/*
* Get next message from message queue. Return NULL if no message
* present. User must call next_message() to move to next message.
* rmq message queue
*/
void *gru_get_next_message(struct gru_message_queue_desc *mqd)
{
struct message_queue *mq = mqd->mq;
struct message_header *mhdr = mq->next;
int present = mhdr->present;
/* skip NOOP messages */
while (present == MQS_NOOP) {
gru_free_message(mqd, mhdr);
mhdr = mq->next;
present = mhdr->present;
}
/* Wait for both halves of 2 line messages */
if (present == MQS_FULL && mhdr->lines == 2 &&
get_present2(mhdr) == MQS_EMPTY)
present = MQS_EMPTY;
if (!present) {
STAT(mesq_receive_none);
return NULL;
}
if (mhdr->lines == 2)
restore_present2(mhdr, mhdr->present2);
STAT(mesq_receive);
return mhdr;
}
/*
* Send a message to a message queue
* cb GRU control block to use to send message
* mq message queue
* mesg message. ust be vaddr within a GSEG
* bytes message size (<= 2 CL)
*/
int gru_send_message_gpa(unsigned long mq, void *mesg, unsigned int bytes)
{
struct message_header *mhdr;
void *cb;
void *dsr;
int istatus, clines, ret;
STAT(mesq_send);
BUG_ON(bytes < sizeof(int) || bytes > 2 * GRU_CACHE_LINE_BYTES);
clines = DIV_ROUND_UP(bytes, GRU_CACHE_LINE_BYTES);
if (gru_get_cpu_resources(bytes, &cb, &dsr))
return MQE_BUG_NO_RESOURCES;
memcpy(dsr, mesg, bytes);
mhdr = dsr;
mhdr->present = MQS_FULL;
mhdr->lines = clines;
if (clines == 2) {
mhdr->present2 = get_present2(mhdr);
restore_present2(mhdr, MQS_FULL);
}
do {
ret = MQE_OK;
gru_mesq(cb, mq, gru_get_tri(mhdr), clines, IMA);
istatus = gru_wait(cb);
if (istatus != CBS_IDLE)
ret = send_message_failure(cb, mq, dsr, clines);
} while (ret == MQIE_AGAIN);
gru_free_cpu_resources(cb, dsr);
if (ret)
STAT(mesq_send_failed);
return ret;
}
