https://github.com/torvalds/linux
Tip revision: 219d54332a09e8d8741c1e1982f5eae56099de85 authored by Linus Torvalds on 25 November 2019, 00:32:01 UTC
Linux 5.4
Linux 5.4
Tip revision: 219d543
tb.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;
};
struct tb_hotplug_event {
struct work_struct work;
struct tb *tb;
u64 route;
u8 port;
bool unplug;
};
static void tb_handle_hotplug(struct work_struct *work);
static void tb_queue_hotplug(struct tb *tb, u64 route, u8 port, bool unplug)
{
struct tb_hotplug_event *ev;
ev = kmalloc(sizeof(*ev), GFP_KERNEL);
if (!ev)
return;
ev->tb = tb;
ev->route = route;
ev->port = port;
ev->unplug = unplug;
INIT_WORK(&ev->work, tb_handle_hotplug);
queue_work(tb->wq, &ev->work);
}
/* 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_DP_HDMI_IN:
tunnel = tb_tunnel_discover_dp(tb, port);
break;
case TB_TYPE_PCIE_DOWN:
tunnel = tb_tunnel_discover_pci(tb, port);
break;
default:
break;
}
if (!tunnel)
continue;
if (tb_tunnel_is_pci(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_xdomain(struct tb_port *port)
{
struct tb_switch *sw = port->sw;
struct tb *tb = sw->tb;
struct tb_xdomain *xd;
u64 route;
route = tb_downstream_route(port);
xd = tb_xdomain_find_by_route(tb, route);
if (xd) {
tb_xdomain_put(xd);
return;
}
xd = tb_xdomain_alloc(tb, &sw->dev, route, tb->root_switch->uuid,
NULL);
if (xd) {
tb_port_at(route, sw)->xdomain = xd;
tb_xdomain_add(xd);
}
}
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 (tb_port_is_dpout(port) && tb_dp_port_hpd_is_active(port) == 1 &&
!tb_dp_port_is_enabled(port)) {
tb_port_dbg(port, "DP adapter HPD set, queuing hotplug\n");
tb_queue_hotplug(port->sw->tb, tb_route(port->sw), port->port,
false);
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_dbg(port, "port already has a remote\n");
return;
}
sw = tb_switch_alloc(port->sw->tb, &port->sw->dev,
tb_downstream_route(port));
if (IS_ERR(sw)) {
/*
* If there is an error accessing the connected switch
* it may be connected to another domain. Also we allow
* the other domain to be connected to a max depth switch.
*/
if (PTR_ERR(sw) == -EIO || PTR_ERR(sw) == -EADDRNOTAVAIL)
tb_scan_xdomain(port);
return;
}
if (tb_switch_configure(sw)) {
tb_switch_put(sw);
return;
}
/*
* If there was previously another domain connected remove it
* first.
*/
if (port->xdomain) {
tb_xdomain_remove(port->xdomain);
port->xdomain = NULL;
}
/*
* 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);
}
static int tb_free_tunnel(struct tb *tb, enum tb_tunnel_type type,
struct tb_port *src_port, struct tb_port *dst_port)
{
struct tb_cm *tcm = tb_priv(tb);
struct tb_tunnel *tunnel;
list_for_each_entry(tunnel, &tcm->tunnel_list, list) {
if (tunnel->type == type &&
((src_port && src_port == tunnel->src_port) ||
(dst_port && dst_port == tunnel->dst_port))) {
tb_tunnel_deactivate(tunnel);
list_del(&tunnel->list);
tb_tunnel_free(tunnel);
return 0;
}
}
return -ENODEV;
}
/**
* 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_dp(struct tb *tb, struct tb_port *out)
{
struct tb_cm *tcm = tb_priv(tb);
struct tb_switch *sw = out->sw;
struct tb_tunnel *tunnel;
struct tb_port *in;
if (tb_port_is_enabled(out))
return 0;
do {
sw = tb_to_switch(sw->dev.parent);
if (!sw)
return 0;
in = tb_find_unused_port(sw, TB_TYPE_DP_HDMI_IN);
} while (!in);
tunnel = tb_tunnel_alloc_dp(tb, in, out);
if (!tunnel) {
tb_port_dbg(out, "DP tunnel allocation failed\n");
return -ENOMEM;
}
if (tb_tunnel_activate(tunnel)) {
tb_port_info(out, "DP tunnel activation failed, aborting\n");
tb_tunnel_free(tunnel);
return -EIO;
}
list_add_tail(&tunnel->list, &tcm->tunnel_list);
return 0;
}
static void tb_teardown_dp(struct tb *tb, struct tb_port *out)
{
tb_free_tunnel(tb, TB_TUNNEL_DP, NULL, out);
}
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;
}
static int tb_approve_xdomain_paths(struct tb *tb, struct tb_xdomain *xd)
{
struct tb_cm *tcm = tb_priv(tb);
struct tb_port *nhi_port, *dst_port;
struct tb_tunnel *tunnel;
struct tb_switch *sw;
sw = tb_to_switch(xd->dev.parent);
dst_port = tb_port_at(xd->route, sw);
nhi_port = tb_find_port(tb->root_switch, TB_TYPE_NHI);
mutex_lock(&tb->lock);
tunnel = tb_tunnel_alloc_dma(tb, nhi_port, dst_port, xd->transmit_ring,
xd->transmit_path, xd->receive_ring,
xd->receive_path);
if (!tunnel) {
mutex_unlock(&tb->lock);
return -ENOMEM;
}
if (tb_tunnel_activate(tunnel)) {
tb_port_info(nhi_port,
"DMA tunnel activation failed, aborting\n");
tb_tunnel_free(tunnel);
mutex_unlock(&tb->lock);
return -EIO;
}
list_add_tail(&tunnel->list, &tcm->tunnel_list);
mutex_unlock(&tb->lock);
return 0;
}
static void __tb_disconnect_xdomain_paths(struct tb *tb, struct tb_xdomain *xd)
{
struct tb_port *dst_port;
struct tb_switch *sw;
sw = tb_to_switch(xd->dev.parent);
dst_port = tb_port_at(xd->route, sw);
/*
* It is possible that the tunnel was already teared down (in
* case of cable disconnect) so it is fine if we cannot find it
* here anymore.
*/
tb_free_tunnel(tb, TB_TUNNEL_DMA, NULL, dst_port);
}
static int tb_disconnect_xdomain_paths(struct tb *tb, struct tb_xdomain *xd)
{
if (!xd->is_unplugged) {
mutex_lock(&tb->lock);
__tb_disconnect_xdomain_paths(tb, xd);
mutex_unlock(&tb->lock);
}
return 0;
}
/* hotplug handling */
/**
* 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_dbg(port, "switch 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 if (port->xdomain) {
struct tb_xdomain *xd = tb_xdomain_get(port->xdomain);
tb_port_dbg(port, "xdomain unplugged\n");
/*
* Service drivers are unbound during
* tb_xdomain_remove() so setting XDomain as
* unplugged here prevents deadlock if they call
* tb_xdomain_disable_paths(). We will tear down
* the path below.
*/
xd->is_unplugged = true;
tb_xdomain_remove(xd);
port->xdomain = NULL;
__tb_disconnect_xdomain_paths(tb, xd);
tb_xdomain_put(xd);
} else if (tb_port_is_dpout(port)) {
tb_teardown_dp(tb, port);
} else {
tb_port_dbg(port,
"got unplug event for disconnected port, ignoring\n");
}
} else if (port->remote) {
tb_port_dbg(port, "got plug event for connected port, ignoring\n");
} else {
if (tb_port_is_null(port)) {
tb_port_dbg(port, "hotplug: scanning\n");
tb_scan_port(port);
if (!port->remote)
tb_port_dbg(port, "hotplug: no switch found\n");
} else if (tb_port_is_dpout(port)) {
tb_tunnel_dp(tb, port);
}
}
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;
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);
}
tb_queue_hotplug(tb, route, pkg->port, pkg->unplug);
}
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) {
/*
* DMA tunnels require the driver to be functional so we
* tear them down. Other protocol tunnels can be left
* intact.
*/
if (tb_tunnel_is_dma(tunnel))
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 (IS_ERR(tb->root_switch))
return PTR_ERR(tb->root_switch);
/*
* 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 int tb_free_unplugged_xdomains(struct tb_switch *sw)
{
int i, ret = 0;
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->xdomain && port->xdomain->is_unplugged) {
tb_xdomain_remove(port->xdomain);
port->xdomain = NULL;
ret++;
} else if (port->remote) {
ret += tb_free_unplugged_xdomains(port->remote->sw);
}
}
return ret;
}
static void tb_complete(struct tb *tb)
{
/*
* Release any unplugged XDomains and if there is a case where
* another domain is swapped in place of unplugged XDomain we
* need to run another rescan.
*/
mutex_lock(&tb->lock);
if (tb_free_unplugged_xdomains(tb->root_switch))
tb_scan_switch(tb->root_switch);
mutex_unlock(&tb->lock);
}
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,
.complete = tb_complete,
.handle_event = tb_handle_event,
.approve_switch = tb_tunnel_pci,
.approve_xdomain_paths = tb_approve_xdomain_paths,
.disconnect_xdomain_paths = tb_disconnect_xdomain_paths,
};
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;
}