xref: /openbmc/qemu/hw/net/mipsnet.c (revision 135b03cb)
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 
10 /* MIPSnet register offsets */
11 
12 #define MIPSNET_DEV_ID		0x00
13 #define MIPSNET_BUSY		0x08
14 #define MIPSNET_RX_DATA_COUNT	0x0c
15 #define MIPSNET_TX_DATA_COUNT	0x10
16 #define MIPSNET_INT_CTL		0x14
17 # define MIPSNET_INTCTL_TXDONE		0x00000001
18 # define MIPSNET_INTCTL_RXDONE		0x00000002
19 # define MIPSNET_INTCTL_TESTBIT		0x80000000
20 #define MIPSNET_INTERRUPT_INFO	0x18
21 #define MIPSNET_RX_DATA_BUFFER	0x1c
22 #define MIPSNET_TX_DATA_BUFFER	0x20
23 
24 #define MAX_ETH_FRAME_SIZE	1514
25 
26 #define TYPE_MIPS_NET "mipsnet"
27 #define MIPS_NET(obj) OBJECT_CHECK(MIPSnetState, (obj), TYPE_MIPS_NET)
28 
29 typedef struct MIPSnetState {
30     SysBusDevice parent_obj;
31 
32     uint32_t busy;
33     uint32_t rx_count;
34     uint32_t rx_read;
35     uint32_t tx_count;
36     uint32_t tx_written;
37     uint32_t intctl;
38     uint8_t rx_buffer[MAX_ETH_FRAME_SIZE];
39     uint8_t tx_buffer[MAX_ETH_FRAME_SIZE];
40     MemoryRegion io;
41     qemu_irq irq;
42     NICState *nic;
43     NICConf conf;
44 } MIPSnetState;
45 
46 static void mipsnet_reset(MIPSnetState *s)
47 {
48     s->busy = 1;
49     s->rx_count = 0;
50     s->rx_read = 0;
51     s->tx_count = 0;
52     s->tx_written = 0;
53     s->intctl = 0;
54     memset(s->rx_buffer, 0, MAX_ETH_FRAME_SIZE);
55     memset(s->tx_buffer, 0, MAX_ETH_FRAME_SIZE);
56 }
57 
58 static void mipsnet_update_irq(MIPSnetState *s)
59 {
60     int isr = !!s->intctl;
61     trace_mipsnet_irq(isr, s->intctl);
62     qemu_set_irq(s->irq, isr);
63 }
64 
65 static int mipsnet_buffer_full(MIPSnetState *s)
66 {
67     if (s->rx_count >= MAX_ETH_FRAME_SIZE)
68         return 1;
69     return 0;
70 }
71 
72 static int mipsnet_can_receive(NetClientState *nc)
73 {
74     MIPSnetState *s = qemu_get_nic_opaque(nc);
75 
76     if (s->busy)
77         return 0;
78     return !mipsnet_buffer_full(s);
79 }
80 
81 static ssize_t mipsnet_receive(NetClientState *nc, const uint8_t *buf, size_t size)
82 {
83     MIPSnetState *s = qemu_get_nic_opaque(nc);
84 
85     trace_mipsnet_receive(size);
86     if (!mipsnet_can_receive(nc))
87         return 0;
88 
89     if (size >= sizeof(s->rx_buffer)) {
90         return 0;
91     }
92     s->busy = 1;
93 
94     /* Just accept everything. */
95 
96     /* Write packet data. */
97     memcpy(s->rx_buffer, buf, size);
98 
99     s->rx_count = size;
100     s->rx_read = 0;
101 
102     /* Now we can signal we have received something. */
103     s->intctl |= MIPSNET_INTCTL_RXDONE;
104     mipsnet_update_irq(s);
105 
106     return size;
107 }
108 
109 static uint64_t mipsnet_ioport_read(void *opaque, hwaddr addr,
110                                     unsigned int size)
111 {
112     MIPSnetState *s = opaque;
113     int ret = 0;
114 
115     addr &= 0x3f;
116     switch (addr) {
117     case MIPSNET_DEV_ID:
118         ret = be32_to_cpu(0x4d495053);		/* MIPS */
119         break;
120     case MIPSNET_DEV_ID + 4:
121         ret = be32_to_cpu(0x4e455430);		/* NET0 */
122         break;
123     case MIPSNET_BUSY:
124         ret = s->busy;
125         break;
126     case MIPSNET_RX_DATA_COUNT:
127         ret = s->rx_count;
128         break;
129     case MIPSNET_TX_DATA_COUNT:
130         ret = s->tx_count;
131         break;
132     case MIPSNET_INT_CTL:
133         ret = s->intctl;
134         s->intctl &= ~MIPSNET_INTCTL_TESTBIT;
135         break;
136     case MIPSNET_INTERRUPT_INFO:
137         /* XXX: This seems to be a per-VPE interrupt number. */
138         ret = 0;
139         break;
140     case MIPSNET_RX_DATA_BUFFER:
141         if (s->rx_count) {
142             s->rx_count--;
143             ret = s->rx_buffer[s->rx_read++];
144             if (mipsnet_can_receive(s->nic->ncs)) {
145                 qemu_flush_queued_packets(qemu_get_queue(s->nic));
146             }
147         }
148         break;
149     /* Reads as zero. */
150     case MIPSNET_TX_DATA_BUFFER:
151     default:
152         break;
153     }
154     trace_mipsnet_read(addr, ret);
155     return ret;
156 }
157 
158 static void mipsnet_ioport_write(void *opaque, hwaddr addr,
159                                  uint64_t val, unsigned int size)
160 {
161     MIPSnetState *s = opaque;
162 
163     addr &= 0x3f;
164     trace_mipsnet_write(addr, val);
165     switch (addr) {
166     case MIPSNET_TX_DATA_COUNT:
167         s->tx_count = (val <= MAX_ETH_FRAME_SIZE) ? val : 0;
168         s->tx_written = 0;
169         break;
170     case MIPSNET_INT_CTL:
171         if (val & MIPSNET_INTCTL_TXDONE) {
172             s->intctl &= ~MIPSNET_INTCTL_TXDONE;
173         } else if (val & MIPSNET_INTCTL_RXDONE) {
174             s->intctl &= ~MIPSNET_INTCTL_RXDONE;
175         } else if (val & MIPSNET_INTCTL_TESTBIT) {
176             mipsnet_reset(s);
177             s->intctl |= MIPSNET_INTCTL_TESTBIT;
178         } else if (!val) {
179             /* ACK testbit interrupt, flag was cleared on read. */
180         }
181         s->busy = !!s->intctl;
182         mipsnet_update_irq(s);
183         if (mipsnet_can_receive(s->nic->ncs)) {
184             qemu_flush_queued_packets(qemu_get_queue(s->nic));
185         }
186         break;
187     case MIPSNET_TX_DATA_BUFFER:
188         s->tx_buffer[s->tx_written++] = val;
189         if ((s->tx_written >= MAX_ETH_FRAME_SIZE)
190             || (s->tx_written == s->tx_count)) {
191             /* Send buffer. */
192             trace_mipsnet_send(s->tx_written);
193             qemu_send_packet(qemu_get_queue(s->nic),
194                                 s->tx_buffer, s->tx_written);
195             s->tx_count = s->tx_written = 0;
196             s->intctl |= MIPSNET_INTCTL_TXDONE;
197             s->busy = 1;
198             mipsnet_update_irq(s);
199         }
200         break;
201     /* Read-only registers */
202     case MIPSNET_DEV_ID:
203     case MIPSNET_BUSY:
204     case MIPSNET_RX_DATA_COUNT:
205     case MIPSNET_INTERRUPT_INFO:
206     case MIPSNET_RX_DATA_BUFFER:
207     default:
208         break;
209     }
210 }
211 
212 static const VMStateDescription vmstate_mipsnet = {
213     .name = "mipsnet",
214     .version_id = 0,
215     .minimum_version_id = 0,
216     .fields = (VMStateField[]) {
217         VMSTATE_UINT32(busy, MIPSnetState),
218         VMSTATE_UINT32(rx_count, MIPSnetState),
219         VMSTATE_UINT32(rx_read, MIPSnetState),
220         VMSTATE_UINT32(tx_count, MIPSnetState),
221         VMSTATE_UINT32(tx_written, MIPSnetState),
222         VMSTATE_UINT32(intctl, MIPSnetState),
223         VMSTATE_BUFFER(rx_buffer, MIPSnetState),
224         VMSTATE_BUFFER(tx_buffer, MIPSnetState),
225         VMSTATE_END_OF_LIST()
226     }
227 };
228 
229 static NetClientInfo net_mipsnet_info = {
230     .type = NET_CLIENT_DRIVER_NIC,
231     .size = sizeof(NICState),
232     .receive = mipsnet_receive,
233 };
234 
235 static const MemoryRegionOps mipsnet_ioport_ops = {
236     .read = mipsnet_ioport_read,
237     .write = mipsnet_ioport_write,
238     .impl.min_access_size = 1,
239     .impl.max_access_size = 4,
240 };
241 
242 static void mipsnet_realize(DeviceState *dev, Error **errp)
243 {
244     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
245     MIPSnetState *s = MIPS_NET(dev);
246 
247     memory_region_init_io(&s->io, OBJECT(dev), &mipsnet_ioport_ops, s,
248                           "mipsnet-io", 36);
249     sysbus_init_mmio(sbd, &s->io);
250     sysbus_init_irq(sbd, &s->irq);
251 
252     s->nic = qemu_new_nic(&net_mipsnet_info, &s->conf,
253                           object_get_typename(OBJECT(dev)), dev->id, s);
254     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
255 }
256 
257 static void mipsnet_sysbus_reset(DeviceState *dev)
258 {
259     MIPSnetState *s = MIPS_NET(dev);
260     mipsnet_reset(s);
261 }
262 
263 static Property mipsnet_properties[] = {
264     DEFINE_NIC_PROPERTIES(MIPSnetState, conf),
265     DEFINE_PROP_END_OF_LIST(),
266 };
267 
268 static void mipsnet_class_init(ObjectClass *klass, void *data)
269 {
270     DeviceClass *dc = DEVICE_CLASS(klass);
271 
272     dc->realize = mipsnet_realize;
273     set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
274     dc->desc = "MIPS Simulator network device";
275     dc->reset = mipsnet_sysbus_reset;
276     dc->vmsd = &vmstate_mipsnet;
277     dc->props = mipsnet_properties;
278 }
279 
280 static const TypeInfo mipsnet_info = {
281     .name          = TYPE_MIPS_NET,
282     .parent        = TYPE_SYS_BUS_DEVICE,
283     .instance_size = sizeof(MIPSnetState),
284     .class_init    = mipsnet_class_init,
285 };
286 
287 static void mipsnet_register_types(void)
288 {
289     type_register_static(&mipsnet_info);
290 }
291 
292 type_init(mipsnet_register_types)
293