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
count_ports(u32 * sid,int * total_port_count,int * child_port_count)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
get_port_type(u32 * sid,int port_index)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
fw_node_create(u32 sid,int port_count,int color)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->initiated_reset = SELF_ID_PHY_INITIATOR(sid);
112 node->port_count = port_count;
113
114 atomic_set(&node->ref_count, 1);
115 INIT_LIST_HEAD(&node->link);
116
117 return node;
118 }
119
120 /*
121 * Compute the maximum hop count for this node and it's children. The
122 * maximum hop count is the maximum number of connections between any
123 * two nodes in the subtree rooted at this node. We need this for
124 * setting the gap count. As we build the tree bottom up in
125 * build_tree() below, this is fairly easy to do: for each node we
126 * maintain the max hop count and the max depth, ie the number of hops
127 * to the furthest leaf. Computing the max hop count breaks down into
128 * two cases: either the path goes through this node, in which case
129 * the hop count is the sum of the two biggest child depths plus 2.
130 * Or it could be the case that the max hop path is entirely
131 * containted in a child tree, in which case the max hop count is just
132 * the max hop count of this child.
133 */
update_hop_count(struct fw_node * node)134 static void update_hop_count(struct fw_node *node)
135 {
136 int depths[2] = { -1, -1 };
137 int max_child_hops = 0;
138 int i;
139
140 for (i = 0; i < node->port_count; i++) {
141 if (node->ports[i] == NULL)
142 continue;
143
144 if (node->ports[i]->max_hops > max_child_hops)
145 max_child_hops = node->ports[i]->max_hops;
146
147 if (node->ports[i]->max_depth > depths[0]) {
148 depths[1] = depths[0];
149 depths[0] = node->ports[i]->max_depth;
150 } else if (node->ports[i]->max_depth > depths[1])
151 depths[1] = node->ports[i]->max_depth;
152 }
153
154 node->max_depth = depths[0] + 1;
155 node->max_hops = max(max_child_hops, depths[0] + depths[1] + 2);
156 }
157
fw_node(struct list_head * l)158 static inline struct fw_node *fw_node(struct list_head *l)
159 {
160 return list_entry(l, struct fw_node, link);
161 }
162
163 /**
164 * build_tree - Build the tree representation of the topology
165 * @self_ids: array of self IDs to create the tree from
166 * @self_id_count: the length of the self_ids array
167 * @local_id: the node ID of the local node
168 *
169 * This function builds the tree representation of the topology given
170 * by the self IDs from the latest bus reset. During the construction
171 * of the tree, the function checks that the self IDs are valid and
172 * internally consistent. On succcess this function returns the
173 * fw_node corresponding to the local card otherwise NULL.
174 */
build_tree(struct fw_card * card,u32 * sid,int self_id_count)175 static struct fw_node *build_tree(struct fw_card *card,
176 u32 *sid, int self_id_count)
177 {
178 struct fw_node *node, *child, *local_node, *irm_node;
179 struct list_head stack, *h;
180 u32 *next_sid, *end, q;
181 int i, port_count, child_port_count, phy_id, parent_count, stack_depth;
182 int gap_count;
183 bool beta_repeaters_present;
184
185 local_node = NULL;
186 node = NULL;
187 INIT_LIST_HEAD(&stack);
188 stack_depth = 0;
189 end = sid + self_id_count;
190 phy_id = 0;
191 irm_node = NULL;
192 gap_count = SELF_ID_GAP_COUNT(*sid);
193 beta_repeaters_present = false;
194
195 while (sid < end) {
196 next_sid = count_ports(sid, &port_count, &child_port_count);
197
198 if (next_sid == NULL) {
199 fw_error("Inconsistent extended self IDs.\n");
200 return NULL;
201 }
202
203 q = *sid;
204 if (phy_id != SELF_ID_PHY_ID(q)) {
205 fw_error("PHY ID mismatch in self ID: %d != %d.\n",
206 phy_id, SELF_ID_PHY_ID(q));
207 return NULL;
208 }
209
210 if (child_port_count > stack_depth) {
211 fw_error("Topology stack underflow\n");
212 return NULL;
213 }
214
215 /*
216 * Seek back from the top of our stack to find the
217 * start of the child nodes for this node.
218 */
219 for (i = 0, h = &stack; i < child_port_count; i++)
220 h = h->prev;
221 /*
222 * When the stack is empty, this yields an invalid value,
223 * but that pointer will never be dereferenced.
224 */
225 child = fw_node(h);
226
227 node = fw_node_create(q, port_count, card->color);
228 if (node == NULL) {
229 fw_error("Out of memory while building topology.\n");
230 return NULL;
231 }
232
233 if (phy_id == (card->node_id & 0x3f))
234 local_node = node;
235
236 if (SELF_ID_CONTENDER(q))
237 irm_node = node;
238
239 parent_count = 0;
240
241 for (i = 0; i < port_count; i++) {
242 switch (get_port_type(sid, i)) {
243 case SELFID_PORT_PARENT:
244 /*
245 * Who's your daddy? We dont know the
246 * parent node at this time, so we
247 * temporarily abuse node->color for
248 * remembering the entry in the
249 * node->ports array where the parent
250 * node should be. Later, when we
251 * handle the parent node, we fix up
252 * the reference.
253 */
254 parent_count++;
255 node->color = i;
256 break;
257
258 case SELFID_PORT_CHILD:
259 node->ports[i] = child;
260 /*
261 * Fix up parent reference for this
262 * child node.
263 */
264 child->ports[child->color] = node;
265 child->color = card->color;
266 child = fw_node(child->link.next);
267 break;
268 }
269 }
270
271 /*
272 * Check that the node reports exactly one parent
273 * port, except for the root, which of course should
274 * have no parents.
275 */
276 if ((next_sid == end && parent_count != 0) ||
277 (next_sid < end && parent_count != 1)) {
278 fw_error("Parent port inconsistency for node %d: "
279 "parent_count=%d\n", phy_id, parent_count);
280 return NULL;
281 }
282
283 /* Pop the child nodes off the stack and push the new node. */
284 __list_del(h->prev, &stack);
285 list_add_tail(&node->link, &stack);
286 stack_depth += 1 - child_port_count;
287
288 if (node->phy_speed == SCODE_BETA &&
289 parent_count + child_port_count > 1)
290 beta_repeaters_present = true;
291
292 /*
293 * If PHYs report different gap counts, set an invalid count
294 * which will force a gap count reconfiguration and a reset.
295 */
296 if (SELF_ID_GAP_COUNT(q) != gap_count)
297 gap_count = 0;
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
for_each_fw_node(struct fw_card * card,struct fw_node * root,fw_node_callback_t callback)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
report_lost_node(struct fw_card * card,struct fw_node * node,struct fw_node * parent)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 /* Topology has changed - reset bus manager retry counter */
360 card->bm_retries = 0;
361 }
362
363 static void
report_found_node(struct fw_card * card,struct fw_node * node,struct fw_node * parent)364 report_found_node(struct fw_card *card,
365 struct fw_node *node, struct fw_node *parent)
366 {
367 int b_path = (node->phy_speed == SCODE_BETA);
368
369 if (parent != NULL) {
370 /* min() macro doesn't work here with gcc 3.4 */
371 node->max_speed = parent->max_speed < node->phy_speed ?
372 parent->max_speed : node->phy_speed;
373 node->b_path = parent->b_path && b_path;
374 } else {
375 node->max_speed = node->phy_speed;
376 node->b_path = b_path;
377 }
378
379 fw_node_event(card, node, FW_NODE_CREATED);
380
381 /* Topology has changed - reset bus manager retry counter */
382 card->bm_retries = 0;
383 }
384
fw_destroy_nodes(struct fw_card * card)385 void fw_destroy_nodes(struct fw_card *card)
386 {
387 unsigned long flags;
388
389 spin_lock_irqsave(&card->lock, flags);
390 card->color++;
391 if (card->local_node != NULL)
392 for_each_fw_node(card, card->local_node, report_lost_node);
393 card->local_node = NULL;
394 spin_unlock_irqrestore(&card->lock, flags);
395 }
396
move_tree(struct fw_node * node0,struct fw_node * node1,int port)397 static void move_tree(struct fw_node *node0, struct fw_node *node1, int port)
398 {
399 struct fw_node *tree;
400 int i;
401
402 tree = node1->ports[port];
403 node0->ports[port] = tree;
404 for (i = 0; i < tree->port_count; i++) {
405 if (tree->ports[i] == node1) {
406 tree->ports[i] = node0;
407 break;
408 }
409 }
410 }
411
412 /**
413 * update_tree - compare the old topology tree for card with the new
414 * one specified by root. Queue the nodes and mark them as either
415 * found, lost or updated. Update the nodes in the card topology tree
416 * as we go.
417 */
418 static void
update_tree(struct fw_card * card,struct fw_node * root)419 update_tree(struct fw_card *card, struct fw_node *root)
420 {
421 struct list_head list0, list1;
422 struct fw_node *node0, *node1, *next1;
423 int i, event;
424
425 INIT_LIST_HEAD(&list0);
426 list_add_tail(&card->local_node->link, &list0);
427 INIT_LIST_HEAD(&list1);
428 list_add_tail(&root->link, &list1);
429
430 node0 = fw_node(list0.next);
431 node1 = fw_node(list1.next);
432
433 while (&node0->link != &list0) {
434 WARN_ON(node0->port_count != node1->port_count);
435
436 if (node0->link_on && !node1->link_on)
437 event = FW_NODE_LINK_OFF;
438 else if (!node0->link_on && node1->link_on)
439 event = FW_NODE_LINK_ON;
440 else if (node1->initiated_reset && node1->link_on)
441 event = FW_NODE_INITIATED_RESET;
442 else
443 event = FW_NODE_UPDATED;
444
445 node0->node_id = node1->node_id;
446 node0->color = card->color;
447 node0->link_on = node1->link_on;
448 node0->initiated_reset = node1->initiated_reset;
449 node0->max_hops = node1->max_hops;
450 node1->color = card->color;
451 fw_node_event(card, node0, event);
452
453 if (card->root_node == node1)
454 card->root_node = node0;
455 if (card->irm_node == node1)
456 card->irm_node = node0;
457
458 for (i = 0; i < node0->port_count; i++) {
459 if (node0->ports[i] && node1->ports[i]) {
460 /*
461 * This port didn't change, queue the
462 * connected node for further
463 * investigation.
464 */
465 if (node0->ports[i]->color == card->color)
466 continue;
467 list_add_tail(&node0->ports[i]->link, &list0);
468 list_add_tail(&node1->ports[i]->link, &list1);
469 } else if (node0->ports[i]) {
470 /*
471 * The nodes connected here were
472 * unplugged; unref the lost nodes and
473 * queue FW_NODE_LOST callbacks for
474 * them.
475 */
476
477 for_each_fw_node(card, node0->ports[i],
478 report_lost_node);
479 node0->ports[i] = NULL;
480 } else if (node1->ports[i]) {
481 /*
482 * One or more node were connected to
483 * this port. Move the new nodes into
484 * the tree and queue FW_NODE_CREATED
485 * callbacks for them.
486 */
487 move_tree(node0, node1, i);
488 for_each_fw_node(card, node0->ports[i],
489 report_found_node);
490 }
491 }
492
493 node0 = fw_node(node0->link.next);
494 next1 = fw_node(node1->link.next);
495 fw_node_put(node1);
496 node1 = next1;
497 }
498 }
499
500 static void
update_topology_map(struct fw_card * card,u32 * self_ids,int self_id_count)501 update_topology_map(struct fw_card *card, u32 *self_ids, int self_id_count)
502 {
503 int node_count;
504
505 card->topology_map[1]++;
506 node_count = (card->root_node->node_id & 0x3f) + 1;
507 card->topology_map[2] = (node_count << 16) | self_id_count;
508 card->topology_map[0] = (self_id_count + 2) << 16;
509 memcpy(&card->topology_map[3], self_ids, self_id_count * 4);
510 fw_compute_block_crc(card->topology_map);
511 }
512
513 void
fw_core_handle_bus_reset(struct fw_card * card,int node_id,int generation,int self_id_count,u32 * self_ids)514 fw_core_handle_bus_reset(struct fw_card *card,
515 int node_id, int generation,
516 int self_id_count, u32 * self_ids)
517 {
518 struct fw_node *local_node;
519 unsigned long flags;
520
521 /*
522 * If the selfID buffer is not the immediate successor of the
523 * previously processed one, we cannot reliably compare the
524 * old and new topologies.
525 */
526 if (!is_next_generation(generation, card->generation) &&
527 card->local_node != NULL) {
528 fw_notify("skipped bus generations, destroying all nodes\n");
529 fw_destroy_nodes(card);
530 card->bm_retries = 0;
531 }
532
533 spin_lock_irqsave(&card->lock, flags);
534
535 card->node_id = node_id;
536 /*
537 * Update node_id before generation to prevent anybody from using
538 * a stale node_id together with a current generation.
539 */
540 smp_wmb();
541 card->generation = generation;
542 card->reset_jiffies = jiffies;
543 fw_schedule_bm_work(card, 0);
544
545 local_node = build_tree(card, self_ids, self_id_count);
546
547 update_topology_map(card, self_ids, self_id_count);
548
549 card->color++;
550
551 if (local_node == NULL) {
552 fw_error("topology build failed\n");
553 /* FIXME: We need to issue a bus reset in this case. */
554 } else if (card->local_node == NULL) {
555 card->local_node = local_node;
556 for_each_fw_node(card, local_node, report_found_node);
557 } else {
558 update_tree(card, local_node);
559 }
560
561 spin_unlock_irqrestore(&card->lock, flags);
562 }
563 EXPORT_SYMBOL(fw_core_handle_bus_reset);
564