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* fix off-by-wrap case where current datagram aligns exactly with 

the end of the bus
* clarify the "can we still use the device's next pointer" calculation
  and move it to its own routine
* sprinkle dprintf
This commit is contained in:
pooka 2010-08-17 11:35:23 +00:00
parent 6846d4aa28
commit 86ea9bb1a9
2 changed files with 74 additions and 39 deletions
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85
sys/rump/net/lib/libshmif/if_shmem.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: if_shmem.c,v 1.26 2010/08/16 17:33:52 pooka Exp $ */
/* $NetBSD: if_shmem.c,v 1.27 2010/08/17 11:35:23 pooka Exp $ */
/*
* Copyright (c) 2009 Antti Kantee. All Rights Reserved.
@ -28,7 +28,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: if_shmem.c,v 1.26 2010/08/16 17:33:52 pooka Exp $");
__KERNEL_RCSID(0, "$NetBSD: if_shmem.c,v 1.27 2010/08/17 11:35:23 pooka Exp $");
#include <sys/param.h>
#include <sys/atomic.h>
@ -267,16 +267,17 @@ shmif_start(struct ifnet *ifp)
mtod(m, void *), m->m_len, &wrap);
}
KASSERT(pktwrote == pktsize);
if (wrap)
if (wrap) {
busmem->shm_gen++;
DPRINTF(("bus generation now %d\n", busmem->shm_gen));
}
shmif_unlockbus(busmem);
m_freem(m0);
wrote = true;
DPRINTF(("shmif_start: send %d bytes at off %d\n",
pktsize, npktlenoff));
pktsize, busmem->shm_last));
}
ifp->if_flags &= ~IFF_OACTIVE;
@ -294,6 +295,44 @@ shmif_stop(struct ifnet *ifp, int disable)
panic("%s: unimpl", __func__);
}
/*
* Check if we have been sleeping too long. Basically,
* our in-sc nextpkt must by first <= nextpkt <= last"+1".
* We use the fact that first is guaranteed to never overlap
* with the last frame in the ring.
*/
static __inline bool
stillvalid_p(struct shmif_sc *sc)
{
struct shmif_mem *busmem = sc->sc_busmem;
unsigned gendiff = busmem->shm_gen - sc->sc_devgen;
uint32_t lastoff, devoff;
KASSERT(busmem->shm_first != busmem->shm_last);
/* normalize onto a 2x busmem chunk */
devoff = sc->sc_nextpacket;
lastoff = shmif_nextpktoff(busmem, busmem->shm_last);
/* trivial case */
if (gendiff > 1)
return false;
KASSERT(gendiff <= 1);
/* Normalize onto 2x busmem chunk */
if (busmem->shm_first >= lastoff) {
lastoff += BUSMEM_DATASIZE;
if (gendiff == 0)
devoff += BUSMEM_DATASIZE;
} else {
if (gendiff)
return false;
}
return devoff >= busmem->shm_first && devoff <= lastoff;
}
static void
shmif_rcv(void *arg)
{
@ -302,7 +341,7 @@ shmif_rcv(void *arg)
struct shmif_mem *busmem = sc->sc_busmem;
struct mbuf *m = NULL;
struct ether_header *eth;
uint32_t nextpkt, busgen;
uint32_t nextpkt;
bool wrap;
int error;
@ -318,12 +357,11 @@ shmif_rcv(void *arg)
KASSERT(m->m_flags & M_EXT);
shmif_lockbus(busmem);
busgen = busmem->shm_gen;
KASSERT(busmem->shm_magic == SHMIF_MAGIC);
KASSERT(busgen >= sc->sc_devgen);
KASSERT(busmem->shm_gen >= sc->sc_devgen);
/* need more data? */
if (sc->sc_devgen == busgen &&
if (sc->sc_devgen == busmem->shm_gen &&
shmif_nextpktoff(busmem, busmem->shm_last)
== sc->sc_nextpacket) {
shmif_unlockbus(busmem);
@ -334,23 +372,17 @@ shmif_rcv(void *arg)
continue;
}
/*
* Check if we have been sleeping too long. There are
* basically two scenarios:
* 1) our next packet is behind the first packet and
* we are a generation behind
* 2) we are over two generations behind
*/
if ((sc->sc_nextpacket < busmem->shm_first
&& sc->sc_devgen < busgen) || (sc->sc_devgen+1 < busgen)) {
KASSERT(busgen > 0);
if (stillvalid_p(sc)) {
nextpkt = sc->sc_nextpacket;
} else {
KASSERT(busmem->shm_gen > 0);
nextpkt = busmem->shm_first;
if (busmem->shm_first > busmem->shm_last)
sc->sc_devgen = busgen - 1;
sc->sc_devgen = busmem->shm_gen - 1;
else
sc->sc_devgen = busgen;
} else {
nextpkt = sc->sc_nextpacket;
sc->sc_devgen = busmem->shm_gen;
DPRINTF(("dev %p overrun, new data: %d/%d\n",
sc, nextpkt, sc->sc_devgen));
}
/*
@ -358,7 +390,7 @@ shmif_rcv(void *arg)
* generation must be one behind.
*/
KASSERT(!(nextpkt > busmem->shm_last
&& sc->sc_devgen == busgen));
&& sc->sc_devgen == busmem->shm_gen));
wrap = false;
nextpkt = shmif_busread(busmem, &sp,
@ -373,8 +405,11 @@ shmif_rcv(void *arg)
sc->sc_nextpacket = nextpkt;
shmif_unlockbus(sc->sc_busmem);
if (wrap)
if (wrap) {
sc->sc_devgen++;
DPRINTF(("dev %p generation now %d\n",
sc, sc->sc_devgen));
}
m->m_len = m->m_pkthdr.len = sp.sp_len;
m->m_pkthdr.rcvif = ifp;

28
sys/rump/net/lib/libshmif/shmif_busops.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: shmif_busops.c,v 1.5 2010/08/16 17:33:52 pooka Exp $ */
/* $NetBSD: shmif_busops.c,v 1.6 2010/08/17 11:35:23 pooka Exp $ */
/*
* Copyright (c) 2009 Antti Kantee. All Rights Reserved.
@ -28,7 +28,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: shmif_busops.c,v 1.5 2010/08/16 17:33:52 pooka Exp $");
__KERNEL_RCSID(0, "$NetBSD: shmif_busops.c,v 1.6 2010/08/17 11:35:23 pooka Exp $");
#include <sys/param.h>
#include <sys/atomic.h>
@ -64,11 +64,12 @@ shmif_busread(struct shmif_mem *busmem, void *dest, uint32_t off, size_t len,
memcpy(dest, busmem->shm_data + off, chunk);
len -= chunk;
if (len == 0)
return off + chunk;
if (off + chunk == BUSMEM_DATASIZE)
*wrap = true;
/* else, wraps around */
*wrap = true;
if (len == 0) {
return (off + chunk) % BUSMEM_DATASIZE;
}
/* finish reading */
memcpy((uint8_t *)dest + chunk, busmem->shm_data, len);
@ -104,22 +105,21 @@ shmif_buswrite(struct shmif_mem *busmem, uint32_t off, void *data, size_t len,
DPRINTF(("buswrite: wrote %d bytes to %d", chunk, off));
if (off + chunk == BUSMEM_DATASIZE)
*wrap = true;
if (len == 0) {
DPRINTF(("\n"));
return off + chunk;
return (off + chunk) % BUSMEM_DATASIZE;
}
DPRINTF((", wrapped bytes %d to 0\n", len));
/* else, wraps around */
off = 0;
*wrap = true;
shmif_advancefirst(busmem, off, len);
shmif_advancefirst(busmem, 0, len);
/* finish writing */
memcpy(busmem->shm_data + off, (uint8_t *)data + chunk, len);
return off + len;
memcpy(busmem->shm_data, (uint8_t *)data + chunk, len);
return len;
}
uint32_t