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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Incremental bus scan, based on bus topology
4 *
5 * Copyright (C) 2004-2006 Kristian Hoegsberg <krh@bitplanet.net>
6 */
7
8#include <linux/bug.h>
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>
18
19#include <linux/atomic.h>
20#include <asm/byteorder.h>
21
22#include "core.h"
23#include "phy-packet-definitions.h"
24#include <trace/events/firewire.h>
25
26static struct fw_node *fw_node_create(u32 sid, int port_count, int color)
27{
28 struct fw_node *node;
29
30 node = kzalloc(struct_size(node, ports, port_count), GFP_ATOMIC);
31 if (node == NULL)
32 return NULL;
33
34 node->color = color;
35 node->node_id = LOCAL_BUS | phy_packet_self_id_get_phy_id(sid);
36 node->link_on = phy_packet_self_id_zero_get_link_active(sid);
37 // NOTE: Only two bits, thus only for SCODE_100, SCODE_200, SCODE_400, and SCODE_BETA.
38 node->phy_speed = phy_packet_self_id_zero_get_scode(sid);
39 node->initiated_reset = phy_packet_self_id_zero_get_initiated_reset(sid);
40 node->port_count = port_count;
41
42 kref_init(&node->kref);
43 INIT_LIST_HEAD(&node->link);
44
45 return node;
46}
47
48/*
49 * Compute the maximum hop count for this node and it's children. The
50 * maximum hop count is the maximum number of connections between any
51 * two nodes in the subtree rooted at this node. We need this for
52 * setting the gap count. As we build the tree bottom up in
53 * build_tree() below, this is fairly easy to do: for each node we
54 * maintain the max hop count and the max depth, ie the number of hops
55 * to the furthest leaf. Computing the max hop count breaks down into
56 * two cases: either the path goes through this node, in which case
57 * the hop count is the sum of the two biggest child depths plus 2.
58 * Or it could be the case that the max hop path is entirely
59 * contained in a child tree, in which case the max hop count is just
60 * the max hop count of this child.
61 */
62static void update_hop_count(struct fw_node *node)
63{
64 int depths[2] = { -1, -1 };
65 int max_child_hops = 0;
66 int i;
67
68 for (i = 0; i < node->port_count; i++) {
69 if (node->ports[i] == NULL)
70 continue;
71
72 if (node->ports[i]->max_hops > max_child_hops)
73 max_child_hops = node->ports[i]->max_hops;
74
75 if (node->ports[i]->max_depth > depths[0]) {
76 depths[1] = depths[0];
77 depths[0] = node->ports[i]->max_depth;
78 } else if (node->ports[i]->max_depth > depths[1])
79 depths[1] = node->ports[i]->max_depth;
80 }
81
82 node->max_depth = depths[0] + 1;
83 node->max_hops = max(max_child_hops, depths[0] + depths[1] + 2);
84}
85
86static inline struct fw_node *fw_node(struct list_head *l)
87{
88 return list_entry(l, struct fw_node, link);
89}
90
91/*
92 * This function builds the tree representation of the topology given
93 * by the self IDs from the latest bus reset. During the construction
94 * of the tree, the function checks that the self IDs are valid and
95 * internally consistent. On success this function returns the
96 * fw_node corresponding to the local card otherwise NULL.
97 */
98static struct fw_node *build_tree(struct fw_card *card, const u32 *sid, int self_id_count,
99 unsigned int generation)
100{
101 struct self_id_sequence_enumerator enumerator = {
102 .cursor = sid,
103 .quadlet_count = self_id_count,
104 };
105 struct fw_node *node, *child, *local_node, *irm_node;
106 struct list_head stack;
107 int phy_id, stack_depth;
108 int gap_count;
109 bool beta_repeaters_present;
110
111 local_node = NULL;
112 node = NULL;
113 INIT_LIST_HEAD(&stack);
114 stack_depth = 0;
115 phy_id = 0;
116 irm_node = NULL;
117 gap_count = phy_packet_self_id_zero_get_gap_count(*sid);
118 beta_repeaters_present = false;
119
120 while (enumerator.quadlet_count > 0) {
121 unsigned int child_port_count = 0;
122 unsigned int total_port_count = 0;
123 unsigned int parent_count = 0;
124 unsigned int quadlet_count;
125 const u32 *self_id_sequence;
126 unsigned int port_capacity;
127 enum phy_packet_self_id_port_status port_status;
128 unsigned int port_index;
129 struct list_head *h;
130 int i;
131
132 self_id_sequence = self_id_sequence_enumerator_next(&enumerator, &quadlet_count);
133 if (IS_ERR(self_id_sequence)) {
134 if (PTR_ERR(self_id_sequence) != -ENODATA) {
135 fw_err(card, "inconsistent extended self IDs: %ld\n",
136 PTR_ERR(self_id_sequence));
137 return NULL;
138 }
139 break;
140 }
141
142 port_capacity = self_id_sequence_get_port_capacity(quadlet_count);
143 trace_self_id_sequence(card->index, self_id_sequence, quadlet_count, generation);
144
145 for (port_index = 0; port_index < port_capacity; ++port_index) {
146 port_status = self_id_sequence_get_port_status(self_id_sequence, quadlet_count,
147 port_index);
148 switch (port_status) {
149 case PHY_PACKET_SELF_ID_PORT_STATUS_CHILD:
150 ++child_port_count;
151 fallthrough;
152 case PHY_PACKET_SELF_ID_PORT_STATUS_PARENT:
153 case PHY_PACKET_SELF_ID_PORT_STATUS_NCONN:
154 ++total_port_count;
155 fallthrough;
156 case PHY_PACKET_SELF_ID_PORT_STATUS_NONE:
157 default:
158 break;
159 }
160 }
161
162 if (phy_id != phy_packet_self_id_get_phy_id(self_id_sequence[0])) {
163 fw_err(card, "PHY ID mismatch in self ID: %d != %d\n",
164 phy_id, phy_packet_self_id_get_phy_id(self_id_sequence[0]));
165 return NULL;
166 }
167
168 if (child_port_count > stack_depth) {
169 fw_err(card, "topology stack underflow\n");
170 return NULL;
171 }
172
173 /*
174 * Seek back from the top of our stack to find the
175 * start of the child nodes for this node.
176 */
177 for (i = 0, h = &stack; i < child_port_count; i++)
178 h = h->prev;
179 /*
180 * When the stack is empty, this yields an invalid value,
181 * but that pointer will never be dereferenced.
182 */
183 child = fw_node(h);
184
185 node = fw_node_create(self_id_sequence[0], total_port_count, card->color);
186 if (node == NULL) {
187 fw_err(card, "out of memory while building topology\n");
188 return NULL;
189 }
190
191 if (phy_id == (card->node_id & 0x3f))
192 local_node = node;
193
194 if (phy_packet_self_id_zero_get_contender(self_id_sequence[0]))
195 irm_node = node;
196
197 for (port_index = 0; port_index < total_port_count; ++port_index) {
198 port_status = self_id_sequence_get_port_status(self_id_sequence, quadlet_count,
199 port_index);
200 switch (port_status) {
201 case PHY_PACKET_SELF_ID_PORT_STATUS_PARENT:
202 // Who's your daddy? We dont know the parent node at this time, so
203 // we temporarily abuse node->color for remembering the entry in
204 // the node->ports array where the parent node should be. Later,
205 // when we handle the parent node, we fix up the reference.
206 ++parent_count;
207 node->color = port_index;
208 break;
209
210 case PHY_PACKET_SELF_ID_PORT_STATUS_CHILD:
211 node->ports[port_index] = child;
212 // Fix up parent reference for this child node.
213 child->ports[child->color] = node;
214 child->color = card->color;
215 child = fw_node(child->link.next);
216 break;
217 case PHY_PACKET_SELF_ID_PORT_STATUS_NCONN:
218 case PHY_PACKET_SELF_ID_PORT_STATUS_NONE:
219 default:
220 break;
221 }
222 }
223
224 // Check that the node reports exactly one parent port, except for the root, which
225 // of course should have no parents.
226 if ((enumerator.quadlet_count == 0 && parent_count != 0) ||
227 (enumerator.quadlet_count > 0 && parent_count != 1)) {
228 fw_err(card, "parent port inconsistency for node %d: "
229 "parent_count=%d\n", phy_id, parent_count);
230 return NULL;
231 }
232
233 /* Pop the child nodes off the stack and push the new node. */
234 __list_del(h->prev, &stack);
235 list_add_tail(&node->link, &stack);
236 stack_depth += 1 - child_port_count;
237
238 if (node->phy_speed == SCODE_BETA && parent_count + child_port_count > 1)
239 beta_repeaters_present = true;
240
241 // If PHYs report different gap counts, set an invalid count which will force a gap
242 // count reconfiguration and a reset.
243 if (phy_packet_self_id_zero_get_gap_count(self_id_sequence[0]) != gap_count)
244 gap_count = 0;
245
246 update_hop_count(node);
247
248 phy_id++;
249 }
250
251 card->root_node = node;
252 card->irm_node = irm_node;
253 card->gap_count = gap_count;
254 card->beta_repeaters_present = beta_repeaters_present;
255
256 return local_node;
257}
258
259typedef void (*fw_node_callback_t)(struct fw_card * card,
260 struct fw_node * node,
261 struct fw_node * parent);
262
263static void for_each_fw_node(struct fw_card *card, struct fw_node *root,
264 fw_node_callback_t callback)
265{
266 struct list_head list;
267 struct fw_node *node, *next, *child, *parent;
268 int i;
269
270 INIT_LIST_HEAD(&list);
271
272 fw_node_get(root);
273 list_add_tail(&root->link, &list);
274 parent = NULL;
275 list_for_each_entry(node, &list, link) {
276 node->color = card->color;
277
278 for (i = 0; i < node->port_count; i++) {
279 child = node->ports[i];
280 if (!child)
281 continue;
282 if (child->color == card->color)
283 parent = child;
284 else {
285 fw_node_get(child);
286 list_add_tail(&child->link, &list);
287 }
288 }
289
290 callback(card, node, parent);
291 }
292
293 list_for_each_entry_safe(node, next, &list, link)
294 fw_node_put(node);
295}
296
297static void report_lost_node(struct fw_card *card,
298 struct fw_node *node, struct fw_node *parent)
299{
300 fw_node_event(card, node, FW_NODE_DESTROYED);
301 fw_node_put(node);
302
303 /* Topology has changed - reset bus manager retry counter */
304 card->bm_retries = 0;
305}
306
307static void report_found_node(struct fw_card *card,
308 struct fw_node *node, struct fw_node *parent)
309{
310 int b_path = (node->phy_speed == SCODE_BETA);
311
312 if (parent != NULL) {
313 /* min() macro doesn't work here with gcc 3.4 */
314 node->max_speed = parent->max_speed < node->phy_speed ?
315 parent->max_speed : node->phy_speed;
316 node->b_path = parent->b_path && b_path;
317 } else {
318 node->max_speed = node->phy_speed;
319 node->b_path = b_path;
320 }
321
322 fw_node_event(card, node, FW_NODE_CREATED);
323
324 /* Topology has changed - reset bus manager retry counter */
325 card->bm_retries = 0;
326}
327
328/* Must be called with card->lock held */
329void fw_destroy_nodes(struct fw_card *card)
330{
331 card->color++;
332 if (card->local_node != NULL)
333 for_each_fw_node(card, card->local_node, report_lost_node);
334 card->local_node = NULL;
335}
336
337static void move_tree(struct fw_node *node0, struct fw_node *node1, int port)
338{
339 struct fw_node *tree;
340 int i;
341
342 tree = node1->ports[port];
343 node0->ports[port] = tree;
344 for (i = 0; i < tree->port_count; i++) {
345 if (tree->ports[i] == node1) {
346 tree->ports[i] = node0;
347 break;
348 }
349 }
350}
351
352/*
353 * Compare the old topology tree for card with the new one specified by root.
354 * Queue the nodes and mark them as either found, lost or updated.
355 * Update the nodes in the card topology tree as we go.
356 */
357static void update_tree(struct fw_card *card, struct fw_node *root)
358{
359 struct list_head list0, list1;
360 struct fw_node *node0, *node1, *next1;
361 int i, event;
362
363 INIT_LIST_HEAD(&list0);
364 list_add_tail(&card->local_node->link, &list0);
365 INIT_LIST_HEAD(&list1);
366 list_add_tail(&root->link, &list1);
367
368 node0 = fw_node(list0.next);
369 node1 = fw_node(list1.next);
370
371 while (&node0->link != &list0) {
372 WARN_ON(node0->port_count != node1->port_count);
373
374 if (node0->link_on && !node1->link_on)
375 event = FW_NODE_LINK_OFF;
376 else if (!node0->link_on && node1->link_on)
377 event = FW_NODE_LINK_ON;
378 else if (node1->initiated_reset && node1->link_on)
379 event = FW_NODE_INITIATED_RESET;
380 else
381 event = FW_NODE_UPDATED;
382
383 node0->node_id = node1->node_id;
384 node0->color = card->color;
385 node0->link_on = node1->link_on;
386 node0->initiated_reset = node1->initiated_reset;
387 node0->max_hops = node1->max_hops;
388 node1->color = card->color;
389 fw_node_event(card, node0, event);
390
391 if (card->root_node == node1)
392 card->root_node = node0;
393 if (card->irm_node == node1)
394 card->irm_node = node0;
395
396 for (i = 0; i < node0->port_count; i++) {
397 if (node0->ports[i] && node1->ports[i]) {
398 /*
399 * This port didn't change, queue the
400 * connected node for further
401 * investigation.
402 */
403 if (node0->ports[i]->color == card->color)
404 continue;
405 list_add_tail(&node0->ports[i]->link, &list0);
406 list_add_tail(&node1->ports[i]->link, &list1);
407 } else if (node0->ports[i]) {
408 /*
409 * The nodes connected here were
410 * unplugged; unref the lost nodes and
411 * queue FW_NODE_LOST callbacks for
412 * them.
413 */
414
415 for_each_fw_node(card, node0->ports[i],
416 report_lost_node);
417 node0->ports[i] = NULL;
418 } else if (node1->ports[i]) {
419 /*
420 * One or more node were connected to
421 * this port. Move the new nodes into
422 * the tree and queue FW_NODE_CREATED
423 * callbacks for them.
424 */
425 move_tree(node0, node1, i);
426 for_each_fw_node(card, node0->ports[i],
427 report_found_node);
428 }
429 }
430
431 node0 = fw_node(node0->link.next);
432 next1 = fw_node(node1->link.next);
433 fw_node_put(node1);
434 node1 = next1;
435 }
436}
437
438static void update_topology_map(struct fw_card *card,
439 u32 *self_ids, int self_id_count)
440{
441 int node_count = (card->root_node->node_id & 0x3f) + 1;
442 __be32 *map = card->topology_map;
443
444 *map++ = cpu_to_be32((self_id_count + 2) << 16);
445 *map++ = cpu_to_be32(be32_to_cpu(card->topology_map[1]) + 1);
446 *map++ = cpu_to_be32((node_count << 16) | self_id_count);
447
448 while (self_id_count--)
449 *map++ = cpu_to_be32p(self_ids++);
450
451 fw_compute_block_crc(card->topology_map);
452}
453
454void fw_core_handle_bus_reset(struct fw_card *card, int node_id, int generation,
455 int self_id_count, u32 *self_ids, bool bm_abdicate)
456{
457 struct fw_node *local_node;
458
459 trace_bus_reset_handle(card->index, generation, node_id, bm_abdicate, self_ids, self_id_count);
460
461 guard(spinlock_irqsave)(&card->lock);
462
463 /*
464 * If the selfID buffer is not the immediate successor of the
465 * previously processed one, we cannot reliably compare the
466 * old and new topologies.
467 */
468 if (!is_next_generation(generation, card->generation) &&
469 card->local_node != NULL) {
470 fw_destroy_nodes(card);
471 card->bm_retries = 0;
472 }
473
474 card->broadcast_channel_allocated = card->broadcast_channel_auto_allocated;
475 card->node_id = node_id;
476 /*
477 * Update node_id before generation to prevent anybody from using
478 * a stale node_id together with a current generation.
479 */
480 smp_wmb();
481 card->generation = generation;
482 card->reset_jiffies = get_jiffies_64();
483 card->bm_node_id = 0xffff;
484 card->bm_abdicate = bm_abdicate;
485 fw_schedule_bm_work(card, 0);
486
487 local_node = build_tree(card, self_ids, self_id_count, generation);
488
489 update_topology_map(card, self_ids, self_id_count);
490
491 card->color++;
492
493 if (local_node == NULL) {
494 fw_err(card, "topology build failed\n");
495 /* FIXME: We need to issue a bus reset in this case. */
496 } else if (card->local_node == NULL) {
497 card->local_node = local_node;
498 for_each_fw_node(card, local_node, report_found_node);
499 } else {
500 update_tree(card, local_node);
501 }
502}
503EXPORT_SYMBOL(fw_core_handle_bus_reset);
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/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>
31
32#include <linux/atomic.h>
33#include <asm/byteorder.h>
34#include <asm/system.h>
35
36#include "core.h"
37
38#define SELF_ID_PHY_ID(q) (((q) >> 24) & 0x3f)
39#define SELF_ID_EXTENDED(q) (((q) >> 23) & 0x01)
40#define SELF_ID_LINK_ON(q) (((q) >> 22) & 0x01)
41#define SELF_ID_GAP_COUNT(q) (((q) >> 16) & 0x3f)
42#define SELF_ID_PHY_SPEED(q) (((q) >> 14) & 0x03)
43#define SELF_ID_CONTENDER(q) (((q) >> 11) & 0x01)
44#define SELF_ID_PHY_INITIATOR(q) (((q) >> 1) & 0x01)
45#define SELF_ID_MORE_PACKETS(q) (((q) >> 0) & 0x01)
46
47#define SELF_ID_EXT_SEQUENCE(q) (((q) >> 20) & 0x07)
48
49#define SELFID_PORT_CHILD 0x3
50#define SELFID_PORT_PARENT 0x2
51#define SELFID_PORT_NCONN 0x1
52#define SELFID_PORT_NONE 0x0
53
54static u32 *count_ports(u32 *sid, int *total_port_count, int *child_port_count)
55{
56 u32 q;
57 int port_type, shift, seq;
58
59 *total_port_count = 0;
60 *child_port_count = 0;
61
62 shift = 6;
63 q = *sid;
64 seq = 0;
65
66 while (1) {
67 port_type = (q >> shift) & 0x03;
68 switch (port_type) {
69 case SELFID_PORT_CHILD:
70 (*child_port_count)++;
71 case SELFID_PORT_PARENT:
72 case SELFID_PORT_NCONN:
73 (*total_port_count)++;
74 case SELFID_PORT_NONE:
75 break;
76 }
77
78 shift -= 2;
79 if (shift == 0) {
80 if (!SELF_ID_MORE_PACKETS(q))
81 return sid + 1;
82
83 shift = 16;
84 sid++;
85 q = *sid;
86
87 /*
88 * Check that the extra packets actually are
89 * extended self ID packets and that the
90 * sequence numbers in the extended self ID
91 * packets increase as expected.
92 */
93
94 if (!SELF_ID_EXTENDED(q) ||
95 seq != SELF_ID_EXT_SEQUENCE(q))
96 return NULL;
97
98 seq++;
99 }
100 }
101}
102
103static int get_port_type(u32 *sid, int port_index)
104{
105 int index, shift;
106
107 index = (port_index + 5) / 8;
108 shift = 16 - ((port_index + 5) & 7) * 2;
109 return (sid[index] >> shift) & 0x03;
110}
111
112static struct fw_node *fw_node_create(u32 sid, int port_count, int color)
113{
114 struct fw_node *node;
115
116 node = kzalloc(sizeof(*node) + port_count * sizeof(node->ports[0]),
117 GFP_ATOMIC);
118 if (node == NULL)
119 return NULL;
120
121 node->color = color;
122 node->node_id = LOCAL_BUS | SELF_ID_PHY_ID(sid);
123 node->link_on = SELF_ID_LINK_ON(sid);
124 node->phy_speed = SELF_ID_PHY_SPEED(sid);
125 node->initiated_reset = SELF_ID_PHY_INITIATOR(sid);
126 node->port_count = port_count;
127
128 atomic_set(&node->ref_count, 1);
129 INIT_LIST_HEAD(&node->link);
130
131 return node;
132}
133
134/*
135 * Compute the maximum hop count for this node and it's children. The
136 * maximum hop count is the maximum number of connections between any
137 * two nodes in the subtree rooted at this node. We need this for
138 * setting the gap count. As we build the tree bottom up in
139 * build_tree() below, this is fairly easy to do: for each node we
140 * maintain the max hop count and the max depth, ie the number of hops
141 * to the furthest leaf. Computing the max hop count breaks down into
142 * two cases: either the path goes through this node, in which case
143 * the hop count is the sum of the two biggest child depths plus 2.
144 * Or it could be the case that the max hop path is entirely
145 * containted in a child tree, in which case the max hop count is just
146 * the max hop count of this child.
147 */
148static void update_hop_count(struct fw_node *node)
149{
150 int depths[2] = { -1, -1 };
151 int max_child_hops = 0;
152 int i;
153
154 for (i = 0; i < node->port_count; i++) {
155 if (node->ports[i] == NULL)
156 continue;
157
158 if (node->ports[i]->max_hops > max_child_hops)
159 max_child_hops = node->ports[i]->max_hops;
160
161 if (node->ports[i]->max_depth > depths[0]) {
162 depths[1] = depths[0];
163 depths[0] = node->ports[i]->max_depth;
164 } else if (node->ports[i]->max_depth > depths[1])
165 depths[1] = node->ports[i]->max_depth;
166 }
167
168 node->max_depth = depths[0] + 1;
169 node->max_hops = max(max_child_hops, depths[0] + depths[1] + 2);
170}
171
172static inline struct fw_node *fw_node(struct list_head *l)
173{
174 return list_entry(l, struct fw_node, link);
175}
176
177/*
178 * This function builds the tree representation of the topology given
179 * by the self IDs from the latest bus reset. During the construction
180 * of the tree, the function checks that the self IDs are valid and
181 * internally consistent. On success this function returns the
182 * fw_node corresponding to the local card otherwise NULL.
183 */
184static struct fw_node *build_tree(struct fw_card *card,
185 u32 *sid, int self_id_count)
186{
187 struct fw_node *node, *child, *local_node, *irm_node;
188 struct list_head stack, *h;
189 u32 *next_sid, *end, q;
190 int i, port_count, child_port_count, phy_id, parent_count, stack_depth;
191 int gap_count;
192 bool beta_repeaters_present;
193
194 local_node = NULL;
195 node = NULL;
196 INIT_LIST_HEAD(&stack);
197 stack_depth = 0;
198 end = sid + self_id_count;
199 phy_id = 0;
200 irm_node = NULL;
201 gap_count = SELF_ID_GAP_COUNT(*sid);
202 beta_repeaters_present = false;
203
204 while (sid < end) {
205 next_sid = count_ports(sid, &port_count, &child_port_count);
206
207 if (next_sid == NULL) {
208 fw_error("Inconsistent extended self IDs.\n");
209 return NULL;
210 }
211
212 q = *sid;
213 if (phy_id != SELF_ID_PHY_ID(q)) {
214 fw_error("PHY ID mismatch in self ID: %d != %d.\n",
215 phy_id, SELF_ID_PHY_ID(q));
216 return NULL;
217 }
218
219 if (child_port_count > stack_depth) {
220 fw_error("Topology stack underflow\n");
221 return NULL;
222 }
223
224 /*
225 * Seek back from the top of our stack to find the
226 * start of the child nodes for this node.
227 */
228 for (i = 0, h = &stack; i < child_port_count; i++)
229 h = h->prev;
230 /*
231 * When the stack is empty, this yields an invalid value,
232 * but that pointer will never be dereferenced.
233 */
234 child = fw_node(h);
235
236 node = fw_node_create(q, port_count, card->color);
237 if (node == NULL) {
238 fw_error("Out of memory while building topology.\n");
239 return NULL;
240 }
241
242 if (phy_id == (card->node_id & 0x3f))
243 local_node = node;
244
245 if (SELF_ID_CONTENDER(q))
246 irm_node = node;
247
248 parent_count = 0;
249
250 for (i = 0; i < port_count; i++) {
251 switch (get_port_type(sid, i)) {
252 case SELFID_PORT_PARENT:
253 /*
254 * Who's your daddy? We dont know the
255 * parent node at this time, so we
256 * temporarily abuse node->color for
257 * remembering the entry in the
258 * node->ports array where the parent
259 * node should be. Later, when we
260 * handle the parent node, we fix up
261 * the reference.
262 */
263 parent_count++;
264 node->color = i;
265 break;
266
267 case SELFID_PORT_CHILD:
268 node->ports[i] = child;
269 /*
270 * Fix up parent reference for this
271 * child node.
272 */
273 child->ports[child->color] = node;
274 child->color = card->color;
275 child = fw_node(child->link.next);
276 break;
277 }
278 }
279
280 /*
281 * Check that the node reports exactly one parent
282 * port, except for the root, which of course should
283 * have no parents.
284 */
285 if ((next_sid == end && parent_count != 0) ||
286 (next_sid < end && parent_count != 1)) {
287 fw_error("Parent port inconsistency for node %d: "
288 "parent_count=%d\n", phy_id, parent_count);
289 return NULL;
290 }
291
292 /* Pop the child nodes off the stack and push the new node. */
293 __list_del(h->prev, &stack);
294 list_add_tail(&node->link, &stack);
295 stack_depth += 1 - child_port_count;
296
297 if (node->phy_speed == SCODE_BETA &&
298 parent_count + child_port_count > 1)
299 beta_repeaters_present = true;
300
301 /*
302 * If PHYs report different gap counts, set an invalid count
303 * which will force a gap count reconfiguration and a reset.
304 */
305 if (SELF_ID_GAP_COUNT(q) != gap_count)
306 gap_count = 0;
307
308 update_hop_count(node);
309
310 sid = next_sid;
311 phy_id++;
312 }
313
314 card->root_node = node;
315 card->irm_node = irm_node;
316 card->gap_count = gap_count;
317 card->beta_repeaters_present = beta_repeaters_present;
318
319 return local_node;
320}
321
322typedef void (*fw_node_callback_t)(struct fw_card * card,
323 struct fw_node * node,
324 struct fw_node * parent);
325
326static void for_each_fw_node(struct fw_card *card, struct fw_node *root,
327 fw_node_callback_t callback)
328{
329 struct list_head list;
330 struct fw_node *node, *next, *child, *parent;
331 int i;
332
333 INIT_LIST_HEAD(&list);
334
335 fw_node_get(root);
336 list_add_tail(&root->link, &list);
337 parent = NULL;
338 list_for_each_entry(node, &list, link) {
339 node->color = card->color;
340
341 for (i = 0; i < node->port_count; i++) {
342 child = node->ports[i];
343 if (!child)
344 continue;
345 if (child->color == card->color)
346 parent = child;
347 else {
348 fw_node_get(child);
349 list_add_tail(&child->link, &list);
350 }
351 }
352
353 callback(card, node, parent);
354 }
355
356 list_for_each_entry_safe(node, next, &list, link)
357 fw_node_put(node);
358}
359
360static void report_lost_node(struct fw_card *card,
361 struct fw_node *node, struct fw_node *parent)
362{
363 fw_node_event(card, node, FW_NODE_DESTROYED);
364 fw_node_put(node);
365
366 /* Topology has changed - reset bus manager retry counter */
367 card->bm_retries = 0;
368}
369
370static void report_found_node(struct fw_card *card,
371 struct fw_node *node, struct fw_node *parent)
372{
373 int b_path = (node->phy_speed == SCODE_BETA);
374
375 if (parent != NULL) {
376 /* min() macro doesn't work here with gcc 3.4 */
377 node->max_speed = parent->max_speed < node->phy_speed ?
378 parent->max_speed : node->phy_speed;
379 node->b_path = parent->b_path && b_path;
380 } else {
381 node->max_speed = node->phy_speed;
382 node->b_path = b_path;
383 }
384
385 fw_node_event(card, node, FW_NODE_CREATED);
386
387 /* Topology has changed - reset bus manager retry counter */
388 card->bm_retries = 0;
389}
390
391void fw_destroy_nodes(struct fw_card *card)
392{
393 unsigned long flags;
394
395 spin_lock_irqsave(&card->lock, flags);
396 card->color++;
397 if (card->local_node != NULL)
398 for_each_fw_node(card, card->local_node, report_lost_node);
399 card->local_node = NULL;
400 spin_unlock_irqrestore(&card->lock, flags);
401}
402
403static void move_tree(struct fw_node *node0, struct fw_node *node1, int port)
404{
405 struct fw_node *tree;
406 int i;
407
408 tree = node1->ports[port];
409 node0->ports[port] = tree;
410 for (i = 0; i < tree->port_count; i++) {
411 if (tree->ports[i] == node1) {
412 tree->ports[i] = node0;
413 break;
414 }
415 }
416}
417
418/*
419 * Compare the old topology tree for card with the new one specified by root.
420 * Queue the nodes and mark them as either found, lost or updated.
421 * Update the nodes in the card topology tree as we go.
422 */
423static void update_tree(struct fw_card *card, struct fw_node *root)
424{
425 struct list_head list0, list1;
426 struct fw_node *node0, *node1, *next1;
427 int i, event;
428
429 INIT_LIST_HEAD(&list0);
430 list_add_tail(&card->local_node->link, &list0);
431 INIT_LIST_HEAD(&list1);
432 list_add_tail(&root->link, &list1);
433
434 node0 = fw_node(list0.next);
435 node1 = fw_node(list1.next);
436
437 while (&node0->link != &list0) {
438 WARN_ON(node0->port_count != node1->port_count);
439
440 if (node0->link_on && !node1->link_on)
441 event = FW_NODE_LINK_OFF;
442 else if (!node0->link_on && node1->link_on)
443 event = FW_NODE_LINK_ON;
444 else if (node1->initiated_reset && node1->link_on)
445 event = FW_NODE_INITIATED_RESET;
446 else
447 event = FW_NODE_UPDATED;
448
449 node0->node_id = node1->node_id;
450 node0->color = card->color;
451 node0->link_on = node1->link_on;
452 node0->initiated_reset = node1->initiated_reset;
453 node0->max_hops = node1->max_hops;
454 node1->color = card->color;
455 fw_node_event(card, node0, event);
456
457 if (card->root_node == node1)
458 card->root_node = node0;
459 if (card->irm_node == node1)
460 card->irm_node = node0;
461
462 for (i = 0; i < node0->port_count; i++) {
463 if (node0->ports[i] && node1->ports[i]) {
464 /*
465 * This port didn't change, queue the
466 * connected node for further
467 * investigation.
468 */
469 if (node0->ports[i]->color == card->color)
470 continue;
471 list_add_tail(&node0->ports[i]->link, &list0);
472 list_add_tail(&node1->ports[i]->link, &list1);
473 } else if (node0->ports[i]) {
474 /*
475 * The nodes connected here were
476 * unplugged; unref the lost nodes and
477 * queue FW_NODE_LOST callbacks for
478 * them.
479 */
480
481 for_each_fw_node(card, node0->ports[i],
482 report_lost_node);
483 node0->ports[i] = NULL;
484 } else if (node1->ports[i]) {
485 /*
486 * One or more node were connected to
487 * this port. Move the new nodes into
488 * the tree and queue FW_NODE_CREATED
489 * callbacks for them.
490 */
491 move_tree(node0, node1, i);
492 for_each_fw_node(card, node0->ports[i],
493 report_found_node);
494 }
495 }
496
497 node0 = fw_node(node0->link.next);
498 next1 = fw_node(node1->link.next);
499 fw_node_put(node1);
500 node1 = next1;
501 }
502}
503
504static void update_topology_map(struct fw_card *card,
505 u32 *self_ids, int self_id_count)
506{
507 int node_count = (card->root_node->node_id & 0x3f) + 1;
508 __be32 *map = card->topology_map;
509
510 *map++ = cpu_to_be32((self_id_count + 2) << 16);
511 *map++ = cpu_to_be32(be32_to_cpu(card->topology_map[1]) + 1);
512 *map++ = cpu_to_be32((node_count << 16) | self_id_count);
513
514 while (self_id_count--)
515 *map++ = cpu_to_be32p(self_ids++);
516
517 fw_compute_block_crc(card->topology_map);
518}
519
520void fw_core_handle_bus_reset(struct fw_card *card, int node_id, int generation,
521 int self_id_count, u32 *self_ids, bool bm_abdicate)
522{
523 struct fw_node *local_node;
524 unsigned long flags;
525
526 /*
527 * If the selfID buffer is not the immediate successor of the
528 * previously processed one, we cannot reliably compare the
529 * old and new topologies.
530 */
531 if (!is_next_generation(generation, card->generation) &&
532 card->local_node != NULL) {
533 fw_notify("skipped bus generations, destroying all nodes\n");
534 fw_destroy_nodes(card);
535 card->bm_retries = 0;
536 }
537
538 spin_lock_irqsave(&card->lock, flags);
539
540 card->broadcast_channel_allocated = card->broadcast_channel_auto_allocated;
541 card->node_id = node_id;
542 /*
543 * Update node_id before generation to prevent anybody from using
544 * a stale node_id together with a current generation.
545 */
546 smp_wmb();
547 card->generation = generation;
548 card->reset_jiffies = get_jiffies_64();
549 card->bm_node_id = 0xffff;
550 card->bm_abdicate = bm_abdicate;
551 fw_schedule_bm_work(card, 0);
552
553 local_node = build_tree(card, self_ids, self_id_count);
554
555 update_topology_map(card, self_ids, self_id_count);
556
557 card->color++;
558
559 if (local_node == NULL) {
560 fw_error("topology build failed\n");
561 /* FIXME: We need to issue a bus reset in this case. */
562 } else if (card->local_node == NULL) {
563 card->local_node = local_node;
564 for_each_fw_node(card, local_node, report_found_node);
565 } else {
566 update_tree(card, local_node);
567 }
568
569 spin_unlock_irqrestore(&card->lock, flags);
570}
571EXPORT_SYMBOL(fw_core_handle_bus_reset);