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 "fw-transaction.h" 25#include "fw-topology.h" 26 27#define SELF_ID_PHY_ID(q) (((q) >> 24) & 0x3f) 28#define SELF_ID_EXTENDED(q) (((q) >> 23) & 0x01) 29#define SELF_ID_LINK_ON(q) (((q) >> 22) & 0x01) 30#define SELF_ID_GAP_COUNT(q) (((q) >> 16) & 0x3f) 31#define SELF_ID_PHY_SPEED(q) (((q) >> 14) & 0x03) 32#define SELF_ID_CONTENDER(q) (((q) >> 11) & 0x01) 33#define SELF_ID_PHY_INITIATOR(q) (((q) >> 1) & 0x01) 34#define SELF_ID_MORE_PACKETS(q) (((q) >> 0) & 0x01) 35 36#define SELF_ID_EXT_SEQUENCE(q) (((q) >> 20) & 0x07) 37 38static u32 *count_ports(u32 *sid, int *total_port_count, int *child_port_count) 39{ 40 u32 q; 41 int port_type, shift, seq; 42 43 *total_port_count = 0; 44 *child_port_count = 0; 45 46 shift = 6; 47 q = *sid; 48 seq = 0; 49 50 while (1) { 51 port_type = (q >> shift) & 0x03; 52 switch (port_type) { 53 case SELFID_PORT_CHILD: 54 (*child_port_count)++; 55 case SELFID_PORT_PARENT: 56 case SELFID_PORT_NCONN: 57 (*total_port_count)++; 58 case SELFID_PORT_NONE: 59 break; 60 } 61 62 shift -= 2; 63 if (shift == 0) { 64 if (!SELF_ID_MORE_PACKETS(q)) 65 return sid + 1; 66 67 shift = 16; 68 sid++; 69 q = *sid; 70 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 78 if (!SELF_ID_EXTENDED(q) || 79 seq != SELF_ID_EXT_SEQUENCE(q)) 80 return NULL; 81 82 seq++; 83 } 84 } 85} 86 87static int get_port_type(u32 *sid, int port_index) 88{ 89 int index, shift; 90 91 index = (port_index + 5) / 8; 92 shift = 16 - ((port_index + 5) & 7) * 2; 93 return (sid[index] >> shift) & 0x03; 94} 95 96static struct fw_node *fw_node_create(u32 sid, int port_count, int color) 97{ 98 struct fw_node *node; 99 100 node = kzalloc(sizeof(*node) + port_count * sizeof(node->ports[0]), 101 GFP_ATOMIC); 102 if (node == NULL) 103 return NULL; 104 105 node->color = color; 106 node->node_id = LOCAL_BUS | SELF_ID_PHY_ID(sid); 107 node->link_on = SELF_ID_LINK_ON(sid); 108 node->phy_speed = SELF_ID_PHY_SPEED(sid); 109 node->port_count = port_count; 110 111 atomic_set(&node->ref_count, 1); 112 INIT_LIST_HEAD(&node->link); 113 114 return node; 115} 116 117/* 118 * Compute the maximum hop count for this node and it's children. The 119 * maximum hop count is the maximum number of connections between any 120 * two nodes in the subtree rooted at this node. We need this for 121 * setting the gap count. As we build the tree bottom up in 122 * build_tree() below, this is fairly easy to do: for each node we 123 * maintain the max hop count and the max depth, ie the number of hops 124 * to the furthest leaf. Computing the max hop count breaks down into 125 * two cases: either the path goes through this node, in which case 126 * the hop count is the sum of the two biggest child depths plus 2. 127 * Or it could be the case that the max hop path is entirely 128 * containted in a child tree, in which case the max hop count is just 129 * the max hop count of this child. 130 */ 131static void update_hop_count(struct fw_node *node) 132{ 133 int depths[2] = { -1, -1 }; 134 int max_child_hops = 0; 135 int i; 136 137 for (i = 0; i < node->port_count; i++) { 138 if (node->ports[i].node == NULL) 139 continue; 140 141 if (node->ports[i].node->max_hops > max_child_hops) 142 max_child_hops = node->ports[i].node->max_hops; 143 144 if (node->ports[i].node->max_depth > depths[0]) { 145 depths[1] = depths[0]; 146 depths[0] = node->ports[i].node->max_depth; 147 } else if (node->ports[i].node->max_depth > depths[1]) 148 depths[1] = node->ports[i].node->max_depth; 149 } 150 151 node->max_depth = depths[0] + 1; 152 node->max_hops = max(max_child_hops, depths[0] + depths[1] + 2); 153} 154 155 156/** 157 * build_tree - Build the tree representation of the topology 158 * @self_ids: array of self IDs to create the tree from 159 * @self_id_count: the length of the self_ids array 160 * @local_id: the node ID of the local node 161 * 162 * This function builds the tree representation of the topology given 163 * by the self IDs from the latest bus reset. During the construction 164 * of the tree, the function checks that the self IDs are valid and 165 * internally consistent. On succcess this funtions returns the 166 * fw_node corresponding to the local card otherwise NULL. 167 */ 168static struct fw_node *build_tree(struct fw_card *card, 169 u32 *sid, int self_id_count) 170{ 171 struct fw_node *node, *child, *local_node, *irm_node; 172 struct list_head stack, *h; 173 u32 *next_sid, *end, q; 174 int i, port_count, child_port_count, phy_id, parent_count, stack_depth; 175 int gap_count, topology_type; 176 177 local_node = NULL; 178 node = NULL; 179 INIT_LIST_HEAD(&stack); 180 stack_depth = 0; 181 end = sid + self_id_count; 182 phy_id = 0; 183 irm_node = NULL; 184 gap_count = SELF_ID_GAP_COUNT(*sid); 185 topology_type = 0; 186 187 while (sid < end) { 188 next_sid = count_ports(sid, &port_count, &child_port_count); 189 190 if (next_sid == NULL) { 191 fw_error("Inconsistent extended self IDs.\n"); 192 return NULL; 193 } 194 195 q = *sid; 196 if (phy_id != SELF_ID_PHY_ID(q)) { 197 fw_error("PHY ID mismatch in self ID: %d != %d.\n", 198 phy_id, SELF_ID_PHY_ID(q)); 199 return NULL; 200 } 201 202 if (child_port_count > stack_depth) { 203 fw_error("Topology stack underflow\n"); 204 return NULL; 205 } 206 207 /* 208 * Seek back from the top of our stack to find the 209 * start of the child nodes for this node. 210 */ 211 for (i = 0, h = &stack; i < child_port_count; i++) 212 h = h->prev; 213 child = fw_node(h); 214 215 node = fw_node_create(q, port_count, card->color); 216 if (node == NULL) { 217 fw_error("Out of memory while building topology."); 218 return NULL; 219 } 220 221 if (phy_id == (card->node_id & 0x3f)) 222 local_node = node; 223 224 if (SELF_ID_CONTENDER(q)) 225 irm_node = node; 226 227 if (node->phy_speed == SCODE_BETA) 228 topology_type |= FW_TOPOLOGY_B; 229 else 230 topology_type |= FW_TOPOLOGY_A; 231 232 parent_count = 0; 233 234 for (i = 0; i < port_count; i++) { 235 switch (get_port_type(sid, i)) { 236 case SELFID_PORT_PARENT: 237 /* 238 * Who's your daddy? We dont know the 239 * parent node at this time, so we 240 * temporarily abuse node->color for 241 * remembering the entry in the 242 * node->ports array where the parent 243 * node should be. Later, when we 244 * handle the parent node, we fix up 245 * the reference. 246 */ 247 parent_count++; 248 node->color = i; 249 break; 250 251 case SELFID_PORT_CHILD: 252 node->ports[i].node = child; 253 /* 254 * Fix up parent reference for this 255 * child node. 256 */ 257 child->ports[child->color].node = node; 258 child->color = card->color; 259 child = fw_node(child->link.next); 260 break; 261 } 262 } 263 264 /* 265 * Check that the node reports exactly one parent 266 * port, except for the root, which of course should 267 * have no parents. 268 */ 269 if ((next_sid == end && parent_count != 0) || 270 (next_sid < end && parent_count != 1)) { 271 fw_error("Parent port inconsistency for node %d: " 272 "parent_count=%d\n", phy_id, parent_count); 273 return NULL; 274 } 275 276 /* Pop the child nodes off the stack and push the new node. */ 277 __list_del(h->prev, &stack); 278 list_add_tail(&node->link, &stack); 279 stack_depth += 1 - child_port_count; 280 281 /* 282 * If all PHYs does not report the same gap count 283 * setting, we fall back to 63 which will force a gap 284 * count reconfiguration and a reset. 285 */ 286 if (SELF_ID_GAP_COUNT(q) != gap_count) 287 gap_count = 63; 288 289 update_hop_count(node); 290 291 sid = next_sid; 292 phy_id++; 293 } 294 295 card->root_node = node; 296 card->irm_node = irm_node; 297 card->gap_count = gap_count; 298 card->topology_type = topology_type; 299 300 return local_node; 301} 302 303typedef void (*fw_node_callback_t)(struct fw_card * card, 304 struct fw_node * node, 305 struct fw_node * parent); 306 307static void 308for_each_fw_node(struct fw_card *card, struct fw_node *root, 309 fw_node_callback_t callback) 310{ 311 struct list_head list; 312 struct fw_node *node, *next, *child, *parent; 313 int i; 314 315 INIT_LIST_HEAD(&list); 316 317 fw_node_get(root); 318 list_add_tail(&root->link, &list); 319 parent = NULL; 320 list_for_each_entry(node, &list, link) { 321 node->color = card->color; 322 323 for (i = 0; i < node->port_count; i++) { 324 child = node->ports[i].node; 325 if (!child) 326 continue; 327 if (child->color == card->color) 328 parent = child; 329 else { 330 fw_node_get(child); 331 list_add_tail(&child->link, &list); 332 } 333 } 334 335 callback(card, node, parent); 336 } 337 338 list_for_each_entry_safe(node, next, &list, link) 339 fw_node_put(node); 340} 341 342static void 343report_lost_node(struct fw_card *card, 344 struct fw_node *node, struct fw_node *parent) 345{ 346 fw_node_event(card, node, FW_NODE_DESTROYED); 347 fw_node_put(node); 348} 349 350static void 351report_found_node(struct fw_card *card, 352 struct fw_node *node, struct fw_node *parent) 353{ 354 int b_path = (node->phy_speed == SCODE_BETA); 355 356 if (parent != NULL) { 357 /* min() macro doesn't work here with gcc 3.4 */ 358 node->max_speed = parent->max_speed < node->phy_speed ? 359 parent->max_speed : node->phy_speed; 360 node->b_path = parent->b_path && b_path; 361 } else { 362 node->max_speed = node->phy_speed; 363 node->b_path = b_path; 364 } 365 366 fw_node_event(card, node, FW_NODE_CREATED); 367} 368 369void fw_destroy_nodes(struct fw_card *card) 370{ 371 unsigned long flags; 372 373 spin_lock_irqsave(&card->lock, flags); 374 card->color++; 375 if (card->local_node != NULL) 376 for_each_fw_node(card, card->local_node, report_lost_node); 377 spin_unlock_irqrestore(&card->lock, flags); 378} 379 380static void move_tree(struct fw_node *node0, struct fw_node *node1, int port) 381{ 382 struct fw_node *tree; 383 int i; 384 385 tree = node1->ports[port].node; 386 node0->ports[port].node = tree; 387 for (i = 0; i < tree->port_count; i++) { 388 if (tree->ports[i].node == node1) { 389 tree->ports[i].node = node0; 390 break; 391 } 392 } 393} 394 395/** 396 * update_tree - compare the old topology tree for card with the new 397 * one specified by root. Queue the nodes and mark them as either 398 * found, lost or updated. Update the nodes in the card topology tree 399 * as we go. 400 */ 401static void 402update_tree(struct fw_card *card, struct fw_node *root) 403{ 404 struct list_head list0, list1; 405 struct fw_node *node0, *node1; 406 int i, event; 407 408 INIT_LIST_HEAD(&list0); 409 list_add_tail(&card->local_node->link, &list0); 410 INIT_LIST_HEAD(&list1); 411 list_add_tail(&root->link, &list1); 412 413 node0 = fw_node(list0.next); 414 node1 = fw_node(list1.next); 415 416 while (&node0->link != &list0) { 417 418 /* assert(node0->port_count == node1->port_count); */ 419 if (node0->link_on && !node1->link_on) 420 event = FW_NODE_LINK_OFF; 421 else if (!node0->link_on && node1->link_on) 422 event = FW_NODE_LINK_ON; 423 else 424 event = FW_NODE_UPDATED; 425 426 node0->node_id = node1->node_id; 427 node0->color = card->color; 428 node0->link_on = node1->link_on; 429 node0->initiated_reset = node1->initiated_reset; 430 node0->max_hops = node1->max_hops; 431 node1->color = card->color; 432 fw_node_event(card, node0, event); 433 434 if (card->root_node == node1) 435 card->root_node = node0; 436 if (card->irm_node == node1) 437 card->irm_node = node0; 438 439 for (i = 0; i < node0->port_count; i++) { 440 if (node0->ports[i].node && node1->ports[i].node) { 441 /* 442 * This port didn't change, queue the 443 * connected node for further 444 * investigation. 445 */ 446 if (node0->ports[i].node->color == card->color) 447 continue; 448 list_add_tail(&node0->ports[i].node->link, 449 &list0); 450 list_add_tail(&node1->ports[i].node->link, 451 &list1); 452 } else if (node0->ports[i].node) { 453 /* 454 * The nodes connected here were 455 * unplugged; unref the lost nodes and 456 * queue FW_NODE_LOST callbacks for 457 * them. 458 */ 459 460 for_each_fw_node(card, node0->ports[i].node, 461 report_lost_node); 462 node0->ports[i].node = NULL; 463 } else if (node1->ports[i].node) { 464 /* 465 * One or more node were connected to 466 * this port. Move the new nodes into 467 * the tree and queue FW_NODE_CREATED 468 * callbacks for them. 469 */ 470 move_tree(node0, node1, i); 471 for_each_fw_node(card, node0->ports[i].node, 472 report_found_node); 473 } 474 } 475 476 node0 = fw_node(node0->link.next); 477 node1 = fw_node(node1->link.next); 478 } 479} 480 481static void 482update_topology_map(struct fw_card *card, u32 *self_ids, int self_id_count) 483{ 484 int node_count; 485 486 card->topology_map[1]++; 487 node_count = (card->root_node->node_id & 0x3f) + 1; 488 card->topology_map[2] = (node_count << 16) | self_id_count; 489 card->topology_map[0] = (self_id_count + 2) << 16; 490 memcpy(&card->topology_map[3], self_ids, self_id_count * 4); 491 fw_compute_block_crc(card->topology_map); 492} 493 494void 495fw_core_handle_bus_reset(struct fw_card *card, 496 int node_id, int generation, 497 int self_id_count, u32 * self_ids) 498{ 499 struct fw_node *local_node; 500 unsigned long flags; 501 502 fw_flush_transactions(card); 503 504 spin_lock_irqsave(&card->lock, flags); 505 506 /* 507 * If the new topology has a different self_id_count the topology 508 * changed, either nodes were added or removed. In that case we 509 * reset the IRM reset counter. 510 */ 511 if (card->self_id_count != self_id_count) 512 card->bm_retries = 0; 513 514 card->node_id = node_id; 515 card->generation = generation; 516 card->reset_jiffies = jiffies; 517 schedule_delayed_work(&card->work, 0); 518 519 local_node = build_tree(card, self_ids, self_id_count); 520 521 update_topology_map(card, self_ids, self_id_count); 522 523 card->color++; 524 525 if (local_node == NULL) { 526 fw_error("topology build failed\n"); 527 } else if (card->local_node == NULL) { 528 card->local_node = local_node; 529 for_each_fw_node(card, local_node, report_found_node); 530 } else { 531 update_tree(card, local_node); 532 } 533 534 spin_unlock_irqrestore(&card->lock, flags); 535} 536EXPORT_SYMBOL(fw_core_handle_bus_reset); 537