Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394...
[linux-2.6-block.git] / drivers / firewire / core-device.c
1 /*
2  * Device probing and sysfs code.
3  *
4  * Copyright (C) 2005-2006  Kristian Hoegsberg <krh@bitplanet.net>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software Foundation,
18  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19  */
20
21 #include <linux/ctype.h>
22 #include <linux/delay.h>
23 #include <linux/device.h>
24 #include <linux/errno.h>
25 #include <linux/firewire.h>
26 #include <linux/firewire-constants.h>
27 #include <linux/idr.h>
28 #include <linux/jiffies.h>
29 #include <linux/kobject.h>
30 #include <linux/list.h>
31 #include <linux/mod_devicetable.h>
32 #include <linux/module.h>
33 #include <linux/mutex.h>
34 #include <linux/rwsem.h>
35 #include <linux/semaphore.h>
36 #include <linux/spinlock.h>
37 #include <linux/string.h>
38 #include <linux/workqueue.h>
39
40 #include <asm/atomic.h>
41 #include <asm/byteorder.h>
42 #include <asm/system.h>
43
44 #include "core.h"
45
46 void fw_csr_iterator_init(struct fw_csr_iterator *ci, u32 * p)
47 {
48         ci->p = p + 1;
49         ci->end = ci->p + (p[0] >> 16);
50 }
51 EXPORT_SYMBOL(fw_csr_iterator_init);
52
53 int fw_csr_iterator_next(struct fw_csr_iterator *ci, int *key, int *value)
54 {
55         *key = *ci->p >> 24;
56         *value = *ci->p & 0xffffff;
57
58         return ci->p++ < ci->end;
59 }
60 EXPORT_SYMBOL(fw_csr_iterator_next);
61
62 static bool is_fw_unit(struct device *dev);
63
64 static int match_unit_directory(u32 *directory, u32 match_flags,
65                                 const struct ieee1394_device_id *id)
66 {
67         struct fw_csr_iterator ci;
68         int key, value, match;
69
70         match = 0;
71         fw_csr_iterator_init(&ci, directory);
72         while (fw_csr_iterator_next(&ci, &key, &value)) {
73                 if (key == CSR_VENDOR && value == id->vendor_id)
74                         match |= IEEE1394_MATCH_VENDOR_ID;
75                 if (key == CSR_MODEL && value == id->model_id)
76                         match |= IEEE1394_MATCH_MODEL_ID;
77                 if (key == CSR_SPECIFIER_ID && value == id->specifier_id)
78                         match |= IEEE1394_MATCH_SPECIFIER_ID;
79                 if (key == CSR_VERSION && value == id->version)
80                         match |= IEEE1394_MATCH_VERSION;
81         }
82
83         return (match & match_flags) == match_flags;
84 }
85
86 static int fw_unit_match(struct device *dev, struct device_driver *drv)
87 {
88         struct fw_unit *unit = fw_unit(dev);
89         struct fw_device *device;
90         const struct ieee1394_device_id *id;
91
92         /* We only allow binding to fw_units. */
93         if (!is_fw_unit(dev))
94                 return 0;
95
96         device = fw_parent_device(unit);
97         id = container_of(drv, struct fw_driver, driver)->id_table;
98
99         for (; id->match_flags != 0; id++) {
100                 if (match_unit_directory(unit->directory, id->match_flags, id))
101                         return 1;
102
103                 /* Also check vendor ID in the root directory. */
104                 if ((id->match_flags & IEEE1394_MATCH_VENDOR_ID) &&
105                     match_unit_directory(&device->config_rom[5],
106                                 IEEE1394_MATCH_VENDOR_ID, id) &&
107                     match_unit_directory(unit->directory, id->match_flags
108                                 & ~IEEE1394_MATCH_VENDOR_ID, id))
109                         return 1;
110         }
111
112         return 0;
113 }
114
115 static int get_modalias(struct fw_unit *unit, char *buffer, size_t buffer_size)
116 {
117         struct fw_device *device = fw_parent_device(unit);
118         struct fw_csr_iterator ci;
119
120         int key, value;
121         int vendor = 0;
122         int model = 0;
123         int specifier_id = 0;
124         int version = 0;
125
126         fw_csr_iterator_init(&ci, &device->config_rom[5]);
127         while (fw_csr_iterator_next(&ci, &key, &value)) {
128                 switch (key) {
129                 case CSR_VENDOR:
130                         vendor = value;
131                         break;
132                 case CSR_MODEL:
133                         model = value;
134                         break;
135                 }
136         }
137
138         fw_csr_iterator_init(&ci, unit->directory);
139         while (fw_csr_iterator_next(&ci, &key, &value)) {
140                 switch (key) {
141                 case CSR_SPECIFIER_ID:
142                         specifier_id = value;
143                         break;
144                 case CSR_VERSION:
145                         version = value;
146                         break;
147                 }
148         }
149
150         return snprintf(buffer, buffer_size,
151                         "ieee1394:ven%08Xmo%08Xsp%08Xver%08X",
152                         vendor, model, specifier_id, version);
153 }
154
155 static int fw_unit_uevent(struct device *dev, struct kobj_uevent_env *env)
156 {
157         struct fw_unit *unit = fw_unit(dev);
158         char modalias[64];
159
160         get_modalias(unit, modalias, sizeof(modalias));
161
162         if (add_uevent_var(env, "MODALIAS=%s", modalias))
163                 return -ENOMEM;
164
165         return 0;
166 }
167
168 struct bus_type fw_bus_type = {
169         .name = "firewire",
170         .match = fw_unit_match,
171 };
172 EXPORT_SYMBOL(fw_bus_type);
173
174 int fw_device_enable_phys_dma(struct fw_device *device)
175 {
176         int generation = device->generation;
177
178         /* device->node_id, accessed below, must not be older than generation */
179         smp_rmb();
180
181         return device->card->driver->enable_phys_dma(device->card,
182                                                      device->node_id,
183                                                      generation);
184 }
185 EXPORT_SYMBOL(fw_device_enable_phys_dma);
186
187 struct config_rom_attribute {
188         struct device_attribute attr;
189         u32 key;
190 };
191
192 static ssize_t show_immediate(struct device *dev,
193                               struct device_attribute *dattr, char *buf)
194 {
195         struct config_rom_attribute *attr =
196                 container_of(dattr, struct config_rom_attribute, attr);
197         struct fw_csr_iterator ci;
198         u32 *dir;
199         int key, value, ret = -ENOENT;
200
201         down_read(&fw_device_rwsem);
202
203         if (is_fw_unit(dev))
204                 dir = fw_unit(dev)->directory;
205         else
206                 dir = fw_device(dev)->config_rom + 5;
207
208         fw_csr_iterator_init(&ci, dir);
209         while (fw_csr_iterator_next(&ci, &key, &value))
210                 if (attr->key == key) {
211                         ret = snprintf(buf, buf ? PAGE_SIZE : 0,
212                                        "0x%06x\n", value);
213                         break;
214                 }
215
216         up_read(&fw_device_rwsem);
217
218         return ret;
219 }
220
221 #define IMMEDIATE_ATTR(name, key)                               \
222         { __ATTR(name, S_IRUGO, show_immediate, NULL), key }
223
224 static ssize_t show_text_leaf(struct device *dev,
225                               struct device_attribute *dattr, char *buf)
226 {
227         struct config_rom_attribute *attr =
228                 container_of(dattr, struct config_rom_attribute, attr);
229         struct fw_csr_iterator ci;
230         u32 *dir, *block = NULL, *p, *end;
231         int length, key, value, last_key = 0, ret = -ENOENT;
232         char *b;
233
234         down_read(&fw_device_rwsem);
235
236         if (is_fw_unit(dev))
237                 dir = fw_unit(dev)->directory;
238         else
239                 dir = fw_device(dev)->config_rom + 5;
240
241         fw_csr_iterator_init(&ci, dir);
242         while (fw_csr_iterator_next(&ci, &key, &value)) {
243                 if (attr->key == last_key &&
244                     key == (CSR_DESCRIPTOR | CSR_LEAF))
245                         block = ci.p - 1 + value;
246                 last_key = key;
247         }
248
249         if (block == NULL)
250                 goto out;
251
252         length = min(block[0] >> 16, 256U);
253         if (length < 3)
254                 goto out;
255
256         if (block[1] != 0 || block[2] != 0)
257                 /* Unknown encoding. */
258                 goto out;
259
260         if (buf == NULL) {
261                 ret = length * 4;
262                 goto out;
263         }
264
265         b = buf;
266         end = &block[length + 1];
267         for (p = &block[3]; p < end; p++, b += 4)
268                 * (u32 *) b = (__force u32) __cpu_to_be32(*p);
269
270         /* Strip trailing whitespace and add newline. */
271         while (b--, (isspace(*b) || *b == '\0') && b > buf);
272         strcpy(b + 1, "\n");
273         ret = b + 2 - buf;
274  out:
275         up_read(&fw_device_rwsem);
276
277         return ret;
278 }
279
280 #define TEXT_LEAF_ATTR(name, key)                               \
281         { __ATTR(name, S_IRUGO, show_text_leaf, NULL), key }
282
283 static struct config_rom_attribute config_rom_attributes[] = {
284         IMMEDIATE_ATTR(vendor, CSR_VENDOR),
285         IMMEDIATE_ATTR(hardware_version, CSR_HARDWARE_VERSION),
286         IMMEDIATE_ATTR(specifier_id, CSR_SPECIFIER_ID),
287         IMMEDIATE_ATTR(version, CSR_VERSION),
288         IMMEDIATE_ATTR(model, CSR_MODEL),
289         TEXT_LEAF_ATTR(vendor_name, CSR_VENDOR),
290         TEXT_LEAF_ATTR(model_name, CSR_MODEL),
291         TEXT_LEAF_ATTR(hardware_version_name, CSR_HARDWARE_VERSION),
292 };
293
294 static void init_fw_attribute_group(struct device *dev,
295                                     struct device_attribute *attrs,
296                                     struct fw_attribute_group *group)
297 {
298         struct device_attribute *attr;
299         int i, j;
300
301         for (j = 0; attrs[j].attr.name != NULL; j++)
302                 group->attrs[j] = &attrs[j].attr;
303
304         for (i = 0; i < ARRAY_SIZE(config_rom_attributes); i++) {
305                 attr = &config_rom_attributes[i].attr;
306                 if (attr->show(dev, attr, NULL) < 0)
307                         continue;
308                 group->attrs[j++] = &attr->attr;
309         }
310
311         group->attrs[j] = NULL;
312         group->groups[0] = &group->group;
313         group->groups[1] = NULL;
314         group->group.attrs = group->attrs;
315         dev->groups = (const struct attribute_group **) group->groups;
316 }
317
318 static ssize_t modalias_show(struct device *dev,
319                              struct device_attribute *attr, char *buf)
320 {
321         struct fw_unit *unit = fw_unit(dev);
322         int length;
323
324         length = get_modalias(unit, buf, PAGE_SIZE);
325         strcpy(buf + length, "\n");
326
327         return length + 1;
328 }
329
330 static ssize_t rom_index_show(struct device *dev,
331                               struct device_attribute *attr, char *buf)
332 {
333         struct fw_device *device = fw_device(dev->parent);
334         struct fw_unit *unit = fw_unit(dev);
335
336         return snprintf(buf, PAGE_SIZE, "%d\n",
337                         (int)(unit->directory - device->config_rom));
338 }
339
340 static struct device_attribute fw_unit_attributes[] = {
341         __ATTR_RO(modalias),
342         __ATTR_RO(rom_index),
343         __ATTR_NULL,
344 };
345
346 static ssize_t config_rom_show(struct device *dev,
347                                struct device_attribute *attr, char *buf)
348 {
349         struct fw_device *device = fw_device(dev);
350         size_t length;
351
352         down_read(&fw_device_rwsem);
353         length = device->config_rom_length * 4;
354         memcpy(buf, device->config_rom, length);
355         up_read(&fw_device_rwsem);
356
357         return length;
358 }
359
360 static ssize_t guid_show(struct device *dev,
361                          struct device_attribute *attr, char *buf)
362 {
363         struct fw_device *device = fw_device(dev);
364         int ret;
365
366         down_read(&fw_device_rwsem);
367         ret = snprintf(buf, PAGE_SIZE, "0x%08x%08x\n",
368                        device->config_rom[3], device->config_rom[4]);
369         up_read(&fw_device_rwsem);
370
371         return ret;
372 }
373
374 static int units_sprintf(char *buf, u32 *directory)
375 {
376         struct fw_csr_iterator ci;
377         int key, value;
378         int specifier_id = 0;
379         int version = 0;
380
381         fw_csr_iterator_init(&ci, directory);
382         while (fw_csr_iterator_next(&ci, &key, &value)) {
383                 switch (key) {
384                 case CSR_SPECIFIER_ID:
385                         specifier_id = value;
386                         break;
387                 case CSR_VERSION:
388                         version = value;
389                         break;
390                 }
391         }
392
393         return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version);
394 }
395
396 static ssize_t units_show(struct device *dev,
397                           struct device_attribute *attr, char *buf)
398 {
399         struct fw_device *device = fw_device(dev);
400         struct fw_csr_iterator ci;
401         int key, value, i = 0;
402
403         down_read(&fw_device_rwsem);
404         fw_csr_iterator_init(&ci, &device->config_rom[5]);
405         while (fw_csr_iterator_next(&ci, &key, &value)) {
406                 if (key != (CSR_UNIT | CSR_DIRECTORY))
407                         continue;
408                 i += units_sprintf(&buf[i], ci.p + value - 1);
409                 if (i >= PAGE_SIZE - (8 + 1 + 8 + 1))
410                         break;
411         }
412         up_read(&fw_device_rwsem);
413
414         if (i)
415                 buf[i - 1] = '\n';
416
417         return i;
418 }
419
420 static struct device_attribute fw_device_attributes[] = {
421         __ATTR_RO(config_rom),
422         __ATTR_RO(guid),
423         __ATTR_RO(units),
424         __ATTR_NULL,
425 };
426
427 static int read_rom(struct fw_device *device,
428                     int generation, int index, u32 *data)
429 {
430         int rcode;
431
432         /* device->node_id, accessed below, must not be older than generation */
433         smp_rmb();
434
435         rcode = fw_run_transaction(device->card, TCODE_READ_QUADLET_REQUEST,
436                         device->node_id, generation, device->max_speed,
437                         (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4,
438                         data, 4);
439         be32_to_cpus(data);
440
441         return rcode;
442 }
443
444 #define READ_BIB_ROM_SIZE       256
445 #define READ_BIB_STACK_SIZE     16
446
447 /*
448  * Read the bus info block, perform a speed probe, and read all of the rest of
449  * the config ROM.  We do all this with a cached bus generation.  If the bus
450  * generation changes under us, read_bus_info_block will fail and get retried.
451  * It's better to start all over in this case because the node from which we
452  * are reading the ROM may have changed the ROM during the reset.
453  */
454 static int read_bus_info_block(struct fw_device *device, int generation)
455 {
456         u32 *rom, *stack, *old_rom, *new_rom;
457         u32 sp, key;
458         int i, end, length, ret = -1;
459
460         rom = kmalloc(sizeof(*rom) * READ_BIB_ROM_SIZE +
461                       sizeof(*stack) * READ_BIB_STACK_SIZE, GFP_KERNEL);
462         if (rom == NULL)
463                 return -ENOMEM;
464
465         stack = &rom[READ_BIB_ROM_SIZE];
466
467         device->max_speed = SCODE_100;
468
469         /* First read the bus info block. */
470         for (i = 0; i < 5; i++) {
471                 if (read_rom(device, generation, i, &rom[i]) != RCODE_COMPLETE)
472                         goto out;
473                 /*
474                  * As per IEEE1212 7.2, during power-up, devices can
475                  * reply with a 0 for the first quadlet of the config
476                  * rom to indicate that they are booting (for example,
477                  * if the firmware is on the disk of a external
478                  * harddisk).  In that case we just fail, and the
479                  * retry mechanism will try again later.
480                  */
481                 if (i == 0 && rom[i] == 0)
482                         goto out;
483         }
484
485         device->max_speed = device->node->max_speed;
486
487         /*
488          * Determine the speed of
489          *   - devices with link speed less than PHY speed,
490          *   - devices with 1394b PHY (unless only connected to 1394a PHYs),
491          *   - all devices if there are 1394b repeaters.
492          * Note, we cannot use the bus info block's link_spd as starting point
493          * because some buggy firmwares set it lower than necessary and because
494          * 1394-1995 nodes do not have the field.
495          */
496         if ((rom[2] & 0x7) < device->max_speed ||
497             device->max_speed == SCODE_BETA ||
498             device->card->beta_repeaters_present) {
499                 u32 dummy;
500
501                 /* for S1600 and S3200 */
502                 if (device->max_speed == SCODE_BETA)
503                         device->max_speed = device->card->link_speed;
504
505                 while (device->max_speed > SCODE_100) {
506                         if (read_rom(device, generation, 0, &dummy) ==
507                             RCODE_COMPLETE)
508                                 break;
509                         device->max_speed--;
510                 }
511         }
512
513         /*
514          * Now parse the config rom.  The config rom is a recursive
515          * directory structure so we parse it using a stack of
516          * references to the blocks that make up the structure.  We
517          * push a reference to the root directory on the stack to
518          * start things off.
519          */
520         length = i;
521         sp = 0;
522         stack[sp++] = 0xc0000005;
523         while (sp > 0) {
524                 /*
525                  * Pop the next block reference of the stack.  The
526                  * lower 24 bits is the offset into the config rom,
527                  * the upper 8 bits are the type of the reference the
528                  * block.
529                  */
530                 key = stack[--sp];
531                 i = key & 0xffffff;
532                 if (i >= READ_BIB_ROM_SIZE)
533                         /*
534                          * The reference points outside the standard
535                          * config rom area, something's fishy.
536                          */
537                         goto out;
538
539                 /* Read header quadlet for the block to get the length. */
540                 if (read_rom(device, generation, i, &rom[i]) != RCODE_COMPLETE)
541                         goto out;
542                 end = i + (rom[i] >> 16) + 1;
543                 i++;
544                 if (end > READ_BIB_ROM_SIZE)
545                         /*
546                          * This block extends outside standard config
547                          * area (and the array we're reading it
548                          * into).  That's broken, so ignore this
549                          * device.
550                          */
551                         goto out;
552
553                 /*
554                  * Now read in the block.  If this is a directory
555                  * block, check the entries as we read them to see if
556                  * it references another block, and push it in that case.
557                  */
558                 while (i < end) {
559                         if (read_rom(device, generation, i, &rom[i]) !=
560                             RCODE_COMPLETE)
561                                 goto out;
562                         if ((key >> 30) == 3 && (rom[i] >> 30) > 1 &&
563                             sp < READ_BIB_STACK_SIZE)
564                                 stack[sp++] = i + rom[i];
565                         i++;
566                 }
567                 if (length < i)
568                         length = i;
569         }
570
571         old_rom = device->config_rom;
572         new_rom = kmemdup(rom, length * 4, GFP_KERNEL);
573         if (new_rom == NULL)
574                 goto out;
575
576         down_write(&fw_device_rwsem);
577         device->config_rom = new_rom;
578         device->config_rom_length = length;
579         up_write(&fw_device_rwsem);
580
581         kfree(old_rom);
582         ret = 0;
583         device->max_rec = rom[2] >> 12 & 0xf;
584         device->cmc     = rom[2] >> 30 & 1;
585         device->irmc    = rom[2] >> 31 & 1;
586  out:
587         kfree(rom);
588
589         return ret;
590 }
591
592 static void fw_unit_release(struct device *dev)
593 {
594         struct fw_unit *unit = fw_unit(dev);
595
596         kfree(unit);
597 }
598
599 static struct device_type fw_unit_type = {
600         .uevent         = fw_unit_uevent,
601         .release        = fw_unit_release,
602 };
603
604 static bool is_fw_unit(struct device *dev)
605 {
606         return dev->type == &fw_unit_type;
607 }
608
609 static void create_units(struct fw_device *device)
610 {
611         struct fw_csr_iterator ci;
612         struct fw_unit *unit;
613         int key, value, i;
614
615         i = 0;
616         fw_csr_iterator_init(&ci, &device->config_rom[5]);
617         while (fw_csr_iterator_next(&ci, &key, &value)) {
618                 if (key != (CSR_UNIT | CSR_DIRECTORY))
619                         continue;
620
621                 /*
622                  * Get the address of the unit directory and try to
623                  * match the drivers id_tables against it.
624                  */
625                 unit = kzalloc(sizeof(*unit), GFP_KERNEL);
626                 if (unit == NULL) {
627                         fw_error("failed to allocate memory for unit\n");
628                         continue;
629                 }
630
631                 unit->directory = ci.p + value - 1;
632                 unit->device.bus = &fw_bus_type;
633                 unit->device.type = &fw_unit_type;
634                 unit->device.parent = &device->device;
635                 dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++);
636
637                 BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) <
638                                 ARRAY_SIZE(fw_unit_attributes) +
639                                 ARRAY_SIZE(config_rom_attributes));
640                 init_fw_attribute_group(&unit->device,
641                                         fw_unit_attributes,
642                                         &unit->attribute_group);
643
644                 if (device_register(&unit->device) < 0)
645                         goto skip_unit;
646
647                 continue;
648
649         skip_unit:
650                 kfree(unit);
651         }
652 }
653
654 static int shutdown_unit(struct device *device, void *data)
655 {
656         device_unregister(device);
657
658         return 0;
659 }
660
661 /*
662  * fw_device_rwsem acts as dual purpose mutex:
663  *   - serializes accesses to fw_device_idr,
664  *   - serializes accesses to fw_device.config_rom/.config_rom_length and
665  *     fw_unit.directory, unless those accesses happen at safe occasions
666  */
667 DECLARE_RWSEM(fw_device_rwsem);
668
669 DEFINE_IDR(fw_device_idr);
670 int fw_cdev_major;
671
672 struct fw_device *fw_device_get_by_devt(dev_t devt)
673 {
674         struct fw_device *device;
675
676         down_read(&fw_device_rwsem);
677         device = idr_find(&fw_device_idr, MINOR(devt));
678         if (device)
679                 fw_device_get(device);
680         up_read(&fw_device_rwsem);
681
682         return device;
683 }
684
685 /*
686  * These defines control the retry behavior for reading the config
687  * rom.  It shouldn't be necessary to tweak these; if the device
688  * doesn't respond to a config rom read within 10 seconds, it's not
689  * going to respond at all.  As for the initial delay, a lot of
690  * devices will be able to respond within half a second after bus
691  * reset.  On the other hand, it's not really worth being more
692  * aggressive than that, since it scales pretty well; if 10 devices
693  * are plugged in, they're all getting read within one second.
694  */
695
696 #define MAX_RETRIES     10
697 #define RETRY_DELAY     (3 * HZ)
698 #define INITIAL_DELAY   (HZ / 2)
699 #define SHUTDOWN_DELAY  (2 * HZ)
700
701 static void fw_device_shutdown(struct work_struct *work)
702 {
703         struct fw_device *device =
704                 container_of(work, struct fw_device, work.work);
705         int minor = MINOR(device->device.devt);
706
707         if (time_is_after_jiffies(device->card->reset_jiffies + SHUTDOWN_DELAY)
708             && !list_empty(&device->card->link)) {
709                 schedule_delayed_work(&device->work, SHUTDOWN_DELAY);
710                 return;
711         }
712
713         if (atomic_cmpxchg(&device->state,
714                            FW_DEVICE_GONE,
715                            FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE)
716                 return;
717
718         fw_device_cdev_remove(device);
719         device_for_each_child(&device->device, NULL, shutdown_unit);
720         device_unregister(&device->device);
721
722         down_write(&fw_device_rwsem);
723         idr_remove(&fw_device_idr, minor);
724         up_write(&fw_device_rwsem);
725
726         fw_device_put(device);
727 }
728
729 static void fw_device_release(struct device *dev)
730 {
731         struct fw_device *device = fw_device(dev);
732         struct fw_card *card = device->card;
733         unsigned long flags;
734
735         /*
736          * Take the card lock so we don't set this to NULL while a
737          * FW_NODE_UPDATED callback is being handled or while the
738          * bus manager work looks at this node.
739          */
740         spin_lock_irqsave(&card->lock, flags);
741         device->node->data = NULL;
742         spin_unlock_irqrestore(&card->lock, flags);
743
744         fw_node_put(device->node);
745         kfree(device->config_rom);
746         kfree(device);
747         fw_card_put(card);
748 }
749
750 static struct device_type fw_device_type = {
751         .release = fw_device_release,
752 };
753
754 static bool is_fw_device(struct device *dev)
755 {
756         return dev->type == &fw_device_type;
757 }
758
759 static int update_unit(struct device *dev, void *data)
760 {
761         struct fw_unit *unit = fw_unit(dev);
762         struct fw_driver *driver = (struct fw_driver *)dev->driver;
763
764         if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) {
765                 down(&dev->sem);
766                 driver->update(unit);
767                 up(&dev->sem);
768         }
769
770         return 0;
771 }
772
773 static void fw_device_update(struct work_struct *work)
774 {
775         struct fw_device *device =
776                 container_of(work, struct fw_device, work.work);
777
778         fw_device_cdev_update(device);
779         device_for_each_child(&device->device, NULL, update_unit);
780 }
781
782 /*
783  * If a device was pending for deletion because its node went away but its
784  * bus info block and root directory header matches that of a newly discovered
785  * device, revive the existing fw_device.
786  * The newly allocated fw_device becomes obsolete instead.
787  */
788 static int lookup_existing_device(struct device *dev, void *data)
789 {
790         struct fw_device *old = fw_device(dev);
791         struct fw_device *new = data;
792         struct fw_card *card = new->card;
793         int match = 0;
794
795         if (!is_fw_device(dev))
796                 return 0;
797
798         down_read(&fw_device_rwsem); /* serialize config_rom access */
799         spin_lock_irq(&card->lock);  /* serialize node access */
800
801         if (memcmp(old->config_rom, new->config_rom, 6 * 4) == 0 &&
802             atomic_cmpxchg(&old->state,
803                            FW_DEVICE_GONE,
804                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
805                 struct fw_node *current_node = new->node;
806                 struct fw_node *obsolete_node = old->node;
807
808                 new->node = obsolete_node;
809                 new->node->data = new;
810                 old->node = current_node;
811                 old->node->data = old;
812
813                 old->max_speed = new->max_speed;
814                 old->node_id = current_node->node_id;
815                 smp_wmb();  /* update node_id before generation */
816                 old->generation = card->generation;
817                 old->config_rom_retries = 0;
818                 fw_notify("rediscovered device %s\n", dev_name(dev));
819
820                 PREPARE_DELAYED_WORK(&old->work, fw_device_update);
821                 schedule_delayed_work(&old->work, 0);
822
823                 if (current_node == card->root_node)
824                         fw_schedule_bm_work(card, 0);
825
826                 match = 1;
827         }
828
829         spin_unlock_irq(&card->lock);
830         up_read(&fw_device_rwsem);
831
832         return match;
833 }
834
835 enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, };
836
837 static void set_broadcast_channel(struct fw_device *device, int generation)
838 {
839         struct fw_card *card = device->card;
840         __be32 data;
841         int rcode;
842
843         if (!card->broadcast_channel_allocated)
844                 return;
845
846         /*
847          * The Broadcast_Channel Valid bit is required by nodes which want to
848          * transmit on this channel.  Such transmissions are practically
849          * exclusive to IP over 1394 (RFC 2734).  IP capable nodes are required
850          * to be IRM capable and have a max_rec of 8 or more.  We use this fact
851          * to narrow down to which nodes we send Broadcast_Channel updates.
852          */
853         if (!device->irmc || device->max_rec < 8)
854                 return;
855
856         /*
857          * Some 1394-1995 nodes crash if this 1394a-2000 register is written.
858          * Perform a read test first.
859          */
860         if (device->bc_implemented == BC_UNKNOWN) {
861                 rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST,
862                                 device->node_id, generation, device->max_speed,
863                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
864                                 &data, 4);
865                 switch (rcode) {
866                 case RCODE_COMPLETE:
867                         if (data & cpu_to_be32(1 << 31)) {
868                                 device->bc_implemented = BC_IMPLEMENTED;
869                                 break;
870                         }
871                         /* else fall through to case address error */
872                 case RCODE_ADDRESS_ERROR:
873                         device->bc_implemented = BC_UNIMPLEMENTED;
874                 }
875         }
876
877         if (device->bc_implemented == BC_IMPLEMENTED) {
878                 data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL |
879                                    BROADCAST_CHANNEL_VALID);
880                 fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
881                                 device->node_id, generation, device->max_speed,
882                                 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
883                                 &data, 4);
884         }
885 }
886
887 int fw_device_set_broadcast_channel(struct device *dev, void *gen)
888 {
889         if (is_fw_device(dev))
890                 set_broadcast_channel(fw_device(dev), (long)gen);
891
892         return 0;
893 }
894
895 static void fw_device_init(struct work_struct *work)
896 {
897         struct fw_device *device =
898                 container_of(work, struct fw_device, work.work);
899         struct device *revived_dev;
900         int minor, ret;
901
902         /*
903          * All failure paths here set node->data to NULL, so that we
904          * don't try to do device_for_each_child() on a kfree()'d
905          * device.
906          */
907
908         if (read_bus_info_block(device, device->generation) < 0) {
909                 if (device->config_rom_retries < MAX_RETRIES &&
910                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
911                         device->config_rom_retries++;
912                         schedule_delayed_work(&device->work, RETRY_DELAY);
913                 } else {
914                         fw_notify("giving up on config rom for node id %x\n",
915                                   device->node_id);
916                         if (device->node == device->card->root_node)
917                                 fw_schedule_bm_work(device->card, 0);
918                         fw_device_release(&device->device);
919                 }
920                 return;
921         }
922
923         revived_dev = device_find_child(device->card->device,
924                                         device, lookup_existing_device);
925         if (revived_dev) {
926                 put_device(revived_dev);
927                 fw_device_release(&device->device);
928
929                 return;
930         }
931
932         device_initialize(&device->device);
933
934         fw_device_get(device);
935         down_write(&fw_device_rwsem);
936         ret = idr_pre_get(&fw_device_idr, GFP_KERNEL) ?
937               idr_get_new(&fw_device_idr, device, &minor) :
938               -ENOMEM;
939         up_write(&fw_device_rwsem);
940
941         if (ret < 0)
942                 goto error;
943
944         device->device.bus = &fw_bus_type;
945         device->device.type = &fw_device_type;
946         device->device.parent = device->card->device;
947         device->device.devt = MKDEV(fw_cdev_major, minor);
948         dev_set_name(&device->device, "fw%d", minor);
949
950         BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) <
951                         ARRAY_SIZE(fw_device_attributes) +
952                         ARRAY_SIZE(config_rom_attributes));
953         init_fw_attribute_group(&device->device,
954                                 fw_device_attributes,
955                                 &device->attribute_group);
956
957         if (device_add(&device->device)) {
958                 fw_error("Failed to add device.\n");
959                 goto error_with_cdev;
960         }
961
962         create_units(device);
963
964         /*
965          * Transition the device to running state.  If it got pulled
966          * out from under us while we did the intialization work, we
967          * have to shut down the device again here.  Normally, though,
968          * fw_node_event will be responsible for shutting it down when
969          * necessary.  We have to use the atomic cmpxchg here to avoid
970          * racing with the FW_NODE_DESTROYED case in
971          * fw_node_event().
972          */
973         if (atomic_cmpxchg(&device->state,
974                            FW_DEVICE_INITIALIZING,
975                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
976                 PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
977                 schedule_delayed_work(&device->work, SHUTDOWN_DELAY);
978         } else {
979                 if (device->config_rom_retries)
980                         fw_notify("created device %s: GUID %08x%08x, S%d00, "
981                                   "%d config ROM retries\n",
982                                   dev_name(&device->device),
983                                   device->config_rom[3], device->config_rom[4],
984                                   1 << device->max_speed,
985                                   device->config_rom_retries);
986                 else
987                         fw_notify("created device %s: GUID %08x%08x, S%d00\n",
988                                   dev_name(&device->device),
989                                   device->config_rom[3], device->config_rom[4],
990                                   1 << device->max_speed);
991                 device->config_rom_retries = 0;
992
993                 set_broadcast_channel(device, device->generation);
994         }
995
996         /*
997          * Reschedule the IRM work if we just finished reading the
998          * root node config rom.  If this races with a bus reset we
999          * just end up running the IRM work a couple of extra times -
1000          * pretty harmless.
1001          */
1002         if (device->node == device->card->root_node)
1003                 fw_schedule_bm_work(device->card, 0);
1004
1005         return;
1006
1007  error_with_cdev:
1008         down_write(&fw_device_rwsem);
1009         idr_remove(&fw_device_idr, minor);
1010         up_write(&fw_device_rwsem);
1011  error:
1012         fw_device_put(device);          /* fw_device_idr's reference */
1013
1014         put_device(&device->device);    /* our reference */
1015 }
1016
1017 enum {
1018         REREAD_BIB_ERROR,
1019         REREAD_BIB_GONE,
1020         REREAD_BIB_UNCHANGED,
1021         REREAD_BIB_CHANGED,
1022 };
1023
1024 /* Reread and compare bus info block and header of root directory */
1025 static int reread_bus_info_block(struct fw_device *device, int generation)
1026 {
1027         u32 q;
1028         int i;
1029
1030         for (i = 0; i < 6; i++) {
1031                 if (read_rom(device, generation, i, &q) != RCODE_COMPLETE)
1032                         return REREAD_BIB_ERROR;
1033
1034                 if (i == 0 && q == 0)
1035                         return REREAD_BIB_GONE;
1036
1037                 if (q != device->config_rom[i])
1038                         return REREAD_BIB_CHANGED;
1039         }
1040
1041         return REREAD_BIB_UNCHANGED;
1042 }
1043
1044 static void fw_device_refresh(struct work_struct *work)
1045 {
1046         struct fw_device *device =
1047                 container_of(work, struct fw_device, work.work);
1048         struct fw_card *card = device->card;
1049         int node_id = device->node_id;
1050
1051         switch (reread_bus_info_block(device, device->generation)) {
1052         case REREAD_BIB_ERROR:
1053                 if (device->config_rom_retries < MAX_RETRIES / 2 &&
1054                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1055                         device->config_rom_retries++;
1056                         schedule_delayed_work(&device->work, RETRY_DELAY / 2);
1057
1058                         return;
1059                 }
1060                 goto give_up;
1061
1062         case REREAD_BIB_GONE:
1063                 goto gone;
1064
1065         case REREAD_BIB_UNCHANGED:
1066                 if (atomic_cmpxchg(&device->state,
1067                                    FW_DEVICE_INITIALIZING,
1068                                    FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1069                         goto gone;
1070
1071                 fw_device_update(work);
1072                 device->config_rom_retries = 0;
1073                 goto out;
1074
1075         case REREAD_BIB_CHANGED:
1076                 break;
1077         }
1078
1079         /*
1080          * Something changed.  We keep things simple and don't investigate
1081          * further.  We just destroy all previous units and create new ones.
1082          */
1083         device_for_each_child(&device->device, NULL, shutdown_unit);
1084
1085         if (read_bus_info_block(device, device->generation) < 0) {
1086                 if (device->config_rom_retries < MAX_RETRIES &&
1087                     atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1088                         device->config_rom_retries++;
1089                         schedule_delayed_work(&device->work, RETRY_DELAY);
1090
1091                         return;
1092                 }
1093                 goto give_up;
1094         }
1095
1096         create_units(device);
1097
1098         /* Userspace may want to re-read attributes. */
1099         kobject_uevent(&device->device.kobj, KOBJ_CHANGE);
1100
1101         if (atomic_cmpxchg(&device->state,
1102                            FW_DEVICE_INITIALIZING,
1103                            FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1104                 goto gone;
1105
1106         fw_notify("refreshed device %s\n", dev_name(&device->device));
1107         device->config_rom_retries = 0;
1108         goto out;
1109
1110  give_up:
1111         fw_notify("giving up on refresh of device %s\n", dev_name(&device->device));
1112  gone:
1113         atomic_set(&device->state, FW_DEVICE_GONE);
1114         PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1115         schedule_delayed_work(&device->work, SHUTDOWN_DELAY);
1116  out:
1117         if (node_id == card->root_node->node_id)
1118                 fw_schedule_bm_work(card, 0);
1119 }
1120
1121 void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
1122 {
1123         struct fw_device *device;
1124
1125         switch (event) {
1126         case FW_NODE_CREATED:
1127         case FW_NODE_LINK_ON:
1128                 if (!node->link_on)
1129                         break;
1130  create:
1131                 device = kzalloc(sizeof(*device), GFP_ATOMIC);
1132                 if (device == NULL)
1133                         break;
1134
1135                 /*
1136                  * Do minimal intialization of the device here, the
1137                  * rest will happen in fw_device_init().
1138                  *
1139                  * Attention:  A lot of things, even fw_device_get(),
1140                  * cannot be done before fw_device_init() finished!
1141                  * You can basically just check device->state and
1142                  * schedule work until then, but only while holding
1143                  * card->lock.
1144                  */
1145                 atomic_set(&device->state, FW_DEVICE_INITIALIZING);
1146                 device->card = fw_card_get(card);
1147                 device->node = fw_node_get(node);
1148                 device->node_id = node->node_id;
1149                 device->generation = card->generation;
1150                 device->is_local = node == card->local_node;
1151                 mutex_init(&device->client_list_mutex);
1152                 INIT_LIST_HEAD(&device->client_list);
1153
1154                 /*
1155                  * Set the node data to point back to this device so
1156                  * FW_NODE_UPDATED callbacks can update the node_id
1157                  * and generation for the device.
1158                  */
1159                 node->data = device;
1160
1161                 /*
1162                  * Many devices are slow to respond after bus resets,
1163                  * especially if they are bus powered and go through
1164                  * power-up after getting plugged in.  We schedule the
1165                  * first config rom scan half a second after bus reset.
1166                  */
1167                 INIT_DELAYED_WORK(&device->work, fw_device_init);
1168                 schedule_delayed_work(&device->work, INITIAL_DELAY);
1169                 break;
1170
1171         case FW_NODE_INITIATED_RESET:
1172                 device = node->data;
1173                 if (device == NULL)
1174                         goto create;
1175
1176                 device->node_id = node->node_id;
1177                 smp_wmb();  /* update node_id before generation */
1178                 device->generation = card->generation;
1179                 if (atomic_cmpxchg(&device->state,
1180                             FW_DEVICE_RUNNING,
1181                             FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) {
1182                         PREPARE_DELAYED_WORK(&device->work, fw_device_refresh);
1183                         schedule_delayed_work(&device->work,
1184                                 device->is_local ? 0 : INITIAL_DELAY);
1185                 }
1186                 break;
1187
1188         case FW_NODE_UPDATED:
1189                 if (!node->link_on || node->data == NULL)
1190                         break;
1191
1192                 device = node->data;
1193                 device->node_id = node->node_id;
1194                 smp_wmb();  /* update node_id before generation */
1195                 device->generation = card->generation;
1196                 if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
1197                         PREPARE_DELAYED_WORK(&device->work, fw_device_update);
1198                         schedule_delayed_work(&device->work, 0);
1199                 }
1200                 break;
1201
1202         case FW_NODE_DESTROYED:
1203         case FW_NODE_LINK_OFF:
1204                 if (!node->data)
1205                         break;
1206
1207                 /*
1208                  * Destroy the device associated with the node.  There
1209                  * are two cases here: either the device is fully
1210                  * initialized (FW_DEVICE_RUNNING) or we're in the
1211                  * process of reading its config rom
1212                  * (FW_DEVICE_INITIALIZING).  If it is fully
1213                  * initialized we can reuse device->work to schedule a
1214                  * full fw_device_shutdown().  If not, there's work
1215                  * scheduled to read it's config rom, and we just put
1216                  * the device in shutdown state to have that code fail
1217                  * to create the device.
1218                  */
1219                 device = node->data;
1220                 if (atomic_xchg(&device->state,
1221                                 FW_DEVICE_GONE) == FW_DEVICE_RUNNING) {
1222                         PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1223                         schedule_delayed_work(&device->work,
1224                                 list_empty(&card->link) ? 0 : SHUTDOWN_DELAY);
1225                 }
1226                 break;
1227         }
1228 }