Archipelago » qemu

#include "hw/hw.h"

#include "net/net.h"

#include "trace.h"

#include "hw/sysbus.h"

/* MIPSnet register offsets */

#define MIPSNET_DEV_ID                0x00

#define MIPSNET_BUSY                0x08

#define MIPSNET_RX_DATA_COUNT        0x0c

#define MIPSNET_TX_DATA_COUNT        0x10

#define MIPSNET_INT_CTL                0x14

# define MIPSNET_INTCTL_TXDONE                0x00000001

# define MIPSNET_INTCTL_RXDONE                0x00000002

# define MIPSNET_INTCTL_TESTBIT                0x80000000

#define MIPSNET_INTERRUPT_INFO        0x18

#define MIPSNET_RX_DATA_BUFFER        0x1c

#define MIPSNET_TX_DATA_BUFFER        0x20

#define MAX_ETH_FRAME_SIZE        1514

#define TYPE_MIPS_NET "mipsnet"

#define MIPS_NET(obj) OBJECT_CHECK(MIPSnetState, (obj), TYPE_MIPS_NET)

typedef struct MIPSnetState {

    SysBusDevice parent_obj;

    uint32_t busy;

    uint32_t rx_count;

    uint32_t rx_read;

    uint32_t tx_count;

    uint32_t tx_written;

    uint32_t intctl;

    uint8_t rx_buffer[MAX_ETH_FRAME_SIZE];

    uint8_t tx_buffer[MAX_ETH_FRAME_SIZE];

    MemoryRegion io;

    qemu_irq irq;

    NICState *nic;

    NICConf conf;

} MIPSnetState;

static void mipsnet_reset(MIPSnetState *s)

{

    s->busy = 1;

    s->rx_count = 0;

    s->rx_read = 0;

    s->tx_count = 0;

    s->tx_written = 0;

    s->intctl = 0;

    memset(s->rx_buffer, 0, MAX_ETH_FRAME_SIZE);

    memset(s->tx_buffer, 0, MAX_ETH_FRAME_SIZE);

}

static void mipsnet_update_irq(MIPSnetState *s)

{

    int isr = !!s->intctl;

    trace_mipsnet_irq(isr, s->intctl);

    qemu_set_irq(s->irq, isr);

}

static int mipsnet_buffer_full(MIPSnetState *s)

{

    if (s->rx_count >= MAX_ETH_FRAME_SIZE)

        return 1;

    return 0;

}

static int mipsnet_can_receive(NetClientState *nc)

{

    MIPSnetState *s = qemu_get_nic_opaque(nc);

    if (s->busy)

        return 0;

    return !mipsnet_buffer_full(s);

}

static ssize_t mipsnet_receive(NetClientState *nc, const uint8_t *buf, size_t size)

{

    MIPSnetState *s = qemu_get_nic_opaque(nc);

    trace_mipsnet_receive(size);

    if (!mipsnet_can_receive(nc))

        return -1;

    s->busy = 1;

    /* Just accept everything. */

    /* Write packet data. */

    memcpy(s->rx_buffer, buf, size);

    s->rx_count = size;

    s->rx_read = 0;

    /* Now we can signal we have received something. */

    s->intctl |= MIPSNET_INTCTL_RXDONE;

    mipsnet_update_irq(s);

    return size;

}

static uint64_t mipsnet_ioport_read(void *opaque, hwaddr addr,

                                    unsigned int size)

{

    MIPSnetState *s = opaque;

    int ret = 0;

    addr &= 0x3f;

    switch (addr) {

    case MIPSNET_DEV_ID:

        ret = be32_to_cpu(0x4d495053);                /* MIPS */

        break;

    case MIPSNET_DEV_ID + 4:

        ret = be32_to_cpu(0x4e455430);                /* NET0 */

        break;

    case MIPSNET_BUSY:

        ret = s->busy;

        break;

    case MIPSNET_RX_DATA_COUNT:

        ret = s->rx_count;

        break;

    case MIPSNET_TX_DATA_COUNT:

        ret = s->tx_count;

        break;

    case MIPSNET_INT_CTL:

        ret = s->intctl;

        s->intctl &= ~MIPSNET_INTCTL_TESTBIT;

        break;

    case MIPSNET_INTERRUPT_INFO:

        /* XXX: This seems to be a per-VPE interrupt number. */

        ret = 0;

        break;

    case MIPSNET_RX_DATA_BUFFER:

        if (s->rx_count) {

            s->rx_count--;

            ret = s->rx_buffer[s->rx_read++];

        }

        break;

    /* Reads as zero. */

    case MIPSNET_TX_DATA_BUFFER:

    default:

        break;

    }

    trace_mipsnet_read(addr, ret);

    return ret;

}

static void mipsnet_ioport_write(void *opaque, hwaddr addr,

                                 uint64_t val, unsigned int size)

{

    MIPSnetState *s = opaque;

    addr &= 0x3f;

    trace_mipsnet_write(addr, val);

    switch (addr) {

    case MIPSNET_TX_DATA_COUNT:

        s->tx_count = (val <= MAX_ETH_FRAME_SIZE) ? val : 0;

        s->tx_written = 0;

        break;

    case MIPSNET_INT_CTL:

        if (val & MIPSNET_INTCTL_TXDONE) {

            s->intctl &= ~MIPSNET_INTCTL_TXDONE;

        } else if (val & MIPSNET_INTCTL_RXDONE) {

            s->intctl &= ~MIPSNET_INTCTL_RXDONE;

        } else if (val & MIPSNET_INTCTL_TESTBIT) {

            mipsnet_reset(s);

            s->intctl |= MIPSNET_INTCTL_TESTBIT;

        } else if (!val) {

            /* ACK testbit interrupt, flag was cleared on read. */

        }

        s->busy = !!s->intctl;

        mipsnet_update_irq(s);

        break;

    case MIPSNET_TX_DATA_BUFFER:

        s->tx_buffer[s->tx_written++] = val;

        if (s->tx_written == s->tx_count) {

            /* Send buffer. */

            trace_mipsnet_send(s->tx_count);

            qemu_send_packet(qemu_get_queue(s->nic), s->tx_buffer, s->tx_count);

            s->tx_count = s->tx_written = 0;

            s->intctl |= MIPSNET_INTCTL_TXDONE;

            s->busy = 1;

            mipsnet_update_irq(s);

        }

        break;

    /* Read-only registers */

    case MIPSNET_DEV_ID:

    case MIPSNET_BUSY:

    case MIPSNET_RX_DATA_COUNT:

    case MIPSNET_INTERRUPT_INFO:

    case MIPSNET_RX_DATA_BUFFER:

    default:

        break;

    }

}

static const VMStateDescription vmstate_mipsnet = {

    .name = "mipsnet",

    .version_id = 0,

    .minimum_version_id = 0,

    .minimum_version_id_old = 0,

    .fields      = (VMStateField[]) {

        VMSTATE_UINT32(busy, MIPSnetState),

        VMSTATE_UINT32(rx_count, MIPSnetState),

        VMSTATE_UINT32(rx_read, MIPSnetState),

        VMSTATE_UINT32(tx_count, MIPSnetState),

        VMSTATE_UINT32(tx_written, MIPSnetState),

        VMSTATE_UINT32(intctl, MIPSnetState),

        VMSTATE_BUFFER(rx_buffer, MIPSnetState),

        VMSTATE_BUFFER(tx_buffer, MIPSnetState),

        VMSTATE_END_OF_LIST()

    }

};

static void mipsnet_cleanup(NetClientState *nc)

{

    MIPSnetState *s = qemu_get_nic_opaque(nc);

    s->nic = NULL;

}

static NetClientInfo net_mipsnet_info = {

    .type = NET_CLIENT_OPTIONS_KIND_NIC,

    .size = sizeof(NICState),

    .can_receive = mipsnet_can_receive,

    .receive = mipsnet_receive,

    .cleanup = mipsnet_cleanup,

};

static const MemoryRegionOps mipsnet_ioport_ops = {

    .read = mipsnet_ioport_read,

    .write = mipsnet_ioport_write,

    .impl.min_access_size = 1,

    .impl.max_access_size = 4,

};

static int mipsnet_sysbus_init(SysBusDevice *sbd)

{

    DeviceState *dev = DEVICE(sbd);

    MIPSnetState *s = MIPS_NET(dev);

    memory_region_init_io(&s->io, OBJECT(dev), &mipsnet_ioport_ops, s,

                          "mipsnet-io", 36);

    sysbus_init_mmio(sbd, &s->io);

    sysbus_init_irq(sbd, &s->irq);

    s->nic = qemu_new_nic(&net_mipsnet_info, &s->conf,

                          object_get_typename(OBJECT(dev)), dev->id, s);

    qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);

    return 0;

}

static void mipsnet_sysbus_reset(DeviceState *dev)

{

    MIPSnetState *s = MIPS_NET(dev);

    mipsnet_reset(s);

}

static Property mipsnet_properties[] = {

    DEFINE_NIC_PROPERTIES(MIPSnetState, conf),

    DEFINE_PROP_END_OF_LIST(),

};

static void mipsnet_class_init(ObjectClass *klass, void *data)

{

    DeviceClass *dc = DEVICE_CLASS(klass);

    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);

    k->init = mipsnet_sysbus_init;

    set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);

    dc->desc = "MIPS Simulator network device";

    dc->reset = mipsnet_sysbus_reset;

    dc->vmsd = &vmstate_mipsnet;

    dc->props = mipsnet_properties;

}

static const TypeInfo mipsnet_info = {

    .name          = TYPE_MIPS_NET,

    .parent        = TYPE_SYS_BUS_DEVICE,

    .instance_size = sizeof(MIPSnetState),

    .class_init    = mipsnet_class_init,

};

static void mipsnet_register_types(void)

{

    type_register_static(&mipsnet_info);

}

type_init(mipsnet_register_types)