freebsd-nq/sys/dev/hatm/if_hatm_intr.c
Hartmut Brandt 445b5e54cf Use the default arguments for lockfunc and lockfuncarg in
bus_dma_tag_create. We need to be sure that our packets are
kept in-sequence (that's how ATM is supposed to work) and
therefor use BUS_DMA_NOWAIT in all calls to bus_dmamap_load.

For memory allocated with bus_dmamem_alloc the use of anything
other than NULL arguments for the locking is anyway bogus because
this memory never should need bouncing and hence the load should never
be defered.

Allow the receipt of OAM and RM cells on raw connections. Caveat: it seems
that RM cells are still processed by the hardware even when we open the
connection as UBR.
2003-07-10 13:55:09 +00:00

683 lines
17 KiB
C

/*
* Copyright (c) 2001-2003
* Fraunhofer Institute for Open Communication Systems (FhG Fokus).
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* Author: Hartmut Brandt <harti@freebsd.org>
*
* ForeHE driver.
*
* Interrupt handler.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_natm.h"
#include <sys/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/errno.h>
#include <sys/conf.h>
#include <sys/module.h>
#include <sys/queue.h>
#include <sys/syslog.h>
#include <sys/condvar.h>
#include <sys/sysctl.h>
#include <vm/uma.h>
#include <sys/sockio.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_media.h>
#include <net/if_atm.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/if_atm.h>
#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/bus.h>
#include <sys/rman.h>
#include <pci/pcireg.h>
#include <pci/pcivar.h>
#include <dev/utopia/utopia.h>
#include <dev/hatm/if_hatmconf.h>
#include <dev/hatm/if_hatmreg.h>
#include <dev/hatm/if_hatmvar.h>
CTASSERT(sizeof(struct mbuf_page) == MBUF_ALLOC_SIZE);
CTASSERT(sizeof(struct mbuf0_chunk) == MBUF0_CHUNK);
CTASSERT(sizeof(struct mbuf1_chunk) == MBUF1_CHUNK);
CTASSERT(sizeof(((struct mbuf0_chunk *)NULL)->storage) >= MBUF0_SIZE);
CTASSERT(sizeof(((struct mbuf1_chunk *)NULL)->storage) >= MBUF1_SIZE);
CTASSERT(sizeof(struct tpd) <= HE_TPD_SIZE);
/*
* Either the queue treshold was crossed or a TPD with the INTR bit set
* was transmitted.
*/
static void
he_intr_tbrq(struct hatm_softc *sc, struct hetbrq *q, u_int group)
{
uint32_t *tailp = &sc->hsp->group[group].tbrq_tail;
u_int no;
while (q->head != (*tailp >> 2)) {
no = (q->tbrq[q->head].addr & HE_REGM_TBRQ_ADDR) >>
HE_REGS_TPD_ADDR;
hatm_tx_complete(sc, TPD_ADDR(sc, no),
(q->tbrq[q->head].addr & HE_REGM_TBRQ_FLAGS));
if (++q->head == q->size)
q->head = 0;
}
WRITE4(sc, HE_REGO_TBRQ_H(group), q->head << 2);
}
/*
* DMA loader function for external mbuf page.
*/
static void
hatm_extbuf_helper(void *arg, bus_dma_segment_t *segs, int nsegs,
int error)
{
if (error) {
printf("%s: mapping error %d\n", __func__, error);
return;
}
KASSERT(nsegs == 1,
("too many segments for DMA: %d", nsegs));
KASSERT(segs[0].ds_addr <= 0xffffffffLU,
("phys addr too large %lx", (u_long)segs[0].ds_addr));
*(uint32_t *)arg = segs[0].ds_addr;
}
/*
* Allocate a page of external mbuf storage for the small pools.
* Create a DMA map and load it. Put all the chunks onto the right
* free list.
*/
static void
hatm_mbuf_page_alloc(struct hatm_softc *sc, u_int group)
{
struct mbuf_page *pg;
int err;
u_int i;
if (sc->mbuf_npages == HE_CONFIG_MAX_MBUF_PAGES)
return;
if ((pg = malloc(MBUF_ALLOC_SIZE, M_DEVBUF, M_NOWAIT)) == NULL)
return;
bzero(pg->hdr.card, sizeof(pg->hdr.card));
bzero(pg->hdr.used, sizeof(pg->hdr.used));
err = bus_dmamap_create(sc->mbuf_tag, 0, &pg->hdr.map);
if (err != 0) {
if_printf(&sc->ifatm.ifnet, "%s -- bus_dmamap_create: %d\n",
__func__, err);
free(pg, M_DEVBUF);
return;
}
err = bus_dmamap_load(sc->mbuf_tag, pg->hdr.map, pg, MBUF_ALLOC_SIZE,
hatm_extbuf_helper, &pg->hdr.phys, BUS_DMA_NOWAIT);
if (err != 0) {
if_printf(&sc->ifatm.ifnet, "%s -- mbuf mapping failed %d\n",
__func__, err);
bus_dmamap_destroy(sc->mbuf_tag, pg->hdr.map);
free(pg, M_DEVBUF);
return;
}
sc->mbuf_pages[sc->mbuf_npages] = pg;
if (group == 0) {
struct mbuf0_chunk *c;
pg->hdr.nchunks = MBUF0_PER_PAGE;
pg->hdr.chunksize = MBUF0_CHUNK;
pg->hdr.hdroff = sizeof(c->storage);
c = (struct mbuf0_chunk *)pg;
for (i = 0; i < MBUF0_PER_PAGE; i++, c++) {
c->hdr.pageno = sc->mbuf_npages;
c->hdr.chunkno = i;
SLIST_INSERT_HEAD(&sc->mbuf0_list,
(struct mbufx_free *)c, link);
}
} else {
struct mbuf1_chunk *c;
pg->hdr.nchunks = MBUF1_PER_PAGE;
pg->hdr.chunksize = MBUF1_CHUNK;
pg->hdr.hdroff = sizeof(c->storage);
c = (struct mbuf1_chunk *)pg;
for (i = 0; i < MBUF1_PER_PAGE; i++, c++) {
c->hdr.pageno = sc->mbuf_npages;
c->hdr.chunkno = i;
SLIST_INSERT_HEAD(&sc->mbuf1_list,
(struct mbufx_free *)c, link);
}
}
sc->mbuf_npages++;
}
/*
* Free an mbuf and put it onto the free list.
*/
static void
hatm_mbuf0_free(void *buf, void *args)
{
struct hatm_softc *sc = args;
struct mbuf0_chunk *c = buf;
mtx_lock(&sc->mbuf0_mtx);
SLIST_INSERT_HEAD(&sc->mbuf0_list, (struct mbufx_free *)c, link);
MBUF_CLR_BIT(sc->mbuf_pages[c->hdr.pageno]->hdr.used, c->hdr.chunkno);
mtx_unlock(&sc->mbuf0_mtx);
}
static void
hatm_mbuf1_free(void *buf, void *args)
{
struct hatm_softc *sc = args;
struct mbuf1_chunk *c = buf;
mtx_lock(&sc->mbuf1_mtx);
SLIST_INSERT_HEAD(&sc->mbuf1_list, (struct mbufx_free *)c, link);
MBUF_CLR_BIT(sc->mbuf_pages[c->hdr.pageno]->hdr.used, c->hdr.chunkno);
mtx_unlock(&sc->mbuf1_mtx);
}
/*
* Allocate an external mbuf storage
*/
static int
hatm_mbuf_alloc(struct hatm_softc *sc, u_int group, struct mbuf *m,
uint32_t *phys, uint32_t *handle)
{
struct mbufx_free *cf;
struct mbuf_page *pg;
if (group == 0) {
struct mbuf0_chunk *buf0;
mtx_lock(&sc->mbuf0_mtx);
if ((cf = SLIST_FIRST(&sc->mbuf0_list)) == NULL) {
hatm_mbuf_page_alloc(sc, group);
if ((cf = SLIST_FIRST(&sc->mbuf0_list)) == NULL) {
mtx_unlock(&sc->mbuf0_mtx);
return (0);
}
}
SLIST_REMOVE_HEAD(&sc->mbuf0_list, link);
buf0 = (struct mbuf0_chunk *)cf;
pg = sc->mbuf_pages[buf0->hdr.pageno];
MBUF_SET_BIT(pg->hdr.card, buf0->hdr.chunkno);
mtx_unlock(&sc->mbuf0_mtx);
m_extadd(m, (caddr_t)buf0, MBUF0_SIZE, hatm_mbuf0_free, sc,
M_PKTHDR, EXT_NET_DRV);
m->m_data += MBUF0_OFFSET;
buf0->hdr.mbuf = m;
*handle = MBUF_MAKE_HANDLE(buf0->hdr.pageno, buf0->hdr.chunkno);
} else if (group == 1) {
struct mbuf1_chunk *buf1;
mtx_lock(&sc->mbuf1_mtx);
if ((cf = SLIST_FIRST(&sc->mbuf1_list)) == NULL) {
hatm_mbuf_page_alloc(sc, group);
if ((cf = SLIST_FIRST(&sc->mbuf1_list)) == NULL) {
mtx_unlock(&sc->mbuf1_mtx);
return (0);
}
}
SLIST_REMOVE_HEAD(&sc->mbuf1_list, link);
buf1 = (struct mbuf1_chunk *)cf;
pg = sc->mbuf_pages[buf1->hdr.pageno];
MBUF_SET_BIT(pg->hdr.card, buf1->hdr.chunkno);
mtx_unlock(&sc->mbuf1_mtx);
m_extadd(m, (caddr_t)buf1, MBUF1_SIZE, hatm_mbuf1_free, sc,
M_PKTHDR, EXT_NET_DRV);
m->m_data += MBUF1_OFFSET;
buf1->hdr.mbuf = m;
*handle = MBUF_MAKE_HANDLE(buf1->hdr.pageno, buf1->hdr.chunkno);
} else
return (-1);
*phys = pg->hdr.phys + (mtod(m, char *) - (char *)pg);
bus_dmamap_sync(sc->mbuf_tag, pg->hdr.map, BUS_DMASYNC_PREREAD);
return (0);
}
static void
hatm_mbuf_helper(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
{
uint32_t *ptr = (uint32_t *)arg;
if (nsegs == 0) {
printf("%s: error=%d\n", __func__, error);
return;
}
KASSERT(nsegs == 1, ("too many segments for mbuf: %d", nsegs));
KASSERT(segs[0].ds_addr <= 0xffffffffLU,
("phys addr too large %lx", (u_long)segs[0].ds_addr));
*ptr = segs[0].ds_addr;
}
/*
* Receive buffer pool interrupt. This means the number of entries in the
* queue has dropped below the threshold. Try to supply new buffers.
*/
static void
he_intr_rbp(struct hatm_softc *sc, struct herbp *rbp, u_int large,
u_int group)
{
u_int ntail, upd;
struct mbuf *m;
int error;
DBG(sc, INTR, ("%s buffer supply threshold crossed for group %u",
large ? "large" : "small", group));
rbp->head = (READ4(sc, HE_REGO_RBP_S(large, group)) >> HE_REGS_RBP_HEAD)
& (rbp->size - 1);
upd = 0;
for (;;) {
if ((ntail = rbp->tail + 1) == rbp->size)
ntail = 0;
if (ntail == rbp->head)
break;
/* allocate the MBUF */
if (large) {
if ((m = m_getcl(M_DONTWAIT, MT_DATA,
M_PKTHDR)) == NULL) {
if_printf(&sc->ifatm.ifnet,
"no mbuf clusters\n");
break;
}
m->m_data += MBUFL_OFFSET;
if (sc->lbufs[sc->lbufs_next] != NULL)
panic("hatm: lbufs full %u", sc->lbufs_next);
sc->lbufs[sc->lbufs_next] = m;
if ((error = bus_dmamap_load(sc->mbuf_tag,
sc->rmaps[sc->lbufs_next],
m->m_data, rbp->bsize, hatm_mbuf_helper,
&rbp->rbp[rbp->tail].phys, BUS_DMA_NOWAIT)) != NULL)
panic("hatm: mbuf mapping failed %d", error);
bus_dmamap_sync(sc->mbuf_tag,
sc->rmaps[sc->lbufs_next],
BUS_DMASYNC_PREREAD);
rbp->rbp[rbp->tail].handle = sc->lbufs_next |
MBUF_LARGE_FLAG;
if (++sc->lbufs_next == sc->lbufs_size)
sc->lbufs_next = 0;
} else {
MGETHDR(m, M_DONTWAIT, MT_DATA);
if (m == NULL) {
if_printf(&sc->ifatm.ifnet, "no mbufs\n");
break;
}
if (hatm_mbuf_alloc(sc, group, m,
&rbp->rbp[rbp->tail].phys,
&rbp->rbp[rbp->tail].handle)) {
m_freem(m);
break;
}
}
DBG(sc, DMA, ("MBUF loaded: handle=%x m=%p phys=%x",
rbp->rbp[rbp->tail].handle, m, rbp->rbp[rbp->tail].phys));
rbp->rbp[rbp->tail].handle <<= HE_REGS_RBRQ_ADDR;
rbp->tail = ntail;
upd++;
}
if (upd) {
WRITE4(sc, HE_REGO_RBP_T(large, group),
(rbp->tail << HE_REGS_RBP_TAIL));
}
}
/*
* Extract the buffer and hand it to the receive routine
*/
static struct mbuf *
hatm_rx_buffer(struct hatm_softc *sc, u_int group, u_int handle)
{
u_int pageno;
u_int chunkno;
struct mbuf *m;
if (handle & MBUF_LARGE_FLAG) {
/* large buffer - sync and unload */
handle &= ~MBUF_LARGE_FLAG;
DBG(sc, RX, ("RX large handle=%x", handle));
bus_dmamap_sync(sc->mbuf_tag, sc->rmaps[handle],
BUS_DMASYNC_POSTREAD);
bus_dmamap_unload(sc->mbuf_tag, sc->rmaps[handle]);
m = sc->lbufs[handle];
sc->lbufs[handle] = NULL;
return (m);
}
MBUF_PARSE_HANDLE(handle, pageno, chunkno);
DBG(sc, RX, ("RX group=%u handle=%x page=%u chunk=%u", group, handle,
pageno, chunkno));
if (group == 0) {
struct mbuf0_chunk *c0;
c0 = (struct mbuf0_chunk *)sc->mbuf_pages[pageno] + chunkno;
KASSERT(c0->hdr.pageno == pageno, ("pageno = %u/%u",
c0->hdr.pageno, pageno));
KASSERT(c0->hdr.chunkno == chunkno, ("chunkno = %u/%u",
c0->hdr.chunkno, chunkno));
m = c0->hdr.mbuf;
} else {
struct mbuf1_chunk *c1;
c1 = (struct mbuf1_chunk *)sc->mbuf_pages[pageno] + chunkno;
KASSERT(c1->hdr.pageno == pageno, ("pageno = %u/%u",
c1->hdr.pageno, pageno));
KASSERT(c1->hdr.chunkno == chunkno, ("chunkno = %u/%u",
c1->hdr.chunkno, chunkno));
m = c1->hdr.mbuf;
}
MBUF_CLR_BIT(sc->mbuf_pages[pageno]->hdr.card, chunkno);
MBUF_SET_BIT(sc->mbuf_pages[pageno]->hdr.used, chunkno);
bus_dmamap_sync(sc->mbuf_tag, sc->mbuf_pages[pageno]->hdr.map,
BUS_DMASYNC_POSTREAD);
return (m);
}
/*
* Interrupt because of receive buffer returned.
*/
static void
he_intr_rbrq(struct hatm_softc *sc, struct herbrq *rq, u_int group)
{
struct he_rbrqen *e;
uint32_t flags, tail;
u_int cid, len;
struct mbuf *m;
for (;;) {
tail = sc->hsp->group[group].rbrq_tail >> 3;
if (rq->head == tail)
break;
e = &rq->rbrq[rq->head];
flags = e->addr & HE_REGM_RBRQ_FLAGS;
if (!(flags & HE_REGM_RBRQ_HBUF_ERROR))
m = hatm_rx_buffer(sc, group,
(e->addr & HE_REGM_RBRQ_ADDR) >> HE_REGS_RBRQ_ADDR);
else
m = NULL;
cid = (e->len & HE_REGM_RBRQ_CID) >> HE_REGS_RBRQ_CID;
len = 4 * (e->len & HE_REGM_RBRQ_LEN);
hatm_rx(sc, cid, flags, m, len);
if (++rq->head == rq->size)
rq->head = 0;
}
WRITE4(sc, HE_REGO_RBRQ_H(group), rq->head << 3);
}
void
hatm_intr(void *p)
{
struct heirq *q = p;
struct hatm_softc *sc = q->sc;
u_int status;
u_int tail;
/* if we have a stray interrupt with a non-initialized card,
* we cannot even lock before looking at the flag */
if (!(sc->ifatm.ifnet.if_flags & IFF_RUNNING))
return;
mtx_lock(&sc->mtx);
(void)READ4(sc, HE_REGO_INT_FIFO);
tail = *q->tailp;
if (q->head == tail) {
/* workaround for tail pointer not updated bug (8.1.1) */
DBG(sc, INTR, ("hatm: intr tailq not updated bug triggered"));
/* read the tail pointer from the card */
tail = READ4(sc, HE_REGO_IRQ_BASE(q->group)) &
HE_REGM_IRQ_BASE_TAIL;
BARRIER_R(sc);
sc->istats.bug_no_irq_upd++;
}
/* clear the interrupt */
WRITE4(sc, HE_REGO_INT_FIFO, HE_REGM_INT_FIFO_CLRA);
BARRIER_W(sc);
while (q->head != tail) {
status = q->irq[q->head];
q->irq[q->head] = HE_REGM_ITYPE_INVALID;
if (++q->head == (q->size - 1))
q->head = 0;
switch (status & HE_REGM_ITYPE) {
case HE_REGM_ITYPE_TBRQ:
DBG(sc, INTR, ("TBRQ treshold %u", status & HE_REGM_IGROUP));
sc->istats.itype_tbrq++;
he_intr_tbrq(sc, &sc->tbrq, status & HE_REGM_IGROUP);
break;
case HE_REGM_ITYPE_TPD:
DBG(sc, INTR, ("TPD ready %u", status & HE_REGM_IGROUP));
sc->istats.itype_tpd++;
he_intr_tbrq(sc, &sc->tbrq, status & HE_REGM_IGROUP);
break;
case HE_REGM_ITYPE_RBPS:
sc->istats.itype_rbps++;
switch (status & HE_REGM_IGROUP) {
case 0:
he_intr_rbp(sc, &sc->rbp_s0, 0, 0);
break;
case 1:
he_intr_rbp(sc, &sc->rbp_s1, 0, 1);
break;
default:
if_printf(&sc->ifatm.ifnet, "bad INTR RBPS%u\n",
status & HE_REGM_IGROUP);
break;
}
break;
case HE_REGM_ITYPE_RBPL:
sc->istats.itype_rbpl++;
switch (status & HE_REGM_IGROUP) {
case 0:
he_intr_rbp(sc, &sc->rbp_l0, 1, 0);
break;
default:
if_printf(&sc->ifatm.ifnet, "bad INTR RBPL%u\n",
status & HE_REGM_IGROUP);
break;
}
break;
case HE_REGM_ITYPE_RBRQ:
DBG(sc, INTR, ("INTERRUPT RBRQ %u", status & HE_REGM_IGROUP));
sc->istats.itype_rbrq++;
switch (status & HE_REGM_IGROUP) {
case 0:
he_intr_rbrq(sc, &sc->rbrq_0, 0);
break;
case 1:
if (sc->rbrq_1.size > 0) {
he_intr_rbrq(sc, &sc->rbrq_1, 1);
break;
}
/* FALLTHRU */
default:
if_printf(&sc->ifatm.ifnet, "bad INTR RBRQ%u\n",
status & HE_REGM_IGROUP);
break;
}
break;
case HE_REGM_ITYPE_RBRQT:
DBG(sc, INTR, ("INTERRUPT RBRQT %u", status & HE_REGM_IGROUP));
sc->istats.itype_rbrqt++;
switch (status & HE_REGM_IGROUP) {
case 0:
he_intr_rbrq(sc, &sc->rbrq_0, 0);
break;
case 1:
if (sc->rbrq_1.size > 0) {
he_intr_rbrq(sc, &sc->rbrq_1, 1);
break;
}
/* FALLTHRU */
default:
if_printf(&sc->ifatm.ifnet, "bad INTR RBRQT%u\n",
status & HE_REGM_IGROUP);
break;
}
break;
case HE_REGM_ITYPE_PHYS:
sc->istats.itype_phys++;
utopia_intr(&sc->utopia);
break;
#if HE_REGM_ITYPE_UNKNOWN != HE_REGM_ITYPE_INVALID
case HE_REGM_ITYPE_UNKNOWN:
sc->istats.itype_unknown++;
if_printf(&sc->ifatm.ifnet, "bad interrupt\n");
break;
#endif
case HE_REGM_ITYPE_ERR:
sc->istats.itype_err++;
switch (status) {
case HE_REGM_ITYPE_PERR:
if_printf(&sc->ifatm.ifnet, "parity error\n");
break;
case HE_REGM_ITYPE_ABORT:
if_printf(&sc->ifatm.ifnet, "abort interrupt "
"addr=0x%08x\n",
READ4(sc, HE_REGO_ABORT_ADDR));
break;
default:
if_printf(&sc->ifatm.ifnet,
"bad interrupt type %08x\n", status);
break;
}
break;
case HE_REGM_ITYPE_INVALID:
/* this is the documented fix for the ISW bug 8.1.1
* Note, that the documented fix is partly wrong:
* the ISWs should be intialized to 0xf8 not 0xff */
sc->istats.bug_bad_isw++;
DBG(sc, INTR, ("hatm: invalid ISW bug triggered"));
he_intr_tbrq(sc, &sc->tbrq, 0);
he_intr_rbp(sc, &sc->rbp_s0, 0, 0);
he_intr_rbp(sc, &sc->rbp_l0, 1, 0);
he_intr_rbp(sc, &sc->rbp_s1, 0, 1);
he_intr_rbrq(sc, &sc->rbrq_0, 0);
he_intr_rbrq(sc, &sc->rbrq_1, 1);
utopia_intr(&sc->utopia);
break;
default:
if_printf(&sc->ifatm.ifnet, "bad interrupt type %08x\n",
status);
break;
}
}
/* write back head to clear queue */
WRITE4(sc, HE_REGO_IRQ_HEAD(0),
((q->size - 1) << HE_REGS_IRQ_HEAD_SIZE) |
(q->thresh << HE_REGS_IRQ_HEAD_THRESH) |
(q->head << HE_REGS_IRQ_HEAD_HEAD));
BARRIER_W(sc);
/* workaround the back-to-back irq access problem (8.1.2) */
(void)READ4(sc, HE_REGO_INT_FIFO);
BARRIER_R(sc);
mtx_unlock(&sc->mtx);
}