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freebsd/sys/dev/usb/usb_ethersubr.c
Jonathan Lemon df5e198723 Lock down the network interface queues. The queue mutex must be obtained
before adding/removing packets from the queue.  Also, the if_obytes and
if_omcasts fields should only be manipulated under protection of the mutex.

IF_ENQUEUE, IF_PREPEND, and IF_DEQUEUE perform all necessary locking on
the queue.  An IF_LOCK macro is provided, as well as the old (mutex-less)
versions of the macros in the form _IF_ENQUEUE, _IF_QFULL, for code which
needs them, but their use is discouraged.

Two new macros are introduced: IF_DRAIN() to drain a queue, and IF_HANDOFF,
which takes care of locking/enqueue, and also statistics updating/start
if necessary.
2000-11-25 07:35:38 +00:00

152 lines
4.4 KiB
C

/*
* Copyright (c) 1997, 1998, 1999, 2000
* Bill Paul <wpaul@ee.columbia.edu>. 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Bill Paul.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY Bill Paul 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 Bill Paul OR THE VOICES IN HIS HEAD
* 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.
*
* $FreeBSD$
*/
/*
* Callbacks in the USB code operate at splusb() (actually splbio()
* in FreeBSD). However adding packets to the input queues has to be
* done at splimp(). It is conceivable that this arrangement could
* trigger a condition where the splimp() is ignored and the input
* queues could get trampled in spite of our best effors to prevent
* it. To work around this, we implement a special input queue for
* USB ethernet adapter drivers. Rather than passing the frames directly
* to ether_input(), we pass them here, then schedule a soft interrupt
* to hand them to ether_input() later, outside of the USB interrupt
* context.
*
* It's questional as to whether this code should be expanded to
* handle other kinds of devices, or handle USB transfer callbacks
* in general. Right now, I need USB network interfaces to work
* properly.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sockio.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/if_arp.h>
#include <net/ethernet.h>
#include <net/netisr.h>
#include <net/bpf.h>
#include <dev/usb/usb.h>
#include <dev/usb/usb_ethersubr.h>
#ifndef lint
Static const char rcsid[] =
"$FreeBSD$";
#endif
Static struct ifqueue usbq_rx;
Static struct ifqueue usbq_tx;
Static int mtx_inited = 0;
Static void usbintr __P((void));
Static void usbintr()
{
struct ether_header *eh;
struct mbuf *m;
struct usb_qdat *q;
struct ifnet *ifp;
/* Check the RX queue */
while(1) {
IF_DEQUEUE(&usbq_rx, m);
if (m == NULL)
break;
eh = mtod(m, struct ether_header *);
q = (struct usb_qdat *)m->m_pkthdr.rcvif;
ifp = q->ifp;
m->m_pkthdr.rcvif = ifp;
m_adj(m, sizeof(struct ether_header));
ether_input(ifp, eh, m);
/* Re-arm the receiver */
(*q->if_rxstart)(ifp);
if (ifp->if_snd.ifq_head != NULL)
(*ifp->if_start)(ifp);
}
/* Check the TX queue */
while(1) {
IF_DEQUEUE(&usbq_tx, m);
if (m == NULL)
break;
ifp = m->m_pkthdr.rcvif;
m_freem(m);
if (ifp->if_snd.ifq_head != NULL)
(*ifp->if_start)(ifp);
}
return;
}
void usb_register_netisr()
{
if (mtx_inited)
return;
register_netisr(NETISR_USB, usbintr);
mtx_init(&usbq_tx.ifq_mtx, "usbq_tx_mtx", MTX_DEF);
mtx_init(&usbq_rx.ifq_mtx, "usbq_rx_mtx", MTX_DEF);
mtx_inited++;
return;
}
/*
* Must be called at splusp() (actually splbio()). This should be
* the case when called from a transfer callback routine.
*/
void usb_ether_input(m)
struct mbuf *m;
{
IF_ENQUEUE(&usbq_rx, m);
schednetisr(NETISR_USB);
return;
}
void usb_tx_done(m)
struct mbuf *m;
{
IF_ENQUEUE(&usbq_tx, m);
schednetisr(NETISR_USB);
return;
}