summaryrefslogtreecommitdiffstats
path: root/drivers/firewire/fw-topology.c
blob: 213b0ff8f3d6dd55d5edf5af91efdc21a50b638b (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
548
549
550
551
552
553
/*
 * Incremental bus scan, based on bus topology
 *
 * Copyright (C) 2004-2006 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/wait.h>
#include <linux/errno.h>
#include <asm/bug.h>
#include <asm/system.h>
#include "fw-transaction.h"
#include "fw-topology.h"

#define SELF_ID_PHY_ID(q)		(((q) >> 24) & 0x3f)
#define SELF_ID_EXTENDED(q)		(((q) >> 23) & 0x01)
#define SELF_ID_LINK_ON(q)		(((q) >> 22) & 0x01)
#define SELF_ID_GAP_COUNT(q)		(((q) >> 16) & 0x3f)
#define SELF_ID_PHY_SPEED(q)		(((q) >> 14) & 0x03)
#define SELF_ID_CONTENDER(q)		(((q) >> 11) & 0x01)
#define SELF_ID_PHY_INITIATOR(q)	(((q) >>  1) & 0x01)
#define SELF_ID_MORE_PACKETS(q)		(((q) >>  0) & 0x01)

#define SELF_ID_EXT_SEQUENCE(q)		(((q) >> 20) & 0x07)

static u32 *count_ports(u32 *sid, int *total_port_count, int *child_port_count)
{
	u32 q;
	int port_type, shift, seq;

	*total_port_count = 0;
	*child_port_count = 0;

	shift = 6;
	q = *sid;
	seq = 0;

	while (1) {
		port_type = (q >> shift) & 0x03;
		switch (port_type) {
		case SELFID_PORT_CHILD:
			(*child_port_count)++;
		case SELFID_PORT_PARENT:
		case SELFID_PORT_NCONN:
			(*total_port_count)++;
		case SELFID_PORT_NONE:
			break;
		}

		shift -= 2;
		if (shift == 0) {
			if (!SELF_ID_MORE_PACKETS(q))
				return sid + 1;

			shift = 16;
			sid++;
			q = *sid;

			/*
			 * Check that the extra packets actually are
			 * extended self ID packets and that the
			 * sequence numbers in the extended self ID
			 * packets increase as expected.
			 */

			if (!SELF_ID_EXTENDED(q) ||
			    seq != SELF_ID_EXT_SEQUENCE(q))
				return NULL;

			seq++;
		}
	}
}

static int get_port_type(u32 *sid, int port_index)
{
	int index, shift;

	index = (port_index + 5) / 8;
	shift = 16 - ((port_index + 5) & 7) * 2;
	return (sid[index] >> shift) & 0x03;
}

static struct fw_node *fw_node_create(u32 sid, int port_count, int color)
{
	struct fw_node *node;

	node = kzalloc(sizeof(*node) + port_count * sizeof(node->ports[0]),
		       GFP_ATOMIC);
	if (node == NULL)
		return NULL;

	node->color = color;
	node->node_id = LOCAL_BUS | SELF_ID_PHY_ID(sid);
	node->link_on = SELF_ID_LINK_ON(sid);
	node->phy_speed = SELF_ID_PHY_SPEED(sid);
	node->initiated_reset = SELF_ID_PHY_INITIATOR(sid);
	node->port_count = port_count;

	atomic_set(&node->ref_count, 1);
	INIT_LIST_HEAD(&node->link);

	return node;
}

/*
 * Compute the maximum hop count for this node and it's children.  The
 * maximum hop count is the maximum number of connections between any
 * two nodes in the subtree rooted at this node.  We need this for
 * setting the gap count.  As we build the tree bottom up in
 * build_tree() below, this is fairly easy to do: for each node we
 * maintain the max hop count and the max depth, ie the number of hops
 * to the furthest leaf.  Computing the max hop count breaks down into
 * two cases: either the path goes through this node, in which case
 * the hop count is the sum of the two biggest child depths plus 2.
 * Or it could be the case that the max hop path is entirely
 * containted in a child tree, in which case the max hop count is just
 * the max hop count of this child.
 */
static void update_hop_count(struct fw_node *node)
{
	int depths[2] = { -1, -1 };
	int max_child_hops = 0;
	int i;

	for (i = 0; i < node->port_count; i++) {
		if (node->ports[i] == NULL)
			continue;

		if (node->ports[i]->max_hops > max_child_hops)
			max_child_hops = node->ports[i]->max_hops;

		if (node->ports[i]->max_depth > depths[0]) {
			depths[1] = depths[0];
			depths[0] = node->ports[i]->max_depth;
		} else if (node->ports[i]->max_depth > depths[1])
			depths[1] = node->ports[i]->max_depth;
	}

	node->max_depth = depths[0] + 1;
	node->max_hops = max(max_child_hops, depths[0] + depths[1] + 2);
}

static inline struct fw_node *fw_node(struct list_head *l)
{
	return list_entry(l, struct fw_node, link);
}

/**
 * build_tree - Build the tree representation of the topology
 * @self_ids: array of self IDs to create the tree from
 * @self_id_count: the length of the self_ids array
 * @local_id: the node ID of the local node
 *
 * This function builds the tree representation of the topology given
 * by the self IDs from the latest bus reset.  During the construction
 * of the tree, the function checks that the self IDs are valid and
 * internally consistent.  On succcess this function returns the
 * fw_node corresponding to the local card otherwise NULL.
 */
static struct fw_node *build_tree(struct fw_card *card,
				  u32 *sid, int self_id_count)
{
	struct fw_node *node, *child, *local_node, *irm_node;
	struct list_head stack, *h;
	u32 *next_sid, *end, q;
	int i, port_count, child_port_count, phy_id, parent_count, stack_depth;
	int gap_count;
	bool beta_repeaters_present;

	local_node = NULL;
	node = NULL;
	INIT_LIST_HEAD(&stack);
	stack_depth = 0;
	end = sid + self_id_count;
	phy_id = 0;
	irm_node = NULL;
	gap_count = SELF_ID_GAP_COUNT(*sid);
	beta_repeaters_present = false;

	while (sid < end) {
		next_sid = count_ports(sid, &port_count, &child_port_count);

		if (next_sid == NULL) {
			fw_error("Inconsistent extended self IDs.\n");
			return NULL;
		}

		q = *sid;
		if (phy_id != SELF_ID_PHY_ID(q)) {
			fw_error("PHY ID mismatch in self ID: %d != %d.\n",
				 phy_id, SELF_ID_PHY_ID(q));
			return NULL;
		}

		if (child_port_count > stack_depth) {
			fw_error("Topology stack underflow\n");
			return NULL;
		}

		/*
		 * Seek back from the top of our stack to find the
		 * start of the child nodes for this node.
		 */
		for (i = 0, h = &stack; i < child_port_count; i++)
			h = h->prev;
		/*
		 * When the stack is empty, this yields an invalid value,
		 * but that pointer will never be dereferenced.
		 */
		child = fw_node(h);

		node = fw_node_create(q, port_count, card->color);
		if (node == NULL) {
			fw_error("Out of memory while building topology.\n");
			return NULL;
		}

		if (phy_id == (card->node_id & 0x3f))
			local_node = node;

		if (SELF_ID_CONTENDER(q))
			irm_node = node;

		parent_count = 0;

		for (i = 0; i < port_count; i++) {
			switch (get_port_type(sid, i)) {
			case SELFID_PORT_PARENT:
				/*
				 * Who's your daddy?  We dont know the
				 * parent node at this time, so we
				 * temporarily abuse node->color for
				 * remembering the entry in the
				 * node->ports array where the parent
				 * node should be.  Later, when we
				 * handle the parent node, we fix up
				 * the reference.
				 */
				parent_count++;
				node->color = i;
				break;

			case SELFID_PORT_CHILD:
				node->ports[i] = child;
				/*
				 * Fix up parent reference for this
				 * child node.
				 */
				child->ports[child->color] = node;
				child->color = card->color;
				child = fw_node(child->link.next);
				break;
			}
		}

		/*
		 * Check that the node reports exactly one parent
		 * port, except for the root, which of course should
		 * have no parents.
		 */
		if ((next_sid == end && parent_count != 0) ||
		    (next_sid < end && parent_count != 1)) {
			fw_error("Parent port inconsistency for node %d: "
				 "parent_count=%d\n", phy_id, parent_count);
			return NULL;
		}

		/* Pop the child nodes off the stack and push the new node. */
		__list_del(h->prev, &stack);
		list_add_tail(&node->link, &stack);
		stack_depth += 1 - child_port_count;

		if (node->phy_speed == SCODE_BETA &&
		    parent_count + child_port_count > 1)
			beta_repeaters_present = true;

		/*
		 * If PHYs report different gap counts, set an invalid count
		 * which will force a gap count reconfiguration and a reset.
		 */
		if (SELF_ID_GAP_COUNT(q) != gap_count)
			gap_count = 0;

		update_hop_count(node);

		sid = next_sid;
		phy_id++;
	}

	card->root_node = node;
	card->irm_node = irm_node;
	card->gap_count = gap_count;
	card->beta_repeaters_present = beta_repeaters_present;

	return local_node;
}

typedef void (*fw_node_callback_t)(struct fw_card * card,
				   struct fw_node * node,
				   struct fw_node * parent);

static void
for_each_fw_node(struct fw_card *card, struct fw_node *root,
		 fw_node_callback_t callback)
{
	struct list_head list;
	struct fw_node *node, *next, *child, *parent;
	int i;

	INIT_LIST_HEAD(&list);

	fw_node_get(root);
	list_add_tail(&root->link, &list);
	parent = NULL;
	list_for_each_entry(node, &list, link) {
		node->color = card->color;

		for (i = 0; i < node->port_count; i++) {
			child = node->ports[i];
			if (!child)
				continue;
			if (child->color == card->color)
				parent = child;
			else {
				fw_node_get(child);
				list_add_tail(&child->link, &list);
			}
		}

		callback(card, node, parent);
	}

	list_for_each_entry_safe(node, next, &list, link)
		fw_node_put(node);
}

static void
report_lost_node(struct fw_card *card,
		 struct fw_node *node, struct fw_node *parent)
{
	fw_node_event(card, node, FW_NODE_DESTROYED);
	fw_node_put(node);
}

static void
report_found_node(struct fw_card *card,
		  struct fw_node *node, struct fw_node *parent)
{
	int b_path = (node->phy_speed == SCODE_BETA);

	if (parent != NULL) {
		/* min() macro doesn't work here with gcc 3.4 */
		node->max_speed = parent->max_speed < node->phy_speed ?
					parent->max_speed : node->phy_speed;
		node->b_path = parent->b_path && b_path;
	} else {
		node->max_speed = node->phy_speed;
		node->b_path = b_path;
	}

	fw_node_event(card, node, FW_NODE_CREATED);
}

void fw_destroy_nodes(struct fw_card *card)
{
	unsigned long flags;

	spin_lock_irqsave(&card->lock, flags);
	card->color++;
	if (card->local_node != NULL)
		for_each_fw_node(card, card->local_node, report_lost_node);
	card->local_node = NULL;
	spin_unlock_irqrestore(&card->lock, flags);
}

static void move_tree(struct fw_node *node0, struct fw_node *node1, int port)
{
	struct fw_node *tree;
	int i;

	tree = node1->ports[port];
	node0->ports[port] = tree;
	for (i = 0; i < tree->port_count; i++) {
		if (tree->ports[i] == node1) {
			tree->ports[i] = node0;
			break;
		}
	}
}

/**
 * update_tree - compare the old topology tree for card with the new
 * one specified by root.  Queue the nodes and mark them as either
 * found, lost or updated.  Update the nodes in the card topology tree
 * as we go.
 */
static void
update_tree(struct fw_card *card, struct fw_node *root)
{
	struct list_head list0, list1;
	struct fw_node *node0, *node1;
	int i, event;

	INIT_LIST_HEAD(&list0);
	list_add_tail(&card->local_node->link, &list0);
	INIT_LIST_HEAD(&list1);
	list_add_tail(&root->link, &list1);

	node0 = fw_node(list0.next);
	node1 = fw_node(list1.next);

	while (&node0->link != &list0) {
		WARN_ON(node0->port_count != node1->port_count);

		if (node0->link_on && !node1->link_on)
			event = FW_NODE_LINK_OFF;
		else if (!node0->link_on && node1->link_on)
			event = FW_NODE_LINK_ON;
		else if (node1->initiated_reset && node1->link_on)
			event = FW_NODE_INITIATED_RESET;
		else
			event = FW_NODE_UPDATED;

		node0->node_id = node1->node_id;
		node0->color = card->color;
		node0->link_on = node1->link_on;
		node0->initiated_reset = node1->initiated_reset;
		node0->max_hops = node1->max_hops;
		node1->color = card->color;
		fw_node_event(card, node0, event);

		if (card->root_node == node1)
			card->root_node = node0;
		if (card->irm_node == node1)
			card->irm_node = node0;

		for (i = 0; i < node0->port_count; i++) {
			if (node0->ports[i] && node1->ports[i]) {
				/*
				 * This port didn't change, queue the
				 * connected node for further
				 * investigation.
				 */
				if (node0->ports[i]->color == card->color)
					continue;
				list_add_tail(&node0->ports[i]->link, &list0);
				list_add_tail(&node1->ports[i]->link, &list1);
			} else if (node0->ports[i]) {
				/*
				 * The nodes connected here were
				 * unplugged; unref the lost nodes and
				 * queue FW_NODE_LOST callbacks for
				 * them.
				 */

				for_each_fw_node(card, node0->ports[i],
						 report_lost_node);
				node0->ports[i] = NULL;
			} else if (node1->ports[i]) {
				/*
				 * One or more node were connected to
				 * this port. Move the new nodes into
				 * the tree and queue FW_NODE_CREATED
				 * callbacks for them.
				 */
				move_tree(node0, node1, i);
				for_each_fw_node(card, node0->ports[i],
						 report_found_node);
			}
		}

		node0 = fw_node(node0->link.next);
		node1 = fw_node(node1->link.next);
	}
}

static void
update_topology_map(struct fw_card *card, u32 *self_ids, int self_id_count)
{
	int node_count;

	card->topology_map[1]++;
	node_count = (card->root_node->node_id & 0x3f) + 1;
	card->topology_map[2] = (node_count << 16) | self_id_count;
	card->topology_map[0] = (self_id_count + 2) << 16;
	memcpy(&card->topology_map[3], self_ids, self_id_count * 4);
	fw_compute_block_crc(card->topology_map);
}

void
fw_core_handle_bus_reset(struct fw_card *card,
			 int node_id, int generation,
			 int self_id_count, u32 * self_ids)
{
	struct fw_node *local_node;
	unsigned long flags;

	fw_flush_transactions(card);

	spin_lock_irqsave(&card->lock, flags);

	/*
	 * If the new topology has a different self_id_count the topology
	 * changed, either nodes were added or removed. In that case we
	 * reset the IRM reset counter.
	 */
	if (card->self_id_count != self_id_count)
		card->bm_retries = 0;

	card->node_id = node_id;
	/*
	 * Update node_id before generation to prevent anybody from using
	 * a stale node_id together with a current generation.
	 */
	smp_wmb();
	card->generation = generation;
	card->reset_jiffies = jiffies;
	schedule_delayed_work(&card->work, 0);

	local_node = build_tree(card, self_ids, self_id_count);

	update_topology_map(card, self_ids, self_id_count);

	card->color++;

	if (local_node == NULL) {
		fw_error("topology build failed\n");
		/* FIXME: We need to issue a bus reset in this case. */
	} else if (card->local_node == NULL) {
		card->local_node = local_node;
		for_each_fw_node(card, local_node, report_found_node);
	} else {
		update_tree(card, local_node);
	}

	spin_unlock_irqrestore(&card->lock, flags);
}
EXPORT_SYMBOL(fw_core_handle_bus_reset);
OpenPOWER on IntegriCloud