xref: /qemu/hw/net/mipsnet.c (revision db1015e92e04835c9eb50c29625fe566d1202dbd)
1 #include "qemu/osdep.h"
2 #include "hw/irq.h"
3 #include "hw/qdev-properties.h"
4 #include "net/net.h"
5 #include "qemu/module.h"
6 #include "trace.h"
7 #include "hw/sysbus.h"
8 #include "migration/vmstate.h"
9 #include "qom/object.h"
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 #define TYPE_MIPS_NET "mipsnet"
28 typedef struct MIPSnetState MIPSnetState;
29 #define MIPS_NET(obj) OBJECT_CHECK(MIPSnetState, (obj), TYPE_MIPS_NET)
30 
31 struct MIPSnetState {
32     SysBusDevice parent_obj;
33 
34     uint32_t busy;
35     uint32_t rx_count;
36     uint32_t rx_read;
37     uint32_t tx_count;
38     uint32_t tx_written;
39     uint32_t intctl;
40     uint8_t rx_buffer[MAX_ETH_FRAME_SIZE];
41     uint8_t tx_buffer[MAX_ETH_FRAME_SIZE];
42     MemoryRegion io;
43     qemu_irq irq;
44     NICState *nic;
45     NICConf conf;
46 };
47 
48 static void mipsnet_reset(MIPSnetState *s)
49 {
50     s->busy = 1;
51     s->rx_count = 0;
52     s->rx_read = 0;
53     s->tx_count = 0;
54     s->tx_written = 0;
55     s->intctl = 0;
56     memset(s->rx_buffer, 0, MAX_ETH_FRAME_SIZE);
57     memset(s->tx_buffer, 0, MAX_ETH_FRAME_SIZE);
58 }
59 
60 static void mipsnet_update_irq(MIPSnetState *s)
61 {
62     int isr = !!s->intctl;
63     trace_mipsnet_irq(isr, s->intctl);
64     qemu_set_irq(s->irq, isr);
65 }
66 
67 static int mipsnet_buffer_full(MIPSnetState *s)
68 {
69     if (s->rx_count >= MAX_ETH_FRAME_SIZE) {
70         return 1;
71     }
72     return 0;
73 }
74 
75 static int mipsnet_can_receive(NetClientState *nc)
76 {
77     MIPSnetState *s = qemu_get_nic_opaque(nc);
78 
79     if (s->busy) {
80         return 0;
81     }
82     return !mipsnet_buffer_full(s);
83 }
84 
85 static ssize_t mipsnet_receive(NetClientState *nc,
86                                const uint8_t *buf, size_t size)
87 {
88     MIPSnetState *s = qemu_get_nic_opaque(nc);
89 
90     trace_mipsnet_receive(size);
91     if (!mipsnet_can_receive(nc)) {
92         return 0;
93     }
94 
95     if (size >= sizeof(s->rx_buffer)) {
96         return 0;
97     }
98     s->busy = 1;
99 
100     /* Just accept everything. */
101 
102     /* Write packet data. */
103     memcpy(s->rx_buffer, buf, size);
104 
105     s->rx_count = size;
106     s->rx_read = 0;
107 
108     /* Now we can signal we have received something. */
109     s->intctl |= MIPSNET_INTCTL_RXDONE;
110     mipsnet_update_irq(s);
111 
112     return size;
113 }
114 
115 static uint64_t mipsnet_ioport_read(void *opaque, hwaddr addr,
116                                     unsigned int size)
117 {
118     MIPSnetState *s = opaque;
119     int ret = 0;
120 
121     addr &= 0x3f;
122     switch (addr) {
123     case MIPSNET_DEV_ID:
124         ret = be32_to_cpu(0x4d495053);          /* MIPS */
125         break;
126     case MIPSNET_DEV_ID + 4:
127         ret = be32_to_cpu(0x4e455430);          /* NET0 */
128         break;
129     case MIPSNET_BUSY:
130         ret = s->busy;
131         break;
132     case MIPSNET_RX_DATA_COUNT:
133         ret = s->rx_count;
134         break;
135     case MIPSNET_TX_DATA_COUNT:
136         ret = s->tx_count;
137         break;
138     case MIPSNET_INT_CTL:
139         ret = s->intctl;
140         s->intctl &= ~MIPSNET_INTCTL_TESTBIT;
141         break;
142     case MIPSNET_INTERRUPT_INFO:
143         /* XXX: This seems to be a per-VPE interrupt number. */
144         ret = 0;
145         break;
146     case MIPSNET_RX_DATA_BUFFER:
147         if (s->rx_count) {
148             s->rx_count--;
149             ret = s->rx_buffer[s->rx_read++];
150             if (mipsnet_can_receive(s->nic->ncs)) {
151                 qemu_flush_queued_packets(qemu_get_queue(s->nic));
152             }
153         }
154         break;
155     /* Reads as zero. */
156     case MIPSNET_TX_DATA_BUFFER:
157     default:
158         break;
159     }
160     trace_mipsnet_read(addr, ret);
161     return ret;
162 }
163 
164 static void mipsnet_ioport_write(void *opaque, hwaddr addr,
165                                  uint64_t val, unsigned int size)
166 {
167     MIPSnetState *s = opaque;
168 
169     addr &= 0x3f;
170     trace_mipsnet_write(addr, val);
171     switch (addr) {
172     case MIPSNET_TX_DATA_COUNT:
173         s->tx_count = (val <= MAX_ETH_FRAME_SIZE) ? val : 0;
174         s->tx_written = 0;
175         break;
176     case MIPSNET_INT_CTL:
177         if (val & MIPSNET_INTCTL_TXDONE) {
178             s->intctl &= ~MIPSNET_INTCTL_TXDONE;
179         } else if (val & MIPSNET_INTCTL_RXDONE) {
180             s->intctl &= ~MIPSNET_INTCTL_RXDONE;
181         } else if (val & MIPSNET_INTCTL_TESTBIT) {
182             mipsnet_reset(s);
183             s->intctl |= MIPSNET_INTCTL_TESTBIT;
184         } else if (!val) {
185             /* ACK testbit interrupt, flag was cleared on read. */
186         }
187         s->busy = !!s->intctl;
188         mipsnet_update_irq(s);
189         if (mipsnet_can_receive(s->nic->ncs)) {
190             qemu_flush_queued_packets(qemu_get_queue(s->nic));
191         }
192         break;
193     case MIPSNET_TX_DATA_BUFFER:
194         s->tx_buffer[s->tx_written++] = val;
195         if ((s->tx_written >= MAX_ETH_FRAME_SIZE)
196             || (s->tx_written == s->tx_count)) {
197             /* Send buffer. */
198             trace_mipsnet_send(s->tx_written);
199             qemu_send_packet(qemu_get_queue(s->nic),
200                                 s->tx_buffer, s->tx_written);
201             s->tx_count = s->tx_written = 0;
202             s->intctl |= MIPSNET_INTCTL_TXDONE;
203             s->busy = 1;
204             mipsnet_update_irq(s);
205         }
206         break;
207     /* Read-only registers */
208     case MIPSNET_DEV_ID:
209     case MIPSNET_BUSY:
210     case MIPSNET_RX_DATA_COUNT:
211     case MIPSNET_INTERRUPT_INFO:
212     case MIPSNET_RX_DATA_BUFFER:
213     default:
214         break;
215     }
216 }
217 
218 static const VMStateDescription vmstate_mipsnet = {
219     .name = "mipsnet",
220     .version_id = 0,
221     .minimum_version_id = 0,
222     .fields = (VMStateField[]) {
223         VMSTATE_UINT32(busy, MIPSnetState),
224         VMSTATE_UINT32(rx_count, MIPSnetState),
225         VMSTATE_UINT32(rx_read, MIPSnetState),
226         VMSTATE_UINT32(tx_count, MIPSnetState),
227         VMSTATE_UINT32(tx_written, MIPSnetState),
228         VMSTATE_UINT32(intctl, MIPSnetState),
229         VMSTATE_BUFFER(rx_buffer, MIPSnetState),
230         VMSTATE_BUFFER(tx_buffer, MIPSnetState),
231         VMSTATE_END_OF_LIST()
232     }
233 };
234 
235 static NetClientInfo net_mipsnet_info = {
236     .type = NET_CLIENT_DRIVER_NIC,
237     .size = sizeof(NICState),
238     .receive = mipsnet_receive,
239 };
240 
241 static const MemoryRegionOps mipsnet_ioport_ops = {
242     .read = mipsnet_ioport_read,
243     .write = mipsnet_ioport_write,
244     .impl.min_access_size = 1,
245     .impl.max_access_size = 4,
246 };
247 
248 static void mipsnet_realize(DeviceState *dev, Error **errp)
249 {
250     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
251     MIPSnetState *s = MIPS_NET(dev);
252 
253     memory_region_init_io(&s->io, OBJECT(dev), &mipsnet_ioport_ops, s,
254                           "mipsnet-io", 36);
255     sysbus_init_mmio(sbd, &s->io);
256     sysbus_init_irq(sbd, &s->irq);
257 
258     s->nic = qemu_new_nic(&net_mipsnet_info, &s->conf,
259                           object_get_typename(OBJECT(dev)), dev->id, s);
260     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
261 }
262 
263 static void mipsnet_sysbus_reset(DeviceState *dev)
264 {
265     MIPSnetState *s = MIPS_NET(dev);
266     mipsnet_reset(s);
267 }
268 
269 static Property mipsnet_properties[] = {
270     DEFINE_NIC_PROPERTIES(MIPSnetState, conf),
271     DEFINE_PROP_END_OF_LIST(),
272 };
273 
274 static void mipsnet_class_init(ObjectClass *klass, void *data)
275 {
276     DeviceClass *dc = DEVICE_CLASS(klass);
277 
278     dc->realize = mipsnet_realize;
279     set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
280     dc->desc = "MIPS Simulator network device";
281     dc->reset = mipsnet_sysbus_reset;
282     dc->vmsd = &vmstate_mipsnet;
283     device_class_set_props(dc, mipsnet_properties);
284 }
285 
286 static const TypeInfo mipsnet_info = {
287     .name          = TYPE_MIPS_NET,
288     .parent        = TYPE_SYS_BUS_DEVICE,
289     .instance_size = sizeof(MIPSnetState),
290     .class_init    = mipsnet_class_init,
291 };
292 
293 static void mipsnet_register_types(void)
294 {
295     type_register_static(&mipsnet_info);
296 }
297 
298 type_init(mipsnet_register_types)
299