diff options
Diffstat (limited to 'drivers/thunderbolt/tb.c')
| -rw-r--r-- | drivers/thunderbolt/tb.c | 475 |
1 files changed, 475 insertions, 0 deletions
diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c new file mode 100644 index 000000000..146f261bf --- /dev/null +++ b/drivers/thunderbolt/tb.c @@ -0,0 +1,475 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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 <linux/platform_data/x86/apple.h> + +#include "tb.h" +#include "tb_regs.h" +#include "tunnel_pci.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_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, &port->sw->dev, + tb_downstream_route(port)); + if (!sw) + return; + + if (tb_switch_configure(sw)) { + tb_switch_put(sw); + return; + } + + sw->authorized = true; + + if (tb_switch_add(sw)) { + tb_switch_put(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_cm *tcm = tb_priv(tb); + struct tb_pci_tunnel *tunnel; + struct tb_pci_tunnel *n; + + list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) { + if (tb_pci_is_invalid(tunnel)) { + tb_pci_deactivate(tunnel); + list_del(&tunnel->list); + 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_remove(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_port_find_cap(&sw->ports[i], TB_PORT_CAP_ADAP); + 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; + struct tb_cm *tcm = tb_priv(tb); + + /* 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_port_find_cap(up_port, TB_PORT_CAP_ADAP); + 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); + continue; + } + + list_add(&tunnel->list, &tcm->tunnel_list); + } +} + +/* 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_warn(tb, + "hotplug event for upstream port %llx:%x (unplug: %d)\n", + ev->route, ev->port, ev->unplug); + goto put_sw; + } + if (ev->unplug) { + if (port->remote) { + 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; + } 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); + } + } + +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_pci_tunnel *tunnel; + struct tb_pci_tunnel *n; + + /* tunnels are only present after everything has been initialized */ + list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) { + tb_pci_deactivate(tunnel); + tb_pci_free(tunnel); + } + tb_switch_remove(tb->root_switch); + tcm->hotplug_active = false; /* signal tb_handle_hotplug to quit */ +} + +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); + tb_activate_pcie_devices(tb); + + /* 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_info(tb, "suspending...\n"); + tb_switch_suspend(tb->root_switch); + tcm->hotplug_active = false; /* signal tb_handle_hotplug to quit */ + tb_info(tb, "suspend finished\n"); + + return 0; +} + +static int tb_resume_noirq(struct tb *tb) +{ + struct tb_cm *tcm = tb_priv(tb); + struct tb_pci_tunnel *tunnel, *n; + + tb_info(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_pci_restart(tunnel); + if (!list_empty(&tcm->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 */ + tcm->hotplug_active = true; + tb_info(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, +}; + +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_NONE; + tb->cm_ops = &tb_cm_ops; + + tcm = tb_priv(tb); + INIT_LIST_HEAD(&tcm->tunnel_list); + + return tb; +} |