xref: /qemu/hw/net/smc91c111.c (revision aad6f264add3f2be72acb660816588fe09110069)
1 /*
2  * SMSC 91C111 Ethernet interface emulation
3  *
4  * Copyright (c) 2005 CodeSourcery, LLC.
5  * Written by Paul Brook
6  *
7  * This code is licensed under the GPL
8  */
9 
10 #include "qemu/osdep.h"
11 #include "hw/sysbus.h"
12 #include "migration/vmstate.h"
13 #include "net/net.h"
14 #include "hw/irq.h"
15 #include "hw/net/smc91c111.h"
16 #include "hw/qdev-properties.h"
17 #include "qapi/error.h"
18 #include "qemu/log.h"
19 #include "qemu/module.h"
20 #include <zlib.h> /* for crc32 */
21 #include "qom/object.h"
22 
23 /* Number of 2k memory pages available.  */
24 #define NUM_PACKETS 4
25 /*
26  * Maximum size of a data frame, including the leading status word
27  * and byte count fields and the trailing CRC, last data byte
28  * and control byte (per figure 8-1 in the Microchip Technology
29  * LAN91C111 datasheet).
30  */
31 #define MAX_PACKET_SIZE 2048
32 
33 #define TYPE_SMC91C111 "smc91c111"
34 OBJECT_DECLARE_SIMPLE_TYPE(smc91c111_state, SMC91C111)
35 
36 struct smc91c111_state {
37     SysBusDevice parent_obj;
38 
39     NICState *nic;
40     NICConf conf;
41     uint16_t tcr;
42     uint16_t rcr;
43     uint16_t cr;
44     uint16_t ctr;
45     uint16_t gpr;
46     uint16_t ptr;
47     uint16_t ercv;
48     qemu_irq irq;
49     int bank;
50     int packet_num;
51     int tx_alloc;
52     /* Bitmask of allocated packets.  */
53     int allocated;
54     int tx_fifo_len;
55     int tx_fifo[NUM_PACKETS];
56     int rx_fifo_len;
57     int rx_fifo[NUM_PACKETS];
58     int tx_fifo_done_len;
59     int tx_fifo_done[NUM_PACKETS];
60     /* Packet buffer memory.  */
61     uint8_t data[NUM_PACKETS][2048];
62     uint8_t int_level;
63     uint8_t int_mask;
64     MemoryRegion mmio;
65 };
66 
67 static const VMStateDescription vmstate_smc91c111 = {
68     .name = "smc91c111",
69     .version_id = 1,
70     .minimum_version_id = 1,
71     .fields = (const VMStateField[]) {
72         VMSTATE_UINT16(tcr, smc91c111_state),
73         VMSTATE_UINT16(rcr, smc91c111_state),
74         VMSTATE_UINT16(cr, smc91c111_state),
75         VMSTATE_UINT16(ctr, smc91c111_state),
76         VMSTATE_UINT16(gpr, smc91c111_state),
77         VMSTATE_UINT16(ptr, smc91c111_state),
78         VMSTATE_UINT16(ercv, smc91c111_state),
79         VMSTATE_INT32(bank, smc91c111_state),
80         VMSTATE_INT32(packet_num, smc91c111_state),
81         VMSTATE_INT32(tx_alloc, smc91c111_state),
82         VMSTATE_INT32(allocated, smc91c111_state),
83         VMSTATE_INT32(tx_fifo_len, smc91c111_state),
84         VMSTATE_INT32_ARRAY(tx_fifo, smc91c111_state, NUM_PACKETS),
85         VMSTATE_INT32(rx_fifo_len, smc91c111_state),
86         VMSTATE_INT32_ARRAY(rx_fifo, smc91c111_state, NUM_PACKETS),
87         VMSTATE_INT32(tx_fifo_done_len, smc91c111_state),
88         VMSTATE_INT32_ARRAY(tx_fifo_done, smc91c111_state, NUM_PACKETS),
89         VMSTATE_BUFFER_UNSAFE(data, smc91c111_state, 0, NUM_PACKETS * 2048),
90         VMSTATE_UINT8(int_level, smc91c111_state),
91         VMSTATE_UINT8(int_mask, smc91c111_state),
92         VMSTATE_END_OF_LIST()
93     }
94 };
95 
96 #define RCR_SOFT_RST  0x8000
97 #define RCR_STRIP_CRC 0x0200
98 #define RCR_RXEN      0x0100
99 
100 #define TCR_EPH_LOOP  0x2000
101 #define TCR_NOCRC     0x0100
102 #define TCR_PAD_EN    0x0080
103 #define TCR_FORCOL    0x0004
104 #define TCR_LOOP      0x0002
105 #define TCR_TXEN      0x0001
106 
107 #define INT_MD        0x80
108 #define INT_ERCV      0x40
109 #define INT_EPH       0x20
110 #define INT_RX_OVRN   0x10
111 #define INT_ALLOC     0x08
112 #define INT_TX_EMPTY  0x04
113 #define INT_TX        0x02
114 #define INT_RCV       0x01
115 
116 #define CTR_AUTO_RELEASE  0x0800
117 #define CTR_RELOAD        0x0002
118 #define CTR_STORE         0x0001
119 
120 #define RS_ALGNERR      0x8000
121 #define RS_BRODCAST     0x4000
122 #define RS_BADCRC       0x2000
123 #define RS_ODDFRAME     0x1000
124 #define RS_TOOLONG      0x0800
125 #define RS_TOOSHORT     0x0400
126 #define RS_MULTICAST    0x0001
127 
128 static inline bool packetnum_valid(int packet_num)
129 {
130     return packet_num >= 0 && packet_num < NUM_PACKETS;
131 }
132 
133 /* Update interrupt status.  */
134 static void smc91c111_update(smc91c111_state *s)
135 {
136     int level;
137 
138     if (s->tx_fifo_len == 0)
139         s->int_level |= INT_TX_EMPTY;
140     if (s->tx_fifo_done_len != 0)
141         s->int_level |= INT_TX;
142     level = (s->int_level & s->int_mask) != 0;
143     qemu_set_irq(s->irq, level);
144 }
145 
146 static bool smc91c111_can_receive(smc91c111_state *s)
147 {
148     if ((s->rcr & RCR_RXEN) == 0 || (s->rcr & RCR_SOFT_RST)) {
149         return true;
150     }
151     if (s->allocated == (1 << NUM_PACKETS) - 1 ||
152         s->rx_fifo_len == NUM_PACKETS) {
153         return false;
154     }
155     return true;
156 }
157 
158 static inline void smc91c111_flush_queued_packets(smc91c111_state *s)
159 {
160     if (smc91c111_can_receive(s)) {
161         qemu_flush_queued_packets(qemu_get_queue(s->nic));
162     }
163 }
164 
165 /* Try to allocate a packet.  Returns 0x80 on failure.  */
166 static int smc91c111_allocate_packet(smc91c111_state *s)
167 {
168     int i;
169     if (s->allocated == (1 << NUM_PACKETS) - 1) {
170         return 0x80;
171     }
172 
173     for (i = 0; i < NUM_PACKETS; i++) {
174         if ((s->allocated & (1 << i)) == 0)
175             break;
176     }
177     s->allocated |= 1 << i;
178     return i;
179 }
180 
181 
182 /* Process a pending TX allocate.  */
183 static void smc91c111_tx_alloc(smc91c111_state *s)
184 {
185     s->tx_alloc = smc91c111_allocate_packet(s);
186     if (s->tx_alloc == 0x80)
187         return;
188     s->int_level |= INT_ALLOC;
189     smc91c111_update(s);
190 }
191 
192 /* Remove and item from the RX FIFO.  */
193 static void smc91c111_pop_rx_fifo(smc91c111_state *s)
194 {
195     int i;
196 
197     if (s->rx_fifo_len == 0) {
198         /*
199          * The datasheet doesn't document what the behaviour is if the
200          * guest tries to pop an empty RX FIFO, and there's no obvious
201          * error status register to report it. Just ignore the attempt.
202          */
203         return;
204     }
205 
206     s->rx_fifo_len--;
207     if (s->rx_fifo_len) {
208         for (i = 0; i < s->rx_fifo_len; i++)
209             s->rx_fifo[i] = s->rx_fifo[i + 1];
210         s->int_level |= INT_RCV;
211     } else {
212         s->int_level &= ~INT_RCV;
213     }
214     smc91c111_flush_queued_packets(s);
215     smc91c111_update(s);
216 }
217 
218 /* Remove an item from the TX completion FIFO.  */
219 static void smc91c111_pop_tx_fifo_done(smc91c111_state *s)
220 {
221     int i;
222 
223     if (s->tx_fifo_done_len == 0)
224         return;
225     s->tx_fifo_done_len--;
226     for (i = 0; i < s->tx_fifo_done_len; i++)
227         s->tx_fifo_done[i] = s->tx_fifo_done[i + 1];
228 }
229 
230 /* Release the memory allocated to a packet.  */
231 static void smc91c111_release_packet(smc91c111_state *s, int packet)
232 {
233     if (!packetnum_valid(packet)) {
234         /*
235          * Data sheet doesn't document behaviour in this guest error
236          * case, and there is no error status register to report it.
237          * Log and ignore the attempt.
238          */
239         qemu_log_mask(LOG_GUEST_ERROR,
240                       "smc91c111: attempt to release invalid packet %d\n",
241                       packet);
242         return;
243     }
244     s->allocated &= ~(1 << packet);
245     if (s->tx_alloc == 0x80)
246         smc91c111_tx_alloc(s);
247     smc91c111_flush_queued_packets(s);
248 }
249 
250 static void smc91c111_complete_tx_packet(smc91c111_state *s, int packetnum)
251 {
252     if (s->ctr & CTR_AUTO_RELEASE) {
253         /* Race?  */
254         smc91c111_release_packet(s, packetnum);
255     } else if (s->tx_fifo_done_len < NUM_PACKETS) {
256         s->tx_fifo_done[s->tx_fifo_done_len++] = packetnum;
257     }
258 }
259 
260 /* Flush the TX FIFO.  */
261 static void smc91c111_do_tx(smc91c111_state *s)
262 {
263     int i;
264     int len;
265     int control;
266     int packetnum;
267     uint8_t *p;
268 
269     if ((s->tcr & TCR_TXEN) == 0)
270         return;
271     if (s->tx_fifo_len == 0)
272         return;
273     for (i = 0; i < s->tx_fifo_len; i++) {
274         packetnum = s->tx_fifo[i];
275         /* queue_tx checked the packet number was valid */
276         assert(packetnum_valid(packetnum));
277         p = &s->data[packetnum][0];
278         /* Set status word.  */
279         *(p++) = 0x01;
280         *(p++) = 0x40;
281         len = *(p++);
282         len |= ((int)*(p++)) << 8;
283         if (len > MAX_PACKET_SIZE) {
284             /*
285              * Datasheet doesn't say what to do here, and there is no
286              * relevant tx error condition listed. Log, and drop the packet.
287              */
288             qemu_log_mask(LOG_GUEST_ERROR,
289                           "smc91c111: tx packet with bad length %d, dropping\n",
290                           len);
291             smc91c111_complete_tx_packet(s, packetnum);
292             continue;
293         }
294         len -= 6;
295         control = p[len + 1];
296         if (control & 0x20)
297             len++;
298         /* ??? This overwrites the data following the buffer.
299            Don't know what real hardware does.  */
300         if (len < 64 && (s->tcr & TCR_PAD_EN)) {
301             memset(p + len, 0, 64 - len);
302             len = 64;
303         }
304 #if 0
305         {
306             int add_crc;
307 
308             /* The card is supposed to append the CRC to the frame.
309                However none of the other network traffic has the CRC
310                appended.  Suspect this is low level ethernet detail we
311                don't need to worry about.  */
312             add_crc = (control & 0x10) || (s->tcr & TCR_NOCRC) == 0;
313             if (add_crc) {
314                 uint32_t crc;
315 
316                 crc = crc32(~0, p, len);
317                 memcpy(p + len, &crc, 4);
318                 len += 4;
319             }
320         }
321 #endif
322         smc91c111_complete_tx_packet(s, packetnum);
323         qemu_send_packet(qemu_get_queue(s->nic), p, len);
324     }
325     s->tx_fifo_len = 0;
326     smc91c111_update(s);
327 }
328 
329 /* Add a packet to the TX FIFO.  */
330 static void smc91c111_queue_tx(smc91c111_state *s, int packet)
331 {
332     if (!packetnum_valid(packet)) {
333         /*
334          * Datasheet doesn't document behaviour in this error case, and
335          * there's no error status register we could report it in.
336          * Log and ignore.
337          */
338         qemu_log_mask(LOG_GUEST_ERROR,
339                       "smc91c111: attempt to queue invalid packet %d\n",
340                       packet);
341         return;
342     }
343     if (s->tx_fifo_len == NUM_PACKETS)
344         return;
345     s->tx_fifo[s->tx_fifo_len++] = packet;
346     smc91c111_do_tx(s);
347 }
348 
349 static void smc91c111_reset(DeviceState *dev)
350 {
351     smc91c111_state *s = SMC91C111(dev);
352 
353     s->bank = 0;
354     s->tx_fifo_len = 0;
355     s->tx_fifo_done_len = 0;
356     s->rx_fifo_len = 0;
357     s->allocated = 0;
358     s->packet_num = 0;
359     s->tx_alloc = 0;
360     s->tcr = 0;
361     s->rcr = 0;
362     s->cr = 0xa0b1;
363     s->ctr = 0x1210;
364     s->ptr = 0;
365     s->ercv = 0x1f;
366     s->int_level = INT_TX_EMPTY;
367     s->int_mask = 0;
368     smc91c111_update(s);
369 }
370 
371 #define SET_LOW(name, val) s->name = (s->name & 0xff00) | val
372 #define SET_HIGH(name, val) s->name = (s->name & 0xff) | (val << 8)
373 
374 static void smc91c111_writeb(void *opaque, hwaddr offset,
375                              uint32_t value)
376 {
377     smc91c111_state *s = (smc91c111_state *)opaque;
378 
379     offset = offset & 0xf;
380     if (offset == 14) {
381         s->bank = value;
382         return;
383     }
384     if (offset == 15)
385         return;
386     switch (s->bank) {
387     case 0:
388         switch (offset) {
389         case 0: /* TCR */
390             SET_LOW(tcr, value);
391             return;
392         case 1:
393             SET_HIGH(tcr, value);
394             return;
395         case 4: /* RCR */
396             SET_LOW(rcr, value);
397             return;
398         case 5:
399             SET_HIGH(rcr, value);
400             if (s->rcr & RCR_SOFT_RST) {
401                 smc91c111_reset(DEVICE(s));
402             }
403             smc91c111_flush_queued_packets(s);
404             return;
405         case 10: case 11: /* RPCR */
406             /* Ignored */
407             return;
408         case 12: case 13: /* Reserved */
409             return;
410         }
411         break;
412 
413     case 1:
414         switch (offset) {
415         case 0: /* CONFIG */
416             SET_LOW(cr, value);
417             return;
418         case 1:
419             SET_HIGH(cr,value);
420             return;
421         case 2: case 3: /* BASE */
422         case 4: case 5: case 6: case 7: case 8: case 9: /* IA */
423             /* Not implemented.  */
424             return;
425         case 10: /* General Purpose */
426             SET_LOW(gpr, value);
427             return;
428         case 11:
429             SET_HIGH(gpr, value);
430             return;
431         case 12: /* Control */
432             if (value & 1) {
433                 qemu_log_mask(LOG_UNIMP,
434                               "smc91c111: EEPROM store not implemented\n");
435             }
436             if (value & 2) {
437                 qemu_log_mask(LOG_UNIMP,
438                               "smc91c111: EEPROM reload not implemented\n");
439             }
440             value &= ~3;
441             SET_LOW(ctr, value);
442             return;
443         case 13:
444             SET_HIGH(ctr, value);
445             return;
446         }
447         break;
448 
449     case 2:
450         switch (offset) {
451         case 0: /* MMU Command */
452             switch (value >> 5) {
453             case 0: /* no-op */
454                 break;
455             case 1: /* Allocate for TX.  */
456                 s->tx_alloc = 0x80;
457                 s->int_level &= ~INT_ALLOC;
458                 smc91c111_update(s);
459                 smc91c111_tx_alloc(s);
460                 break;
461             case 2: /* Reset MMU.  */
462                 s->allocated = 0;
463                 s->tx_fifo_len = 0;
464                 s->tx_fifo_done_len = 0;
465                 s->rx_fifo_len = 0;
466                 s->tx_alloc = 0;
467                 break;
468             case 3: /* Remove from RX FIFO.  */
469                 smc91c111_pop_rx_fifo(s);
470                 break;
471             case 4: /* Remove from RX FIFO and release.  */
472                 if (s->rx_fifo_len > 0) {
473                     smc91c111_release_packet(s, s->rx_fifo[0]);
474                 }
475                 smc91c111_pop_rx_fifo(s);
476                 break;
477             case 5: /* Release.  */
478                 smc91c111_release_packet(s, s->packet_num);
479                 break;
480             case 6: /* Add to TX FIFO.  */
481                 smc91c111_queue_tx(s, s->packet_num);
482                 break;
483             case 7: /* Reset TX FIFO.  */
484                 s->tx_fifo_len = 0;
485                 s->tx_fifo_done_len = 0;
486                 break;
487             }
488             return;
489         case 1:
490             /* Ignore.  */
491             return;
492         case 2: /* Packet Number Register */
493             s->packet_num = value;
494             return;
495         case 3: case 4: case 5:
496             /* Should be readonly, but linux writes to them anyway. Ignore.  */
497             return;
498         case 6: /* Pointer */
499             SET_LOW(ptr, value);
500             return;
501         case 7:
502             SET_HIGH(ptr, value);
503             return;
504         case 8: case 9: case 10: case 11: /* Data */
505             {
506                 int p;
507                 int n;
508 
509                 if (s->ptr & 0x8000)
510                     n = s->rx_fifo[0];
511                 else
512                     n = s->packet_num;
513                 if (!packetnum_valid(n)) {
514                     /* Datasheet doesn't document what to do here */
515                     qemu_log_mask(LOG_GUEST_ERROR,
516                                   "smc91c111: attempt to write data to invalid packet %d\n",
517                                   n);
518                     return;
519                 }
520                 p = s->ptr & 0x07ff;
521                 if (s->ptr & 0x4000) {
522                     s->ptr = (s->ptr & 0xf800) | ((s->ptr + 1) & 0x7ff);
523                 } else {
524                     p += (offset & 3);
525                 }
526                 s->data[n][p] = value;
527             }
528             return;
529         case 12: /* Interrupt ACK.  */
530             s->int_level &= ~(value & 0xd6);
531             if (value & INT_TX)
532                 smc91c111_pop_tx_fifo_done(s);
533             smc91c111_update(s);
534             return;
535         case 13: /* Interrupt mask.  */
536             s->int_mask = value;
537             smc91c111_update(s);
538             return;
539         }
540         break;
541 
542     case 3:
543         switch (offset) {
544         case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:
545             /* Multicast table.  */
546             /* Not implemented.  */
547             return;
548         case 8: case 9: /* Management Interface.  */
549             /* Not implemented.  */
550             return;
551         case 12: /* Early receive.  */
552             s->ercv = value & 0x1f;
553             return;
554         case 13:
555             /* Ignore.  */
556             return;
557         }
558         break;
559     }
560     qemu_log_mask(LOG_GUEST_ERROR, "smc91c111_write(bank:%d) Illegal register"
561                                    " 0x%" HWADDR_PRIx " = 0x%x\n",
562                   s->bank, offset, value);
563 }
564 
565 static uint32_t smc91c111_readb(void *opaque, hwaddr offset)
566 {
567     smc91c111_state *s = (smc91c111_state *)opaque;
568 
569     offset = offset & 0xf;
570     if (offset == 14) {
571         return s->bank;
572     }
573     if (offset == 15)
574         return 0x33;
575     switch (s->bank) {
576     case 0:
577         switch (offset) {
578         case 0: /* TCR */
579             return s->tcr & 0xff;
580         case 1:
581             return s->tcr >> 8;
582         case 2: /* EPH Status */
583             return 0;
584         case 3:
585             return 0x40;
586         case 4: /* RCR */
587             return s->rcr & 0xff;
588         case 5:
589             return s->rcr >> 8;
590         case 6: /* Counter */
591         case 7:
592             /* Not implemented.  */
593             return 0;
594         case 8: /* Memory size.  */
595             return NUM_PACKETS;
596         case 9: /* Free memory available.  */
597             {
598                 int i;
599                 int n;
600                 n = 0;
601                 for (i = 0; i < NUM_PACKETS; i++) {
602                     if (s->allocated & (1 << i))
603                         n++;
604                 }
605                 return n;
606             }
607         case 10: case 11: /* RPCR */
608             /* Not implemented.  */
609             return 0;
610         case 12: case 13: /* Reserved */
611             return 0;
612         }
613         break;
614 
615     case 1:
616         switch (offset) {
617         case 0: /* CONFIG */
618             return s->cr & 0xff;
619         case 1:
620             return s->cr >> 8;
621         case 2: case 3: /* BASE */
622             /* Not implemented.  */
623             return 0;
624         case 4: case 5: case 6: case 7: case 8: case 9: /* IA */
625             return s->conf.macaddr.a[offset - 4];
626         case 10: /* General Purpose */
627             return s->gpr & 0xff;
628         case 11:
629             return s->gpr >> 8;
630         case 12: /* Control */
631             return s->ctr & 0xff;
632         case 13:
633             return s->ctr >> 8;
634         }
635         break;
636 
637     case 2:
638         switch (offset) {
639         case 0: case 1: /* MMUCR Busy bit.  */
640             return 0;
641         case 2: /* Packet Number.  */
642             return s->packet_num;
643         case 3: /* Allocation Result.  */
644             return s->tx_alloc;
645         case 4: /* TX FIFO */
646             if (s->tx_fifo_done_len == 0)
647                 return 0x80;
648             else
649                 return s->tx_fifo_done[0];
650         case 5: /* RX FIFO */
651             if (s->rx_fifo_len == 0)
652                 return 0x80;
653             else
654                 return s->rx_fifo[0];
655         case 6: /* Pointer */
656             return s->ptr & 0xff;
657         case 7:
658             return (s->ptr >> 8) & 0xf7;
659         case 8: case 9: case 10: case 11: /* Data */
660             {
661                 int p;
662                 int n;
663 
664                 if (s->ptr & 0x8000)
665                     n = s->rx_fifo[0];
666                 else
667                     n = s->packet_num;
668                 if (!packetnum_valid(n)) {
669                     /* Datasheet doesn't document what to do here */
670                     qemu_log_mask(LOG_GUEST_ERROR,
671                                   "smc91c111: attempt to read data from invalid packet %d\n",
672                                   n);
673                     return 0;
674                 }
675                 p = s->ptr & 0x07ff;
676                 if (s->ptr & 0x4000) {
677                     s->ptr = (s->ptr & 0xf800) | ((s->ptr + 1) & 0x07ff);
678                 } else {
679                     p += (offset & 3);
680                 }
681                 return s->data[n][p];
682             }
683         case 12: /* Interrupt status.  */
684             return s->int_level;
685         case 13: /* Interrupt mask.  */
686             return s->int_mask;
687         }
688         break;
689 
690     case 3:
691         switch (offset) {
692         case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:
693             /* Multicast table.  */
694             /* Not implemented.  */
695             return 0;
696         case 8: /* Management Interface.  */
697             /* Not implemented.  */
698             return 0x30;
699         case 9:
700             return 0x33;
701         case 10: /* Revision.  */
702             return 0x91;
703         case 11:
704             return 0x33;
705         case 12:
706             return s->ercv;
707         case 13:
708             return 0;
709         }
710         break;
711     }
712     qemu_log_mask(LOG_GUEST_ERROR, "smc91c111_read(bank:%d) Illegal register"
713                                    " 0x%" HWADDR_PRIx "\n",
714                   s->bank, offset);
715     return 0;
716 }
717 
718 static uint64_t smc91c111_readfn(void *opaque, hwaddr addr, unsigned size)
719 {
720     int i;
721     uint32_t val = 0;
722 
723     for (i = 0; i < size; i++) {
724         val |= smc91c111_readb(opaque, addr + i) << (i * 8);
725     }
726     return val;
727 }
728 
729 static void smc91c111_writefn(void *opaque, hwaddr addr,
730                                uint64_t value, unsigned size)
731 {
732     int i = 0;
733 
734     /* 32-bit writes to offset 0xc only actually write to the bank select
735      * register (offset 0xe), so skip the first two bytes we would write.
736      */
737     if (addr == 0xc && size == 4) {
738         i += 2;
739     }
740 
741     for (; i < size; i++) {
742         smc91c111_writeb(opaque, addr + i,
743                          extract32(value, i * 8, 8));
744     }
745 }
746 
747 static bool smc91c111_can_receive_nc(NetClientState *nc)
748 {
749     smc91c111_state *s = qemu_get_nic_opaque(nc);
750 
751     return smc91c111_can_receive(s);
752 }
753 
754 static ssize_t smc91c111_receive(NetClientState *nc, const uint8_t *buf, size_t size)
755 {
756     smc91c111_state *s = qemu_get_nic_opaque(nc);
757     int status;
758     int packetsize;
759     uint32_t crc;
760     int packetnum;
761     uint8_t *p;
762 
763     if ((s->rcr & RCR_RXEN) == 0 || (s->rcr & RCR_SOFT_RST))
764         return -1;
765     /* Short packets are padded with zeros.  Receiving a packet
766        < 64 bytes long is considered an error condition.  */
767     if (size < 64)
768         packetsize = 64;
769     else
770         packetsize = (size & ~1);
771     packetsize += 6;
772     crc = (s->rcr & RCR_STRIP_CRC) == 0;
773     if (crc)
774         packetsize += 4;
775     /* TODO: Flag overrun and receive errors.  */
776     if (packetsize > 2048)
777         return -1;
778     packetnum = smc91c111_allocate_packet(s);
779     if (packetnum == 0x80)
780         return -1;
781     s->rx_fifo[s->rx_fifo_len++] = packetnum;
782 
783     /* allocate_packet() will not hand us back an invalid packet number */
784     assert(packetnum_valid(packetnum));
785     p = &s->data[packetnum][0];
786     /* ??? Multicast packets?  */
787     status = 0;
788     if (size > 1518)
789         status |= RS_TOOLONG;
790     if (size & 1)
791         status |= RS_ODDFRAME;
792     *(p++) = status & 0xff;
793     *(p++) = status >> 8;
794     *(p++) = packetsize & 0xff;
795     *(p++) = packetsize >> 8;
796     memcpy(p, buf, size & ~1);
797     p += (size & ~1);
798     /* Pad short packets.  */
799     if (size < 64) {
800         int pad;
801 
802         if (size & 1)
803             *(p++) = buf[size - 1];
804         pad = 64 - size;
805         memset(p, 0, pad);
806         p += pad;
807         size = 64;
808     }
809     /* It's not clear if the CRC should go before or after the last byte in
810        odd sized packets.  Linux disables the CRC, so that's no help.
811        The pictures in the documentation show the CRC aligned on a 16-bit
812        boundary before the last odd byte, so that's what we do.  */
813     if (crc) {
814         crc = crc32(~0, buf, size);
815         *(p++) = crc & 0xff; crc >>= 8;
816         *(p++) = crc & 0xff; crc >>= 8;
817         *(p++) = crc & 0xff; crc >>= 8;
818         *(p++) = crc & 0xff;
819     }
820     if (size & 1) {
821         *(p++) = buf[size - 1];
822         *p = 0x60;
823     } else {
824         *(p++) = 0;
825         *p = 0x40;
826     }
827     /* TODO: Raise early RX interrupt?  */
828     s->int_level |= INT_RCV;
829     smc91c111_update(s);
830 
831     return size;
832 }
833 
834 static const MemoryRegionOps smc91c111_mem_ops = {
835     /* The special case for 32 bit writes to 0xc means we can't just
836      * set .impl.min/max_access_size to 1, unfortunately
837      */
838     .read = smc91c111_readfn,
839     .write = smc91c111_writefn,
840     .valid.min_access_size = 1,
841     .valid.max_access_size = 4,
842     .endianness = DEVICE_NATIVE_ENDIAN,
843 };
844 
845 static NetClientInfo net_smc91c111_info = {
846     .type = NET_CLIENT_DRIVER_NIC,
847     .size = sizeof(NICState),
848     .can_receive = smc91c111_can_receive_nc,
849     .receive = smc91c111_receive,
850 };
851 
852 static void smc91c111_realize(DeviceState *dev, Error **errp)
853 {
854     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
855     smc91c111_state *s = SMC91C111(dev);
856 
857     memory_region_init_io(&s->mmio, OBJECT(s), &smc91c111_mem_ops, s,
858                           "smc91c111-mmio", 16);
859     sysbus_init_mmio(sbd, &s->mmio);
860     sysbus_init_irq(sbd, &s->irq);
861     qemu_macaddr_default_if_unset(&s->conf.macaddr);
862     s->nic = qemu_new_nic(&net_smc91c111_info, &s->conf,
863                           object_get_typename(OBJECT(dev)), dev->id,
864                           &dev->mem_reentrancy_guard, s);
865     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
866     /* ??? Save/restore.  */
867 }
868 
869 static const Property smc91c111_properties[] = {
870     DEFINE_NIC_PROPERTIES(smc91c111_state, conf),
871 };
872 
873 static void smc91c111_class_init(ObjectClass *klass, void *data)
874 {
875     DeviceClass *dc = DEVICE_CLASS(klass);
876 
877     dc->realize = smc91c111_realize;
878     device_class_set_legacy_reset(dc, smc91c111_reset);
879     dc->vmsd = &vmstate_smc91c111;
880     device_class_set_props(dc, smc91c111_properties);
881 }
882 
883 static const TypeInfo smc91c111_info = {
884     .name          = TYPE_SMC91C111,
885     .parent        = TYPE_SYS_BUS_DEVICE,
886     .instance_size = sizeof(smc91c111_state),
887     .class_init    = smc91c111_class_init,
888 };
889 
890 static void smc91c111_register_types(void)
891 {
892     type_register_static(&smc91c111_info);
893 }
894 
895 /* Legacy helper function.  Should go away when machine config files are
896    implemented.  */
897 void smc91c111_init(uint32_t base, qemu_irq irq)
898 {
899     DeviceState *dev;
900     SysBusDevice *s;
901 
902     dev = qdev_new(TYPE_SMC91C111);
903     qemu_configure_nic_device(dev, true, NULL);
904     s = SYS_BUS_DEVICE(dev);
905     sysbus_realize_and_unref(s, &error_fatal);
906     sysbus_mmio_map(s, 0, base);
907     sysbus_connect_irq(s, 0, irq);
908 }
909 
910 type_init(smc91c111_register_types)
911