drivers/firewire/fw-topology.c

   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 <<<<<<< HEAD:drivers/firewire/fw-topology.c
  25 =======
  26 #include <asm/bug.h>
  27 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:drivers/firewire/fw-topology.c
  28 #include <asm/system.h>
  29 #include "fw-transaction.h"
  30 #include "fw-topology.h"
  31
  32 #define SELF_ID_PHY_ID(q)               (((q) >> 24) & 0x3f)
  33 #define SELF_ID_EXTENDED(q)             (((q) >> 23) & 0x01)
  34 #define SELF_ID_LINK_ON(q)              (((q) >> 22) & 0x01)
  35 #define SELF_ID_GAP_COUNT(q)            (((q) >> 16) & 0x3f)
  36 #define SELF_ID_PHY_SPEED(q)            (((q) >> 14) & 0x03)
  37 #define SELF_ID_CONTENDER(q)            (((q) >> 11) & 0x01)
  38 #define SELF_ID_PHY_INITIATOR(q)        (((q) >>  1) & 0x01)
  39 #define SELF_ID_MORE_PACKETS(q)         (((q) >>  0) & 0x01)
  40
  41 #define SELF_ID_EXT_SEQUENCE(q)         (((q) >> 20) & 0x07)
  42
  43 static u32 *count_ports(u32 *sid, int *total_port_count, int *child_port_count)
  44 {
  45         u32 q;
  46         int port_type, shift, seq;
  47
  48         *total_port_count = 0;
  49         *child_port_count = 0;
  50
  51         shift = 6;
  52         q = *sid;
  53         seq = 0;
  54
  55         while (1) {
  56                 port_type = (q >> shift) & 0x03;
  57                 switch (port_type) {
  58                 case SELFID_PORT_CHILD:
  59                         (*child_port_count)++;
  60                 case SELFID_PORT_PARENT:
  61                 case SELFID_PORT_NCONN:
  62                         (*total_port_count)++;
  63                 case SELFID_PORT_NONE:
  64                         break;
  65                 }
  66
  67                 shift -= 2;
  68                 if (shift == 0) {
  69                         if (!SELF_ID_MORE_PACKETS(q))
  70                                 return sid + 1;
  71
  72                         shift = 16;
  73                         sid++;
  74                         q = *sid;
  75
  76                         /*
  77                          * Check that the extra packets actually are
  78                          * extended self ID packets and that the
  79                          * sequence numbers in the extended self ID
  80                          * packets increase as expected.
  81                          */
  82
  83                         if (!SELF_ID_EXTENDED(q) ||
  84                             seq != SELF_ID_EXT_SEQUENCE(q))
  85                                 return NULL;
  86
  87                         seq++;
  88                 }
  89         }
  90 }
  91
  92 static int get_port_type(u32 *sid, int port_index)
  93 {
  94         int index, shift;
  95
  96         index = (port_index + 5) / 8;
  97         shift = 16 - ((port_index + 5) & 7) * 2;
  98         return (sid[index] >> shift) & 0x03;
  99 }
 100
 101 static struct fw_node *fw_node_create(u32 sid, int port_count, int color)
 102 {
 103         struct fw_node *node;
 104
 105         node = kzalloc(sizeof(*node) + port_count * sizeof(node->ports[0]),
 106                        GFP_ATOMIC);
 107         if (node == NULL)
 108                 return NULL;
 109
 110         node->color = color;
 111         node->node_id = LOCAL_BUS | SELF_ID_PHY_ID(sid);
 112         node->link_on = SELF_ID_LINK_ON(sid);
 113         node->phy_speed = SELF_ID_PHY_SPEED(sid);
 114         node->port_count = port_count;
 115
 116         atomic_set(&node->ref_count, 1);
 117         INIT_LIST_HEAD(&node->link);
 118
 119         return node;
 120 }
 121
 122 /*
 123  * Compute the maximum hop count for this node and it's children.  The
 124  * maximum hop count is the maximum number of connections between any
 125  * two nodes in the subtree rooted at this node.  We need this for
 126  * setting the gap count.  As we build the tree bottom up in
 127  * build_tree() below, this is fairly easy to do: for each node we
 128  * maintain the max hop count and the max depth, ie the number of hops
 129  * to the furthest leaf.  Computing the max hop count breaks down into
 130  * two cases: either the path goes through this node, in which case
 131  * the hop count is the sum of the two biggest child depths plus 2.
 132  * Or it could be the case that the max hop path is entirely
 133  * containted in a child tree, in which case the max hop count is just
 134  * the max hop count of this child.
 135  */
 136 static void update_hop_count(struct fw_node *node)
 137 {
 138         int depths[2] = { -1, -1 };
 139         int max_child_hops = 0;
 140         int i;
 141
 142         for (i = 0; i < node->port_count; i++) {
 143                 if (node->ports[i] == NULL)
 144                         continue;
 145
 146                 if (node->ports[i]->max_hops > max_child_hops)
 147                         max_child_hops = node->ports[i]->max_hops;
 148
 149                 if (node->ports[i]->max_depth > depths[0]) {
 150                         depths[1] = depths[0];
 151                         depths[0] = node->ports[i]->max_depth;
 152                 } else if (node->ports[i]->max_depth > depths[1])
 153                         depths[1] = node->ports[i]->max_depth;
 154         }
 155
 156         node->max_depth = depths[0] + 1;
 157         node->max_hops = max(max_child_hops, depths[0] + depths[1] + 2);
 158 }
 159
 160 static inline struct fw_node *fw_node(struct list_head *l)
 161 {
 162         return list_entry(l, struct fw_node, link);
 163 }
 164
 165 /**
 166  * build_tree - Build the tree representation of the topology
 167  * @self_ids: array of self IDs to create the tree from
 168  * @self_id_count: the length of the self_ids array
 169  * @local_id: the node ID of the local node
 170  *
 171  * This function builds the tree representation of the topology given
 172  * by the self IDs from the latest bus reset.  During the construction
 173  * of the tree, the function checks that the self IDs are valid and
 174  * internally consistent.  On succcess this function returns the
 175  * fw_node corresponding to the local card otherwise NULL.
 176  */
 177 static struct fw_node *build_tree(struct fw_card *card,
 178                                   u32 *sid, int self_id_count)
 179 {
 180         struct fw_node *node, *child, *local_node, *irm_node;
 181         struct list_head stack, *h;
 182         u32 *next_sid, *end, q;
 183         int i, port_count, child_port_count, phy_id, parent_count, stack_depth;
 184         int gap_count;
 185         bool beta_repeaters_present;
 186
 187         local_node = NULL;
 188         node = NULL;
 189         INIT_LIST_HEAD(&stack);
 190         stack_depth = 0;
 191         end = sid + self_id_count;
 192         phy_id = 0;
 193         irm_node = NULL;
 194         gap_count = SELF_ID_GAP_COUNT(*sid);
 195         beta_repeaters_present = false;
 196
 197         while (sid < end) {
 198                 next_sid = count_ports(sid, &port_count, &child_port_count);
 199
 200                 if (next_sid == NULL) {
 201                         fw_error("Inconsistent extended self IDs.\n");
 202                         return NULL;
 203                 }
 204
 205                 q = *sid;
 206                 if (phy_id != SELF_ID_PHY_ID(q)) {
 207                         fw_error("PHY ID mismatch in self ID: %d != %d.\n",
 208                                  phy_id, SELF_ID_PHY_ID(q));
 209                         return NULL;
 210                 }
 211
 212                 if (child_port_count > stack_depth) {
 213                         fw_error("Topology stack underflow\n");
 214                         return NULL;
 215                 }
 216
 217                 /*
 218                  * Seek back from the top of our stack to find the
 219                  * start of the child nodes for this node.
 220                  */
 221                 for (i = 0, h = &stack; i < child_port_count; i++)
 222                         h = h->prev;
 223                 /*
 224                  * When the stack is empty, this yields an invalid value,
 225                  * but that pointer will never be dereferenced.
 226                  */
 227                 child = fw_node(h);
 228
 229                 node = fw_node_create(q, port_count, card->color);
 230                 if (node == NULL) {
 231                         fw_error("Out of memory while building topology.\n");
 232                         return NULL;
 233                 }
 234
 235                 if (phy_id == (card->node_id & 0x3f))
 236                         local_node = node;
 237
 238                 if (SELF_ID_CONTENDER(q))
 239                         irm_node = node;
 240
 241                 parent_count = 0;
 242
 243                 for (i = 0; i < port_count; i++) {
 244                         switch (get_port_type(sid, i)) {
 245                         case SELFID_PORT_PARENT:
 246                                 /*
 247                                  * Who's your daddy?  We dont know the
 248                                  * parent node at this time, so we
 249                                  * temporarily abuse node->color for
 250                                  * remembering the entry in the
 251                                  * node->ports array where the parent
 252                                  * node should be.  Later, when we
 253                                  * handle the parent node, we fix up
 254                                  * the reference.
 255                                  */
 256                                 parent_count++;
 257                                 node->color = i;
 258                                 break;
 259
 260                         case SELFID_PORT_CHILD:
 261                                 node->ports[i] = child;
 262                                 /*
 263                                  * Fix up parent reference for this
 264                                  * child node.
 265                                  */
 266                                 child->ports[child->color] = node;
 267                                 child->color = card->color;
 268                                 child = fw_node(child->link.next);
 269                                 break;
 270                         }
 271                 }
 272
 273                 /*
 274                  * Check that the node reports exactly one parent
 275                  * port, except for the root, which of course should
 276                  * have no parents.
 277                  */
 278                 if ((next_sid == end && parent_count != 0) ||
 279                     (next_sid < end && parent_count != 1)) {
 280                         fw_error("Parent port inconsistency for node %d: "
 281                                  "parent_count=%d\n", phy_id, parent_count);
 282                         return NULL;
 283                 }
 284
 285                 /* Pop the child nodes off the stack and push the new node. */
 286                 __list_del(h->prev, &stack);
 287                 list_add_tail(&node->link, &stack);
 288                 stack_depth += 1 - child_port_count;
 289
 290                 if (node->phy_speed == SCODE_BETA &&
 291                     parent_count + child_port_count > 1)
 292                         beta_repeaters_present = true;
 293
 294                 /*
 295                  * If all PHYs does not report the same gap count
 296                  * setting, we fall back to 63 which will force a gap
 297                  * count reconfiguration and a reset.
 298                  */
 299                 if (SELF_ID_GAP_COUNT(q) != gap_count)
 300                         gap_count = 63;
 301
 302                 update_hop_count(node);
 303
 304                 sid = next_sid;
 305                 phy_id++;
 306         }
 307
 308         card->root_node = node;
 309         card->irm_node = irm_node;
 310         card->gap_count = gap_count;
 311         card->beta_repeaters_present = beta_repeaters_present;
 312
 313         return local_node;
 314 }
 315
 316 typedef void (*fw_node_callback_t)(struct fw_card * card,
 317                                    struct fw_node * node,
 318                                    struct fw_node * parent);
 319
 320 static void
 321 for_each_fw_node(struct fw_card *card, struct fw_node *root,
 322                  fw_node_callback_t callback)
 323 {
 324         struct list_head list;
 325         struct fw_node *node, *next, *child, *parent;
 326         int i;
 327
 328         INIT_LIST_HEAD(&list);
 329
 330         fw_node_get(root);
 331         list_add_tail(&root->link, &list);
 332         parent = NULL;
 333         list_for_each_entry(node, &list, link) {
 334                 node->color = card->color;
 335
 336                 for (i = 0; i < node->port_count; i++) {
 337                         child = node->ports[i];
 338                         if (!child)
 339                                 continue;
 340                         if (child->color == card->color)
 341                                 parent = child;
 342                         else {
 343                                 fw_node_get(child);
 344                                 list_add_tail(&child->link, &list);
 345                         }
 346                 }
 347
 348                 callback(card, node, parent);
 349         }
 350
 351         list_for_each_entry_safe(node, next, &list, link)
 352                 fw_node_put(node);
 353 }
 354
 355 static void
 356 report_lost_node(struct fw_card *card,
 357                  struct fw_node *node, struct fw_node *parent)
 358 {
 359         fw_node_event(card, node, FW_NODE_DESTROYED);
 360         fw_node_put(node);
 361 }
 362
 363 static void
 364 report_found_node(struct fw_card *card,
 365                   struct fw_node *node, struct fw_node *parent)
 366 {
 367         int b_path = (node->phy_speed == SCODE_BETA);
 368
 369         if (parent != NULL) {
 370                 /* min() macro doesn't work here with gcc 3.4 */
 371                 node->max_speed = parent->max_speed < node->phy_speed ?
 372                                         parent->max_speed : node->phy_speed;
 373                 node->b_path = parent->b_path && b_path;
 374         } else {
 375                 node->max_speed = node->phy_speed;
 376                 node->b_path = b_path;
 377         }
 378
 379         fw_node_event(card, node, FW_NODE_CREATED);
 380 }
 381
 382 void fw_destroy_nodes(struct fw_card *card)
 383 {
 384         unsigned long flags;
 385
 386         spin_lock_irqsave(&card->lock, flags);
 387         card->color++;
 388         if (card->local_node != NULL)
 389                 for_each_fw_node(card, card->local_node, report_lost_node);
 390 <<<<<<< HEAD:drivers/firewire/fw-topology.c
 391 =======
 392         card->local_node = NULL;
 393 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:drivers/firewire/fw-topology.c
 394         spin_unlock_irqrestore(&card->lock, flags);
 395 }
 396
 397 static void move_tree(struct fw_node *node0, struct fw_node *node1, int port)
 398 {
 399         struct fw_node *tree;
 400         int i;
 401
 402         tree = node1->ports[port];
 403         node0->ports[port] = tree;
 404         for (i = 0; i < tree->port_count; i++) {
 405                 if (tree->ports[i] == node1) {
 406                         tree->ports[i] = node0;
 407                         break;
 408                 }
 409         }
 410 }
 411
 412 /**
 413  * update_tree - compare the old topology tree for card with the new
 414  * one specified by root.  Queue the nodes and mark them as either
 415  * found, lost or updated.  Update the nodes in the card topology tree
 416  * as we go.
 417  */
 418 static void
 419 update_tree(struct fw_card *card, struct fw_node *root)
 420 {
 421         struct list_head list0, list1;
 422         struct fw_node *node0, *node1;
 423         int i, event;
 424
 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);
 429
 430         node0 = fw_node(list0.next);
 431         node1 = fw_node(list1.next);
 432
 433         while (&node0->link != &list0) {
 434 <<<<<<< HEAD:drivers/firewire/fw-topology.c
 435 =======
 436                 WARN_ON(node0->port_count != node1->port_count);
 437 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:drivers/firewire/fw-topology.c
 438
 439 <<<<<<< HEAD:drivers/firewire/fw-topology.c
 440                 /* assert(node0->port_count == node1->port_count); */
 441 =======
 442 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:drivers/firewire/fw-topology.c
 443                 if (node0->link_on && !node1->link_on)
 444                         event = FW_NODE_LINK_OFF;
 445                 else if (!node0->link_on && node1->link_on)
 446                         event = FW_NODE_LINK_ON;
 447                 else
 448                         event = FW_NODE_UPDATED;
 449
 450                 node0->node_id = node1->node_id;
 451                 node0->color = card->color;
 452                 node0->link_on = node1->link_on;
 453                 node0->initiated_reset = node1->initiated_reset;
 454                 node0->max_hops = node1->max_hops;
 455                 node1->color = card->color;
 456                 fw_node_event(card, node0, event);
 457
 458                 if (card->root_node == node1)
 459                         card->root_node = node0;
 460                 if (card->irm_node == node1)
 461                         card->irm_node = node0;
 462
 463                 for (i = 0; i < node0->port_count; i++) {
 464                         if (node0->ports[i] && node1->ports[i]) {
 465                                 /*
 466                                  * This port didn't change, queue the
 467                                  * connected node for further
 468                                  * investigation.
 469                                  */
 470                                 if (node0->ports[i]->color == card->color)
 471                                         continue;
 472                                 list_add_tail(&node0->ports[i]->link, &list0);
 473                                 list_add_tail(&node1->ports[i]->link, &list1);
 474                         } else if (node0->ports[i]) {
 475                                 /*
 476                                  * The nodes connected here were
 477                                  * unplugged; unref the lost nodes and
 478                                  * queue FW_NODE_LOST callbacks for
 479                                  * them.
 480                                  */
 481
 482                                 for_each_fw_node(card, node0->ports[i],
 483                                                  report_lost_node);
 484                                 node0->ports[i] = NULL;
 485                         } else if (node1->ports[i]) {
 486                                 /*
 487                                  * One or more node were connected to
 488                                  * this port. Move the new nodes into
 489                                  * the tree and queue FW_NODE_CREATED
 490                                  * callbacks for them.
 491                                  */
 492                                 move_tree(node0, node1, i);
 493                                 for_each_fw_node(card, node0->ports[i],
 494                                                  report_found_node);
 495                         }
 496                 }
 497
 498                 node0 = fw_node(node0->link.next);
 499                 node1 = fw_node(node1->link.next);
 500         }
 501 }
 502
 503 static void
 504 update_topology_map(struct fw_card *card, u32 *self_ids, int self_id_count)
 505 {
 506         int node_count;
 507
 508         card->topology_map[1]++;
 509         node_count = (card->root_node->node_id & 0x3f) + 1;
 510         card->topology_map[2] = (node_count << 16) | self_id_count;
 511         card->topology_map[0] = (self_id_count + 2) << 16;
 512         memcpy(&card->topology_map[3], self_ids, self_id_count * 4);
 513         fw_compute_block_crc(card->topology_map);
 514 }
 515
 516 void
 517 fw_core_handle_bus_reset(struct fw_card *card,
 518                          int node_id, int generation,
 519                          int self_id_count, u32 * self_ids)
 520 {
 521         struct fw_node *local_node;
 522         unsigned long flags;
 523
 524         fw_flush_transactions(card);
 525
 526         spin_lock_irqsave(&card->lock, flags);
 527
 528         /*
 529          * If the new topology has a different self_id_count the topology
 530          * changed, either nodes were added or removed. In that case we
 531          * reset the IRM reset counter.
 532          */
 533         if (card->self_id_count != self_id_count)
 534                 card->bm_retries = 0;
 535
 536         card->node_id = node_id;
 537         /*
 538          * Update node_id before generation to prevent anybody from using
 539          * a stale node_id together with a current generation.
 540          */
 541         smp_wmb();
 542         card->generation = generation;
 543         card->reset_jiffies = jiffies;
 544         schedule_delayed_work(&card->work, 0);
 545
 546         local_node = build_tree(card, self_ids, self_id_count);
 547
 548         update_topology_map(card, self_ids, self_id_count);
 549
 550         card->color++;
 551
 552         if (local_node == NULL) {
 553                 fw_error("topology build failed\n");
 554                 /* FIXME: We need to issue a bus reset in this case. */
 555         } else if (card->local_node == NULL) {
 556                 card->local_node = local_node;
 557                 for_each_fw_node(card, local_node, report_found_node);
 558         } else {
 559                 update_tree(card, local_node);
 560         }
 561
 562         spin_unlock_irqrestore(&card->lock, flags);
 563 }
 564 EXPORT_SYMBOL(fw_core_handle_bus_reset);