]> nv-tegra.nvidia Code Review - linux-2.6.git/blob - drivers/scsi/scsi_transport_spi.c
[SCSI] implement parameter limits in the SPI transport class
[linux-2.6.git] / drivers / scsi / scsi_transport_spi.c
1 /* 
2  *  Parallel SCSI (SPI) transport specific attributes exported to sysfs.
3  *
4  *  Copyright (c) 2003 Silicon Graphics, Inc.  All rights reserved.
5  *  Copyright (c) 2004, 2005 James Bottomley <James.Bottomley@SteelEye.com>
6  *
7  *  This program is free software; you can redistribute it and/or modify
8  *  it under the terms of the GNU General Public License as published by
9  *  the Free Software Foundation; either version 2 of the License, or
10  *  (at your option) any later version.
11  *
12  *  This program is distributed in the hope that it will be useful,
13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  *  GNU General Public License for more details.
16  *
17  *  You should have received a copy of the GNU General Public License
18  *  along with this program; if not, write to the Free Software
19  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
20  */
21 #include <linux/ctype.h>
22 #include <linux/init.h>
23 #include <linux/module.h>
24 #include <linux/workqueue.h>
25 #include <linux/blkdev.h>
26 #include <asm/semaphore.h>
27 #include <scsi/scsi.h>
28 #include "scsi_priv.h"
29 #include <scsi/scsi_device.h>
30 #include <scsi/scsi_host.h>
31 #include <scsi/scsi_request.h>
32 #include <scsi/scsi_eh.h>
33 #include <scsi/scsi_transport.h>
34 #include <scsi/scsi_transport_spi.h>
35
36 #define SPI_PRINTK(x, l, f, a...)       dev_printk(l, &(x)->dev, f , ##a)
37
38 #define SPI_NUM_ATTRS 13        /* increase this if you add attributes */
39 #define SPI_OTHER_ATTRS 1       /* Increase this if you add "always
40                                  * on" attributes */
41 #define SPI_HOST_ATTRS  1
42
43 #define SPI_MAX_ECHO_BUFFER_SIZE        4096
44
45 #define DV_LOOPS        3
46 #define DV_TIMEOUT      (10*HZ)
47 #define DV_RETRIES      3       /* should only need at most 
48                                  * two cc/ua clears */
49
50 /* Private data accessors (keep these out of the header file) */
51 #define spi_dv_pending(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_pending)
52 #define spi_dv_sem(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_sem)
53
54 struct spi_internal {
55         struct scsi_transport_template t;
56         struct spi_function_template *f;
57         /* The actual attributes */
58         struct class_device_attribute private_attrs[SPI_NUM_ATTRS];
59         /* The array of null terminated pointers to attributes 
60          * needed by scsi_sysfs.c */
61         struct class_device_attribute *attrs[SPI_NUM_ATTRS + SPI_OTHER_ATTRS + 1];
62         struct class_device_attribute private_host_attrs[SPI_HOST_ATTRS];
63         struct class_device_attribute *host_attrs[SPI_HOST_ATTRS + 1];
64 };
65
66 #define to_spi_internal(tmpl)   container_of(tmpl, struct spi_internal, t)
67
68 static const int ppr_to_ps[] = {
69         /* The PPR values 0-6 are reserved, fill them in when
70          * the committee defines them */
71         -1,                     /* 0x00 */
72         -1,                     /* 0x01 */
73         -1,                     /* 0x02 */
74         -1,                     /* 0x03 */
75         -1,                     /* 0x04 */
76         -1,                     /* 0x05 */
77         -1,                     /* 0x06 */
78          3125,                  /* 0x07 */
79          6250,                  /* 0x08 */
80         12500,                  /* 0x09 */
81         25000,                  /* 0x0a */
82         30300,                  /* 0x0b */
83         50000,                  /* 0x0c */
84 };
85 /* The PPR values at which you calculate the period in ns by multiplying
86  * by 4 */
87 #define SPI_STATIC_PPR  0x0c
88
89 static int sprint_frac(char *dest, int value, int denom)
90 {
91         int frac = value % denom;
92         int result = sprintf(dest, "%d", value / denom);
93
94         if (frac == 0)
95                 return result;
96         dest[result++] = '.';
97
98         do {
99                 denom /= 10;
100                 sprintf(dest + result, "%d", frac / denom);
101                 result++;
102                 frac %= denom;
103         } while (frac);
104
105         dest[result++] = '\0';
106         return result;
107 }
108
109 /* Modification of scsi_wait_req that will clear UNIT ATTENTION conditions
110  * resulting from (likely) bus and device resets */
111 static void spi_wait_req(struct scsi_request *sreq, const void *cmd,
112                          void *buffer, unsigned bufflen)
113 {
114         int i;
115
116         for(i = 0; i < DV_RETRIES; i++) {
117                 sreq->sr_request->flags |= REQ_FAILFAST;
118
119                 scsi_wait_req(sreq, cmd, buffer, bufflen,
120                               DV_TIMEOUT, /* retries */ 1);
121                 if (sreq->sr_result & DRIVER_SENSE) {
122                         struct scsi_sense_hdr sshdr;
123
124                         if (scsi_request_normalize_sense(sreq, &sshdr)
125                             && sshdr.sense_key == UNIT_ATTENTION)
126                                 continue;
127                 }
128                 break;
129         }
130 }
131
132 static struct {
133         enum spi_signal_type    value;
134         char                    *name;
135 } signal_types[] = {
136         { SPI_SIGNAL_UNKNOWN, "unknown" },
137         { SPI_SIGNAL_SE, "SE" },
138         { SPI_SIGNAL_LVD, "LVD" },
139         { SPI_SIGNAL_HVD, "HVD" },
140 };
141
142 static inline const char *spi_signal_to_string(enum spi_signal_type type)
143 {
144         int i;
145
146         for (i = 0; i < sizeof(signal_types)/sizeof(signal_types[0]); i++) {
147                 if (type == signal_types[i].value)
148                         return signal_types[i].name;
149         }
150         return NULL;
151 }
152 static inline enum spi_signal_type spi_signal_to_value(const char *name)
153 {
154         int i, len;
155
156         for (i = 0; i < sizeof(signal_types)/sizeof(signal_types[0]); i++) {
157                 len =  strlen(signal_types[i].name);
158                 if (strncmp(name, signal_types[i].name, len) == 0 &&
159                     (name[len] == '\n' || name[len] == '\0'))
160                         return signal_types[i].value;
161         }
162         return SPI_SIGNAL_UNKNOWN;
163 }
164
165 static int spi_host_setup(struct device *dev)
166 {
167         struct Scsi_Host *shost = dev_to_shost(dev);
168
169         spi_signalling(shost) = SPI_SIGNAL_UNKNOWN;
170
171         return 0;
172 }
173
174 static DECLARE_TRANSPORT_CLASS(spi_host_class,
175                                "spi_host",
176                                spi_host_setup,
177                                NULL,
178                                NULL);
179
180 static int spi_host_match(struct attribute_container *cont,
181                           struct device *dev)
182 {
183         struct Scsi_Host *shost;
184         struct spi_internal *i;
185
186         if (!scsi_is_host_device(dev))
187                 return 0;
188
189         shost = dev_to_shost(dev);
190         if (!shost->transportt  || shost->transportt->host_attrs.ac.class
191             != &spi_host_class.class)
192                 return 0;
193
194         i = to_spi_internal(shost->transportt);
195         
196         return &i->t.host_attrs.ac == cont;
197 }
198
199 static int spi_device_configure(struct device *dev)
200 {
201         struct scsi_device *sdev = to_scsi_device(dev);
202         struct scsi_target *starget = sdev->sdev_target;
203
204         /* Populate the target capability fields with the values
205          * gleaned from the device inquiry */
206
207         spi_support_sync(starget) = scsi_device_sync(sdev);
208         spi_support_wide(starget) = scsi_device_wide(sdev);
209         spi_support_dt(starget) = scsi_device_dt(sdev);
210         spi_support_dt_only(starget) = scsi_device_dt_only(sdev);
211         spi_support_ius(starget) = scsi_device_ius(sdev);
212         spi_support_qas(starget) = scsi_device_qas(sdev);
213
214         return 0;
215 }
216
217 static int spi_setup_transport_attrs(struct device *dev)
218 {
219         struct scsi_target *starget = to_scsi_target(dev);
220
221         spi_period(starget) = -1;       /* illegal value */
222         spi_min_period(starget) = 0;
223         spi_offset(starget) = 0;        /* async */
224         spi_max_offset(starget) = 255;
225         spi_width(starget) = 0; /* narrow */
226         spi_max_width(starget) = 1;
227         spi_iu(starget) = 0;    /* no IU */
228         spi_dt(starget) = 0;    /* ST */
229         spi_qas(starget) = 0;
230         spi_wr_flow(starget) = 0;
231         spi_rd_strm(starget) = 0;
232         spi_rti(starget) = 0;
233         spi_pcomp_en(starget) = 0;
234         spi_dv_pending(starget) = 0;
235         spi_initial_dv(starget) = 0;
236         init_MUTEX(&spi_dv_sem(starget));
237
238         return 0;
239 }
240
241 #define spi_transport_show_simple(field, format_string)                 \
242                                                                         \
243 static ssize_t                                                          \
244 show_spi_transport_##field(struct class_device *cdev, char *buf)        \
245 {                                                                       \
246         struct scsi_target *starget = transport_class_to_starget(cdev); \
247         struct spi_transport_attrs *tp;                                 \
248                                                                         \
249         tp = (struct spi_transport_attrs *)&starget->starget_data;      \
250         return snprintf(buf, 20, format_string, tp->field);             \
251 }
252
253 #define spi_transport_store_simple(field, format_string)                \
254                                                                         \
255 static ssize_t                                                          \
256 store_spi_transport_##field(struct class_device *cdev, const char *buf, \
257                             size_t count)                               \
258 {                                                                       \
259         int val;                                                        \
260         struct scsi_target *starget = transport_class_to_starget(cdev); \
261         struct spi_transport_attrs *tp;                                 \
262                                                                         \
263         tp = (struct spi_transport_attrs *)&starget->starget_data;      \
264         val = simple_strtoul(buf, NULL, 0);                             \
265         tp->field = val;                                                \
266         return count;                                                   \
267 }
268
269 #define spi_transport_show_function(field, format_string)               \
270                                                                         \
271 static ssize_t                                                          \
272 show_spi_transport_##field(struct class_device *cdev, char *buf)        \
273 {                                                                       \
274         struct scsi_target *starget = transport_class_to_starget(cdev); \
275         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);    \
276         struct spi_transport_attrs *tp;                                 \
277         struct spi_internal *i = to_spi_internal(shost->transportt);    \
278         tp = (struct spi_transport_attrs *)&starget->starget_data;      \
279         if (i->f->get_##field)                                          \
280                 i->f->get_##field(starget);                             \
281         return snprintf(buf, 20, format_string, tp->field);             \
282 }
283
284 #define spi_transport_store_function(field, format_string)              \
285 static ssize_t                                                          \
286 store_spi_transport_##field(struct class_device *cdev, const char *buf, \
287                             size_t count)                               \
288 {                                                                       \
289         int val;                                                        \
290         struct scsi_target *starget = transport_class_to_starget(cdev); \
291         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);    \
292         struct spi_internal *i = to_spi_internal(shost->transportt);    \
293                                                                         \
294         val = simple_strtoul(buf, NULL, 0);                             \
295         i->f->set_##field(starget, val);                        \
296         return count;                                                   \
297 }
298
299 #define spi_transport_store_max(field, format_string)                   \
300 static ssize_t                                                          \
301 store_spi_transport_##field(struct class_device *cdev, const char *buf, \
302                             size_t count)                               \
303 {                                                                       \
304         int val;                                                        \
305         struct scsi_target *starget = transport_class_to_starget(cdev); \
306         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);    \
307         struct spi_internal *i = to_spi_internal(shost->transportt);    \
308         struct spi_transport_attrs *tp                                  \
309                 = (struct spi_transport_attrs *)&starget->starget_data; \
310                                                                         \
311         val = simple_strtoul(buf, NULL, 0);                             \
312         if (val > tp->max_##field)                                      \
313                 val = tp->max_##field;                                  \
314         i->f->set_##field(starget, val);                                \
315         return count;                                                   \
316 }
317
318 #define spi_transport_rd_attr(field, format_string)                     \
319         spi_transport_show_function(field, format_string)               \
320         spi_transport_store_function(field, format_string)              \
321 static CLASS_DEVICE_ATTR(field, S_IRUGO | S_IWUSR,                      \
322                          show_spi_transport_##field,                    \
323                          store_spi_transport_##field);
324
325 #define spi_transport_simple_attr(field, format_string)                 \
326         spi_transport_show_simple(field, format_string)                 \
327         spi_transport_store_simple(field, format_string)                \
328 static CLASS_DEVICE_ATTR(field, S_IRUGO | S_IWUSR,                      \
329                          show_spi_transport_##field,                    \
330                          store_spi_transport_##field);
331
332 #define spi_transport_max_attr(field, format_string)                    \
333         spi_transport_show_function(field, format_string)               \
334         spi_transport_store_max(field, format_string)                   \
335         spi_transport_simple_attr(max_##field, format_string)           \
336 static CLASS_DEVICE_ATTR(field, S_IRUGO | S_IWUSR,                      \
337                          show_spi_transport_##field,                    \
338                          store_spi_transport_##field);
339
340 /* The Parallel SCSI Tranport Attributes: */
341 spi_transport_max_attr(offset, "%d\n");
342 spi_transport_max_attr(width, "%d\n");
343 spi_transport_rd_attr(iu, "%d\n");
344 spi_transport_rd_attr(dt, "%d\n");
345 spi_transport_rd_attr(qas, "%d\n");
346 spi_transport_rd_attr(wr_flow, "%d\n");
347 spi_transport_rd_attr(rd_strm, "%d\n");
348 spi_transport_rd_attr(rti, "%d\n");
349 spi_transport_rd_attr(pcomp_en, "%d\n");
350
351 static ssize_t
352 store_spi_revalidate(struct class_device *cdev, const char *buf, size_t count)
353 {
354         struct scsi_target *starget = transport_class_to_starget(cdev);
355
356         /* FIXME: we're relying on an awful lot of device internals
357          * here.  We really need a function to get the first available
358          * child */
359         struct device *dev = container_of(starget->dev.children.next, struct device, node);
360         struct scsi_device *sdev = to_scsi_device(dev);
361         spi_dv_device(sdev);
362         return count;
363 }
364 static CLASS_DEVICE_ATTR(revalidate, S_IWUSR, NULL, store_spi_revalidate);
365
366 /* Translate the period into ns according to the current spec
367  * for SDTR/PPR messages */
368 static ssize_t
369 show_spi_transport_period_helper(struct class_device *cdev, char *buf,
370                                  int period)
371 {
372         int len, picosec;
373
374         if (period < 0 || period > 0xff) {
375                 picosec = -1;
376         } else if (period <= SPI_STATIC_PPR) {
377                 picosec = ppr_to_ps[period];
378         } else {
379                 picosec = period * 4000;
380         }
381
382         if (picosec == -1) {
383                 len = sprintf(buf, "reserved");
384         } else {
385                 len = sprint_frac(buf, picosec, 1000);
386         }
387
388         buf[len++] = '\n';
389         buf[len] = '\0';
390         return len;
391 }
392
393 static ssize_t
394 store_spi_transport_period_helper(struct class_device *cdev, const char *buf,
395                                   size_t count, int *periodp)
396 {
397         int j, picosec, period = -1;
398         char *endp;
399
400         picosec = simple_strtoul(buf, &endp, 10) * 1000;
401         if (*endp == '.') {
402                 int mult = 100;
403                 do {
404                         endp++;
405                         if (!isdigit(*endp))
406                                 break;
407                         picosec += (*endp - '0') * mult;
408                         mult /= 10;
409                 } while (mult > 0);
410         }
411
412         for (j = 0; j <= SPI_STATIC_PPR; j++) {
413                 if (ppr_to_ps[j] < picosec)
414                         continue;
415                 period = j;
416                 break;
417         }
418
419         if (period == -1)
420                 period = picosec / 4000;
421
422         if (period > 0xff)
423                 period = 0xff;
424
425         *periodp = period;
426
427         return count;
428 }
429
430 static ssize_t
431 show_spi_transport_period(struct class_device *cdev, char *buf)
432 {
433         struct scsi_target *starget = transport_class_to_starget(cdev);
434         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
435         struct spi_internal *i = to_spi_internal(shost->transportt);
436         struct spi_transport_attrs *tp =
437                 (struct spi_transport_attrs *)&starget->starget_data;
438
439         if (i->f->get_period)
440                 i->f->get_period(starget);
441
442         return show_spi_transport_period_helper(cdev, buf, tp->period);
443 }
444
445 static ssize_t
446 store_spi_transport_period(struct class_device *cdev, const char *buf,
447                             size_t count)
448 {
449         struct scsi_target *starget = transport_class_to_starget(cdev);
450         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
451         struct spi_internal *i = to_spi_internal(shost->transportt);
452         struct spi_transport_attrs *tp =
453                 (struct spi_transport_attrs *)&starget->starget_data;
454         int period, retval;
455
456         retval = store_spi_transport_period_helper(cdev, buf, count, &period);
457
458         if (period < tp->min_period)
459                 period = tp->min_period;
460
461         i->f->set_period(starget, period);
462
463         return retval;
464 }
465
466 static CLASS_DEVICE_ATTR(period, S_IRUGO | S_IWUSR, 
467                          show_spi_transport_period,
468                          store_spi_transport_period);
469
470 static ssize_t
471 show_spi_transport_min_period(struct class_device *cdev, char *buf)
472 {
473         struct scsi_target *starget = transport_class_to_starget(cdev);
474         struct spi_transport_attrs *tp =
475                 (struct spi_transport_attrs *)&starget->starget_data;
476
477         return show_spi_transport_period_helper(cdev, buf, tp->min_period);
478 }
479
480 static ssize_t
481 store_spi_transport_min_period(struct class_device *cdev, const char *buf,
482                             size_t count)
483 {
484         struct scsi_target *starget = transport_class_to_starget(cdev);
485         struct spi_transport_attrs *tp =
486                 (struct spi_transport_attrs *)&starget->starget_data;
487
488         return store_spi_transport_period_helper(cdev, buf, count,
489                                                  &tp->min_period);
490 }
491
492
493 static CLASS_DEVICE_ATTR(min_period, S_IRUGO | S_IWUSR, 
494                          show_spi_transport_min_period,
495                          store_spi_transport_min_period);
496
497
498 static ssize_t show_spi_host_signalling(struct class_device *cdev, char *buf)
499 {
500         struct Scsi_Host *shost = transport_class_to_shost(cdev);
501         struct spi_internal *i = to_spi_internal(shost->transportt);
502
503         if (i->f->get_signalling)
504                 i->f->get_signalling(shost);
505
506         return sprintf(buf, "%s\n", spi_signal_to_string(spi_signalling(shost)));
507 }
508 static ssize_t store_spi_host_signalling(struct class_device *cdev,
509                                          const char *buf, size_t count)
510 {
511         struct Scsi_Host *shost = transport_class_to_shost(cdev);
512         struct spi_internal *i = to_spi_internal(shost->transportt);
513         enum spi_signal_type type = spi_signal_to_value(buf);
514
515         if (type != SPI_SIGNAL_UNKNOWN)
516                 i->f->set_signalling(shost, type);
517
518         return count;
519 }
520 static CLASS_DEVICE_ATTR(signalling, S_IRUGO | S_IWUSR,
521                          show_spi_host_signalling,
522                          store_spi_host_signalling);
523
524 #define DV_SET(x, y)                    \
525         if(i->f->set_##x)               \
526                 i->f->set_##x(sdev->sdev_target, y)
527
528 enum spi_compare_returns {
529         SPI_COMPARE_SUCCESS,
530         SPI_COMPARE_FAILURE,
531         SPI_COMPARE_SKIP_TEST,
532 };
533
534
535 /* This is for read/write Domain Validation:  If the device supports
536  * an echo buffer, we do read/write tests to it */
537 static enum spi_compare_returns
538 spi_dv_device_echo_buffer(struct scsi_request *sreq, u8 *buffer,
539                           u8 *ptr, const int retries)
540 {
541         struct scsi_device *sdev = sreq->sr_device;
542         int len = ptr - buffer;
543         int j, k, r;
544         unsigned int pattern = 0x0000ffff;
545
546         const char spi_write_buffer[] = {
547                 WRITE_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
548         };
549         const char spi_read_buffer[] = {
550                 READ_BUFFER, 0x0a, 0, 0, 0, 0, 0, len >> 8, len & 0xff, 0
551         };
552
553         /* set up the pattern buffer.  Doesn't matter if we spill
554          * slightly beyond since that's where the read buffer is */
555         for (j = 0; j < len; ) {
556
557                 /* fill the buffer with counting (test a) */
558                 for ( ; j < min(len, 32); j++)
559                         buffer[j] = j;
560                 k = j;
561                 /* fill the buffer with alternating words of 0x0 and
562                  * 0xffff (test b) */
563                 for ( ; j < min(len, k + 32); j += 2) {
564                         u16 *word = (u16 *)&buffer[j];
565                         
566                         *word = (j & 0x02) ? 0x0000 : 0xffff;
567                 }
568                 k = j;
569                 /* fill with crosstalk (alternating 0x5555 0xaaa)
570                  * (test c) */
571                 for ( ; j < min(len, k + 32); j += 2) {
572                         u16 *word = (u16 *)&buffer[j];
573
574                         *word = (j & 0x02) ? 0x5555 : 0xaaaa;
575                 }
576                 k = j;
577                 /* fill with shifting bits (test d) */
578                 for ( ; j < min(len, k + 32); j += 4) {
579                         u32 *word = (unsigned int *)&buffer[j];
580                         u32 roll = (pattern & 0x80000000) ? 1 : 0;
581                         
582                         *word = pattern;
583                         pattern = (pattern << 1) | roll;
584                 }
585                 /* don't bother with random data (test e) */
586         }
587
588         for (r = 0; r < retries; r++) {
589                 sreq->sr_cmd_len = 0;   /* wait_req to fill in */
590                 sreq->sr_data_direction = DMA_TO_DEVICE;
591                 spi_wait_req(sreq, spi_write_buffer, buffer, len);
592                 if(sreq->sr_result || !scsi_device_online(sdev)) {
593                         struct scsi_sense_hdr sshdr;
594
595                         scsi_device_set_state(sdev, SDEV_QUIESCE);
596                         if (scsi_request_normalize_sense(sreq, &sshdr)
597                             && sshdr.sense_key == ILLEGAL_REQUEST
598                             /* INVALID FIELD IN CDB */
599                             && sshdr.asc == 0x24 && sshdr.ascq == 0x00)
600                                 /* This would mean that the drive lied
601                                  * to us about supporting an echo
602                                  * buffer (unfortunately some Western
603                                  * Digital drives do precisely this)
604                                  */
605                                 return SPI_COMPARE_SKIP_TEST;
606
607
608                         SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Write Buffer failure %x\n", sreq->sr_result);
609                         return SPI_COMPARE_FAILURE;
610                 }
611
612                 memset(ptr, 0, len);
613                 sreq->sr_cmd_len = 0;   /* wait_req to fill in */
614                 sreq->sr_data_direction = DMA_FROM_DEVICE;
615                 spi_wait_req(sreq, spi_read_buffer, ptr, len);
616                 scsi_device_set_state(sdev, SDEV_QUIESCE);
617
618                 if (memcmp(buffer, ptr, len) != 0)
619                         return SPI_COMPARE_FAILURE;
620         }
621         return SPI_COMPARE_SUCCESS;
622 }
623
624 /* This is for the simplest form of Domain Validation: a read test
625  * on the inquiry data from the device */
626 static enum spi_compare_returns
627 spi_dv_device_compare_inquiry(struct scsi_request *sreq, u8 *buffer,
628                               u8 *ptr, const int retries)
629 {
630         int r;
631         const int len = sreq->sr_device->inquiry_len;
632         struct scsi_device *sdev = sreq->sr_device;
633         const char spi_inquiry[] = {
634                 INQUIRY, 0, 0, 0, len, 0
635         };
636
637         for (r = 0; r < retries; r++) {
638                 sreq->sr_cmd_len = 0;   /* wait_req to fill in */
639                 sreq->sr_data_direction = DMA_FROM_DEVICE;
640
641                 memset(ptr, 0, len);
642
643                 spi_wait_req(sreq, spi_inquiry, ptr, len);
644                 
645                 if(sreq->sr_result || !scsi_device_online(sdev)) {
646                         scsi_device_set_state(sdev, SDEV_QUIESCE);
647                         return SPI_COMPARE_FAILURE;
648                 }
649
650                 /* If we don't have the inquiry data already, the
651                  * first read gets it */
652                 if (ptr == buffer) {
653                         ptr += len;
654                         --r;
655                         continue;
656                 }
657
658                 if (memcmp(buffer, ptr, len) != 0)
659                         /* failure */
660                         return SPI_COMPARE_FAILURE;
661         }
662         return SPI_COMPARE_SUCCESS;
663 }
664
665 static enum spi_compare_returns
666 spi_dv_retrain(struct scsi_request *sreq, u8 *buffer, u8 *ptr,
667                enum spi_compare_returns 
668                (*compare_fn)(struct scsi_request *, u8 *, u8 *, int))
669 {
670         struct spi_internal *i = to_spi_internal(sreq->sr_host->transportt);
671         struct scsi_device *sdev = sreq->sr_device;
672         int period = 0, prevperiod = 0; 
673         enum spi_compare_returns retval;
674
675
676         for (;;) {
677                 int newperiod;
678                 retval = compare_fn(sreq, buffer, ptr, DV_LOOPS);
679
680                 if (retval == SPI_COMPARE_SUCCESS
681                     || retval == SPI_COMPARE_SKIP_TEST)
682                         break;
683
684                 /* OK, retrain, fallback */
685                 if (i->f->get_period)
686                         i->f->get_period(sdev->sdev_target);
687                 newperiod = spi_period(sdev->sdev_target);
688                 period = newperiod > period ? newperiod : period;
689                 if (period < 0x0d)
690                         period++;
691                 else
692                         period += period >> 1;
693
694                 if (unlikely(period > 0xff || period == prevperiod)) {
695                         /* Total failure; set to async and return */
696                         SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Domain Validation Failure, dropping back to Asynchronous\n");
697                         DV_SET(offset, 0);
698                         return SPI_COMPARE_FAILURE;
699                 }
700                 SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Domain Validation detected failure, dropping back\n");
701                 DV_SET(period, period);
702                 prevperiod = period;
703         }
704         return retval;
705 }
706
707 static int
708 spi_dv_device_get_echo_buffer(struct scsi_request *sreq, u8 *buffer)
709 {
710         int l;
711
712         /* first off do a test unit ready.  This can error out 
713          * because of reservations or some other reason.  If it
714          * fails, the device won't let us write to the echo buffer
715          * so just return failure */
716         
717         const char spi_test_unit_ready[] = {
718                 TEST_UNIT_READY, 0, 0, 0, 0, 0
719         };
720
721         const char spi_read_buffer_descriptor[] = {
722                 READ_BUFFER, 0x0b, 0, 0, 0, 0, 0, 0, 4, 0
723         };
724
725         
726         sreq->sr_cmd_len = 0;
727         sreq->sr_data_direction = DMA_NONE;
728
729         /* We send a set of three TURs to clear any outstanding 
730          * unit attention conditions if they exist (Otherwise the
731          * buffer tests won't be happy).  If the TUR still fails
732          * (reservation conflict, device not ready, etc) just
733          * skip the write tests */
734         for (l = 0; ; l++) {
735                 spi_wait_req(sreq, spi_test_unit_ready, NULL, 0);
736
737                 if(sreq->sr_result) {
738                         if(l >= 3)
739                                 return 0;
740                 } else {
741                         /* TUR succeeded */
742                         break;
743                 }
744         }
745
746         sreq->sr_cmd_len = 0;
747         sreq->sr_data_direction = DMA_FROM_DEVICE;
748
749         spi_wait_req(sreq, spi_read_buffer_descriptor, buffer, 4);
750
751         if (sreq->sr_result)
752                 /* Device has no echo buffer */
753                 return 0;
754
755         return buffer[3] + ((buffer[2] & 0x1f) << 8);
756 }
757
758 static void
759 spi_dv_device_internal(struct scsi_request *sreq, u8 *buffer)
760 {
761         struct spi_internal *i = to_spi_internal(sreq->sr_host->transportt);
762         struct scsi_device *sdev = sreq->sr_device;
763         struct scsi_target *starget = sdev->sdev_target;
764         int len = sdev->inquiry_len;
765         /* first set us up for narrow async */
766         DV_SET(offset, 0);
767         DV_SET(width, 0);
768         
769         if (spi_dv_device_compare_inquiry(sreq, buffer, buffer, DV_LOOPS)
770             != SPI_COMPARE_SUCCESS) {
771                 SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Domain Validation Initial Inquiry Failed\n");
772                 /* FIXME: should probably offline the device here? */
773                 return;
774         }
775
776         /* test width */
777         if (i->f->set_width && spi_max_width(starget) && sdev->wdtr) {
778                 i->f->set_width(sdev->sdev_target, 1);
779
780                 printk("WIDTH IS %d\n", spi_max_width(starget));
781
782                 if (spi_dv_device_compare_inquiry(sreq, buffer,
783                                                    buffer + len,
784                                                    DV_LOOPS)
785                     != SPI_COMPARE_SUCCESS) {
786                         SPI_PRINTK(sdev->sdev_target, KERN_ERR, "Wide Transfers Fail\n");
787                         i->f->set_width(sdev->sdev_target, 0);
788                 }
789         }
790
791         if (!i->f->set_period)
792                 return;
793
794         /* device can't handle synchronous */
795         if(!sdev->ppr && !sdev->sdtr)
796                 return;
797
798         /* see if the device has an echo buffer.  If it does we can
799          * do the SPI pattern write tests */
800
801         len = 0;
802         if (sdev->ppr)
803                 len = spi_dv_device_get_echo_buffer(sreq, buffer);
804
805  retry:
806
807         /* now set up to the maximum */
808         DV_SET(offset, spi_max_offset(starget));
809         DV_SET(period, spi_min_period(starget));
810
811         if (len == 0) {
812                 SPI_PRINTK(sdev->sdev_target, KERN_INFO, "Domain Validation skipping write tests\n");
813                 spi_dv_retrain(sreq, buffer, buffer + len,
814                                spi_dv_device_compare_inquiry);
815                 return;
816         }
817
818         if (len > SPI_MAX_ECHO_BUFFER_SIZE) {
819                 SPI_PRINTK(sdev->sdev_target, KERN_WARNING, "Echo buffer size %d is too big, trimming to %d\n", len, SPI_MAX_ECHO_BUFFER_SIZE);
820                 len = SPI_MAX_ECHO_BUFFER_SIZE;
821         }
822
823         if (spi_dv_retrain(sreq, buffer, buffer + len,
824                            spi_dv_device_echo_buffer)
825             == SPI_COMPARE_SKIP_TEST) {
826                 /* OK, the stupid drive can't do a write echo buffer
827                  * test after all, fall back to the read tests */
828                 len = 0;
829                 goto retry;
830         }
831 }
832
833
834 /**     spi_dv_device - Do Domain Validation on the device
835  *      @sdev:          scsi device to validate
836  *
837  *      Performs the domain validation on the given device in the
838  *      current execution thread.  Since DV operations may sleep,
839  *      the current thread must have user context.  Also no SCSI
840  *      related locks that would deadlock I/O issued by the DV may
841  *      be held.
842  */
843 void
844 spi_dv_device(struct scsi_device *sdev)
845 {
846         struct scsi_request *sreq = scsi_allocate_request(sdev, GFP_KERNEL);
847         struct scsi_target *starget = sdev->sdev_target;
848         u8 *buffer;
849         const int len = SPI_MAX_ECHO_BUFFER_SIZE*2;
850
851         if (unlikely(!sreq))
852                 return;
853
854         if (unlikely(scsi_device_get(sdev)))
855                 goto out_free_req;
856
857         buffer = kmalloc(len, GFP_KERNEL);
858
859         if (unlikely(!buffer))
860                 goto out_put;
861
862         memset(buffer, 0, len);
863
864         /* We need to verify that the actual device will quiesce; the
865          * later target quiesce is just a nice to have */
866         if (unlikely(scsi_device_quiesce(sdev)))
867                 goto out_free;
868
869         scsi_target_quiesce(starget);
870
871         spi_dv_pending(starget) = 1;
872         down(&spi_dv_sem(starget));
873
874         SPI_PRINTK(starget, KERN_INFO, "Beginning Domain Validation\n");
875
876         spi_dv_device_internal(sreq, buffer);
877
878         SPI_PRINTK(starget, KERN_INFO, "Ending Domain Validation\n");
879
880         up(&spi_dv_sem(starget));
881         spi_dv_pending(starget) = 0;
882
883         scsi_target_resume(starget);
884
885         spi_initial_dv(starget) = 1;
886
887  out_free:
888         kfree(buffer);
889  out_put:
890         scsi_device_put(sdev);
891  out_free_req:
892         scsi_release_request(sreq);
893 }
894 EXPORT_SYMBOL(spi_dv_device);
895
896 struct work_queue_wrapper {
897         struct work_struct      work;
898         struct scsi_device      *sdev;
899 };
900
901 static void
902 spi_dv_device_work_wrapper(void *data)
903 {
904         struct work_queue_wrapper *wqw = (struct work_queue_wrapper *)data;
905         struct scsi_device *sdev = wqw->sdev;
906
907         kfree(wqw);
908         spi_dv_device(sdev);
909         spi_dv_pending(sdev->sdev_target) = 0;
910         scsi_device_put(sdev);
911 }
912
913
914 /**
915  *      spi_schedule_dv_device - schedule domain validation to occur on the device
916  *      @sdev:  The device to validate
917  *
918  *      Identical to spi_dv_device() above, except that the DV will be
919  *      scheduled to occur in a workqueue later.  All memory allocations
920  *      are atomic, so may be called from any context including those holding
921  *      SCSI locks.
922  */
923 void
924 spi_schedule_dv_device(struct scsi_device *sdev)
925 {
926         struct work_queue_wrapper *wqw =
927                 kmalloc(sizeof(struct work_queue_wrapper), GFP_ATOMIC);
928
929         if (unlikely(!wqw))
930                 return;
931
932         if (unlikely(spi_dv_pending(sdev->sdev_target))) {
933                 kfree(wqw);
934                 return;
935         }
936         /* Set pending early (dv_device doesn't check it, only sets it) */
937         spi_dv_pending(sdev->sdev_target) = 1;
938         if (unlikely(scsi_device_get(sdev))) {
939                 kfree(wqw);
940                 spi_dv_pending(sdev->sdev_target) = 0;
941                 return;
942         }
943
944         INIT_WORK(&wqw->work, spi_dv_device_work_wrapper, wqw);
945         wqw->sdev = sdev;
946
947         schedule_work(&wqw->work);
948 }
949 EXPORT_SYMBOL(spi_schedule_dv_device);
950
951 /**
952  * spi_display_xfer_agreement - Print the current target transfer agreement
953  * @starget: The target for which to display the agreement
954  *
955  * Each SPI port is required to maintain a transfer agreement for each
956  * other port on the bus.  This function prints a one-line summary of
957  * the current agreement; more detailed information is available in sysfs.
958  */
959 void spi_display_xfer_agreement(struct scsi_target *starget)
960 {
961         struct spi_transport_attrs *tp;
962         tp = (struct spi_transport_attrs *)&starget->starget_data;
963
964         if (tp->offset > 0 && tp->period > 0) {
965                 unsigned int picosec, kb100;
966                 char *scsi = "FAST-?";
967                 char tmp[8];
968
969                 if (tp->period <= SPI_STATIC_PPR) {
970                         picosec = ppr_to_ps[tp->period];
971                         switch (tp->period) {
972                                 case  7: scsi = "FAST-320"; break;
973                                 case  8: scsi = "FAST-160"; break;
974                                 case  9: scsi = "FAST-80"; break;
975                                 case 10:
976                                 case 11: scsi = "FAST-40"; break;
977                                 case 12: scsi = "FAST-20"; break;
978                         }
979                 } else {
980                         picosec = tp->period * 4000;
981                         if (tp->period < 25)
982                                 scsi = "FAST-20";
983                         else if (tp->period < 50)
984                                 scsi = "FAST-10";
985                         else
986                                 scsi = "FAST-5";
987                 }
988
989                 kb100 = (10000000 + picosec / 2) / picosec;
990                 if (tp->width)
991                         kb100 *= 2;
992                 sprint_frac(tmp, picosec, 1000);
993
994                 dev_info(&starget->dev,
995                         "%s %sSCSI %d.%d MB/s %s%s%s (%s ns, offset %d)\n",
996                         scsi, tp->width ? "WIDE " : "", kb100/10, kb100 % 10,
997                         tp->dt ? "DT" : "ST", tp->iu ? " IU" : "",
998                         tp->qas  ? " QAS" : "", tmp, tp->offset);
999         } else {
1000                 dev_info(&starget->dev, "%sasynchronous.\n",
1001                                 tp->width ? "wide " : "");
1002         }
1003 }
1004 EXPORT_SYMBOL(spi_display_xfer_agreement);
1005
1006 #define SETUP_ATTRIBUTE(field)                                          \
1007         i->private_attrs[count] = class_device_attr_##field;            \
1008         if (!i->f->set_##field) {                                       \
1009                 i->private_attrs[count].attr.mode = S_IRUGO;            \
1010                 i->private_attrs[count].store = NULL;                   \
1011         }                                                               \
1012         i->attrs[count] = &i->private_attrs[count];                     \
1013         if (i->f->show_##field)                                         \
1014                 count++
1015
1016 #define SETUP_RELATED_ATTRIBUTE(field, rel_field)                       \
1017         i->private_attrs[count] = class_device_attr_##field;            \
1018         if (!i->f->set_##rel_field) {                                   \
1019                 i->private_attrs[count].attr.mode = S_IRUGO;            \
1020                 i->private_attrs[count].store = NULL;                   \
1021         }                                                               \
1022         i->attrs[count] = &i->private_attrs[count];                     \
1023         if (i->f->show_##rel_field)                                     \
1024                 count++
1025
1026 #define SETUP_HOST_ATTRIBUTE(field)                                     \
1027         i->private_host_attrs[count] = class_device_attr_##field;       \
1028         if (!i->f->set_##field) {                                       \
1029                 i->private_host_attrs[count].attr.mode = S_IRUGO;       \
1030                 i->private_host_attrs[count].store = NULL;              \
1031         }                                                               \
1032         i->host_attrs[count] = &i->private_host_attrs[count];           \
1033         count++
1034
1035 static int spi_device_match(struct attribute_container *cont,
1036                             struct device *dev)
1037 {
1038         struct scsi_device *sdev;
1039         struct Scsi_Host *shost;
1040
1041         if (!scsi_is_sdev_device(dev))
1042                 return 0;
1043
1044         sdev = to_scsi_device(dev);
1045         shost = sdev->host;
1046         if (!shost->transportt  || shost->transportt->host_attrs.ac.class
1047             != &spi_host_class.class)
1048                 return 0;
1049         /* Note: this class has no device attributes, so it has
1050          * no per-HBA allocation and thus we don't need to distinguish
1051          * the attribute containers for the device */
1052         return 1;
1053 }
1054
1055 static int spi_target_match(struct attribute_container *cont,
1056                             struct device *dev)
1057 {
1058         struct Scsi_Host *shost;
1059         struct spi_internal *i;
1060
1061         if (!scsi_is_target_device(dev))
1062                 return 0;
1063
1064         shost = dev_to_shost(dev->parent);
1065         if (!shost->transportt  || shost->transportt->host_attrs.ac.class
1066             != &spi_host_class.class)
1067                 return 0;
1068
1069         i = to_spi_internal(shost->transportt);
1070         
1071         return &i->t.target_attrs.ac == cont;
1072 }
1073
1074 static DECLARE_TRANSPORT_CLASS(spi_transport_class,
1075                                "spi_transport",
1076                                spi_setup_transport_attrs,
1077                                NULL,
1078                                NULL);
1079
1080 static DECLARE_ANON_TRANSPORT_CLASS(spi_device_class,
1081                                     spi_device_match,
1082                                     spi_device_configure);
1083
1084 struct scsi_transport_template *
1085 spi_attach_transport(struct spi_function_template *ft)
1086 {
1087         struct spi_internal *i = kmalloc(sizeof(struct spi_internal),
1088                                          GFP_KERNEL);
1089         int count = 0;
1090         if (unlikely(!i))
1091                 return NULL;
1092
1093         memset(i, 0, sizeof(struct spi_internal));
1094
1095
1096         i->t.target_attrs.ac.class = &spi_transport_class.class;
1097         i->t.target_attrs.ac.attrs = &i->attrs[0];
1098         i->t.target_attrs.ac.match = spi_target_match;
1099         transport_container_register(&i->t.target_attrs);
1100         i->t.target_size = sizeof(struct spi_transport_attrs);
1101         i->t.host_attrs.ac.class = &spi_host_class.class;
1102         i->t.host_attrs.ac.attrs = &i->host_attrs[0];
1103         i->t.host_attrs.ac.match = spi_host_match;
1104         transport_container_register(&i->t.host_attrs);
1105         i->t.host_size = sizeof(struct spi_host_attrs);
1106         i->f = ft;
1107
1108         SETUP_ATTRIBUTE(period);
1109         SETUP_RELATED_ATTRIBUTE(min_period, period);
1110         SETUP_ATTRIBUTE(offset);
1111         SETUP_RELATED_ATTRIBUTE(max_offset, offset);
1112         SETUP_ATTRIBUTE(width);
1113         SETUP_RELATED_ATTRIBUTE(max_width, width);
1114         SETUP_ATTRIBUTE(iu);
1115         SETUP_ATTRIBUTE(dt);
1116         SETUP_ATTRIBUTE(qas);
1117         SETUP_ATTRIBUTE(wr_flow);
1118         SETUP_ATTRIBUTE(rd_strm);
1119         SETUP_ATTRIBUTE(rti);
1120         SETUP_ATTRIBUTE(pcomp_en);
1121
1122         /* if you add an attribute but forget to increase SPI_NUM_ATTRS
1123          * this bug will trigger */
1124         BUG_ON(count > SPI_NUM_ATTRS);
1125
1126         i->attrs[count++] = &class_device_attr_revalidate;
1127
1128         i->attrs[count] = NULL;
1129
1130         count = 0;
1131         SETUP_HOST_ATTRIBUTE(signalling);
1132
1133         BUG_ON(count > SPI_HOST_ATTRS);
1134
1135         i->host_attrs[count] = NULL;
1136
1137         return &i->t;
1138 }
1139 EXPORT_SYMBOL(spi_attach_transport);
1140
1141 void spi_release_transport(struct scsi_transport_template *t)
1142 {
1143         struct spi_internal *i = to_spi_internal(t);
1144
1145         transport_container_unregister(&i->t.target_attrs);
1146         transport_container_unregister(&i->t.host_attrs);
1147
1148         kfree(i);
1149 }
1150 EXPORT_SYMBOL(spi_release_transport);
1151
1152 static __init int spi_transport_init(void)
1153 {
1154         int error = transport_class_register(&spi_transport_class);
1155         if (error)
1156                 return error;
1157         error = anon_transport_class_register(&spi_device_class);
1158         return transport_class_register(&spi_host_class);
1159 }
1160
1161 static void __exit spi_transport_exit(void)
1162 {
1163         transport_class_unregister(&spi_transport_class);
1164         anon_transport_class_unregister(&spi_device_class);
1165         transport_class_unregister(&spi_host_class);
1166 }
1167
1168 MODULE_AUTHOR("Martin Hicks");
1169 MODULE_DESCRIPTION("SPI Transport Attributes");
1170 MODULE_LICENSE("GPL");
1171
1172 module_init(spi_transport_init);
1173 module_exit(spi_transport_exit);