d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

iflib: refactor netmap_fl_refill and fix off-by-one issue

Browse Source 
First, fix the initialization of the fl->ifl_rxd_idxs array,
which was affected by an off-by-one bug.
Once there, refactor the function to use better names for
local variables, optimize the variable assignments, and
merge the bus_dmamap_sync() inner loop with the outer one.

PR:	248494
MFC after:	3 weeks
This commit is contained in:
vmaffione 2020-08-12 14:17:38 +00:00
parent 74d5c2d5af
commit 63440469a3
1 changed files with 21 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

48
sys/net/iflib.c
View File

@ -838,39 +838,41 @@ netmap_fl_refill(iflib_rxq_t rxq, struct netmap_kring *kring, uint32_t nm_i, boo
struct if_rxd_update iru;
if_ctx_t ctx = rxq->ifr_ctx;
iflib_fl_t fl = &rxq->ifr_fl[0];
uint32_t refill_pidx, nic_i;
uint32_t nic_i_first, nic_i;
int i;
#if IFLIB_DEBUG_COUNTERS
int rf_count = 0;
#endif
if (nm_i == head && __predict_true(!init))
return 0;
return (0);
iru_init(&iru, rxq, 0 /* flid */);
map = fl->ifl_sds.ifsd_map;
refill_pidx = netmap_idx_k2n(kring, nm_i);
nic_i = netmap_idx_k2n(kring, nm_i);
/*
* IMPORTANT: we must leave one free slot in the ring,
* so move head back by one unit
*/
head = nm_prev(head, lim);
nic_i = UINT_MAX;
DBG_COUNTER_INC(fl_refills);
while (nm_i != head) {
#if IFLIB_DEBUG_COUNTERS
if (++rf_count == 9)
DBG_COUNTER_INC(fl_refills_large);
#endif
for (int tmp_pidx = 0; tmp_pidx < IFLIB_MAX_RX_REFRESH && nm_i != head; tmp_pidx++) {
nic_i_first = nic_i;
for (i = 0; i < IFLIB_MAX_RX_REFRESH && nm_i != head; i++) {
struct netmap_slot *slot = &ring->slot[nm_i];
void *addr = PNMB(na, slot, &fl->ifl_bus_addrs[tmp_pidx]);
uint32_t nic_i_dma = refill_pidx;
nic_i = netmap_idx_k2n(kring, nm_i);
void *addr = PNMB(na, slot, &fl->ifl_bus_addrs[i]);
MPASS(tmp_pidx < IFLIB_MAX_RX_REFRESH);
MPASS(i < IFLIB_MAX_RX_REFRESH);
if (addr == NETMAP_BUF_BASE(na)) /* bad buf */
return netmap_ring_reinit(kring);
fl->ifl_rxd_idxs[i] = nic_i;
if (__predict_false(init)) {
netmap_load_map(na, fl->ifl_buf_tag,
map[nic_i], addr);
@ -879,33 +881,25 @@ netmap_fl_refill(iflib_rxq_t rxq, struct netmap_kring *kring, uint32_t nm_i, boo
netmap_reload_map(na, fl->ifl_buf_tag,
map[nic_i], addr);
}
bus_dmamap_sync(fl->ifl_buf_tag, map[nic_i],
BUS_DMASYNC_PREREAD);
slot->flags &= ~NS_BUF_CHANGED;
nm_i = nm_next(nm_i, lim);
fl->ifl_rxd_idxs[tmp_pidx] = nic_i = nm_next(nic_i, lim);
if (nm_i != head && tmp_pidx < IFLIB_MAX_RX_REFRESH-1)
continue;
iru.iru_pidx = refill_pidx;
iru.iru_count = tmp_pidx+1;
ctx->isc_rxd_refill(ctx->ifc_softc, &iru);
refill_pidx = nic_i;
for (int n = 0; n < iru.iru_count; n++) {
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);
}
nic_i = nm_next(nic_i, lim);
}
iru.iru_pidx = nic_i_first;
iru.iru_count = i;
ctx->isc_rxd_refill(ctx->ifc_softc, &iru);
}
kring->nr_hwcur = head;
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);
}
ctx->isc_rxd_flush(ctx->ifc_softc, rxq->ifr_id, fl->ifl_id, nic_i);
DBG_COUNTER_INC(rxd_flush);
return (0);
}