if_shmem.c revision 1.4.2.2
1 1.4.2.2 skrll /* $NetBSD: if_shmem.c,v 1.4.2.2 2009/03/03 18:34:31 skrll Exp $ */ 2 1.4.2.2 skrll 3 1.4.2.2 skrll /* 4 1.4.2.2 skrll * Copyright (c) 2009 Antti Kantee. All Rights Reserved. 5 1.4.2.2 skrll * 6 1.4.2.2 skrll * Development of this software was supported by The Nokia Foundation. 7 1.4.2.2 skrll * 8 1.4.2.2 skrll * Redistribution and use in source and binary forms, with or without 9 1.4.2.2 skrll * modification, are permitted provided that the following conditions 10 1.4.2.2 skrll * are met: 11 1.4.2.2 skrll * 1. Redistributions of source code must retain the above copyright 12 1.4.2.2 skrll * notice, this list of conditions and the following disclaimer. 13 1.4.2.2 skrll * 2. Redistributions in binary form must reproduce the above copyright 14 1.4.2.2 skrll * notice, this list of conditions and the following disclaimer in the 15 1.4.2.2 skrll * documentation and/or other materials provided with the distribution. 16 1.4.2.2 skrll * 17 1.4.2.2 skrll * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 18 1.4.2.2 skrll * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 19 1.4.2.2 skrll * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 20 1.4.2.2 skrll * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 1.4.2.2 skrll * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 1.4.2.2 skrll * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 23 1.4.2.2 skrll * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 1.4.2.2 skrll * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 1.4.2.2 skrll * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 1.4.2.2 skrll * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 1.4.2.2 skrll * SUCH DAMAGE. 28 1.4.2.2 skrll */ 29 1.4.2.2 skrll 30 1.4.2.2 skrll #include <sys/cdefs.h> 31 1.4.2.2 skrll __KERNEL_RCSID(0, "$NetBSD: if_shmem.c,v 1.4.2.2 2009/03/03 18:34:31 skrll Exp $"); 32 1.4.2.2 skrll 33 1.4.2.2 skrll #include <sys/param.h> 34 1.4.2.2 skrll #include <sys/fcntl.h> 35 1.4.2.2 skrll #include <sys/kmem.h> 36 1.4.2.2 skrll #include <sys/kthread.h> 37 1.4.2.2 skrll #include <sys/lock.h> 38 1.4.2.2 skrll #include <sys/atomic.h> 39 1.4.2.2 skrll 40 1.4.2.2 skrll #include <net/if.h> 41 1.4.2.2 skrll #include <net/if_ether.h> 42 1.4.2.2 skrll 43 1.4.2.2 skrll #include <netinet/in.h> 44 1.4.2.2 skrll #include <netinet/in_var.h> 45 1.4.2.2 skrll 46 1.4.2.2 skrll #include <rump/rump.h> 47 1.4.2.2 skrll #include <rump/rumpuser.h> 48 1.4.2.2 skrll 49 1.4.2.2 skrll #include "rump_private.h" 50 1.4.2.2 skrll 51 1.4.2.2 skrll /* 52 1.4.2.2 skrll * A virtual ethernet interface which uses shared memory from a 53 1.4.2.2 skrll * memory mapped file as the bus. 54 1.4.2.2 skrll */ 55 1.4.2.2 skrll 56 1.4.2.2 skrll static int shmif_init(struct ifnet *); 57 1.4.2.2 skrll static int shmif_ioctl(struct ifnet *, u_long, void *); 58 1.4.2.2 skrll static void shmif_start(struct ifnet *); 59 1.4.2.2 skrll static void shmif_stop(struct ifnet *, int); 60 1.4.2.2 skrll 61 1.4.2.2 skrll struct shmif_sc { 62 1.4.2.2 skrll struct ethercom sc_ec; 63 1.4.2.2 skrll uint8_t sc_myaddr[6]; 64 1.4.2.2 skrll uint8_t *sc_busmem; 65 1.4.2.2 skrll int sc_memfd; 66 1.4.2.2 skrll int sc_kq; 67 1.4.2.2 skrll 68 1.4.2.2 skrll uint32_t sc_nextpacket; 69 1.4.2.2 skrll uint32_t sc_prevgen; 70 1.4.2.2 skrll }; 71 1.4.2.2 skrll #define IFMEM_LOCK (0) 72 1.4.2.2 skrll #define IFMEM_GENERATION (8) 73 1.4.2.2 skrll #define IFMEM_LASTPACKET (12) 74 1.4.2.2 skrll #define IFMEM_WAKEUP (16) 75 1.4.2.2 skrll #define IFMEM_DATA (20) 76 1.4.2.2 skrll 77 1.4.2.2 skrll #define BUSCTRL_ATOFF(sc, off) ((uint32_t *)(sc->sc_busmem+(off))) 78 1.4.2.2 skrll 79 1.4.2.2 skrll #define BUSMEM_SIZE 65536 /* enough? */ 80 1.4.2.2 skrll 81 1.4.2.2 skrll static void shmif_rcv(void *); 82 1.4.2.2 skrll 83 1.4.2.2 skrll static uint32_t numif; 84 1.4.2.2 skrll 85 1.4.2.2 skrll /* 86 1.4.2.2 skrll * This locking needs work and will misbehave severely if: 87 1.4.2.2 skrll * 1) the backing memory has to be paged in 88 1.4.2.2 skrll * 2) some lockholder exits while holding the lock 89 1.4.2.2 skrll */ 90 1.4.2.2 skrll static void 91 1.4.2.2 skrll lockbus(struct shmif_sc *sc) 92 1.4.2.2 skrll { 93 1.4.2.2 skrll 94 1.4.2.2 skrll __cpu_simple_lock((__cpu_simple_lock_t *)sc->sc_busmem); 95 1.4.2.2 skrll } 96 1.4.2.2 skrll 97 1.4.2.2 skrll static void 98 1.4.2.2 skrll unlockbus(struct shmif_sc *sc) 99 1.4.2.2 skrll { 100 1.4.2.2 skrll 101 1.4.2.2 skrll __cpu_simple_unlock((__cpu_simple_lock_t *)sc->sc_busmem); 102 1.4.2.2 skrll } 103 1.4.2.2 skrll 104 1.4.2.2 skrll static uint32_t 105 1.4.2.2 skrll busread(struct shmif_sc *sc, void *dest, uint32_t off, size_t len) 106 1.4.2.2 skrll { 107 1.4.2.2 skrll size_t chunk; 108 1.4.2.2 skrll 109 1.4.2.2 skrll KASSERT(len < (BUSMEM_SIZE - IFMEM_DATA) && off <= BUSMEM_SIZE); 110 1.4.2.2 skrll chunk = MIN(len, BUSMEM_SIZE - off); 111 1.4.2.2 skrll memcpy(dest, sc->sc_busmem + off, chunk); 112 1.4.2.2 skrll len -= chunk; 113 1.4.2.2 skrll 114 1.4.2.2 skrll if (len == 0) 115 1.4.2.2 skrll return off + chunk; 116 1.4.2.2 skrll 117 1.4.2.2 skrll /* else, wraps around */ 118 1.4.2.2 skrll off = IFMEM_DATA; 119 1.4.2.2 skrll sc->sc_prevgen = *BUSCTRL_ATOFF(sc, IFMEM_GENERATION); 120 1.4.2.2 skrll 121 1.4.2.2 skrll /* finish reading */ 122 1.4.2.2 skrll memcpy((uint8_t *)dest + chunk, sc->sc_busmem + off, len); 123 1.4.2.2 skrll return off + len; 124 1.4.2.2 skrll } 125 1.4.2.2 skrll 126 1.4.2.2 skrll static uint32_t 127 1.4.2.2 skrll buswrite(struct shmif_sc *sc, uint32_t off, void *data, size_t len) 128 1.4.2.2 skrll { 129 1.4.2.2 skrll size_t chunk; 130 1.4.2.2 skrll 131 1.4.2.2 skrll KASSERT(len < (BUSMEM_SIZE - IFMEM_DATA) && off <= BUSMEM_SIZE); 132 1.4.2.2 skrll 133 1.4.2.2 skrll chunk = MIN(len, BUSMEM_SIZE - off); 134 1.4.2.2 skrll memcpy(sc->sc_busmem + off, data, chunk); 135 1.4.2.2 skrll len -= chunk; 136 1.4.2.2 skrll 137 1.4.2.2 skrll if (len == 0) 138 1.4.2.2 skrll return off + chunk; 139 1.4.2.2 skrll 140 1.4.2.2 skrll DPRINTF(("buswrite wrap: wrote %d bytes to %d, left %d to %d", 141 1.4.2.2 skrll chunk, off, len, IFMEM_DATA)); 142 1.4.2.2 skrll 143 1.4.2.2 skrll /* else, wraps around */ 144 1.4.2.2 skrll off = IFMEM_DATA; 145 1.4.2.2 skrll (*BUSCTRL_ATOFF(sc, IFMEM_GENERATION))++; 146 1.4.2.2 skrll sc->sc_prevgen = *BUSCTRL_ATOFF(sc, IFMEM_GENERATION); 147 1.4.2.2 skrll 148 1.4.2.2 skrll /* finish writing */ 149 1.4.2.2 skrll memcpy(sc->sc_busmem + off, (uint8_t *)data + chunk, len); 150 1.4.2.2 skrll return off + len; 151 1.4.2.2 skrll } 152 1.4.2.2 skrll 153 1.4.2.2 skrll static inline uint32_t 154 1.4.2.2 skrll advance(uint32_t oldoff, uint32_t delta) 155 1.4.2.2 skrll { 156 1.4.2.2 skrll uint32_t newoff; 157 1.4.2.2 skrll 158 1.4.2.2 skrll newoff = oldoff + delta; 159 1.4.2.2 skrll if (newoff >= BUSMEM_SIZE) 160 1.4.2.2 skrll newoff -= (BUSMEM_SIZE - IFMEM_DATA); 161 1.4.2.2 skrll return newoff; 162 1.4.2.2 skrll 163 1.4.2.2 skrll } 164 1.4.2.2 skrll 165 1.4.2.2 skrll static uint32_t 166 1.4.2.2 skrll nextpktoff(struct shmif_sc *sc, uint32_t oldoff) 167 1.4.2.2 skrll { 168 1.4.2.2 skrll uint32_t oldlen; 169 1.4.2.2 skrll 170 1.4.2.2 skrll busread(sc, &oldlen, oldoff, 4); 171 1.4.2.2 skrll KASSERT(oldlen < BUSMEM_SIZE - IFMEM_DATA); 172 1.4.2.2 skrll 173 1.4.2.2 skrll return advance(oldoff, 4 + oldlen); 174 1.4.2.2 skrll } 175 1.4.2.2 skrll 176 1.4.2.2 skrll int rump_shmif_create(const char *, int *); /* XXX */ 177 1.4.2.2 skrll 178 1.4.2.2 skrll int 179 1.4.2.2 skrll rump_shmif_create(const char *path, int *ifnum) 180 1.4.2.2 skrll { 181 1.4.2.2 skrll struct shmif_sc *sc; 182 1.4.2.2 skrll struct ifnet *ifp; 183 1.4.2.2 skrll uint8_t enaddr[ETHER_ADDR_LEN] = { 0xb2, 0xa0, 0x00, 0x00, 0x00, 0x00 }; 184 1.4.2.2 skrll uint32_t randnum; 185 1.4.2.2 skrll unsigned mynum; 186 1.4.2.2 skrll int error; 187 1.4.2.2 skrll 188 1.4.2.2 skrll randnum = arc4random(); 189 1.4.2.2 skrll memcpy(&enaddr[2], &randnum, 4); 190 1.4.2.2 skrll mynum = atomic_inc_uint_nv(&numif)-1; 191 1.4.2.2 skrll 192 1.4.2.2 skrll sc = kmem_zalloc(sizeof(*sc), KM_SLEEP); 193 1.4.2.2 skrll ifp = &sc->sc_ec.ec_if; 194 1.4.2.2 skrll memcpy(sc->sc_myaddr, enaddr, sizeof(enaddr)); 195 1.4.2.2 skrll 196 1.4.2.2 skrll sc->sc_memfd = rumpuser_open(path, O_RDWR | O_CREAT, &error); 197 1.4.2.2 skrll if (sc->sc_memfd == -1) 198 1.4.2.2 skrll goto fail; 199 1.4.2.2 skrll sc->sc_busmem = rumpuser_filemmap(sc->sc_memfd, 0, BUSMEM_SIZE, 200 1.4.2.2 skrll 1, 1, &error); 201 1.4.2.2 skrll if (error) 202 1.4.2.2 skrll goto fail; 203 1.4.2.2 skrll 204 1.4.2.2 skrll lockbus(sc); 205 1.4.2.2 skrll if (*BUSCTRL_ATOFF(sc, IFMEM_LASTPACKET) == 0) 206 1.4.2.2 skrll *BUSCTRL_ATOFF(sc, IFMEM_LASTPACKET) = IFMEM_DATA; 207 1.4.2.2 skrll sc->sc_nextpacket = *BUSCTRL_ATOFF(sc, IFMEM_LASTPACKET); 208 1.4.2.2 skrll sc->sc_prevgen = *BUSCTRL_ATOFF(sc, IFMEM_GENERATION); 209 1.4.2.2 skrll unlockbus(sc); 210 1.4.2.2 skrll 211 1.4.2.2 skrll sc->sc_kq = rumpuser_writewatchfile_setup(-1, sc->sc_memfd, 0, &error); 212 1.4.2.2 skrll if (sc->sc_kq == -1) 213 1.4.2.2 skrll goto fail; 214 1.4.2.2 skrll 215 1.4.2.2 skrll sprintf(ifp->if_xname, "shmif%d", mynum); 216 1.4.2.2 skrll ifp->if_softc = sc; 217 1.4.2.2 skrll ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST; 218 1.4.2.2 skrll ifp->if_init = shmif_init; 219 1.4.2.2 skrll ifp->if_ioctl = shmif_ioctl; 220 1.4.2.2 skrll ifp->if_start = shmif_start; 221 1.4.2.2 skrll ifp->if_stop = shmif_stop; 222 1.4.2.2 skrll ifp->if_mtu = 1518; 223 1.4.2.2 skrll 224 1.4.2.2 skrll if_attach(ifp); 225 1.4.2.2 skrll ether_ifattach(ifp, enaddr); 226 1.4.2.2 skrll 227 1.4.2.2 skrll if (ifnum) 228 1.4.2.2 skrll *ifnum = mynum; 229 1.4.2.2 skrll return 0; 230 1.4.2.2 skrll 231 1.4.2.2 skrll fail: 232 1.4.2.2 skrll panic("rump_shmemif_create: fixme"); 233 1.4.2.2 skrll } 234 1.4.2.2 skrll 235 1.4.2.2 skrll static int 236 1.4.2.2 skrll shmif_init(struct ifnet *ifp) 237 1.4.2.2 skrll { 238 1.4.2.2 skrll int error = 0; 239 1.4.2.2 skrll 240 1.4.2.2 skrll if (rump_threads) { 241 1.4.2.2 skrll error = kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL, 242 1.4.2.2 skrll shmif_rcv, ifp, NULL, "shmif"); 243 1.4.2.2 skrll } else { 244 1.4.2.2 skrll printf("WARNING: threads not enabled, shmif NOT working\n"); 245 1.4.2.2 skrll } 246 1.4.2.2 skrll 247 1.4.2.2 skrll ifp->if_flags |= IFF_RUNNING; 248 1.4.2.2 skrll return error; 249 1.4.2.2 skrll } 250 1.4.2.2 skrll 251 1.4.2.2 skrll static int 252 1.4.2.2 skrll shmif_ioctl(struct ifnet *ifp, u_long cmd, void *data) 253 1.4.2.2 skrll { 254 1.4.2.2 skrll int s, rv; 255 1.4.2.2 skrll 256 1.4.2.2 skrll s = splnet(); 257 1.4.2.2 skrll rv = ether_ioctl(ifp, cmd, data); 258 1.4.2.2 skrll splx(s); 259 1.4.2.2 skrll 260 1.4.2.2 skrll return rv; 261 1.4.2.2 skrll } 262 1.4.2.2 skrll 263 1.4.2.2 skrll /* send everything in-context */ 264 1.4.2.2 skrll static void 265 1.4.2.2 skrll shmif_start(struct ifnet *ifp) 266 1.4.2.2 skrll { 267 1.4.2.2 skrll struct shmif_sc *sc = ifp->if_softc; 268 1.4.2.2 skrll struct mbuf *m, *m0; 269 1.4.2.2 skrll uint32_t lastoff, dataoff, npktlenoff; 270 1.4.2.2 skrll uint32_t pktsize = 0; 271 1.4.2.2 skrll bool wrote = false; 272 1.4.2.2 skrll int error; 273 1.4.2.2 skrll 274 1.4.2.2 skrll for (;;) { 275 1.4.2.2 skrll IF_DEQUEUE(&ifp->if_snd, m0); 276 1.4.2.2 skrll if (m0 == NULL) { 277 1.4.2.2 skrll break; 278 1.4.2.2 skrll } 279 1.4.2.2 skrll 280 1.4.2.2 skrll lockbus(sc); 281 1.4.2.2 skrll lastoff = *BUSCTRL_ATOFF(sc, IFMEM_LASTPACKET); 282 1.4.2.2 skrll 283 1.4.2.2 skrll npktlenoff = nextpktoff(sc, lastoff); 284 1.4.2.2 skrll dataoff = advance(npktlenoff, 4); 285 1.4.2.2 skrll 286 1.4.2.2 skrll for (m = m0; m != NULL; m = m->m_next) { 287 1.4.2.2 skrll pktsize += m->m_len; 288 1.4.2.2 skrll dataoff = buswrite(sc, dataoff, mtod(m, void *), 289 1.4.2.2 skrll m->m_len); 290 1.4.2.2 skrll } 291 1.4.2.2 skrll buswrite(sc, npktlenoff, &pktsize, 4); 292 1.4.2.2 skrll *BUSCTRL_ATOFF(sc, IFMEM_LASTPACKET) = npktlenoff; 293 1.4.2.2 skrll unlockbus(sc); 294 1.4.2.2 skrll 295 1.4.2.2 skrll m_freem(m0); 296 1.4.2.2 skrll wrote = true; 297 1.4.2.2 skrll 298 1.4.2.2 skrll DPRINTF(("shmif_start: send %d bytes at off %d\n", 299 1.4.2.2 skrll pktsize, npktlenoff)); 300 1.4.2.2 skrll } 301 1.4.2.2 skrll /* wakeup */ 302 1.4.2.2 skrll if (wrote) 303 1.4.2.2 skrll rumpuser_pwrite(sc->sc_memfd, &error, 4, IFMEM_WAKEUP, &error); 304 1.4.2.2 skrll } 305 1.4.2.2 skrll 306 1.4.2.2 skrll static void 307 1.4.2.2 skrll shmif_stop(struct ifnet *ifp, int disable) 308 1.4.2.2 skrll { 309 1.4.2.2 skrll 310 1.4.2.2 skrll panic("%s: unimpl", __func__); 311 1.4.2.2 skrll } 312 1.4.2.2 skrll 313 1.4.2.2 skrll static void 314 1.4.2.2 skrll shmif_rcv(void *arg) 315 1.4.2.2 skrll { 316 1.4.2.2 skrll struct ifnet *ifp = arg; 317 1.4.2.2 skrll struct shmif_sc *sc = ifp->if_softc; 318 1.4.2.2 skrll struct mbuf *m = NULL; 319 1.4.2.2 skrll struct ether_header *eth; 320 1.4.2.2 skrll uint32_t nextpkt, pktlen, lastpkt, busgen, lastnext; 321 1.4.2.2 skrll int error; 322 1.4.2.2 skrll 323 1.4.2.2 skrll for (;;) { 324 1.4.2.2 skrll if (m == NULL) { 325 1.4.2.2 skrll m = m_gethdr(M_WAIT, MT_DATA); 326 1.4.2.2 skrll MCLGET(m, M_WAIT); 327 1.4.2.2 skrll } 328 1.4.2.2 skrll 329 1.4.2.2 skrll DPRINTF(("waiting %d/%d\n", sc->sc_nextpacket, sc->sc_prevgen)); 330 1.4.2.2 skrll 331 1.4.2.2 skrll KASSERT(m->m_flags & M_EXT); 332 1.4.2.2 skrll lockbus(sc); 333 1.4.2.2 skrll lastpkt = *BUSCTRL_ATOFF(sc, IFMEM_LASTPACKET); 334 1.4.2.2 skrll busgen = *BUSCTRL_ATOFF(sc, IFMEM_GENERATION); 335 1.4.2.2 skrll lastnext = nextpktoff(sc, lastpkt); 336 1.4.2.2 skrll if ((lastnext > sc->sc_nextpacket && busgen > sc->sc_prevgen) 337 1.4.2.2 skrll || (busgen > sc->sc_prevgen+1)) { 338 1.4.2.2 skrll nextpkt = lastpkt; 339 1.4.2.2 skrll sc->sc_prevgen = busgen; 340 1.4.2.2 skrll printf("DROPPING\n"); 341 1.4.2.2 skrll } else { 342 1.4.2.2 skrll nextpkt = sc->sc_nextpacket; 343 1.4.2.2 skrll } 344 1.4.2.2 skrll 345 1.4.2.2 skrll /* need more data? */ 346 1.4.2.2 skrll if (lastnext == nextpkt && sc->sc_prevgen == busgen){ 347 1.4.2.2 skrll unlockbus(sc); 348 1.4.2.2 skrll error = 0; 349 1.4.2.2 skrll rumpuser_writewatchfile_wait(sc->sc_kq, NULL, &error); 350 1.4.2.2 skrll if (__predict_false(error)) 351 1.4.2.2 skrll printf("shmif_rcv: wait failed %d\n", error); 352 1.4.2.2 skrll continue; 353 1.4.2.2 skrll } 354 1.4.2.2 skrll 355 1.4.2.2 skrll busread(sc, &pktlen, nextpkt, 4); 356 1.4.2.2 skrll busread(sc, mtod(m, void *), advance(nextpkt, 4), pktlen); 357 1.4.2.2 skrll 358 1.4.2.2 skrll DPRINTF(("shmif_rcv: read packet of length %d at %d\n", 359 1.4.2.2 skrll pktlen, nextpkt)); 360 1.4.2.2 skrll 361 1.4.2.2 skrll sc->sc_nextpacket = nextpktoff(sc, nextpkt); 362 1.4.2.2 skrll sc->sc_prevgen = busgen; 363 1.4.2.2 skrll unlockbus(sc); 364 1.4.2.2 skrll 365 1.4.2.2 skrll m->m_len = m->m_pkthdr.len = pktlen; 366 1.4.2.2 skrll m->m_pkthdr.rcvif = ifp; 367 1.4.2.2 skrll 368 1.4.2.2 skrll /* if it's to us, don't pass up and reuse storage space */ 369 1.4.2.2 skrll eth = mtod(m, struct ether_header *); 370 1.4.2.2 skrll if (memcmp(eth->ether_shost, sc->sc_myaddr, 6) != 0) { 371 1.4.2.2 skrll ifp->if_input(ifp, m); 372 1.4.2.2 skrll m = NULL; 373 1.4.2.2 skrll } 374 1.4.2.2 skrll } 375 1.4.2.2 skrll 376 1.4.2.2 skrll panic("shmif_worker is a lazy boy %d\n", error); 377 1.4.2.2 skrll } 378
Indexes created Fri Sep 26 20:09:58 GMT 2025