xref: /openbmc/qemu/hw/net/mipsnet.c (revision 4305d482)
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 
10 /* MIPSnet register offsets */
11 
12 #define MIPSNET_DEV_ID          0x00
13 #define MIPSNET_BUSY            0x08
14 #define MIPSNET_RX_DATA_COUNT   0x0c
15 #define MIPSNET_TX_DATA_COUNT   0x10
16 #define MIPSNET_INT_CTL         0x14
17 # define MIPSNET_INTCTL_TXDONE          0x00000001
18 # define MIPSNET_INTCTL_RXDONE          0x00000002
19 # define MIPSNET_INTCTL_TESTBIT         0x80000000
20 #define MIPSNET_INTERRUPT_INFO  0x18
21 #define MIPSNET_RX_DATA_BUFFER  0x1c
22 #define MIPSNET_TX_DATA_BUFFER  0x20
23 
24 #define MAX_ETH_FRAME_SIZE      1514
25 
26 #define TYPE_MIPS_NET "mipsnet"
27 #define MIPS_NET(obj) OBJECT_CHECK(MIPSnetState, (obj), TYPE_MIPS_NET)
28 
29 typedef struct MIPSnetState {
30     SysBusDevice parent_obj;
31 
32     uint32_t busy;
33     uint32_t rx_count;
34     uint32_t rx_read;
35     uint32_t tx_count;
36     uint32_t tx_written;
37     uint32_t intctl;
38     uint8_t rx_buffer[MAX_ETH_FRAME_SIZE];
39     uint8_t tx_buffer[MAX_ETH_FRAME_SIZE];
40     MemoryRegion io;
41     qemu_irq irq;
42     NICState *nic;
43     NICConf conf;
44 } MIPSnetState;
45 
46 static void mipsnet_reset(MIPSnetState *s)
47 {
48     s->busy = 1;
49     s->rx_count = 0;
50     s->rx_read = 0;
51     s->tx_count = 0;
52     s->tx_written = 0;
53     s->intctl = 0;
54     memset(s->rx_buffer, 0, MAX_ETH_FRAME_SIZE);
55     memset(s->tx_buffer, 0, MAX_ETH_FRAME_SIZE);
56 }
57 
58 static void mipsnet_update_irq(MIPSnetState *s)
59 {
60     int isr = !!s->intctl;
61     trace_mipsnet_irq(isr, s->intctl);
62     qemu_set_irq(s->irq, isr);
63 }
64 
65 static int mipsnet_buffer_full(MIPSnetState *s)
66 {
67     if (s->rx_count >= MAX_ETH_FRAME_SIZE) {
68         return 1;
69     }
70     return 0;
71 }
72 
73 static int mipsnet_can_receive(NetClientState *nc)
74 {
75     MIPSnetState *s = qemu_get_nic_opaque(nc);
76 
77     if (s->busy) {
78         return 0;
79     }
80     return !mipsnet_buffer_full(s);
81 }
82 
83 static ssize_t mipsnet_receive(NetClientState *nc,
84                                const uint8_t *buf, size_t size)
85 {
86     MIPSnetState *s = qemu_get_nic_opaque(nc);
87 
88     trace_mipsnet_receive(size);
89     if (!mipsnet_can_receive(nc)) {
90         return 0;
91     }
92 
93     if (size >= sizeof(s->rx_buffer)) {
94         return 0;
95     }
96     s->busy = 1;
97 
98     /* Just accept everything. */
99 
100     /* Write packet data. */
101     memcpy(s->rx_buffer, buf, size);
102 
103     s->rx_count = size;
104     s->rx_read = 0;
105 
106     /* Now we can signal we have received something. */
107     s->intctl |= MIPSNET_INTCTL_RXDONE;
108     mipsnet_update_irq(s);
109 
110     return size;
111 }
112 
113 static uint64_t mipsnet_ioport_read(void *opaque, hwaddr addr,
114                                     unsigned int size)
115 {
116     MIPSnetState *s = opaque;
117     int ret = 0;
118 
119     addr &= 0x3f;
120     switch (addr) {
121     case MIPSNET_DEV_ID:
122         ret = be32_to_cpu(0x4d495053);          /* MIPS */
123         break;
124     case MIPSNET_DEV_ID + 4:
125         ret = be32_to_cpu(0x4e455430);          /* NET0 */
126         break;
127     case MIPSNET_BUSY:
128         ret = s->busy;
129         break;
130     case MIPSNET_RX_DATA_COUNT:
131         ret = s->rx_count;
132         break;
133     case MIPSNET_TX_DATA_COUNT:
134         ret = s->tx_count;
135         break;
136     case MIPSNET_INT_CTL:
137         ret = s->intctl;
138         s->intctl &= ~MIPSNET_INTCTL_TESTBIT;
139         break;
140     case MIPSNET_INTERRUPT_INFO:
141         /* XXX: This seems to be a per-VPE interrupt number. */
142         ret = 0;
143         break;
144     case MIPSNET_RX_DATA_BUFFER:
145         if (s->rx_count) {
146             s->rx_count--;
147             ret = s->rx_buffer[s->rx_read++];
148             if (mipsnet_can_receive(s->nic->ncs)) {
149                 qemu_flush_queued_packets(qemu_get_queue(s->nic));
150             }
151         }
152         break;
153     /* Reads as zero. */
154     case MIPSNET_TX_DATA_BUFFER:
155     default:
156         break;
157     }
158     trace_mipsnet_read(addr, ret);
159     return ret;
160 }
161 
162 static void mipsnet_ioport_write(void *opaque, hwaddr addr,
163                                  uint64_t val, unsigned int size)
164 {
165     MIPSnetState *s = opaque;
166 
167     addr &= 0x3f;
168     trace_mipsnet_write(addr, val);
169     switch (addr) {
170     case MIPSNET_TX_DATA_COUNT:
171         s->tx_count = (val <= MAX_ETH_FRAME_SIZE) ? val : 0;
172         s->tx_written = 0;
173         break;
174     case MIPSNET_INT_CTL:
175         if (val & MIPSNET_INTCTL_TXDONE) {
176             s->intctl &= ~MIPSNET_INTCTL_TXDONE;
177         } else if (val & MIPSNET_INTCTL_RXDONE) {
178             s->intctl &= ~MIPSNET_INTCTL_RXDONE;
179         } else if (val & MIPSNET_INTCTL_TESTBIT) {
180             mipsnet_reset(s);
181             s->intctl |= MIPSNET_INTCTL_TESTBIT;
182         } else if (!val) {
183             /* ACK testbit interrupt, flag was cleared on read. */
184         }
185         s->busy = !!s->intctl;
186         mipsnet_update_irq(s);
187         if (mipsnet_can_receive(s->nic->ncs)) {
188             qemu_flush_queued_packets(qemu_get_queue(s->nic));
189         }
190         break;
191     case MIPSNET_TX_DATA_BUFFER:
192         s->tx_buffer[s->tx_written++] = val;
193         if ((s->tx_written >= MAX_ETH_FRAME_SIZE)
194             || (s->tx_written == s->tx_count)) {
195             /* Send buffer. */
196             trace_mipsnet_send(s->tx_written);
197             qemu_send_packet(qemu_get_queue(s->nic),
198                                 s->tx_buffer, s->tx_written);
199             s->tx_count = s->tx_written = 0;
200             s->intctl |= MIPSNET_INTCTL_TXDONE;
201             s->busy = 1;
202             mipsnet_update_irq(s);
203         }
204         break;
205     /* Read-only registers */
206     case MIPSNET_DEV_ID:
207     case MIPSNET_BUSY:
208     case MIPSNET_RX_DATA_COUNT:
209     case MIPSNET_INTERRUPT_INFO:
210     case MIPSNET_RX_DATA_BUFFER:
211     default:
212         break;
213     }
214 }
215 
216 static const VMStateDescription vmstate_mipsnet = {
217     .name = "mipsnet",
218     .version_id = 0,
219     .minimum_version_id = 0,
220     .fields = (VMStateField[]) {
221         VMSTATE_UINT32(busy, MIPSnetState),
222         VMSTATE_UINT32(rx_count, MIPSnetState),
223         VMSTATE_UINT32(rx_read, MIPSnetState),
224         VMSTATE_UINT32(tx_count, MIPSnetState),
225         VMSTATE_UINT32(tx_written, MIPSnetState),
226         VMSTATE_UINT32(intctl, MIPSnetState),
227         VMSTATE_BUFFER(rx_buffer, MIPSnetState),
228         VMSTATE_BUFFER(tx_buffer, MIPSnetState),
229         VMSTATE_END_OF_LIST()
230     }
231 };
232 
233 static NetClientInfo net_mipsnet_info = {
234     .type = NET_CLIENT_DRIVER_NIC,
235     .size = sizeof(NICState),
236     .receive = mipsnet_receive,
237 };
238 
239 static const MemoryRegionOps mipsnet_ioport_ops = {
240     .read = mipsnet_ioport_read,
241     .write = mipsnet_ioport_write,
242     .impl.min_access_size = 1,
243     .impl.max_access_size = 4,
244 };
245 
246 static void mipsnet_realize(DeviceState *dev, Error **errp)
247 {
248     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
249     MIPSnetState *s = MIPS_NET(dev);
250 
251     memory_region_init_io(&s->io, OBJECT(dev), &mipsnet_ioport_ops, s,
252                           "mipsnet-io", 36);
253     sysbus_init_mmio(sbd, &s->io);
254     sysbus_init_irq(sbd, &s->irq);
255 
256     s->nic = qemu_new_nic(&net_mipsnet_info, &s->conf,
257                           object_get_typename(OBJECT(dev)), dev->id, s);
258     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
259 }
260 
261 static void mipsnet_sysbus_reset(DeviceState *dev)
262 {
263     MIPSnetState *s = MIPS_NET(dev);
264     mipsnet_reset(s);
265 }
266 
267 static Property mipsnet_properties[] = {
268     DEFINE_NIC_PROPERTIES(MIPSnetState, conf),
269     DEFINE_PROP_END_OF_LIST(),
270 };
271 
272 static void mipsnet_class_init(ObjectClass *klass, void *data)
273 {
274     DeviceClass *dc = DEVICE_CLASS(klass);
275 
276     dc->realize = mipsnet_realize;
277     set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
278     dc->desc = "MIPS Simulator network device";
279     dc->reset = mipsnet_sysbus_reset;
280     dc->vmsd = &vmstate_mipsnet;
281     dc->props = mipsnet_properties;
282 }
283 
284 static const TypeInfo mipsnet_info = {
285     .name          = TYPE_MIPS_NET,
286     .parent        = TYPE_SYS_BUS_DEVICE,
287     .instance_size = sizeof(MIPSnetState),
288     .class_init    = mipsnet_class_init,
289 };
290 
291 static void mipsnet_register_types(void)
292 {
293     type_register_static(&mipsnet_info);
294 }
295 
296 type_init(mipsnet_register_types)
297