/*!
* \brief This function sends a message to an endpoint. The data is NOT copied
* from the user-app. buffer but the pointer to already filled message buffer is
* provided.
*
* The application has to take the responsibility for:
* 1. MCC buffer de-allocation
* 2. filling the data to be sent into the pre-allocated MCC buffer
* 3. not exceeding the buffer size when filling the data (MCC_ATTR_BUFFER_SIZE_IN_BYTES)
*
* Once the data cache is used on the target platform it is good to have MCC buffers
* in shared RAM aligned to the cache line size in order not to corrupt entities placed
* just before and just after the MCC buffer when flushing the MCC buffer content into
* the shared RAM. It is also the application responsibility to flush the data in
* that case. If the alignment condition is not fulfilled the application
* has to take care about the data cache coherency.
* The following scenarios can happen:
* A. Data cache is OFF:
* - No cache operation needs to be done, the application just
* 1. calls the mcc_get_buffer() function,
* 2. fills data into the provided MCC buffer,
* 3. and finally issues the mcc_send_nocopy() function.
* B. Data cache is ON, shared RAM MCC buffers ALIGNED to the cache line size:
* - The application has to perform following steps:
* 1. call the mcc_get_buffer() to get the pointer to a free message buffer
* 2. copy data to be sent into the message buffer
* 3. flush all cache lines occupied by the message buffer new data
* (maximum of MCC_ATTR_BUFFER_SIZE_IN_BYTES bytes).
* 4. call the mcc_send_nocopy() with the correct buffer pointer and the message size passed
* C. Data cache is ON, shared RAM MCC buffers NOT ALIGNED:
* - The application has to perform following steps:
* 1. call the mcc_get_buffer() to get the pointer to a free message buffer
* 2. grab the hw semaphore by calling the mcc_get_semaphore() low level MCC function.
* 3. invalidate all cache lines occupied by data to be filled into the free message buffer.
* (maximum of MCC_ATTR_BUFFER_SIZE_IN_BYTES bytes).
* 4. copy data to be sent into the message buffer.
* 5. flush all cache lines occupied by the message buffer new data
* (maximum of MCC_ATTR_BUFFER_SIZE_IN_BYTES bytes).
* 6. release the hw semaphore by calling the mcc_release_semaphore() low level MCC function.
* 7. call the mcc_send_nocopy() with the correct buffer pointer and the message size passed.
*
* After the mcc_send_nocopy() function is issued the message buffer is no more owned
* by the sending task and must not be touched anymore unless the mcc_send_nocopy()
* function fails and returns an error. In that case the application should try
* to re-issue the mcc_send_nocopy() again and if it is still not possible to send
* the message and the application wants to give it up from whatever reasons
* (for instance the MCC_ERR_ENDPOINT error is returned meaning the endpoint
* has not been created yet) the mcc_free_buffer() function could be called,
* passing the pointer to the buffer to be freed as a parameter.
*
* \param[in] src_endpoint Pointer to the local endpoint identifying the source endpoint.
* \param[in] dest_endpoint Pointer to the destination endpoint to send the message to.
* \param[in] buffer_p Pointer to the MCC buffer of the shared memory where the
* data to be sent is stored.
* \param[in] msg_size Size of the message to be sent in bytes.
*
* \return MCC_SUCCESS
* \return MCC_ERR_INVAL (the msg_size exceeds the size of a data buffer)
* \return MCC_ERR_ENDPOINT (the endpoint does not exist)
* \return MCC_ERR_SEMAPHORE (semaphore handling error)
* \return MCC_ERR_SQ_FULL (signal queue is full)
*
* \see mcc_send
* \see mcc_get_buffer
* \see MCC_ENDPOINT
*/
int mcc_send_nocopy(MCC_ENDPOINT *src_endpoint, MCC_ENDPOINT *dest_endpoint, void *buffer_p, MCC_MEM_SIZE msg_size)
{
int return_value;
MCC_RECEIVE_BUFFER * buf;
MCC_RECEIVE_LIST *list;
MCC_SIGNAL affiliated_signal;
/* Check if the size of the message to be sent does not exceed the size of the mcc buffer */
if(msg_size > sizeof(bookeeping_data->r_buffers[0].data)) {
return MCC_ERR_INVAL;
}
/* Semaphore-protected section start */
return_value = mcc_get_semaphore();
if(return_value != MCC_SUCCESS)
return return_value;
/* Get list of buffers kept by the particular endpoint */
list = mcc_get_endpoint_list(*dest_endpoint);
if(list == null) {
/* The endpoint does not exists (has not been registered so far) */
mcc_release_semaphore();
return MCC_ERR_ENDPOINT;
}
/* Store the message size and the source endpoint in the MCC_RECEIVE_BUFFER structure */
buf = (MCC_RECEIVE_BUFFER *)((unsigned int)buffer_p - (unsigned int)(&(((MCC_RECEIVE_BUFFER*)0)->data)));
MCC_DCACHE_INVALIDATE_MLINES((void*)&buf->source, sizeof(MCC_ENDPOINT) + sizeof(MCC_MEM_SIZE));
((MCC_RECEIVE_BUFFER*)buf)->data_len = msg_size;
mcc_memcpy((void*)src_endpoint, (void*)&buf->source, sizeof(MCC_ENDPOINT));
MCC_DCACHE_FLUSH_MLINES((void*)(void*)&buf->source, sizeof(MCC_ENDPOINT) + sizeof(MCC_MEM_SIZE));
/* Write the signal type into the signal queue of the particular core */
affiliated_signal.type = BUFFER_QUEUED;
affiliated_signal.destination = *dest_endpoint;
return_value = mcc_queue_signal(dest_endpoint->core, affiliated_signal);
if(return_value != MCC_SUCCESS) {
/* Signal queue is full - error */
mcc_release_semaphore();
return return_value;
}
/* Enqueue the buffer into the endpoint buffer list */
mcc_queue_buffer(list, (MCC_RECEIVE_BUFFER*)buf);
/* Semaphore-protected section end */
mcc_release_semaphore();
if(return_value != MCC_SUCCESS)
return return_value;
/* Signal the other core by generating the CPU-to-CPU interrupt */
return_value = mcc_generate_cpu_to_cpu_interrupt();
return return_value;
}
/*!
* \brief This function returns information about the MCC sub system.
*
* The function returns implementation-specific information.
*
* \param[in] node Node number.
* \param[out] info_data Pointer to the MCC_INFO_STRUCT structure to hold returned data.
*
* \return MCC_SUCCESS
* \return MCC_ERR_SEMAPHORE (semaphore handling error)
*
* \see MCC_INFO_STRUCT
*/
int mcc_get_info(MCC_NODE node, MCC_INFO_STRUCT* info_data)
{
int return_value;
/* Semaphore-protected section start */
return_value = mcc_get_semaphore();
if(return_value != MCC_SUCCESS)
return return_value;
mcc_memcpy(bookeeping_data->version_string, (void*)info_data->version_string, (unsigned int)sizeof(bookeeping_data->version_string));
/* Semaphore-protected section end */
return_value = mcc_release_semaphore();
if(return_value != MCC_SUCCESS)
return return_value;
return return_value;
}
/*!
* \brief This function receives a message from the specified endpoint if one is available. The data is NOT copied into the user-app. buffer.
*
* This is the "zero-copy receive" version of the MCC receive function. No data is copied.
* Only the pointer to the data is returned. This version is fast, but it requires the user to manage
* buffer allocation. Specifically, the user must decide when a buffer is no longer in use and
* make the appropriate API call to free it, see mcc_free_buffer.
*
* \param[out] src_endpoint Pointer to the MCC_ENDPOINT structure to be filled by the endpoint identifying the message sender.
* \param[in] dest_endpoint Pointer to the local receiving endpoint to receive from.
* \param[out] buffer_p Pointer to the MCC buffer of the shared memory where the received data is stored.
* \param[out] recv_size Pointer to an MCC_MEM_SIZE that will contain the number of valid bytes in the buffer.
* \param[in] timeout_ms Timeout, in milliseconds, to wait for a free buffer. A value of 0 means don't wait (non-blocking call). A value of 0xffffffff means wait forever (blocking call).
*
* \return MCC_SUCCESS
* \return MCC_ERR_ENDPOINT (the endpoint does not exist)
* \return MCC_ERR_SEMAPHORE (semaphore handling error)
* \return MCC_ERR_TIMEOUT (timeout exceeded before a new message came)
*
* \see mcc_send
* \see mcc_recv
* \see MCC_ENDPOINT
*/
int mcc_recv_nocopy(MCC_ENDPOINT *src_endpoint, MCC_ENDPOINT *dest_endpoint, void **buffer_p, MCC_MEM_SIZE *recv_size, unsigned int timeout_ms)
{
MCC_RECEIVE_LIST *list = null;
int return_value;
return_value = mcc_recv_common_part(dest_endpoint, timeout_ms, (MCC_RECEIVE_LIST**)&list);
if(return_value != MCC_SUCCESS)
return return_value;
/* Semaphore-protected section start */
return_value = mcc_get_semaphore();
if(return_value != MCC_SUCCESS)
return return_value;
MCC_DCACHE_INVALIDATE_MLINES((void*)list, sizeof(MCC_RECEIVE_LIST*));
if(list->head == (MCC_RECEIVE_BUFFER*)0) {
/* Buffer not dequeued before the timeout */
mcc_release_semaphore();
return MCC_ERR_TIMEOUT;
}
/* Get the message pointer from the head of the receive buffer list */
MCC_DCACHE_INVALIDATE_MLINES((void*)&list->head->data, list->head->data_len);
*buffer_p = (void*)&list->head->data;
MCC_DCACHE_INVALIDATE_MLINES((void*)&list->head->source, sizeof(MCC_ENDPOINT) + sizeof(MCC_MEM_SIZE));
mcc_memcpy((void*)&list->head->source, (void*)src_endpoint, sizeof(MCC_ENDPOINT));
*recv_size = (MCC_MEM_SIZE)(list->head->data_len);
/* Dequeue the buffer from the endpoint list */
mcc_dequeue_buffer(list);
/* Semaphore-protected section end */
return_value = mcc_release_semaphore();
if(return_value != MCC_SUCCESS)
return return_value;
return return_value;
}
/*!
* \brief This function initializes the Multi Core Communication subsystem for a given node.
*
* This function should only be called once per node (once in MQX, once per process in Linux).
*
* \param[in] node Node number that will be used in endpoints created by this process.
*
* \return MCC_SUCCESS
* \return MCC_ERR_SEMAPHORE (semaphore handling error)
* \return MCC_ERR_INT (interrupt registration error)
*
* \see mcc_destroy
* \see MCC_BOOKEEPING_STRUCT
*/
int mcc_initialize(MCC_NODE node)
{
int i,j = 0;
int return_value = MCC_SUCCESS;
MCC_SIGNAL tmp_signals_received = {(MCC_SIGNAL_TYPE)0, (MCC_CORE)0, (MCC_NODE)0, (MCC_PORT)0};
#if (MCC_OS_USED == MCC_MQX)
for(i=0; i<MCC_MQX_LWEVENT_COMPONENTS_COUNT; i++) {
_lwevent_create(&lwevent_buffer_queued[i],0);
}
_lwevent_create(&lwevent_buffer_freed,0);
#endif
/* Initialize synchronization module */
return_value = mcc_init_semaphore(MCC_SHMEM_SEMAPHORE_NUMBER);
if(return_value != MCC_SUCCESS)
return return_value;
/* Register CPU-to-CPU interrupt for inter-core signaling */
//mcc_register_cpu_to_cpu_isr(MCC_CORE0_CPU_TO_CPU_VECTOR);
return_value = mcc_register_cpu_to_cpu_isr();
if(return_value != MCC_SUCCESS)
return return_value;
/* Initialize the bookeeping structure */
bookeeping_data = (MCC_BOOKEEPING_STRUCT *)MCC_BASE_ADDRESS;
MCC_DCACHE_INVALIDATE_MLINES(bookeeping_data, sizeof(MCC_BOOKEEPING_STRUCT));
if(strcmp(bookeeping_data->init_string, init_string) != 0) {
/* Zero it all - no guarantee Linux or uboot didnt touch it before it was reserved */
_mem_zero((void*) bookeeping_data, (_mem_size) sizeof(struct mcc_bookeeping_struct));
/* Set init_string in case it has not been set yet by another core */
mcc_memcpy((void*)init_string, bookeeping_data->init_string, (unsigned int)sizeof(bookeeping_data->init_string));
/* Set version_string */
mcc_memcpy((void*)version_string, bookeeping_data->version_string, (unsigned int)sizeof(bookeeping_data->version_string));
/* Initialize the free list */
bookeeping_data->free_list.head = &bookeeping_data->r_buffers[0];
bookeeping_data->free_list.tail = &bookeeping_data->r_buffers[MCC_ATTR_NUM_RECEIVE_BUFFERS-1];
/* Initialize receive buffers */
for(i=0; i<MCC_ATTR_NUM_RECEIVE_BUFFERS-1; i++) {
bookeeping_data->r_buffers[i].next = &bookeeping_data->r_buffers[i+1];
}
bookeeping_data->r_buffers[MCC_ATTR_NUM_RECEIVE_BUFFERS-1].next = null;
/* Initialize signal queues */
for(i=0; i<MCC_NUM_CORES; i++) {
for(j=0; j<MCC_MAX_OUTSTANDING_SIGNALS; j++) {
bookeeping_data->signals_received[i][j] = tmp_signals_received;
}
bookeeping_data->signal_queue_head[i] = 0;
bookeeping_data->signal_queue_tail[i] = 0;
}
/* Mark all endpoint ports as free */
for(i=0; i<MCC_ATTR_MAX_RECEIVE_ENDPOINTS; i++) {
bookeeping_data->endpoint_table[i].endpoint.port = MCC_RESERVED_PORT_NUMBER;
}
}
MCC_DCACHE_FLUSH_MLINES(bookeeping_data, sizeof(MCC_BOOKEEPING_STRUCT));
return return_value;
}
/*!
* \brief This function receives a message from the specified endpoint if one is available.
* The data will be copied from the receive buffer into the user supplied buffer.
*
* This is the "receive with copy" version of the MCC receive function. This version is simple
* to use but it requires copying data from shared memory into the user space buffer.
* The user has no obligation or burden to manage the shared memory buffers.
*
* \param[in] endpoint Pointer to the receiving endpoint to receive from.
* \param[in] buffer Pointer to the user-app. buffer where data will be copied into.
* \param[in] buffer_size The maximum number of bytes to copy.
* \param[out] recv_size Pointer to an MCC_MEM_SIZE that will contain the number of bytes actually copied into the buffer.
* \param[in] timeout_us Timeout, in microseconds, to wait for a free buffer. A value of 0 means don't wait (non-blocking call). A value of 0xffffffff means wait forever (blocking call).
*
* \return MCC_SUCCESS
* \return MCC_ERR_ENDPOINT (the endpoint does not exist)
* \return MCC_ERR_SEMAPHORE (semaphore handling error)
* \return MCC_ERR_TIMEOUT (timeout exceeded before a new message came)
*
* \see mcc_send
* \see mcc_recv_nocopy
* \see MCC_ENDPOINT
*/
int mcc_recv_copy(MCC_ENDPOINT *endpoint, void *buffer, MCC_MEM_SIZE buffer_size, MCC_MEM_SIZE *recv_size, unsigned int timeout_us)
{
MCC_RECEIVE_LIST *list;
MCC_RECEIVE_BUFFER * buf;
MCC_SIGNAL affiliated_signal;
MCC_ENDPOINT tmp_destination = {(MCC_CORE)0, (MCC_NODE)0, (MCC_PORT)0};
int return_value, i = 0;
#if (MCC_OS_USED == MCC_MQX)
unsigned int time_us_tmp;
unsigned int lwevent_index = endpoint->port / MCC_MQX_LWEVENT_GROUP_SIZE;
unsigned int lwevent_group_index = endpoint->port % MCC_MQX_LWEVENT_GROUP_SIZE;
MQX_TICK_STRUCT tick_time;
#endif
/* Semaphore-protected section start */
return_value = mcc_get_semaphore();
if(return_value != MCC_SUCCESS)
return return_value;
/* Get list of buffers kept by the particular endpoint */
list = mcc_get_endpoint_list(*endpoint);
/* Semaphore-protected section end */
return_value = mcc_release_semaphore();
if(return_value != MCC_SUCCESS)
return return_value;
/* The endpoint is not valid */
if(list == null) {
return MCC_ERR_ENDPOINT;
}
if(list->head == (MCC_RECEIVE_BUFFER*)0) {
/* Non-blocking call */
if(timeout_us == 0) {
return MCC_ERR_TIMEOUT;
}
/* Blocking call */
else {
#if (MCC_OS_USED == MCC_MQX)
if(timeout_us == 0xFFFFFFFF) {
_lwevent_wait_ticks(&lwevent_buffer_queued[lwevent_index], 1<<lwevent_group_index, TRUE, 0);
}
/* timeout_us > 0 */
else {
_time_get_ticks(&tick_time);
_time_add_usec_to_ticks(&tick_time, timeout_us);
_lwevent_wait_until(&lwevent_buffer_queued[lwevent_index], 1<<lwevent_group_index, TRUE, &tick_time);
}
#endif
MCC_DCACHE_INVALIDATE_MLINES((void*)list, sizeof(MCC_RECEIVE_LIST*));
}
}
/* Clear event bit specified for the particular endpoint in the lwevent_buffer_queued lwevent group */
_lwevent_clear(&lwevent_buffer_queued[lwevent_index], 1<<lwevent_group_index);
if(list->head == (MCC_RECEIVE_BUFFER*)0) {
/* Buffer not dequeued before the timeout */
return MCC_ERR_TIMEOUT;
}
/* Copy the message from the MCC receive buffer into the user-app. buffer */
MCC_DCACHE_INVALIDATE_MLINES((void*)&list->head->data_len, sizeof(MCC_MEM_SIZE));
if (list->head->data_len > buffer_size) {
list->head->data_len = buffer_size;
}
*recv_size = (MCC_MEM_SIZE)(list->head->data_len);
MCC_DCACHE_INVALIDATE_MLINES((void*)&list->head->data, list->head->data_len);
mcc_memcpy((void*)list->head->data, buffer, list->head->data_len);
/* Semaphore-protected section start */
return_value = mcc_get_semaphore();
if(return_value != MCC_SUCCESS)
return return_value;
/* Dequeue the buffer from the endpoint list */
buf = mcc_dequeue_buffer(list);
/* Enqueue the buffer into the free list */
MCC_DCACHE_INVALIDATE_MLINES((void*)&bookeeping_data->free_list, sizeof(MCC_RECEIVE_LIST*));
mcc_queue_buffer(&bookeeping_data->free_list, buf);
/* Notify all cores (except of itself) via CPU-to-CPU interrupt that a buffer has been freed */
affiliated_signal.type = BUFFER_FREED;
affiliated_signal.destination = tmp_destination;
for (i=0; i<MCC_NUM_CORES; i++) {
if(i != MCC_CORE_NUMBER) {
mcc_queue_signal(i, affiliated_signal);
}
}
mcc_generate_cpu_to_cpu_interrupt();
/* Semaphore-protected section end */
return_value = mcc_release_semaphore();
if(return_value != MCC_SUCCESS)
return return_value;
return return_value;
}
/*!
* \brief This function sends a message to an endpoint.
*
* The message is copied into the MCC buffer and the destination core is signaled.
*
* \param[in] endpoint Pointer to the receiving endpoint to send to.
* \param[in] msg Pointer to the message to be sent.
* \param[in] msg_size Size of the message to be sent in bytes.
* \param[in] timeout_us Timeout, in microseconds, to wait for a free buffer. A value of 0 means don't wait (non-blocking call). A value of 0xffffffff means wait forever (blocking call).
*
* \return MCC_SUCCESS
* \return MCC_ERR_ENDPOINT (the endpoint does not exist)
* \return MCC_ERR_SEMAPHORE (semaphore handling error)
* \return MCC_ERR_INVAL (the msg_size exceeds the size of a data buffer)
* \return MCC_ERR_TIMEOUT (timeout exceeded before a buffer became available)
* \return MCC_ERR_NOMEM (no free buffer available and timeout_us set to 0)
* \return MCC_ERR_SQ_FULL (signal queue is full)
*
* \see mcc_recv_copy
* \see mcc_recv_nocopy
* \see MCC_ENDPOINT
*/
int mcc_send(MCC_ENDPOINT *endpoint, void *msg, MCC_MEM_SIZE msg_size, unsigned int timeout_us)
{
int return_value, end_time_set_flag = 0;
MCC_RECEIVE_LIST *list;
MCC_RECEIVE_BUFFER * buf;
MCC_SIGNAL affiliated_signal;
#if (MCC_OS_USED == MCC_MQX)
unsigned int time_us_tmp;
MQX_TICK_STRUCT tick_time;
#endif
/* Check if the size of the message to be sent does not exceed the size of the mcc buffer */
if(msg_size > sizeof(bookeeping_data->r_buffers[0].data)) {
return MCC_ERR_INVAL;
}
/* Semaphore-protected section start */
return_value = mcc_get_semaphore();
if(return_value != MCC_SUCCESS)
return return_value;
/* Dequeue the buffer from the free list */
MCC_DCACHE_INVALIDATE_MLINES((void*)&bookeeping_data->free_list, sizeof(MCC_RECEIVE_LIST*));
buf = mcc_dequeue_buffer(&bookeeping_data->free_list);
while(buf == null) {
mcc_release_semaphore();
/* Non-blocking call */
if(timeout_us == 0) {
return MCC_ERR_NOMEM;
}
/* Blocking calls: CPU-to-CPU ISR sets the event and thus resumes tasks waiting for a free MCC buffer.
* As the interrupt request is send to all cores when a buffer is freed it could happen that several
* tasks from different cores/nodes are waiting for a free buffer and all of them are notified that the buffer
* has been freed. This function has to check (after the wake up) that a buffer is really available and has not been already
* grabbed by another "competitor task" that has been faster. If so, it has to wait again for the next notification. */
/* wait forever */
else if(timeout_us == 0xFFFFFFFF) {
#if (MCC_OS_USED == MCC_MQX)
_lwevent_wait_ticks(&lwevent_buffer_freed, 1, TRUE, 0);
_lwevent_clear(&lwevent_buffer_freed, 1);
#endif
}
/* timeout_us > 0 */
else {
#if (MCC_OS_USED == MCC_MQX)
if(!end_time_set_flag) {
_time_get_ticks(&tick_time);
_time_add_usec_to_ticks(&tick_time, timeout_us);
end_time_set_flag = 1;
}
return_value = _lwevent_wait_until(&lwevent_buffer_freed, 1, TRUE, &tick_time);
if(return_value == LWEVENT_WAIT_TIMEOUT) {
/* Buffer not dequeued before the timeout */
return MCC_ERR_TIMEOUT;
}
_lwevent_clear(&lwevent_buffer_freed, 1);
#endif
}
MCC_DCACHE_INVALIDATE_MLINES((void*)&bookeeping_data->free_list, sizeof(MCC_RECEIVE_LIST*));
mcc_get_semaphore();
buf = mcc_dequeue_buffer(&bookeeping_data->free_list);
}
/* Semaphore-protected section end */
mcc_release_semaphore();
if(return_value != MCC_SUCCESS)
return return_value;
/* Copy the message into the MCC receive buffer */
mcc_memcpy(msg, (void*)buf->data, (unsigned int)msg_size);
MCC_DCACHE_FLUSH_MLINES((void*)buf->data, msg_size);
buf->data_len = msg_size;
MCC_DCACHE_FLUSH_MLINES((void*)&buf->data_len, sizeof(MCC_MEM_SIZE));
/* Semaphore-protected section start */
return_value = mcc_get_semaphore();
if(return_value != MCC_SUCCESS)
return return_value;
/* Get list of buffers kept by the particular endpoint */
list = mcc_get_endpoint_list(*endpoint);
if(list == null) {
/* The endpoint does not exists (has not been registered so far),
free the buffer and return immediately - error */
/* Enqueue the buffer back into the free list */
MCC_DCACHE_INVALIDATE_MLINES((void*)&bookeeping_data->free_list, sizeof(MCC_RECEIVE_LIST*));
mcc_queue_buffer(&bookeeping_data->free_list, buf);
mcc_release_semaphore();
return MCC_ERR_ENDPOINT;
}
/* Write the signal type into the signal queue of the particular core */
affiliated_signal.type = BUFFER_QUEUED;
affiliated_signal.destination = *endpoint;
return_value = mcc_queue_signal(endpoint->core, affiliated_signal);
if(return_value != MCC_SUCCESS) {
/* Signal queue is full, free the buffer and return immediately - error */
MCC_DCACHE_INVALIDATE_MLINES((void*)&bookeeping_data->free_list, sizeof(MCC_RECEIVE_LIST*));
mcc_queue_buffer(&bookeeping_data->free_list, buf);
mcc_release_semaphore();
return return_value;
}
/* Enqueue the buffer into the endpoint buffer list */
mcc_queue_buffer(list, buf);
/* Semaphore-protected section end */
mcc_release_semaphore();
if(return_value != MCC_SUCCESS)
return return_value;
/* Signal the other core by generating the CPU-to-CPU interrupt */
return_value = mcc_generate_cpu_to_cpu_interrupt();
return return_value;
}
/*!
* \brief This function receives a message from the specified endpoint if one is available.
* The data is copied from the receive buffer into the user supplied buffer.
*
* This is the "receive with copy" version of the MCC receive function. This version is simple
* to use but it requires copying data from shared memory into the user space buffer.
* The user has no obligation or burden to manage the shared memory buffers.
*
* \param[out] src_endpoint Pointer to the MCC_ENDPOINT structure to be filled by the endpoint identifying the message sender.
* \param[in] dest_endpoint Pointer to the local receiving endpoint to receive from.
* \param[in] buffer Pointer to the user-app. buffer where data will be copied into.
* \param[in] buffer_size The maximum number of bytes to copy.
* \param[out] recv_size Pointer to an MCC_MEM_SIZE that will contain the number of bytes actually copied into the buffer.
* \param[in] timeout_ms Timeout, in milliseconds, to wait for a free buffer. A value of 0 means don't wait (non-blocking call). A value of 0xffffffff means wait forever (blocking call).
*
* \return MCC_SUCCESS
* \return MCC_ERR_ENDPOINT (the endpoint does not exist)
* \return MCC_ERR_SEMAPHORE (semaphore handling error)
* \return MCC_ERR_TIMEOUT (timeout exceeded before a new message came)
*
* \see mcc_send
* \see mcc_recv_nocopy
* \see MCC_ENDPOINT
*/
int mcc_recv(MCC_ENDPOINT *src_endpoint, MCC_ENDPOINT *dest_endpoint, void *buffer, MCC_MEM_SIZE buffer_size, MCC_MEM_SIZE *recv_size, unsigned int timeout_ms)
{
MCC_RECEIVE_LIST *list = null;
MCC_RECEIVE_BUFFER * buf;
MCC_SIGNAL affiliated_signal;
MCC_ENDPOINT tmp_destination = {(MCC_CORE)0, (MCC_NODE)0, (MCC_PORT)0};
int return_value, i = 0;
return_value = mcc_recv_common_part(dest_endpoint, timeout_ms, (MCC_RECEIVE_LIST**)&list);
if(return_value != MCC_SUCCESS)
return return_value;
/* Semaphore-protected section start */
return_value = mcc_get_semaphore();
if(return_value != MCC_SUCCESS)
return return_value;
MCC_DCACHE_INVALIDATE_MLINES((void*)list, sizeof(MCC_RECEIVE_LIST*));
if(list->head == (MCC_RECEIVE_BUFFER*)0) {
/* Buffer not dequeued before the timeout */
mcc_release_semaphore();
return MCC_ERR_TIMEOUT;
}
/* Copy the message from the MCC receive buffer into the user-app. buffer */
MCC_DCACHE_INVALIDATE_MLINES((void*)&list->head->source, sizeof(MCC_ENDPOINT) + sizeof(MCC_MEM_SIZE));
mcc_memcpy((void*)&list->head->source, (void*)src_endpoint, sizeof(MCC_ENDPOINT));
if (list->head->data_len > buffer_size) {
list->head->data_len = buffer_size;
}
*recv_size = (MCC_MEM_SIZE)(list->head->data_len);
MCC_DCACHE_INVALIDATE_MLINES((void*)&list->head->data, list->head->data_len);
mcc_memcpy((void*)list->head->data, buffer, list->head->data_len);
/* Dequeue the buffer from the endpoint list */
list->head = (MCC_RECEIVE_BUFFER*)MCC_MEM_VIRT_TO_PHYS(list->head);
buf = mcc_dequeue_buffer(list);
/* Enqueue the buffer into the free list */
MCC_DCACHE_INVALIDATE_MLINES((void*)&bookeeping_data->free_list, sizeof(MCC_RECEIVE_LIST*));
mcc_queue_buffer(&bookeeping_data->free_list, buf);
/* Notify all cores (except of itself) via CPU-to-CPU interrupt that a buffer has been freed */
affiliated_signal.type = BUFFER_FREED;
affiliated_signal.destination = tmp_destination;
for (i=0; i<MCC_NUM_CORES; i++) {
if(i != MCC_CORE_NUMBER) {
mcc_queue_signal(i, affiliated_signal);
}
}
/* Semaphore-protected section end */
return_value = mcc_release_semaphore();
mcc_generate_cpu_to_cpu_interrupt();
if(return_value != MCC_SUCCESS)
return return_value;
return return_value;
}
/*!
* \brief This function initializes the Multi Core Communication subsystem for a given node.
*
* This function should only be called once per node (once in MQX, once per a process in Linux).
* It tries to initialize the bookkeeping structure when the init_string member of this structure
* is not equal to MCC_INIT_STRING, i.e. when no other core had performed the initialization yet.
* Note, that this way of bookkeeping data re-initialization protection is not powerful enough and
* the user application should not rely on this method. Instead, the application should be designed
* to unambiguously assign the core that will perform the MCC initialization.
* Clear the shared memory before the first core is attempting to initialize the MCC
* (in some cases MCC_INIT_STRING remains in the shared memory after the application reset and could
* cause that the bookkeeping data structure is not initialized correctly).
*
* \param[in] node Node number that will be used in endpoints created by this process.
*
* \return MCC_SUCCESS
* \return MCC_ERR_SEMAPHORE (semaphore handling error)
* \return MCC_ERR_INT (interrupt registration error)
* \return MCC_ERR_VERSION (incorrect MCC version used - compatibility issue)
* \return MCC_ERR_OSSYNC (OS synchronization module(s) initialization failed)
*
* \see mcc_destroy
* \see MCC_BOOKEEPING_STRUCT
*/
int mcc_initialize(MCC_NODE node)
{
int i,j = 0;
int return_value = MCC_SUCCESS;
MCC_SIGNAL tmp_signals_received = {(MCC_SIGNAL_TYPE)0, {(MCC_CORE)0, (MCC_NODE)0, (MCC_PORT)0}};
/* Initialize synchronization module for shared data protection */
return_value = mcc_init_semaphore(MCC_SHMEM_SEMAPHORE_NUMBER);
if(return_value != MCC_SUCCESS)
return return_value;
/* Initialize all necessary OS synchronization module(s)
(for unblocking tasks waiting for new received data and for unblocking tasks waiting for a free buffer) */
return_value = mcc_init_os_sync();
if(return_value != MCC_SUCCESS)
return return_value;
/* Register CPU-to-CPU interrupt for inter-core signaling */
//mcc_register_cpu_to_cpu_isr(MCC_CORE0_CPU_TO_CPU_VECTOR);
return_value = mcc_register_cpu_to_cpu_isr();
if(return_value != MCC_SUCCESS)
return return_value;
/* Initialize the bookeeping structure */
bookeeping_data = (MCC_BOOKEEPING_STRUCT *)mcc_get_bookeeping_data();
MCC_DCACHE_INVALIDATE_MLINES(bookeeping_data, sizeof(MCC_BOOKEEPING_STRUCT));
if(strcmp(bookeeping_data->init_string, init_string) != 0) {
/* MCC not initialized yet, do it now */
/* Zero it all - no guarantee Linux or uboot didnt touch it before it was reserved */
memset((void*) bookeeping_data, 0, sizeof(struct mcc_bookeeping_struct));
/* Set init_string in case it has not been set yet by another core */
mcc_memcpy((void*)init_string, bookeeping_data->init_string, (unsigned int)sizeof(bookeeping_data->init_string));
/* Set version_string */
mcc_memcpy((void*)version_string, bookeeping_data->version_string, (unsigned int)sizeof(bookeeping_data->version_string));
/* Initialize the free list */
bookeeping_data->free_list.head = (MCC_RECEIVE_BUFFER*)MCC_MEM_VIRT_TO_PHYS(&bookeeping_data->r_buffers[0]);
bookeeping_data->free_list.tail = (MCC_RECEIVE_BUFFER*)MCC_MEM_VIRT_TO_PHYS(&bookeeping_data->r_buffers[MCC_ATTR_NUM_RECEIVE_BUFFERS-1]);
/* Initialize receive buffers */
for(i=0; i<MCC_ATTR_NUM_RECEIVE_BUFFERS-1; i++) {
bookeeping_data->r_buffers[i].next = (MCC_RECEIVE_BUFFER*)MCC_MEM_VIRT_TO_PHYS(&bookeeping_data->r_buffers[i+1]);
}
bookeeping_data->r_buffers[MCC_ATTR_NUM_RECEIVE_BUFFERS-1].next = null;
/* Initialize signal queues */
for(i=0; i<MCC_NUM_CORES; i++) {
for(j=0; j<MCC_MAX_OUTSTANDING_SIGNALS; j++) {
bookeeping_data->signals_received[i][j] = tmp_signals_received;
}
bookeeping_data->signal_queue_head[i] = 0;
bookeeping_data->signal_queue_tail[i] = 0;
}
/* Mark all endpoint ports as free */
for(i=0; i<MCC_ATTR_MAX_RECEIVE_ENDPOINTS; i++) {
bookeeping_data->endpoint_table[i].endpoint.port = MCC_RESERVED_PORT_NUMBER;
}
}
else {
/* MCC already initialized - check the major number of the version string to ensure compatibility */
if(strncmp(bookeeping_data->version_string, version_string, 4) != 0) {
return_value = MCC_ERR_VERSION;
}
}
MCC_DCACHE_FLUSH_MLINES(bookeeping_data, sizeof(MCC_BOOKEEPING_STRUCT));
return return_value;
}
/*!
* \brief This function sends a message to an endpoint.
*
* The message is copied into the MCC buffer and the destination core is signaled.
*
* \param[in] src_endpoint Pointer to the local endpoint identifying the source endpoint.
* \param[in] dest_endpoint Pointer to the destination endpoint to send the message to.
* \param[in] msg Pointer to the message to be sent.
* \param[in] msg_size Size of the message to be sent in bytes.
* \param[in] timeout_ms Timeout, in milliseconds, to wait for a free buffer. A value of 0 means don't wait (non-blocking call). A value of 0xffffffff means wait forever (blocking call).
*
* \return MCC_SUCCESS
* \return MCC_ERR_ENDPOINT (the endpoint does not exist)
* \return MCC_ERR_SEMAPHORE (semaphore handling error)
* \return MCC_ERR_INVAL (the msg_size exceeds the size of a data buffer)
* \return MCC_ERR_TIMEOUT (timeout exceeded before a buffer became available)
* \return MCC_ERR_NOMEM (no free buffer available and timeout_ms set to 0)
* \return MCC_ERR_SQ_FULL (signal queue is full)
*
* \see mcc_recv
* \see mcc_recv_nocopy
* \see MCC_ENDPOINT
*/
int mcc_send(MCC_ENDPOINT *src_endpoint, MCC_ENDPOINT *dest_endpoint, void *msg, MCC_MEM_SIZE msg_size, unsigned int timeout_ms)
{
int return_value;
MCC_RECEIVE_LIST *list;
MCC_RECEIVE_BUFFER * buf;
MCC_SIGNAL affiliated_signal;
MCC_MEM_SIZE buffer_size;
/* Reuse the mcc_get_buffer_internal() function to get the MCC buffer pointer. */
return_value = mcc_get_buffer_internal((void**)&buf, &buffer_size, timeout_ms);
if(return_value != MCC_SUCCESS)
return return_value;
/* Check if the size of the message to be sent does not exceed the size of the mcc buffer */
if(msg_size > buffer_size) {
while(MCC_SUCCESS != mcc_free_buffer_internal(buf)) {};
return MCC_ERR_INVAL;
}
/* Semaphore-protected section start */
return_value = mcc_get_semaphore();
if(return_value != MCC_SUCCESS)
return return_value;
/* As the mcc_get_buffer_internal() returns the pointer to the data field, it
is necessary to adjust the pointer to point at the MCC buffer structure beginning. */
buf = (MCC_RECEIVE_BUFFER *)((unsigned int)buf - (unsigned int)(&(((MCC_RECEIVE_BUFFER*)0)->data)));
/* Copy the message into the MCC receive buffer */
MCC_DCACHE_INVALIDATE_MLINES((void*)buf, sizeof(MCC_RECEIVE_BUFFER));
mcc_memcpy(msg, (void*)buf->data, (unsigned int)msg_size);
mcc_memcpy((void*)src_endpoint, (void*)&buf->source, sizeof(MCC_ENDPOINT));
buf->data_len = msg_size;
MCC_DCACHE_FLUSH_MLINES((void*)buf, sizeof(MCC_RECEIVE_BUFFER));
/* Get list of buffers kept by the particular endpoint */
list = mcc_get_endpoint_list(*dest_endpoint);
if(list == null) {
/* The endpoint does not exists (has not been registered so far),
free the buffer and return immediately - error */
/* Enqueue the buffer back into the free list */
MCC_DCACHE_INVALIDATE_MLINES((void*)&bookeeping_data->free_list, sizeof(MCC_RECEIVE_LIST*));
mcc_queue_buffer(&bookeeping_data->free_list, buf);
mcc_release_semaphore();
return MCC_ERR_ENDPOINT;
}
/* Write the signal type into the signal queue of the particular core */
affiliated_signal.type = BUFFER_QUEUED;
affiliated_signal.destination = *dest_endpoint;
return_value = mcc_queue_signal(dest_endpoint->core, affiliated_signal);
if(return_value != MCC_SUCCESS) {
/* Signal queue is full, free the buffer and return immediately - error */
MCC_DCACHE_INVALIDATE_MLINES((void*)&bookeeping_data->free_list, sizeof(MCC_RECEIVE_LIST*));
mcc_queue_buffer(&bookeeping_data->free_list, buf);
mcc_release_semaphore();
return return_value;
}
/* Enqueue the buffer into the endpoint buffer list */
mcc_queue_buffer(list, buf);
/* Semaphore-protected section end */
return_value = mcc_release_semaphore();
if(return_value != MCC_SUCCESS)
return return_value;
/* Signal the other core by generating the CPU-to-CPU interrupt */
return_value = mcc_generate_cpu_to_cpu_interrupt();
return return_value;
}
