git: 04a32b802ec7 - main - if_epair: refactor interface creation and enqueue code.
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Date: Tue, 27 Sep 2022 13:34:57 UTC
The branch main has been updated by melifaro:
URL: https://cgit.FreeBSD.org/src/commit/?id=04a32b802ec718f8b9277f79e9b713d7aa06002c
commit 04a32b802ec718f8b9277f79e9b713d7aa06002c
Author: Alexander V. Chernikov <melifaro@FreeBSD.org>
AuthorDate: 2022-09-27 13:24:29 +0000
Commit: Alexander V. Chernikov <melifaro@FreeBSD.org>
CommitDate: 2022-09-27 13:34:19 +0000
if_epair: refactor interface creation and enqueue code.
* Factor out queue selection (epair_select_queue()) and mbuf
preparation (epair_prepare_mbuf()) from epair_menq(). It simplifies
epair_menq() implementation and reduces the amount of dependencies
on the neighbouring epair.
* Use dedicated epair_set_state() instead of 2-lines copy-paste
* Factor out unit selection code (epair_handle_unit()) from
epair_clone_create(). It simplifies the clone creation logic.
Reviewed By: kp
Differential Revision: https://reviews.freebsd.org/D36689
---
sys/net/if_epair.c | 165 +++++++++++++++++++++++++++++++++--------------------
1 file changed, 102 insertions(+), 63 deletions(-)
diff --git a/sys/net/if_epair.c b/sys/net/if_epair.c
index 6bf7481065cd..04b96ea49ec7 100644
--- a/sys/net/if_epair.c
+++ b/sys/net/if_epair.c
@@ -184,39 +184,13 @@ epair_tx_start_deferred(void *arg, int pending)
if_rele(sc->ifp);
}
-static int
-epair_menq(struct mbuf *m, struct epair_softc *osc)
+static struct epair_queue *
+epair_select_queue(struct epair_softc *sc, const struct mbuf *m)
{
- struct ifnet *ifp, *oifp;
- int len, ret;
- int ridx;
- short mflags;
- struct epair_queue *q = NULL;
uint32_t bucket;
#ifdef RSS
struct ether_header *eh;
-#endif
-
- /*
- * I know this looks weird. We pass the "other sc" as we need that one
- * and can get both ifps from it as well.
- */
- oifp = osc->ifp;
- ifp = osc->oifp;
-
- M_ASSERTPKTHDR(m);
- epair_clear_mbuf(m);
- if_setrcvif(m, oifp);
- M_SETFIB(m, oifp->if_fib);
-
- /* Save values as once the mbuf is queued, it's not ours anymore. */
- len = m->m_pkthdr.len;
- mflags = m->m_flags;
-
- MPASS(m->m_nextpkt == NULL);
- MPASS((m->m_pkthdr.csum_flags & CSUM_SND_TAG) == 0);
-#ifdef RSS
ret = rss_m2bucket(m, &bucket);
if (ret) {
/* Actually hash the packet. */
@@ -238,11 +212,47 @@ epair_menq(struct mbuf *m, struct epair_softc *osc)
break;
}
}
- bucket %= osc->num_queues;
+ bucket %= sc->num_queues;
#else
bucket = 0;
#endif
- q = &osc->queues[bucket];
+ return (&sc->queues[bucket]);
+}
+
+static void
+epair_prepare_mbuf(struct mbuf *m, struct ifnet *src_ifp)
+{
+ M_ASSERTPKTHDR(m);
+ epair_clear_mbuf(m);
+ if_setrcvif(m, src_ifp);
+ M_SETFIB(m, src_ifp->if_fib);
+
+ MPASS(m->m_nextpkt == NULL);
+ MPASS((m->m_pkthdr.csum_flags & CSUM_SND_TAG) == 0);
+}
+
+static void
+epair_menq(struct mbuf *m, struct epair_softc *osc)
+{
+ struct ifnet *ifp, *oifp;
+ int len, ret;
+ int ridx;
+ short mflags;
+
+ /*
+ * I know this looks weird. We pass the "other sc" as we need that one
+ * and can get both ifps from it as well.
+ */
+ oifp = osc->ifp;
+ ifp = osc->oifp;
+
+ epair_prepare_mbuf(m, oifp);
+
+ /* Save values as once the mbuf is queued, it's not ours anymore. */
+ len = m->m_pkthdr.len;
+ mflags = m->m_flags;
+
+ struct epair_queue *q = epair_select_queue(osc, m);
atomic_set_long(&q->state, (1 << BIT_MBUF_QUEUED));
ridx = atomic_load_int(&q->ridx);
@@ -251,7 +261,7 @@ epair_menq(struct mbuf *m, struct epair_softc *osc)
/* Ring is full. */
if_inc_counter(ifp, IFCOUNTER_OQDROPS, 1);
m_freem(m);
- return (0);
+ return;
}
if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
@@ -267,9 +277,7 @@ epair_menq(struct mbuf *m, struct epair_softc *osc)
if_inc_counter(oifp, IFCOUNTER_IPACKETS, 1);
if (!atomic_testandset_long(&q->state, BIT_QUEUE_TASK))
- taskqueue_enqueue(epair_tasks.tq[bucket], &q->tx_task);
-
- return (0);
+ taskqueue_enqueue(epair_tasks.tq[q->id], &q->tx_task);
}
static void
@@ -304,7 +312,7 @@ epair_start(struct ifnet *ifp)
continue;
}
- (void) epair_menq(m, sc);
+ epair_menq(m, sc);
}
}
@@ -313,7 +321,6 @@ epair_transmit(struct ifnet *ifp, struct mbuf *m)
{
struct epair_softc *sc;
struct ifnet *oifp;
- int error;
#ifdef ALTQ
int len;
short mflags;
@@ -358,6 +365,7 @@ epair_transmit(struct ifnet *ifp, struct mbuf *m)
#ifdef ALTQ
len = m->m_pkthdr.len;
mflags = m->m_flags;
+ int error = 0;
/* Support ALTQ via the classic if_start() path. */
IF_LOCK(&ifp->if_snd);
@@ -377,8 +385,8 @@ epair_transmit(struct ifnet *ifp, struct mbuf *m)
IF_UNLOCK(&ifp->if_snd);
#endif
- error = epair_menq(m, oifp->if_softc);
- return (error);
+ epair_menq(m, oifp->if_softc);
+ return (0);
}
static void
@@ -607,15 +615,23 @@ epair_free_sc(struct epair_softc *sc)
free(sc, M_EPAIR);
}
+static void
+epair_set_state(struct ifnet *ifp, bool running)
+{
+ if (running) {
+ ifp->if_drv_flags |= IFF_DRV_RUNNING;
+ if_link_state_change(ifp, LINK_STATE_UP);
+ } else {
+ if_link_state_change(ifp, LINK_STATE_DOWN);
+ ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
+ }
+}
+
static int
-epair_clone_create(struct if_clone *ifc, char *name, size_t len,
- struct ifc_data *ifd, struct ifnet **ifpp)
+epair_handle_unit(struct if_clone *ifc, char *name, size_t len, int *punit)
{
- struct epair_softc *sca, *scb;
- struct ifnet *ifp;
+ int error = 0, unit, wildcard;
char *dp;
- int error, unit, wildcard;
- uint8_t eaddr[ETHER_ADDR_LEN]; /* 00:00:00:00:00:00 */
/* Try to see if a special unit was requested. */
error = ifc_name2unit(name, &unit);
@@ -633,29 +649,55 @@ epair_clone_create(struct if_clone *ifc, char *name, size_t len,
*/
for (dp = name; *dp != '\0'; dp++);
if (wildcard) {
- error = snprintf(dp, len - (dp - name), "%d", unit);
- if (error > len - (dp - name) - 1) {
+ int slen = snprintf(dp, len - (dp - name), "%d", unit);
+ if (slen > len - (dp - name) - 1) {
/* ifName too long. */
- ifc_free_unit(ifc, unit);
- return (ENOSPC);
+ error = ENOSPC;
+ goto done;
}
- dp += error;
+ dp += slen;
}
if (len - (dp - name) - 1 < 1) {
/* No space left for our [ab] suffix. */
- ifc_free_unit(ifc, unit);
- return (ENOSPC);
+ error = ENOSPC;
+ goto done;
}
*dp = 'b';
/* Must not change dp so we can replace 'a' by 'b' later. */
*(dp+1) = '\0';
/* Check if 'a' and 'b' interfaces already exist. */
- if (ifunit(name) != NULL)
- return (EEXIST);
+ if (ifunit(name) != NULL) {
+ error = EEXIST;
+ goto done;
+ }
+
*dp = 'a';
- if (ifunit(name) != NULL)
- return (EEXIST);
+ if (ifunit(name) != NULL) {
+ error = EEXIST;
+ goto done;
+ }
+ *punit = unit;
+done:
+ if (error != 0)
+ ifc_free_unit(ifc, unit);
+
+ return (error);
+}
+
+static int
+epair_clone_create(struct if_clone *ifc, char *name, size_t len,
+ struct ifc_data *ifd, struct ifnet **ifpp)
+{
+ struct epair_softc *sca, *scb;
+ struct ifnet *ifp;
+ char *dp;
+ int error, unit;
+ uint8_t eaddr[ETHER_ADDR_LEN]; /* 00:00:00:00:00:00 */
+
+ error = epair_handle_unit(ifc, name, len, &unit);
+ if (error != 0)
+ return (error);
/* Allocate memory for both [ab] interfaces */
sca = epair_alloc_sc(ifc);
@@ -681,6 +723,7 @@ epair_clone_create(struct if_clone *ifc, char *name, size_t len,
ether_ifattach(ifp, eaddr);
/* Swap the name and finish initialization of interface <n>b. */
+ dp = name + strlen(name) - 1;
*dp = 'b';
epair_setup_ifp(scb, name, unit);
@@ -700,10 +743,8 @@ epair_clone_create(struct if_clone *ifc, char *name, size_t len,
strlcpy(name, sca->ifp->if_xname, len);
/* Tell the world, that we are ready to rock. */
- sca->ifp->if_drv_flags |= IFF_DRV_RUNNING;
- if_link_state_change(sca->ifp, LINK_STATE_UP);
- scb->ifp->if_drv_flags |= IFF_DRV_RUNNING;
- if_link_state_change(scb->ifp, LINK_STATE_UP);
+ epair_set_state(sca->ifp, true);
+ epair_set_state(scb->ifp, true);
*ifpp = sca->ifp;
@@ -750,10 +791,8 @@ epair_clone_destroy(struct if_clone *ifc, struct ifnet *ifp, uint32_t flags)
scb = oifp->if_softc;
/* Frist get the interfaces down and detached. */
- if_link_state_change(ifp, LINK_STATE_DOWN);
- ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
- if_link_state_change(oifp, LINK_STATE_DOWN);
- oifp->if_drv_flags &= ~IFF_DRV_RUNNING;
+ epair_set_state(ifp, false);
+ epair_set_state(oifp, false);
ether_ifdetach(ifp);
ether_ifdetach(oifp);