kernel-ark/drivers/thunderbolt/tb.c
Andreas Noever 343fcb8c70 thunderbolt: Fix nontrivial endpoint devices.
Fix issues observed with the Startech docking station:

Fix the type of the route parameter in tb_ctl_rx. It should be u64 and not
u8 (which only worked for short routes).

A thunderbolt cable contains two lanes. If both endpoints support it a
connection will be established on both lanes. Previously we tried to
scan below both "dual link ports". Use the information extracted from
the drom to only scan behind ports with lane_nr == 0.

Endpoints with more complex thunderbolt controllers have some of their
ports disabled (for example the NHI port or one of the HDMI/DP ports).
Accessing them results in an error so we now ignore ports which are
marked as disabled in the drom.

Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-19 14:14:35 -07:00

437 lines
10 KiB
C

/*
* Thunderbolt Cactus Ridge driver - bus logic (NHI independent)
*
* Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
*/
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include "tb.h"
#include "tb_regs.h"
#include "tunnel_pci.h"
/* enumeration & hot plug handling */
static void tb_scan_port(struct tb_port *port);
/**
* tb_scan_switch() - scan for and initialize downstream switches
*/
static void tb_scan_switch(struct tb_switch *sw)
{
int i;
for (i = 1; i <= sw->config.max_port_number; i++)
tb_scan_port(&sw->ports[i]);
}
/**
* tb_scan_port() - check for and initialize switches below port
*/
static void tb_scan_port(struct tb_port *port)
{
struct tb_switch *sw;
if (tb_is_upstream_port(port))
return;
if (port->config.type != TB_TYPE_PORT)
return;
if (port->dual_link_port && port->link_nr)
return; /*
* Downstream switch is reachable through two ports.
* Only scan on the primary port (link_nr == 0).
*/
if (tb_wait_for_port(port, false) <= 0)
return;
if (port->remote) {
tb_port_WARN(port, "port already has a remote!\n");
return;
}
sw = tb_switch_alloc(port->sw->tb, tb_downstream_route(port));
if (!sw)
return;
port->remote = tb_upstream_port(sw);
tb_upstream_port(sw)->remote = port;
tb_scan_switch(sw);
}
/**
* tb_free_invalid_tunnels() - destroy tunnels of devices that have gone away
*/
static void tb_free_invalid_tunnels(struct tb *tb)
{
struct tb_pci_tunnel *tunnel;
struct tb_pci_tunnel *n;
list_for_each_entry_safe(tunnel, n, &tb->tunnel_list, list)
{
if (tb_pci_is_invalid(tunnel)) {
tb_pci_deactivate(tunnel);
tb_pci_free(tunnel);
}
}
}
/**
* tb_free_unplugged_children() - traverse hierarchy and free unplugged switches
*/
static void tb_free_unplugged_children(struct tb_switch *sw)
{
int i;
for (i = 1; i <= sw->config.max_port_number; i++) {
struct tb_port *port = &sw->ports[i];
if (tb_is_upstream_port(port))
continue;
if (!port->remote)
continue;
if (port->remote->sw->is_unplugged) {
tb_switch_free(port->remote->sw);
port->remote = NULL;
} else {
tb_free_unplugged_children(port->remote->sw);
}
}
}
/**
* find_pci_up_port() - return the first PCIe up port on @sw or NULL
*/
static struct tb_port *tb_find_pci_up_port(struct tb_switch *sw)
{
int i;
for (i = 1; i <= sw->config.max_port_number; i++)
if (sw->ports[i].config.type == TB_TYPE_PCIE_UP)
return &sw->ports[i];
return NULL;
}
/**
* find_unused_down_port() - return the first inactive PCIe down port on @sw
*/
static struct tb_port *tb_find_unused_down_port(struct tb_switch *sw)
{
int i;
int cap;
int res;
int data;
for (i = 1; i <= sw->config.max_port_number; i++) {
if (tb_is_upstream_port(&sw->ports[i]))
continue;
if (sw->ports[i].config.type != TB_TYPE_PCIE_DOWN)
continue;
cap = tb_find_cap(&sw->ports[i], TB_CFG_PORT, TB_CAP_PCIE);
if (cap <= 0)
continue;
res = tb_port_read(&sw->ports[i], &data, TB_CFG_PORT, cap, 1);
if (res < 0)
continue;
if (data & 0x80000000)
continue;
return &sw->ports[i];
}
return NULL;
}
/**
* tb_activate_pcie_devices() - scan for and activate PCIe devices
*
* This method is somewhat ad hoc. For now it only supports one device
* per port and only devices at depth 1.
*/
static void tb_activate_pcie_devices(struct tb *tb)
{
int i;
int cap;
u32 data;
struct tb_switch *sw;
struct tb_port *up_port;
struct tb_port *down_port;
struct tb_pci_tunnel *tunnel;
/* scan for pcie devices at depth 1*/
for (i = 1; i <= tb->root_switch->config.max_port_number; i++) {
if (tb_is_upstream_port(&tb->root_switch->ports[i]))
continue;
if (tb->root_switch->ports[i].config.type != TB_TYPE_PORT)
continue;
if (!tb->root_switch->ports[i].remote)
continue;
sw = tb->root_switch->ports[i].remote->sw;
up_port = tb_find_pci_up_port(sw);
if (!up_port) {
tb_sw_info(sw, "no PCIe devices found, aborting\n");
continue;
}
/* check whether port is already activated */
cap = tb_find_cap(up_port, TB_CFG_PORT, TB_CAP_PCIE);
if (cap <= 0)
continue;
if (tb_port_read(up_port, &data, TB_CFG_PORT, cap, 1))
continue;
if (data & 0x80000000) {
tb_port_info(up_port,
"PCIe port already activated, aborting\n");
continue;
}
down_port = tb_find_unused_down_port(tb->root_switch);
if (!down_port) {
tb_port_info(up_port,
"All PCIe down ports are occupied, aborting\n");
continue;
}
tunnel = tb_pci_alloc(tb, up_port, down_port);
if (!tunnel) {
tb_port_info(up_port,
"PCIe tunnel allocation failed, aborting\n");
continue;
}
if (tb_pci_activate(tunnel)) {
tb_port_info(up_port,
"PCIe tunnel activation failed, aborting\n");
tb_pci_free(tunnel);
}
}
}
/* hotplug handling */
struct tb_hotplug_event {
struct work_struct work;
struct tb *tb;
u64 route;
u8 port;
bool unplug;
};
/**
* tb_handle_hotplug() - handle hotplug event
*
* Executes on tb->wq.
*/
static void tb_handle_hotplug(struct work_struct *work)
{
struct tb_hotplug_event *ev = container_of(work, typeof(*ev), work);
struct tb *tb = ev->tb;
struct tb_switch *sw;
struct tb_port *port;
mutex_lock(&tb->lock);
if (!tb->hotplug_active)
goto out; /* during init, suspend or shutdown */
sw = get_switch_at_route(tb->root_switch, ev->route);
if (!sw) {
tb_warn(tb,
"hotplug event from non existent switch %llx:%x (unplug: %d)\n",
ev->route, ev->port, ev->unplug);
goto out;
}
if (ev->port > sw->config.max_port_number) {
tb_warn(tb,
"hotplug event from non existent port %llx:%x (unplug: %d)\n",
ev->route, ev->port, ev->unplug);
goto out;
}
port = &sw->ports[ev->port];
if (tb_is_upstream_port(port)) {
tb_warn(tb,
"hotplug event for upstream port %llx:%x (unplug: %d)\n",
ev->route, ev->port, ev->unplug);
goto out;
}
if (ev->unplug) {
if (port->remote) {
tb_port_info(port, "unplugged\n");
tb_sw_set_unpplugged(port->remote->sw);
tb_free_invalid_tunnels(tb);
tb_switch_free(port->remote->sw);
port->remote = NULL;
} else {
tb_port_info(port,
"got unplug event for disconnected port, ignoring\n");
}
} else if (port->remote) {
tb_port_info(port,
"got plug event for connected port, ignoring\n");
} else {
tb_port_info(port, "hotplug: scanning\n");
tb_scan_port(port);
if (!port->remote) {
tb_port_info(port, "hotplug: no switch found\n");
} else if (port->remote->sw->config.depth > 1) {
tb_sw_warn(port->remote->sw,
"hotplug: chaining not supported\n");
} else {
tb_sw_info(port->remote->sw,
"hotplug: activating pcie devices\n");
tb_activate_pcie_devices(tb);
}
}
out:
mutex_unlock(&tb->lock);
kfree(ev);
}
/**
* tb_schedule_hotplug_handler() - callback function for the control channel
*
* Delegates to tb_handle_hotplug.
*/
static void tb_schedule_hotplug_handler(void *data, u64 route, u8 port,
bool unplug)
{
struct tb *tb = data;
struct tb_hotplug_event *ev = kmalloc(sizeof(*ev), GFP_KERNEL);
if (!ev)
return;
INIT_WORK(&ev->work, tb_handle_hotplug);
ev->tb = tb;
ev->route = route;
ev->port = port;
ev->unplug = unplug;
queue_work(tb->wq, &ev->work);
}
/**
* thunderbolt_shutdown_and_free() - shutdown everything
*
* Free all switches and the config channel.
*
* Used in the error path of thunderbolt_alloc_and_start.
*/
void thunderbolt_shutdown_and_free(struct tb *tb)
{
struct tb_pci_tunnel *tunnel;
struct tb_pci_tunnel *n;
mutex_lock(&tb->lock);
/* tunnels are only present after everything has been initialized */
list_for_each_entry_safe(tunnel, n, &tb->tunnel_list, list) {
tb_pci_deactivate(tunnel);
tb_pci_free(tunnel);
}
if (tb->root_switch)
tb_switch_free(tb->root_switch);
tb->root_switch = NULL;
if (tb->ctl) {
tb_ctl_stop(tb->ctl);
tb_ctl_free(tb->ctl);
}
tb->ctl = NULL;
tb->hotplug_active = false; /* signal tb_handle_hotplug to quit */
/* allow tb_handle_hotplug to acquire the lock */
mutex_unlock(&tb->lock);
if (tb->wq) {
flush_workqueue(tb->wq);
destroy_workqueue(tb->wq);
tb->wq = NULL;
}
mutex_destroy(&tb->lock);
kfree(tb);
}
/**
* thunderbolt_alloc_and_start() - setup the thunderbolt bus
*
* Allocates a tb_cfg control channel, initializes the root switch, enables
* plug events and activates pci devices.
*
* Return: Returns NULL on error.
*/
struct tb *thunderbolt_alloc_and_start(struct tb_nhi *nhi)
{
struct tb *tb;
BUILD_BUG_ON(sizeof(struct tb_regs_switch_header) != 5 * 4);
BUILD_BUG_ON(sizeof(struct tb_regs_port_header) != 8 * 4);
BUILD_BUG_ON(sizeof(struct tb_regs_hop) != 2 * 4);
tb = kzalloc(sizeof(*tb), GFP_KERNEL);
if (!tb)
return NULL;
tb->nhi = nhi;
mutex_init(&tb->lock);
mutex_lock(&tb->lock);
INIT_LIST_HEAD(&tb->tunnel_list);
tb->wq = alloc_ordered_workqueue("thunderbolt", 0);
if (!tb->wq)
goto err_locked;
tb->ctl = tb_ctl_alloc(tb->nhi, tb_schedule_hotplug_handler, tb);
if (!tb->ctl)
goto err_locked;
/*
* tb_schedule_hotplug_handler may be called as soon as the config
* channel is started. Thats why we have to hold the lock here.
*/
tb_ctl_start(tb->ctl);
tb->root_switch = tb_switch_alloc(tb, 0);
if (!tb->root_switch)
goto err_locked;
/* Full scan to discover devices added before the driver was loaded. */
tb_scan_switch(tb->root_switch);
tb_activate_pcie_devices(tb);
/* Allow tb_handle_hotplug to progress events */
tb->hotplug_active = true;
mutex_unlock(&tb->lock);
return tb;
err_locked:
mutex_unlock(&tb->lock);
thunderbolt_shutdown_and_free(tb);
return NULL;
}
void thunderbolt_suspend(struct tb *tb)
{
tb_info(tb, "suspending...\n");
mutex_lock(&tb->lock);
tb_switch_suspend(tb->root_switch);
tb_ctl_stop(tb->ctl);
tb->hotplug_active = false; /* signal tb_handle_hotplug to quit */
mutex_unlock(&tb->lock);
tb_info(tb, "suspend finished\n");
}
void thunderbolt_resume(struct tb *tb)
{
struct tb_pci_tunnel *tunnel, *n;
tb_info(tb, "resuming...\n");
mutex_lock(&tb->lock);
tb_ctl_start(tb->ctl);
/* remove any pci devices the firmware might have setup */
tb_switch_reset(tb, 0);
tb_switch_resume(tb->root_switch);
tb_free_invalid_tunnels(tb);
tb_free_unplugged_children(tb->root_switch);
list_for_each_entry_safe(tunnel, n, &tb->tunnel_list, list)
tb_pci_restart(tunnel);
if (!list_empty(&tb->tunnel_list)) {
/*
* the pcie links need some time to get going.
* 100ms works for me...
*/
tb_info(tb, "tunnels restarted, sleeping for 100ms\n");
msleep(100);
}
/* Allow tb_handle_hotplug to progress events */
tb->hotplug_active = true;
mutex_unlock(&tb->lock);
tb_info(tb, "resume finished\n");
}