firewire: Add core firewire stack.

Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

1 files changed, 446 insertions, 0 deletions

diff --git a/drivers/firewire/fw-topology.c b/drivers/firewire/fw-topology.c
new file mode 100644
index 000000000000..2778aa3da8e4
--- /dev/null
+++ b/drivers/firewire/fw-topology.c
@@ -0,0 +1,446 @@
+/*                                              -*- c-basic-offset: 8 -*-
+ *
+ * fw-topology.c - 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/module.h>
+#include <linux/wait.h>
+#include <linux/errno.h>
+#include "fw-transaction.h"
+#include "fw-topology.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)
+
+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;
+}
+
+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 = self_id_phy_id(sid);
+        node->link_on = self_id_link_on(sid);
+        node->phy_speed = self_id_phy_speed(sid);
+        node->port_count = port_count;
+
+        atomic_set(&node->ref_count, 1);
+        INIT_LIST_HEAD(&node->link);
+
+        return node;
+}
+
+/**
+ * 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 funtions returns the
+ * fw_node corresponding to the local card otherwise NULL.
+ */
+static struct fw_node *build_tree(struct fw_card *card)
+{
+        struct fw_node *node, *child, *local_node;
+        struct list_head stack, *h;
+        u32 *sid, *next_sid, *end, q;
+        int i, port_count, child_port_count, phy_id, parent_count, stack_depth;
+
+        local_node = NULL;
+        node = NULL;
+        INIT_LIST_HEAD(&stack);
+        stack_depth = 0;
+        sid = card->self_ids;
+        end = sid + card->self_id_count;
+        phy_id = 0;
+        card->irm_node = NULL;
+
+        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;
+                child = fw_node(h);
+
+                node = fw_node_create(q, port_count, card->color);
+                if (node == NULL) {
+                        fw_error("Out of memory while building topology.");
+                        return NULL;
+                }
+
+                if (phy_id == (card->node_id & 0x3f))
+                        local_node = node;
+
+                if (self_id_contender(q))
+                        card->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].node = child;
+                                /* Fix up parent reference for this
+                                 * child node. */
+                                child->ports[child->color].node = 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;
+
+                sid = next_sid;
+                phy_id++;
+        }
+
+        card->root_node = node;
+
+        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].node;
+                        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);
+}
+
+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) {
+                node->max_speed = min(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);
+}
+
+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);
+        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].node;
+        node0->ports[port].node = tree;
+        for (i = 0; i < tree->port_count; i++) {
+                if (tree->ports[i].node == node1) {
+                        tree->ports[i].node = 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, int *changed)
+{
+        struct list_head list0, list1;
+        struct fw_node *node0, *node1;
+        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);
+        *changed = 0;
+
+        while (&node0->link != &list0) {
+
+                /* assert(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
+                        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;
+                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].node && node1->ports[i].node) {
+                                /* This port didn't change, queue the
+                                 * connected node for further
+                                 * investigation. */
+                                if (node0->ports[i].node->color == card->color)
+                                        continue;
+                                list_add_tail(&node0->ports[i].node->link,
+                                              &list0);
+                                list_add_tail(&node1->ports[i].node->link,
+                                              &list1);
+                        } else if (node0->ports[i].node) {
+                                /* 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].node,
+                                                 report_lost_node);
+                                node0->ports[i].node = NULL;
+                                *changed = 1;
+                        } else if (node1->ports[i].node) {
+                                /* 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].node,
+                                                 report_found_node);
+                                *changed = 1;
+                        }
+                }
+
+                node0 = fw_node(node0->link.next);
+                node1 = fw_node(node1->link.next);
+        }
+}
+
+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;
+        int changed;
+
+        fw_flush_transactions(card);
+
+        spin_lock_irqsave(&card->lock, flags);
+
+        card->node_id = node_id;
+        card->self_id_count = self_id_count;
+        card->generation = generation;
+        memcpy(card->self_ids, self_ids, self_id_count * 4);
+
+        local_node = build_tree(card);
+
+        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, &changed);
+        }
+
+        spin_unlock_irqrestore(&card->lock, flags);
+}
+
+EXPORT_SYMBOL(fw_core_handle_bus_reset);
+
+void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
+{
+}