ISMT_RING_NENTS
ismt->ismt_tail = (ismt->ismt_tail + 1) % ISMT_RING_NENTS;
ismt->ismt_head = (ismt->ismt_head + 1) % ISMT_RING_NENTS;
#define ISMT_RING_DMA_SIZE (ISMT_RING_NENTS * sizeof (ismt_desc_t))
#define ISMT_ICL_DMA_SIZE (ISMT_RING_NENTS * sizeof (uint32_t) * 2)
val = ISMT_R_MDS_SET_SIZE(0, ISMT_RING_NENTS - 1);