xref: /openbmc/qemu/hw/net/stellaris_enet.c (revision b45c03f5)
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         return 0;
232     }
233 
234     DPRINTF("Received packet len=%zu\n", size);
235     n = s->next_packet + s->np;
236     if (n >= 31)
237         n -= 31;
238     s->np++;
239 
240     s->rx[n].len = size + 6;
241     p = s->rx[n].data;
242     *(p++) = (size + 6);
243     *(p++) = (size + 6) >> 8;
244     memcpy (p, buf, size);
245     p += size;
246     crc = crc32(~0, buf, size);
247     *(p++) = crc;
248     *(p++) = crc >> 8;
249     *(p++) = crc >> 16;
250     *(p++) = crc >> 24;
251     /* Clear the remaining bytes in the last word.  */
252     if ((size & 3) != 2) {
253         memset(p, 0, (6 - size) & 3);
254     }
255 
256     s->ris |= SE_INT_RX;
257     stellaris_enet_update(s);
258 
259     return size;
260 }
261 
262 static int stellaris_enet_can_receive(stellaris_enet_state *s)
263 {
264     return (s->np < 31);
265 }
266 
267 static uint64_t stellaris_enet_read(void *opaque, hwaddr offset,
268                                     unsigned size)
269 {
270     stellaris_enet_state *s = (stellaris_enet_state *)opaque;
271     uint32_t val;
272 
273     switch (offset) {
274     case 0x00: /* RIS */
275         DPRINTF("IRQ status %02x\n", s->ris);
276         return s->ris;
277     case 0x04: /* IM */
278         return s->im;
279     case 0x08: /* RCTL */
280         return s->rctl;
281     case 0x0c: /* TCTL */
282         return s->tctl;
283     case 0x10: /* DATA */
284     {
285         uint8_t *rx_fifo;
286 
287         if (s->np == 0) {
288             BADF("RX underflow\n");
289             return 0;
290         }
291 
292         rx_fifo = s->rx[s->next_packet].data + s->rx_fifo_offset;
293 
294         val = rx_fifo[0] | (rx_fifo[1] << 8) | (rx_fifo[2] << 16)
295               | (rx_fifo[3] << 24);
296         s->rx_fifo_offset += 4;
297         if (s->rx_fifo_offset >= s->rx[s->next_packet].len) {
298             s->rx_fifo_offset = 0;
299             s->next_packet++;
300             if (s->next_packet >= 31)
301                 s->next_packet = 0;
302             s->np--;
303             DPRINTF("RX done np=%d\n", s->np);
304             if (!s->np && stellaris_enet_can_receive(s)) {
305                 qemu_flush_queued_packets(qemu_get_queue(s->nic));
306             }
307         }
308         return val;
309     }
310     case 0x14: /* IA0 */
311         return s->conf.macaddr.a[0] | (s->conf.macaddr.a[1] << 8)
312             | (s->conf.macaddr.a[2] << 16)
313             | ((uint32_t)s->conf.macaddr.a[3] << 24);
314     case 0x18: /* IA1 */
315         return s->conf.macaddr.a[4] | (s->conf.macaddr.a[5] << 8);
316     case 0x1c: /* THR */
317         return s->thr;
318     case 0x20: /* MCTL */
319         return s->mctl;
320     case 0x24: /* MDV */
321         return s->mdv;
322     case 0x28: /* MADD */
323         return 0;
324     case 0x2c: /* MTXD */
325         return s->mtxd;
326     case 0x30: /* MRXD */
327         return s->mrxd;
328     case 0x34: /* NP */
329         return s->np;
330     case 0x38: /* TR */
331         return 0;
332     case 0x3c: /* Undocuented: Timestamp? */
333         return 0;
334     default:
335         hw_error("stellaris_enet_read: Bad offset %x\n", (int)offset);
336         return 0;
337     }
338 }
339 
340 static void stellaris_enet_write(void *opaque, hwaddr offset,
341                                  uint64_t value, unsigned size)
342 {
343     stellaris_enet_state *s = (stellaris_enet_state *)opaque;
344 
345     switch (offset) {
346     case 0x00: /* IACK */
347         s->ris &= ~value;
348         DPRINTF("IRQ ack %02" PRIx64 "/%02x\n", value, s->ris);
349         stellaris_enet_update(s);
350         /* Clearing TXER also resets the TX fifo.  */
351         if (value & SE_INT_TXER) {
352             s->tx_fifo_len = 0;
353         }
354         break;
355     case 0x04: /* IM */
356         DPRINTF("IRQ mask %02" PRIx64 "/%02x\n", value, s->ris);
357         s->im = value;
358         stellaris_enet_update(s);
359         break;
360     case 0x08: /* RCTL */
361         s->rctl = value;
362         if (value & SE_RCTL_RSTFIFO) {
363             s->np = 0;
364             s->rx_fifo_offset = 0;
365             stellaris_enet_update(s);
366         }
367         break;
368     case 0x0c: /* TCTL */
369         s->tctl = value;
370         break;
371     case 0x10: /* DATA */
372         if (s->tx_fifo_len == 0) {
373             /* The first word is special, it contains the data length */
374             int framelen = value & 0xffff;
375             if (framelen > 2032) {
376                 DPRINTF("TX frame too long (%d)\n", framelen);
377                 s->ris |= SE_INT_TXER;
378                 stellaris_enet_update(s);
379                 break;
380             }
381         }
382 
383         if (s->tx_fifo_len + 4 <= ARRAY_SIZE(s->tx_fifo)) {
384             s->tx_fifo[s->tx_fifo_len++] = value;
385             s->tx_fifo[s->tx_fifo_len++] = value >> 8;
386             s->tx_fifo[s->tx_fifo_len++] = value >> 16;
387             s->tx_fifo[s->tx_fifo_len++] = value >> 24;
388         }
389 
390         if (stellaris_tx_thr_reached(s) && stellaris_txpacket_complete(s)) {
391             stellaris_enet_send(s);
392         }
393         break;
394     case 0x14: /* IA0 */
395         s->conf.macaddr.a[0] = value;
396         s->conf.macaddr.a[1] = value >> 8;
397         s->conf.macaddr.a[2] = value >> 16;
398         s->conf.macaddr.a[3] = value >> 24;
399         break;
400     case 0x18: /* IA1 */
401         s->conf.macaddr.a[4] = value;
402         s->conf.macaddr.a[5] = value >> 8;
403         break;
404     case 0x1c: /* THR */
405         s->thr = value;
406         break;
407     case 0x20: /* MCTL */
408         s->mctl = value;
409         break;
410     case 0x24: /* MDV */
411         s->mdv = value;
412         break;
413     case 0x28: /* MADD */
414         /* ignored.  */
415         break;
416     case 0x2c: /* MTXD */
417         s->mtxd = value & 0xff;
418         break;
419     case 0x38: /* TR */
420         if (value & 1) {
421             stellaris_enet_send(s);
422         }
423         break;
424     case 0x30: /* MRXD */
425     case 0x34: /* NP */
426         /* Ignored.  */
427     case 0x3c: /* Undocuented: Timestamp? */
428         /* Ignored.  */
429         break;
430     default:
431         hw_error("stellaris_enet_write: Bad offset %x\n", (int)offset);
432     }
433 }
434 
435 static const MemoryRegionOps stellaris_enet_ops = {
436     .read = stellaris_enet_read,
437     .write = stellaris_enet_write,
438     .endianness = DEVICE_NATIVE_ENDIAN,
439 };
440 
441 static void stellaris_enet_reset(stellaris_enet_state *s)
442 {
443     s->mdv = 0x80;
444     s->rctl = SE_RCTL_BADCRC;
445     s->im = SE_INT_PHY | SE_INT_MD | SE_INT_RXER | SE_INT_FOV | SE_INT_TXEMP
446             | SE_INT_TXER | SE_INT_RX;
447     s->thr = 0x3f;
448     s->tx_fifo_len = 0;
449 }
450 
451 static NetClientInfo net_stellaris_enet_info = {
452     .type = NET_CLIENT_OPTIONS_KIND_NIC,
453     .size = sizeof(NICState),
454     .receive = stellaris_enet_receive,
455 };
456 
457 static int stellaris_enet_init(SysBusDevice *sbd)
458 {
459     DeviceState *dev = DEVICE(sbd);
460     stellaris_enet_state *s = STELLARIS_ENET(dev);
461 
462     memory_region_init_io(&s->mmio, OBJECT(s), &stellaris_enet_ops, s,
463                           "stellaris_enet", 0x1000);
464     sysbus_init_mmio(sbd, &s->mmio);
465     sysbus_init_irq(sbd, &s->irq);
466     qemu_macaddr_default_if_unset(&s->conf.macaddr);
467 
468     s->nic = qemu_new_nic(&net_stellaris_enet_info, &s->conf,
469                           object_get_typename(OBJECT(dev)), dev->id, s);
470     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
471 
472     stellaris_enet_reset(s);
473     return 0;
474 }
475 
476 static Property stellaris_enet_properties[] = {
477     DEFINE_NIC_PROPERTIES(stellaris_enet_state, conf),
478     DEFINE_PROP_END_OF_LIST(),
479 };
480 
481 static void stellaris_enet_class_init(ObjectClass *klass, void *data)
482 {
483     DeviceClass *dc = DEVICE_CLASS(klass);
484     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
485 
486     k->init = stellaris_enet_init;
487     dc->props = stellaris_enet_properties;
488     dc->vmsd = &vmstate_stellaris_enet;
489 }
490 
491 static const TypeInfo stellaris_enet_info = {
492     .name          = TYPE_STELLARIS_ENET,
493     .parent        = TYPE_SYS_BUS_DEVICE,
494     .instance_size = sizeof(stellaris_enet_state),
495     .class_init    = stellaris_enet_class_init,
496 };
497 
498 static void stellaris_enet_register_types(void)
499 {
500     type_register_static(&stellaris_enet_info);
501 }
502 
503 type_init(stellaris_enet_register_types)
504