hw/mipsnet.c

   1 #include "hw.h"
   2 #include "mips.h"
   3 #include "net.h"
   4 #include "isa.h"
   5
   6 //#define DEBUG_MIPSNET_SEND
   7 //#define DEBUG_MIPSNET_RECEIVE
   8 //#define DEBUG_MIPSNET_DATA
   9 //#define DEBUG_MIPSNET_IRQ
  10
  11 /* MIPSnet register offsets */
  12
  13 #define MIPSNET_DEV_ID          0x00
  14 #define MIPSNET_BUSY            0x08
  15 #define MIPSNET_RX_DATA_COUNT   0x0c
  16 #define MIPSNET_TX_DATA_COUNT   0x10
  17 #define MIPSNET_INT_CTL         0x14
  18 # define MIPSNET_INTCTL_TXDONE          0x00000001
  19 # define MIPSNET_INTCTL_RXDONE          0x00000002
  20 # define MIPSNET_INTCTL_TESTBIT         0x80000000
  21 #define MIPSNET_INTERRUPT_INFO  0x18
  22 #define MIPSNET_RX_DATA_BUFFER  0x1c
  23 #define MIPSNET_TX_DATA_BUFFER  0x20
  24
  25 #define MAX_ETH_FRAME_SIZE      1514
  26
  27 typedef struct MIPSnetState {
  28     uint32_t busy;
  29     uint32_t rx_count;
  30     uint32_t rx_read;
  31     uint32_t tx_count;
  32     uint32_t tx_written;
  33     uint32_t intctl;
  34     uint8_t rx_buffer[MAX_ETH_FRAME_SIZE];
  35     uint8_t tx_buffer[MAX_ETH_FRAME_SIZE];
  36     int io_base;
  37     qemu_irq irq;
  38     NICState *nic;
  39     NICConf conf;
  40 } MIPSnetState;
  41
  42 static void mipsnet_reset(MIPSnetState *s)
  43 {
  44     s->busy = 1;
  45     s->rx_count = 0;
  46     s->rx_read = 0;
  47     s->tx_count = 0;
  48     s->tx_written = 0;
  49     s->intctl = 0;
  50     memset(s->rx_buffer, 0, MAX_ETH_FRAME_SIZE);
  51     memset(s->tx_buffer, 0, MAX_ETH_FRAME_SIZE);
  52 }
  53
  54 static void mipsnet_update_irq(MIPSnetState *s)
  55 {
  56     int isr = !!s->intctl;
  57 #ifdef DEBUG_MIPSNET_IRQ
  58     printf("mipsnet: Set IRQ to %d (%02x)\n", isr, s->intctl);
  59 #endif
  60     qemu_set_irq(s->irq, isr);
  61 }
  62
  63 static int mipsnet_buffer_full(MIPSnetState *s)
  64 {
  65     if (s->rx_count >= MAX_ETH_FRAME_SIZE)
  66         return 1;
  67     return 0;
  68 }
  69
  70 static int mipsnet_can_receive(VLANClientState *nc)
  71 {
  72     MIPSnetState *s = DO_UPCAST(NICState, nc, nc)->opaque;
  73
  74     if (s->busy)
  75         return 0;
  76     return !mipsnet_buffer_full(s);
  77 }
  78
  79 static ssize_t mipsnet_receive(VLANClientState *nc, const uint8_t *buf, size_t size)
  80 {
  81     MIPSnetState *s = DO_UPCAST(NICState, nc, nc)->opaque;
  82
  83 #ifdef DEBUG_MIPSNET_RECEIVE
  84     printf("mipsnet: receiving len=%zu\n", size);
  85 #endif
  86     if (!mipsnet_can_receive(nc))
  87         return -1;
  88
  89     s->busy = 1;
  90
  91     /* Just accept everything. */
  92
  93     /* Write packet data. */
  94     memcpy(s->rx_buffer, buf, size);
  95
  96     s->rx_count = size;
  97     s->rx_read = 0;
  98
  99     /* Now we can signal we have received something. */
 100     s->intctl |= MIPSNET_INTCTL_RXDONE;
 101     mipsnet_update_irq(s);
 102
 103     return size;
 104 }
 105
 106 static uint32_t mipsnet_ioport_read(void *opaque, uint32_t addr)
 107 {
 108     MIPSnetState *s = opaque;
 109     int ret = 0;
 110
 111     addr &= 0x3f;
 112     switch (addr) {
 113     case MIPSNET_DEV_ID:
 114         ret = be32_to_cpu(0x4d495053);          /* MIPS */
 115         break;
 116     case MIPSNET_DEV_ID + 4:
 117         ret = be32_to_cpu(0x4e455430);          /* NET0 */
 118         break;
 119     case MIPSNET_BUSY:
 120         ret = s->busy;
 121         break;
 122     case MIPSNET_RX_DATA_COUNT:
 123         ret = s->rx_count;
 124         break;
 125     case MIPSNET_TX_DATA_COUNT:
 126         ret = s->tx_count;
 127         break;
 128     case MIPSNET_INT_CTL:
 129         ret = s->intctl;
 130         s->intctl &= ~MIPSNET_INTCTL_TESTBIT;
 131         break;
 132     case MIPSNET_INTERRUPT_INFO:
 133         /* XXX: This seems to be a per-VPE interrupt number. */
 134         ret = 0;
 135         break;
 136     case MIPSNET_RX_DATA_BUFFER:
 137         if (s->rx_count) {
 138             s->rx_count--;
 139             ret = s->rx_buffer[s->rx_read++];
 140         }
 141         break;
 142     /* Reads as zero. */
 143     case MIPSNET_TX_DATA_BUFFER:
 144     default:
 145         break;
 146     }
 147 #ifdef DEBUG_MIPSNET_DATA
 148     printf("mipsnet: read addr=0x%02x val=0x%02x\n", addr, ret);
 149 #endif
 150     return ret;
 151 }
 152
 153 static void mipsnet_ioport_write(void *opaque, uint32_t addr, uint32_t val)
 154 {
 155     MIPSnetState *s = opaque;
 156
 157     addr &= 0x3f;
 158 #ifdef DEBUG_MIPSNET_DATA
 159     printf("mipsnet: write addr=0x%02x val=0x%02x\n", addr, val);
 160 #endif
 161     switch (addr) {
 162     case MIPSNET_TX_DATA_COUNT:
 163         s->tx_count = (val <= MAX_ETH_FRAME_SIZE) ? val : 0;
 164         s->tx_written = 0;
 165         break;
 166     case MIPSNET_INT_CTL:
 167         if (val & MIPSNET_INTCTL_TXDONE) {
 168             s->intctl &= ~MIPSNET_INTCTL_TXDONE;
 169         } else if (val & MIPSNET_INTCTL_RXDONE) {
 170             s->intctl &= ~MIPSNET_INTCTL_RXDONE;
 171         } else if (val & MIPSNET_INTCTL_TESTBIT) {
 172             mipsnet_reset(s);
 173             s->intctl |= MIPSNET_INTCTL_TESTBIT;
 174         } else if (!val) {
 175             /* ACK testbit interrupt, flag was cleared on read. */
 176         }
 177         s->busy = !!s->intctl;
 178         mipsnet_update_irq(s);
 179         break;
 180     case MIPSNET_TX_DATA_BUFFER:
 181         s->tx_buffer[s->tx_written++] = val;
 182         if (s->tx_written == s->tx_count) {
 183             /* Send buffer. */
 184 #ifdef DEBUG_MIPSNET_SEND
 185             printf("mipsnet: sending len=%d\n", s->tx_count);
 186 #endif
 187             qemu_send_packet(&s->nic->nc, s->tx_buffer, s->tx_count);
 188             s->tx_count = s->tx_written = 0;
 189             s->intctl |= MIPSNET_INTCTL_TXDONE;
 190             s->busy = 1;
 191             mipsnet_update_irq(s);
 192         }
 193         break;
 194     /* Read-only registers */
 195     case MIPSNET_DEV_ID:
 196     case MIPSNET_BUSY:
 197     case MIPSNET_RX_DATA_COUNT:
 198     case MIPSNET_INTERRUPT_INFO:
 199     case MIPSNET_RX_DATA_BUFFER:
 200     default:
 201         break;
 202     }
 203 }
 204
 205 static const VMStateDescription vmstate_mipsnet = {
 206     .name = "mipsnet",
 207     .version_id = 0,
 208     .minimum_version_id = 0,
 209     .minimum_version_id_old = 0,
 210     .fields      = (VMStateField[]) {
 211         VMSTATE_UINT32(busy, MIPSnetState),
 212         VMSTATE_UINT32(rx_count, MIPSnetState),
 213         VMSTATE_UINT32(rx_read, MIPSnetState),
 214         VMSTATE_UINT32(tx_count, MIPSnetState),
 215         VMSTATE_UINT32(tx_written, MIPSnetState),
 216         VMSTATE_UINT32(intctl, MIPSnetState),
 217         VMSTATE_BUFFER(rx_buffer, MIPSnetState),
 218         VMSTATE_BUFFER(tx_buffer, MIPSnetState),
 219         VMSTATE_END_OF_LIST()
 220     }
 221 };
 222
 223 static void mipsnet_cleanup(VLANClientState *nc)
 224 {
 225     MIPSnetState *s = DO_UPCAST(NICState, nc, nc)->opaque;
 226
 227     vmstate_unregister(NULL, &vmstate_mipsnet, s);
 228
 229     isa_unassign_ioport(s->io_base, 36);
 230
 231     qemu_free(s);
 232 }
 233
 234 static NetClientInfo net_mipsnet_info = {
 235     .type = NET_CLIENT_TYPE_NIC,
 236     .size = sizeof(NICState),
 237     .can_receive = mipsnet_can_receive,
 238     .receive = mipsnet_receive,
 239     .cleanup = mipsnet_cleanup,
 240 };
 241
 242 void mipsnet_init (int base, qemu_irq irq, NICInfo *nd)
 243 {
 244     MIPSnetState *s;
 245
 246     qemu_check_nic_model(nd, "mipsnet");
 247
 248     s = qemu_mallocz(sizeof(MIPSnetState));
 249
 250     register_ioport_write(base, 36, 1, mipsnet_ioport_write, s);
 251     register_ioport_read(base, 36, 1, mipsnet_ioport_read, s);
 252     register_ioport_write(base, 36, 2, mipsnet_ioport_write, s);
 253     register_ioport_read(base, 36, 2, mipsnet_ioport_read, s);
 254     register_ioport_write(base, 36, 4, mipsnet_ioport_write, s);
 255     register_ioport_read(base, 36, 4, mipsnet_ioport_read, s);
 256
 257     s->io_base = base;
 258     s->irq = irq;
 259
 260     if (nd) {
 261         s->conf.macaddr = nd->macaddr;
 262         s->conf.vlan = nd->vlan;
 263         s->conf.peer = nd->netdev;
 264
 265         s->nic = qemu_new_nic(&net_mipsnet_info, &s->conf,
 266                               nd->model, nd->name, s);
 267
 268         qemu_format_nic_info_str(&s->nic->nc, s->conf.macaddr.a);
 269     }
 270
 271     mipsnet_reset(s);
 272     vmstate_register(NULL, 0, &vmstate_mipsnet, s);
 273 }