diff options
Diffstat (limited to 'drivers/greybus/connection.c')
| -rw-r--r-- | drivers/greybus/connection.c | 942 |
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); |