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freebsd-dev/sys/dev/netmap/if_igb_netmap.h
Luigi Rizzo 64ae02c365 A bunch of netmap fixes: 
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.
2012-02-27 19:05:01 +00:00

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/*
* Copyright (C) 2011 Universita` di Pisa. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* $FreeBSD$
* $Id: if_igb_netmap.h 10627 2012-02-23 19:37:15Z luigi $
*
* Netmap support for igb, partly contributed by Ahmed Kooli
* For details on netmap support please see ixgbe_netmap.h
*/
#include <net/netmap.h>
#include <sys/selinfo.h>
#include <vm/vm.h>
#include <vm/pmap.h> /* vtophys ? */
#include <dev/netmap/netmap_kern.h>
/*
* wrapper to export locks to the generic code
*/
static void
igb_netmap_lock_wrapper(struct ifnet *ifp, int what, u_int queueid)
{
struct adapter *adapter = ifp->if_softc;
ASSERT(queueid < adapter->num_queues);
switch (what) {
case NETMAP_CORE_LOCK:
IGB_CORE_LOCK(adapter);
break;
case NETMAP_CORE_UNLOCK:
IGB_CORE_UNLOCK(adapter);
break;
case NETMAP_TX_LOCK:
IGB_TX_LOCK(&adapter->tx_rings[queueid]);
break;
case NETMAP_TX_UNLOCK:
IGB_TX_UNLOCK(&adapter->tx_rings[queueid]);
break;
case NETMAP_RX_LOCK:
IGB_RX_LOCK(&adapter->rx_rings[queueid]);
break;
case NETMAP_RX_UNLOCK:
IGB_RX_UNLOCK(&adapter->rx_rings[queueid]);
break;
}
}
/*
* register-unregister routine
*/
static int
igb_netmap_reg(struct ifnet *ifp, int onoff)
{
struct adapter *adapter = ifp->if_softc;
struct netmap_adapter *na = NA(ifp);
int error = 0;
if (na == NULL)
return EINVAL; /* no netmap support here */
igb_disable_intr(adapter);
/* Tell the stack that the interface is no longer active */
ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
if (onoff) {
ifp->if_capenable |= IFCAP_NETMAP;
na->if_transmit = ifp->if_transmit;
ifp->if_transmit = netmap_start;
igb_init_locked(adapter);
if ((ifp->if_drv_flags & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) == 0) {
error = ENOMEM;
goto fail;
}
} else {
fail:
/* restore if_transmit */
ifp->if_transmit = na->if_transmit;
ifp->if_capenable &= ~IFCAP_NETMAP;
igb_init_locked(adapter); /* also enable intr */
}
return (error);
}
/*
* Reconcile kernel and user view of the transmit ring.
*/
static int
igb_netmap_txsync(struct ifnet *ifp, u_int ring_nr, int do_lock)
{
struct adapter *adapter = ifp->if_softc;
struct tx_ring *txr = &adapter->tx_rings[ring_nr];
struct netmap_adapter *na = NA(ifp);
struct netmap_kring *kring = &na->tx_rings[ring_nr];
struct netmap_ring *ring = kring->ring;
u_int j, k, l, n = 0, lim = kring->nkr_num_slots - 1;
/* generate an interrupt approximately every half ring */
int report_frequency = kring->nkr_num_slots >> 1;
k = ring->cur;
if (k > lim)
return netmap_ring_reinit(kring);
if (do_lock)
IGB_TX_LOCK(txr);
bus_dmamap_sync(txr->txdma.dma_tag, txr->txdma.dma_map,
BUS_DMASYNC_POSTREAD);
/* check for new packets to send.
* j indexes the netmap ring, l indexes the nic ring, and
* j = kring->nr_hwcur, l = E1000_TDT (not tracked),
* j == (l + kring->nkr_hwofs) % ring_size
*/
j = kring->nr_hwcur;
if (j != k) { /* we have new packets to send */
/* 82575 needs the queue index added */
u32 olinfo_status =
(adapter->hw.mac.type == e1000_82575) ? (txr->me << 4) : 0;
l = netmap_idx_k2n(kring, j);
for (n = 0; j != k; n++) {
/* slot is the current slot in the netmap ring */
struct netmap_slot *slot = &ring->slot[j];
/* curr is the current slot in the nic ring */
union e1000_adv_tx_desc *curr =
(union e1000_adv_tx_desc *)&txr->tx_base[l];
struct igb_tx_buffer *txbuf = &txr->tx_buffers[l];
int flags = ((slot->flags & NS_REPORT) ||
j == 0 || j == report_frequency) ?
E1000_ADVTXD_DCMD_RS : 0;
uint64_t paddr;
void *addr = PNMB(slot, &paddr);
u_int len = slot->len;
if (addr == netmap_buffer_base || len > NETMAP_BUF_SIZE) {
if (do_lock)
IGB_TX_UNLOCK(txr);
return netmap_ring_reinit(kring);
}
slot->flags &= ~NS_REPORT;
if (slot->flags & NS_BUF_CHANGED) {
/* buffer has changed, reload map */
netmap_reload_map(txr->txtag, txbuf->map, addr);
slot->flags &= ~NS_BUF_CHANGED;
}
curr->read.buffer_addr = htole64(paddr);
// XXX check olinfo and cmd_type_len
curr->read.olinfo_status =
htole32(olinfo_status |
(len<< E1000_ADVTXD_PAYLEN_SHIFT));
curr->read.cmd_type_len =
htole32(len | E1000_ADVTXD_DTYP_DATA |
E1000_ADVTXD_DCMD_IFCS |
E1000_ADVTXD_DCMD_DEXT |
E1000_ADVTXD_DCMD_EOP | flags);
bus_dmamap_sync(txr->txtag, txbuf->map,
BUS_DMASYNC_PREWRITE);
j = (j == lim) ? 0 : j + 1;
l = (l == lim) ? 0 : l + 1;
}
kring->nr_hwcur = k; /* the saved ring->cur */
kring->nr_hwavail -= n;
/* Set the watchdog XXX ? */
txr->queue_status = IGB_QUEUE_WORKING;
txr->watchdog_time = ticks;
bus_dmamap_sync(txr->txdma.dma_tag, txr->txdma.dma_map,
BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
E1000_WRITE_REG(&adapter->hw, E1000_TDT(txr->me), l);
}
if (n == 0 || kring->nr_hwavail < 1) {
int delta;
/* record completed transmissions using TDH */
l = E1000_READ_REG(&adapter->hw, E1000_TDH(ring_nr));
if (l >= kring->nkr_num_slots) { /* XXX can it happen ? */
D("TDH wrap %d", l);
l -= kring->nkr_num_slots;
}
delta = l - txr->next_to_clean;
if (delta) {
/* some completed, increment hwavail. */
if (delta < 0)
delta += kring->nkr_num_slots;
txr->next_to_clean = l;
kring->nr_hwavail += delta;
}
}
/* update avail to what the kernel knows */
ring->avail = kring->nr_hwavail;
if (do_lock)
IGB_TX_UNLOCK(txr);
return 0;
}
/*
* Reconcile kernel and user view of the receive ring.
*/
static int
igb_netmap_rxsync(struct ifnet *ifp, u_int ring_nr, int do_lock)
{
struct adapter *adapter = ifp->if_softc;
struct rx_ring *rxr = &adapter->rx_rings[ring_nr];
struct netmap_adapter *na = NA(ifp);
struct netmap_kring *kring = &na->rx_rings[ring_nr];
struct netmap_ring *ring = kring->ring;
u_int j, l, n, lim = kring->nkr_num_slots - 1;
int force_update = do_lock || kring->nr_kflags & NKR_PENDINTR;
u_int k = ring->cur, resvd = ring->reserved;
k = ring->cur;
if (k > lim)
return netmap_ring_reinit(kring);
if (do_lock)
IGB_RX_LOCK(rxr);
/* XXX check sync modes */
bus_dmamap_sync(rxr->rxdma.dma_tag, rxr->rxdma.dma_map,
BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
/*
* import newly received packets into the netmap ring.
* j is an index in the netmap ring, l in the NIC ring.
*/
l = rxr->next_to_check;
j = netmap_idx_n2k(kring, l);
if (netmap_no_pendintr || force_update) {
for (n = 0; ; n++) {
union e1000_adv_rx_desc *curr = &rxr->rx_base[l];
uint32_t staterr = le32toh(curr->wb.upper.status_error);
if ((staterr & E1000_RXD_STAT_DD) == 0)
break;
ring->slot[j].len = le16toh(curr->wb.upper.length);
bus_dmamap_sync(rxr->ptag,
rxr->rx_buffers[l].pmap, BUS_DMASYNC_POSTREAD);
j = (j == lim) ? 0 : j + 1;
l = (l == lim) ? 0 : l + 1;
}
if (n) { /* update the state variables */
rxr->next_to_check = l;
kring->nr_hwavail += n;
}
kring->nr_kflags &= ~NKR_PENDINTR;
}
/* skip past packets that userspace has released */
j = kring->nr_hwcur; /* netmap ring index */
if (resvd > 0) {
if (resvd + ring->avail >= lim + 1) {
D("XXX invalid reserve/avail %d %d", resvd, ring->avail);
ring->reserved = resvd = 0; // XXX panic...
}
k = (k >= resvd) ? k - resvd : k + lim + 1 - resvd;
}
if (j != k) { /* userspace has released some packets. */
l = netmap_idx_k2n(kring, j);
for (n = 0; j != k; n++) {
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;
uint64_t paddr;
void *addr = PNMB(slot, &paddr);
if (addr == netmap_buffer_base) { /* bad buf */
if (do_lock)
IGB_RX_UNLOCK(rxr);
return netmap_ring_reinit(kring);
}
if (slot->flags & NS_BUF_CHANGED) {
netmap_reload_map(rxr->ptag, rxbuf->pmap, addr);
slot->flags &= ~NS_BUF_CHANGED;
}
curr->read.pkt_addr = htole64(paddr);
curr->wb.upper.status_error = 0;
bus_dmamap_sync(rxr->ptag, rxbuf->pmap,
BUS_DMASYNC_PREREAD);
j = (j == lim) ? 0 : j + 1;
l = (l == lim) ? 0 : l + 1;
}
kring->nr_hwavail -= n;
kring->nr_hwcur = k;
bus_dmamap_sync(rxr->rxdma.dma_tag, rxr->rxdma.dma_map,
BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
/*
* IMPORTANT: we must leave one free slot in the ring,
* so move l back by one unit
*/
l = (l == 0) ? lim : l - 1;
E1000_WRITE_REG(&adapter->hw, E1000_RDT(rxr->me), l);
}
/* tell userspace that there are new packets */
ring->avail = kring->nr_hwavail - resvd;
if (do_lock)
IGB_RX_UNLOCK(rxr);
return 0;
}
static void
igb_netmap_attach(struct adapter *adapter)
{
struct netmap_adapter na;
bzero(&na, sizeof(na));
na.ifp = adapter->ifp;
na.separate_locks = 1;
na.num_tx_desc = adapter->num_tx_desc;
na.num_rx_desc = adapter->num_rx_desc;
na.nm_txsync = igb_netmap_txsync;
na.nm_rxsync = igb_netmap_rxsync;
na.nm_lock = igb_netmap_lock_wrapper;
na.nm_register = igb_netmap_reg;
netmap_attach(&na, adapter->num_queues);
}
/* end of file */
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