drivers/firewire/fw-topology.c

   1 /*                                              -*- c-basic-offset: 8 -*-
   2  *
   3  * fw-topology.c - Incremental bus scan, based on bus topology
   4  *
   5  * Copyright (C) 2004-2006 Kristian Hoegsberg <krh@bitplanet.net>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software Foundation,
  19  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  20  */
  21
  22 #include <linux/module.h>
  23 #include <linux/wait.h>
  24 #include <linux/errno.h>
  25 #include "fw-transaction.h"
  26 #include "fw-topology.h"
  27
  28 #define self_id_phy_id(q)               (((q) >> 24) & 0x3f)
  29 #define self_id_extended(q)             (((q) >> 23) & 0x01)
  30 #define self_id_link_on(q)              (((q) >> 22) & 0x01)
  31 #define self_id_gap_count(q)            (((q) >> 16) & 0x3f)
  32 #define self_id_phy_speed(q)            (((q) >> 14) & 0x03)
  33 #define self_id_contender(q)            (((q) >> 11) & 0x01)
  34 #define self_id_phy_initiator(q)        (((q) >>  1) & 0x01)
  35 #define self_id_more_packets(q)         (((q) >>  0) & 0x01)
  36
  37 #define self_id_ext_sequence(q)         (((q) >> 20) & 0x07)
  38
  39 static u32 *count_ports(u32 *sid, int *total_port_count, int *child_port_count)
  40 {
  41         u32 q;
  42         int port_type, shift, seq;
  43
  44         *total_port_count = 0;
  45         *child_port_count = 0;
  46
  47         shift = 6;
  48         q = *sid;
  49         seq = 0;
  50
  51         while (1) {
  52                 port_type = (q >> shift) & 0x03;
  53                 switch (port_type) {
  54                 case SELFID_PORT_CHILD:
  55                         (*child_port_count)++;
  56                 case SELFID_PORT_PARENT:
  57                 case SELFID_PORT_NCONN:
  58                         (*total_port_count)++;
  59                 case SELFID_PORT_NONE:
  60                         break;
  61                 }
  62
  63                 shift -= 2;
  64                 if (shift == 0) {
  65                         if (!self_id_more_packets(q))
  66                                 return sid + 1;
  67
  68                         shift = 16;
  69                         sid++;
  70                         q = *sid;
  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                         if (!self_id_extended(q) ||
  78                             seq != self_id_ext_sequence(q))
  79                                 return NULL;
  80
  81                         seq++;
  82                 }
  83         }
  84 }
  85
  86 static int get_port_type(u32 *sid, int port_index)
  87 {
  88         int index, shift;
  89
  90         index = (port_index + 5) / 8;
  91         shift = 16 - ((port_index + 5) & 7) * 2;
  92         return (sid[index] >> shift) & 0x03;
  93 }
  94
  95 struct fw_node *fw_node_create(u32 sid, int port_count, int color)
  96 {
  97         struct fw_node *node;
  98
  99         node = kzalloc(sizeof *node + port_count * sizeof node->ports[0],
 100                        GFP_ATOMIC);
 101         if (node == NULL)
 102                 return NULL;
 103
 104         node->color = color;
 105         node->node_id = self_id_phy_id(sid);
 106         node->link_on = self_id_link_on(sid);
 107         node->phy_speed = self_id_phy_speed(sid);
 108         node->port_count = port_count;
 109
 110         atomic_set(&node->ref_count, 1);
 111         INIT_LIST_HEAD(&node->link);
 112
 113         return node;
 114 }
 115
 116 /**
 117  * build_tree - Build the tree representation of the topology
 118  * @self_ids: array of self IDs to create the tree from
 119  * @self_id_count: the length of the self_ids array
 120  * @local_id: the node ID of the local node
 121  *
 122  * This function builds the tree representation of the topology given
 123  * by the self IDs from the latest bus reset.  During the construction
 124  * of the tree, the function checks that the self IDs are valid and
 125  * internally consistent.  On succcess this funtions returns the
 126  * fw_node corresponding to the local card otherwise NULL.
 127  */
 128 static struct fw_node *build_tree(struct fw_card *card)
 129 {
 130         struct fw_node *node, *child, *local_node;
 131         struct list_head stack, *h;
 132         u32 *sid, *next_sid, *end, q;
 133         int i, port_count, child_port_count, phy_id, parent_count, stack_depth;
 134
 135         local_node = NULL;
 136         node = NULL;
 137         INIT_LIST_HEAD(&stack);
 138         stack_depth = 0;
 139         sid = card->self_ids;
 140         end = sid + card->self_id_count;
 141         phy_id = 0;
 142         card->irm_node = NULL;
 143
 144         while (sid < end) {
 145                 next_sid = count_ports(sid, &port_count, &child_port_count);
 146
 147                 if (next_sid == NULL) {
 148                         fw_error("Inconsistent extended self IDs.\n");
 149                         return NULL;
 150                 }
 151
 152                 q = *sid;
 153                 if (phy_id != self_id_phy_id(q)) {
 154                         fw_error("PHY ID mismatch in self ID: %d != %d.\n",
 155                                  phy_id, self_id_phy_id(q));
 156                         return NULL;
 157                 }
 158
 159                 if (child_port_count > stack_depth) {
 160                         fw_error("Topology stack underflow\n");
 161                         return NULL;
 162                 }
 163
 164                 /* Seek back from the top of our stack to find the
 165                  * start of the child nodes for this node. */
 166                 for (i = 0, h = &stack; i < child_port_count; i++)
 167                         h = h->prev;
 168                 child = fw_node(h);
 169
 170                 node = fw_node_create(q, port_count, card->color);
 171                 if (node == NULL) {
 172                         fw_error("Out of memory while building topology.");
 173                         return NULL;
 174                 }
 175
 176                 if (phy_id == (card->node_id & 0x3f))
 177                         local_node = node;
 178
 179                 if (self_id_contender(q))
 180                         card->irm_node = node;
 181
 182                 parent_count = 0;
 183
 184                 for (i = 0; i < port_count; i++) {
 185                         switch (get_port_type(sid, i)) {
 186                         case SELFID_PORT_PARENT:
 187                                 /* Who's your daddy?  We dont know the
 188                                  * parent node at this time, so we
 189                                  * temporarily abuse node->color for
 190                                  * remembering the entry in the
 191                                  * node->ports array where the parent
 192                                  * node should be.  Later, when we
 193                                  * handle the parent node, we fix up
 194                                  * the reference.
 195                                  */
 196                                 parent_count++;
 197                                 node->color = i;
 198                                 break;
 199
 200                         case SELFID_PORT_CHILD:
 201                                 node->ports[i].node = child;
 202                                 /* Fix up parent reference for this
 203                                  * child node. */
 204                                 child->ports[child->color].node = node;
 205                                 child->color = card->color;
 206                                 child = fw_node(child->link.next);
 207                                 break;
 208                         }
 209                 }
 210
 211                 /* Check that the node reports exactly one parent
 212                  * port, except for the root, which of course should
 213                  * have no parents. */
 214                 if ((next_sid == end && parent_count != 0) ||
 215                     (next_sid < end && parent_count != 1)) {
 216                         fw_error("Parent port inconsistency for node %d: "
 217                                  "parent_count=%d\n", phy_id, parent_count);
 218                         return NULL;
 219                 }
 220
 221                 /* Pop the child nodes off the stack and push the new node. */
 222                 __list_del(h->prev, &stack);
 223                 list_add_tail(&node->link, &stack);
 224                 stack_depth += 1 - child_port_count;
 225
 226                 sid = next_sid;
 227                 phy_id++;
 228         }
 229
 230         card->root_node = node;
 231
 232         return local_node;
 233 }
 234
 235 typedef void (*fw_node_callback_t) (struct fw_card * card,
 236                                     struct fw_node * node,
 237                                     struct fw_node * parent);
 238
 239 static void
 240 for_each_fw_node(struct fw_card *card, struct fw_node *root,
 241                  fw_node_callback_t callback)
 242 {
 243         struct list_head list;
 244         struct fw_node *node, *next, *child, *parent;
 245         int i;
 246
 247         INIT_LIST_HEAD(&list);
 248
 249         fw_node_get(root);
 250         list_add_tail(&root->link, &list);
 251         parent = NULL;
 252         list_for_each_entry(node, &list, link) {
 253                 node->color = card->color;
 254
 255                 for (i = 0; i < node->port_count; i++) {
 256                         child = node->ports[i].node;
 257                         if (!child)
 258                                 continue;
 259                         if (child->color == card->color)
 260                                 parent = child;
 261                         else {
 262                                 fw_node_get(child);
 263                                 list_add_tail(&child->link, &list);
 264                         }
 265                 }
 266
 267                 callback(card, node, parent);
 268         }
 269
 270         list_for_each_entry_safe(node, next, &list, link)
 271                 fw_node_put(node);
 272 }
 273
 274 static void
 275 report_lost_node(struct fw_card *card,
 276                  struct fw_node *node, struct fw_node *parent)
 277 {
 278         fw_node_event(card, node, FW_NODE_DESTROYED);
 279         fw_node_put(node);
 280 }
 281
 282 static void
 283 report_found_node(struct fw_card *card,
 284                   struct fw_node *node, struct fw_node *parent)
 285 {
 286         int b_path = (node->phy_speed == SCODE_BETA);
 287
 288         if (parent != NULL) {
 289                 node->max_speed = min(parent->max_speed, node->phy_speed);
 290                 node->b_path = parent->b_path && b_path;
 291         } else {
 292                 node->max_speed = node->phy_speed;
 293                 node->b_path = b_path;
 294         }
 295
 296         fw_node_event(card, node, FW_NODE_CREATED);
 297 }
 298
 299 void fw_destroy_nodes(struct fw_card *card)
 300 {
 301         unsigned long flags;
 302
 303         spin_lock_irqsave(&card->lock, flags);
 304         card->color++;
 305         if (card->local_node != NULL)
 306                 for_each_fw_node(card, card->local_node, report_lost_node);
 307         spin_unlock_irqrestore(&card->lock, flags);
 308 }
 309
 310 static void move_tree(struct fw_node *node0, struct fw_node *node1, int port)
 311 {
 312         struct fw_node *tree;
 313         int i;
 314
 315         tree = node1->ports[port].node;
 316         node0->ports[port].node = tree;
 317         for (i = 0; i < tree->port_count; i++) {
 318                 if (tree->ports[i].node == node1) {
 319                         tree->ports[i].node = node0;
 320                         break;
 321                 }
 322         }
 323 }
 324
 325 /**
 326  * update_tree - compare the old topology tree for card with the new
 327  * one specified by root.  Queue the nodes and mark them as either
 328  * found, lost or updated.  Update the nodes in the card topology tree
 329  * as we go.
 330  */
 331 static void
 332 update_tree(struct fw_card *card, struct fw_node *root, int *changed)
 333 {
 334         struct list_head list0, list1;
 335         struct fw_node *node0, *node1;
 336         int i, event;
 337
 338         INIT_LIST_HEAD(&list0);
 339         list_add_tail(&card->local_node->link, &list0);
 340         INIT_LIST_HEAD(&list1);
 341         list_add_tail(&root->link, &list1);
 342
 343         node0 = fw_node(list0.next);
 344         node1 = fw_node(list1.next);
 345         *changed = 0;
 346
 347         while (&node0->link != &list0) {
 348
 349                 /* assert(node0->port_count == node1->port_count); */
 350                 if (node0->link_on && !node1->link_on)
 351                         event = FW_NODE_LINK_OFF;
 352                 else if (!node0->link_on && node1->link_on)
 353                         event = FW_NODE_LINK_ON;
 354                 else
 355                         event = FW_NODE_UPDATED;
 356
 357                 node0->node_id = node1->node_id;
 358                 node0->color = card->color;
 359                 node0->link_on = node1->link_on;
 360                 node0->initiated_reset = node1->initiated_reset;
 361                 node1->color = card->color;
 362                 fw_node_event(card, node0, event);
 363
 364                 if (card->root_node == node1)
 365                         card->root_node = node0;
 366                 if (card->irm_node == node1)
 367                         card->irm_node = node0;
 368
 369                 for (i = 0; i < node0->port_count; i++) {
 370                         if (node0->ports[i].node && node1->ports[i].node) {
 371                                 /* This port didn't change, queue the
 372                                  * connected node for further
 373                                  * investigation. */
 374                                 if (node0->ports[i].node->color == card->color)
 375                                         continue;
 376                                 list_add_tail(&node0->ports[i].node->link,
 377                                               &list0);
 378                                 list_add_tail(&node1->ports[i].node->link,
 379                                               &list1);
 380                         } else if (node0->ports[i].node) {
 381                                 /* The nodes connected here were
 382                                  * unplugged; unref the lost nodes and
 383                                  * queue FW_NODE_LOST callbacks for
 384                                  * them. */
 385
 386                                 for_each_fw_node(card, node0->ports[i].node,
 387                                                  report_lost_node);
 388                                 node0->ports[i].node = NULL;
 389                                 *changed = 1;
 390                         } else if (node1->ports[i].node) {
 391                                 /* One or more node were connected to
 392                                  * this port. Move the new nodes into
 393                                  * the tree and queue FW_NODE_CREATED
 394                                  * callbacks for them. */
 395                                 move_tree(node0, node1, i);
 396                                 for_each_fw_node(card, node0->ports[i].node,
 397                                                  report_found_node);
 398                                 *changed = 1;
 399                         }
 400                 }
 401
 402                 node0 = fw_node(node0->link.next);
 403                 node1 = fw_node(node1->link.next);
 404         }
 405 }
 406
 407 void
 408 fw_core_handle_bus_reset(struct fw_card *card,
 409                          int node_id, int generation,
 410                          int self_id_count, u32 * self_ids)
 411 {
 412         struct fw_node *local_node;
 413         unsigned long flags;
 414         int changed;
 415
 416         fw_flush_transactions(card);
 417
 418         spin_lock_irqsave(&card->lock, flags);
 419
 420         card->node_id = node_id;
 421         card->self_id_count = self_id_count;
 422         card->generation = generation;
 423         memcpy(card->self_ids, self_ids, self_id_count * 4);
 424
 425         local_node = build_tree(card);
 426
 427         card->color++;
 428
 429         if (local_node == NULL) {
 430                 fw_error("topology build failed\n");
 431                 /* FIXME: We need to issue a bus reset in this case. */
 432         } else if (card->local_node == NULL) {
 433                 card->local_node = local_node;
 434                 for_each_fw_node(card, local_node, report_found_node);
 435         } else {
 436                 update_tree(card, local_node, &changed);
 437         }
 438
 439         spin_unlock_irqrestore(&card->lock, flags);
 440 }
 441
 442 EXPORT_SYMBOL(fw_core_handle_bus_reset);
 443
 444 void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
 445 {
 446 }