xref: /openbmc/qemu/hw/net/mipsnet.c (revision 335d52f4)
1 #include "qemu/osdep.h"
2 #include "hw/hw.h"
3 #include "net/net.h"
4 #include "trace.h"
5 #include "hw/sysbus.h"
6 
7 /* MIPSnet register offsets */
8 
9 #define MIPSNET_DEV_ID		0x00
10 #define MIPSNET_BUSY		0x08
11 #define MIPSNET_RX_DATA_COUNT	0x0c
12 #define MIPSNET_TX_DATA_COUNT	0x10
13 #define MIPSNET_INT_CTL		0x14
14 # define MIPSNET_INTCTL_TXDONE		0x00000001
15 # define MIPSNET_INTCTL_RXDONE		0x00000002
16 # define MIPSNET_INTCTL_TESTBIT		0x80000000
17 #define MIPSNET_INTERRUPT_INFO	0x18
18 #define MIPSNET_RX_DATA_BUFFER	0x1c
19 #define MIPSNET_TX_DATA_BUFFER	0x20
20 
21 #define MAX_ETH_FRAME_SIZE	1514
22 
23 #define TYPE_MIPS_NET "mipsnet"
24 #define MIPS_NET(obj) OBJECT_CHECK(MIPSnetState, (obj), TYPE_MIPS_NET)
25 
26 typedef struct MIPSnetState {
27     SysBusDevice parent_obj;
28 
29     uint32_t busy;
30     uint32_t rx_count;
31     uint32_t rx_read;
32     uint32_t tx_count;
33     uint32_t tx_written;
34     uint32_t intctl;
35     uint8_t rx_buffer[MAX_ETH_FRAME_SIZE];
36     uint8_t tx_buffer[MAX_ETH_FRAME_SIZE];
37     MemoryRegion io;
38     qemu_irq irq;
39     NICState *nic;
40     NICConf conf;
41 } MIPSnetState;
42 
43 static void mipsnet_reset(MIPSnetState *s)
44 {
45     s->busy = 1;
46     s->rx_count = 0;
47     s->rx_read = 0;
48     s->tx_count = 0;
49     s->tx_written = 0;
50     s->intctl = 0;
51     memset(s->rx_buffer, 0, MAX_ETH_FRAME_SIZE);
52     memset(s->tx_buffer, 0, MAX_ETH_FRAME_SIZE);
53 }
54 
55 static void mipsnet_update_irq(MIPSnetState *s)
56 {
57     int isr = !!s->intctl;
58     trace_mipsnet_irq(isr, s->intctl);
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(NetClientState *nc)
70 {
71     MIPSnetState *s = qemu_get_nic_opaque(nc);
72 
73     if (s->busy)
74         return 0;
75     return !mipsnet_buffer_full(s);
76 }
77 
78 static ssize_t mipsnet_receive(NetClientState *nc, const uint8_t *buf, size_t size)
79 {
80     MIPSnetState *s = qemu_get_nic_opaque(nc);
81 
82     trace_mipsnet_receive(size);
83     if (!mipsnet_can_receive(nc))
84         return 0;
85 
86     if (size >= sizeof(s->rx_buffer)) {
87         return 0;
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 uint64_t mipsnet_ioport_read(void *opaque, hwaddr addr,
107                                     unsigned int size)
108 {
109     MIPSnetState *s = opaque;
110     int ret = 0;
111 
112     addr &= 0x3f;
113     switch (addr) {
114     case MIPSNET_DEV_ID:
115 	ret = be32_to_cpu(0x4d495053);		/* MIPS */
116         break;
117     case MIPSNET_DEV_ID + 4:
118 	ret = be32_to_cpu(0x4e455430);		/* NET0 */
119         break;
120     case MIPSNET_BUSY:
121 	ret = s->busy;
122         break;
123     case MIPSNET_RX_DATA_COUNT:
124 	ret = s->rx_count;
125         break;
126     case MIPSNET_TX_DATA_COUNT:
127 	ret = s->tx_count;
128         break;
129     case MIPSNET_INT_CTL:
130 	ret = s->intctl;
131         s->intctl &= ~MIPSNET_INTCTL_TESTBIT;
132         break;
133     case MIPSNET_INTERRUPT_INFO:
134         /* XXX: This seems to be a per-VPE interrupt number. */
135 	ret = 0;
136         break;
137     case MIPSNET_RX_DATA_BUFFER:
138         if (s->rx_count) {
139             s->rx_count--;
140             ret = s->rx_buffer[s->rx_read++];
141             if (mipsnet_can_receive(s->nic->ncs)) {
142                 qemu_flush_queued_packets(qemu_get_queue(s->nic));
143             }
144         }
145         break;
146     /* Reads as zero. */
147     case MIPSNET_TX_DATA_BUFFER:
148     default:
149         break;
150     }
151     trace_mipsnet_read(addr, ret);
152     return ret;
153 }
154 
155 static void mipsnet_ioport_write(void *opaque, hwaddr addr,
156                                  uint64_t val, unsigned int size)
157 {
158     MIPSnetState *s = opaque;
159 
160     addr &= 0x3f;
161     trace_mipsnet_write(addr, val);
162     switch (addr) {
163     case MIPSNET_TX_DATA_COUNT:
164 	s->tx_count = (val <= MAX_ETH_FRAME_SIZE) ? val : 0;
165         s->tx_written = 0;
166         break;
167     case MIPSNET_INT_CTL:
168         if (val & MIPSNET_INTCTL_TXDONE) {
169             s->intctl &= ~MIPSNET_INTCTL_TXDONE;
170         } else if (val & MIPSNET_INTCTL_RXDONE) {
171             s->intctl &= ~MIPSNET_INTCTL_RXDONE;
172         } else if (val & MIPSNET_INTCTL_TESTBIT) {
173             mipsnet_reset(s);
174             s->intctl |= MIPSNET_INTCTL_TESTBIT;
175         } else if (!val) {
176             /* ACK testbit interrupt, flag was cleared on read. */
177         }
178         s->busy = !!s->intctl;
179         mipsnet_update_irq(s);
180         if (mipsnet_can_receive(s->nic->ncs)) {
181             qemu_flush_queued_packets(qemu_get_queue(s->nic));
182         }
183         break;
184     case MIPSNET_TX_DATA_BUFFER:
185         s->tx_buffer[s->tx_written++] = val;
186         if ((s->tx_written >= MAX_ETH_FRAME_SIZE)
187             || (s->tx_written == s->tx_count)) {
188             /* Send buffer. */
189             trace_mipsnet_send(s->tx_written);
190             qemu_send_packet(qemu_get_queue(s->nic),
191                                 s->tx_buffer, s->tx_written);
192             s->tx_count = s->tx_written = 0;
193             s->intctl |= MIPSNET_INTCTL_TXDONE;
194             s->busy = 1;
195             mipsnet_update_irq(s);
196         }
197         break;
198     /* Read-only registers */
199     case MIPSNET_DEV_ID:
200     case MIPSNET_BUSY:
201     case MIPSNET_RX_DATA_COUNT:
202     case MIPSNET_INTERRUPT_INFO:
203     case MIPSNET_RX_DATA_BUFFER:
204     default:
205         break;
206     }
207 }
208 
209 static const VMStateDescription vmstate_mipsnet = {
210     .name = "mipsnet",
211     .version_id = 0,
212     .minimum_version_id = 0,
213     .fields = (VMStateField[]) {
214         VMSTATE_UINT32(busy, MIPSnetState),
215         VMSTATE_UINT32(rx_count, MIPSnetState),
216         VMSTATE_UINT32(rx_read, MIPSnetState),
217         VMSTATE_UINT32(tx_count, MIPSnetState),
218         VMSTATE_UINT32(tx_written, MIPSnetState),
219         VMSTATE_UINT32(intctl, MIPSnetState),
220         VMSTATE_BUFFER(rx_buffer, MIPSnetState),
221         VMSTATE_BUFFER(tx_buffer, MIPSnetState),
222         VMSTATE_END_OF_LIST()
223     }
224 };
225 
226 static NetClientInfo net_mipsnet_info = {
227     .type = NET_CLIENT_DRIVER_NIC,
228     .size = sizeof(NICState),
229     .receive = mipsnet_receive,
230 };
231 
232 static const MemoryRegionOps mipsnet_ioport_ops = {
233     .read = mipsnet_ioport_read,
234     .write = mipsnet_ioport_write,
235     .impl.min_access_size = 1,
236     .impl.max_access_size = 4,
237 };
238 
239 static void mipsnet_realize(DeviceState *dev, Error **errp)
240 {
241     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
242     MIPSnetState *s = MIPS_NET(dev);
243 
244     memory_region_init_io(&s->io, OBJECT(dev), &mipsnet_ioport_ops, s,
245                           "mipsnet-io", 36);
246     sysbus_init_mmio(sbd, &s->io);
247     sysbus_init_irq(sbd, &s->irq);
248 
249     s->nic = qemu_new_nic(&net_mipsnet_info, &s->conf,
250                           object_get_typename(OBJECT(dev)), dev->id, s);
251     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
252 }
253 
254 static void mipsnet_sysbus_reset(DeviceState *dev)
255 {
256     MIPSnetState *s = MIPS_NET(dev);
257     mipsnet_reset(s);
258 }
259 
260 static Property mipsnet_properties[] = {
261     DEFINE_NIC_PROPERTIES(MIPSnetState, conf),
262     DEFINE_PROP_END_OF_LIST(),
263 };
264 
265 static void mipsnet_class_init(ObjectClass *klass, void *data)
266 {
267     DeviceClass *dc = DEVICE_CLASS(klass);
268 
269     dc->realize = mipsnet_realize;
270     set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
271     dc->desc = "MIPS Simulator network device";
272     dc->reset = mipsnet_sysbus_reset;
273     dc->vmsd = &vmstate_mipsnet;
274     dc->props = mipsnet_properties;
275 }
276 
277 static const TypeInfo mipsnet_info = {
278     .name          = TYPE_MIPS_NET,
279     .parent        = TYPE_SYS_BUS_DEVICE,
280     .instance_size = sizeof(MIPSnetState),
281     .class_init    = mipsnet_class_init,
282 };
283 
284 static void mipsnet_register_types(void)
285 {
286     type_register_static(&mipsnet_info);
287 }
288 
289 type_init(mipsnet_register_types)
290