xref: /openbmc/qemu/hw/net/stellaris_enet.c (revision a68694cd)
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/qdev-properties.h"
13 #include "hw/sysbus.h"
14 #include "migration/vmstate.h"
15 #include "net/net.h"
16 #include "qemu/log.h"
17 #include "qemu/module.h"
18 #include <zlib.h>
19 #include "qom/object.h"
20 
21 //#define DEBUG_STELLARIS_ENET 1
22 
23 #ifdef DEBUG_STELLARIS_ENET
24 #define DPRINTF(fmt, ...) \
25 do { printf("stellaris_enet: " fmt , ## __VA_ARGS__); } while (0)
26 #define BADF(fmt, ...) \
27 do { fprintf(stderr, "stellaris_enet: error: " fmt , ## __VA_ARGS__); exit(1);} while (0)
28 #else
29 #define DPRINTF(fmt, ...) do {} while(0)
30 #define BADF(fmt, ...) \
31 do { fprintf(stderr, "stellaris_enet: error: " fmt , ## __VA_ARGS__);} while (0)
32 #endif
33 
34 #define SE_INT_RX       0x01
35 #define SE_INT_TXER     0x02
36 #define SE_INT_TXEMP    0x04
37 #define SE_INT_FOV      0x08
38 #define SE_INT_RXER     0x10
39 #define SE_INT_MD       0x20
40 #define SE_INT_PHY      0x40
41 
42 #define SE_RCTL_RXEN    0x01
43 #define SE_RCTL_AMUL    0x02
44 #define SE_RCTL_PRMS    0x04
45 #define SE_RCTL_BADCRC  0x08
46 #define SE_RCTL_RSTFIFO 0x10
47 
48 #define SE_TCTL_TXEN    0x01
49 #define SE_TCTL_PADEN   0x02
50 #define SE_TCTL_CRC     0x04
51 #define SE_TCTL_DUPLEX  0x08
52 
53 #define TYPE_STELLARIS_ENET "stellaris_enet"
54 typedef struct stellaris_enet_state stellaris_enet_state;
55 DECLARE_INSTANCE_CHECKER(stellaris_enet_state, STELLARIS_ENET,
56                          TYPE_STELLARIS_ENET)
57 
58 typedef struct {
59     uint8_t data[2048];
60     uint32_t len;
61 } StellarisEnetRxFrame;
62 
63 struct stellaris_enet_state {
64     SysBusDevice parent_obj;
65 
66     uint32_t ris;
67     uint32_t im;
68     uint32_t rctl;
69     uint32_t tctl;
70     uint32_t thr;
71     uint32_t mctl;
72     uint32_t mdv;
73     uint32_t mtxd;
74     uint32_t mrxd;
75     uint32_t np;
76     uint32_t tx_fifo_len;
77     uint8_t tx_fifo[2048];
78     /* Real hardware has a 2k fifo, which works out to be at most 31 packets.
79        We implement a full 31 packet fifo.  */
80     StellarisEnetRxFrame rx[31];
81     uint32_t rx_fifo_offset;
82     uint32_t next_packet;
83     NICState *nic;
84     NICConf conf;
85     qemu_irq irq;
86     MemoryRegion mmio;
87 };
88 
89 static const VMStateDescription vmstate_rx_frame = {
90     .name = "stellaris_enet/rx_frame",
91     .version_id = 1,
92     .minimum_version_id = 1,
93     .fields = (VMStateField[]) {
94         VMSTATE_UINT8_ARRAY(data, StellarisEnetRxFrame, 2048),
95         VMSTATE_UINT32(len, StellarisEnetRxFrame),
96         VMSTATE_END_OF_LIST()
97     }
98 };
99 
100 static int stellaris_enet_post_load(void *opaque, int version_id)
101 {
102     stellaris_enet_state *s = opaque;
103     int i;
104 
105     /* Sanitize inbound state. Note that next_packet is an index but
106      * np is a size; hence their valid upper bounds differ.
107      */
108     if (s->next_packet >= ARRAY_SIZE(s->rx)) {
109         return -1;
110     }
111 
112     if (s->np > ARRAY_SIZE(s->rx)) {
113         return -1;
114     }
115 
116     for (i = 0; i < ARRAY_SIZE(s->rx); i++) {
117         if (s->rx[i].len > ARRAY_SIZE(s->rx[i].data)) {
118             return -1;
119         }
120     }
121 
122     if (s->rx_fifo_offset > ARRAY_SIZE(s->rx[0].data) - 4) {
123         return -1;
124     }
125 
126     if (s->tx_fifo_len > ARRAY_SIZE(s->tx_fifo)) {
127         return -1;
128     }
129 
130     return 0;
131 }
132 
133 static const VMStateDescription vmstate_stellaris_enet = {
134     .name = "stellaris_enet",
135     .version_id = 2,
136     .minimum_version_id = 2,
137     .post_load = stellaris_enet_post_load,
138     .fields = (VMStateField[]) {
139         VMSTATE_UINT32(ris, stellaris_enet_state),
140         VMSTATE_UINT32(im, stellaris_enet_state),
141         VMSTATE_UINT32(rctl, stellaris_enet_state),
142         VMSTATE_UINT32(tctl, stellaris_enet_state),
143         VMSTATE_UINT32(thr, stellaris_enet_state),
144         VMSTATE_UINT32(mctl, stellaris_enet_state),
145         VMSTATE_UINT32(mdv, stellaris_enet_state),
146         VMSTATE_UINT32(mtxd, stellaris_enet_state),
147         VMSTATE_UINT32(mrxd, stellaris_enet_state),
148         VMSTATE_UINT32(np, stellaris_enet_state),
149         VMSTATE_UINT32(tx_fifo_len, stellaris_enet_state),
150         VMSTATE_UINT8_ARRAY(tx_fifo, stellaris_enet_state, 2048),
151         VMSTATE_STRUCT_ARRAY(rx, stellaris_enet_state, 31, 1,
152                              vmstate_rx_frame, StellarisEnetRxFrame),
153         VMSTATE_UINT32(rx_fifo_offset, stellaris_enet_state),
154         VMSTATE_UINT32(next_packet, stellaris_enet_state),
155         VMSTATE_END_OF_LIST()
156     }
157 };
158 
159 static void stellaris_enet_update(stellaris_enet_state *s)
160 {
161     qemu_set_irq(s->irq, (s->ris & s->im) != 0);
162 }
163 
164 /* Return the data length of the packet currently being assembled
165  * in the TX fifo.
166  */
167 static inline int stellaris_txpacket_datalen(stellaris_enet_state *s)
168 {
169     return s->tx_fifo[0] | (s->tx_fifo[1] << 8);
170 }
171 
172 /* Return true if the packet currently in the TX FIFO is complete,
173 * ie the FIFO holds enough bytes for the data length, ethernet header,
174 * payload and optionally CRC.
175 */
176 static inline bool stellaris_txpacket_complete(stellaris_enet_state *s)
177 {
178     int framelen = stellaris_txpacket_datalen(s);
179     framelen += 16;
180     if (!(s->tctl & SE_TCTL_CRC)) {
181         framelen += 4;
182     }
183     /* Cover the corner case of a 2032 byte payload with auto-CRC disabled:
184      * this requires more bytes than will fit in the FIFO. It's not totally
185      * clear how the h/w handles this, but if using threshold-based TX
186      * it will definitely try to transmit something.
187      */
188     framelen = MIN(framelen, ARRAY_SIZE(s->tx_fifo));
189     return s->tx_fifo_len >= framelen;
190 }
191 
192 /* Return true if the TX FIFO threshold is enabled and the FIFO
193  * has filled enough to reach it.
194  */
195 static inline bool stellaris_tx_thr_reached(stellaris_enet_state *s)
196 {
197     return (s->thr < 0x3f &&
198             (s->tx_fifo_len >= 4 * (s->thr * 8 + 1)));
199 }
200 
201 /* Send the packet currently in the TX FIFO */
202 static void stellaris_enet_send(stellaris_enet_state *s)
203 {
204     int framelen = stellaris_txpacket_datalen(s);
205 
206     /* Ethernet header is in the FIFO but not in the datacount.
207      * We don't implement explicit CRC, so just ignore any
208      * CRC value in the FIFO.
209      */
210     framelen += 14;
211     if ((s->tctl & SE_TCTL_PADEN) && framelen < 60) {
212         memset(&s->tx_fifo[framelen + 2], 0, 60 - framelen);
213         framelen = 60;
214     }
215     /* This MIN will have no effect unless the FIFO data is corrupt
216      * (eg bad data from an incoming migration); otherwise the check
217      * on the datalen at the start of writing the data into the FIFO
218      * will have caught this. Silently write a corrupt half-packet,
219      * which is what the hardware does in FIFO underrun situations.
220      */
221     framelen = MIN(framelen, ARRAY_SIZE(s->tx_fifo) - 2);
222     qemu_send_packet(qemu_get_queue(s->nic), s->tx_fifo + 2, framelen);
223     s->tx_fifo_len = 0;
224     s->ris |= SE_INT_TXEMP;
225     stellaris_enet_update(s);
226     DPRINTF("Done TX\n");
227 }
228 
229 /* TODO: Implement MAC address filtering.  */
230 static ssize_t stellaris_enet_receive(NetClientState *nc, const uint8_t *buf, size_t size)
231 {
232     stellaris_enet_state *s = qemu_get_nic_opaque(nc);
233     int n;
234     uint8_t *p;
235     uint32_t crc;
236 
237     if ((s->rctl & SE_RCTL_RXEN) == 0)
238         return -1;
239     if (s->np >= 31) {
240         return 0;
241     }
242 
243     DPRINTF("Received packet len=%zu\n", size);
244     n = s->next_packet + s->np;
245     if (n >= 31)
246         n -= 31;
247 
248     if (size >= sizeof(s->rx[n].data) - 6) {
249         /* If the packet won't fit into the
250          * emulated 2K RAM, this is reported
251          * as a FIFO overrun error.
252          */
253         s->ris |= SE_INT_FOV;
254         stellaris_enet_update(s);
255         return -1;
256     }
257 
258     s->np++;
259     s->rx[n].len = size + 6;
260     p = s->rx[n].data;
261     *(p++) = (size + 6);
262     *(p++) = (size + 6) >> 8;
263     memcpy (p, buf, size);
264     p += size;
265     crc = crc32(~0, buf, size);
266     *(p++) = crc;
267     *(p++) = crc >> 8;
268     *(p++) = crc >> 16;
269     *(p++) = crc >> 24;
270     /* Clear the remaining bytes in the last word.  */
271     if ((size & 3) != 2) {
272         memset(p, 0, (6 - size) & 3);
273     }
274 
275     s->ris |= SE_INT_RX;
276     stellaris_enet_update(s);
277 
278     return size;
279 }
280 
281 static int stellaris_enet_can_receive(stellaris_enet_state *s)
282 {
283     return (s->np < 31);
284 }
285 
286 static uint64_t stellaris_enet_read(void *opaque, hwaddr offset,
287                                     unsigned size)
288 {
289     stellaris_enet_state *s = (stellaris_enet_state *)opaque;
290     uint32_t val;
291 
292     switch (offset) {
293     case 0x00: /* RIS */
294         DPRINTF("IRQ status %02x\n", s->ris);
295         return s->ris;
296     case 0x04: /* IM */
297         return s->im;
298     case 0x08: /* RCTL */
299         return s->rctl;
300     case 0x0c: /* TCTL */
301         return s->tctl;
302     case 0x10: /* DATA */
303     {
304         uint8_t *rx_fifo;
305 
306         if (s->np == 0) {
307             BADF("RX underflow\n");
308             return 0;
309         }
310 
311         rx_fifo = s->rx[s->next_packet].data + s->rx_fifo_offset;
312 
313         val = rx_fifo[0] | (rx_fifo[1] << 8) | (rx_fifo[2] << 16)
314               | (rx_fifo[3] << 24);
315         s->rx_fifo_offset += 4;
316         if (s->rx_fifo_offset >= s->rx[s->next_packet].len) {
317             s->rx_fifo_offset = 0;
318             s->next_packet++;
319             if (s->next_packet >= 31)
320                 s->next_packet = 0;
321             s->np--;
322             DPRINTF("RX done np=%d\n", s->np);
323             if (!s->np && stellaris_enet_can_receive(s)) {
324                 qemu_flush_queued_packets(qemu_get_queue(s->nic));
325             }
326         }
327         return val;
328     }
329     case 0x14: /* IA0 */
330         return s->conf.macaddr.a[0] | (s->conf.macaddr.a[1] << 8)
331             | (s->conf.macaddr.a[2] << 16)
332             | ((uint32_t)s->conf.macaddr.a[3] << 24);
333     case 0x18: /* IA1 */
334         return s->conf.macaddr.a[4] | (s->conf.macaddr.a[5] << 8);
335     case 0x1c: /* THR */
336         return s->thr;
337     case 0x20: /* MCTL */
338         return s->mctl;
339     case 0x24: /* MDV */
340         return s->mdv;
341     case 0x28: /* MADD */
342         return 0;
343     case 0x2c: /* MTXD */
344         return s->mtxd;
345     case 0x30: /* MRXD */
346         return s->mrxd;
347     case 0x34: /* NP */
348         return s->np;
349     case 0x38: /* TR */
350         return 0;
351     case 0x3c: /* Undocumented: Timestamp? */
352         return 0;
353     default:
354         qemu_log_mask(LOG_GUEST_ERROR, "stellaris_enet_rd%d: Illegal register"
355                                        " 0x02%" HWADDR_PRIx "\n",
356                       size * 8, offset);
357         return 0;
358     }
359 }
360 
361 static void stellaris_enet_write(void *opaque, hwaddr offset,
362                                  uint64_t value, unsigned size)
363 {
364     stellaris_enet_state *s = (stellaris_enet_state *)opaque;
365 
366     switch (offset) {
367     case 0x00: /* IACK */
368         s->ris &= ~value;
369         DPRINTF("IRQ ack %02" PRIx64 "/%02x\n", value, s->ris);
370         stellaris_enet_update(s);
371         /* Clearing TXER also resets the TX fifo.  */
372         if (value & SE_INT_TXER) {
373             s->tx_fifo_len = 0;
374         }
375         break;
376     case 0x04: /* IM */
377         DPRINTF("IRQ mask %02" PRIx64 "/%02x\n", value, s->ris);
378         s->im = value;
379         stellaris_enet_update(s);
380         break;
381     case 0x08: /* RCTL */
382         s->rctl = value;
383         if (value & SE_RCTL_RSTFIFO) {
384             s->np = 0;
385             s->rx_fifo_offset = 0;
386             stellaris_enet_update(s);
387         }
388         break;
389     case 0x0c: /* TCTL */
390         s->tctl = value;
391         break;
392     case 0x10: /* DATA */
393         if (s->tx_fifo_len == 0) {
394             /* The first word is special, it contains the data length */
395             int framelen = value & 0xffff;
396             if (framelen > 2032) {
397                 DPRINTF("TX frame too long (%d)\n", framelen);
398                 s->ris |= SE_INT_TXER;
399                 stellaris_enet_update(s);
400                 break;
401             }
402         }
403 
404         if (s->tx_fifo_len + 4 <= ARRAY_SIZE(s->tx_fifo)) {
405             s->tx_fifo[s->tx_fifo_len++] = value;
406             s->tx_fifo[s->tx_fifo_len++] = value >> 8;
407             s->tx_fifo[s->tx_fifo_len++] = value >> 16;
408             s->tx_fifo[s->tx_fifo_len++] = value >> 24;
409         }
410 
411         if (stellaris_tx_thr_reached(s) && stellaris_txpacket_complete(s)) {
412             stellaris_enet_send(s);
413         }
414         break;
415     case 0x14: /* IA0 */
416         s->conf.macaddr.a[0] = value;
417         s->conf.macaddr.a[1] = value >> 8;
418         s->conf.macaddr.a[2] = value >> 16;
419         s->conf.macaddr.a[3] = value >> 24;
420         break;
421     case 0x18: /* IA1 */
422         s->conf.macaddr.a[4] = value;
423         s->conf.macaddr.a[5] = value >> 8;
424         break;
425     case 0x1c: /* THR */
426         s->thr = value;
427         break;
428     case 0x20: /* MCTL */
429         /* TODO: MII registers aren't modelled.
430          * Clear START, indicating that the operation completes immediately.
431          */
432         s->mctl = value & ~1;
433         break;
434     case 0x24: /* MDV */
435         s->mdv = value;
436         break;
437     case 0x28: /* MADD */
438         /* ignored.  */
439         break;
440     case 0x2c: /* MTXD */
441         s->mtxd = value & 0xff;
442         break;
443     case 0x38: /* TR */
444         if (value & 1) {
445             stellaris_enet_send(s);
446         }
447         break;
448     case 0x30: /* MRXD */
449     case 0x34: /* NP */
450         /* Ignored.  */
451     case 0x3c: /* Undocuented: Timestamp? */
452         /* Ignored.  */
453         break;
454     default:
455         qemu_log_mask(LOG_GUEST_ERROR, "stellaris_enet_wr%d: Illegal register "
456                                        "0x02%" HWADDR_PRIx " = 0x%" PRIx64 "\n",
457                       size * 8, offset, value);
458     }
459 }
460 
461 static const MemoryRegionOps stellaris_enet_ops = {
462     .read = stellaris_enet_read,
463     .write = stellaris_enet_write,
464     .endianness = DEVICE_NATIVE_ENDIAN,
465 };
466 
467 static void stellaris_enet_reset(DeviceState *dev)
468 {
469     stellaris_enet_state *s =  STELLARIS_ENET(dev);
470 
471     s->mdv = 0x80;
472     s->rctl = SE_RCTL_BADCRC;
473     s->im = SE_INT_PHY | SE_INT_MD | SE_INT_RXER | SE_INT_FOV | SE_INT_TXEMP
474             | SE_INT_TXER | SE_INT_RX;
475     s->thr = 0x3f;
476     s->tx_fifo_len = 0;
477 }
478 
479 static NetClientInfo net_stellaris_enet_info = {
480     .type = NET_CLIENT_DRIVER_NIC,
481     .size = sizeof(NICState),
482     .receive = stellaris_enet_receive,
483 };
484 
485 static void stellaris_enet_realize(DeviceState *dev, Error **errp)
486 {
487     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
488     stellaris_enet_state *s = STELLARIS_ENET(dev);
489 
490     memory_region_init_io(&s->mmio, OBJECT(s), &stellaris_enet_ops, s,
491                           "stellaris_enet", 0x1000);
492     sysbus_init_mmio(sbd, &s->mmio);
493     sysbus_init_irq(sbd, &s->irq);
494     qemu_macaddr_default_if_unset(&s->conf.macaddr);
495 
496     s->nic = qemu_new_nic(&net_stellaris_enet_info, &s->conf,
497                           object_get_typename(OBJECT(dev)), dev->id, s);
498     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
499 }
500 
501 static Property stellaris_enet_properties[] = {
502     DEFINE_NIC_PROPERTIES(stellaris_enet_state, conf),
503     DEFINE_PROP_END_OF_LIST(),
504 };
505 
506 static void stellaris_enet_class_init(ObjectClass *klass, void *data)
507 {
508     DeviceClass *dc = DEVICE_CLASS(klass);
509 
510     dc->realize = stellaris_enet_realize;
511     dc->reset = stellaris_enet_reset;
512     device_class_set_props(dc, stellaris_enet_properties);
513     dc->vmsd = &vmstate_stellaris_enet;
514 }
515 
516 static const TypeInfo stellaris_enet_info = {
517     .name          = TYPE_STELLARIS_ENET,
518     .parent        = TYPE_SYS_BUS_DEVICE,
519     .instance_size = sizeof(stellaris_enet_state),
520     .class_init    = stellaris_enet_class_init,
521 };
522 
523 static void stellaris_enet_register_types(void)
524 {
525     type_register_static(&stellaris_enet_info);
526 }
527 
528 type_init(stellaris_enet_register_types)
529