// SPDX-License-Identifier: GPL-2.0
/*
* Thunderbolt Cactus Ridge driver - PCIe tunnel
*
* Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
*/
#include <linux/slab.h>
#include <linux/list.h>
#include "tunnel_pci.h"
#include "tb.h"
#define __TB_TUNNEL_PRINT(level, tunnel, fmt, arg...) \
do { \
struct tb_pci_tunnel *__tunnel = (tunnel); \
level(__tunnel->tb, "%llx:%x <-> %llx:%x (PCI): " fmt, \
tb_route(__tunnel->down_port->sw), \
__tunnel->down_port->port, \
tb_route(__tunnel->up_port->sw), \
__tunnel->up_port->port, \
## arg); \
} while (0)
#define tb_tunnel_WARN(tunnel, fmt, arg...) \
__TB_TUNNEL_PRINT(tb_WARN, tunnel, fmt, ##arg)
#define tb_tunnel_warn(tunnel, fmt, arg...) \
__TB_TUNNEL_PRINT(tb_warn, tunnel, fmt, ##arg)
#define tb_tunnel_info(tunnel, fmt, arg...) \
__TB_TUNNEL_PRINT(tb_info, tunnel, fmt, ##arg)
static void tb_pci_init_path(struct tb_path *path)
{
path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
path->egress_shared_buffer = TB_PATH_NONE;
path->ingress_fc_enable = TB_PATH_ALL;
path->ingress_shared_buffer = TB_PATH_NONE;
path->priority = 3;
path->weight = 1;
path->drop_packages = 0;
path->nfc_credits = 0;
}
/**
* tb_pci_alloc() - allocate a pci tunnel
*
* Allocate a PCI tunnel. The ports must be of type TB_TYPE_PCIE_UP and
* TB_TYPE_PCIE_DOWN.
*
* Currently only paths consisting of two hops are supported (that is the
* ports must be on "adjacent" switches).
*
* The paths are hard-coded to use hop 8 (the only working hop id available on
* my thunderbolt devices). Therefore at most ONE path per device may be
* activated.
*
* Return: Returns a tb_pci_tunnel on success or NULL on failure.
*/
struct tb_pci_tunnel *tb_pci_alloc(struct tb *tb, struct tb_port *up,
struct tb_port *down)
{
struct tb_pci_tunnel *tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL);
if (!tunnel)
goto err;
tunnel->tb = tb;
tunnel->down_port = down;
tunnel->up_port = up;
INIT_LIST_HEAD(&tunnel->list);
tunnel->path_to_up = tb_path_alloc(up->sw->tb, 2);
if (!tunnel->path_to_up)
goto err;
tunnel->path_to_down = tb_path_alloc(up->sw->tb, 2);
if (!tunnel->path_to_down)
goto err;
tb_pci_init_path(tunnel->path_to_up);
tb_pci_init_path(tunnel->path_to_down);
tunnel->path_to_up->hops[0].in_port = down;
tunnel->path_to_up->hops[0].in_hop_index = 8;
tunnel->path_to_up->hops[0].in_counter_index = -1;
tunnel->path_to_up->hops[0].out_port = tb_upstream_port(up->sw)->remote;
tunnel->path_to_up->hops[0].next_hop_index = 8;
tunnel->path_to_up->hops[1].in_port = tb_upstream_port(up->sw);
tunnel->path_to_up->hops[1].in_hop_index = 8;
tunnel->path_to_up->hops[1].in_counter_index = -1;
tunnel->path_to_up->hops[1].out_port = up;
tunnel->path_to_up->hops[1].next_hop_index = 8;
tunnel->path_to_down->hops[0].in_port = up;
tunnel->path_to_down->hops[0].in_hop_index = 8;
tunnel->path_to_down->hops[0].in_counter_index = -1;
tunnel->path_to_down->hops[0].out_port = tb_upstream_port(up->sw);
tunnel->path_to_down->hops[0].next_hop_index = 8;
tunnel->path_to_down->hops[1].in_port =
tb_upstream_port(up->sw)->remote;
tunnel->path_to_down->hops[1].in_hop_index = 8;
tunnel->path_to_down->hops[1].in_counter_index = -1;
tunnel->path_to_down->hops[1].out_port = down;
tunnel->path_to_down->hops[1].next_hop_index = 8;
return tunnel;
err:
if (tunnel) {
if (tunnel->path_to_down)
tb_path_free(tunnel->path_to_down);
if (tunnel->path_to_up)
tb_path_free(tunnel->path_to_up);
kfree(tunnel);
}
return NULL;
}
/**
* tb_pci_free() - free a tunnel
*
* The tunnel must have been deactivated.
*/
void tb_pci_free(struct tb_pci_tunnel *tunnel)
{
if (tunnel->path_to_up->activated || tunnel->path_to_down->activated) {
tb_tunnel_WARN(tunnel, "trying to free an activated tunnel\n");
return;
}
tb_path_free(tunnel->path_to_up);
tb_path_free(tunnel->path_to_down);
kfree(tunnel);
}
/**
* tb_pci_is_invalid - check whether an activated path is still valid
*/
bool tb_pci_is_invalid(struct tb_pci_tunnel *tunnel)
{
WARN_ON(!tunnel->path_to_up->activated);
WARN_ON(!tunnel->path_to_down->activated);
return tb_path_is_invalid(tunnel->path_to_up)
|| tb_path_is_invalid(tunnel->path_to_down);
}
/**
* tb_pci_port_active() - activate/deactivate PCI capability
*
* Return: Returns 0 on success or an error code on failure.
*/
static int tb_pci_port_active(struct tb_port *port, bool active)
{
u32 word = active ? 0x80000000 : 0x0;
int cap = tb_port_find_cap(port, TB_PORT_CAP_ADAP);
if (cap < 0) {
tb_port_warn(port, "TB_PORT_CAP_ADAP not found: %d\n", cap);
return cap;
}
return tb_port_write(port, &word, TB_CFG_PORT, cap, 1);
}
/**
* tb_pci_restart() - activate a tunnel after a hardware reset
*/
int tb_pci_restart(struct tb_pci_tunnel *tunnel)
{
int res;
tunnel->path_to_up->activated = false;
tunnel->path_to_down->activated = false;
tb_tunnel_info(tunnel, "activating\n");
res = tb_path_activate(tunnel->path_to_up);
if (res)
goto err;
res = tb_path_activate(tunnel->path_to_down);
if (res)
goto err;
res = tb_pci_port_active(tunnel->down_port, true);
if (res)
goto err;
res = tb_pci_port_active(tunnel->up_port, true);
if (res)
goto err;
return 0;
err:
tb_tunnel_warn(tunnel, "activation failed\n");
tb_pci_deactivate(tunnel);
return res;
}
/**
* tb_pci_activate() - activate a tunnel
*
* Return: Returns 0 on success or an error code on failure.
*/
int tb_pci_activate(struct tb_pci_tunnel *tunnel)
{
if (tunnel->path_to_up->activated || tunnel->path_to_down->activated) {
tb_tunnel_WARN(tunnel,
"trying to activate an already activated tunnel\n");
return -EINVAL;
}
return tb_pci_restart(tunnel);
}
/**
* tb_pci_deactivate() - deactivate a tunnel
*/
void tb_pci_deactivate(struct tb_pci_tunnel *tunnel)
{
tb_tunnel_info(tunnel, "deactivating\n");
/*
* TODO: enable reset by writing 0x04000000 to TB_CAP_PCIE + 1 on up
* port. Seems to have no effect?
*/
tb_pci_port_active(tunnel->up_port, false);
tb_pci_port_active(tunnel->down_port, false);
if (tunnel->path_to_down->activated)
tb_path_deactivate(tunnel->path_to_down);
if (tunnel->path_to_up->activated)
tb_path_deactivate(tunnel->path_to_up);
}
