xref: /openbmc/qemu/hw/net/stellaris_enet.c (revision ba632924)
1 /*
2  * Luminary Micro Stellaris Ethernet Controller
3  *
4  * Copyright (c) 2007 CodeSourcery.
5  * Written by Paul Brook
6  *
7  * This code is licensed under the GPL.
8  */
9 #include "qemu/osdep.h"
10 #include "hw/sysbus.h"
11 #include "net/net.h"
12 #include "qemu/log.h"
13 #include <zlib.h>
14 
15 //#define DEBUG_STELLARIS_ENET 1
16 
17 #ifdef DEBUG_STELLARIS_ENET
18 #define DPRINTF(fmt, ...) \
19 do { printf("stellaris_enet: " fmt , ## __VA_ARGS__); } while (0)
20 #define BADF(fmt, ...) \
21 do { fprintf(stderr, "stellaris_enet: error: " fmt , ## __VA_ARGS__); exit(1);} while (0)
22 #else
23 #define DPRINTF(fmt, ...) do {} while(0)
24 #define BADF(fmt, ...) \
25 do { fprintf(stderr, "stellaris_enet: error: " fmt , ## __VA_ARGS__);} while (0)
26 #endif
27 
28 #define SE_INT_RX       0x01
29 #define SE_INT_TXER     0x02
30 #define SE_INT_TXEMP    0x04
31 #define SE_INT_FOV      0x08
32 #define SE_INT_RXER     0x10
33 #define SE_INT_MD       0x20
34 #define SE_INT_PHY      0x40
35 
36 #define SE_RCTL_RXEN    0x01
37 #define SE_RCTL_AMUL    0x02
38 #define SE_RCTL_PRMS    0x04
39 #define SE_RCTL_BADCRC  0x08
40 #define SE_RCTL_RSTFIFO 0x10
41 
42 #define SE_TCTL_TXEN    0x01
43 #define SE_TCTL_PADEN   0x02
44 #define SE_TCTL_CRC     0x04
45 #define SE_TCTL_DUPLEX  0x08
46 
47 #define TYPE_STELLARIS_ENET "stellaris_enet"
48 #define STELLARIS_ENET(obj) \
49     OBJECT_CHECK(stellaris_enet_state, (obj), TYPE_STELLARIS_ENET)
50 
51 typedef struct {
52     uint8_t data[2048];
53     uint32_t len;
54 } StellarisEnetRxFrame;
55 
56 typedef struct {
57     SysBusDevice parent_obj;
58 
59     uint32_t ris;
60     uint32_t im;
61     uint32_t rctl;
62     uint32_t tctl;
63     uint32_t thr;
64     uint32_t mctl;
65     uint32_t mdv;
66     uint32_t mtxd;
67     uint32_t mrxd;
68     uint32_t np;
69     uint32_t tx_fifo_len;
70     uint8_t tx_fifo[2048];
71     /* Real hardware has a 2k fifo, which works out to be at most 31 packets.
72        We implement a full 31 packet fifo.  */
73     StellarisEnetRxFrame rx[31];
74     uint32_t rx_fifo_offset;
75     uint32_t next_packet;
76     NICState *nic;
77     NICConf conf;
78     qemu_irq irq;
79     MemoryRegion mmio;
80 } stellaris_enet_state;
81 
82 static const VMStateDescription vmstate_rx_frame = {
83     .name = "stellaris_enet/rx_frame",
84     .version_id = 1,
85     .minimum_version_id = 1,
86     .fields = (VMStateField[]) {
87         VMSTATE_UINT8_ARRAY(data, StellarisEnetRxFrame, 2048),
88         VMSTATE_UINT32(len, StellarisEnetRxFrame),
89         VMSTATE_END_OF_LIST()
90     }
91 };
92 
93 static int stellaris_enet_post_load(void *opaque, int version_id)
94 {
95     stellaris_enet_state *s = opaque;
96     int i;
97 
98     /* Sanitize inbound state. Note that next_packet is an index but
99      * np is a size; hence their valid upper bounds differ.
100      */
101     if (s->next_packet >= ARRAY_SIZE(s->rx)) {
102         return -1;
103     }
104 
105     if (s->np > ARRAY_SIZE(s->rx)) {
106         return -1;
107     }
108 
109     for (i = 0; i < ARRAY_SIZE(s->rx); i++) {
110         if (s->rx[i].len > ARRAY_SIZE(s->rx[i].data)) {
111             return -1;
112         }
113     }
114 
115     if (s->rx_fifo_offset > ARRAY_SIZE(s->rx[0].data) - 4) {
116         return -1;
117     }
118 
119     if (s->tx_fifo_len > ARRAY_SIZE(s->tx_fifo)) {
120         return -1;
121     }
122 
123     return 0;
124 }
125 
126 static const VMStateDescription vmstate_stellaris_enet = {
127     .name = "stellaris_enet",
128     .version_id = 2,
129     .minimum_version_id = 2,
130     .post_load = stellaris_enet_post_load,
131     .fields = (VMStateField[]) {
132         VMSTATE_UINT32(ris, stellaris_enet_state),
133         VMSTATE_UINT32(im, stellaris_enet_state),
134         VMSTATE_UINT32(rctl, stellaris_enet_state),
135         VMSTATE_UINT32(tctl, stellaris_enet_state),
136         VMSTATE_UINT32(thr, stellaris_enet_state),
137         VMSTATE_UINT32(mctl, stellaris_enet_state),
138         VMSTATE_UINT32(mdv, stellaris_enet_state),
139         VMSTATE_UINT32(mtxd, stellaris_enet_state),
140         VMSTATE_UINT32(mrxd, stellaris_enet_state),
141         VMSTATE_UINT32(np, stellaris_enet_state),
142         VMSTATE_UINT32(tx_fifo_len, stellaris_enet_state),
143         VMSTATE_UINT8_ARRAY(tx_fifo, stellaris_enet_state, 2048),
144         VMSTATE_STRUCT_ARRAY(rx, stellaris_enet_state, 31, 1,
145                              vmstate_rx_frame, StellarisEnetRxFrame),
146         VMSTATE_UINT32(rx_fifo_offset, stellaris_enet_state),
147         VMSTATE_UINT32(next_packet, stellaris_enet_state),
148         VMSTATE_END_OF_LIST()
149     }
150 };
151 
152 static void stellaris_enet_update(stellaris_enet_state *s)
153 {
154     qemu_set_irq(s->irq, (s->ris & s->im) != 0);
155 }
156 
157 /* Return the data length of the packet currently being assembled
158  * in the TX fifo.
159  */
160 static inline int stellaris_txpacket_datalen(stellaris_enet_state *s)
161 {
162     return s->tx_fifo[0] | (s->tx_fifo[1] << 8);
163 }
164 
165 /* Return true if the packet currently in the TX FIFO is complete,
166 * ie the FIFO holds enough bytes for the data length, ethernet header,
167 * payload and optionally CRC.
168 */
169 static inline bool stellaris_txpacket_complete(stellaris_enet_state *s)
170 {
171     int framelen = stellaris_txpacket_datalen(s);
172     framelen += 16;
173     if (!(s->tctl & SE_TCTL_CRC)) {
174         framelen += 4;
175     }
176     /* Cover the corner case of a 2032 byte payload with auto-CRC disabled:
177      * this requires more bytes than will fit in the FIFO. It's not totally
178      * clear how the h/w handles this, but if using threshold-based TX
179      * it will definitely try to transmit something.
180      */
181     framelen = MIN(framelen, ARRAY_SIZE(s->tx_fifo));
182     return s->tx_fifo_len >= framelen;
183 }
184 
185 /* Return true if the TX FIFO threshold is enabled and the FIFO
186  * has filled enough to reach it.
187  */
188 static inline bool stellaris_tx_thr_reached(stellaris_enet_state *s)
189 {
190     return (s->thr < 0x3f &&
191             (s->tx_fifo_len >= 4 * (s->thr * 8 + 1)));
192 }
193 
194 /* Send the packet currently in the TX FIFO */
195 static void stellaris_enet_send(stellaris_enet_state *s)
196 {
197     int framelen = stellaris_txpacket_datalen(s);
198 
199     /* Ethernet header is in the FIFO but not in the datacount.
200      * We don't implement explicit CRC, so just ignore any
201      * CRC value in the FIFO.
202      */
203     framelen += 14;
204     if ((s->tctl & SE_TCTL_PADEN) && framelen < 60) {
205         memset(&s->tx_fifo[framelen + 2], 0, 60 - framelen);
206         framelen = 60;
207     }
208     /* This MIN will have no effect unless the FIFO data is corrupt
209      * (eg bad data from an incoming migration); otherwise the check
210      * on the datalen at the start of writing the data into the FIFO
211      * will have caught this. Silently write a corrupt half-packet,
212      * which is what the hardware does in FIFO underrun situations.
213      */
214     framelen = MIN(framelen, ARRAY_SIZE(s->tx_fifo) - 2);
215     qemu_send_packet(qemu_get_queue(s->nic), s->tx_fifo + 2, framelen);
216     s->tx_fifo_len = 0;
217     s->ris |= SE_INT_TXEMP;
218     stellaris_enet_update(s);
219     DPRINTF("Done TX\n");
220 }
221 
222 /* TODO: Implement MAC address filtering.  */
223 static ssize_t stellaris_enet_receive(NetClientState *nc, const uint8_t *buf, size_t size)
224 {
225     stellaris_enet_state *s = qemu_get_nic_opaque(nc);
226     int n;
227     uint8_t *p;
228     uint32_t crc;
229 
230     if ((s->rctl & SE_RCTL_RXEN) == 0)
231         return -1;
232     if (s->np >= 31) {
233         return 0;
234     }
235 
236     DPRINTF("Received packet len=%zu\n", size);
237     n = s->next_packet + s->np;
238     if (n >= 31)
239         n -= 31;
240 
241     if (size >= sizeof(s->rx[n].data) - 6) {
242         /* If the packet won't fit into the
243          * emulated 2K RAM, this is reported
244          * as a FIFO overrun error.
245          */
246         s->ris |= SE_INT_FOV;
247         stellaris_enet_update(s);
248         return -1;
249     }
250 
251     s->np++;
252     s->rx[n].len = size + 6;
253     p = s->rx[n].data;
254     *(p++) = (size + 6);
255     *(p++) = (size + 6) >> 8;
256     memcpy (p, buf, size);
257     p += size;
258     crc = crc32(~0, buf, size);
259     *(p++) = crc;
260     *(p++) = crc >> 8;
261     *(p++) = crc >> 16;
262     *(p++) = crc >> 24;
263     /* Clear the remaining bytes in the last word.  */
264     if ((size & 3) != 2) {
265         memset(p, 0, (6 - size) & 3);
266     }
267 
268     s->ris |= SE_INT_RX;
269     stellaris_enet_update(s);
270 
271     return size;
272 }
273 
274 static int stellaris_enet_can_receive(stellaris_enet_state *s)
275 {
276     return (s->np < 31);
277 }
278 
279 static uint64_t stellaris_enet_read(void *opaque, hwaddr offset,
280                                     unsigned size)
281 {
282     stellaris_enet_state *s = (stellaris_enet_state *)opaque;
283     uint32_t val;
284 
285     switch (offset) {
286     case 0x00: /* RIS */
287         DPRINTF("IRQ status %02x\n", s->ris);
288         return s->ris;
289     case 0x04: /* IM */
290         return s->im;
291     case 0x08: /* RCTL */
292         return s->rctl;
293     case 0x0c: /* TCTL */
294         return s->tctl;
295     case 0x10: /* DATA */
296     {
297         uint8_t *rx_fifo;
298 
299         if (s->np == 0) {
300             BADF("RX underflow\n");
301             return 0;
302         }
303 
304         rx_fifo = s->rx[s->next_packet].data + s->rx_fifo_offset;
305 
306         val = rx_fifo[0] | (rx_fifo[1] << 8) | (rx_fifo[2] << 16)
307               | (rx_fifo[3] << 24);
308         s->rx_fifo_offset += 4;
309         if (s->rx_fifo_offset >= s->rx[s->next_packet].len) {
310             s->rx_fifo_offset = 0;
311             s->next_packet++;
312             if (s->next_packet >= 31)
313                 s->next_packet = 0;
314             s->np--;
315             DPRINTF("RX done np=%d\n", s->np);
316             if (!s->np && stellaris_enet_can_receive(s)) {
317                 qemu_flush_queued_packets(qemu_get_queue(s->nic));
318             }
319         }
320         return val;
321     }
322     case 0x14: /* IA0 */
323         return s->conf.macaddr.a[0] | (s->conf.macaddr.a[1] << 8)
324             | (s->conf.macaddr.a[2] << 16)
325             | ((uint32_t)s->conf.macaddr.a[3] << 24);
326     case 0x18: /* IA1 */
327         return s->conf.macaddr.a[4] | (s->conf.macaddr.a[5] << 8);
328     case 0x1c: /* THR */
329         return s->thr;
330     case 0x20: /* MCTL */
331         return s->mctl;
332     case 0x24: /* MDV */
333         return s->mdv;
334     case 0x28: /* MADD */
335         return 0;
336     case 0x2c: /* MTXD */
337         return s->mtxd;
338     case 0x30: /* MRXD */
339         return s->mrxd;
340     case 0x34: /* NP */
341         return s->np;
342     case 0x38: /* TR */
343         return 0;
344     case 0x3c: /* Undocumented: Timestamp? */
345         return 0;
346     default:
347         qemu_log_mask(LOG_GUEST_ERROR, "stellaris_enet_rd%d: Illegal register"
348                                        " 0x02%" HWADDR_PRIx "\n",
349                       size * 8, offset);
350         return 0;
351     }
352 }
353 
354 static void stellaris_enet_write(void *opaque, hwaddr offset,
355                                  uint64_t value, unsigned size)
356 {
357     stellaris_enet_state *s = (stellaris_enet_state *)opaque;
358 
359     switch (offset) {
360     case 0x00: /* IACK */
361         s->ris &= ~value;
362         DPRINTF("IRQ ack %02" PRIx64 "/%02x\n", value, s->ris);
363         stellaris_enet_update(s);
364         /* Clearing TXER also resets the TX fifo.  */
365         if (value & SE_INT_TXER) {
366             s->tx_fifo_len = 0;
367         }
368         break;
369     case 0x04: /* IM */
370         DPRINTF("IRQ mask %02" PRIx64 "/%02x\n", value, s->ris);
371         s->im = value;
372         stellaris_enet_update(s);
373         break;
374     case 0x08: /* RCTL */
375         s->rctl = value;
376         if (value & SE_RCTL_RSTFIFO) {
377             s->np = 0;
378             s->rx_fifo_offset = 0;
379             stellaris_enet_update(s);
380         }
381         break;
382     case 0x0c: /* TCTL */
383         s->tctl = value;
384         break;
385     case 0x10: /* DATA */
386         if (s->tx_fifo_len == 0) {
387             /* The first word is special, it contains the data length */
388             int framelen = value & 0xffff;
389             if (framelen > 2032) {
390                 DPRINTF("TX frame too long (%d)\n", framelen);
391                 s->ris |= SE_INT_TXER;
392                 stellaris_enet_update(s);
393                 break;
394             }
395         }
396 
397         if (s->tx_fifo_len + 4 <= ARRAY_SIZE(s->tx_fifo)) {
398             s->tx_fifo[s->tx_fifo_len++] = value;
399             s->tx_fifo[s->tx_fifo_len++] = value >> 8;
400             s->tx_fifo[s->tx_fifo_len++] = value >> 16;
401             s->tx_fifo[s->tx_fifo_len++] = value >> 24;
402         }
403 
404         if (stellaris_tx_thr_reached(s) && stellaris_txpacket_complete(s)) {
405             stellaris_enet_send(s);
406         }
407         break;
408     case 0x14: /* IA0 */
409         s->conf.macaddr.a[0] = value;
410         s->conf.macaddr.a[1] = value >> 8;
411         s->conf.macaddr.a[2] = value >> 16;
412         s->conf.macaddr.a[3] = value >> 24;
413         break;
414     case 0x18: /* IA1 */
415         s->conf.macaddr.a[4] = value;
416         s->conf.macaddr.a[5] = value >> 8;
417         break;
418     case 0x1c: /* THR */
419         s->thr = value;
420         break;
421     case 0x20: /* MCTL */
422         /* TODO: MII registers aren't modelled.
423          * Clear START, indicating that the operation completes immediately.
424          */
425         s->mctl = value & ~1;
426         break;
427     case 0x24: /* MDV */
428         s->mdv = value;
429         break;
430     case 0x28: /* MADD */
431         /* ignored.  */
432         break;
433     case 0x2c: /* MTXD */
434         s->mtxd = value & 0xff;
435         break;
436     case 0x38: /* TR */
437         if (value & 1) {
438             stellaris_enet_send(s);
439         }
440         break;
441     case 0x30: /* MRXD */
442     case 0x34: /* NP */
443         /* Ignored.  */
444     case 0x3c: /* Undocuented: Timestamp? */
445         /* Ignored.  */
446         break;
447     default:
448         qemu_log_mask(LOG_GUEST_ERROR, "stellaris_enet_wr%d: Illegal register "
449                                        "0x02%" HWADDR_PRIx " = 0x%" PRIx64 "\n",
450                       size * 8, offset, value);
451     }
452 }
453 
454 static const MemoryRegionOps stellaris_enet_ops = {
455     .read = stellaris_enet_read,
456     .write = stellaris_enet_write,
457     .endianness = DEVICE_NATIVE_ENDIAN,
458 };
459 
460 static void stellaris_enet_reset(DeviceState *dev)
461 {
462     stellaris_enet_state *s =  STELLARIS_ENET(dev);
463 
464     s->mdv = 0x80;
465     s->rctl = SE_RCTL_BADCRC;
466     s->im = SE_INT_PHY | SE_INT_MD | SE_INT_RXER | SE_INT_FOV | SE_INT_TXEMP
467             | SE_INT_TXER | SE_INT_RX;
468     s->thr = 0x3f;
469     s->tx_fifo_len = 0;
470 }
471 
472 static NetClientInfo net_stellaris_enet_info = {
473     .type = NET_CLIENT_DRIVER_NIC,
474     .size = sizeof(NICState),
475     .receive = stellaris_enet_receive,
476 };
477 
478 static void stellaris_enet_realize(DeviceState *dev, Error **errp)
479 {
480     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
481     stellaris_enet_state *s = STELLARIS_ENET(dev);
482 
483     memory_region_init_io(&s->mmio, OBJECT(s), &stellaris_enet_ops, s,
484                           "stellaris_enet", 0x1000);
485     sysbus_init_mmio(sbd, &s->mmio);
486     sysbus_init_irq(sbd, &s->irq);
487     qemu_macaddr_default_if_unset(&s->conf.macaddr);
488 
489     s->nic = qemu_new_nic(&net_stellaris_enet_info, &s->conf,
490                           object_get_typename(OBJECT(dev)), dev->id, s);
491     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
492 }
493 
494 static Property stellaris_enet_properties[] = {
495     DEFINE_NIC_PROPERTIES(stellaris_enet_state, conf),
496     DEFINE_PROP_END_OF_LIST(),
497 };
498 
499 static void stellaris_enet_class_init(ObjectClass *klass, void *data)
500 {
501     DeviceClass *dc = DEVICE_CLASS(klass);
502 
503     dc->realize = stellaris_enet_realize;
504     dc->reset = stellaris_enet_reset;
505     dc->props = stellaris_enet_properties;
506     dc->vmsd = &vmstate_stellaris_enet;
507 }
508 
509 static const TypeInfo stellaris_enet_info = {
510     .name          = TYPE_STELLARIS_ENET,
511     .parent        = TYPE_SYS_BUS_DEVICE,
512     .instance_size = sizeof(stellaris_enet_state),
513     .class_init    = stellaris_enet_class_init,
514 };
515 
516 static void stellaris_enet_register_types(void)
517 {
518     type_register_static(&stellaris_enet_info);
519 }
520 
521 type_init(stellaris_enet_register_types)
522