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Root/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/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
46	void 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	}
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 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
79	static 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	*/
119	int 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	}
127	EXPORT_SYMBOL(fw_csr_string);
128
129	static 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
145	static 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
151	static 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
167	static bool is_fw_unit(struct device *dev);
168
169	static 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
188	static 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
199	static 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
212	struct bus_type fw_bus_type = {
213	.name = "firewire",
214	.match = fw_unit_match,
215	};
216	EXPORT_SYMBOL(fw_bus_type);
217
218	int 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	}
229	EXPORT_SYMBOL(fw_device_enable_phys_dma);
230
231	struct config_rom_attribute {
232	struct device_attribute attr;
233	u32 key;
234	};
235
236	static 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
268	static 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
310	static 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
321	static 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
345	static 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
357	static 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
367	static struct device_attribute fw_unit_attributes[] = {
368	__ATTR_RO(modalias),
369	__ATTR_RO(rom_index),
370	__ATTR_NULL,
371	};
372
373	static 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
387	static 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
401	static ssize_t is_local_show(struct device *dev,
402	struct device_attribute attr, char buf)
403	{
404	struct fw_device *device = fw_device(dev);
405
406	return sprintf(buf, "%u\n", device->is_local);
407	}
408
409	static int units_sprintf(char buf, const u32 directory)
410	{
411	struct fw_csr_iterator ci;
412	int key, value;
413	int specifier_id = 0;
414	int version = 0;
415
416	fw_csr_iterator_init(&ci, directory);
417	while (fw_csr_iterator_next(&ci, &key, &value)) {
418	switch (key) {
419	case CSR_SPECIFIER_ID:
420	specifier_id = value;
421	break;
422	case CSR_VERSION:
423	version = value;
424	break;
425	}
426	}
427
428	return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version);
429	}
430
431	static ssize_t units_show(struct device *dev,
432	struct device_attribute attr, char buf)
433	{
434	struct fw_device *device = fw_device(dev);
435	struct fw_csr_iterator ci;
436	int key, value, i = 0;
437
438	down_read(&fw_device_rwsem);
439	fw_csr_iterator_init(&ci, &device->config_rom[5]);
440	while (fw_csr_iterator_next(&ci, &key, &value)) {
441	if (key != (CSR_UNIT \| CSR_DIRECTORY))
442	continue;
443	i += units_sprintf(&buf[i], ci.p + value - 1);
444	if (i >= PAGE_SIZE - (8 + 1 + 8 + 1))
445	break;
446	}
447	up_read(&fw_device_rwsem);
448
449	if (i)
450	buf[i - 1] = '\n';
451
452	return i;
453	}
454
455	static struct device_attribute fw_device_attributes[] = {
456	__ATTR_RO(config_rom),
457	__ATTR_RO(guid),
458	__ATTR_RO(is_local),
459	__ATTR_RO(units),
460	__ATTR_NULL,
461	};
462
463	static int read_rom(struct fw_device *device,
464	int generation, int index, u32 *data)
465	{
466	u64 offset = (CSR_REGISTER_BASE \| CSR_CONFIG_ROM) + index * 4;
467	int i, rcode;
468
469	/* device->node_id, accessed below, must not be older than generation */
470	smp_rmb();
471
472	for (i = 10; i < 100; i += 10) {
473	rcode = fw_run_transaction(device->card,
474	TCODE_READ_QUADLET_REQUEST, device->node_id,
475	generation, device->max_speed, offset, data, 4);
476	if (rcode != RCODE_BUSY)
477	break;
478	msleep(i);
479	}
480	be32_to_cpus(data);
481
482	return rcode;
483	}
484
485	#define MAX_CONFIG_ROM_SIZE 256
486
487	/*
488	* Read the bus info block, perform a speed probe, and read all of the rest of
489	* the config ROM. We do all this with a cached bus generation. If the bus
490	* generation changes under us, read_config_rom will fail and get retried.
491	* It's better to start all over in this case because the node from which we
492	* are reading the ROM may have changed the ROM during the reset.
493	* Returns either a result code or a negative error code.
494	*/
495	static int read_config_rom(struct fw_device *device, int generation)
496	{
497	struct fw_card *card = device->card;
498	const u32 old_rom, new_rom;
499	u32 rom, stack;
500	u32 sp, key;
501	int i, end, length, ret;
502
503	rom = kmalloc(sizeof(rom) MAX_CONFIG_ROM_SIZE +
504	sizeof(stack) MAX_CONFIG_ROM_SIZE, GFP_KERNEL);
505	if (rom == NULL)
506	return -ENOMEM;
507
508	stack = &rom[MAX_CONFIG_ROM_SIZE];
509	memset(rom, 0, sizeof(rom) MAX_CONFIG_ROM_SIZE);
510
511	device->max_speed = SCODE_100;
512
513	/* First read the bus info block. */
514	for (i = 0; i < 5; i++) {
515	ret = read_rom(device, generation, i, &rom[i]);
516	if (ret != RCODE_COMPLETE)
517	goto out;
518	/*
519	* As per IEEE1212 7.2, during initialization, devices can
520	* reply with a 0 for the first quadlet of the config
521	* rom to indicate that they are booting (for example,
522	* if the firmware is on the disk of a external
523	* harddisk). In that case we just fail, and the
524	* retry mechanism will try again later.
525	*/
526	if (i == 0 && rom[i] == 0) {
527	ret = RCODE_BUSY;
528	goto out;
529	}
530	}
531
532	device->max_speed = device->node->max_speed;
533
534	/*
535	* Determine the speed of
536	* - devices with link speed less than PHY speed,
537	* - devices with 1394b PHY (unless only connected to 1394a PHYs),
538	* - all devices if there are 1394b repeaters.
539	* Note, we cannot use the bus info block's link_spd as starting point
540	* because some buggy firmwares set it lower than necessary and because
541	* 1394-1995 nodes do not have the field.
542	*/
543	if ((rom[2] & 0x7) < device->max_speed \|\|
544	device->max_speed == SCODE_BETA \|\|
545	card->beta_repeaters_present) {
546	u32 dummy;
547
548	/* for S1600 and S3200 */
549	if (device->max_speed == SCODE_BETA)
550	device->max_speed = card->link_speed;
551
552	while (device->max_speed > SCODE_100) {
553	if (read_rom(device, generation, 0, &dummy) ==
554	RCODE_COMPLETE)
555	break;
556	device->max_speed--;
557	}
558	}
559
560	/*
561	* Now parse the config rom. The config rom is a recursive
562	* directory structure so we parse it using a stack of
563	* references to the blocks that make up the structure. We
564	* push a reference to the root directory on the stack to
565	* start things off.
566	*/
567	length = i;
568	sp = 0;
569	stack[sp++] = 0xc0000005;
570	while (sp > 0) {
571	/*
572	* Pop the next block reference of the stack. The
573	* lower 24 bits is the offset into the config rom,
574	* the upper 8 bits are the type of the reference the
575	* block.
576	*/
577	key = stack[--sp];
578	i = key & 0xffffff;
579	if (WARN_ON(i >= MAX_CONFIG_ROM_SIZE)) {
580	ret = -ENXIO;
581	goto out;
582	}
583
584	/* Read header quadlet for the block to get the length. */
585	ret = read_rom(device, generation, i, &rom[i]);
586	if (ret != RCODE_COMPLETE)
587	goto out;
588	end = i + (rom[i] >> 16) + 1;
589	if (end > MAX_CONFIG_ROM_SIZE) {
590	/*
591	* This block extends outside the config ROM which is
592	* a firmware bug. Ignore this whole block, i.e.
593	* simply set a fake block length of 0.
594	*/
595	fw_err(card, "skipped invalid ROM block %x at %llx\n",
596	rom[i],
597	i * 4 \| CSR_REGISTER_BASE \| CSR_CONFIG_ROM);
598	rom[i] = 0;
599	end = i;
600	}
601	i++;
602
603	/*
604	* Now read in the block. If this is a directory
605	* block, check the entries as we read them to see if
606	* it references another block, and push it in that case.
607	*/
608	for (; i < end; i++) {
609	ret = read_rom(device, generation, i, &rom[i]);
610	if (ret != RCODE_COMPLETE)
611	goto out;
612
613	if ((key >> 30) != 3 \|\| (rom[i] >> 30) < 2)
614	continue;
615	/*
616	* Offset points outside the ROM. May be a firmware
617	* bug or an Extended ROM entry (IEEE 1212-2001 clause
618	* 7.7.18). Simply overwrite this pointer here by a
619	* fake immediate entry so that later iterators over
620	* the ROM don't have to check offsets all the time.
621	*/
622	if (i + (rom[i] & 0xffffff) >= MAX_CONFIG_ROM_SIZE) {
623	fw_err(card,
624	"skipped unsupported ROM entry %x at %llx\n",
625	rom[i],
626	i * 4 \| CSR_REGISTER_BASE \| CSR_CONFIG_ROM);
627	rom[i] = 0;
628	continue;
629	}
630	stack[sp++] = i + rom[i];
631	}
632	if (length < i)
633	length = i;
634	}
635
636	old_rom = device->config_rom;
637	new_rom = kmemdup(rom, length * 4, GFP_KERNEL);
638	if (new_rom == NULL) {
639	ret = -ENOMEM;
640	goto out;
641	}
642
643	down_write(&fw_device_rwsem);
644	device->config_rom = new_rom;
645	device->config_rom_length = length;
646	up_write(&fw_device_rwsem);
647
648	kfree(old_rom);
649	ret = RCODE_COMPLETE;
650	device->max_rec = rom[2] >> 12 & 0xf;
651	device->cmc = rom[2] >> 30 & 1;
652	device->irmc = rom[2] >> 31 & 1;
653	out:
654	kfree(rom);
655
656	return ret;
657	}
658
659	static void fw_unit_release(struct device *dev)
660	{
661	struct fw_unit *unit = fw_unit(dev);
662
663	fw_device_put(fw_parent_device(unit));
664	kfree(unit);
665	}
666
667	static struct device_type fw_unit_type = {
668	.uevent = fw_unit_uevent,
669	.release = fw_unit_release,
670	};
671
672	static bool is_fw_unit(struct device *dev)
673	{
674	return dev->type == &fw_unit_type;
675	}
676
677	static void create_units(struct fw_device *device)
678	{
679	struct fw_csr_iterator ci;
680	struct fw_unit *unit;
681	int key, value, i;
682
683	i = 0;
684	fw_csr_iterator_init(&ci, &device->config_rom[5]);
685	while (fw_csr_iterator_next(&ci, &key, &value)) {
686	if (key != (CSR_UNIT \| CSR_DIRECTORY))
687	continue;
688
689	/*
690	* Get the address of the unit directory and try to
691	* match the drivers id_tables against it.
692	*/
693	unit = kzalloc(sizeof(*unit), GFP_KERNEL);
694	if (unit == NULL) {
695	fw_err(device->card, "out of memory for unit\n");
696	continue;
697	}
698
699	unit->directory = ci.p + value - 1;
700	unit->device.bus = &fw_bus_type;
701	unit->device.type = &fw_unit_type;
702	unit->device.parent = &device->device;
703	dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++);
704
705	BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) <
706	ARRAY_SIZE(fw_unit_attributes) +
707	ARRAY_SIZE(config_rom_attributes));
708	init_fw_attribute_group(&unit->device,
709	fw_unit_attributes,
710	&unit->attribute_group);
711
712	if (device_register(&unit->device) < 0)
713	goto skip_unit;
714
715	fw_device_get(device);
716	continue;
717
718	skip_unit:
719	kfree(unit);
720	}
721	}
722
723	static int shutdown_unit(struct device device, void data)
724	{
725	device_unregister(device);
726
727	return 0;
728	}
729
730	/*
731	* fw_device_rwsem acts as dual purpose mutex:
732	* - serializes accesses to fw_device_idr,
733	* - serializes accesses to fw_device.config_rom/.config_rom_length and
734	* fw_unit.directory, unless those accesses happen at safe occasions
735	*/
736	DECLARE_RWSEM(fw_device_rwsem);
737
738	DEFINE_IDR(fw_device_idr);
739	int fw_cdev_major;
740
741	struct fw_device *fw_device_get_by_devt(dev_t devt)
742	{
743	struct fw_device *device;
744
745	down_read(&fw_device_rwsem);
746	device = idr_find(&fw_device_idr, MINOR(devt));
747	if (device)
748	fw_device_get(device);
749	up_read(&fw_device_rwsem);
750
751	return device;
752	}
753
754	struct workqueue_struct *fw_workqueue;
755	EXPORT_SYMBOL(fw_workqueue);
756
757	static void fw_schedule_device_work(struct fw_device *device,
758	unsigned long delay)
759	{
760	queue_delayed_work(fw_workqueue, &device->work, delay);
761	}
762
763	/*
764	* These defines control the retry behavior for reading the config
765	* rom. It shouldn't be necessary to tweak these; if the device
766	* doesn't respond to a config rom read within 10 seconds, it's not
767	* going to respond at all. As for the initial delay, a lot of
768	* devices will be able to respond within half a second after bus
769	* reset. On the other hand, it's not really worth being more
770	* aggressive than that, since it scales pretty well; if 10 devices
771	* are plugged in, they're all getting read within one second.
772	*/
773
774	#define MAX_RETRIES 10
775	#define RETRY_DELAY (3 * HZ)
776	#define INITIAL_DELAY (HZ / 2)
777	#define SHUTDOWN_DELAY (2 * HZ)
778
779	static void fw_device_shutdown(struct work_struct *work)
780	{
781	struct fw_device *device =
782	container_of(work, struct fw_device, work.work);
783	int minor = MINOR(device->device.devt);
784
785	if (time_before64(get_jiffies_64(),
786	device->card->reset_jiffies + SHUTDOWN_DELAY)
787	&& !list_empty(&device->card->link)) {
788	fw_schedule_device_work(device, SHUTDOWN_DELAY);
789	return;
790	}
791
792	if (atomic_cmpxchg(&device->state,
793	FW_DEVICE_GONE,
794	FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE)
795	return;
796
797	fw_device_cdev_remove(device);
798	device_for_each_child(&device->device, NULL, shutdown_unit);
799	device_unregister(&device->device);
800
801	down_write(&fw_device_rwsem);
802	idr_remove(&fw_device_idr, minor);
803	up_write(&fw_device_rwsem);
804
805	fw_device_put(device);
806	}
807
808	static void fw_device_release(struct device *dev)
809	{
810	struct fw_device *device = fw_device(dev);
811	struct fw_card *card = device->card;
812	unsigned long flags;
813
814	/*
815	* Take the card lock so we don't set this to NULL while a
816	* FW_NODE_UPDATED callback is being handled or while the
817	* bus manager work looks at this node.
818	*/
819	spin_lock_irqsave(&card->lock, flags);
820	device->node->data = NULL;
821	spin_unlock_irqrestore(&card->lock, flags);
822
823	fw_node_put(device->node);
824	kfree(device->config_rom);
825	kfree(device);
826	fw_card_put(card);
827	}
828
829	static struct device_type fw_device_type = {
830	.release = fw_device_release,
831	};
832
833	static bool is_fw_device(struct device *dev)
834	{
835	return dev->type == &fw_device_type;
836	}
837
838	static int update_unit(struct device dev, void data)
839	{
840	struct fw_unit *unit = fw_unit(dev);
841	struct fw_driver driver = (struct fw_driver )dev->driver;
842
843	if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) {
844	device_lock(dev);
845	driver->update(unit);
846	device_unlock(dev);
847	}
848
849	return 0;
850	}
851
852	static void fw_device_update(struct work_struct *work)
853	{
854	struct fw_device *device =
855	container_of(work, struct fw_device, work.work);
856
857	fw_device_cdev_update(device);
858	device_for_each_child(&device->device, NULL, update_unit);
859	}
860
861	/*
862	* If a device was pending for deletion because its node went away but its
863	* bus info block and root directory header matches that of a newly discovered
864	* device, revive the existing fw_device.
865	* The newly allocated fw_device becomes obsolete instead.
866	*/
867	static int lookup_existing_device(struct device dev, void data)
868	{
869	struct fw_device *old = fw_device(dev);
870	struct fw_device *new = data;
871	struct fw_card *card = new->card;
872	int match = 0;
873
874	if (!is_fw_device(dev))
875	return 0;
876
877	down_read(&fw_device_rwsem); /* serialize config_rom access */
878	spin_lock_irq(&card->lock); /* serialize node access */
879
880	if (memcmp(old->config_rom, new->config_rom, 6 * 4) == 0 &&
881	atomic_cmpxchg(&old->state,
882	FW_DEVICE_GONE,
883	FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
884	struct fw_node *current_node = new->node;
885	struct fw_node *obsolete_node = old->node;
886
887	new->node = obsolete_node;
888	new->node->data = new;
889	old->node = current_node;
890	old->node->data = old;
891
892	old->max_speed = new->max_speed;
893	old->node_id = current_node->node_id;
894	smp_wmb(); /* update node_id before generation */
895	old->generation = card->generation;
896	old->config_rom_retries = 0;
897	fw_notice(card, "rediscovered device %s\n", dev_name(dev));
898
899	PREPARE_DELAYED_WORK(&old->work, fw_device_update);
900	fw_schedule_device_work(old, 0);
901
902	if (current_node == card->root_node)
903	fw_schedule_bm_work(card, 0);
904
905	match = 1;
906	}
907
908	spin_unlock_irq(&card->lock);
909	up_read(&fw_device_rwsem);
910
911	return match;
912	}
913
914	enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, };
915
916	static void set_broadcast_channel(struct fw_device *device, int generation)
917	{
918	struct fw_card *card = device->card;
919	__be32 data;
920	int rcode;
921
922	if (!card->broadcast_channel_allocated)
923	return;
924
925	/*
926	* The Broadcast_Channel Valid bit is required by nodes which want to
927	* transmit on this channel. Such transmissions are practically
928	* exclusive to IP over 1394 (RFC 2734). IP capable nodes are required
929	* to be IRM capable and have a max_rec of 8 or more. We use this fact
930	* to narrow down to which nodes we send Broadcast_Channel updates.
931	*/
932	if (!device->irmc \|\| device->max_rec < 8)
933	return;
934
935	/*
936	* Some 1394-1995 nodes crash if this 1394a-2000 register is written.
937	* Perform a read test first.
938	*/
939	if (device->bc_implemented == BC_UNKNOWN) {
940	rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST,
941	device->node_id, generation, device->max_speed,
942	CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
943	&data, 4);
944	switch (rcode) {
945	case RCODE_COMPLETE:
946	if (data & cpu_to_be32(1 << 31)) {
947	device->bc_implemented = BC_IMPLEMENTED;
948	break;
949	}
950	/* else fall through to case address error */
951	case RCODE_ADDRESS_ERROR:
952	device->bc_implemented = BC_UNIMPLEMENTED;
953	}
954	}
955
956	if (device->bc_implemented == BC_IMPLEMENTED) {
957	data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL \|
958	BROADCAST_CHANNEL_VALID);
959	fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST,
960	device->node_id, generation, device->max_speed,
961	CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL,
962	&data, 4);
963	}
964	}
965
966	int fw_device_set_broadcast_channel(struct device dev, void gen)
967	{
968	if (is_fw_device(dev))
969	set_broadcast_channel(fw_device(dev), (long)gen);
970
971	return 0;
972	}
973
974	static void fw_device_init(struct work_struct *work)
975	{
976	struct fw_device *device =
977	container_of(work, struct fw_device, work.work);
978	struct fw_card *card = device->card;
979	struct device *revived_dev;
980	int minor, ret;
981
982	/*
983	* All failure paths here set node->data to NULL, so that we
984	* don't try to do device_for_each_child() on a kfree()'d
985	* device.
986	*/
987
988	ret = read_config_rom(device, device->generation);
989	if (ret != RCODE_COMPLETE) {
990	if (device->config_rom_retries < MAX_RETRIES &&
991	atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
992	device->config_rom_retries++;
993	fw_schedule_device_work(device, RETRY_DELAY);
994	} else {
995	if (device->node->link_on)
996	fw_notice(card, "giving up on node %x: reading config rom failed: %s\n",
997	device->node_id,
998	fw_rcode_string(ret));
999	if (device->node == card->root_node)
1000	fw_schedule_bm_work(card, 0);
1001	fw_device_release(&device->device);
1002	}
1003	return;
1004	}
1005
1006	revived_dev = device_find_child(card->device,
1007	device, lookup_existing_device);
1008	if (revived_dev) {
1009	put_device(revived_dev);
1010	fw_device_release(&device->device);
1011
1012	return;
1013	}
1014
1015	device_initialize(&device->device);
1016
1017	fw_device_get(device);
1018	down_write(&fw_device_rwsem);
1019	ret = idr_pre_get(&fw_device_idr, GFP_KERNEL) ?
1020	idr_get_new(&fw_device_idr, device, &minor) :
1021	-ENOMEM;
1022	up_write(&fw_device_rwsem);
1023
1024	if (ret < 0)
1025	goto error;
1026
1027	device->device.bus = &fw_bus_type;
1028	device->device.type = &fw_device_type;
1029	device->device.parent = card->device;
1030	device->device.devt = MKDEV(fw_cdev_major, minor);
1031	dev_set_name(&device->device, "fw%d", minor);
1032
1033	BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) <
1034	ARRAY_SIZE(fw_device_attributes) +
1035	ARRAY_SIZE(config_rom_attributes));
1036	init_fw_attribute_group(&device->device,
1037	fw_device_attributes,
1038	&device->attribute_group);
1039
1040	if (device_add(&device->device)) {
1041	fw_err(card, "failed to add device\n");
1042	goto error_with_cdev;
1043	}
1044
1045	create_units(device);
1046
1047	/*
1048	* Transition the device to running state. If it got pulled
1049	* out from under us while we did the intialization work, we
1050	* have to shut down the device again here. Normally, though,
1051	* fw_node_event will be responsible for shutting it down when
1052	* necessary. We have to use the atomic cmpxchg here to avoid
1053	* racing with the FW_NODE_DESTROYED case in
1054	* fw_node_event().
1055	*/
1056	if (atomic_cmpxchg(&device->state,
1057	FW_DEVICE_INITIALIZING,
1058	FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
1059	PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1060	fw_schedule_device_work(device, SHUTDOWN_DELAY);
1061	} else {
1062	fw_notice(card, "created device %s: GUID %08x%08x, S%d00\n",
1063	dev_name(&device->device),
1064	device->config_rom[3], device->config_rom[4],
1065	1 << device->max_speed);
1066	device->config_rom_retries = 0;
1067
1068	set_broadcast_channel(device, device->generation);
1069	}
1070
1071	/*
1072	* Reschedule the IRM work if we just finished reading the
1073	* root node config rom. If this races with a bus reset we
1074	* just end up running the IRM work a couple of extra times -
1075	* pretty harmless.
1076	*/
1077	if (device->node == card->root_node)
1078	fw_schedule_bm_work(card, 0);
1079
1080	return;
1081
1082	error_with_cdev:
1083	down_write(&fw_device_rwsem);
1084	idr_remove(&fw_device_idr, minor);
1085	up_write(&fw_device_rwsem);
1086	error:
1087	fw_device_put(device); /* fw_device_idr's reference */
1088
1089	put_device(&device->device); /* our reference */
1090	}
1091
1092	/* Reread and compare bus info block and header of root directory */
1093	static int reread_config_rom(struct fw_device *device, int generation,
1094	bool *changed)
1095	{
1096	u32 q;
1097	int i, rcode;
1098
1099	for (i = 0; i < 6; i++) {
1100	rcode = read_rom(device, generation, i, &q);
1101	if (rcode != RCODE_COMPLETE)
1102	return rcode;
1103
1104	if (i == 0 && q == 0)
1105	/* inaccessible (see read_config_rom); retry later */
1106	return RCODE_BUSY;
1107
1108	if (q != device->config_rom[i]) {
1109	*changed = true;
1110	return RCODE_COMPLETE;
1111	}
1112	}
1113
1114	*changed = false;
1115	return RCODE_COMPLETE;
1116	}
1117
1118	static void fw_device_refresh(struct work_struct *work)
1119	{
1120	struct fw_device *device =
1121	container_of(work, struct fw_device, work.work);
1122	struct fw_card *card = device->card;
1123	int ret, node_id = device->node_id;
1124	bool changed;
1125
1126	ret = reread_config_rom(device, device->generation, &changed);
1127	if (ret != RCODE_COMPLETE)
1128	goto failed_config_rom;
1129
1130	if (!changed) {
1131	if (atomic_cmpxchg(&device->state,
1132	FW_DEVICE_INITIALIZING,
1133	FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1134	goto gone;
1135
1136	fw_device_update(work);
1137	device->config_rom_retries = 0;
1138	goto out;
1139	}
1140
1141	/*
1142	* Something changed. We keep things simple and don't investigate
1143	* further. We just destroy all previous units and create new ones.
1144	*/
1145	device_for_each_child(&device->device, NULL, shutdown_unit);
1146
1147	ret = read_config_rom(device, device->generation);
1148	if (ret != RCODE_COMPLETE)
1149	goto failed_config_rom;
1150
1151	fw_device_cdev_update(device);
1152	create_units(device);
1153
1154	/* Userspace may want to re-read attributes. */
1155	kobject_uevent(&device->device.kobj, KOBJ_CHANGE);
1156
1157	if (atomic_cmpxchg(&device->state,
1158	FW_DEVICE_INITIALIZING,
1159	FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
1160	goto gone;
1161
1162	fw_notice(card, "refreshed device %s\n", dev_name(&device->device));
1163	device->config_rom_retries = 0;
1164	goto out;
1165
1166	failed_config_rom:
1167	if (device->config_rom_retries < MAX_RETRIES &&
1168	atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
1169	device->config_rom_retries++;
1170	fw_schedule_device_work(device, RETRY_DELAY);
1171	return;
1172	}
1173
1174	fw_notice(card, "giving up on refresh of device %s: %s\n",
1175	dev_name(&device->device), fw_rcode_string(ret));
1176	gone:
1177	atomic_set(&device->state, FW_DEVICE_GONE);
1178	PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1179	fw_schedule_device_work(device, SHUTDOWN_DELAY);
1180	out:
1181	if (node_id == card->root_node->node_id)
1182	fw_schedule_bm_work(card, 0);
1183	}
1184
1185	void fw_node_event(struct fw_card card, struct fw_node node, int event)
1186	{
1187	struct fw_device *device;
1188
1189	switch (event) {
1190	case FW_NODE_CREATED:
1191	/*
1192	* Attempt to scan the node, regardless whether its self ID has
1193	* the L (link active) flag set or not. Some broken devices
1194	* send L=0 but have an up-and-running link; others send L=1
1195	* without actually having a link.
1196	*/
1197	create:
1198	device = kzalloc(sizeof(*device), GFP_ATOMIC);
1199	if (device == NULL)
1200	break;
1201
1202	/*
1203	* Do minimal intialization of the device here, the
1204	* rest will happen in fw_device_init().
1205	*
1206	* Attention: A lot of things, even fw_device_get(),
1207	* cannot be done before fw_device_init() finished!
1208	* You can basically just check device->state and
1209	* schedule work until then, but only while holding
1210	* card->lock.
1211	*/
1212	atomic_set(&device->state, FW_DEVICE_INITIALIZING);
1213	device->card = fw_card_get(card);
1214	device->node = fw_node_get(node);
1215	device->node_id = node->node_id;
1216	device->generation = card->generation;
1217	device->is_local = node == card->local_node;
1218	mutex_init(&device->client_list_mutex);
1219	INIT_LIST_HEAD(&device->client_list);
1220
1221	/*
1222	* Set the node data to point back to this device so
1223	* FW_NODE_UPDATED callbacks can update the node_id
1224	* and generation for the device.
1225	*/
1226	node->data = device;
1227
1228	/*
1229	* Many devices are slow to respond after bus resets,
1230	* especially if they are bus powered and go through
1231	* power-up after getting plugged in. We schedule the
1232	* first config rom scan half a second after bus reset.
1233	*/
1234	INIT_DELAYED_WORK(&device->work, fw_device_init);
1235	fw_schedule_device_work(device, INITIAL_DELAY);
1236	break;
1237
1238	case FW_NODE_INITIATED_RESET:
1239	case FW_NODE_LINK_ON:
1240	device = node->data;
1241	if (device == NULL)
1242	goto create;
1243
1244	device->node_id = node->node_id;
1245	smp_wmb(); /* update node_id before generation */
1246	device->generation = card->generation;
1247	if (atomic_cmpxchg(&device->state,
1248	FW_DEVICE_RUNNING,
1249	FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) {
1250	PREPARE_DELAYED_WORK(&device->work, fw_device_refresh);
1251	fw_schedule_device_work(device,
1252	device->is_local ? 0 : INITIAL_DELAY);
1253	}
1254	break;
1255
1256	case FW_NODE_UPDATED:
1257	device = node->data;
1258	if (device == NULL)
1259	break;
1260
1261	device->node_id = node->node_id;
1262	smp_wmb(); /* update node_id before generation */
1263	device->generation = card->generation;
1264	if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
1265	PREPARE_DELAYED_WORK(&device->work, fw_device_update);
1266	fw_schedule_device_work(device, 0);
1267	}
1268	break;
1269
1270	case FW_NODE_DESTROYED:
1271	case FW_NODE_LINK_OFF:
1272	if (!node->data)
1273	break;
1274
1275	/*
1276	* Destroy the device associated with the node. There
1277	* are two cases here: either the device is fully
1278	* initialized (FW_DEVICE_RUNNING) or we're in the
1279	* process of reading its config rom
1280	* (FW_DEVICE_INITIALIZING). If it is fully
1281	* initialized we can reuse device->work to schedule a
1282	* full fw_device_shutdown(). If not, there's work
1283	* scheduled to read it's config rom, and we just put
1284	* the device in shutdown state to have that code fail
1285	* to create the device.
1286	*/
1287	device = node->data;
1288	if (atomic_xchg(&device->state,
1289	FW_DEVICE_GONE) == FW_DEVICE_RUNNING) {
1290	PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
1291	fw_schedule_device_work(device,
1292	list_empty(&card->link) ? 0 : SHUTDOWN_DELAY);
1293	}
1294	break;
1295	}
1296	}
1297

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