Add support for TLS 1.3 using AES-GCM to the OCF backend for KTLS.

[jhb]

Test Plan

• tested against openssl master with both client and server using cryptosoft, aesni, and ccr

head/sys/opencrypto/ktls_ocf.c

 struct awg_txring {
         bus_dma_tag_t           desc_tag;
         bus_dmamap_t            desc_map;
         struct emac_desc        *desc_ring;
         bus_addr_t              desc_ring_paddr;
         bus_dma_tag_t           buf_tag;
         struct awg_bufmap       buf_map[TX_DESC_COUNT];
         u_int                        cur, next, queued;
+        u_int                   segs;
 };
 
 struct awg_rxring {
         bus_dma_tag_t           desc_tag;
         bus_dmamap_t            desc_map;
         struct emac_desc        *desc_ring;
         bus_addr_t              desc_ring_paddr;
         bus_dma_tag_t           buf_tag;
awg_setup_txdesc(struct awg_softc *sc, int index, int flags, bus_addr_t paddr,
 
         if (paddr == 0 || len == 0) {
                 status = 0;
                 size = 0;
                 --sc->tx.queued;
         } else {
                 status = TX_DESC_CTL;
                 size = flags | len;
-                if ((index & (awg_tx_interval - 1)) == 0)
-                        size |= TX_INT_CTL;
                 ++sc->tx.queued;
         }
 
         sc->tx.desc_ring[index].addr = htole32((uint32_t)paddr);
         sc->tx.desc_ring[index].size = htole32(size);
         sc->tx.desc_ring[index].status = htole32(status);
 }
 
if ((m->m_pkthdr.csum_flags & (CSUM_TCP|CSUM_UDP)) != 0)
                         csum_flags = TX_CHECKSUM_CTL_FULL;
                 else
                         csum_flags = TX_CHECKSUM_CTL_IP;
                 flags |= (csum_flags << TX_CHECKSUM_CTL_SHIFT);
         }
 
         for (cur = index, i = 0; i < nsegs; i++) {
                 sc->tx.buf_map[cur].mbuf = (i == 0 ? m : NULL);
-                if (i == nsegs - 1)
+                sc->tx.segs++;
+                if (i == nsegs - 1) {
                         flags |= TX_LAST_DESC;
+                        /*
+                         * Can only request TX completion
+                         * interrupt on last descriptor.
+                         */
+                        if (sc->tx.segs >= awg_tx_interval) {
+                                sc->tx.segs = 0;
+                                flags |= TX_INT_CTL;
+                        }
+                }
                 awg_setup_txdesc(sc, cur, flags, segs[i].ds_addr,
                     segs[i].ds_len);
                 flags &= ~TX_FIR_DESC;
                 cur = TX_NEXT(cur);
         }
 
         return (nsegs);
 }