linux/drivers/thunderbolt/tb.c
Mika Westerberg e78db6f08b thunderbolt: Generalize port finding routines to support all port types
We will be needing these routines to find Display Port adapters as well
so modify them to take port type as the second parameter.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2019-04-18 11:18:53 +03:00

558 lines
13 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Thunderbolt driver - bus logic (NHI independent)
*
* Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
* Copyright (C) 2019, Intel Corporation
*/
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/platform_data/x86/apple.h>
#include "tb.h"
#include "tb_regs.h"
#include "tunnel.h"
/**
* struct tb_cm - Simple Thunderbolt connection manager
* @tunnel_list: List of active tunnels
* @hotplug_active: tb_handle_hotplug will stop progressing plug
* events and exit if this is not set (it needs to
* acquire the lock one more time). Used to drain wq
* after cfg has been paused.
*/
struct tb_cm {
struct list_head tunnel_list;
bool hotplug_active;
};
/* enumeration & hot plug handling */
static void tb_discover_tunnels(struct tb_switch *sw)
{
struct tb *tb = sw->tb;
struct tb_cm *tcm = tb_priv(tb);
struct tb_port *port;
int i;
for (i = 1; i <= sw->config.max_port_number; i++) {
struct tb_tunnel *tunnel = NULL;
port = &sw->ports[i];
switch (port->config.type) {
case TB_TYPE_PCIE_DOWN:
tunnel = tb_tunnel_discover_pci(tb, port);
break;
default:
break;
}
if (tunnel) {
struct tb_switch *parent = tunnel->dst_port->sw;
while (parent != tunnel->src_port->sw) {
parent->boot = true;
parent = tb_switch_parent(parent);
}
list_add_tail(&tunnel->list, &tcm->tunnel_list);
}
}
for (i = 1; i <= sw->config.max_port_number; i++) {
if (tb_port_has_remote(&sw->ports[i]))
tb_discover_tunnels(sw->ports[i].remote->sw);
}
}
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_cm *tcm = tb_priv(port->sw->tb);
struct tb_port *upstream_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, &port->sw->dev,
tb_downstream_route(port));
if (!sw)
return;
if (tb_switch_configure(sw)) {
tb_switch_put(sw);
return;
}
/*
* Do not send uevents until we have discovered all existing
* tunnels and know which switches were authorized already by
* the boot firmware.
*/
if (!tcm->hotplug_active)
dev_set_uevent_suppress(&sw->dev, true);
if (tb_switch_add(sw)) {
tb_switch_put(sw);
return;
}
/* Link the switches using both links if available */
upstream_port = tb_upstream_port(sw);
port->remote = upstream_port;
upstream_port->remote = port;
if (port->dual_link_port && upstream_port->dual_link_port) {
port->dual_link_port->remote = upstream_port->dual_link_port;
upstream_port->dual_link_port->remote = port->dual_link_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_cm *tcm = tb_priv(tb);
struct tb_tunnel *tunnel;
struct tb_tunnel *n;
list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) {
if (tb_tunnel_is_invalid(tunnel)) {
tb_tunnel_deactivate(tunnel);
list_del(&tunnel->list);
tb_tunnel_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_port_has_remote(port))
continue;
if (port->remote->sw->is_unplugged) {
tb_switch_remove(port->remote->sw);
port->remote = NULL;
if (port->dual_link_port)
port->dual_link_port->remote = NULL;
} else {
tb_free_unplugged_children(port->remote->sw);
}
}
}
/**
* tb_find_port() - return the first port of @type on @sw or NULL
* @sw: Switch to find the port from
* @type: Port type to look for
*/
static struct tb_port *tb_find_port(struct tb_switch *sw,
enum tb_port_type type)
{
int i;
for (i = 1; i <= sw->config.max_port_number; i++)
if (sw->ports[i].config.type == type)
return &sw->ports[i];
return NULL;
}
/**
* tb_find_unused_port() - return the first inactive port on @sw
* @sw: Switch to find the port on
* @type: Port type to look for
*/
static struct tb_port *tb_find_unused_port(struct tb_switch *sw,
enum tb_port_type type)
{
int i;
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 != type)
continue;
if (!sw->ports[i].cap_adap)
continue;
if (tb_port_is_enabled(&sw->ports[i]))
continue;
return &sw->ports[i];
}
return NULL;
}
static struct tb_port *tb_find_pcie_down(struct tb_switch *sw,
const struct tb_port *port)
{
/*
* To keep plugging devices consistently in the same PCIe
* hierarchy, do mapping here for root switch downstream PCIe
* ports.
*/
if (!tb_route(sw)) {
int phy_port = tb_phy_port_from_link(port->port);
int index;
/*
* Hard-coded Thunderbolt port to PCIe down port mapping
* per controller.
*/
if (tb_switch_is_cr(sw))
index = !phy_port ? 6 : 7;
else if (tb_switch_is_fr(sw))
index = !phy_port ? 6 : 8;
else
goto out;
/* Validate the hard-coding */
if (WARN_ON(index > sw->config.max_port_number))
goto out;
if (WARN_ON(!tb_port_is_pcie_down(&sw->ports[index])))
goto out;
if (WARN_ON(tb_pci_port_is_enabled(&sw->ports[index])))
goto out;
return &sw->ports[index];
}
out:
return tb_find_unused_port(sw, TB_TYPE_PCIE_DOWN);
}
static int tb_tunnel_pci(struct tb *tb, struct tb_switch *sw)
{
struct tb_port *up, *down, *port;
struct tb_cm *tcm = tb_priv(tb);
struct tb_switch *parent_sw;
struct tb_tunnel *tunnel;
up = tb_find_port(sw, TB_TYPE_PCIE_UP);
if (!up)
return 0;
/*
* Look up available down port. Since we are chaining it should
* be found right above this switch.
*/
parent_sw = tb_to_switch(sw->dev.parent);
port = tb_port_at(tb_route(sw), parent_sw);
down = tb_find_pcie_down(parent_sw, port);
if (!down)
return 0;
tunnel = tb_tunnel_alloc_pci(tb, up, down);
if (!tunnel)
return -ENOMEM;
if (tb_tunnel_activate(tunnel)) {
tb_port_info(up,
"PCIe tunnel activation failed, aborting\n");
tb_tunnel_free(tunnel);
return -EIO;
}
list_add_tail(&tunnel->list, &tcm->tunnel_list);
return 0;
}
/* 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_cm *tcm = tb_priv(tb);
struct tb_switch *sw;
struct tb_port *port;
mutex_lock(&tb->lock);
if (!tcm->hotplug_active)
goto out; /* during init, suspend or shutdown */
sw = tb_switch_find_by_route(tb, 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 put_sw;
}
port = &sw->ports[ev->port];
if (tb_is_upstream_port(port)) {
tb_dbg(tb, "hotplug event for upstream port %llx:%x (unplug: %d)\n",
ev->route, ev->port, ev->unplug);
goto put_sw;
}
if (ev->unplug) {
if (tb_port_has_remote(port)) {
tb_port_info(port, "unplugged\n");
tb_sw_set_unplugged(port->remote->sw);
tb_free_invalid_tunnels(tb);
tb_switch_remove(port->remote->sw);
port->remote = NULL;
if (port->dual_link_port)
port->dual_link_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 {
if (tb_port_is_null(port)) {
tb_port_info(port, "hotplug: scanning\n");
tb_scan_port(port);
if (!port->remote)
tb_port_info(port, "hotplug: no switch found\n");
}
}
put_sw:
tb_switch_put(sw);
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_handle_event(struct tb *tb, enum tb_cfg_pkg_type type,
const void *buf, size_t size)
{
const struct cfg_event_pkg *pkg = buf;
struct tb_hotplug_event *ev;
u64 route;
if (type != TB_CFG_PKG_EVENT) {
tb_warn(tb, "unexpected event %#x, ignoring\n", type);
return;
}
route = tb_cfg_get_route(&pkg->header);
if (tb_cfg_error(tb->ctl, route, pkg->port,
TB_CFG_ERROR_ACK_PLUG_EVENT)) {
tb_warn(tb, "could not ack plug event on %llx:%x\n", route,
pkg->port);
}
ev = kmalloc(sizeof(*ev), GFP_KERNEL);
if (!ev)
return;
INIT_WORK(&ev->work, tb_handle_hotplug);
ev->tb = tb;
ev->route = route;
ev->port = pkg->port;
ev->unplug = pkg->unplug;
queue_work(tb->wq, &ev->work);
}
static void tb_stop(struct tb *tb)
{
struct tb_cm *tcm = tb_priv(tb);
struct tb_tunnel *tunnel;
struct tb_tunnel *n;
/* tunnels are only present after everything has been initialized */
list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) {
tb_tunnel_deactivate(tunnel);
tb_tunnel_free(tunnel);
}
tb_switch_remove(tb->root_switch);
tcm->hotplug_active = false; /* signal tb_handle_hotplug to quit */
}
static int tb_scan_finalize_switch(struct device *dev, void *data)
{
if (tb_is_switch(dev)) {
struct tb_switch *sw = tb_to_switch(dev);
/*
* If we found that the switch was already setup by the
* boot firmware, mark it as authorized now before we
* send uevent to userspace.
*/
if (sw->boot)
sw->authorized = 1;
dev_set_uevent_suppress(dev, false);
kobject_uevent(&dev->kobj, KOBJ_ADD);
device_for_each_child(dev, NULL, tb_scan_finalize_switch);
}
return 0;
}
static int tb_start(struct tb *tb)
{
struct tb_cm *tcm = tb_priv(tb);
int ret;
tb->root_switch = tb_switch_alloc(tb, &tb->dev, 0);
if (!tb->root_switch)
return -ENOMEM;
/*
* ICM firmware upgrade needs running firmware and in native
* mode that is not available so disable firmware upgrade of the
* root switch.
*/
tb->root_switch->no_nvm_upgrade = true;
ret = tb_switch_configure(tb->root_switch);
if (ret) {
tb_switch_put(tb->root_switch);
return ret;
}
/* Announce the switch to the world */
ret = tb_switch_add(tb->root_switch);
if (ret) {
tb_switch_put(tb->root_switch);
return ret;
}
/* Full scan to discover devices added before the driver was loaded. */
tb_scan_switch(tb->root_switch);
/* Find out tunnels created by the boot firmware */
tb_discover_tunnels(tb->root_switch);
/* Make the discovered switches available to the userspace */
device_for_each_child(&tb->root_switch->dev, NULL,
tb_scan_finalize_switch);
/* Allow tb_handle_hotplug to progress events */
tcm->hotplug_active = true;
return 0;
}
static int tb_suspend_noirq(struct tb *tb)
{
struct tb_cm *tcm = tb_priv(tb);
tb_dbg(tb, "suspending...\n");
tb_switch_suspend(tb->root_switch);
tcm->hotplug_active = false; /* signal tb_handle_hotplug to quit */
tb_dbg(tb, "suspend finished\n");
return 0;
}
static int tb_resume_noirq(struct tb *tb)
{
struct tb_cm *tcm = tb_priv(tb);
struct tb_tunnel *tunnel, *n;
tb_dbg(tb, "resuming...\n");
/* 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, &tcm->tunnel_list, list)
tb_tunnel_restart(tunnel);
if (!list_empty(&tcm->tunnel_list)) {
/*
* the pcie links need some time to get going.
* 100ms works for me...
*/
tb_dbg(tb, "tunnels restarted, sleeping for 100ms\n");
msleep(100);
}
/* Allow tb_handle_hotplug to progress events */
tcm->hotplug_active = true;
tb_dbg(tb, "resume finished\n");
return 0;
}
static const struct tb_cm_ops tb_cm_ops = {
.start = tb_start,
.stop = tb_stop,
.suspend_noirq = tb_suspend_noirq,
.resume_noirq = tb_resume_noirq,
.handle_event = tb_handle_event,
.approve_switch = tb_tunnel_pci,
};
struct tb *tb_probe(struct tb_nhi *nhi)
{
struct tb_cm *tcm;
struct tb *tb;
if (!x86_apple_machine)
return NULL;
tb = tb_domain_alloc(nhi, sizeof(*tcm));
if (!tb)
return NULL;
tb->security_level = TB_SECURITY_USER;
tb->cm_ops = &tb_cm_ops;
tcm = tb_priv(tb);
INIT_LIST_HEAD(&tcm->tunnel_list);
return tb;
}