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if_shmem.c revision 1.40
      1  1.40  rmind /*	$NetBSD: if_shmem.c,v 1.40 2011/08/07 14:03:16 rmind Exp $	*/
      2   1.1  pooka 
      3   1.1  pooka /*
      4  1.39  pooka  * Copyright (c) 2009, 2010 Antti Kantee.  All Rights Reserved.
      5   1.1  pooka  *
      6   1.1  pooka  * Development of this software was supported by The Nokia Foundation.
      7   1.1  pooka  *
      8   1.1  pooka  * Redistribution and use in source and binary forms, with or without
      9   1.1  pooka  * modification, are permitted provided that the following conditions
     10   1.1  pooka  * are met:
     11   1.1  pooka  * 1. Redistributions of source code must retain the above copyright
     12   1.1  pooka  *    notice, this list of conditions and the following disclaimer.
     13   1.1  pooka  * 2. Redistributions in binary form must reproduce the above copyright
     14   1.1  pooka  *    notice, this list of conditions and the following disclaimer in the
     15   1.1  pooka  *    documentation and/or other materials provided with the distribution.
     16   1.1  pooka  *
     17   1.1  pooka  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
     18   1.1  pooka  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     19   1.1  pooka  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     20   1.1  pooka  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     21   1.1  pooka  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     22   1.1  pooka  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     23   1.1  pooka  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     24   1.1  pooka  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     25   1.1  pooka  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     26   1.1  pooka  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     27   1.1  pooka  * SUCH DAMAGE.
     28   1.1  pooka  */
     29   1.1  pooka 
     30   1.1  pooka #include <sys/cdefs.h>
     31  1.40  rmind __KERNEL_RCSID(0, "$NetBSD: if_shmem.c,v 1.40 2011/08/07 14:03:16 rmind Exp $");
     32   1.1  pooka 
     33   1.1  pooka #include <sys/param.h>
     34  1.13  pooka #include <sys/atomic.h>
     35   1.1  pooka #include <sys/fcntl.h>
     36   1.1  pooka #include <sys/kmem.h>
     37   1.1  pooka #include <sys/kthread.h>
     38   1.1  pooka #include <sys/lock.h>
     39  1.31  pooka #include <sys/vmem.h>
     40   1.1  pooka 
     41  1.35  pooka #include <net/bpf.h>
     42   1.1  pooka #include <net/if.h>
     43  1.37  pooka #include <net/if_dl.h>
     44   1.1  pooka #include <net/if_ether.h>
     45   1.1  pooka 
     46   1.1  pooka #include <netinet/in.h>
     47   1.1  pooka #include <netinet/in_var.h>
     48   1.1  pooka 
     49   1.1  pooka #include <rump/rump.h>
     50   1.1  pooka #include <rump/rumpuser.h>
     51   1.1  pooka 
     52   1.1  pooka #include "rump_private.h"
     53   1.9  pooka #include "rump_net_private.h"
     54   1.1  pooka 
     55  1.29  pooka static int shmif_clone(struct if_clone *, int);
     56  1.29  pooka static int shmif_unclone(struct ifnet *);
     57  1.29  pooka 
     58  1.29  pooka struct if_clone shmif_cloner =
     59  1.29  pooka     IF_CLONE_INITIALIZER("shmif", shmif_clone, shmif_unclone);
     60  1.29  pooka 
     61   1.1  pooka /*
     62  1.28  pooka  * Do r/w prefault for backend pages when attaching the interface.
     63  1.29  pooka  * At least logically thinking improves performance (although no
     64  1.29  pooka  * mlocking is done, so they might go away).
     65  1.28  pooka  */
     66  1.28  pooka #define PREFAULT_RW
     67  1.28  pooka 
     68  1.28  pooka /*
     69   1.1  pooka  * A virtual ethernet interface which uses shared memory from a
     70   1.1  pooka  * memory mapped file as the bus.
     71   1.1  pooka  */
     72   1.1  pooka 
     73   1.1  pooka static int	shmif_init(struct ifnet *);
     74   1.1  pooka static int	shmif_ioctl(struct ifnet *, u_long, void *);
     75   1.1  pooka static void	shmif_start(struct ifnet *);
     76   1.1  pooka static void	shmif_stop(struct ifnet *, int);
     77   1.1  pooka 
     78  1.16  pooka #include "shmifvar.h"
     79  1.16  pooka 
     80   1.1  pooka struct shmif_sc {
     81   1.1  pooka 	struct ethercom sc_ec;
     82  1.16  pooka 	struct shmif_mem *sc_busmem;
     83   1.1  pooka 	int sc_memfd;
     84   1.1  pooka 	int sc_kq;
     85  1.32  pooka 	int sc_unit;
     86   1.1  pooka 
     87  1.29  pooka 	char *sc_backfile;
     88  1.29  pooka 	size_t sc_backfilelen;
     89  1.29  pooka 
     90  1.26  pooka 	uint64_t sc_devgen;
     91   1.1  pooka 	uint32_t sc_nextpacket;
     92  1.32  pooka 
     93  1.32  pooka 	kmutex_t sc_mtx;
     94  1.32  pooka 	kcondvar_t sc_cv;
     95  1.32  pooka 
     96  1.32  pooka 	struct lwp *sc_rcvl;
     97  1.32  pooka 	bool sc_dying;
     98   1.1  pooka };
     99   1.1  pooka 
    100  1.17  pooka static const uint32_t busversion = SHMIF_VERSION;
    101   1.1  pooka 
    102   1.1  pooka static void shmif_rcv(void *);
    103   1.1  pooka 
    104  1.23  pooka #define LOCK_UNLOCKED	0
    105  1.23  pooka #define LOCK_LOCKED	1
    106  1.23  pooka #define LOCK_COOLDOWN	1001
    107  1.23  pooka 
    108  1.31  pooka vmem_t *shmif_units;
    109  1.31  pooka 
    110  1.23  pooka /*
    111  1.23  pooka  * This locking needs work and will misbehave severely if:
    112  1.23  pooka  * 1) the backing memory has to be paged in
    113  1.23  pooka  * 2) some lockholder exits while holding the lock
    114  1.23  pooka  */
    115  1.23  pooka static void
    116  1.23  pooka shmif_lockbus(struct shmif_mem *busmem)
    117  1.23  pooka {
    118  1.23  pooka 	int i = 0;
    119  1.23  pooka 
    120  1.23  pooka 	while (__predict_false(atomic_cas_32(&busmem->shm_lock,
    121  1.23  pooka 	    LOCK_UNLOCKED, LOCK_LOCKED) == LOCK_LOCKED)) {
    122  1.23  pooka 		if (__predict_false(++i > LOCK_COOLDOWN)) {
    123  1.23  pooka 			uint64_t sec, nsec;
    124  1.23  pooka 			int error;
    125  1.23  pooka 
    126  1.23  pooka 			sec = 0;
    127  1.23  pooka 			nsec = 1000*1000; /* 1ms */
    128  1.23  pooka 			rumpuser_nanosleep(&sec, &nsec, &error);
    129  1.23  pooka 			i = 0;
    130  1.23  pooka 		}
    131  1.23  pooka 		continue;
    132  1.23  pooka 	}
    133  1.23  pooka 	membar_enter();
    134  1.23  pooka }
    135  1.23  pooka 
    136  1.23  pooka static void
    137  1.23  pooka shmif_unlockbus(struct shmif_mem *busmem)
    138  1.23  pooka {
    139  1.23  pooka 	unsigned int old;
    140  1.23  pooka 
    141  1.23  pooka 	membar_exit();
    142  1.23  pooka 	old = atomic_swap_32(&busmem->shm_lock, LOCK_UNLOCKED);
    143  1.23  pooka 	KASSERT(old == LOCK_LOCKED);
    144  1.23  pooka }
    145  1.23  pooka 
    146  1.29  pooka static int
    147  1.29  pooka allocif(int unit, struct shmif_sc **scp)
    148   1.1  pooka {
    149  1.29  pooka 	uint8_t enaddr[ETHER_ADDR_LEN] = { 0xb2, 0xa0, 0x00, 0x00, 0x00, 0x00 };
    150   1.1  pooka 	struct shmif_sc *sc;
    151   1.1  pooka 	struct ifnet *ifp;
    152   1.1  pooka 	uint32_t randnum;
    153  1.32  pooka 	int error;
    154   1.1  pooka 
    155   1.1  pooka 	randnum = arc4random();
    156  1.15  pooka 	memcpy(&enaddr[2], &randnum, sizeof(randnum));
    157   1.1  pooka 
    158   1.1  pooka 	sc = kmem_zalloc(sizeof(*sc), KM_SLEEP);
    159  1.29  pooka 	sc->sc_memfd = -1;
    160  1.32  pooka 	sc->sc_unit = unit;
    161  1.29  pooka 
    162   1.1  pooka 	ifp = &sc->sc_ec.ec_if;
    163   1.1  pooka 
    164  1.32  pooka 	sprintf(ifp->if_xname, "shmif%d", unit);
    165  1.29  pooka 	ifp->if_softc = sc;
    166  1.29  pooka 	ifp->if_flags = IFF_BROADCAST | IFF_MULTICAST;
    167  1.29  pooka 	ifp->if_init = shmif_init;
    168  1.29  pooka 	ifp->if_ioctl = shmif_ioctl;
    169  1.29  pooka 	ifp->if_start = shmif_start;
    170  1.29  pooka 	ifp->if_stop = shmif_stop;
    171  1.29  pooka 	ifp->if_mtu = ETHERMTU;
    172  1.37  pooka 	ifp->if_dlt = DLT_EN10MB;
    173  1.29  pooka 
    174  1.32  pooka 	mutex_init(&sc->sc_mtx, MUTEX_DEFAULT, IPL_NONE);
    175  1.32  pooka 	cv_init(&sc->sc_cv, "shmifcv");
    176  1.32  pooka 
    177  1.29  pooka 	if_attach(ifp);
    178  1.29  pooka 	ether_ifattach(ifp, enaddr);
    179  1.29  pooka 
    180  1.29  pooka 	aprint_verbose("shmif%d: Ethernet address %s\n",
    181  1.32  pooka 	    unit, ether_sprintf(enaddr));
    182  1.29  pooka 
    183  1.29  pooka 	if (scp)
    184  1.29  pooka 		*scp = sc;
    185  1.29  pooka 
    186  1.32  pooka 	error = 0;
    187  1.32  pooka 	if (rump_threads) {
    188  1.32  pooka 		error = kthread_create(PRI_NONE,
    189  1.40  rmind 		    KTHREAD_MPSAFE | KTHREAD_MUSTJOIN, NULL,
    190  1.32  pooka 		    shmif_rcv, ifp, &sc->sc_rcvl, "shmif");
    191  1.32  pooka 	} else {
    192  1.32  pooka 		printf("WARNING: threads not enabled, shmif NOT working\n");
    193  1.32  pooka 	}
    194  1.32  pooka 
    195  1.32  pooka 	if (error) {
    196  1.32  pooka 		shmif_unclone(ifp);
    197  1.32  pooka 	}
    198  1.32  pooka 
    199  1.32  pooka 	return error;
    200  1.29  pooka }
    201  1.29  pooka 
    202  1.29  pooka static int
    203  1.29  pooka initbackend(struct shmif_sc *sc, int memfd)
    204  1.29  pooka {
    205  1.29  pooka 	volatile uint8_t v;
    206  1.29  pooka 	volatile uint8_t *p;
    207  1.29  pooka 	int error;
    208  1.29  pooka 
    209  1.29  pooka 	sc->sc_busmem = rumpuser_filemmap(memfd, 0, BUSMEM_SIZE,
    210   1.5  pooka 	    RUMPUSER_FILEMMAP_TRUNCATE | RUMPUSER_FILEMMAP_SHARED
    211   1.5  pooka 	    | RUMPUSER_FILEMMAP_READ | RUMPUSER_FILEMMAP_WRITE, &error);
    212   1.1  pooka 	if (error)
    213  1.29  pooka 		return error;
    214  1.17  pooka 
    215  1.29  pooka 	if (sc->sc_busmem->shm_magic
    216  1.29  pooka 	    && sc->sc_busmem->shm_magic != SHMIF_MAGIC) {
    217  1.29  pooka 		printf("bus is not magical");
    218  1.29  pooka 		rumpuser_unmap(sc->sc_busmem, BUSMEM_SIZE);
    219  1.29  pooka 		return ENOEXEC;
    220  1.29  pooka 	}
    221  1.28  pooka 
    222  1.36  pooka 	/*
    223  1.36  pooka 	 * Prefault in pages to minimize runtime penalty with buslock.
    224  1.36  pooka 	 * Use 512 instead of PAGE_SIZE to make sure we catch cases where
    225  1.36  pooka 	 * rump kernel PAGE_SIZE > host page size.
    226  1.36  pooka 	 */
    227  1.28  pooka 	for (p = (uint8_t *)sc->sc_busmem;
    228  1.28  pooka 	    p < (uint8_t *)sc->sc_busmem + BUSMEM_SIZE;
    229  1.36  pooka 	    p += 512)
    230  1.28  pooka 		v = *p;
    231  1.28  pooka 
    232  1.19  pooka 	shmif_lockbus(sc->sc_busmem);
    233  1.19  pooka 	/* we're first?  initialize bus */
    234  1.19  pooka 	if (sc->sc_busmem->shm_magic == 0) {
    235  1.19  pooka 		sc->sc_busmem->shm_magic = SHMIF_MAGIC;
    236  1.19  pooka 		sc->sc_busmem->shm_first = BUSMEM_DATASIZE;
    237  1.19  pooka 	}
    238  1.19  pooka 
    239  1.16  pooka 	sc->sc_nextpacket = sc->sc_busmem->shm_last;
    240  1.26  pooka 	sc->sc_devgen = sc->sc_busmem->shm_gen;
    241  1.28  pooka 
    242  1.28  pooka #ifdef PREFAULT_RW
    243  1.28  pooka 	for (p = (uint8_t *)sc->sc_busmem;
    244  1.28  pooka 	    p < (uint8_t *)sc->sc_busmem + BUSMEM_SIZE;
    245  1.28  pooka 	    p += PAGE_SIZE) {
    246  1.28  pooka 		v = *p;
    247  1.28  pooka 		*p = v;
    248  1.28  pooka 	}
    249  1.28  pooka #endif
    250  1.19  pooka 	shmif_unlockbus(sc->sc_busmem);
    251   1.1  pooka 
    252  1.29  pooka 	sc->sc_kq = rumpuser_writewatchfile_setup(-1, memfd, 0, &error);
    253  1.32  pooka 	if (sc->sc_kq == -1) {
    254  1.32  pooka 		rumpuser_unmap(sc->sc_busmem, BUSMEM_SIZE);
    255  1.29  pooka 		return error;
    256  1.32  pooka 	}
    257   1.1  pooka 
    258  1.29  pooka 	sc->sc_memfd = memfd;
    259  1.32  pooka 
    260  1.32  pooka 	return error;
    261  1.29  pooka }
    262  1.29  pooka 
    263  1.29  pooka static void
    264  1.29  pooka finibackend(struct shmif_sc *sc)
    265  1.29  pooka {
    266  1.29  pooka 
    267  1.32  pooka 	if (sc->sc_backfile == NULL)
    268  1.32  pooka 		return;
    269  1.32  pooka 
    270  1.32  pooka 	if (sc->sc_backfile) {
    271  1.32  pooka 		kmem_free(sc->sc_backfile, sc->sc_backfilelen);
    272  1.32  pooka 		sc->sc_backfile = NULL;
    273  1.32  pooka 		sc->sc_backfilelen = 0;
    274  1.32  pooka 	}
    275  1.29  pooka 
    276  1.29  pooka 	rumpuser_unmap(sc->sc_busmem, BUSMEM_SIZE);
    277  1.32  pooka 	rumpuser_close(sc->sc_memfd, NULL);
    278  1.32  pooka 	rumpuser_close(sc->sc_kq, NULL);
    279  1.32  pooka 
    280  1.32  pooka 	sc->sc_memfd = -1;
    281  1.29  pooka }
    282  1.29  pooka 
    283  1.29  pooka int
    284  1.29  pooka rump_shmif_create(const char *path, int *ifnum)
    285  1.29  pooka {
    286  1.29  pooka 	struct shmif_sc *sc;
    287  1.33  pooka 	int unit, error;
    288  1.33  pooka 	int memfd = -1; /* XXXgcc */
    289  1.29  pooka 
    290  1.33  pooka 	if (path) {
    291  1.33  pooka 		memfd = rumpuser_open(path, O_RDWR | O_CREAT, &error);
    292  1.33  pooka 		if (memfd == -1)
    293  1.33  pooka 			return error;
    294  1.33  pooka 	}
    295   1.1  pooka 
    296  1.32  pooka 	unit = vmem_xalloc(shmif_units, 1, 0, 0, 0, 0, 0,
    297  1.31  pooka 	    VM_INSTANTFIT | VM_SLEEP) - 1;
    298  1.31  pooka 
    299  1.32  pooka 	if ((error = allocif(unit, &sc)) != 0) {
    300  1.33  pooka 		if (path)
    301  1.33  pooka 			rumpuser_close(memfd, NULL);
    302  1.29  pooka 		return error;
    303  1.29  pooka 	}
    304  1.33  pooka 
    305  1.33  pooka 	if (!path)
    306  1.33  pooka 		goto out;
    307  1.33  pooka 
    308  1.29  pooka 	error = initbackend(sc, memfd);
    309  1.29  pooka 	if (error) {
    310  1.32  pooka 		shmif_unclone(&sc->sc_ec.ec_if);
    311  1.29  pooka 		return error;
    312  1.29  pooka 	}
    313   1.1  pooka 
    314  1.29  pooka 	sc->sc_backfilelen = strlen(path)+1;
    315  1.29  pooka 	sc->sc_backfile = kmem_alloc(sc->sc_backfilelen, KM_SLEEP);
    316  1.29  pooka 	strcpy(sc->sc_backfile, path);
    317  1.12  pooka 
    318  1.33  pooka  out:
    319   1.2  pooka 	if (ifnum)
    320  1.32  pooka 		*ifnum = unit;
    321  1.29  pooka 
    322   1.1  pooka 	return 0;
    323  1.29  pooka }
    324   1.1  pooka 
    325  1.29  pooka static int
    326  1.29  pooka shmif_clone(struct if_clone *ifc, int unit)
    327  1.29  pooka {
    328  1.31  pooka 	int unit2;
    329  1.29  pooka 
    330  1.31  pooka 	/*
    331  1.31  pooka 	 * Ok, we know the unit number, but we must still reserve it.
    332  1.31  pooka 	 * Otherwise the wildcard-side of things might get the same one.
    333  1.31  pooka 	 * This is slightly offset-happy due to vmem.  First, we offset
    334  1.31  pooka 	 * the range of unit numbers by +1 since vmem cannot deal with
    335  1.31  pooka 	 * ranges starting from 0.  Second, since vmem_xalloc() allocates
    336  1.31  pooka 	 * from [min,max) (half-*open* interval), we need to add one extra
    337  1.31  pooka 	 * to the one extra we add to maxaddr.  Talk about uuuh.
    338  1.31  pooka 	 */
    339  1.31  pooka 	unit2 = vmem_xalloc(shmif_units, 1, 0, 0, 0, unit+1, unit+3,
    340  1.31  pooka 	    VM_SLEEP | VM_INSTANTFIT);
    341  1.31  pooka 	KASSERT(unit2-1 == unit);
    342  1.29  pooka 
    343  1.29  pooka 	return allocif(unit, NULL);
    344  1.29  pooka }
    345  1.29  pooka 
    346  1.29  pooka static int
    347  1.29  pooka shmif_unclone(struct ifnet *ifp)
    348  1.29  pooka {
    349  1.32  pooka 	struct shmif_sc *sc = ifp->if_softc;
    350  1.32  pooka 
    351  1.32  pooka 	shmif_stop(ifp, 1);
    352  1.32  pooka 	if_down(ifp);
    353  1.32  pooka 	finibackend(sc);
    354  1.32  pooka 
    355  1.32  pooka 	mutex_enter(&sc->sc_mtx);
    356  1.32  pooka 	sc->sc_dying = true;
    357  1.32  pooka 	cv_broadcast(&sc->sc_cv);
    358  1.32  pooka 	mutex_exit(&sc->sc_mtx);
    359  1.29  pooka 
    360  1.32  pooka 	if (sc->sc_rcvl)
    361  1.32  pooka 		kthread_join(sc->sc_rcvl);
    362  1.32  pooka 	sc->sc_rcvl = NULL;
    363  1.32  pooka 
    364  1.32  pooka 	vmem_xfree(shmif_units, sc->sc_unit+1, 1);
    365  1.32  pooka 
    366  1.32  pooka 	ether_ifdetach(ifp);
    367  1.32  pooka 	if_detach(ifp);
    368  1.32  pooka 
    369  1.32  pooka 	cv_destroy(&sc->sc_cv);
    370  1.32  pooka 	mutex_destroy(&sc->sc_mtx);
    371  1.32  pooka 
    372  1.32  pooka 	kmem_free(sc, sizeof(*sc));
    373  1.32  pooka 
    374  1.32  pooka 	return 0;
    375   1.1  pooka }
    376   1.1  pooka 
    377   1.1  pooka static int
    378   1.1  pooka shmif_init(struct ifnet *ifp)
    379   1.1  pooka {
    380  1.29  pooka 	struct shmif_sc *sc = ifp->if_softc;
    381   1.4  pooka 	int error = 0;
    382   1.4  pooka 
    383  1.29  pooka 	if (sc->sc_memfd == -1)
    384  1.29  pooka 		return ENXIO;
    385  1.32  pooka 	KASSERT(sc->sc_busmem);
    386  1.29  pooka 
    387  1.32  pooka 	ifp->if_flags |= IFF_RUNNING;
    388  1.32  pooka 
    389  1.32  pooka 	mutex_enter(&sc->sc_mtx);
    390  1.32  pooka 	sc->sc_nextpacket = sc->sc_busmem->shm_last;
    391  1.32  pooka 	sc->sc_devgen = sc->sc_busmem->shm_gen;
    392  1.32  pooka 
    393  1.32  pooka 	cv_broadcast(&sc->sc_cv);
    394  1.32  pooka 	mutex_exit(&sc->sc_mtx);
    395   1.1  pooka 
    396   1.4  pooka 	return error;
    397   1.1  pooka }
    398   1.1  pooka 
    399   1.1  pooka static int
    400   1.1  pooka shmif_ioctl(struct ifnet *ifp, u_long cmd, void *data)
    401   1.1  pooka {
    402  1.29  pooka 	struct shmif_sc *sc = ifp->if_softc;
    403  1.29  pooka 	struct ifdrv *ifd;
    404  1.29  pooka 	char *path;
    405  1.32  pooka 	int s, rv, memfd;
    406   1.1  pooka 
    407   1.1  pooka 	s = splnet();
    408  1.29  pooka 	switch (cmd) {
    409  1.29  pooka 	case SIOCGLINKSTR:
    410  1.29  pooka 		ifd = data;
    411  1.29  pooka 
    412  1.29  pooka 		if (sc->sc_backfilelen == 0) {
    413  1.29  pooka 			rv = ENOENT;
    414  1.29  pooka 			break;
    415  1.29  pooka 		}
    416  1.29  pooka 
    417  1.29  pooka 		ifd->ifd_len = sc->sc_backfilelen;
    418  1.29  pooka 		if (ifd->ifd_cmd == IFLINKSTR_QUERYLEN) {
    419  1.29  pooka 			rv = 0;
    420  1.29  pooka 			break;
    421  1.29  pooka 		}
    422  1.29  pooka 
    423  1.29  pooka 		if (ifd->ifd_cmd != 0) {
    424  1.29  pooka 			rv = EINVAL;
    425  1.29  pooka 			break;
    426  1.29  pooka 		}
    427  1.29  pooka 
    428  1.29  pooka 		rv = copyoutstr(sc->sc_backfile, ifd->ifd_data,
    429  1.29  pooka 		    MIN(sc->sc_backfilelen, ifd->ifd_len), NULL);
    430  1.29  pooka 		break;
    431  1.29  pooka 	case SIOCSLINKSTR:
    432  1.29  pooka 		if (ifp->if_flags & IFF_UP) {
    433  1.29  pooka 			rv = EBUSY;
    434  1.29  pooka 			break;
    435  1.29  pooka 		}
    436  1.29  pooka 
    437  1.29  pooka 		ifd = data;
    438  1.29  pooka 		if (ifd->ifd_cmd == IFLINKSTR_UNSET) {
    439  1.29  pooka 			finibackend(sc);
    440  1.29  pooka 			rv = 0;
    441  1.29  pooka 			break;
    442  1.29  pooka 		} else if (ifd->ifd_cmd != 0) {
    443  1.29  pooka 			rv = EINVAL;
    444  1.29  pooka 			break;
    445  1.29  pooka 		} else if (sc->sc_backfile) {
    446  1.29  pooka 			rv = EBUSY;
    447  1.29  pooka 			break;
    448  1.29  pooka 		}
    449  1.29  pooka 
    450  1.29  pooka 		if (ifd->ifd_len > MAXPATHLEN) {
    451  1.29  pooka 			rv = E2BIG;
    452  1.29  pooka 			break;
    453  1.29  pooka 		} else if (ifd->ifd_len < 1) {
    454  1.29  pooka 			rv = EINVAL;
    455  1.29  pooka 			break;
    456  1.29  pooka 		}
    457  1.29  pooka 
    458  1.29  pooka 		path = kmem_alloc(ifd->ifd_len, KM_SLEEP);
    459  1.29  pooka 		rv = copyinstr(ifd->ifd_data, path, ifd->ifd_len, NULL);
    460  1.29  pooka 		if (rv) {
    461  1.29  pooka 			kmem_free(path, ifd->ifd_len);
    462  1.29  pooka 			break;
    463  1.29  pooka 		}
    464  1.29  pooka 		memfd = rumpuser_open(path, O_RDWR | O_CREAT, &rv);
    465  1.29  pooka 		if (memfd == -1) {
    466  1.29  pooka 			kmem_free(path, ifd->ifd_len);
    467  1.29  pooka 			break;
    468  1.29  pooka 		}
    469  1.29  pooka 		rv = initbackend(sc, memfd);
    470  1.29  pooka 		if (rv) {
    471  1.29  pooka 			kmem_free(path, ifd->ifd_len);
    472  1.32  pooka 			rumpuser_close(memfd, NULL);
    473  1.29  pooka 			break;
    474  1.29  pooka 		}
    475  1.29  pooka 		sc->sc_backfile = path;
    476  1.29  pooka 		sc->sc_backfilelen = ifd->ifd_len;
    477  1.29  pooka 
    478  1.29  pooka 		break;
    479  1.29  pooka 	default:
    480  1.29  pooka 		rv = ether_ioctl(ifp, cmd, data);
    481  1.29  pooka 		if (rv == ENETRESET)
    482  1.29  pooka 			rv = 0;
    483  1.29  pooka 		break;
    484  1.29  pooka 	}
    485   1.1  pooka 	splx(s);
    486   1.1  pooka 
    487   1.1  pooka 	return rv;
    488   1.1  pooka }
    489   1.1  pooka 
    490  1.32  pooka /* send everything in-context since it's just a matter of mem-to-mem copy */
    491   1.1  pooka static void
    492   1.1  pooka shmif_start(struct ifnet *ifp)
    493   1.1  pooka {
    494   1.1  pooka 	struct shmif_sc *sc = ifp->if_softc;
    495  1.26  pooka 	struct shmif_mem *busmem = sc->sc_busmem;
    496   1.1  pooka 	struct mbuf *m, *m0;
    497  1.26  pooka 	uint32_t dataoff;
    498  1.26  pooka 	uint32_t pktsize, pktwrote;
    499   1.1  pooka 	bool wrote = false;
    500  1.24  pooka 	bool wrap;
    501   1.1  pooka 	int error;
    502   1.1  pooka 
    503  1.26  pooka 	ifp->if_flags |= IFF_OACTIVE;
    504  1.26  pooka 
    505   1.1  pooka 	for (;;) {
    506  1.20  pooka 		struct shmif_pkthdr sp;
    507  1.20  pooka 		struct timeval tv;
    508  1.20  pooka 
    509   1.1  pooka 		IF_DEQUEUE(&ifp->if_snd, m0);
    510   1.1  pooka 		if (m0 == NULL) {
    511   1.1  pooka 			break;
    512   1.1  pooka 		}
    513   1.1  pooka 
    514  1.25  pooka 		pktsize = 0;
    515  1.19  pooka 		for (m = m0; m != NULL; m = m->m_next) {
    516  1.19  pooka 			pktsize += m->m_len;
    517  1.19  pooka 		}
    518  1.26  pooka 		KASSERT(pktsize <= ETHERMTU + ETHER_HDR_LEN);
    519  1.19  pooka 
    520  1.20  pooka 		getmicrouptime(&tv);
    521  1.20  pooka 		sp.sp_len = pktsize;
    522  1.20  pooka 		sp.sp_sec = tv.tv_sec;
    523  1.20  pooka 		sp.sp_usec = tv.tv_usec;
    524  1.20  pooka 
    525  1.35  pooka 		bpf_mtap(ifp, m0);
    526  1.35  pooka 
    527  1.26  pooka 		shmif_lockbus(busmem);
    528  1.26  pooka 		KASSERT(busmem->shm_magic == SHMIF_MAGIC);
    529  1.26  pooka 		busmem->shm_last = shmif_nextpktoff(busmem, busmem->shm_last);
    530  1.21  pooka 
    531  1.24  pooka 		wrap = false;
    532  1.26  pooka 		dataoff = shmif_buswrite(busmem,
    533  1.26  pooka 		    busmem->shm_last, &sp, sizeof(sp), &wrap);
    534  1.26  pooka 		pktwrote = 0;
    535   1.1  pooka 		for (m = m0; m != NULL; m = m->m_next) {
    536  1.26  pooka 			pktwrote += m->m_len;
    537  1.26  pooka 			dataoff = shmif_buswrite(busmem, dataoff,
    538  1.19  pooka 			    mtod(m, void *), m->m_len, &wrap);
    539   1.1  pooka 		}
    540  1.26  pooka 		KASSERT(pktwrote == pktsize);
    541  1.27  pooka 		if (wrap) {
    542  1.26  pooka 			busmem->shm_gen++;
    543  1.27  pooka 			DPRINTF(("bus generation now %d\n", busmem->shm_gen));
    544  1.27  pooka 		}
    545  1.26  pooka 		shmif_unlockbus(busmem);
    546   1.1  pooka 
    547   1.1  pooka 		m_freem(m0);
    548   1.1  pooka 		wrote = true;
    549   1.1  pooka 
    550   1.1  pooka 		DPRINTF(("shmif_start: send %d bytes at off %d\n",
    551  1.27  pooka 		    pktsize, busmem->shm_last));
    552   1.1  pooka 	}
    553  1.26  pooka 
    554  1.26  pooka 	ifp->if_flags &= ~IFF_OACTIVE;
    555  1.26  pooka 
    556  1.32  pooka 	/* wakeup? */
    557   1.1  pooka 	if (wrote)
    558  1.15  pooka 		rumpuser_pwrite(sc->sc_memfd,
    559  1.15  pooka 		    &busversion, sizeof(busversion), IFMEM_WAKEUP, &error);
    560   1.1  pooka }
    561   1.1  pooka 
    562   1.1  pooka static void
    563   1.1  pooka shmif_stop(struct ifnet *ifp, int disable)
    564   1.1  pooka {
    565  1.32  pooka 	struct shmif_sc *sc = ifp->if_softc;
    566   1.1  pooka 
    567  1.32  pooka 	ifp->if_flags &= ~IFF_RUNNING;
    568  1.32  pooka 	membar_producer();
    569  1.32  pooka 
    570  1.32  pooka 	/*
    571  1.32  pooka 	 * wakeup thread.  this will of course wake up all bus
    572  1.32  pooka 	 * listeners, but that's life.
    573  1.32  pooka 	 */
    574  1.32  pooka 	if (sc->sc_memfd != -1)
    575  1.32  pooka 		rumpuser_pwrite(sc->sc_memfd,
    576  1.32  pooka 		    &busversion, sizeof(busversion), IFMEM_WAKEUP, NULL);
    577   1.1  pooka }
    578   1.1  pooka 
    579  1.27  pooka 
    580  1.27  pooka /*
    581  1.27  pooka  * Check if we have been sleeping too long.  Basically,
    582  1.27  pooka  * our in-sc nextpkt must by first <= nextpkt <= last"+1".
    583  1.27  pooka  * We use the fact that first is guaranteed to never overlap
    584  1.27  pooka  * with the last frame in the ring.
    585  1.27  pooka  */
    586  1.27  pooka static __inline bool
    587  1.27  pooka stillvalid_p(struct shmif_sc *sc)
    588  1.27  pooka {
    589  1.27  pooka 	struct shmif_mem *busmem = sc->sc_busmem;
    590  1.27  pooka 	unsigned gendiff = busmem->shm_gen - sc->sc_devgen;
    591  1.27  pooka 	uint32_t lastoff, devoff;
    592  1.27  pooka 
    593  1.27  pooka 	KASSERT(busmem->shm_first != busmem->shm_last);
    594  1.27  pooka 
    595  1.27  pooka 	/* normalize onto a 2x busmem chunk */
    596  1.27  pooka 	devoff = sc->sc_nextpacket;
    597  1.27  pooka 	lastoff = shmif_nextpktoff(busmem, busmem->shm_last);
    598  1.27  pooka 
    599  1.27  pooka 	/* trivial case */
    600  1.27  pooka 	if (gendiff > 1)
    601  1.27  pooka 		return false;
    602  1.27  pooka 	KASSERT(gendiff <= 1);
    603  1.27  pooka 
    604  1.27  pooka 	/* Normalize onto 2x busmem chunk */
    605  1.27  pooka 	if (busmem->shm_first >= lastoff) {
    606  1.27  pooka 		lastoff += BUSMEM_DATASIZE;
    607  1.27  pooka 		if (gendiff == 0)
    608  1.27  pooka 			devoff += BUSMEM_DATASIZE;
    609  1.27  pooka 	} else {
    610  1.27  pooka 		if (gendiff)
    611  1.27  pooka 			return false;
    612  1.27  pooka 	}
    613  1.27  pooka 
    614  1.27  pooka 	return devoff >= busmem->shm_first && devoff <= lastoff;
    615  1.27  pooka }
    616  1.27  pooka 
    617   1.1  pooka static void
    618   1.1  pooka shmif_rcv(void *arg)
    619   1.1  pooka {
    620   1.1  pooka 	struct ifnet *ifp = arg;
    621   1.1  pooka 	struct shmif_sc *sc = ifp->if_softc;
    622  1.32  pooka 	struct shmif_mem *busmem;
    623   1.1  pooka 	struct mbuf *m = NULL;
    624   1.1  pooka 	struct ether_header *eth;
    625  1.27  pooka 	uint32_t nextpkt;
    626  1.37  pooka 	bool wrap, passup;
    627   1.1  pooka 	int error;
    628   1.1  pooka 
    629  1.32  pooka  reup:
    630  1.32  pooka 	mutex_enter(&sc->sc_mtx);
    631  1.32  pooka 	while ((ifp->if_flags & IFF_RUNNING) == 0 && !sc->sc_dying)
    632  1.32  pooka 		cv_wait(&sc->sc_cv, &sc->sc_mtx);
    633  1.32  pooka 	mutex_exit(&sc->sc_mtx);
    634  1.32  pooka 
    635  1.32  pooka 	busmem = sc->sc_busmem;
    636  1.32  pooka 
    637  1.32  pooka 	while (ifp->if_flags & IFF_RUNNING) {
    638  1.20  pooka 		struct shmif_pkthdr sp;
    639  1.20  pooka 
    640   1.1  pooka 		if (m == NULL) {
    641   1.1  pooka 			m = m_gethdr(M_WAIT, MT_DATA);
    642   1.1  pooka 			MCLGET(m, M_WAIT);
    643   1.1  pooka 		}
    644   1.1  pooka 
    645  1.26  pooka 		DPRINTF(("waiting %d/%d\n", sc->sc_nextpacket, sc->sc_devgen));
    646  1.26  pooka 		KASSERT(m->m_flags & M_EXT);
    647   1.1  pooka 
    648  1.26  pooka 		shmif_lockbus(busmem);
    649  1.26  pooka 		KASSERT(busmem->shm_magic == SHMIF_MAGIC);
    650  1.27  pooka 		KASSERT(busmem->shm_gen >= sc->sc_devgen);
    651   1.1  pooka 
    652   1.1  pooka 		/* need more data? */
    653  1.27  pooka 		if (sc->sc_devgen == busmem->shm_gen &&
    654  1.26  pooka 		    shmif_nextpktoff(busmem, busmem->shm_last)
    655  1.26  pooka 		     == sc->sc_nextpacket) {
    656  1.26  pooka 			shmif_unlockbus(busmem);
    657   1.1  pooka 			error = 0;
    658   1.1  pooka 			rumpuser_writewatchfile_wait(sc->sc_kq, NULL, &error);
    659   1.1  pooka 			if (__predict_false(error))
    660   1.1  pooka 				printf("shmif_rcv: wait failed %d\n", error);
    661  1.32  pooka 			membar_consumer();
    662   1.1  pooka 			continue;
    663   1.1  pooka 		}
    664   1.1  pooka 
    665  1.27  pooka 		if (stillvalid_p(sc)) {
    666  1.27  pooka 			nextpkt = sc->sc_nextpacket;
    667  1.27  pooka 		} else {
    668  1.27  pooka 			KASSERT(busmem->shm_gen > 0);
    669  1.26  pooka 			nextpkt = busmem->shm_first;
    670  1.26  pooka 			if (busmem->shm_first > busmem->shm_last)
    671  1.27  pooka 				sc->sc_devgen = busmem->shm_gen - 1;
    672  1.26  pooka 			else
    673  1.27  pooka 				sc->sc_devgen = busmem->shm_gen;
    674  1.27  pooka 			DPRINTF(("dev %p overrun, new data: %d/%d\n",
    675  1.27  pooka 			    sc, nextpkt, sc->sc_devgen));
    676  1.26  pooka 		}
    677  1.26  pooka 
    678  1.26  pooka 		/*
    679  1.26  pooka 		 * If our read pointer is ahead the bus last write, our
    680  1.26  pooka 		 * generation must be one behind.
    681  1.26  pooka 		 */
    682  1.26  pooka 		KASSERT(!(nextpkt > busmem->shm_last
    683  1.27  pooka 		    && sc->sc_devgen == busmem->shm_gen));
    684  1.26  pooka 
    685  1.24  pooka 		wrap = false;
    686  1.26  pooka 		nextpkt = shmif_busread(busmem, &sp,
    687  1.26  pooka 		    nextpkt, sizeof(sp), &wrap);
    688  1.26  pooka 		KASSERT(sp.sp_len <= ETHERMTU + ETHER_HDR_LEN);
    689  1.26  pooka 		nextpkt = shmif_busread(busmem, mtod(m, void *),
    690  1.26  pooka 		    nextpkt, sp.sp_len, &wrap);
    691   1.1  pooka 
    692   1.1  pooka 		DPRINTF(("shmif_rcv: read packet of length %d at %d\n",
    693  1.20  pooka 		    sp.sp_len, nextpkt));
    694   1.1  pooka 
    695  1.26  pooka 		sc->sc_nextpacket = nextpkt;
    696  1.19  pooka 		shmif_unlockbus(sc->sc_busmem);
    697   1.1  pooka 
    698  1.27  pooka 		if (wrap) {
    699  1.26  pooka 			sc->sc_devgen++;
    700  1.27  pooka 			DPRINTF(("dev %p generation now %d\n",
    701  1.27  pooka 			    sc, sc->sc_devgen));
    702  1.27  pooka 		}
    703  1.26  pooka 
    704  1.20  pooka 		m->m_len = m->m_pkthdr.len = sp.sp_len;
    705   1.1  pooka 		m->m_pkthdr.rcvif = ifp;
    706   1.1  pooka 
    707  1.37  pooka 		/*
    708  1.37  pooka 		 * Test if we want to pass the packet upwards
    709  1.37  pooka 		 */
    710   1.1  pooka 		eth = mtod(m, struct ether_header *);
    711  1.37  pooka 		if (memcmp(eth->ether_dhost, CLLADDR(ifp->if_sadl),
    712  1.37  pooka 		    ETHER_ADDR_LEN) == 0) {
    713  1.37  pooka 			passup = true;
    714  1.37  pooka 		} else if (memcmp(eth->ether_dhost, etherbroadcastaddr,
    715  1.37  pooka 		    ETHER_ADDR_LEN) == 0) {
    716  1.37  pooka 			passup = true;
    717  1.37  pooka 		} else if (ifp->if_flags & IFF_PROMISC) {
    718  1.37  pooka 			m->m_flags |= M_PROMISC;
    719  1.37  pooka 			passup = true;
    720  1.38  pooka 		} else {
    721  1.38  pooka 			passup = false;
    722  1.37  pooka 		}
    723  1.37  pooka 
    724  1.37  pooka 		if (passup) {
    725  1.22  pooka 			KERNEL_LOCK(1, NULL);
    726  1.35  pooka 			bpf_mtap(ifp, m);
    727   1.1  pooka 			ifp->if_input(ifp, m);
    728  1.22  pooka 			KERNEL_UNLOCK_ONE(NULL);
    729   1.1  pooka 			m = NULL;
    730   1.1  pooka 		}
    731  1.37  pooka 		/* else: reuse mbuf for a future packet */
    732   1.1  pooka 	}
    733  1.32  pooka 	m_freem(m);
    734  1.32  pooka 	m = NULL;
    735  1.32  pooka 
    736  1.32  pooka 	if (!sc->sc_dying)
    737  1.32  pooka 		goto reup;
    738   1.1  pooka 
    739  1.32  pooka 	kthread_exit(0);
    740   1.1  pooka }
    741