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Improve if_dwc:

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- refactorize packet receive path. Make sure that we don't leak mbufs
   and/or that we don't create holes in RX descriptor ring
 - slightly simplify handling with TX descriptors

MFC after:	4 weeks
This commit is contained in:
Michal Meloun 2020-06-19 19:26:55 +00:00
parent 0bc6f34c3d
commit b72e2878ab
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=362415
2 changed files with 103 additions and 62 deletions
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164
sys/dev/dwc/if_dwc.c
View File

@ -235,45 +235,39 @@ dwc_get1paddr(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
*(bus_addr_t *)arg = segs[0].ds_addr;
}
inline static uint32_t
inline static void
dwc_setup_txdesc(struct dwc_softc *sc, int idx, bus_addr_t paddr,
uint32_t len)
{
uint32_t flags;
uint32_t nidx;
nidx = next_txidx(sc, idx);
uint32_t desc0, desc1;
/* Addr/len 0 means we're clearing the descriptor after xmit done. */
if (paddr == 0 || len == 0) {
flags = 0;
desc0 = 0;
desc1 = 0;
--sc->txcount;
} else {
if (sc->mactype != DWC_GMAC_EXT_DESC)
flags = NTDESC1_TCH | NTDESC1_FS
| NTDESC1_LS | NTDESC1_IC;
else
flags = ETDESC0_TCH | ETDESC0_FS | ETDESC0_LS |
ETDESC0_IC;
if (sc->mactype != DWC_GMAC_EXT_DESC) {
desc0 = 0;
desc1 = NTDESC1_TCH | NTDESC1_FS | NTDESC1_LS |
NTDESC1_IC | len;
} else {
desc0 = ETDESC0_TCH | ETDESC0_FS | ETDESC0_LS |
ETDESC0_IC;
desc1 = len;
}
++sc->txcount;
}
sc->txdesc_ring[idx].addr1 = (uint32_t)(paddr);
if (sc->mactype != DWC_GMAC_EXT_DESC) {
sc->txdesc_ring[idx].desc0 = 0;
sc->txdesc_ring[idx].desc1 = flags | len;
} else {
sc->txdesc_ring[idx].desc0 = flags;
sc->txdesc_ring[idx].desc1 = len;
}
sc->txdesc_ring[idx].desc0 = desc0;
sc->txdesc_ring[idx].desc1 = desc1;
if (paddr && len) {
wmb();
sc->txdesc_ring[idx].desc0 |= TDESC0_OWN;
wmb();
}
return (nidx);
}
static int
@ -528,6 +522,7 @@ dwc_init(void *if_softc)
DWC_UNLOCK(sc);
}
inline static uint32_t
dwc_setup_rxdesc(struct dwc_softc *sc, int idx, bus_addr_t paddr)
{
@ -538,14 +533,15 @@ dwc_setup_rxdesc(struct dwc_softc *sc, int idx, bus_addr_t paddr)
sc->rxdesc_ring[idx].addr2 = sc->rxdesc_ring_paddr +
(nidx * sizeof(struct dwc_hwdesc));
if (sc->mactype != DWC_GMAC_EXT_DESC)
sc->rxdesc_ring[idx].desc1 = NRDESC1_RCH | RX_MAX_PACKET;
sc->rxdesc_ring[idx].desc1 = NRDESC1_RCH |
MIN(MCLBYTES, NRDESC1_RBS1_MASK);
else
sc->rxdesc_ring[idx].desc1 = ERDESC1_RCH | MCLBYTES;
sc->rxdesc_ring[idx].desc1 = ERDESC1_RCH |
MIN(MCLBYTES, ERDESC1_RBS1_MASK);
wmb();
sc->rxdesc_ring[idx].desc0 = RDESC0_OWN;
wmb();
return (nidx);
}
@ -585,6 +581,74 @@ dwc_alloc_mbufcl(struct dwc_softc *sc)
return (m);
}
static struct mbuf *
dwc_rxfinish_one(struct dwc_softc *sc, struct dwc_hwdesc *desc,
struct dwc_bufmap *map)
{
struct ifnet *ifp;
struct mbuf *m, *m0;
int len;
uint32_t rdesc0;
m = map->mbuf;
ifp = sc->ifp;
rdesc0 = desc ->desc0;
/* Validate descriptor. */
if (rdesc0 & RDESC0_ES) {
/*
* Errored packet. Statistic counters are updated
* globally, so do nothing
*/
return (NULL);
}
if ((rdesc0 & (RDESC0_FS | RDESC0_LS)) !=
(RDESC0_FS | RDESC0_LS)) {
/*
* Something very wrong happens. The whole packet should be
* recevied in one descriptr. Report problem.
*/
device_printf(sc->dev,
"%s: RX descriptor without FIRST and LAST bit set: 0x%08X",
__func__, rdesc0);
return (NULL);
}
len = (rdesc0 >> RDESC0_FL_SHIFT) & RDESC0_FL_MASK;
if (len < 64) {
/*
* Lenght is invalid, recycle old mbuf
* Probably impossible case
*/
return (NULL);
}
/* Allocate new buffer */
m0 = dwc_alloc_mbufcl(sc);
if (m0 == NULL) {
/* no new mbuf available, recycle old */
if_inc_counter(sc->ifp, IFCOUNTER_IQDROPS, 1);
return (NULL);
}
/* Do dmasync for newly received packet */
bus_dmamap_sync(sc->rxbuf_tag, map->map, BUS_DMASYNC_POSTREAD);
bus_dmamap_unload(sc->rxbuf_tag, map->map);
/* Received packet is valid, process it */
m->m_pkthdr.rcvif = ifp;
m->m_pkthdr.len = len;
m->m_len = len;
if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
/* Remove trailing FCS */
m_adj(m, -ETHER_CRC_LEN);
DWC_UNLOCK(sc);
(*ifp->if_input)(ifp, m);
DWC_LOCK(sc);
return (m0);
}
static void
dwc_media_status(struct ifnet * ifp, struct ifmediareq *ifmr)
{
@ -820,52 +884,30 @@ static void
dwc_rxfinish_locked(struct dwc_softc *sc)
{
struct ifnet *ifp;
struct mbuf *m0;
struct mbuf *m;
int error, idx, len;
uint32_t rdes0;
int error, idx;
struct dwc_hwdesc *desc;
DWC_ASSERT_LOCKED(sc);
ifp = sc->ifp;
for (;;) {
idx = sc->rx_idx;
rdes0 = sc->rxdesc_ring[idx].desc0;
if ((rdes0 & RDESC0_OWN) != 0)
desc = sc->rxdesc_ring + idx;
if ((desc->desc0 & RDESC0_OWN) != 0)
break;
bus_dmamap_sync(sc->rxbuf_tag, sc->rxbuf_map[idx].map,
BUS_DMASYNC_POSTREAD);
bus_dmamap_unload(sc->rxbuf_tag, sc->rxbuf_map[idx].map);
len = (rdes0 >> RDESC0_FL_SHIFT) & RDESC0_FL_MASK;
if (len != 0) {
m = sc->rxbuf_map[idx].mbuf;
m->m_pkthdr.rcvif = ifp;
m->m_pkthdr.len = len;
m->m_len = len;
if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
/* Remove trailing FCS */
m_adj(m, -ETHER_CRC_LEN);
DWC_UNLOCK(sc);
(*ifp->if_input)(ifp, m);
DWC_LOCK(sc);
m = dwc_rxfinish_one(sc, desc, sc->rxbuf_map + idx);
if (m == NULL) {
wmb();
desc->desc0 = RDESC0_OWN;
wmb();
} else {
/* XXX Zero-length packet ? */
/* We cannot create hole in RX ring */
error = dwc_setup_rxbuf(sc, idx, m);
if (error != 0)
panic("dwc_setup_rxbuf failed: error %d\n",
error);
}
if ((m0 = dwc_alloc_mbufcl(sc)) != NULL) {
if ((error = dwc_setup_rxbuf(sc, idx, m0)) != 0) {
/*
* XXX Now what?
* We've got a hole in the rx ring.
*/
}
} else
if_inc_counter(sc->ifp, IFCOUNTER_IQDROPS, 1);
sc->rx_idx = next_rxidx(sc, sc->rx_idx);
}
}

1
sys/dev/dwc/if_dwcvar.h
View File

@ -44,7 +44,6 @@
/*
* Driver data and defines.
*/
#define RX_MAX_PACKET 0x7ff
#define RX_DESC_COUNT 1024
#define RX_DESC_SIZE (sizeof(struct dwc_hwdesc) * RX_DESC_COUNT)
#define TX_DESC_COUNT 1024