2 * Incremental bus scan, based on bus topology
4 * Copyright (C) 2004-2006 Kristian Hoegsberg <krh@bitplanet.net>
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.
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.
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.
21 #include <linux/bug.h>
22 #include <linux/errno.h>
23 #include <linux/firewire.h>
24 #include <linux/firewire-constants.h>
25 #include <linux/jiffies.h>
26 #include <linux/kernel.h>
27 #include <linux/list.h>
28 #include <linux/module.h>
29 #include <linux/slab.h>
30 #include <linux/spinlock.h>
32 #include <linux/atomic.h>
33 #include <asm/byteorder.h>
37 #define SELF_ID_PHY_ID(q) (((q) >> 24) & 0x3f)
38 #define SELF_ID_EXTENDED(q) (((q) >> 23) & 0x01)
39 #define SELF_ID_LINK_ON(q) (((q) >> 22) & 0x01)
40 #define SELF_ID_GAP_COUNT(q) (((q) >> 16) & 0x3f)
41 #define SELF_ID_PHY_SPEED(q) (((q) >> 14) & 0x03)
42 #define SELF_ID_CONTENDER(q) (((q) >> 11) & 0x01)
43 #define SELF_ID_PHY_INITIATOR(q) (((q) >> 1) & 0x01)
44 #define SELF_ID_MORE_PACKETS(q) (((q) >> 0) & 0x01)
46 #define SELF_ID_EXT_SEQUENCE(q) (((q) >> 20) & 0x07)
48 #define SELFID_PORT_CHILD 0x3
49 #define SELFID_PORT_PARENT 0x2
50 #define SELFID_PORT_NCONN 0x1
51 #define SELFID_PORT_NONE 0x0
53 static u32 *count_ports(u32 *sid, int *total_port_count, int *child_port_count)
56 int port_type, shift, seq;
58 *total_port_count = 0;
59 *child_port_count = 0;
66 port_type = (q >> shift) & 0x03;
68 case SELFID_PORT_CHILD:
69 (*child_port_count)++;
70 case SELFID_PORT_PARENT:
71 case SELFID_PORT_NCONN:
72 (*total_port_count)++;
73 case SELFID_PORT_NONE:
79 if (!SELF_ID_MORE_PACKETS(q))
87 * Check that the extra packets actually are
88 * extended self ID packets and that the
89 * sequence numbers in the extended self ID
90 * packets increase as expected.
93 if (!SELF_ID_EXTENDED(q) ||
94 seq != SELF_ID_EXT_SEQUENCE(q))
102 static int get_port_type(u32 *sid, int port_index)
106 index = (port_index + 5) / 8;
107 shift = 16 - ((port_index + 5) & 7) * 2;
108 return (sid[index] >> shift) & 0x03;
111 static struct fw_node *fw_node_create(u32 sid, int port_count, int color)
113 struct fw_node *node;
115 node = kzalloc(sizeof(*node) + port_count * sizeof(node->ports[0]),
121 node->node_id = LOCAL_BUS | SELF_ID_PHY_ID(sid);
122 node->link_on = SELF_ID_LINK_ON(sid);
123 node->phy_speed = SELF_ID_PHY_SPEED(sid);
124 node->initiated_reset = SELF_ID_PHY_INITIATOR(sid);
125 node->port_count = port_count;
127 refcount_set(&node->ref_count, 1);
128 INIT_LIST_HEAD(&node->link);
134 * Compute the maximum hop count for this node and it's children. The
135 * maximum hop count is the maximum number of connections between any
136 * two nodes in the subtree rooted at this node. We need this for
137 * setting the gap count. As we build the tree bottom up in
138 * build_tree() below, this is fairly easy to do: for each node we
139 * maintain the max hop count and the max depth, ie the number of hops
140 * to the furthest leaf. Computing the max hop count breaks down into
141 * two cases: either the path goes through this node, in which case
142 * the hop count is the sum of the two biggest child depths plus 2.
143 * Or it could be the case that the max hop path is entirely
144 * containted in a child tree, in which case the max hop count is just
145 * the max hop count of this child.
147 static void update_hop_count(struct fw_node *node)
149 int depths[2] = { -1, -1 };
150 int max_child_hops = 0;
153 for (i = 0; i < node->port_count; i++) {
154 if (node->ports[i] == NULL)
157 if (node->ports[i]->max_hops > max_child_hops)
158 max_child_hops = node->ports[i]->max_hops;
160 if (node->ports[i]->max_depth > depths[0]) {
161 depths[1] = depths[0];
162 depths[0] = node->ports[i]->max_depth;
163 } else if (node->ports[i]->max_depth > depths[1])
164 depths[1] = node->ports[i]->max_depth;
167 node->max_depth = depths[0] + 1;
168 node->max_hops = max(max_child_hops, depths[0] + depths[1] + 2);
171 static inline struct fw_node *fw_node(struct list_head *l)
173 return list_entry(l, struct fw_node, link);
177 * This function builds the tree representation of the topology given
178 * by the self IDs from the latest bus reset. During the construction
179 * of the tree, the function checks that the self IDs are valid and
180 * internally consistent. On success this function returns the
181 * fw_node corresponding to the local card otherwise NULL.
183 static struct fw_node *build_tree(struct fw_card *card,
184 u32 *sid, int self_id_count)
186 struct fw_node *node, *child, *local_node, *irm_node;
187 struct list_head stack, *h;
188 u32 *next_sid, *end, q;
189 int i, port_count, child_port_count, phy_id, parent_count, stack_depth;
191 bool beta_repeaters_present;
195 INIT_LIST_HEAD(&stack);
197 end = sid + self_id_count;
200 gap_count = SELF_ID_GAP_COUNT(*sid);
201 beta_repeaters_present = false;
204 next_sid = count_ports(sid, &port_count, &child_port_count);
206 if (next_sid == NULL) {
207 fw_err(card, "inconsistent extended self IDs\n");
212 if (phy_id != SELF_ID_PHY_ID(q)) {
213 fw_err(card, "PHY ID mismatch in self ID: %d != %d\n",
214 phy_id, SELF_ID_PHY_ID(q));
218 if (child_port_count > stack_depth) {
219 fw_err(card, "topology stack underflow\n");
224 * Seek back from the top of our stack to find the
225 * start of the child nodes for this node.
227 for (i = 0, h = &stack; i < child_port_count; i++)
230 * When the stack is empty, this yields an invalid value,
231 * but that pointer will never be dereferenced.
235 node = fw_node_create(q, port_count, card->color);
237 fw_err(card, "out of memory while building topology\n");
241 if (phy_id == (card->node_id & 0x3f))
244 if (SELF_ID_CONTENDER(q))
249 for (i = 0; i < port_count; i++) {
250 switch (get_port_type(sid, i)) {
251 case SELFID_PORT_PARENT:
253 * Who's your daddy? We dont know the
254 * parent node at this time, so we
255 * temporarily abuse node->color for
256 * remembering the entry in the
257 * node->ports array where the parent
258 * node should be. Later, when we
259 * handle the parent node, we fix up
266 case SELFID_PORT_CHILD:
267 node->ports[i] = child;
269 * Fix up parent reference for this
272 child->ports[child->color] = node;
273 child->color = card->color;
274 child = fw_node(child->link.next);
280 * Check that the node reports exactly one parent
281 * port, except for the root, which of course should
284 if ((next_sid == end && parent_count != 0) ||
285 (next_sid < end && parent_count != 1)) {
286 fw_err(card, "parent port inconsistency for node %d: "
287 "parent_count=%d\n", phy_id, parent_count);
291 /* Pop the child nodes off the stack and push the new node. */
292 __list_del(h->prev, &stack);
293 list_add_tail(&node->link, &stack);
294 stack_depth += 1 - child_port_count;
296 if (node->phy_speed == SCODE_BETA &&
297 parent_count + child_port_count > 1)
298 beta_repeaters_present = true;
301 * If PHYs report different gap counts, set an invalid count
302 * which will force a gap count reconfiguration and a reset.
304 if (SELF_ID_GAP_COUNT(q) != gap_count)
307 update_hop_count(node);
313 card->root_node = node;
314 card->irm_node = irm_node;
315 card->gap_count = gap_count;
316 card->beta_repeaters_present = beta_repeaters_present;
321 typedef void (*fw_node_callback_t)(struct fw_card * card,
322 struct fw_node * node,
323 struct fw_node * parent);
325 static void for_each_fw_node(struct fw_card *card, struct fw_node *root,
326 fw_node_callback_t callback)
328 struct list_head list;
329 struct fw_node *node, *next, *child, *parent;
332 INIT_LIST_HEAD(&list);
335 list_add_tail(&root->link, &list);
337 list_for_each_entry(node, &list, link) {
338 node->color = card->color;
340 for (i = 0; i < node->port_count; i++) {
341 child = node->ports[i];
344 if (child->color == card->color)
348 list_add_tail(&child->link, &list);
352 callback(card, node, parent);
355 list_for_each_entry_safe(node, next, &list, link)
359 static void report_lost_node(struct fw_card *card,
360 struct fw_node *node, struct fw_node *parent)
362 fw_node_event(card, node, FW_NODE_DESTROYED);
365 /* Topology has changed - reset bus manager retry counter */
366 card->bm_retries = 0;
369 static void report_found_node(struct fw_card *card,
370 struct fw_node *node, struct fw_node *parent)
372 int b_path = (node->phy_speed == SCODE_BETA);
374 if (parent != NULL) {
375 /* min() macro doesn't work here with gcc 3.4 */
376 node->max_speed = parent->max_speed < node->phy_speed ?
377 parent->max_speed : node->phy_speed;
378 node->b_path = parent->b_path && b_path;
380 node->max_speed = node->phy_speed;
381 node->b_path = b_path;
384 fw_node_event(card, node, FW_NODE_CREATED);
386 /* Topology has changed - reset bus manager retry counter */
387 card->bm_retries = 0;
390 /* Must be called with card->lock held */
391 void fw_destroy_nodes(struct fw_card *card)
394 if (card->local_node != NULL)
395 for_each_fw_node(card, card->local_node, report_lost_node);
396 card->local_node = NULL;
399 static void move_tree(struct fw_node *node0, struct fw_node *node1, int port)
401 struct fw_node *tree;
404 tree = node1->ports[port];
405 node0->ports[port] = tree;
406 for (i = 0; i < tree->port_count; i++) {
407 if (tree->ports[i] == node1) {
408 tree->ports[i] = node0;
415 * Compare the old topology tree for card with the new one specified by root.
416 * Queue the nodes and mark them as either found, lost or updated.
417 * Update the nodes in the card topology tree as we go.
419 static void update_tree(struct fw_card *card, struct fw_node *root)
421 struct list_head list0, list1;
422 struct fw_node *node0, *node1, *next1;
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);
430 node0 = fw_node(list0.next);
431 node1 = fw_node(list1.next);
433 while (&node0->link != &list0) {
434 WARN_ON(node0->port_count != node1->port_count);
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;
443 event = FW_NODE_UPDATED;
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);
453 if (card->root_node == node1)
454 card->root_node = node0;
455 if (card->irm_node == node1)
456 card->irm_node = node0;
458 for (i = 0; i < node0->port_count; i++) {
459 if (node0->ports[i] && node1->ports[i]) {
461 * This port didn't change, queue the
462 * connected node for further
465 if (node0->ports[i]->color == card->color)
467 list_add_tail(&node0->ports[i]->link, &list0);
468 list_add_tail(&node1->ports[i]->link, &list1);
469 } else if (node0->ports[i]) {
471 * The nodes connected here were
472 * unplugged; unref the lost nodes and
473 * queue FW_NODE_LOST callbacks for
477 for_each_fw_node(card, node0->ports[i],
479 node0->ports[i] = NULL;
480 } else if (node1->ports[i]) {
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.
487 move_tree(node0, node1, i);
488 for_each_fw_node(card, node0->ports[i],
493 node0 = fw_node(node0->link.next);
494 next1 = fw_node(node1->link.next);
500 static void update_topology_map(struct fw_card *card,
501 u32 *self_ids, int self_id_count)
503 int node_count = (card->root_node->node_id & 0x3f) + 1;
504 __be32 *map = card->topology_map;
506 *map++ = cpu_to_be32((self_id_count + 2) << 16);
507 *map++ = cpu_to_be32(be32_to_cpu(card->topology_map[1]) + 1);
508 *map++ = cpu_to_be32((node_count << 16) | self_id_count);
510 while (self_id_count--)
511 *map++ = cpu_to_be32p(self_ids++);
513 fw_compute_block_crc(card->topology_map);
516 void fw_core_handle_bus_reset(struct fw_card *card, int node_id, int generation,
517 int self_id_count, u32 *self_ids, bool bm_abdicate)
519 struct fw_node *local_node;
522 spin_lock_irqsave(&card->lock, flags);
525 * If the selfID buffer is not the immediate successor of the
526 * previously processed one, we cannot reliably compare the
527 * old and new topologies.
529 if (!is_next_generation(generation, card->generation) &&
530 card->local_node != NULL) {
531 fw_destroy_nodes(card);
532 card->bm_retries = 0;
535 card->broadcast_channel_allocated = card->broadcast_channel_auto_allocated;
536 card->node_id = node_id;
538 * Update node_id before generation to prevent anybody from using
539 * a stale node_id together with a current generation.
542 card->generation = generation;
543 card->reset_jiffies = get_jiffies_64();
544 card->bm_node_id = 0xffff;
545 card->bm_abdicate = bm_abdicate;
546 fw_schedule_bm_work(card, 0);
548 local_node = build_tree(card, self_ids, self_id_count);
550 update_topology_map(card, self_ids, self_id_count);
554 if (local_node == NULL) {
555 fw_err(card, "topology build failed\n");
556 /* FIXME: We need to issue a bus reset in this case. */
557 } else if (card->local_node == NULL) {
558 card->local_node = local_node;
559 for_each_fw_node(card, local_node, report_found_node);
561 update_tree(card, local_node);
564 spin_unlock_irqrestore(&card->lock, flags);
566 EXPORT_SYMBOL(fw_core_handle_bus_reset);