[SCSI] correct transport class abstraction to work outside SCSI
[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 transport_container *tc, struct device *dev,
166                           struct class_device *cdev)
167 {
168         struct Scsi_Host *shost = dev_to_shost(dev);
169
170         spi_signalling(shost) = SPI_SIGNAL_UNKNOWN;
171
172         return 0;
173 }
174
175 static DECLARE_TRANSPORT_CLASS(spi_host_class,
176                                "spi_host",
177                                spi_host_setup,
178                                NULL,
179                                NULL);
180
181 static int spi_host_match(struct attribute_container *cont,
182                           struct device *dev)
183 {
184         struct Scsi_Host *shost;
185         struct spi_internal *i;
186
187         if (!scsi_is_host_device(dev))
188                 return 0;
189
190         shost = dev_to_shost(dev);
191         if (!shost->transportt  || shost->transportt->host_attrs.ac.class
192             != &spi_host_class.class)
193                 return 0;
194
195         i = to_spi_internal(shost->transportt);
196         
197         return &i->t.host_attrs.ac == cont;
198 }
199
200 static int spi_device_configure(struct transport_container *tc,
201                                 struct device *dev,
202                                 struct class_device *cdev)
203 {
204         struct scsi_device *sdev = to_scsi_device(dev);
205         struct scsi_target *starget = sdev->sdev_target;
206
207         /* Populate the target capability fields with the values
208          * gleaned from the device inquiry */
209
210         spi_support_sync(starget) = scsi_device_sync(sdev);
211         spi_support_wide(starget) = scsi_device_wide(sdev);
212         spi_support_dt(starget) = scsi_device_dt(sdev);
213         spi_support_dt_only(starget) = scsi_device_dt_only(sdev);
214         spi_support_ius(starget) = scsi_device_ius(sdev);
215         spi_support_qas(starget) = scsi_device_qas(sdev);
216
217         return 0;
218 }
219
220 static int spi_setup_transport_attrs(struct transport_container *tc,
221                                      struct device *dev,
222                                      struct class_device *cdev)
223 {
224         struct scsi_target *starget = to_scsi_target(dev);
225
226         spi_period(starget) = -1;       /* illegal value */
227         spi_min_period(starget) = 0;
228         spi_offset(starget) = 0;        /* async */
229         spi_max_offset(starget) = 255;
230         spi_width(starget) = 0; /* narrow */
231         spi_max_width(starget) = 1;
232         spi_iu(starget) = 0;    /* no IU */
233         spi_dt(starget) = 0;    /* ST */
234         spi_qas(starget) = 0;
235         spi_wr_flow(starget) = 0;
236         spi_rd_strm(starget) = 0;
237         spi_rti(starget) = 0;
238         spi_pcomp_en(starget) = 0;
239         spi_hold_mcs(starget) = 0;
240         spi_dv_pending(starget) = 0;
241         spi_initial_dv(starget) = 0;
242         init_MUTEX(&spi_dv_sem(starget));
243
244         return 0;
245 }
246
247 #define spi_transport_show_simple(field, format_string)                 \
248                                                                         \
249 static ssize_t                                                          \
250 show_spi_transport_##field(struct class_device *cdev, char *buf)        \
251 {                                                                       \
252         struct scsi_target *starget = transport_class_to_starget(cdev); \
253         struct spi_transport_attrs *tp;                                 \
254                                                                         \
255         tp = (struct spi_transport_attrs *)&starget->starget_data;      \
256         return snprintf(buf, 20, format_string, tp->field);             \
257 }
258
259 #define spi_transport_store_simple(field, format_string)                \
260                                                                         \
261 static ssize_t                                                          \
262 store_spi_transport_##field(struct class_device *cdev, const char *buf, \
263                             size_t count)                               \
264 {                                                                       \
265         int val;                                                        \
266         struct scsi_target *starget = transport_class_to_starget(cdev); \
267         struct spi_transport_attrs *tp;                                 \
268                                                                         \
269         tp = (struct spi_transport_attrs *)&starget->starget_data;      \
270         val = simple_strtoul(buf, NULL, 0);                             \
271         tp->field = val;                                                \
272         return count;                                                   \
273 }
274
275 #define spi_transport_show_function(field, format_string)               \
276                                                                         \
277 static ssize_t                                                          \
278 show_spi_transport_##field(struct class_device *cdev, char *buf)        \
279 {                                                                       \
280         struct scsi_target *starget = transport_class_to_starget(cdev); \
281         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);    \
282         struct spi_transport_attrs *tp;                                 \
283         struct spi_internal *i = to_spi_internal(shost->transportt);    \
284         tp = (struct spi_transport_attrs *)&starget->starget_data;      \
285         if (i->f->get_##field)                                          \
286                 i->f->get_##field(starget);                             \
287         return snprintf(buf, 20, format_string, tp->field);             \
288 }
289
290 #define spi_transport_store_function(field, format_string)              \
291 static ssize_t                                                          \
292 store_spi_transport_##field(struct class_device *cdev, const char *buf, \
293                             size_t count)                               \
294 {                                                                       \
295         int val;                                                        \
296         struct scsi_target *starget = transport_class_to_starget(cdev); \
297         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);    \
298         struct spi_internal *i = to_spi_internal(shost->transportt);    \
299                                                                         \
300         val = simple_strtoul(buf, NULL, 0);                             \
301         i->f->set_##field(starget, val);                        \
302         return count;                                                   \
303 }
304
305 #define spi_transport_store_max(field, format_string)                   \
306 static ssize_t                                                          \
307 store_spi_transport_##field(struct class_device *cdev, const char *buf, \
308                             size_t count)                               \
309 {                                                                       \
310         int val;                                                        \
311         struct scsi_target *starget = transport_class_to_starget(cdev); \
312         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);    \
313         struct spi_internal *i = to_spi_internal(shost->transportt);    \
314         struct spi_transport_attrs *tp                                  \
315                 = (struct spi_transport_attrs *)&starget->starget_data; \
316                                                                         \
317         val = simple_strtoul(buf, NULL, 0);                             \
318         if (val > tp->max_##field)                                      \
319                 val = tp->max_##field;                                  \
320         i->f->set_##field(starget, val);                                \
321         return count;                                                   \
322 }
323
324 #define spi_transport_rd_attr(field, format_string)                     \
325         spi_transport_show_function(field, format_string)               \
326         spi_transport_store_function(field, format_string)              \
327 static CLASS_DEVICE_ATTR(field, S_IRUGO | S_IWUSR,                      \
328                          show_spi_transport_##field,                    \
329                          store_spi_transport_##field);
330
331 #define spi_transport_simple_attr(field, format_string)                 \
332         spi_transport_show_simple(field, format_string)                 \
333         spi_transport_store_simple(field, format_string)                \
334 static CLASS_DEVICE_ATTR(field, S_IRUGO | S_IWUSR,                      \
335                          show_spi_transport_##field,                    \
336                          store_spi_transport_##field);
337
338 #define spi_transport_max_attr(field, format_string)                    \
339         spi_transport_show_function(field, format_string)               \
340         spi_transport_store_max(field, format_string)                   \
341         spi_transport_simple_attr(max_##field, format_string)           \
342 static CLASS_DEVICE_ATTR(field, S_IRUGO | S_IWUSR,                      \
343                          show_spi_transport_##field,                    \
344                          store_spi_transport_##field);
345
346 /* The Parallel SCSI Tranport Attributes: */
347 spi_transport_max_attr(offset, "%d\n");
348 spi_transport_max_attr(width, "%d\n");
349 spi_transport_rd_attr(iu, "%d\n");
350 spi_transport_rd_attr(dt, "%d\n");
351 spi_transport_rd_attr(qas, "%d\n");
352 spi_transport_rd_attr(wr_flow, "%d\n");
353 spi_transport_rd_attr(rd_strm, "%d\n");
354 spi_transport_rd_attr(rti, "%d\n");
355 spi_transport_rd_attr(pcomp_en, "%d\n");
356 spi_transport_rd_attr(hold_mcs, "%d\n");
357
358 /* we only care about the first child device so we return 1 */
359 static int child_iter(struct device *dev, void *data)
360 {
361         struct scsi_device *sdev = to_scsi_device(dev);
362
363         spi_dv_device(sdev);
364         return 1;
365 }
366
367 static ssize_t
368 store_spi_revalidate(struct class_device *cdev, const char *buf, size_t count)
369 {
370         struct scsi_target *starget = transport_class_to_starget(cdev);
371
372         device_for_each_child(&starget->dev, NULL, child_iter);
373         return count;
374 }
375 static CLASS_DEVICE_ATTR(revalidate, S_IWUSR, NULL, store_spi_revalidate);
376
377 /* Translate the period into ns according to the current spec
378  * for SDTR/PPR messages */
379 static ssize_t
380 show_spi_transport_period_helper(struct class_device *cdev, char *buf,
381                                  int period)
382 {
383         int len, picosec;
384
385         if (period < 0 || period > 0xff) {
386                 picosec = -1;
387         } else if (period <= SPI_STATIC_PPR) {
388                 picosec = ppr_to_ps[period];
389         } else {
390                 picosec = period * 4000;
391         }
392
393         if (picosec == -1) {
394                 len = sprintf(buf, "reserved");
395         } else {
396                 len = sprint_frac(buf, picosec, 1000);
397         }
398
399         buf[len++] = '\n';
400         buf[len] = '\0';
401         return len;
402 }
403
404 static ssize_t
405 store_spi_transport_period_helper(struct class_device *cdev, const char *buf,
406                                   size_t count, int *periodp)
407 {
408         int j, picosec, period = -1;
409         char *endp;
410
411         picosec = simple_strtoul(buf, &endp, 10) * 1000;
412         if (*endp == '.') {
413                 int mult = 100;
414                 do {
415                         endp++;
416                         if (!isdigit(*endp))
417                                 break;
418                         picosec += (*endp - '0') * mult;
419                         mult /= 10;
420                 } while (mult > 0);
421         }
422
423         for (j = 0; j <= SPI_STATIC_PPR; j++) {
424                 if (ppr_to_ps[j] < picosec)
425                         continue;
426                 period = j;
427                 break;
428         }
429
430         if (period == -1)
431                 period = picosec / 4000;
432
433         if (period > 0xff)
434                 period = 0xff;
435
436         *periodp = period;
437
438         return count;
439 }
440
441 static ssize_t
442 show_spi_transport_period(struct class_device *cdev, char *buf)
443 {
444         struct scsi_target *starget = transport_class_to_starget(cdev);
445         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
446         struct spi_internal *i = to_spi_internal(shost->transportt);
447         struct spi_transport_attrs *tp =
448                 (struct spi_transport_attrs *)&starget->starget_data;
449
450         if (i->f->get_period)
451                 i->f->get_period(starget);
452
453         return show_spi_transport_period_helper(cdev, buf, tp->period);
454 }
455
456 static ssize_t
457 store_spi_transport_period(struct class_device *cdev, const char *buf,
458                             size_t count)
459 {
460         struct scsi_target *starget = transport_class_to_starget(cdev);
461         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
462         struct spi_internal *i = to_spi_internal(shost->transportt);
463         struct spi_transport_attrs *tp =
464                 (struct spi_transport_attrs *)&starget->starget_data;
465         int period, retval;
466
467         retval = store_spi_transport_period_helper(cdev, buf, count, &period);
468
469         if (period < tp->min_period)
470                 period = tp->min_period;
471
472         i->f->set_period(starget, period);
473
474         return retval;
475 }
476
477 static CLASS_DEVICE_ATTR(period, S_IRUGO | S_IWUSR, 
478                          show_spi_transport_period,
479                          store_spi_transport_period);
480
481 static ssize_t
482 show_spi_transport_min_period(struct class_device *cdev, char *buf)
483 {
484         struct scsi_target *starget = transport_class_to_starget(cdev);
485         struct spi_transport_attrs *tp =
486                 (struct spi_transport_attrs *)&starget->starget_data;
487
488         return show_spi_transport_period_helper(cdev, buf, tp->min_period);
489 }
490
491 static ssize_t
492 store_spi_transport_min_period(struct class_device *cdev, const char *buf,
493                             size_t count)
494 {
495         struct scsi_target *starget = transport_class_to_starget(cdev);
496         struct spi_transport_attrs *tp =
497                 (struct spi_transport_attrs *)&starget->starget_data;
498
499         return store_spi_transport_period_helper(cdev, buf, count,
500                                                  &tp->min_period);
501 }
502
503
504 static CLASS_DEVICE_ATTR(min_period, S_IRUGO | S_IWUSR, 
505                          show_spi_transport_min_period,
506                          store_spi_transport_min_period);
507
508
509 static ssize_t show_spi_host_signalling(struct class_device *cdev, char *buf)
510 {
511         struct Scsi_Host *shost = transport_class_to_shost(cdev);
512         struct spi_internal *i = to_spi_internal(shost->transportt);
513
514         if (i->f->get_signalling)
515                 i->f->get_signalling(shost);
516
517         return sprintf(buf, "%s\n", spi_signal_to_string(spi_signalling(shost)));
518 }
519 static ssize_t store_spi_host_signalling(struct class_device *cdev,
520                                          const char *buf, size_t count)
521 {
522         struct Scsi_Host *shost = transport_class_to_shost(cdev);
523         struct spi_internal *i = to_spi_internal(shost->transportt);
524         enum spi_signal_type type = spi_signal_to_value(buf);
525
526         if (type != SPI_SIGNAL_UNKNOWN)
527                 i->f->set_signalling(shost, type);
528
529         return count;
530 }
531 static CLASS_DEVICE_ATTR(signalling, S_IRUGO | S_IWUSR,
532                          show_spi_host_signalling,
533                          store_spi_host_signalling);
534
535 #define DV_SET(x, y)                    \
536         if(i->f->set_##x)               \
537                 i->f->set_##x(sdev->sdev_target, y)
538
539 enum spi_compare_returns {
540         SPI_COMPARE_SUCCESS,
541         SPI_COMPARE_FAILURE,
542         SPI_COMPARE_SKIP_TEST,
543 };
544
545
546 /* This is for read/write Domain Validation:  If the device supports
547  * an echo buffer, we do read/write tests to it */
548 static enum spi_compare_returns
549 spi_dv_device_echo_buffer(struct scsi_request *sreq, u8 *buffer,
550                           u8 *ptr, const int retries)
551 {
552         struct scsi_device *sdev = sreq->sr_device;
553         int len = ptr - buffer;
554         int j, k, r;
555         unsigned int pattern = 0x0000ffff;
556
557         const char spi_write_buffer[] = {
558                 WRITE_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
559         };
560         const char spi_read_buffer[] = {
561                 READ_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
562         };
563
564         /* set up the pattern buffer.  Doesn't matter if we spill
565          * slightly beyond since that's where the read buffer is */
566         for (j = 0; j < len; ) {
567
568                 /* fill the buffer with counting (test a) */
569                 for ( ; j < min(len, 32); j++)
570                         buffer[j] = j;
571                 k = j;
572                 /* fill the buffer with alternating words of 0x0 and
573                  * 0xffff (test b) */
574                 for ( ; j < min(len, k + 32); j += 2) {
575                         u16 *word = (u16 *)&buffer[j];
576                         
577                         *word = (j & 0x02) ? 0x0000 : 0xffff;
578                 }
579                 k = j;
580                 /* fill with crosstalk (alternating 0x5555 0xaaa)
581                  * (test c) */
582                 for ( ; j < min(len, k + 32); j += 2) {
583                         u16 *word = (u16 *)&buffer[j];
584
585                         *word = (j & 0x02) ? 0x5555 : 0xaaaa;
586                 }
587                 k = j;
588                 /* fill with shifting bits (test d) */
589                 for ( ; j < min(len, k + 32); j += 4) {
590                         u32 *word = (unsigned int *)&buffer[j];
591                         u32 roll = (pattern & 0x80000000) ? 1 : 0;
592                         
593                         *word = pattern;
594                         pattern = (pattern << 1) | roll;
595                 }
596                 /* don't bother with random data (test e) */
597         }
598
599         for (r = 0; r < retries; r++) {
600                 sreq->sr_cmd_len = 0;   /* wait_req to fill in */
601                 sreq->sr_data_direction = DMA_TO_DEVICE;
602                 spi_wait_req(sreq, spi_write_buffer, buffer, len);
603                 if(sreq->sr_result || !scsi_device_online(sdev)) {
604                         struct scsi_sense_hdr sshdr;
605
606                         scsi_device_set_state(sdev, SDEV_QUIESCE);
607                         if (scsi_request_normalize_sense(sreq, &sshdr)
608                             && sshdr.sense_key == ILLEGAL_REQUEST
609                             /* INVALID FIELD IN CDB */
610                             && sshdr.asc == 0x24 && sshdr.ascq == 0x00)
611                                 /* This would mean that the drive lied
612                                  * to us about supporting an echo
613                                  * buffer (unfortunately some Western
614                                  * Digital drives do precisely this)
615                                  */
616                                 return SPI_COMPARE_SKIP_TEST;
617
618
619                         SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Write Buffer failure %x\n", sreq->sr_result);
620                         return SPI_COMPARE_FAILURE;
621                 }
622
623                 memset(ptr, 0, len);
624                 sreq->sr_cmd_len = 0;   /* wait_req to fill in */
625                 sreq->sr_data_direction = DMA_FROM_DEVICE;
626                 spi_wait_req(sreq, spi_read_buffer, ptr, len);
627                 scsi_device_set_state(sdev, SDEV_QUIESCE);
628
629                 if (memcmp(buffer, ptr, len) != 0)
630                         return SPI_COMPARE_FAILURE;
631         }
632         return SPI_COMPARE_SUCCESS;
633 }
634
635 /* This is for the simplest form of Domain Validation: a read test
636  * on the inquiry data from the device */
637 static enum spi_compare_returns
638 spi_dv_device_compare_inquiry(struct scsi_request *sreq, u8 *buffer,
639                               u8 *ptr, const int retries)
640 {
641         int r;
642         const int len = sreq->sr_device->inquiry_len;
643         struct scsi_device *sdev = sreq->sr_device;
644         const char spi_inquiry[] = {
645                 INQUIRY, 0, 0, 0, len, 0
646         };
647
648         for (r = 0; r < retries; r++) {
649                 sreq->sr_cmd_len = 0;   /* wait_req to fill in */
650                 sreq->sr_data_direction = DMA_FROM_DEVICE;
651
652                 memset(ptr, 0, len);
653
654                 spi_wait_req(sreq, spi_inquiry, ptr, len);
655                 
656                 if(sreq->sr_result || !scsi_device_online(sdev)) {
657                         scsi_device_set_state(sdev, SDEV_QUIESCE);
658                         return SPI_COMPARE_FAILURE;
659                 }
660
661                 /* If we don't have the inquiry data already, the
662                  * first read gets it */
663                 if (ptr == buffer) {
664                         ptr += len;
665                         --r;
666                         continue;
667                 }
668
669                 if (memcmp(buffer, ptr, len) != 0)
670                         /* failure */
671                         return SPI_COMPARE_FAILURE;
672         }
673         return SPI_COMPARE_SUCCESS;
674 }
675
676 static enum spi_compare_returns
677 spi_dv_retrain(struct scsi_request *sreq, u8 *buffer, u8 *ptr,
678                enum spi_compare_returns 
679                (*compare_fn)(struct scsi_request *, u8 *, u8 *, int))
680 {
681         struct spi_internal *i = to_spi_internal(sreq->sr_host->transportt);
682         struct scsi_device *sdev = sreq->sr_device;
683         struct scsi_target *starget = sdev->sdev_target;
684         int period = 0, prevperiod = 0; 
685         enum spi_compare_returns retval;
686
687
688         for (;;) {
689                 int newperiod;
690                 retval = compare_fn(sreq, buffer, ptr, DV_LOOPS);
691
692                 if (retval == SPI_COMPARE_SUCCESS
693                     || retval == SPI_COMPARE_SKIP_TEST)
694                         break;
695
696                 /* OK, retrain, fallback */
697                 if (i->f->get_iu)
698                         i->f->get_iu(starget);
699                 if (i->f->get_qas)
700                         i->f->get_qas(starget);
701                 if (i->f->get_period)
702                         i->f->get_period(sdev->sdev_target);
703
704                 /* Here's the fallback sequence; first try turning off
705                  * IU, then QAS (if we can control them), then finally
706                  * fall down the periods */
707                 if (i->f->set_iu && spi_iu(starget)) {
708                         SPI_PRINTK(starget, KERN_ERR, "Domain Validation Disabing Information Units\n");
709                         DV_SET(iu, 0);
710                 } else if (i->f->set_qas && spi_qas(starget)) {
711                         SPI_PRINTK(starget, KERN_ERR, "Domain Validation Disabing Quick Arbitration and Selection\n");
712                         DV_SET(qas, 0);
713                 } else {
714                         newperiod = spi_period(starget);
715                         period = newperiod > period ? newperiod : period;
716                         if (period < 0x0d)
717                                 period++;
718                         else
719                                 period += period >> 1;
720
721                         if (unlikely(period > 0xff || period == prevperiod)) {
722                                 /* Total failure; set to async and return */
723                                 SPI_PRINTK(starget, KERN_ERR, "Domain Validation Failure, dropping back to Asynchronous\n");
724                                 DV_SET(offset, 0);
725                                 return SPI_COMPARE_FAILURE;
726                         }
727                         SPI_PRINTK(starget, KERN_ERR, "Domain Validation detected failure, dropping back\n");
728                         DV_SET(period, period);
729                         prevperiod = period;
730                 }
731         }
732         return retval;
733 }
734
735 static int
736 spi_dv_device_get_echo_buffer(struct scsi_request *sreq, u8 *buffer)
737 {
738         int l;
739
740         /* first off do a test unit ready.  This can error out 
741          * because of reservations or some other reason.  If it
742          * fails, the device won't let us write to the echo buffer
743          * so just return failure */
744         
745         const char spi_test_unit_ready[] = {
746                 TEST_UNIT_READY, 0, 0, 0, 0, 0
747         };
748
749         const char spi_read_buffer_descriptor[] = {
750                 READ_BUFFER, 0x0b, 0, 0, 0, 0, 0, 0, 4, 0
751         };
752
753         
754         sreq->sr_cmd_len = 0;
755         sreq->sr_data_direction = DMA_NONE;
756
757         /* We send a set of three TURs to clear any outstanding 
758          * unit attention conditions if they exist (Otherwise the
759          * buffer tests won't be happy).  If the TUR still fails
760          * (reservation conflict, device not ready, etc) just
761          * skip the write tests */
762         for (l = 0; ; l++) {
763                 spi_wait_req(sreq, spi_test_unit_ready, NULL, 0);
764
765                 if(sreq->sr_result) {
766                         if(l >= 3)
767                                 return 0;
768                 } else {
769                         /* TUR succeeded */
770                         break;
771                 }
772         }
773
774         sreq->sr_cmd_len = 0;
775         sreq->sr_data_direction = DMA_FROM_DEVICE;
776
777         spi_wait_req(sreq, spi_read_buffer_descriptor, buffer, 4);
778
779         if (sreq->sr_result)
780                 /* Device has no echo buffer */
781                 return 0;
782
783         return buffer[3] + ((buffer[2] & 0x1f) << 8);
784 }
785
786 static void
787 spi_dv_device_internal(struct scsi_request *sreq, u8 *buffer)
788 {
789         struct spi_internal *i = to_spi_internal(sreq->sr_host->transportt);
790         struct scsi_device *sdev = sreq->sr_device;
791         struct scsi_target *starget = sdev->sdev_target;
792         int len = sdev->inquiry_len;
793         /* first set us up for narrow async */
794         DV_SET(offset, 0);
795         DV_SET(width, 0);
796         
797         if (spi_dv_device_compare_inquiry(sreq, buffer, buffer, DV_LOOPS)
798             != SPI_COMPARE_SUCCESS) {
799                 SPI_PRINTK(starget, KERN_ERR, "Domain Validation Initial Inquiry Failed\n");
800                 /* FIXME: should probably offline the device here? */
801                 return;
802         }
803
804         /* test width */
805         if (i->f->set_width && spi_max_width(starget) &&
806             scsi_device_wide(sdev)) {
807                 i->f->set_width(starget, 1);
808
809                 if (spi_dv_device_compare_inquiry(sreq, buffer,
810                                                    buffer + len,
811                                                    DV_LOOPS)
812                     != SPI_COMPARE_SUCCESS) {
813                         SPI_PRINTK(starget, KERN_ERR, "Wide Transfers Fail\n");
814                         i->f->set_width(starget, 0);
815                 }
816         }
817
818         if (!i->f->set_period)
819                 return;
820
821         /* device can't handle synchronous */
822         if (!scsi_device_sync(sdev) && !scsi_device_dt(sdev))
823                 return;
824
825         /* see if the device has an echo buffer.  If it does we can
826          * do the SPI pattern write tests */
827
828         len = 0;
829         if (scsi_device_dt(sdev))
830                 len = spi_dv_device_get_echo_buffer(sreq, buffer);
831
832  retry:
833
834         /* now set up to the maximum */
835         DV_SET(offset, spi_max_offset(starget));
836         DV_SET(period, spi_min_period(starget));
837         /* try QAS requests; this should be harmless to set if the
838          * target supports it */
839         if (scsi_device_qas(sdev))
840                 DV_SET(qas, 1);
841         /* Also try IU transfers */
842         if (scsi_device_ius(sdev))
843                 DV_SET(iu, 1);
844         if (spi_min_period(starget) < 9) {
845                 /* This u320 (or u640). Ignore the coupled parameters
846                  * like DT and IU, but set the optional ones */
847                 DV_SET(rd_strm, 1);
848                 DV_SET(wr_flow, 1);
849                 DV_SET(rti, 1);
850                 if (spi_min_period(starget) == 8)
851                         DV_SET(pcomp_en, 1);
852         }
853
854         if (len == 0) {
855                 SPI_PRINTK(starget, KERN_INFO, "Domain Validation skipping write tests\n");
856                 spi_dv_retrain(sreq, buffer, buffer + len,
857                                spi_dv_device_compare_inquiry);
858                 return;
859         }
860
861         if (len > SPI_MAX_ECHO_BUFFER_SIZE) {
862                 SPI_PRINTK(starget, KERN_WARNING, "Echo buffer size %d is too big, trimming to %d\n", len, SPI_MAX_ECHO_BUFFER_SIZE);
863                 len = SPI_MAX_ECHO_BUFFER_SIZE;
864         }
865
866         if (spi_dv_retrain(sreq, buffer, buffer + len,
867                            spi_dv_device_echo_buffer)
868             == SPI_COMPARE_SKIP_TEST) {
869                 /* OK, the stupid drive can't do a write echo buffer
870                  * test after all, fall back to the read tests */
871                 len = 0;
872                 goto retry;
873         }
874 }
875
876
877 /**     spi_dv_device - Do Domain Validation on the device
878  *      @sdev:          scsi device to validate
879  *
880  *      Performs the domain validation on the given device in the
881  *      current execution thread.  Since DV operations may sleep,
882  *      the current thread must have user context.  Also no SCSI
883  *      related locks that would deadlock I/O issued by the DV may
884  *      be held.
885  */
886 void
887 spi_dv_device(struct scsi_device *sdev)
888 {
889         struct scsi_request *sreq = scsi_allocate_request(sdev, GFP_KERNEL);
890         struct scsi_target *starget = sdev->sdev_target;
891         u8 *buffer;
892         const int len = SPI_MAX_ECHO_BUFFER_SIZE*2;
893
894         if (unlikely(!sreq))
895                 return;
896
897         if (unlikely(scsi_device_get(sdev)))
898                 goto out_free_req;
899
900         buffer = kmalloc(len, GFP_KERNEL);
901
902         if (unlikely(!buffer))
903                 goto out_put;
904
905         memset(buffer, 0, len);
906
907         /* We need to verify that the actual device will quiesce; the
908          * later target quiesce is just a nice to have */
909         if (unlikely(scsi_device_quiesce(sdev)))
910                 goto out_free;
911
912         scsi_target_quiesce(starget);
913
914         spi_dv_pending(starget) = 1;
915         down(&spi_dv_sem(starget));
916
917         SPI_PRINTK(starget, KERN_INFO, "Beginning Domain Validation\n");
918
919         spi_dv_device_internal(sreq, buffer);
920
921         SPI_PRINTK(starget, KERN_INFO, "Ending Domain Validation\n");
922
923         up(&spi_dv_sem(starget));
924         spi_dv_pending(starget) = 0;
925
926         scsi_target_resume(starget);
927
928         spi_initial_dv(starget) = 1;
929
930  out_free:
931         kfree(buffer);
932  out_put:
933         scsi_device_put(sdev);
934  out_free_req:
935         scsi_release_request(sreq);
936 }
937 EXPORT_SYMBOL(spi_dv_device);
938
939 struct work_queue_wrapper {
940         struct work_struct      work;
941         struct scsi_device      *sdev;
942 };
943
944 static void
945 spi_dv_device_work_wrapper(void *data)
946 {
947         struct work_queue_wrapper *wqw = (struct work_queue_wrapper *)data;
948         struct scsi_device *sdev = wqw->sdev;
949
950         kfree(wqw);
951         spi_dv_device(sdev);
952         spi_dv_pending(sdev->sdev_target) = 0;
953         scsi_device_put(sdev);
954 }
955
956
957 /**
958  *      spi_schedule_dv_device - schedule domain validation to occur on the device
959  *      @sdev:  The device to validate
960  *
961  *      Identical to spi_dv_device() above, except that the DV will be
962  *      scheduled to occur in a workqueue later.  All memory allocations
963  *      are atomic, so may be called from any context including those holding
964  *      SCSI locks.
965  */
966 void
967 spi_schedule_dv_device(struct scsi_device *sdev)
968 {
969         struct work_queue_wrapper *wqw =
970                 kmalloc(sizeof(struct work_queue_wrapper), GFP_ATOMIC);
971
972         if (unlikely(!wqw))
973                 return;
974
975         if (unlikely(spi_dv_pending(sdev->sdev_target))) {
976                 kfree(wqw);
977                 return;
978         }
979         /* Set pending early (dv_device doesn't check it, only sets it) */
980         spi_dv_pending(sdev->sdev_target) = 1;
981         if (unlikely(scsi_device_get(sdev))) {
982                 kfree(wqw);
983                 spi_dv_pending(sdev->sdev_target) = 0;
984                 return;
985         }
986
987         INIT_WORK(&wqw->work, spi_dv_device_work_wrapper, wqw);
988         wqw->sdev = sdev;
989
990         schedule_work(&wqw->work);
991 }
992 EXPORT_SYMBOL(spi_schedule_dv_device);
993
994 /**
995  * spi_display_xfer_agreement - Print the current target transfer agreement
996  * @starget: The target for which to display the agreement
997  *
998  * Each SPI port is required to maintain a transfer agreement for each
999  * other port on the bus.  This function prints a one-line summary of
1000  * the current agreement; more detailed information is available in sysfs.
1001  */
1002 void spi_display_xfer_agreement(struct scsi_target *starget)
1003 {
1004         struct spi_transport_attrs *tp;
1005         tp = (struct spi_transport_attrs *)&starget->starget_data;
1006
1007         if (tp->offset > 0 && tp->period > 0) {
1008                 unsigned int picosec, kb100;
1009                 char *scsi = "FAST-?";
1010                 char tmp[8];
1011
1012                 if (tp->period <= SPI_STATIC_PPR) {
1013                         picosec = ppr_to_ps[tp->period];
1014                         switch (tp->period) {
1015                                 case  7: scsi = "FAST-320"; break;
1016                                 case  8: scsi = "FAST-160"; break;
1017                                 case  9: scsi = "FAST-80"; break;
1018                                 case 10:
1019                                 case 11: scsi = "FAST-40"; break;
1020                                 case 12: scsi = "FAST-20"; break;
1021                         }
1022                 } else {
1023                         picosec = tp->period * 4000;
1024                         if (tp->period < 25)
1025                                 scsi = "FAST-20";
1026                         else if (tp->period < 50)
1027                                 scsi = "FAST-10";
1028                         else
1029                                 scsi = "FAST-5";
1030                 }
1031
1032                 kb100 = (10000000 + picosec / 2) / picosec;
1033                 if (tp->width)
1034                         kb100 *= 2;
1035                 sprint_frac(tmp, picosec, 1000);
1036
1037                 dev_info(&starget->dev,
1038                          "%s %sSCSI %d.%d MB/s %s%s%s%s%s%s%s%s (%s ns, offset %d)\n",
1039                          scsi, tp->width ? "WIDE " : "", kb100/10, kb100 % 10,
1040                          tp->dt ? "DT" : "ST",
1041                          tp->iu ? " IU" : "",
1042                          tp->qas  ? " QAS" : "",
1043                          tp->rd_strm ? " RDSTRM" : "",
1044                          tp->rti ? " RTI" : "",
1045                          tp->wr_flow ? " WRFLOW" : "",
1046                          tp->pcomp_en ? " PCOMP" : "",
1047                          tp->hold_mcs ? " HMCS" : "",
1048                          tmp, tp->offset);
1049         } else {
1050                 dev_info(&starget->dev, "%sasynchronous.\n",
1051                                 tp->width ? "wide " : "");
1052         }
1053 }
1054 EXPORT_SYMBOL(spi_display_xfer_agreement);
1055
1056 #define SETUP_ATTRIBUTE(field)                                          \
1057         i->private_attrs[count] = class_device_attr_##field;            \
1058         if (!i->f->set_##field) {                                       \
1059                 i->private_attrs[count].attr.mode = S_IRUGO;            \
1060                 i->private_attrs[count].store = NULL;                   \
1061         }                                                               \
1062         i->attrs[count] = &i->private_attrs[count];                     \
1063         if (i->f->show_##field)                                         \
1064                 count++
1065
1066 #define SETUP_RELATED_ATTRIBUTE(field, rel_field)                       \
1067         i->private_attrs[count] = class_device_attr_##field;            \
1068         if (!i->f->set_##rel_field) {                                   \
1069                 i->private_attrs[count].attr.mode = S_IRUGO;            \
1070                 i->private_attrs[count].store = NULL;                   \
1071         }                                                               \
1072         i->attrs[count] = &i->private_attrs[count];                     \
1073         if (i->f->show_##rel_field)                                     \
1074                 count++
1075
1076 #define SETUP_HOST_ATTRIBUTE(field)                                     \
1077         i->private_host_attrs[count] = class_device_attr_##field;       \
1078         if (!i->f->set_##field) {                                       \
1079                 i->private_host_attrs[count].attr.mode = S_IRUGO;       \
1080                 i->private_host_attrs[count].store = NULL;              \
1081         }                                                               \
1082         i->host_attrs[count] = &i->private_host_attrs[count];           \
1083         count++
1084
1085 static int spi_device_match(struct attribute_container *cont,
1086                             struct device *dev)
1087 {
1088         struct scsi_device *sdev;
1089         struct Scsi_Host *shost;
1090         struct spi_internal *i;
1091
1092         if (!scsi_is_sdev_device(dev))
1093                 return 0;
1094
1095         sdev = to_scsi_device(dev);
1096         shost = sdev->host;
1097         if (!shost->transportt  || shost->transportt->host_attrs.ac.class
1098             != &spi_host_class.class)
1099                 return 0;
1100         /* Note: this class has no device attributes, so it has
1101          * no per-HBA allocation and thus we don't need to distinguish
1102          * the attribute containers for the device */
1103         i = to_spi_internal(shost->transportt);
1104         if (i->f->deny_binding && i->f->deny_binding(sdev->sdev_target))
1105                 return 0;
1106         return 1;
1107 }
1108
1109 static int spi_target_match(struct attribute_container *cont,
1110                             struct device *dev)
1111 {
1112         struct Scsi_Host *shost;
1113         struct scsi_target *starget;
1114         struct spi_internal *i;
1115
1116         if (!scsi_is_target_device(dev))
1117                 return 0;
1118
1119         shost = dev_to_shost(dev->parent);
1120         if (!shost->transportt  || shost->transportt->host_attrs.ac.class
1121             != &spi_host_class.class)
1122                 return 0;
1123
1124         i = to_spi_internal(shost->transportt);
1125         starget = to_scsi_target(dev);
1126
1127         if (i->f->deny_binding && i->f->deny_binding(starget))
1128                 return 0;
1129
1130         return &i->t.target_attrs.ac == cont;
1131 }
1132
1133 static DECLARE_TRANSPORT_CLASS(spi_transport_class,
1134                                "spi_transport",
1135                                spi_setup_transport_attrs,
1136                                NULL,
1137                                NULL);
1138
1139 static DECLARE_ANON_TRANSPORT_CLASS(spi_device_class,
1140                                     spi_device_match,
1141                                     spi_device_configure);
1142
1143 struct scsi_transport_template *
1144 spi_attach_transport(struct spi_function_template *ft)
1145 {
1146         struct spi_internal *i = kmalloc(sizeof(struct spi_internal),
1147                                          GFP_KERNEL);
1148         int count = 0;
1149         if (unlikely(!i))
1150                 return NULL;
1151
1152         memset(i, 0, sizeof(struct spi_internal));
1153
1154
1155         i->t.target_attrs.ac.class = &spi_transport_class.class;
1156         i->t.target_attrs.ac.attrs = &i->attrs[0];
1157         i->t.target_attrs.ac.match = spi_target_match;
1158         transport_container_register(&i->t.target_attrs);
1159         i->t.target_size = sizeof(struct spi_transport_attrs);
1160         i->t.host_attrs.ac.class = &spi_host_class.class;
1161         i->t.host_attrs.ac.attrs = &i->host_attrs[0];
1162         i->t.host_attrs.ac.match = spi_host_match;
1163         transport_container_register(&i->t.host_attrs);
1164         i->t.host_size = sizeof(struct spi_host_attrs);
1165         i->f = ft;
1166
1167         SETUP_ATTRIBUTE(period);
1168         SETUP_RELATED_ATTRIBUTE(min_period, period);
1169         SETUP_ATTRIBUTE(offset);
1170         SETUP_RELATED_ATTRIBUTE(max_offset, offset);
1171         SETUP_ATTRIBUTE(width);
1172         SETUP_RELATED_ATTRIBUTE(max_width, width);
1173         SETUP_ATTRIBUTE(iu);
1174         SETUP_ATTRIBUTE(dt);
1175         SETUP_ATTRIBUTE(qas);
1176         SETUP_ATTRIBUTE(wr_flow);
1177         SETUP_ATTRIBUTE(rd_strm);
1178         SETUP_ATTRIBUTE(rti);
1179         SETUP_ATTRIBUTE(pcomp_en);
1180         SETUP_ATTRIBUTE(hold_mcs);
1181
1182         /* if you add an attribute but forget to increase SPI_NUM_ATTRS
1183          * this bug will trigger */
1184         BUG_ON(count > SPI_NUM_ATTRS);
1185
1186         i->attrs[count++] = &class_device_attr_revalidate;
1187
1188         i->attrs[count] = NULL;
1189
1190         count = 0;
1191         SETUP_HOST_ATTRIBUTE(signalling);
1192
1193         BUG_ON(count > SPI_HOST_ATTRS);
1194
1195         i->host_attrs[count] = NULL;
1196
1197         return &i->t;
1198 }
1199 EXPORT_SYMBOL(spi_attach_transport);
1200
1201 void spi_release_transport(struct scsi_transport_template *t)
1202 {
1203         struct spi_internal *i = to_spi_internal(t);
1204
1205         transport_container_unregister(&i->t.target_attrs);
1206         transport_container_unregister(&i->t.host_attrs);
1207
1208         kfree(i);
1209 }
1210 EXPORT_SYMBOL(spi_release_transport);
1211
1212 static __init int spi_transport_init(void)
1213 {
1214         int error = transport_class_register(&spi_transport_class);
1215         if (error)
1216                 return error;
1217         error = anon_transport_class_register(&spi_device_class);
1218         return transport_class_register(&spi_host_class);
1219 }
1220
1221 static void __exit spi_transport_exit(void)
1222 {
1223         transport_class_unregister(&spi_transport_class);
1224         anon_transport_class_unregister(&spi_device_class);
1225         transport_class_unregister(&spi_host_class);
1226 }
1227
1228 MODULE_AUTHOR("Martin Hicks");
1229 MODULE_DESCRIPTION("SPI Transport Attributes");
1230 MODULE_LICENSE("GPL");
1231
1232 module_init(spi_transport_init);
1233 module_exit(spi_transport_exit);