xref: /openbmc/qemu/hw/net/stellaris_enet.c (revision dc5bd18f)
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 "qemu/osdep.h"
10 #include "hw/sysbus.h"
11 #include "net/net.h"
12 #include <zlib.h>
13 
14 //#define DEBUG_STELLARIS_ENET 1
15 
16 #ifdef DEBUG_STELLARIS_ENET
17 #define DPRINTF(fmt, ...) \
18 do { printf("stellaris_enet: " fmt , ## __VA_ARGS__); } while (0)
19 #define BADF(fmt, ...) \
20 do { fprintf(stderr, "stellaris_enet: error: " fmt , ## __VA_ARGS__); exit(1);} while (0)
21 #else
22 #define DPRINTF(fmt, ...) do {} while(0)
23 #define BADF(fmt, ...) \
24 do { fprintf(stderr, "stellaris_enet: error: " fmt , ## __VA_ARGS__);} while (0)
25 #endif
26 
27 #define SE_INT_RX       0x01
28 #define SE_INT_TXER     0x02
29 #define SE_INT_TXEMP    0x04
30 #define SE_INT_FOV      0x08
31 #define SE_INT_RXER     0x10
32 #define SE_INT_MD       0x20
33 #define SE_INT_PHY      0x40
34 
35 #define SE_RCTL_RXEN    0x01
36 #define SE_RCTL_AMUL    0x02
37 #define SE_RCTL_PRMS    0x04
38 #define SE_RCTL_BADCRC  0x08
39 #define SE_RCTL_RSTFIFO 0x10
40 
41 #define SE_TCTL_TXEN    0x01
42 #define SE_TCTL_PADEN   0x02
43 #define SE_TCTL_CRC     0x04
44 #define SE_TCTL_DUPLEX  0x08
45 
46 #define TYPE_STELLARIS_ENET "stellaris_enet"
47 #define STELLARIS_ENET(obj) \
48     OBJECT_CHECK(stellaris_enet_state, (obj), TYPE_STELLARIS_ENET)
49 
50 typedef struct {
51     uint8_t data[2048];
52     uint32_t len;
53 } StellarisEnetRxFrame;
54 
55 typedef struct {
56     SysBusDevice parent_obj;
57 
58     uint32_t ris;
59     uint32_t im;
60     uint32_t rctl;
61     uint32_t tctl;
62     uint32_t thr;
63     uint32_t mctl;
64     uint32_t mdv;
65     uint32_t mtxd;
66     uint32_t mrxd;
67     uint32_t np;
68     uint32_t tx_fifo_len;
69     uint8_t tx_fifo[2048];
70     /* Real hardware has a 2k fifo, which works out to be at most 31 packets.
71        We implement a full 31 packet fifo.  */
72     StellarisEnetRxFrame rx[31];
73     uint32_t rx_fifo_offset;
74     uint32_t next_packet;
75     NICState *nic;
76     NICConf conf;
77     qemu_irq irq;
78     MemoryRegion mmio;
79 } stellaris_enet_state;
80 
81 static const VMStateDescription vmstate_rx_frame = {
82     .name = "stellaris_enet/rx_frame",
83     .version_id = 1,
84     .minimum_version_id = 1,
85     .fields = (VMStateField[]) {
86         VMSTATE_UINT8_ARRAY(data, StellarisEnetRxFrame, 2048),
87         VMSTATE_UINT32(len, StellarisEnetRxFrame),
88         VMSTATE_END_OF_LIST()
89     }
90 };
91 
92 static int stellaris_enet_post_load(void *opaque, int version_id)
93 {
94     stellaris_enet_state *s = opaque;
95     int i;
96 
97     /* Sanitize inbound state. Note that next_packet is an index but
98      * np is a size; hence their valid upper bounds differ.
99      */
100     if (s->next_packet >= ARRAY_SIZE(s->rx)) {
101         return -1;
102     }
103 
104     if (s->np > ARRAY_SIZE(s->rx)) {
105         return -1;
106     }
107 
108     for (i = 0; i < ARRAY_SIZE(s->rx); i++) {
109         if (s->rx[i].len > ARRAY_SIZE(s->rx[i].data)) {
110             return -1;
111         }
112     }
113 
114     if (s->rx_fifo_offset > ARRAY_SIZE(s->rx[0].data) - 4) {
115         return -1;
116     }
117 
118     if (s->tx_fifo_len > ARRAY_SIZE(s->tx_fifo)) {
119         return -1;
120     }
121 
122     return 0;
123 }
124 
125 static const VMStateDescription vmstate_stellaris_enet = {
126     .name = "stellaris_enet",
127     .version_id = 2,
128     .minimum_version_id = 2,
129     .post_load = stellaris_enet_post_load,
130     .fields = (VMStateField[]) {
131         VMSTATE_UINT32(ris, stellaris_enet_state),
132         VMSTATE_UINT32(im, stellaris_enet_state),
133         VMSTATE_UINT32(rctl, stellaris_enet_state),
134         VMSTATE_UINT32(tctl, stellaris_enet_state),
135         VMSTATE_UINT32(thr, stellaris_enet_state),
136         VMSTATE_UINT32(mctl, stellaris_enet_state),
137         VMSTATE_UINT32(mdv, stellaris_enet_state),
138         VMSTATE_UINT32(mtxd, stellaris_enet_state),
139         VMSTATE_UINT32(mrxd, stellaris_enet_state),
140         VMSTATE_UINT32(np, stellaris_enet_state),
141         VMSTATE_UINT32(tx_fifo_len, stellaris_enet_state),
142         VMSTATE_UINT8_ARRAY(tx_fifo, stellaris_enet_state, 2048),
143         VMSTATE_STRUCT_ARRAY(rx, stellaris_enet_state, 31, 1,
144                              vmstate_rx_frame, StellarisEnetRxFrame),
145         VMSTATE_UINT32(rx_fifo_offset, stellaris_enet_state),
146         VMSTATE_UINT32(next_packet, stellaris_enet_state),
147         VMSTATE_END_OF_LIST()
148     }
149 };
150 
151 static void stellaris_enet_update(stellaris_enet_state *s)
152 {
153     qemu_set_irq(s->irq, (s->ris & s->im) != 0);
154 }
155 
156 /* Return the data length of the packet currently being assembled
157  * in the TX fifo.
158  */
159 static inline int stellaris_txpacket_datalen(stellaris_enet_state *s)
160 {
161     return s->tx_fifo[0] | (s->tx_fifo[1] << 8);
162 }
163 
164 /* Return true if the packet currently in the TX FIFO is complete,
165 * ie the FIFO holds enough bytes for the data length, ethernet header,
166 * payload and optionally CRC.
167 */
168 static inline bool stellaris_txpacket_complete(stellaris_enet_state *s)
169 {
170     int framelen = stellaris_txpacket_datalen(s);
171     framelen += 16;
172     if (!(s->tctl & SE_TCTL_CRC)) {
173         framelen += 4;
174     }
175     /* Cover the corner case of a 2032 byte payload with auto-CRC disabled:
176      * this requires more bytes than will fit in the FIFO. It's not totally
177      * clear how the h/w handles this, but if using threshold-based TX
178      * it will definitely try to transmit something.
179      */
180     framelen = MIN(framelen, ARRAY_SIZE(s->tx_fifo));
181     return s->tx_fifo_len >= framelen;
182 }
183 
184 /* Return true if the TX FIFO threshold is enabled and the FIFO
185  * has filled enough to reach it.
186  */
187 static inline bool stellaris_tx_thr_reached(stellaris_enet_state *s)
188 {
189     return (s->thr < 0x3f &&
190             (s->tx_fifo_len >= 4 * (s->thr * 8 + 1)));
191 }
192 
193 /* Send the packet currently in the TX FIFO */
194 static void stellaris_enet_send(stellaris_enet_state *s)
195 {
196     int framelen = stellaris_txpacket_datalen(s);
197 
198     /* Ethernet header is in the FIFO but not in the datacount.
199      * We don't implement explicit CRC, so just ignore any
200      * CRC value in the FIFO.
201      */
202     framelen += 14;
203     if ((s->tctl & SE_TCTL_PADEN) && framelen < 60) {
204         memset(&s->tx_fifo[framelen + 2], 0, 60 - framelen);
205         framelen = 60;
206     }
207     /* This MIN will have no effect unless the FIFO data is corrupt
208      * (eg bad data from an incoming migration); otherwise the check
209      * on the datalen at the start of writing the data into the FIFO
210      * will have caught this. Silently write a corrupt half-packet,
211      * which is what the hardware does in FIFO underrun situations.
212      */
213     framelen = MIN(framelen, ARRAY_SIZE(s->tx_fifo) - 2);
214     qemu_send_packet(qemu_get_queue(s->nic), s->tx_fifo + 2, framelen);
215     s->tx_fifo_len = 0;
216     s->ris |= SE_INT_TXEMP;
217     stellaris_enet_update(s);
218     DPRINTF("Done TX\n");
219 }
220 
221 /* TODO: Implement MAC address filtering.  */
222 static ssize_t stellaris_enet_receive(NetClientState *nc, const uint8_t *buf, size_t size)
223 {
224     stellaris_enet_state *s = qemu_get_nic_opaque(nc);
225     int n;
226     uint8_t *p;
227     uint32_t crc;
228 
229     if ((s->rctl & SE_RCTL_RXEN) == 0)
230         return -1;
231     if (s->np >= 31) {
232         return 0;
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 
240     if (size >= sizeof(s->rx[n].data) - 6) {
241         /* If the packet won't fit into the
242          * emulated 2K RAM, this is reported
243          * as a FIFO overrun error.
244          */
245         s->ris |= SE_INT_FOV;
246         stellaris_enet_update(s);
247         return -1;
248     }
249 
250     s->np++;
251     s->rx[n].len = size + 6;
252     p = s->rx[n].data;
253     *(p++) = (size + 6);
254     *(p++) = (size + 6) >> 8;
255     memcpy (p, buf, size);
256     p += size;
257     crc = crc32(~0, buf, size);
258     *(p++) = crc;
259     *(p++) = crc >> 8;
260     *(p++) = crc >> 16;
261     *(p++) = crc >> 24;
262     /* Clear the remaining bytes in the last word.  */
263     if ((size & 3) != 2) {
264         memset(p, 0, (6 - size) & 3);
265     }
266 
267     s->ris |= SE_INT_RX;
268     stellaris_enet_update(s);
269 
270     return size;
271 }
272 
273 static int stellaris_enet_can_receive(stellaris_enet_state *s)
274 {
275     return (s->np < 31);
276 }
277 
278 static uint64_t stellaris_enet_read(void *opaque, hwaddr offset,
279                                     unsigned size)
280 {
281     stellaris_enet_state *s = (stellaris_enet_state *)opaque;
282     uint32_t val;
283 
284     switch (offset) {
285     case 0x00: /* RIS */
286         DPRINTF("IRQ status %02x\n", s->ris);
287         return s->ris;
288     case 0x04: /* IM */
289         return s->im;
290     case 0x08: /* RCTL */
291         return s->rctl;
292     case 0x0c: /* TCTL */
293         return s->tctl;
294     case 0x10: /* DATA */
295     {
296         uint8_t *rx_fifo;
297 
298         if (s->np == 0) {
299             BADF("RX underflow\n");
300             return 0;
301         }
302 
303         rx_fifo = s->rx[s->next_packet].data + s->rx_fifo_offset;
304 
305         val = rx_fifo[0] | (rx_fifo[1] << 8) | (rx_fifo[2] << 16)
306               | (rx_fifo[3] << 24);
307         s->rx_fifo_offset += 4;
308         if (s->rx_fifo_offset >= s->rx[s->next_packet].len) {
309             s->rx_fifo_offset = 0;
310             s->next_packet++;
311             if (s->next_packet >= 31)
312                 s->next_packet = 0;
313             s->np--;
314             DPRINTF("RX done np=%d\n", s->np);
315             if (!s->np && stellaris_enet_can_receive(s)) {
316                 qemu_flush_queued_packets(qemu_get_queue(s->nic));
317             }
318         }
319         return val;
320     }
321     case 0x14: /* IA0 */
322         return s->conf.macaddr.a[0] | (s->conf.macaddr.a[1] << 8)
323             | (s->conf.macaddr.a[2] << 16)
324             | ((uint32_t)s->conf.macaddr.a[3] << 24);
325     case 0x18: /* IA1 */
326         return s->conf.macaddr.a[4] | (s->conf.macaddr.a[5] << 8);
327     case 0x1c: /* THR */
328         return s->thr;
329     case 0x20: /* MCTL */
330         return s->mctl;
331     case 0x24: /* MDV */
332         return s->mdv;
333     case 0x28: /* MADD */
334         return 0;
335     case 0x2c: /* MTXD */
336         return s->mtxd;
337     case 0x30: /* MRXD */
338         return s->mrxd;
339     case 0x34: /* NP */
340         return s->np;
341     case 0x38: /* TR */
342         return 0;
343     case 0x3c: /* Undocuented: Timestamp? */
344         return 0;
345     default:
346         hw_error("stellaris_enet_read: Bad offset %x\n", (int)offset);
347         return 0;
348     }
349 }
350 
351 static void stellaris_enet_write(void *opaque, hwaddr offset,
352                                  uint64_t value, unsigned size)
353 {
354     stellaris_enet_state *s = (stellaris_enet_state *)opaque;
355 
356     switch (offset) {
357     case 0x00: /* IACK */
358         s->ris &= ~value;
359         DPRINTF("IRQ ack %02" PRIx64 "/%02x\n", value, s->ris);
360         stellaris_enet_update(s);
361         /* Clearing TXER also resets the TX fifo.  */
362         if (value & SE_INT_TXER) {
363             s->tx_fifo_len = 0;
364         }
365         break;
366     case 0x04: /* IM */
367         DPRINTF("IRQ mask %02" PRIx64 "/%02x\n", value, s->ris);
368         s->im = value;
369         stellaris_enet_update(s);
370         break;
371     case 0x08: /* RCTL */
372         s->rctl = value;
373         if (value & SE_RCTL_RSTFIFO) {
374             s->np = 0;
375             s->rx_fifo_offset = 0;
376             stellaris_enet_update(s);
377         }
378         break;
379     case 0x0c: /* TCTL */
380         s->tctl = value;
381         break;
382     case 0x10: /* DATA */
383         if (s->tx_fifo_len == 0) {
384             /* The first word is special, it contains the data length */
385             int framelen = value & 0xffff;
386             if (framelen > 2032) {
387                 DPRINTF("TX frame too long (%d)\n", framelen);
388                 s->ris |= SE_INT_TXER;
389                 stellaris_enet_update(s);
390                 break;
391             }
392         }
393 
394         if (s->tx_fifo_len + 4 <= ARRAY_SIZE(s->tx_fifo)) {
395             s->tx_fifo[s->tx_fifo_len++] = value;
396             s->tx_fifo[s->tx_fifo_len++] = value >> 8;
397             s->tx_fifo[s->tx_fifo_len++] = value >> 16;
398             s->tx_fifo[s->tx_fifo_len++] = value >> 24;
399         }
400 
401         if (stellaris_tx_thr_reached(s) && stellaris_txpacket_complete(s)) {
402             stellaris_enet_send(s);
403         }
404         break;
405     case 0x14: /* IA0 */
406         s->conf.macaddr.a[0] = value;
407         s->conf.macaddr.a[1] = value >> 8;
408         s->conf.macaddr.a[2] = value >> 16;
409         s->conf.macaddr.a[3] = value >> 24;
410         break;
411     case 0x18: /* IA1 */
412         s->conf.macaddr.a[4] = value;
413         s->conf.macaddr.a[5] = value >> 8;
414         break;
415     case 0x1c: /* THR */
416         s->thr = value;
417         break;
418     case 0x20: /* MCTL */
419         /* TODO: MII registers aren't modelled.
420          * Clear START, indicating that the operation completes immediately.
421          */
422         s->mctl = value & ~1;
423         break;
424     case 0x24: /* MDV */
425         s->mdv = value;
426         break;
427     case 0x28: /* MADD */
428         /* ignored.  */
429         break;
430     case 0x2c: /* MTXD */
431         s->mtxd = value & 0xff;
432         break;
433     case 0x38: /* TR */
434         if (value & 1) {
435             stellaris_enet_send(s);
436         }
437         break;
438     case 0x30: /* MRXD */
439     case 0x34: /* NP */
440         /* Ignored.  */
441     case 0x3c: /* Undocuented: Timestamp? */
442         /* Ignored.  */
443         break;
444     default:
445         hw_error("stellaris_enet_write: Bad offset %x\n", (int)offset);
446     }
447 }
448 
449 static const MemoryRegionOps stellaris_enet_ops = {
450     .read = stellaris_enet_read,
451     .write = stellaris_enet_write,
452     .endianness = DEVICE_NATIVE_ENDIAN,
453 };
454 
455 static void stellaris_enet_reset(stellaris_enet_state *s)
456 {
457     s->mdv = 0x80;
458     s->rctl = SE_RCTL_BADCRC;
459     s->im = SE_INT_PHY | SE_INT_MD | SE_INT_RXER | SE_INT_FOV | SE_INT_TXEMP
460             | SE_INT_TXER | SE_INT_RX;
461     s->thr = 0x3f;
462     s->tx_fifo_len = 0;
463 }
464 
465 static NetClientInfo net_stellaris_enet_info = {
466     .type = NET_CLIENT_DRIVER_NIC,
467     .size = sizeof(NICState),
468     .receive = stellaris_enet_receive,
469 };
470 
471 static int stellaris_enet_init(SysBusDevice *sbd)
472 {
473     DeviceState *dev = DEVICE(sbd);
474     stellaris_enet_state *s = STELLARIS_ENET(dev);
475 
476     memory_region_init_io(&s->mmio, OBJECT(s), &stellaris_enet_ops, s,
477                           "stellaris_enet", 0x1000);
478     sysbus_init_mmio(sbd, &s->mmio);
479     sysbus_init_irq(sbd, &s->irq);
480     qemu_macaddr_default_if_unset(&s->conf.macaddr);
481 
482     s->nic = qemu_new_nic(&net_stellaris_enet_info, &s->conf,
483                           object_get_typename(OBJECT(dev)), dev->id, s);
484     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
485 
486     stellaris_enet_reset(s);
487     return 0;
488 }
489 
490 static Property stellaris_enet_properties[] = {
491     DEFINE_NIC_PROPERTIES(stellaris_enet_state, conf),
492     DEFINE_PROP_END_OF_LIST(),
493 };
494 
495 static void stellaris_enet_class_init(ObjectClass *klass, void *data)
496 {
497     DeviceClass *dc = DEVICE_CLASS(klass);
498     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
499 
500     k->init = stellaris_enet_init;
501     dc->props = stellaris_enet_properties;
502     dc->vmsd = &vmstate_stellaris_enet;
503 }
504 
505 static const TypeInfo stellaris_enet_info = {
506     .name          = TYPE_STELLARIS_ENET,
507     .parent        = TYPE_SYS_BUS_DEVICE,
508     .instance_size = sizeof(stellaris_enet_state),
509     .class_init    = stellaris_enet_class_init,
510 };
511 
512 static void stellaris_enet_register_types(void)
513 {
514     type_register_static(&stellaris_enet_info);
515 }
516 
517 type_init(stellaris_enet_register_types)
518