xref: /openbmc/qemu/hw/net/mipsnet.c (revision 49ab747f)
1 #include "hw/hw.h"
2 #include "net/net.h"
3 #include "trace.h"
4 #include "hw/sysbus.h"
5 
6 /* MIPSnet register offsets */
7 
8 #define MIPSNET_DEV_ID		0x00
9 #define MIPSNET_BUSY		0x08
10 #define MIPSNET_RX_DATA_COUNT	0x0c
11 #define MIPSNET_TX_DATA_COUNT	0x10
12 #define MIPSNET_INT_CTL		0x14
13 # define MIPSNET_INTCTL_TXDONE		0x00000001
14 # define MIPSNET_INTCTL_RXDONE		0x00000002
15 # define MIPSNET_INTCTL_TESTBIT		0x80000000
16 #define MIPSNET_INTERRUPT_INFO	0x18
17 #define MIPSNET_RX_DATA_BUFFER	0x1c
18 #define MIPSNET_TX_DATA_BUFFER	0x20
19 
20 #define MAX_ETH_FRAME_SIZE	1514
21 
22 typedef struct MIPSnetState {
23     SysBusDevice busdev;
24 
25     uint32_t busy;
26     uint32_t rx_count;
27     uint32_t rx_read;
28     uint32_t tx_count;
29     uint32_t tx_written;
30     uint32_t intctl;
31     uint8_t rx_buffer[MAX_ETH_FRAME_SIZE];
32     uint8_t tx_buffer[MAX_ETH_FRAME_SIZE];
33     MemoryRegion io;
34     qemu_irq irq;
35     NICState *nic;
36     NICConf conf;
37 } MIPSnetState;
38 
39 static void mipsnet_reset(MIPSnetState *s)
40 {
41     s->busy = 1;
42     s->rx_count = 0;
43     s->rx_read = 0;
44     s->tx_count = 0;
45     s->tx_written = 0;
46     s->intctl = 0;
47     memset(s->rx_buffer, 0, MAX_ETH_FRAME_SIZE);
48     memset(s->tx_buffer, 0, MAX_ETH_FRAME_SIZE);
49 }
50 
51 static void mipsnet_update_irq(MIPSnetState *s)
52 {
53     int isr = !!s->intctl;
54     trace_mipsnet_irq(isr, s->intctl);
55     qemu_set_irq(s->irq, isr);
56 }
57 
58 static int mipsnet_buffer_full(MIPSnetState *s)
59 {
60     if (s->rx_count >= MAX_ETH_FRAME_SIZE)
61         return 1;
62     return 0;
63 }
64 
65 static int mipsnet_can_receive(NetClientState *nc)
66 {
67     MIPSnetState *s = qemu_get_nic_opaque(nc);
68 
69     if (s->busy)
70         return 0;
71     return !mipsnet_buffer_full(s);
72 }
73 
74 static ssize_t mipsnet_receive(NetClientState *nc, const uint8_t *buf, size_t size)
75 {
76     MIPSnetState *s = qemu_get_nic_opaque(nc);
77 
78     trace_mipsnet_receive(size);
79     if (!mipsnet_can_receive(nc))
80         return -1;
81 
82     s->busy = 1;
83 
84     /* Just accept everything. */
85 
86     /* Write packet data. */
87     memcpy(s->rx_buffer, buf, size);
88 
89     s->rx_count = size;
90     s->rx_read = 0;
91 
92     /* Now we can signal we have received something. */
93     s->intctl |= MIPSNET_INTCTL_RXDONE;
94     mipsnet_update_irq(s);
95 
96     return size;
97 }
98 
99 static uint64_t mipsnet_ioport_read(void *opaque, hwaddr addr,
100                                     unsigned int size)
101 {
102     MIPSnetState *s = opaque;
103     int ret = 0;
104 
105     addr &= 0x3f;
106     switch (addr) {
107     case MIPSNET_DEV_ID:
108 	ret = be32_to_cpu(0x4d495053);		/* MIPS */
109         break;
110     case MIPSNET_DEV_ID + 4:
111 	ret = be32_to_cpu(0x4e455430);		/* NET0 */
112         break;
113     case MIPSNET_BUSY:
114 	ret = s->busy;
115         break;
116     case MIPSNET_RX_DATA_COUNT:
117 	ret = s->rx_count;
118         break;
119     case MIPSNET_TX_DATA_COUNT:
120 	ret = s->tx_count;
121         break;
122     case MIPSNET_INT_CTL:
123 	ret = s->intctl;
124         s->intctl &= ~MIPSNET_INTCTL_TESTBIT;
125         break;
126     case MIPSNET_INTERRUPT_INFO:
127         /* XXX: This seems to be a per-VPE interrupt number. */
128 	ret = 0;
129         break;
130     case MIPSNET_RX_DATA_BUFFER:
131         if (s->rx_count) {
132             s->rx_count--;
133             ret = s->rx_buffer[s->rx_read++];
134         }
135         break;
136     /* Reads as zero. */
137     case MIPSNET_TX_DATA_BUFFER:
138     default:
139         break;
140     }
141     trace_mipsnet_read(addr, ret);
142     return ret;
143 }
144 
145 static void mipsnet_ioport_write(void *opaque, hwaddr addr,
146                                  uint64_t val, unsigned int size)
147 {
148     MIPSnetState *s = opaque;
149 
150     addr &= 0x3f;
151     trace_mipsnet_write(addr, val);
152     switch (addr) {
153     case MIPSNET_TX_DATA_COUNT:
154 	s->tx_count = (val <= MAX_ETH_FRAME_SIZE) ? val : 0;
155         s->tx_written = 0;
156         break;
157     case MIPSNET_INT_CTL:
158         if (val & MIPSNET_INTCTL_TXDONE) {
159             s->intctl &= ~MIPSNET_INTCTL_TXDONE;
160         } else if (val & MIPSNET_INTCTL_RXDONE) {
161             s->intctl &= ~MIPSNET_INTCTL_RXDONE;
162         } else if (val & MIPSNET_INTCTL_TESTBIT) {
163             mipsnet_reset(s);
164             s->intctl |= MIPSNET_INTCTL_TESTBIT;
165         } else if (!val) {
166             /* ACK testbit interrupt, flag was cleared on read. */
167         }
168         s->busy = !!s->intctl;
169         mipsnet_update_irq(s);
170         break;
171     case MIPSNET_TX_DATA_BUFFER:
172         s->tx_buffer[s->tx_written++] = val;
173         if (s->tx_written == s->tx_count) {
174             /* Send buffer. */
175             trace_mipsnet_send(s->tx_count);
176             qemu_send_packet(qemu_get_queue(s->nic), s->tx_buffer, s->tx_count);
177             s->tx_count = s->tx_written = 0;
178             s->intctl |= MIPSNET_INTCTL_TXDONE;
179             s->busy = 1;
180             mipsnet_update_irq(s);
181         }
182         break;
183     /* Read-only registers */
184     case MIPSNET_DEV_ID:
185     case MIPSNET_BUSY:
186     case MIPSNET_RX_DATA_COUNT:
187     case MIPSNET_INTERRUPT_INFO:
188     case MIPSNET_RX_DATA_BUFFER:
189     default:
190         break;
191     }
192 }
193 
194 static const VMStateDescription vmstate_mipsnet = {
195     .name = "mipsnet",
196     .version_id = 0,
197     .minimum_version_id = 0,
198     .minimum_version_id_old = 0,
199     .fields      = (VMStateField[]) {
200         VMSTATE_UINT32(busy, MIPSnetState),
201         VMSTATE_UINT32(rx_count, MIPSnetState),
202         VMSTATE_UINT32(rx_read, MIPSnetState),
203         VMSTATE_UINT32(tx_count, MIPSnetState),
204         VMSTATE_UINT32(tx_written, MIPSnetState),
205         VMSTATE_UINT32(intctl, MIPSnetState),
206         VMSTATE_BUFFER(rx_buffer, MIPSnetState),
207         VMSTATE_BUFFER(tx_buffer, MIPSnetState),
208         VMSTATE_END_OF_LIST()
209     }
210 };
211 
212 static void mipsnet_cleanup(NetClientState *nc)
213 {
214     MIPSnetState *s = qemu_get_nic_opaque(nc);
215 
216     s->nic = NULL;
217 }
218 
219 static NetClientInfo net_mipsnet_info = {
220     .type = NET_CLIENT_OPTIONS_KIND_NIC,
221     .size = sizeof(NICState),
222     .can_receive = mipsnet_can_receive,
223     .receive = mipsnet_receive,
224     .cleanup = mipsnet_cleanup,
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 *dev)
235 {
236     MIPSnetState *s = DO_UPCAST(MIPSnetState, busdev, dev);
237 
238     memory_region_init_io(&s->io, &mipsnet_ioport_ops, s, "mipsnet-io", 36);
239     sysbus_init_mmio(dev, &s->io);
240     sysbus_init_irq(dev, &s->irq);
241 
242     s->nic = qemu_new_nic(&net_mipsnet_info, &s->conf,
243                           object_get_typename(OBJECT(dev)), dev->qdev.id, s);
244     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
245 
246     return 0;
247 }
248 
249 static void mipsnet_sysbus_reset(DeviceState *dev)
250 {
251     MIPSnetState *s = DO_UPCAST(MIPSnetState, busdev.qdev, dev);
252     mipsnet_reset(s);
253 }
254 
255 static Property mipsnet_properties[] = {
256     DEFINE_NIC_PROPERTIES(MIPSnetState, conf),
257     DEFINE_PROP_END_OF_LIST(),
258 };
259 
260 static void mipsnet_class_init(ObjectClass *klass, void *data)
261 {
262     DeviceClass *dc = DEVICE_CLASS(klass);
263     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
264 
265     k->init = mipsnet_sysbus_init;
266     dc->desc = "MIPS Simulator network device";
267     dc->reset = mipsnet_sysbus_reset;
268     dc->vmsd = &vmstate_mipsnet;
269     dc->props = mipsnet_properties;
270 }
271 
272 static const TypeInfo mipsnet_info = {
273     .name          = "mipsnet",
274     .parent        = TYPE_SYS_BUS_DEVICE,
275     .instance_size = sizeof(MIPSnetState),
276     .class_init    = mipsnet_class_init,
277 };
278 
279 static void mipsnet_register_types(void)
280 {
281     type_register_static(&mipsnet_info);
282 }
283 
284 type_init(mipsnet_register_types)
285