xref: /openbmc/qemu/hw/net/stellaris_enet.c (revision 3d9569b8)
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 
10 #include "qemu/osdep.h"
11 #include "hw/sysbus.h"
12 #include "net/net.h"
13 #include "qemu/log.h"
14 #include "qemu/module.h"
15 #include <zlib.h>
16 
17 //#define DEBUG_STELLARIS_ENET 1
18 
19 #ifdef DEBUG_STELLARIS_ENET
20 #define DPRINTF(fmt, ...) \
21 do { printf("stellaris_enet: " fmt , ## __VA_ARGS__); } while (0)
22 #define BADF(fmt, ...) \
23 do { fprintf(stderr, "stellaris_enet: error: " fmt , ## __VA_ARGS__); exit(1);} while (0)
24 #else
25 #define DPRINTF(fmt, ...) do {} while(0)
26 #define BADF(fmt, ...) \
27 do { fprintf(stderr, "stellaris_enet: error: " fmt , ## __VA_ARGS__);} while (0)
28 #endif
29 
30 #define SE_INT_RX       0x01
31 #define SE_INT_TXER     0x02
32 #define SE_INT_TXEMP    0x04
33 #define SE_INT_FOV      0x08
34 #define SE_INT_RXER     0x10
35 #define SE_INT_MD       0x20
36 #define SE_INT_PHY      0x40
37 
38 #define SE_RCTL_RXEN    0x01
39 #define SE_RCTL_AMUL    0x02
40 #define SE_RCTL_PRMS    0x04
41 #define SE_RCTL_BADCRC  0x08
42 #define SE_RCTL_RSTFIFO 0x10
43 
44 #define SE_TCTL_TXEN    0x01
45 #define SE_TCTL_PADEN   0x02
46 #define SE_TCTL_CRC     0x04
47 #define SE_TCTL_DUPLEX  0x08
48 
49 #define TYPE_STELLARIS_ENET "stellaris_enet"
50 #define STELLARIS_ENET(obj) \
51     OBJECT_CHECK(stellaris_enet_state, (obj), TYPE_STELLARIS_ENET)
52 
53 typedef struct {
54     uint8_t data[2048];
55     uint32_t len;
56 } StellarisEnetRxFrame;
57 
58 typedef struct {
59     SysBusDevice parent_obj;
60 
61     uint32_t ris;
62     uint32_t im;
63     uint32_t rctl;
64     uint32_t tctl;
65     uint32_t thr;
66     uint32_t mctl;
67     uint32_t mdv;
68     uint32_t mtxd;
69     uint32_t mrxd;
70     uint32_t np;
71     uint32_t tx_fifo_len;
72     uint8_t tx_fifo[2048];
73     /* Real hardware has a 2k fifo, which works out to be at most 31 packets.
74        We implement a full 31 packet fifo.  */
75     StellarisEnetRxFrame rx[31];
76     uint32_t rx_fifo_offset;
77     uint32_t next_packet;
78     NICState *nic;
79     NICConf conf;
80     qemu_irq irq;
81     MemoryRegion mmio;
82 } stellaris_enet_state;
83 
84 static const VMStateDescription vmstate_rx_frame = {
85     .name = "stellaris_enet/rx_frame",
86     .version_id = 1,
87     .minimum_version_id = 1,
88     .fields = (VMStateField[]) {
89         VMSTATE_UINT8_ARRAY(data, StellarisEnetRxFrame, 2048),
90         VMSTATE_UINT32(len, StellarisEnetRxFrame),
91         VMSTATE_END_OF_LIST()
92     }
93 };
94 
95 static int stellaris_enet_post_load(void *opaque, int version_id)
96 {
97     stellaris_enet_state *s = opaque;
98     int i;
99 
100     /* Sanitize inbound state. Note that next_packet is an index but
101      * np is a size; hence their valid upper bounds differ.
102      */
103     if (s->next_packet >= ARRAY_SIZE(s->rx)) {
104         return -1;
105     }
106 
107     if (s->np > ARRAY_SIZE(s->rx)) {
108         return -1;
109     }
110 
111     for (i = 0; i < ARRAY_SIZE(s->rx); i++) {
112         if (s->rx[i].len > ARRAY_SIZE(s->rx[i].data)) {
113             return -1;
114         }
115     }
116 
117     if (s->rx_fifo_offset > ARRAY_SIZE(s->rx[0].data) - 4) {
118         return -1;
119     }
120 
121     if (s->tx_fifo_len > ARRAY_SIZE(s->tx_fifo)) {
122         return -1;
123     }
124 
125     return 0;
126 }
127 
128 static const VMStateDescription vmstate_stellaris_enet = {
129     .name = "stellaris_enet",
130     .version_id = 2,
131     .minimum_version_id = 2,
132     .post_load = stellaris_enet_post_load,
133     .fields = (VMStateField[]) {
134         VMSTATE_UINT32(ris, stellaris_enet_state),
135         VMSTATE_UINT32(im, stellaris_enet_state),
136         VMSTATE_UINT32(rctl, stellaris_enet_state),
137         VMSTATE_UINT32(tctl, stellaris_enet_state),
138         VMSTATE_UINT32(thr, stellaris_enet_state),
139         VMSTATE_UINT32(mctl, stellaris_enet_state),
140         VMSTATE_UINT32(mdv, stellaris_enet_state),
141         VMSTATE_UINT32(mtxd, stellaris_enet_state),
142         VMSTATE_UINT32(mrxd, stellaris_enet_state),
143         VMSTATE_UINT32(np, stellaris_enet_state),
144         VMSTATE_UINT32(tx_fifo_len, stellaris_enet_state),
145         VMSTATE_UINT8_ARRAY(tx_fifo, stellaris_enet_state, 2048),
146         VMSTATE_STRUCT_ARRAY(rx, stellaris_enet_state, 31, 1,
147                              vmstate_rx_frame, StellarisEnetRxFrame),
148         VMSTATE_UINT32(rx_fifo_offset, stellaris_enet_state),
149         VMSTATE_UINT32(next_packet, stellaris_enet_state),
150         VMSTATE_END_OF_LIST()
151     }
152 };
153 
154 static void stellaris_enet_update(stellaris_enet_state *s)
155 {
156     qemu_set_irq(s->irq, (s->ris & s->im) != 0);
157 }
158 
159 /* Return the data length of the packet currently being assembled
160  * in the TX fifo.
161  */
162 static inline int stellaris_txpacket_datalen(stellaris_enet_state *s)
163 {
164     return s->tx_fifo[0] | (s->tx_fifo[1] << 8);
165 }
166 
167 /* Return true if the packet currently in the TX FIFO is complete,
168 * ie the FIFO holds enough bytes for the data length, ethernet header,
169 * payload and optionally CRC.
170 */
171 static inline bool stellaris_txpacket_complete(stellaris_enet_state *s)
172 {
173     int framelen = stellaris_txpacket_datalen(s);
174     framelen += 16;
175     if (!(s->tctl & SE_TCTL_CRC)) {
176         framelen += 4;
177     }
178     /* Cover the corner case of a 2032 byte payload with auto-CRC disabled:
179      * this requires more bytes than will fit in the FIFO. It's not totally
180      * clear how the h/w handles this, but if using threshold-based TX
181      * it will definitely try to transmit something.
182      */
183     framelen = MIN(framelen, ARRAY_SIZE(s->tx_fifo));
184     return s->tx_fifo_len >= framelen;
185 }
186 
187 /* Return true if the TX FIFO threshold is enabled and the FIFO
188  * has filled enough to reach it.
189  */
190 static inline bool stellaris_tx_thr_reached(stellaris_enet_state *s)
191 {
192     return (s->thr < 0x3f &&
193             (s->tx_fifo_len >= 4 * (s->thr * 8 + 1)));
194 }
195 
196 /* Send the packet currently in the TX FIFO */
197 static void stellaris_enet_send(stellaris_enet_state *s)
198 {
199     int framelen = stellaris_txpacket_datalen(s);
200 
201     /* Ethernet header is in the FIFO but not in the datacount.
202      * We don't implement explicit CRC, so just ignore any
203      * CRC value in the FIFO.
204      */
205     framelen += 14;
206     if ((s->tctl & SE_TCTL_PADEN) && framelen < 60) {
207         memset(&s->tx_fifo[framelen + 2], 0, 60 - framelen);
208         framelen = 60;
209     }
210     /* This MIN will have no effect unless the FIFO data is corrupt
211      * (eg bad data from an incoming migration); otherwise the check
212      * on the datalen at the start of writing the data into the FIFO
213      * will have caught this. Silently write a corrupt half-packet,
214      * which is what the hardware does in FIFO underrun situations.
215      */
216     framelen = MIN(framelen, ARRAY_SIZE(s->tx_fifo) - 2);
217     qemu_send_packet(qemu_get_queue(s->nic), s->tx_fifo + 2, framelen);
218     s->tx_fifo_len = 0;
219     s->ris |= SE_INT_TXEMP;
220     stellaris_enet_update(s);
221     DPRINTF("Done TX\n");
222 }
223 
224 /* TODO: Implement MAC address filtering.  */
225 static ssize_t stellaris_enet_receive(NetClientState *nc, const uint8_t *buf, size_t size)
226 {
227     stellaris_enet_state *s = qemu_get_nic_opaque(nc);
228     int n;
229     uint8_t *p;
230     uint32_t crc;
231 
232     if ((s->rctl & SE_RCTL_RXEN) == 0)
233         return -1;
234     if (s->np >= 31) {
235         return 0;
236     }
237 
238     DPRINTF("Received packet len=%zu\n", size);
239     n = s->next_packet + s->np;
240     if (n >= 31)
241         n -= 31;
242 
243     if (size >= sizeof(s->rx[n].data) - 6) {
244         /* If the packet won't fit into the
245          * emulated 2K RAM, this is reported
246          * as a FIFO overrun error.
247          */
248         s->ris |= SE_INT_FOV;
249         stellaris_enet_update(s);
250         return -1;
251     }
252 
253     s->np++;
254     s->rx[n].len = size + 6;
255     p = s->rx[n].data;
256     *(p++) = (size + 6);
257     *(p++) = (size + 6) >> 8;
258     memcpy (p, buf, size);
259     p += size;
260     crc = crc32(~0, buf, size);
261     *(p++) = crc;
262     *(p++) = crc >> 8;
263     *(p++) = crc >> 16;
264     *(p++) = crc >> 24;
265     /* Clear the remaining bytes in the last word.  */
266     if ((size & 3) != 2) {
267         memset(p, 0, (6 - size) & 3);
268     }
269 
270     s->ris |= SE_INT_RX;
271     stellaris_enet_update(s);
272 
273     return size;
274 }
275 
276 static int stellaris_enet_can_receive(stellaris_enet_state *s)
277 {
278     return (s->np < 31);
279 }
280 
281 static uint64_t stellaris_enet_read(void *opaque, hwaddr offset,
282                                     unsigned size)
283 {
284     stellaris_enet_state *s = (stellaris_enet_state *)opaque;
285     uint32_t val;
286 
287     switch (offset) {
288     case 0x00: /* RIS */
289         DPRINTF("IRQ status %02x\n", s->ris);
290         return s->ris;
291     case 0x04: /* IM */
292         return s->im;
293     case 0x08: /* RCTL */
294         return s->rctl;
295     case 0x0c: /* TCTL */
296         return s->tctl;
297     case 0x10: /* DATA */
298     {
299         uint8_t *rx_fifo;
300 
301         if (s->np == 0) {
302             BADF("RX underflow\n");
303             return 0;
304         }
305 
306         rx_fifo = s->rx[s->next_packet].data + s->rx_fifo_offset;
307 
308         val = rx_fifo[0] | (rx_fifo[1] << 8) | (rx_fifo[2] << 16)
309               | (rx_fifo[3] << 24);
310         s->rx_fifo_offset += 4;
311         if (s->rx_fifo_offset >= s->rx[s->next_packet].len) {
312             s->rx_fifo_offset = 0;
313             s->next_packet++;
314             if (s->next_packet >= 31)
315                 s->next_packet = 0;
316             s->np--;
317             DPRINTF("RX done np=%d\n", s->np);
318             if (!s->np && stellaris_enet_can_receive(s)) {
319                 qemu_flush_queued_packets(qemu_get_queue(s->nic));
320             }
321         }
322         return val;
323     }
324     case 0x14: /* IA0 */
325         return s->conf.macaddr.a[0] | (s->conf.macaddr.a[1] << 8)
326             | (s->conf.macaddr.a[2] << 16)
327             | ((uint32_t)s->conf.macaddr.a[3] << 24);
328     case 0x18: /* IA1 */
329         return s->conf.macaddr.a[4] | (s->conf.macaddr.a[5] << 8);
330     case 0x1c: /* THR */
331         return s->thr;
332     case 0x20: /* MCTL */
333         return s->mctl;
334     case 0x24: /* MDV */
335         return s->mdv;
336     case 0x28: /* MADD */
337         return 0;
338     case 0x2c: /* MTXD */
339         return s->mtxd;
340     case 0x30: /* MRXD */
341         return s->mrxd;
342     case 0x34: /* NP */
343         return s->np;
344     case 0x38: /* TR */
345         return 0;
346     case 0x3c: /* Undocumented: Timestamp? */
347         return 0;
348     default:
349         qemu_log_mask(LOG_GUEST_ERROR, "stellaris_enet_rd%d: Illegal register"
350                                        " 0x02%" HWADDR_PRIx "\n",
351                       size * 8, offset);
352         return 0;
353     }
354 }
355 
356 static void stellaris_enet_write(void *opaque, hwaddr offset,
357                                  uint64_t value, unsigned size)
358 {
359     stellaris_enet_state *s = (stellaris_enet_state *)opaque;
360 
361     switch (offset) {
362     case 0x00: /* IACK */
363         s->ris &= ~value;
364         DPRINTF("IRQ ack %02" PRIx64 "/%02x\n", value, s->ris);
365         stellaris_enet_update(s);
366         /* Clearing TXER also resets the TX fifo.  */
367         if (value & SE_INT_TXER) {
368             s->tx_fifo_len = 0;
369         }
370         break;
371     case 0x04: /* IM */
372         DPRINTF("IRQ mask %02" PRIx64 "/%02x\n", value, s->ris);
373         s->im = value;
374         stellaris_enet_update(s);
375         break;
376     case 0x08: /* RCTL */
377         s->rctl = value;
378         if (value & SE_RCTL_RSTFIFO) {
379             s->np = 0;
380             s->rx_fifo_offset = 0;
381             stellaris_enet_update(s);
382         }
383         break;
384     case 0x0c: /* TCTL */
385         s->tctl = value;
386         break;
387     case 0x10: /* DATA */
388         if (s->tx_fifo_len == 0) {
389             /* The first word is special, it contains the data length */
390             int framelen = value & 0xffff;
391             if (framelen > 2032) {
392                 DPRINTF("TX frame too long (%d)\n", framelen);
393                 s->ris |= SE_INT_TXER;
394                 stellaris_enet_update(s);
395                 break;
396             }
397         }
398 
399         if (s->tx_fifo_len + 4 <= ARRAY_SIZE(s->tx_fifo)) {
400             s->tx_fifo[s->tx_fifo_len++] = value;
401             s->tx_fifo[s->tx_fifo_len++] = value >> 8;
402             s->tx_fifo[s->tx_fifo_len++] = value >> 16;
403             s->tx_fifo[s->tx_fifo_len++] = value >> 24;
404         }
405 
406         if (stellaris_tx_thr_reached(s) && stellaris_txpacket_complete(s)) {
407             stellaris_enet_send(s);
408         }
409         break;
410     case 0x14: /* IA0 */
411         s->conf.macaddr.a[0] = value;
412         s->conf.macaddr.a[1] = value >> 8;
413         s->conf.macaddr.a[2] = value >> 16;
414         s->conf.macaddr.a[3] = value >> 24;
415         break;
416     case 0x18: /* IA1 */
417         s->conf.macaddr.a[4] = value;
418         s->conf.macaddr.a[5] = value >> 8;
419         break;
420     case 0x1c: /* THR */
421         s->thr = value;
422         break;
423     case 0x20: /* MCTL */
424         /* TODO: MII registers aren't modelled.
425          * Clear START, indicating that the operation completes immediately.
426          */
427         s->mctl = value & ~1;
428         break;
429     case 0x24: /* MDV */
430         s->mdv = value;
431         break;
432     case 0x28: /* MADD */
433         /* ignored.  */
434         break;
435     case 0x2c: /* MTXD */
436         s->mtxd = value & 0xff;
437         break;
438     case 0x38: /* TR */
439         if (value & 1) {
440             stellaris_enet_send(s);
441         }
442         break;
443     case 0x30: /* MRXD */
444     case 0x34: /* NP */
445         /* Ignored.  */
446     case 0x3c: /* Undocuented: Timestamp? */
447         /* Ignored.  */
448         break;
449     default:
450         qemu_log_mask(LOG_GUEST_ERROR, "stellaris_enet_wr%d: Illegal register "
451                                        "0x02%" HWADDR_PRIx " = 0x%" PRIx64 "\n",
452                       size * 8, offset, value);
453     }
454 }
455 
456 static const MemoryRegionOps stellaris_enet_ops = {
457     .read = stellaris_enet_read,
458     .write = stellaris_enet_write,
459     .endianness = DEVICE_NATIVE_ENDIAN,
460 };
461 
462 static void stellaris_enet_reset(DeviceState *dev)
463 {
464     stellaris_enet_state *s =  STELLARIS_ENET(dev);
465 
466     s->mdv = 0x80;
467     s->rctl = SE_RCTL_BADCRC;
468     s->im = SE_INT_PHY | SE_INT_MD | SE_INT_RXER | SE_INT_FOV | SE_INT_TXEMP
469             | SE_INT_TXER | SE_INT_RX;
470     s->thr = 0x3f;
471     s->tx_fifo_len = 0;
472 }
473 
474 static NetClientInfo net_stellaris_enet_info = {
475     .type = NET_CLIENT_DRIVER_NIC,
476     .size = sizeof(NICState),
477     .receive = stellaris_enet_receive,
478 };
479 
480 static void stellaris_enet_realize(DeviceState *dev, Error **errp)
481 {
482     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
483     stellaris_enet_state *s = STELLARIS_ENET(dev);
484 
485     memory_region_init_io(&s->mmio, OBJECT(s), &stellaris_enet_ops, s,
486                           "stellaris_enet", 0x1000);
487     sysbus_init_mmio(sbd, &s->mmio);
488     sysbus_init_irq(sbd, &s->irq);
489     qemu_macaddr_default_if_unset(&s->conf.macaddr);
490 
491     s->nic = qemu_new_nic(&net_stellaris_enet_info, &s->conf,
492                           object_get_typename(OBJECT(dev)), dev->id, s);
493     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
494 }
495 
496 static Property stellaris_enet_properties[] = {
497     DEFINE_NIC_PROPERTIES(stellaris_enet_state, conf),
498     DEFINE_PROP_END_OF_LIST(),
499 };
500 
501 static void stellaris_enet_class_init(ObjectClass *klass, void *data)
502 {
503     DeviceClass *dc = DEVICE_CLASS(klass);
504 
505     dc->realize = stellaris_enet_realize;
506     dc->reset = stellaris_enet_reset;
507     dc->props = stellaris_enet_properties;
508     dc->vmsd = &vmstate_stellaris_enet;
509 }
510 
511 static const TypeInfo stellaris_enet_info = {
512     .name          = TYPE_STELLARIS_ENET,
513     .parent        = TYPE_SYS_BUS_DEVICE,
514     .instance_size = sizeof(stellaris_enet_state),
515     .class_init    = stellaris_enet_class_init,
516 };
517 
518 static void stellaris_enet_register_types(void)
519 {
520     type_register_static(&stellaris_enet_info);
521 }
522 
523 type_init(stellaris_enet_register_types)
524