xref: /qemu/hw/net/stellaris_enet.c (revision 7a4e543d)
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     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(stellaris_enet_state *s)
264 {
265     return (s->np < 31);
266 }
267 
268 static uint64_t stellaris_enet_read(void *opaque, hwaddr offset,
269                                     unsigned size)
270 {
271     stellaris_enet_state *s = (stellaris_enet_state *)opaque;
272     uint32_t val;
273 
274     switch (offset) {
275     case 0x00: /* RIS */
276         DPRINTF("IRQ status %02x\n", s->ris);
277         return s->ris;
278     case 0x04: /* IM */
279         return s->im;
280     case 0x08: /* RCTL */
281         return s->rctl;
282     case 0x0c: /* TCTL */
283         return s->tctl;
284     case 0x10: /* DATA */
285     {
286         uint8_t *rx_fifo;
287 
288         if (s->np == 0) {
289             BADF("RX underflow\n");
290             return 0;
291         }
292 
293         rx_fifo = s->rx[s->next_packet].data + s->rx_fifo_offset;
294 
295         val = rx_fifo[0] | (rx_fifo[1] << 8) | (rx_fifo[2] << 16)
296               | (rx_fifo[3] << 24);
297         s->rx_fifo_offset += 4;
298         if (s->rx_fifo_offset >= s->rx[s->next_packet].len) {
299             s->rx_fifo_offset = 0;
300             s->next_packet++;
301             if (s->next_packet >= 31)
302                 s->next_packet = 0;
303             s->np--;
304             DPRINTF("RX done np=%d\n", s->np);
305             if (!s->np && stellaris_enet_can_receive(s)) {
306                 qemu_flush_queued_packets(qemu_get_queue(s->nic));
307             }
308         }
309         return val;
310     }
311     case 0x14: /* IA0 */
312         return s->conf.macaddr.a[0] | (s->conf.macaddr.a[1] << 8)
313             | (s->conf.macaddr.a[2] << 16)
314             | ((uint32_t)s->conf.macaddr.a[3] << 24);
315     case 0x18: /* IA1 */
316         return s->conf.macaddr.a[4] | (s->conf.macaddr.a[5] << 8);
317     case 0x1c: /* THR */
318         return s->thr;
319     case 0x20: /* MCTL */
320         return s->mctl;
321     case 0x24: /* MDV */
322         return s->mdv;
323     case 0x28: /* MADD */
324         return 0;
325     case 0x2c: /* MTXD */
326         return s->mtxd;
327     case 0x30: /* MRXD */
328         return s->mrxd;
329     case 0x34: /* NP */
330         return s->np;
331     case 0x38: /* TR */
332         return 0;
333     case 0x3c: /* Undocuented: Timestamp? */
334         return 0;
335     default:
336         hw_error("stellaris_enet_read: Bad offset %x\n", (int)offset);
337         return 0;
338     }
339 }
340 
341 static void stellaris_enet_write(void *opaque, hwaddr offset,
342                                  uint64_t value, unsigned size)
343 {
344     stellaris_enet_state *s = (stellaris_enet_state *)opaque;
345 
346     switch (offset) {
347     case 0x00: /* IACK */
348         s->ris &= ~value;
349         DPRINTF("IRQ ack %02" PRIx64 "/%02x\n", value, s->ris);
350         stellaris_enet_update(s);
351         /* Clearing TXER also resets the TX fifo.  */
352         if (value & SE_INT_TXER) {
353             s->tx_fifo_len = 0;
354         }
355         break;
356     case 0x04: /* IM */
357         DPRINTF("IRQ mask %02" PRIx64 "/%02x\n", value, s->ris);
358         s->im = value;
359         stellaris_enet_update(s);
360         break;
361     case 0x08: /* RCTL */
362         s->rctl = value;
363         if (value & SE_RCTL_RSTFIFO) {
364             s->np = 0;
365             s->rx_fifo_offset = 0;
366             stellaris_enet_update(s);
367         }
368         break;
369     case 0x0c: /* TCTL */
370         s->tctl = value;
371         break;
372     case 0x10: /* DATA */
373         if (s->tx_fifo_len == 0) {
374             /* The first word is special, it contains the data length */
375             int framelen = value & 0xffff;
376             if (framelen > 2032) {
377                 DPRINTF("TX frame too long (%d)\n", framelen);
378                 s->ris |= SE_INT_TXER;
379                 stellaris_enet_update(s);
380                 break;
381             }
382         }
383 
384         if (s->tx_fifo_len + 4 <= ARRAY_SIZE(s->tx_fifo)) {
385             s->tx_fifo[s->tx_fifo_len++] = value;
386             s->tx_fifo[s->tx_fifo_len++] = value >> 8;
387             s->tx_fifo[s->tx_fifo_len++] = value >> 16;
388             s->tx_fifo[s->tx_fifo_len++] = value >> 24;
389         }
390 
391         if (stellaris_tx_thr_reached(s) && stellaris_txpacket_complete(s)) {
392             stellaris_enet_send(s);
393         }
394         break;
395     case 0x14: /* IA0 */
396         s->conf.macaddr.a[0] = value;
397         s->conf.macaddr.a[1] = value >> 8;
398         s->conf.macaddr.a[2] = value >> 16;
399         s->conf.macaddr.a[3] = value >> 24;
400         break;
401     case 0x18: /* IA1 */
402         s->conf.macaddr.a[4] = value;
403         s->conf.macaddr.a[5] = value >> 8;
404         break;
405     case 0x1c: /* THR */
406         s->thr = value;
407         break;
408     case 0x20: /* MCTL */
409         s->mctl = value;
410         break;
411     case 0x24: /* MDV */
412         s->mdv = value;
413         break;
414     case 0x28: /* MADD */
415         /* ignored.  */
416         break;
417     case 0x2c: /* MTXD */
418         s->mtxd = value & 0xff;
419         break;
420     case 0x38: /* TR */
421         if (value & 1) {
422             stellaris_enet_send(s);
423         }
424         break;
425     case 0x30: /* MRXD */
426     case 0x34: /* NP */
427         /* Ignored.  */
428     case 0x3c: /* Undocuented: Timestamp? */
429         /* Ignored.  */
430         break;
431     default:
432         hw_error("stellaris_enet_write: Bad offset %x\n", (int)offset);
433     }
434 }
435 
436 static const MemoryRegionOps stellaris_enet_ops = {
437     .read = stellaris_enet_read,
438     .write = stellaris_enet_write,
439     .endianness = DEVICE_NATIVE_ENDIAN,
440 };
441 
442 static void stellaris_enet_reset(stellaris_enet_state *s)
443 {
444     s->mdv = 0x80;
445     s->rctl = SE_RCTL_BADCRC;
446     s->im = SE_INT_PHY | SE_INT_MD | SE_INT_RXER | SE_INT_FOV | SE_INT_TXEMP
447             | SE_INT_TXER | SE_INT_RX;
448     s->thr = 0x3f;
449     s->tx_fifo_len = 0;
450 }
451 
452 static NetClientInfo net_stellaris_enet_info = {
453     .type = NET_CLIENT_OPTIONS_KIND_NIC,
454     .size = sizeof(NICState),
455     .receive = stellaris_enet_receive,
456 };
457 
458 static int stellaris_enet_init(SysBusDevice *sbd)
459 {
460     DeviceState *dev = DEVICE(sbd);
461     stellaris_enet_state *s = STELLARIS_ENET(dev);
462 
463     memory_region_init_io(&s->mmio, OBJECT(s), &stellaris_enet_ops, s,
464                           "stellaris_enet", 0x1000);
465     sysbus_init_mmio(sbd, &s->mmio);
466     sysbus_init_irq(sbd, &s->irq);
467     qemu_macaddr_default_if_unset(&s->conf.macaddr);
468 
469     s->nic = qemu_new_nic(&net_stellaris_enet_info, &s->conf,
470                           object_get_typename(OBJECT(dev)), dev->id, s);
471     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
472 
473     stellaris_enet_reset(s);
474     return 0;
475 }
476 
477 static Property stellaris_enet_properties[] = {
478     DEFINE_NIC_PROPERTIES(stellaris_enet_state, conf),
479     DEFINE_PROP_END_OF_LIST(),
480 };
481 
482 static void stellaris_enet_class_init(ObjectClass *klass, void *data)
483 {
484     DeviceClass *dc = DEVICE_CLASS(klass);
485     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
486 
487     k->init = stellaris_enet_init;
488     dc->props = stellaris_enet_properties;
489     dc->vmsd = &vmstate_stellaris_enet;
490 }
491 
492 static const TypeInfo stellaris_enet_info = {
493     .name          = TYPE_STELLARIS_ENET,
494     .parent        = TYPE_SYS_BUS_DEVICE,
495     .instance_size = sizeof(stellaris_enet_state),
496     .class_init    = stellaris_enet_class_init,
497 };
498 
499 static void stellaris_enet_register_types(void)
500 {
501     type_register_static(&stellaris_enet_info);
502 }
503 
504 type_init(stellaris_enet_register_types)
505