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if_shmem.c revision 1.61
      1  1.61    justin /*	$NetBSD: if_shmem.c,v 1.61 2014/05/28 20:57:22 justin 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  1.61    justin __KERNEL_RCSID(0, "$NetBSD: if_shmem.c,v 1.61 2014/05/28 20:57:22 justin 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  1.44       tls #include <sys/cprng.h>
     41   1.1     pooka 
     42  1.35     pooka #include <net/bpf.h>
     43   1.1     pooka #include <net/if.h>
     44  1.37     pooka #include <net/if_dl.h>
     45   1.1     pooka #include <net/if_ether.h>
     46   1.1     pooka 
     47   1.1     pooka #include <netinet/in.h>
     48   1.1     pooka #include <netinet/in_var.h>
     49   1.1     pooka 
     50   1.1     pooka #include <rump/rump.h>
     51   1.1     pooka #include <rump/rumpuser.h>
     52   1.1     pooka 
     53   1.1     pooka #include "rump_private.h"
     54   1.9     pooka #include "rump_net_private.h"
     55  1.59     pooka #include "shmif_user.h"
     56   1.1     pooka 
     57  1.29     pooka static int shmif_clone(struct if_clone *, int);
     58  1.29     pooka static int shmif_unclone(struct ifnet *);
     59  1.29     pooka 
     60  1.29     pooka struct if_clone shmif_cloner =
     61  1.29     pooka     IF_CLONE_INITIALIZER("shmif", shmif_clone, shmif_unclone);
     62  1.29     pooka 
     63   1.1     pooka /*
     64  1.28     pooka  * Do r/w prefault for backend pages when attaching the interface.
     65  1.29     pooka  * At least logically thinking improves performance (although no
     66  1.29     pooka  * mlocking is done, so they might go away).
     67  1.28     pooka  */
     68  1.28     pooka #define PREFAULT_RW
     69  1.28     pooka 
     70  1.28     pooka /*
     71   1.1     pooka  * A virtual ethernet interface which uses shared memory from a
     72   1.1     pooka  * memory mapped file as the bus.
     73   1.1     pooka  */
     74   1.1     pooka 
     75   1.1     pooka static int	shmif_init(struct ifnet *);
     76   1.1     pooka static int	shmif_ioctl(struct ifnet *, u_long, void *);
     77   1.1     pooka static void	shmif_start(struct ifnet *);
     78   1.1     pooka static void	shmif_stop(struct ifnet *, int);
     79   1.1     pooka 
     80  1.16     pooka #include "shmifvar.h"
     81  1.16     pooka 
     82   1.1     pooka struct shmif_sc {
     83   1.1     pooka 	struct ethercom sc_ec;
     84  1.16     pooka 	struct shmif_mem *sc_busmem;
     85   1.1     pooka 	int sc_memfd;
     86   1.1     pooka 	int sc_kq;
     87  1.32     pooka 	int sc_unit;
     88   1.1     pooka 
     89  1.29     pooka 	char *sc_backfile;
     90  1.29     pooka 	size_t sc_backfilelen;
     91  1.29     pooka 
     92  1.26     pooka 	uint64_t sc_devgen;
     93   1.1     pooka 	uint32_t sc_nextpacket;
     94  1.32     pooka 
     95  1.32     pooka 	kmutex_t sc_mtx;
     96  1.32     pooka 	kcondvar_t sc_cv;
     97  1.32     pooka 
     98  1.32     pooka 	struct lwp *sc_rcvl;
     99  1.32     pooka 	bool sc_dying;
    100   1.1     pooka };
    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  1.52     pooka static void
    111  1.52     pooka dowakeup(struct shmif_sc *sc)
    112  1.52     pooka {
    113  1.52     pooka 	struct rumpuser_iovec iov;
    114  1.52     pooka 	uint32_t ver = SHMIF_VERSION;
    115  1.53     pooka 	size_t n;
    116  1.52     pooka 
    117  1.52     pooka 	iov.iov_base = &ver;
    118  1.52     pooka 	iov.iov_len = sizeof(ver);
    119  1.53     pooka 	rumpuser_iovwrite(sc->sc_memfd, &iov, 1, IFMEM_WAKEUP, &n);
    120  1.52     pooka }
    121  1.52     pooka 
    122  1.23     pooka /*
    123  1.23     pooka  * This locking needs work and will misbehave severely if:
    124  1.23     pooka  * 1) the backing memory has to be paged in
    125  1.23     pooka  * 2) some lockholder exits while holding the lock
    126  1.23     pooka  */
    127  1.23     pooka static void
    128  1.23     pooka shmif_lockbus(struct shmif_mem *busmem)
    129  1.23     pooka {
    130  1.23     pooka 	int i = 0;
    131  1.23     pooka 
    132  1.23     pooka 	while (__predict_false(atomic_cas_32(&busmem->shm_lock,
    133  1.23     pooka 	    LOCK_UNLOCKED, LOCK_LOCKED) == LOCK_LOCKED)) {
    134  1.23     pooka 		if (__predict_false(++i > LOCK_COOLDOWN)) {
    135  1.50     pooka 			/* wait 1ms */
    136  1.54     pooka 			rumpuser_clock_sleep(RUMPUSER_CLOCK_RELWALL,
    137  1.54     pooka 			    0, 1000*1000);
    138  1.23     pooka 			i = 0;
    139  1.23     pooka 		}
    140  1.23     pooka 		continue;
    141  1.23     pooka 	}
    142  1.23     pooka 	membar_enter();
    143  1.23     pooka }
    144  1.23     pooka 
    145  1.23     pooka static void
    146  1.23     pooka shmif_unlockbus(struct shmif_mem *busmem)
    147  1.23     pooka {
    148  1.61    justin 	unsigned int old __diagused;
    149  1.23     pooka 
    150  1.23     pooka 	membar_exit();
    151  1.23     pooka 	old = atomic_swap_32(&busmem->shm_lock, LOCK_UNLOCKED);
    152  1.23     pooka 	KASSERT(old == LOCK_LOCKED);
    153  1.23     pooka }
    154  1.23     pooka 
    155  1.29     pooka static int
    156  1.29     pooka allocif(int unit, struct shmif_sc **scp)
    157   1.1     pooka {
    158  1.29     pooka 	uint8_t enaddr[ETHER_ADDR_LEN] = { 0xb2, 0xa0, 0x00, 0x00, 0x00, 0x00 };
    159   1.1     pooka 	struct shmif_sc *sc;
    160   1.1     pooka 	struct ifnet *ifp;
    161   1.1     pooka 	uint32_t randnum;
    162  1.32     pooka 	int error;
    163   1.1     pooka 
    164  1.44       tls 	randnum = cprng_fast32();
    165  1.15     pooka 	memcpy(&enaddr[2], &randnum, sizeof(randnum));
    166   1.1     pooka 
    167   1.1     pooka 	sc = kmem_zalloc(sizeof(*sc), KM_SLEEP);
    168  1.29     pooka 	sc->sc_memfd = -1;
    169  1.32     pooka 	sc->sc_unit = unit;
    170  1.29     pooka 
    171   1.1     pooka 	ifp = &sc->sc_ec.ec_if;
    172   1.1     pooka 
    173  1.60  christos 	snprintf(ifp->if_xname, sizeof(ifp->if_xname), "shmif%d", unit);
    174  1.29     pooka 	ifp->if_softc = sc;
    175  1.29     pooka 	ifp->if_flags = IFF_BROADCAST | IFF_MULTICAST;
    176  1.29     pooka 	ifp->if_init = shmif_init;
    177  1.29     pooka 	ifp->if_ioctl = shmif_ioctl;
    178  1.29     pooka 	ifp->if_start = shmif_start;
    179  1.29     pooka 	ifp->if_stop = shmif_stop;
    180  1.29     pooka 	ifp->if_mtu = ETHERMTU;
    181  1.37     pooka 	ifp->if_dlt = DLT_EN10MB;
    182  1.29     pooka 
    183  1.32     pooka 	mutex_init(&sc->sc_mtx, MUTEX_DEFAULT, IPL_NONE);
    184  1.32     pooka 	cv_init(&sc->sc_cv, "shmifcv");
    185  1.32     pooka 
    186  1.29     pooka 	if_attach(ifp);
    187  1.29     pooka 	ether_ifattach(ifp, enaddr);
    188  1.29     pooka 
    189  1.29     pooka 	aprint_verbose("shmif%d: Ethernet address %s\n",
    190  1.32     pooka 	    unit, ether_sprintf(enaddr));
    191  1.29     pooka 
    192  1.29     pooka 	if (scp)
    193  1.29     pooka 		*scp = sc;
    194  1.29     pooka 
    195  1.32     pooka 	error = 0;
    196  1.32     pooka 	if (rump_threads) {
    197  1.32     pooka 		error = kthread_create(PRI_NONE,
    198  1.40     rmind 		    KTHREAD_MPSAFE | KTHREAD_MUSTJOIN, NULL,
    199  1.32     pooka 		    shmif_rcv, ifp, &sc->sc_rcvl, "shmif");
    200  1.32     pooka 	} else {
    201  1.32     pooka 		printf("WARNING: threads not enabled, shmif NOT working\n");
    202  1.32     pooka 	}
    203  1.32     pooka 
    204  1.32     pooka 	if (error) {
    205  1.32     pooka 		shmif_unclone(ifp);
    206  1.32     pooka 	}
    207  1.32     pooka 
    208  1.32     pooka 	return error;
    209  1.29     pooka }
    210  1.29     pooka 
    211  1.29     pooka static int
    212  1.29     pooka initbackend(struct shmif_sc *sc, int memfd)
    213  1.29     pooka {
    214  1.29     pooka 	volatile uint8_t v;
    215  1.29     pooka 	volatile uint8_t *p;
    216  1.53     pooka 	void *mem;
    217  1.29     pooka 	int error;
    218  1.29     pooka 
    219  1.53     pooka 	error = rumpcomp_shmif_mmap(memfd, BUSMEM_SIZE, &mem);
    220   1.1     pooka 	if (error)
    221  1.29     pooka 		return error;
    222  1.53     pooka 	sc->sc_busmem = mem;
    223  1.17     pooka 
    224  1.29     pooka 	if (sc->sc_busmem->shm_magic
    225  1.29     pooka 	    && sc->sc_busmem->shm_magic != SHMIF_MAGIC) {
    226  1.29     pooka 		printf("bus is not magical");
    227  1.29     pooka 		rumpuser_unmap(sc->sc_busmem, BUSMEM_SIZE);
    228  1.29     pooka 		return ENOEXEC;
    229  1.29     pooka 	}
    230  1.28     pooka 
    231  1.36     pooka 	/*
    232  1.36     pooka 	 * Prefault in pages to minimize runtime penalty with buslock.
    233  1.36     pooka 	 * Use 512 instead of PAGE_SIZE to make sure we catch cases where
    234  1.36     pooka 	 * rump kernel PAGE_SIZE > host page size.
    235  1.36     pooka 	 */
    236  1.28     pooka 	for (p = (uint8_t *)sc->sc_busmem;
    237  1.28     pooka 	    p < (uint8_t *)sc->sc_busmem + BUSMEM_SIZE;
    238  1.36     pooka 	    p += 512)
    239  1.28     pooka 		v = *p;
    240  1.28     pooka 
    241  1.19     pooka 	shmif_lockbus(sc->sc_busmem);
    242  1.19     pooka 	/* we're first?  initialize bus */
    243  1.19     pooka 	if (sc->sc_busmem->shm_magic == 0) {
    244  1.19     pooka 		sc->sc_busmem->shm_magic = SHMIF_MAGIC;
    245  1.19     pooka 		sc->sc_busmem->shm_first = BUSMEM_DATASIZE;
    246  1.19     pooka 	}
    247  1.19     pooka 
    248  1.16     pooka 	sc->sc_nextpacket = sc->sc_busmem->shm_last;
    249  1.26     pooka 	sc->sc_devgen = sc->sc_busmem->shm_gen;
    250  1.28     pooka 
    251  1.28     pooka #ifdef PREFAULT_RW
    252  1.28     pooka 	for (p = (uint8_t *)sc->sc_busmem;
    253  1.28     pooka 	    p < (uint8_t *)sc->sc_busmem + BUSMEM_SIZE;
    254  1.28     pooka 	    p += PAGE_SIZE) {
    255  1.28     pooka 		v = *p;
    256  1.28     pooka 		*p = v;
    257  1.28     pooka 	}
    258  1.28     pooka #endif
    259  1.19     pooka 	shmif_unlockbus(sc->sc_busmem);
    260   1.1     pooka 
    261  1.53     pooka 	sc->sc_kq = -1;
    262  1.53     pooka 	error = rumpcomp_shmif_watchsetup(&sc->sc_kq, memfd);
    263  1.53     pooka 	if (error) {
    264  1.32     pooka 		rumpuser_unmap(sc->sc_busmem, BUSMEM_SIZE);
    265  1.29     pooka 		return error;
    266  1.32     pooka 	}
    267   1.1     pooka 
    268  1.29     pooka 	sc->sc_memfd = memfd;
    269  1.32     pooka 
    270  1.32     pooka 	return error;
    271  1.29     pooka }
    272  1.29     pooka 
    273  1.29     pooka static void
    274  1.29     pooka finibackend(struct shmif_sc *sc)
    275  1.29     pooka {
    276  1.29     pooka 
    277  1.32     pooka 	if (sc->sc_backfile == NULL)
    278  1.32     pooka 		return;
    279  1.32     pooka 
    280  1.32     pooka 	if (sc->sc_backfile) {
    281  1.32     pooka 		kmem_free(sc->sc_backfile, sc->sc_backfilelen);
    282  1.32     pooka 		sc->sc_backfile = NULL;
    283  1.32     pooka 		sc->sc_backfilelen = 0;
    284  1.32     pooka 	}
    285  1.29     pooka 
    286  1.29     pooka 	rumpuser_unmap(sc->sc_busmem, BUSMEM_SIZE);
    287  1.53     pooka 	rumpuser_close(sc->sc_memfd);
    288  1.53     pooka 	rumpuser_close(sc->sc_kq);
    289  1.32     pooka 
    290  1.32     pooka 	sc->sc_memfd = -1;
    291  1.29     pooka }
    292  1.29     pooka 
    293  1.29     pooka int
    294  1.29     pooka rump_shmif_create(const char *path, int *ifnum)
    295  1.29     pooka {
    296  1.29     pooka 	struct shmif_sc *sc;
    297  1.43    dyoung 	vmem_addr_t t;
    298  1.33     pooka 	int unit, error;
    299  1.33     pooka 	int memfd = -1; /* XXXgcc */
    300  1.29     pooka 
    301  1.33     pooka 	if (path) {
    302  1.53     pooka 		error = rumpuser_open(path,
    303  1.53     pooka 		    RUMPUSER_OPEN_RDWR | RUMPUSER_OPEN_CREATE, &memfd);
    304  1.53     pooka 		if (error)
    305  1.33     pooka 			return error;
    306  1.33     pooka 	}
    307   1.1     pooka 
    308  1.43    dyoung 	error = vmem_xalloc(shmif_units, 1, 0, 0, 0,
    309  1.43    dyoung 	    VMEM_ADDR_MIN, VMEM_ADDR_MAX, VM_INSTANTFIT | VM_SLEEP, &t);
    310  1.43    dyoung 
    311  1.43    dyoung 	if (error != 0) {
    312  1.43    dyoung 		if (path)
    313  1.53     pooka 			rumpuser_close(memfd);
    314  1.43    dyoung 		return error;
    315  1.43    dyoung 	}
    316  1.43    dyoung 
    317  1.43    dyoung 	unit = t - 1;
    318  1.31     pooka 
    319  1.32     pooka 	if ((error = allocif(unit, &sc)) != 0) {
    320  1.33     pooka 		if (path)
    321  1.53     pooka 			rumpuser_close(memfd);
    322  1.29     pooka 		return error;
    323  1.29     pooka 	}
    324  1.33     pooka 
    325  1.33     pooka 	if (!path)
    326  1.33     pooka 		goto out;
    327  1.33     pooka 
    328  1.29     pooka 	error = initbackend(sc, memfd);
    329  1.29     pooka 	if (error) {
    330  1.32     pooka 		shmif_unclone(&sc->sc_ec.ec_if);
    331  1.29     pooka 		return error;
    332  1.29     pooka 	}
    333   1.1     pooka 
    334  1.29     pooka 	sc->sc_backfilelen = strlen(path)+1;
    335  1.29     pooka 	sc->sc_backfile = kmem_alloc(sc->sc_backfilelen, KM_SLEEP);
    336  1.29     pooka 	strcpy(sc->sc_backfile, path);
    337  1.12     pooka 
    338  1.33     pooka  out:
    339   1.2     pooka 	if (ifnum)
    340  1.32     pooka 		*ifnum = unit;
    341  1.29     pooka 
    342   1.1     pooka 	return 0;
    343  1.29     pooka }
    344   1.1     pooka 
    345  1.29     pooka static int
    346  1.29     pooka shmif_clone(struct if_clone *ifc, int unit)
    347  1.29     pooka {
    348  1.61    justin 	int rc __diagused;
    349  1.43    dyoung 	vmem_addr_t unit2;
    350  1.29     pooka 
    351  1.31     pooka 	/*
    352  1.31     pooka 	 * Ok, we know the unit number, but we must still reserve it.
    353  1.31     pooka 	 * Otherwise the wildcard-side of things might get the same one.
    354  1.31     pooka 	 * This is slightly offset-happy due to vmem.  First, we offset
    355  1.31     pooka 	 * the range of unit numbers by +1 since vmem cannot deal with
    356  1.41    dyoung 	 * ranges starting from 0.  Talk about uuuh.
    357  1.31     pooka 	 */
    358  1.43    dyoung 	rc = vmem_xalloc(shmif_units, 1, 0, 0, 0, unit+1, unit+1,
    359  1.43    dyoung 	    VM_SLEEP | VM_INSTANTFIT, &unit2);
    360  1.43    dyoung 	KASSERT(rc == 0 && unit2-1 == unit);
    361  1.29     pooka 
    362  1.29     pooka 	return allocif(unit, NULL);
    363  1.29     pooka }
    364  1.29     pooka 
    365  1.29     pooka static int
    366  1.29     pooka shmif_unclone(struct ifnet *ifp)
    367  1.29     pooka {
    368  1.32     pooka 	struct shmif_sc *sc = ifp->if_softc;
    369  1.32     pooka 
    370  1.32     pooka 	shmif_stop(ifp, 1);
    371  1.32     pooka 	if_down(ifp);
    372  1.32     pooka 	finibackend(sc);
    373  1.32     pooka 
    374  1.32     pooka 	mutex_enter(&sc->sc_mtx);
    375  1.32     pooka 	sc->sc_dying = true;
    376  1.32     pooka 	cv_broadcast(&sc->sc_cv);
    377  1.32     pooka 	mutex_exit(&sc->sc_mtx);
    378  1.29     pooka 
    379  1.32     pooka 	if (sc->sc_rcvl)
    380  1.32     pooka 		kthread_join(sc->sc_rcvl);
    381  1.32     pooka 	sc->sc_rcvl = NULL;
    382  1.32     pooka 
    383  1.32     pooka 	vmem_xfree(shmif_units, sc->sc_unit+1, 1);
    384  1.32     pooka 
    385  1.32     pooka 	ether_ifdetach(ifp);
    386  1.32     pooka 	if_detach(ifp);
    387  1.32     pooka 
    388  1.32     pooka 	cv_destroy(&sc->sc_cv);
    389  1.32     pooka 	mutex_destroy(&sc->sc_mtx);
    390  1.32     pooka 
    391  1.32     pooka 	kmem_free(sc, sizeof(*sc));
    392  1.32     pooka 
    393  1.32     pooka 	return 0;
    394   1.1     pooka }
    395   1.1     pooka 
    396   1.1     pooka static int
    397   1.1     pooka shmif_init(struct ifnet *ifp)
    398   1.1     pooka {
    399  1.29     pooka 	struct shmif_sc *sc = ifp->if_softc;
    400   1.4     pooka 	int error = 0;
    401   1.4     pooka 
    402  1.29     pooka 	if (sc->sc_memfd == -1)
    403  1.29     pooka 		return ENXIO;
    404  1.32     pooka 	KASSERT(sc->sc_busmem);
    405  1.29     pooka 
    406  1.32     pooka 	ifp->if_flags |= IFF_RUNNING;
    407  1.32     pooka 
    408  1.32     pooka 	mutex_enter(&sc->sc_mtx);
    409  1.32     pooka 	sc->sc_nextpacket = sc->sc_busmem->shm_last;
    410  1.32     pooka 	sc->sc_devgen = sc->sc_busmem->shm_gen;
    411  1.32     pooka 
    412  1.32     pooka 	cv_broadcast(&sc->sc_cv);
    413  1.32     pooka 	mutex_exit(&sc->sc_mtx);
    414   1.1     pooka 
    415   1.4     pooka 	return error;
    416   1.1     pooka }
    417   1.1     pooka 
    418   1.1     pooka static int
    419   1.1     pooka shmif_ioctl(struct ifnet *ifp, u_long cmd, void *data)
    420   1.1     pooka {
    421  1.29     pooka 	struct shmif_sc *sc = ifp->if_softc;
    422  1.29     pooka 	struct ifdrv *ifd;
    423  1.29     pooka 	char *path;
    424  1.32     pooka 	int s, rv, memfd;
    425   1.1     pooka 
    426   1.1     pooka 	s = splnet();
    427  1.29     pooka 	switch (cmd) {
    428  1.29     pooka 	case SIOCGLINKSTR:
    429  1.29     pooka 		ifd = data;
    430  1.29     pooka 
    431  1.29     pooka 		if (sc->sc_backfilelen == 0) {
    432  1.29     pooka 			rv = ENOENT;
    433  1.29     pooka 			break;
    434  1.29     pooka 		}
    435  1.29     pooka 
    436  1.29     pooka 		ifd->ifd_len = sc->sc_backfilelen;
    437  1.29     pooka 		if (ifd->ifd_cmd == IFLINKSTR_QUERYLEN) {
    438  1.29     pooka 			rv = 0;
    439  1.29     pooka 			break;
    440  1.29     pooka 		}
    441  1.29     pooka 
    442  1.29     pooka 		if (ifd->ifd_cmd != 0) {
    443  1.29     pooka 			rv = EINVAL;
    444  1.29     pooka 			break;
    445  1.29     pooka 		}
    446  1.29     pooka 
    447  1.29     pooka 		rv = copyoutstr(sc->sc_backfile, ifd->ifd_data,
    448  1.29     pooka 		    MIN(sc->sc_backfilelen, ifd->ifd_len), NULL);
    449  1.29     pooka 		break;
    450  1.29     pooka 	case SIOCSLINKSTR:
    451  1.29     pooka 		if (ifp->if_flags & IFF_UP) {
    452  1.29     pooka 			rv = EBUSY;
    453  1.29     pooka 			break;
    454  1.29     pooka 		}
    455  1.29     pooka 
    456  1.29     pooka 		ifd = data;
    457  1.29     pooka 		if (ifd->ifd_cmd == IFLINKSTR_UNSET) {
    458  1.29     pooka 			finibackend(sc);
    459  1.29     pooka 			rv = 0;
    460  1.29     pooka 			break;
    461  1.29     pooka 		} else if (ifd->ifd_cmd != 0) {
    462  1.29     pooka 			rv = EINVAL;
    463  1.29     pooka 			break;
    464  1.29     pooka 		} else if (sc->sc_backfile) {
    465  1.29     pooka 			rv = EBUSY;
    466  1.29     pooka 			break;
    467  1.29     pooka 		}
    468  1.29     pooka 
    469  1.29     pooka 		if (ifd->ifd_len > MAXPATHLEN) {
    470  1.29     pooka 			rv = E2BIG;
    471  1.29     pooka 			break;
    472  1.29     pooka 		} else if (ifd->ifd_len < 1) {
    473  1.29     pooka 			rv = EINVAL;
    474  1.29     pooka 			break;
    475  1.29     pooka 		}
    476  1.29     pooka 
    477  1.29     pooka 		path = kmem_alloc(ifd->ifd_len, KM_SLEEP);
    478  1.29     pooka 		rv = copyinstr(ifd->ifd_data, path, ifd->ifd_len, NULL);
    479  1.29     pooka 		if (rv) {
    480  1.29     pooka 			kmem_free(path, ifd->ifd_len);
    481  1.29     pooka 			break;
    482  1.29     pooka 		}
    483  1.53     pooka 		rv = rumpuser_open(path,
    484  1.53     pooka 		    RUMPUSER_OPEN_RDWR | RUMPUSER_OPEN_CREATE, &memfd);
    485  1.53     pooka 		if (rv) {
    486  1.29     pooka 			kmem_free(path, ifd->ifd_len);
    487  1.29     pooka 			break;
    488  1.29     pooka 		}
    489  1.29     pooka 		rv = initbackend(sc, memfd);
    490  1.29     pooka 		if (rv) {
    491  1.29     pooka 			kmem_free(path, ifd->ifd_len);
    492  1.53     pooka 			rumpuser_close(memfd);
    493  1.29     pooka 			break;
    494  1.29     pooka 		}
    495  1.29     pooka 		sc->sc_backfile = path;
    496  1.29     pooka 		sc->sc_backfilelen = ifd->ifd_len;
    497  1.29     pooka 
    498  1.29     pooka 		break;
    499  1.29     pooka 	default:
    500  1.29     pooka 		rv = ether_ioctl(ifp, cmd, data);
    501  1.29     pooka 		if (rv == ENETRESET)
    502  1.29     pooka 			rv = 0;
    503  1.29     pooka 		break;
    504  1.29     pooka 	}
    505   1.1     pooka 	splx(s);
    506   1.1     pooka 
    507   1.1     pooka 	return rv;
    508   1.1     pooka }
    509   1.1     pooka 
    510  1.32     pooka /* send everything in-context since it's just a matter of mem-to-mem copy */
    511   1.1     pooka static void
    512   1.1     pooka shmif_start(struct ifnet *ifp)
    513   1.1     pooka {
    514   1.1     pooka 	struct shmif_sc *sc = ifp->if_softc;
    515  1.26     pooka 	struct shmif_mem *busmem = sc->sc_busmem;
    516   1.1     pooka 	struct mbuf *m, *m0;
    517  1.26     pooka 	uint32_t dataoff;
    518  1.26     pooka 	uint32_t pktsize, pktwrote;
    519   1.1     pooka 	bool wrote = false;
    520  1.24     pooka 	bool wrap;
    521   1.1     pooka 
    522  1.26     pooka 	ifp->if_flags |= IFF_OACTIVE;
    523  1.26     pooka 
    524   1.1     pooka 	for (;;) {
    525  1.20     pooka 		struct shmif_pkthdr sp;
    526  1.20     pooka 		struct timeval tv;
    527  1.20     pooka 
    528   1.1     pooka 		IF_DEQUEUE(&ifp->if_snd, m0);
    529   1.1     pooka 		if (m0 == NULL) {
    530   1.1     pooka 			break;
    531   1.1     pooka 		}
    532   1.1     pooka 
    533  1.25     pooka 		pktsize = 0;
    534  1.19     pooka 		for (m = m0; m != NULL; m = m->m_next) {
    535  1.19     pooka 			pktsize += m->m_len;
    536  1.19     pooka 		}
    537  1.26     pooka 		KASSERT(pktsize <= ETHERMTU + ETHER_HDR_LEN);
    538  1.19     pooka 
    539  1.20     pooka 		getmicrouptime(&tv);
    540  1.20     pooka 		sp.sp_len = pktsize;
    541  1.20     pooka 		sp.sp_sec = tv.tv_sec;
    542  1.20     pooka 		sp.sp_usec = tv.tv_usec;
    543  1.20     pooka 
    544  1.35     pooka 		bpf_mtap(ifp, m0);
    545  1.35     pooka 
    546  1.26     pooka 		shmif_lockbus(busmem);
    547  1.26     pooka 		KASSERT(busmem->shm_magic == SHMIF_MAGIC);
    548  1.26     pooka 		busmem->shm_last = shmif_nextpktoff(busmem, busmem->shm_last);
    549  1.21     pooka 
    550  1.24     pooka 		wrap = false;
    551  1.26     pooka 		dataoff = shmif_buswrite(busmem,
    552  1.26     pooka 		    busmem->shm_last, &sp, sizeof(sp), &wrap);
    553  1.26     pooka 		pktwrote = 0;
    554   1.1     pooka 		for (m = m0; m != NULL; m = m->m_next) {
    555  1.26     pooka 			pktwrote += m->m_len;
    556  1.26     pooka 			dataoff = shmif_buswrite(busmem, dataoff,
    557  1.19     pooka 			    mtod(m, void *), m->m_len, &wrap);
    558   1.1     pooka 		}
    559  1.26     pooka 		KASSERT(pktwrote == pktsize);
    560  1.27     pooka 		if (wrap) {
    561  1.26     pooka 			busmem->shm_gen++;
    562  1.47     pooka 			DPRINTF(("bus generation now %" PRIu64 "\n",
    563  1.47     pooka 			    busmem->shm_gen));
    564  1.27     pooka 		}
    565  1.26     pooka 		shmif_unlockbus(busmem);
    566   1.1     pooka 
    567   1.1     pooka 		m_freem(m0);
    568   1.1     pooka 		wrote = true;
    569   1.1     pooka 
    570   1.1     pooka 		DPRINTF(("shmif_start: send %d bytes at off %d\n",
    571  1.27     pooka 		    pktsize, busmem->shm_last));
    572   1.1     pooka 	}
    573  1.26     pooka 
    574  1.26     pooka 	ifp->if_flags &= ~IFF_OACTIVE;
    575  1.26     pooka 
    576  1.32     pooka 	/* wakeup? */
    577  1.52     pooka 	if (wrote) {
    578  1.52     pooka 		dowakeup(sc);
    579  1.52     pooka 	}
    580   1.1     pooka }
    581   1.1     pooka 
    582   1.1     pooka static void
    583   1.1     pooka shmif_stop(struct ifnet *ifp, int disable)
    584   1.1     pooka {
    585  1.32     pooka 	struct shmif_sc *sc = ifp->if_softc;
    586   1.1     pooka 
    587  1.32     pooka 	ifp->if_flags &= ~IFF_RUNNING;
    588  1.32     pooka 	membar_producer();
    589  1.32     pooka 
    590  1.32     pooka 	/*
    591  1.32     pooka 	 * wakeup thread.  this will of course wake up all bus
    592  1.32     pooka 	 * listeners, but that's life.
    593  1.32     pooka 	 */
    594  1.52     pooka 	if (sc->sc_memfd != -1) {
    595  1.52     pooka 		dowakeup(sc);
    596  1.52     pooka 	}
    597   1.1     pooka }
    598   1.1     pooka 
    599  1.27     pooka 
    600  1.27     pooka /*
    601  1.27     pooka  * Check if we have been sleeping too long.  Basically,
    602  1.27     pooka  * our in-sc nextpkt must by first <= nextpkt <= last"+1".
    603  1.27     pooka  * We use the fact that first is guaranteed to never overlap
    604  1.27     pooka  * with the last frame in the ring.
    605  1.27     pooka  */
    606  1.27     pooka static __inline bool
    607  1.27     pooka stillvalid_p(struct shmif_sc *sc)
    608  1.27     pooka {
    609  1.27     pooka 	struct shmif_mem *busmem = sc->sc_busmem;
    610  1.27     pooka 	unsigned gendiff = busmem->shm_gen - sc->sc_devgen;
    611  1.27     pooka 	uint32_t lastoff, devoff;
    612  1.27     pooka 
    613  1.27     pooka 	KASSERT(busmem->shm_first != busmem->shm_last);
    614  1.27     pooka 
    615  1.27     pooka 	/* normalize onto a 2x busmem chunk */
    616  1.27     pooka 	devoff = sc->sc_nextpacket;
    617  1.27     pooka 	lastoff = shmif_nextpktoff(busmem, busmem->shm_last);
    618  1.27     pooka 
    619  1.27     pooka 	/* trivial case */
    620  1.27     pooka 	if (gendiff > 1)
    621  1.27     pooka 		return false;
    622  1.27     pooka 	KASSERT(gendiff <= 1);
    623  1.27     pooka 
    624  1.27     pooka 	/* Normalize onto 2x busmem chunk */
    625  1.27     pooka 	if (busmem->shm_first >= lastoff) {
    626  1.27     pooka 		lastoff += BUSMEM_DATASIZE;
    627  1.27     pooka 		if (gendiff == 0)
    628  1.27     pooka 			devoff += BUSMEM_DATASIZE;
    629  1.27     pooka 	} else {
    630  1.27     pooka 		if (gendiff)
    631  1.27     pooka 			return false;
    632  1.27     pooka 	}
    633  1.27     pooka 
    634  1.27     pooka 	return devoff >= busmem->shm_first && devoff <= lastoff;
    635  1.27     pooka }
    636  1.27     pooka 
    637   1.1     pooka static void
    638   1.1     pooka shmif_rcv(void *arg)
    639   1.1     pooka {
    640   1.1     pooka 	struct ifnet *ifp = arg;
    641   1.1     pooka 	struct shmif_sc *sc = ifp->if_softc;
    642  1.32     pooka 	struct shmif_mem *busmem;
    643   1.1     pooka 	struct mbuf *m = NULL;
    644   1.1     pooka 	struct ether_header *eth;
    645  1.27     pooka 	uint32_t nextpkt;
    646  1.37     pooka 	bool wrap, passup;
    647   1.1     pooka 	int error;
    648  1.57     pooka 	const int align
    649  1.57     pooka 	    = ALIGN(sizeof(struct ether_header)) - sizeof(struct ether_header);
    650   1.1     pooka 
    651  1.32     pooka  reup:
    652  1.32     pooka 	mutex_enter(&sc->sc_mtx);
    653  1.32     pooka 	while ((ifp->if_flags & IFF_RUNNING) == 0 && !sc->sc_dying)
    654  1.32     pooka 		cv_wait(&sc->sc_cv, &sc->sc_mtx);
    655  1.32     pooka 	mutex_exit(&sc->sc_mtx);
    656  1.32     pooka 
    657  1.32     pooka 	busmem = sc->sc_busmem;
    658  1.32     pooka 
    659  1.32     pooka 	while (ifp->if_flags & IFF_RUNNING) {
    660  1.20     pooka 		struct shmif_pkthdr sp;
    661  1.20     pooka 
    662   1.1     pooka 		if (m == NULL) {
    663   1.1     pooka 			m = m_gethdr(M_WAIT, MT_DATA);
    664   1.1     pooka 			MCLGET(m, M_WAIT);
    665  1.57     pooka 			m->m_data += align;
    666   1.1     pooka 		}
    667   1.1     pooka 
    668  1.47     pooka 		DPRINTF(("waiting %d/%" PRIu64 "\n",
    669  1.47     pooka 		    sc->sc_nextpacket, sc->sc_devgen));
    670  1.26     pooka 		KASSERT(m->m_flags & M_EXT);
    671   1.1     pooka 
    672  1.26     pooka 		shmif_lockbus(busmem);
    673  1.26     pooka 		KASSERT(busmem->shm_magic == SHMIF_MAGIC);
    674  1.27     pooka 		KASSERT(busmem->shm_gen >= sc->sc_devgen);
    675   1.1     pooka 
    676   1.1     pooka 		/* need more data? */
    677  1.27     pooka 		if (sc->sc_devgen == busmem->shm_gen &&
    678  1.26     pooka 		    shmif_nextpktoff(busmem, busmem->shm_last)
    679  1.26     pooka 		     == sc->sc_nextpacket) {
    680  1.26     pooka 			shmif_unlockbus(busmem);
    681   1.1     pooka 			error = 0;
    682  1.53     pooka 			rumpcomp_shmif_watchwait(sc->sc_kq);
    683   1.1     pooka 			if (__predict_false(error))
    684   1.1     pooka 				printf("shmif_rcv: wait failed %d\n", error);
    685  1.32     pooka 			membar_consumer();
    686   1.1     pooka 			continue;
    687   1.1     pooka 		}
    688   1.1     pooka 
    689  1.27     pooka 		if (stillvalid_p(sc)) {
    690  1.27     pooka 			nextpkt = sc->sc_nextpacket;
    691  1.27     pooka 		} else {
    692  1.27     pooka 			KASSERT(busmem->shm_gen > 0);
    693  1.26     pooka 			nextpkt = busmem->shm_first;
    694  1.26     pooka 			if (busmem->shm_first > busmem->shm_last)
    695  1.27     pooka 				sc->sc_devgen = busmem->shm_gen - 1;
    696  1.26     pooka 			else
    697  1.27     pooka 				sc->sc_devgen = busmem->shm_gen;
    698  1.47     pooka 			DPRINTF(("dev %p overrun, new data: %d/%" PRIu64 "\n",
    699  1.27     pooka 			    sc, nextpkt, sc->sc_devgen));
    700  1.26     pooka 		}
    701  1.26     pooka 
    702  1.26     pooka 		/*
    703  1.26     pooka 		 * If our read pointer is ahead the bus last write, our
    704  1.26     pooka 		 * generation must be one behind.
    705  1.26     pooka 		 */
    706  1.26     pooka 		KASSERT(!(nextpkt > busmem->shm_last
    707  1.27     pooka 		    && sc->sc_devgen == busmem->shm_gen));
    708  1.26     pooka 
    709  1.24     pooka 		wrap = false;
    710  1.26     pooka 		nextpkt = shmif_busread(busmem, &sp,
    711  1.26     pooka 		    nextpkt, sizeof(sp), &wrap);
    712  1.26     pooka 		KASSERT(sp.sp_len <= ETHERMTU + ETHER_HDR_LEN);
    713  1.26     pooka 		nextpkt = shmif_busread(busmem, mtod(m, void *),
    714  1.26     pooka 		    nextpkt, sp.sp_len, &wrap);
    715   1.1     pooka 
    716   1.1     pooka 		DPRINTF(("shmif_rcv: read packet of length %d at %d\n",
    717  1.20     pooka 		    sp.sp_len, nextpkt));
    718   1.1     pooka 
    719  1.26     pooka 		sc->sc_nextpacket = nextpkt;
    720  1.19     pooka 		shmif_unlockbus(sc->sc_busmem);
    721   1.1     pooka 
    722  1.27     pooka 		if (wrap) {
    723  1.26     pooka 			sc->sc_devgen++;
    724  1.47     pooka 			DPRINTF(("dev %p generation now %" PRIu64 "\n",
    725  1.27     pooka 			    sc, sc->sc_devgen));
    726  1.27     pooka 		}
    727  1.26     pooka 
    728  1.56     pooka 		/*
    729  1.56     pooka 		 * Ignore packets too short to possibly be valid.
    730  1.56     pooka 		 * This is hit at least for the first frame on a new bus.
    731  1.56     pooka 		 */
    732  1.55     pooka 		if (__predict_false(sp.sp_len < ETHER_HDR_LEN)) {
    733  1.55     pooka 			DPRINTF(("shmif read packet len %d < ETHER_HDR_LEN\n",
    734  1.55     pooka 			    sp.sp_len));
    735  1.55     pooka 			continue;
    736  1.55     pooka 		}
    737  1.55     pooka 
    738  1.20     pooka 		m->m_len = m->m_pkthdr.len = sp.sp_len;
    739   1.1     pooka 		m->m_pkthdr.rcvif = ifp;
    740   1.1     pooka 
    741  1.37     pooka 		/*
    742  1.37     pooka 		 * Test if we want to pass the packet upwards
    743  1.37     pooka 		 */
    744   1.1     pooka 		eth = mtod(m, struct ether_header *);
    745  1.37     pooka 		if (memcmp(eth->ether_dhost, CLLADDR(ifp->if_sadl),
    746  1.37     pooka 		    ETHER_ADDR_LEN) == 0) {
    747  1.37     pooka 			passup = true;
    748  1.46     pooka 		} else if (ETHER_IS_MULTICAST(eth->ether_dhost)) {
    749  1.37     pooka 			passup = true;
    750  1.37     pooka 		} else if (ifp->if_flags & IFF_PROMISC) {
    751  1.37     pooka 			m->m_flags |= M_PROMISC;
    752  1.37     pooka 			passup = true;
    753  1.38     pooka 		} else {
    754  1.38     pooka 			passup = false;
    755  1.37     pooka 		}
    756  1.37     pooka 
    757  1.37     pooka 		if (passup) {
    758  1.22     pooka 			KERNEL_LOCK(1, NULL);
    759  1.35     pooka 			bpf_mtap(ifp, m);
    760   1.1     pooka 			ifp->if_input(ifp, m);
    761  1.22     pooka 			KERNEL_UNLOCK_ONE(NULL);
    762   1.1     pooka 			m = NULL;
    763   1.1     pooka 		}
    764  1.37     pooka 		/* else: reuse mbuf for a future packet */
    765   1.1     pooka 	}
    766  1.32     pooka 	m_freem(m);
    767  1.32     pooka 	m = NULL;
    768  1.32     pooka 
    769  1.32     pooka 	if (!sc->sc_dying)
    770  1.32     pooka 		goto reup;
    771   1.1     pooka 
    772  1.32     pooka 	kthread_exit(0);
    773   1.1     pooka }
    774