qemu/hw/net/smc91c111.c
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   1/*
   2 * SMSC 91C111 Ethernet interface emulation
   3 *
   4 * Copyright (c) 2005 CodeSourcery, LLC.
   5 * Written by Paul Brook
   6 *
   7 * This code is licensed under the GPL
   8 */
   9
  10#include "qemu/osdep.h"
  11#include "hw/sysbus.h"
  12#include "migration/vmstate.h"
  13#include "net/net.h"
  14#include "hw/irq.h"
  15#include "hw/net/smc91c111.h"
  16#include "hw/qdev-properties.h"
  17#include "qemu/log.h"
  18#include "qemu/module.h"
  19/* For crc32 */
  20#include <zlib.h>
  21
  22/* Number of 2k memory pages available.  */
  23#define NUM_PACKETS 4
  24
  25#define TYPE_SMC91C111 "smc91c111"
  26#define SMC91C111(obj) OBJECT_CHECK(smc91c111_state, (obj), TYPE_SMC91C111)
  27
  28typedef struct {
  29    SysBusDevice parent_obj;
  30
  31    NICState *nic;
  32    NICConf conf;
  33    uint16_t tcr;
  34    uint16_t rcr;
  35    uint16_t cr;
  36    uint16_t ctr;
  37    uint16_t gpr;
  38    uint16_t ptr;
  39    uint16_t ercv;
  40    qemu_irq irq;
  41    int bank;
  42    int packet_num;
  43    int tx_alloc;
  44    /* Bitmask of allocated packets.  */
  45    int allocated;
  46    int tx_fifo_len;
  47    int tx_fifo[NUM_PACKETS];
  48    int rx_fifo_len;
  49    int rx_fifo[NUM_PACKETS];
  50    int tx_fifo_done_len;
  51    int tx_fifo_done[NUM_PACKETS];
  52    /* Packet buffer memory.  */
  53    uint8_t data[NUM_PACKETS][2048];
  54    uint8_t int_level;
  55    uint8_t int_mask;
  56    MemoryRegion mmio;
  57} smc91c111_state;
  58
  59static const VMStateDescription vmstate_smc91c111 = {
  60    .name = "smc91c111",
  61    .version_id = 1,
  62    .minimum_version_id = 1,
  63    .fields = (VMStateField[]) {
  64        VMSTATE_UINT16(tcr, smc91c111_state),
  65        VMSTATE_UINT16(rcr, smc91c111_state),
  66        VMSTATE_UINT16(cr, smc91c111_state),
  67        VMSTATE_UINT16(ctr, smc91c111_state),
  68        VMSTATE_UINT16(gpr, smc91c111_state),
  69        VMSTATE_UINT16(ptr, smc91c111_state),
  70        VMSTATE_UINT16(ercv, smc91c111_state),
  71        VMSTATE_INT32(bank, smc91c111_state),
  72        VMSTATE_INT32(packet_num, smc91c111_state),
  73        VMSTATE_INT32(tx_alloc, smc91c111_state),
  74        VMSTATE_INT32(allocated, smc91c111_state),
  75        VMSTATE_INT32(tx_fifo_len, smc91c111_state),
  76        VMSTATE_INT32_ARRAY(tx_fifo, smc91c111_state, NUM_PACKETS),
  77        VMSTATE_INT32(rx_fifo_len, smc91c111_state),
  78        VMSTATE_INT32_ARRAY(rx_fifo, smc91c111_state, NUM_PACKETS),
  79        VMSTATE_INT32(tx_fifo_done_len, smc91c111_state),
  80        VMSTATE_INT32_ARRAY(tx_fifo_done, smc91c111_state, NUM_PACKETS),
  81        VMSTATE_BUFFER_UNSAFE(data, smc91c111_state, 0, NUM_PACKETS * 2048),
  82        VMSTATE_UINT8(int_level, smc91c111_state),
  83        VMSTATE_UINT8(int_mask, smc91c111_state),
  84        VMSTATE_END_OF_LIST()
  85    }
  86};
  87
  88#define RCR_SOFT_RST  0x8000
  89#define RCR_STRIP_CRC 0x0200
  90#define RCR_RXEN      0x0100
  91
  92#define TCR_EPH_LOOP  0x2000
  93#define TCR_NOCRC     0x0100
  94#define TCR_PAD_EN    0x0080
  95#define TCR_FORCOL    0x0004
  96#define TCR_LOOP      0x0002
  97#define TCR_TXEN      0x0001
  98
  99#define INT_MD        0x80
 100#define INT_ERCV      0x40
 101#define INT_EPH       0x20
 102#define INT_RX_OVRN   0x10
 103#define INT_ALLOC     0x08
 104#define INT_TX_EMPTY  0x04
 105#define INT_TX        0x02
 106#define INT_RCV       0x01
 107
 108#define CTR_AUTO_RELEASE  0x0800
 109#define CTR_RELOAD        0x0002
 110#define CTR_STORE         0x0001
 111
 112#define RS_ALGNERR      0x8000
 113#define RS_BRODCAST     0x4000
 114#define RS_BADCRC       0x2000
 115#define RS_ODDFRAME     0x1000
 116#define RS_TOOLONG      0x0800
 117#define RS_TOOSHORT     0x0400
 118#define RS_MULTICAST    0x0001
 119
 120/* Update interrupt status.  */
 121static void smc91c111_update(smc91c111_state *s)
 122{
 123    int level;
 124
 125    if (s->tx_fifo_len == 0)
 126        s->int_level |= INT_TX_EMPTY;
 127    if (s->tx_fifo_done_len != 0)
 128        s->int_level |= INT_TX;
 129    level = (s->int_level & s->int_mask) != 0;
 130    qemu_set_irq(s->irq, level);
 131}
 132
 133static int smc91c111_can_receive(smc91c111_state *s)
 134{
 135    if ((s->rcr & RCR_RXEN) == 0 || (s->rcr & RCR_SOFT_RST)) {
 136        return 1;
 137    }
 138    if (s->allocated == (1 << NUM_PACKETS) - 1 ||
 139        s->rx_fifo_len == NUM_PACKETS) {
 140        return 0;
 141    }
 142    return 1;
 143}
 144
 145static inline void smc91c111_flush_queued_packets(smc91c111_state *s)
 146{
 147    if (smc91c111_can_receive(s)) {
 148        qemu_flush_queued_packets(qemu_get_queue(s->nic));
 149    }
 150}
 151
 152/* Try to allocate a packet.  Returns 0x80 on failure.  */
 153static int smc91c111_allocate_packet(smc91c111_state *s)
 154{
 155    int i;
 156    if (s->allocated == (1 << NUM_PACKETS) - 1) {
 157        return 0x80;
 158    }
 159
 160    for (i = 0; i < NUM_PACKETS; i++) {
 161        if ((s->allocated & (1 << i)) == 0)
 162            break;
 163    }
 164    s->allocated |= 1 << i;
 165    return i;
 166}
 167
 168
 169/* Process a pending TX allocate.  */
 170static void smc91c111_tx_alloc(smc91c111_state *s)
 171{
 172    s->tx_alloc = smc91c111_allocate_packet(s);
 173    if (s->tx_alloc == 0x80)
 174        return;
 175    s->int_level |= INT_ALLOC;
 176    smc91c111_update(s);
 177}
 178
 179/* Remove and item from the RX FIFO.  */
 180static void smc91c111_pop_rx_fifo(smc91c111_state *s)
 181{
 182    int i;
 183
 184    s->rx_fifo_len--;
 185    if (s->rx_fifo_len) {
 186        for (i = 0; i < s->rx_fifo_len; i++)
 187            s->rx_fifo[i] = s->rx_fifo[i + 1];
 188        s->int_level |= INT_RCV;
 189    } else {
 190        s->int_level &= ~INT_RCV;
 191    }
 192    smc91c111_flush_queued_packets(s);
 193    smc91c111_update(s);
 194}
 195
 196/* Remove an item from the TX completion FIFO.  */
 197static void smc91c111_pop_tx_fifo_done(smc91c111_state *s)
 198{
 199    int i;
 200
 201    if (s->tx_fifo_done_len == 0)
 202        return;
 203    s->tx_fifo_done_len--;
 204    for (i = 0; i < s->tx_fifo_done_len; i++)
 205        s->tx_fifo_done[i] = s->tx_fifo_done[i + 1];
 206}
 207
 208/* Release the memory allocated to a packet.  */
 209static void smc91c111_release_packet(smc91c111_state *s, int packet)
 210{
 211    s->allocated &= ~(1 << packet);
 212    if (s->tx_alloc == 0x80)
 213        smc91c111_tx_alloc(s);
 214    smc91c111_flush_queued_packets(s);
 215}
 216
 217/* Flush the TX FIFO.  */
 218static void smc91c111_do_tx(smc91c111_state *s)
 219{
 220    int i;
 221    int len;
 222    int control;
 223    int packetnum;
 224    uint8_t *p;
 225
 226    if ((s->tcr & TCR_TXEN) == 0)
 227        return;
 228    if (s->tx_fifo_len == 0)
 229        return;
 230    for (i = 0; i < s->tx_fifo_len; i++) {
 231        packetnum = s->tx_fifo[i];
 232        p = &s->data[packetnum][0];
 233        /* Set status word.  */
 234        *(p++) = 0x01;
 235        *(p++) = 0x40;
 236        len = *(p++);
 237        len |= ((int)*(p++)) << 8;
 238        len -= 6;
 239        control = p[len + 1];
 240        if (control & 0x20)
 241            len++;
 242        /* ??? This overwrites the data following the buffer.
 243           Don't know what real hardware does.  */
 244        if (len < 64 && (s->tcr & TCR_PAD_EN)) {
 245            memset(p + len, 0, 64 - len);
 246            len = 64;
 247        }
 248#if 0
 249        {
 250            int add_crc;
 251
 252            /* The card is supposed to append the CRC to the frame.
 253               However none of the other network traffic has the CRC
 254               appended.  Suspect this is low level ethernet detail we
 255               don't need to worry about.  */
 256            add_crc = (control & 0x10) || (s->tcr & TCR_NOCRC) == 0;
 257            if (add_crc) {
 258                uint32_t crc;
 259
 260                crc = crc32(~0, p, len);
 261                memcpy(p + len, &crc, 4);
 262                len += 4;
 263            }
 264        }
 265#endif
 266        if (s->ctr & CTR_AUTO_RELEASE)
 267            /* Race?  */
 268            smc91c111_release_packet(s, packetnum);
 269        else if (s->tx_fifo_done_len < NUM_PACKETS)
 270            s->tx_fifo_done[s->tx_fifo_done_len++] = packetnum;
 271        qemu_send_packet(qemu_get_queue(s->nic), p, len);
 272    }
 273    s->tx_fifo_len = 0;
 274    smc91c111_update(s);
 275}
 276
 277/* Add a packet to the TX FIFO.  */
 278static void smc91c111_queue_tx(smc91c111_state *s, int packet)
 279{
 280    if (s->tx_fifo_len == NUM_PACKETS)
 281        return;
 282    s->tx_fifo[s->tx_fifo_len++] = packet;
 283    smc91c111_do_tx(s);
 284}
 285
 286static void smc91c111_reset(DeviceState *dev)
 287{
 288    smc91c111_state *s = SMC91C111(dev);
 289
 290    s->bank = 0;
 291    s->tx_fifo_len = 0;
 292    s->tx_fifo_done_len = 0;
 293    s->rx_fifo_len = 0;
 294    s->allocated = 0;
 295    s->packet_num = 0;
 296    s->tx_alloc = 0;
 297    s->tcr = 0;
 298    s->rcr = 0;
 299    s->cr = 0xa0b1;
 300    s->ctr = 0x1210;
 301    s->ptr = 0;
 302    s->ercv = 0x1f;
 303    s->int_level = INT_TX_EMPTY;
 304    s->int_mask = 0;
 305    smc91c111_update(s);
 306}
 307
 308#define SET_LOW(name, val) s->name = (s->name & 0xff00) | val
 309#define SET_HIGH(name, val) s->name = (s->name & 0xff) | (val << 8)
 310
 311static void smc91c111_writeb(void *opaque, hwaddr offset,
 312                             uint32_t value)
 313{
 314    smc91c111_state *s = (smc91c111_state *)opaque;
 315
 316    offset = offset & 0xf;
 317    if (offset == 14) {
 318        s->bank = value;
 319        return;
 320    }
 321    if (offset == 15)
 322        return;
 323    switch (s->bank) {
 324    case 0:
 325        switch (offset) {
 326        case 0: /* TCR */
 327            SET_LOW(tcr, value);
 328            return;
 329        case 1:
 330            SET_HIGH(tcr, value);
 331            return;
 332        case 4: /* RCR */
 333            SET_LOW(rcr, value);
 334            return;
 335        case 5:
 336            SET_HIGH(rcr, value);
 337            if (s->rcr & RCR_SOFT_RST) {
 338                smc91c111_reset(DEVICE(s));
 339            }
 340            smc91c111_flush_queued_packets(s);
 341            return;
 342        case 10: case 11: /* RPCR */
 343            /* Ignored */
 344            return;
 345        case 12: case 13: /* Reserved */
 346            return;
 347        }
 348        break;
 349
 350    case 1:
 351        switch (offset) {
 352        case 0: /* CONFIG */
 353            SET_LOW(cr, value);
 354            return;
 355        case 1:
 356            SET_HIGH(cr,value);
 357            return;
 358        case 2: case 3: /* BASE */
 359        case 4: case 5: case 6: case 7: case 8: case 9: /* IA */
 360            /* Not implemented.  */
 361            return;
 362        case 10: /* Genral Purpose */
 363            SET_LOW(gpr, value);
 364            return;
 365        case 11:
 366            SET_HIGH(gpr, value);
 367            return;
 368        case 12: /* Control */
 369            if (value & 1) {
 370                qemu_log_mask(LOG_UNIMP,
 371                              "smc91c111: EEPROM store not implemented\n");
 372            }
 373            if (value & 2) {
 374                qemu_log_mask(LOG_UNIMP,
 375                              "smc91c111: EEPROM reload not implemented\n");
 376            }
 377            value &= ~3;
 378            SET_LOW(ctr, value);
 379            return;
 380        case 13:
 381            SET_HIGH(ctr, value);
 382            return;
 383        }
 384        break;
 385
 386    case 2:
 387        switch (offset) {
 388        case 0: /* MMU Command */
 389            switch (value >> 5) {
 390            case 0: /* no-op */
 391                break;
 392            case 1: /* Allocate for TX.  */
 393                s->tx_alloc = 0x80;
 394                s->int_level &= ~INT_ALLOC;
 395                smc91c111_update(s);
 396                smc91c111_tx_alloc(s);
 397                break;
 398            case 2: /* Reset MMU.  */
 399                s->allocated = 0;
 400                s->tx_fifo_len = 0;
 401                s->tx_fifo_done_len = 0;
 402                s->rx_fifo_len = 0;
 403                s->tx_alloc = 0;
 404                break;
 405            case 3: /* Remove from RX FIFO.  */
 406                smc91c111_pop_rx_fifo(s);
 407                break;
 408            case 4: /* Remove from RX FIFO and release.  */
 409                if (s->rx_fifo_len > 0) {
 410                    smc91c111_release_packet(s, s->rx_fifo[0]);
 411                }
 412                smc91c111_pop_rx_fifo(s);
 413                break;
 414            case 5: /* Release.  */
 415                smc91c111_release_packet(s, s->packet_num);
 416                break;
 417            case 6: /* Add to TX FIFO.  */
 418                smc91c111_queue_tx(s, s->packet_num);
 419                break;
 420            case 7: /* Reset TX FIFO.  */
 421                s->tx_fifo_len = 0;
 422                s->tx_fifo_done_len = 0;
 423                break;
 424            }
 425            return;
 426        case 1:
 427            /* Ignore.  */
 428            return;
 429        case 2: /* Packet Number Register */
 430            s->packet_num = value;
 431            return;
 432        case 3: case 4: case 5:
 433            /* Should be readonly, but linux writes to them anyway. Ignore.  */
 434            return;
 435        case 6: /* Pointer */
 436            SET_LOW(ptr, value);
 437            return;
 438        case 7:
 439            SET_HIGH(ptr, value);
 440            return;
 441        case 8: case 9: case 10: case 11: /* Data */
 442            {
 443                int p;
 444                int n;
 445
 446                if (s->ptr & 0x8000)
 447                    n = s->rx_fifo[0];
 448                else
 449                    n = s->packet_num;
 450                p = s->ptr & 0x07ff;
 451                if (s->ptr & 0x4000) {
 452                    s->ptr = (s->ptr & 0xf800) | ((s->ptr + 1) & 0x7ff);
 453                } else {
 454                    p += (offset & 3);
 455                }
 456                s->data[n][p] = value;
 457            }
 458            return;
 459        case 12: /* Interrupt ACK.  */
 460            s->int_level &= ~(value & 0xd6);
 461            if (value & INT_TX)
 462                smc91c111_pop_tx_fifo_done(s);
 463            smc91c111_update(s);
 464            return;
 465        case 13: /* Interrupt mask.  */
 466            s->int_mask = value;
 467            smc91c111_update(s);
 468            return;
 469        }
 470        break;
 471
 472    case 3:
 473        switch (offset) {
 474        case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:
 475            /* Multicast table.  */
 476            /* Not implemented.  */
 477            return;
 478        case 8: case 9: /* Management Interface.  */
 479            /* Not implemented.  */
 480            return;
 481        case 12: /* Early receive.  */
 482            s->ercv = value & 0x1f;
 483            return;
 484        case 13:
 485            /* Ignore.  */
 486            return;
 487        }
 488        break;
 489    }
 490    qemu_log_mask(LOG_GUEST_ERROR, "smc91c111_write(bank:%d) Illegal register"
 491                                   " 0x%" HWADDR_PRIx " = 0x%x\n",
 492                  s->bank, offset, value);
 493}
 494
 495static uint32_t smc91c111_readb(void *opaque, hwaddr offset)
 496{
 497    smc91c111_state *s = (smc91c111_state *)opaque;
 498
 499    offset = offset & 0xf;
 500    if (offset == 14) {
 501        return s->bank;
 502    }
 503    if (offset == 15)
 504        return 0x33;
 505    switch (s->bank) {
 506    case 0:
 507        switch (offset) {
 508        case 0: /* TCR */
 509            return s->tcr & 0xff;
 510        case 1:
 511            return s->tcr >> 8;
 512        case 2: /* EPH Status */
 513            return 0;
 514        case 3:
 515            return 0x40;
 516        case 4: /* RCR */
 517            return s->rcr & 0xff;
 518        case 5:
 519            return s->rcr >> 8;
 520        case 6: /* Counter */
 521        case 7:
 522            /* Not implemented.  */
 523            return 0;
 524        case 8: /* Memory size.  */
 525            return NUM_PACKETS;
 526        case 9: /* Free memory available.  */
 527            {
 528                int i;
 529                int n;
 530                n = 0;
 531                for (i = 0; i < NUM_PACKETS; i++) {
 532                    if (s->allocated & (1 << i))
 533                        n++;
 534                }
 535                return n;
 536            }
 537        case 10: case 11: /* RPCR */
 538            /* Not implemented.  */
 539            return 0;
 540        case 12: case 13: /* Reserved */
 541            return 0;
 542        }
 543        break;
 544
 545    case 1:
 546        switch (offset) {
 547        case 0: /* CONFIG */
 548            return s->cr & 0xff;
 549        case 1:
 550            return s->cr >> 8;
 551        case 2: case 3: /* BASE */
 552            /* Not implemented.  */
 553            return 0;
 554        case 4: case 5: case 6: case 7: case 8: case 9: /* IA */
 555            return s->conf.macaddr.a[offset - 4];
 556        case 10: /* General Purpose */
 557            return s->gpr & 0xff;
 558        case 11:
 559            return s->gpr >> 8;
 560        case 12: /* Control */
 561            return s->ctr & 0xff;
 562        case 13:
 563            return s->ctr >> 8;
 564        }
 565        break;
 566
 567    case 2:
 568        switch (offset) {
 569        case 0: case 1: /* MMUCR Busy bit.  */
 570            return 0;
 571        case 2: /* Packet Number.  */
 572            return s->packet_num;
 573        case 3: /* Allocation Result.  */
 574            return s->tx_alloc;
 575        case 4: /* TX FIFO */
 576            if (s->tx_fifo_done_len == 0)
 577                return 0x80;
 578            else
 579                return s->tx_fifo_done[0];
 580        case 5: /* RX FIFO */
 581            if (s->rx_fifo_len == 0)
 582                return 0x80;
 583            else
 584                return s->rx_fifo[0];
 585        case 6: /* Pointer */
 586            return s->ptr & 0xff;
 587        case 7:
 588            return (s->ptr >> 8) & 0xf7;
 589        case 8: case 9: case 10: case 11: /* Data */
 590            {
 591                int p;
 592                int n;
 593
 594                if (s->ptr & 0x8000)
 595                    n = s->rx_fifo[0];
 596                else
 597                    n = s->packet_num;
 598                p = s->ptr & 0x07ff;
 599                if (s->ptr & 0x4000) {
 600                    s->ptr = (s->ptr & 0xf800) | ((s->ptr + 1) & 0x07ff);
 601                } else {
 602                    p += (offset & 3);
 603                }
 604                return s->data[n][p];
 605            }
 606        case 12: /* Interrupt status.  */
 607            return s->int_level;
 608        case 13: /* Interrupt mask.  */
 609            return s->int_mask;
 610        }
 611        break;
 612
 613    case 3:
 614        switch (offset) {
 615        case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:
 616            /* Multicast table.  */
 617            /* Not implemented.  */
 618            return 0;
 619        case 8: /* Management Interface.  */
 620            /* Not implemented.  */
 621            return 0x30;
 622        case 9:
 623            return 0x33;
 624        case 10: /* Revision.  */
 625            return 0x91;
 626        case 11:
 627            return 0x33;
 628        case 12:
 629            return s->ercv;
 630        case 13:
 631            return 0;
 632        }
 633        break;
 634    }
 635    qemu_log_mask(LOG_GUEST_ERROR, "smc91c111_read(bank:%d) Illegal register"
 636                                   " 0x%" HWADDR_PRIx "\n",
 637                  s->bank, offset);
 638    return 0;
 639}
 640
 641static uint64_t smc91c111_readfn(void *opaque, hwaddr addr, unsigned size)
 642{
 643    int i;
 644    uint32_t val = 0;
 645
 646    for (i = 0; i < size; i++) {
 647        val |= smc91c111_readb(opaque, addr + i) << (i * 8);
 648    }
 649    return val;
 650}
 651
 652static void smc91c111_writefn(void *opaque, hwaddr addr,
 653                               uint64_t value, unsigned size)
 654{
 655    int i = 0;
 656
 657    /* 32-bit writes to offset 0xc only actually write to the bank select
 658     * register (offset 0xe), so skip the first two bytes we would write.
 659     */
 660    if (addr == 0xc && size == 4) {
 661        i += 2;
 662    }
 663
 664    for (; i < size; i++) {
 665        smc91c111_writeb(opaque, addr + i,
 666                         extract32(value, i * 8, 8));
 667    }
 668}
 669
 670static int smc91c111_can_receive_nc(NetClientState *nc)
 671{
 672    smc91c111_state *s = qemu_get_nic_opaque(nc);
 673
 674    return smc91c111_can_receive(s);
 675}
 676
 677static ssize_t smc91c111_receive(NetClientState *nc, const uint8_t *buf, size_t size)
 678{
 679    smc91c111_state *s = qemu_get_nic_opaque(nc);
 680    int status;
 681    int packetsize;
 682    uint32_t crc;
 683    int packetnum;
 684    uint8_t *p;
 685
 686    if ((s->rcr & RCR_RXEN) == 0 || (s->rcr & RCR_SOFT_RST))
 687        return -1;
 688    /* Short packets are padded with zeros.  Receiving a packet
 689       < 64 bytes long is considered an error condition.  */
 690    if (size < 64)
 691        packetsize = 64;
 692    else
 693        packetsize = (size & ~1);
 694    packetsize += 6;
 695    crc = (s->rcr & RCR_STRIP_CRC) == 0;
 696    if (crc)
 697        packetsize += 4;
 698    /* TODO: Flag overrun and receive errors.  */
 699    if (packetsize > 2048)
 700        return -1;
 701    packetnum = smc91c111_allocate_packet(s);
 702    if (packetnum == 0x80)
 703        return -1;
 704    s->rx_fifo[s->rx_fifo_len++] = packetnum;
 705
 706    p = &s->data[packetnum][0];
 707    /* ??? Multicast packets?  */
 708    status = 0;
 709    if (size > 1518)
 710        status |= RS_TOOLONG;
 711    if (size & 1)
 712        status |= RS_ODDFRAME;
 713    *(p++) = status & 0xff;
 714    *(p++) = status >> 8;
 715    *(p++) = packetsize & 0xff;
 716    *(p++) = packetsize >> 8;
 717    memcpy(p, buf, size & ~1);
 718    p += (size & ~1);
 719    /* Pad short packets.  */
 720    if (size < 64) {
 721        int pad;
 722
 723        if (size & 1)
 724            *(p++) = buf[size - 1];
 725        pad = 64 - size;
 726        memset(p, 0, pad);
 727        p += pad;
 728        size = 64;
 729    }
 730    /* It's not clear if the CRC should go before or after the last byte in
 731       odd sized packets.  Linux disables the CRC, so that's no help.
 732       The pictures in the documentation show the CRC aligned on a 16-bit
 733       boundary before the last odd byte, so that's what we do.  */
 734    if (crc) {
 735        crc = crc32(~0, buf, size);
 736        *(p++) = crc & 0xff; crc >>= 8;
 737        *(p++) = crc & 0xff; crc >>= 8;
 738        *(p++) = crc & 0xff; crc >>= 8;
 739        *(p++) = crc & 0xff;
 740    }
 741    if (size & 1) {
 742        *(p++) = buf[size - 1];
 743        *p = 0x60;
 744    } else {
 745        *(p++) = 0;
 746        *p = 0x40;
 747    }
 748    /* TODO: Raise early RX interrupt?  */
 749    s->int_level |= INT_RCV;
 750    smc91c111_update(s);
 751
 752    return size;
 753}
 754
 755static const MemoryRegionOps smc91c111_mem_ops = {
 756    /* The special case for 32 bit writes to 0xc means we can't just
 757     * set .impl.min/max_access_size to 1, unfortunately
 758     */
 759    .read = smc91c111_readfn,
 760    .write = smc91c111_writefn,
 761    .valid.min_access_size = 1,
 762    .valid.max_access_size = 4,
 763    .endianness = DEVICE_NATIVE_ENDIAN,
 764};
 765
 766static NetClientInfo net_smc91c111_info = {
 767    .type = NET_CLIENT_DRIVER_NIC,
 768    .size = sizeof(NICState),
 769    .can_receive = smc91c111_can_receive_nc,
 770    .receive = smc91c111_receive,
 771};
 772
 773static void smc91c111_realize(DeviceState *dev, Error **errp)
 774{
 775    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
 776    smc91c111_state *s = SMC91C111(dev);
 777
 778    memory_region_init_io(&s->mmio, OBJECT(s), &smc91c111_mem_ops, s,
 779                          "smc91c111-mmio", 16);
 780    sysbus_init_mmio(sbd, &s->mmio);
 781    sysbus_init_irq(sbd, &s->irq);
 782    qemu_macaddr_default_if_unset(&s->conf.macaddr);
 783    s->nic = qemu_new_nic(&net_smc91c111_info, &s->conf,
 784                          object_get_typename(OBJECT(dev)), dev->id, s);
 785    qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
 786    /* ??? Save/restore.  */
 787}
 788
 789static Property smc91c111_properties[] = {
 790    DEFINE_NIC_PROPERTIES(smc91c111_state, conf),
 791    DEFINE_PROP_END_OF_LIST(),
 792};
 793
 794static void smc91c111_class_init(ObjectClass *klass, void *data)
 795{
 796    DeviceClass *dc = DEVICE_CLASS(klass);
 797
 798    dc->realize = smc91c111_realize;
 799    dc->reset = smc91c111_reset;
 800    dc->vmsd = &vmstate_smc91c111;
 801    dc->props = smc91c111_properties;
 802}
 803
 804static const TypeInfo smc91c111_info = {
 805    .name          = TYPE_SMC91C111,
 806    .parent        = TYPE_SYS_BUS_DEVICE,
 807    .instance_size = sizeof(smc91c111_state),
 808    .class_init    = smc91c111_class_init,
 809};
 810
 811static void smc91c111_register_types(void)
 812{
 813    type_register_static(&smc91c111_info);
 814}
 815
 816/* Legacy helper function.  Should go away when machine config files are
 817   implemented.  */
 818void smc91c111_init(NICInfo *nd, uint32_t base, qemu_irq irq)
 819{
 820    DeviceState *dev;
 821    SysBusDevice *s;
 822
 823    qemu_check_nic_model(nd, "smc91c111");
 824    dev = qdev_create(NULL, TYPE_SMC91C111);
 825    qdev_set_nic_properties(dev, nd);
 826    qdev_init_nofail(dev);
 827    s = SYS_BUS_DEVICE(dev);
 828    sysbus_mmio_map(s, 0, base);
 829    sysbus_connect_irq(s, 0, irq);
 830}
 831
 832type_init(smc91c111_register_types)
 833