4 * Copyright 2014-2015 Google Inc.
5 * Copyright 2014-2015 Linaro Ltd.
7 * Released under the GPLv2 only.
10 #include <linux/kernel.h>
11 #include <linux/slab.h>
12 #include <linux/module.h>
13 #include <linux/sched.h>
14 #include <linux/wait.h>
15 #include <linux/workqueue.h>
18 #include "greybus_trace.h"
20 static struct kmem_cache *gb_operation_cache;
21 static struct kmem_cache *gb_message_cache;
23 /* Workqueue to handle Greybus operation completions. */
24 static struct workqueue_struct *gb_operation_completion_wq;
26 /* Wait queue for synchronous cancellations. */
27 static DECLARE_WAIT_QUEUE_HEAD(gb_operation_cancellation_queue);
30 * Protects updates to operation->errno.
32 static DEFINE_SPINLOCK(gb_operations_lock);
34 static int gb_operation_response_send(struct gb_operation *operation,
38 * Increment operation active count and add to connection list unless the
39 * connection is going away.
41 * Caller holds operation reference.
43 static int gb_operation_get_active(struct gb_operation *operation)
45 struct gb_connection *connection = operation->connection;
48 spin_lock_irqsave(&connection->lock, flags);
49 switch (connection->state) {
50 case GB_CONNECTION_STATE_ENABLED:
52 case GB_CONNECTION_STATE_ENABLED_TX:
53 if (gb_operation_is_incoming(operation))
56 case GB_CONNECTION_STATE_DISCONNECTING:
57 if (!gb_operation_is_core(operation))
64 if (operation->active++ == 0)
65 list_add_tail(&operation->links, &connection->operations);
67 trace_gb_operation_get_active(operation);
69 spin_unlock_irqrestore(&connection->lock, flags);
74 spin_unlock_irqrestore(&connection->lock, flags);
79 /* Caller holds operation reference. */
80 static void gb_operation_put_active(struct gb_operation *operation)
82 struct gb_connection *connection = operation->connection;
85 spin_lock_irqsave(&connection->lock, flags);
87 trace_gb_operation_put_active(operation);
89 if (--operation->active == 0) {
90 list_del(&operation->links);
91 if (atomic_read(&operation->waiters))
92 wake_up(&gb_operation_cancellation_queue);
94 spin_unlock_irqrestore(&connection->lock, flags);
97 static bool gb_operation_is_active(struct gb_operation *operation)
99 struct gb_connection *connection = operation->connection;
103 spin_lock_irqsave(&connection->lock, flags);
104 ret = operation->active;
105 spin_unlock_irqrestore(&connection->lock, flags);
111 * Set an operation's result.
113 * Initially an outgoing operation's errno value is -EBADR.
114 * If no error occurs before sending the request message the only
115 * valid value operation->errno can be set to is -EINPROGRESS,
116 * indicating the request has been (or rather is about to be) sent.
117 * At that point nobody should be looking at the result until the
120 * The first time the result gets set after the request has been
121 * sent, that result "sticks." That is, if two concurrent threads
122 * race to set the result, the first one wins. The return value
123 * tells the caller whether its result was recorded; if not the
124 * caller has nothing more to do.
126 * The result value -EILSEQ is reserved to signal an implementation
127 * error; if it's ever observed, the code performing the request has
128 * done something fundamentally wrong. It is an error to try to set
129 * the result to -EBADR, and attempts to do so result in a warning,
130 * and -EILSEQ is used instead. Similarly, the only valid result
131 * value to set for an operation in initial state is -EINPROGRESS.
132 * Attempts to do otherwise will also record a (successful) -EILSEQ
135 static bool gb_operation_result_set(struct gb_operation *operation, int result)
140 if (result == -EINPROGRESS) {
142 * -EINPROGRESS is used to indicate the request is
143 * in flight. It should be the first result value
144 * set after the initial -EBADR. Issue a warning
145 * and record an implementation error if it's
146 * set at any other time.
148 spin_lock_irqsave(&gb_operations_lock, flags);
149 prev = operation->errno;
151 operation->errno = result;
153 operation->errno = -EILSEQ;
154 spin_unlock_irqrestore(&gb_operations_lock, flags);
155 WARN_ON(prev != -EBADR);
161 * The first result value set after a request has been sent
162 * will be the final result of the operation. Subsequent
163 * attempts to set the result are ignored.
165 * Note that -EBADR is a reserved "initial state" result
166 * value. Attempts to set this value result in a warning,
167 * and the result code is set to -EILSEQ instead.
169 if (WARN_ON(result == -EBADR))
170 result = -EILSEQ; /* Nobody should be setting -EBADR */
172 spin_lock_irqsave(&gb_operations_lock, flags);
173 prev = operation->errno;
174 if (prev == -EINPROGRESS)
175 operation->errno = result; /* First and final result */
176 spin_unlock_irqrestore(&gb_operations_lock, flags);
178 return prev == -EINPROGRESS;
181 int gb_operation_result(struct gb_operation *operation)
183 int result = operation->errno;
185 WARN_ON(result == -EBADR);
186 WARN_ON(result == -EINPROGRESS);
190 EXPORT_SYMBOL_GPL(gb_operation_result);
193 * Looks up an outgoing operation on a connection and returns a refcounted
194 * pointer if found, or NULL otherwise.
196 static struct gb_operation *
197 gb_operation_find_outgoing(struct gb_connection *connection, u16 operation_id)
199 struct gb_operation *operation;
203 spin_lock_irqsave(&connection->lock, flags);
204 list_for_each_entry(operation, &connection->operations, links)
205 if (operation->id == operation_id &&
206 !gb_operation_is_incoming(operation)) {
207 gb_operation_get(operation);
211 spin_unlock_irqrestore(&connection->lock, flags);
213 return found ? operation : NULL;
216 static int gb_message_send(struct gb_message *message, gfp_t gfp)
218 struct gb_connection *connection = message->operation->connection;
220 trace_gb_message_send(message);
221 return connection->hd->driver->message_send(connection->hd,
222 connection->hd_cport_id,
228 * Cancel a message we have passed to the host device layer to be sent.
230 static void gb_message_cancel(struct gb_message *message)
232 struct gb_host_device *hd = message->operation->connection->hd;
234 hd->driver->message_cancel(message);
237 static void gb_operation_request_handle(struct gb_operation *operation)
239 struct gb_connection *connection = operation->connection;
243 if (connection->handler) {
244 status = connection->handler(operation);
246 dev_err(&connection->hd->dev,
247 "%s: unexpected incoming request of type 0x%02x\n",
248 connection->name, operation->type);
250 status = -EPROTONOSUPPORT;
253 ret = gb_operation_response_send(operation, status);
255 dev_err(&connection->hd->dev,
256 "%s: failed to send response %d for type 0x%02x: %d\n",
257 connection->name, status, operation->type, ret);
263 * Process operation work.
265 * For incoming requests, call the protocol request handler. The operation
266 * result should be -EINPROGRESS at this point.
268 * For outgoing requests, the operation result value should have
269 * been set before queueing this. The operation callback function
270 * allows the original requester to know the request has completed
271 * and its result is available.
273 static void gb_operation_work(struct work_struct *work)
275 struct gb_operation *operation;
277 operation = container_of(work, struct gb_operation, work);
279 if (gb_operation_is_incoming(operation))
280 gb_operation_request_handle(operation);
282 operation->callback(operation);
284 gb_operation_put_active(operation);
285 gb_operation_put(operation);
288 static void gb_operation_message_init(struct gb_host_device *hd,
289 struct gb_message *message, u16 operation_id,
290 size_t payload_size, u8 type)
292 struct gb_operation_msg_hdr *header;
294 header = message->buffer;
296 message->header = header;
297 message->payload = payload_size ? header + 1 : NULL;
298 message->payload_size = payload_size;
301 * The type supplied for incoming message buffers will be
302 * GB_REQUEST_TYPE_INVALID. Such buffers will be overwritten by
303 * arriving data so there's no need to initialize the message header.
305 if (type != GB_REQUEST_TYPE_INVALID) {
306 u16 message_size = (u16)(sizeof(*header) + payload_size);
309 * For a request, the operation id gets filled in
310 * when the message is sent. For a response, it
311 * will be copied from the request by the caller.
313 * The result field in a request message must be
314 * zero. It will be set just prior to sending for
317 header->size = cpu_to_le16(message_size);
318 header->operation_id = 0;
325 * Allocate a message to be used for an operation request or response.
326 * Both types of message contain a common header. The request message
327 * for an outgoing operation is outbound, as is the response message
328 * for an incoming operation. The message header for an outbound
329 * message is partially initialized here.
331 * The headers for inbound messages don't need to be initialized;
332 * they'll be filled in by arriving data.
334 * Our message buffers have the following layout:
335 * message header \_ these combined are
336 * message payload / the message size
338 static struct gb_message *
339 gb_operation_message_alloc(struct gb_host_device *hd, u8 type,
340 size_t payload_size, gfp_t gfp_flags)
342 struct gb_message *message;
343 struct gb_operation_msg_hdr *header;
344 size_t message_size = payload_size + sizeof(*header);
346 if (message_size > hd->buffer_size_max) {
347 dev_warn(&hd->dev, "requested message size too big (%zu > %zu)\n",
348 message_size, hd->buffer_size_max);
352 /* Allocate the message structure and buffer. */
353 message = kmem_cache_zalloc(gb_message_cache, gfp_flags);
357 message->buffer = kzalloc(message_size, gfp_flags);
358 if (!message->buffer)
359 goto err_free_message;
361 /* Initialize the message. Operation id is filled in later. */
362 gb_operation_message_init(hd, message, 0, payload_size, type);
367 kmem_cache_free(gb_message_cache, message);
372 static void gb_operation_message_free(struct gb_message *message)
374 kfree(message->buffer);
375 kmem_cache_free(gb_message_cache, message);
379 * Map an enum gb_operation_status value (which is represented in a
380 * message as a single byte) to an appropriate Linux negative errno.
382 static int gb_operation_status_map(u8 status)
387 case GB_OP_INTERRUPTED:
391 case GB_OP_NO_MEMORY:
393 case GB_OP_PROTOCOL_BAD:
394 return -EPROTONOSUPPORT;
401 case GB_OP_NONEXISTENT:
403 case GB_OP_MALFUNCTION:
405 case GB_OP_UNKNOWN_ERROR:
412 * Map a Linux errno value (from operation->errno) into the value
413 * that should represent it in a response message status sent
414 * over the wire. Returns an enum gb_operation_status value (which
415 * is represented in a message as a single byte).
417 static u8 gb_operation_errno_map(int errno)
421 return GB_OP_SUCCESS;
423 return GB_OP_INTERRUPTED;
425 return GB_OP_TIMEOUT;
427 return GB_OP_NO_MEMORY;
428 case -EPROTONOSUPPORT:
429 return GB_OP_PROTOCOL_BAD;
431 return GB_OP_OVERFLOW; /* Could be underflow too */
433 return GB_OP_INVALID;
437 return GB_OP_MALFUNCTION;
439 return GB_OP_NONEXISTENT;
442 return GB_OP_UNKNOWN_ERROR;
446 bool gb_operation_response_alloc(struct gb_operation *operation,
447 size_t response_size, gfp_t gfp)
449 struct gb_host_device *hd = operation->connection->hd;
450 struct gb_operation_msg_hdr *request_header;
451 struct gb_message *response;
454 type = operation->type | GB_MESSAGE_TYPE_RESPONSE;
455 response = gb_operation_message_alloc(hd, type, response_size, gfp);
458 response->operation = operation;
461 * Size and type get initialized when the message is
462 * allocated. The errno will be set before sending. All
463 * that's left is the operation id, which we copy from the
464 * request message header (as-is, in little-endian order).
466 request_header = operation->request->header;
467 response->header->operation_id = request_header->operation_id;
468 operation->response = response;
472 EXPORT_SYMBOL_GPL(gb_operation_response_alloc);
475 * Create a Greybus operation to be sent over the given connection.
476 * The request buffer will be big enough for a payload of the given
479 * For outgoing requests, the request message's header will be
480 * initialized with the type of the request and the message size.
481 * Outgoing operations must also specify the response buffer size,
482 * which must be sufficient to hold all expected response data. The
483 * response message header will eventually be overwritten, so there's
484 * no need to initialize it here.
486 * Request messages for incoming operations can arrive in interrupt
487 * context, so they must be allocated with GFP_ATOMIC. In this case
488 * the request buffer will be immediately overwritten, so there is
489 * no need to initialize the message header. Responsibility for
490 * allocating a response buffer lies with the incoming request
491 * handler for a protocol. So we don't allocate that here.
493 * Returns a pointer to the new operation or a null pointer if an
496 static struct gb_operation *
497 gb_operation_create_common(struct gb_connection *connection, u8 type,
498 size_t request_size, size_t response_size,
499 unsigned long op_flags, gfp_t gfp_flags)
501 struct gb_host_device *hd = connection->hd;
502 struct gb_operation *operation;
504 operation = kmem_cache_zalloc(gb_operation_cache, gfp_flags);
507 operation->connection = connection;
509 operation->request = gb_operation_message_alloc(hd, type, request_size,
511 if (!operation->request)
513 operation->request->operation = operation;
515 /* Allocate the response buffer for outgoing operations */
516 if (!(op_flags & GB_OPERATION_FLAG_INCOMING)) {
517 if (!gb_operation_response_alloc(operation, response_size,
523 operation->flags = op_flags;
524 operation->type = type;
525 operation->errno = -EBADR; /* Initial value--means "never set" */
527 INIT_WORK(&operation->work, gb_operation_work);
528 init_completion(&operation->completion);
529 kref_init(&operation->kref);
530 atomic_set(&operation->waiters, 0);
535 gb_operation_message_free(operation->request);
537 kmem_cache_free(gb_operation_cache, operation);
543 * Create a new operation associated with the given connection. The
544 * request and response sizes provided are the number of bytes
545 * required to hold the request/response payload only. Both of
546 * these are allowed to be 0. Note that 0x00 is reserved as an
547 * invalid operation type for all protocols, and this is enforced
550 struct gb_operation *
551 gb_operation_create_flags(struct gb_connection *connection,
552 u8 type, size_t request_size,
553 size_t response_size, unsigned long flags,
556 struct gb_operation *operation;
558 if (WARN_ON_ONCE(type == GB_REQUEST_TYPE_INVALID))
560 if (WARN_ON_ONCE(type & GB_MESSAGE_TYPE_RESPONSE))
561 type &= ~GB_MESSAGE_TYPE_RESPONSE;
563 if (WARN_ON_ONCE(flags & ~GB_OPERATION_FLAG_USER_MASK))
564 flags &= GB_OPERATION_FLAG_USER_MASK;
566 operation = gb_operation_create_common(connection, type,
567 request_size, response_size,
570 trace_gb_operation_create(operation);
574 EXPORT_SYMBOL_GPL(gb_operation_create_flags);
576 struct gb_operation *
577 gb_operation_create_core(struct gb_connection *connection,
578 u8 type, size_t request_size,
579 size_t response_size, unsigned long flags,
582 struct gb_operation *operation;
584 flags |= GB_OPERATION_FLAG_CORE;
586 operation = gb_operation_create_common(connection, type,
587 request_size, response_size,
590 trace_gb_operation_create_core(operation);
594 /* Do not export this function. */
596 size_t gb_operation_get_payload_size_max(struct gb_connection *connection)
598 struct gb_host_device *hd = connection->hd;
600 return hd->buffer_size_max - sizeof(struct gb_operation_msg_hdr);
602 EXPORT_SYMBOL_GPL(gb_operation_get_payload_size_max);
604 static struct gb_operation *
605 gb_operation_create_incoming(struct gb_connection *connection, u16 id,
606 u8 type, void *data, size_t size)
608 struct gb_operation *operation;
610 unsigned long flags = GB_OPERATION_FLAG_INCOMING;
612 /* Caller has made sure we at least have a message header. */
613 request_size = size - sizeof(struct gb_operation_msg_hdr);
616 flags |= GB_OPERATION_FLAG_UNIDIRECTIONAL;
618 operation = gb_operation_create_common(connection, type,
620 GB_REQUEST_TYPE_INVALID,
626 memcpy(operation->request->header, data, size);
627 trace_gb_operation_create_incoming(operation);
633 * Get an additional reference on an operation.
635 void gb_operation_get(struct gb_operation *operation)
637 kref_get(&operation->kref);
639 EXPORT_SYMBOL_GPL(gb_operation_get);
642 * Destroy a previously created operation.
644 static void _gb_operation_destroy(struct kref *kref)
646 struct gb_operation *operation;
648 operation = container_of(kref, struct gb_operation, kref);
650 trace_gb_operation_destroy(operation);
652 if (operation->response)
653 gb_operation_message_free(operation->response);
654 gb_operation_message_free(operation->request);
656 kmem_cache_free(gb_operation_cache, operation);
660 * Drop a reference on an operation, and destroy it when the last
663 void gb_operation_put(struct gb_operation *operation)
665 if (WARN_ON(!operation))
668 kref_put(&operation->kref, _gb_operation_destroy);
670 EXPORT_SYMBOL_GPL(gb_operation_put);
672 /* Tell the requester we're done */
673 static void gb_operation_sync_callback(struct gb_operation *operation)
675 complete(&operation->completion);
679 * gb_operation_request_send() - send an operation request message
680 * @operation: the operation to initiate
681 * @callback: the operation completion callback
682 * @gfp: the memory flags to use for any allocations
684 * The caller has filled in any payload so the request message is ready to go.
685 * The callback function supplied will be called when the response message has
686 * arrived, a unidirectional request has been sent, or the operation is
687 * cancelled, indicating that the operation is complete. The callback function
688 * can fetch the result of the operation using gb_operation_result() if
691 * Return: 0 if the request was successfully queued in the host-driver queues,
692 * or a negative errno.
694 int gb_operation_request_send(struct gb_operation *operation,
695 gb_operation_callback callback,
698 struct gb_connection *connection = operation->connection;
699 struct gb_operation_msg_hdr *header;
703 if (gb_connection_is_offloaded(connection))
710 * Record the callback function, which is executed in
711 * non-atomic (workqueue) context when the final result
712 * of an operation has been set.
714 operation->callback = callback;
717 * Assign the operation's id, and store it in the request header.
718 * Zero is a reserved operation id for unidirectional operations.
720 if (gb_operation_is_unidirectional(operation)) {
723 cycle = (unsigned int)atomic_inc_return(&connection->op_cycle);
724 operation->id = (u16)(cycle % U16_MAX + 1);
727 header = operation->request->header;
728 header->operation_id = cpu_to_le16(operation->id);
730 gb_operation_result_set(operation, -EINPROGRESS);
733 * Get an extra reference on the operation. It'll be dropped when the
734 * operation completes.
736 gb_operation_get(operation);
737 ret = gb_operation_get_active(operation);
741 ret = gb_message_send(operation->request, gfp);
748 gb_operation_put_active(operation);
750 gb_operation_put(operation);
754 EXPORT_SYMBOL_GPL(gb_operation_request_send);
757 * Send a synchronous operation. This function is expected to
758 * block, returning only when the response has arrived, (or when an
759 * error is detected. The return value is the result of the
762 int gb_operation_request_send_sync_timeout(struct gb_operation *operation,
763 unsigned int timeout)
766 unsigned long timeout_jiffies;
768 ret = gb_operation_request_send(operation, gb_operation_sync_callback,
774 timeout_jiffies = msecs_to_jiffies(timeout);
776 timeout_jiffies = MAX_SCHEDULE_TIMEOUT;
778 ret = wait_for_completion_interruptible_timeout(&operation->completion,
781 /* Cancel the operation if interrupted */
782 gb_operation_cancel(operation, -ECANCELED);
783 } else if (ret == 0) {
784 /* Cancel the operation if op timed out */
785 gb_operation_cancel(operation, -ETIMEDOUT);
788 return gb_operation_result(operation);
790 EXPORT_SYMBOL_GPL(gb_operation_request_send_sync_timeout);
793 * Send a response for an incoming operation request. A non-zero
794 * errno indicates a failed operation.
796 * If there is any response payload, the incoming request handler is
797 * responsible for allocating the response message. Otherwise the
798 * it can simply supply the result errno; this function will
799 * allocate the response message if necessary.
801 static int gb_operation_response_send(struct gb_operation *operation,
804 struct gb_connection *connection = operation->connection;
807 if (!operation->response &&
808 !gb_operation_is_unidirectional(operation)) {
809 if (!gb_operation_response_alloc(operation, 0, GFP_KERNEL))
813 /* Record the result */
814 if (!gb_operation_result_set(operation, errno)) {
815 dev_err(&connection->hd->dev, "request result already set\n");
816 return -EIO; /* Shouldn't happen */
819 /* Sender of request does not care about response. */
820 if (gb_operation_is_unidirectional(operation))
823 /* Reference will be dropped when message has been sent. */
824 gb_operation_get(operation);
825 ret = gb_operation_get_active(operation);
829 /* Fill in the response header and send it */
830 operation->response->header->result = gb_operation_errno_map(errno);
832 ret = gb_message_send(operation->response, GFP_KERNEL);
839 gb_operation_put_active(operation);
841 gb_operation_put(operation);
847 * This function is called when a message send request has completed.
849 void greybus_message_sent(struct gb_host_device *hd,
850 struct gb_message *message, int status)
852 struct gb_operation *operation = message->operation;
853 struct gb_connection *connection = operation->connection;
856 * If the message was a response, we just need to drop our
857 * reference to the operation. If an error occurred, report
860 * For requests, if there's no error and the operation in not
861 * unidirectional, there's nothing more to do until the response
862 * arrives. If an error occurred attempting to send it, or if the
863 * operation is unidrectional, record the result of the operation and
864 * schedule its completion.
866 if (message == operation->response) {
868 dev_err(&connection->hd->dev,
869 "%s: error sending response 0x%02x: %d\n",
870 connection->name, operation->type, status);
873 gb_operation_put_active(operation);
874 gb_operation_put(operation);
875 } else if (status || gb_operation_is_unidirectional(operation)) {
876 if (gb_operation_result_set(operation, status)) {
877 queue_work(gb_operation_completion_wq,
882 EXPORT_SYMBOL_GPL(greybus_message_sent);
885 * We've received data on a connection, and it doesn't look like a
886 * response, so we assume it's a request.
888 * This is called in interrupt context, so just copy the incoming
889 * data into the request buffer and handle the rest via workqueue.
891 static void gb_connection_recv_request(struct gb_connection *connection,
892 u16 operation_id, u8 type,
893 void *data, size_t size)
895 struct gb_operation *operation;
898 operation = gb_operation_create_incoming(connection, operation_id,
901 dev_err(&connection->hd->dev,
902 "%s: can't create incoming operation\n",
907 ret = gb_operation_get_active(operation);
909 gb_operation_put(operation);
912 trace_gb_message_recv_request(operation->request);
915 * The initial reference to the operation will be dropped when the
916 * request handler returns.
918 if (gb_operation_result_set(operation, -EINPROGRESS))
919 queue_work(connection->wq, &operation->work);
923 * We've received data that appears to be an operation response
924 * message. Look up the operation, and record that we've received
927 * This is called in interrupt context, so just copy the incoming
928 * data into the response buffer and handle the rest via workqueue.
930 static void gb_connection_recv_response(struct gb_connection *connection,
931 const struct gb_operation_msg_hdr *header,
932 void *data, size_t size)
934 struct gb_operation *operation;
935 struct gb_message *message;
940 operation_id = le16_to_cpu(header->operation_id);
943 dev_err_ratelimited(&connection->hd->dev,
944 "%s: invalid response id 0 received\n",
949 operation = gb_operation_find_outgoing(connection, operation_id);
951 dev_err_ratelimited(&connection->hd->dev,
952 "%s: unexpected response id 0x%04x received\n",
953 connection->name, operation_id);
957 errno = gb_operation_status_map(header->result);
958 message = operation->response;
959 message_size = sizeof(*header) + message->payload_size;
960 if (!errno && size > message_size) {
961 dev_err_ratelimited(&connection->hd->dev,
962 "%s: malformed response 0x%02x received (%zu > %zu)\n",
963 connection->name, header->type,
966 } else if (!errno && size < message_size) {
967 if (gb_operation_short_response_allowed(operation)) {
968 message->payload_size = size - sizeof(*header);
970 dev_err_ratelimited(&connection->hd->dev,
971 "%s: short response 0x%02x received (%zu < %zu)\n",
972 connection->name, header->type,
978 /* We must ignore the payload if a bad status is returned */
980 size = sizeof(*header);
982 /* The rest will be handled in work queue context */
983 if (gb_operation_result_set(operation, errno)) {
984 memcpy(message->buffer, data, size);
986 trace_gb_message_recv_response(message);
988 queue_work(gb_operation_completion_wq, &operation->work);
991 gb_operation_put(operation);
995 * Handle data arriving on a connection. As soon as we return the
996 * supplied data buffer will be reused (so unless we do something
997 * with, it's effectively dropped).
999 void gb_connection_recv(struct gb_connection *connection,
1000 void *data, size_t size)
1002 struct gb_operation_msg_hdr header;
1003 struct device *dev = &connection->hd->dev;
1007 if (connection->state == GB_CONNECTION_STATE_DISABLED ||
1008 gb_connection_is_offloaded(connection)) {
1009 dev_warn_ratelimited(dev, "%s: dropping %zu received bytes\n",
1010 connection->name, size);
1014 if (size < sizeof(header)) {
1015 dev_err_ratelimited(dev, "%s: short message received\n",
1020 /* Use memcpy as data may be unaligned */
1021 memcpy(&header, data, sizeof(header));
1022 msg_size = le16_to_cpu(header.size);
1023 if (size < msg_size) {
1024 dev_err_ratelimited(dev,
1025 "%s: incomplete message 0x%04x of type 0x%02x received (%zu < %zu)\n",
1027 le16_to_cpu(header.operation_id),
1028 header.type, size, msg_size);
1029 return; /* XXX Should still complete operation */
1032 operation_id = le16_to_cpu(header.operation_id);
1033 if (header.type & GB_MESSAGE_TYPE_RESPONSE)
1034 gb_connection_recv_response(connection, &header, data,
1037 gb_connection_recv_request(connection, operation_id,
1038 header.type, data, msg_size);
1042 * Cancel an outgoing operation synchronously, and record the given error to
1045 void gb_operation_cancel(struct gb_operation *operation, int errno)
1047 if (WARN_ON(gb_operation_is_incoming(operation)))
1050 if (gb_operation_result_set(operation, errno)) {
1051 gb_message_cancel(operation->request);
1052 queue_work(gb_operation_completion_wq, &operation->work);
1054 trace_gb_message_cancel_outgoing(operation->request);
1056 atomic_inc(&operation->waiters);
1057 wait_event(gb_operation_cancellation_queue,
1058 !gb_operation_is_active(operation));
1059 atomic_dec(&operation->waiters);
1061 EXPORT_SYMBOL_GPL(gb_operation_cancel);
1064 * Cancel an incoming operation synchronously. Called during connection tear
1067 void gb_operation_cancel_incoming(struct gb_operation *operation, int errno)
1069 if (WARN_ON(!gb_operation_is_incoming(operation)))
1072 if (!gb_operation_is_unidirectional(operation)) {
1074 * Make sure the request handler has submitted the response
1075 * before cancelling it.
1077 flush_work(&operation->work);
1078 if (!gb_operation_result_set(operation, errno))
1079 gb_message_cancel(operation->response);
1081 trace_gb_message_cancel_incoming(operation->response);
1083 atomic_inc(&operation->waiters);
1084 wait_event(gb_operation_cancellation_queue,
1085 !gb_operation_is_active(operation));
1086 atomic_dec(&operation->waiters);
1090 * gb_operation_sync_timeout() - implement a "simple" synchronous operation
1091 * @connection: the Greybus connection to send this to
1092 * @type: the type of operation to send
1093 * @request: pointer to a memory buffer to copy the request from
1094 * @request_size: size of @request
1095 * @response: pointer to a memory buffer to copy the response to
1096 * @response_size: the size of @response.
1097 * @timeout: operation timeout in milliseconds
1099 * This function implements a simple synchronous Greybus operation. It sends
1100 * the provided operation request and waits (sleeps) until the corresponding
1101 * operation response message has been successfully received, or an error
1102 * occurs. @request and @response are buffers to hold the request and response
1103 * data respectively, and if they are not NULL, their size must be specified in
1104 * @request_size and @response_size.
1106 * If a response payload is to come back, and @response is not NULL,
1107 * @response_size number of bytes will be copied into @response if the operation
1110 * If there is an error, the response buffer is left alone.
1112 int gb_operation_sync_timeout(struct gb_connection *connection, int type,
1113 void *request, int request_size,
1114 void *response, int response_size,
1115 unsigned int timeout)
1117 struct gb_operation *operation;
1120 if ((response_size && !response) ||
1121 (request_size && !request))
1124 operation = gb_operation_create(connection, type,
1125 request_size, response_size,
1131 memcpy(operation->request->payload, request, request_size);
1133 ret = gb_operation_request_send_sync_timeout(operation, timeout);
1135 dev_err(&connection->hd->dev,
1136 "%s: synchronous operation id 0x%04x of type 0x%02x failed: %d\n",
1137 connection->name, operation->id, type, ret);
1139 if (response_size) {
1140 memcpy(response, operation->response->payload,
1145 gb_operation_put(operation);
1149 EXPORT_SYMBOL_GPL(gb_operation_sync_timeout);
1152 * gb_operation_unidirectional_timeout() - initiate a unidirectional operation
1153 * @connection: connection to use
1154 * @type: type of operation to send
1155 * @request: memory buffer to copy the request from
1156 * @request_size: size of @request
1157 * @timeout: send timeout in milliseconds
1159 * Initiate a unidirectional operation by sending a request message and
1160 * waiting for it to be acknowledged as sent by the host device.
1162 * Note that successful send of a unidirectional operation does not imply that
1163 * the request as actually reached the remote end of the connection.
1165 int gb_operation_unidirectional_timeout(struct gb_connection *connection,
1166 int type, void *request, int request_size,
1167 unsigned int timeout)
1169 struct gb_operation *operation;
1172 if (request_size && !request)
1175 operation = gb_operation_create_flags(connection, type,
1177 GB_OPERATION_FLAG_UNIDIRECTIONAL,
1183 memcpy(operation->request->payload, request, request_size);
1185 ret = gb_operation_request_send_sync_timeout(operation, timeout);
1187 dev_err(&connection->hd->dev,
1188 "%s: unidirectional operation of type 0x%02x failed: %d\n",
1189 connection->name, type, ret);
1192 gb_operation_put(operation);
1196 EXPORT_SYMBOL_GPL(gb_operation_unidirectional_timeout);
1198 int __init gb_operation_init(void)
1200 gb_message_cache = kmem_cache_create("gb_message_cache",
1201 sizeof(struct gb_message), 0, 0, NULL);
1202 if (!gb_message_cache)
1205 gb_operation_cache = kmem_cache_create("gb_operation_cache",
1206 sizeof(struct gb_operation), 0, 0, NULL);
1207 if (!gb_operation_cache)
1208 goto err_destroy_message_cache;
1210 gb_operation_completion_wq = alloc_workqueue("greybus_completion",
1212 if (!gb_operation_completion_wq)
1213 goto err_destroy_operation_cache;
1217 err_destroy_operation_cache:
1218 kmem_cache_destroy(gb_operation_cache);
1219 gb_operation_cache = NULL;
1220 err_destroy_message_cache:
1221 kmem_cache_destroy(gb_message_cache);
1222 gb_message_cache = NULL;
1227 void gb_operation_exit(void)
1229 destroy_workqueue(gb_operation_completion_wq);
1230 gb_operation_completion_wq = NULL;
1231 kmem_cache_destroy(gb_operation_cache);
1232 gb_operation_cache = NULL;
1233 kmem_cache_destroy(gb_message_cache);
1234 gb_message_cache = NULL;