summaryrefslogtreecommitdiffstats
path: root/drivers/firewire/fw-card.c
blob: 681bb8d4ef63444e5a6207e90c56ad3523ddcdd3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
/*
 * Copyright (C) 2005-2007  Kristian Hoegsberg <krh@bitplanet.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/crc-itu-t.h>
#include "fw-transaction.h"
#include "fw-topology.h"
#include "fw-device.h"

int fw_compute_block_crc(u32 *block)
{
	__be32 be32_block[256];
	int i, length;

	length = (*block >> 16) & 0xff;
	for (i = 0; i < length; i++)
		be32_block[i] = cpu_to_be32(block[i + 1]);
	*block |= crc_itu_t(0, (u8 *) be32_block, length * 4);

	return length;
}

static DEFINE_MUTEX(card_mutex);
static LIST_HEAD(card_list);

static LIST_HEAD(descriptor_list);
static int descriptor_count;

#define BIB_CRC(v)		((v) <<  0)
#define BIB_CRC_LENGTH(v)	((v) << 16)
#define BIB_INFO_LENGTH(v)	((v) << 24)

#define BIB_LINK_SPEED(v)	((v) <<  0)
#define BIB_GENERATION(v)	((v) <<  4)
#define BIB_MAX_ROM(v)		((v) <<  8)
#define BIB_MAX_RECEIVE(v)	((v) << 12)
#define BIB_CYC_CLK_ACC(v)	((v) << 16)
#define BIB_PMC			((1) << 27)
#define BIB_BMC			((1) << 28)
#define BIB_ISC			((1) << 29)
#define BIB_CMC			((1) << 30)
#define BIB_IMC			((1) << 31)

static u32 *
generate_config_rom(struct fw_card *card, size_t *config_rom_length)
{
	struct fw_descriptor *desc;
	static u32 config_rom[256];
	int i, j, length;

	/*
	 * Initialize contents of config rom buffer.  On the OHCI
	 * controller, block reads to the config rom accesses the host
	 * memory, but quadlet read access the hardware bus info block
	 * registers.  That's just crack, but it means we should make
	 * sure the contents of bus info block in host memory mathces
	 * the version stored in the OHCI registers.
	 */

	memset(config_rom, 0, sizeof(config_rom));
	config_rom[0] = BIB_CRC_LENGTH(4) | BIB_INFO_LENGTH(4) | BIB_CRC(0);
	config_rom[1] = 0x31333934;

	config_rom[2] =
		BIB_LINK_SPEED(card->link_speed) |
		BIB_GENERATION(card->config_rom_generation++ % 14 + 2) |
		BIB_MAX_ROM(2) |
		BIB_MAX_RECEIVE(card->max_receive) |
		BIB_BMC | BIB_ISC | BIB_CMC | BIB_IMC;
	config_rom[3] = card->guid >> 32;
	config_rom[4] = card->guid;

	/* Generate root directory. */
	i = 5;
	config_rom[i++] = 0;
	config_rom[i++] = 0x0c0083c0; /* node capabilities */
	j = i + descriptor_count;

	/* Generate root directory entries for descriptors. */
	list_for_each_entry (desc, &descriptor_list, link) {
		if (desc->immediate > 0)
			config_rom[i++] = desc->immediate;
		config_rom[i] = desc->key | (j - i);
		i++;
		j += desc->length;
	}

	/* Update root directory length. */
	config_rom[5] = (i - 5 - 1) << 16;

	/* End of root directory, now copy in descriptors. */
	list_for_each_entry (desc, &descriptor_list, link) {
		memcpy(&config_rom[i], desc->data, desc->length * 4);
		i += desc->length;
	}

	/* Calculate CRCs for all blocks in the config rom.  This
	 * assumes that CRC length and info length are identical for
	 * the bus info block, which is always the case for this
	 * implementation. */
	for (i = 0; i < j; i += length + 1)
		length = fw_compute_block_crc(config_rom + i);

	*config_rom_length = j;

	return config_rom;
}

static void
update_config_roms(void)
{
	struct fw_card *card;
	u32 *config_rom;
	size_t length;

	list_for_each_entry (card, &card_list, link) {
		config_rom = generate_config_rom(card, &length);
		card->driver->set_config_rom(card, config_rom, length);
	}
}

int
fw_core_add_descriptor(struct fw_descriptor *desc)
{
	size_t i;

	/*
	 * Check descriptor is valid; the length of all blocks in the
	 * descriptor has to add up to exactly the length of the
	 * block.
	 */
	i = 0;
	while (i < desc->length)
		i += (desc->data[i] >> 16) + 1;

	if (i != desc->length)
		return -EINVAL;

	mutex_lock(&card_mutex);

	list_add_tail(&desc->link, &descriptor_list);
	descriptor_count++;
	if (desc->immediate > 0)
		descriptor_count++;
	update_config_roms();

	mutex_unlock(&card_mutex);

	return 0;
}
EXPORT_SYMBOL(fw_core_add_descriptor);

void
fw_core_remove_descriptor(struct fw_descriptor *desc)
{
	mutex_lock(&card_mutex);

	list_del(&desc->link);
	descriptor_count--;
	if (desc->immediate > 0)
		descriptor_count--;
	update_config_roms();

	mutex_unlock(&card_mutex);
}
EXPORT_SYMBOL(fw_core_remove_descriptor);

static const char gap_count_table[] = {
	63, 5, 7, 8, 10, 13, 16, 18, 21, 24, 26, 29, 32, 35, 37, 40
};

struct bm_data {
	struct fw_transaction t;
	struct {
		__be32 arg;
		__be32 data;
	} lock;
	u32 old;
	int rcode;
	struct completion done;
};

static void
complete_bm_lock(struct fw_card *card, int rcode,
		 void *payload, size_t length, void *data)
{
	struct bm_data *bmd = data;

	if (rcode == RCODE_COMPLETE)
		bmd->old = be32_to_cpu(*(__be32 *) payload);
	bmd->rcode = rcode;
	complete(&bmd->done);
}

static void
fw_card_bm_work(struct work_struct *work)
{
	struct fw_card *card = container_of(work, struct fw_card, work.work);
	struct fw_device *root_device;
	struct fw_node *root_node, *local_node;
	struct bm_data bmd;
	unsigned long flags;
	int root_id, new_root_id, irm_id, gap_count, generation, grace;
	bool do_reset = false;

	spin_lock_irqsave(&card->lock, flags);
	local_node = card->local_node;
	root_node  = card->root_node;

	if (local_node == NULL) {
		spin_unlock_irqrestore(&card->lock, flags);
		return;
	}
	fw_node_get(local_node);
	fw_node_get(root_node);

	generation = card->generation;
	root_device = root_node->data;
	if (root_device)
		fw_device_get(root_device);
	root_id = root_node->node_id;
	grace = time_after(jiffies, card->reset_jiffies + DIV_ROUND_UP(HZ, 10));

	if (card->bm_generation + 1 == generation ||
	    (card->bm_generation != generation && grace)) {
		/*
		 * This first step is to figure out who is IRM and
		 * then try to become bus manager.  If the IRM is not
		 * well defined (e.g. does not have an active link
		 * layer or does not responds to our lock request, we
		 * will have to do a little vigilante bus management.
		 * In that case, we do a goto into the gap count logic
		 * so that when we do the reset, we still optimize the
		 * gap count.  That could well save a reset in the
		 * next generation.
		 */

		irm_id = card->irm_node->node_id;
		if (!card->irm_node->link_on) {
			new_root_id = local_node->node_id;
			fw_notify("IRM has link off, making local node (%02x) root.\n",
				  new_root_id);
			goto pick_me;
		}

		bmd.lock.arg = cpu_to_be32(0x3f);
		bmd.lock.data = cpu_to_be32(local_node->node_id);

		spin_unlock_irqrestore(&card->lock, flags);

		init_completion(&bmd.done);
		fw_send_request(card, &bmd.t, TCODE_LOCK_COMPARE_SWAP,
				irm_id, generation,
				SCODE_100, CSR_REGISTER_BASE + CSR_BUS_MANAGER_ID,
				&bmd.lock, sizeof(bmd.lock),
				complete_bm_lock, &bmd);
		wait_for_completion(&bmd.done);

		if (bmd.rcode == RCODE_GENERATION) {
			/*
			 * Another bus reset happened. Just return,
			 * the BM work has been rescheduled.
			 */
			goto out;
		}

		if (bmd.rcode == RCODE_COMPLETE && bmd.old != 0x3f)
			/* Somebody else is BM, let them do the work. */
			goto out;

		spin_lock_irqsave(&card->lock, flags);
		if (bmd.rcode != RCODE_COMPLETE) {
			/*
			 * The lock request failed, maybe the IRM
			 * isn't really IRM capable after all. Let's
			 * do a bus reset and pick the local node as
			 * root, and thus, IRM.
			 */
			new_root_id = local_node->node_id;
			fw_notify("BM lock failed, making local node (%02x) root.\n",
				  new_root_id);
			goto pick_me;
		}
	} else if (card->bm_generation != generation) {
		/*
		 * OK, we weren't BM in the last generation, and it's
		 * less than 100ms since last bus reset. Reschedule
		 * this task 100ms from now.
		 */
		spin_unlock_irqrestore(&card->lock, flags);
		schedule_delayed_work(&card->work, DIV_ROUND_UP(HZ, 10));
		goto out;
	}

	/*
	 * We're bus manager for this generation, so next step is to
	 * make sure we have an active cycle master and do gap count
	 * optimization.
	 */
	card->bm_generation = generation;

	if (root_device == NULL) {
		/*
		 * Either link_on is false, or we failed to read the
		 * config rom.  In either case, pick another root.
		 */
		new_root_id = local_node->node_id;
	} else if (atomic_read(&root_device->state) != FW_DEVICE_RUNNING) {
		/*
		 * If we haven't probed this device yet, bail out now
		 * and let's try again once that's done.
		 */
		spin_unlock_irqrestore(&card->lock, flags);
		goto out;
	} else if (root_device->cmc) {
		/*
		 * FIXME: I suppose we should set the cmstr bit in the
		 * STATE_CLEAR register of this node, as described in
		 * 1394-1995, 8.4.2.6.  Also, send out a force root
		 * packet for this node.
		 */
		new_root_id = root_id;
	} else {
		/*
		 * Current root has an active link layer and we
		 * successfully read the config rom, but it's not
		 * cycle master capable.
		 */
		new_root_id = local_node->node_id;
	}

 pick_me:
	/*
	 * Pick a gap count from 1394a table E-1.  The table doesn't cover
	 * the typically much larger 1394b beta repeater delays though.
	 */
	if (!card->beta_repeaters_present &&
	    root_node->max_hops < ARRAY_SIZE(gap_count_table))
		gap_count = gap_count_table[root_node->max_hops];
	else
		gap_count = 63;

	/*
	 * Finally, figure out if we should do a reset or not.  If we have
	 * done less than 5 resets with the same physical topology and we
	 * have either a new root or a new gap count setting, let's do it.
	 */

	if (card->bm_retries++ < 5 &&
	    (card->gap_count != gap_count || new_root_id != root_id))
		do_reset = true;

	spin_unlock_irqrestore(&card->lock, flags);

	if (do_reset) {
		fw_notify("phy config: card %d, new root=%x, gap_count=%d\n",
			  card->index, new_root_id, gap_count);
		fw_send_phy_config(card, new_root_id, generation, gap_count);
		fw_core_initiate_bus_reset(card, 1);
	}
 out:
	if (root_device)
		fw_device_put(root_device);
	fw_node_put(root_node);
	fw_node_put(local_node);
}

static void
flush_timer_callback(unsigned long data)
{
	struct fw_card *card = (struct fw_card *)data;

	fw_flush_transactions(card);
}

void
fw_card_initialize(struct fw_card *card, const struct fw_card_driver *driver,
		   struct device *device)
{
	static atomic_t index = ATOMIC_INIT(-1);

	atomic_set(&card->device_count, 0);
	card->index = atomic_inc_return(&index);
	card->driver = driver;
	card->device = device;
	card->current_tlabel = 0;
	card->tlabel_mask = 0;
	card->color = 0;

	INIT_LIST_HEAD(&card->transaction_list);
	spin_lock_init(&card->lock);
	setup_timer(&card->flush_timer,
		    flush_timer_callback, (unsigned long)card);

	card->local_node = NULL;

	INIT_DELAYED_WORK(&card->work, fw_card_bm_work);
}
EXPORT_SYMBOL(fw_card_initialize);

int
fw_card_add(struct fw_card *card,
	    u32 max_receive, u32 link_speed, u64 guid)
{
	u32 *config_rom;
	size_t length;

	card->max_receive = max_receive;
	card->link_speed = link_speed;
	card->guid = guid;

	mutex_lock(&card_mutex);
	config_rom = generate_config_rom(card, &length);
	list_add_tail(&card->link, &card_list);
	mutex_unlock(&card_mutex);

	return card->driver->enable(card, config_rom, length);
}
EXPORT_SYMBOL(fw_card_add);


/*
 * The next few functions implements a dummy driver that use once a
 * card driver shuts down an fw_card.  This allows the driver to
 * cleanly unload, as all IO to the card will be handled by the dummy
 * driver instead of calling into the (possibly) unloaded module.  The
 * dummy driver just fails all IO.
 */

static int
dummy_enable(struct fw_card *card, u32 *config_rom, size_t length)
{
	BUG();
	return -1;
}

static int
dummy_update_phy_reg(struct fw_card *card, int address,
		     int clear_bits, int set_bits)
{
	return -ENODEV;
}

static int
dummy_set_config_rom(struct fw_card *card,
		     u32 *config_rom, size_t length)
{
	/*
	 * We take the card out of card_list before setting the dummy
	 * driver, so this should never get called.
	 */
	BUG();
	return -1;
}

static void
dummy_send_request(struct fw_card *card, struct fw_packet *packet)
{
	packet->callback(packet, card, -ENODEV);
}

static void
dummy_send_response(struct fw_card *card, struct fw_packet *packet)
{
	packet->callback(packet, card, -ENODEV);
}

static int
dummy_cancel_packet(struct fw_card *card, struct fw_packet *packet)
{
	return -ENOENT;
}

static int
dummy_enable_phys_dma(struct fw_card *card,
		      int node_id, int generation)
{
	return -ENODEV;
}

static struct fw_card_driver dummy_driver = {
	.name            = "dummy",
	.enable          = dummy_enable,
	.update_phy_reg  = dummy_update_phy_reg,
	.set_config_rom  = dummy_set_config_rom,
	.send_request    = dummy_send_request,
	.cancel_packet   = dummy_cancel_packet,
	.send_response   = dummy_send_response,
	.enable_phys_dma = dummy_enable_phys_dma,
};

void
fw_core_remove_card(struct fw_card *card)
{
	card->driver->update_phy_reg(card, 4,
				     PHY_LINK_ACTIVE | PHY_CONTENDER, 0);
	fw_core_initiate_bus_reset(card, 1);

	mutex_lock(&card_mutex);
	list_del(&card->link);
	mutex_unlock(&card_mutex);

	/* Set up the dummy driver. */
	card->driver = &dummy_driver;

	fw_destroy_nodes(card);
	/*
	 * Wait for all device workqueue jobs to finish.  Otherwise the
	 * firewire-core module could be unloaded before the jobs ran.
	 */
	while (atomic_read(&card->device_count) > 0)
		msleep(100);

	cancel_delayed_work_sync(&card->work);
	fw_flush_transactions(card);
	del_timer_sync(&card->flush_timer);
}
EXPORT_SYMBOL(fw_core_remove_card);

int
fw_core_initiate_bus_reset(struct fw_card *card, int short_reset)
{
	int reg = short_reset ? 5 : 1;
	int bit = short_reset ? PHY_BUS_SHORT_RESET : PHY_BUS_RESET;

	return card->driver->update_phy_reg(card, reg, 0, bit);
}
EXPORT_SYMBOL(fw_core_initiate_bus_reset);
OpenPOWER on IntegriCloud