diff options
Diffstat (limited to 'drivers/thunderbolt/path.c')
| -rw-r--r-- | drivers/thunderbolt/path.c | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/drivers/thunderbolt/path.c b/drivers/thunderbolt/path.c new file mode 100644 index 000000000..ff49ad880 --- /dev/null +++ b/drivers/thunderbolt/path.c @@ -0,0 +1,235 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Thunderbolt Cactus Ridge driver - path/tunnel functionality + * + * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com> + */ + +#include <linux/slab.h> +#include <linux/errno.h> + +#include "tb.h" + + +static void tb_dump_hop(struct tb_port *port, struct tb_regs_hop *hop) +{ + tb_port_info(port, " Hop through port %d to hop %d (%s)\n", + hop->out_port, hop->next_hop, + hop->enable ? "enabled" : "disabled"); + tb_port_info(port, " Weight: %d Priority: %d Credits: %d Drop: %d\n", + hop->weight, hop->priority, + hop->initial_credits, hop->drop_packages); + tb_port_info(port, " Counter enabled: %d Counter index: %d\n", + hop->counter_enable, hop->counter); + tb_port_info(port, " Flow Control (In/Eg): %d/%d Shared Buffer (In/Eg): %d/%d\n", + hop->ingress_fc, hop->egress_fc, + hop->ingress_shared_buffer, hop->egress_shared_buffer); + tb_port_info(port, " Unknown1: %#x Unknown2: %#x Unknown3: %#x\n", + hop->unknown1, hop->unknown2, hop->unknown3); +} + +/** + * tb_path_alloc() - allocate a thunderbolt path + * + * Return: Returns a tb_path on success or NULL on failure. + */ +struct tb_path *tb_path_alloc(struct tb *tb, int num_hops) +{ + struct tb_path *path = kzalloc(sizeof(*path), GFP_KERNEL); + if (!path) + return NULL; + path->hops = kcalloc(num_hops, sizeof(*path->hops), GFP_KERNEL); + if (!path->hops) { + kfree(path); + return NULL; + } + path->tb = tb; + path->path_length = num_hops; + return path; +} + +/** + * tb_path_free() - free a deactivated path + */ +void tb_path_free(struct tb_path *path) +{ + if (path->activated) { + tb_WARN(path->tb, "trying to free an activated path\n") + return; + } + kfree(path->hops); + kfree(path); +} + +static void __tb_path_deallocate_nfc(struct tb_path *path, int first_hop) +{ + int i, res; + for (i = first_hop; i < path->path_length; i++) { + res = tb_port_add_nfc_credits(path->hops[i].in_port, + -path->nfc_credits); + if (res) + tb_port_warn(path->hops[i].in_port, + "nfc credits deallocation failed for hop %d\n", + i); + } +} + +static void __tb_path_deactivate_hops(struct tb_path *path, int first_hop) +{ + int i, res; + struct tb_regs_hop hop = { }; + for (i = first_hop; i < path->path_length; i++) { + res = tb_port_write(path->hops[i].in_port, &hop, TB_CFG_HOPS, + 2 * path->hops[i].in_hop_index, 2); + if (res) + tb_port_warn(path->hops[i].in_port, + "hop deactivation failed for hop %d, index %d\n", + i, path->hops[i].in_hop_index); + } +} + +void tb_path_deactivate(struct tb_path *path) +{ + if (!path->activated) { + tb_WARN(path->tb, "trying to deactivate an inactive path\n"); + return; + } + tb_info(path->tb, + "deactivating path from %llx:%x to %llx:%x\n", + tb_route(path->hops[0].in_port->sw), + path->hops[0].in_port->port, + tb_route(path->hops[path->path_length - 1].out_port->sw), + path->hops[path->path_length - 1].out_port->port); + __tb_path_deactivate_hops(path, 0); + __tb_path_deallocate_nfc(path, 0); + path->activated = false; +} + +/** + * tb_path_activate() - activate a path + * + * Activate a path starting with the last hop and iterating backwards. The + * caller must fill path->hops before calling tb_path_activate(). + * + * Return: Returns 0 on success or an error code on failure. + */ +int tb_path_activate(struct tb_path *path) +{ + int i, res; + enum tb_path_port out_mask, in_mask; + if (path->activated) { + tb_WARN(path->tb, "trying to activate already activated path\n"); + return -EINVAL; + } + + tb_info(path->tb, + "activating path from %llx:%x to %llx:%x\n", + tb_route(path->hops[0].in_port->sw), + path->hops[0].in_port->port, + tb_route(path->hops[path->path_length - 1].out_port->sw), + path->hops[path->path_length - 1].out_port->port); + + /* Clear counters. */ + for (i = path->path_length - 1; i >= 0; i--) { + if (path->hops[i].in_counter_index == -1) + continue; + res = tb_port_clear_counter(path->hops[i].in_port, + path->hops[i].in_counter_index); + if (res) + goto err; + } + + /* Add non flow controlled credits. */ + for (i = path->path_length - 1; i >= 0; i--) { + res = tb_port_add_nfc_credits(path->hops[i].in_port, + path->nfc_credits); + if (res) { + __tb_path_deallocate_nfc(path, i); + goto err; + } + } + + /* Activate hops. */ + for (i = path->path_length - 1; i >= 0; i--) { + struct tb_regs_hop hop = { 0 }; + + /* + * We do (currently) not tear down paths setup by the firmeware. + * If a firmware device is unplugged and plugged in again then + * it can happen that we reuse some of the hops from the (now + * defunct) firmeware path. This causes the hotplug operation to + * fail (the pci device does not show up). Clearing the hop + * before overwriting it fixes the problem. + * + * Should be removed once we discover and tear down firmeware + * paths. + */ + res = tb_port_write(path->hops[i].in_port, &hop, TB_CFG_HOPS, + 2 * path->hops[i].in_hop_index, 2); + if (res) { + __tb_path_deactivate_hops(path, i); + __tb_path_deallocate_nfc(path, 0); + goto err; + } + + /* dword 0 */ + hop.next_hop = path->hops[i].next_hop_index; + hop.out_port = path->hops[i].out_port->port; + /* TODO: figure out why these are good values */ + hop.initial_credits = (i == path->path_length - 1) ? 16 : 7; + hop.unknown1 = 0; + hop.enable = 1; + + /* dword 1 */ + out_mask = (i == path->path_length - 1) ? + TB_PATH_DESTINATION : TB_PATH_INTERNAL; + in_mask = (i == 0) ? TB_PATH_SOURCE : TB_PATH_INTERNAL; + hop.weight = path->weight; + hop.unknown2 = 0; + hop.priority = path->priority; + hop.drop_packages = path->drop_packages; + hop.counter = path->hops[i].in_counter_index; + hop.counter_enable = path->hops[i].in_counter_index != -1; + hop.ingress_fc = path->ingress_fc_enable & in_mask; + hop.egress_fc = path->egress_fc_enable & out_mask; + hop.ingress_shared_buffer = path->ingress_shared_buffer + & in_mask; + hop.egress_shared_buffer = path->egress_shared_buffer + & out_mask; + hop.unknown3 = 0; + + tb_port_info(path->hops[i].in_port, "Writing hop %d, index %d", + i, path->hops[i].in_hop_index); + tb_dump_hop(path->hops[i].in_port, &hop); + res = tb_port_write(path->hops[i].in_port, &hop, TB_CFG_HOPS, + 2 * path->hops[i].in_hop_index, 2); + if (res) { + __tb_path_deactivate_hops(path, i); + __tb_path_deallocate_nfc(path, 0); + goto err; + } + } + path->activated = true; + tb_info(path->tb, "path activation complete\n"); + return 0; +err: + tb_WARN(path->tb, "path activation failed\n"); + return res; +} + +/** + * tb_path_is_invalid() - check whether any ports on the path are invalid + * + * Return: Returns true if the path is invalid, false otherwise. + */ +bool tb_path_is_invalid(struct tb_path *path) +{ + int i = 0; + for (i = 0; i < path->path_length; i++) { + if (path->hops[i].in_port->sw->is_unplugged) + return true; + if (path->hops[i].out_port->sw->is_unplugged) + return true; + } + return false; +} |