Further correct and optimize the bus_dma(9) usage of iflib(4):

o Correct the obvious bugs in the netmap(4) parts:
  - No longer check for the existence of DMA maps as bus_dma(9)
    is used unconditionally in iflib(4) since r341095.
  - Supply the correct DMA tag and map pairs to bus_dma(9)
    functions (see also the commit message of r343753).
  - In iflib_netmap_timer_adjust(), add synchronization of the
    TX descriptors before calling the ift_txd_credits_update
    method as the latter evaluates the TX descriptors possibly
    updated by the MAC.
  - In _task_fn_tx(), wrap the netmap(4)-specific bits in
    #ifdef DEV_NETMAP just as done in _task_fn_admin() and
    _task_fn_rx() respectively.
o In iflib_fast_intr_rxtx(), synchronize the TX rather than
  the RX descriptors before calling the ift_txd_credits_update
  method (see also above).
o There's no need to synchronize an RX buffer that is going to
  be recycled in iflib_rxd_pkt_get(), yet; it's sufficient to
  do that as late as passing RX buffers to the MAC via the
  ift_rxd_refill method. Hence, combine that synchronization
  with the synchronization of new buffers into a common spot
  in _iflib_fl_refill().
o There's no need to synchronize the RX descriptors of a free
  list in preparation of the MAC updating their statuses with
  every invocation of rxd_frag_to_sd(); it's enough to do this
  once before handing control over to the MAC, i. e. before
  calling ift_rxd_flush method in _iflib_fl_refill(), which
  already performs the necessary synchronization.
o Given that the ift_rxd_available method evaluates the RX
  descriptors which possibly have been altered by the MAC,
  synchronize as appropriate beforehand. Most notably this
  is now done in iflib_rxd_avail(), which in turn means that
  we don't need to issue the same synchronization yet again
  before calling the ift_rxd_pkt_get method in iflib_rxeof().
o In iflib_txd_db_check(), synchronize the TX descriptors
  before handing them over to the MAC for transmission via
  the ift_txd_flush method.
o In iflib_encap(), move the TX buffer synchronization after
  the invocation of the ift_txd_encap() method. If the MAC
  driver fails to encapsulate the packet and we retry with
  a defragmented mbuf chain or finally fail, the cycles for
  TX buffer synchronization have been wasted. Synchronizing
  afterwards matches what non-iflib(4) drivers typically do
  and is sufficient as the MAC will not actually start with
  the transmission before - in this case - the ift_txd_flush
  method is called.
  Moreover, for the latter reason the synchronization of the
  TX descriptors in iflib_encap() can go as it's enough to
  synchronize them before passing control over to the MAC by
  issuing the ift_txd_flush() method (see above).
o In iflib_txq_can_drain(), only synchronize TX descriptors
  if the ift_txd_credits_update method accessing these is
  actually called.

Differential Revision:	https://reviews.freebsd.org/D19081
This commit is contained in:
Marius Strobl 2019-02-12 21:08:44 +00:00
parent 50619ae7d5
commit 95dcf343b7

View File

@ -845,11 +845,13 @@ netmap_fl_refill(iflib_rxq_t rxq, struct netmap_kring *kring, uint32_t nm_i, boo
return netmap_ring_reinit(kring);
fl->ifl_vm_addrs[tmp_pidx] = addr;
if (__predict_false(init) && map) {
netmap_load_map(na, fl->ifl_ifdi->idi_tag, map[nic_i], addr);
} else if (map && (slot->flags & NS_BUF_CHANGED)) {
if (__predict_false(init)) {
netmap_load_map(na, fl->ifl_buf_tag,
map[nic_i], addr);
} else if (slot->flags & NS_BUF_CHANGED) {
/* buffer has changed, reload map */
netmap_reload_map(na, fl->ifl_ifdi->idi_tag, map[nic_i], addr);
netmap_reload_map(na, fl->ifl_buf_tag,
map[nic_i], addr);
}
slot->flags &= ~NS_BUF_CHANGED;
@ -861,13 +863,9 @@ netmap_fl_refill(iflib_rxq_t rxq, struct netmap_kring *kring, uint32_t nm_i, boo
iru.iru_pidx = refill_pidx;
iru.iru_count = tmp_pidx+1;
ctx->isc_rxd_refill(ctx->ifc_softc, &iru);
refill_pidx = nic_i;
if (map == NULL)
continue;
for (int n = 0; n < iru.iru_count; n++) {
bus_dmamap_sync(fl->ifl_ifdi->idi_tag, map[nic_i_dma],
bus_dmamap_sync(fl->ifl_buf_tag, map[nic_i_dma],
BUS_DMASYNC_PREREAD);
/* XXX - change this to not use the netmap func*/
nic_i_dma = nm_next(nic_i_dma, lim);
@ -876,9 +874,8 @@ netmap_fl_refill(iflib_rxq_t rxq, struct netmap_kring *kring, uint32_t nm_i, boo
}
kring->nr_hwcur = head;
if (map)
bus_dmamap_sync(fl->ifl_ifdi->idi_tag, fl->ifl_ifdi->idi_map,
BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
bus_dmamap_sync(fl->ifl_ifdi->idi_tag, fl->ifl_ifdi->idi_map,
BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
if (__predict_true(nic_i != UINT_MAX)) {
ctx->isc_rxd_flush(ctx->ifc_softc, rxq->ifr_id, fl->ifl_id, nic_i);
DBG_COUNTER_INC(rxd_flush);
@ -922,7 +919,7 @@ iflib_netmap_txsync(struct netmap_kring *kring, int flags)
if_ctx_t ctx = ifp->if_softc;
iflib_txq_t txq = &ctx->ifc_txqs[kring->ring_id];
bus_dmamap_sync(txq->ift_buf_tag, txq->ift_ifdi->idi_map,
bus_dmamap_sync(txq->ift_ifdi->idi_tag, txq->ift_ifdi->idi_map,
BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
/*
@ -956,8 +953,7 @@ iflib_netmap_txsync(struct netmap_kring *kring, int flags)
__builtin_prefetch(&ring->slot[nm_i]);
__builtin_prefetch(&txq->ift_sds.ifsd_m[nic_i]);
if (txq->ift_sds.ifsd_map)
__builtin_prefetch(&txq->ift_sds.ifsd_map[nic_i]);
__builtin_prefetch(&txq->ift_sds.ifsd_map[nic_i]);
for (n = 0; nm_i != head; n++) {
struct netmap_slot *slot = &ring->slot[nm_i];
@ -984,20 +980,20 @@ iflib_netmap_txsync(struct netmap_kring *kring, int flags)
/* prefetch for next round */
__builtin_prefetch(&ring->slot[nm_i + 1]);
__builtin_prefetch(&txq->ift_sds.ifsd_m[nic_i + 1]);
if (txq->ift_sds.ifsd_map) {
__builtin_prefetch(&txq->ift_sds.ifsd_map[nic_i + 1]);
__builtin_prefetch(&txq->ift_sds.ifsd_map[nic_i + 1]);
NM_CHECK_ADDR_LEN(na, addr, len);
NM_CHECK_ADDR_LEN(na, addr, len);
if (slot->flags & NS_BUF_CHANGED) {
/* buffer has changed, reload map */
netmap_reload_map(na, txq->ift_buf_tag,
txq->ift_sds.ifsd_map[nic_i], addr);
}
/* make sure changes to the buffer are synced */
bus_dmamap_sync(txq->ift_ifdi->idi_tag, txq->ift_sds.ifsd_map[nic_i],
BUS_DMASYNC_PREWRITE);
if (slot->flags & NS_BUF_CHANGED) {
/* buffer has changed, reload map */
netmap_reload_map(na, txq->ift_buf_tag,
txq->ift_sds.ifsd_map[nic_i], addr);
}
/* make sure changes to the buffer are synced */
bus_dmamap_sync(txq->ift_buf_tag,
txq->ift_sds.ifsd_map[nic_i],
BUS_DMASYNC_PREWRITE);
slot->flags &= ~(NS_REPORT | NS_BUF_CHANGED);
nm_i = nm_next(nm_i, lim);
nic_i = nm_next(nic_i, lim);
@ -1005,7 +1001,7 @@ iflib_netmap_txsync(struct netmap_kring *kring, int flags)
kring->nr_hwcur = nm_i;
/* synchronize the NIC ring */
bus_dmamap_sync(txq->ift_buf_tag, txq->ift_ifdi->idi_map,
bus_dmamap_sync(txq->ift_ifdi->idi_tag, txq->ift_ifdi->idi_map,
BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
/* (re)start the tx unit up to slot nic_i (excluded) */
@ -1053,6 +1049,7 @@ iflib_netmap_rxsync(struct netmap_kring *kring, int flags)
{
struct netmap_adapter *na = kring->na;
struct netmap_ring *ring = kring->ring;
iflib_fl_t fl;
uint32_t nm_i; /* index into the netmap ring */
uint32_t nic_i; /* index into the NIC ring */
u_int i, n;
@ -1064,18 +1061,18 @@ iflib_netmap_rxsync(struct netmap_kring *kring, int flags)
struct ifnet *ifp = na->ifp;
if_ctx_t ctx = ifp->if_softc;
iflib_rxq_t rxq = &ctx->ifc_rxqs[kring->ring_id];
iflib_fl_t fl = rxq->ifr_fl;
if (head > lim)
return netmap_ring_reinit(kring);
/* XXX check sync modes */
/*
* XXX netmap_fl_refill() only ever (re)fills free list 0 so far.
*/
for (i = 0, fl = rxq->ifr_fl; i < rxq->ifr_nfl; i++, fl++) {
if (fl->ifl_sds.ifsd_map == NULL)
continue;
bus_dmamap_sync(rxq->ifr_fl[i].ifl_buf_tag,
fl->ifl_ifdi->idi_map,
bus_dmamap_sync(fl->ifl_ifdi->idi_tag, fl->ifl_ifdi->idi_map,
BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
}
/*
* First part: import newly received packets.
*
@ -1099,7 +1096,8 @@ iflib_netmap_rxsync(struct netmap_kring *kring, int flags)
fl = &rxq->ifr_fl[i];
nic_i = fl->ifl_cidx;
nm_i = netmap_idx_n2k(kring, nic_i);
avail = iflib_rxd_avail(ctx, rxq, nic_i, USHRT_MAX);
avail = ctx->isc_rxd_available(ctx->ifc_softc,
rxq->ifr_id, nic_i, USHRT_MAX);
for (n = 0; avail > 0; n++, avail--) {
rxd_info_zero(&ri);
ri.iri_frags = rxq->ifr_frags;
@ -1110,7 +1108,7 @@ iflib_netmap_rxsync(struct netmap_kring *kring, int flags)
error = ctx->isc_rxd_pkt_get(ctx->ifc_softc, &ri);
ring->slot[nm_i].len = error ? 0 : ri.iri_len - crclen;
ring->slot[nm_i].flags = 0;
bus_dmamap_sync(fl->ifl_ifdi->idi_tag,
bus_dmamap_sync(fl->ifl_buf_tag,
fl->ifl_sds.ifsd_map[nic_i], BUS_DMASYNC_POSTREAD);
nm_i = nm_next(nm_i, lim);
nic_i = nm_next(nic_i, lim);
@ -1221,13 +1219,17 @@ iflib_netmap_rxq_init(if_ctx_t ctx, iflib_rxq_t rxq)
}
static void
iflib_netmap_timer_adjust(if_ctx_t ctx, uint16_t txqid, uint32_t *reset_on)
iflib_netmap_timer_adjust(if_ctx_t ctx, iflib_txq_t txq, uint32_t *reset_on)
{
struct netmap_kring *kring;
uint16_t txqid;
txqid = txq->ift_id;
kring = NA(ctx->ifc_ifp)->tx_rings[txqid];
if (kring->nr_hwcur != nm_next(kring->nr_hwtail, kring->nkr_num_slots - 1)) {
bus_dmamap_sync(txq->ift_ifdi->idi_tag, txq->ift_ifdi->idi_map,
BUS_DMASYNC_POSTREAD);
if (ctx->isc_txd_credits_update(ctx->ifc_softc, txqid, false))
netmap_tx_irq(ctx->ifc_ifp, txqid);
if (!(ctx->ifc_flags & IFC_NETMAP_TX_IRQ)) {
@ -1249,7 +1251,7 @@ iflib_netmap_timer_adjust(if_ctx_t ctx, uint16_t txqid, uint32_t *reset_on)
#define iflib_netmap_attach(ctx) (0)
#define netmap_rx_irq(ifp, qid, budget) (0)
#define netmap_tx_irq(ifp, qid) do {} while (0)
#define iflib_netmap_timer_adjust(ctx, txqid, reset_on)
#define iflib_netmap_timer_adjust(ctx, txq, reset_on)
#endif
@ -1482,9 +1484,12 @@ iflib_fast_intr_rxtx(void *arg)
{
iflib_filter_info_t info = arg;
struct grouptask *gtask = info->ifi_task;
if_ctx_t ctx;
iflib_rxq_t rxq = (iflib_rxq_t)info->ifi_ctx;
if_ctx_t ctx = NULL;;
iflib_txq_t txq;
void *sc;
int i, cidx;
qidx_t txqid;
if (!iflib_started)
return (FILTER_HANDLED);
@ -1493,19 +1498,19 @@ iflib_fast_intr_rxtx(void *arg)
if (info->ifi_filter != NULL && info->ifi_filter(info->ifi_filter_arg) == FILTER_HANDLED)
return (FILTER_HANDLED);
ctx = rxq->ifr_ctx;
sc = ctx->ifc_softc;
MPASS(rxq->ifr_ntxqirq);
for (i = 0; i < rxq->ifr_ntxqirq; i++) {
qidx_t txqid = rxq->ifr_txqid[i];
ctx = rxq->ifr_ctx;
bus_dmamap_sync(rxq->ifr_ifdi->idi_tag, rxq->ifr_ifdi->idi_map,
txqid = rxq->ifr_txqid[i];
txq = &ctx->ifc_txqs[txqid];
bus_dmamap_sync(txq->ift_ifdi->idi_tag, txq->ift_ifdi->idi_map,
BUS_DMASYNC_POSTREAD);
if (!ctx->isc_txd_credits_update(ctx->ifc_softc, txqid, false)) {
if (!ctx->isc_txd_credits_update(sc, txqid, false)) {
IFDI_TX_QUEUE_INTR_ENABLE(ctx, txqid);
continue;
}
GROUPTASK_ENQUEUE(&ctx->ifc_txqs[txqid].ift_task);
GROUPTASK_ENQUEUE(&txq->ift_task);
}
if (ctx->ifc_sctx->isc_flags & IFLIB_HAS_RXCQ)
cidx = rxq->ifr_cq_cidx;
@ -1804,7 +1809,7 @@ iflib_txq_setup(iflib_txq_t txq)
IFDI_TXQ_SETUP(ctx, txq->ift_id);
for (i = 0, di = txq->ift_ifdi; i < sctx->isc_ntxqs; i++, di++)
bus_dmamap_sync(di->idi_tag, di->idi_map,
BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
return (0);
}
@ -2008,8 +2013,6 @@ _iflib_fl_refill(if_ctx_t ctx, iflib_fl_t fl, int count)
break;
}
bus_dmamap_sync(fl->ifl_buf_tag, sd_map[frag_idx],
BUS_DMASYNC_PREREAD);
sd_ba[frag_idx] = bus_addr = cb_arg.seg.ds_addr;
sd_cl[frag_idx] = cl;
#if MEMORY_LOGGING
@ -2018,6 +2021,8 @@ _iflib_fl_refill(if_ctx_t ctx, iflib_fl_t fl, int count)
} else {
bus_addr = sd_ba[frag_idx];
}
bus_dmamap_sync(fl->ifl_buf_tag, sd_map[frag_idx],
BUS_DMASYNC_PREREAD);
MPASS(sd_m[frag_idx] == NULL);
if ((m = m_gethdr(M_NOWAIT, MT_NOINIT)) == NULL) {
@ -2285,7 +2290,7 @@ iflib_timer(void *arg)
}
#ifdef DEV_NETMAP
if (if_getcapenable(ctx->ifc_ifp) & IFCAP_NETMAP)
iflib_netmap_timer_adjust(ctx, txq->ift_id, &reset_on);
iflib_netmap_timer_adjust(ctx, txq, &reset_on);
#endif
/* handle any laggards */
if (txq->ift_db_pending)
@ -2494,7 +2499,6 @@ rxd_frag_to_sd(iflib_rxq_t rxq, if_rxd_frag_t irf, int unload, if_rxsd_t sd)
int flid, cidx;
bus_dmamap_t map;
iflib_fl_t fl;
iflib_dma_info_t di;
int next;
map = NULL;
@ -2514,7 +2518,6 @@ rxd_frag_to_sd(iflib_rxq_t rxq, if_rxd_frag_t irf, int unload, if_rxsd_t sd)
next = (cidx + CACHE_PTR_INCREMENT) & (fl->ifl_size-1);
prefetch(&fl->ifl_sds.ifsd_map[next]);
map = fl->ifl_sds.ifsd_map[cidx];
di = fl->ifl_ifdi;
next = (cidx + CACHE_LINE_SIZE) & (fl->ifl_size-1);
/* not valid assert if bxe really does SGE from non-contiguous elements */
@ -2525,8 +2528,6 @@ rxd_frag_to_sd(iflib_rxq_t rxq, if_rxd_frag_t irf, int unload, if_rxsd_t sd)
fl->ifl_cidx = (fl->ifl_cidx + 1) & (fl->ifl_size-1);
if (__predict_false(fl->ifl_cidx == 0))
fl->ifl_gen = 0;
bus_dmamap_sync(fl->ifl_ifdi->idi_tag, fl->ifl_ifdi->idi_map,
BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
bit_clear(fl->ifl_rx_bitmap, cidx);
}
@ -2604,9 +2605,6 @@ iflib_rxd_pkt_get(iflib_rxq_t rxq, if_rxd_info_t ri)
m->m_data += 2;
#endif
memcpy(m->m_data, *sd.ifsd_cl, ri->iri_len);
bus_dmamap_sync(rxq->ifr_fl->ifl_buf_tag,
rxq->ifr_fl->ifl_sds.ifsd_map[ri->iri_frags[0].irf_idx],
BUS_DMASYNC_PREREAD);
m->m_len = ri->iri_frags[0].irf_len;
} else {
m = assemble_segments(rxq, ri, &sd);
@ -2675,7 +2673,6 @@ iflib_rxeof(iflib_rxq_t rxq, qidx_t budget)
if_ctx_t ctx = rxq->ifr_ctx;
if_shared_ctx_t sctx = ctx->ifc_sctx;
if_softc_ctx_t scctx = &ctx->ifc_softc_ctx;
iflib_dma_info_t di;
int avail, i;
qidx_t *cidxp;
struct if_rxd_info ri;
@ -2720,9 +2717,6 @@ iflib_rxeof(iflib_rxq_t rxq, qidx_t budget)
ri.iri_cidx = *cidxp;
ri.iri_ifp = ifp;
ri.iri_frags = rxq->ifr_frags;
di = rxq->ifr_fl[rxq->ifr_frags[0].irf_flid].ifl_ifdi;
bus_dmamap_sync(di->idi_tag, di->idi_map,
BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
err = ctx->isc_rxd_pkt_get(ctx->ifc_softc, &ri);
if (err)
@ -2891,6 +2885,8 @@ iflib_txd_db_check(if_ctx_t ctx, iflib_txq_t txq, int ring, qidx_t in_use)
max = TXQ_MAX_DB_DEFERRED(txq, in_use);
if (ring || txq->ift_db_pending >= max) {
dbval = txq->ift_npending ? txq->ift_npending : txq->ift_pidx;
bus_dmamap_sync(txq->ift_ifdi->idi_tag, txq->ift_ifdi->idi_map,
BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
ctx->isc_txd_flush(ctx->ifc_softc, txq->ift_id, dbval);
txq->ift_db_pending = txq->ift_npending = 0;
rang = true;
@ -3333,10 +3329,8 @@ iflib_encap(iflib_txq_t txq, struct mbuf **m_headp)
#ifdef PKT_DEBUG
print_pkt(&pi);
#endif
bus_dmamap_sync(buf_tag, map, BUS_DMASYNC_PREWRITE);
if ((err = ctx->isc_txd_encap(ctx->ifc_softc, &pi)) == 0) {
bus_dmamap_sync(txq->ift_ifdi->idi_tag, txq->ift_ifdi->idi_map,
BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
bus_dmamap_sync(buf_tag, map, BUS_DMASYNC_PREWRITE);
DBG_COUNTER_INC(tx_encap);
MPASS(pi.ipi_new_pidx < txq->ift_size);
@ -3505,10 +3499,12 @@ iflib_txq_can_drain(struct ifmp_ring *r)
iflib_txq_t txq = r->cookie;
if_ctx_t ctx = txq->ift_ctx;
if (TXQ_AVAIL(txq) > MAX_TX_DESC(ctx) + 2)
return (1);
bus_dmamap_sync(txq->ift_ifdi->idi_tag, txq->ift_ifdi->idi_map,
BUS_DMASYNC_POSTREAD);
return ((TXQ_AVAIL(txq) > MAX_TX_DESC(ctx) + 2) ||
ctx->isc_txd_credits_update(ctx->ifc_softc, txq->ift_id, false));
return (ctx->isc_txd_credits_update(ctx->ifc_softc, txq->ift_id,
false));
}
static uint32_t
@ -3662,7 +3658,6 @@ _task_fn_tx(void *context)
{
iflib_txq_t txq = context;
if_ctx_t ctx = txq->ift_ctx;
struct ifnet *ifp = ctx->ifc_ifp;
int abdicate = ctx->ifc_sysctl_tx_abdicate;
#ifdef IFLIB_DIAGNOSTICS
@ -3670,14 +3665,16 @@ _task_fn_tx(void *context)
#endif
if (!(if_getdrvflags(ctx->ifc_ifp) & IFF_DRV_RUNNING))
return;
if (if_getcapenable(ifp) & IFCAP_NETMAP) {
#ifdef DEV_NETMAP
if (if_getcapenable(ctx->ifc_ifp) & IFCAP_NETMAP) {
bus_dmamap_sync(txq->ift_ifdi->idi_tag, txq->ift_ifdi->idi_map,
BUS_DMASYNC_POSTREAD);
if (ctx->isc_txd_credits_update(ctx->ifc_softc, txq->ift_id, false))
netmap_tx_irq(ifp, txq->ift_id);
netmap_tx_irq(ctx->ifc_ifp, txq->ift_id);
IFDI_TX_QUEUE_INTR_ENABLE(ctx, txq->ift_id);
return;
}
#endif
#ifdef ALTQ
if (ALTQ_IS_ENABLED(&ifp->if_snd))
iflib_altq_if_start(ifp);
@ -3785,7 +3782,7 @@ _task_fn_admin(void *context)
#ifdef DEV_NETMAP
reset_on = hz / 2;
if (if_getcapenable(ctx->ifc_ifp) & IFCAP_NETMAP)
iflib_netmap_timer_adjust(ctx, txq->ift_id, &reset_on);
iflib_netmap_timer_adjust(ctx, txq, &reset_on);
#endif
callout_reset_on(&txq->ift_timer, reset_on, iflib_timer, txq, txq->ift_timer.c_cpu);
}
@ -5953,7 +5950,12 @@ iflib_tx_credits_update(if_ctx_t ctx, iflib_txq_t txq)
static int
iflib_rxd_avail(if_ctx_t ctx, iflib_rxq_t rxq, qidx_t cidx, qidx_t budget)
{
iflib_fl_t fl;
u_int i;
for (i = 0, fl = &rxq->ifr_fl[0]; i < rxq->ifr_nfl; i++, fl++)
bus_dmamap_sync(fl->ifl_ifdi->idi_tag, fl->ifl_ifdi->idi_map,
BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
return (ctx->isc_rxd_available(ctx->ifc_softc, rxq->ifr_id, cidx,
budget));
}