1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Incremental bus scan, based on bus topology
5 * Copyright (C) 2004-2006 Kristian Hoegsberg <krh@bitplanet.net>
9 #include <linux/errno.h>
10 #include <linux/firewire.h>
11 #include <linux/firewire-constants.h>
12 #include <linux/jiffies.h>
13 #include <linux/kernel.h>
14 #include <linux/list.h>
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/spinlock.h>
19 #include <linux/atomic.h>
20 #include <asm/byteorder.h>
24 #define SELF_ID_PHY_ID(q) (((q) >> 24) & 0x3f)
25 #define SELF_ID_EXTENDED(q) (((q) >> 23) & 0x01)
26 #define SELF_ID_LINK_ON(q) (((q) >> 22) & 0x01)
27 #define SELF_ID_GAP_COUNT(q) (((q) >> 16) & 0x3f)
28 #define SELF_ID_PHY_SPEED(q) (((q) >> 14) & 0x03)
29 #define SELF_ID_CONTENDER(q) (((q) >> 11) & 0x01)
30 #define SELF_ID_PHY_INITIATOR(q) (((q) >> 1) & 0x01)
31 #define SELF_ID_MORE_PACKETS(q) (((q) >> 0) & 0x01)
33 #define SELF_ID_EXT_SEQUENCE(q) (((q) >> 20) & 0x07)
35 #define SELFID_PORT_CHILD 0x3
36 #define SELFID_PORT_PARENT 0x2
37 #define SELFID_PORT_NCONN 0x1
38 #define SELFID_PORT_NONE 0x0
40 static u32 *count_ports(u32 *sid, int *total_port_count, int *child_port_count)
43 int port_type, shift, seq;
45 *total_port_count = 0;
46 *child_port_count = 0;
53 port_type = (q >> shift) & 0x03;
55 case SELFID_PORT_CHILD:
56 (*child_port_count)++;
58 case SELFID_PORT_PARENT:
59 case SELFID_PORT_NCONN:
60 (*total_port_count)++;
62 case SELFID_PORT_NONE:
68 if (!SELF_ID_MORE_PACKETS(q))
76 * Check that the extra packets actually are
77 * extended self ID packets and that the
78 * sequence numbers in the extended self ID
79 * packets increase as expected.
82 if (!SELF_ID_EXTENDED(q) ||
83 seq != SELF_ID_EXT_SEQUENCE(q))
91 static int get_port_type(u32 *sid, int port_index)
95 index = (port_index + 5) / 8;
96 shift = 16 - ((port_index + 5) & 7) * 2;
97 return (sid[index] >> shift) & 0x03;
100 static struct fw_node *fw_node_create(u32 sid, int port_count, int color)
102 struct fw_node *node;
104 node = kzalloc(struct_size(node, ports, port_count), GFP_ATOMIC);
109 node->node_id = LOCAL_BUS | SELF_ID_PHY_ID(sid);
110 node->link_on = SELF_ID_LINK_ON(sid);
111 node->phy_speed = SELF_ID_PHY_SPEED(sid);
112 node->initiated_reset = SELF_ID_PHY_INITIATOR(sid);
113 node->port_count = port_count;
115 refcount_set(&node->ref_count, 1);
116 INIT_LIST_HEAD(&node->link);
122 * Compute the maximum hop count for this node and it's children. The
123 * maximum hop count is the maximum number of connections between any
124 * two nodes in the subtree rooted at this node. We need this for
125 * setting the gap count. As we build the tree bottom up in
126 * build_tree() below, this is fairly easy to do: for each node we
127 * maintain the max hop count and the max depth, ie the number of hops
128 * to the furthest leaf. Computing the max hop count breaks down into
129 * two cases: either the path goes through this node, in which case
130 * the hop count is the sum of the two biggest child depths plus 2.
131 * Or it could be the case that the max hop path is entirely
132 * containted in a child tree, in which case the max hop count is just
133 * the max hop count of this child.
135 static void update_hop_count(struct fw_node *node)
137 int depths[2] = { -1, -1 };
138 int max_child_hops = 0;
141 for (i = 0; i < node->port_count; i++) {
142 if (node->ports[i] == NULL)
145 if (node->ports[i]->max_hops > max_child_hops)
146 max_child_hops = node->ports[i]->max_hops;
148 if (node->ports[i]->max_depth > depths[0]) {
149 depths[1] = depths[0];
150 depths[0] = node->ports[i]->max_depth;
151 } else if (node->ports[i]->max_depth > depths[1])
152 depths[1] = node->ports[i]->max_depth;
155 node->max_depth = depths[0] + 1;
156 node->max_hops = max(max_child_hops, depths[0] + depths[1] + 2);
159 static inline struct fw_node *fw_node(struct list_head *l)
161 return list_entry(l, struct fw_node, link);
165 * This function builds the tree representation of the topology given
166 * by the self IDs from the latest bus reset. During the construction
167 * of the tree, the function checks that the self IDs are valid and
168 * internally consistent. On success this function returns the
169 * fw_node corresponding to the local card otherwise NULL.
171 static struct fw_node *build_tree(struct fw_card *card,
172 u32 *sid, int self_id_count)
174 struct fw_node *node, *child, *local_node, *irm_node;
175 struct list_head stack, *h;
176 u32 *next_sid, *end, q;
177 int i, port_count, child_port_count, phy_id, parent_count, stack_depth;
179 bool beta_repeaters_present;
183 INIT_LIST_HEAD(&stack);
185 end = sid + self_id_count;
188 gap_count = SELF_ID_GAP_COUNT(*sid);
189 beta_repeaters_present = false;
192 next_sid = count_ports(sid, &port_count, &child_port_count);
194 if (next_sid == NULL) {
195 fw_err(card, "inconsistent extended self IDs\n");
200 if (phy_id != SELF_ID_PHY_ID(q)) {
201 fw_err(card, "PHY ID mismatch in self ID: %d != %d\n",
202 phy_id, SELF_ID_PHY_ID(q));
206 if (child_port_count > stack_depth) {
207 fw_err(card, "topology stack underflow\n");
212 * Seek back from the top of our stack to find the
213 * start of the child nodes for this node.
215 for (i = 0, h = &stack; i < child_port_count; i++)
218 * When the stack is empty, this yields an invalid value,
219 * but that pointer will never be dereferenced.
223 node = fw_node_create(q, port_count, card->color);
225 fw_err(card, "out of memory while building topology\n");
229 if (phy_id == (card->node_id & 0x3f))
232 if (SELF_ID_CONTENDER(q))
237 for (i = 0; i < port_count; i++) {
238 switch (get_port_type(sid, i)) {
239 case SELFID_PORT_PARENT:
241 * Who's your daddy? We dont know the
242 * parent node at this time, so we
243 * temporarily abuse node->color for
244 * remembering the entry in the
245 * node->ports array where the parent
246 * node should be. Later, when we
247 * handle the parent node, we fix up
254 case SELFID_PORT_CHILD:
255 node->ports[i] = child;
257 * Fix up parent reference for this
260 child->ports[child->color] = node;
261 child->color = card->color;
262 child = fw_node(child->link.next);
268 * Check that the node reports exactly one parent
269 * port, except for the root, which of course should
272 if ((next_sid == end && parent_count != 0) ||
273 (next_sid < end && parent_count != 1)) {
274 fw_err(card, "parent port inconsistency for node %d: "
275 "parent_count=%d\n", phy_id, parent_count);
279 /* Pop the child nodes off the stack and push the new node. */
280 __list_del(h->prev, &stack);
281 list_add_tail(&node->link, &stack);
282 stack_depth += 1 - child_port_count;
284 if (node->phy_speed == SCODE_BETA &&
285 parent_count + child_port_count > 1)
286 beta_repeaters_present = true;
289 * If PHYs report different gap counts, set an invalid count
290 * which will force a gap count reconfiguration and a reset.
292 if (SELF_ID_GAP_COUNT(q) != gap_count)
295 update_hop_count(node);
301 card->root_node = node;
302 card->irm_node = irm_node;
303 card->gap_count = gap_count;
304 card->beta_repeaters_present = beta_repeaters_present;
309 typedef void (*fw_node_callback_t)(struct fw_card * card,
310 struct fw_node * node,
311 struct fw_node * parent);
313 static void for_each_fw_node(struct fw_card *card, struct fw_node *root,
314 fw_node_callback_t callback)
316 struct list_head list;
317 struct fw_node *node, *next, *child, *parent;
320 INIT_LIST_HEAD(&list);
323 list_add_tail(&root->link, &list);
325 list_for_each_entry(node, &list, link) {
326 node->color = card->color;
328 for (i = 0; i < node->port_count; i++) {
329 child = node->ports[i];
332 if (child->color == card->color)
336 list_add_tail(&child->link, &list);
340 callback(card, node, parent);
343 list_for_each_entry_safe(node, next, &list, link)
347 static void report_lost_node(struct fw_card *card,
348 struct fw_node *node, struct fw_node *parent)
350 fw_node_event(card, node, FW_NODE_DESTROYED);
353 /* Topology has changed - reset bus manager retry counter */
354 card->bm_retries = 0;
357 static void report_found_node(struct fw_card *card,
358 struct fw_node *node, struct fw_node *parent)
360 int b_path = (node->phy_speed == SCODE_BETA);
362 if (parent != NULL) {
363 /* min() macro doesn't work here with gcc 3.4 */
364 node->max_speed = parent->max_speed < node->phy_speed ?
365 parent->max_speed : node->phy_speed;
366 node->b_path = parent->b_path && b_path;
368 node->max_speed = node->phy_speed;
369 node->b_path = b_path;
372 fw_node_event(card, node, FW_NODE_CREATED);
374 /* Topology has changed - reset bus manager retry counter */
375 card->bm_retries = 0;
378 void fw_destroy_nodes(struct fw_card *card)
382 spin_lock_irqsave(&card->lock, flags);
384 if (card->local_node != NULL)
385 for_each_fw_node(card, card->local_node, report_lost_node);
386 card->local_node = NULL;
387 spin_unlock_irqrestore(&card->lock, flags);
390 static void move_tree(struct fw_node *node0, struct fw_node *node1, int port)
392 struct fw_node *tree;
395 tree = node1->ports[port];
396 node0->ports[port] = tree;
397 for (i = 0; i < tree->port_count; i++) {
398 if (tree->ports[i] == node1) {
399 tree->ports[i] = node0;
406 * Compare the old topology tree for card with the new one specified by root.
407 * Queue the nodes and mark them as either found, lost or updated.
408 * Update the nodes in the card topology tree as we go.
410 static void update_tree(struct fw_card *card, struct fw_node *root)
412 struct list_head list0, list1;
413 struct fw_node *node0, *node1, *next1;
416 INIT_LIST_HEAD(&list0);
417 list_add_tail(&card->local_node->link, &list0);
418 INIT_LIST_HEAD(&list1);
419 list_add_tail(&root->link, &list1);
421 node0 = fw_node(list0.next);
422 node1 = fw_node(list1.next);
424 while (&node0->link != &list0) {
425 WARN_ON(node0->port_count != node1->port_count);
427 if (node0->link_on && !node1->link_on)
428 event = FW_NODE_LINK_OFF;
429 else if (!node0->link_on && node1->link_on)
430 event = FW_NODE_LINK_ON;
431 else if (node1->initiated_reset && node1->link_on)
432 event = FW_NODE_INITIATED_RESET;
434 event = FW_NODE_UPDATED;
436 node0->node_id = node1->node_id;
437 node0->color = card->color;
438 node0->link_on = node1->link_on;
439 node0->initiated_reset = node1->initiated_reset;
440 node0->max_hops = node1->max_hops;
441 node1->color = card->color;
442 fw_node_event(card, node0, event);
444 if (card->root_node == node1)
445 card->root_node = node0;
446 if (card->irm_node == node1)
447 card->irm_node = node0;
449 for (i = 0; i < node0->port_count; i++) {
450 if (node0->ports[i] && node1->ports[i]) {
452 * This port didn't change, queue the
453 * connected node for further
456 if (node0->ports[i]->color == card->color)
458 list_add_tail(&node0->ports[i]->link, &list0);
459 list_add_tail(&node1->ports[i]->link, &list1);
460 } else if (node0->ports[i]) {
462 * The nodes connected here were
463 * unplugged; unref the lost nodes and
464 * queue FW_NODE_LOST callbacks for
468 for_each_fw_node(card, node0->ports[i],
470 node0->ports[i] = NULL;
471 } else if (node1->ports[i]) {
473 * One or more node were connected to
474 * this port. Move the new nodes into
475 * the tree and queue FW_NODE_CREATED
476 * callbacks for them.
478 move_tree(node0, node1, i);
479 for_each_fw_node(card, node0->ports[i],
484 node0 = fw_node(node0->link.next);
485 next1 = fw_node(node1->link.next);
491 static void update_topology_map(struct fw_card *card,
492 u32 *self_ids, int self_id_count)
494 int node_count = (card->root_node->node_id & 0x3f) + 1;
495 __be32 *map = card->topology_map;
497 *map++ = cpu_to_be32((self_id_count + 2) << 16);
498 *map++ = cpu_to_be32(be32_to_cpu(card->topology_map[1]) + 1);
499 *map++ = cpu_to_be32((node_count << 16) | self_id_count);
501 while (self_id_count--)
502 *map++ = cpu_to_be32p(self_ids++);
504 fw_compute_block_crc(card->topology_map);
507 void fw_core_handle_bus_reset(struct fw_card *card, int node_id, int generation,
508 int self_id_count, u32 *self_ids, bool bm_abdicate)
510 struct fw_node *local_node;
514 * If the selfID buffer is not the immediate successor of the
515 * previously processed one, we cannot reliably compare the
516 * old and new topologies.
518 if (!is_next_generation(generation, card->generation) &&
519 card->local_node != NULL) {
520 fw_destroy_nodes(card);
521 card->bm_retries = 0;
524 spin_lock_irqsave(&card->lock, flags);
526 card->broadcast_channel_allocated = card->broadcast_channel_auto_allocated;
527 card->node_id = node_id;
529 * Update node_id before generation to prevent anybody from using
530 * a stale node_id together with a current generation.
533 card->generation = generation;
534 card->reset_jiffies = get_jiffies_64();
535 card->bm_node_id = 0xffff;
536 card->bm_abdicate = bm_abdicate;
537 fw_schedule_bm_work(card, 0);
539 local_node = build_tree(card, self_ids, self_id_count);
541 update_topology_map(card, self_ids, self_id_count);
545 if (local_node == NULL) {
546 fw_err(card, "topology build failed\n");
547 /* FIXME: We need to issue a bus reset in this case. */
548 } else if (card->local_node == NULL) {
549 card->local_node = local_node;
550 for_each_fw_node(card, local_node, report_found_node);
552 update_tree(card, local_node);
555 spin_unlock_irqrestore(&card->lock, flags);
557 EXPORT_SYMBOL(fw_core_handle_bus_reset);