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
  10 #include "qemu/osdep.h"
  11 #include "hw/irq.h"
  12 #include "hw/qdev-properties.h"
  13 #include "hw/sysbus.h"
  14 #include "migration/vmstate.h"
  15 #include "net/net.h"
  16 #include "qemu/log.h"
  17 #include "qemu/module.h"
  18 #include <zlib.h>
  19 #include "qom/object.h"
  20
  21 //#define DEBUG_STELLARIS_ENET 1
  22
  23 #ifdef DEBUG_STELLARIS_ENET
  24 #define DPRINTF(fmt, ...) \
  25 do { printf("stellaris_enet: " fmt , ## __VA_ARGS__); } while (0)
  26 #define BADF(fmt, ...) \
  27 do { fprintf(stderr, "stellaris_enet: error: " fmt , ## __VA_ARGS__); exit(1);} while (0)
  28 #else
  29 #define DPRINTF(fmt, ...) do {} while(0)
  30 #define BADF(fmt, ...) \
  31 do { fprintf(stderr, "stellaris_enet: error: " fmt , ## __VA_ARGS__);} while (0)
  32 #endif
  33
  34 #define SE_INT_RX       0x01
  35 #define SE_INT_TXER     0x02
  36 #define SE_INT_TXEMP    0x04
  37 #define SE_INT_FOV      0x08
  38 #define SE_INT_RXER     0x10
  39 #define SE_INT_MD       0x20
  40 #define SE_INT_PHY      0x40
  41
  42 #define SE_RCTL_RXEN    0x01
  43 #define SE_RCTL_AMUL    0x02
  44 #define SE_RCTL_PRMS    0x04
  45 #define SE_RCTL_BADCRC  0x08
  46 #define SE_RCTL_RSTFIFO 0x10
  47
  48 #define SE_TCTL_TXEN    0x01
  49 #define SE_TCTL_PADEN   0x02
  50 #define SE_TCTL_CRC     0x04
  51 #define SE_TCTL_DUPLEX  0x08
  52
  53 #define TYPE_STELLARIS_ENET "stellaris_enet"
  54 OBJECT_DECLARE_SIMPLE_TYPE(stellaris_enet_state, STELLARIS_ENET)
  55
  56 typedef struct {
  57     uint8_t data[2048];
  58     uint32_t len;
  59 } StellarisEnetRxFrame;
  60
  61 struct stellaris_enet_state {
  62     SysBusDevice parent_obj;
  63
  64     uint32_t ris;
  65     uint32_t im;
  66     uint32_t rctl;
  67     uint32_t tctl;
  68     uint32_t thr;
  69     uint32_t mctl;
  70     uint32_t mdv;
  71     uint32_t mtxd;
  72     uint32_t mrxd;
  73     uint32_t np;
  74     uint32_t tx_fifo_len;
  75     uint8_t tx_fifo[2048];
  76     /* Real hardware has a 2k fifo, which works out to be at most 31 packets.
  77        We implement a full 31 packet fifo.  */
  78     StellarisEnetRxFrame rx[31];
  79     uint32_t rx_fifo_offset;
  80     uint32_t next_packet;
  81     NICState *nic;
  82     NICConf conf;
  83     qemu_irq irq;
  84     MemoryRegion mmio;
  85 };
  86
  87 static const VMStateDescription vmstate_rx_frame = {
  88     .name = "stellaris_enet/rx_frame",
  89     .version_id = 1,
  90     .minimum_version_id = 1,
  91     .fields = (const VMStateField[]) {
  92         VMSTATE_UINT8_ARRAY(data, StellarisEnetRxFrame, 2048),
  93         VMSTATE_UINT32(len, StellarisEnetRxFrame),
  94         VMSTATE_END_OF_LIST()
  95     }
  96 };
  97
  98 static int stellaris_enet_post_load(void *opaque, int version_id)
  99 {
 100     stellaris_enet_state *s = opaque;
 101     int i;
 102
 103     /* Sanitize inbound state. Note that next_packet is an index but
 104      * np is a size; hence their valid upper bounds differ.
 105      */
 106     if (s->next_packet >= ARRAY_SIZE(s->rx)) {
 107         return -1;
 108     }
 109
 110     if (s->np > ARRAY_SIZE(s->rx)) {
 111         return -1;
 112     }
 113
 114     for (i = 0; i < ARRAY_SIZE(s->rx); i++) {
 115         if (s->rx[i].len > ARRAY_SIZE(s->rx[i].data)) {
 116             return -1;
 117         }
 118     }
 119
 120     if (s->rx_fifo_offset > ARRAY_SIZE(s->rx[0].data) - 4) {
 121         return -1;
 122     }
 123
 124     if (s->tx_fifo_len > ARRAY_SIZE(s->tx_fifo)) {
 125         return -1;
 126     }
 127
 128     return 0;
 129 }
 130
 131 static const VMStateDescription vmstate_stellaris_enet = {
 132     .name = "stellaris_enet",
 133     .version_id = 2,
 134     .minimum_version_id = 2,
 135     .post_load = stellaris_enet_post_load,
 136     .fields = (const VMStateField[]) {
 137         VMSTATE_UINT32(ris, stellaris_enet_state),
 138         VMSTATE_UINT32(im, stellaris_enet_state),
 139         VMSTATE_UINT32(rctl, stellaris_enet_state),
 140         VMSTATE_UINT32(tctl, stellaris_enet_state),
 141         VMSTATE_UINT32(thr, stellaris_enet_state),
 142         VMSTATE_UINT32(mctl, stellaris_enet_state),
 143         VMSTATE_UINT32(mdv, stellaris_enet_state),
 144         VMSTATE_UINT32(mtxd, stellaris_enet_state),
 145         VMSTATE_UINT32(mrxd, stellaris_enet_state),
 146         VMSTATE_UINT32(np, stellaris_enet_state),
 147         VMSTATE_UINT32(tx_fifo_len, stellaris_enet_state),
 148         VMSTATE_UINT8_ARRAY(tx_fifo, stellaris_enet_state, 2048),
 149         VMSTATE_STRUCT_ARRAY(rx, stellaris_enet_state, 31, 1,
 150                              vmstate_rx_frame, StellarisEnetRxFrame),
 151         VMSTATE_UINT32(rx_fifo_offset, stellaris_enet_state),
 152         VMSTATE_UINT32(next_packet, stellaris_enet_state),
 153         VMSTATE_END_OF_LIST()
 154     }
 155 };
 156
 157 static void stellaris_enet_update(stellaris_enet_state *s)
 158 {
 159     qemu_set_irq(s->irq, (s->ris & s->im) != 0);
 160 }
 161
 162 /* Return the data length of the packet currently being assembled
 163  * in the TX fifo.
 164  */
 165 static inline int stellaris_txpacket_datalen(stellaris_enet_state *s)
 166 {
 167     return s->tx_fifo[0] | (s->tx_fifo[1] << 8);
 168 }
 169
 170 /* Return true if the packet currently in the TX FIFO is complete,
 171 * ie the FIFO holds enough bytes for the data length, ethernet header,
 172 * payload and optionally CRC.
 173 */
 174 static inline bool stellaris_txpacket_complete(stellaris_enet_state *s)
 175 {
 176     int framelen = stellaris_txpacket_datalen(s);
 177     framelen += 16;
 178     if (!(s->tctl & SE_TCTL_CRC)) {
 179         framelen += 4;
 180     }
 181     /* Cover the corner case of a 2032 byte payload with auto-CRC disabled:
 182      * this requires more bytes than will fit in the FIFO. It's not totally
 183      * clear how the h/w handles this, but if using threshold-based TX
 184      * it will definitely try to transmit something.
 185      */
 186     framelen = MIN(framelen, ARRAY_SIZE(s->tx_fifo));
 187     return s->tx_fifo_len >= framelen;
 188 }
 189
 190 /* Return true if the TX FIFO threshold is enabled and the FIFO
 191  * has filled enough to reach it.
 192  */
 193 static inline bool stellaris_tx_thr_reached(stellaris_enet_state *s)
 194 {
 195     return (s->thr < 0x3f &&
 196             (s->tx_fifo_len >= 4 * (s->thr * 8 + 1)));
 197 }
 198
 199 /* Send the packet currently in the TX FIFO */
 200 static void stellaris_enet_send(stellaris_enet_state *s)
 201 {
 202     int framelen = stellaris_txpacket_datalen(s);
 203
 204     /* Ethernet header is in the FIFO but not in the datacount.
 205      * We don't implement explicit CRC, so just ignore any
 206      * CRC value in the FIFO.
 207      */
 208     framelen += 14;
 209     if ((s->tctl & SE_TCTL_PADEN) && framelen < 60) {
 210         memset(&s->tx_fifo[framelen + 2], 0, 60 - framelen);
 211         framelen = 60;
 212     }
 213     /* This MIN will have no effect unless the FIFO data is corrupt
 214      * (eg bad data from an incoming migration); otherwise the check
 215      * on the datalen at the start of writing the data into the FIFO
 216      * will have caught this. Silently write a corrupt half-packet,
 217      * which is what the hardware does in FIFO underrun situations.
 218      */
 219     framelen = MIN(framelen, ARRAY_SIZE(s->tx_fifo) - 2);
 220     qemu_send_packet(qemu_get_queue(s->nic), s->tx_fifo + 2, framelen);
 221     s->tx_fifo_len = 0;
 222     s->ris |= SE_INT_TXEMP;
 223     stellaris_enet_update(s);
 224     DPRINTF("Done TX\n");
 225 }
 226
 227 /* TODO: Implement MAC address filtering.  */
 228 static ssize_t stellaris_enet_receive(NetClientState *nc, const uint8_t *buf, size_t size)
 229 {
 230     stellaris_enet_state *s = qemu_get_nic_opaque(nc);
 231     int n;
 232     uint8_t *p;
 233     uint32_t crc;
 234
 235     if ((s->rctl & SE_RCTL_RXEN) == 0)
 236         return -1;
 237     if (s->np >= 31) {
 238         return 0;
 239     }
 240
 241     DPRINTF("Received packet len=%zu\n", size);
 242     n = s->next_packet + s->np;
 243     if (n >= 31)
 244         n -= 31;
 245
 246     if (size >= sizeof(s->rx[n].data) - 6) {
 247         /* If the packet won't fit into the
 248          * emulated 2K RAM, this is reported
 249          * as a FIFO overrun error.
 250          */
 251         s->ris |= SE_INT_FOV;
 252         stellaris_enet_update(s);
 253         return -1;
 254     }
 255
 256     s->np++;
 257     s->rx[n].len = size + 6;
 258     p = s->rx[n].data;
 259     *(p++) = (size + 6);
 260     *(p++) = (size + 6) >> 8;
 261     memcpy (p, buf, size);
 262     p += size;
 263     crc = crc32(~0, buf, size);
 264     *(p++) = crc;
 265     *(p++) = crc >> 8;
 266     *(p++) = crc >> 16;
 267     *(p++) = crc >> 24;
 268     /* Clear the remaining bytes in the last word.  */
 269     if ((size & 3) != 2) {
 270         memset(p, 0, (6 - size) & 3);
 271     }
 272
 273     s->ris |= SE_INT_RX;
 274     stellaris_enet_update(s);
 275
 276     return size;
 277 }
 278
 279 static int stellaris_enet_can_receive(stellaris_enet_state *s)
 280 {
 281     return (s->np < 31);
 282 }
 283
 284 static uint64_t stellaris_enet_read(void *opaque, hwaddr offset,
 285                                     unsigned size)
 286 {
 287     stellaris_enet_state *s = (stellaris_enet_state *)opaque;
 288     uint32_t val;
 289
 290     switch (offset) {
 291     case 0x00: /* RIS */
 292         DPRINTF("IRQ status %02x\n", s->ris);
 293         return s->ris;
 294     case 0x04: /* IM */
 295         return s->im;
 296     case 0x08: /* RCTL */
 297         return s->rctl;
 298     case 0x0c: /* TCTL */
 299         return s->tctl;
 300     case 0x10: /* DATA */
 301     {
 302         uint8_t *rx_fifo;
 303
 304         if (s->np == 0) {
 305             BADF("RX underflow\n");
 306             return 0;
 307         }
 308
 309         rx_fifo = s->rx[s->next_packet].data + s->rx_fifo_offset;
 310
 311         val = rx_fifo[0] | (rx_fifo[1] << 8) | (rx_fifo[2] << 16)
 312               | (rx_fifo[3] << 24);
 313         s->rx_fifo_offset += 4;
 314         if (s->rx_fifo_offset >= s->rx[s->next_packet].len) {
 315             s->rx_fifo_offset = 0;
 316             s->next_packet++;
 317             if (s->next_packet >= 31)
 318                 s->next_packet = 0;
 319             s->np--;
 320             DPRINTF("RX done np=%d\n", s->np);
 321             if (!s->np && stellaris_enet_can_receive(s)) {
 322                 qemu_flush_queued_packets(qemu_get_queue(s->nic));
 323             }
 324         }
 325         return val;
 326     }
 327     case 0x14: /* IA0 */
 328         return s->conf.macaddr.a[0] | (s->conf.macaddr.a[1] << 8)
 329             | (s->conf.macaddr.a[2] << 16)
 330             | ((uint32_t)s->conf.macaddr.a[3] << 24);
 331     case 0x18: /* IA1 */
 332         return s->conf.macaddr.a[4] | (s->conf.macaddr.a[5] << 8);
 333     case 0x1c: /* THR */
 334         return s->thr;
 335     case 0x20: /* MCTL */
 336         return s->mctl;
 337     case 0x24: /* MDV */
 338         return s->mdv;
 339     case 0x28: /* MADD */
 340         return 0;
 341     case 0x2c: /* MTXD */
 342         return s->mtxd;
 343     case 0x30: /* MRXD */
 344         return s->mrxd;
 345     case 0x34: /* NP */
 346         return s->np;
 347     case 0x38: /* TR */
 348         return 0;
 349     case 0x3c: /* Undocumented: Timestamp? */
 350         return 0;
 351     default:
 352         qemu_log_mask(LOG_GUEST_ERROR, "stellaris_enet_rd%d: Illegal register"
 353                                        " 0x02%" HWADDR_PRIx "\n",
 354                       size * 8, offset);
 355         return 0;
 356     }
 357 }
 358
 359 static void stellaris_enet_write(void *opaque, hwaddr offset,
 360                                  uint64_t value, unsigned size)
 361 {
 362     stellaris_enet_state *s = (stellaris_enet_state *)opaque;
 363
 364     switch (offset) {
 365     case 0x00: /* IACK */
 366         s->ris &= ~value;
 367         DPRINTF("IRQ ack %02" PRIx64 "/%02x\n", value, s->ris);
 368         stellaris_enet_update(s);
 369         /* Clearing TXER also resets the TX fifo.  */
 370         if (value & SE_INT_TXER) {
 371             s->tx_fifo_len = 0;
 372         }
 373         break;
 374     case 0x04: /* IM */
 375         DPRINTF("IRQ mask %02" PRIx64 "/%02x\n", value, s->ris);
 376         s->im = value;
 377         stellaris_enet_update(s);
 378         break;
 379     case 0x08: /* RCTL */
 380         s->rctl = value;
 381         if (value & SE_RCTL_RSTFIFO) {
 382             s->np = 0;
 383             s->rx_fifo_offset = 0;
 384             stellaris_enet_update(s);
 385         }
 386         break;
 387     case 0x0c: /* TCTL */
 388         s->tctl = value;
 389         break;
 390     case 0x10: /* DATA */
 391         if (s->tx_fifo_len == 0) {
 392             /* The first word is special, it contains the data length */
 393             int framelen = value & 0xffff;
 394             if (framelen > 2032) {
 395                 DPRINTF("TX frame too long (%d)\n", framelen);
 396                 s->ris |= SE_INT_TXER;
 397                 stellaris_enet_update(s);
 398                 break;
 399             }
 400         }
 401
 402         if (s->tx_fifo_len + 4 <= ARRAY_SIZE(s->tx_fifo)) {
 403             s->tx_fifo[s->tx_fifo_len++] = value;
 404             s->tx_fifo[s->tx_fifo_len++] = value >> 8;
 405             s->tx_fifo[s->tx_fifo_len++] = value >> 16;
 406             s->tx_fifo[s->tx_fifo_len++] = value >> 24;
 407         }
 408
 409         if (stellaris_tx_thr_reached(s) && stellaris_txpacket_complete(s)) {
 410             stellaris_enet_send(s);
 411         }
 412         break;
 413     case 0x14: /* IA0 */
 414         s->conf.macaddr.a[0] = value;
 415         s->conf.macaddr.a[1] = value >> 8;
 416         s->conf.macaddr.a[2] = value >> 16;
 417         s->conf.macaddr.a[3] = value >> 24;
 418         break;
 419     case 0x18: /* IA1 */
 420         s->conf.macaddr.a[4] = value;
 421         s->conf.macaddr.a[5] = value >> 8;
 422         break;
 423     case 0x1c: /* THR */
 424         s->thr = value;
 425         break;
 426     case 0x20: /* MCTL */
 427         /* TODO: MII registers aren't modelled.
 428          * Clear START, indicating that the operation completes immediately.
 429          */
 430         s->mctl = value & ~1;
 431         break;
 432     case 0x24: /* MDV */
 433         s->mdv = value;
 434         break;
 435     case 0x28: /* MADD */
 436         /* ignored.  */
 437         break;
 438     case 0x2c: /* MTXD */
 439         s->mtxd = value & 0xff;
 440         break;
 441     case 0x38: /* TR */
 442         if (value & 1) {
 443             stellaris_enet_send(s);
 444         }
 445         break;
 446     case 0x30: /* MRXD */
 447     case 0x34: /* NP */
 448         /* Ignored.  */
 449     case 0x3c: /* Undocuented: Timestamp? */
 450         /* Ignored.  */
 451         break;
 452     default:
 453         qemu_log_mask(LOG_GUEST_ERROR, "stellaris_enet_wr%d: Illegal register "
 454                                        "0x02%" HWADDR_PRIx " = 0x%" PRIx64 "\n",
 455                       size * 8, offset, value);
 456     }
 457 }
 458
 459 static const MemoryRegionOps stellaris_enet_ops = {
 460     .read = stellaris_enet_read,
 461     .write = stellaris_enet_write,
 462     .endianness = DEVICE_NATIVE_ENDIAN,
 463 };
 464
 465 static void stellaris_enet_reset(DeviceState *dev)
 466 {
 467     stellaris_enet_state *s =  STELLARIS_ENET(dev);
 468
 469     s->mdv = 0x80;
 470     s->rctl = SE_RCTL_BADCRC;
 471     s->im = SE_INT_PHY | SE_INT_MD | SE_INT_RXER | SE_INT_FOV | SE_INT_TXEMP
 472             | SE_INT_TXER | SE_INT_RX;
 473     s->thr = 0x3f;
 474     s->tx_fifo_len = 0;
 475 }
 476
 477 static NetClientInfo net_stellaris_enet_info = {
 478     .type = NET_CLIENT_DRIVER_NIC,
 479     .size = sizeof(NICState),
 480     .receive = stellaris_enet_receive,
 481 };
 482
 483 static void stellaris_enet_realize(DeviceState *dev, Error **errp)
 484 {
 485     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
 486     stellaris_enet_state *s = STELLARIS_ENET(dev);
 487
 488     memory_region_init_io(&s->mmio, OBJECT(s), &stellaris_enet_ops, s,
 489                           "stellaris_enet", 0x1000);
 490     sysbus_init_mmio(sbd, &s->mmio);
 491     sysbus_init_irq(sbd, &s->irq);
 492     qemu_macaddr_default_if_unset(&s->conf.macaddr);
 493
 494     s->nic = qemu_new_nic(&net_stellaris_enet_info, &s->conf,
 495                           object_get_typename(OBJECT(dev)), dev->id,
 496                           &dev->mem_reentrancy_guard, s);
 497     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
 498 }
 499
 500 static Property stellaris_enet_properties[] = {
 501     DEFINE_NIC_PROPERTIES(stellaris_enet_state, conf),
 502     DEFINE_PROP_END_OF_LIST(),
 503 };
 504
 505 static void stellaris_enet_class_init(ObjectClass *klass, void *data)
 506 {
 507     DeviceClass *dc = DEVICE_CLASS(klass);
 508
 509     dc->realize = stellaris_enet_realize;
 510     dc->reset = stellaris_enet_reset;
 511     device_class_set_props(dc, stellaris_enet_properties);
 512     dc->vmsd = &vmstate_stellaris_enet;
 513 }
 514
 515 static const TypeInfo stellaris_enet_info = {
 516     .name          = TYPE_STELLARIS_ENET,
 517     .parent        = TYPE_SYS_BUS_DEVICE,
 518     .instance_size = sizeof(stellaris_enet_state),
 519     .class_init    = stellaris_enet_class_init,
 520 };
 521
 522 static void stellaris_enet_register_types(void)
 523 {
 524     type_register_static(&stellaris_enet_info);
 525 }
 526
 527 type_init(stellaris_enet_register_types)