xref: /openbmc/qemu/hw/net/mipsnet.c (revision 3d9569b8)
1 #include "qemu/osdep.h"
2 #include "hw/hw.h"
3 #include "net/net.h"
4 #include "qemu/module.h"
5 #include "trace.h"
6 #include "hw/sysbus.h"
7 
8 /* MIPSnet register offsets */
9 
10 #define MIPSNET_DEV_ID		0x00
11 #define MIPSNET_BUSY		0x08
12 #define MIPSNET_RX_DATA_COUNT	0x0c
13 #define MIPSNET_TX_DATA_COUNT	0x10
14 #define MIPSNET_INT_CTL		0x14
15 # define MIPSNET_INTCTL_TXDONE		0x00000001
16 # define MIPSNET_INTCTL_RXDONE		0x00000002
17 # define MIPSNET_INTCTL_TESTBIT		0x80000000
18 #define MIPSNET_INTERRUPT_INFO	0x18
19 #define MIPSNET_RX_DATA_BUFFER	0x1c
20 #define MIPSNET_TX_DATA_BUFFER	0x20
21 
22 #define MAX_ETH_FRAME_SIZE	1514
23 
24 #define TYPE_MIPS_NET "mipsnet"
25 #define MIPS_NET(obj) OBJECT_CHECK(MIPSnetState, (obj), TYPE_MIPS_NET)
26 
27 typedef struct MIPSnetState {
28     SysBusDevice parent_obj;
29 
30     uint32_t busy;
31     uint32_t rx_count;
32     uint32_t rx_read;
33     uint32_t tx_count;
34     uint32_t tx_written;
35     uint32_t intctl;
36     uint8_t rx_buffer[MAX_ETH_FRAME_SIZE];
37     uint8_t tx_buffer[MAX_ETH_FRAME_SIZE];
38     MemoryRegion io;
39     qemu_irq irq;
40     NICState *nic;
41     NICConf conf;
42 } MIPSnetState;
43 
44 static void mipsnet_reset(MIPSnetState *s)
45 {
46     s->busy = 1;
47     s->rx_count = 0;
48     s->rx_read = 0;
49     s->tx_count = 0;
50     s->tx_written = 0;
51     s->intctl = 0;
52     memset(s->rx_buffer, 0, MAX_ETH_FRAME_SIZE);
53     memset(s->tx_buffer, 0, MAX_ETH_FRAME_SIZE);
54 }
55 
56 static void mipsnet_update_irq(MIPSnetState *s)
57 {
58     int isr = !!s->intctl;
59     trace_mipsnet_irq(isr, s->intctl);
60     qemu_set_irq(s->irq, isr);
61 }
62 
63 static int mipsnet_buffer_full(MIPSnetState *s)
64 {
65     if (s->rx_count >= MAX_ETH_FRAME_SIZE)
66         return 1;
67     return 0;
68 }
69 
70 static int mipsnet_can_receive(NetClientState *nc)
71 {
72     MIPSnetState *s = qemu_get_nic_opaque(nc);
73 
74     if (s->busy)
75         return 0;
76     return !mipsnet_buffer_full(s);
77 }
78 
79 static ssize_t mipsnet_receive(NetClientState *nc, const uint8_t *buf, size_t size)
80 {
81     MIPSnetState *s = qemu_get_nic_opaque(nc);
82 
83     trace_mipsnet_receive(size);
84     if (!mipsnet_can_receive(nc))
85         return 0;
86 
87     if (size >= sizeof(s->rx_buffer)) {
88         return 0;
89     }
90     s->busy = 1;
91 
92     /* Just accept everything. */
93 
94     /* Write packet data. */
95     memcpy(s->rx_buffer, buf, size);
96 
97     s->rx_count = size;
98     s->rx_read = 0;
99 
100     /* Now we can signal we have received something. */
101     s->intctl |= MIPSNET_INTCTL_RXDONE;
102     mipsnet_update_irq(s);
103 
104     return size;
105 }
106 
107 static uint64_t mipsnet_ioport_read(void *opaque, hwaddr addr,
108                                     unsigned int size)
109 {
110     MIPSnetState *s = opaque;
111     int ret = 0;
112 
113     addr &= 0x3f;
114     switch (addr) {
115     case MIPSNET_DEV_ID:
116         ret = be32_to_cpu(0x4d495053);		/* MIPS */
117         break;
118     case MIPSNET_DEV_ID + 4:
119         ret = be32_to_cpu(0x4e455430);		/* NET0 */
120         break;
121     case MIPSNET_BUSY:
122         ret = s->busy;
123         break;
124     case MIPSNET_RX_DATA_COUNT:
125         ret = s->rx_count;
126         break;
127     case MIPSNET_TX_DATA_COUNT:
128         ret = s->tx_count;
129         break;
130     case MIPSNET_INT_CTL:
131         ret = s->intctl;
132         s->intctl &= ~MIPSNET_INTCTL_TESTBIT;
133         break;
134     case MIPSNET_INTERRUPT_INFO:
135         /* XXX: This seems to be a per-VPE interrupt number. */
136         ret = 0;
137         break;
138     case MIPSNET_RX_DATA_BUFFER:
139         if (s->rx_count) {
140             s->rx_count--;
141             ret = s->rx_buffer[s->rx_read++];
142             if (mipsnet_can_receive(s->nic->ncs)) {
143                 qemu_flush_queued_packets(qemu_get_queue(s->nic));
144             }
145         }
146         break;
147     /* Reads as zero. */
148     case MIPSNET_TX_DATA_BUFFER:
149     default:
150         break;
151     }
152     trace_mipsnet_read(addr, ret);
153     return ret;
154 }
155 
156 static void mipsnet_ioport_write(void *opaque, hwaddr addr,
157                                  uint64_t val, unsigned int size)
158 {
159     MIPSnetState *s = opaque;
160 
161     addr &= 0x3f;
162     trace_mipsnet_write(addr, val);
163     switch (addr) {
164     case MIPSNET_TX_DATA_COUNT:
165         s->tx_count = (val <= MAX_ETH_FRAME_SIZE) ? val : 0;
166         s->tx_written = 0;
167         break;
168     case MIPSNET_INT_CTL:
169         if (val & MIPSNET_INTCTL_TXDONE) {
170             s->intctl &= ~MIPSNET_INTCTL_TXDONE;
171         } else if (val & MIPSNET_INTCTL_RXDONE) {
172             s->intctl &= ~MIPSNET_INTCTL_RXDONE;
173         } else if (val & MIPSNET_INTCTL_TESTBIT) {
174             mipsnet_reset(s);
175             s->intctl |= MIPSNET_INTCTL_TESTBIT;
176         } else if (!val) {
177             /* ACK testbit interrupt, flag was cleared on read. */
178         }
179         s->busy = !!s->intctl;
180         mipsnet_update_irq(s);
181         if (mipsnet_can_receive(s->nic->ncs)) {
182             qemu_flush_queued_packets(qemu_get_queue(s->nic));
183         }
184         break;
185     case MIPSNET_TX_DATA_BUFFER:
186         s->tx_buffer[s->tx_written++] = val;
187         if ((s->tx_written >= MAX_ETH_FRAME_SIZE)
188             || (s->tx_written == s->tx_count)) {
189             /* Send buffer. */
190             trace_mipsnet_send(s->tx_written);
191             qemu_send_packet(qemu_get_queue(s->nic),
192                                 s->tx_buffer, s->tx_written);
193             s->tx_count = s->tx_written = 0;
194             s->intctl |= MIPSNET_INTCTL_TXDONE;
195             s->busy = 1;
196             mipsnet_update_irq(s);
197         }
198         break;
199     /* Read-only registers */
200     case MIPSNET_DEV_ID:
201     case MIPSNET_BUSY:
202     case MIPSNET_RX_DATA_COUNT:
203     case MIPSNET_INTERRUPT_INFO:
204     case MIPSNET_RX_DATA_BUFFER:
205     default:
206         break;
207     }
208 }
209 
210 static const VMStateDescription vmstate_mipsnet = {
211     .name = "mipsnet",
212     .version_id = 0,
213     .minimum_version_id = 0,
214     .fields = (VMStateField[]) {
215         VMSTATE_UINT32(busy, MIPSnetState),
216         VMSTATE_UINT32(rx_count, MIPSnetState),
217         VMSTATE_UINT32(rx_read, MIPSnetState),
218         VMSTATE_UINT32(tx_count, MIPSnetState),
219         VMSTATE_UINT32(tx_written, MIPSnetState),
220         VMSTATE_UINT32(intctl, MIPSnetState),
221         VMSTATE_BUFFER(rx_buffer, MIPSnetState),
222         VMSTATE_BUFFER(tx_buffer, MIPSnetState),
223         VMSTATE_END_OF_LIST()
224     }
225 };
226 
227 static NetClientInfo net_mipsnet_info = {
228     .type = NET_CLIENT_DRIVER_NIC,
229     .size = sizeof(NICState),
230     .receive = mipsnet_receive,
231 };
232 
233 static const MemoryRegionOps mipsnet_ioport_ops = {
234     .read = mipsnet_ioport_read,
235     .write = mipsnet_ioport_write,
236     .impl.min_access_size = 1,
237     .impl.max_access_size = 4,
238 };
239 
240 static void mipsnet_realize(DeviceState *dev, Error **errp)
241 {
242     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
243     MIPSnetState *s = MIPS_NET(dev);
244 
245     memory_region_init_io(&s->io, OBJECT(dev), &mipsnet_ioport_ops, s,
246                           "mipsnet-io", 36);
247     sysbus_init_mmio(sbd, &s->io);
248     sysbus_init_irq(sbd, &s->irq);
249 
250     s->nic = qemu_new_nic(&net_mipsnet_info, &s->conf,
251                           object_get_typename(OBJECT(dev)), dev->id, s);
252     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
253 }
254 
255 static void mipsnet_sysbus_reset(DeviceState *dev)
256 {
257     MIPSnetState *s = MIPS_NET(dev);
258     mipsnet_reset(s);
259 }
260 
261 static Property mipsnet_properties[] = {
262     DEFINE_NIC_PROPERTIES(MIPSnetState, conf),
263     DEFINE_PROP_END_OF_LIST(),
264 };
265 
266 static void mipsnet_class_init(ObjectClass *klass, void *data)
267 {
268     DeviceClass *dc = DEVICE_CLASS(klass);
269 
270     dc->realize = mipsnet_realize;
271     set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
272     dc->desc = "MIPS Simulator network device";
273     dc->reset = mipsnet_sysbus_reset;
274     dc->vmsd = &vmstate_mipsnet;
275     dc->props = mipsnet_properties;
276 }
277 
278 static const TypeInfo mipsnet_info = {
279     .name          = TYPE_MIPS_NET,
280     .parent        = TYPE_SYS_BUS_DEVICE,
281     .instance_size = sizeof(MIPSnetState),
282     .class_init    = mipsnet_class_init,
283 };
284 
285 static void mipsnet_register_types(void)
286 {
287     type_register_static(&mipsnet_info);
288 }
289 
290 type_init(mipsnet_register_types)
291