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     VLANClientState *vc;
  39 } MIPSnetState;
  40
  41 static void mipsnet_reset(MIPSnetState *s)
  42 {
  43     s->busy = 1;
  44     s->rx_count = 0;
  45     s->rx_read = 0;
  46     s->tx_count = 0;
  47     s->tx_written = 0;
  48     s->intctl = 0;
  49     memset(s->rx_buffer, 0, MAX_ETH_FRAME_SIZE);
  50     memset(s->tx_buffer, 0, MAX_ETH_FRAME_SIZE);
  51 }
  52
  53 static void mipsnet_update_irq(MIPSnetState *s)
  54 {
  55     int isr = !!s->intctl;
  56 #ifdef DEBUG_MIPSNET_IRQ
  57     printf("mipsnet: Set IRQ to %d (%02x)\n", isr, s->intctl);
  58 #endif
  59     qemu_set_irq(s->irq, isr);
  60 }
  61
  62 static int mipsnet_buffer_full(MIPSnetState *s)
  63 {
  64     if (s->rx_count >= MAX_ETH_FRAME_SIZE)
  65         return 1;
  66     return 0;
  67 }
  68
  69 static int mipsnet_can_receive(VLANClientState *vc)
  70 {
  71     MIPSnetState *s = vc->opaque;
  72
  73     if (s->busy)
  74         return 0;
  75     return !mipsnet_buffer_full(s);
  76 }
  77
  78 static ssize_t mipsnet_receive(VLANClientState *vc, const uint8_t *buf, size_t size)
  79 {
  80     MIPSnetState *s = vc->opaque;
  81
  82 #ifdef DEBUG_MIPSNET_RECEIVE
  83     printf("mipsnet: receiving len=%d\n", size);
  84 #endif
  85     if (!mipsnet_can_receive(vc))
  86         return -1;
  87
  88     s->busy = 1;
  89
  90     /* Just accept everything. */
  91
  92     /* Write packet data. */
  93     memcpy(s->rx_buffer, buf, size);
  94
  95     s->rx_count = size;
  96     s->rx_read = 0;
  97
  98     /* Now we can signal we have received something. */
  99     s->intctl |= MIPSNET_INTCTL_RXDONE;
 100     mipsnet_update_irq(s);
 101
 102     return size;
 103 }
 104
 105 static uint32_t mipsnet_ioport_read(void *opaque, uint32_t addr)
 106 {
 107     MIPSnetState *s = opaque;
 108     int ret = 0;
 109
 110     addr &= 0x3f;
 111     switch (addr) {
 112     case MIPSNET_DEV_ID:
 113         ret = be32_to_cpu(0x4d495053);          /* MIPS */
 114         break;
 115     case MIPSNET_DEV_ID + 4:
 116         ret = be32_to_cpu(0x4e455430);          /* NET0 */
 117         break;
 118     case MIPSNET_BUSY:
 119         ret = s->busy;
 120         break;
 121     case MIPSNET_RX_DATA_COUNT:
 122         ret = s->rx_count;
 123         break;
 124     case MIPSNET_TX_DATA_COUNT:
 125         ret = s->tx_count;
 126         break;
 127     case MIPSNET_INT_CTL:
 128         ret = s->intctl;
 129         s->intctl &= ~MIPSNET_INTCTL_TESTBIT;
 130         break;
 131     case MIPSNET_INTERRUPT_INFO:
 132         /* XXX: This seems to be a per-VPE interrupt number. */
 133         ret = 0;
 134         break;
 135     case MIPSNET_RX_DATA_BUFFER:
 136         if (s->rx_count) {
 137             s->rx_count--;
 138             ret = s->rx_buffer[s->rx_read++];
 139         }
 140         break;
 141     /* Reads as zero. */
 142     case MIPSNET_TX_DATA_BUFFER:
 143     default:
 144         break;
 145     }
 146 #ifdef DEBUG_MIPSNET_DATA
 147     printf("mipsnet: read addr=0x%02x val=0x%02x\n", addr, ret);
 148 #endif
 149     return ret;
 150 }
 151
 152 static void mipsnet_ioport_write(void *opaque, uint32_t addr, uint32_t val)
 153 {
 154     MIPSnetState *s = opaque;
 155
 156     addr &= 0x3f;
 157 #ifdef DEBUG_MIPSNET_DATA
 158     printf("mipsnet: write addr=0x%02x val=0x%02x\n", addr, val);
 159 #endif
 160     switch (addr) {
 161     case MIPSNET_TX_DATA_COUNT:
 162         s->tx_count = (val <= MAX_ETH_FRAME_SIZE) ? val : 0;
 163         s->tx_written = 0;
 164         break;
 165     case MIPSNET_INT_CTL:
 166         if (val & MIPSNET_INTCTL_TXDONE) {
 167             s->intctl &= ~MIPSNET_INTCTL_TXDONE;
 168         } else if (val & MIPSNET_INTCTL_RXDONE) {
 169             s->intctl &= ~MIPSNET_INTCTL_RXDONE;
 170         } else if (val & MIPSNET_INTCTL_TESTBIT) {
 171             mipsnet_reset(s);
 172             s->intctl |= MIPSNET_INTCTL_TESTBIT;
 173         } else if (!val) {
 174             /* ACK testbit interrupt, flag was cleared on read. */
 175         }
 176         s->busy = !!s->intctl;
 177         mipsnet_update_irq(s);
 178         break;
 179     case MIPSNET_TX_DATA_BUFFER:
 180         s->tx_buffer[s->tx_written++] = val;
 181         if (s->tx_written == s->tx_count) {
 182             /* Send buffer. */
 183 #ifdef DEBUG_MIPSNET_SEND
 184             printf("mipsnet: sending len=%d\n", s->tx_count);
 185 #endif
 186             qemu_send_packet(s->vc, s->tx_buffer, s->tx_count);
 187             s->tx_count = s->tx_written = 0;
 188             s->intctl |= MIPSNET_INTCTL_TXDONE;
 189             s->busy = 1;
 190             mipsnet_update_irq(s);
 191         }
 192         break;
 193     /* Read-only registers */
 194     case MIPSNET_DEV_ID:
 195     case MIPSNET_BUSY:
 196     case MIPSNET_RX_DATA_COUNT:
 197     case MIPSNET_INTERRUPT_INFO:
 198     case MIPSNET_RX_DATA_BUFFER:
 199     default:
 200         break;
 201     }
 202 }
 203
 204 static void mipsnet_save(QEMUFile *f, void *opaque)
 205 {
 206     MIPSnetState *s = opaque;
 207
 208     qemu_put_be32s(f, &s->busy);
 209     qemu_put_be32s(f, &s->rx_count);
 210     qemu_put_be32s(f, &s->rx_read);
 211     qemu_put_be32s(f, &s->tx_count);
 212     qemu_put_be32s(f, &s->tx_written);
 213     qemu_put_be32s(f, &s->intctl);
 214     qemu_put_buffer(f, s->rx_buffer, MAX_ETH_FRAME_SIZE);
 215     qemu_put_buffer(f, s->tx_buffer, MAX_ETH_FRAME_SIZE);
 216 }
 217
 218 static int mipsnet_load(QEMUFile *f, void *opaque, int version_id)
 219 {
 220     MIPSnetState *s = opaque;
 221
 222     if (version_id > 0)
 223         return -EINVAL;
 224
 225     qemu_get_be32s(f, &s->busy);
 226     qemu_get_be32s(f, &s->rx_count);
 227     qemu_get_be32s(f, &s->rx_read);
 228     qemu_get_be32s(f, &s->tx_count);
 229     qemu_get_be32s(f, &s->tx_written);
 230     qemu_get_be32s(f, &s->intctl);
 231     qemu_get_buffer(f, s->rx_buffer, MAX_ETH_FRAME_SIZE);
 232     qemu_get_buffer(f, s->tx_buffer, MAX_ETH_FRAME_SIZE);
 233
 234     return 0;
 235 }
 236
 237 static void mipsnet_cleanup(VLANClientState *vc)
 238 {
 239     MIPSnetState *s = vc->opaque;
 240
 241     unregister_savevm("mipsnet", s);
 242
 243     isa_unassign_ioport(s->io_base, 36);
 244
 245     qemu_free(s);
 246 }
 247
 248 void mipsnet_init (int base, qemu_irq irq, NICInfo *nd)
 249 {
 250     MIPSnetState *s;
 251
 252     qemu_check_nic_model(nd, "mipsnet");
 253
 254     s = qemu_mallocz(sizeof(MIPSnetState));
 255
 256     register_ioport_write(base, 36, 1, mipsnet_ioport_write, s);
 257     register_ioport_read(base, 36, 1, mipsnet_ioport_read, s);
 258     register_ioport_write(base, 36, 2, mipsnet_ioport_write, s);
 259     register_ioport_read(base, 36, 2, mipsnet_ioport_read, s);
 260     register_ioport_write(base, 36, 4, mipsnet_ioport_write, s);
 261     register_ioport_read(base, 36, 4, mipsnet_ioport_read, s);
 262
 263     s->io_base = base;
 264     s->irq = irq;
 265     if (nd) {
 266         s->vc = nd->vc = qemu_new_vlan_client(nd->vlan, nd->netdev,
 267                                               nd->model, nd->name,
 268                                               mipsnet_can_receive, mipsnet_receive,
 269                                               NULL, mipsnet_cleanup, s);
 270     } else {
 271         s->vc = NULL;
 272     }
 273
 274     qemu_format_nic_info_str(s->vc, nd->macaddr);
 275
 276     mipsnet_reset(s);
 277     register_savevm("mipsnet", 0, 0, mipsnet_save, mipsnet_load, s);
 278 }