qemu/hw/net/allwinner_emac.c
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   1/*
   2 * Emulation of Allwinner EMAC Fast Ethernet controller and
   3 * Realtek RTL8201CP PHY
   4 *
   5 * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
   6 *
   7 * This model is based on reverse-engineering of Linux kernel driver.
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License version 2 as
  11 * published by the Free Software Foundation.
  12 *
  13 * This program is distributed in the hope that it will be useful,
  14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16 * GNU General Public License for more details.
  17 *
  18 */
  19#include "qemu/osdep.h"
  20#include "hw/sysbus.h"
  21#include "net/net.h"
  22#include "qemu/fifo8.h"
  23#include "hw/net/allwinner_emac.h"
  24#include "qemu/log.h"
  25#include <zlib.h>
  26
  27static uint8_t padding[60];
  28
  29static void mii_set_link(RTL8201CPState *mii, bool link_ok)
  30{
  31    if (link_ok) {
  32        mii->bmsr |= MII_BMSR_LINK_ST | MII_BMSR_AN_COMP;
  33        mii->anlpar |= MII_ANAR_TXFD | MII_ANAR_10FD | MII_ANAR_10 |
  34                       MII_ANAR_CSMACD;
  35    } else {
  36        mii->bmsr &= ~(MII_BMSR_LINK_ST | MII_BMSR_AN_COMP);
  37        mii->anlpar = MII_ANAR_TX;
  38    }
  39}
  40
  41static void mii_reset(RTL8201CPState *mii, bool link_ok)
  42{
  43    mii->bmcr = MII_BMCR_FD | MII_BMCR_AUTOEN | MII_BMCR_SPEED;
  44    mii->bmsr = MII_BMSR_100TX_FD | MII_BMSR_100TX_HD | MII_BMSR_10T_FD |
  45                MII_BMSR_10T_HD | MII_BMSR_MFPS | MII_BMSR_AUTONEG;
  46    mii->anar = MII_ANAR_TXFD | MII_ANAR_TX | MII_ANAR_10FD | MII_ANAR_10 |
  47                MII_ANAR_CSMACD;
  48    mii->anlpar = MII_ANAR_TX;
  49
  50    mii_set_link(mii, link_ok);
  51}
  52
  53static uint16_t RTL8201CP_mdio_read(AwEmacState *s, uint8_t addr, uint8_t reg)
  54{
  55    RTL8201CPState *mii = &s->mii;
  56    uint16_t ret = 0xffff;
  57
  58    if (addr == s->phy_addr) {
  59        switch (reg) {
  60        case MII_BMCR:
  61            return mii->bmcr;
  62        case MII_BMSR:
  63            return mii->bmsr;
  64        case MII_PHYID1:
  65            return RTL8201CP_PHYID1;
  66        case MII_PHYID2:
  67            return RTL8201CP_PHYID2;
  68        case MII_ANAR:
  69            return mii->anar;
  70        case MII_ANLPAR:
  71            return mii->anlpar;
  72        case MII_ANER:
  73        case MII_NSR:
  74        case MII_LBREMR:
  75        case MII_REC:
  76        case MII_SNRDR:
  77        case MII_TEST:
  78            qemu_log_mask(LOG_UNIMP,
  79                          "allwinner_emac: read from unimpl. mii reg 0x%x\n",
  80                          reg);
  81            return 0;
  82        default:
  83            qemu_log_mask(LOG_GUEST_ERROR,
  84                          "allwinner_emac: read from invalid mii reg 0x%x\n",
  85                          reg);
  86            return 0;
  87        }
  88    }
  89    return ret;
  90}
  91
  92static void RTL8201CP_mdio_write(AwEmacState *s, uint8_t addr, uint8_t reg,
  93                                 uint16_t value)
  94{
  95    RTL8201CPState *mii = &s->mii;
  96    NetClientState *nc;
  97
  98    if (addr == s->phy_addr) {
  99        switch (reg) {
 100        case MII_BMCR:
 101            if (value & MII_BMCR_RESET) {
 102                nc = qemu_get_queue(s->nic);
 103                mii_reset(mii, !nc->link_down);
 104            } else {
 105                mii->bmcr = value;
 106            }
 107            break;
 108        case MII_ANAR:
 109            mii->anar = value;
 110            break;
 111        case MII_BMSR:
 112        case MII_PHYID1:
 113        case MII_PHYID2:
 114        case MII_ANLPAR:
 115        case MII_ANER:
 116            qemu_log_mask(LOG_GUEST_ERROR,
 117                          "allwinner_emac: write to read-only mii reg 0x%x\n",
 118                          reg);
 119            break;
 120        case MII_NSR:
 121        case MII_LBREMR:
 122        case MII_REC:
 123        case MII_SNRDR:
 124        case MII_TEST:
 125            qemu_log_mask(LOG_UNIMP,
 126                          "allwinner_emac: write to unimpl. mii reg 0x%x\n",
 127                          reg);
 128            break;
 129        default:
 130            qemu_log_mask(LOG_GUEST_ERROR,
 131                          "allwinner_emac: write to invalid mii reg 0x%x\n",
 132                          reg);
 133        }
 134    }
 135}
 136
 137static void aw_emac_update_irq(AwEmacState *s)
 138{
 139    qemu_set_irq(s->irq, (s->int_sta & s->int_ctl) != 0);
 140}
 141
 142static void aw_emac_tx_reset(AwEmacState *s, int chan)
 143{
 144    fifo8_reset(&s->tx_fifo[chan]);
 145    s->tx_length[chan] = 0;
 146}
 147
 148static void aw_emac_rx_reset(AwEmacState *s)
 149{
 150    fifo8_reset(&s->rx_fifo);
 151    s->rx_num_packets = 0;
 152    s->rx_packet_size = 0;
 153    s->rx_packet_pos = 0;
 154}
 155
 156static void fifo8_push_word(Fifo8 *fifo, uint32_t val)
 157{
 158    fifo8_push(fifo, val);
 159    fifo8_push(fifo, val >> 8);
 160    fifo8_push(fifo, val >> 16);
 161    fifo8_push(fifo, val >> 24);
 162}
 163
 164static uint32_t fifo8_pop_word(Fifo8 *fifo)
 165{
 166    uint32_t ret;
 167
 168    ret = fifo8_pop(fifo);
 169    ret |= fifo8_pop(fifo) << 8;
 170    ret |= fifo8_pop(fifo) << 16;
 171    ret |= fifo8_pop(fifo) << 24;
 172
 173    return ret;
 174}
 175
 176static int aw_emac_can_receive(NetClientState *nc)
 177{
 178    AwEmacState *s = qemu_get_nic_opaque(nc);
 179
 180    /*
 181     * To avoid packet drops, allow reception only when there is space
 182     * for a full frame: 1522 + 8 (rx headers) + 2 (padding).
 183     */
 184    return (s->ctl & EMAC_CTL_RX_EN) && (fifo8_num_free(&s->rx_fifo) >= 1532);
 185}
 186
 187static ssize_t aw_emac_receive(NetClientState *nc, const uint8_t *buf,
 188                               size_t size)
 189{
 190    AwEmacState *s = qemu_get_nic_opaque(nc);
 191    Fifo8 *fifo = &s->rx_fifo;
 192    size_t padded_size, total_size;
 193    uint32_t crc;
 194
 195    padded_size = size > 60 ? size : 60;
 196    total_size = QEMU_ALIGN_UP(RX_HDR_SIZE + padded_size + CRC_SIZE, 4);
 197
 198    if (!(s->ctl & EMAC_CTL_RX_EN) || (fifo8_num_free(fifo) < total_size)) {
 199        return -1;
 200    }
 201
 202    fifo8_push_word(fifo, EMAC_UNDOCUMENTED_MAGIC);
 203    fifo8_push_word(fifo, EMAC_RX_HEADER(padded_size + CRC_SIZE,
 204                                         EMAC_RX_IO_DATA_STATUS_OK));
 205    fifo8_push_all(fifo, buf, size);
 206    crc = crc32(~0, buf, size);
 207
 208    if (padded_size != size) {
 209        fifo8_push_all(fifo, padding, padded_size - size);
 210        crc = crc32(crc, padding, padded_size - size);
 211    }
 212
 213    fifo8_push_word(fifo, crc);
 214    fifo8_push_all(fifo, padding, QEMU_ALIGN_UP(padded_size, 4) - padded_size);
 215    s->rx_num_packets++;
 216
 217    s->int_sta |= EMAC_INT_RX;
 218    aw_emac_update_irq(s);
 219
 220    return size;
 221}
 222
 223static void aw_emac_reset(DeviceState *dev)
 224{
 225    AwEmacState *s = AW_EMAC(dev);
 226    NetClientState *nc = qemu_get_queue(s->nic);
 227
 228    s->ctl = 0;
 229    s->tx_mode = 0;
 230    s->int_ctl = 0;
 231    s->int_sta = 0;
 232    s->tx_channel = 0;
 233    s->phy_target = 0;
 234
 235    aw_emac_tx_reset(s, 0);
 236    aw_emac_tx_reset(s, 1);
 237    aw_emac_rx_reset(s);
 238
 239    mii_reset(&s->mii, !nc->link_down);
 240}
 241
 242static uint64_t aw_emac_read(void *opaque, hwaddr offset, unsigned size)
 243{
 244    AwEmacState *s = opaque;
 245    Fifo8 *fifo = &s->rx_fifo;
 246    NetClientState *nc;
 247    uint64_t ret;
 248
 249    switch (offset) {
 250    case EMAC_CTL_REG:
 251        return s->ctl;
 252    case EMAC_TX_MODE_REG:
 253        return s->tx_mode;
 254    case EMAC_TX_INS_REG:
 255        return s->tx_channel;
 256    case EMAC_RX_CTL_REG:
 257        return s->rx_ctl;
 258    case EMAC_RX_IO_DATA_REG:
 259        if (!s->rx_num_packets) {
 260            qemu_log_mask(LOG_GUEST_ERROR,
 261                          "Read IO data register when no packet available");
 262            return 0;
 263        }
 264
 265        ret = fifo8_pop_word(fifo);
 266
 267        switch (s->rx_packet_pos) {
 268        case 0:     /* Word is magic header */
 269            s->rx_packet_pos += 4;
 270            break;
 271        case 4:     /* Word is rx info header */
 272            s->rx_packet_pos += 4;
 273            s->rx_packet_size = QEMU_ALIGN_UP(extract32(ret, 0, 16), 4);
 274            break;
 275        default:    /* Word is packet data */
 276            s->rx_packet_pos += 4;
 277            s->rx_packet_size -= 4;
 278
 279            if (!s->rx_packet_size) {
 280                s->rx_packet_pos = 0;
 281                s->rx_num_packets--;
 282                nc = qemu_get_queue(s->nic);
 283                if (aw_emac_can_receive(nc)) {
 284                    qemu_flush_queued_packets(nc);
 285                }
 286            }
 287        }
 288        return ret;
 289    case EMAC_RX_FBC_REG:
 290        return s->rx_num_packets;
 291    case EMAC_INT_CTL_REG:
 292        return s->int_ctl;
 293    case EMAC_INT_STA_REG:
 294        return s->int_sta;
 295    case EMAC_MAC_MRDD_REG:
 296        return RTL8201CP_mdio_read(s,
 297                                   extract32(s->phy_target, PHY_ADDR_SHIFT, 8),
 298                                   extract32(s->phy_target, PHY_REG_SHIFT, 8));
 299    default:
 300        qemu_log_mask(LOG_UNIMP,
 301                      "allwinner_emac: read access to unknown register 0x"
 302                      TARGET_FMT_plx "\n", offset);
 303        ret = 0;
 304    }
 305
 306    return ret;
 307}
 308
 309static void aw_emac_write(void *opaque, hwaddr offset, uint64_t value,
 310                          unsigned size)
 311{
 312    AwEmacState *s = opaque;
 313    Fifo8 *fifo;
 314    NetClientState *nc = qemu_get_queue(s->nic);
 315    int chan;
 316
 317    switch (offset) {
 318    case EMAC_CTL_REG:
 319        if (value & EMAC_CTL_RESET) {
 320            aw_emac_reset(DEVICE(s));
 321            value &= ~EMAC_CTL_RESET;
 322        }
 323        s->ctl = value;
 324        if (aw_emac_can_receive(nc)) {
 325            qemu_flush_queued_packets(nc);
 326        }
 327        break;
 328    case EMAC_TX_MODE_REG:
 329        s->tx_mode = value;
 330        break;
 331    case EMAC_TX_CTL0_REG:
 332    case EMAC_TX_CTL1_REG:
 333        chan = (offset == EMAC_TX_CTL0_REG ? 0 : 1);
 334        if ((value & 1) && (s->ctl & EMAC_CTL_TX_EN)) {
 335            uint32_t len, ret;
 336            const uint8_t *data;
 337
 338            fifo = &s->tx_fifo[chan];
 339            len = s->tx_length[chan];
 340
 341            if (len > fifo8_num_used(fifo)) {
 342                len = fifo8_num_used(fifo);
 343                qemu_log_mask(LOG_GUEST_ERROR,
 344                              "allwinner_emac: TX length > fifo data length\n");
 345            }
 346            if (len > 0) {
 347                data = fifo8_pop_buf(fifo, len, &ret);
 348                qemu_send_packet(nc, data, ret);
 349                aw_emac_tx_reset(s, chan);
 350                /* Raise TX interrupt */
 351                s->int_sta |= EMAC_INT_TX_CHAN(chan);
 352                aw_emac_update_irq(s);
 353            }
 354        }
 355        break;
 356    case EMAC_TX_INS_REG:
 357        s->tx_channel = value < NUM_TX_FIFOS ? value : 0;
 358        break;
 359    case EMAC_TX_PL0_REG:
 360    case EMAC_TX_PL1_REG:
 361        chan = (offset == EMAC_TX_PL0_REG ? 0 : 1);
 362        if (value > TX_FIFO_SIZE) {
 363            qemu_log_mask(LOG_GUEST_ERROR,
 364                          "allwinner_emac: invalid TX frame length %d\n",
 365                          (int)value);
 366            value = TX_FIFO_SIZE;
 367        }
 368        s->tx_length[chan] = value;
 369        break;
 370    case EMAC_TX_IO_DATA_REG:
 371        fifo = &s->tx_fifo[s->tx_channel];
 372        if (fifo8_num_free(fifo) < 4) {
 373            qemu_log_mask(LOG_GUEST_ERROR,
 374                          "allwinner_emac: TX data overruns fifo\n");
 375            break;
 376        }
 377        fifo8_push_word(fifo, value);
 378        break;
 379    case EMAC_RX_CTL_REG:
 380        s->rx_ctl = value;
 381        break;
 382    case EMAC_RX_FBC_REG:
 383        if (value == 0) {
 384            aw_emac_rx_reset(s);
 385        }
 386        break;
 387    case EMAC_INT_CTL_REG:
 388        s->int_ctl = value;
 389        aw_emac_update_irq(s);
 390        break;
 391    case EMAC_INT_STA_REG:
 392        s->int_sta &= ~value;
 393        aw_emac_update_irq(s);
 394        break;
 395    case EMAC_MAC_MADR_REG:
 396        s->phy_target = value;
 397        break;
 398    case EMAC_MAC_MWTD_REG:
 399        RTL8201CP_mdio_write(s, extract32(s->phy_target, PHY_ADDR_SHIFT, 8),
 400                             extract32(s->phy_target, PHY_REG_SHIFT, 8), value);
 401        break;
 402    default:
 403        qemu_log_mask(LOG_UNIMP,
 404                      "allwinner_emac: write access to unknown register 0x"
 405                      TARGET_FMT_plx "\n", offset);
 406    }
 407}
 408
 409static void aw_emac_set_link(NetClientState *nc)
 410{
 411    AwEmacState *s = qemu_get_nic_opaque(nc);
 412
 413    mii_set_link(&s->mii, !nc->link_down);
 414}
 415
 416static const MemoryRegionOps aw_emac_mem_ops = {
 417    .read = aw_emac_read,
 418    .write = aw_emac_write,
 419    .endianness = DEVICE_NATIVE_ENDIAN,
 420    .valid = {
 421        .min_access_size = 4,
 422        .max_access_size = 4,
 423    },
 424};
 425
 426static NetClientInfo net_aw_emac_info = {
 427    .type = NET_CLIENT_OPTIONS_KIND_NIC,
 428    .size = sizeof(NICState),
 429    .can_receive = aw_emac_can_receive,
 430    .receive = aw_emac_receive,
 431    .link_status_changed = aw_emac_set_link,
 432};
 433
 434static void aw_emac_init(Object *obj)
 435{
 436    SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
 437    AwEmacState *s = AW_EMAC(obj);
 438
 439    memory_region_init_io(&s->iomem, OBJECT(s), &aw_emac_mem_ops, s,
 440                          "aw_emac", 0x1000);
 441    sysbus_init_mmio(sbd, &s->iomem);
 442    sysbus_init_irq(sbd, &s->irq);
 443}
 444
 445static void aw_emac_realize(DeviceState *dev, Error **errp)
 446{
 447    AwEmacState *s = AW_EMAC(dev);
 448
 449    qemu_macaddr_default_if_unset(&s->conf.macaddr);
 450    s->nic = qemu_new_nic(&net_aw_emac_info, &s->conf,
 451                          object_get_typename(OBJECT(dev)), dev->id, s);
 452    qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
 453
 454    fifo8_create(&s->rx_fifo, RX_FIFO_SIZE);
 455    fifo8_create(&s->tx_fifo[0], TX_FIFO_SIZE);
 456    fifo8_create(&s->tx_fifo[1], TX_FIFO_SIZE);
 457}
 458
 459static Property aw_emac_properties[] = {
 460    DEFINE_NIC_PROPERTIES(AwEmacState, conf),
 461    DEFINE_PROP_UINT8("phy-addr", AwEmacState, phy_addr, 0),
 462    DEFINE_PROP_END_OF_LIST(),
 463};
 464
 465static const VMStateDescription vmstate_mii = {
 466    .name = "rtl8201cp",
 467    .version_id = 1,
 468    .minimum_version_id = 1,
 469    .fields = (VMStateField[]) {
 470        VMSTATE_UINT16(bmcr, RTL8201CPState),
 471        VMSTATE_UINT16(bmsr, RTL8201CPState),
 472        VMSTATE_UINT16(anar, RTL8201CPState),
 473        VMSTATE_UINT16(anlpar, RTL8201CPState),
 474        VMSTATE_END_OF_LIST()
 475    }
 476};
 477
 478static int aw_emac_post_load(void *opaque, int version_id)
 479{
 480    AwEmacState *s = opaque;
 481
 482    aw_emac_set_link(qemu_get_queue(s->nic));
 483
 484    return 0;
 485}
 486
 487static const VMStateDescription vmstate_aw_emac = {
 488    .name = "allwinner_emac",
 489    .version_id = 1,
 490    .minimum_version_id = 1,
 491    .post_load = aw_emac_post_load,
 492    .fields = (VMStateField[]) {
 493        VMSTATE_STRUCT(mii, AwEmacState, 1, vmstate_mii, RTL8201CPState),
 494        VMSTATE_UINT32(ctl, AwEmacState),
 495        VMSTATE_UINT32(tx_mode, AwEmacState),
 496        VMSTATE_UINT32(rx_ctl, AwEmacState),
 497        VMSTATE_UINT32(int_ctl, AwEmacState),
 498        VMSTATE_UINT32(int_sta, AwEmacState),
 499        VMSTATE_UINT32(phy_target, AwEmacState),
 500        VMSTATE_FIFO8(rx_fifo, AwEmacState),
 501        VMSTATE_UINT32(rx_num_packets, AwEmacState),
 502        VMSTATE_UINT32(rx_packet_size, AwEmacState),
 503        VMSTATE_UINT32(rx_packet_pos, AwEmacState),
 504        VMSTATE_STRUCT_ARRAY(tx_fifo, AwEmacState, NUM_TX_FIFOS, 1,
 505                             vmstate_fifo8, Fifo8),
 506        VMSTATE_UINT32_ARRAY(tx_length, AwEmacState, NUM_TX_FIFOS),
 507        VMSTATE_UINT32(tx_channel, AwEmacState),
 508        VMSTATE_END_OF_LIST()
 509    }
 510};
 511
 512static void aw_emac_class_init(ObjectClass *klass, void *data)
 513{
 514    DeviceClass *dc = DEVICE_CLASS(klass);
 515
 516    dc->realize = aw_emac_realize;
 517    dc->props = aw_emac_properties;
 518    dc->reset = aw_emac_reset;
 519    dc->vmsd = &vmstate_aw_emac;
 520}
 521
 522static const TypeInfo aw_emac_info = {
 523    .name           = TYPE_AW_EMAC,
 524    .parent         = TYPE_SYS_BUS_DEVICE,
 525    .instance_size  = sizeof(AwEmacState),
 526    .instance_init   = aw_emac_init,
 527    .class_init     = aw_emac_class_init,
 528};
 529
 530static void aw_emac_register_types(void)
 531{
 532    type_register_static(&aw_emac_info);
 533}
 534
 535type_init(aw_emac_register_types)
 536