/*
* 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;
}
