hw/net/stellaris_enet.c

   1 /*
   2  * Luminary Micro Stellaris Ethernet Controller
   3  *
   4  * Copyright (c) 2007 CodeSourcery.
   5  * Written by Paul Brook
   6  *
   7  * This code is licensed under the GPL.
   8  */
   9 #include "qemu/osdep.h"
  10 #include "hw/sysbus.h"
  11 #include "net/net.h"
  12 #include <zlib.h>
  13
  14 //#define DEBUG_STELLARIS_ENET 1
  15
  16 #ifdef DEBUG_STELLARIS_ENET
  17 #define DPRINTF(fmt, ...) \
  18 do { printf("stellaris_enet: " fmt , ## __VA_ARGS__); } while (0)
  19 #define BADF(fmt, ...) \
  20 do { fprintf(stderr, "stellaris_enet: error: " fmt , ## __VA_ARGS__); exit(1);} while (0)
  21 #else
  22 #define DPRINTF(fmt, ...) do {} while(0)
  23 #define BADF(fmt, ...) \
  24 do { fprintf(stderr, "stellaris_enet: error: " fmt , ## __VA_ARGS__);} while (0)
  25 #endif
  26
  27 #define SE_INT_RX       0x01
  28 #define SE_INT_TXER     0x02
  29 #define SE_INT_TXEMP    0x04
  30 #define SE_INT_FOV      0x08
  31 #define SE_INT_RXER     0x10
  32 #define SE_INT_MD       0x20
  33 #define SE_INT_PHY      0x40
  34
  35 #define SE_RCTL_RXEN    0x01
  36 #define SE_RCTL_AMUL    0x02
  37 #define SE_RCTL_PRMS    0x04
  38 #define SE_RCTL_BADCRC  0x08
  39 #define SE_RCTL_RSTFIFO 0x10
  40
  41 #define SE_TCTL_TXEN    0x01
  42 #define SE_TCTL_PADEN   0x02
  43 #define SE_TCTL_CRC     0x04
  44 #define SE_TCTL_DUPLEX  0x08
  45
  46 #define TYPE_STELLARIS_ENET "stellaris_enet"
  47 #define STELLARIS_ENET(obj) \
  48     OBJECT_CHECK(stellaris_enet_state, (obj), TYPE_STELLARIS_ENET)
  49
  50 typedef struct {
  51     uint8_t data[2048];
  52     uint32_t len;
  53 } StellarisEnetRxFrame;
  54
  55 typedef struct {
  56     SysBusDevice parent_obj;
  57
  58     uint32_t ris;
  59     uint32_t im;
  60     uint32_t rctl;
  61     uint32_t tctl;
  62     uint32_t thr;
  63     uint32_t mctl;
  64     uint32_t mdv;
  65     uint32_t mtxd;
  66     uint32_t mrxd;
  67     uint32_t np;
  68     uint32_t tx_fifo_len;
  69     uint8_t tx_fifo[2048];
  70     /* Real hardware has a 2k fifo, which works out to be at most 31 packets.
  71        We implement a full 31 packet fifo.  */
  72     StellarisEnetRxFrame rx[31];
  73     uint32_t rx_fifo_offset;
  74     uint32_t next_packet;
  75     NICState *nic;
  76     NICConf conf;
  77     qemu_irq irq;
  78     MemoryRegion mmio;
  79 } stellaris_enet_state;
  80
  81 static const VMStateDescription vmstate_rx_frame = {
  82     .name = "stellaris_enet/rx_frame",
  83     .version_id = 1,
  84     .minimum_version_id = 1,
  85     .fields = (VMStateField[]) {
  86         VMSTATE_UINT8_ARRAY(data, StellarisEnetRxFrame, 2048),
  87         VMSTATE_UINT32(len, StellarisEnetRxFrame),
  88         VMSTATE_END_OF_LIST()
  89     }
  90 };
  91
  92 static int stellaris_enet_post_load(void *opaque, int version_id)
  93 {
  94     stellaris_enet_state *s = opaque;
  95     int i;
  96
  97     /* Sanitize inbound state. Note that next_packet is an index but
  98      * np is a size; hence their valid upper bounds differ.
  99      */
 100     if (s->next_packet >= ARRAY_SIZE(s->rx)) {
 101         return -1;
 102     }
 103
 104     if (s->np > ARRAY_SIZE(s->rx)) {
 105         return -1;
 106     }
 107
 108     for (i = 0; i < ARRAY_SIZE(s->rx); i++) {
 109         if (s->rx[i].len > ARRAY_SIZE(s->rx[i].data)) {
 110             return -1;
 111         }
 112     }
 113
 114     if (s->rx_fifo_offset > ARRAY_SIZE(s->rx[0].data) - 4) {
 115         return -1;
 116     }
 117
 118     if (s->tx_fifo_len > ARRAY_SIZE(s->tx_fifo)) {
 119         return -1;
 120     }
 121
 122     return 0;
 123 }
 124
 125 static const VMStateDescription vmstate_stellaris_enet = {
 126     .name = "stellaris_enet",
 127     .version_id = 2,
 128     .minimum_version_id = 2,
 129     .post_load = stellaris_enet_post_load,
 130     .fields = (VMStateField[]) {
 131         VMSTATE_UINT32(ris, stellaris_enet_state),
 132         VMSTATE_UINT32(im, stellaris_enet_state),
 133         VMSTATE_UINT32(rctl, stellaris_enet_state),
 134         VMSTATE_UINT32(tctl, stellaris_enet_state),
 135         VMSTATE_UINT32(thr, stellaris_enet_state),
 136         VMSTATE_UINT32(mctl, stellaris_enet_state),
 137         VMSTATE_UINT32(mdv, stellaris_enet_state),
 138         VMSTATE_UINT32(mtxd, stellaris_enet_state),
 139         VMSTATE_UINT32(mrxd, stellaris_enet_state),
 140         VMSTATE_UINT32(np, stellaris_enet_state),
 141         VMSTATE_UINT32(tx_fifo_len, stellaris_enet_state),
 142         VMSTATE_UINT8_ARRAY(tx_fifo, stellaris_enet_state, 2048),
 143         VMSTATE_STRUCT_ARRAY(rx, stellaris_enet_state, 31, 1,
 144                              vmstate_rx_frame, StellarisEnetRxFrame),
 145         VMSTATE_UINT32(rx_fifo_offset, stellaris_enet_state),
 146         VMSTATE_UINT32(next_packet, stellaris_enet_state),
 147         VMSTATE_END_OF_LIST()
 148     }
 149 };
 150
 151 static void stellaris_enet_update(stellaris_enet_state *s)
 152 {
 153     qemu_set_irq(s->irq, (s->ris & s->im) != 0);
 154 }
 155
 156 /* Return the data length of the packet currently being assembled
 157  * in the TX fifo.
 158  */
 159 static inline int stellaris_txpacket_datalen(stellaris_enet_state *s)
 160 {
 161     return s->tx_fifo[0] | (s->tx_fifo[1] << 8);
 162 }
 163
 164 /* Return true if the packet currently in the TX FIFO is complete,
 165 * ie the FIFO holds enough bytes for the data length, ethernet header,
 166 * payload and optionally CRC.
 167 */
 168 static inline bool stellaris_txpacket_complete(stellaris_enet_state *s)
 169 {
 170     int framelen = stellaris_txpacket_datalen(s);
 171     framelen += 16;
 172     if (!(s->tctl & SE_TCTL_CRC)) {
 173         framelen += 4;
 174     }
 175     /* Cover the corner case of a 2032 byte payload with auto-CRC disabled:
 176      * this requires more bytes than will fit in the FIFO. It's not totally
 177      * clear how the h/w handles this, but if using threshold-based TX
 178      * it will definitely try to transmit something.
 179      */
 180     framelen = MIN(framelen, ARRAY_SIZE(s->tx_fifo));
 181     return s->tx_fifo_len >= framelen;
 182 }
 183
 184 /* Return true if the TX FIFO threshold is enabled and the FIFO
 185  * has filled enough to reach it.
 186  */
 187 static inline bool stellaris_tx_thr_reached(stellaris_enet_state *s)
 188 {
 189     return (s->thr < 0x3f &&
 190             (s->tx_fifo_len >= 4 * (s->thr * 8 + 1)));
 191 }
 192
 193 /* Send the packet currently in the TX FIFO */
 194 static void stellaris_enet_send(stellaris_enet_state *s)
 195 {
 196     int framelen = stellaris_txpacket_datalen(s);
 197
 198     /* Ethernet header is in the FIFO but not in the datacount.
 199      * We don't implement explicit CRC, so just ignore any
 200      * CRC value in the FIFO.
 201      */
 202     framelen += 14;
 203     if ((s->tctl & SE_TCTL_PADEN) && framelen < 60) {
 204         memset(&s->tx_fifo[framelen + 2], 0, 60 - framelen);
 205         framelen = 60;
 206     }
 207     /* This MIN will have no effect unless the FIFO data is corrupt
 208      * (eg bad data from an incoming migration); otherwise the check
 209      * on the datalen at the start of writing the data into the FIFO
 210      * will have caught this. Silently write a corrupt half-packet,
 211      * which is what the hardware does in FIFO underrun situations.
 212      */
 213     framelen = MIN(framelen, ARRAY_SIZE(s->tx_fifo) - 2);
 214     qemu_send_packet(qemu_get_queue(s->nic), s->tx_fifo + 2, framelen);
 215     s->tx_fifo_len = 0;
 216     s->ris |= SE_INT_TXEMP;
 217     stellaris_enet_update(s);
 218     DPRINTF("Done TX\n");
 219 }
 220
 221 /* TODO: Implement MAC address filtering.  */
 222 static ssize_t stellaris_enet_receive(NetClientState *nc, const uint8_t *buf, size_t size)
 223 {
 224     stellaris_enet_state *s = qemu_get_nic_opaque(nc);
 225     int n;
 226     uint8_t *p;
 227     uint32_t crc;
 228
 229     if ((s->rctl & SE_RCTL_RXEN) == 0)
 230         return -1;
 231     if (s->np >= 31) {
 232         return 0;
 233     }
 234
 235     DPRINTF("Received packet len=%zu\n", size);
 236     n = s->next_packet + s->np;
 237     if (n >= 31)
 238         n -= 31;
 239
 240     if (size >= sizeof(s->rx[n].data) - 6) {
 241         /* If the packet won't fit into the
 242          * emulated 2K RAM, this is reported
 243          * as a FIFO overrun error.
 244          */
 245         s->ris |= SE_INT_FOV;
 246         stellaris_enet_update(s);
 247         return -1;
 248     }
 249
 250     s->np++;
 251     s->rx[n].len = size + 6;
 252     p = s->rx[n].data;
 253     *(p++) = (size + 6);
 254     *(p++) = (size + 6) >> 8;
 255     memcpy (p, buf, size);
 256     p += size;
 257     crc = crc32(~0, buf, size);
 258     *(p++) = crc;
 259     *(p++) = crc >> 8;
 260     *(p++) = crc >> 16;
 261     *(p++) = crc >> 24;
 262     /* Clear the remaining bytes in the last word.  */
 263     if ((size & 3) != 2) {
 264         memset(p, 0, (6 - size) & 3);
 265     }
 266
 267     s->ris |= SE_INT_RX;
 268     stellaris_enet_update(s);
 269
 270     return size;
 271 }
 272
 273 static int stellaris_enet_can_receive(stellaris_enet_state *s)
 274 {
 275     return (s->np < 31);
 276 }
 277
 278 static uint64_t stellaris_enet_read(void *opaque, hwaddr offset,
 279                                     unsigned size)
 280 {
 281     stellaris_enet_state *s = (stellaris_enet_state *)opaque;
 282     uint32_t val;
 283
 284     switch (offset) {
 285     case 0x00: /* RIS */
 286         DPRINTF("IRQ status %02x\n", s->ris);
 287         return s->ris;
 288     case 0x04: /* IM */
 289         return s->im;
 290     case 0x08: /* RCTL */
 291         return s->rctl;
 292     case 0x0c: /* TCTL */
 293         return s->tctl;
 294     case 0x10: /* DATA */
 295     {
 296         uint8_t *rx_fifo;
 297
 298         if (s->np == 0) {
 299             BADF("RX underflow\n");
 300             return 0;
 301         }
 302
 303         rx_fifo = s->rx[s->next_packet].data + s->rx_fifo_offset;
 304
 305         val = rx_fifo[0] | (rx_fifo[1] << 8) | (rx_fifo[2] << 16)
 306               | (rx_fifo[3] << 24);
 307         s->rx_fifo_offset += 4;
 308         if (s->rx_fifo_offset >= s->rx[s->next_packet].len) {
 309             s->rx_fifo_offset = 0;
 310             s->next_packet++;
 311             if (s->next_packet >= 31)
 312                 s->next_packet = 0;
 313             s->np--;
 314             DPRINTF("RX done np=%d\n", s->np);
 315             if (!s->np && stellaris_enet_can_receive(s)) {
 316                 qemu_flush_queued_packets(qemu_get_queue(s->nic));
 317             }
 318         }
 319         return val;
 320     }
 321     case 0x14: /* IA0 */
 322         return s->conf.macaddr.a[0] | (s->conf.macaddr.a[1] << 8)
 323             | (s->conf.macaddr.a[2] << 16)
 324             | ((uint32_t)s->conf.macaddr.a[3] << 24);
 325     case 0x18: /* IA1 */
 326         return s->conf.macaddr.a[4] | (s->conf.macaddr.a[5] << 8);
 327     case 0x1c: /* THR */
 328         return s->thr;
 329     case 0x20: /* MCTL */
 330         return s->mctl;
 331     case 0x24: /* MDV */
 332         return s->mdv;
 333     case 0x28: /* MADD */
 334         return 0;
 335     case 0x2c: /* MTXD */
 336         return s->mtxd;
 337     case 0x30: /* MRXD */
 338         return s->mrxd;
 339     case 0x34: /* NP */
 340         return s->np;
 341     case 0x38: /* TR */
 342         return 0;
 343     case 0x3c: /* Undocuented: Timestamp? */
 344         return 0;
 345     default:
 346         hw_error("stellaris_enet_read: Bad offset %x\n", (int)offset);
 347         return 0;
 348     }
 349 }
 350
 351 static void stellaris_enet_write(void *opaque, hwaddr offset,
 352                                  uint64_t value, unsigned size)
 353 {
 354     stellaris_enet_state *s = (stellaris_enet_state *)opaque;
 355
 356     switch (offset) {
 357     case 0x00: /* IACK */
 358         s->ris &= ~value;
 359         DPRINTF("IRQ ack %02" PRIx64 "/%02x\n", value, s->ris);
 360         stellaris_enet_update(s);
 361         /* Clearing TXER also resets the TX fifo.  */
 362         if (value & SE_INT_TXER) {
 363             s->tx_fifo_len = 0;
 364         }
 365         break;
 366     case 0x04: /* IM */
 367         DPRINTF("IRQ mask %02" PRIx64 "/%02x\n", value, s->ris);
 368         s->im = value;
 369         stellaris_enet_update(s);
 370         break;
 371     case 0x08: /* RCTL */
 372         s->rctl = value;
 373         if (value & SE_RCTL_RSTFIFO) {
 374             s->np = 0;
 375             s->rx_fifo_offset = 0;
 376             stellaris_enet_update(s);
 377         }
 378         break;
 379     case 0x0c: /* TCTL */
 380         s->tctl = value;
 381         break;
 382     case 0x10: /* DATA */
 383         if (s->tx_fifo_len == 0) {
 384             /* The first word is special, it contains the data length */
 385             int framelen = value & 0xffff;
 386             if (framelen > 2032) {
 387                 DPRINTF("TX frame too long (%d)\n", framelen);
 388                 s->ris |= SE_INT_TXER;
 389                 stellaris_enet_update(s);
 390                 break;
 391             }
 392         }
 393
 394         if (s->tx_fifo_len + 4 <= ARRAY_SIZE(s->tx_fifo)) {
 395             s->tx_fifo[s->tx_fifo_len++] = value;
 396             s->tx_fifo[s->tx_fifo_len++] = value >> 8;
 397             s->tx_fifo[s->tx_fifo_len++] = value >> 16;
 398             s->tx_fifo[s->tx_fifo_len++] = value >> 24;
 399         }
 400
 401         if (stellaris_tx_thr_reached(s) && stellaris_txpacket_complete(s)) {
 402             stellaris_enet_send(s);
 403         }
 404         break;
 405     case 0x14: /* IA0 */
 406         s->conf.macaddr.a[0] = value;
 407         s->conf.macaddr.a[1] = value >> 8;
 408         s->conf.macaddr.a[2] = value >> 16;
 409         s->conf.macaddr.a[3] = value >> 24;
 410         break;
 411     case 0x18: /* IA1 */
 412         s->conf.macaddr.a[4] = value;
 413         s->conf.macaddr.a[5] = value >> 8;
 414         break;
 415     case 0x1c: /* THR */
 416         s->thr = value;
 417         break;
 418     case 0x20: /* MCTL */
 419         s->mctl = value;
 420         break;
 421     case 0x24: /* MDV */
 422         s->mdv = value;
 423         break;
 424     case 0x28: /* MADD */
 425         /* ignored.  */
 426         break;
 427     case 0x2c: /* MTXD */
 428         s->mtxd = value & 0xff;
 429         break;
 430     case 0x38: /* TR */
 431         if (value & 1) {
 432             stellaris_enet_send(s);
 433         }
 434         break;
 435     case 0x30: /* MRXD */
 436     case 0x34: /* NP */
 437         /* Ignored.  */
 438     case 0x3c: /* Undocuented: Timestamp? */
 439         /* Ignored.  */
 440         break;
 441     default:
 442         hw_error("stellaris_enet_write: Bad offset %x\n", (int)offset);
 443     }
 444 }
 445
 446 static const MemoryRegionOps stellaris_enet_ops = {
 447     .read = stellaris_enet_read,
 448     .write = stellaris_enet_write,
 449     .endianness = DEVICE_NATIVE_ENDIAN,
 450 };
 451
 452 static void stellaris_enet_reset(stellaris_enet_state *s)
 453 {
 454     s->mdv = 0x80;
 455     s->rctl = SE_RCTL_BADCRC;
 456     s->im = SE_INT_PHY | SE_INT_MD | SE_INT_RXER | SE_INT_FOV | SE_INT_TXEMP
 457             | SE_INT_TXER | SE_INT_RX;
 458     s->thr = 0x3f;
 459     s->tx_fifo_len = 0;
 460 }
 461
 462 static NetClientInfo net_stellaris_enet_info = {
 463     .type = NET_CLIENT_OPTIONS_KIND_NIC,
 464     .size = sizeof(NICState),
 465     .receive = stellaris_enet_receive,
 466 };
 467
 468 static int stellaris_enet_init(SysBusDevice *sbd)
 469 {
 470     DeviceState *dev = DEVICE(sbd);
 471     stellaris_enet_state *s = STELLARIS_ENET(dev);
 472
 473     memory_region_init_io(&s->mmio, OBJECT(s), &stellaris_enet_ops, s,
 474                           "stellaris_enet", 0x1000);
 475     sysbus_init_mmio(sbd, &s->mmio);
 476     sysbus_init_irq(sbd, &s->irq);
 477     qemu_macaddr_default_if_unset(&s->conf.macaddr);
 478
 479     s->nic = qemu_new_nic(&net_stellaris_enet_info, &s->conf,
 480                           object_get_typename(OBJECT(dev)), dev->id, s);
 481     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
 482
 483     stellaris_enet_reset(s);
 484     return 0;
 485 }
 486
 487 static Property stellaris_enet_properties[] = {
 488     DEFINE_NIC_PROPERTIES(stellaris_enet_state, conf),
 489     DEFINE_PROP_END_OF_LIST(),
 490 };
 491
 492 static void stellaris_enet_class_init(ObjectClass *klass, void *data)
 493 {
 494     DeviceClass *dc = DEVICE_CLASS(klass);
 495     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
 496
 497     k->init = stellaris_enet_init;
 498     dc->props = stellaris_enet_properties;
 499     dc->vmsd = &vmstate_stellaris_enet;
 500 }
 501
 502 static const TypeInfo stellaris_enet_info = {
 503     .name          = TYPE_STELLARIS_ENET,
 504     .parent        = TYPE_SYS_BUS_DEVICE,
 505     .instance_size = sizeof(stellaris_enet_state),
 506     .class_init    = stellaris_enet_class_init,
 507 };
 508
 509 static void stellaris_enet_register_types(void)
 510 {
 511     type_register_static(&stellaris_enet_info);
 512 }
 513
 514 type_init(stellaris_enet_register_types)