1 files changed, 554 insertions, 0 deletions

diff --git a/drivers/firewire/core-topology.c b/drivers/firewire/core-topology.c
new file mode 100644
index 000000000..f40c81534
--- /dev/null
+++ b/drivers/firewire/core-topology.c
@@ -0,0 +1,554 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Incremental bus scan, based on bus topology
+ *
+ * Copyright (C) 2004-2006 Kristian Hoegsberg <krh@bitplanet.net>
+ */
+
+#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/atomic.h>
+#include <asm/byteorder.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)++;
+			fallthrough;
+		case SELFID_PORT_PARENT:
+		case SELFID_PORT_NCONN:
+			(*total_port_count)++;
+			fallthrough;
+		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(struct_size(node, ports, port_count), 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;
+
+	refcount_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);
+}
+
+/*
+ * 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 success 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_err(card, "inconsistent extended self IDs\n");
+			return NULL;
+		}
+
+		q = *sid;
+		if (phy_id != SELF_ID_PHY_ID(q)) {
+			fw_err(card, "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_err(card, "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_err(card, "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_err(card, "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;
+}
+
+/* Must be called with card->lock held */
+void fw_destroy_nodes(struct fw_card *card)
+{
+	card->color++;
+	if (card->local_node != NULL)
+		for_each_fw_node(card, card->local_node, report_lost_node);
+	card->local_node = NULL;
+}
+
+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;
+		}
+	}
+}
+
+/*
+ * 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->root_node->node_id & 0x3f) + 1;
+	__be32 *map = card->topology_map;
+
+	*map++ = cpu_to_be32((self_id_count + 2) << 16);
+	*map++ = cpu_to_be32(be32_to_cpu(card->topology_map[1]) + 1);
+	*map++ = cpu_to_be32((node_count << 16) | self_id_count);
+
+	while (self_id_count--)
+		*map++ = cpu_to_be32p(self_ids++);
+
+	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, bool bm_abdicate)
+{
+	struct fw_node *local_node;
+	unsigned long flags;
+
+	spin_lock_irqsave(&card->lock, 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_destroy_nodes(card);
+		card->bm_retries = 0;
+	}
+
+	card->broadcast_channel_allocated = card->broadcast_channel_auto_allocated;
+	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 = get_jiffies_64();
+	card->bm_node_id  = 0xffff;
+	card->bm_abdicate = bm_abdicate;
+	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_err(card, "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);