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Kristian Høgsberg3038e352006-12-19 19:58:27 -05001/* -*- c-basic-offset: 8 -*-
2 *
3 * fw-topology.c - Incremental bus scan, based on bus topology
4 *
5 * Copyright (C) 2004-2006 Kristian Hoegsberg <krh@bitplanet.net>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software Foundation,
19 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
20 */
21
22#include <linux/module.h>
23#include <linux/wait.h>
24#include <linux/errno.h>
25#include "fw-transaction.h"
26#include "fw-topology.h"
27
28#define self_id_phy_id(q) (((q) >> 24) & 0x3f)
29#define self_id_extended(q) (((q) >> 23) & 0x01)
30#define self_id_link_on(q) (((q) >> 22) & 0x01)
31#define self_id_gap_count(q) (((q) >> 16) & 0x3f)
32#define self_id_phy_speed(q) (((q) >> 14) & 0x03)
33#define self_id_contender(q) (((q) >> 11) & 0x01)
34#define self_id_phy_initiator(q) (((q) >> 1) & 0x01)
35#define self_id_more_packets(q) (((q) >> 0) & 0x01)
36
37#define self_id_ext_sequence(q) (((q) >> 20) & 0x07)
38
39static u32 *count_ports(u32 *sid, int *total_port_count, int *child_port_count)
40{
41 u32 q;
42 int port_type, shift, seq;
43
44 *total_port_count = 0;
45 *child_port_count = 0;
46
47 shift = 6;
48 q = *sid;
49 seq = 0;
50
51 while (1) {
52 port_type = (q >> shift) & 0x03;
53 switch (port_type) {
54 case SELFID_PORT_CHILD:
55 (*child_port_count)++;
56 case SELFID_PORT_PARENT:
57 case SELFID_PORT_NCONN:
58 (*total_port_count)++;
59 case SELFID_PORT_NONE:
60 break;
61 }
62
63 shift -= 2;
64 if (shift == 0) {
65 if (!self_id_more_packets(q))
66 return sid + 1;
67
68 shift = 16;
69 sid++;
70 q = *sid;
71
72 /* Check that the extra packets actually are
73 * extended self ID packets and that the
74 * sequence numbers in the extended self ID
75 * packets increase as expected. */
76
77 if (!self_id_extended(q) ||
78 seq != self_id_ext_sequence(q))
79 return NULL;
80
81 seq++;
82 }
83 }
84}
85
86static int get_port_type(u32 *sid, int port_index)
87{
88 int index, shift;
89
90 index = (port_index + 5) / 8;
91 shift = 16 - ((port_index + 5) & 7) * 2;
92 return (sid[index] >> shift) & 0x03;
93}
94
Adrian Bunk95688e92007-01-22 19:17:37 +010095static struct fw_node *fw_node_create(u32 sid, int port_count, int color)
Kristian Høgsberg3038e352006-12-19 19:58:27 -050096{
97 struct fw_node *node;
98
99 node = kzalloc(sizeof *node + port_count * sizeof node->ports[0],
100 GFP_ATOMIC);
101 if (node == NULL)
102 return NULL;
103
104 node->color = color;
Stefan Richter907293d2007-01-23 21:11:43 +0100105 node->node_id = LOCAL_BUS | self_id_phy_id(sid);
Kristian Høgsberg3038e352006-12-19 19:58:27 -0500106 node->link_on = self_id_link_on(sid);
107 node->phy_speed = self_id_phy_speed(sid);
108 node->port_count = port_count;
109
110 atomic_set(&node->ref_count, 1);
111 INIT_LIST_HEAD(&node->link);
112
113 return node;
114}
115
Kristian Høgsberg83db8012007-01-26 00:37:50 -0500116/* Compute the maximum hop count for this node and it's children. The
117 * maximum hop count is the maximum number of connections between any
118 * two nodes in the subtree rooted at this node. We need this for
119 * setting the gap count. As we build the tree bottom up in
120 * build_tree() below, this is fairly easy to do: for each node we
121 * maintain the max hop count and the max depth, ie the number of hops
122 * to the furthest leaf. Computing the max hop count breaks down into
123 * two cases: either the path goes through this node, in which case
124 * the hop count is the sum of the two biggest child depths plus 2.
125 * Or it could be the case that the max hop path is entirely
126 * containted in a child tree, in which case the max hop count is just
127 * the max hop count of this child.
128 */
129static void update_hop_count(struct fw_node *node)
130{
131 int depths[2] = { -1, -1 };
132 int max_child_hops = 0;
133 int i;
134
135 for (i = 0; i < node->port_count; i++) {
136 if (node->ports[i].node == NULL)
137 continue;
138
139 if (node->ports[i].node->max_hops > max_child_hops)
140 max_child_hops = node->ports[i].node->max_hops;
141
142 if (node->ports[i].node->max_depth > depths[0]) {
143 depths[1] = depths[0];
144 depths[0] = node->ports[i].node->max_depth;
145 } else if (node->ports[i].node->max_depth > depths[1])
146 depths[1] = node->ports[i].node->max_depth;
147 }
148
149 node->max_depth = depths[0] + 1;
150 node->max_hops = max(max_child_hops, depths[0] + depths[1] + 2);
151}
152
153
Kristian Høgsberg3038e352006-12-19 19:58:27 -0500154/**
155 * build_tree - Build the tree representation of the topology
156 * @self_ids: array of self IDs to create the tree from
157 * @self_id_count: the length of the self_ids array
158 * @local_id: the node ID of the local node
159 *
160 * This function builds the tree representation of the topology given
161 * by the self IDs from the latest bus reset. During the construction
162 * of the tree, the function checks that the self IDs are valid and
163 * internally consistent. On succcess this funtions returns the
164 * fw_node corresponding to the local card otherwise NULL.
165 */
166static struct fw_node *build_tree(struct fw_card *card)
167{
168 struct fw_node *node, *child, *local_node;
169 struct list_head stack, *h;
170 u32 *sid, *next_sid, *end, q;
171 int i, port_count, child_port_count, phy_id, parent_count, stack_depth;
Kristian Høgsberg83db8012007-01-26 00:37:50 -0500172 int gap_count, topology_type;
Kristian Høgsberg3038e352006-12-19 19:58:27 -0500173
174 local_node = NULL;
175 node = NULL;
176 INIT_LIST_HEAD(&stack);
177 stack_depth = 0;
178 sid = card->self_ids;
179 end = sid + card->self_id_count;
180 phy_id = 0;
181 card->irm_node = NULL;
Kristian Høgsberg83db8012007-01-26 00:37:50 -0500182 gap_count = self_id_gap_count(*sid);
183 topology_type = 0;
Kristian Høgsberg3038e352006-12-19 19:58:27 -0500184
185 while (sid < end) {
186 next_sid = count_ports(sid, &port_count, &child_port_count);
187
188 if (next_sid == NULL) {
189 fw_error("Inconsistent extended self IDs.\n");
190 return NULL;
191 }
192
193 q = *sid;
194 if (phy_id != self_id_phy_id(q)) {
195 fw_error("PHY ID mismatch in self ID: %d != %d.\n",
196 phy_id, self_id_phy_id(q));
197 return NULL;
198 }
199
200 if (child_port_count > stack_depth) {
201 fw_error("Topology stack underflow\n");
202 return NULL;
203 }
204
205 /* Seek back from the top of our stack to find the
206 * start of the child nodes for this node. */
207 for (i = 0, h = &stack; i < child_port_count; i++)
208 h = h->prev;
209 child = fw_node(h);
210
211 node = fw_node_create(q, port_count, card->color);
212 if (node == NULL) {
213 fw_error("Out of memory while building topology.");
214 return NULL;
215 }
216
217 if (phy_id == (card->node_id & 0x3f))
218 local_node = node;
219
220 if (self_id_contender(q))
221 card->irm_node = node;
222
Kristian Høgsberg83db8012007-01-26 00:37:50 -0500223 if (node->phy_speed == SCODE_BETA)
224 topology_type |= FW_TOPOLOGY_B;
225 else
226 topology_type |= FW_TOPOLOGY_A;
227
Kristian Høgsberg3038e352006-12-19 19:58:27 -0500228 parent_count = 0;
229
230 for (i = 0; i < port_count; i++) {
231 switch (get_port_type(sid, i)) {
232 case SELFID_PORT_PARENT:
233 /* Who's your daddy? We dont know the
234 * parent node at this time, so we
235 * temporarily abuse node->color for
236 * remembering the entry in the
237 * node->ports array where the parent
238 * node should be. Later, when we
239 * handle the parent node, we fix up
240 * the reference.
241 */
242 parent_count++;
243 node->color = i;
244 break;
245
246 case SELFID_PORT_CHILD:
247 node->ports[i].node = child;
248 /* Fix up parent reference for this
249 * child node. */
250 child->ports[child->color].node = node;
251 child->color = card->color;
252 child = fw_node(child->link.next);
253 break;
254 }
255 }
256
257 /* Check that the node reports exactly one parent
258 * port, except for the root, which of course should
259 * have no parents. */
260 if ((next_sid == end && parent_count != 0) ||
261 (next_sid < end && parent_count != 1)) {
262 fw_error("Parent port inconsistency for node %d: "
263 "parent_count=%d\n", phy_id, parent_count);
264 return NULL;
265 }
266
267 /* Pop the child nodes off the stack and push the new node. */
268 __list_del(h->prev, &stack);
269 list_add_tail(&node->link, &stack);
270 stack_depth += 1 - child_port_count;
271
Kristian Høgsberg83db8012007-01-26 00:37:50 -0500272 /* If all PHYs does not report the same gap count
273 * setting, we fall back to 63 which will force a gap
274 * count reconfiguration and a reset. */
275 if (self_id_gap_count(q) != gap_count)
276 gap_count = 63;
277
278 update_hop_count(node);
279
Kristian Høgsberg3038e352006-12-19 19:58:27 -0500280 sid = next_sid;
281 phy_id++;
282 }
283
284 card->root_node = node;
Kristian Høgsberg83db8012007-01-26 00:37:50 -0500285 card->gap_count = gap_count;
286 card->topology_type = topology_type;
Kristian Høgsberg3038e352006-12-19 19:58:27 -0500287
288 return local_node;
289}
290
291typedef void (*fw_node_callback_t) (struct fw_card * card,
292 struct fw_node * node,
293 struct fw_node * parent);
294
295static void
296for_each_fw_node(struct fw_card *card, struct fw_node *root,
297 fw_node_callback_t callback)
298{
299 struct list_head list;
300 struct fw_node *node, *next, *child, *parent;
301 int i;
302
303 INIT_LIST_HEAD(&list);
304
305 fw_node_get(root);
306 list_add_tail(&root->link, &list);
307 parent = NULL;
308 list_for_each_entry(node, &list, link) {
309 node->color = card->color;
310
311 for (i = 0; i < node->port_count; i++) {
312 child = node->ports[i].node;
313 if (!child)
314 continue;
315 if (child->color == card->color)
316 parent = child;
317 else {
318 fw_node_get(child);
319 list_add_tail(&child->link, &list);
320 }
321 }
322
323 callback(card, node, parent);
324 }
325
326 list_for_each_entry_safe(node, next, &list, link)
327 fw_node_put(node);
328}
329
330static void
331report_lost_node(struct fw_card *card,
332 struct fw_node *node, struct fw_node *parent)
333{
334 fw_node_event(card, node, FW_NODE_DESTROYED);
335 fw_node_put(node);
336}
337
338static void
339report_found_node(struct fw_card *card,
340 struct fw_node *node, struct fw_node *parent)
341{
342 int b_path = (node->phy_speed == SCODE_BETA);
343
344 if (parent != NULL) {
Kristian Høgsberg83db8012007-01-26 00:37:50 -0500345 node->max_speed = min((u8)parent->max_speed,
346 (u8)node->phy_speed);
Kristian Høgsberg3038e352006-12-19 19:58:27 -0500347 node->b_path = parent->b_path && b_path;
348 } else {
349 node->max_speed = node->phy_speed;
350 node->b_path = b_path;
351 }
352
353 fw_node_event(card, node, FW_NODE_CREATED);
354}
355
356void fw_destroy_nodes(struct fw_card *card)
357{
358 unsigned long flags;
359
360 spin_lock_irqsave(&card->lock, flags);
361 card->color++;
362 if (card->local_node != NULL)
363 for_each_fw_node(card, card->local_node, report_lost_node);
364 spin_unlock_irqrestore(&card->lock, flags);
365}
366
367static void move_tree(struct fw_node *node0, struct fw_node *node1, int port)
368{
369 struct fw_node *tree;
370 int i;
371
372 tree = node1->ports[port].node;
373 node0->ports[port].node = tree;
374 for (i = 0; i < tree->port_count; i++) {
375 if (tree->ports[i].node == node1) {
376 tree->ports[i].node = node0;
377 break;
378 }
379 }
380}
381
382/**
383 * update_tree - compare the old topology tree for card with the new
384 * one specified by root. Queue the nodes and mark them as either
385 * found, lost or updated. Update the nodes in the card topology tree
386 * as we go.
387 */
388static void
Kristian Høgsberg83db8012007-01-26 00:37:50 -0500389update_tree(struct fw_card *card, struct fw_node *root)
Kristian Høgsberg3038e352006-12-19 19:58:27 -0500390{
391 struct list_head list0, list1;
392 struct fw_node *node0, *node1;
393 int i, event;
394
395 INIT_LIST_HEAD(&list0);
396 list_add_tail(&card->local_node->link, &list0);
397 INIT_LIST_HEAD(&list1);
398 list_add_tail(&root->link, &list1);
399
400 node0 = fw_node(list0.next);
401 node1 = fw_node(list1.next);
Kristian Høgsberg3038e352006-12-19 19:58:27 -0500402
403 while (&node0->link != &list0) {
404
405 /* assert(node0->port_count == node1->port_count); */
406 if (node0->link_on && !node1->link_on)
407 event = FW_NODE_LINK_OFF;
408 else if (!node0->link_on && node1->link_on)
409 event = FW_NODE_LINK_ON;
410 else
411 event = FW_NODE_UPDATED;
412
413 node0->node_id = node1->node_id;
414 node0->color = card->color;
415 node0->link_on = node1->link_on;
416 node0->initiated_reset = node1->initiated_reset;
Kristian Høgsberg83db8012007-01-26 00:37:50 -0500417 node0->max_hops = node1->max_hops;
Kristian Høgsberg3038e352006-12-19 19:58:27 -0500418 node1->color = card->color;
419 fw_node_event(card, node0, event);
420
421 if (card->root_node == node1)
422 card->root_node = node0;
423 if (card->irm_node == node1)
424 card->irm_node = node0;
425
426 for (i = 0; i < node0->port_count; i++) {
427 if (node0->ports[i].node && node1->ports[i].node) {
428 /* This port didn't change, queue the
429 * connected node for further
430 * investigation. */
431 if (node0->ports[i].node->color == card->color)
432 continue;
433 list_add_tail(&node0->ports[i].node->link,
434 &list0);
435 list_add_tail(&node1->ports[i].node->link,
436 &list1);
437 } else if (node0->ports[i].node) {
438 /* The nodes connected here were
439 * unplugged; unref the lost nodes and
440 * queue FW_NODE_LOST callbacks for
441 * them. */
442
443 for_each_fw_node(card, node0->ports[i].node,
444 report_lost_node);
445 node0->ports[i].node = NULL;
Kristian Høgsberg3038e352006-12-19 19:58:27 -0500446 } else if (node1->ports[i].node) {
447 /* One or more node were connected to
448 * this port. Move the new nodes into
449 * the tree and queue FW_NODE_CREATED
450 * callbacks for them. */
451 move_tree(node0, node1, i);
452 for_each_fw_node(card, node0->ports[i].node,
453 report_found_node);
Kristian Høgsberg3038e352006-12-19 19:58:27 -0500454 }
455 }
456
457 node0 = fw_node(node0->link.next);
458 node1 = fw_node(node1->link.next);
459 }
460}
461
462void
463fw_core_handle_bus_reset(struct fw_card *card,
464 int node_id, int generation,
465 int self_id_count, u32 * self_ids)
466{
467 struct fw_node *local_node;
468 unsigned long flags;
Kristian Høgsberg3038e352006-12-19 19:58:27 -0500469
470 fw_flush_transactions(card);
471
472 spin_lock_irqsave(&card->lock, flags);
473
Kristian Høgsberg83db8012007-01-26 00:37:50 -0500474 /* If the new topology has a different self_id_count the topology
475 * changed, either nodes were added or removed. In that case we
476 * reset the IRM reset counter. */
477 if (card->self_id_count != self_id_count)
478 card->irm_retries = 0;
479
Kristian Høgsberg3038e352006-12-19 19:58:27 -0500480 card->node_id = node_id;
481 card->self_id_count = self_id_count;
482 card->generation = generation;
483 memcpy(card->self_ids, self_ids, self_id_count * 4);
484
485 local_node = build_tree(card);
486
487 card->color++;
488
489 if (local_node == NULL) {
490 fw_error("topology build failed\n");
491 /* FIXME: We need to issue a bus reset in this case. */
492 } else if (card->local_node == NULL) {
493 card->local_node = local_node;
494 for_each_fw_node(card, local_node, report_found_node);
495 } else {
Kristian Høgsberg83db8012007-01-26 00:37:50 -0500496 update_tree(card, local_node);
Kristian Høgsberg3038e352006-12-19 19:58:27 -0500497 }
498
Kristian Høgsberg19a15b92006-12-19 19:58:31 -0500499 /* If we're not the root node, we may have to do some IRM work. */
500 if (card->local_node != card->root_node)
501 schedule_delayed_work(&card->work, 0);
502
Kristian Høgsberg3038e352006-12-19 19:58:27 -0500503 spin_unlock_irqrestore(&card->lock, flags);
504}
Kristian Høgsberg3038e352006-12-19 19:58:27 -0500505EXPORT_SYMBOL(fw_core_handle_bus_reset);