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path: root/drivers/greybus/connection.c
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-rw-r--r--drivers/greybus/connection.c942
1 files changed, 942 insertions, 0 deletions
diff --git a/drivers/greybus/connection.c b/drivers/greybus/connection.c
new file mode 100644
index 000000000000..fc8f57f97ce6
--- /dev/null
+++ b/drivers/greybus/connection.c
@@ -0,0 +1,942 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Greybus connections
+ *
+ * Copyright 2014 Google Inc.
+ * Copyright 2014 Linaro Ltd.
+ */
+
+#include <linux/workqueue.h>
+#include <linux/greybus.h>
+
+#include "greybus_trace.h"
+
+#define GB_CONNECTION_CPORT_QUIESCE_TIMEOUT 1000
+
+static void gb_connection_kref_release(struct kref *kref);
+
+static DEFINE_SPINLOCK(gb_connections_lock);
+static DEFINE_MUTEX(gb_connection_mutex);
+
+/* Caller holds gb_connection_mutex. */
+static bool gb_connection_cport_in_use(struct gb_interface *intf, u16 cport_id)
+{
+ struct gb_host_device *hd = intf->hd;
+ struct gb_connection *connection;
+
+ list_for_each_entry(connection, &hd->connections, hd_links) {
+ if (connection->intf == intf &&
+ connection->intf_cport_id == cport_id)
+ return true;
+ }
+
+ return false;
+}
+
+static void gb_connection_get(struct gb_connection *connection)
+{
+ kref_get(&connection->kref);
+
+ trace_gb_connection_get(connection);
+}
+
+static void gb_connection_put(struct gb_connection *connection)
+{
+ trace_gb_connection_put(connection);
+
+ kref_put(&connection->kref, gb_connection_kref_release);
+}
+
+/*
+ * Returns a reference-counted pointer to the connection if found.
+ */
+static struct gb_connection *
+gb_connection_hd_find(struct gb_host_device *hd, u16 cport_id)
+{
+ struct gb_connection *connection;
+ unsigned long flags;
+
+ spin_lock_irqsave(&gb_connections_lock, flags);
+ list_for_each_entry(connection, &hd->connections, hd_links)
+ if (connection->hd_cport_id == cport_id) {
+ gb_connection_get(connection);
+ goto found;
+ }
+ connection = NULL;
+found:
+ spin_unlock_irqrestore(&gb_connections_lock, flags);
+
+ return connection;
+}
+
+/*
+ * Callback from the host driver to let us know that data has been
+ * received on the bundle.
+ */
+void greybus_data_rcvd(struct gb_host_device *hd, u16 cport_id,
+ u8 *data, size_t length)
+{
+ struct gb_connection *connection;
+
+ trace_gb_hd_in(hd);
+
+ connection = gb_connection_hd_find(hd, cport_id);
+ if (!connection) {
+ dev_err(&hd->dev,
+ "nonexistent connection (%zu bytes dropped)\n", length);
+ return;
+ }
+ gb_connection_recv(connection, data, length);
+ gb_connection_put(connection);
+}
+EXPORT_SYMBOL_GPL(greybus_data_rcvd);
+
+static void gb_connection_kref_release(struct kref *kref)
+{
+ struct gb_connection *connection;
+
+ connection = container_of(kref, struct gb_connection, kref);
+
+ trace_gb_connection_release(connection);
+
+ kfree(connection);
+}
+
+static void gb_connection_init_name(struct gb_connection *connection)
+{
+ u16 hd_cport_id = connection->hd_cport_id;
+ u16 cport_id = 0;
+ u8 intf_id = 0;
+
+ if (connection->intf) {
+ intf_id = connection->intf->interface_id;
+ cport_id = connection->intf_cport_id;
+ }
+
+ snprintf(connection->name, sizeof(connection->name),
+ "%u/%u:%u", hd_cport_id, intf_id, cport_id);
+}
+
+/*
+ * _gb_connection_create() - create a Greybus connection
+ * @hd: host device of the connection
+ * @hd_cport_id: host-device cport id, or -1 for dynamic allocation
+ * @intf: remote interface, or NULL for static connections
+ * @bundle: remote-interface bundle (may be NULL)
+ * @cport_id: remote-interface cport id, or 0 for static connections
+ * @handler: request handler (may be NULL)
+ * @flags: connection flags
+ *
+ * Create a Greybus connection, representing the bidirectional link
+ * between a CPort on a (local) Greybus host device and a CPort on
+ * another Greybus interface.
+ *
+ * A connection also maintains the state of operations sent over the
+ * connection.
+ *
+ * Serialised against concurrent create and destroy using the
+ * gb_connection_mutex.
+ *
+ * Return: A pointer to the new connection if successful, or an ERR_PTR
+ * otherwise.
+ */
+static struct gb_connection *
+_gb_connection_create(struct gb_host_device *hd, int hd_cport_id,
+ struct gb_interface *intf,
+ struct gb_bundle *bundle, int cport_id,
+ gb_request_handler_t handler,
+ unsigned long flags)
+{
+ struct gb_connection *connection;
+ int ret;
+
+ mutex_lock(&gb_connection_mutex);
+
+ if (intf && gb_connection_cport_in_use(intf, cport_id)) {
+ dev_err(&intf->dev, "cport %u already in use\n", cport_id);
+ ret = -EBUSY;
+ goto err_unlock;
+ }
+
+ ret = gb_hd_cport_allocate(hd, hd_cport_id, flags);
+ if (ret < 0) {
+ dev_err(&hd->dev, "failed to allocate cport: %d\n", ret);
+ goto err_unlock;
+ }
+ hd_cport_id = ret;
+
+ connection = kzalloc(sizeof(*connection), GFP_KERNEL);
+ if (!connection) {
+ ret = -ENOMEM;
+ goto err_hd_cport_release;
+ }
+
+ connection->hd_cport_id = hd_cport_id;
+ connection->intf_cport_id = cport_id;
+ connection->hd = hd;
+ connection->intf = intf;
+ connection->bundle = bundle;
+ connection->handler = handler;
+ connection->flags = flags;
+ if (intf && (intf->quirks & GB_INTERFACE_QUIRK_NO_CPORT_FEATURES))
+ connection->flags |= GB_CONNECTION_FLAG_NO_FLOWCTRL;
+ connection->state = GB_CONNECTION_STATE_DISABLED;
+
+ atomic_set(&connection->op_cycle, 0);
+ mutex_init(&connection->mutex);
+ spin_lock_init(&connection->lock);
+ INIT_LIST_HEAD(&connection->operations);
+
+ connection->wq = alloc_workqueue("%s:%d", WQ_UNBOUND, 1,
+ dev_name(&hd->dev), hd_cport_id);
+ if (!connection->wq) {
+ ret = -ENOMEM;
+ goto err_free_connection;
+ }
+
+ kref_init(&connection->kref);
+
+ gb_connection_init_name(connection);
+
+ spin_lock_irq(&gb_connections_lock);
+ list_add(&connection->hd_links, &hd->connections);
+
+ if (bundle)
+ list_add(&connection->bundle_links, &bundle->connections);
+ else
+ INIT_LIST_HEAD(&connection->bundle_links);
+
+ spin_unlock_irq(&gb_connections_lock);
+
+ mutex_unlock(&gb_connection_mutex);
+
+ trace_gb_connection_create(connection);
+
+ return connection;
+
+err_free_connection:
+ kfree(connection);
+err_hd_cport_release:
+ gb_hd_cport_release(hd, hd_cport_id);
+err_unlock:
+ mutex_unlock(&gb_connection_mutex);
+
+ return ERR_PTR(ret);
+}
+
+struct gb_connection *
+gb_connection_create_static(struct gb_host_device *hd, u16 hd_cport_id,
+ gb_request_handler_t handler)
+{
+ return _gb_connection_create(hd, hd_cport_id, NULL, NULL, 0, handler,
+ GB_CONNECTION_FLAG_HIGH_PRIO);
+}
+
+struct gb_connection *
+gb_connection_create_control(struct gb_interface *intf)
+{
+ return _gb_connection_create(intf->hd, -1, intf, NULL, 0, NULL,
+ GB_CONNECTION_FLAG_CONTROL |
+ GB_CONNECTION_FLAG_HIGH_PRIO);
+}
+
+struct gb_connection *
+gb_connection_create(struct gb_bundle *bundle, u16 cport_id,
+ gb_request_handler_t handler)
+{
+ struct gb_interface *intf = bundle->intf;
+
+ return _gb_connection_create(intf->hd, -1, intf, bundle, cport_id,
+ handler, 0);
+}
+EXPORT_SYMBOL_GPL(gb_connection_create);
+
+struct gb_connection *
+gb_connection_create_flags(struct gb_bundle *bundle, u16 cport_id,
+ gb_request_handler_t handler,
+ unsigned long flags)
+{
+ struct gb_interface *intf = bundle->intf;
+
+ if (WARN_ON_ONCE(flags & GB_CONNECTION_FLAG_CORE_MASK))
+ flags &= ~GB_CONNECTION_FLAG_CORE_MASK;
+
+ return _gb_connection_create(intf->hd, -1, intf, bundle, cport_id,
+ handler, flags);
+}
+EXPORT_SYMBOL_GPL(gb_connection_create_flags);
+
+struct gb_connection *
+gb_connection_create_offloaded(struct gb_bundle *bundle, u16 cport_id,
+ unsigned long flags)
+{
+ flags |= GB_CONNECTION_FLAG_OFFLOADED;
+
+ return gb_connection_create_flags(bundle, cport_id, NULL, flags);
+}
+EXPORT_SYMBOL_GPL(gb_connection_create_offloaded);
+
+static int gb_connection_hd_cport_enable(struct gb_connection *connection)
+{
+ struct gb_host_device *hd = connection->hd;
+ int ret;
+
+ if (!hd->driver->cport_enable)
+ return 0;
+
+ ret = hd->driver->cport_enable(hd, connection->hd_cport_id,
+ connection->flags);
+ if (ret) {
+ dev_err(&hd->dev, "%s: failed to enable host cport: %d\n",
+ connection->name, ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void gb_connection_hd_cport_disable(struct gb_connection *connection)
+{
+ struct gb_host_device *hd = connection->hd;
+ int ret;
+
+ if (!hd->driver->cport_disable)
+ return;
+
+ ret = hd->driver->cport_disable(hd, connection->hd_cport_id);
+ if (ret) {
+ dev_err(&hd->dev, "%s: failed to disable host cport: %d\n",
+ connection->name, ret);
+ }
+}
+
+static int gb_connection_hd_cport_connected(struct gb_connection *connection)
+{
+ struct gb_host_device *hd = connection->hd;
+ int ret;
+
+ if (!hd->driver->cport_connected)
+ return 0;
+
+ ret = hd->driver->cport_connected(hd, connection->hd_cport_id);
+ if (ret) {
+ dev_err(&hd->dev, "%s: failed to set connected state: %d\n",
+ connection->name, ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int gb_connection_hd_cport_flush(struct gb_connection *connection)
+{
+ struct gb_host_device *hd = connection->hd;
+ int ret;
+
+ if (!hd->driver->cport_flush)
+ return 0;
+
+ ret = hd->driver->cport_flush(hd, connection->hd_cport_id);
+ if (ret) {
+ dev_err(&hd->dev, "%s: failed to flush host cport: %d\n",
+ connection->name, ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int gb_connection_hd_cport_quiesce(struct gb_connection *connection)
+{
+ struct gb_host_device *hd = connection->hd;
+ size_t peer_space;
+ int ret;
+
+ if (!hd->driver->cport_quiesce)
+ return 0;
+
+ peer_space = sizeof(struct gb_operation_msg_hdr) +
+ sizeof(struct gb_cport_shutdown_request);
+
+ if (connection->mode_switch)
+ peer_space += sizeof(struct gb_operation_msg_hdr);
+
+ if (!hd->driver->cport_quiesce)
+ return 0;
+
+ ret = hd->driver->cport_quiesce(hd, connection->hd_cport_id,
+ peer_space,
+ GB_CONNECTION_CPORT_QUIESCE_TIMEOUT);
+ if (ret) {
+ dev_err(&hd->dev, "%s: failed to quiesce host cport: %d\n",
+ connection->name, ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int gb_connection_hd_cport_clear(struct gb_connection *connection)
+{
+ struct gb_host_device *hd = connection->hd;
+ int ret;
+
+ if (!hd->driver->cport_clear)
+ return 0;
+
+ ret = hd->driver->cport_clear(hd, connection->hd_cport_id);
+ if (ret) {
+ dev_err(&hd->dev, "%s: failed to clear host cport: %d\n",
+ connection->name, ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+/*
+ * Request the SVC to create a connection from AP's cport to interface's
+ * cport.
+ */
+static int
+gb_connection_svc_connection_create(struct gb_connection *connection)
+{
+ struct gb_host_device *hd = connection->hd;
+ struct gb_interface *intf;
+ u8 cport_flags;
+ int ret;
+
+ if (gb_connection_is_static(connection))
+ return 0;
+
+ intf = connection->intf;
+
+ /*
+ * Enable either E2EFC or CSD, unless no flow control is requested.
+ */
+ cport_flags = GB_SVC_CPORT_FLAG_CSV_N;
+ if (gb_connection_flow_control_disabled(connection)) {
+ cport_flags |= GB_SVC_CPORT_FLAG_CSD_N;
+ } else if (gb_connection_e2efc_enabled(connection)) {
+ cport_flags |= GB_SVC_CPORT_FLAG_CSD_N |
+ GB_SVC_CPORT_FLAG_E2EFC;
+ }
+
+ ret = gb_svc_connection_create(hd->svc,
+ hd->svc->ap_intf_id,
+ connection->hd_cport_id,
+ intf->interface_id,
+ connection->intf_cport_id,
+ cport_flags);
+ if (ret) {
+ dev_err(&connection->hd->dev,
+ "%s: failed to create svc connection: %d\n",
+ connection->name, ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void
+gb_connection_svc_connection_destroy(struct gb_connection *connection)
+{
+ if (gb_connection_is_static(connection))
+ return;
+
+ gb_svc_connection_destroy(connection->hd->svc,
+ connection->hd->svc->ap_intf_id,
+ connection->hd_cport_id,
+ connection->intf->interface_id,
+ connection->intf_cport_id);
+}
+
+/* Inform Interface about active CPorts */
+static int gb_connection_control_connected(struct gb_connection *connection)
+{
+ struct gb_control *control;
+ u16 cport_id = connection->intf_cport_id;
+ int ret;
+
+ if (gb_connection_is_static(connection))
+ return 0;
+
+ if (gb_connection_is_control(connection))
+ return 0;
+
+ control = connection->intf->control;
+
+ ret = gb_control_connected_operation(control, cport_id);
+ if (ret) {
+ dev_err(&connection->bundle->dev,
+ "failed to connect cport: %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void
+gb_connection_control_disconnecting(struct gb_connection *connection)
+{
+ struct gb_control *control;
+ u16 cport_id = connection->intf_cport_id;
+ int ret;
+
+ if (gb_connection_is_static(connection))
+ return;
+
+ control = connection->intf->control;
+
+ ret = gb_control_disconnecting_operation(control, cport_id);
+ if (ret) {
+ dev_err(&connection->hd->dev,
+ "%s: failed to send disconnecting: %d\n",
+ connection->name, ret);
+ }
+}
+
+static void
+gb_connection_control_disconnected(struct gb_connection *connection)
+{
+ struct gb_control *control;
+ u16 cport_id = connection->intf_cport_id;
+ int ret;
+
+ if (gb_connection_is_static(connection))
+ return;
+
+ control = connection->intf->control;
+
+ if (gb_connection_is_control(connection)) {
+ if (connection->mode_switch) {
+ ret = gb_control_mode_switch_operation(control);
+ if (ret) {
+ /*
+ * Allow mode switch to time out waiting for
+ * mailbox event.
+ */
+ return;
+ }
+ }
+
+ return;
+ }
+
+ ret = gb_control_disconnected_operation(control, cport_id);
+ if (ret) {
+ dev_warn(&connection->bundle->dev,
+ "failed to disconnect cport: %d\n", ret);
+ }
+}
+
+static int gb_connection_shutdown_operation(struct gb_connection *connection,
+ u8 phase)
+{
+ struct gb_cport_shutdown_request *req;
+ struct gb_operation *operation;
+ int ret;
+
+ operation = gb_operation_create_core(connection,
+ GB_REQUEST_TYPE_CPORT_SHUTDOWN,
+ sizeof(*req), 0, 0,
+ GFP_KERNEL);
+ if (!operation)
+ return -ENOMEM;
+
+ req = operation->request->payload;
+ req->phase = phase;
+
+ ret = gb_operation_request_send_sync(operation);
+
+ gb_operation_put(operation);
+
+ return ret;
+}
+
+static int gb_connection_cport_shutdown(struct gb_connection *connection,
+ u8 phase)
+{
+ struct gb_host_device *hd = connection->hd;
+ const struct gb_hd_driver *drv = hd->driver;
+ int ret;
+
+ if (gb_connection_is_static(connection))
+ return 0;
+
+ if (gb_connection_is_offloaded(connection)) {
+ if (!drv->cport_shutdown)
+ return 0;
+
+ ret = drv->cport_shutdown(hd, connection->hd_cport_id, phase,
+ GB_OPERATION_TIMEOUT_DEFAULT);
+ } else {
+ ret = gb_connection_shutdown_operation(connection, phase);
+ }
+
+ if (ret) {
+ dev_err(&hd->dev, "%s: failed to send cport shutdown (phase %d): %d\n",
+ connection->name, phase, ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int
+gb_connection_cport_shutdown_phase_1(struct gb_connection *connection)
+{
+ return gb_connection_cport_shutdown(connection, 1);
+}
+
+static int
+gb_connection_cport_shutdown_phase_2(struct gb_connection *connection)
+{
+ return gb_connection_cport_shutdown(connection, 2);
+}
+
+/*
+ * Cancel all active operations on a connection.
+ *
+ * Locking: Called with connection lock held and state set to DISABLED or
+ * DISCONNECTING.
+ */
+static void gb_connection_cancel_operations(struct gb_connection *connection,
+ int errno)
+ __must_hold(&connection->lock)
+{
+ struct gb_operation *operation;
+
+ while (!list_empty(&connection->operations)) {
+ operation = list_last_entry(&connection->operations,
+ struct gb_operation, links);
+ gb_operation_get(operation);
+ spin_unlock_irq(&connection->lock);
+
+ if (gb_operation_is_incoming(operation))
+ gb_operation_cancel_incoming(operation, errno);
+ else
+ gb_operation_cancel(operation, errno);
+
+ gb_operation_put(operation);
+
+ spin_lock_irq(&connection->lock);
+ }
+}
+
+/*
+ * Cancel all active incoming operations on a connection.
+ *
+ * Locking: Called with connection lock held and state set to ENABLED_TX.
+ */
+static void
+gb_connection_flush_incoming_operations(struct gb_connection *connection,
+ int errno)
+ __must_hold(&connection->lock)
+{
+ struct gb_operation *operation;
+ bool incoming;
+
+ while (!list_empty(&connection->operations)) {
+ incoming = false;
+ list_for_each_entry(operation, &connection->operations,
+ links) {
+ if (gb_operation_is_incoming(operation)) {
+ gb_operation_get(operation);
+ incoming = true;
+ break;
+ }
+ }
+
+ if (!incoming)
+ break;
+
+ spin_unlock_irq(&connection->lock);
+
+ /* FIXME: flush, not cancel? */
+ gb_operation_cancel_incoming(operation, errno);
+ gb_operation_put(operation);
+
+ spin_lock_irq(&connection->lock);
+ }
+}
+
+/*
+ * _gb_connection_enable() - enable a connection
+ * @connection: connection to enable
+ * @rx: whether to enable incoming requests
+ *
+ * Connection-enable helper for DISABLED->ENABLED, DISABLED->ENABLED_TX, and
+ * ENABLED_TX->ENABLED state transitions.
+ *
+ * Locking: Caller holds connection->mutex.
+ */
+static int _gb_connection_enable(struct gb_connection *connection, bool rx)
+{
+ int ret;
+
+ /* Handle ENABLED_TX -> ENABLED transitions. */
+ if (connection->state == GB_CONNECTION_STATE_ENABLED_TX) {
+ if (!(connection->handler && rx))
+ return 0;
+
+ spin_lock_irq(&connection->lock);
+ connection->state = GB_CONNECTION_STATE_ENABLED;
+ spin_unlock_irq(&connection->lock);
+
+ return 0;
+ }
+
+ ret = gb_connection_hd_cport_enable(connection);
+ if (ret)
+ return ret;
+
+ ret = gb_connection_svc_connection_create(connection);
+ if (ret)
+ goto err_hd_cport_clear;
+
+ ret = gb_connection_hd_cport_connected(connection);
+ if (ret)
+ goto err_svc_connection_destroy;
+
+ spin_lock_irq(&connection->lock);
+ if (connection->handler && rx)
+ connection->state = GB_CONNECTION_STATE_ENABLED;
+ else
+ connection->state = GB_CONNECTION_STATE_ENABLED_TX;
+ spin_unlock_irq(&connection->lock);
+
+ ret = gb_connection_control_connected(connection);
+ if (ret)
+ goto err_control_disconnecting;
+
+ return 0;
+
+err_control_disconnecting:
+ spin_lock_irq(&connection->lock);
+ connection->state = GB_CONNECTION_STATE_DISCONNECTING;
+ gb_connection_cancel_operations(connection, -ESHUTDOWN);
+ spin_unlock_irq(&connection->lock);
+
+ /* Transmit queue should already be empty. */
+ gb_connection_hd_cport_flush(connection);
+
+ gb_connection_control_disconnecting(connection);
+ gb_connection_cport_shutdown_phase_1(connection);
+ gb_connection_hd_cport_quiesce(connection);
+ gb_connection_cport_shutdown_phase_2(connection);
+ gb_connection_control_disconnected(connection);
+ connection->state = GB_CONNECTION_STATE_DISABLED;
+err_svc_connection_destroy:
+ gb_connection_svc_connection_destroy(connection);
+err_hd_cport_clear:
+ gb_connection_hd_cport_clear(connection);
+
+ gb_connection_hd_cport_disable(connection);
+
+ return ret;
+}
+
+int gb_connection_enable(struct gb_connection *connection)
+{
+ int ret = 0;
+
+ mutex_lock(&connection->mutex);
+
+ if (connection->state == GB_CONNECTION_STATE_ENABLED)
+ goto out_unlock;
+
+ ret = _gb_connection_enable(connection, true);
+ if (!ret)
+ trace_gb_connection_enable(connection);
+
+out_unlock:
+ mutex_unlock(&connection->mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(gb_connection_enable);
+
+int gb_connection_enable_tx(struct gb_connection *connection)
+{
+ int ret = 0;
+
+ mutex_lock(&connection->mutex);
+
+ if (connection->state == GB_CONNECTION_STATE_ENABLED) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+
+ if (connection->state == GB_CONNECTION_STATE_ENABLED_TX)
+ goto out_unlock;
+
+ ret = _gb_connection_enable(connection, false);
+ if (!ret)
+ trace_gb_connection_enable(connection);
+
+out_unlock:
+ mutex_unlock(&connection->mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(gb_connection_enable_tx);
+
+void gb_connection_disable_rx(struct gb_connection *connection)
+{
+ mutex_lock(&connection->mutex);
+
+ spin_lock_irq(&connection->lock);
+ if (connection->state != GB_CONNECTION_STATE_ENABLED) {
+ spin_unlock_irq(&connection->lock);
+ goto out_unlock;
+ }
+ connection->state = GB_CONNECTION_STATE_ENABLED_TX;
+ gb_connection_flush_incoming_operations(connection, -ESHUTDOWN);
+ spin_unlock_irq(&connection->lock);
+
+ trace_gb_connection_disable(connection);
+
+out_unlock:
+ mutex_unlock(&connection->mutex);
+}
+EXPORT_SYMBOL_GPL(gb_connection_disable_rx);
+
+void gb_connection_mode_switch_prepare(struct gb_connection *connection)
+{
+ connection->mode_switch = true;
+}
+
+void gb_connection_mode_switch_complete(struct gb_connection *connection)
+{
+ gb_connection_svc_connection_destroy(connection);
+ gb_connection_hd_cport_clear(connection);
+
+ gb_connection_hd_cport_disable(connection);
+
+ connection->mode_switch = false;
+}
+
+void gb_connection_disable(struct gb_connection *connection)
+{
+ mutex_lock(&connection->mutex);
+
+ if (connection->state == GB_CONNECTION_STATE_DISABLED)
+ goto out_unlock;
+
+ trace_gb_connection_disable(connection);
+
+ spin_lock_irq(&connection->lock);
+ connection->state = GB_CONNECTION_STATE_DISCONNECTING;
+ gb_connection_cancel_operations(connection, -ESHUTDOWN);
+ spin_unlock_irq(&connection->lock);
+
+ gb_connection_hd_cport_flush(connection);
+
+ gb_connection_control_disconnecting(connection);
+ gb_connection_cport_shutdown_phase_1(connection);
+ gb_connection_hd_cport_quiesce(connection);
+ gb_connection_cport_shutdown_phase_2(connection);
+ gb_connection_control_disconnected(connection);
+
+ connection->state = GB_CONNECTION_STATE_DISABLED;
+
+ /* control-connection tear down is deferred when mode switching */
+ if (!connection->mode_switch) {
+ gb_connection_svc_connection_destroy(connection);
+ gb_connection_hd_cport_clear(connection);
+
+ gb_connection_hd_cport_disable(connection);
+ }
+
+out_unlock:
+ mutex_unlock(&connection->mutex);
+}
+EXPORT_SYMBOL_GPL(gb_connection_disable);
+
+/* Disable a connection without communicating with the remote end. */
+void gb_connection_disable_forced(struct gb_connection *connection)
+{
+ mutex_lock(&connection->mutex);
+
+ if (connection->state == GB_CONNECTION_STATE_DISABLED)
+ goto out_unlock;
+
+ trace_gb_connection_disable(connection);
+
+ spin_lock_irq(&connection->lock);
+ connection->state = GB_CONNECTION_STATE_DISABLED;
+ gb_connection_cancel_operations(connection, -ESHUTDOWN);
+ spin_unlock_irq(&connection->lock);
+
+ gb_connection_hd_cport_flush(connection);
+
+ gb_connection_svc_connection_destroy(connection);
+ gb_connection_hd_cport_clear(connection);
+
+ gb_connection_hd_cport_disable(connection);
+out_unlock:
+ mutex_unlock(&connection->mutex);
+}
+EXPORT_SYMBOL_GPL(gb_connection_disable_forced);
+
+/* Caller must have disabled the connection before destroying it. */
+void gb_connection_destroy(struct gb_connection *connection)
+{
+ if (!connection)
+ return;
+
+ if (WARN_ON(connection->state != GB_CONNECTION_STATE_DISABLED))
+ gb_connection_disable(connection);
+
+ mutex_lock(&gb_connection_mutex);
+
+ spin_lock_irq(&gb_connections_lock);
+ list_del(&connection->bundle_links);
+ list_del(&connection->hd_links);
+ spin_unlock_irq(&gb_connections_lock);
+
+ destroy_workqueue(connection->wq);
+
+ gb_hd_cport_release(connection->hd, connection->hd_cport_id);
+ connection->hd_cport_id = CPORT_ID_BAD;
+
+ mutex_unlock(&gb_connection_mutex);
+
+ gb_connection_put(connection);
+}
+EXPORT_SYMBOL_GPL(gb_connection_destroy);
+
+void gb_connection_latency_tag_enable(struct gb_connection *connection)
+{
+ struct gb_host_device *hd = connection->hd;
+ int ret;
+
+ if (!hd->driver->latency_tag_enable)
+ return;
+
+ ret = hd->driver->latency_tag_enable(hd, connection->hd_cport_id);
+ if (ret) {
+ dev_err(&connection->hd->dev,
+ "%s: failed to enable latency tag: %d\n",
+ connection->name, ret);
+ }
+}
+EXPORT_SYMBOL_GPL(gb_connection_latency_tag_enable);
+
+void gb_connection_latency_tag_disable(struct gb_connection *connection)
+{
+ struct gb_host_device *hd = connection->hd;
+ int ret;
+
+ if (!hd->driver->latency_tag_disable)
+ return;
+
+ ret = hd->driver->latency_tag_disable(hd, connection->hd_cport_id);
+ if (ret) {
+ dev_err(&connection->hd->dev,
+ "%s: failed to disable latency tag: %d\n",
+ connection->name, ret);
+ }
+}
+EXPORT_SYMBOL_GPL(gb_connection_latency_tag_disable);