1 /*
2 * Incremental bus scan, based on bus topology
3 *
4 * Copyright (C) 2004-2006 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/module.h>
22 #include <linux/wait.h>
23 #include <linux/errno.h>
24 #include <asm/bug.h>
25 #include <asm/system.h>
26 #include "fw-transaction.h"
27 #include "fw-topology.h"
28
29 #define SELF_ID_PHY_ID(q) (((q) >> 24) & 0x3f)
30 #define SELF_ID_EXTENDED(q) (((q) >> 23) & 0x01)
31 #define SELF_ID_LINK_ON(q) (((q) >> 22) & 0x01)
32 #define SELF_ID_GAP_COUNT(q) (((q) >> 16) & 0x3f)
33 #define SELF_ID_PHY_SPEED(q) (((q) >> 14) & 0x03)
34 #define SELF_ID_CONTENDER(q) (((q) >> 11) & 0x01)
35 #define SELF_ID_PHY_INITIATOR(q) (((q) >> 1) & 0x01)
36 #define SELF_ID_MORE_PACKETS(q) (((q) >> 0) & 0x01)
37
38 #define SELF_ID_EXT_SEQUENCE(q) (((q) >> 20) & 0x07)
39
40 static u32 *count_ports(u32 *sid, int *total_port_count, int *child_port_count)
41 {
42 u32 q;
43 int port_type, shift, seq;
44
45 *total_port_count = 0;
46 *child_port_count = 0;
47
48 shift = 6;
49 q = *sid;
50 seq = 0;
51
52 while (1) {
53 port_type = (q >> shift) & 0x03;
54 switch (port_type) {
55 case SELFID_PORT_CHILD:
56 (*child_port_count)++;
57 case SELFID_PORT_PARENT:
58 case SELFID_PORT_NCONN:
59 (*total_port_count)++;
60 case SELFID_PORT_NONE:
61 break;
62 }
63
64 shift -= 2;
65 if (shift == 0) {
66 if (!SELF_ID_MORE_PACKETS(q))
67 return sid + 1;
68
69 shift = 16;
70 sid++;
71 q = *sid;
72
73 /*
74 * Check that the extra packets actually are
75 * extended self ID packets and that the
76 * sequence numbers in the extended self ID
77 * packets increase as expected.
78 */
79
80 if (!SELF_ID_EXTENDED(q) ||
81 seq != SELF_ID_EXT_SEQUENCE(q))
82 return NULL;
83
84 seq++;
85 }
86 }
87 }
88
89 static int get_port_type(u32 *sid, int port_index)
90 {
91 int index, shift;
92
93 index = (port_index + 5) / 8;
94 shift = 16 - ((port_index + 5) & 7) * 2;
95 return (sid[index] >> shift) & 0x03;
96 }
97
98 static struct fw_node *fw_node_create(u32 sid, int port_count, int color)
99 {
100 struct fw_node *node;
101
102 node = kzalloc(sizeof(*node) + port_count * sizeof(node->ports[0]),
103 GFP_ATOMIC);
104 if (node == NULL)
105 return NULL;
106
107 node->color = color;
108 node->node_id = LOCAL_BUS | SELF_ID_PHY_ID(sid);
109 node->link_on = SELF_ID_LINK_ON(sid);
110 node->phy_speed = SELF_ID_PHY_SPEED(sid);
111 node->port_count = port_count;
112
113 atomic_set(&node->ref_count, 1);
114 INIT_LIST_HEAD(&node->link);
115
116 return node;
117 }
118
119 /*
120 * Compute the maximum hop count for this node and it's children. The
121 * maximum hop count is the maximum number of connections between any
122 * two nodes in the subtree rooted at this node. We need this for
123 * setting the gap count. As we build the tree bottom up in
124 * build_tree() below, this is fairly easy to do: for each node we
125 * maintain the max hop count and the max depth, ie the number of hops
126 * to the furthest leaf. Computing the max hop count breaks down into
127 * two cases: either the path goes through this node, in which case
128 * the hop count is the sum of the two biggest child depths plus 2.
129 * Or it could be the case that the max hop path is entirely
130 * containted in a child tree, in which case the max hop count is just
131 * the max hop count of this child.
132 */
133 static void update_hop_count(struct fw_node *node)
134 {
135 int depths[2] = { -1, -1 };
136 int max_child_hops = 0;
137 int i;
138
139 for (i = 0; i < node->port_count; i++) {
140 if (node->ports[i] == NULL)
141 continue;
142
143 if (node->ports[i]->max_hops > max_child_hops)
144 max_child_hops = node->ports[i]->max_hops;
145
146 if (node->ports[i]->max_depth > depths[0]) {
147 depths[1] = depths[0];
148 depths[0] = node->ports[i]->max_depth;
149 } else if (node->ports[i]->max_depth > depths[1])
150 depths[1] = node->ports[i]->max_depth;
151 }
152
153 node->max_depth = depths[0] + 1;
154 node->max_hops = max(max_child_hops, depths[0] + depths[1] + 2);
155 }
156
157 static inline struct fw_node *fw_node(struct list_head *l)
158 {
159 return list_entry(l, struct fw_node, link);
160 }
161
162 /**
163 * build_tree - Build the tree representation of the topology
164 * @self_ids: array of self IDs to create the tree from
165 * @self_id_count: the length of the self_ids array
166 * @local_id: the node ID of the local node
167 *
168 * This function builds the tree representation of the topology given
169 * by the self IDs from the latest bus reset. During the construction
170 * of the tree, the function checks that the self IDs are valid and
171 * internally consistent. On succcess this function returns the
172 * fw_node corresponding to the local card otherwise NULL.
173 */
174 static struct fw_node *build_tree(struct fw_card *card,
175 u32 *sid, int self_id_count)
176 {
177 struct fw_node *node, *child, *local_node, *irm_node;
178 struct list_head stack, *h;
179 u32 *next_sid, *end, q;
180 int i, port_count, child_port_count, phy_id, parent_count, stack_depth;
181 int gap_count;
182 bool beta_repeaters_present;
183
184 local_node = NULL;
185 node = NULL;
186 INIT_LIST_HEAD(&stack);
187 stack_depth = 0;
188 end = sid + self_id_count;
189 phy_id = 0;
190 irm_node = NULL;
191 gap_count = SELF_ID_GAP_COUNT(*sid);
192 beta_repeaters_present = false;
193
194 while (sid < end) {
195 next_sid = count_ports(sid, &port_count, &child_port_count);
196
197 if (next_sid == NULL) {
198 fw_error("Inconsistent extended self IDs.\n");
199 return NULL;
200 }
201
202 q = *sid;
203 if (phy_id != SELF_ID_PHY_ID(q)) {
204 fw_error("PHY ID mismatch in self ID: %d != %d.\n",
205 phy_id, SELF_ID_PHY_ID(q));
206 return NULL;
207 }
208
209 if (child_port_count > stack_depth) {
210 fw_error("Topology stack underflow\n");
211 return NULL;
212 }
213
214 /*
215 * Seek back from the top of our stack to find the
216 * start of the child nodes for this node.
217 */
218 for (i = 0, h = &stack; i < child_port_count; i++)
219 h = h->prev;
220 /*
221 * When the stack is empty, this yields an invalid value,
222 * but that pointer will never be dereferenced.
223 */
224 child = fw_node(h);
225
226 node = fw_node_create(q, port_count, card->color);
227 if (node == NULL) {
228 fw_error("Out of memory while building topology.\n");
229 return NULL;
230 }
231
232 if (phy_id == (card->node_id & 0x3f))
233 local_node = node;
234
235 if (SELF_ID_CONTENDER(q))
236 irm_node = node;
237
238 parent_count = 0;
239
240 for (i = 0; i < port_count; i++) {
241 switch (get_port_type(sid, i)) {
242 case SELFID_PORT_PARENT:
243 /*
244 * Who's your daddy? We dont know the
245 * parent node at this time, so we
246 * temporarily abuse node->color for
247 * remembering the entry in the
248 * node->ports array where the parent
249 * node should be. Later, when we
250 * handle the parent node, we fix up
251 * the reference.
252 */
253 parent_count++;
254 node->color = i;
255 break;
256
257 case SELFID_PORT_CHILD:
258 node->ports[i] = child;
259 /*
260 * Fix up parent reference for this
261 * child node.
262 */
263 child->ports[child->color] = node;
264 child->color = card->color;
265 child = fw_node(child->link.next);
266 break;
267 }
268 }
269
270 /*
271 * Check that the node reports exactly one parent
272 * port, except for the root, which of course should
273 * have no parents.
274 */
275 if ((next_sid == end && parent_count != 0) ||
276 (next_sid < end && parent_count != 1)) {
277 fw_error("Parent port inconsistency for node %d: "
278 "parent_count=%d\n", phy_id, parent_count);
279 return NULL;
280 }
281
282 /* Pop the child nodes off the stack and push the new node. */
283 __list_del(h->prev, &stack);
284 list_add_tail(&node->link, &stack);
285 stack_depth += 1 - child_port_count;
286
287 if (node->phy_speed == SCODE_BETA &&
288 parent_count + child_port_count > 1)
289 beta_repeaters_present = true;
290
291 /*
292 * If all PHYs does not report the same gap count
293 * setting, we fall back to 63 which will force a gap
294 * count reconfiguration and a reset.
295 */
296 if (SELF_ID_GAP_COUNT(q) != gap_count)
297 gap_count = 63;
298
299 update_hop_count(node);
300
301 sid = next_sid;
302 phy_id++;
303 }
304
305 card->root_node = node;
306 card->irm_node = irm_node;
307 card->gap_count = gap_count;
308 card->beta_repeaters_present = beta_repeaters_present;
309
310 return local_node;
311 }
312
313 typedef void (*fw_node_callback_t)(struct fw_card * card,
314 struct fw_node * node,
315 struct fw_node * parent);
316
317 static void
318 for_each_fw_node(struct fw_card *card, struct fw_node *root,
319 fw_node_callback_t callback)
320 {
321 struct list_head list;
322 struct fw_node *node, *next, *child, *parent;
323 int i;
324
325 INIT_LIST_HEAD(&list);
326
327 fw_node_get(root);
328 list_add_tail(&root->link, &list);
329 parent = NULL;
330 list_for_each_entry(node, &list, link) {
331 node->color = card->color;
332
333 for (i = 0; i < node->port_count; i++) {
334 child = node->ports[i];
335 if (!child)
336 continue;
337 if (child->color == card->color)
338 parent = child;
339 else {
340 fw_node_get(child);
341 list_add_tail(&child->link, &list);
342 }
343 }
344
345 callback(card, node, parent);
346 }
347
348 list_for_each_entry_safe(node, next, &list, link)
349 fw_node_put(node);
350 }
351
352 static void
353 report_lost_node(struct fw_card *card,
354 struct fw_node *node, struct fw_node *parent)
355 {
356 fw_node_event(card, node, FW_NODE_DESTROYED);
357 fw_node_put(node);
358 }
359
360 static void
361 report_found_node(struct fw_card *card,
362 struct fw_node *node, struct fw_node *parent)
363 {
364 int b_path = (node->phy_speed == SCODE_BETA);
365
366 if (parent != NULL) {
367 /* min() macro doesn't work here with gcc 3.4 */
368 node->max_speed = parent->max_speed < node->phy_speed ?
369 parent->max_speed : node->phy_speed;
370 node->b_path = parent->b_path && b_path;
371 } else {
372 node->max_speed = node->phy_speed;
373 node->b_path = b_path;
374 }
375
376 fw_node_event(card, node, FW_NODE_CREATED);
377 }
378
379 void fw_destroy_nodes(struct fw_card *card)
380 {
381 unsigned long flags;
382
383 spin_lock_irqsave(&card->lock, flags);
384 card->color++;
385 if (card->local_node != NULL)
386 for_each_fw_node(card, card->local_node, report_lost_node);
387 card->local_node = NULL;
388 spin_unlock_irqrestore(&card->lock, flags);
389 }
390
391 static void move_tree(struct fw_node *node0, struct fw_node *node1, int port)
392 {
393 struct fw_node *tree;
394 int i;
395
396 tree = node1->ports[port];
397 node0->ports[port] = tree;
398 for (i = 0; i < tree->port_count; i++) {
399 if (tree->ports[i] == node1) {
400 tree->ports[i] = node0;
401 break;
402 }
403 }
404 }
405
406 /**
407 * update_tree - compare the old topology tree for card with the new
408 * one specified by root. Queue the nodes and mark them as either
409 * found, lost or updated. Update the nodes in the card topology tree
410 * as we go.
411 */
412 static void
413 update_tree(struct fw_card *card, struct fw_node *root)
414 {
415 struct list_head list0, list1;
416 struct fw_node *node0, *node1;
417 int i, event;
418
419 INIT_LIST_HEAD(&list0);
420 list_add_tail(&card->local_node->link, &list0);
421 INIT_LIST_HEAD(&list1);
422 list_add_tail(&root->link, &list1);
423
424 node0 = fw_node(list0.next);
425 node1 = fw_node(list1.next);
426
427 while (&node0->link != &list0) {
428 WARN_ON(node0->port_count != node1->port_count);
429
430 if (node0->link_on && !node1->link_on)
431 event = FW_NODE_LINK_OFF;
432 else if (!node0->link_on && node1->link_on)
433 event = FW_NODE_LINK_ON;
434 else
435 event = FW_NODE_UPDATED;
436
437 node0->node_id = node1->node_id;
438 node0->color = card->color;
439 node0->link_on = node1->link_on;
440 node0->initiated_reset = node1->initiated_reset;
441 node0->max_hops = node1->max_hops;
442 node1->color = card->color;
443 fw_node_event(card, node0, event);
444
445 if (card->root_node == node1)
446 card->root_node = node0;
447 if (card->irm_node == node1)
448 card->irm_node = node0;
449
450 for (i = 0; i < node0->port_count; i++) {
451 if (node0->ports[i] && node1->ports[i]) {
452 /*
453 * This port didn't change, queue the
454 * connected node for further
455 * investigation.
456 */
457 if (node0->ports[i]->color == card->color)
458 continue;
459 list_add_tail(&node0->ports[i]->link, &list0);
460 list_add_tail(&node1->ports[i]->link, &list1);
461 } else if (node0->ports[i]) {
462 /*
463 * The nodes connected here were
464 * unplugged; unref the lost nodes and
465 * queue FW_NODE_LOST callbacks for
466 * them.
467 */
468
469 for_each_fw_node(card, node0->ports[i],
470 report_lost_node);
471 node0->ports[i] = NULL;
472 } else if (node1->ports[i]) {
473 /*
474 * One or more node were connected to
475 * this port. Move the new nodes into
476 * the tree and queue FW_NODE_CREATED
477 * callbacks for them.
478 */
479 move_tree(node0, node1, i);
480 for_each_fw_node(card, node0->ports[i],
481 report_found_node);
482 }
483 }
484
485 node0 = fw_node(node0->link.next);
486 node1 = fw_node(node1->link.next);
487 }
488 }
489
490 static void
491 update_topology_map(struct fw_card *card, u32 *self_ids, int self_id_count)
492 {
493 int node_count;
494
495 card->topology_map[1]++;
496 node_count = (card->root_node->node_id & 0x3f) + 1;
497 card->topology_map[2] = (node_count << 16) | self_id_count;
498 card->topology_map[0] = (self_id_count + 2) << 16;
499 memcpy(&card->topology_map[3], self_ids, self_id_count * 4);
500 fw_compute_block_crc(card->topology_map);
501 }
502
503 void
504 fw_core_handle_bus_reset(struct fw_card *card,
505 int node_id, int generation,
506 int self_id_count, u32 * self_ids)
507 {
508 struct fw_node *local_node;
509 unsigned long flags;
510
511 fw_flush_transactions(card);
512
513 spin_lock_irqsave(&card->lock, flags);
514
515 /*
516 * If the new topology has a different self_id_count the topology
517 * changed, either nodes were added or removed. In that case we
518 * reset the IRM reset counter.
519 */
520 if (card->self_id_count != self_id_count)
521 card->bm_retries = 0;
522
523 card->node_id = node_id;
524 /*
525 * Update node_id before generation to prevent anybody from using
526 * a stale node_id together with a current generation.
527 */
528 smp_wmb();
529 card->generation = generation;
530 card->reset_jiffies = jiffies;
531 schedule_delayed_work(&card->work, 0);
532
533 local_node = build_tree(card, self_ids, self_id_count);
534
535 update_topology_map(card, self_ids, self_id_count);
536
537 card->color++;
538
539 if (local_node == NULL) {
540 fw_error("topology build failed\n");
541 /* FIXME: We need to issue a bus reset in this case. */
542 } else if (card->local_node == NULL) {
543 card->local_node = local_node;
544 for_each_fw_node(card, local_node, report_found_node);
545 } else {
546 update_tree(card, local_node);
547 }
548
549 spin_unlock_irqrestore(&card->lock, flags);
550 }
551 EXPORT_SYMBOL(fw_core_handle_bus_reset);
552
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