Date: Fri, 26 Jan 2007 00:37:50 -0500 From: Kristian =?utf-8?B?SMO4Z3NiZXJn?= Subject: [PATCH 1/10] firewire: Implement gap count optimization. Signed-off-by: Kristian Høgsberg Signed-off-by: Stefan Richter --- drivers/firewire/fw-card.c | 46 +++++++++++++++------- drivers/firewire/fw-topology.c | 76 ++++++++++++++++++++++++++++++++---- drivers/firewire/fw-topology.h | 15 +++++-- drivers/firewire/fw-transaction.c | 8 +++- drivers/firewire/fw-transaction.h | 6 ++- 5 files changed, 120 insertions(+), 31 deletions(-) diff --git a/drivers/firewire/fw-card.c b/drivers/firewire/fw-card.c index c8b7d69..307c8b8 100644 --- a/drivers/firewire/fw-card.c +++ b/drivers/firewire/fw-card.c @@ -186,14 +186,17 @@ fw_core_remove_descriptor (struct fw_descriptor *desc) } EXPORT_SYMBOL(fw_core_remove_descriptor); +static const char gap_count_table[] = { + 63, 5, 7, 8, 10, 13, 16, 18, 21, 24, 26, 29, 32, 35, 37, 40 +}; + static void fw_card_irm_work(struct work_struct *work) { - struct fw_card *card = - container_of(work, struct fw_card, work.work); + struct fw_card *card = container_of(work, struct fw_card, work.work); struct fw_device *root; unsigned long flags; - int new_irm_id, generation; + int root_id, new_irm_id, gap_count, generation, do_reset = 0; /* FIXME: This simple bus management unconditionally picks a * cycle master if the current root can't do it. We need to @@ -206,35 +209,50 @@ fw_card_irm_work(struct work_struct *work) generation = card->generation; root = card->root_node->data; + root_id = card->root_node->node_id; - if (root == NULL) + if (root == NULL) { /* Either link_on is false, or we failed to read the * config rom. In either case, pick another root. */ new_irm_id = card->local_node->node_id; - else if (root->state != FW_DEVICE_RUNNING) + } else if (root->state != FW_DEVICE_RUNNING) { /* If we haven't probed this device yet, bail out now * and let's try again once that's done. */ - new_irm_id = -1; - else if (root->config_rom[2] & bib_cmc) + new_irm_id = root_id; + } else if (root->config_rom[2] & bib_cmc) { /* FIXME: I suppose we should set the cmstr bit in the * STATE_CLEAR register of this node, as described in * 1394-1995, 8.4.2.6. Also, send out a force root * packet for this node. */ - new_irm_id = -1; - else + new_irm_id = root_id; + } else { /* Current root has an active link layer and we * successfully read the config rom, but it's not * cycle master capable. */ new_irm_id = card->local_node->node_id; + } + + /* Now figure out what gap count to set. */ + if (card->topology_type == FW_TOPOLOGY_A && + card->root_node->max_hops < ARRAY_SIZE(gap_count_table)) + gap_count = gap_count_table[card->root_node->max_hops]; + else + gap_count = 63; + + /* Finally, figure out if we should do a reset or not. If we've + * done less that 5 resets with the same physical topology and we + * have either a new root or a new gap count setting, let's do it. */ - if (card->irm_retries++ > 5) - new_irm_id = -1; + if (card->irm_retries++ < 5 && + (card->gap_count != gap_count || new_irm_id != root_id)) + do_reset = 1; spin_unlock_irqrestore(&card->lock, flags); - if (new_irm_id > 0) { - fw_notify("Trying to become root (card %d)\n", card->index); - fw_send_force_root(card, new_irm_id, generation); + if (do_reset) { + fw_notify("phy config: card %d, new root=%x, gap_count=%d\n", + card->index, new_irm_id, gap_count); + fw_send_phy_config(card, new_irm_id, generation, gap_count); fw_core_initiate_bus_reset(card, 1); } } diff --git a/drivers/firewire/fw-topology.c b/drivers/firewire/fw-topology.c index 684d87d..d3131e7 100644 --- a/drivers/firewire/fw-topology.c +++ b/drivers/firewire/fw-topology.c @@ -113,6 +113,44 @@ static struct fw_node *fw_node_create(u32 sid, int port_count, int color) 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].node == NULL) + continue; + + if (node->ports[i].node->max_hops > max_child_hops) + max_child_hops = node->ports[i].node->max_hops; + + if (node->ports[i].node->max_depth > depths[0]) { + depths[1] = depths[0]; + depths[0] = node->ports[i].node->max_depth; + } else if (node->ports[i].node->max_depth > depths[1]) + depths[1] = node->ports[i].node->max_depth; + } + + node->max_depth = depths[0] + 1; + node->max_hops = max(max_child_hops, depths[0] + depths[1] + 2); +} + + /** * build_tree - Build the tree representation of the topology * @self_ids: array of self IDs to create the tree from @@ -131,6 +169,7 @@ static struct fw_node *build_tree(struct fw_card *card) struct list_head stack, *h; u32 *sid, *next_sid, *end, q; int i, port_count, child_port_count, phy_id, parent_count, stack_depth; + int gap_count, topology_type; local_node = NULL; node = NULL; @@ -140,6 +179,8 @@ static struct fw_node *build_tree(struct fw_card *card) end = sid + card->self_id_count; phy_id = 0; card->irm_node = NULL; + gap_count = self_id_gap_count(*sid); + topology_type = 0; while (sid < end) { next_sid = count_ports(sid, &port_count, &child_port_count); @@ -179,6 +220,11 @@ static struct fw_node *build_tree(struct fw_card *card) if (self_id_contender(q)) card->irm_node = node; + if (node->phy_speed == SCODE_BETA) + topology_type |= FW_TOPOLOGY_B; + else + topology_type |= FW_TOPOLOGY_A; + parent_count = 0; for (i = 0; i < port_count; i++) { @@ -223,11 +269,21 @@ static struct fw_node *build_tree(struct fw_card *card) list_add_tail(&node->link, &stack); stack_depth += 1 - child_port_count; + /* If all PHYs does not report the same gap count + * setting, we fall back to 63 which will force a gap + * count reconfiguration and a reset. */ + if (self_id_gap_count(q) != gap_count) + gap_count = 63; + + update_hop_count(node); + sid = next_sid; phy_id++; } card->root_node = node; + card->gap_count = gap_count; + card->topology_type = topology_type; return local_node; } @@ -286,7 +342,8 @@ report_found_node(struct fw_card *card, int b_path = (node->phy_speed == SCODE_BETA); if (parent != NULL) { - node->max_speed = min(parent->max_speed, node->phy_speed); + node->max_speed = min((u8)parent->max_speed, + (u8)node->phy_speed); node->b_path = parent->b_path && b_path; } else { node->max_speed = node->phy_speed; @@ -329,7 +386,7 @@ static void move_tree(struct fw_node *node0, struct fw_node *node1, int port) * as we go. */ static void -update_tree(struct fw_card *card, struct fw_node *root, int *changed) +update_tree(struct fw_card *card, struct fw_node *root) { struct list_head list0, list1; struct fw_node *node0, *node1; @@ -342,7 +399,6 @@ update_tree(struct fw_card *card, struct fw_node *root, int *changed) node0 = fw_node(list0.next); node1 = fw_node(list1.next); - *changed = 0; while (&node0->link != &list0) { @@ -358,6 +414,7 @@ update_tree(struct fw_card *card, struct fw_node *root, int *changed) 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); @@ -386,7 +443,6 @@ update_tree(struct fw_card *card, struct fw_node *root, int *changed) 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 @@ -395,7 +451,6 @@ update_tree(struct fw_card *card, struct fw_node *root, int *changed) move_tree(node0, node1, i); for_each_fw_node(card, node0->ports[i].node, report_found_node); - *changed = 1; } } @@ -411,12 +466,17 @@ fw_core_handle_bus_reset(struct fw_card *card, { struct fw_node *local_node; unsigned long flags; - int changed; fw_flush_transactions(card); spin_lock_irqsave(&card->lock, flags); + /* If the new topology has a different self_id_count the topology + * changed, either nodes were added or removed. In that case we + * reset the IRM reset counter. */ + if (card->self_id_count != self_id_count) + card->irm_retries = 0; + card->node_id = node_id; card->self_id_count = self_id_count; card->generation = generation; @@ -433,9 +493,7 @@ fw_core_handle_bus_reset(struct fw_card *card, card->local_node = local_node; for_each_fw_node(card, local_node, report_found_node); } else { - update_tree(card, local_node, &changed); - if (changed) - card->irm_retries = 0; + update_tree(card, local_node); } /* If we're not the root node, we may have to do some IRM work. */ diff --git a/drivers/firewire/fw-topology.h b/drivers/firewire/fw-topology.h index ab03059..f2a575e 100644 --- a/drivers/firewire/fw-topology.h +++ b/drivers/firewire/fw-topology.h @@ -23,6 +23,12 @@ #define __fw_topology_h enum { + FW_TOPOLOGY_A = 0x01, + FW_TOPOLOGY_B = 0x02, + FW_TOPOLOGY_MIXED = 0x03, +}; + +enum { FW_NODE_CREATED = 0x00, FW_NODE_UPDATED = 0x01, FW_NODE_DESTROYED = 0x02, @@ -42,10 +48,11 @@ struct fw_node { unsigned link_on : 1; unsigned initiated_reset : 1; unsigned b_path : 1; - u8 phy_speed; /* As in the self ID packet. */ - u8 max_speed; /* Minimum of all phy-speeds and port speeds on - * the path from the local node to this node. */ - + u8 phy_speed : 3; /* As in the self ID packet. */ + u8 max_speed : 5; /* Minimum of all phy-speeds and port speeds on + * the path from the local node to this node. */ + u8 max_depth : 4; /* Maximum depth to any leaf node */ + u8 max_hops : 4; /* Max hops in this sub tree */ atomic_t ref_count; /* For serializing node topology into a list. */ diff --git a/drivers/firewire/fw-transaction.c b/drivers/firewire/fw-transaction.c index 439a3e3..57ecf95 100644 --- a/drivers/firewire/fw-transaction.c +++ b/drivers/firewire/fw-transaction.c @@ -274,11 +274,15 @@ static void send_phy_packet(struct fw_card *card, u32 data, int generation) card->driver->send_request(card, packet); } -void fw_send_force_root(struct fw_card *card, int node_id, int generation) +void fw_send_phy_config(struct fw_card *card, + int node_id, int generation, int gap_count) { u32 q; - q = phy_identifier(PHY_PACKET_CONFIG) | phy_config_root_id(node_id); + q = phy_identifier(PHY_PACKET_CONFIG) | + phy_config_root_id(node_id) | + phy_config_gap_count(gap_count); + send_phy_packet(card, q, generation); } diff --git a/drivers/firewire/fw-transaction.h b/drivers/firewire/fw-transaction.h index 22d2871..df65245 100644 --- a/drivers/firewire/fw-transaction.h +++ b/drivers/firewire/fw-transaction.h @@ -259,6 +259,8 @@ struct fw_card { struct fw_node *root_node; struct fw_node *irm_node; int color; + int gap_count; + int topology_type; int index; @@ -386,8 +388,8 @@ fw_send_request(struct fw_card *card, struct fw_transaction *t, void fw_flush_transactions(struct fw_card *card); -void -fw_send_force_root(struct fw_card *card, int node_id, int generation); +void fw_send_phy_config(struct fw_card *card, + int node_id, int generation, int gap_count); /* Called by the topology code to inform the device code of node * activity; found, lost, or updated nodes */ --