xref: /openbmc/qemu/hw/net/stellaris_enet.c (revision d0f0cd5b)
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> /* for crc32 */
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 OBJECT_DECLARE_SIMPLE_TYPE(stellaris_enet_state, STELLARIS_ENET)
55 
56 typedef struct {
57     uint8_t data[2048];
58     uint32_t len;
59 } StellarisEnetRxFrame;
60 
61 struct stellaris_enet_state {
62     SysBusDevice parent_obj;
63 
64     uint32_t ris;
65     uint32_t im;
66     uint32_t rctl;
67     uint32_t tctl;
68     uint32_t thr;
69     uint32_t mctl;
70     uint32_t mdv;
71     uint32_t mtxd;
72     uint32_t mrxd;
73     uint32_t np;
74     uint32_t tx_fifo_len;
75     uint8_t tx_fifo[2048];
76     /* Real hardware has a 2k fifo, which works out to be at most 31 packets.
77        We implement a full 31 packet fifo.  */
78     StellarisEnetRxFrame rx[31];
79     uint32_t rx_fifo_offset;
80     uint32_t next_packet;
81     NICState *nic;
82     NICConf conf;
83     qemu_irq irq;
84     MemoryRegion mmio;
85 };
86 
87 static const VMStateDescription vmstate_rx_frame = {
88     .name = "stellaris_enet/rx_frame",
89     .version_id = 1,
90     .minimum_version_id = 1,
91     .fields = (const VMStateField[]) {
92         VMSTATE_UINT8_ARRAY(data, StellarisEnetRxFrame, 2048),
93         VMSTATE_UINT32(len, StellarisEnetRxFrame),
94         VMSTATE_END_OF_LIST()
95     }
96 };
97 
98 static int stellaris_enet_post_load(void *opaque, int version_id)
99 {
100     stellaris_enet_state *s = opaque;
101     int i;
102 
103     /* Sanitize inbound state. Note that next_packet is an index but
104      * np is a size; hence their valid upper bounds differ.
105      */
106     if (s->next_packet >= ARRAY_SIZE(s->rx)) {
107         return -1;
108     }
109 
110     if (s->np > ARRAY_SIZE(s->rx)) {
111         return -1;
112     }
113 
114     for (i = 0; i < ARRAY_SIZE(s->rx); i++) {
115         if (s->rx[i].len > ARRAY_SIZE(s->rx[i].data)) {
116             return -1;
117         }
118     }
119 
120     if (s->rx_fifo_offset > ARRAY_SIZE(s->rx[0].data) - 4) {
121         return -1;
122     }
123 
124     if (s->tx_fifo_len > ARRAY_SIZE(s->tx_fifo)) {
125         return -1;
126     }
127 
128     return 0;
129 }
130 
131 static const VMStateDescription vmstate_stellaris_enet = {
132     .name = "stellaris_enet",
133     .version_id = 2,
134     .minimum_version_id = 2,
135     .post_load = stellaris_enet_post_load,
136     .fields = (const VMStateField[]) {
137         VMSTATE_UINT32(ris, stellaris_enet_state),
138         VMSTATE_UINT32(im, stellaris_enet_state),
139         VMSTATE_UINT32(rctl, stellaris_enet_state),
140         VMSTATE_UINT32(tctl, stellaris_enet_state),
141         VMSTATE_UINT32(thr, stellaris_enet_state),
142         VMSTATE_UINT32(mctl, stellaris_enet_state),
143         VMSTATE_UINT32(mdv, stellaris_enet_state),
144         VMSTATE_UINT32(mtxd, stellaris_enet_state),
145         VMSTATE_UINT32(mrxd, stellaris_enet_state),
146         VMSTATE_UINT32(np, stellaris_enet_state),
147         VMSTATE_UINT32(tx_fifo_len, stellaris_enet_state),
148         VMSTATE_UINT8_ARRAY(tx_fifo, stellaris_enet_state, 2048),
149         VMSTATE_STRUCT_ARRAY(rx, stellaris_enet_state, 31, 1,
150                              vmstate_rx_frame, StellarisEnetRxFrame),
151         VMSTATE_UINT32(rx_fifo_offset, stellaris_enet_state),
152         VMSTATE_UINT32(next_packet, stellaris_enet_state),
153         VMSTATE_END_OF_LIST()
154     }
155 };
156 
157 static void stellaris_enet_update(stellaris_enet_state *s)
158 {
159     qemu_set_irq(s->irq, (s->ris & s->im) != 0);
160 }
161 
162 /* Return the data length of the packet currently being assembled
163  * in the TX fifo.
164  */
165 static inline int stellaris_txpacket_datalen(stellaris_enet_state *s)
166 {
167     return s->tx_fifo[0] | (s->tx_fifo[1] << 8);
168 }
169 
170 /* Return true if the packet currently in the TX FIFO is complete,
171 * ie the FIFO holds enough bytes for the data length, ethernet header,
172 * payload and optionally CRC.
173 */
174 static inline bool stellaris_txpacket_complete(stellaris_enet_state *s)
175 {
176     int framelen = stellaris_txpacket_datalen(s);
177     framelen += 16;
178     if (!(s->tctl & SE_TCTL_CRC)) {
179         framelen += 4;
180     }
181     /* Cover the corner case of a 2032 byte payload with auto-CRC disabled:
182      * this requires more bytes than will fit in the FIFO. It's not totally
183      * clear how the h/w handles this, but if using threshold-based TX
184      * it will definitely try to transmit something.
185      */
186     framelen = MIN(framelen, ARRAY_SIZE(s->tx_fifo));
187     return s->tx_fifo_len >= framelen;
188 }
189 
190 /* Return true if the TX FIFO threshold is enabled and the FIFO
191  * has filled enough to reach it.
192  */
193 static inline bool stellaris_tx_thr_reached(stellaris_enet_state *s)
194 {
195     return (s->thr < 0x3f &&
196             (s->tx_fifo_len >= 4 * (s->thr * 8 + 1)));
197 }
198 
199 /* Send the packet currently in the TX FIFO */
200 static void stellaris_enet_send(stellaris_enet_state *s)
201 {
202     int framelen = stellaris_txpacket_datalen(s);
203 
204     /* Ethernet header is in the FIFO but not in the datacount.
205      * We don't implement explicit CRC, so just ignore any
206      * CRC value in the FIFO.
207      */
208     framelen += 14;
209     if ((s->tctl & SE_TCTL_PADEN) && framelen < 60) {
210         memset(&s->tx_fifo[framelen + 2], 0, 60 - framelen);
211         framelen = 60;
212     }
213     /* This MIN will have no effect unless the FIFO data is corrupt
214      * (eg bad data from an incoming migration); otherwise the check
215      * on the datalen at the start of writing the data into the FIFO
216      * will have caught this. Silently write a corrupt half-packet,
217      * which is what the hardware does in FIFO underrun situations.
218      */
219     framelen = MIN(framelen, ARRAY_SIZE(s->tx_fifo) - 2);
220     qemu_send_packet(qemu_get_queue(s->nic), s->tx_fifo + 2, framelen);
221     s->tx_fifo_len = 0;
222     s->ris |= SE_INT_TXEMP;
223     stellaris_enet_update(s);
224     DPRINTF("Done TX\n");
225 }
226 
227 /* TODO: Implement MAC address filtering.  */
228 static ssize_t stellaris_enet_receive(NetClientState *nc, const uint8_t *buf, size_t size)
229 {
230     stellaris_enet_state *s = qemu_get_nic_opaque(nc);
231     int n;
232     uint8_t *p;
233     uint32_t crc;
234 
235     if ((s->rctl & SE_RCTL_RXEN) == 0)
236         return -1;
237     if (s->np >= 31) {
238         return 0;
239     }
240 
241     DPRINTF("Received packet len=%zu\n", size);
242     n = s->next_packet + s->np;
243     if (n >= 31)
244         n -= 31;
245 
246     if (size >= sizeof(s->rx[n].data) - 6) {
247         /* If the packet won't fit into the
248          * emulated 2K RAM, this is reported
249          * as a FIFO overrun error.
250          */
251         s->ris |= SE_INT_FOV;
252         stellaris_enet_update(s);
253         return -1;
254     }
255 
256     s->np++;
257     s->rx[n].len = size + 6;
258     p = s->rx[n].data;
259     *(p++) = (size + 6);
260     *(p++) = (size + 6) >> 8;
261     memcpy (p, buf, size);
262     p += size;
263     crc = crc32(~0, buf, size);
264     *(p++) = crc;
265     *(p++) = crc >> 8;
266     *(p++) = crc >> 16;
267     *(p++) = crc >> 24;
268     /* Clear the remaining bytes in the last word.  */
269     if ((size & 3) != 2) {
270         memset(p, 0, (6 - size) & 3);
271     }
272 
273     s->ris |= SE_INT_RX;
274     stellaris_enet_update(s);
275 
276     return size;
277 }
278 
279 static int stellaris_enet_can_receive(stellaris_enet_state *s)
280 {
281     return (s->np < 31);
282 }
283 
284 static uint64_t stellaris_enet_read(void *opaque, hwaddr offset,
285                                     unsigned size)
286 {
287     stellaris_enet_state *s = (stellaris_enet_state *)opaque;
288     uint32_t val;
289 
290     switch (offset) {
291     case 0x00: /* RIS */
292         DPRINTF("IRQ status %02x\n", s->ris);
293         return s->ris;
294     case 0x04: /* IM */
295         return s->im;
296     case 0x08: /* RCTL */
297         return s->rctl;
298     case 0x0c: /* TCTL */
299         return s->tctl;
300     case 0x10: /* DATA */
301     {
302         uint8_t *rx_fifo;
303 
304         if (s->np == 0) {
305             BADF("RX underflow\n");
306             return 0;
307         }
308 
309         rx_fifo = s->rx[s->next_packet].data + s->rx_fifo_offset;
310 
311         val = rx_fifo[0] | (rx_fifo[1] << 8) | (rx_fifo[2] << 16)
312               | (rx_fifo[3] << 24);
313         s->rx_fifo_offset += 4;
314         if (s->rx_fifo_offset >= s->rx[s->next_packet].len) {
315             s->rx_fifo_offset = 0;
316             s->next_packet++;
317             if (s->next_packet >= 31)
318                 s->next_packet = 0;
319             s->np--;
320             DPRINTF("RX done np=%d\n", s->np);
321             if (!s->np && stellaris_enet_can_receive(s)) {
322                 qemu_flush_queued_packets(qemu_get_queue(s->nic));
323             }
324         }
325         return val;
326     }
327     case 0x14: /* IA0 */
328         return s->conf.macaddr.a[0] | (s->conf.macaddr.a[1] << 8)
329             | (s->conf.macaddr.a[2] << 16)
330             | ((uint32_t)s->conf.macaddr.a[3] << 24);
331     case 0x18: /* IA1 */
332         return s->conf.macaddr.a[4] | (s->conf.macaddr.a[5] << 8);
333     case 0x1c: /* THR */
334         return s->thr;
335     case 0x20: /* MCTL */
336         return s->mctl;
337     case 0x24: /* MDV */
338         return s->mdv;
339     case 0x28: /* MADD */
340         return 0;
341     case 0x2c: /* MTXD */
342         return s->mtxd;
343     case 0x30: /* MRXD */
344         return s->mrxd;
345     case 0x34: /* NP */
346         return s->np;
347     case 0x38: /* TR */
348         return 0;
349     case 0x3c: /* Undocumented: Timestamp? */
350         return 0;
351     default:
352         qemu_log_mask(LOG_GUEST_ERROR, "stellaris_enet_rd%d: Illegal register"
353                                        " 0x02%" HWADDR_PRIx "\n",
354                       size * 8, offset);
355         return 0;
356     }
357 }
358 
359 static void stellaris_enet_write(void *opaque, hwaddr offset,
360                                  uint64_t value, unsigned size)
361 {
362     stellaris_enet_state *s = (stellaris_enet_state *)opaque;
363 
364     switch (offset) {
365     case 0x00: /* IACK */
366         s->ris &= ~value;
367         DPRINTF("IRQ ack %02" PRIx64 "/%02x\n", value, s->ris);
368         stellaris_enet_update(s);
369         /* Clearing TXER also resets the TX fifo.  */
370         if (value & SE_INT_TXER) {
371             s->tx_fifo_len = 0;
372         }
373         break;
374     case 0x04: /* IM */
375         DPRINTF("IRQ mask %02" PRIx64 "/%02x\n", value, s->ris);
376         s->im = value;
377         stellaris_enet_update(s);
378         break;
379     case 0x08: /* RCTL */
380         s->rctl = value;
381         if (value & SE_RCTL_RSTFIFO) {
382             s->np = 0;
383             s->rx_fifo_offset = 0;
384             stellaris_enet_update(s);
385         }
386         break;
387     case 0x0c: /* TCTL */
388         s->tctl = value;
389         break;
390     case 0x10: /* DATA */
391         if (s->tx_fifo_len == 0) {
392             /* The first word is special, it contains the data length */
393             int framelen = value & 0xffff;
394             if (framelen > 2032) {
395                 DPRINTF("TX frame too long (%d)\n", framelen);
396                 s->ris |= SE_INT_TXER;
397                 stellaris_enet_update(s);
398                 break;
399             }
400         }
401 
402         if (s->tx_fifo_len + 4 <= ARRAY_SIZE(s->tx_fifo)) {
403             s->tx_fifo[s->tx_fifo_len++] = value;
404             s->tx_fifo[s->tx_fifo_len++] = value >> 8;
405             s->tx_fifo[s->tx_fifo_len++] = value >> 16;
406             s->tx_fifo[s->tx_fifo_len++] = value >> 24;
407         }
408 
409         if (stellaris_tx_thr_reached(s) && stellaris_txpacket_complete(s)) {
410             stellaris_enet_send(s);
411         }
412         break;
413     case 0x14: /* IA0 */
414         s->conf.macaddr.a[0] = value;
415         s->conf.macaddr.a[1] = value >> 8;
416         s->conf.macaddr.a[2] = value >> 16;
417         s->conf.macaddr.a[3] = value >> 24;
418         break;
419     case 0x18: /* IA1 */
420         s->conf.macaddr.a[4] = value;
421         s->conf.macaddr.a[5] = value >> 8;
422         break;
423     case 0x1c: /* THR */
424         s->thr = value;
425         break;
426     case 0x20: /* MCTL */
427         /* TODO: MII registers aren't modelled.
428          * Clear START, indicating that the operation completes immediately.
429          */
430         s->mctl = value & ~1;
431         break;
432     case 0x24: /* MDV */
433         s->mdv = value;
434         break;
435     case 0x28: /* MADD */
436         /* ignored.  */
437         break;
438     case 0x2c: /* MTXD */
439         s->mtxd = value & 0xff;
440         break;
441     case 0x38: /* TR */
442         if (value & 1) {
443             stellaris_enet_send(s);
444         }
445         break;
446     case 0x30: /* MRXD */
447     case 0x34: /* NP */
448         /* Ignored.  */
449     case 0x3c: /* Undocuented: Timestamp? */
450         /* Ignored.  */
451         break;
452     default:
453         qemu_log_mask(LOG_GUEST_ERROR, "stellaris_enet_wr%d: Illegal register "
454                                        "0x02%" HWADDR_PRIx " = 0x%" PRIx64 "\n",
455                       size * 8, offset, value);
456     }
457 }
458 
459 static const MemoryRegionOps stellaris_enet_ops = {
460     .read = stellaris_enet_read,
461     .write = stellaris_enet_write,
462     .endianness = DEVICE_NATIVE_ENDIAN,
463 };
464 
465 static void stellaris_enet_reset(DeviceState *dev)
466 {
467     stellaris_enet_state *s =  STELLARIS_ENET(dev);
468 
469     s->mdv = 0x80;
470     s->rctl = SE_RCTL_BADCRC;
471     s->im = SE_INT_PHY | SE_INT_MD | SE_INT_RXER | SE_INT_FOV | SE_INT_TXEMP
472             | SE_INT_TXER | SE_INT_RX;
473     s->thr = 0x3f;
474     s->tx_fifo_len = 0;
475 }
476 
477 static NetClientInfo net_stellaris_enet_info = {
478     .type = NET_CLIENT_DRIVER_NIC,
479     .size = sizeof(NICState),
480     .receive = stellaris_enet_receive,
481 };
482 
483 static void stellaris_enet_realize(DeviceState *dev, Error **errp)
484 {
485     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
486     stellaris_enet_state *s = STELLARIS_ENET(dev);
487 
488     memory_region_init_io(&s->mmio, OBJECT(s), &stellaris_enet_ops, s,
489                           "stellaris_enet", 0x1000);
490     sysbus_init_mmio(sbd, &s->mmio);
491     sysbus_init_irq(sbd, &s->irq);
492     qemu_macaddr_default_if_unset(&s->conf.macaddr);
493 
494     s->nic = qemu_new_nic(&net_stellaris_enet_info, &s->conf,
495                           object_get_typename(OBJECT(dev)), dev->id,
496                           &dev->mem_reentrancy_guard, s);
497     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
498 }
499 
500 static Property stellaris_enet_properties[] = {
501     DEFINE_NIC_PROPERTIES(stellaris_enet_state, conf),
502     DEFINE_PROP_END_OF_LIST(),
503 };
504 
505 static void stellaris_enet_class_init(ObjectClass *klass, void *data)
506 {
507     DeviceClass *dc = DEVICE_CLASS(klass);
508 
509     dc->realize = stellaris_enet_realize;
510     device_class_set_legacy_reset(dc, stellaris_enet_reset);
511     device_class_set_props(dc, stellaris_enet_properties);
512     dc->vmsd = &vmstate_stellaris_enet;
513 }
514 
515 static const TypeInfo stellaris_enet_info = {
516     .name          = TYPE_STELLARIS_ENET,
517     .parent        = TYPE_SYS_BUS_DEVICE,
518     .instance_size = sizeof(stellaris_enet_state),
519     .class_init    = stellaris_enet_class_init,
520 };
521 
522 static void stellaris_enet_register_types(void)
523 {
524     type_register_static(&stellaris_enet_info);
525 }
526 
527 type_init(stellaris_enet_register_types)
528