Lines Matching refs:head
486 int head, tail;
511 head = dmar_readq(iommu->reg + DMAR_PQH_REG) & PRQ_RING_MASK;
512 while (head != tail) {
515 req = &iommu->prq[head / sizeof(*req)];
517 head = (head + sizeof(*req)) & PRQ_RING_MASK;
656 int head, tail, handled;
661 * Clear PPR bit before reading head/tail registers, to ensure that
667 head = dmar_readq(iommu->reg + DMAR_PQH_REG) & PRQ_RING_MASK;
668 handled = (head != tail);
669 while (head != tail) {
670 req = &iommu->prq[head / sizeof(*req)];
721 head = (head + sizeof(*req)) & PRQ_RING_MASK;
733 head = dmar_readq(iommu->reg + DMAR_PQH_REG) & PRQ_RING_MASK;
735 if (head == tail) {