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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Device probing and sysfs code.
4 *
5 * Copyright (C) 2005-2006 Kristian Hoegsberg <krh@bitplanet.net>
6 */
7
8#include <linux/bug.h>
9#include <linux/ctype.h>
10#include <linux/delay.h>
11#include <linux/device.h>
12#include <linux/errno.h>
13#include <linux/firewire.h>
14#include <linux/firewire-constants.h>
15#include <linux/jiffies.h>
16#include <linux/kobject.h>
17#include <linux/list.h>
18#include <linux/mod_devicetable.h>
19#include <linux/module.h>
20#include <linux/mutex.h>
21#include <linux/random.h>
22#include <linux/rwsem.h>
23#include <linux/slab.h>
24#include <linux/spinlock.h>
25#include <linux/string.h>
26#include <linux/workqueue.h>
27
28#include <linux/atomic.h>
29#include <asm/byteorder.h>
30
31#include "core.h"
32
33#define ROOT_DIR_OFFSET 5
34
35void fw_csr_iterator_init(struct fw_csr_iterator *ci, const u32 *p)
36{
37 ci->p = p + 1;
38 ci->end = ci->p + (p[0] >> 16);
39}
40EXPORT_SYMBOL(fw_csr_iterator_init);
41
42int fw_csr_iterator_next(struct fw_csr_iterator *ci, int *key, int *value)
43{
44 *key = *ci->p >> 24;
45 *value = *ci->p & 0xffffff;
46
47 return ci->p++ < ci->end;
48}
49EXPORT_SYMBOL(fw_csr_iterator_next);
50
51static const u32 *search_directory(const u32 *directory, int search_key)
52{
53 struct fw_csr_iterator ci;
54 int key, value;
55
56 search_key |= CSR_DIRECTORY;
57
58 fw_csr_iterator_init(&ci, directory);
59 while (fw_csr_iterator_next(&ci, &key, &value)) {
60 if (key == search_key)
61 return ci.p - 1 + value;
62 }
63
64 return NULL;
65}
66
67static const u32 *search_leaf(const u32 *directory, int search_key)
68{
69 struct fw_csr_iterator ci;
70 int last_key = 0, key, value;
71
72 fw_csr_iterator_init(&ci, directory);
73 while (fw_csr_iterator_next(&ci, &key, &value)) {
74 if (last_key == search_key &&
75 key == (CSR_DESCRIPTOR | CSR_LEAF))
76 return ci.p - 1 + value;
77
78 last_key = key;
79 }
80
81 return NULL;
82}
83
84static int textual_leaf_to_string(const u32 *block, char *buf, size_t size)
85{
86 unsigned int quadlets, i;
87 char c;
88
89 if (!size || !buf)
90 return -EINVAL;
91
92 quadlets = min(block[0] >> 16, 256U);
93 if (quadlets < 2)
94 return -ENODATA;
95
96 if (block[1] != 0 || block[2] != 0)
97 /* unknown language/character set */
98 return -ENODATA;
99
100 block += 3;
101 quadlets -= 2;
102 for (i = 0; i < quadlets * 4 && i < size - 1; i++) {
103 c = block[i / 4] >> (24 - 8 * (i % 4));
104 if (c == '\0')
105 break;
106 buf[i] = c;
107 }
108 buf[i] = '\0';
109
110 return i;
111}
112
113/**
114 * fw_csr_string() - reads a string from the configuration ROM
115 * @directory: e.g. root directory or unit directory
116 * @key: the key of the preceding directory entry
117 * @buf: where to put the string
118 * @size: size of @buf, in bytes
119 *
120 * The string is taken from a minimal ASCII text descriptor leaf just after the entry with the
121 * @key. The string is zero-terminated. An overlong string is silently truncated such that it
122 * and the zero byte fit into @size.
123 *
124 * Returns strlen(buf) or a negative error code.
125 */
126int fw_csr_string(const u32 *directory, int key, char *buf, size_t size)
127{
128 const u32 *leaf = search_leaf(directory, key);
129 if (!leaf)
130 return -ENOENT;
131
132 return textual_leaf_to_string(leaf, buf, size);
133}
134EXPORT_SYMBOL(fw_csr_string);
135
136static void get_ids(const u32 *directory, int *id)
137{
138 struct fw_csr_iterator ci;
139 int key, value;
140
141 fw_csr_iterator_init(&ci, directory);
142 while (fw_csr_iterator_next(&ci, &key, &value)) {
143 switch (key) {
144 case CSR_VENDOR: id[0] = value; break;
145 case CSR_MODEL: id[1] = value; break;
146 case CSR_SPECIFIER_ID: id[2] = value; break;
147 case CSR_VERSION: id[3] = value; break;
148 }
149 }
150}
151
152static void get_modalias_ids(const struct fw_unit *unit, int *id)
153{
154 const u32 *root_directory = &fw_parent_device(unit)->config_rom[ROOT_DIR_OFFSET];
155 const u32 *directories[] = {NULL, NULL, NULL};
156 const u32 *vendor_directory;
157 int i;
158
159 directories[0] = root_directory;
160
161 // Legacy layout of configuration ROM described in Annex 1 of 'Configuration ROM for AV/C
162 // Devices 1.0 (December 12, 2000, 1394 Trading Association, TA Document 1999027)'.
163 vendor_directory = search_directory(root_directory, CSR_VENDOR);
164 if (!vendor_directory) {
165 directories[1] = unit->directory;
166 } else {
167 directories[1] = vendor_directory;
168 directories[2] = unit->directory;
169 }
170
171 for (i = 0; i < ARRAY_SIZE(directories) && !!directories[i]; ++i)
172 get_ids(directories[i], id);
173}
174
175static bool match_ids(const struct ieee1394_device_id *id_table, int *id)
176{
177 int match = 0;
178
179 if (id[0] == id_table->vendor_id)
180 match |= IEEE1394_MATCH_VENDOR_ID;
181 if (id[1] == id_table->model_id)
182 match |= IEEE1394_MATCH_MODEL_ID;
183 if (id[2] == id_table->specifier_id)
184 match |= IEEE1394_MATCH_SPECIFIER_ID;
185 if (id[3] == id_table->version)
186 match |= IEEE1394_MATCH_VERSION;
187
188 return (match & id_table->match_flags) == id_table->match_flags;
189}
190
191static const struct ieee1394_device_id *unit_match(struct device *dev,
192 const struct device_driver *drv)
193{
194 const struct ieee1394_device_id *id_table =
195 container_of_const(drv, struct fw_driver, driver)->id_table;
196 int id[] = {0, 0, 0, 0};
197
198 get_modalias_ids(fw_unit(dev), id);
199
200 for (; id_table->match_flags != 0; id_table++)
201 if (match_ids(id_table, id))
202 return id_table;
203
204 return NULL;
205}
206
207static bool is_fw_unit(const struct device *dev);
208
209static int fw_unit_match(struct device *dev, const struct device_driver *drv)
210{
211 /* We only allow binding to fw_units. */
212 return is_fw_unit(dev) && unit_match(dev, drv) != NULL;
213}
214
215static int fw_unit_probe(struct device *dev)
216{
217 struct fw_driver *driver =
218 container_of(dev->driver, struct fw_driver, driver);
219
220 return driver->probe(fw_unit(dev), unit_match(dev, dev->driver));
221}
222
223static void fw_unit_remove(struct device *dev)
224{
225 struct fw_driver *driver =
226 container_of(dev->driver, struct fw_driver, driver);
227
228 driver->remove(fw_unit(dev));
229}
230
231static int get_modalias(const struct fw_unit *unit, char *buffer, size_t buffer_size)
232{
233 int id[] = {0, 0, 0, 0};
234
235 get_modalias_ids(unit, id);
236
237 return snprintf(buffer, buffer_size,
238 "ieee1394:ven%08Xmo%08Xsp%08Xver%08X",
239 id[0], id[1], id[2], id[3]);
240}
241
242static int fw_unit_uevent(const struct device *dev, struct kobj_uevent_env *env)
243{
244 const struct fw_unit *unit = fw_unit(dev);
245 char modalias[64];
246
247 get_modalias(unit, modalias, sizeof(modalias));
248
249 if (add_uevent_var(env, "MODALIAS=%s", modalias))
250 return -ENOMEM;
251
252 return 0;
253}
254
255const struct bus_type fw_bus_type = {
256 .name = "firewire",
257 .match = fw_unit_match,
258 .probe = fw_unit_probe,
259 .remove = fw_unit_remove,
260};
261EXPORT_SYMBOL(fw_bus_type);
262
263int fw_device_enable_phys_dma(struct fw_device *device)
264{
265 int generation = device->generation;
266
267 /* device->node_id, accessed below, must not be older than generation */
268 smp_rmb();
269
270 return device->card->driver->enable_phys_dma(device->card,
271 device->node_id,
272 generation);
273}
274EXPORT_SYMBOL(fw_device_enable_phys_dma);
275
276struct config_rom_attribute {
277 struct device_attribute attr;
278 u32 key;
279};
280
281static ssize_t show_immediate(struct device *dev,
282 struct device_attribute *dattr, char *buf)
283{
284 struct config_rom_attribute *attr =
285 container_of(dattr, struct config_rom_attribute, attr);
286 struct fw_csr_iterator ci;
287 const u32 *directories[] = {NULL, NULL};
288 int i, value = -1;
289
290 guard(rwsem_read)(&fw_device_rwsem);
291
292 if (is_fw_unit(dev)) {
293 directories[0] = fw_unit(dev)->directory;
294 } else {
295 const u32 *root_directory = fw_device(dev)->config_rom + ROOT_DIR_OFFSET;
296 const u32 *vendor_directory = search_directory(root_directory, CSR_VENDOR);
297
298 if (!vendor_directory) {
299 directories[0] = root_directory;
300 } else {
301 // Legacy layout of configuration ROM described in Annex 1 of
302 // 'Configuration ROM for AV/C Devices 1.0 (December 12, 2000, 1394 Trading
303 // Association, TA Document 1999027)'.
304 directories[0] = vendor_directory;
305 directories[1] = root_directory;
306 }
307 }
308
309 for (i = 0; i < ARRAY_SIZE(directories) && !!directories[i]; ++i) {
310 int key, val;
311
312 fw_csr_iterator_init(&ci, directories[i]);
313 while (fw_csr_iterator_next(&ci, &key, &val)) {
314 if (attr->key == key)
315 value = val;
316 }
317 }
318
319 if (value < 0)
320 return -ENOENT;
321
322 // Note that this function is also called by init_fw_attribute_group() with NULL pointer.
323 return buf ? sysfs_emit(buf, "0x%06x\n", value) : 0;
324}
325
326#define IMMEDIATE_ATTR(name, key) \
327 { __ATTR(name, S_IRUGO, show_immediate, NULL), key }
328
329static ssize_t show_text_leaf(struct device *dev,
330 struct device_attribute *dattr, char *buf)
331{
332 struct config_rom_attribute *attr =
333 container_of(dattr, struct config_rom_attribute, attr);
334 const u32 *directories[] = {NULL, NULL};
335 size_t bufsize;
336 char dummy_buf[2];
337 int i, ret = -ENOENT;
338
339 guard(rwsem_read)(&fw_device_rwsem);
340
341 if (is_fw_unit(dev)) {
342 directories[0] = fw_unit(dev)->directory;
343 } else {
344 const u32 *root_directory = fw_device(dev)->config_rom + ROOT_DIR_OFFSET;
345 const u32 *vendor_directory = search_directory(root_directory, CSR_VENDOR);
346
347 if (!vendor_directory) {
348 directories[0] = root_directory;
349 } else {
350 // Legacy layout of configuration ROM described in Annex 1 of
351 // 'Configuration ROM for AV/C Devices 1.0 (December 12, 2000, 1394
352 // Trading Association, TA Document 1999027)'.
353 directories[0] = root_directory;
354 directories[1] = vendor_directory;
355 }
356 }
357
358 // Note that this function is also called by init_fw_attribute_group() with NULL pointer.
359 if (buf) {
360 bufsize = PAGE_SIZE - 1;
361 } else {
362 buf = dummy_buf;
363 bufsize = 1;
364 }
365
366 for (i = 0; i < ARRAY_SIZE(directories) && !!directories[i]; ++i) {
367 int result = fw_csr_string(directories[i], attr->key, buf, bufsize);
368 // Detected.
369 if (result >= 0) {
370 ret = result;
371 } else if (i == 0 && attr->key == CSR_VENDOR) {
372 // Sony DVMC-DA1 has configuration ROM such that the descriptor leaf entry
373 // in the root directory follows to the directory entry for vendor ID
374 // instead of the immediate value for vendor ID.
375 result = fw_csr_string(directories[i], CSR_DIRECTORY | attr->key, buf,
376 bufsize);
377 if (result >= 0)
378 ret = result;
379 }
380 }
381
382 if (ret < 0)
383 return ret;
384
385 // Strip trailing whitespace and add newline.
386 while (ret > 0 && isspace(buf[ret - 1]))
387 ret--;
388 strcpy(buf + ret, "\n");
389 ret++;
390
391 return ret;
392}
393
394#define TEXT_LEAF_ATTR(name, key) \
395 { __ATTR(name, S_IRUGO, show_text_leaf, NULL), key }
396
397static struct config_rom_attribute config_rom_attributes[] = {
398 IMMEDIATE_ATTR(vendor, CSR_VENDOR),
399 IMMEDIATE_ATTR(hardware_version, CSR_HARDWARE_VERSION),
400 IMMEDIATE_ATTR(specifier_id, CSR_SPECIFIER_ID),
401 IMMEDIATE_ATTR(version, CSR_VERSION),
402 IMMEDIATE_ATTR(model, CSR_MODEL),
403 TEXT_LEAF_ATTR(vendor_name, CSR_VENDOR),
404 TEXT_LEAF_ATTR(model_name, CSR_MODEL),
405 TEXT_LEAF_ATTR(hardware_version_name, CSR_HARDWARE_VERSION),
406};
407
408static void init_fw_attribute_group(struct device *dev,
409 struct device_attribute *attrs,
410 struct fw_attribute_group *group)
411{
412 struct device_attribute *attr;
413 int i, j;
414
415 for (j = 0; attrs[j].attr.name != NULL; j++)
416 group->attrs[j] = &attrs[j].attr;
417
418 for (i = 0; i < ARRAY_SIZE(config_rom_attributes); i++) {
419 attr = &config_rom_attributes[i].attr;
420 if (attr->show(dev, attr, NULL) < 0)
421 continue;
422 group->attrs[j++] = &attr->attr;
423 }
424
425 group->attrs[j] = NULL;
426 group->groups[0] = &group->group;
427 group->groups[1] = NULL;
428 group->group.attrs = group->attrs;
429 dev->groups = (const struct attribute_group **) group->groups;
430}
431
432static ssize_t modalias_show(struct device *dev,
433 struct device_attribute *attr, char *buf)
434{
435 struct fw_unit *unit = fw_unit(dev);
436 int length;
437
438 length = get_modalias(unit, buf, PAGE_SIZE);
439 strcpy(buf + length, "\n");
440
441 return length + 1;
442}
443
444static ssize_t rom_index_show(struct device *dev,
445 struct device_attribute *attr, char *buf)
446{
447 struct fw_device *device = fw_device(dev->parent);
448 struct fw_unit *unit = fw_unit(dev);
449
450 return sysfs_emit(buf, "%td\n", unit->directory - device->config_rom);
451}
452
453static struct device_attribute fw_unit_attributes[] = {
454 __ATTR_RO(modalias),
455 __ATTR_RO(rom_index),
456 __ATTR_NULL,
457};
458
459static ssize_t config_rom_show(struct device *dev,
460 struct device_attribute *attr, char *buf)
461{
462 struct fw_device *device = fw_device(dev);
463 size_t length;
464
465 guard(rwsem_read)(&fw_device_rwsem);
466
467 length = device->config_rom_length * 4;
468 memcpy(buf, device->config_rom, length);
469
470 return length;
471}
472
473static ssize_t guid_show(struct device *dev,
474 struct device_attribute *attr, char *buf)
475{
476 struct fw_device *device = fw_device(dev);
477
478 guard(rwsem_read)(&fw_device_rwsem);
479
480 return sysfs_emit(buf, "0x%08x%08x\n", device->config_rom[3], device->config_rom[4]);
481}
482
483static ssize_t is_local_show(struct device *dev,
484 struct device_attribute *attr, char *buf)
485{
486 struct fw_device *device = fw_device(dev);
487
488 return sysfs_emit(buf, "%u\n", device->is_local);
489}
490
491static int units_sprintf(char *buf, const u32 *directory)
492{
493 struct fw_csr_iterator ci;
494 int key, value;
495 int specifier_id = 0;
496 int version = 0;
497
498 fw_csr_iterator_init(&ci, directory);
499 while (fw_csr_iterator_next(&ci, &key, &value)) {
500 switch (key) {
501 case CSR_SPECIFIER_ID:
502 specifier_id = value;
503 break;
504 case CSR_VERSION:
505 version = value;
506 break;
507 }
508 }
509
510 return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version);
511}
512
513static ssize_t units_show(struct device *dev,
514 struct device_attribute *attr, char *buf)
515{
516 struct fw_device *device = fw_device(dev);
517 struct fw_csr_iterator ci;
518 int key, value, i = 0;
519
520 guard(rwsem_read)(&fw_device_rwsem);
521
522 fw_csr_iterator_init(&ci, &device->config_rom[ROOT_DIR_OFFSET]);
523 while (fw_csr_iterator_next(&ci, &key, &value)) {
524 if (key != (CSR_UNIT | CSR_DIRECTORY))
525 continue;
526 i += units_sprintf(&buf[i], ci.p + value - 1);
527 if (i >= PAGE_SIZE - (8 + 1 + 8 + 1))
528 break;
529 }
530
531 if (i)
532 buf[i - 1] = '\n';
533
534 return i;
535}
536
537static struct device_attribute fw_device_attributes[] = {
538 __ATTR_RO(config_rom),
539 __ATTR_RO(guid),
540 __ATTR_RO(is_local),
541 __ATTR_RO(units),
542 __ATTR_NULL,
543};
544
545static int read_rom(struct fw_device *device,
546 int generation, int index, u32 *data)
547{
548 u64 offset = (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4;
549 int i, rcode;
550
551 /* device->node_id, accessed below, must not be older than generation */
552 smp_rmb();
553
554 for (i = 10; i < 100; i += 10) {
555 rcode = fw_run_transaction(device->card,
556 TCODE_READ_QUADLET_REQUEST, device->node_id,
557 generation, device->max_speed, offset, data, 4);
558 if (rcode != RCODE_BUSY)
559 break;
560 msleep(i);
561 }
562 be32_to_cpus(data);
563
564 return rcode;
565}
566
567// By quadlet unit.
568#define MAX_CONFIG_ROM_SIZE ((CSR_CONFIG_ROM_END - CSR_CONFIG_ROM) / sizeof(u32))
569
570/*
571 * Read the bus info block, perform a speed probe, and read all of the rest of
572 * the config ROM. We do all this with a cached bus generation. If the bus
573 * generation changes under us, read_config_rom will fail and get retried.
574 * It's better to start all over in this case because the node from which we
575 * are reading the ROM may have changed the ROM during the reset.
576 * Returns either a result code or a negative error code.
577 */
578static int read_config_rom(struct fw_device *device, int generation)
579{
580 struct fw_card *card = device->card;
581 const u32 *old_rom, *new_rom;
582 u32 *rom, *stack;
583 u32 sp, key;
584 int i, end, length, ret;
585
586 rom = kmalloc(sizeof(*rom) * MAX_CONFIG_ROM_SIZE +
587 sizeof(*stack) * MAX_CONFIG_ROM_SIZE, GFP_KERNEL);
588 if (rom == NULL)
589 return -ENOMEM;
590
591 stack = &rom[MAX_CONFIG_ROM_SIZE];
592 memset(rom, 0, sizeof(*rom) * MAX_CONFIG_ROM_SIZE);
593
594 device->max_speed = SCODE_100;
595
596 /* First read the bus info block. */
597 for (i = 0; i < 5; i++) {
598 ret = read_rom(device, generation, i, &rom[i]);
599 if (ret != RCODE_COMPLETE)
600 goto out;
601 /*
602 * As per IEEE1212 7.2, during initialization, devices can
603 * reply with a 0 for the first quadlet of the config
604 * rom to indicate that they are booting (for example,
605 * if the firmware is on the disk of a external
606 * harddisk). In that case we just fail, and the
607 * retry mechanism will try again later.
608 */
609 if (i == 0 && rom[i] == 0) {
610 ret = RCODE_BUSY;
611 goto out;
612 }
613 }
614
615 device->max_speed = device->node->max_speed;
616
617 /*
618 * Determine the speed of
619 * - devices with link speed less than PHY speed,
620 * - devices with 1394b PHY (unless only connected to 1394a PHYs),
621 * - all devices if there are 1394b repeaters.
622 * Note, we cannot use the bus info block's link_spd as starting point
623 * because some buggy firmwares set it lower than necessary and because
624 * 1394-1995 nodes do not have the field.
625 */
626 if ((rom[2] & 0x7) < device->max_speed ||
627 device->max_speed == SCODE_BETA ||
628 card->beta_repeaters_present) {
629 u32 dummy;
630
631 /* for S1600 and S3200 */
632 if (device->max_speed == SCODE_BETA)
633 device->max_speed = card->link_speed;
634
635 while (device->max_speed > SCODE_100) {
636 if (read_rom(device, generation, 0, &dummy) ==
637 RCODE_COMPLETE)
638 break;
639 device->max_speed--;
640 }
641 }
642
643 /*
644 * Now parse the config rom. The config rom is a recursive
645 * directory structure so we parse it using a stack of
646 * references to the blocks that make up the structure. We
647 * push a reference to the root directory on the stack to
648 * start things off.
649 */
650 length = i;
651 sp = 0;
652 stack[sp++] = 0xc0000005;
653 while (sp > 0) {
654 /*
655 * Pop the next block reference of the stack. The
656 * lower 24 bits is the offset into the config rom,
657 * the upper 8 bits are the type of the reference the
658 * block.
659 */
660 key = stack[--sp];
661 i = key & 0xffffff;
662 if (WARN_ON(i >= MAX_CONFIG_ROM_SIZE)) {
663 ret = -ENXIO;
664 goto out;
665 }
666
667 /* Read header quadlet for the block to get the length. */
668 ret = read_rom(device, generation, i, &rom[i]);
669 if (ret != RCODE_COMPLETE)
670 goto out;
671 end = i + (rom[i] >> 16) + 1;
672 if (end > MAX_CONFIG_ROM_SIZE) {
673 /*
674 * This block extends outside the config ROM which is
675 * a firmware bug. Ignore this whole block, i.e.
676 * simply set a fake block length of 0.
677 */
678 fw_err(card, "skipped invalid ROM block %x at %llx\n",
679 rom[i],
680 i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
681 rom[i] = 0;
682 end = i;
683 }
684 i++;
685
686 /*
687 * Now read in the block. If this is a directory
688 * block, check the entries as we read them to see if
689 * it references another block, and push it in that case.
690 */
691 for (; i < end; i++) {
692 ret = read_rom(device, generation, i, &rom[i]);
693 if (ret != RCODE_COMPLETE)
694 goto out;
695
696 if ((key >> 30) != 3 || (rom[i] >> 30) < 2)
697 continue;
698 /*
699 * Offset points outside the ROM. May be a firmware
700 * bug or an Extended ROM entry (IEEE 1212-2001 clause
701 * 7.7.18). Simply overwrite this pointer here by a
702 * fake immediate entry so that later iterators over
703 * the ROM don't have to check offsets all the time.
704 */
705 if (i + (rom[i] & 0xffffff) >= MAX_CONFIG_ROM_SIZE) {
706 fw_err(card,
707 "skipped unsupported ROM entry %x at %llx\n",
708 rom[i],
709 i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
710 rom[i] = 0;
711 continue;
712 }
713 stack[sp++] = i + rom[i];
714 }
715 if (length < i)
716 length = i;
717 }
718
719 old_rom = device->config_rom;
720 new_rom = kmemdup(rom, length * 4, GFP_KERNEL);
721 if (new_rom == NULL) {
722 ret = -ENOMEM;
723 goto out;
724 }
725
726 scoped_guard(rwsem_write, &fw_device_rwsem) {
727 device->config_rom = new_rom;
728 device->config_rom_length = length;
729 }
730
731 kfree(old_rom);
732 ret = RCODE_COMPLETE;
733 device->max_rec = rom[2] >> 12 & 0xf;
734 device->cmc = rom[2] >> 30 & 1;
735 device->irmc = rom[2] >> 31 & 1;
736 out:
737 kfree(rom);
738
739 return ret;
740}
741
742static void fw_unit_release(struct device *dev)
743{
744 struct fw_unit *unit = fw_unit(dev);
745
746 fw_device_put(fw_parent_device(unit));
747 kfree(unit);
748}
749
750static struct device_type fw_unit_type = {
751 .uevent = fw_unit_uevent,
752 .release = fw_unit_release,
753};
754
755static bool is_fw_unit(const struct device *dev)
756{
757 return dev->type == &fw_unit_type;
758}
759
760static void create_units(struct fw_device *device)
761{
762 struct fw_csr_iterator ci;
763 struct fw_unit *unit;
764 int key, value, i;
765
766 i = 0;
767 fw_csr_iterator_init(&ci, &device->config_rom[ROOT_DIR_OFFSET]);
768 while (fw_csr_iterator_next(&ci, &key, &value)) {
769 if (key != (CSR_UNIT | CSR_DIRECTORY))
770 continue;
771
772 /*
773 * Get the address of the unit directory and try to
774 * match the drivers id_tables against it.
775 */
776 unit = kzalloc(sizeof(*unit), GFP_KERNEL);
777 if (unit == NULL)
778 continue;
779
780 unit->directory = ci.p + value - 1;
781 unit->device.bus = &fw_bus_type;
782 unit->device.type = &fw_unit_type;
783 unit->device.parent = &device->device;
784 dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++);
785
786 BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) <
787 ARRAY_SIZE(fw_unit_attributes) +
788 ARRAY_SIZE(config_rom_attributes));
789 init_fw_attribute_group(&unit->device,
790 fw_unit_attributes,
791 &unit->attribute_group);
792
793 fw_device_get(device);
794 if (device_register(&unit->device) < 0) {
795 put_device(&unit->device);
796 continue;
797 }
798 }
799}
800
801static int shutdown_unit(struct device *device, void *data)
802{
803 device_unregister(device);
804
805 return 0;
806}
807
808/*
809 * fw_device_rwsem acts as dual purpose mutex:
810 * - serializes accesses to fw_device.config_rom/.config_rom_length and
811 * fw_unit.directory, unless those accesses happen at safe occasions
812 */
813DECLARE_RWSEM(fw_device_rwsem);
814
815DEFINE_XARRAY_ALLOC(fw_device_xa);
816int fw_cdev_major;
817
818struct fw_device *fw_device_get_by_devt(dev_t devt)
819{
820 struct fw_device *device;
821
822 device = xa_load(&fw_device_xa, MINOR(devt));
823 if (device)
824 fw_device_get(device);
825
826 return device;
827}
828
829struct workqueue_struct *fw_workqueue;
830EXPORT_SYMBOL(fw_workqueue);
831
832static void fw_schedule_device_work(struct fw_device *device,
833 unsigned long delay)
834{
835 queue_delayed_work(fw_workqueue, &device->work, delay);
836}
837
838/*
839 * These defines control the retry behavior for reading the config
840 * rom. It shouldn't be necessary to tweak these; if the device
841 * doesn't respond to a config rom read within 10 seconds, it's not
842 * going to respond at all. As for the initial delay, a lot of
843 * devices will be able to respond within half a second after bus
844 * reset. On the other hand, it's not really worth being more
845 * aggressive than that, since it scales pretty well; if 10 devices
846 * are plugged in, they're all getting read within one second.
847 */
848
849#define MAX_RETRIES 10
850#define RETRY_DELAY (3 * HZ)
851#define INITIAL_DELAY (HZ / 2)
852#define SHUTDOWN_DELAY (2 * HZ)
853
854static void fw_device_shutdown(struct work_struct *work)
855{
856 struct fw_device *device =
857 container_of(work, struct fw_device, work.work);
858
859 if (time_before64(get_jiffies_64(),
860 device->card->reset_jiffies + SHUTDOWN_DELAY)
861 && !list_empty(&device->card->link)) {
862 fw_schedule_device_work(device, SHUTDOWN_DELAY);
863 return;
864 }
865
866 if (atomic_cmpxchg(&device->state,
867 FW_DEVICE_GONE,
868 FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE)
869 return;
870
871 fw_device_cdev_remove(device);
872 device_for_each_child(&device->device, NULL, shutdown_unit);
873 device_unregister(&device->device);
874
875 xa_erase(&fw_device_xa, MINOR(device->device.devt));
876
877 fw_device_put(device);
878}
879
880static void fw_device_release(struct device *dev)
881{
882 struct fw_device *device = fw_device(dev);
883 struct fw_card *card = device->card;
884
885 /*
886 * Take the card lock so we don't set this to NULL while a
887 * FW_NODE_UPDATED callback is being handled or while the
888 * bus manager work looks at this node.
889 */
890 scoped_guard(spinlock_irqsave, &card->lock)
891 device->node->data = NULL;
892
893 fw_node_put(device->node);
894 kfree(device->config_rom);
895 kfree(device);
896 fw_card_put(card);
897}
898
899static struct device_type fw_device_type = {
900 .release = fw_device_release,
901};
902
903static bool is_fw_device(const struct device *dev)
904{
905 return dev->type == &fw_device_type;
906}
907
908static int update_unit(struct device *dev, void *data)
909{
910 struct fw_unit *unit = fw_unit(dev);
911 struct fw_driver *driver = (struct fw_driver *)dev->driver;
912
913 if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) {
914 device_lock(dev);
915 driver->update(unit);
916 device_unlock(dev);
917 }
918
919 return 0;
920}
921
922static void fw_device_update(struct work_struct *work)
923{
924 struct fw_device *device =
925 container_of(work, struct fw_device, work.work);
926
927 fw_device_cdev_update(device);
928 device_for_each_child(&device->device, NULL, update_unit);
929}
930
931enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, };
932
933static void set_broadcast_channel(struct fw_device *device, int generation)
934{
935 struct fw_card *card = device->card;
936 __be32 data;
937 int rcode;
938
939 if (!card->broadcast_channel_allocated)
940 return;
941
942 /*
943 * The Broadcast_Channel Valid bit is required by nodes which want to
944 * transmit on this channel. Such transmissions are practically
945 * exclusive to IP over 1394 (RFC 2734). IP capable nodes are required
946 * to be IRM capable and have a max_rec of 8 or more. We use this fact
947 * to narrow down to which nodes we send Broadcast_Channel updates.
948 */
949 if (!device->irmc || device->max_rec < 8)
950 return;
951
952 /*
953 * Some 1394-1995 nodes crash if this 1394a-2000 register is written.
954 * Perform a read test first.
955 */
956 if (device->bc_implemented == BC_UNKNOWN) {
957 rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST,
958 device->node_id, generation, device->max_speed,
959 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
960 &data, 4);
961 switch (rcode) {
962 case RCODE_COMPLETE:
963 if (data & cpu_to_be32(1 << 31)) {
964 device->bc_implemented = BC_IMPLEMENTED;
965 break;
966 }
967 fallthrough; /* to case address error */
968 case RCODE_ADDRESS_ERROR:
969 device->bc_implemented = BC_UNIMPLEMENTED;
970 }
971 }
972
973 if (device->bc_implemented == BC_IMPLEMENTED) {
974 data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL |
975 BROADCAST_CHANNEL_VALID);
976 fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
977 device->node_id, generation, device->max_speed,
978 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
979 &data, 4);
980 }
981}
982
983int fw_device_set_broadcast_channel(struct device *dev, void *gen)
984{
985 if (is_fw_device(dev))
986 set_broadcast_channel(fw_device(dev), (long)gen);
987
988 return 0;
989}
990
991static int compare_configuration_rom(struct device *dev, void *data)
992{
993 const struct fw_device *old = fw_device(dev);
994 const u32 *config_rom = data;
995
996 if (!is_fw_device(dev))
997 return 0;
998
999 // Compare the bus information block and root_length/root_crc.
1000 return !memcmp(old->config_rom, config_rom, 6 * 4);
1001}
1002
1003static void fw_device_init(struct work_struct *work)
1004{
1005 struct fw_device *device =
1006 container_of(work, struct fw_device, work.work);
1007 struct fw_card *card = device->card;
1008 struct device *found;
1009 u32 minor;
1010 int ret;
1011
1012 /*
1013 * All failure paths here set node->data to NULL, so that we
1014 * don't try to do device_for_each_child() on a kfree()'d
1015 * device.
1016 */
1017
1018 ret = read_config_rom(device, device->generation);
1019 if (ret != RCODE_COMPLETE) {
1020 if (device->config_rom_retries < MAX_RETRIES &&
1021 atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1022 device->config_rom_retries++;
1023 fw_schedule_device_work(device, RETRY_DELAY);
1024 } else {
1025 if (device->node->link_on)
1026 fw_notice(card, "giving up on node %x: reading config rom failed: %s\n",
1027 device->node_id,
1028 fw_rcode_string(ret));
1029 if (device->node == card->root_node)
1030 fw_schedule_bm_work(card, 0);
1031 fw_device_release(&device->device);
1032 }
1033 return;
1034 }
1035
1036 // If a device was pending for deletion because its node went away but its bus info block
1037 // and root directory header matches that of a newly discovered device, revive the
1038 // existing fw_device. The newly allocated fw_device becomes obsolete instead.
1039 //
1040 // serialize config_rom access.
1041 scoped_guard(rwsem_read, &fw_device_rwsem) {
1042 found = device_find_child(card->device, (void *)device->config_rom,
1043 compare_configuration_rom);
1044 }
1045 if (found) {
1046 struct fw_device *reused = fw_device(found);
1047
1048 if (atomic_cmpxchg(&reused->state,
1049 FW_DEVICE_GONE,
1050 FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
1051 // serialize node access
1052 scoped_guard(spinlock_irq, &card->lock) {
1053 struct fw_node *current_node = device->node;
1054 struct fw_node *obsolete_node = reused->node;
1055
1056 device->node = obsolete_node;
1057 device->node->data = device;
1058 reused->node = current_node;
1059 reused->node->data = reused;
1060
1061 reused->max_speed = device->max_speed;
1062 reused->node_id = current_node->node_id;
1063 smp_wmb(); /* update node_id before generation */
1064 reused->generation = card->generation;
1065 reused->config_rom_retries = 0;
1066 fw_notice(card, "rediscovered device %s\n",
1067 dev_name(found));
1068
1069 reused->workfn = fw_device_update;
1070 fw_schedule_device_work(reused, 0);
1071
1072 if (current_node == card->root_node)
1073 fw_schedule_bm_work(card, 0);
1074 }
1075
1076 put_device(found);
1077 fw_device_release(&device->device);
1078
1079 return;
1080 }
1081
1082 put_device(found);
1083 }
1084
1085 device_initialize(&device->device);
1086
1087 fw_device_get(device);
1088
1089 // The index of allocated entry is used for minor identifier of device node.
1090 ret = xa_alloc(&fw_device_xa, &minor, device, XA_LIMIT(0, MINORMASK), GFP_KERNEL);
1091 if (ret < 0)
1092 goto error;
1093
1094 device->device.bus = &fw_bus_type;
1095 device->device.type = &fw_device_type;
1096 device->device.parent = card->device;
1097 device->device.devt = MKDEV(fw_cdev_major, minor);
1098 dev_set_name(&device->device, "fw%d", minor);
1099
1100 BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) <
1101 ARRAY_SIZE(fw_device_attributes) +
1102 ARRAY_SIZE(config_rom_attributes));
1103 init_fw_attribute_group(&device->device,
1104 fw_device_attributes,
1105 &device->attribute_group);
1106
1107 if (device_add(&device->device)) {
1108 fw_err(card, "failed to add device\n");
1109 goto error_with_cdev;
1110 }
1111
1112 create_units(device);
1113
1114 /*
1115 * Transition the device to running state. If it got pulled
1116 * out from under us while we did the initialization work, we
1117 * have to shut down the device again here. Normally, though,
1118 * fw_node_event will be responsible for shutting it down when
1119 * necessary. We have to use the atomic cmpxchg here to avoid
1120 * racing with the FW_NODE_DESTROYED case in
1121 * fw_node_event().
1122 */
1123 if (atomic_cmpxchg(&device->state,
1124 FW_DEVICE_INITIALIZING,
1125 FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
1126 device->workfn = fw_device_shutdown;
1127 fw_schedule_device_work(device, SHUTDOWN_DELAY);
1128 } else {
1129 fw_notice(card, "created device %s: GUID %08x%08x, S%d00\n",
1130 dev_name(&device->device),
1131 device->config_rom[3], device->config_rom[4],
1132 1 << device->max_speed);
1133 device->config_rom_retries = 0;
1134
1135 set_broadcast_channel(device, device->generation);
1136
1137 add_device_randomness(&device->config_rom[3], 8);
1138 }
1139
1140 /*
1141 * Reschedule the IRM work if we just finished reading the
1142 * root node config rom. If this races with a bus reset we
1143 * just end up running the IRM work a couple of extra times -
1144 * pretty harmless.
1145 */
1146 if (device->node == card->root_node)
1147 fw_schedule_bm_work(card, 0);
1148
1149 return;
1150
1151 error_with_cdev:
1152 xa_erase(&fw_device_xa, minor);
1153 error:
1154 fw_device_put(device); // fw_device_xa's reference.
1155
1156 put_device(&device->device); /* our reference */
1157}
1158
1159/* Reread and compare bus info block and header of root directory */
1160static int reread_config_rom(struct fw_device *device, int generation,
1161 bool *changed)
1162{
1163 u32 q;
1164 int i, rcode;
1165
1166 for (i = 0; i < 6; i++) {
1167 rcode = read_rom(device, generation, i, &q);
1168 if (rcode != RCODE_COMPLETE)
1169 return rcode;
1170
1171 if (i == 0 && q == 0)
1172 /* inaccessible (see read_config_rom); retry later */
1173 return RCODE_BUSY;
1174
1175 if (q != device->config_rom[i]) {
1176 *changed = true;
1177 return RCODE_COMPLETE;
1178 }
1179 }
1180
1181 *changed = false;
1182 return RCODE_COMPLETE;
1183}
1184
1185static void fw_device_refresh(struct work_struct *work)
1186{
1187 struct fw_device *device =
1188 container_of(work, struct fw_device, work.work);
1189 struct fw_card *card = device->card;
1190 int ret, node_id = device->node_id;
1191 bool changed;
1192
1193 ret = reread_config_rom(device, device->generation, &changed);
1194 if (ret != RCODE_COMPLETE)
1195 goto failed_config_rom;
1196
1197 if (!changed) {
1198 if (atomic_cmpxchg(&device->state,
1199 FW_DEVICE_INITIALIZING,
1200 FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1201 goto gone;
1202
1203 fw_device_update(work);
1204 device->config_rom_retries = 0;
1205 goto out;
1206 }
1207
1208 /*
1209 * Something changed. We keep things simple and don't investigate
1210 * further. We just destroy all previous units and create new ones.
1211 */
1212 device_for_each_child(&device->device, NULL, shutdown_unit);
1213
1214 ret = read_config_rom(device, device->generation);
1215 if (ret != RCODE_COMPLETE)
1216 goto failed_config_rom;
1217
1218 fw_device_cdev_update(device);
1219 create_units(device);
1220
1221 /* Userspace may want to re-read attributes. */
1222 kobject_uevent(&device->device.kobj, KOBJ_CHANGE);
1223
1224 if (atomic_cmpxchg(&device->state,
1225 FW_DEVICE_INITIALIZING,
1226 FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1227 goto gone;
1228
1229 fw_notice(card, "refreshed device %s\n", dev_name(&device->device));
1230 device->config_rom_retries = 0;
1231 goto out;
1232
1233 failed_config_rom:
1234 if (device->config_rom_retries < MAX_RETRIES &&
1235 atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1236 device->config_rom_retries++;
1237 fw_schedule_device_work(device, RETRY_DELAY);
1238 return;
1239 }
1240
1241 fw_notice(card, "giving up on refresh of device %s: %s\n",
1242 dev_name(&device->device), fw_rcode_string(ret));
1243 gone:
1244 atomic_set(&device->state, FW_DEVICE_GONE);
1245 device->workfn = fw_device_shutdown;
1246 fw_schedule_device_work(device, SHUTDOWN_DELAY);
1247 out:
1248 if (node_id == card->root_node->node_id)
1249 fw_schedule_bm_work(card, 0);
1250}
1251
1252static void fw_device_workfn(struct work_struct *work)
1253{
1254 struct fw_device *device = container_of(to_delayed_work(work),
1255 struct fw_device, work);
1256 device->workfn(work);
1257}
1258
1259void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
1260{
1261 struct fw_device *device;
1262
1263 switch (event) {
1264 case FW_NODE_CREATED:
1265 /*
1266 * Attempt to scan the node, regardless whether its self ID has
1267 * the L (link active) flag set or not. Some broken devices
1268 * send L=0 but have an up-and-running link; others send L=1
1269 * without actually having a link.
1270 */
1271 create:
1272 device = kzalloc(sizeof(*device), GFP_ATOMIC);
1273 if (device == NULL)
1274 break;
1275
1276 /*
1277 * Do minimal initialization of the device here, the
1278 * rest will happen in fw_device_init().
1279 *
1280 * Attention: A lot of things, even fw_device_get(),
1281 * cannot be done before fw_device_init() finished!
1282 * You can basically just check device->state and
1283 * schedule work until then, but only while holding
1284 * card->lock.
1285 */
1286 atomic_set(&device->state, FW_DEVICE_INITIALIZING);
1287 device->card = fw_card_get(card);
1288 device->node = fw_node_get(node);
1289 device->node_id = node->node_id;
1290 device->generation = card->generation;
1291 device->is_local = node == card->local_node;
1292 mutex_init(&device->client_list_mutex);
1293 INIT_LIST_HEAD(&device->client_list);
1294
1295 /*
1296 * Set the node data to point back to this device so
1297 * FW_NODE_UPDATED callbacks can update the node_id
1298 * and generation for the device.
1299 */
1300 node->data = device;
1301
1302 /*
1303 * Many devices are slow to respond after bus resets,
1304 * especially if they are bus powered and go through
1305 * power-up after getting plugged in. We schedule the
1306 * first config rom scan half a second after bus reset.
1307 */
1308 device->workfn = fw_device_init;
1309 INIT_DELAYED_WORK(&device->work, fw_device_workfn);
1310 fw_schedule_device_work(device, INITIAL_DELAY);
1311 break;
1312
1313 case FW_NODE_INITIATED_RESET:
1314 case FW_NODE_LINK_ON:
1315 device = node->data;
1316 if (device == NULL)
1317 goto create;
1318
1319 device->node_id = node->node_id;
1320 smp_wmb(); /* update node_id before generation */
1321 device->generation = card->generation;
1322 if (atomic_cmpxchg(&device->state,
1323 FW_DEVICE_RUNNING,
1324 FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) {
1325 device->workfn = fw_device_refresh;
1326 fw_schedule_device_work(device,
1327 device->is_local ? 0 : INITIAL_DELAY);
1328 }
1329 break;
1330
1331 case FW_NODE_UPDATED:
1332 device = node->data;
1333 if (device == NULL)
1334 break;
1335
1336 device->node_id = node->node_id;
1337 smp_wmb(); /* update node_id before generation */
1338 device->generation = card->generation;
1339 if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
1340 device->workfn = fw_device_update;
1341 fw_schedule_device_work(device, 0);
1342 }
1343 break;
1344
1345 case FW_NODE_DESTROYED:
1346 case FW_NODE_LINK_OFF:
1347 if (!node->data)
1348 break;
1349
1350 /*
1351 * Destroy the device associated with the node. There
1352 * are two cases here: either the device is fully
1353 * initialized (FW_DEVICE_RUNNING) or we're in the
1354 * process of reading its config rom
1355 * (FW_DEVICE_INITIALIZING). If it is fully
1356 * initialized we can reuse device->work to schedule a
1357 * full fw_device_shutdown(). If not, there's work
1358 * scheduled to read it's config rom, and we just put
1359 * the device in shutdown state to have that code fail
1360 * to create the device.
1361 */
1362 device = node->data;
1363 if (atomic_xchg(&device->state,
1364 FW_DEVICE_GONE) == FW_DEVICE_RUNNING) {
1365 device->workfn = fw_device_shutdown;
1366 fw_schedule_device_work(device,
1367 list_empty(&card->link) ? 0 : SHUTDOWN_DELAY);
1368 }
1369 break;
1370 }
1371}
1372
1373#ifdef CONFIG_FIREWIRE_KUNIT_DEVICE_ATTRIBUTE_TEST
1374#include "device-attribute-test.c"
1375#endif
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/bug.h>
22#include <linux/ctype.h>
23#include <linux/delay.h>
24#include <linux/device.h>
25#include <linux/errno.h>
26#include <linux/firewire.h>
27#include <linux/firewire-constants.h>
28#include <linux/idr.h>
29#include <linux/jiffies.h>
30#include <linux/kobject.h>
31#include <linux/list.h>
32#include <linux/mod_devicetable.h>
33#include <linux/module.h>
34#include <linux/mutex.h>
35#include <linux/rwsem.h>
36#include <linux/slab.h>
37#include <linux/spinlock.h>
38#include <linux/string.h>
39#include <linux/workqueue.h>
40
41#include <linux/atomic.h>
42#include <asm/byteorder.h>
43
44#include "core.h"
45
46void fw_csr_iterator_init(struct fw_csr_iterator *ci, const u32 *p)
47{
48 ci->p = p + 1;
49 ci->end = ci->p + (p[0] >> 16);
50}
51EXPORT_SYMBOL(fw_csr_iterator_init);
52
53int 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}
60EXPORT_SYMBOL(fw_csr_iterator_next);
61
62static const u32 *search_leaf(const u32 *directory, int search_key)
63{
64 struct fw_csr_iterator ci;
65 int last_key = 0, key, value;
66
67 fw_csr_iterator_init(&ci, directory);
68 while (fw_csr_iterator_next(&ci, &key, &value)) {
69 if (last_key == search_key &&
70 key == (CSR_DESCRIPTOR | CSR_LEAF))
71 return ci.p - 1 + value;
72
73 last_key = key;
74 }
75
76 return NULL;
77}
78
79static int textual_leaf_to_string(const u32 *block, char *buf, size_t size)
80{
81 unsigned int quadlets, i;
82 char c;
83
84 if (!size || !buf)
85 return -EINVAL;
86
87 quadlets = min(block[0] >> 16, 256U);
88 if (quadlets < 2)
89 return -ENODATA;
90
91 if (block[1] != 0 || block[2] != 0)
92 /* unknown language/character set */
93 return -ENODATA;
94
95 block += 3;
96 quadlets -= 2;
97 for (i = 0; i < quadlets * 4 && i < size - 1; i++) {
98 c = block[i / 4] >> (24 - 8 * (i % 4));
99 if (c == '\0')
100 break;
101 buf[i] = c;
102 }
103 buf[i] = '\0';
104
105 return i;
106}
107
108/**
109 * fw_csr_string() - reads a string from the configuration ROM
110 * @directory: e.g. root directory or unit directory
111 * @key: the key of the preceding directory entry
112 * @buf: where to put the string
113 * @size: size of @buf, in bytes
114 *
115 * The string is taken from a minimal ASCII text descriptor leaf after
116 * the immediate entry with @key. The string is zero-terminated.
117 * Returns strlen(buf) or a negative error code.
118 */
119int fw_csr_string(const u32 *directory, int key, char *buf, size_t size)
120{
121 const u32 *leaf = search_leaf(directory, key);
122 if (!leaf)
123 return -ENOENT;
124
125 return textual_leaf_to_string(leaf, buf, size);
126}
127EXPORT_SYMBOL(fw_csr_string);
128
129static void get_ids(const u32 *directory, int *id)
130{
131 struct fw_csr_iterator ci;
132 int key, value;
133
134 fw_csr_iterator_init(&ci, directory);
135 while (fw_csr_iterator_next(&ci, &key, &value)) {
136 switch (key) {
137 case CSR_VENDOR: id[0] = value; break;
138 case CSR_MODEL: id[1] = value; break;
139 case CSR_SPECIFIER_ID: id[2] = value; break;
140 case CSR_VERSION: id[3] = value; break;
141 }
142 }
143}
144
145static void get_modalias_ids(struct fw_unit *unit, int *id)
146{
147 get_ids(&fw_parent_device(unit)->config_rom[5], id);
148 get_ids(unit->directory, id);
149}
150
151static bool match_ids(const struct ieee1394_device_id *id_table, int *id)
152{
153 int match = 0;
154
155 if (id[0] == id_table->vendor_id)
156 match |= IEEE1394_MATCH_VENDOR_ID;
157 if (id[1] == id_table->model_id)
158 match |= IEEE1394_MATCH_MODEL_ID;
159 if (id[2] == id_table->specifier_id)
160 match |= IEEE1394_MATCH_SPECIFIER_ID;
161 if (id[3] == id_table->version)
162 match |= IEEE1394_MATCH_VERSION;
163
164 return (match & id_table->match_flags) == id_table->match_flags;
165}
166
167static bool is_fw_unit(struct device *dev);
168
169static int fw_unit_match(struct device *dev, struct device_driver *drv)
170{
171 const struct ieee1394_device_id *id_table =
172 container_of(drv, struct fw_driver, driver)->id_table;
173 int id[] = {0, 0, 0, 0};
174
175 /* We only allow binding to fw_units. */
176 if (!is_fw_unit(dev))
177 return 0;
178
179 get_modalias_ids(fw_unit(dev), id);
180
181 for (; id_table->match_flags != 0; id_table++)
182 if (match_ids(id_table, id))
183 return 1;
184
185 return 0;
186}
187
188static int get_modalias(struct fw_unit *unit, char *buffer, size_t buffer_size)
189{
190 int id[] = {0, 0, 0, 0};
191
192 get_modalias_ids(unit, id);
193
194 return snprintf(buffer, buffer_size,
195 "ieee1394:ven%08Xmo%08Xsp%08Xver%08X",
196 id[0], id[1], id[2], id[3]);
197}
198
199static int fw_unit_uevent(struct device *dev, struct kobj_uevent_env *env)
200{
201 struct fw_unit *unit = fw_unit(dev);
202 char modalias[64];
203
204 get_modalias(unit, modalias, sizeof(modalias));
205
206 if (add_uevent_var(env, "MODALIAS=%s", modalias))
207 return -ENOMEM;
208
209 return 0;
210}
211
212struct bus_type fw_bus_type = {
213 .name = "firewire",
214 .match = fw_unit_match,
215};
216EXPORT_SYMBOL(fw_bus_type);
217
218int fw_device_enable_phys_dma(struct fw_device *device)
219{
220 int generation = device->generation;
221
222 /* device->node_id, accessed below, must not be older than generation */
223 smp_rmb();
224
225 return device->card->driver->enable_phys_dma(device->card,
226 device->node_id,
227 generation);
228}
229EXPORT_SYMBOL(fw_device_enable_phys_dma);
230
231struct config_rom_attribute {
232 struct device_attribute attr;
233 u32 key;
234};
235
236static ssize_t show_immediate(struct device *dev,
237 struct device_attribute *dattr, char *buf)
238{
239 struct config_rom_attribute *attr =
240 container_of(dattr, struct config_rom_attribute, attr);
241 struct fw_csr_iterator ci;
242 const u32 *dir;
243 int key, value, ret = -ENOENT;
244
245 down_read(&fw_device_rwsem);
246
247 if (is_fw_unit(dev))
248 dir = fw_unit(dev)->directory;
249 else
250 dir = fw_device(dev)->config_rom + 5;
251
252 fw_csr_iterator_init(&ci, dir);
253 while (fw_csr_iterator_next(&ci, &key, &value))
254 if (attr->key == key) {
255 ret = snprintf(buf, buf ? PAGE_SIZE : 0,
256 "0x%06x\n", value);
257 break;
258 }
259
260 up_read(&fw_device_rwsem);
261
262 return ret;
263}
264
265#define IMMEDIATE_ATTR(name, key) \
266 { __ATTR(name, S_IRUGO, show_immediate, NULL), key }
267
268static ssize_t show_text_leaf(struct device *dev,
269 struct device_attribute *dattr, char *buf)
270{
271 struct config_rom_attribute *attr =
272 container_of(dattr, struct config_rom_attribute, attr);
273 const u32 *dir;
274 size_t bufsize;
275 char dummy_buf[2];
276 int ret;
277
278 down_read(&fw_device_rwsem);
279
280 if (is_fw_unit(dev))
281 dir = fw_unit(dev)->directory;
282 else
283 dir = fw_device(dev)->config_rom + 5;
284
285 if (buf) {
286 bufsize = PAGE_SIZE - 1;
287 } else {
288 buf = dummy_buf;
289 bufsize = 1;
290 }
291
292 ret = fw_csr_string(dir, attr->key, buf, bufsize);
293
294 if (ret >= 0) {
295 /* Strip trailing whitespace and add newline. */
296 while (ret > 0 && isspace(buf[ret - 1]))
297 ret--;
298 strcpy(buf + ret, "\n");
299 ret++;
300 }
301
302 up_read(&fw_device_rwsem);
303
304 return ret;
305}
306
307#define TEXT_LEAF_ATTR(name, key) \
308 { __ATTR(name, S_IRUGO, show_text_leaf, NULL), key }
309
310static struct config_rom_attribute config_rom_attributes[] = {
311 IMMEDIATE_ATTR(vendor, CSR_VENDOR),
312 IMMEDIATE_ATTR(hardware_version, CSR_HARDWARE_VERSION),
313 IMMEDIATE_ATTR(specifier_id, CSR_SPECIFIER_ID),
314 IMMEDIATE_ATTR(version, CSR_VERSION),
315 IMMEDIATE_ATTR(model, CSR_MODEL),
316 TEXT_LEAF_ATTR(vendor_name, CSR_VENDOR),
317 TEXT_LEAF_ATTR(model_name, CSR_MODEL),
318 TEXT_LEAF_ATTR(hardware_version_name, CSR_HARDWARE_VERSION),
319};
320
321static void init_fw_attribute_group(struct device *dev,
322 struct device_attribute *attrs,
323 struct fw_attribute_group *group)
324{
325 struct device_attribute *attr;
326 int i, j;
327
328 for (j = 0; attrs[j].attr.name != NULL; j++)
329 group->attrs[j] = &attrs[j].attr;
330
331 for (i = 0; i < ARRAY_SIZE(config_rom_attributes); i++) {
332 attr = &config_rom_attributes[i].attr;
333 if (attr->show(dev, attr, NULL) < 0)
334 continue;
335 group->attrs[j++] = &attr->attr;
336 }
337
338 group->attrs[j] = NULL;
339 group->groups[0] = &group->group;
340 group->groups[1] = NULL;
341 group->group.attrs = group->attrs;
342 dev->groups = (const struct attribute_group **) group->groups;
343}
344
345static ssize_t modalias_show(struct device *dev,
346 struct device_attribute *attr, char *buf)
347{
348 struct fw_unit *unit = fw_unit(dev);
349 int length;
350
351 length = get_modalias(unit, buf, PAGE_SIZE);
352 strcpy(buf + length, "\n");
353
354 return length + 1;
355}
356
357static ssize_t rom_index_show(struct device *dev,
358 struct device_attribute *attr, char *buf)
359{
360 struct fw_device *device = fw_device(dev->parent);
361 struct fw_unit *unit = fw_unit(dev);
362
363 return snprintf(buf, PAGE_SIZE, "%d\n",
364 (int)(unit->directory - device->config_rom));
365}
366
367static struct device_attribute fw_unit_attributes[] = {
368 __ATTR_RO(modalias),
369 __ATTR_RO(rom_index),
370 __ATTR_NULL,
371};
372
373static ssize_t config_rom_show(struct device *dev,
374 struct device_attribute *attr, char *buf)
375{
376 struct fw_device *device = fw_device(dev);
377 size_t length;
378
379 down_read(&fw_device_rwsem);
380 length = device->config_rom_length * 4;
381 memcpy(buf, device->config_rom, length);
382 up_read(&fw_device_rwsem);
383
384 return length;
385}
386
387static ssize_t guid_show(struct device *dev,
388 struct device_attribute *attr, char *buf)
389{
390 struct fw_device *device = fw_device(dev);
391 int ret;
392
393 down_read(&fw_device_rwsem);
394 ret = snprintf(buf, PAGE_SIZE, "0x%08x%08x\n",
395 device->config_rom[3], device->config_rom[4]);
396 up_read(&fw_device_rwsem);
397
398 return ret;
399}
400
401static int units_sprintf(char *buf, const u32 *directory)
402{
403 struct fw_csr_iterator ci;
404 int key, value;
405 int specifier_id = 0;
406 int version = 0;
407
408 fw_csr_iterator_init(&ci, directory);
409 while (fw_csr_iterator_next(&ci, &key, &value)) {
410 switch (key) {
411 case CSR_SPECIFIER_ID:
412 specifier_id = value;
413 break;
414 case CSR_VERSION:
415 version = value;
416 break;
417 }
418 }
419
420 return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version);
421}
422
423static ssize_t units_show(struct device *dev,
424 struct device_attribute *attr, char *buf)
425{
426 struct fw_device *device = fw_device(dev);
427 struct fw_csr_iterator ci;
428 int key, value, i = 0;
429
430 down_read(&fw_device_rwsem);
431 fw_csr_iterator_init(&ci, &device->config_rom[5]);
432 while (fw_csr_iterator_next(&ci, &key, &value)) {
433 if (key != (CSR_UNIT | CSR_DIRECTORY))
434 continue;
435 i += units_sprintf(&buf[i], ci.p + value - 1);
436 if (i >= PAGE_SIZE - (8 + 1 + 8 + 1))
437 break;
438 }
439 up_read(&fw_device_rwsem);
440
441 if (i)
442 buf[i - 1] = '\n';
443
444 return i;
445}
446
447static struct device_attribute fw_device_attributes[] = {
448 __ATTR_RO(config_rom),
449 __ATTR_RO(guid),
450 __ATTR_RO(units),
451 __ATTR_NULL,
452};
453
454static int read_rom(struct fw_device *device,
455 int generation, int index, u32 *data)
456{
457 u64 offset = (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4;
458 int i, rcode;
459
460 /* device->node_id, accessed below, must not be older than generation */
461 smp_rmb();
462
463 for (i = 10; i < 100; i += 10) {
464 rcode = fw_run_transaction(device->card,
465 TCODE_READ_QUADLET_REQUEST, device->node_id,
466 generation, device->max_speed, offset, data, 4);
467 if (rcode != RCODE_BUSY)
468 break;
469 msleep(i);
470 }
471 be32_to_cpus(data);
472
473 return rcode;
474}
475
476#define MAX_CONFIG_ROM_SIZE 256
477
478/*
479 * Read the bus info block, perform a speed probe, and read all of the rest of
480 * the config ROM. We do all this with a cached bus generation. If the bus
481 * generation changes under us, read_config_rom will fail and get retried.
482 * It's better to start all over in this case because the node from which we
483 * are reading the ROM may have changed the ROM during the reset.
484 * Returns either a result code or a negative error code.
485 */
486static int read_config_rom(struct fw_device *device, int generation)
487{
488 struct fw_card *card = device->card;
489 const u32 *old_rom, *new_rom;
490 u32 *rom, *stack;
491 u32 sp, key;
492 int i, end, length, ret;
493
494 rom = kmalloc(sizeof(*rom) * MAX_CONFIG_ROM_SIZE +
495 sizeof(*stack) * MAX_CONFIG_ROM_SIZE, GFP_KERNEL);
496 if (rom == NULL)
497 return -ENOMEM;
498
499 stack = &rom[MAX_CONFIG_ROM_SIZE];
500 memset(rom, 0, sizeof(*rom) * MAX_CONFIG_ROM_SIZE);
501
502 device->max_speed = SCODE_100;
503
504 /* First read the bus info block. */
505 for (i = 0; i < 5; i++) {
506 ret = read_rom(device, generation, i, &rom[i]);
507 if (ret != RCODE_COMPLETE)
508 goto out;
509 /*
510 * As per IEEE1212 7.2, during initialization, devices can
511 * reply with a 0 for the first quadlet of the config
512 * rom to indicate that they are booting (for example,
513 * if the firmware is on the disk of a external
514 * harddisk). In that case we just fail, and the
515 * retry mechanism will try again later.
516 */
517 if (i == 0 && rom[i] == 0) {
518 ret = RCODE_BUSY;
519 goto out;
520 }
521 }
522
523 device->max_speed = device->node->max_speed;
524
525 /*
526 * Determine the speed of
527 * - devices with link speed less than PHY speed,
528 * - devices with 1394b PHY (unless only connected to 1394a PHYs),
529 * - all devices if there are 1394b repeaters.
530 * Note, we cannot use the bus info block's link_spd as starting point
531 * because some buggy firmwares set it lower than necessary and because
532 * 1394-1995 nodes do not have the field.
533 */
534 if ((rom[2] & 0x7) < device->max_speed ||
535 device->max_speed == SCODE_BETA ||
536 card->beta_repeaters_present) {
537 u32 dummy;
538
539 /* for S1600 and S3200 */
540 if (device->max_speed == SCODE_BETA)
541 device->max_speed = card->link_speed;
542
543 while (device->max_speed > SCODE_100) {
544 if (read_rom(device, generation, 0, &dummy) ==
545 RCODE_COMPLETE)
546 break;
547 device->max_speed--;
548 }
549 }
550
551 /*
552 * Now parse the config rom. The config rom is a recursive
553 * directory structure so we parse it using a stack of
554 * references to the blocks that make up the structure. We
555 * push a reference to the root directory on the stack to
556 * start things off.
557 */
558 length = i;
559 sp = 0;
560 stack[sp++] = 0xc0000005;
561 while (sp > 0) {
562 /*
563 * Pop the next block reference of the stack. The
564 * lower 24 bits is the offset into the config rom,
565 * the upper 8 bits are the type of the reference the
566 * block.
567 */
568 key = stack[--sp];
569 i = key & 0xffffff;
570 if (WARN_ON(i >= MAX_CONFIG_ROM_SIZE)) {
571 ret = -ENXIO;
572 goto out;
573 }
574
575 /* Read header quadlet for the block to get the length. */
576 ret = read_rom(device, generation, i, &rom[i]);
577 if (ret != RCODE_COMPLETE)
578 goto out;
579 end = i + (rom[i] >> 16) + 1;
580 if (end > MAX_CONFIG_ROM_SIZE) {
581 /*
582 * This block extends outside the config ROM which is
583 * a firmware bug. Ignore this whole block, i.e.
584 * simply set a fake block length of 0.
585 */
586 fw_err(card, "skipped invalid ROM block %x at %llx\n",
587 rom[i],
588 i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
589 rom[i] = 0;
590 end = i;
591 }
592 i++;
593
594 /*
595 * Now read in the block. If this is a directory
596 * block, check the entries as we read them to see if
597 * it references another block, and push it in that case.
598 */
599 for (; i < end; i++) {
600 ret = read_rom(device, generation, i, &rom[i]);
601 if (ret != RCODE_COMPLETE)
602 goto out;
603
604 if ((key >> 30) != 3 || (rom[i] >> 30) < 2)
605 continue;
606 /*
607 * Offset points outside the ROM. May be a firmware
608 * bug or an Extended ROM entry (IEEE 1212-2001 clause
609 * 7.7.18). Simply overwrite this pointer here by a
610 * fake immediate entry so that later iterators over
611 * the ROM don't have to check offsets all the time.
612 */
613 if (i + (rom[i] & 0xffffff) >= MAX_CONFIG_ROM_SIZE) {
614 fw_err(card,
615 "skipped unsupported ROM entry %x at %llx\n",
616 rom[i],
617 i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM);
618 rom[i] = 0;
619 continue;
620 }
621 stack[sp++] = i + rom[i];
622 }
623 if (length < i)
624 length = i;
625 }
626
627 old_rom = device->config_rom;
628 new_rom = kmemdup(rom, length * 4, GFP_KERNEL);
629 if (new_rom == NULL) {
630 ret = -ENOMEM;
631 goto out;
632 }
633
634 down_write(&fw_device_rwsem);
635 device->config_rom = new_rom;
636 device->config_rom_length = length;
637 up_write(&fw_device_rwsem);
638
639 kfree(old_rom);
640 ret = RCODE_COMPLETE;
641 device->max_rec = rom[2] >> 12 & 0xf;
642 device->cmc = rom[2] >> 30 & 1;
643 device->irmc = rom[2] >> 31 & 1;
644 out:
645 kfree(rom);
646
647 return ret;
648}
649
650static void fw_unit_release(struct device *dev)
651{
652 struct fw_unit *unit = fw_unit(dev);
653
654 fw_device_put(fw_parent_device(unit));
655 kfree(unit);
656}
657
658static struct device_type fw_unit_type = {
659 .uevent = fw_unit_uevent,
660 .release = fw_unit_release,
661};
662
663static bool is_fw_unit(struct device *dev)
664{
665 return dev->type == &fw_unit_type;
666}
667
668static void create_units(struct fw_device *device)
669{
670 struct fw_csr_iterator ci;
671 struct fw_unit *unit;
672 int key, value, i;
673
674 i = 0;
675 fw_csr_iterator_init(&ci, &device->config_rom[5]);
676 while (fw_csr_iterator_next(&ci, &key, &value)) {
677 if (key != (CSR_UNIT | CSR_DIRECTORY))
678 continue;
679
680 /*
681 * Get the address of the unit directory and try to
682 * match the drivers id_tables against it.
683 */
684 unit = kzalloc(sizeof(*unit), GFP_KERNEL);
685 if (unit == NULL) {
686 fw_err(device->card, "out of memory for unit\n");
687 continue;
688 }
689
690 unit->directory = ci.p + value - 1;
691 unit->device.bus = &fw_bus_type;
692 unit->device.type = &fw_unit_type;
693 unit->device.parent = &device->device;
694 dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++);
695
696 BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) <
697 ARRAY_SIZE(fw_unit_attributes) +
698 ARRAY_SIZE(config_rom_attributes));
699 init_fw_attribute_group(&unit->device,
700 fw_unit_attributes,
701 &unit->attribute_group);
702
703 if (device_register(&unit->device) < 0)
704 goto skip_unit;
705
706 fw_device_get(device);
707 continue;
708
709 skip_unit:
710 kfree(unit);
711 }
712}
713
714static int shutdown_unit(struct device *device, void *data)
715{
716 device_unregister(device);
717
718 return 0;
719}
720
721/*
722 * fw_device_rwsem acts as dual purpose mutex:
723 * - serializes accesses to fw_device_idr,
724 * - serializes accesses to fw_device.config_rom/.config_rom_length and
725 * fw_unit.directory, unless those accesses happen at safe occasions
726 */
727DECLARE_RWSEM(fw_device_rwsem);
728
729DEFINE_IDR(fw_device_idr);
730int fw_cdev_major;
731
732struct fw_device *fw_device_get_by_devt(dev_t devt)
733{
734 struct fw_device *device;
735
736 down_read(&fw_device_rwsem);
737 device = idr_find(&fw_device_idr, MINOR(devt));
738 if (device)
739 fw_device_get(device);
740 up_read(&fw_device_rwsem);
741
742 return device;
743}
744
745struct workqueue_struct *fw_workqueue;
746EXPORT_SYMBOL(fw_workqueue);
747
748static void fw_schedule_device_work(struct fw_device *device,
749 unsigned long delay)
750{
751 queue_delayed_work(fw_workqueue, &device->work, delay);
752}
753
754/*
755 * These defines control the retry behavior for reading the config
756 * rom. It shouldn't be necessary to tweak these; if the device
757 * doesn't respond to a config rom read within 10 seconds, it's not
758 * going to respond at all. As for the initial delay, a lot of
759 * devices will be able to respond within half a second after bus
760 * reset. On the other hand, it's not really worth being more
761 * aggressive than that, since it scales pretty well; if 10 devices
762 * are plugged in, they're all getting read within one second.
763 */
764
765#define MAX_RETRIES 10
766#define RETRY_DELAY (3 * HZ)
767#define INITIAL_DELAY (HZ / 2)
768#define SHUTDOWN_DELAY (2 * HZ)
769
770static void fw_device_shutdown(struct work_struct *work)
771{
772 struct fw_device *device =
773 container_of(work, struct fw_device, work.work);
774 int minor = MINOR(device->device.devt);
775
776 if (time_before64(get_jiffies_64(),
777 device->card->reset_jiffies + SHUTDOWN_DELAY)
778 && !list_empty(&device->card->link)) {
779 fw_schedule_device_work(device, SHUTDOWN_DELAY);
780 return;
781 }
782
783 if (atomic_cmpxchg(&device->state,
784 FW_DEVICE_GONE,
785 FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE)
786 return;
787
788 fw_device_cdev_remove(device);
789 device_for_each_child(&device->device, NULL, shutdown_unit);
790 device_unregister(&device->device);
791
792 down_write(&fw_device_rwsem);
793 idr_remove(&fw_device_idr, minor);
794 up_write(&fw_device_rwsem);
795
796 fw_device_put(device);
797}
798
799static void fw_device_release(struct device *dev)
800{
801 struct fw_device *device = fw_device(dev);
802 struct fw_card *card = device->card;
803 unsigned long flags;
804
805 /*
806 * Take the card lock so we don't set this to NULL while a
807 * FW_NODE_UPDATED callback is being handled or while the
808 * bus manager work looks at this node.
809 */
810 spin_lock_irqsave(&card->lock, flags);
811 device->node->data = NULL;
812 spin_unlock_irqrestore(&card->lock, flags);
813
814 fw_node_put(device->node);
815 kfree(device->config_rom);
816 kfree(device);
817 fw_card_put(card);
818}
819
820static struct device_type fw_device_type = {
821 .release = fw_device_release,
822};
823
824static bool is_fw_device(struct device *dev)
825{
826 return dev->type == &fw_device_type;
827}
828
829static int update_unit(struct device *dev, void *data)
830{
831 struct fw_unit *unit = fw_unit(dev);
832 struct fw_driver *driver = (struct fw_driver *)dev->driver;
833
834 if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) {
835 device_lock(dev);
836 driver->update(unit);
837 device_unlock(dev);
838 }
839
840 return 0;
841}
842
843static void fw_device_update(struct work_struct *work)
844{
845 struct fw_device *device =
846 container_of(work, struct fw_device, work.work);
847
848 fw_device_cdev_update(device);
849 device_for_each_child(&device->device, NULL, update_unit);
850}
851
852/*
853 * If a device was pending for deletion because its node went away but its
854 * bus info block and root directory header matches that of a newly discovered
855 * device, revive the existing fw_device.
856 * The newly allocated fw_device becomes obsolete instead.
857 */
858static int lookup_existing_device(struct device *dev, void *data)
859{
860 struct fw_device *old = fw_device(dev);
861 struct fw_device *new = data;
862 struct fw_card *card = new->card;
863 int match = 0;
864
865 if (!is_fw_device(dev))
866 return 0;
867
868 down_read(&fw_device_rwsem); /* serialize config_rom access */
869 spin_lock_irq(&card->lock); /* serialize node access */
870
871 if (memcmp(old->config_rom, new->config_rom, 6 * 4) == 0 &&
872 atomic_cmpxchg(&old->state,
873 FW_DEVICE_GONE,
874 FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
875 struct fw_node *current_node = new->node;
876 struct fw_node *obsolete_node = old->node;
877
878 new->node = obsolete_node;
879 new->node->data = new;
880 old->node = current_node;
881 old->node->data = old;
882
883 old->max_speed = new->max_speed;
884 old->node_id = current_node->node_id;
885 smp_wmb(); /* update node_id before generation */
886 old->generation = card->generation;
887 old->config_rom_retries = 0;
888 fw_notice(card, "rediscovered device %s\n", dev_name(dev));
889
890 PREPARE_DELAYED_WORK(&old->work, fw_device_update);
891 fw_schedule_device_work(old, 0);
892
893 if (current_node == card->root_node)
894 fw_schedule_bm_work(card, 0);
895
896 match = 1;
897 }
898
899 spin_unlock_irq(&card->lock);
900 up_read(&fw_device_rwsem);
901
902 return match;
903}
904
905enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, };
906
907static void set_broadcast_channel(struct fw_device *device, int generation)
908{
909 struct fw_card *card = device->card;
910 __be32 data;
911 int rcode;
912
913 if (!card->broadcast_channel_allocated)
914 return;
915
916 /*
917 * The Broadcast_Channel Valid bit is required by nodes which want to
918 * transmit on this channel. Such transmissions are practically
919 * exclusive to IP over 1394 (RFC 2734). IP capable nodes are required
920 * to be IRM capable and have a max_rec of 8 or more. We use this fact
921 * to narrow down to which nodes we send Broadcast_Channel updates.
922 */
923 if (!device->irmc || device->max_rec < 8)
924 return;
925
926 /*
927 * Some 1394-1995 nodes crash if this 1394a-2000 register is written.
928 * Perform a read test first.
929 */
930 if (device->bc_implemented == BC_UNKNOWN) {
931 rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST,
932 device->node_id, generation, device->max_speed,
933 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
934 &data, 4);
935 switch (rcode) {
936 case RCODE_COMPLETE:
937 if (data & cpu_to_be32(1 << 31)) {
938 device->bc_implemented = BC_IMPLEMENTED;
939 break;
940 }
941 /* else fall through to case address error */
942 case RCODE_ADDRESS_ERROR:
943 device->bc_implemented = BC_UNIMPLEMENTED;
944 }
945 }
946
947 if (device->bc_implemented == BC_IMPLEMENTED) {
948 data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL |
949 BROADCAST_CHANNEL_VALID);
950 fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
951 device->node_id, generation, device->max_speed,
952 CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
953 &data, 4);
954 }
955}
956
957int fw_device_set_broadcast_channel(struct device *dev, void *gen)
958{
959 if (is_fw_device(dev))
960 set_broadcast_channel(fw_device(dev), (long)gen);
961
962 return 0;
963}
964
965static void fw_device_init(struct work_struct *work)
966{
967 struct fw_device *device =
968 container_of(work, struct fw_device, work.work);
969 struct fw_card *card = device->card;
970 struct device *revived_dev;
971 int minor, ret;
972
973 /*
974 * All failure paths here set node->data to NULL, so that we
975 * don't try to do device_for_each_child() on a kfree()'d
976 * device.
977 */
978
979 ret = read_config_rom(device, device->generation);
980 if (ret != RCODE_COMPLETE) {
981 if (device->config_rom_retries < MAX_RETRIES &&
982 atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
983 device->config_rom_retries++;
984 fw_schedule_device_work(device, RETRY_DELAY);
985 } else {
986 if (device->node->link_on)
987 fw_notice(card, "giving up on node %x: reading config rom failed: %s\n",
988 device->node_id,
989 fw_rcode_string(ret));
990 if (device->node == card->root_node)
991 fw_schedule_bm_work(card, 0);
992 fw_device_release(&device->device);
993 }
994 return;
995 }
996
997 revived_dev = device_find_child(card->device,
998 device, lookup_existing_device);
999 if (revived_dev) {
1000 put_device(revived_dev);
1001 fw_device_release(&device->device);
1002
1003 return;
1004 }
1005
1006 device_initialize(&device->device);
1007
1008 fw_device_get(device);
1009 down_write(&fw_device_rwsem);
1010 ret = idr_pre_get(&fw_device_idr, GFP_KERNEL) ?
1011 idr_get_new(&fw_device_idr, device, &minor) :
1012 -ENOMEM;
1013 up_write(&fw_device_rwsem);
1014
1015 if (ret < 0)
1016 goto error;
1017
1018 device->device.bus = &fw_bus_type;
1019 device->device.type = &fw_device_type;
1020 device->device.parent = card->device;
1021 device->device.devt = MKDEV(fw_cdev_major, minor);
1022 dev_set_name(&device->device, "fw%d", minor);
1023
1024 BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) <
1025 ARRAY_SIZE(fw_device_attributes) +
1026 ARRAY_SIZE(config_rom_attributes));
1027 init_fw_attribute_group(&device->device,
1028 fw_device_attributes,
1029 &device->attribute_group);
1030
1031 if (device_add(&device->device)) {
1032 fw_err(card, "failed to add device\n");
1033 goto error_with_cdev;
1034 }
1035
1036 create_units(device);
1037
1038 /*
1039 * Transition the device to running state. If it got pulled
1040 * out from under us while we did the intialization work, we
1041 * have to shut down the device again here. Normally, though,
1042 * fw_node_event will be responsible for shutting it down when
1043 * necessary. We have to use the atomic cmpxchg here to avoid
1044 * racing with the FW_NODE_DESTROYED case in
1045 * fw_node_event().
1046 */
1047 if (atomic_cmpxchg(&device->state,
1048 FW_DEVICE_INITIALIZING,
1049 FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
1050 PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1051 fw_schedule_device_work(device, SHUTDOWN_DELAY);
1052 } else {
1053 fw_notice(card, "created device %s: GUID %08x%08x, S%d00\n",
1054 dev_name(&device->device),
1055 device->config_rom[3], device->config_rom[4],
1056 1 << device->max_speed);
1057 device->config_rom_retries = 0;
1058
1059 set_broadcast_channel(device, device->generation);
1060 }
1061
1062 /*
1063 * Reschedule the IRM work if we just finished reading the
1064 * root node config rom. If this races with a bus reset we
1065 * just end up running the IRM work a couple of extra times -
1066 * pretty harmless.
1067 */
1068 if (device->node == card->root_node)
1069 fw_schedule_bm_work(card, 0);
1070
1071 return;
1072
1073 error_with_cdev:
1074 down_write(&fw_device_rwsem);
1075 idr_remove(&fw_device_idr, minor);
1076 up_write(&fw_device_rwsem);
1077 error:
1078 fw_device_put(device); /* fw_device_idr's reference */
1079
1080 put_device(&device->device); /* our reference */
1081}
1082
1083/* Reread and compare bus info block and header of root directory */
1084static int reread_config_rom(struct fw_device *device, int generation,
1085 bool *changed)
1086{
1087 u32 q;
1088 int i, rcode;
1089
1090 for (i = 0; i < 6; i++) {
1091 rcode = read_rom(device, generation, i, &q);
1092 if (rcode != RCODE_COMPLETE)
1093 return rcode;
1094
1095 if (i == 0 && q == 0)
1096 /* inaccessible (see read_config_rom); retry later */
1097 return RCODE_BUSY;
1098
1099 if (q != device->config_rom[i]) {
1100 *changed = true;
1101 return RCODE_COMPLETE;
1102 }
1103 }
1104
1105 *changed = false;
1106 return RCODE_COMPLETE;
1107}
1108
1109static void fw_device_refresh(struct work_struct *work)
1110{
1111 struct fw_device *device =
1112 container_of(work, struct fw_device, work.work);
1113 struct fw_card *card = device->card;
1114 int ret, node_id = device->node_id;
1115 bool changed;
1116
1117 ret = reread_config_rom(device, device->generation, &changed);
1118 if (ret != RCODE_COMPLETE)
1119 goto failed_config_rom;
1120
1121 if (!changed) {
1122 if (atomic_cmpxchg(&device->state,
1123 FW_DEVICE_INITIALIZING,
1124 FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1125 goto gone;
1126
1127 fw_device_update(work);
1128 device->config_rom_retries = 0;
1129 goto out;
1130 }
1131
1132 /*
1133 * Something changed. We keep things simple and don't investigate
1134 * further. We just destroy all previous units and create new ones.
1135 */
1136 device_for_each_child(&device->device, NULL, shutdown_unit);
1137
1138 ret = read_config_rom(device, device->generation);
1139 if (ret != RCODE_COMPLETE)
1140 goto failed_config_rom;
1141
1142 fw_device_cdev_update(device);
1143 create_units(device);
1144
1145 /* Userspace may want to re-read attributes. */
1146 kobject_uevent(&device->device.kobj, KOBJ_CHANGE);
1147
1148 if (atomic_cmpxchg(&device->state,
1149 FW_DEVICE_INITIALIZING,
1150 FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1151 goto gone;
1152
1153 fw_notice(card, "refreshed device %s\n", dev_name(&device->device));
1154 device->config_rom_retries = 0;
1155 goto out;
1156
1157 failed_config_rom:
1158 if (device->config_rom_retries < MAX_RETRIES &&
1159 atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1160 device->config_rom_retries++;
1161 fw_schedule_device_work(device, RETRY_DELAY);
1162 return;
1163 }
1164
1165 fw_notice(card, "giving up on refresh of device %s: %s\n",
1166 dev_name(&device->device), fw_rcode_string(ret));
1167 gone:
1168 atomic_set(&device->state, FW_DEVICE_GONE);
1169 PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1170 fw_schedule_device_work(device, SHUTDOWN_DELAY);
1171 out:
1172 if (node_id == card->root_node->node_id)
1173 fw_schedule_bm_work(card, 0);
1174}
1175
1176void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
1177{
1178 struct fw_device *device;
1179
1180 switch (event) {
1181 case FW_NODE_CREATED:
1182 /*
1183 * Attempt to scan the node, regardless whether its self ID has
1184 * the L (link active) flag set or not. Some broken devices
1185 * send L=0 but have an up-and-running link; others send L=1
1186 * without actually having a link.
1187 */
1188 create:
1189 device = kzalloc(sizeof(*device), GFP_ATOMIC);
1190 if (device == NULL)
1191 break;
1192
1193 /*
1194 * Do minimal intialization of the device here, the
1195 * rest will happen in fw_device_init().
1196 *
1197 * Attention: A lot of things, even fw_device_get(),
1198 * cannot be done before fw_device_init() finished!
1199 * You can basically just check device->state and
1200 * schedule work until then, but only while holding
1201 * card->lock.
1202 */
1203 atomic_set(&device->state, FW_DEVICE_INITIALIZING);
1204 device->card = fw_card_get(card);
1205 device->node = fw_node_get(node);
1206 device->node_id = node->node_id;
1207 device->generation = card->generation;
1208 device->is_local = node == card->local_node;
1209 mutex_init(&device->client_list_mutex);
1210 INIT_LIST_HEAD(&device->client_list);
1211
1212 /*
1213 * Set the node data to point back to this device so
1214 * FW_NODE_UPDATED callbacks can update the node_id
1215 * and generation for the device.
1216 */
1217 node->data = device;
1218
1219 /*
1220 * Many devices are slow to respond after bus resets,
1221 * especially if they are bus powered and go through
1222 * power-up after getting plugged in. We schedule the
1223 * first config rom scan half a second after bus reset.
1224 */
1225 INIT_DELAYED_WORK(&device->work, fw_device_init);
1226 fw_schedule_device_work(device, INITIAL_DELAY);
1227 break;
1228
1229 case FW_NODE_INITIATED_RESET:
1230 case FW_NODE_LINK_ON:
1231 device = node->data;
1232 if (device == NULL)
1233 goto create;
1234
1235 device->node_id = node->node_id;
1236 smp_wmb(); /* update node_id before generation */
1237 device->generation = card->generation;
1238 if (atomic_cmpxchg(&device->state,
1239 FW_DEVICE_RUNNING,
1240 FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) {
1241 PREPARE_DELAYED_WORK(&device->work, fw_device_refresh);
1242 fw_schedule_device_work(device,
1243 device->is_local ? 0 : INITIAL_DELAY);
1244 }
1245 break;
1246
1247 case FW_NODE_UPDATED:
1248 device = node->data;
1249 if (device == NULL)
1250 break;
1251
1252 device->node_id = node->node_id;
1253 smp_wmb(); /* update node_id before generation */
1254 device->generation = card->generation;
1255 if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
1256 PREPARE_DELAYED_WORK(&device->work, fw_device_update);
1257 fw_schedule_device_work(device, 0);
1258 }
1259 break;
1260
1261 case FW_NODE_DESTROYED:
1262 case FW_NODE_LINK_OFF:
1263 if (!node->data)
1264 break;
1265
1266 /*
1267 * Destroy the device associated with the node. There
1268 * are two cases here: either the device is fully
1269 * initialized (FW_DEVICE_RUNNING) or we're in the
1270 * process of reading its config rom
1271 * (FW_DEVICE_INITIALIZING). If it is fully
1272 * initialized we can reuse device->work to schedule a
1273 * full fw_device_shutdown(). If not, there's work
1274 * scheduled to read it's config rom, and we just put
1275 * the device in shutdown state to have that code fail
1276 * to create the device.
1277 */
1278 device = node->data;
1279 if (atomic_xchg(&device->state,
1280 FW_DEVICE_GONE) == FW_DEVICE_RUNNING) {
1281 PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1282 fw_schedule_device_work(device,
1283 list_empty(&card->link) ? 0 : SHUTDOWN_DELAY);
1284 }
1285 break;
1286 }
1287}