Function gdma_poll_completion_queue

dpdk/drivers/net/mana/gdma.c:347–394

* Poll completion queue for completions. */

 * Poll completion queue for completions.
 */
uint32_t
gdma_poll_completion_queue(struct mana_gdma_queue *cq,
			   struct gdma_comp *gdma_comp, uint32_t max_comp)
{
	struct gdma_hardware_completion_entry *cqe;
	uint32_t new_owner_bits, old_owner_bits;
	uint32_t cqe_owner_bits;
	uint32_t num_comp = 0;
	struct gdma_hardware_completion_entry *buffer = cq->buffer;

	while (num_comp < max_comp) {
		cqe = &buffer[cq->head % cq->count];
		new_owner_bits = (cq->head / cq->count) &
					COMPLETION_QUEUE_OWNER_MASK;
		old_owner_bits = (cq->head / cq->count - 1) &
					COMPLETION_QUEUE_OWNER_MASK;
		cqe_owner_bits = cqe->owner_bits;

		DP_LOG(DEBUG, "comp cqe bits 0x%x owner bits 0x%x",
			cqe_owner_bits, old_owner_bits);

		/* No new entry */
		if (cqe_owner_bits == old_owner_bits)
			break;

		if (cqe_owner_bits != new_owner_bits) {
			DRV_LOG(ERR, "CQ overflowed, ID %u cqe 0x%x new 0x%x",
				cq->id, cqe_owner_bits, new_owner_bits);
			break;
		}

		gdma_comp[num_comp].cqe_data = cqe->dma_client_data;
		num_comp++;

		cq->head++;

		DP_LOG(DEBUG, "comp new 0x%x old 0x%x cqe 0x%x wq %u sq %u head %u",
		       new_owner_bits, old_owner_bits, cqe_owner_bits,
		       cqe->wq_num, cqe->is_sq, cq->head);
	}

	/* Make sure the CQE owner bits are checked before we access the data
	 * in CQE
	 */
	rte_rmb();

	return num_comp;
}