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