freebsd-nq/sys/dev/netmap/if_em_netmap.h
Luigi Rizzo 506cc70cce 1. Fix the handling of link reset while in netmap more.
A link reset now is completely transparent for the netmap client:
   even if the NIC resets its own ring (e.g. restarting from 0),
   the client will not see any change in the current rx/tx positions,
   because the driver will keep track of the offset between the two.

2. make the device-specific code more uniform across different drivers
   There were some inconsistencies in the implementation of the netmap
   support routines, now drivers have been aligned to a common
   code structure.

3. import netmap support for ixgbe . This is implemented as a very
   small patch for ixgbe.c (233 lines, 11 chunks, mostly comments:
   in total the patch has only 54 lines of new code) , as most of
   the code is in an external file sys/dev/netmap/ixgbe_netmap.h ,
   following some initial comments from Jack Vogel about making
   changes less intrusive.
   (Note, i have emailed Jack multiple times asking if he had
   comments on this structure of the code; i got no reply so
   i assume he is fine with it).

Support for other drivers (em, lem, re, igb) will come later.

"ixgbe" is now the reference driver for netmap support. Both the
external file (sys/dev/netmap/ixgbe_netmap.h) and the device-specific
patches (in sys/dev/ixgbe/ixgbe.c) are heavily commented and should
serve as a reference for other device drivers.

Tested on i386 and amd64 with the pkt-gen program in tools/tools/netmap,
the sender does 14.88 Mpps at 1050 Mhz and 14.2 Mpps at 900 MHz
on an i7-860 with 4 cores and 82599 card. Haven't tried yet more
aggressive optimizations such as adding 'prefetch' instructions
in the time-critical parts of the code.
2011-12-05 12:06:53 +00:00

399 lines
11 KiB
C

/*
* Copyright (C) 2011 Matteo Landi, Luigi Rizzo. 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_em_netmap.h 9802 2011-12-02 18:42:37Z luigi $
*
* netmap changes for if_em.
*
* For structure and details on the individual functions 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>
static void em_netmap_block_tasks(struct adapter *);
static void em_netmap_unblock_tasks(struct adapter *);
static int em_netmap_reg(struct ifnet *, int onoff);
static int em_netmap_txsync(void *, u_int, int);
static int em_netmap_rxsync(void *, u_int, int);
static void em_netmap_lock_wrapper(void *, int, u_int);
static void
em_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 = em_netmap_txsync;
na.nm_rxsync = em_netmap_rxsync;
na.nm_lock = em_netmap_lock_wrapper;
na.nm_register = em_netmap_reg;
na.buff_size = NETMAP_BUF_SIZE;
netmap_attach(&na, adapter->num_queues);
}
/*
* wrapper to export locks to the generic code
*/
static void
em_netmap_lock_wrapper(void *_a, int what, u_int queueid)
{
struct adapter *adapter = _a;
ASSERT(queueid < adapter->num_queues);
switch (what) {
case NETMAP_CORE_LOCK:
EM_CORE_LOCK(adapter);
break;
case NETMAP_CORE_UNLOCK:
EM_CORE_UNLOCK(adapter);
break;
case NETMAP_TX_LOCK:
EM_TX_LOCK(&adapter->tx_rings[queueid]);
break;
case NETMAP_TX_UNLOCK:
EM_TX_UNLOCK(&adapter->tx_rings[queueid]);
break;
case NETMAP_RX_LOCK:
EM_RX_LOCK(&adapter->rx_rings[queueid]);
break;
case NETMAP_RX_UNLOCK:
EM_RX_UNLOCK(&adapter->rx_rings[queueid]);
break;
}
}
// XXX do we need to block/unblock the tasks ?
static void
em_netmap_block_tasks(struct adapter *adapter)
{
if (adapter->msix > 1) { /* MSIX */
int i;
struct tx_ring *txr = adapter->tx_rings;
struct rx_ring *rxr = adapter->rx_rings;
for (i = 0; i < adapter->num_queues; i++, txr++, rxr++) {
taskqueue_block(txr->tq);
taskqueue_drain(txr->tq, &txr->tx_task);
taskqueue_block(rxr->tq);
taskqueue_drain(rxr->tq, &rxr->rx_task);
}
} else { /* legacy */
taskqueue_block(adapter->tq);
taskqueue_drain(adapter->tq, &adapter->link_task);
taskqueue_drain(adapter->tq, &adapter->que_task);
}
}
static void
em_netmap_unblock_tasks(struct adapter *adapter)
{
if (adapter->msix > 1) {
struct tx_ring *txr = adapter->tx_rings;
struct rx_ring *rxr = adapter->rx_rings;
int i;
for (i = 0; i < adapter->num_queues; i++) {
taskqueue_unblock(txr->tq);
taskqueue_unblock(rxr->tq);
}
} else { /* legacy */
taskqueue_unblock(adapter->tq);
}
}
/*
* register-unregister routine
*/
static int
em_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 */
em_disable_intr(adapter);
/* Tell the stack that the interface is no longer active */
ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
em_netmap_block_tasks(adapter);
if (onoff) {
ifp->if_capenable |= IFCAP_NETMAP;
na->if_transmit = ifp->if_transmit;
ifp->if_transmit = netmap_start;
em_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;
em_init_locked(adapter); /* also enable intr */
}
em_netmap_unblock_tasks(adapter);
return (error);
}
/*
* Reconcile hardware and user view of the transmit ring.
*/
static int
em_netmap_txsync(void *a, u_int ring_nr, int do_lock)
{
struct adapter *adapter = a;
struct tx_ring *txr = &adapter->tx_rings[ring_nr];
struct netmap_adapter *na = NA(adapter->ifp);
struct netmap_kring *kring = &na->tx_rings[ring_nr];
struct netmap_ring *ring = kring->ring;
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)
EM_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 packets to send */
l = j - kring->nkr_hwofs;
if (l < 0)
l += lim + 1;
while (j != k) {
struct netmap_slot *slot = &ring->slot[j];
struct e1000_tx_desc *curr = &txr->tx_base[l];
struct em_buffer *txbuf = &txr->tx_buffers[l];
int flags = ((slot->flags & NS_REPORT) ||
j == 0 || j == report_frequency) ?
E1000_TXD_CMD_RS : 0;
void *addr = NMB(slot);
int len = slot->len;
if (addr == netmap_buffer_base || len > NETMAP_BUF_SIZE) {
if (do_lock)
EM_TX_UNLOCK(txr);
return netmap_ring_reinit(kring);
}
slot->flags &= ~NS_REPORT;
curr->upper.data = 0;
curr->lower.data =
htole32(adapter->txd_cmd | len |
(E1000_TXD_CMD_EOP | flags) );
if (slot->flags & NS_BUF_CHANGED) {
curr->buffer_addr = htole64(vtophys(addr));
/* buffer has changed, reload map */
netmap_reload_map(txr->txtag, txbuf->map,
addr, na->buff_size);
slot->flags &= ~NS_BUF_CHANGED;
}
bus_dmamap_sync(txr->txtag, txbuf->map,
BUS_DMASYNC_PREWRITE);
j = (j == lim) ? 0 : j + 1;
l = (l == lim) ? 0 : l + 1;
n++;
}
kring->nr_hwcur = k;
/* decrease avail by number of sent packets */
kring->nr_hwavail -= n;
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 THD. */
l = E1000_READ_REG(&adapter->hw, E1000_TDH(ring_nr));
if (l >= kring->nkr_num_slots) { /* XXX can 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 hardware knows */
ring->avail = kring->nr_hwavail;
if (do_lock)
EM_TX_UNLOCK(txr);
return 0;
}
/*
* Reconcile kernel and user view of the receive ring.
*/
static int
em_netmap_rxsync(void *a, u_int ring_nr, int do_lock)
{
struct adapter *adapter = a;
struct rx_ring *rxr = &adapter->rx_rings[ring_nr];
struct netmap_adapter *na = NA(adapter->ifp);
struct netmap_kring *kring = &na->rx_rings[ring_nr];
struct netmap_ring *ring = kring->ring;
int j, k, l, n, lim = kring->nkr_num_slots - 1;
k = ring->cur;
if (k > lim)
return netmap_ring_reinit(kring);
if (do_lock)
EM_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, and
* j = (kring->nr_hwcur + kring->nr_hwavail) % ring_size
* l = rxr->next_to_check;
* and
* j == (l + kring->nkr_hwofs) % ring_size
*/
l = rxr->next_to_check;
j = l + kring->nkr_hwofs;
/* here nkr_hwofs can be negative so must check for j < 0 */
if (j < 0)
j += lim + 1;
else if (j > lim)
j -= lim + 1;
for (n = 0; ; n++) {
struct e1000_rx_desc *curr = &rxr->rx_base[l];
if ((curr->status & E1000_RXD_STAT_DD) == 0)
break;
ring->slot[j].len = le16toh(curr->length);
bus_dmamap_sync(rxr->tag, rxr->rx_buffers[l].map,
BUS_DMASYNC_POSTREAD);
j = (j == lim) ? 0 : j + 1;
/* make sure next_to_refresh follows next_to_check */
rxr->next_to_refresh = l; // XXX
l = (l == lim) ? 0 : l + 1;
}
if (n) {
rxr->next_to_check = l;
kring->nr_hwavail += n;
}
/* skip past packets that userspace has already processed */
j = kring->nr_hwcur;
if (j != k) { /* userspace has read some packets. */
n = 0;
l = j - kring->nkr_hwofs; /* NIC ring index */
/* here nkr_hwofs can be negative so check for l > lim */
if (l < 0)
l += lim + 1;
else if (l > lim)
l -= lim + 1;
while (j != k) {
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);
if (addr == netmap_buffer_base) { /* bad buf */
if (do_lock)
EM_RX_UNLOCK(rxr);
return netmap_ring_reinit(kring);
}
curr->status = 0;
if (slot->flags & NS_BUF_CHANGED) {
curr->buffer_addr = htole64(vtophys(addr));
/* buffer has changed, reload map */
netmap_reload_map(rxr->rxtag, rxbuf->map,
addr, na->buff_size);
slot->flags &= ~NS_BUF_CHANGED;
}
bus_dmamap_sync(rxr->rxtag, rxbuf->map,
BUS_DMASYNC_PREREAD);
j = (j == lim) ? 0 : j + 1;
l = (l == lim) ? 0 : l + 1;
n++;
}
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 ;
if (do_lock)
EM_RX_UNLOCK(rxr);
return 0;
}