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Update if_dc to use m_defrag, removing the semi-duplicate dc_coal

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function.

Also, use m_defrag where appropriate to defrag long mbuf chains
in the same fashion as was done in if_sis.c.  Before this change,
if_dc would blow up and take down the interface if fed a really long
mbuf chain.

MFC after:	2 weeks
This commit is contained in:
Mike Silbersack 2003-03-29 21:27:07 +00:00
parent 2af5e4d96f
commit cda97c506e
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=112819
2 changed files with 60 additions and 70 deletions
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65
sys/dev/dc/if_dc.c
View file

@ -208,7 +208,6 @@ static void dc_acpi (device_t);
static struct dc_type *dc_devtype (device_t);
static int dc_newbuf (struct dc_softc *, int, struct mbuf *);
static int dc_encap (struct dc_softc *, struct mbuf *, u_int32_t *);
static int dc_coal (struct dc_softc *, struct mbuf **);
static void dc_pnic_rx_bug_war (struct dc_softc *, int);
static int dc_rx_resync (struct dc_softc *);
static void dc_rxeof (struct dc_softc *);
@ -3126,8 +3125,32 @@ dc_encap(sc, m_head, txidx)
{
struct dc_desc *f = NULL;
struct mbuf *m;
int frag, cur, cnt = 0;
int frag, cur, cnt = 0, chainlen = 0;
/*
* If there's no way we can send any packets, return now.
*/
if (DC_TX_LIST_CNT - sc->dc_cdata.dc_tx_cnt < 6)
return (ENOBUFS);
/*
* Count the number of frags in this chain to see if
* we need to m_defrag. Since the descriptor list is shared
* by all packets, we'll m_defrag long chains so that they
* do not use up the entire list, even if they would fit.
*/
for (m = m_head; m != NULL; m = m->m_next)
chainlen++;
if ((chainlen > DC_TX_LIST_CNT / 4) ||
((DC_TX_LIST_CNT - (chainlen + sc->dc_cdata.dc_tx_cnt)) < 6)) {
m = m_defrag(m_head, M_DONTWAIT);
if (m == NULL)
return (ENOBUFS);
m_head = m;
}
/*
* Start packing the mbufs in this chain into
* the fragment pointers. Stop when we run out
@ -3179,37 +3202,6 @@ dc_encap(sc, m_head, txidx)
return(0);
}
/*
* Coalesce an mbuf chain into a single mbuf cluster buffer.
* Needed for some really badly behaved chips that just can't
* do scatter/gather correctly.
*/
static int
dc_coal(sc, m_head)
struct dc_softc *sc;
struct mbuf **m_head;
{
struct mbuf *m_new, *m;
m = *m_head;
MGETHDR(m_new, M_DONTWAIT, MT_DATA);
if (m_new == NULL)
return(ENOBUFS);
if (m->m_pkthdr.len > MHLEN) {
MCLGET(m_new, M_DONTWAIT);
if (!(m_new->m_flags & M_EXT)) {
m_freem(m_new);
return(ENOBUFS);
}
}
m_copydata(m, 0, m->m_pkthdr.len, mtod(m_new, caddr_t));
m_new->m_pkthdr.len = m_new->m_len = m->m_pkthdr.len;
m_freem(m);
*m_head = m_new;
return(0);
}
/*
* Main transmit routine. To avoid having to do mbuf copies, we put pointers
* to the mbuf data regions directly in the transmit lists. We also save a
@ -3222,7 +3214,7 @@ dc_start(ifp)
struct ifnet *ifp;
{
struct dc_softc *sc;
struct mbuf *m_head = NULL;
struct mbuf *m_head = NULL, *m;
int idx;
sc = ifp->if_softc;
@ -3249,10 +3241,13 @@ dc_start(ifp)
if (sc->dc_flags & DC_TX_COALESCE &&
(m_head->m_next != NULL ||
sc->dc_flags & DC_TX_ALIGN)) {
if (dc_coal(sc, &m_head)) {
m = m_defrag(m_head, M_DONTWAIT);
if (m == NULL) {
IF_PREPEND(&ifp->if_snd, m_head);
ifp->if_flags |= IFF_OACTIVE;
break;
} else {
m_head = m;
}
}

65
sys/pci/if_dc.c
View file

@ -208,7 +208,6 @@ static void dc_acpi (device_t);
static struct dc_type *dc_devtype (device_t);
static int dc_newbuf (struct dc_softc *, int, struct mbuf *);
static int dc_encap (struct dc_softc *, struct mbuf *, u_int32_t *);
static int dc_coal (struct dc_softc *, struct mbuf **);
static void dc_pnic_rx_bug_war (struct dc_softc *, int);
static int dc_rx_resync (struct dc_softc *);
static void dc_rxeof (struct dc_softc *);
@ -3126,8 +3125,32 @@ dc_encap(sc, m_head, txidx)
{
struct dc_desc *f = NULL;
struct mbuf *m;
int frag, cur, cnt = 0;
int frag, cur, cnt = 0, chainlen = 0;
/*
* If there's no way we can send any packets, return now.
*/
if (DC_TX_LIST_CNT - sc->dc_cdata.dc_tx_cnt < 6)
return (ENOBUFS);
/*
* Count the number of frags in this chain to see if
* we need to m_defrag. Since the descriptor list is shared
* by all packets, we'll m_defrag long chains so that they
* do not use up the entire list, even if they would fit.
*/
for (m = m_head; m != NULL; m = m->m_next)
chainlen++;
if ((chainlen > DC_TX_LIST_CNT / 4) ||
((DC_TX_LIST_CNT - (chainlen + sc->dc_cdata.dc_tx_cnt)) < 6)) {
m = m_defrag(m_head, M_DONTWAIT);
if (m == NULL)
return (ENOBUFS);
m_head = m;
}
/*
* Start packing the mbufs in this chain into
* the fragment pointers. Stop when we run out
@ -3179,37 +3202,6 @@ dc_encap(sc, m_head, txidx)
return(0);
}
/*
* Coalesce an mbuf chain into a single mbuf cluster buffer.
* Needed for some really badly behaved chips that just can't
* do scatter/gather correctly.
*/
static int
dc_coal(sc, m_head)
struct dc_softc *sc;
struct mbuf **m_head;
{
struct mbuf *m_new, *m;
m = *m_head;
MGETHDR(m_new, M_DONTWAIT, MT_DATA);
if (m_new == NULL)
return(ENOBUFS);
if (m->m_pkthdr.len > MHLEN) {
MCLGET(m_new, M_DONTWAIT);
if (!(m_new->m_flags & M_EXT)) {
m_freem(m_new);
return(ENOBUFS);
}
}
m_copydata(m, 0, m->m_pkthdr.len, mtod(m_new, caddr_t));
m_new->m_pkthdr.len = m_new->m_len = m->m_pkthdr.len;
m_freem(m);
*m_head = m_new;
return(0);
}
/*
* Main transmit routine. To avoid having to do mbuf copies, we put pointers
* to the mbuf data regions directly in the transmit lists. We also save a
@ -3222,7 +3214,7 @@ dc_start(ifp)
struct ifnet *ifp;
{
struct dc_softc *sc;
struct mbuf *m_head = NULL;
struct mbuf *m_head = NULL, *m;
int idx;
sc = ifp->if_softc;
@ -3249,10 +3241,13 @@ dc_start(ifp)
if (sc->dc_flags & DC_TX_COALESCE &&
(m_head->m_next != NULL ||
sc->dc_flags & DC_TX_ALIGN)) {
if (dc_coal(sc, &m_head)) {
m = m_defrag(m_head, M_DONTWAIT);
if (m == NULL) {
IF_PREPEND(&ifp->if_snd, m_head);
ifp->if_flags |= IFF_OACTIVE;
break;
} else {
m_head = m;
}
}