4 * Copyright 2014 Google Inc.
5 * Copyright 2014 Linaro Ltd.
7 * Released under the GPLv2 only.
10 #include <linux/workqueue.h>
13 #include "greybus_trace.h"
16 #define GB_CONNECTION_CPORT_QUIESCE_TIMEOUT 1000
19 static void gb_connection_kref_release(struct kref *kref);
22 static DEFINE_SPINLOCK(gb_connections_lock);
23 static DEFINE_MUTEX(gb_connection_mutex);
26 /* Caller holds gb_connection_mutex. */
27 static bool gb_connection_cport_in_use(struct gb_interface *intf, u16 cport_id)
29 struct gb_host_device *hd = intf->hd;
30 struct gb_connection *connection;
32 list_for_each_entry(connection, &hd->connections, hd_links) {
33 if (connection->intf == intf &&
34 connection->intf_cport_id == cport_id)
41 static void gb_connection_get(struct gb_connection *connection)
43 kref_get(&connection->kref);
45 trace_gb_connection_get(connection);
48 static void gb_connection_put(struct gb_connection *connection)
50 trace_gb_connection_put(connection);
52 kref_put(&connection->kref, gb_connection_kref_release);
56 * Returns a reference-counted pointer to the connection if found.
58 static struct gb_connection *
59 gb_connection_hd_find(struct gb_host_device *hd, u16 cport_id)
61 struct gb_connection *connection;
64 spin_lock_irqsave(&gb_connections_lock, flags);
65 list_for_each_entry(connection, &hd->connections, hd_links)
66 if (connection->hd_cport_id == cport_id) {
67 gb_connection_get(connection);
72 spin_unlock_irqrestore(&gb_connections_lock, flags);
78 * Callback from the host driver to let us know that data has been
79 * received on the bundle.
81 void greybus_data_rcvd(struct gb_host_device *hd, u16 cport_id,
82 u8 *data, size_t length)
84 struct gb_connection *connection;
88 connection = gb_connection_hd_find(hd, cport_id);
91 "nonexistent connection (%zu bytes dropped)\n", length);
94 gb_connection_recv(connection, data, length);
95 gb_connection_put(connection);
97 EXPORT_SYMBOL_GPL(greybus_data_rcvd);
99 static void gb_connection_kref_release(struct kref *kref)
101 struct gb_connection *connection;
103 connection = container_of(kref, struct gb_connection, kref);
105 trace_gb_connection_release(connection);
110 static void gb_connection_init_name(struct gb_connection *connection)
112 u16 hd_cport_id = connection->hd_cport_id;
116 if (connection->intf) {
117 intf_id = connection->intf->interface_id;
118 cport_id = connection->intf_cport_id;
121 snprintf(connection->name, sizeof(connection->name),
122 "%u/%u:%u", hd_cport_id, intf_id, cport_id);
126 * _gb_connection_create() - create a Greybus connection
127 * @hd: host device of the connection
128 * @hd_cport_id: host-device cport id, or -1 for dynamic allocation
129 * @intf: remote interface, or NULL for static connections
130 * @bundle: remote-interface bundle (may be NULL)
131 * @cport_id: remote-interface cport id, or 0 for static connections
132 * @handler: request handler (may be NULL)
133 * @flags: connection flags
135 * Create a Greybus connection, representing the bidirectional link
136 * between a CPort on a (local) Greybus host device and a CPort on
137 * another Greybus interface.
139 * A connection also maintains the state of operations sent over the
142 * Serialised against concurrent create and destroy using the
143 * gb_connection_mutex.
145 * Return: A pointer to the new connection if successful, or an ERR_PTR
148 static struct gb_connection *
149 _gb_connection_create(struct gb_host_device *hd, int hd_cport_id,
150 struct gb_interface *intf,
151 struct gb_bundle *bundle, int cport_id,
152 gb_request_handler_t handler,
155 struct gb_connection *connection;
158 mutex_lock(&gb_connection_mutex);
160 if (intf && gb_connection_cport_in_use(intf, cport_id)) {
161 dev_err(&intf->dev, "cport %u already in use\n", cport_id);
166 ret = gb_hd_cport_allocate(hd, hd_cport_id, flags);
168 dev_err(&hd->dev, "failed to allocate cport: %d\n", ret);
173 connection = kzalloc(sizeof(*connection), GFP_KERNEL);
176 goto err_hd_cport_release;
179 connection->hd_cport_id = hd_cport_id;
180 connection->intf_cport_id = cport_id;
182 connection->intf = intf;
183 connection->bundle = bundle;
184 connection->handler = handler;
185 connection->flags = flags;
186 if (intf && (intf->quirks & GB_INTERFACE_QUIRK_NO_CPORT_FEATURES))
187 connection->flags |= GB_CONNECTION_FLAG_NO_FLOWCTRL;
188 connection->state = GB_CONNECTION_STATE_DISABLED;
190 atomic_set(&connection->op_cycle, 0);
191 mutex_init(&connection->mutex);
192 spin_lock_init(&connection->lock);
193 INIT_LIST_HEAD(&connection->operations);
195 connection->wq = alloc_workqueue("%s:%d", WQ_UNBOUND, 1,
196 dev_name(&hd->dev), hd_cport_id);
197 if (!connection->wq) {
199 goto err_free_connection;
202 kref_init(&connection->kref);
204 gb_connection_init_name(connection);
206 spin_lock_irq(&gb_connections_lock);
207 list_add(&connection->hd_links, &hd->connections);
210 list_add(&connection->bundle_links, &bundle->connections);
212 INIT_LIST_HEAD(&connection->bundle_links);
214 spin_unlock_irq(&gb_connections_lock);
216 mutex_unlock(&gb_connection_mutex);
218 trace_gb_connection_create(connection);
224 err_hd_cport_release:
225 gb_hd_cport_release(hd, hd_cport_id);
227 mutex_unlock(&gb_connection_mutex);
232 struct gb_connection *
233 gb_connection_create_static(struct gb_host_device *hd, u16 hd_cport_id,
234 gb_request_handler_t handler)
236 return _gb_connection_create(hd, hd_cport_id, NULL, NULL, 0, handler,
237 GB_CONNECTION_FLAG_HIGH_PRIO);
240 struct gb_connection *
241 gb_connection_create_control(struct gb_interface *intf)
243 return _gb_connection_create(intf->hd, -1, intf, NULL, 0, NULL,
244 GB_CONNECTION_FLAG_CONTROL |
245 GB_CONNECTION_FLAG_HIGH_PRIO);
248 struct gb_connection *
249 gb_connection_create(struct gb_bundle *bundle, u16 cport_id,
250 gb_request_handler_t handler)
252 struct gb_interface *intf = bundle->intf;
254 return _gb_connection_create(intf->hd, -1, intf, bundle, cport_id,
257 EXPORT_SYMBOL_GPL(gb_connection_create);
259 struct gb_connection *
260 gb_connection_create_flags(struct gb_bundle *bundle, u16 cport_id,
261 gb_request_handler_t handler,
264 struct gb_interface *intf = bundle->intf;
266 if (WARN_ON_ONCE(flags & GB_CONNECTION_FLAG_CORE_MASK))
267 flags &= ~GB_CONNECTION_FLAG_CORE_MASK;
269 return _gb_connection_create(intf->hd, -1, intf, bundle, cport_id,
272 EXPORT_SYMBOL_GPL(gb_connection_create_flags);
274 struct gb_connection *
275 gb_connection_create_offloaded(struct gb_bundle *bundle, u16 cport_id,
278 flags |= GB_CONNECTION_FLAG_OFFLOADED;
280 return gb_connection_create_flags(bundle, cport_id, NULL, flags);
282 EXPORT_SYMBOL_GPL(gb_connection_create_offloaded);
284 static int gb_connection_hd_cport_enable(struct gb_connection *connection)
286 struct gb_host_device *hd = connection->hd;
289 if (!hd->driver->cport_enable)
292 ret = hd->driver->cport_enable(hd, connection->hd_cport_id,
295 dev_err(&hd->dev, "%s: failed to enable host cport: %d\n",
296 connection->name, ret);
303 static void gb_connection_hd_cport_disable(struct gb_connection *connection)
305 struct gb_host_device *hd = connection->hd;
308 if (!hd->driver->cport_disable)
311 ret = hd->driver->cport_disable(hd, connection->hd_cport_id);
313 dev_err(&hd->dev, "%s: failed to disable host cport: %d\n",
314 connection->name, ret);
318 static int gb_connection_hd_cport_connected(struct gb_connection *connection)
320 struct gb_host_device *hd = connection->hd;
323 if (!hd->driver->cport_connected)
326 ret = hd->driver->cport_connected(hd, connection->hd_cport_id);
328 dev_err(&hd->dev, "%s: failed to set connected state: %d\n",
329 connection->name, ret);
336 static int gb_connection_hd_cport_flush(struct gb_connection *connection)
338 struct gb_host_device *hd = connection->hd;
341 if (!hd->driver->cport_flush)
344 ret = hd->driver->cport_flush(hd, connection->hd_cport_id);
346 dev_err(&hd->dev, "%s: failed to flush host cport: %d\n",
347 connection->name, ret);
354 static int gb_connection_hd_cport_quiesce(struct gb_connection *connection)
356 struct gb_host_device *hd = connection->hd;
360 if (!hd->driver->cport_quiesce)
363 peer_space = sizeof(struct gb_operation_msg_hdr) +
364 sizeof(struct gb_cport_shutdown_request);
366 if (connection->mode_switch)
367 peer_space += sizeof(struct gb_operation_msg_hdr);
369 ret = hd->driver->cport_quiesce(hd, connection->hd_cport_id,
371 GB_CONNECTION_CPORT_QUIESCE_TIMEOUT);
373 dev_err(&hd->dev, "%s: failed to quiesce host cport: %d\n",
374 connection->name, ret);
381 static int gb_connection_hd_cport_clear(struct gb_connection *connection)
383 struct gb_host_device *hd = connection->hd;
386 if (!hd->driver->cport_clear)
389 ret = hd->driver->cport_clear(hd, connection->hd_cport_id);
391 dev_err(&hd->dev, "%s: failed to clear host cport: %d\n",
392 connection->name, ret);
400 * Request the SVC to create a connection from AP's cport to interface's
404 gb_connection_svc_connection_create(struct gb_connection *connection)
406 struct gb_host_device *hd = connection->hd;
407 struct gb_interface *intf;
411 if (gb_connection_is_static(connection))
414 intf = connection->intf;
417 * Enable either E2EFC or CSD, unless no flow control is requested.
419 cport_flags = GB_SVC_CPORT_FLAG_CSV_N;
420 if (gb_connection_flow_control_disabled(connection)) {
421 cport_flags |= GB_SVC_CPORT_FLAG_CSD_N;
422 } else if (gb_connection_e2efc_enabled(connection)) {
423 cport_flags |= GB_SVC_CPORT_FLAG_CSD_N |
424 GB_SVC_CPORT_FLAG_E2EFC;
427 ret = gb_svc_connection_create(hd->svc,
429 connection->hd_cport_id,
431 connection->intf_cport_id,
434 dev_err(&connection->hd->dev,
435 "%s: failed to create svc connection: %d\n",
436 connection->name, ret);
444 gb_connection_svc_connection_destroy(struct gb_connection *connection)
446 if (gb_connection_is_static(connection))
449 gb_svc_connection_destroy(connection->hd->svc,
450 connection->hd->svc->ap_intf_id,
451 connection->hd_cport_id,
452 connection->intf->interface_id,
453 connection->intf_cport_id);
456 /* Inform Interface about active CPorts */
457 static int gb_connection_control_connected(struct gb_connection *connection)
459 struct gb_control *control;
460 u16 cport_id = connection->intf_cport_id;
463 if (gb_connection_is_static(connection))
466 if (gb_connection_is_control(connection))
469 control = connection->intf->control;
471 ret = gb_control_connected_operation(control, cport_id);
473 dev_err(&connection->bundle->dev,
474 "failed to connect cport: %d\n", ret);
482 gb_connection_control_disconnecting(struct gb_connection *connection)
484 struct gb_control *control;
485 u16 cport_id = connection->intf_cport_id;
488 if (gb_connection_is_static(connection))
491 control = connection->intf->control;
493 ret = gb_control_disconnecting_operation(control, cport_id);
495 dev_err(&connection->hd->dev,
496 "%s: failed to send disconnecting: %d\n",
497 connection->name, ret);
502 gb_connection_control_disconnected(struct gb_connection *connection)
504 struct gb_control *control;
505 u16 cport_id = connection->intf_cport_id;
508 if (gb_connection_is_static(connection))
511 control = connection->intf->control;
513 if (gb_connection_is_control(connection)) {
514 if (connection->mode_switch) {
515 ret = gb_control_mode_switch_operation(control);
518 * Allow mode switch to time out waiting for
528 ret = gb_control_disconnected_operation(control, cport_id);
530 dev_warn(&connection->bundle->dev,
531 "failed to disconnect cport: %d\n", ret);
535 static int gb_connection_shutdown_operation(struct gb_connection *connection,
538 struct gb_cport_shutdown_request *req;
539 struct gb_operation *operation;
542 operation = gb_operation_create_core(connection,
543 GB_REQUEST_TYPE_CPORT_SHUTDOWN,
549 req = operation->request->payload;
552 ret = gb_operation_request_send_sync(operation);
554 gb_operation_put(operation);
559 static int gb_connection_cport_shutdown(struct gb_connection *connection,
562 struct gb_host_device *hd = connection->hd;
563 const struct gb_hd_driver *drv = hd->driver;
566 if (gb_connection_is_static(connection))
569 if (gb_connection_is_offloaded(connection)) {
570 if (!drv->cport_shutdown)
573 ret = drv->cport_shutdown(hd, connection->hd_cport_id, phase,
574 GB_OPERATION_TIMEOUT_DEFAULT);
576 ret = gb_connection_shutdown_operation(connection, phase);
580 dev_err(&hd->dev, "%s: failed to send cport shutdown (phase %d): %d\n",
581 connection->name, phase, ret);
589 gb_connection_cport_shutdown_phase_1(struct gb_connection *connection)
591 return gb_connection_cport_shutdown(connection, 1);
595 gb_connection_cport_shutdown_phase_2(struct gb_connection *connection)
597 return gb_connection_cport_shutdown(connection, 2);
601 * Cancel all active operations on a connection.
603 * Locking: Called with connection lock held and state set to DISABLED or
606 static void gb_connection_cancel_operations(struct gb_connection *connection,
608 __must_hold(&connection->lock)
610 struct gb_operation *operation;
612 while (!list_empty(&connection->operations)) {
613 operation = list_last_entry(&connection->operations,
614 struct gb_operation, links);
615 gb_operation_get(operation);
616 spin_unlock_irq(&connection->lock);
618 if (gb_operation_is_incoming(operation))
619 gb_operation_cancel_incoming(operation, errno);
621 gb_operation_cancel(operation, errno);
623 gb_operation_put(operation);
625 spin_lock_irq(&connection->lock);
630 * Cancel all active incoming operations on a connection.
632 * Locking: Called with connection lock held and state set to ENABLED_TX.
635 gb_connection_flush_incoming_operations(struct gb_connection *connection,
637 __must_hold(&connection->lock)
639 struct gb_operation *operation;
642 while (!list_empty(&connection->operations)) {
644 list_for_each_entry(operation, &connection->operations,
646 if (gb_operation_is_incoming(operation)) {
647 gb_operation_get(operation);
656 spin_unlock_irq(&connection->lock);
658 /* FIXME: flush, not cancel? */
659 gb_operation_cancel_incoming(operation, errno);
660 gb_operation_put(operation);
662 spin_lock_irq(&connection->lock);
667 * _gb_connection_enable() - enable a connection
668 * @connection: connection to enable
669 * @rx: whether to enable incoming requests
671 * Connection-enable helper for DISABLED->ENABLED, DISABLED->ENABLED_TX, and
672 * ENABLED_TX->ENABLED state transitions.
674 * Locking: Caller holds connection->mutex.
676 static int _gb_connection_enable(struct gb_connection *connection, bool rx)
680 /* Handle ENABLED_TX -> ENABLED transitions. */
681 if (connection->state == GB_CONNECTION_STATE_ENABLED_TX) {
682 if (!(connection->handler && rx))
685 spin_lock_irq(&connection->lock);
686 connection->state = GB_CONNECTION_STATE_ENABLED;
687 spin_unlock_irq(&connection->lock);
692 ret = gb_connection_hd_cport_enable(connection);
696 ret = gb_connection_svc_connection_create(connection);
698 goto err_hd_cport_clear;
700 ret = gb_connection_hd_cport_connected(connection);
702 goto err_svc_connection_destroy;
704 spin_lock_irq(&connection->lock);
705 if (connection->handler && rx)
706 connection->state = GB_CONNECTION_STATE_ENABLED;
708 connection->state = GB_CONNECTION_STATE_ENABLED_TX;
709 spin_unlock_irq(&connection->lock);
711 ret = gb_connection_control_connected(connection);
713 goto err_control_disconnecting;
717 err_control_disconnecting:
718 spin_lock_irq(&connection->lock);
719 connection->state = GB_CONNECTION_STATE_DISCONNECTING;
720 gb_connection_cancel_operations(connection, -ESHUTDOWN);
721 spin_unlock_irq(&connection->lock);
723 /* Transmit queue should already be empty. */
724 gb_connection_hd_cport_flush(connection);
726 gb_connection_control_disconnecting(connection);
727 gb_connection_cport_shutdown_phase_1(connection);
728 gb_connection_hd_cport_quiesce(connection);
729 gb_connection_cport_shutdown_phase_2(connection);
730 gb_connection_control_disconnected(connection);
731 connection->state = GB_CONNECTION_STATE_DISABLED;
732 err_svc_connection_destroy:
733 gb_connection_svc_connection_destroy(connection);
735 gb_connection_hd_cport_clear(connection);
737 gb_connection_hd_cport_disable(connection);
742 int gb_connection_enable(struct gb_connection *connection)
746 mutex_lock(&connection->mutex);
748 if (connection->state == GB_CONNECTION_STATE_ENABLED)
751 ret = _gb_connection_enable(connection, true);
753 trace_gb_connection_enable(connection);
756 mutex_unlock(&connection->mutex);
760 EXPORT_SYMBOL_GPL(gb_connection_enable);
762 int gb_connection_enable_tx(struct gb_connection *connection)
766 mutex_lock(&connection->mutex);
768 if (connection->state == GB_CONNECTION_STATE_ENABLED) {
773 if (connection->state == GB_CONNECTION_STATE_ENABLED_TX)
776 ret = _gb_connection_enable(connection, false);
778 trace_gb_connection_enable(connection);
781 mutex_unlock(&connection->mutex);
785 EXPORT_SYMBOL_GPL(gb_connection_enable_tx);
787 void gb_connection_disable_rx(struct gb_connection *connection)
789 mutex_lock(&connection->mutex);
791 spin_lock_irq(&connection->lock);
792 if (connection->state != GB_CONNECTION_STATE_ENABLED) {
793 spin_unlock_irq(&connection->lock);
796 connection->state = GB_CONNECTION_STATE_ENABLED_TX;
797 gb_connection_flush_incoming_operations(connection, -ESHUTDOWN);
798 spin_unlock_irq(&connection->lock);
800 trace_gb_connection_disable(connection);
803 mutex_unlock(&connection->mutex);
805 EXPORT_SYMBOL_GPL(gb_connection_disable_rx);
807 void gb_connection_mode_switch_prepare(struct gb_connection *connection)
809 connection->mode_switch = true;
812 void gb_connection_mode_switch_complete(struct gb_connection *connection)
814 gb_connection_svc_connection_destroy(connection);
815 gb_connection_hd_cport_clear(connection);
817 gb_connection_hd_cport_disable(connection);
819 connection->mode_switch = false;
822 void gb_connection_disable(struct gb_connection *connection)
824 mutex_lock(&connection->mutex);
826 if (connection->state == GB_CONNECTION_STATE_DISABLED)
829 trace_gb_connection_disable(connection);
831 spin_lock_irq(&connection->lock);
832 connection->state = GB_CONNECTION_STATE_DISCONNECTING;
833 gb_connection_cancel_operations(connection, -ESHUTDOWN);
834 spin_unlock_irq(&connection->lock);
836 gb_connection_hd_cport_flush(connection);
838 gb_connection_control_disconnecting(connection);
839 gb_connection_cport_shutdown_phase_1(connection);
840 gb_connection_hd_cport_quiesce(connection);
841 gb_connection_cport_shutdown_phase_2(connection);
842 gb_connection_control_disconnected(connection);
844 connection->state = GB_CONNECTION_STATE_DISABLED;
846 /* control-connection tear down is deferred when mode switching */
847 if (!connection->mode_switch) {
848 gb_connection_svc_connection_destroy(connection);
849 gb_connection_hd_cport_clear(connection);
851 gb_connection_hd_cport_disable(connection);
855 mutex_unlock(&connection->mutex);
857 EXPORT_SYMBOL_GPL(gb_connection_disable);
859 /* Disable a connection without communicating with the remote end. */
860 void gb_connection_disable_forced(struct gb_connection *connection)
862 mutex_lock(&connection->mutex);
864 if (connection->state == GB_CONNECTION_STATE_DISABLED)
867 trace_gb_connection_disable(connection);
869 spin_lock_irq(&connection->lock);
870 connection->state = GB_CONNECTION_STATE_DISABLED;
871 gb_connection_cancel_operations(connection, -ESHUTDOWN);
872 spin_unlock_irq(&connection->lock);
874 gb_connection_hd_cport_flush(connection);
876 gb_connection_svc_connection_destroy(connection);
877 gb_connection_hd_cport_clear(connection);
879 gb_connection_hd_cport_disable(connection);
881 mutex_unlock(&connection->mutex);
883 EXPORT_SYMBOL_GPL(gb_connection_disable_forced);
885 /* Caller must have disabled the connection before destroying it. */
886 void gb_connection_destroy(struct gb_connection *connection)
891 if (WARN_ON(connection->state != GB_CONNECTION_STATE_DISABLED))
892 gb_connection_disable(connection);
894 mutex_lock(&gb_connection_mutex);
896 spin_lock_irq(&gb_connections_lock);
897 list_del(&connection->bundle_links);
898 list_del(&connection->hd_links);
899 spin_unlock_irq(&gb_connections_lock);
901 destroy_workqueue(connection->wq);
903 gb_hd_cport_release(connection->hd, connection->hd_cport_id);
904 connection->hd_cport_id = CPORT_ID_BAD;
906 mutex_unlock(&gb_connection_mutex);
908 gb_connection_put(connection);
910 EXPORT_SYMBOL_GPL(gb_connection_destroy);
912 void gb_connection_latency_tag_enable(struct gb_connection *connection)
914 struct gb_host_device *hd = connection->hd;
917 if (!hd->driver->latency_tag_enable)
920 ret = hd->driver->latency_tag_enable(hd, connection->hd_cport_id);
922 dev_err(&connection->hd->dev,
923 "%s: failed to enable latency tag: %d\n",
924 connection->name, ret);
927 EXPORT_SYMBOL_GPL(gb_connection_latency_tag_enable);
929 void gb_connection_latency_tag_disable(struct gb_connection *connection)
931 struct gb_host_device *hd = connection->hd;
934 if (!hd->driver->latency_tag_disable)
937 ret = hd->driver->latency_tag_disable(hd, connection->hd_cport_id);
939 dev_err(&connection->hd->dev,
940 "%s: failed to disable latency tag: %d\n",
941 connection->name, ret);
944 EXPORT_SYMBOL_GPL(gb_connection_latency_tag_disable);