freebsd-dev/sys/dev/netmap/if_lem_netmap.h
2014-09-19 03:51:26 +00:00

498 lines
14 KiB
C

/*
* Copyright (C) 2011-2014 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.
*/
/*
* $FreeBSD$
*
* netmap support for: lem
*
* 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>
extern int netmap_adaptive_io;
/*
* Register/unregister. We are already under netmap lock.
*/
static int
lem_netmap_reg(struct netmap_adapter *na, int onoff)
{
struct ifnet *ifp = na->ifp;
struct adapter *adapter = ifp->if_softc;
EM_CORE_LOCK(adapter);
lem_disable_intr(adapter);
/* Tell the stack that the interface is no longer active */
ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
#ifndef EM_LEGACY_IRQ // XXX do we need this ?
taskqueue_block(adapter->tq);
taskqueue_drain(adapter->tq, &adapter->rxtx_task);
taskqueue_drain(adapter->tq, &adapter->link_task);
#endif /* !EM_LEGCY_IRQ */
/* enable or disable flags and callbacks in na and ifp */
if (onoff) {
nm_set_native_flags(na);
} else {
nm_clear_native_flags(na);
}
lem_init_locked(adapter); /* also enable intr */
#ifndef EM_LEGACY_IRQ
taskqueue_unblock(adapter->tq); // XXX do we need this ?
#endif /* !EM_LEGCY_IRQ */
EM_CORE_UNLOCK(adapter);
return (ifp->if_drv_flags & IFF_DRV_RUNNING ? 0 : 1);
}
/*
* Reconcile kernel and user view of the transmit ring.
*/
static int
lem_netmap_txsync(struct netmap_kring *kring, int flags)
{
struct netmap_adapter *na = kring->na;
struct ifnet *ifp = na->ifp;
struct netmap_ring *ring = kring->ring;
u_int nm_i; /* index into the netmap ring */
u_int nic_i; /* index into the NIC ring */
u_int const lim = kring->nkr_num_slots - 1;
u_int const head = kring->rhead;
/* generate an interrupt approximately every half ring */
u_int report_frequency = kring->nkr_num_slots >> 1;
/* device-specific */
struct adapter *adapter = ifp->if_softc;
#ifdef NIC_PARAVIRT
struct paravirt_csb *csb = adapter->csb;
uint64_t *csbd = (uint64_t *)(csb + 1);
#endif /* NIC_PARAVIRT */
bus_dmamap_sync(adapter->txdma.dma_tag, adapter->txdma.dma_map,
BUS_DMASYNC_POSTREAD);
/*
* First part: process new packets to send.
*/
nm_i = kring->nr_hwcur;
if (nm_i != head) { /* we have new packets to send */
#ifdef NIC_PARAVIRT
int do_kick = 0;
uint64_t t = 0; // timestamp
int n = head - nm_i;
if (n < 0)
n += lim + 1;
if (csb) {
t = rdtsc(); /* last timestamp */
csbd[16] += t - csbd[0]; /* total Wg */
csbd[17] += n; /* Wg count */
csbd[0] = t;
}
#endif /* NIC_PARAVIRT */
nic_i = netmap_idx_k2n(kring, nm_i);
while (nm_i != head) {
struct netmap_slot *slot = &ring->slot[nm_i];
u_int len = slot->len;
uint64_t paddr;
void *addr = PNMB(na, slot, &paddr);
/* device-specific */
struct e1000_tx_desc *curr = &adapter->tx_desc_base[nic_i];
struct em_buffer *txbuf = &adapter->tx_buffer_area[nic_i];
int flags = (slot->flags & NS_REPORT ||
nic_i == 0 || nic_i == report_frequency) ?
E1000_TXD_CMD_RS : 0;
NM_CHECK_ADDR_LEN(na, addr, len);
if (slot->flags & NS_BUF_CHANGED) {
/* buffer has changed, reload map */
curr->buffer_addr = htole64(paddr);
netmap_reload_map(na, adapter->txtag, txbuf->map, addr);
}
slot->flags &= ~(NS_REPORT | NS_BUF_CHANGED);
/* Fill the slot in the NIC ring. */
curr->upper.data = 0;
curr->lower.data = htole32(adapter->txd_cmd | len |
(E1000_TXD_CMD_EOP | flags) );
bus_dmamap_sync(adapter->txtag, txbuf->map,
BUS_DMASYNC_PREWRITE);
nm_i = nm_next(nm_i, lim);
nic_i = nm_next(nic_i, lim);
// XXX might try an early kick
}
kring->nr_hwcur = head;
/* synchronize the NIC ring */
bus_dmamap_sync(adapter->txdma.dma_tag, adapter->txdma.dma_map,
BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
#ifdef NIC_PARAVIRT
/* set unconditionally, then also kick if needed */
if (csb) {
t = rdtsc();
if (csb->host_need_txkick == 2) {
/* can compute an update of delta */
int64_t delta = t - csbd[3];
if (delta < 0)
delta = -delta;
if (csbd[8] == 0 || delta < csbd[8]) {
csbd[8] = delta;
csbd[9]++;
}
csbd[10]++;
}
csb->guest_tdt = nic_i;
csbd[18] += t - csbd[0]; // total wp
csbd[19] += n;
}
if (!csb || !csb->guest_csb_on || (csb->host_need_txkick & 1))
do_kick = 1;
if (do_kick)
#endif /* NIC_PARAVIRT */
/* (re)start the tx unit up to slot nic_i (excluded) */
E1000_WRITE_REG(&adapter->hw, E1000_TDT(0), nic_i);
#ifdef NIC_PARAVIRT
if (do_kick) {
uint64_t t1 = rdtsc();
csbd[20] += t1 - t; // total Np
csbd[21]++;
}
#endif /* NIC_PARAVIRT */
}
/*
* Second part: reclaim buffers for completed transmissions.
*/
if (ticks != kring->last_reclaim || flags & NAF_FORCE_RECLAIM || nm_kr_txempty(kring)) {
kring->last_reclaim = ticks;
/* record completed transmissions using TDH */
#ifdef NIC_PARAVIRT
/* host updates tdh unconditionally, and we have
* no side effects on reads, so we can read from there
* instead of exiting.
*/
if (csb) {
static int drain = 0, nodrain=0, good = 0, bad = 0, fail = 0;
u_int x = adapter->next_tx_to_clean;
csbd[19]++; // XXX count reclaims
nic_i = csb->host_tdh;
if (csb->guest_csb_on) {
if (nic_i == x) {
bad++;
csbd[24]++; // failed reclaims
/* no progress, request kick and retry */
csb->guest_need_txkick = 1;
mb(); // XXX barrier
nic_i = csb->host_tdh;
} else {
good++;
}
if (nic_i != x) {
csb->guest_need_txkick = 2;
if (nic_i == csb->guest_tdt)
drain++;
else
nodrain++;
#if 1
if (netmap_adaptive_io) {
/* new mechanism: last half ring (or so)
* released one slot at a time.
* This effectively makes the system spin.
*
* Take next_to_clean + 1 as a reference.
* tdh must be ahead or equal
* On entry, the logical order is
* x < tdh = nic_i
* We first push tdh up to avoid wraps.
* The limit is tdh-ll (half ring).
* if tdh-256 < x we report x;
* else we report tdh-256
*/
u_int tdh = nic_i;
u_int ll = csbd[15];
u_int delta = lim/8;
if (netmap_adaptive_io == 2 || ll > delta)
csbd[15] = ll = delta;
else if (netmap_adaptive_io == 1 && ll > 1) {
csbd[15]--;
}
if (nic_i >= kring->nkr_num_slots) {
RD(5, "bad nic_i %d on input", nic_i);
}
x = nm_next(x, lim);
if (tdh < x)
tdh += lim + 1;
if (tdh <= x + ll) {
nic_i = x;
csbd[25]++; //report n + 1;
} else {
tdh = nic_i;
if (tdh < ll)
tdh += lim + 1;
nic_i = tdh - ll;
csbd[26]++; // report tdh - ll
}
}
#endif
} else {
/* we stop, count whether we are idle or not */
int bh_active = csb->host_need_txkick & 2 ? 4 : 0;
csbd[27+ csb->host_need_txkick]++;
if (netmap_adaptive_io == 1) {
if (bh_active && csbd[15] > 1)
csbd[15]--;
else if (!bh_active && csbd[15] < lim/2)
csbd[15]++;
}
bad--;
fail++;
}
}
RD(1, "drain %d nodrain %d good %d retry %d fail %d",
drain, nodrain, good, bad, fail);
} else
#endif /* !NIC_PARAVIRT */
nic_i = E1000_READ_REG(&adapter->hw, E1000_TDH(0));
if (nic_i >= kring->nkr_num_slots) { /* XXX can it happen ? */
D("TDH wrap %d", nic_i);
nic_i -= kring->nkr_num_slots;
}
adapter->next_tx_to_clean = nic_i;
kring->nr_hwtail = nm_prev(netmap_idx_n2k(kring, nic_i), lim);
}
nm_txsync_finalize(kring);
return 0;
}
/*
* Reconcile kernel and user view of the receive ring.
*/
static int
lem_netmap_rxsync(struct netmap_kring *kring, int flags)
{
struct netmap_adapter *na = kring->na;
struct ifnet *ifp = na->ifp;
struct netmap_ring *ring = kring->ring;
u_int nm_i; /* index into the netmap ring */
u_int nic_i; /* index into the NIC ring */
u_int n;
u_int const lim = kring->nkr_num_slots - 1;
u_int const head = nm_rxsync_prologue(kring);
int force_update = (flags & NAF_FORCE_READ) || kring->nr_kflags & NKR_PENDINTR;
/* device-specific */
struct adapter *adapter = ifp->if_softc;
#ifdef NIC_PARAVIRT
struct paravirt_csb *csb = adapter->csb;
uint32_t csb_mode = csb && csb->guest_csb_on;
uint32_t do_host_rxkick = 0;
#endif /* NIC_PARAVIRT */
if (head > lim)
return netmap_ring_reinit(kring);
#ifdef NIC_PARAVIRT
if (csb_mode) {
force_update = 1;
csb->guest_need_rxkick = 0;
}
#endif /* NIC_PARAVIRT */
/* XXX check sync modes */
bus_dmamap_sync(adapter->rxdma.dma_tag, adapter->rxdma.dma_map,
BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
/*
* First part: import newly received packets.
*/
if (netmap_no_pendintr || force_update) {
uint16_t slot_flags = kring->nkr_slot_flags;
nic_i = adapter->next_rx_desc_to_check;
nm_i = netmap_idx_n2k(kring, nic_i);
for (n = 0; ; n++) {
struct e1000_rx_desc *curr = &adapter->rx_desc_base[nic_i];
uint32_t staterr = le32toh(curr->status);
int len;
#ifdef NIC_PARAVIRT
if (csb_mode) {
if ((staterr & E1000_RXD_STAT_DD) == 0) {
/* don't bother to retry if more than 1 pkt */
if (n > 1)
break;
csb->guest_need_rxkick = 1;
wmb();
staterr = le32toh(curr->status);
if ((staterr & E1000_RXD_STAT_DD) == 0) {
break;
} else { /* we are good */
csb->guest_need_rxkick = 0;
}
}
} else
#endif /* NIC_PARAVIRT */
if ((staterr & E1000_RXD_STAT_DD) == 0)
break;
len = le16toh(curr->length) - 4; // CRC
if (len < 0) {
RD(5, "bogus pkt (%d) size %d nic idx %d", n, len, nic_i);
len = 0;
}
ring->slot[nm_i].len = len;
ring->slot[nm_i].flags = slot_flags;
bus_dmamap_sync(adapter->rxtag,
adapter->rx_buffer_area[nic_i].map,
BUS_DMASYNC_POSTREAD);
nm_i = nm_next(nm_i, lim);
nic_i = nm_next(nic_i, lim);
}
if (n) { /* update the state variables */
#ifdef NIC_PARAVIRT
if (csb_mode) {
if (n > 1) {
/* leave one spare buffer so we avoid rxkicks */
nm_i = nm_prev(nm_i, lim);
nic_i = nm_prev(nic_i, lim);
n--;
} else {
csb->guest_need_rxkick = 1;
}
}
#endif /* NIC_PARAVIRT */
ND("%d new packets at nic %d nm %d tail %d",
n,
adapter->next_rx_desc_to_check,
netmap_idx_n2k(kring, adapter->next_rx_desc_to_check),
kring->nr_hwtail);
adapter->next_rx_desc_to_check = nic_i;
// if_inc_counter(ifp, IFCOUNTER_IPACKETS, n);
kring->nr_hwtail = nm_i;
}
kring->nr_kflags &= ~NKR_PENDINTR;
}
/*
* Second part: skip past packets that userspace has released.
*/
nm_i = kring->nr_hwcur;
if (nm_i != head) {
nic_i = netmap_idx_k2n(kring, nm_i);
for (n = 0; nm_i != head; n++) {
struct netmap_slot *slot = &ring->slot[nm_i];
uint64_t paddr;
void *addr = PNMB(na, slot, &paddr);
struct e1000_rx_desc *curr = &adapter->rx_desc_base[nic_i];
struct em_buffer *rxbuf = &adapter->rx_buffer_area[nic_i];
if (addr == NETMAP_BUF_BASE(na)) /* bad buf */
goto ring_reset;
if (slot->flags & NS_BUF_CHANGED) {
/* buffer has changed, reload map */
curr->buffer_addr = htole64(paddr);
netmap_reload_map(na, adapter->rxtag, rxbuf->map, addr);
slot->flags &= ~NS_BUF_CHANGED;
}
curr->status = 0;
bus_dmamap_sync(adapter->rxtag, rxbuf->map,
BUS_DMASYNC_PREREAD);
#ifdef NIC_PARAVIRT
if (csb_mode && csb->host_rxkick_at == nic_i)
do_host_rxkick = 1;
#endif /* NIC_PARAVIRT */
nm_i = nm_next(nm_i, lim);
nic_i = nm_next(nic_i, lim);
}
kring->nr_hwcur = head;
bus_dmamap_sync(adapter->rxdma.dma_tag, adapter->rxdma.dma_map,
BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
/*
* IMPORTANT: we must leave one free slot in the ring,
* so move nic_i back by one unit
*/
nic_i = nm_prev(nic_i, lim);
#ifdef NIC_PARAVIRT
/* set unconditionally, then also kick if needed */
if (csb)
csb->guest_rdt = nic_i;
if (!csb_mode || do_host_rxkick)
#endif /* NIC_PARAVIRT */
E1000_WRITE_REG(&adapter->hw, E1000_RDT(0), nic_i);
}
/* tell userspace that there might be new packets */
nm_rxsync_finalize(kring);
return 0;
ring_reset:
return netmap_ring_reinit(kring);
}
static void
lem_netmap_attach(struct adapter *adapter)
{
struct netmap_adapter na;
bzero(&na, sizeof(na));
na.ifp = adapter->ifp;
na.na_flags = NAF_BDG_MAYSLEEP;
na.num_tx_desc = adapter->num_tx_desc;
na.num_rx_desc = adapter->num_rx_desc;
na.nm_txsync = lem_netmap_txsync;
na.nm_rxsync = lem_netmap_rxsync;
na.nm_register = lem_netmap_reg;
na.num_tx_rings = na.num_rx_rings = 1;
netmap_attach(&na);
}
/* end of file */