xref: /openbmc/qemu/hw/net/stellaris_enet.c (revision 469b046e)
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 "hw/sysbus.h"
10 #include "net/net.h"
11 #include <zlib.h>
12 
13 //#define DEBUG_STELLARIS_ENET 1
14 
15 #ifdef DEBUG_STELLARIS_ENET
16 #define DPRINTF(fmt, ...) \
17 do { printf("stellaris_enet: " fmt , ## __VA_ARGS__); } while (0)
18 #define BADF(fmt, ...) \
19 do { fprintf(stderr, "stellaris_enet: error: " fmt , ## __VA_ARGS__); exit(1);} while (0)
20 #else
21 #define DPRINTF(fmt, ...) do {} while(0)
22 #define BADF(fmt, ...) \
23 do { fprintf(stderr, "stellaris_enet: error: " fmt , ## __VA_ARGS__);} while (0)
24 #endif
25 
26 #define SE_INT_RX       0x01
27 #define SE_INT_TXER     0x02
28 #define SE_INT_TXEMP    0x04
29 #define SE_INT_FOV      0x08
30 #define SE_INT_RXER     0x10
31 #define SE_INT_MD       0x20
32 #define SE_INT_PHY      0x40
33 
34 #define SE_RCTL_RXEN    0x01
35 #define SE_RCTL_AMUL    0x02
36 #define SE_RCTL_PRMS    0x04
37 #define SE_RCTL_BADCRC  0x08
38 #define SE_RCTL_RSTFIFO 0x10
39 
40 #define SE_TCTL_TXEN    0x01
41 #define SE_TCTL_PADEN   0x02
42 #define SE_TCTL_CRC     0x04
43 #define SE_TCTL_DUPLEX  0x08
44 
45 #define TYPE_STELLARIS_ENET "stellaris_enet"
46 #define STELLARIS_ENET(obj) \
47     OBJECT_CHECK(stellaris_enet_state, (obj), TYPE_STELLARIS_ENET)
48 
49 typedef struct {
50     uint8_t data[2048];
51     uint32_t len;
52 } StellarisEnetRxFrame;
53 
54 typedef struct {
55     SysBusDevice parent_obj;
56 
57     uint32_t ris;
58     uint32_t im;
59     uint32_t rctl;
60     uint32_t tctl;
61     uint32_t thr;
62     uint32_t mctl;
63     uint32_t mdv;
64     uint32_t mtxd;
65     uint32_t mrxd;
66     uint32_t np;
67     uint32_t tx_fifo_len;
68     uint8_t tx_fifo[2048];
69     /* Real hardware has a 2k fifo, which works out to be at most 31 packets.
70        We implement a full 31 packet fifo.  */
71     StellarisEnetRxFrame rx[31];
72     uint32_t rx_fifo_offset;
73     uint32_t next_packet;
74     NICState *nic;
75     NICConf conf;
76     qemu_irq irq;
77     MemoryRegion mmio;
78 } stellaris_enet_state;
79 
80 static const VMStateDescription vmstate_rx_frame = {
81     .name = "stellaris_enet/rx_frame",
82     .version_id = 1,
83     .minimum_version_id = 1,
84     .fields = (VMStateField[]) {
85         VMSTATE_UINT8_ARRAY(data, StellarisEnetRxFrame, 2048),
86         VMSTATE_UINT32(len, StellarisEnetRxFrame),
87         VMSTATE_END_OF_LIST()
88     }
89 };
90 
91 static int stellaris_enet_post_load(void *opaque, int version_id)
92 {
93     stellaris_enet_state *s = opaque;
94     int i;
95 
96     /* Sanitize inbound state. Note that next_packet is an index but
97      * np is a size; hence their valid upper bounds differ.
98      */
99     if (s->next_packet >= ARRAY_SIZE(s->rx)) {
100         return -1;
101     }
102 
103     if (s->np > ARRAY_SIZE(s->rx)) {
104         return -1;
105     }
106 
107     for (i = 0; i < ARRAY_SIZE(s->rx); i++) {
108         if (s->rx[i].len > ARRAY_SIZE(s->rx[i].data)) {
109             return -1;
110         }
111     }
112 
113     if (s->rx_fifo_offset > ARRAY_SIZE(s->rx[0].data) - 4) {
114         return -1;
115     }
116 
117     if (s->tx_fifo_len > ARRAY_SIZE(s->tx_fifo)) {
118         return -1;
119     }
120 
121     return 0;
122 }
123 
124 static const VMStateDescription vmstate_stellaris_enet = {
125     .name = "stellaris_enet",
126     .version_id = 2,
127     .minimum_version_id = 2,
128     .post_load = stellaris_enet_post_load,
129     .fields = (VMStateField[]) {
130         VMSTATE_UINT32(ris, stellaris_enet_state),
131         VMSTATE_UINT32(im, stellaris_enet_state),
132         VMSTATE_UINT32(rctl, stellaris_enet_state),
133         VMSTATE_UINT32(tctl, stellaris_enet_state),
134         VMSTATE_UINT32(thr, stellaris_enet_state),
135         VMSTATE_UINT32(mctl, stellaris_enet_state),
136         VMSTATE_UINT32(mdv, stellaris_enet_state),
137         VMSTATE_UINT32(mtxd, stellaris_enet_state),
138         VMSTATE_UINT32(mrxd, stellaris_enet_state),
139         VMSTATE_UINT32(np, stellaris_enet_state),
140         VMSTATE_UINT32(tx_fifo_len, stellaris_enet_state),
141         VMSTATE_UINT8_ARRAY(tx_fifo, stellaris_enet_state, 2048),
142         VMSTATE_STRUCT_ARRAY(rx, stellaris_enet_state, 31, 1,
143                              vmstate_rx_frame, StellarisEnetRxFrame),
144         VMSTATE_UINT32(rx_fifo_offset, stellaris_enet_state),
145         VMSTATE_UINT32(next_packet, stellaris_enet_state),
146         VMSTATE_END_OF_LIST()
147     }
148 };
149 
150 static void stellaris_enet_update(stellaris_enet_state *s)
151 {
152     qemu_set_irq(s->irq, (s->ris & s->im) != 0);
153 }
154 
155 /* Return the data length of the packet currently being assembled
156  * in the TX fifo.
157  */
158 static inline int stellaris_txpacket_datalen(stellaris_enet_state *s)
159 {
160     return s->tx_fifo[0] | (s->tx_fifo[1] << 8);
161 }
162 
163 /* Return true if the packet currently in the TX FIFO is complete,
164 * ie the FIFO holds enough bytes for the data length, ethernet header,
165 * payload and optionally CRC.
166 */
167 static inline bool stellaris_txpacket_complete(stellaris_enet_state *s)
168 {
169     int framelen = stellaris_txpacket_datalen(s);
170     framelen += 16;
171     if (!(s->tctl & SE_TCTL_CRC)) {
172         framelen += 4;
173     }
174     /* Cover the corner case of a 2032 byte payload with auto-CRC disabled:
175      * this requires more bytes than will fit in the FIFO. It's not totally
176      * clear how the h/w handles this, but if using threshold-based TX
177      * it will definitely try to transmit something.
178      */
179     framelen = MIN(framelen, ARRAY_SIZE(s->tx_fifo));
180     return s->tx_fifo_len >= framelen;
181 }
182 
183 /* Return true if the TX FIFO threshold is enabled and the FIFO
184  * has filled enough to reach it.
185  */
186 static inline bool stellaris_tx_thr_reached(stellaris_enet_state *s)
187 {
188     return (s->thr < 0x3f &&
189             (s->tx_fifo_len >= 4 * (s->thr * 8 + 1)));
190 }
191 
192 /* Send the packet currently in the TX FIFO */
193 static void stellaris_enet_send(stellaris_enet_state *s)
194 {
195     int framelen = stellaris_txpacket_datalen(s);
196 
197     /* Ethernet header is in the FIFO but not in the datacount.
198      * We don't implement explicit CRC, so just ignore any
199      * CRC value in the FIFO.
200      */
201     framelen += 14;
202     if ((s->tctl & SE_TCTL_PADEN) && framelen < 60) {
203         memset(&s->tx_fifo[framelen + 2], 0, 60 - framelen);
204         framelen = 60;
205     }
206     /* This MIN will have no effect unless the FIFO data is corrupt
207      * (eg bad data from an incoming migration); otherwise the check
208      * on the datalen at the start of writing the data into the FIFO
209      * will have caught this. Silently write a corrupt half-packet,
210      * which is what the hardware does in FIFO underrun situations.
211      */
212     framelen = MIN(framelen, ARRAY_SIZE(s->tx_fifo) - 2);
213     qemu_send_packet(qemu_get_queue(s->nic), s->tx_fifo + 2, framelen);
214     s->tx_fifo_len = 0;
215     s->ris |= SE_INT_TXEMP;
216     stellaris_enet_update(s);
217     DPRINTF("Done TX\n");
218 }
219 
220 /* TODO: Implement MAC address filtering.  */
221 static ssize_t stellaris_enet_receive(NetClientState *nc, const uint8_t *buf, size_t size)
222 {
223     stellaris_enet_state *s = qemu_get_nic_opaque(nc);
224     int n;
225     uint8_t *p;
226     uint32_t crc;
227 
228     if ((s->rctl & SE_RCTL_RXEN) == 0)
229         return -1;
230     if (s->np >= 31) {
231         DPRINTF("Packet dropped\n");
232         return -1;
233     }
234 
235     DPRINTF("Received packet len=%zu\n", size);
236     n = s->next_packet + s->np;
237     if (n >= 31)
238         n -= 31;
239     s->np++;
240 
241     s->rx[n].len = size + 6;
242     p = s->rx[n].data;
243     *(p++) = (size + 6);
244     *(p++) = (size + 6) >> 8;
245     memcpy (p, buf, size);
246     p += size;
247     crc = crc32(~0, buf, size);
248     *(p++) = crc;
249     *(p++) = crc >> 8;
250     *(p++) = crc >> 16;
251     *(p++) = crc >> 24;
252     /* Clear the remaining bytes in the last word.  */
253     if ((size & 3) != 2) {
254         memset(p, 0, (6 - size) & 3);
255     }
256 
257     s->ris |= SE_INT_RX;
258     stellaris_enet_update(s);
259 
260     return size;
261 }
262 
263 static int stellaris_enet_can_receive(NetClientState *nc)
264 {
265     stellaris_enet_state *s = qemu_get_nic_opaque(nc);
266 
267     if ((s->rctl & SE_RCTL_RXEN) == 0)
268         return 1;
269 
270     return (s->np < 31);
271 }
272 
273 static uint64_t stellaris_enet_read(void *opaque, hwaddr offset,
274                                     unsigned size)
275 {
276     stellaris_enet_state *s = (stellaris_enet_state *)opaque;
277     uint32_t val;
278 
279     switch (offset) {
280     case 0x00: /* RIS */
281         DPRINTF("IRQ status %02x\n", s->ris);
282         return s->ris;
283     case 0x04: /* IM */
284         return s->im;
285     case 0x08: /* RCTL */
286         return s->rctl;
287     case 0x0c: /* TCTL */
288         return s->tctl;
289     case 0x10: /* DATA */
290     {
291         uint8_t *rx_fifo;
292 
293         if (s->np == 0) {
294             BADF("RX underflow\n");
295             return 0;
296         }
297 
298         rx_fifo = s->rx[s->next_packet].data + s->rx_fifo_offset;
299 
300         val = rx_fifo[0] | (rx_fifo[1] << 8) | (rx_fifo[2] << 16)
301               | (rx_fifo[3] << 24);
302         s->rx_fifo_offset += 4;
303         if (s->rx_fifo_offset >= s->rx[s->next_packet].len) {
304             s->rx_fifo_offset = 0;
305             s->next_packet++;
306             if (s->next_packet >= 31)
307                 s->next_packet = 0;
308             s->np--;
309             DPRINTF("RX done np=%d\n", s->np);
310         }
311         return val;
312     }
313     case 0x14: /* IA0 */
314         return s->conf.macaddr.a[0] | (s->conf.macaddr.a[1] << 8)
315             | (s->conf.macaddr.a[2] << 16)
316             | ((uint32_t)s->conf.macaddr.a[3] << 24);
317     case 0x18: /* IA1 */
318         return s->conf.macaddr.a[4] | (s->conf.macaddr.a[5] << 8);
319     case 0x1c: /* THR */
320         return s->thr;
321     case 0x20: /* MCTL */
322         return s->mctl;
323     case 0x24: /* MDV */
324         return s->mdv;
325     case 0x28: /* MADD */
326         return 0;
327     case 0x2c: /* MTXD */
328         return s->mtxd;
329     case 0x30: /* MRXD */
330         return s->mrxd;
331     case 0x34: /* NP */
332         return s->np;
333     case 0x38: /* TR */
334         return 0;
335     case 0x3c: /* Undocuented: Timestamp? */
336         return 0;
337     default:
338         hw_error("stellaris_enet_read: Bad offset %x\n", (int)offset);
339         return 0;
340     }
341 }
342 
343 static void stellaris_enet_write(void *opaque, hwaddr offset,
344                                  uint64_t value, unsigned size)
345 {
346     stellaris_enet_state *s = (stellaris_enet_state *)opaque;
347 
348     switch (offset) {
349     case 0x00: /* IACK */
350         s->ris &= ~value;
351         DPRINTF("IRQ ack %02" PRIx64 "/%02x\n", value, s->ris);
352         stellaris_enet_update(s);
353         /* Clearing TXER also resets the TX fifo.  */
354         if (value & SE_INT_TXER) {
355             s->tx_fifo_len = 0;
356         }
357         break;
358     case 0x04: /* IM */
359         DPRINTF("IRQ mask %02" PRIx64 "/%02x\n", value, s->ris);
360         s->im = value;
361         stellaris_enet_update(s);
362         break;
363     case 0x08: /* RCTL */
364         s->rctl = value;
365         if (value & SE_RCTL_RSTFIFO) {
366             s->np = 0;
367             s->rx_fifo_offset = 0;
368             stellaris_enet_update(s);
369         }
370         break;
371     case 0x0c: /* TCTL */
372         s->tctl = value;
373         break;
374     case 0x10: /* DATA */
375         if (s->tx_fifo_len == 0) {
376             /* The first word is special, it contains the data length */
377             int framelen = value & 0xffff;
378             if (framelen > 2032) {
379                 DPRINTF("TX frame too long (%d)\n", framelen);
380                 s->ris |= SE_INT_TXER;
381                 stellaris_enet_update(s);
382                 break;
383             }
384         }
385 
386         if (s->tx_fifo_len + 4 <= ARRAY_SIZE(s->tx_fifo)) {
387             s->tx_fifo[s->tx_fifo_len++] = value;
388             s->tx_fifo[s->tx_fifo_len++] = value >> 8;
389             s->tx_fifo[s->tx_fifo_len++] = value >> 16;
390             s->tx_fifo[s->tx_fifo_len++] = value >> 24;
391         }
392 
393         if (stellaris_tx_thr_reached(s) && stellaris_txpacket_complete(s)) {
394             stellaris_enet_send(s);
395         }
396         break;
397     case 0x14: /* IA0 */
398         s->conf.macaddr.a[0] = value;
399         s->conf.macaddr.a[1] = value >> 8;
400         s->conf.macaddr.a[2] = value >> 16;
401         s->conf.macaddr.a[3] = value >> 24;
402         break;
403     case 0x18: /* IA1 */
404         s->conf.macaddr.a[4] = value;
405         s->conf.macaddr.a[5] = value >> 8;
406         break;
407     case 0x1c: /* THR */
408         s->thr = value;
409         break;
410     case 0x20: /* MCTL */
411         s->mctl = value;
412         break;
413     case 0x24: /* MDV */
414         s->mdv = value;
415         break;
416     case 0x28: /* MADD */
417         /* ignored.  */
418         break;
419     case 0x2c: /* MTXD */
420         s->mtxd = value & 0xff;
421         break;
422     case 0x38: /* TR */
423         if (value & 1) {
424             stellaris_enet_send(s);
425         }
426         break;
427     case 0x30: /* MRXD */
428     case 0x34: /* NP */
429         /* Ignored.  */
430     case 0x3c: /* Undocuented: Timestamp? */
431         /* Ignored.  */
432         break;
433     default:
434         hw_error("stellaris_enet_write: Bad offset %x\n", (int)offset);
435     }
436 }
437 
438 static const MemoryRegionOps stellaris_enet_ops = {
439     .read = stellaris_enet_read,
440     .write = stellaris_enet_write,
441     .endianness = DEVICE_NATIVE_ENDIAN,
442 };
443 
444 static void stellaris_enet_reset(stellaris_enet_state *s)
445 {
446     s->mdv = 0x80;
447     s->rctl = SE_RCTL_BADCRC;
448     s->im = SE_INT_PHY | SE_INT_MD | SE_INT_RXER | SE_INT_FOV | SE_INT_TXEMP
449             | SE_INT_TXER | SE_INT_RX;
450     s->thr = 0x3f;
451     s->tx_fifo_len = 0;
452 }
453 
454 static void stellaris_enet_cleanup(NetClientState *nc)
455 {
456     stellaris_enet_state *s = qemu_get_nic_opaque(nc);
457 
458     s->nic = NULL;
459 }
460 
461 static NetClientInfo net_stellaris_enet_info = {
462     .type = NET_CLIENT_OPTIONS_KIND_NIC,
463     .size = sizeof(NICState),
464     .can_receive = stellaris_enet_can_receive,
465     .receive = stellaris_enet_receive,
466     .cleanup = stellaris_enet_cleanup,
467 };
468 
469 static int stellaris_enet_init(SysBusDevice *sbd)
470 {
471     DeviceState *dev = DEVICE(sbd);
472     stellaris_enet_state *s = STELLARIS_ENET(dev);
473 
474     memory_region_init_io(&s->mmio, OBJECT(s), &stellaris_enet_ops, s,
475                           "stellaris_enet", 0x1000);
476     sysbus_init_mmio(sbd, &s->mmio);
477     sysbus_init_irq(sbd, &s->irq);
478     qemu_macaddr_default_if_unset(&s->conf.macaddr);
479 
480     s->nic = qemu_new_nic(&net_stellaris_enet_info, &s->conf,
481                           object_get_typename(OBJECT(dev)), dev->id, s);
482     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
483 
484     stellaris_enet_reset(s);
485     return 0;
486 }
487 
488 static Property stellaris_enet_properties[] = {
489     DEFINE_NIC_PROPERTIES(stellaris_enet_state, conf),
490     DEFINE_PROP_END_OF_LIST(),
491 };
492 
493 static void stellaris_enet_class_init(ObjectClass *klass, void *data)
494 {
495     DeviceClass *dc = DEVICE_CLASS(klass);
496     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
497 
498     k->init = stellaris_enet_init;
499     dc->props = stellaris_enet_properties;
500     dc->vmsd = &vmstate_stellaris_enet;
501 }
502 
503 static const TypeInfo stellaris_enet_info = {
504     .name          = TYPE_STELLARIS_ENET,
505     .parent        = TYPE_SYS_BUS_DEVICE,
506     .instance_size = sizeof(stellaris_enet_state),
507     .class_init    = stellaris_enet_class_init,
508 };
509 
510 static void stellaris_enet_register_types(void)
511 {
512     type_register_static(&stellaris_enet_info);
513 }
514 
515 type_init(stellaris_enet_register_types)
516