1 files changed, 572 insertions, 0 deletions

diff --git a/drivers/firewire/core-topology.c b/drivers/firewire/core-topology.c
new file mode 100644
index 000000000000..fddf2b358936
--- /dev/null
+++ b/drivers/firewire/core-topology.c
@@ -0,0 +1,572 @@
+/*
+ * Incremental bus scan, based on bus topology
+ *
+ * Copyright (C) 2004-2006 Kristian Hoegsberg <krh@bitplanet.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <linux/bug.h>
+#include <linux/errno.h>
+#include <linux/firewire.h>
+#include <linux/firewire-constants.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+
+#include <asm/atomic.h>
+#include <asm/system.h>
+
+#include "core.h"
+
+#define SELF_ID_PHY_ID(q)               (((q) >> 24) & 0x3f)
+#define SELF_ID_EXTENDED(q)             (((q) >> 23) & 0x01)
+#define SELF_ID_LINK_ON(q)              (((q) >> 22) & 0x01)
+#define SELF_ID_GAP_COUNT(q)            (((q) >> 16) & 0x3f)
+#define SELF_ID_PHY_SPEED(q)            (((q) >> 14) & 0x03)
+#define SELF_ID_CONTENDER(q)            (((q) >> 11) & 0x01)
+#define SELF_ID_PHY_INITIATOR(q)        (((q) >>  1) & 0x01)
+#define SELF_ID_MORE_PACKETS(q)         (((q) >>  0) & 0x01)
+
+#define SELF_ID_EXT_SEQUENCE(q)         (((q) >> 20) & 0x07)
+
+#define SELFID_PORT_CHILD       0x3
+#define SELFID_PORT_PARENT      0x2
+#define SELFID_PORT_NCONN       0x1
+#define SELFID_PORT_NONE        0x0
+
+static u32 *count_ports(u32 *sid, int *total_port_count, int *child_port_count)
+{
+        u32 q;
+        int port_type, shift, seq;
+
+        *total_port_count = 0;
+        *child_port_count = 0;
+
+        shift = 6;
+        q = *sid;
+        seq = 0;
+
+        while (1) {
+                port_type = (q >> shift) & 0x03;
+                switch (port_type) {
+                case SELFID_PORT_CHILD:
+                        (*child_port_count)++;
+                case SELFID_PORT_PARENT:
+                case SELFID_PORT_NCONN:
+                        (*total_port_count)++;
+                case SELFID_PORT_NONE:
+                        break;
+                }
+
+                shift -= 2;
+                if (shift == 0) {
+                        if (!SELF_ID_MORE_PACKETS(q))
+                                return sid + 1;
+
+                        shift = 16;
+                        sid++;
+                        q = *sid;
+
+                        /*
+                         * Check that the extra packets actually are
+                         * extended self ID packets and that the
+                         * sequence numbers in the extended self ID
+                         * packets increase as expected.
+                         */
+
+                        if (!SELF_ID_EXTENDED(q) ||
+                            seq != SELF_ID_EXT_SEQUENCE(q))
+                                return NULL;
+
+                        seq++;
+                }
+        }
+}
+
+static int get_port_type(u32 *sid, int port_index)
+{
+        int index, shift;
+
+        index = (port_index + 5) / 8;
+        shift = 16 - ((port_index + 5) & 7) * 2;
+        return (sid[index] >> shift) & 0x03;
+}
+
+static struct fw_node *fw_node_create(u32 sid, int port_count, int color)
+{
+        struct fw_node *node;
+
+        node = kzalloc(sizeof(*node) + port_count * sizeof(node->ports[0]),
+                       GFP_ATOMIC);
+        if (node == NULL)
+                return NULL;
+
+        node->color = color;
+        node->node_id = LOCAL_BUS | SELF_ID_PHY_ID(sid);
+        node->link_on = SELF_ID_LINK_ON(sid);
+        node->phy_speed = SELF_ID_PHY_SPEED(sid);
+        node->initiated_reset = SELF_ID_PHY_INITIATOR(sid);
+        node->port_count = port_count;
+
+        atomic_set(&node->ref_count, 1);
+        INIT_LIST_HEAD(&node->link);
+
+        return node;
+}
+
+/*
+ * Compute the maximum hop count for this node and it's children.  The
+ * maximum hop count is the maximum number of connections between any
+ * two nodes in the subtree rooted at this node.  We need this for
+ * setting the gap count.  As we build the tree bottom up in
+ * build_tree() below, this is fairly easy to do: for each node we
+ * maintain the max hop count and the max depth, ie the number of hops
+ * to the furthest leaf.  Computing the max hop count breaks down into
+ * two cases: either the path goes through this node, in which case
+ * the hop count is the sum of the two biggest child depths plus 2.
+ * Or it could be the case that the max hop path is entirely
+ * containted in a child tree, in which case the max hop count is just
+ * the max hop count of this child.
+ */
+static void update_hop_count(struct fw_node *node)
+{
+        int depths[2] = { -1, -1 };
+        int max_child_hops = 0;
+        int i;
+
+        for (i = 0; i < node->port_count; i++) {
+                if (node->ports[i] == NULL)
+                        continue;
+
+                if (node->ports[i]->max_hops > max_child_hops)
+                        max_child_hops = node->ports[i]->max_hops;
+
+                if (node->ports[i]->max_depth > depths[0]) {
+                        depths[1] = depths[0];
+                        depths[0] = node->ports[i]->max_depth;
+                } else if (node->ports[i]->max_depth > depths[1])
+                        depths[1] = node->ports[i]->max_depth;
+        }
+
+        node->max_depth = depths[0] + 1;
+        node->max_hops = max(max_child_hops, depths[0] + depths[1] + 2);
+}
+
+static inline struct fw_node *fw_node(struct list_head *l)
+{
+        return list_entry(l, struct fw_node, link);
+}
+
+/**
+ * build_tree - Build the tree representation of the topology
+ * @self_ids: array of self IDs to create the tree from
+ * @self_id_count: the length of the self_ids array
+ * @local_id: the node ID of the local node
+ *
+ * This function builds the tree representation of the topology given
+ * by the self IDs from the latest bus reset.  During the construction
+ * of the tree, the function checks that the self IDs are valid and
+ * internally consistent.  On succcess this function returns the
+ * fw_node corresponding to the local card otherwise NULL.
+ */
+static struct fw_node *build_tree(struct fw_card *card,
+                                  u32 *sid, int self_id_count)
+{
+        struct fw_node *node, *child, *local_node, *irm_node;
+        struct list_head stack, *h;
+        u32 *next_sid, *end, q;
+        int i, port_count, child_port_count, phy_id, parent_count, stack_depth;
+        int gap_count;
+        bool beta_repeaters_present;
+
+        local_node = NULL;
+        node = NULL;
+        INIT_LIST_HEAD(&stack);
+        stack_depth = 0;
+        end = sid + self_id_count;
+        phy_id = 0;
+        irm_node = NULL;
+        gap_count = SELF_ID_GAP_COUNT(*sid);
+        beta_repeaters_present = false;
+
+        while (sid < end) {
+                next_sid = count_ports(sid, &port_count, &child_port_count);
+
+                if (next_sid == NULL) {
+                        fw_error("Inconsistent extended self IDs.\n");
+                        return NULL;
+                }
+
+                q = *sid;
+                if (phy_id != SELF_ID_PHY_ID(q)) {
+                        fw_error("PHY ID mismatch in self ID: %d != %d.\n",
+                                 phy_id, SELF_ID_PHY_ID(q));
+                        return NULL;
+                }
+
+                if (child_port_count > stack_depth) {
+                        fw_error("Topology stack underflow\n");
+                        return NULL;
+                }
+
+                /*
+                 * Seek back from the top of our stack to find the
+                 * start of the child nodes for this node.
+                 */
+                for (i = 0, h = &stack; i < child_port_count; i++)
+                        h = h->prev;
+                /*
+                 * When the stack is empty, this yields an invalid value,
+                 * but that pointer will never be dereferenced.
+                 */
+                child = fw_node(h);
+
+                node = fw_node_create(q, port_count, card->color);
+                if (node == NULL) {
+                        fw_error("Out of memory while building topology.\n");
+                        return NULL;
+                }
+
+                if (phy_id == (card->node_id & 0x3f))
+                        local_node = node;
+
+                if (SELF_ID_CONTENDER(q))
+                        irm_node = node;
+
+                parent_count = 0;
+
+                for (i = 0; i < port_count; i++) {
+                        switch (get_port_type(sid, i)) {
+                        case SELFID_PORT_PARENT:
+                                /*
+                                 * Who's your daddy?  We dont know the
+                                 * parent node at this time, so we
+                                 * temporarily abuse node->color for
+                                 * remembering the entry in the
+                                 * node->ports array where the parent
+                                 * node should be.  Later, when we
+                                 * handle the parent node, we fix up
+                                 * the reference.
+                                 */
+                                parent_count++;
+                                node->color = i;
+                                break;
+
+                        case SELFID_PORT_CHILD:
+                                node->ports[i] = child;
+                                /*
+                                 * Fix up parent reference for this
+                                 * child node.
+                                 */
+                                child->ports[child->color] = node;
+                                child->color = card->color;
+                                child = fw_node(child->link.next);
+                                break;
+                        }
+                }
+
+                /*
+                 * Check that the node reports exactly one parent
+                 * port, except for the root, which of course should
+                 * have no parents.
+                 */
+                if ((next_sid == end && parent_count != 0) ||
+                    (next_sid < end && parent_count != 1)) {
+                        fw_error("Parent port inconsistency for node %d: "
+                                 "parent_count=%d\n", phy_id, parent_count);
+                        return NULL;
+                }
+
+                /* Pop the child nodes off the stack and push the new node. */
+                __list_del(h->prev, &stack);
+                list_add_tail(&node->link, &stack);
+                stack_depth += 1 - child_port_count;
+
+                if (node->phy_speed == SCODE_BETA &&
+                    parent_count + child_port_count > 1)
+                        beta_repeaters_present = true;
+
+                /*
+                 * If PHYs report different gap counts, set an invalid count
+                 * which will force a gap count reconfiguration and a reset.
+                 */
+                if (SELF_ID_GAP_COUNT(q) != gap_count)
+                        gap_count = 0;
+
+                update_hop_count(node);
+
+                sid = next_sid;
+                phy_id++;
+        }
+
+        card->root_node = node;
+        card->irm_node = irm_node;
+        card->gap_count = gap_count;
+        card->beta_repeaters_present = beta_repeaters_present;
+
+        return local_node;
+}
+
+typedef void (*fw_node_callback_t)(struct fw_card * card,
+                                   struct fw_node * node,
+                                   struct fw_node * parent);
+
+static void for_each_fw_node(struct fw_card *card, struct fw_node *root,
+                             fw_node_callback_t callback)
+{
+        struct list_head list;
+        struct fw_node *node, *next, *child, *parent;
+        int i;
+
+        INIT_LIST_HEAD(&list);
+
+        fw_node_get(root);
+        list_add_tail(&root->link, &list);
+        parent = NULL;
+        list_for_each_entry(node, &list, link) {
+                node->color = card->color;
+
+                for (i = 0; i < node->port_count; i++) {
+                        child = node->ports[i];
+                        if (!child)
+                                continue;
+                        if (child->color == card->color)
+                                parent = child;
+                        else {
+                                fw_node_get(child);
+                                list_add_tail(&child->link, &list);
+                        }
+                }
+
+                callback(card, node, parent);
+        }
+
+        list_for_each_entry_safe(node, next, &list, link)
+                fw_node_put(node);
+}
+
+static void report_lost_node(struct fw_card *card,
+                             struct fw_node *node, struct fw_node *parent)
+{
+        fw_node_event(card, node, FW_NODE_DESTROYED);
+        fw_node_put(node);
+
+        /* Topology has changed - reset bus manager retry counter */
+        card->bm_retries = 0;
+}
+
+static void report_found_node(struct fw_card *card,
+                              struct fw_node *node, struct fw_node *parent)
+{
+        int b_path = (node->phy_speed == SCODE_BETA);
+
+        if (parent != NULL) {
+                /* min() macro doesn't work here with gcc 3.4 */
+                node->max_speed = parent->max_speed < node->phy_speed ?
+                                        parent->max_speed : node->phy_speed;
+                node->b_path = parent->b_path && b_path;
+        } else {
+                node->max_speed = node->phy_speed;
+                node->b_path = b_path;
+        }
+
+        fw_node_event(card, node, FW_NODE_CREATED);
+
+        /* Topology has changed - reset bus manager retry counter */
+        card->bm_retries = 0;
+}
+
+void fw_destroy_nodes(struct fw_card *card)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&card->lock, flags);
+        card->color++;
+        if (card->local_node != NULL)
+                for_each_fw_node(card, card->local_node, report_lost_node);
+        card->local_node = NULL;
+        spin_unlock_irqrestore(&card->lock, flags);
+}
+
+static void move_tree(struct fw_node *node0, struct fw_node *node1, int port)
+{
+        struct fw_node *tree;
+        int i;
+
+        tree = node1->ports[port];
+        node0->ports[port] = tree;
+        for (i = 0; i < tree->port_count; i++) {
+                if (tree->ports[i] == node1) {
+                        tree->ports[i] = node0;
+                        break;
+                }
+        }
+}
+
+/**
+ * update_tree - compare the old topology tree for card with the new
+ * one specified by root.  Queue the nodes and mark them as either
+ * found, lost or updated.  Update the nodes in the card topology tree
+ * as we go.
+ */
+static void update_tree(struct fw_card *card, struct fw_node *root)
+{
+        struct list_head list0, list1;
+        struct fw_node *node0, *node1, *next1;
+        int i, event;
+
+        INIT_LIST_HEAD(&list0);
+        list_add_tail(&card->local_node->link, &list0);
+        INIT_LIST_HEAD(&list1);
+        list_add_tail(&root->link, &list1);
+
+        node0 = fw_node(list0.next);
+        node1 = fw_node(list1.next);
+
+        while (&node0->link != &list0) {
+                WARN_ON(node0->port_count != node1->port_count);
+
+                if (node0->link_on && !node1->link_on)
+                        event = FW_NODE_LINK_OFF;
+                else if (!node0->link_on && node1->link_on)
+                        event = FW_NODE_LINK_ON;
+                else if (node1->initiated_reset && node1->link_on)
+                        event = FW_NODE_INITIATED_RESET;
+                else
+                        event = FW_NODE_UPDATED;
+
+                node0->node_id = node1->node_id;
+                node0->color = card->color;
+                node0->link_on = node1->link_on;
+                node0->initiated_reset = node1->initiated_reset;
+                node0->max_hops = node1->max_hops;
+                node1->color = card->color;
+                fw_node_event(card, node0, event);
+
+                if (card->root_node == node1)
+                        card->root_node = node0;
+                if (card->irm_node == node1)
+                        card->irm_node = node0;
+
+                for (i = 0; i < node0->port_count; i++) {
+                        if (node0->ports[i] && node1->ports[i]) {
+                                /*
+                                 * This port didn't change, queue the
+                                 * connected node for further
+                                 * investigation.
+                                 */
+                                if (node0->ports[i]->color == card->color)
+                                        continue;
+                                list_add_tail(&node0->ports[i]->link, &list0);
+                                list_add_tail(&node1->ports[i]->link, &list1);
+                        } else if (node0->ports[i]) {
+                                /*
+                                 * The nodes connected here were
+                                 * unplugged; unref the lost nodes and
+                                 * queue FW_NODE_LOST callbacks for
+                                 * them.
+                                 */
+
+                                for_each_fw_node(card, node0->ports[i],
+                                                 report_lost_node);
+                                node0->ports[i] = NULL;
+                        } else if (node1->ports[i]) {
+                                /*
+                                 * One or more node were connected to
+                                 * this port. Move the new nodes into
+                                 * the tree and queue FW_NODE_CREATED
+                                 * callbacks for them.
+                                 */
+                                move_tree(node0, node1, i);
+                                for_each_fw_node(card, node0->ports[i],
+                                                 report_found_node);
+                        }
+                }
+
+                node0 = fw_node(node0->link.next);
+                next1 = fw_node(node1->link.next);
+                fw_node_put(node1);
+                node1 = next1;
+        }
+}
+
+static void update_topology_map(struct fw_card *card,
+                                u32 *self_ids, int self_id_count)
+{
+        int node_count;
+
+        card->topology_map[1]++;
+        node_count = (card->root_node->node_id & 0x3f) + 1;
+        card->topology_map[2] = (node_count << 16) | self_id_count;
+        card->topology_map[0] = (self_id_count + 2) << 16;
+        memcpy(&card->topology_map[3], self_ids, self_id_count * 4);
+        fw_compute_block_crc(card->topology_map);
+}
+
+void fw_core_handle_bus_reset(struct fw_card *card, int node_id, int generation,
+                              int self_id_count, u32 *self_ids)
+{
+        struct fw_node *local_node;
+        unsigned long flags;
+
+        /*
+         * If the selfID buffer is not the immediate successor of the
+         * previously processed one, we cannot reliably compare the
+         * old and new topologies.
+         */
+        if (!is_next_generation(generation, card->generation) &&
+            card->local_node != NULL) {
+                fw_notify("skipped bus generations, destroying all nodes\n");
+                fw_destroy_nodes(card);
+                card->bm_retries = 0;
+        }
+
+        spin_lock_irqsave(&card->lock, flags);
+
+        card->broadcast_channel_allocated = false;
+        card->node_id = node_id;
+        /*
+         * Update node_id before generation to prevent anybody from using
+         * a stale node_id together with a current generation.
+         */
+        smp_wmb();
+        card->generation = generation;
+        card->reset_jiffies = jiffies;
+        fw_schedule_bm_work(card, 0);
+
+        local_node = build_tree(card, self_ids, self_id_count);
+
+        update_topology_map(card, self_ids, self_id_count);
+
+        card->color++;
+
+        if (local_node == NULL) {
+                fw_error("topology build failed\n");
+                /* FIXME: We need to issue a bus reset in this case. */
+        } else if (card->local_node == NULL) {
+                card->local_node = local_node;
+                for_each_fw_node(card, local_node, report_found_node);
+        } else {
+                update_tree(card, local_node);
+        }
+
+        spin_unlock_irqrestore(&card->lock, flags);
+}
+EXPORT_SYMBOL(fw_core_handle_bus_reset);