diff options
author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-06-18 11:16:55 +1000 |
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committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-06-18 11:16:55 +1000 |
commit | 4b337c5f245b6587ba844ac7bb13c313a2912f7b (patch) | |
tree | 999c6a6580b76a083c8efb9dabff709d1c49fcd0 /drivers/firewire/core-topology.c | |
parent | 492b057c426e4aa747484958e18e9da29003985d (diff) | |
parent | 3fe0344faf7fdcb158bd5c1a9aec960a8d70c8e8 (diff) |
Merge commit 'origin/master' into next
Diffstat (limited to 'drivers/firewire/core-topology.c')
-rw-r--r-- | drivers/firewire/core-topology.c | 572 |
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 00000000000..fddf2b35893 --- /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); |