings */
899         if (i->f->get_signalling)
900                 i->f->get_signalling(shost);
901         if (spi_signalling(shost) == SPI_SIGNAL_SE ||
902             spi_signalling(shost) == SPI_SIGNAL_HVD ||
903             !scsi_device_dt(sdev)) {
904                 DV_SET(dt, 0);
905         } else {
906                 DV_SET(dt, 1);
907         }
908         /* set width last because it will pull all the other
909          * parameters down to required values */
910         DV_SET(width, max_width);
911
912         /* Do the read only INQUIRY tests */
913         spi_dv_retrain(sdev, buffer, buffer + sdev->inquiry_len,
914                        spi_dv_device_compare_inquiry);
915         /* See if we actually managed to negotiate and sustain DT */
916         if (i->f->get_dt)
917                 i->f->get_dt(starget);
918
919         /* see if the device has an echo buffer.  If it does we can do
920          * the SPI pattern write tests.  Because of some broken
921          * devices, we *only* try this on a device that has actually
922          * negotiated DT */
923
924         if (len == -1 && spi_dt(starget))
925                 len = spi_dv_device_get_echo_buffer(sdev, buffer);
926
927         if (len <= 0) {
928                 starget_printk(KERN_INFO, starget, "Domain Validation skipping write tests\n");
929                 return;
930         }
931
932         if (len > SPI_MAX_ECHO_BUFFER_SIZE) {
933                 starget_printk(KERN_WARNING, starget, "Echo buffer size %d is too big, trimming to %d\n", len, SPI_MAX_ECHO_BUFFER_SIZE);
934                 len = SPI_MAX_ECHO_BUFFER_SIZE;
935         }
936
937         if (spi_dv_retrain(sdev, buffer, buffer + len,
938                            spi_dv_device_echo_buffer)
939             == SPI_COMPARE_SKIP_TEST) {
940                 /* OK, the stupid drive can't do a write echo buffer
941                  * test after all, fall back to the read tests */
942                 len = 0;
943                 goto retry;
944         }
945 }
946
947
948 /**     spi_dv_device - Do Domain Validation on the device
949  *      @sdev:          scsi device to validate
950  *
951  *      Performs the domain validation on the given device in the
952  *      current execution thread.  Since DV operations may sleep,
953  *      the current thread must have user context.  Also no SCSI
954  *      related locks that would deadlock I/O issued by the DV may
955  *      be held.
956  */
957 void
958 spi_dv_device(struct scsi_device *sdev)
959 {
960         struct scsi_target *starget = sdev->sdev_target;
961         u8 *buffer;
962         const int len = SPI_MAX_ECHO_BUFFER_SIZE*2;
963
964         if (unlikely(scsi_device_get(sdev)))
965                 return;
966
967         if (unlikely(spi_dv_in_progress(starget)))
968                 return;
969         spi_dv_in_progress(starget) = 1;
970
971         buffer = kzalloc(len, GFP_KERNEL);
972
973         if (unlikely(!buffer))
974                 goto out_put;
975
976         /* We need to verify that the actual device will quiesce; the
977          * later target quiesce is just a nice to have */
978         if (unlikely(scsi_device_quiesce(sdev)))
979                 goto out_free;
980
981         scsi_target_quiesce(starget);
982
983         spi_dv_pending(starget) = 1;
984         mutex_lock(&spi_dv_mutex(starget));
985
986         starget_printk(KERN_INFO, starget, "Beginning Domain Validation\n");
987
988         spi_dv_device_internal(sdev, buffer);
989
990         starget_printk(KERN_INFO, starget, "Ending Domain Validation\n");
991
992         mutex_unlock(&spi_dv_mutex(starget));
993         spi_dv_pending(starget) = 0;
994
995         scsi_target_resume(starget);
996
997         spi_initial_dv(starget) = 1;
998
999  out_free:
1000         kfree(buffer);
1001  out_put:
1002         spi_dv_in_progress(starget) = 0;
1003         scsi_device_put(sdev);
1004 }
1005 EXPORT_SYMBOL(spi_dv_device);
1006
1007 struct work_queue_wrapper {
1008         struct work_struct      work;
1009         struct scsi_device      *sdev;
1010 };
1011
1012 static void
1013 spi_dv_device_work_wrapper(struct work_struct *work)
1014 {
1015         struct work_queue_wrapper *wqw =
1016                 container_of(work, struct work_queue_wrapper, work);
1017         struct scsi_device *sdev = wqw->sdev;
1018
1019         kfree(wqw);
1020         spi_dv_device(sdev);
1021         spi_dv_pending(sdev->sdev_target) = 0;
1022         scsi_device_put(sdev);
1023 }
1024
1025
1026 /**
1027  *      spi_schedule_dv_device - schedule domain validation to occur on the device
1028  *      @sdev:  The device to validate
1029  *
1030  *      Identical to spi_dv_device() above, except that the DV will be
1031  *      scheduled to occur in a workqueue later.  All memory allocations
1032  *      are atomic, so may be called from any context including those holding
1033  *      SCSI locks.
1034  */
1035 void
1036 spi_schedule_dv_device(struct scsi_device *sdev)
1037 {
1038         struct work_queue_wrapper *wqw =
1039                 kmalloc(sizeof(struct work_queue_wrapper), GFP_ATOMIC);
1040
1041         if (unlikely(!wqw))
1042                 return;
1043
1044         if (unlikely(spi_dv_pending(sdev->sdev_target))) {
1045                 kfree(wqw);
1046                 return;
1047         }
1048         /* Set pending early (dv_device doesn't check it, only sets it) */
1049         spi_dv_pending(sdev->sdev_target) = 1;
1050         if (unlikely(scsi_device_get(sdev))) {
1051                 kfree(wqw);
1052                 spi_dv_pending(sdev->sdev_target) = 0;
1053                 return;
1054         }
1055
1056         INIT_WORK(&wqw->work, spi_dv_device_work_wrapper);
1057         wqw->sdev = sdev;
1058
1059         schedule_work(&wqw->work);
1060 }
1061 EXPORT_SYMBOL(spi_schedule_dv_device);
1062
1063 /**
1064  * spi_display_xfer_agreement - Print the current target transfer agreement
1065  * @starget: The target for which to display the agreement
1066  *
1067  * Each SPI port is required to maintain a transfer agreement for each
1068  * other port on the bus.  This function prints a one-line summary of
1069  * the current agreement; more detailed information is available in sysfs.
1070  */
1071 void spi_display_xfer_agreement(struct scsi_target *starget)
1072 {
1073         struct spi_transport_attrs *tp;
1074         tp = (struct spi_transport_attrs *)&starget->starget_data;
1075
1076         if (tp->offset > 0 && tp->period > 0) {
1077                 unsigned int picosec, kb100;
1078                 char *scsi = "FAST-?";
1079                 char tmp[8];
1080
1081                 if (tp->period <= SPI_STATIC_PPR) {
1082                         picosec = ppr_to_ps[tp->period];
1083                         switch (tp->period) {
1084                                 case  7: scsi = "FAST-320"; break;
1085                                 case  8: scsi = "FAST-160"; break;
1086                                 case  9: scsi = "FAST-80"; break;
1087                                 case 10:
1088                                 case 11: scsi = "FAST-40"; break;
1089                                 case 12: scsi = "FAST-20"; break;
1090                         }
1091                 } else {
1092                         picosec = tp->period * 4000;
1093                         if (tp->period < 25)
1094                                 scsi = "FAST-20";
1095                         else if (tp->period < 50)
1096                                 scsi = "FAST-10";
1097                         else
1098                                 scsi = "FAST-5";
1099                 }
1100
1101                 kb100 = (10000000 + picosec / 2) / picosec;
1102                 if (tp->width)
1103                         kb100 *= 2;
1104                 sprint_frac(tmp, picosec, 1000);
1105
1106                 dev_info(&starget->dev,
1107                          "%s %sSCSI %d.%d MB/s %s%s%s%s%s%s%s%s (%s ns, offset %d)\n",
1108                          scsi, tp->width ? "WIDE " : "", kb100/10, kb100 % 10,
1109                          tp->dt ? "DT" : "ST",
1110                          tp->iu ? " IU" : "",
1111                          tp->qas  ? " QAS" : "",
1112                          tp->rd_strm ? " RDSTRM" : "",
1113                          tp->rti ? " RTI" : "",
1114                          tp->wr_flow ? " WRFLOW" : "",
1115                          tp->pcomp_en ? " PCOMP" : "",
1116                          tp->hold_mcs ? " HMCS" : "",
1117                          tmp, tp->offset);
1118         } else {
1119                 dev_info(&starget->dev, "%sasynchronous\n",
1120                                 tp->width ? "wide " : "");
1121         }
1122 }
1123 EXPORT_SYMBOL(spi_display_xfer_agreement);
1124
1125 int spi_populate_width_msg(unsigned char *msg, int width)
1126 {
1127         msg[0] = EXTENDED_MESSAGE;
1128         msg[1] = 2;
1129         msg[2] = EXTENDED_WDTR;
1130         msg[3] = width;
1131         return 4;
1132 }
1133 EXPORT_SYMBOL_GPL(spi_populate_width_msg);
1134
1135 int spi_populate_sync_msg(unsigned char *msg, int period, int offset)
1136 {
1137         msg[0] = EXTENDED_MESSAGE;
1138         msg[1] = 3;
1139         msg[2] = EXTENDED_SDTR;
1140         msg[3] = period;
1141         msg[4] = offset;
1142         return 5;
1143 }
1144 EXPORT_SYMBOL_GPL(spi_populate_sync_msg);
1145
1146 int spi_populate_ppr_msg(unsigned char *msg, int period, int offset,
1147                 int width, int options)
1148 {
1149         msg[0] = EXTENDED_MESSAGE;
1150         msg[1] = 6;
1151         msg[2] = EXTENDED_PPR;
1152         msg[3] = period;
1153         msg[4] = 0;
1154         msg[5] = offset;
1155         msg[6] = width;
1156         msg[7] = options;
1157         return 8;
1158 }
1159 EXPORT_SYMBOL_GPL(spi_populate_ppr_msg);
1160
1161 #ifdef CONFIG_SCSI_CONSTANTS
1162 static const char * const one_byte_msgs[] = {
1163 /* 0x00 */ "Task Complete", NULL /* Extended Message */, "Save Pointers",
1164 /* 0x03 */ "Restore Pointers", "Disconnect", "Initiator Error", 
1165 /* 0x06 */ "Abort Task Set", "Message Reject", "Nop", "Message Parity Error",
1166 /* 0x0a */ "Linked Command Complete", "Linked Command Complete w/flag",
1167 /* 0x0c */ "Target Reset", "Abort Task", "Clear Task Set", 
1168 /* 0x0f */ "Initiate Recovery", "Release Recovery",
1169 /* 0x11 */ "Terminate Process", "Continue Task", "Target Transfer Disable",
1170 /* 0x14 */ NULL, NULL, "Clear ACA", "LUN Reset"
1171 };
1172
1173 static const char * const two_byte_msgs[] = {
1174 /* 0x20 */ "Simple Queue Tag", "Head of Queue Tag", "Ordered Queue Tag",
1175 /* 0x23 */ "Ignore Wide Residue", "ACA"
1176 };
1177
1178 static const char * const extended_msgs[] = {
1179 /* 0x00 */ "Modify Data Pointer", "Synchronous Data Transfer Request",
1180 /* 0x02 */ "SCSI-I Extended Identify", "Wide Data Transfer Request",
1181 /* 0x04 */ "Parallel Protocol Request", "Modify Bidirectional Data Pointer"
1182 };
1183
1184 static void print_nego(const unsigned char *msg, int per, int off, int width)
1185 {
1186         if (per) {
1187                 char buf[20];
1188                 period_to_str(buf, msg[per]);
1189                 printk("period = %s ns ", buf);
1190         }
1191
1192         if (off)
1193                 printk("offset = %d ", msg[off]);
1194         if (width)
1195                 printk("width = %d ", 8 << msg[width]);
1196 }
1197
1198 static void print_ptr(const unsigned char *msg, int msb, const char *desc)
1199 {
1200         int ptr = (msg[msb] << 24) | (msg[msb+1] << 16) | (msg[msb+2] << 8) |
1201                         msg[msb+3];
1202         printk("%s = %d ", desc, ptr);
1203 }
1204
1205 int spi_print_msg(const unsigned char *msg)
1206 {
1207         int len = 1, i;
1208         if (msg[0] == EXTENDED_MESSAGE) {
1209                 len = 2 + msg[1];
1210                 if (len == 2)
1211                         len += 256;
1212                 if (msg[2] < ARRAY_SIZE(extended_msgs))
1213                         printk ("%s ", extended_msgs[msg[2]]); 
1214                 else 
1215                         printk ("Extended Message, reserved code (0x%02x) ",
1216                                 (int) msg[2]);
1217                 switch (msg[2]) {
1218                 case EXTENDED_MODIFY_DATA_POINTER:
1219                         print_ptr(msg, 3, "pointer");
1220                         break;
1221                 case EXTENDED_SDTR:
1222                         print_nego(msg, 3, 4, 0);
1223                         break;
1224                 case EXTENDED_WDTR:
1225                         print_nego(msg, 0, 0, 3);
1226                         break;
1227                 case EXTENDED_PPR:
1228                         print_nego(msg, 3, 5, 6);
1229                         break;
1230                 case EXTENDED_MODIFY_BIDI_DATA_PTR:
1231                         print_ptr(msg, 3, "out");
1232                         print_ptr(msg, 7, "in");
1233                         break;
1234                 default:
1235                 for (i = 2; i < len; ++i) 
1236                         printk("%02x ", msg[i]);
1237                 }
1238         /* Identify */
1239         } else if (msg[0] & 0x80) {
1240                 printk("Identify disconnect %sallowed %s %d ",
1241                         (msg[0] & 0x40) ? "" : "not ",
1242                         (msg[0] & 0x20) ? "target routine" : "lun",
1243                         msg[0] & 0x7);
1244         /* Normal One byte */
1245         } else if (msg[0] < 0x1f) {
1246                 if (msg[0] < ARRAY_SIZE(one_byte_msgs) && one_byte_msgs[msg[0]])
1247                         printk("%s ", one_byte_msgs[msg[0]]);
1248                 else
1249                         printk("reserved (%02x) ", msg[0]);
1250         } else if (msg[0] == 0x55) {
1251                 printk("QAS Request ");
1252         /* Two byte */
1253         } else if (msg[0] <= 0x2f) {
1254                 if ((msg[0] - 0x20) < ARRAY_SIZE(two_byte_msgs))
1255                         printk("%s %02x ", two_byte_msgs[msg[0] - 0x20], 
1256                                 msg[1]);
1257                 else 
1258                         printk("reserved two byte (%02x %02x) ", 
1259                                 msg[0], msg[1]);
1260                 len = 2;
1261         } else 
1262                 printk("reserved ");
1263         return len;
1264 }
1265 EXPORT_SYMBOL(spi_print_msg);
1266
1267 #else  /* ifndef CONFIG_SCSI_CONSTANTS */
1268
1269 int spi_print_msg(const unsigned char *msg)
1270 {
1271         int len = 1, i;
1272
1273         if (msg[0] == EXTENDED_MESSAGE) {
1274                 len = 2 + msg[1];
1275                 if (len == 2)
1276                         len += 256;
1277                 for (i = 0; i < len; ++i)
1278                         printk("%02x ", msg[i]);
1279         /* Identify */
1280         } else if (msg[0] & 0x80) {
1281                 printk("%02x ", msg[0]);
1282         /* Normal One byte */
1283         } else if ((msg[0] < 0x1f) || (msg[0] == 0x55)) {
1284                 printk("%02x ", msg[0]);
1285         /* Two byte */
1286         } else if (msg[0] <= 0x2f) {
1287                 printk("%02x %02x", msg[0], msg[1]);
1288                 len = 2;
1289         } else 
1290                 printk("%02x ", msg[0]);
1291         return len;
1292 }
1293 EXPORT_SYMBOL(spi_print_msg);
1294 #endif /* ! CONFIG_SCSI_CONSTANTS */
1295
1296 static int spi_device_match(struct attribute_container *cont,
1297                             struct device *dev)
1298 {
1299         struct scsi_device *sdev;
1300         struct Scsi_Host *shost;
1301         struct spi_internal *i;
1302
1303         if (!scsi_is_sdev_device(dev))
1304                 return 0;
1305
1306         sdev = to_scsi_device(dev);
1307         shost = sdev->host;
1308         if (!shost->transportt  || shost->transportt->host_attrs.ac.class
1309             != &spi_host_class.class)
1310                 return 0;
1311         /* Note: this class has no device attributes, so it has
1312          * no per-HBA allocation and thus we don't need to distinguish
1313          * the attribute containers for the device */
1314         i = to_spi_internal(shost->transportt);
1315         if (i->f->deny_binding && i->f->deny_binding(sdev->sdev_target))
1316                 return 0;
1317         return 1;
1318 }
1319
1320 static int spi_target_match(struct attribute_container *cont,
1321                             struct device *dev)
1322 {
1323         struct Scsi_Host *shost;
1324         struct scsi_target *starget;
1325         struct spi_internal *i;
1326
1327         if (!scsi_is_target_device(dev))
1328                 return 0;
1329
1330         shost = dev_to_shost(dev->parent);
1331         if (!shost->transportt  || shost->transportt->host_attrs.ac.class
1332             != &spi_host_class.class)
1333                 return 0;
1334
1335         i = to_spi_internal(shost->transportt);
1336         starget = to_scsi_target(dev);
1337
1338         if (i->f->deny_binding && i->f->deny_binding(starget))
1339                 return 0;
1340
1341         return &i->t.target_attrs.ac == cont;
1342 }
1343
1344 static DECLARE_TRANSPORT_CLASS(spi_transport_class,
1345                                "spi_transport",
1346                                spi_setup_transport_attrs,
1347                                NULL,
1348                                spi_target_configure);
1349
1350 static DECLARE_ANON_TRANSPORT_CLASS(spi_device_class,
1351                                     spi_device_match,
1352                                     spi_device_configure);
1353
1354 static struct attribute *host_attributes[] = {
1355         &dev_attr_signalling.attr,
1356         NULL
1357 };
1358
1359 static struct attribute_group host_attribute_group = {
1360         .attrs = host_attributes,
1361 };
1362
1363 static int spi_host_configure(struct transport_container *tc,
1364                               struct device *dev,
1365                               struct device *cdev)
1366 {
1367         struct kobject *kobj = &cdev->kobj;
1368         struct Scsi_Host *shost = transport_class_to_shost(cdev);
1369         struct spi_internal *si = to_spi_internal(shost->transportt);
1370         struct attribute *attr = &dev_attr_signalling.attr;
1371         int rc = 0;
1372
1373         if (si->f->set_signalling)
1374                 rc = sysfs_chmod_file(kobj, attr, attr->mode | S_IWUSR);
1375
1376         return rc;
1377 }
1378
1379 /* returns true if we should be showing the variable.  Also
1380  * overloads the return by setting 1<<1 if the attribute should
1381  * be writeable */
1382 #define TARGET_ATTRIBUTE_HELPER(name) \
1383         (si->f->show_##name ? S_IRUGO : 0) | \
1384         (si->f->set_##name ? S_IWUSR : 0)
1385
1386 static mode_t target_attribute_is_visible(struct kobject *kobj,
1387                                           struct attribute *attr, int i)
1388 {
1389         struct device *cdev = container_of(kobj, struct device, kobj);
1390         struct scsi_target *starget = transport_class_to_starget(cdev);
1391         struct Scsi_Host *shost = transport_class_to_shost(cdev);
1392         struct spi_internal *si = to_spi_internal(shost->transportt);
1393
1394         if (attr == &dev_attr_period.attr &&
1395             spi_support_sync(starget))
1396                 return TARGET_ATTRIBUTE_HELPER(period);
1397         else if (attr == &dev_attr_min_period.attr &&
1398                  spi_support_sync(starget))
1399                 return TARGET_ATTRIBUTE_HELPER(period);
1400         else if (attr == &dev_attr_offset.attr &&
1401                  spi_support_sync(starget))
1402                 return TARGET_ATTRIBUTE_HELPER(offset);
1403         else if (attr == &dev_attr_max_offset.attr &&
1404                  spi_support_sync(starget))
1405                 return TARGET_ATTRIBUTE_HELPER(offset);
1406         else if (attr == &dev_attr_width.attr &&
1407                  spi_support_wide(starget))
1408                 return TARGET_ATTRIBUTE_HELPER(width);
1409         else if (attr == &dev_attr_max_width.attr &&
1410                  spi_support_wide(starget))
1411                 return TARGET_ATTRIBUTE_HELPER(width);
1412         else if (attr == &dev_attr_iu.attr &&
1413                  spi_support_ius(starget))
1414                 return TARGET_ATTRIBUTE_HELPER(iu);
1415         else if (attr == &dev_attr_dt.attr &&
1416                  spi_support_dt(starget))
1417                 return TARGET_ATTRIBUTE_HELPER(dt);
1418         else if (attr == &dev_attr_qas.attr &&
1419                  spi_support_qas(starget))
1420                 return TARGET_ATTRIBUTE_HELPER(qas);
1421         else if (attr == &dev_attr_wr_flow.attr &&
1422                  spi_support_ius(starget))
1423                 return TARGET_ATTRIBUTE_HELPER(wr_flow);
1424         else if (attr == &dev_attr_rd_strm.attr &&
1425                  spi_support_ius(starget))
1426                 return TARGET_ATTRIBUTE_HELPER(rd_strm);
1427         else if (attr == &dev_attr_rti.attr &&
1428                  spi_support_ius(starget))
1429                 return TARGET_ATTRIBUTE_HELPER(rti);
1430         else if (attr == &dev_attr_pcomp_en.attr &&
1431                  spi_support_ius(starget))
1432                 return TARGET_ATTRIBUTE_HELPER(pcomp_en);
1433         else if (attr == &dev_attr_hold_mcs.attr &&
1434                  spi_support_ius(starget))
1435                 return TARGET_ATTRIBUTE_HELPER(hold_mcs);
1436         else if (attr == &dev_attr_revalidate.attr)
1437                 return S_IWUSR;
1438
1439         return 0;
1440 }
1441
1442 static struct attribute *target_attributes[] = {
1443         &dev_attr_period.attr,
1444         &dev_attr_min_period.attr,
1445         &dev_attr_offset.attr,
1446         &dev_attr_max_offset.attr,
1447         &dev_attr_width.attr,
1448         &dev_attr_max_width.attr,
1449         &dev_attr_iu.attr,
1450         &dev_attr_dt.attr,
1451         &dev_attr_qas.attr,
1452         &dev_attr_wr_flow.attr,
1453         &dev_attr_rd_strm.attr,
1454         &dev_attr_rti.attr,
1455         &dev_attr_pcomp_en.attr,
1456         &dev_attr_hold_mcs.attr,
1457         &dev_attr_revalidate.attr,
1458         NULL
1459 };
1460
1461 static struct attribute_group target_attribute_group = {
1462         .attrs = target_attributes,
1463         .is_visible = target_attribute_is_visible,
1464 };
1465
1466 static int spi_target_configure(struct transport_container *tc,
1467                                 struct device *dev,
1468                                 struct device *cdev)
1469 {
1470         struct kobject *kobj = &cdev->kobj;
1471
1472         /* force an update based on parameters read from the device */
1473         sysfs_update_group(kobj, &target_attribute_group);
1474
1475         return 0;
1476 }
1477
1478 struct scsi_transport_template *
1479 spi_attach_transport(struct spi_function_template *ft)
1480 {
1481         struct spi_internal *i = kzalloc(sizeof(struct spi_internal),
1482                                          GFP_KERNEL);
1483
1484         if (unlikely(!i))
1485                 return NULL;
1486
1487         i->t.target_attrs.ac.class = &spi_transport_class.class;
1488         i->t.target_attrs.ac.grp = &target_attribute_group;
1489         i->t.target_attrs.ac.match = spi_target_match;
1490         transport_container_register(&i->t.target_attrs);
1491         i->t.target_size = sizeof(struct spi_transport_attrs);
1492         i->t.host_attrs.ac.class = &spi_host_class.class;
1493         i->t.host_attrs.ac.grp = &host_attribute_group;
1494         i->t.host_attrs.ac.match = spi_host_match;
1495         transport_container_register(&i->t.host_attrs);
1496         i->t.host_size = sizeof(struct spi_host_attrs);
1497         i->f = ft;
1498
1499         return &i->t;
1500 }
1501 EXPORT_SYMBOL(spi_attach_transport);
1502
1503 void spi_release_transport(struct scsi_transport_template *t)
1504 {
1505         struct spi_internal *i = to_spi_internal(t);
1506
1507         transport_container_unregister(&i->t.target_attrs);
1508         transport_container_unregister(&i->t.host_attrs);
1509
1510         kfree(i);
1511 }
1512 EXPORT_SYMBOL(spi_release_transport);
1513
1514 static __init int spi_transport_init(void)
1515 {
1516         int error = transport_class_register(&spi_transport_class);
1517         if (error)
1518                 return error;
1519         error = anon_transport_class_register(&spi_device_class);
1520         return transport_class_register(&spi_host_class);
1521 }
1522
1523 static void __exit spi_transport_exit(void)
1524 {
1525         transport_class_unregister(&spi_transport_class);
1526         anon_transport_class_unregister(&spi_device_class);
1527         transport_class_unregister(&spi_host_class);
1528 }
1529
1530 MODULE_AUTHOR("Martin Hicks");
1531 MODULE_DESCRIPTION("SPI Transport Attributes");
1532 MODULE_LICENSE("GPL");
1533
1534 module_init(spi_transport_init);
1535 module_exit(spi_transport_exit);