xref: /openbmc/qemu/hw/net/mipsnet.c (revision 9c4218e9)
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     s->busy = 1;
87 
88     /* Just accept everything. */
89 
90     /* Write packet data. */
91     memcpy(s->rx_buffer, buf, size);
92 
93     s->rx_count = size;
94     s->rx_read = 0;
95 
96     /* Now we can signal we have received something. */
97     s->intctl |= MIPSNET_INTCTL_RXDONE;
98     mipsnet_update_irq(s);
99 
100     return size;
101 }
102 
103 static uint64_t mipsnet_ioport_read(void *opaque, hwaddr addr,
104                                     unsigned int size)
105 {
106     MIPSnetState *s = opaque;
107     int ret = 0;
108 
109     addr &= 0x3f;
110     switch (addr) {
111     case MIPSNET_DEV_ID:
112 	ret = be32_to_cpu(0x4d495053);		/* MIPS */
113         break;
114     case MIPSNET_DEV_ID + 4:
115 	ret = be32_to_cpu(0x4e455430);		/* NET0 */
116         break;
117     case MIPSNET_BUSY:
118 	ret = s->busy;
119         break;
120     case MIPSNET_RX_DATA_COUNT:
121 	ret = s->rx_count;
122         break;
123     case MIPSNET_TX_DATA_COUNT:
124 	ret = s->tx_count;
125         break;
126     case MIPSNET_INT_CTL:
127 	ret = s->intctl;
128         s->intctl &= ~MIPSNET_INTCTL_TESTBIT;
129         break;
130     case MIPSNET_INTERRUPT_INFO:
131         /* XXX: This seems to be a per-VPE interrupt number. */
132 	ret = 0;
133         break;
134     case MIPSNET_RX_DATA_BUFFER:
135         if (s->rx_count) {
136             s->rx_count--;
137             ret = s->rx_buffer[s->rx_read++];
138             if (mipsnet_can_receive(s->nic->ncs)) {
139                 qemu_flush_queued_packets(qemu_get_queue(s->nic));
140             }
141         }
142         break;
143     /* Reads as zero. */
144     case MIPSNET_TX_DATA_BUFFER:
145     default:
146         break;
147     }
148     trace_mipsnet_read(addr, ret);
149     return ret;
150 }
151 
152 static void mipsnet_ioport_write(void *opaque, hwaddr addr,
153                                  uint64_t val, unsigned int size)
154 {
155     MIPSnetState *s = opaque;
156 
157     addr &= 0x3f;
158     trace_mipsnet_write(addr, val);
159     switch (addr) {
160     case MIPSNET_TX_DATA_COUNT:
161 	s->tx_count = (val <= MAX_ETH_FRAME_SIZE) ? val : 0;
162         s->tx_written = 0;
163         break;
164     case MIPSNET_INT_CTL:
165         if (val & MIPSNET_INTCTL_TXDONE) {
166             s->intctl &= ~MIPSNET_INTCTL_TXDONE;
167         } else if (val & MIPSNET_INTCTL_RXDONE) {
168             s->intctl &= ~MIPSNET_INTCTL_RXDONE;
169         } else if (val & MIPSNET_INTCTL_TESTBIT) {
170             mipsnet_reset(s);
171             s->intctl |= MIPSNET_INTCTL_TESTBIT;
172         } else if (!val) {
173             /* ACK testbit interrupt, flag was cleared on read. */
174         }
175         s->busy = !!s->intctl;
176         mipsnet_update_irq(s);
177         if (mipsnet_can_receive(s->nic->ncs)) {
178             qemu_flush_queued_packets(qemu_get_queue(s->nic));
179         }
180         break;
181     case MIPSNET_TX_DATA_BUFFER:
182         s->tx_buffer[s->tx_written++] = val;
183         if (s->tx_written == s->tx_count) {
184             /* Send buffer. */
185             trace_mipsnet_send(s->tx_count);
186             qemu_send_packet(qemu_get_queue(s->nic), 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 const VMStateDescription vmstate_mipsnet = {
205     .name = "mipsnet",
206     .version_id = 0,
207     .minimum_version_id = 0,
208     .fields = (VMStateField[]) {
209         VMSTATE_UINT32(busy, MIPSnetState),
210         VMSTATE_UINT32(rx_count, MIPSnetState),
211         VMSTATE_UINT32(rx_read, MIPSnetState),
212         VMSTATE_UINT32(tx_count, MIPSnetState),
213         VMSTATE_UINT32(tx_written, MIPSnetState),
214         VMSTATE_UINT32(intctl, MIPSnetState),
215         VMSTATE_BUFFER(rx_buffer, MIPSnetState),
216         VMSTATE_BUFFER(tx_buffer, MIPSnetState),
217         VMSTATE_END_OF_LIST()
218     }
219 };
220 
221 static NetClientInfo net_mipsnet_info = {
222     .type = NET_CLIENT_OPTIONS_KIND_NIC,
223     .size = sizeof(NICState),
224     .receive = mipsnet_receive,
225 };
226 
227 static const MemoryRegionOps mipsnet_ioport_ops = {
228     .read = mipsnet_ioport_read,
229     .write = mipsnet_ioport_write,
230     .impl.min_access_size = 1,
231     .impl.max_access_size = 4,
232 };
233 
234 static int mipsnet_sysbus_init(SysBusDevice *sbd)
235 {
236     DeviceState *dev = DEVICE(sbd);
237     MIPSnetState *s = MIPS_NET(dev);
238 
239     memory_region_init_io(&s->io, OBJECT(dev), &mipsnet_ioport_ops, s,
240                           "mipsnet-io", 36);
241     sysbus_init_mmio(sbd, &s->io);
242     sysbus_init_irq(sbd, &s->irq);
243 
244     s->nic = qemu_new_nic(&net_mipsnet_info, &s->conf,
245                           object_get_typename(OBJECT(dev)), dev->id, s);
246     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
247 
248     return 0;
249 }
250 
251 static void mipsnet_sysbus_reset(DeviceState *dev)
252 {
253     MIPSnetState *s = MIPS_NET(dev);
254     mipsnet_reset(s);
255 }
256 
257 static Property mipsnet_properties[] = {
258     DEFINE_NIC_PROPERTIES(MIPSnetState, conf),
259     DEFINE_PROP_END_OF_LIST(),
260 };
261 
262 static void mipsnet_class_init(ObjectClass *klass, void *data)
263 {
264     DeviceClass *dc = DEVICE_CLASS(klass);
265     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
266 
267     k->init = mipsnet_sysbus_init;
268     set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
269     dc->desc = "MIPS Simulator network device";
270     dc->reset = mipsnet_sysbus_reset;
271     dc->vmsd = &vmstate_mipsnet;
272     dc->props = mipsnet_properties;
273 }
274 
275 static const TypeInfo mipsnet_info = {
276     .name          = TYPE_MIPS_NET,
277     .parent        = TYPE_SYS_BUS_DEVICE,
278     .instance_size = sizeof(MIPSnetState),
279     .class_init    = mipsnet_class_init,
280 };
281 
282 static void mipsnet_register_types(void)
283 {
284     type_register_static(&mipsnet_info);
285 }
286 
287 type_init(mipsnet_register_types)
288