small code cleanup in preparation for future modifications in

the memory allocator used by netmap. No functional change,
two small bug fixes:
- in if_re.c add a missing bus_dmamap_sync()
- in netmap.c comment out a spurious free() in an error handling block

11 files changed, 131 insertions, 111 deletions

diff --git a/sys/dev/e1000/if_em.c b/sys/dev/e1000/if_em.c
index 4d0ad8f..9f090ba 100644
--- a/sys/dev/e1000/if_em.c
+++ b/sys/dev/e1000/if_em.c
@@ -3297,16 +3297,15 @@ em_setup_transmit_ring(struct tx_ring *txr)
 #ifdef DEV_NETMAP
 		if (slot) {
 			int si = i + na->tx_rings[txr->me].nkr_hwofs;
+			uint64_t paddr;
 			void *addr;
 
 			if (si >= na->num_tx_desc)
 				si -= na->num_tx_desc;
-			addr = NMB(slot + si);
-			txr->tx_base[i].buffer_addr =
-			    htole64(vtophys(addr));
+			addr = PNMB(slot + si, &paddr);
+			txr->tx_base[i].buffer_addr = htole64(paddr);
 			/* reload the map for netmap mode */
-			netmap_load_map(txr->txtag,
-			    txbuf->map, addr, na->buff_size);
+			netmap_load_map(txr->txtag, txbuf->map, addr);
 		}
 #endif /* DEV_NETMAP */
 
@@ -4104,9 +4103,6 @@ em_setup_receive_ring(struct rx_ring *rxr)
 		sj += adapter->num_rx_desc;
 
 	for (int j = 0; j != adapter->num_rx_desc; j++, sj++) {
-		void *addr;
-		int sz;
-
 		rxbuf = &rxr->rx_buffers[j];
 		/* no mbuf and regular mode -> skip this entry */
 		if (rxbuf->m_head == NULL && !slot)
@@ -4115,12 +4111,20 @@ em_setup_receive_ring(struct rx_ring *rxr)
 		if (sj >= adapter->num_rx_desc)
 			sj -= adapter->num_rx_desc;
 		/* see comment, set slot addr and map */
-		addr = slot ? NMB(slot + sj) : rxbuf->m_head->m_data;
-		sz = slot ? na->buff_size : adapter->rx_mbuf_sz;
-		// XXX load or reload ?
-		netmap_load_map(rxr->rxtag, rxbuf->map, addr, sz);
-		/* Update descriptor */
-		rxr->rx_base[j].buffer_addr = htole64(vtophys(addr));
+		if (slot) {
+			uint64_t paddr;
+			void *addr = PNMB(slot + sj, &paddr);
+			netmap_load_map(rxr->rxtag, rxbuf->map, addr);
+			/* Update descriptor */
+			rxr->rx_base[j].buffer_addr = htole64(paddr);
+		} else {
+			/* Get the memory mapping */
+			bus_dmamap_load_mbuf_sg(rxr->rxtag,
+			    rxbuf->map, rxbuf->m_head, seg,
+			    &nsegs, BUS_DMA_NOWAIT);
+			/* Update descriptor */
+			rxr->rx_base[j].buffer_addr = htole64(seg[0].ds_addr);
+		}
 		bus_dmamap_sync(rxr->rxtag, rxbuf->map, BUS_DMASYNC_PREREAD);
 	}
     }
diff --git a/sys/dev/e1000/if_igb.c b/sys/dev/e1000/if_igb.c
index d83130c..2c0caa4 100644
--- a/sys/dev/e1000/if_igb.c
+++ b/sys/dev/e1000/if_igb.c
@@ -3320,8 +3320,7 @@ igb_setup_transmit_ring(struct tx_ring *txr)
 
 			if (si < 0)
 				si += na->num_tx_desc;
-			netmap_load_map(txr->txtag, txbuf->map,
-				NMB(slot + si), na->buff_size);
+			netmap_load_map(txr->txtag, txbuf->map, NMB(slot + si));
 		}
 #endif /* DEV_NETMAP */
 		/* clear the watch index */
@@ -4062,15 +4061,15 @@ igb_setup_receive_ring(struct rx_ring *rxr)
 		if (slot) {
 			/* slot sj is mapped to the i-th NIC-ring entry */
 			int sj = j + na->rx_rings[rxr->me].nkr_hwofs;
+			uint64_t paddr;
 			void *addr;
 
 			if (sj < 0)
 				sj += na->num_rx_desc;
-			addr = NMB(slot + sj);
-			netmap_load_map(rxr->ptag,
-			    rxbuf->pmap, addr, na->buff_size);
+			addr = PNMB(slot + sj, &paddr);
+			netmap_load_map(rxr->ptag, rxbuf->pmap, addr);
 			/* Update descriptor */
-			rxr->rx_base[j].read.pkt_addr = htole64(vtophys(addr));
+			rxr->rx_base[j].read.pkt_addr = htole64(paddr);
 			continue;
 		}
 #endif /* DEV_NETMAP */
diff --git a/sys/dev/e1000/if_lem.c b/sys/dev/e1000/if_lem.c
index 216ec95..0774cb9 100644
--- a/sys/dev/e1000/if_lem.c
+++ b/sys/dev/e1000/if_lem.c
@@ -2670,16 +2670,15 @@ lem_setup_transmit_structures(struct adapter *adapter)
 		if (slot) {
 			/* slot si is mapped to the i-th NIC-ring entry */
 			int si = i + na->tx_rings[0].nkr_hwofs;
+			uint64_t paddr;
 			void *addr;
 
 			if (si > na->num_tx_desc)
 				si -= na->num_tx_desc;
-			addr = NMB(slot + si);
-			adapter->tx_desc_base[si].buffer_addr =
-			    htole64(vtophys(addr));
+			addr = PNMB(slot + si, &paddr);
+			adapter->tx_desc_base[si].buffer_addr = htole64(paddr);
 			/* reload the map for netmap mode */
-			netmap_load_map(adapter->txtag,
-			    tx_buffer->map, addr, na->buff_size);
+			netmap_load_map(adapter->txtag, tx_buffer->map, addr);
 		}
 #endif /* DEV_NETMAP */
 		tx_buffer->next_eop = -1;
@@ -3247,16 +3246,15 @@ lem_setup_receive_structures(struct adapter *adapter)
 		if (slot) {
 			/* slot si is mapped to the i-th NIC-ring entry */
 			int si = i + na->rx_rings[0].nkr_hwofs;
+			uint64_t paddr;
 			void *addr;
 
 			if (si > na->num_rx_desc)
 				si -= na->num_rx_desc;
-			addr = NMB(slot + si);
-			netmap_load_map(adapter->rxtag,
-			    rx_buffer->map, addr, na->buff_size);
+			addr = PNMB(slot + si, &paddr);
+			netmap_load_map(adapter->rxtag, rx_buffer->map, addr);
 			/* Update descriptor */
-			adapter->rx_desc_base[i].buffer_addr =
-			    htole64(vtophys(addr));
+			adapter->rx_desc_base[i].buffer_addr = htole64(paddr);
 			continue;
 		}
 #endif /* DEV_NETMAP */
diff --git a/sys/dev/ixgbe/ixgbe.c b/sys/dev/ixgbe/ixgbe.c
index 8e4a7b4..ad6c4ae 100644
--- a/sys/dev/ixgbe/ixgbe.c
+++ b/sys/dev/ixgbe/ixgbe.c
@@ -2876,8 +2876,7 @@ ixgbe_setup_transmit_ring(struct tx_ring *txr)
 
 			if (si >= na->num_tx_desc)
 				si -= na->num_tx_desc;
-			netmap_load_map(txr->txtag, txbuf->map,
-			    NMB(slot + si), na->buff_size);
+			netmap_load_map(txr->txtag, txbuf->map, NMB(slot + si));
 		}
 #endif /* DEV_NETMAP */
 		/* Clear the EOP index */
@@ -3810,16 +3809,15 @@ ixgbe_setup_receive_ring(struct rx_ring *rxr)
 		 */
 		if (slot) {
 			int sj = j + na->rx_rings[rxr->me].nkr_hwofs;
+			uint64_t paddr;
 			void *addr;
 
 			if (sj >= na->num_rx_desc)
 				sj -= na->num_rx_desc;
-			addr = NMB(slot + sj);
-			netmap_load_map(rxr->ptag,
-			    rxbuf->pmap, addr, na->buff_size);
+			addr = PNMB(slot + sj, &paddr);
+			netmap_load_map(rxr->ptag, rxbuf->pmap, addr);
 			/* Update descriptor */
-			rxr->rx_base[j].read.pkt_addr =
-			    htole64(vtophys(addr));
+			rxr->rx_base[j].read.pkt_addr = htole64(paddr);
 			continue;
 		}
 #endif /* DEV_NETMAP */
diff --git a/sys/dev/netmap/if_em_netmap.h b/sys/dev/netmap/if_em_netmap.h
index d75e924..959f52f 100644
--- a/sys/dev/netmap/if_em_netmap.h
+++ b/sys/dev/netmap/if_em_netmap.h
@@ -222,7 +222,8 @@ em_netmap_txsync(void *a, u_int ring_nr, int do_lock)
 			int flags = ((slot->flags & NS_REPORT) ||
 				j == 0 || j == report_frequency) ?
 					E1000_TXD_CMD_RS : 0;
-			void *addr = NMB(slot);
+			uint64_t paddr;
+			void *addr = PNMB(slot, &paddr);
 			int len = slot->len;
 			if (addr == netmap_buffer_base || len > NETMAP_BUF_SIZE) {
 				if (do_lock)
@@ -236,10 +237,9 @@ em_netmap_txsync(void *a, u_int ring_nr, int do_lock)
 			    htole32(adapter->txd_cmd | len |
 				(E1000_TXD_CMD_EOP | flags) );
 			if (slot->flags & NS_BUF_CHANGED) {
-				curr->buffer_addr = htole64(vtophys(addr));
+				curr->buffer_addr = htole64(paddr);
 				/* buffer has changed, reload map */
-				netmap_reload_map(txr->txtag, txbuf->map,
-				    addr, na->buff_size);
+				netmap_reload_map(txr->txtag, txbuf->map, addr);
 				slot->flags &= ~NS_BUF_CHANGED;
 			}
 
@@ -355,7 +355,8 @@ em_netmap_rxsync(void *a, u_int ring_nr, int do_lock)
 			struct netmap_slot *slot = &ring->slot[j];
 			struct e1000_rx_desc *curr = &rxr->rx_base[l];
 			struct em_buffer *rxbuf = &rxr->rx_buffers[l];
-			void *addr = NMB(slot);
+			uint64_t paddr;
+			void *addr = PNMB(slot, &paddr);
 
 			if (addr == netmap_buffer_base) { /* bad buf */
 				if (do_lock)
@@ -365,10 +366,9 @@ em_netmap_rxsync(void *a, u_int ring_nr, int do_lock)
 
 			curr->status = 0;
 			if (slot->flags & NS_BUF_CHANGED) {
-				curr->buffer_addr = htole64(vtophys(addr));
+				curr->buffer_addr = htole64(paddr);
 				/* buffer has changed, reload map */
-				netmap_reload_map(rxr->rxtag, rxbuf->map,
-				    addr, na->buff_size);
+				netmap_reload_map(rxr->rxtag, rxbuf->map, addr);
 				slot->flags &= ~NS_BUF_CHANGED;
 			}
 
diff --git a/sys/dev/netmap/if_igb_netmap.h b/sys/dev/netmap/if_igb_netmap.h
index 5e41742..0e4229b 100644
--- a/sys/dev/netmap/if_igb_netmap.h
+++ b/sys/dev/netmap/if_igb_netmap.h
@@ -181,7 +181,8 @@ igb_netmap_txsync(void *a, u_int ring_nr, int do_lock)
 			struct igb_tx_buffer *txbuf = &txr->tx_buffers[l];
 			union e1000_adv_tx_desc *curr =
 			    (union e1000_adv_tx_desc *)&txr->tx_base[l];
-			void *addr = NMB(slot);
+			uint64_t paddr;
+			void *addr = PNMB(slot, &paddr);
 			int flags = ((slot->flags & NS_REPORT) ||
 				j == 0 || j == report_frequency) ?
 					E1000_ADVTXD_DCMD_RS : 0;
@@ -195,7 +196,7 @@ igb_netmap_txsync(void *a, u_int ring_nr, int do_lock)
 
 			slot->flags &= ~NS_REPORT;
 			// XXX do we need to set the address ?
-			curr->read.buffer_addr = htole64(vtophys(addr));
+			curr->read.buffer_addr = htole64(paddr);
 			curr->read.olinfo_status =
 			    htole32(olinfo_status |
 				(len<< E1000_ADVTXD_PAYLEN_SHIFT));
@@ -206,8 +207,7 @@ igb_netmap_txsync(void *a, u_int ring_nr, int do_lock)
 				    E1000_ADVTXD_DCMD_EOP | flags);
 			if (slot->flags & NS_BUF_CHANGED) {
 				/* buffer has changed, reload map */
-				netmap_reload_map(txr->txtag, txbuf->map,
-					addr, na->buff_size);
+				netmap_reload_map(txr->txtag, txbuf->map, addr);
 				slot->flags &= ~NS_BUF_CHANGED;
 			}
 
@@ -317,7 +317,8 @@ igb_netmap_rxsync(void *a, u_int ring_nr, int do_lock)
 			struct netmap_slot *slot = ring->slot + j;
 			union e1000_adv_rx_desc *curr = &rxr->rx_base[l];
 			struct igb_rx_buf *rxbuf = rxr->rx_buffers + l;
-			void *addr = NMB(slot);
+			uint64_t paddr;
+			void *addr = PNMB(slot, &paddr);
 
 			if (addr == netmap_buffer_base) { /* bad buf */
 				if (do_lock)
@@ -326,10 +327,9 @@ igb_netmap_rxsync(void *a, u_int ring_nr, int do_lock)
 			}
 
 			curr->wb.upper.status_error = 0;
-			curr->read.pkt_addr = htole64(vtophys(addr));
+			curr->read.pkt_addr = htole64(paddr);
 			if (slot->flags & NS_BUF_CHANGED) {
-				netmap_reload_map(rxr->ptag, rxbuf->pmap,
-					addr, na->buff_size);
+				netmap_reload_map(rxr->ptag, rxbuf->pmap, addr);
 				slot->flags &= ~NS_BUF_CHANGED;
 			}
 
diff --git a/sys/dev/netmap/if_lem_netmap.h b/sys/dev/netmap/if_lem_netmap.h
index ae64cd6..b9438fb 100644
--- a/sys/dev/netmap/if_lem_netmap.h
+++ b/sys/dev/netmap/if_lem_netmap.h
@@ -186,7 +186,8 @@ lem_netmap_txsync(void *a, u_int ring_nr, int do_lock)
 			struct netmap_slot *slot = &ring->slot[j];
 			struct e1000_tx_desc *curr = &adapter->tx_desc_base[l];
 			struct em_buffer *txbuf = &adapter->tx_buffer_area[l];
-			void *addr = NMB(slot);
+			uint64_t paddr;
+			void *addr = PNMB(slot, &paddr);
 			int flags = ((slot->flags & NS_REPORT) ||
 				j == 0 || j == report_frequency) ?
 					E1000_TXD_CMD_RS : 0;
@@ -204,10 +205,9 @@ lem_netmap_txsync(void *a, u_int ring_nr, int do_lock)
 			    htole32( adapter->txd_cmd | len |
 				(E1000_TXD_CMD_EOP | flags) );
 			if (slot->flags & NS_BUF_CHANGED) {
-				curr->buffer_addr = htole64(vtophys(addr));
+				curr->buffer_addr = htole64(paddr);
 				/* buffer has changed, reload map */
-				netmap_reload_map(adapter->txtag, txbuf->map,
-				    addr, na->buff_size);
+				netmap_reload_map(adapter->txtag, txbuf->map, addr);
 				slot->flags &= ~NS_BUF_CHANGED;
 			}
 
@@ -314,7 +314,8 @@ lem_netmap_rxsync(void *a, u_int ring_nr, int do_lock)
 			struct netmap_slot *slot = &ring->slot[j];
 			struct e1000_rx_desc *curr = &adapter->rx_desc_base[l];
 			struct em_buffer *rxbuf = &adapter->rx_buffer_area[l];
-			void *addr = NMB(slot);
+			uint64_t paddr;
+			void *addr = PNMB(slot, &paddr);
 
 			if (addr == netmap_buffer_base) { /* bad buf */
 				if (do_lock)
@@ -323,10 +324,9 @@ lem_netmap_rxsync(void *a, u_int ring_nr, int do_lock)
 			}
 			curr->status = 0;
 			if (slot->flags & NS_BUF_CHANGED) {
-				curr->buffer_addr = htole64(vtophys(addr));
+				curr->buffer_addr = htole64(paddr);
 				/* buffer has changed, and reload map */
-				netmap_reload_map(adapter->rxtag, rxbuf->map,
-				    addr, na->buff_size);
+				netmap_reload_map(adapter->rxtag, rxbuf->map, addr);
 				slot->flags &= ~NS_BUF_CHANGED;
 			}
 
diff --git a/sys/dev/netmap/if_re_netmap.h b/sys/dev/netmap/if_re_netmap.h
index 105660c..2f4eed2 100644
--- a/sys/dev/netmap/if_re_netmap.h
+++ b/sys/dev/netmap/if_re_netmap.h
@@ -183,7 +183,8 @@ re_netmap_txsync(void *a, u_int ring_nr, int do_lock)
 			struct rl_desc *desc = &sc->rl_ldata.rl_tx_list[l];
 			int cmd = slot->len | RL_TDESC_CMD_EOF |
 				RL_TDESC_CMD_OWN | RL_TDESC_CMD_SOF ;
-			void *addr = NMB(slot);
+			uint64_t paddr;
+			void *addr = PNMB(slot, &paddr);
 			int len = slot->len;
 
 			if (addr == netmap_buffer_base || len > NETMAP_BUF_SIZE) {
@@ -197,12 +198,11 @@ re_netmap_txsync(void *a, u_int ring_nr, int do_lock)
 				cmd |= RL_TDESC_CMD_EOR;
 
 			if (slot->flags & NS_BUF_CHANGED) {
-				uint64_t paddr = vtophys(addr);
 				desc->rl_bufaddr_lo = htole32(RL_ADDR_LO(paddr));
 				desc->rl_bufaddr_hi = htole32(RL_ADDR_HI(paddr));
 				/* buffer has changed, unload and reload map */
 				netmap_reload_map(sc->rl_ldata.rl_tx_mtag,
-					txd[l].tx_dmamap, addr, na->buff_size);
+					txd[l].tx_dmamap, addr);
 				slot->flags &= ~NS_BUF_CHANGED;
 			}
 			slot->flags &= ~NS_REPORT;
@@ -304,7 +304,8 @@ re_netmap_rxsync(void *a, u_int ring_nr, int do_lock)
 			struct netmap_slot *slot = ring->slot + j;
 			struct rl_desc *desc = &sc->rl_ldata.rl_rx_list[l];
 			int cmd = na->buff_size | RL_RDESC_CMD_OWN;
-			void *addr = NMB(slot);
+			uint64_t paddr;
+			void *addr = PNMB(slot, &paddr);
 
 			if (addr == netmap_buffer_base) { /* bad buf */
 				if (do_lock)
@@ -318,11 +319,10 @@ re_netmap_rxsync(void *a, u_int ring_nr, int do_lock)
 			desc->rl_cmdstat = htole32(cmd);
 			slot->flags &= ~NS_REPORT;
 			if (slot->flags & NS_BUF_CHANGED) {
-				uint64_t paddr = vtophys(addr);
 				desc->rl_bufaddr_lo = htole32(RL_ADDR_LO(paddr));
 				desc->rl_bufaddr_hi = htole32(RL_ADDR_HI(paddr));
 				netmap_reload_map(sc->rl_ldata.rl_rx_mtag,
-					rxd[l].rx_dmamap, addr, na->buff_size);
+					rxd[l].rx_dmamap, addr);
 				slot->flags &= ~NS_BUF_CHANGED;
 			}
 			bus_dmamap_sync(sc->rl_ldata.rl_rx_mtag,
@@ -377,12 +377,11 @@ re_netmap_tx_init(struct rl_softc *sc)
 		if (l >= n)
 			l -= n;
 
-		addr = NMB(slot + l);
-		paddr = vtophys(addr);
+		addr = PNMB(slot + l, &paddr);
 		desc[i].rl_bufaddr_lo = htole32(RL_ADDR_LO(paddr));
 		desc[i].rl_bufaddr_hi = htole32(RL_ADDR_HI(paddr));
 		netmap_load_map(sc->rl_ldata.rl_tx_mtag,
-			txd[i].tx_dmamap, addr, na->buff_size);
+			txd[i].tx_dmamap, addr);
 	}
 }
 
@@ -407,8 +406,12 @@ re_netmap_rx_init(struct rl_softc *sc)
 		if (l >= n)
 			l -= n;
 
-		addr = NMB(slot + l);
-		paddr = vtophys(addr);
+		addr = PNMB(slot + l, &paddr);
+
+		netmap_reload_map(sc->rl_ldata.rl_rx_mtag,
+			sc->rl_ldata.rl_rx_desc[i].rx_dmamap, addr);
+		bus_dmamap_sync(sc->rl_ldata.rl_rx_mtag,
+		    sc->rl_ldata.rl_rx_desc[i].rx_dmamap, BUS_DMASYNC_PREREAD);
 		desc[i].rl_bufaddr_lo = htole32(RL_ADDR_LO(paddr));
 		desc[i].rl_bufaddr_hi = htole32(RL_ADDR_HI(paddr));
 		cmdstat = na->buff_size;
@@ -422,9 +425,5 @@ re_netmap_rx_init(struct rl_softc *sc)
 		if (i < n - 1 - kring->nr_hwavail) // XXX + 1 ?
 			cmdstat |= RL_RDESC_CMD_OWN;
 		desc[i].rl_cmdstat = htole32(cmdstat);
-
-		netmap_reload_map(sc->rl_ldata.rl_rx_mtag,
-			sc->rl_ldata.rl_rx_desc[i].rx_dmamap,
-			addr, na->buff_size);
 	}
 }
diff --git a/sys/dev/netmap/ixgbe_netmap.h b/sys/dev/netmap/ixgbe_netmap.h
index fdf15d8..f456044 100644
--- a/sys/dev/netmap/ixgbe_netmap.h
+++ b/sys/dev/netmap/ixgbe_netmap.h
@@ -253,7 +253,7 @@ ixgbe_netmap_txsync(void *a, u_int ring_nr, int do_lock)
 			 * Note that txbuf and curr are indexed by l.
 			 *
 			 * In this driver we collect the buffer address
-			 * (using the NMB() macro) because we always
+			 * (using the PNMB() macro) because we always
 			 * need to rewrite it into the NIC ring.
 			 * Many other drivers preserve the address, so
 			 * we only need to access it if NS_BUF_CHANGED
@@ -262,7 +262,8 @@ ixgbe_netmap_txsync(void *a, u_int ring_nr, int do_lock)
 			struct netmap_slot *slot = &ring->slot[j];
 			struct ixgbe_tx_buf *txbuf = &txr->tx_buffers[l];
 			union ixgbe_adv_tx_desc *curr = &txr->tx_base[l];
-			void *addr = NMB(slot);
+			uint64_t paddr;
+			void *addr = PNMB(slot, &paddr);
 			// XXX type for flags and len ?
 			int flags = ((slot->flags & NS_REPORT) ||
 				j == 0 || j == report_frequency) ?
@@ -290,7 +291,7 @@ ring_reset:
 			 * address in the NIC ring. Other drivers do not
 			 * need this.
 			 */
-			curr->read.buffer_addr = htole64(vtophys(addr));
+			curr->read.buffer_addr = htole64(paddr);
 			curr->read.olinfo_status = 0;
 			curr->read.cmd_type_len =
 			    htole32(txr->txd_cmd | len |
@@ -303,8 +304,7 @@ ring_reset:
 			 */
 			if (slot->flags & NS_BUF_CHANGED) {
 				/* buffer has changed, unload and reload map */
-				netmap_reload_map(txr->txtag, txbuf->map,
-					addr, na->buff_size);
+				netmap_reload_map(txr->txtag, txbuf->map, addr);
 				slot->flags &= ~NS_BUF_CHANGED;
 			}
 
@@ -479,16 +479,16 @@ ixgbe_netmap_rxsync(void *a, u_int ring_nr, int do_lock)
 			struct netmap_slot *slot = &ring->slot[j];
 			union ixgbe_adv_rx_desc *curr = &rxr->rx_base[l];
 			struct ixgbe_rx_buf *rxbuf = &rxr->rx_buffers[l];
-			void *addr = NMB(slot);
+			uint64_t paddr;
+			void *addr = PNMB(slot, &paddr);
 
 			if (addr == netmap_buffer_base) /* bad buf */
 				goto ring_reset;
 
 			curr->wb.upper.status_error = 0;
-			curr->read.pkt_addr = htole64(vtophys(addr));
+			curr->read.pkt_addr = htole64(paddr);
 			if (slot->flags & NS_BUF_CHANGED) {
-				netmap_reload_map(rxr->ptag, rxbuf->pmap,
-				    addr, na->buff_size);
+				netmap_reload_map(rxr->ptag, rxbuf->pmap, addr);
 				slot->flags &= ~NS_BUF_CHANGED;
 			}
 
diff --git a/sys/dev/netmap/netmap.c b/sys/dev/netmap/netmap.c
index 5c960ac..92c6573 100644
--- a/sys/dev/netmap/netmap.c
+++ b/sys/dev/netmap/netmap.c
@@ -104,6 +104,13 @@ MALLOC_DEFINE(M_NETMAP, "netmap", "Network memory map");
 static void * netmap_malloc(size_t size, const char *msg);
 static void netmap_free(void *addr, const char *msg);
 
+#define netmap_if_malloc(len)   netmap_malloc(len, "nifp")
+#define netmap_if_free(v)	netmap_free((v), "nifp")
+
+#define netmap_ring_malloc(len) netmap_malloc(len, "ring")
+#define netmap_free_rings(na)		\
+	netmap_free((na)->tx_rings[0].ring, "shadow rings");
+
 /*
  * Allocator for a pool of packet buffers. For each buffer we have
  * one entry in the bitmap to signal the state. Allocation scans
@@ -123,7 +130,7 @@ struct netmap_buf_pool {
 struct netmap_buf_pool nm_buf_pool;
 /* XXX move these two vars back into netmap_buf_pool */
 u_int netmap_total_buffers;
-char *netmap_buffer_base;
+char *netmap_buffer_base;	/* address of an invalid buffer */
 
 /* user-controlled variables */
 int netmap_verbose;
@@ -233,6 +240,12 @@ struct netmap_priv_d {
 	uint16_t	np_txpoll;
 };
 
+/* Shorthand to compute a netmap interface offset. */
+#define netmap_if_offset(v)                                     \
+    ((char *) (v) - (char *) netmap_mem_d->nm_buffer)
+/* .. and get a physical address given a memory offset */
+#define netmap_ofstophys(o)                                     \
+    (vtophys(netmap_mem_d->nm_buffer) + (o))
 
 static struct cdev *netmap_dev; /* /dev/netmap character device. */
 static struct netmap_mem_d *netmap_mem_d; /* Our memory allocator. */
@@ -397,10 +410,10 @@ netmap_dtor(void *data)
 					ring->slot[j].buf_idx);
 		}
 		NMA_UNLOCK();
-		netmap_free(na->tx_rings[0].ring, "shadow rings");
+		netmap_free_rings(na);
 		wakeup(na);
 	}
-	netmap_free(nifp, "nifp");
+	netmap_if_free(nifp);
 
 	na->nm_lock(ifp->if_softc, NETMAP_CORE_UNLOCK, 0); 
 
@@ -432,7 +445,7 @@ netmap_if_new(const char *ifname, struct netmap_adapter *na)
 	 * to the tx and rx rings in the shared memory region.
 	 */
 	len = sizeof(struct netmap_if) + 2 * n * sizeof(ssize_t);
-	nifp = netmap_malloc(len, "nifp");
+	nifp = netmap_if_malloc(len);
 	if (nifp == NULL)
 		return (NULL);
 
@@ -455,13 +468,13 @@ netmap_if_new(const char *ifname, struct netmap_adapter *na)
 	len = n * (2 * sizeof(struct netmap_ring) +
 		  (na->num_tx_desc + na->num_rx_desc) *
 		   sizeof(struct netmap_slot) );
-	buff = netmap_malloc(len, "shadow rings");
+	buff = netmap_ring_malloc(len);
 	if (buff == NULL) {
 		D("failed to allocate %d bytes for %s shadow ring",
 			len, ifname);
 error:
 		(na->refcount)--;
-		netmap_free(nifp, "nifp, rings failed");
+		netmap_if_free(nifp);
 		return (NULL);
 	}
 	/* do we have the bufers ? we are in need of num_tx_desc buffers for
@@ -907,11 +920,12 @@ netmap_ioctl(__unused struct cdev *dev, u_long cmd, caddr_t data,
 				/*
 				 * do something similar to netmap_dtor().
 				 */
-				netmap_free(na->tx_rings[0].ring, "rings, reg.failed");
-				free(na->tx_rings, M_DEVBUF);
+				netmap_free_rings(na);
+				// XXX tx_rings is inline, must not be freed.
+				// free(na->tx_rings, M_DEVBUF); // XXX wrong ?
 				na->tx_rings = na->rx_rings = NULL;
 				na->refcount--;
-				netmap_free(nifp, "nifp, rings failed");
+				netmap_if_free(nifp);
 				nifp = NULL;
 			}
 		}
@@ -1388,22 +1402,18 @@ ns_dmamap_cb(__unused void *arg, __unused bus_dma_segment_t * segs,
  * XXX buflen is probably not needed, buffers have constant size.
  */
 void
-netmap_reload_map(bus_dma_tag_t tag, bus_dmamap_t map,
-	void *buf, bus_size_t buflen)
+netmap_reload_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
 {
-	bus_addr_t paddr;
 	bus_dmamap_unload(tag, map);
-	bus_dmamap_load(tag, map, buf, buflen, ns_dmamap_cb, &paddr,
-				BUS_DMA_NOWAIT);
+	bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE, ns_dmamap_cb,
+		NULL, BUS_DMA_NOWAIT);
 }
 
 void
-netmap_load_map(bus_dma_tag_t tag, bus_dmamap_t map,
-	void *buf, bus_size_t buflen)
+netmap_load_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf)
 {
-	bus_addr_t paddr;
-	bus_dmamap_load(tag, map, buf, buflen, ns_dmamap_cb, &paddr,
-				BUS_DMA_NOWAIT);
+	bus_dmamap_load(tag, map, buf, NETMAP_BUF_SIZE, ns_dmamap_cb,
+		NULL, BUS_DMA_NOWAIT);
 }
 
 /*------ netmap memory allocator -------*/
diff --git a/sys/dev/netmap/netmap_kern.h b/sys/dev/netmap/netmap_kern.h
index 8fa95fa..d35e503 100644
--- a/sys/dev/netmap/netmap_kern.h
+++ b/sys/dev/netmap/netmap_kern.h
@@ -169,10 +169,8 @@ int netmap_start(struct ifnet *, struct mbuf *);
 enum txrx { NR_RX = 0, NR_TX = 1 };
 struct netmap_slot *netmap_reset(struct netmap_adapter *na,
 	enum txrx tx, int n, u_int new_cur);
-void netmap_load_map(bus_dma_tag_t tag, bus_dmamap_t map,
-        void *buf, bus_size_t buflen);
-void netmap_reload_map(bus_dma_tag_t tag, bus_dmamap_t map,
-        void *buf, bus_size_t buflen);
+void netmap_load_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf);
+void netmap_reload_map(bus_dma_tag_t tag, bus_dmamap_t map, void *buf);
 int netmap_ring_reinit(struct netmap_kring *);
 
 /*
@@ -206,11 +204,11 @@ enum {                                  /* verbose flags */
 
 
 /*
- * return the address of a buffer.
+ * NMB return the virtual address of a buffer (buffer 0 on bad index)
+ * PNMB also fills the physical address
  * XXX this is a special version with hardwired 2k bufs
- * On error return netmap_buffer_base which is detected as a bad pointer.
  */
-static inline char *
+static inline void *
 NMB(struct netmap_slot *slot)
 {
 	uint32_t i = slot->buf_idx;
@@ -222,4 +220,18 @@ NMB(struct netmap_slot *slot)
 #endif
 }
 
+static inline void *
+PNMB(struct netmap_slot *slot, uint64_t *pp)
+{
+	uint32_t i = slot->buf_idx;
+	void *ret = (i >= netmap_total_buffers) ? netmap_buffer_base :
+#if NETMAP_BUF_SIZE == 2048
+		netmap_buffer_base + (i << 11);
+#else
+		netmap_buffer_base + (i *NETMAP_BUF_SIZE);
+#endif
+	*pp = vtophys(ret);
+	return ret;
+}
+
 #endif /* _NET_NETMAP_KERN_H_ */