xref: /openbmc/qemu/hw/net/mipsnet.c (revision 2822c1b6)
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 #define TYPE_MIPS_NET "mipsnet"
23 #define MIPS_NET(obj) OBJECT_CHECK(MIPSnetState, (obj), TYPE_MIPS_NET)
24 
25 typedef struct MIPSnetState {
26     SysBusDevice parent_obj;
27 
28     uint32_t busy;
29     uint32_t rx_count;
30     uint32_t rx_read;
31     uint32_t tx_count;
32     uint32_t tx_written;
33     uint32_t intctl;
34     uint8_t rx_buffer[MAX_ETH_FRAME_SIZE];
35     uint8_t tx_buffer[MAX_ETH_FRAME_SIZE];
36     MemoryRegion io;
37     qemu_irq irq;
38     NICState *nic;
39     NICConf conf;
40 } MIPSnetState;
41 
42 static void mipsnet_reset(MIPSnetState *s)
43 {
44     s->busy = 1;
45     s->rx_count = 0;
46     s->rx_read = 0;
47     s->tx_count = 0;
48     s->tx_written = 0;
49     s->intctl = 0;
50     memset(s->rx_buffer, 0, MAX_ETH_FRAME_SIZE);
51     memset(s->tx_buffer, 0, MAX_ETH_FRAME_SIZE);
52 }
53 
54 static void mipsnet_update_irq(MIPSnetState *s)
55 {
56     int isr = !!s->intctl;
57     trace_mipsnet_irq(isr, s->intctl);
58     qemu_set_irq(s->irq, isr);
59 }
60 
61 static int mipsnet_buffer_full(MIPSnetState *s)
62 {
63     if (s->rx_count >= MAX_ETH_FRAME_SIZE)
64         return 1;
65     return 0;
66 }
67 
68 static int mipsnet_can_receive(NetClientState *nc)
69 {
70     MIPSnetState *s = qemu_get_nic_opaque(nc);
71 
72     if (s->busy)
73         return 0;
74     return !mipsnet_buffer_full(s);
75 }
76 
77 static ssize_t mipsnet_receive(NetClientState *nc, const uint8_t *buf, size_t size)
78 {
79     MIPSnetState *s = qemu_get_nic_opaque(nc);
80 
81     trace_mipsnet_receive(size);
82     if (!mipsnet_can_receive(nc))
83         return -1;
84 
85     s->busy = 1;
86 
87     /* Just accept everything. */
88 
89     /* Write packet data. */
90     memcpy(s->rx_buffer, buf, size);
91 
92     s->rx_count = size;
93     s->rx_read = 0;
94 
95     /* Now we can signal we have received something. */
96     s->intctl |= MIPSNET_INTCTL_RXDONE;
97     mipsnet_update_irq(s);
98 
99     return size;
100 }
101 
102 static uint64_t mipsnet_ioport_read(void *opaque, hwaddr addr,
103                                     unsigned int size)
104 {
105     MIPSnetState *s = opaque;
106     int ret = 0;
107 
108     addr &= 0x3f;
109     switch (addr) {
110     case MIPSNET_DEV_ID:
111 	ret = be32_to_cpu(0x4d495053);		/* MIPS */
112         break;
113     case MIPSNET_DEV_ID + 4:
114 	ret = be32_to_cpu(0x4e455430);		/* NET0 */
115         break;
116     case MIPSNET_BUSY:
117 	ret = s->busy;
118         break;
119     case MIPSNET_RX_DATA_COUNT:
120 	ret = s->rx_count;
121         break;
122     case MIPSNET_TX_DATA_COUNT:
123 	ret = s->tx_count;
124         break;
125     case MIPSNET_INT_CTL:
126 	ret = s->intctl;
127         s->intctl &= ~MIPSNET_INTCTL_TESTBIT;
128         break;
129     case MIPSNET_INTERRUPT_INFO:
130         /* XXX: This seems to be a per-VPE interrupt number. */
131 	ret = 0;
132         break;
133     case MIPSNET_RX_DATA_BUFFER:
134         if (s->rx_count) {
135             s->rx_count--;
136             ret = s->rx_buffer[s->rx_read++];
137         }
138         break;
139     /* Reads as zero. */
140     case MIPSNET_TX_DATA_BUFFER:
141     default:
142         break;
143     }
144     trace_mipsnet_read(addr, ret);
145     return ret;
146 }
147 
148 static void mipsnet_ioport_write(void *opaque, hwaddr addr,
149                                  uint64_t val, unsigned int size)
150 {
151     MIPSnetState *s = opaque;
152 
153     addr &= 0x3f;
154     trace_mipsnet_write(addr, val);
155     switch (addr) {
156     case MIPSNET_TX_DATA_COUNT:
157 	s->tx_count = (val <= MAX_ETH_FRAME_SIZE) ? val : 0;
158         s->tx_written = 0;
159         break;
160     case MIPSNET_INT_CTL:
161         if (val & MIPSNET_INTCTL_TXDONE) {
162             s->intctl &= ~MIPSNET_INTCTL_TXDONE;
163         } else if (val & MIPSNET_INTCTL_RXDONE) {
164             s->intctl &= ~MIPSNET_INTCTL_RXDONE;
165         } else if (val & MIPSNET_INTCTL_TESTBIT) {
166             mipsnet_reset(s);
167             s->intctl |= MIPSNET_INTCTL_TESTBIT;
168         } else if (!val) {
169             /* ACK testbit interrupt, flag was cleared on read. */
170         }
171         s->busy = !!s->intctl;
172         mipsnet_update_irq(s);
173         break;
174     case MIPSNET_TX_DATA_BUFFER:
175         s->tx_buffer[s->tx_written++] = val;
176         if (s->tx_written == s->tx_count) {
177             /* Send buffer. */
178             trace_mipsnet_send(s->tx_count);
179             qemu_send_packet(qemu_get_queue(s->nic), s->tx_buffer, s->tx_count);
180             s->tx_count = s->tx_written = 0;
181             s->intctl |= MIPSNET_INTCTL_TXDONE;
182             s->busy = 1;
183             mipsnet_update_irq(s);
184         }
185         break;
186     /* Read-only registers */
187     case MIPSNET_DEV_ID:
188     case MIPSNET_BUSY:
189     case MIPSNET_RX_DATA_COUNT:
190     case MIPSNET_INTERRUPT_INFO:
191     case MIPSNET_RX_DATA_BUFFER:
192     default:
193         break;
194     }
195 }
196 
197 static const VMStateDescription vmstate_mipsnet = {
198     .name = "mipsnet",
199     .version_id = 0,
200     .minimum_version_id = 0,
201     .fields = (VMStateField[]) {
202         VMSTATE_UINT32(busy, MIPSnetState),
203         VMSTATE_UINT32(rx_count, MIPSnetState),
204         VMSTATE_UINT32(rx_read, MIPSnetState),
205         VMSTATE_UINT32(tx_count, MIPSnetState),
206         VMSTATE_UINT32(tx_written, MIPSnetState),
207         VMSTATE_UINT32(intctl, MIPSnetState),
208         VMSTATE_BUFFER(rx_buffer, MIPSnetState),
209         VMSTATE_BUFFER(tx_buffer, MIPSnetState),
210         VMSTATE_END_OF_LIST()
211     }
212 };
213 
214 static NetClientInfo net_mipsnet_info = {
215     .type = NET_CLIENT_OPTIONS_KIND_NIC,
216     .size = sizeof(NICState),
217     .can_receive = mipsnet_can_receive,
218     .receive = mipsnet_receive,
219 };
220 
221 static const MemoryRegionOps mipsnet_ioport_ops = {
222     .read = mipsnet_ioport_read,
223     .write = mipsnet_ioport_write,
224     .impl.min_access_size = 1,
225     .impl.max_access_size = 4,
226 };
227 
228 static int mipsnet_sysbus_init(SysBusDevice *sbd)
229 {
230     DeviceState *dev = DEVICE(sbd);
231     MIPSnetState *s = MIPS_NET(dev);
232 
233     memory_region_init_io(&s->io, OBJECT(dev), &mipsnet_ioport_ops, s,
234                           "mipsnet-io", 36);
235     sysbus_init_mmio(sbd, &s->io);
236     sysbus_init_irq(sbd, &s->irq);
237 
238     s->nic = qemu_new_nic(&net_mipsnet_info, &s->conf,
239                           object_get_typename(OBJECT(dev)), dev->id, s);
240     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
241 
242     return 0;
243 }
244 
245 static void mipsnet_sysbus_reset(DeviceState *dev)
246 {
247     MIPSnetState *s = MIPS_NET(dev);
248     mipsnet_reset(s);
249 }
250 
251 static Property mipsnet_properties[] = {
252     DEFINE_NIC_PROPERTIES(MIPSnetState, conf),
253     DEFINE_PROP_END_OF_LIST(),
254 };
255 
256 static void mipsnet_class_init(ObjectClass *klass, void *data)
257 {
258     DeviceClass *dc = DEVICE_CLASS(klass);
259     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
260 
261     k->init = mipsnet_sysbus_init;
262     set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
263     dc->desc = "MIPS Simulator network device";
264     dc->reset = mipsnet_sysbus_reset;
265     dc->vmsd = &vmstate_mipsnet;
266     dc->props = mipsnet_properties;
267 }
268 
269 static const TypeInfo mipsnet_info = {
270     .name          = TYPE_MIPS_NET,
271     .parent        = TYPE_SYS_BUS_DEVICE,
272     .instance_size = sizeof(MIPSnetState),
273     .class_init    = mipsnet_class_init,
274 };
275 
276 static void mipsnet_register_types(void)
277 {
278     type_register_static(&mipsnet_info);
279 }
280 
281 type_init(mipsnet_register_types)
282