1 files changed, 436 insertions, 0 deletions
diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
new file mode 100644
index 000000000000..d2c3fe346e91
--- /dev/null
+++ b/drivers/thunderbolt/tb.c
@@ -0,0 +1,436 @@
+/*
+ * 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");
+}