xref: /openbmc/qemu/hw/net/stellaris_enet.c (revision 6a0acfff)
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/irq.h"
12 #include "hw/sysbus.h"
13 #include "net/net.h"
14 #include "qemu/log.h"
15 #include "qemu/module.h"
16 #include <zlib.h>
17 
18 //#define DEBUG_STELLARIS_ENET 1
19 
20 #ifdef DEBUG_STELLARIS_ENET
21 #define DPRINTF(fmt, ...) \
22 do { printf("stellaris_enet: " fmt , ## __VA_ARGS__); } while (0)
23 #define BADF(fmt, ...) \
24 do { fprintf(stderr, "stellaris_enet: error: " fmt , ## __VA_ARGS__); exit(1);} while (0)
25 #else
26 #define DPRINTF(fmt, ...) do {} while(0)
27 #define BADF(fmt, ...) \
28 do { fprintf(stderr, "stellaris_enet: error: " fmt , ## __VA_ARGS__);} while (0)
29 #endif
30 
31 #define SE_INT_RX       0x01
32 #define SE_INT_TXER     0x02
33 #define SE_INT_TXEMP    0x04
34 #define SE_INT_FOV      0x08
35 #define SE_INT_RXER     0x10
36 #define SE_INT_MD       0x20
37 #define SE_INT_PHY      0x40
38 
39 #define SE_RCTL_RXEN    0x01
40 #define SE_RCTL_AMUL    0x02
41 #define SE_RCTL_PRMS    0x04
42 #define SE_RCTL_BADCRC  0x08
43 #define SE_RCTL_RSTFIFO 0x10
44 
45 #define SE_TCTL_TXEN    0x01
46 #define SE_TCTL_PADEN   0x02
47 #define SE_TCTL_CRC     0x04
48 #define SE_TCTL_DUPLEX  0x08
49 
50 #define TYPE_STELLARIS_ENET "stellaris_enet"
51 #define STELLARIS_ENET(obj) \
52     OBJECT_CHECK(stellaris_enet_state, (obj), TYPE_STELLARIS_ENET)
53 
54 typedef struct {
55     uint8_t data[2048];
56     uint32_t len;
57 } StellarisEnetRxFrame;
58 
59 typedef struct {
60     SysBusDevice parent_obj;
61 
62     uint32_t ris;
63     uint32_t im;
64     uint32_t rctl;
65     uint32_t tctl;
66     uint32_t thr;
67     uint32_t mctl;
68     uint32_t mdv;
69     uint32_t mtxd;
70     uint32_t mrxd;
71     uint32_t np;
72     uint32_t tx_fifo_len;
73     uint8_t tx_fifo[2048];
74     /* Real hardware has a 2k fifo, which works out to be at most 31 packets.
75        We implement a full 31 packet fifo.  */
76     StellarisEnetRxFrame rx[31];
77     uint32_t rx_fifo_offset;
78     uint32_t next_packet;
79     NICState *nic;
80     NICConf conf;
81     qemu_irq irq;
82     MemoryRegion mmio;
83 } stellaris_enet_state;
84 
85 static const VMStateDescription vmstate_rx_frame = {
86     .name = "stellaris_enet/rx_frame",
87     .version_id = 1,
88     .minimum_version_id = 1,
89     .fields = (VMStateField[]) {
90         VMSTATE_UINT8_ARRAY(data, StellarisEnetRxFrame, 2048),
91         VMSTATE_UINT32(len, StellarisEnetRxFrame),
92         VMSTATE_END_OF_LIST()
93     }
94 };
95 
96 static int stellaris_enet_post_load(void *opaque, int version_id)
97 {
98     stellaris_enet_state *s = opaque;
99     int i;
100 
101     /* Sanitize inbound state. Note that next_packet is an index but
102      * np is a size; hence their valid upper bounds differ.
103      */
104     if (s->next_packet >= ARRAY_SIZE(s->rx)) {
105         return -1;
106     }
107 
108     if (s->np > ARRAY_SIZE(s->rx)) {
109         return -1;
110     }
111 
112     for (i = 0; i < ARRAY_SIZE(s->rx); i++) {
113         if (s->rx[i].len > ARRAY_SIZE(s->rx[i].data)) {
114             return -1;
115         }
116     }
117 
118     if (s->rx_fifo_offset > ARRAY_SIZE(s->rx[0].data) - 4) {
119         return -1;
120     }
121 
122     if (s->tx_fifo_len > ARRAY_SIZE(s->tx_fifo)) {
123         return -1;
124     }
125 
126     return 0;
127 }
128 
129 static const VMStateDescription vmstate_stellaris_enet = {
130     .name = "stellaris_enet",
131     .version_id = 2,
132     .minimum_version_id = 2,
133     .post_load = stellaris_enet_post_load,
134     .fields = (VMStateField[]) {
135         VMSTATE_UINT32(ris, stellaris_enet_state),
136         VMSTATE_UINT32(im, stellaris_enet_state),
137         VMSTATE_UINT32(rctl, stellaris_enet_state),
138         VMSTATE_UINT32(tctl, stellaris_enet_state),
139         VMSTATE_UINT32(thr, stellaris_enet_state),
140         VMSTATE_UINT32(mctl, stellaris_enet_state),
141         VMSTATE_UINT32(mdv, stellaris_enet_state),
142         VMSTATE_UINT32(mtxd, stellaris_enet_state),
143         VMSTATE_UINT32(mrxd, stellaris_enet_state),
144         VMSTATE_UINT32(np, stellaris_enet_state),
145         VMSTATE_UINT32(tx_fifo_len, stellaris_enet_state),
146         VMSTATE_UINT8_ARRAY(tx_fifo, stellaris_enet_state, 2048),
147         VMSTATE_STRUCT_ARRAY(rx, stellaris_enet_state, 31, 1,
148                              vmstate_rx_frame, StellarisEnetRxFrame),
149         VMSTATE_UINT32(rx_fifo_offset, stellaris_enet_state),
150         VMSTATE_UINT32(next_packet, stellaris_enet_state),
151         VMSTATE_END_OF_LIST()
152     }
153 };
154 
155 static void stellaris_enet_update(stellaris_enet_state *s)
156 {
157     qemu_set_irq(s->irq, (s->ris & s->im) != 0);
158 }
159 
160 /* Return the data length of the packet currently being assembled
161  * in the TX fifo.
162  */
163 static inline int stellaris_txpacket_datalen(stellaris_enet_state *s)
164 {
165     return s->tx_fifo[0] | (s->tx_fifo[1] << 8);
166 }
167 
168 /* Return true if the packet currently in the TX FIFO is complete,
169 * ie the FIFO holds enough bytes for the data length, ethernet header,
170 * payload and optionally CRC.
171 */
172 static inline bool stellaris_txpacket_complete(stellaris_enet_state *s)
173 {
174     int framelen = stellaris_txpacket_datalen(s);
175     framelen += 16;
176     if (!(s->tctl & SE_TCTL_CRC)) {
177         framelen += 4;
178     }
179     /* Cover the corner case of a 2032 byte payload with auto-CRC disabled:
180      * this requires more bytes than will fit in the FIFO. It's not totally
181      * clear how the h/w handles this, but if using threshold-based TX
182      * it will definitely try to transmit something.
183      */
184     framelen = MIN(framelen, ARRAY_SIZE(s->tx_fifo));
185     return s->tx_fifo_len >= framelen;
186 }
187 
188 /* Return true if the TX FIFO threshold is enabled and the FIFO
189  * has filled enough to reach it.
190  */
191 static inline bool stellaris_tx_thr_reached(stellaris_enet_state *s)
192 {
193     return (s->thr < 0x3f &&
194             (s->tx_fifo_len >= 4 * (s->thr * 8 + 1)));
195 }
196 
197 /* Send the packet currently in the TX FIFO */
198 static void stellaris_enet_send(stellaris_enet_state *s)
199 {
200     int framelen = stellaris_txpacket_datalen(s);
201 
202     /* Ethernet header is in the FIFO but not in the datacount.
203      * We don't implement explicit CRC, so just ignore any
204      * CRC value in the FIFO.
205      */
206     framelen += 14;
207     if ((s->tctl & SE_TCTL_PADEN) && framelen < 60) {
208         memset(&s->tx_fifo[framelen + 2], 0, 60 - framelen);
209         framelen = 60;
210     }
211     /* This MIN will have no effect unless the FIFO data is corrupt
212      * (eg bad data from an incoming migration); otherwise the check
213      * on the datalen at the start of writing the data into the FIFO
214      * will have caught this. Silently write a corrupt half-packet,
215      * which is what the hardware does in FIFO underrun situations.
216      */
217     framelen = MIN(framelen, ARRAY_SIZE(s->tx_fifo) - 2);
218     qemu_send_packet(qemu_get_queue(s->nic), s->tx_fifo + 2, framelen);
219     s->tx_fifo_len = 0;
220     s->ris |= SE_INT_TXEMP;
221     stellaris_enet_update(s);
222     DPRINTF("Done TX\n");
223 }
224 
225 /* TODO: Implement MAC address filtering.  */
226 static ssize_t stellaris_enet_receive(NetClientState *nc, const uint8_t *buf, size_t size)
227 {
228     stellaris_enet_state *s = qemu_get_nic_opaque(nc);
229     int n;
230     uint8_t *p;
231     uint32_t crc;
232 
233     if ((s->rctl & SE_RCTL_RXEN) == 0)
234         return -1;
235     if (s->np >= 31) {
236         return 0;
237     }
238 
239     DPRINTF("Received packet len=%zu\n", size);
240     n = s->next_packet + s->np;
241     if (n >= 31)
242         n -= 31;
243 
244     if (size >= sizeof(s->rx[n].data) - 6) {
245         /* If the packet won't fit into the
246          * emulated 2K RAM, this is reported
247          * as a FIFO overrun error.
248          */
249         s->ris |= SE_INT_FOV;
250         stellaris_enet_update(s);
251         return -1;
252     }
253 
254     s->np++;
255     s->rx[n].len = size + 6;
256     p = s->rx[n].data;
257     *(p++) = (size + 6);
258     *(p++) = (size + 6) >> 8;
259     memcpy (p, buf, size);
260     p += size;
261     crc = crc32(~0, buf, size);
262     *(p++) = crc;
263     *(p++) = crc >> 8;
264     *(p++) = crc >> 16;
265     *(p++) = crc >> 24;
266     /* Clear the remaining bytes in the last word.  */
267     if ((size & 3) != 2) {
268         memset(p, 0, (6 - size) & 3);
269     }
270 
271     s->ris |= SE_INT_RX;
272     stellaris_enet_update(s);
273 
274     return size;
275 }
276 
277 static int stellaris_enet_can_receive(stellaris_enet_state *s)
278 {
279     return (s->np < 31);
280 }
281 
282 static uint64_t stellaris_enet_read(void *opaque, hwaddr offset,
283                                     unsigned size)
284 {
285     stellaris_enet_state *s = (stellaris_enet_state *)opaque;
286     uint32_t val;
287 
288     switch (offset) {
289     case 0x00: /* RIS */
290         DPRINTF("IRQ status %02x\n", s->ris);
291         return s->ris;
292     case 0x04: /* IM */
293         return s->im;
294     case 0x08: /* RCTL */
295         return s->rctl;
296     case 0x0c: /* TCTL */
297         return s->tctl;
298     case 0x10: /* DATA */
299     {
300         uint8_t *rx_fifo;
301 
302         if (s->np == 0) {
303             BADF("RX underflow\n");
304             return 0;
305         }
306 
307         rx_fifo = s->rx[s->next_packet].data + s->rx_fifo_offset;
308 
309         val = rx_fifo[0] | (rx_fifo[1] << 8) | (rx_fifo[2] << 16)
310               | (rx_fifo[3] << 24);
311         s->rx_fifo_offset += 4;
312         if (s->rx_fifo_offset >= s->rx[s->next_packet].len) {
313             s->rx_fifo_offset = 0;
314             s->next_packet++;
315             if (s->next_packet >= 31)
316                 s->next_packet = 0;
317             s->np--;
318             DPRINTF("RX done np=%d\n", s->np);
319             if (!s->np && stellaris_enet_can_receive(s)) {
320                 qemu_flush_queued_packets(qemu_get_queue(s->nic));
321             }
322         }
323         return val;
324     }
325     case 0x14: /* IA0 */
326         return s->conf.macaddr.a[0] | (s->conf.macaddr.a[1] << 8)
327             | (s->conf.macaddr.a[2] << 16)
328             | ((uint32_t)s->conf.macaddr.a[3] << 24);
329     case 0x18: /* IA1 */
330         return s->conf.macaddr.a[4] | (s->conf.macaddr.a[5] << 8);
331     case 0x1c: /* THR */
332         return s->thr;
333     case 0x20: /* MCTL */
334         return s->mctl;
335     case 0x24: /* MDV */
336         return s->mdv;
337     case 0x28: /* MADD */
338         return 0;
339     case 0x2c: /* MTXD */
340         return s->mtxd;
341     case 0x30: /* MRXD */
342         return s->mrxd;
343     case 0x34: /* NP */
344         return s->np;
345     case 0x38: /* TR */
346         return 0;
347     case 0x3c: /* Undocumented: Timestamp? */
348         return 0;
349     default:
350         qemu_log_mask(LOG_GUEST_ERROR, "stellaris_enet_rd%d: Illegal register"
351                                        " 0x02%" HWADDR_PRIx "\n",
352                       size * 8, offset);
353         return 0;
354     }
355 }
356 
357 static void stellaris_enet_write(void *opaque, hwaddr offset,
358                                  uint64_t value, unsigned size)
359 {
360     stellaris_enet_state *s = (stellaris_enet_state *)opaque;
361 
362     switch (offset) {
363     case 0x00: /* IACK */
364         s->ris &= ~value;
365         DPRINTF("IRQ ack %02" PRIx64 "/%02x\n", value, s->ris);
366         stellaris_enet_update(s);
367         /* Clearing TXER also resets the TX fifo.  */
368         if (value & SE_INT_TXER) {
369             s->tx_fifo_len = 0;
370         }
371         break;
372     case 0x04: /* IM */
373         DPRINTF("IRQ mask %02" PRIx64 "/%02x\n", value, s->ris);
374         s->im = value;
375         stellaris_enet_update(s);
376         break;
377     case 0x08: /* RCTL */
378         s->rctl = value;
379         if (value & SE_RCTL_RSTFIFO) {
380             s->np = 0;
381             s->rx_fifo_offset = 0;
382             stellaris_enet_update(s);
383         }
384         break;
385     case 0x0c: /* TCTL */
386         s->tctl = value;
387         break;
388     case 0x10: /* DATA */
389         if (s->tx_fifo_len == 0) {
390             /* The first word is special, it contains the data length */
391             int framelen = value & 0xffff;
392             if (framelen > 2032) {
393                 DPRINTF("TX frame too long (%d)\n", framelen);
394                 s->ris |= SE_INT_TXER;
395                 stellaris_enet_update(s);
396                 break;
397             }
398         }
399 
400         if (s->tx_fifo_len + 4 <= ARRAY_SIZE(s->tx_fifo)) {
401             s->tx_fifo[s->tx_fifo_len++] = value;
402             s->tx_fifo[s->tx_fifo_len++] = value >> 8;
403             s->tx_fifo[s->tx_fifo_len++] = value >> 16;
404             s->tx_fifo[s->tx_fifo_len++] = value >> 24;
405         }
406 
407         if (stellaris_tx_thr_reached(s) && stellaris_txpacket_complete(s)) {
408             stellaris_enet_send(s);
409         }
410         break;
411     case 0x14: /* IA0 */
412         s->conf.macaddr.a[0] = value;
413         s->conf.macaddr.a[1] = value >> 8;
414         s->conf.macaddr.a[2] = value >> 16;
415         s->conf.macaddr.a[3] = value >> 24;
416         break;
417     case 0x18: /* IA1 */
418         s->conf.macaddr.a[4] = value;
419         s->conf.macaddr.a[5] = value >> 8;
420         break;
421     case 0x1c: /* THR */
422         s->thr = value;
423         break;
424     case 0x20: /* MCTL */
425         /* TODO: MII registers aren't modelled.
426          * Clear START, indicating that the operation completes immediately.
427          */
428         s->mctl = value & ~1;
429         break;
430     case 0x24: /* MDV */
431         s->mdv = value;
432         break;
433     case 0x28: /* MADD */
434         /* ignored.  */
435         break;
436     case 0x2c: /* MTXD */
437         s->mtxd = value & 0xff;
438         break;
439     case 0x38: /* TR */
440         if (value & 1) {
441             stellaris_enet_send(s);
442         }
443         break;
444     case 0x30: /* MRXD */
445     case 0x34: /* NP */
446         /* Ignored.  */
447     case 0x3c: /* Undocuented: Timestamp? */
448         /* Ignored.  */
449         break;
450     default:
451         qemu_log_mask(LOG_GUEST_ERROR, "stellaris_enet_wr%d: Illegal register "
452                                        "0x02%" HWADDR_PRIx " = 0x%" PRIx64 "\n",
453                       size * 8, offset, value);
454     }
455 }
456 
457 static const MemoryRegionOps stellaris_enet_ops = {
458     .read = stellaris_enet_read,
459     .write = stellaris_enet_write,
460     .endianness = DEVICE_NATIVE_ENDIAN,
461 };
462 
463 static void stellaris_enet_reset(DeviceState *dev)
464 {
465     stellaris_enet_state *s =  STELLARIS_ENET(dev);
466 
467     s->mdv = 0x80;
468     s->rctl = SE_RCTL_BADCRC;
469     s->im = SE_INT_PHY | SE_INT_MD | SE_INT_RXER | SE_INT_FOV | SE_INT_TXEMP
470             | SE_INT_TXER | SE_INT_RX;
471     s->thr = 0x3f;
472     s->tx_fifo_len = 0;
473 }
474 
475 static NetClientInfo net_stellaris_enet_info = {
476     .type = NET_CLIENT_DRIVER_NIC,
477     .size = sizeof(NICState),
478     .receive = stellaris_enet_receive,
479 };
480 
481 static void stellaris_enet_realize(DeviceState *dev, Error **errp)
482 {
483     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
484     stellaris_enet_state *s = STELLARIS_ENET(dev);
485 
486     memory_region_init_io(&s->mmio, OBJECT(s), &stellaris_enet_ops, s,
487                           "stellaris_enet", 0x1000);
488     sysbus_init_mmio(sbd, &s->mmio);
489     sysbus_init_irq(sbd, &s->irq);
490     qemu_macaddr_default_if_unset(&s->conf.macaddr);
491 
492     s->nic = qemu_new_nic(&net_stellaris_enet_info, &s->conf,
493                           object_get_typename(OBJECT(dev)), dev->id, s);
494     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
495 }
496 
497 static Property stellaris_enet_properties[] = {
498     DEFINE_NIC_PROPERTIES(stellaris_enet_state, conf),
499     DEFINE_PROP_END_OF_LIST(),
500 };
501 
502 static void stellaris_enet_class_init(ObjectClass *klass, void *data)
503 {
504     DeviceClass *dc = DEVICE_CLASS(klass);
505 
506     dc->realize = stellaris_enet_realize;
507     dc->reset = stellaris_enet_reset;
508     dc->props = stellaris_enet_properties;
509     dc->vmsd = &vmstate_stellaris_enet;
510 }
511 
512 static const TypeInfo stellaris_enet_info = {
513     .name          = TYPE_STELLARIS_ENET,
514     .parent        = TYPE_SYS_BUS_DEVICE,
515     .instance_size = sizeof(stellaris_enet_state),
516     .class_init    = stellaris_enet_class_init,
517 };
518 
519 static void stellaris_enet_register_types(void)
520 {
521     type_register_static(&stellaris_enet_info);
522 }
523 
524 type_init(stellaris_enet_register_types)
525