xref: /openbmc/qemu/hw/net/mipsnet.c (revision efb91426)
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 #include "qom/object.h"
10 
11 /* MIPSnet register offsets */
12 
13 #define MIPSNET_DEV_ID          0x00
14 #define MIPSNET_BUSY            0x08
15 #define MIPSNET_RX_DATA_COUNT   0x0c
16 #define MIPSNET_TX_DATA_COUNT   0x10
17 #define MIPSNET_INT_CTL         0x14
18 # define MIPSNET_INTCTL_TXDONE          0x00000001
19 # define MIPSNET_INTCTL_RXDONE          0x00000002
20 # define MIPSNET_INTCTL_TESTBIT         0x80000000
21 #define MIPSNET_INTERRUPT_INFO  0x18
22 #define MIPSNET_RX_DATA_BUFFER  0x1c
23 #define MIPSNET_TX_DATA_BUFFER  0x20
24 
25 #define MAX_ETH_FRAME_SIZE      1514
26 
27 #define TYPE_MIPS_NET "mipsnet"
28 OBJECT_DECLARE_SIMPLE_TYPE(MIPSnetState, MIPS_NET)
29 
30 struct MIPSnetState {
31     SysBusDevice parent_obj;
32 
33     uint32_t busy;
34     uint32_t rx_count;
35     uint32_t rx_read;
36     uint32_t tx_count;
37     uint32_t tx_written;
38     uint32_t intctl;
39     uint8_t rx_buffer[MAX_ETH_FRAME_SIZE];
40     uint8_t tx_buffer[MAX_ETH_FRAME_SIZE];
41     MemoryRegion io;
42     qemu_irq irq;
43     NICState *nic;
44     NICConf conf;
45 };
46 
47 static void mipsnet_reset(MIPSnetState *s)
48 {
49     s->busy = 1;
50     s->rx_count = 0;
51     s->rx_read = 0;
52     s->tx_count = 0;
53     s->tx_written = 0;
54     s->intctl = 0;
55     memset(s->rx_buffer, 0, MAX_ETH_FRAME_SIZE);
56     memset(s->tx_buffer, 0, MAX_ETH_FRAME_SIZE);
57 }
58 
59 static void mipsnet_update_irq(MIPSnetState *s)
60 {
61     int isr = !!s->intctl;
62     trace_mipsnet_irq(isr, s->intctl);
63     qemu_set_irq(s->irq, isr);
64 }
65 
66 static int mipsnet_buffer_full(MIPSnetState *s)
67 {
68     if (s->rx_count >= MAX_ETH_FRAME_SIZE) {
69         return 1;
70     }
71     return 0;
72 }
73 
74 static int mipsnet_can_receive(NetClientState *nc)
75 {
76     MIPSnetState *s = qemu_get_nic_opaque(nc);
77 
78     if (s->busy) {
79         return 0;
80     }
81     return !mipsnet_buffer_full(s);
82 }
83 
84 static ssize_t mipsnet_receive(NetClientState *nc,
85                                const uint8_t *buf, size_t size)
86 {
87     MIPSnetState *s = qemu_get_nic_opaque(nc);
88 
89     trace_mipsnet_receive(size);
90     if (!mipsnet_can_receive(nc)) {
91         return 0;
92     }
93 
94     if (size >= sizeof(s->rx_buffer)) {
95         return 0;
96     }
97     s->busy = 1;
98 
99     /* Just accept everything. */
100 
101     /* Write packet data. */
102     memcpy(s->rx_buffer, buf, size);
103 
104     s->rx_count = size;
105     s->rx_read = 0;
106 
107     /* Now we can signal we have received something. */
108     s->intctl |= MIPSNET_INTCTL_RXDONE;
109     mipsnet_update_irq(s);
110 
111     return size;
112 }
113 
114 static uint64_t mipsnet_ioport_read(void *opaque, hwaddr addr,
115                                     unsigned int size)
116 {
117     MIPSnetState *s = opaque;
118     int ret = 0;
119 
120     addr &= 0x3f;
121     switch (addr) {
122     case MIPSNET_DEV_ID:
123         ret = be32_to_cpu(0x4d495053);          /* MIPS */
124         break;
125     case MIPSNET_DEV_ID + 4:
126         ret = be32_to_cpu(0x4e455430);          /* NET0 */
127         break;
128     case MIPSNET_BUSY:
129         ret = s->busy;
130         break;
131     case MIPSNET_RX_DATA_COUNT:
132         ret = s->rx_count;
133         break;
134     case MIPSNET_TX_DATA_COUNT:
135         ret = s->tx_count;
136         break;
137     case MIPSNET_INT_CTL:
138         ret = s->intctl;
139         s->intctl &= ~MIPSNET_INTCTL_TESTBIT;
140         break;
141     case MIPSNET_INTERRUPT_INFO:
142         /* XXX: This seems to be a per-VPE interrupt number. */
143         ret = 0;
144         break;
145     case MIPSNET_RX_DATA_BUFFER:
146         if (s->rx_count) {
147             s->rx_count--;
148             ret = s->rx_buffer[s->rx_read++];
149             if (mipsnet_can_receive(s->nic->ncs)) {
150                 qemu_flush_queued_packets(qemu_get_queue(s->nic));
151             }
152         }
153         break;
154     /* Reads as zero. */
155     case MIPSNET_TX_DATA_BUFFER:
156     default:
157         break;
158     }
159     trace_mipsnet_read(addr, ret);
160     return ret;
161 }
162 
163 static void mipsnet_ioport_write(void *opaque, hwaddr addr,
164                                  uint64_t val, unsigned int size)
165 {
166     MIPSnetState *s = opaque;
167 
168     addr &= 0x3f;
169     trace_mipsnet_write(addr, val);
170     switch (addr) {
171     case MIPSNET_TX_DATA_COUNT:
172         s->tx_count = (val <= MAX_ETH_FRAME_SIZE) ? val : 0;
173         s->tx_written = 0;
174         break;
175     case MIPSNET_INT_CTL:
176         if (val & MIPSNET_INTCTL_TXDONE) {
177             s->intctl &= ~MIPSNET_INTCTL_TXDONE;
178         } else if (val & MIPSNET_INTCTL_RXDONE) {
179             s->intctl &= ~MIPSNET_INTCTL_RXDONE;
180         } else if (val & MIPSNET_INTCTL_TESTBIT) {
181             mipsnet_reset(s);
182             s->intctl |= MIPSNET_INTCTL_TESTBIT;
183         } else if (!val) {
184             /* ACK testbit interrupt, flag was cleared on read. */
185         }
186         s->busy = !!s->intctl;
187         mipsnet_update_irq(s);
188         if (mipsnet_can_receive(s->nic->ncs)) {
189             qemu_flush_queued_packets(qemu_get_queue(s->nic));
190         }
191         break;
192     case MIPSNET_TX_DATA_BUFFER:
193         s->tx_buffer[s->tx_written++] = val;
194         if ((s->tx_written >= MAX_ETH_FRAME_SIZE)
195             || (s->tx_written == s->tx_count)) {
196             /* Send buffer. */
197             trace_mipsnet_send(s->tx_written);
198             qemu_send_packet(qemu_get_queue(s->nic),
199                                 s->tx_buffer, s->tx_written);
200             s->tx_count = s->tx_written = 0;
201             s->intctl |= MIPSNET_INTCTL_TXDONE;
202             s->busy = 1;
203             mipsnet_update_irq(s);
204         }
205         break;
206     /* Read-only registers */
207     case MIPSNET_DEV_ID:
208     case MIPSNET_BUSY:
209     case MIPSNET_RX_DATA_COUNT:
210     case MIPSNET_INTERRUPT_INFO:
211     case MIPSNET_RX_DATA_BUFFER:
212     default:
213         break;
214     }
215 }
216 
217 static const VMStateDescription vmstate_mipsnet = {
218     .name = "mipsnet",
219     .version_id = 0,
220     .minimum_version_id = 0,
221     .fields = (const VMStateField[]) {
222         VMSTATE_UINT32(busy, MIPSnetState),
223         VMSTATE_UINT32(rx_count, MIPSnetState),
224         VMSTATE_UINT32(rx_read, MIPSnetState),
225         VMSTATE_UINT32(tx_count, MIPSnetState),
226         VMSTATE_UINT32(tx_written, MIPSnetState),
227         VMSTATE_UINT32(intctl, MIPSnetState),
228         VMSTATE_BUFFER(rx_buffer, MIPSnetState),
229         VMSTATE_BUFFER(tx_buffer, MIPSnetState),
230         VMSTATE_END_OF_LIST()
231     }
232 };
233 
234 static NetClientInfo net_mipsnet_info = {
235     .type = NET_CLIENT_DRIVER_NIC,
236     .size = sizeof(NICState),
237     .receive = mipsnet_receive,
238 };
239 
240 static const MemoryRegionOps mipsnet_ioport_ops = {
241     .read = mipsnet_ioport_read,
242     .write = mipsnet_ioport_write,
243     .impl.min_access_size = 1,
244     .impl.max_access_size = 4,
245 };
246 
247 static void mipsnet_realize(DeviceState *dev, Error **errp)
248 {
249     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
250     MIPSnetState *s = MIPS_NET(dev);
251 
252     memory_region_init_io(&s->io, OBJECT(dev), &mipsnet_ioport_ops, s,
253                           "mipsnet-io", 36);
254     sysbus_init_mmio(sbd, &s->io);
255     sysbus_init_irq(sbd, &s->irq);
256 
257     s->nic = qemu_new_nic(&net_mipsnet_info, &s->conf,
258                           object_get_typename(OBJECT(dev)), dev->id,
259                           &dev->mem_reentrancy_guard, s);
260     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
261 }
262 
263 static void mipsnet_sysbus_reset(DeviceState *dev)
264 {
265     MIPSnetState *s = MIPS_NET(dev);
266     mipsnet_reset(s);
267 }
268 
269 static Property mipsnet_properties[] = {
270     DEFINE_NIC_PROPERTIES(MIPSnetState, conf),
271     DEFINE_PROP_END_OF_LIST(),
272 };
273 
274 static void mipsnet_class_init(ObjectClass *klass, void *data)
275 {
276     DeviceClass *dc = DEVICE_CLASS(klass);
277 
278     dc->realize = mipsnet_realize;
279     set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
280     dc->desc = "MIPS Simulator network device";
281     dc->reset = mipsnet_sysbus_reset;
282     dc->vmsd = &vmstate_mipsnet;
283     device_class_set_props(dc, mipsnet_properties);
284 }
285 
286 static const TypeInfo mipsnet_info = {
287     .name          = TYPE_MIPS_NET,
288     .parent        = TYPE_SYS_BUS_DEVICE,
289     .instance_size = sizeof(MIPSnetState),
290     .class_init    = mipsnet_class_init,
291 };
292 
293 static void mipsnet_register_types(void)
294 {
295     type_register_static(&mipsnet_info);
296 }
297 
298 type_init(mipsnet_register_types)
299