[SCSI] fix command retries in spi_transport class
[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 <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 10        /* increase this if you add attributes */
39 #define SPI_OTHER_ATTRS 1       /* Increase this if you add "always
40                                  * on" attributes */
41 #define SPI_HOST_ATTRS  1
42
43 #define SPI_MAX_ECHO_BUFFER_SIZE        4096
44
45 #define DV_LOOPS        3
46 #define DV_TIMEOUT      (10*HZ)
47 #define DV_RETRIES      3       /* should only need at most 
48                                  * two cc/ua clears */
49
50 /* Private data accessors (keep these out of the header file) */
51 #define spi_dv_pending(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_pending)
52 #define spi_dv_sem(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_sem)
53
54 struct spi_internal {
55         struct scsi_transport_template t;
56         struct spi_function_template *f;
57         /* The actual attributes */
58         struct class_device_attribute private_attrs[SPI_NUM_ATTRS];
59         /* The array of null terminated pointers to attributes 
60          * needed by scsi_sysfs.c */
61         struct class_device_attribute *attrs[SPI_NUM_ATTRS + SPI_OTHER_ATTRS + 1];
62         struct class_device_attribute private_host_attrs[SPI_HOST_ATTRS];
63         struct class_device_attribute *host_attrs[SPI_HOST_ATTRS + 1];
64 };
65
66 #define to_spi_internal(tmpl)   container_of(tmpl, struct spi_internal, t)
67
68 static const int ppr_to_ps[] = {
69         /* The PPR values 0-6 are reserved, fill them in when
70          * the committee defines them */
71         -1,                     /* 0x00 */
72         -1,                     /* 0x01 */
73         -1,                     /* 0x02 */
74         -1,                     /* 0x03 */
75         -1,                     /* 0x04 */
76         -1,                     /* 0x05 */
77         -1,                     /* 0x06 */
78          3125,                  /* 0x07 */
79          6250,                  /* 0x08 */
80         12500,                  /* 0x09 */
81         25000,                  /* 0x0a */
82         30300,                  /* 0x0b */
83         50000,                  /* 0x0c */
84 };
85 /* The PPR values at which you calculate the period in ns by multiplying
86  * by 4 */
87 #define SPI_STATIC_PPR  0x0c
88
89 static int sprint_frac(char *dest, int value, int denom)
90 {
91         int frac = value % denom;
92         int result = sprintf(dest, "%d", value / denom);
93
94         if (frac == 0)
95                 return result;
96         dest[result++] = '.';
97
98         do {
99                 denom /= 10;
100                 sprintf(dest + result, "%d", frac / denom);
101                 result++;
102                 frac %= denom;
103         } while (frac);
104
105         dest[result++] = '\0';
106         return result;
107 }
108
109 /* Modification of scsi_wait_req that will clear UNIT ATTENTION conditions
110  * resulting from (likely) bus and device resets */
111 static void spi_wait_req(struct scsi_request *sreq, const void *cmd,
112                          void *buffer, unsigned bufflen)
113 {
114         int i;
115
116         for(i = 0; i < DV_RETRIES; i++) {
117                 sreq->sr_request->flags |= REQ_FAILFAST;
118
119                 scsi_wait_req(sreq, cmd, buffer, bufflen,
120                               DV_TIMEOUT, /* retries */ 1);
121                 if (sreq->sr_result & DRIVER_SENSE) {
122                         struct scsi_sense_hdr sshdr;
123
124                         if (scsi_request_normalize_sense(sreq, &sshdr)
125                             && sshdr.sense_key == UNIT_ATTENTION)
126                                 continue;
127                 }
128                 break;
129         }
130 }
131
132 static struct {
133         enum spi_signal_type    value;
134         char                    *name;
135 } signal_types[] = {
136         { SPI_SIGNAL_UNKNOWN, "unknown" },
137         { SPI_SIGNAL_SE, "SE" },
138         { SPI_SIGNAL_LVD, "LVD" },
139         { SPI_SIGNAL_HVD, "HVD" },
140 };
141
142 static inline const char *spi_signal_to_string(enum spi_signal_type type)
143 {
144         int i;
145
146         for (i = 0; i < sizeof(signal_types)/sizeof(signal_types[0]); i++) {
147                 if (type == signal_types[i].value)
148                         return signal_types[i].name;
149         }
150         return NULL;
151 }
152 static inline enum spi_signal_type spi_signal_to_value(const char *name)
153 {
154         int i, len;
155
156         for (i = 0; i < sizeof(signal_types)/sizeof(signal_types[0]); i++) {
157                 len =  strlen(signal_types[i].name);
158                 if (strncmp(name, signal_types[i].name, len) == 0 &&
159                     (name[len] == '\n' || name[len] == '\0'))
160                         return signal_types[i].value;
161         }
162         return SPI_SIGNAL_UNKNOWN;
163 }
164
165 static int spi_host_setup(struct device *dev)
166 {
167         struct Scsi_Host *shost = dev_to_shost(dev);
168
169         spi_signalling(shost) = SPI_SIGNAL_UNKNOWN;
170
171         return 0;
172 }
173
174 static DECLARE_TRANSPORT_CLASS(spi_host_class,
175                                "spi_host",
176                                spi_host_setup,
177                                NULL,
178                                NULL);
179
180 static int spi_host_match(struct attribute_container *cont,
181                           struct device *dev)
182 {
183         struct Scsi_Host *shost;
184         struct spi_internal *i;
185
186         if (!scsi_is_host_device(dev))
187                 return 0;
188
189         shost = dev_to_shost(dev);
190         if (!shost->transportt  || shost->transportt->host_attrs.ac.class
191             != &spi_host_class.class)
192                 return 0;
193
194         i = to_spi_internal(shost->transportt);
195         
196         return &i->t.host_attrs.ac == cont;
197 }
198
199 static int spi_device_configure(struct device *dev)
200 {
201         struct scsi_device *sdev = to_scsi_device(dev);
202         struct scsi_target *starget = sdev->sdev_target;
203
204         /* Populate the target capability fields with the values
205          * gleaned from the device inquiry */
206
207         spi_support_sync(starget) = scsi_device_sync(sdev);
208         spi_support_wide(starget) = scsi_device_wide(sdev);
209         spi_support_dt(starget) = scsi_device_dt(sdev);
210         spi_support_dt_only(starget) = scsi_device_dt_only(sdev);
211         spi_support_ius(starget) = scsi_device_ius(sdev);
212         spi_support_qas(starget) = scsi_device_qas(sdev);
213
214         return 0;
215 }
216
217 static int spi_setup_transport_attrs(struct device *dev)
218 {
219         struct scsi_target *starget = to_scsi_target(dev);
220
221         spi_period(starget) = -1;       /* illegal value */
222         spi_offset(starget) = 0;        /* async */
223         spi_width(starget) = 0; /* narrow */
224         spi_iu(starget) = 0;    /* no IU */
225         spi_dt(starget) = 0;    /* ST */
226         spi_qas(starget) = 0;
227         spi_wr_flow(starget) = 0;
228         spi_rd_strm(starget) = 0;
229         spi_rti(starget) = 0;
230         spi_pcomp_en(starget) = 0;
231         spi_dv_pending(starget) = 0;
232         spi_initial_dv(starget) = 0;
233         init_MUTEX(&spi_dv_sem(starget));
234
235         return 0;
236 }
237
238 #define spi_transport_show_function(field, format_string)               \
239                                                                         \
240 static ssize_t                                                          \
241 show_spi_transport_##field(struct class_device *cdev, char *buf)        \
242 {                                                                       \
243         struct scsi_target *starget = transport_class_to_starget(cdev); \
244         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);    \
245         struct spi_transport_attrs *tp;                                 \
246         struct spi_internal *i = to_spi_internal(shost->transportt);    \
247         tp = (struct spi_transport_attrs *)&starget->starget_data;      \
248         if (i->f->get_##field)                                          \
249                 i->f->get_##field(starget);                             \
250         return snprintf(buf, 20, format_string, tp->field);             \
251 }
252
253 #define spi_transport_store_function(field, format_string)              \
254 static ssize_t                                                          \
255 store_spi_transport_##field(struct class_device *cdev, const char *buf, \
256                             size_t count)                               \
257 {                                                                       \
258         int val;                                                        \
259         struct scsi_target *starget = transport_class_to_starget(cdev); \
260         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);    \
261         struct spi_internal *i = to_spi_internal(shost->transportt);    \
262                                                                         \
263         val = simple_strtoul(buf, NULL, 0);                             \
264         i->f->set_##field(starget, val);                                \
265         return count;                                                   \
266 }
267
268 #define spi_transport_rd_attr(field, format_string)                     \
269         spi_transport_show_function(field, format_string)               \
270         spi_transport_store_function(field, format_string)              \
271 static CLASS_DEVICE_ATTR(field, S_IRUGO | S_IWUSR,                      \
272                          show_spi_transport_##field,                    \
273                          store_spi_transport_##field);
274
275 /* The Parallel SCSI Tranport Attributes: */
276 spi_transport_rd_attr(offset, "%d\n");
277 spi_transport_rd_attr(width, "%d\n");
278 spi_transport_rd_attr(iu, "%d\n");
279 spi_transport_rd_attr(dt, "%d\n");
280 spi_transport_rd_attr(qas, "%d\n");
281 spi_transport_rd_attr(wr_flow, "%d\n");
282 spi_transport_rd_attr(rd_strm, "%d\n");
283 spi_transport_rd_attr(rti, "%d\n");
284 spi_transport_rd_attr(pcomp_en, "%d\n");
285
286 static ssize_t
287 store_spi_revalidate(struct class_device *cdev, const char *buf, size_t count)
288 {
289         struct scsi_target *starget = transport_class_to_starget(cdev);
290
291         /* FIXME: we're relying on an awful lot of device internals
292          * here.  We really need a function to get the first available
293          * child */
294         struct device *dev = container_of(starget->dev.children.next, struct device, node);
295         struct scsi_device *sdev = to_scsi_device(dev);
296         spi_dv_device(sdev);
297         return count;
298 }
299 static CLASS_DEVICE_ATTR(revalidate, S_IWUSR, NULL, store_spi_revalidate);
300
301 /* Translate the period into ns according to the current spec
302  * for SDTR/PPR messages */
303 static ssize_t show_spi_transport_period(struct class_device *cdev, char *buf)
304
305 {
306         struct scsi_target *starget = transport_class_to_starget(cdev);
307         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
308         struct spi_transport_attrs *tp;
309         int len, picosec;
310         struct spi_internal *i = to_spi_internal(shost->transportt);
311
312         tp = (struct spi_transport_attrs *)&starget->starget_data;
313
314         if (i->f->get_period)
315                 i->f->get_period(starget);
316
317         if (tp->period < 0 || tp->period > 0xff) {
318                 picosec = -1;
319         } else if (tp->period <= SPI_STATIC_PPR) {
320                 picosec = ppr_to_ps[tp->period];
321         } else {
322                 picosec = tp->period * 4000;
323         }
324
325         if (picosec == -1) {
326                 len = sprintf(buf, "reserved");
327         } else {
328                 len = sprint_frac(buf, picosec, 1000);
329         }
330
331         buf[len++] = '\n';
332         buf[len] = '\0';
333         return len;
334 }
335
336 static ssize_t
337 store_spi_transport_period(struct class_device *cdev, const char *buf,
338                             size_t count)
339 {
340         struct scsi_target *starget = transport_class_to_starget(cdev);
341         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
342         struct spi_internal *i = to_spi_internal(shost->transportt);
343         int j, picosec, period = -1;
344         char *endp;
345
346         picosec = simple_strtoul(buf, &endp, 10) * 1000;
347         if (*endp == '.') {
348                 int mult = 100;
349                 do {
350                         endp++;
351                         if (!isdigit(*endp))
352                                 break;
353                         picosec += (*endp - '0') * mult;
354                         mult /= 10;
355                 } while (mult > 0);
356         }
357
358         for (j = 0; j <= SPI_STATIC_PPR; j++) {
359                 if (ppr_to_ps[j] < picosec)
360                         continue;
361                 period = j;
362                 break;
363         }
364
365         if (period == -1)
366                 period = picosec / 4000;
367
368         if (period > 0xff)
369                 period = 0xff;
370
371         i->f->set_period(starget, period);
372
373         return count;
374 }
375
376 static CLASS_DEVICE_ATTR(period, S_IRUGO | S_IWUSR, 
377                          show_spi_transport_period,
378                          store_spi_transport_period);
379
380 static ssize_t show_spi_host_signalling(struct class_device *cdev, char *buf)
381 {
382         struct Scsi_Host *shost = transport_class_to_shost(cdev);
383         struct spi_internal *i = to_spi_internal(shost->transportt);
384
385         if (i->f->get_signalling)
386                 i->f->get_signalling(shost);
387
388         return sprintf(buf, "%s\n", spi_signal_to_string(spi_signalling(shost)));
389 }
390 static ssize_t store_spi_host_signalling(struct class_device *cdev,
391                                          const char *buf, size_t count)
392 {
393         struct Scsi_Host *shost = transport_class_to_shost(cdev);
394         struct spi_internal *i = to_spi_internal(shost->transportt);
395         enum spi_signal_type type = spi_signal_to_value(buf);
396
397         if (type != SPI_SIGNAL_UNKNOWN)
398                 i->f->set_signalling(shost, type);
399
400         return count;
401 }
402 static CLASS_DEVICE_ATTR(signalling, S_IRUGO | S_IWUSR,
403                          show_spi_host_signalling,
404                          store_spi_host_signalling);
405
406 #define DV_SET(x, y)                    \
407         if(i->f->set_##x)               \
408                 i->f->set_##x(sdev->sdev_target, y)
409
410 enum spi_compare_returns {
411         SPI_COMPARE_SUCCESS,
412         SPI_COMPARE_FAILURE,
413         SPI_COMPARE_SKIP_TEST,
414 };
415
416
417 /* This is for read/write Domain Validation:  If the device supports
418  * an echo buffer, we do read/write tests to it */
419 static enum spi_compare_returns
420 spi_dv_device_echo_buffer(struct scsi_request *sreq, u8 *buffer,
421                           u8 *ptr, const int retries)
422 {
423         struct scsi_device *sdev = sreq->sr_device;
424         int len = ptr - buffer;
425         int j, k, r;
426         unsigned int pattern = 0x0000ffff;
427
428         const char spi_write_buffer[] = {
429                 WRITE_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
430         };
431         const char spi_read_buffer[] = {
432                 READ_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
433         };
434
435         /* set up the pattern buffer.  Doesn't matter if we spill
436          * slightly beyond since that's where the read buffer is */
437         for (j = 0; j < len; ) {
438
439                 /* fill the buffer with counting (test a) */
440                 for ( ; j < min(len, 32); j++)
441                         buffer[j] = j;
442                 k = j;
443                 /* fill the buffer with alternating words of 0x0 and
444                  * 0xffff (test b) */
445                 for ( ; j < min(len, k + 32); j += 2) {
446                         u16 *word = (u16 *)&buffer[j];
447                         
448                         *word = (j & 0x02) ? 0x0000 : 0xffff;
449                 }
450                 k = j;
451                 /* fill with crosstalk (alternating 0x5555 0xaaa)
452                  * (test c) */
453                 for ( ; j < min(len, k + 32); j += 2) {
454                         u16 *word = (u16 *)&buffer[j];
455
456                         *word = (j & 0x02) ? 0x5555 : 0xaaaa;
457                 }
458                 k = j;
459                 /* fill with shifting bits (test d) */
460                 for ( ; j < min(len, k + 32); j += 4) {
461                         u32 *word = (unsigned int *)&buffer[j];
462                         u32 roll = (pattern & 0x80000000) ? 1 : 0;
463                         
464                         *word = pattern;
465                         pattern = (pattern << 1) | roll;
466                 }
467                 /* don't bother with random data (test e) */
468         }
469
470         for (r = 0; r < retries; r++) {
471                 sreq->sr_cmd_len = 0;   /* wait_req to fill in */
472                 sreq->sr_data_direction = DMA_TO_DEVICE;
473                 spi_wait_req(sreq, spi_write_buffer, buffer, len);
474                 if(sreq->sr_result || !scsi_device_online(sdev)) {
475                         struct scsi_sense_hdr sshdr;
476
477                         scsi_device_set_state(sdev, SDEV_QUIESCE);
478                         if (scsi_request_normalize_sense(sreq, &sshdr)
479                             && sshdr.sense_key == ILLEGAL_REQUEST
480                             /* INVALID FIELD IN CDB */
481                             && sshdr.asc == 0x24 && sshdr.ascq == 0x00)
482                                 /* This would mean that the drive lied
483                                  * to us about supporting an echo
484                                  * buffer (unfortunately some Western
485                                  * Digital drives do precisely this)
486                                  */
487                                 return SPI_COMPARE_SKIP_TEST;
488
489
490                         SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Write Buffer failure %x\n", sreq->sr_result);
491                         return SPI_COMPARE_FAILURE;
492                 }
493
494                 memset(ptr, 0, len);
495                 sreq->sr_cmd_len = 0;   /* wait_req to fill in */
496                 sreq->sr_data_direction = DMA_FROM_DEVICE;
497                 spi_wait_req(sreq, spi_read_buffer, ptr, len);
498                 scsi_device_set_state(sdev, SDEV_QUIESCE);
499
500                 if (memcmp(buffer, ptr, len) != 0)
501                         return SPI_COMPARE_FAILURE;
502         }
503         return SPI_COMPARE_SUCCESS;
504 }
505
506 /* This is for the simplest form of Domain Validation: a read test
507  * on the inquiry data from the device */
508 static enum spi_compare_returns
509 spi_dv_device_compare_inquiry(struct scsi_request *sreq, u8 *buffer,
510                               u8 *ptr, const int retries)
511 {
512         int r;
513         const int len = sreq->sr_device->inquiry_len;
514         struct scsi_device *sdev = sreq->sr_device;
515         const char spi_inquiry[] = {
516                 INQUIRY, 0, 0, 0, len, 0
517         };
518
519         for (r = 0; r < retries; r++) {
520                 sreq->sr_cmd_len = 0;   /* wait_req to fill in */
521                 sreq->sr_data_direction = DMA_FROM_DEVICE;
522
523                 memset(ptr, 0, len);
524
525                 spi_wait_req(sreq, spi_inquiry, ptr, len);
526                 
527                 if(sreq->sr_result || !scsi_device_online(sdev)) {
528                         scsi_device_set_state(sdev, SDEV_QUIESCE);
529                         return SPI_COMPARE_FAILURE;
530                 }
531
532                 /* If we don't have the inquiry data already, the
533                  * first read gets it */
534                 if (ptr == buffer) {
535                         ptr += len;
536                         --r;
537                         continue;
538                 }
539
540                 if (memcmp(buffer, ptr, len) != 0)
541                         /* failure */
542                         return SPI_COMPARE_FAILURE;
543         }
544         return SPI_COMPARE_SUCCESS;
545 }
546
547 static enum spi_compare_returns
548 spi_dv_retrain(struct scsi_request *sreq, u8 *buffer, u8 *ptr,
549                enum spi_compare_returns 
550                (*compare_fn)(struct scsi_request *, u8 *, u8 *, int))
551 {
552         struct spi_internal *i = to_spi_internal(sreq->sr_host->transportt);
553         struct scsi_device *sdev = sreq->sr_device;
554         int period = 0, prevperiod = 0; 
555         enum spi_compare_returns retval;
556
557
558         for (;;) {
559                 int newperiod;
560                 retval = compare_fn(sreq, buffer, ptr, DV_LOOPS);
561
562                 if (retval == SPI_COMPARE_SUCCESS
563                     || retval == SPI_COMPARE_SKIP_TEST)
564                         break;
565
566                 /* OK, retrain, fallback */
567                 if (i->f->get_period)
568                         i->f->get_period(sdev->sdev_target);
569                 newperiod = spi_period(sdev->sdev_target);
570                 period = newperiod > period ? newperiod : period;
571                 if (period < 0x0d)
572                         period++;
573                 else
574                         period += period >> 1;
575
576                 if (unlikely(period > 0xff || period == prevperiod)) {
577                         /* Total failure; set to async and return */
578                         SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Domain Validation Failure, dropping back to Asynchronous\n");
579                         DV_SET(offset, 0);
580                         return SPI_COMPARE_FAILURE;
581                 }
582                 SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Domain Validation detected failure, dropping back\n");
583                 DV_SET(period, period);
584                 prevperiod = period;
585         }
586         return retval;
587 }
588
589 static int
590 spi_dv_device_get_echo_buffer(struct scsi_request *sreq, u8 *buffer)
591 {
592         int l;
593
594         /* first off do a test unit ready.  This can error out 
595          * because of reservations or some other reason.  If it
596          * fails, the device won't let us write to the echo buffer
597          * so just return failure */
598         
599         const char spi_test_unit_ready[] = {
600                 TEST_UNIT_READY, 0, 0, 0, 0, 0
601         };
602
603         const char spi_read_buffer_descriptor[] = {
604                 READ_BUFFER, 0x0b, 0, 0, 0, 0, 0, 0, 4, 0
605         };
606
607         
608         sreq->sr_cmd_len = 0;
609         sreq->sr_data_direction = DMA_NONE;
610
611         /* We send a set of three TURs to clear any outstanding 
612          * unit attention conditions if they exist (Otherwise the
613          * buffer tests won't be happy).  If the TUR still fails
614          * (reservation conflict, device not ready, etc) just
615          * skip the write tests */
616         for (l = 0; ; l++) {
617                 spi_wait_req(sreq, spi_test_unit_ready, NULL, 0);
618
619                 if(sreq->sr_result) {
620                         if(l >= 3)
621                                 return 0;
622                 } else {
623                         /* TUR succeeded */
624                         break;
625                 }
626         }
627
628         sreq->sr_cmd_len = 0;
629         sreq->sr_data_direction = DMA_FROM_DEVICE;
630
631         spi_wait_req(sreq, spi_read_buffer_descriptor, buffer, 4);
632
633         if (sreq->sr_result)
634                 /* Device has no echo buffer */
635                 return 0;
636
637         return buffer[3] + ((buffer[2] & 0x1f) << 8);
638 }
639
640 static void
641 spi_dv_device_internal(struct scsi_request *sreq, u8 *buffer)
642 {
643         struct spi_internal *i = to_spi_internal(sreq->sr_host->transportt);
644         struct scsi_device *sdev = sreq->sr_device;
645         int len = sdev->inquiry_len;
646         /* first set us up for narrow async */
647         DV_SET(offset, 0);
648         DV_SET(width, 0);
649         
650         if (spi_dv_device_compare_inquiry(sreq, buffer, buffer, DV_LOOPS)
651             != SPI_COMPARE_SUCCESS) {
652                 SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Domain Validation Initial Inquiry Failed\n");
653                 /* FIXME: should probably offline the device here? */
654                 return;
655         }
656
657         /* test width */
658         if (i->f->set_width && sdev->wdtr) {
659                 i->f->set_width(sdev->sdev_target, 1);
660
661                 if (spi_dv_device_compare_inquiry(sreq, buffer,
662                                                    buffer + len,
663                                                    DV_LOOPS)
664                     != SPI_COMPARE_SUCCESS) {
665                         SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Wide Transfers Fail\n");
666                         i->f->set_width(sdev->sdev_target, 0);
667                 }
668         }
669
670         if (!i->f->set_period)
671                 return;
672
673         /* device can't handle synchronous */
674         if(!sdev->ppr && !sdev->sdtr)
675                 return;
676
677         /* see if the device has an echo buffer.  If it does we can
678          * do the SPI pattern write tests */
679
680         len = 0;
681         if (sdev->ppr)
682                 len = spi_dv_device_get_echo_buffer(sreq, buffer);
683
684  retry:
685
686         /* now set up to the maximum */
687         DV_SET(offset, 255);
688         DV_SET(period, 1);
689
690         if (len == 0) {
691                 SPI_PRINTK(sdev->sdev_target, KERN_INFO, "Domain Validation skipping write tests\n");
692                 spi_dv_retrain(sreq, buffer, buffer + len,
693                                spi_dv_device_compare_inquiry);
694                 return;
695         }
696
697         if (len > SPI_MAX_ECHO_BUFFER_SIZE) {
698                 SPI_PRINTK(sdev->sdev_target, KERN_WARNING, "Echo buffer size %d is too big, trimming to %d\n", len, SPI_MAX_ECHO_BUFFER_SIZE);
699                 len = SPI_MAX_ECHO_BUFFER_SIZE;
700         }
701
702         if (spi_dv_retrain(sreq, buffer, buffer + len,
703                            spi_dv_device_echo_buffer)
704             == SPI_COMPARE_SKIP_TEST) {
705                 /* OK, the stupid drive can't do a write echo buffer
706                  * test after all, fall back to the read tests */
707                 len = 0;
708                 goto retry;
709         }
710 }
711
712
713 /**     spi_dv_device - Do Domain Validation on the device
714  *      @sdev:          scsi device to validate
715  *
716  *      Performs the domain validation on the given device in the
717  *      current execution thread.  Since DV operations may sleep,
718  *      the current thread must have user context.  Also no SCSI
719  *      related locks that would deadlock I/O issued by the DV may
720  *      be held.
721  */
722 void
723 spi_dv_device(struct scsi_device *sdev)
724 {
725         struct scsi_request *sreq = scsi_allocate_request(sdev, GFP_KERNEL);
726         struct scsi_target *starget = sdev->sdev_target;
727         u8 *buffer;
728         const int len = SPI_MAX_ECHO_BUFFER_SIZE*2;
729
730         if (unlikely(!sreq))
731                 return;
732
733         if (unlikely(scsi_device_get(sdev)))
734                 goto out_free_req;
735
736         buffer = kmalloc(len, GFP_KERNEL);
737
738         if (unlikely(!buffer))
739                 goto out_put;
740
741         memset(buffer, 0, len);
742
743         /* We need to verify that the actual device will quiesce; the
744          * later target quiesce is just a nice to have */
745         if (unlikely(scsi_device_quiesce(sdev)))
746                 goto out_free;
747
748         scsi_target_quiesce(starget);
749
750         spi_dv_pending(starget) = 1;
751         down(&spi_dv_sem(starget));
752
753         SPI_PRINTK(starget, KERN_INFO, "Beginning Domain Validation\n");
754
755         spi_dv_device_internal(sreq, buffer);
756
757         SPI_PRINTK(starget, KERN_INFO, "Ending Domain Validation\n");
758
759         up(&spi_dv_sem(starget));
760         spi_dv_pending(starget) = 0;
761
762         scsi_target_resume(starget);
763
764         spi_initial_dv(starget) = 1;
765
766  out_free:
767         kfree(buffer);
768  out_put:
769         scsi_device_put(sdev);
770  out_free_req:
771         scsi_release_request(sreq);
772 }
773 EXPORT_SYMBOL(spi_dv_device);
774
775 struct work_queue_wrapper {
776         struct work_struct      work;
777         struct scsi_device      *sdev;
778 };
779
780 static void
781 spi_dv_device_work_wrapper(void *data)
782 {
783         struct work_queue_wrapper *wqw = (struct work_queue_wrapper *)data;
784         struct scsi_device *sdev = wqw->sdev;
785
786         kfree(wqw);
787         spi_dv_device(sdev);
788         spi_dv_pending(sdev->sdev_target) = 0;
789         scsi_device_put(sdev);
790 }
791
792
793 /**
794  *      spi_schedule_dv_device - schedule domain validation to occur on the device
795  *      @sdev:  The device to validate
796  *
797  *      Identical to spi_dv_device() above, except that the DV will be
798  *      scheduled to occur in a workqueue later.  All memory allocations
799  *      are atomic, so may be called from any context including those holding
800  *      SCSI locks.
801  */
802 void
803 spi_schedule_dv_device(struct scsi_device *sdev)
804 {
805         struct work_queue_wrapper *wqw =
806                 kmalloc(sizeof(struct work_queue_wrapper), GFP_ATOMIC);
807
808         if (unlikely(!wqw))
809                 return;
810
811         if (unlikely(spi_dv_pending(sdev->sdev_target))) {
812                 kfree(wqw);
813                 return;
814         }
815         /* Set pending early (dv_device doesn't check it, only sets it) */
816         spi_dv_pending(sdev->sdev_target) = 1;
817         if (unlikely(scsi_device_get(sdev))) {
818                 kfree(wqw);
819                 spi_dv_pending(sdev->sdev_target) = 0;
820                 return;
821         }
822
823         INIT_WORK(&wqw->work, spi_dv_device_work_wrapper, wqw);
824         wqw->sdev = sdev;
825
826         schedule_work(&wqw->work);
827 }
828 EXPORT_SYMBOL(spi_schedule_dv_device);
829
830 /**
831  * spi_display_xfer_agreement - Print the current target transfer agreement
832  * @starget: The target for which to display the agreement
833  *
834  * Each SPI port is required to maintain a transfer agreement for each
835  * other port on the bus.  This function prints a one-line summary of
836  * the current agreement; more detailed information is available in sysfs.
837  */
838 void spi_display_xfer_agreement(struct scsi_target *starget)
839 {
840         struct spi_transport_attrs *tp;
841         tp = (struct spi_transport_attrs *)&starget->starget_data;
842
843         if (tp->offset > 0 && tp->period > 0) {
844                 unsigned int picosec, kb100;
845                 char *scsi = "FAST-?";
846                 char tmp[8];
847
848                 if (tp->period <= SPI_STATIC_PPR) {
849                         picosec = ppr_to_ps[tp->period];
850                         switch (tp->period) {
851                                 case  7: scsi = "FAST-320"; break;
852                                 case  8: scsi = "FAST-160"; break;
853                                 case  9: scsi = "FAST-80"; break;
854                                 case 10:
855                                 case 11: scsi = "FAST-40"; break;
856                                 case 12: scsi = "FAST-20"; break;
857                         }
858                 } else {
859                         picosec = tp->period * 4000;
860                         if (tp->period < 25)
861                                 scsi = "FAST-20";
862                         else if (tp->period < 50)
863                                 scsi = "FAST-10";
864                         else
865                                 scsi = "FAST-5";
866                 }
867
868                 kb100 = (10000000 + picosec / 2) / picosec;
869                 if (tp->width)
870                         kb100 *= 2;
871                 sprint_frac(tmp, picosec, 1000);
872
873                 dev_info(&starget->dev,
874                         "%s %sSCSI %d.%d MB/s %s%s%s (%s ns, offset %d)\n",
875                         scsi, tp->width ? "WIDE " : "", kb100/10, kb100 % 10,
876                         tp->dt ? "DT" : "ST", tp->iu ? " IU" : "",
877                         tp->qas  ? " QAS" : "", tmp, tp->offset);
878         } else {
879                 dev_info(&starget->dev, "%sasynchronous.\n",
880                                 tp->width ? "wide " : "");
881         }
882 }
883 EXPORT_SYMBOL(spi_display_xfer_agreement);
884
885 #define SETUP_ATTRIBUTE(field)                                          \
886         i->private_attrs[count] = class_device_attr_##field;            \
887         if (!i->f->set_##field) {                                       \
888                 i->private_attrs[count].attr.mode = S_IRUGO;            \
889                 i->private_attrs[count].store = NULL;                   \
890         }                                                               \
891         i->attrs[count] = &i->private_attrs[count];                     \
892         if (i->f->show_##field)                                         \
893                 count++
894
895 #define SETUP_HOST_ATTRIBUTE(field)                                     \
896         i->private_host_attrs[count] = class_device_attr_##field;       \
897         if (!i->f->set_##field) {                                       \
898                 i->private_host_attrs[count].attr.mode = S_IRUGO;       \
899                 i->private_host_attrs[count].store = NULL;              \
900         }                                                               \
901         i->host_attrs[count] = &i->private_host_attrs[count];           \
902         count++
903
904 static int spi_device_match(struct attribute_container *cont,
905                             struct device *dev)
906 {
907         struct scsi_device *sdev;
908         struct Scsi_Host *shost;
909
910         if (!scsi_is_sdev_device(dev))
911                 return 0;
912
913         sdev = to_scsi_device(dev);
914         shost = sdev->host;
915         if (!shost->transportt  || shost->transportt->host_attrs.ac.class
916             != &spi_host_class.class)
917                 return 0;
918         /* Note: this class has no device attributes, so it has
919          * no per-HBA allocation and thus we don't need to distinguish
920          * the attribute containers for the device */
921         return 1;
922 }
923
924 static int spi_target_match(struct attribute_container *cont,
925                             struct device *dev)
926 {
927         struct Scsi_Host *shost;
928         struct spi_internal *i;
929
930         if (!scsi_is_target_device(dev))
931                 return 0;
932
933         shost = dev_to_shost(dev->parent);
934         if (!shost->transportt  || shost->transportt->host_attrs.ac.class
935             != &spi_host_class.class)
936                 return 0;
937
938         i = to_spi_internal(shost->transportt);
939         
940         return &i->t.target_attrs.ac == cont;
941 }
942
943 static DECLARE_TRANSPORT_CLASS(spi_transport_class,
944                                "spi_transport",
945                                spi_setup_transport_attrs,
946                                NULL,
947                                NULL);
948
949 static DECLARE_ANON_TRANSPORT_CLASS(spi_device_class,
950                                     spi_device_match,
951                                     spi_device_configure);
952
953 struct scsi_transport_template *
954 spi_attach_transport(struct spi_function_template *ft)
955 {
956         struct spi_internal *i = kmalloc(sizeof(struct spi_internal),
957                                          GFP_KERNEL);
958         int count = 0;
959         if (unlikely(!i))
960                 return NULL;
961
962         memset(i, 0, sizeof(struct spi_internal));
963
964
965         i->t.target_attrs.ac.class = &spi_transport_class.class;
966         i->t.target_attrs.ac.attrs = &i->attrs[0];
967         i->t.target_attrs.ac.match = spi_target_match;
968         transport_container_register(&i->t.target_attrs);
969         i->t.target_size = sizeof(struct spi_transport_attrs);
970         i->t.host_attrs.ac.class = &spi_host_class.class;
971         i->t.host_attrs.ac.attrs = &i->host_attrs[0];
972         i->t.host_attrs.ac.match = spi_host_match;
973         transport_container_register(&i->t.host_attrs);
974         i->t.host_size = sizeof(struct spi_host_attrs);
975         i->f = ft;
976
977         SETUP_ATTRIBUTE(period);
978         SETUP_ATTRIBUTE(offset);
979         SETUP_ATTRIBUTE(width);
980         SETUP_ATTRIBUTE(iu);
981         SETUP_ATTRIBUTE(dt);
982         SETUP_ATTRIBUTE(qas);
983         SETUP_ATTRIBUTE(wr_flow);
984         SETUP_ATTRIBUTE(rd_strm);
985         SETUP_ATTRIBUTE(rti);
986         SETUP_ATTRIBUTE(pcomp_en);
987
988         /* if you add an attribute but forget to increase SPI_NUM_ATTRS
989          * this bug will trigger */
990         BUG_ON(count > SPI_NUM_ATTRS);
991
992         i->attrs[count++] = &class_device_attr_revalidate;
993
994         i->attrs[count] = NULL;
995
996         count = 0;
997         SETUP_HOST_ATTRIBUTE(signalling);
998
999         BUG_ON(count > SPI_HOST_ATTRS);
1000
1001         i->host_attrs[count] = NULL;
1002
1003         return &i->t;
1004 }
1005 EXPORT_SYMBOL(spi_attach_transport);
1006
1007 void spi_release_transport(struct scsi_transport_template *t)
1008 {
1009         struct spi_internal *i = to_spi_internal(t);
1010
1011         transport_container_unregister(&i->t.target_attrs);
1012         transport_container_unregister(&i->t.host_attrs);
1013
1014         kfree(i);
1015 }
1016 EXPORT_SYMBOL(spi_release_transport);
1017
1018 static __init int spi_transport_init(void)
1019 {
1020         int error = transport_class_register(&spi_transport_class);
1021         if (error)
1022                 return error;
1023         error = anon_transport_class_register(&spi_device_class);
1024         return transport_class_register(&spi_host_class);
1025 }
1026
1027 static void __exit spi_transport_exit(void)
1028 {
1029         transport_class_unregister(&spi_transport_class);
1030         anon_transport_class_unregister(&spi_device_class);
1031         transport_class_unregister(&spi_host_class);
1032 }
1033
1034 MODULE_AUTHOR("Martin Hicks");
1035 MODULE_DESCRIPTION("SPI Transport Attributes");
1036 MODULE_LICENSE("GPL");
1037
1038 module_init(spi_transport_init);
1039 module_exit(spi_transport_exit);