xref: /openbmc/qemu/hw/net/mipsnet.c (revision a68694cd)
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 typedef struct MIPSnetState MIPSnetState;
29 DECLARE_INSTANCE_CHECKER(MIPSnetState, MIPS_NET,
30                          TYPE_MIPS_NET)
31 
32 struct MIPSnetState {
33     SysBusDevice parent_obj;
34 
35     uint32_t busy;
36     uint32_t rx_count;
37     uint32_t rx_read;
38     uint32_t tx_count;
39     uint32_t tx_written;
40     uint32_t intctl;
41     uint8_t rx_buffer[MAX_ETH_FRAME_SIZE];
42     uint8_t tx_buffer[MAX_ETH_FRAME_SIZE];
43     MemoryRegion io;
44     qemu_irq irq;
45     NICState *nic;
46     NICConf conf;
47 };
48 
49 static void mipsnet_reset(MIPSnetState *s)
50 {
51     s->busy = 1;
52     s->rx_count = 0;
53     s->rx_read = 0;
54     s->tx_count = 0;
55     s->tx_written = 0;
56     s->intctl = 0;
57     memset(s->rx_buffer, 0, MAX_ETH_FRAME_SIZE);
58     memset(s->tx_buffer, 0, MAX_ETH_FRAME_SIZE);
59 }
60 
61 static void mipsnet_update_irq(MIPSnetState *s)
62 {
63     int isr = !!s->intctl;
64     trace_mipsnet_irq(isr, s->intctl);
65     qemu_set_irq(s->irq, isr);
66 }
67 
68 static int mipsnet_buffer_full(MIPSnetState *s)
69 {
70     if (s->rx_count >= MAX_ETH_FRAME_SIZE) {
71         return 1;
72     }
73     return 0;
74 }
75 
76 static int mipsnet_can_receive(NetClientState *nc)
77 {
78     MIPSnetState *s = qemu_get_nic_opaque(nc);
79 
80     if (s->busy) {
81         return 0;
82     }
83     return !mipsnet_buffer_full(s);
84 }
85 
86 static ssize_t mipsnet_receive(NetClientState *nc,
87                                const uint8_t *buf, size_t size)
88 {
89     MIPSnetState *s = qemu_get_nic_opaque(nc);
90 
91     trace_mipsnet_receive(size);
92     if (!mipsnet_can_receive(nc)) {
93         return 0;
94     }
95 
96     if (size >= sizeof(s->rx_buffer)) {
97         return 0;
98     }
99     s->busy = 1;
100 
101     /* Just accept everything. */
102 
103     /* Write packet data. */
104     memcpy(s->rx_buffer, buf, size);
105 
106     s->rx_count = size;
107     s->rx_read = 0;
108 
109     /* Now we can signal we have received something. */
110     s->intctl |= MIPSNET_INTCTL_RXDONE;
111     mipsnet_update_irq(s);
112 
113     return size;
114 }
115 
116 static uint64_t mipsnet_ioport_read(void *opaque, hwaddr addr,
117                                     unsigned int size)
118 {
119     MIPSnetState *s = opaque;
120     int ret = 0;
121 
122     addr &= 0x3f;
123     switch (addr) {
124     case MIPSNET_DEV_ID:
125         ret = be32_to_cpu(0x4d495053);          /* MIPS */
126         break;
127     case MIPSNET_DEV_ID + 4:
128         ret = be32_to_cpu(0x4e455430);          /* NET0 */
129         break;
130     case MIPSNET_BUSY:
131         ret = s->busy;
132         break;
133     case MIPSNET_RX_DATA_COUNT:
134         ret = s->rx_count;
135         break;
136     case MIPSNET_TX_DATA_COUNT:
137         ret = s->tx_count;
138         break;
139     case MIPSNET_INT_CTL:
140         ret = s->intctl;
141         s->intctl &= ~MIPSNET_INTCTL_TESTBIT;
142         break;
143     case MIPSNET_INTERRUPT_INFO:
144         /* XXX: This seems to be a per-VPE interrupt number. */
145         ret = 0;
146         break;
147     case MIPSNET_RX_DATA_BUFFER:
148         if (s->rx_count) {
149             s->rx_count--;
150             ret = s->rx_buffer[s->rx_read++];
151             if (mipsnet_can_receive(s->nic->ncs)) {
152                 qemu_flush_queued_packets(qemu_get_queue(s->nic));
153             }
154         }
155         break;
156     /* Reads as zero. */
157     case MIPSNET_TX_DATA_BUFFER:
158     default:
159         break;
160     }
161     trace_mipsnet_read(addr, ret);
162     return ret;
163 }
164 
165 static void mipsnet_ioport_write(void *opaque, hwaddr addr,
166                                  uint64_t val, unsigned int size)
167 {
168     MIPSnetState *s = opaque;
169 
170     addr &= 0x3f;
171     trace_mipsnet_write(addr, val);
172     switch (addr) {
173     case MIPSNET_TX_DATA_COUNT:
174         s->tx_count = (val <= MAX_ETH_FRAME_SIZE) ? val : 0;
175         s->tx_written = 0;
176         break;
177     case MIPSNET_INT_CTL:
178         if (val & MIPSNET_INTCTL_TXDONE) {
179             s->intctl &= ~MIPSNET_INTCTL_TXDONE;
180         } else if (val & MIPSNET_INTCTL_RXDONE) {
181             s->intctl &= ~MIPSNET_INTCTL_RXDONE;
182         } else if (val & MIPSNET_INTCTL_TESTBIT) {
183             mipsnet_reset(s);
184             s->intctl |= MIPSNET_INTCTL_TESTBIT;
185         } else if (!val) {
186             /* ACK testbit interrupt, flag was cleared on read. */
187         }
188         s->busy = !!s->intctl;
189         mipsnet_update_irq(s);
190         if (mipsnet_can_receive(s->nic->ncs)) {
191             qemu_flush_queued_packets(qemu_get_queue(s->nic));
192         }
193         break;
194     case MIPSNET_TX_DATA_BUFFER:
195         s->tx_buffer[s->tx_written++] = val;
196         if ((s->tx_written >= MAX_ETH_FRAME_SIZE)
197             || (s->tx_written == s->tx_count)) {
198             /* Send buffer. */
199             trace_mipsnet_send(s->tx_written);
200             qemu_send_packet(qemu_get_queue(s->nic),
201                                 s->tx_buffer, s->tx_written);
202             s->tx_count = s->tx_written = 0;
203             s->intctl |= MIPSNET_INTCTL_TXDONE;
204             s->busy = 1;
205             mipsnet_update_irq(s);
206         }
207         break;
208     /* Read-only registers */
209     case MIPSNET_DEV_ID:
210     case MIPSNET_BUSY:
211     case MIPSNET_RX_DATA_COUNT:
212     case MIPSNET_INTERRUPT_INFO:
213     case MIPSNET_RX_DATA_BUFFER:
214     default:
215         break;
216     }
217 }
218 
219 static const VMStateDescription vmstate_mipsnet = {
220     .name = "mipsnet",
221     .version_id = 0,
222     .minimum_version_id = 0,
223     .fields = (VMStateField[]) {
224         VMSTATE_UINT32(busy, MIPSnetState),
225         VMSTATE_UINT32(rx_count, MIPSnetState),
226         VMSTATE_UINT32(rx_read, MIPSnetState),
227         VMSTATE_UINT32(tx_count, MIPSnetState),
228         VMSTATE_UINT32(tx_written, MIPSnetState),
229         VMSTATE_UINT32(intctl, MIPSnetState),
230         VMSTATE_BUFFER(rx_buffer, MIPSnetState),
231         VMSTATE_BUFFER(tx_buffer, MIPSnetState),
232         VMSTATE_END_OF_LIST()
233     }
234 };
235 
236 static NetClientInfo net_mipsnet_info = {
237     .type = NET_CLIENT_DRIVER_NIC,
238     .size = sizeof(NICState),
239     .receive = mipsnet_receive,
240 };
241 
242 static const MemoryRegionOps mipsnet_ioport_ops = {
243     .read = mipsnet_ioport_read,
244     .write = mipsnet_ioport_write,
245     .impl.min_access_size = 1,
246     .impl.max_access_size = 4,
247 };
248 
249 static void mipsnet_realize(DeviceState *dev, Error **errp)
250 {
251     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
252     MIPSnetState *s = MIPS_NET(dev);
253 
254     memory_region_init_io(&s->io, OBJECT(dev), &mipsnet_ioport_ops, s,
255                           "mipsnet-io", 36);
256     sysbus_init_mmio(sbd, &s->io);
257     sysbus_init_irq(sbd, &s->irq);
258 
259     s->nic = qemu_new_nic(&net_mipsnet_info, &s->conf,
260                           object_get_typename(OBJECT(dev)), dev->id, s);
261     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
262 }
263 
264 static void mipsnet_sysbus_reset(DeviceState *dev)
265 {
266     MIPSnetState *s = MIPS_NET(dev);
267     mipsnet_reset(s);
268 }
269 
270 static Property mipsnet_properties[] = {
271     DEFINE_NIC_PROPERTIES(MIPSnetState, conf),
272     DEFINE_PROP_END_OF_LIST(),
273 };
274 
275 static void mipsnet_class_init(ObjectClass *klass, void *data)
276 {
277     DeviceClass *dc = DEVICE_CLASS(klass);
278 
279     dc->realize = mipsnet_realize;
280     set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
281     dc->desc = "MIPS Simulator network device";
282     dc->reset = mipsnet_sysbus_reset;
283     dc->vmsd = &vmstate_mipsnet;
284     device_class_set_props(dc, mipsnet_properties);
285 }
286 
287 static const TypeInfo mipsnet_info = {
288     .name          = TYPE_MIPS_NET,
289     .parent        = TYPE_SYS_BUS_DEVICE,
290     .instance_size = sizeof(MIPSnetState),
291     .class_init    = mipsnet_class_init,
292 };
293 
294 static void mipsnet_register_types(void)
295 {
296     type_register_static(&mipsnet_info);
297 }
298 
299 type_init(mipsnet_register_types)
300