hw/xilinx_ethlite.c

   1 /*
   2  * QEMU model of the Xilinx Ethernet Lite MAC.
   3  *
   4  * Copyright (c) 2009 Edgar E. Iglesias.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24
  25 #include "sysbus.h"
  26 #include "hw.h"
  27 #include "net.h"
  28
  29 #define D(x)
  30 #define R_TX_BUF0     0
  31 #define R_TX_LEN0     (0x07f4 / 4)
  32 #define R_TX_GIE0     (0x07f8 / 4)
  33 #define R_TX_CTRL0    (0x07fc / 4)
  34 #define R_TX_BUF1     (0x0800 / 4)
  35 #define R_TX_LEN1     (0x0ff4 / 4)
  36 #define R_TX_CTRL1    (0x0ffc / 4)
  37
  38 #define R_RX_BUF0     (0x1000 / 4)
  39 #define R_RX_CTRL0    (0x17fc / 4)
  40 #define R_RX_BUF1     (0x1800 / 4)
  41 #define R_RX_CTRL1    (0x1ffc / 4)
  42 #define R_MAX         (0x2000 / 4)
  43
  44 #define GIE_GIE    0x80000000
  45
  46 #define CTRL_I     0x8
  47 #define CTRL_P     0x2
  48 #define CTRL_S     0x1
  49
  50 struct xlx_ethlite
  51 {
  52     SysBusDevice busdev;
  53     qemu_irq irq;
  54     VLANClientState *vc;
  55
  56     unsigned int c_tx_pingpong;
  57     unsigned int c_rx_pingpong;
  58     unsigned int txbuf;
  59     unsigned int rxbuf;
  60
  61     uint8_t macaddr[6];
  62     uint32_t regs[R_MAX];
  63 };
  64
  65 static inline void eth_pulse_irq(struct xlx_ethlite *s)
  66 {
  67     /* Only the first gie reg is active.  */
  68     if (s->regs[R_TX_GIE0] & GIE_GIE) {
  69         qemu_irq_pulse(s->irq);
  70     }
  71 }
  72
  73 static uint32_t eth_readl (void *opaque, target_phys_addr_t addr)
  74 {
  75     struct xlx_ethlite *s = opaque;
  76     uint32_t r = 0;
  77
  78     addr >>= 2;
  79
  80     switch (addr)
  81     {
  82         case R_TX_GIE0:
  83         case R_TX_LEN0:
  84         case R_TX_LEN1:
  85         case R_TX_CTRL1:
  86         case R_TX_CTRL0:
  87         case R_RX_CTRL1:
  88         case R_RX_CTRL0:
  89             r = s->regs[addr];
  90             D(qemu_log("%s %x=%x\n", __func__, addr * 4, r));
  91             break;
  92
  93         /* Rx packet data is endian fixed at the way into the rx rams. This
  94          * speeds things up because the ethlite MAC does not have a len
  95          * register. That means the CPU will issue MMIO reads for the entire
  96          * 2k rx buffer even for small packets.
  97          */
  98         default:
  99             r = s->regs[addr];
 100             break;
 101     }
 102     return r;
 103 }
 104
 105 static void
 106 eth_writel (void *opaque, target_phys_addr_t addr, uint32_t value)
 107 {
 108     struct xlx_ethlite *s = opaque;
 109     unsigned int base = 0;
 110
 111     addr >>= 2;
 112     switch (addr)
 113     {
 114         case R_TX_CTRL0:
 115         case R_TX_CTRL1:
 116             if (addr == R_TX_CTRL1)
 117                 base = 0x800 / 4;
 118
 119             D(qemu_log("%s addr=%x val=%x\n", __func__, addr * 4, value));
 120             if ((value & (CTRL_P | CTRL_S)) == CTRL_S) {
 121                 qemu_send_packet(s->vc,
 122                                  (void *) &s->regs[base],
 123                                  s->regs[base + R_TX_LEN0]);
 124                 D(qemu_log("eth_tx %d\n", s->regs[base + R_TX_LEN0]));
 125                 if (s->regs[base + R_TX_CTRL0] & CTRL_I)
 126                     eth_pulse_irq(s);
 127             } else if ((value & (CTRL_P | CTRL_S)) == (CTRL_P | CTRL_S)) {
 128                 memcpy(&s->macaddr[0], &s->regs[base], 6);
 129                 if (s->regs[base + R_TX_CTRL0] & CTRL_I)
 130                     eth_pulse_irq(s);
 131             }
 132
 133             /* We are fast and get ready pretty much immediately so
 134                we actually never flip the S nor P bits to one.  */
 135             s->regs[addr] = value & ~(CTRL_P | CTRL_S);
 136             break;
 137
 138         /* Keep these native.  */
 139         case R_TX_LEN0:
 140         case R_TX_LEN1:
 141         case R_TX_GIE0:
 142         case R_RX_CTRL0:
 143         case R_RX_CTRL1:
 144             D(qemu_log("%s addr=%x val=%x\n", __func__, addr * 4, value));
 145             s->regs[addr] = value;
 146             break;
 147
 148         /* Packet data, make sure it stays BE.  */
 149         default:
 150             s->regs[addr] = cpu_to_be32(value);
 151             break;
 152     }
 153 }
 154
 155 static CPUReadMemoryFunc *eth_read[] = {
 156     NULL, NULL, &eth_readl,
 157 };
 158
 159 static CPUWriteMemoryFunc *eth_write[] = {
 160     NULL, NULL, &eth_writel,
 161 };
 162
 163 static int eth_can_rx(VLANClientState *vc)
 164 {
 165     struct xlx_ethlite *s = vc->opaque;
 166     int r;
 167     r = !(s->regs[R_RX_CTRL0] & CTRL_S);
 168     qemu_log("%s %d\n", __func__, r);
 169     return r;
 170 }
 171
 172 static ssize_t eth_rx(VLANClientState *vc, const uint8_t *buf, size_t size)
 173 {
 174     struct xlx_ethlite *s = vc->opaque;
 175     unsigned int rxbase = s->rxbuf * (0x800 / 4);
 176     int i;
 177
 178     /* DA filter.  */
 179     if (!(buf[0] & 0x80) && memcmp(&s->macaddr[0], buf, 6))
 180         return size;
 181
 182     if (s->regs[rxbase + R_RX_CTRL0] & CTRL_S) {
 183         D(qemu_log("ethlite lost packet %x\n", s->regs[R_RX_CTRL0]));
 184         return -1;
 185     }
 186
 187     D(qemu_log("%s %d rxbase=%x\n", __func__, size, rxbase));
 188     memcpy(&s->regs[rxbase + R_RX_BUF0], buf, size);
 189
 190     /* Bring it into host endianess.  */
 191     for (i = 0; i < ((size + 3) / 4); i++) {
 192        uint32_t d = s->regs[rxbase + R_RX_BUF0 + i];
 193        s->regs[rxbase + R_RX_BUF0 + i] = be32_to_cpu(d);
 194     }
 195
 196     s->regs[rxbase + R_RX_CTRL0] |= CTRL_S;
 197     if (s->regs[rxbase + R_RX_CTRL0] & CTRL_I)
 198         eth_pulse_irq(s);
 199
 200     /* If c_rx_pingpong was set flip buffers.  */
 201     s->rxbuf ^= s->c_rx_pingpong;
 202     return size;
 203 }
 204
 205 static void eth_cleanup(VLANClientState *vc)
 206 {
 207     struct xlx_ethlite *s = vc->opaque;
 208     qemu_free(s);
 209 }
 210
 211 static void xilinx_ethlite_init(SysBusDevice *dev)
 212 {
 213     struct xlx_ethlite *s = FROM_SYSBUS(typeof (*s), dev);
 214     int regs;
 215
 216     sysbus_init_irq(dev, &s->irq);
 217     s->c_tx_pingpong = qdev_get_prop_int(&dev->qdev, "txpingpong", 1);
 218     s->c_rx_pingpong = qdev_get_prop_int(&dev->qdev, "rxpingpong", 1);
 219     s->rxbuf = 0;
 220
 221     regs = cpu_register_io_memory(0, eth_read, eth_write, s);
 222     sysbus_init_mmio(dev, R_MAX * 4, regs);
 223
 224     qdev_get_macaddr(&dev->qdev, s->macaddr);
 225     s->vc = qdev_get_vlan_client(&dev->qdev,
 226                                  eth_can_rx, eth_rx, NULL, eth_cleanup, s);
 227 }
 228
 229 static void xilinx_ethlite_register(void)
 230 {
 231     sysbus_register_dev("xilinx,ethlite", sizeof (struct xlx_ethlite),
 232                         xilinx_ethlite_init);
 233 }
 234
 235 device_init(xilinx_ethlite_register)