3ac0fcfb97
USERSPACE: 1. add support for devices with different number of rx and tx queues; 2. add better support for zero-copy operation, adding an extra field to the netmap ring to indicate how many buffers we have already processed but not yet released (with help from Eddie Kohler); 3. The two changes above unfortunately require an API change, so while at it add a version field and some spares to the ioctl() argument to help detect mismatches. 4. update the manual page for the two changes above; 5. update sample applications in tools/tools/netmap KERNEL: 1. simplify the internal structures moving the global wait queues to the 'struct netmap_adapter'; 2. simplify the functions that map kring<->nic ring indexes 3. normalize device-specific code, helps mainteinance; 4. start exploring the impact of micro-optimizations (prefetch etc.) in the ixgbe driver. Use 'legacy' descriptors on the tx ring and prefetch slots gives about 20% speedup at 900 MHz. Another 7-10% would come from removing the explict calls to bus_dmamap* in the core (they are effectively NOPs in this case, but it takes expensive load of the per-buffer dma maps to figure out that they are all NULL. Rx performance not investigated. I am postponing the MFC so i can import a few more improvements before merging.
390 lines
11 KiB
C
390 lines
11 KiB
C
/*
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* Copyright (C) 2011 Matteo Landi, Luigi Rizzo. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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/*
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* $FreeBSD$
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* $Id: if_em_netmap.h 10627 2012-02-23 19:37:15Z luigi $
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*
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* netmap support for em.
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*
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* For more details on netmap support please see ixgbe_netmap.h
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*/
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#include <net/netmap.h>
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#include <sys/selinfo.h>
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#include <vm/vm.h>
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#include <vm/pmap.h> /* vtophys ? */
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#include <dev/netmap/netmap_kern.h>
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static void em_netmap_block_tasks(struct adapter *);
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static void em_netmap_unblock_tasks(struct adapter *);
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static void
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em_netmap_lock_wrapper(struct ifnet *ifp, int what, u_int queueid)
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{
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struct adapter *adapter = ifp->if_softc;
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ASSERT(queueid < adapter->num_queues);
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switch (what) {
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case NETMAP_CORE_LOCK:
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EM_CORE_LOCK(adapter);
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break;
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case NETMAP_CORE_UNLOCK:
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EM_CORE_UNLOCK(adapter);
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break;
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case NETMAP_TX_LOCK:
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EM_TX_LOCK(&adapter->tx_rings[queueid]);
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break;
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case NETMAP_TX_UNLOCK:
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EM_TX_UNLOCK(&adapter->tx_rings[queueid]);
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break;
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case NETMAP_RX_LOCK:
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EM_RX_LOCK(&adapter->rx_rings[queueid]);
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break;
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case NETMAP_RX_UNLOCK:
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EM_RX_UNLOCK(&adapter->rx_rings[queueid]);
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break;
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}
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}
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// XXX do we need to block/unblock the tasks ?
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static void
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em_netmap_block_tasks(struct adapter *adapter)
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{
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if (adapter->msix > 1) { /* MSIX */
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int i;
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struct tx_ring *txr = adapter->tx_rings;
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struct rx_ring *rxr = adapter->rx_rings;
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for (i = 0; i < adapter->num_queues; i++, txr++, rxr++) {
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taskqueue_block(txr->tq);
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taskqueue_drain(txr->tq, &txr->tx_task);
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taskqueue_block(rxr->tq);
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taskqueue_drain(rxr->tq, &rxr->rx_task);
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}
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} else { /* legacy */
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taskqueue_block(adapter->tq);
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taskqueue_drain(adapter->tq, &adapter->link_task);
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taskqueue_drain(adapter->tq, &adapter->que_task);
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}
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}
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static void
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em_netmap_unblock_tasks(struct adapter *adapter)
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{
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if (adapter->msix > 1) {
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struct tx_ring *txr = adapter->tx_rings;
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struct rx_ring *rxr = adapter->rx_rings;
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int i;
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for (i = 0; i < adapter->num_queues; i++) {
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taskqueue_unblock(txr->tq);
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taskqueue_unblock(rxr->tq);
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}
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} else { /* legacy */
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taskqueue_unblock(adapter->tq);
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}
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}
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/*
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* Register/unregister routine
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*/
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static int
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em_netmap_reg(struct ifnet *ifp, int onoff)
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{
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struct adapter *adapter = ifp->if_softc;
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struct netmap_adapter *na = NA(ifp);
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int error = 0;
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if (na == NULL)
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return EINVAL; /* no netmap support here */
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em_disable_intr(adapter);
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/* Tell the stack that the interface is no longer active */
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ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
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em_netmap_block_tasks(adapter);
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if (onoff) {
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ifp->if_capenable |= IFCAP_NETMAP;
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na->if_transmit = ifp->if_transmit;
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ifp->if_transmit = netmap_start;
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em_init_locked(adapter);
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if ((ifp->if_drv_flags & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) == 0) {
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error = ENOMEM;
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goto fail;
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}
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} else {
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fail:
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/* return to non-netmap mode */
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ifp->if_transmit = na->if_transmit;
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ifp->if_capenable &= ~IFCAP_NETMAP;
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em_init_locked(adapter); /* also enable intr */
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}
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em_netmap_unblock_tasks(adapter);
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return (error);
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}
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/*
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* Reconcile kernel and user view of the transmit ring.
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*/
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static int
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em_netmap_txsync(struct ifnet *ifp, u_int ring_nr, int do_lock)
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{
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struct adapter *adapter = ifp->if_softc;
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struct tx_ring *txr = &adapter->tx_rings[ring_nr];
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struct netmap_adapter *na = NA(ifp);
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struct netmap_kring *kring = &na->tx_rings[ring_nr];
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struct netmap_ring *ring = kring->ring;
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u_int j, k, l, n = 0, lim = kring->nkr_num_slots - 1;
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/* generate an interrupt approximately every half ring */
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int report_frequency = kring->nkr_num_slots >> 1;
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k = ring->cur;
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if (k > lim)
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return netmap_ring_reinit(kring);
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if (do_lock)
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EM_TX_LOCK(txr);
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bus_dmamap_sync(txr->txdma.dma_tag, txr->txdma.dma_map,
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BUS_DMASYNC_POSTREAD);
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/*
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* Process new packets to send. j is the current index in the
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* netmap ring, l is the corresponding index in the NIC ring.
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*/
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j = kring->nr_hwcur;
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if (j != k) { /* we have new packets to send */
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l = netmap_idx_k2n(kring, j);
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for (n = 0; j != k; n++) {
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/* slot is the current slot in the netmap ring */
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struct netmap_slot *slot = &ring->slot[j];
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/* curr is the current slot in the nic ring */
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struct e1000_tx_desc *curr = &txr->tx_base[l];
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struct em_buffer *txbuf = &txr->tx_buffers[l];
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int flags = ((slot->flags & NS_REPORT) ||
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j == 0 || j == report_frequency) ?
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E1000_TXD_CMD_RS : 0;
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uint64_t paddr;
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void *addr = PNMB(slot, &paddr);
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u_int len = slot->len;
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if (addr == netmap_buffer_base || len > NETMAP_BUF_SIZE) {
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if (do_lock)
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EM_TX_UNLOCK(txr);
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return netmap_ring_reinit(kring);
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}
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slot->flags &= ~NS_REPORT;
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if (slot->flags & NS_BUF_CHANGED) {
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curr->buffer_addr = htole64(paddr);
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/* buffer has changed, reload map */
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netmap_reload_map(txr->txtag, txbuf->map, addr);
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slot->flags &= ~NS_BUF_CHANGED;
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}
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curr->upper.data = 0;
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curr->lower.data = htole32(adapter->txd_cmd | len |
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(E1000_TXD_CMD_EOP | flags) );
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bus_dmamap_sync(txr->txtag, txbuf->map,
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BUS_DMASYNC_PREWRITE);
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j = (j == lim) ? 0 : j + 1;
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l = (l == lim) ? 0 : l + 1;
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}
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kring->nr_hwcur = k; /* the saved ring->cur */
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kring->nr_hwavail -= n;
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bus_dmamap_sync(txr->txdma.dma_tag, txr->txdma.dma_map,
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BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
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E1000_WRITE_REG(&adapter->hw, E1000_TDT(txr->me), l);
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}
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if (n == 0 || kring->nr_hwavail < 1) {
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int delta;
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/* record completed transmissions using TDH */
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l = E1000_READ_REG(&adapter->hw, E1000_TDH(ring_nr));
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if (l >= kring->nkr_num_slots) { /* XXX can it happen ? */
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D("TDH wrap %d", l);
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l -= kring->nkr_num_slots;
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}
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delta = l - txr->next_to_clean;
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if (delta) {
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/* some completed, increment hwavail. */
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if (delta < 0)
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delta += kring->nkr_num_slots;
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txr->next_to_clean = l;
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kring->nr_hwavail += delta;
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}
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}
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/* update avail to what the kernel knows */
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ring->avail = kring->nr_hwavail;
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if (do_lock)
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EM_TX_UNLOCK(txr);
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return 0;
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}
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/*
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* Reconcile kernel and user view of the receive ring.
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*/
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static int
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em_netmap_rxsync(struct ifnet *ifp, u_int ring_nr, int do_lock)
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{
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struct adapter *adapter = ifp->if_softc;
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struct rx_ring *rxr = &adapter->rx_rings[ring_nr];
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struct netmap_adapter *na = NA(ifp);
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struct netmap_kring *kring = &na->rx_rings[ring_nr];
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struct netmap_ring *ring = kring->ring;
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u_int j, l, n, lim = kring->nkr_num_slots - 1;
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int force_update = do_lock || kring->nr_kflags & NKR_PENDINTR;
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u_int k = ring->cur, resvd = ring->reserved;
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k = ring->cur;
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if (k > lim)
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return netmap_ring_reinit(kring);
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if (do_lock)
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EM_RX_LOCK(rxr);
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/* XXX check sync modes */
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bus_dmamap_sync(rxr->rxdma.dma_tag, rxr->rxdma.dma_map,
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BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
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/*
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* Import newly received packets into the netmap ring.
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* j is an index in the netmap ring, l in the NIC ring.
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*/
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l = rxr->next_to_check;
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j = netmap_idx_n2k(kring, l);
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if (netmap_no_pendintr || force_update) {
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for (n = 0; ; n++) {
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struct e1000_rx_desc *curr = &rxr->rx_base[l];
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uint32_t staterr = le32toh(curr->status);
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if ((staterr & E1000_RXD_STAT_DD) == 0)
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break;
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ring->slot[j].len = le16toh(curr->length);
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bus_dmamap_sync(rxr->rxtag, rxr->rx_buffers[l].map,
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BUS_DMASYNC_POSTREAD);
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j = (j == lim) ? 0 : j + 1;
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/* make sure next_to_refresh follows next_to_check */
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rxr->next_to_refresh = l; // XXX
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l = (l == lim) ? 0 : l + 1;
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}
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if (n) { /* update the state variables */
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rxr->next_to_check = l;
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kring->nr_hwavail += n;
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}
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kring->nr_kflags &= ~NKR_PENDINTR;
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}
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/* skip past packets that userspace has released */
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j = kring->nr_hwcur; /* netmap ring index */
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if (resvd > 0) {
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if (resvd + ring->avail >= lim + 1) {
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D("XXX invalid reserve/avail %d %d", resvd, ring->avail);
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ring->reserved = resvd = 0; // XXX panic...
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}
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k = (k >= resvd) ? k - resvd : k + lim + 1 - resvd;
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}
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if (j != k) { /* userspace has released some packets. */
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l = netmap_idx_k2n(kring, j); /* NIC ring index */
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for (n = 0; j != k; n++) {
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struct netmap_slot *slot = &ring->slot[j];
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struct e1000_rx_desc *curr = &rxr->rx_base[l];
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struct em_buffer *rxbuf = &rxr->rx_buffers[l];
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uint64_t paddr;
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void *addr = PNMB(slot, &paddr);
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if (addr == netmap_buffer_base) { /* bad buf */
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if (do_lock)
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EM_RX_UNLOCK(rxr);
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return netmap_ring_reinit(kring);
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}
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if (slot->flags & NS_BUF_CHANGED) {
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curr->buffer_addr = htole64(paddr);
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/* buffer has changed, reload map */
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netmap_reload_map(rxr->rxtag, rxbuf->map, addr);
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slot->flags &= ~NS_BUF_CHANGED;
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}
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curr->status = 0;
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bus_dmamap_sync(rxr->rxtag, rxbuf->map,
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BUS_DMASYNC_PREREAD);
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j = (j == lim) ? 0 : j + 1;
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l = (l == lim) ? 0 : l + 1;
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}
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kring->nr_hwavail -= n;
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kring->nr_hwcur = k;
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bus_dmamap_sync(rxr->rxdma.dma_tag, rxr->rxdma.dma_map,
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BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
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/*
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* IMPORTANT: we must leave one free slot in the ring,
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* so move l back by one unit
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*/
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l = (l == 0) ? lim : l - 1;
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E1000_WRITE_REG(&adapter->hw, E1000_RDT(rxr->me), l);
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}
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/* tell userspace that there are new packets */
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ring->avail = kring->nr_hwavail - resvd;
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if (do_lock)
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EM_RX_UNLOCK(rxr);
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return 0;
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}
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static void
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em_netmap_attach(struct adapter *adapter)
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{
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struct netmap_adapter na;
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bzero(&na, sizeof(na));
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na.ifp = adapter->ifp;
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na.separate_locks = 1;
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na.num_tx_desc = adapter->num_tx_desc;
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na.num_rx_desc = adapter->num_rx_desc;
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na.nm_txsync = em_netmap_txsync;
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na.nm_rxsync = em_netmap_rxsync;
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na.nm_lock = em_netmap_lock_wrapper;
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na.nm_register = em_netmap_reg;
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netmap_attach(&na, adapter->num_queues);
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}
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/* end of file */
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