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1
/*
2
 * SMSC 91C111 Ethernet interface emulation
3
 *
4
 * Copyright (c) 2005 CodeSourcery, LLC.
5
 * Written by Paul Brook
6
 *
7
 * This code is licenced under the GPL
8
 */
9

    
10
#include "hw.h"
11
#include "net.h"
12
#include "devices.h"
13
/* For crc32 */
14
#include <zlib.h>
15

    
16
/* Number of 2k memory pages available.  */
17
#define NUM_PACKETS 4
18

    
19
typedef struct {
20
    VLANClientState *vc;
21
    uint16_t tcr;
22
    uint16_t rcr;
23
    uint16_t cr;
24
    uint16_t ctr;
25
    uint16_t gpr;
26
    uint16_t ptr;
27
    uint16_t ercv;
28
    qemu_irq irq;
29
    int bank;
30
    int packet_num;
31
    int tx_alloc;
32
    /* Bitmask of allocated packets.  */
33
    int allocated;
34
    int tx_fifo_len;
35
    int tx_fifo[NUM_PACKETS];
36
    int rx_fifo_len;
37
    int rx_fifo[NUM_PACKETS];
38
    int tx_fifo_done_len;
39
    int tx_fifo_done[NUM_PACKETS];
40
    /* Packet buffer memory.  */
41
    uint8_t data[NUM_PACKETS][2048];
42
    uint8_t int_level;
43
    uint8_t int_mask;
44
    uint8_t macaddr[6];
45
} smc91c111_state;
46

    
47
#define RCR_SOFT_RST  0x8000
48
#define RCR_STRIP_CRC 0x0200
49
#define RCR_RXEN      0x0100
50

    
51
#define TCR_EPH_LOOP  0x2000
52
#define TCR_NOCRC     0x0100
53
#define TCR_PAD_EN    0x0080
54
#define TCR_FORCOL    0x0004
55
#define TCR_LOOP      0x0002
56
#define TCR_TXEN      0x0001
57

    
58
#define INT_MD        0x80
59
#define INT_ERCV      0x40
60
#define INT_EPH       0x20
61
#define INT_RX_OVRN   0x10
62
#define INT_ALLOC     0x08
63
#define INT_TX_EMPTY  0x04
64
#define INT_TX        0x02
65
#define INT_RCV       0x01
66

    
67
#define CTR_AUTO_RELEASE  0x0800
68
#define CTR_RELOAD        0x0002
69
#define CTR_STORE         0x0001
70

    
71
#define RS_ALGNERR      0x8000
72
#define RS_BRODCAST     0x4000
73
#define RS_BADCRC       0x2000
74
#define RS_ODDFRAME     0x1000
75
#define RS_TOOLONG      0x0800
76
#define RS_TOOSHORT     0x0400
77
#define RS_MULTICAST    0x0001
78

    
79
/* Update interrupt status.  */
80
static void smc91c111_update(smc91c111_state *s)
81
{
82
    int level;
83

    
84
    if (s->tx_fifo_len == 0)
85
        s->int_level |= INT_TX_EMPTY;
86
    if (s->tx_fifo_done_len != 0)
87
        s->int_level |= INT_TX;
88
    level = (s->int_level & s->int_mask) != 0;
89
    qemu_set_irq(s->irq, level);
90
}
91

    
92
/* Try to allocate a packet.  Returns 0x80 on failure.  */
93
static int smc91c111_allocate_packet(smc91c111_state *s)
94
{
95
    int i;
96
    if (s->allocated == (1 << NUM_PACKETS) - 1) {
97
        return 0x80;
98
    }
99

    
100
    for (i = 0; i < NUM_PACKETS; i++) {
101
        if ((s->allocated & (1 << i)) == 0)
102
            break;
103
    }
104
    s->allocated |= 1 << i;
105
    return i;
106
}
107

    
108

    
109
/* Process a pending TX allocate.  */
110
static void smc91c111_tx_alloc(smc91c111_state *s)
111
{
112
    s->tx_alloc = smc91c111_allocate_packet(s);
113
    if (s->tx_alloc == 0x80)
114
        return;
115
    s->int_level |= INT_ALLOC;
116
    smc91c111_update(s);
117
}
118

    
119
/* Remove and item from the RX FIFO.  */
120
static void smc91c111_pop_rx_fifo(smc91c111_state *s)
121
{
122
    int i;
123

    
124
    s->rx_fifo_len--;
125
    if (s->rx_fifo_len) {
126
        for (i = 0; i < s->rx_fifo_len; i++)
127
            s->rx_fifo[i] = s->rx_fifo[i + 1];
128
        s->int_level |= INT_RCV;
129
    } else {
130
        s->int_level &= ~INT_RCV;
131
    }
132
    smc91c111_update(s);
133
}
134

    
135
/* Remove an item from the TX completion FIFO.  */
136
static void smc91c111_pop_tx_fifo_done(smc91c111_state *s)
137
{
138
    int i;
139

    
140
    if (s->tx_fifo_done_len == 0)
141
        return;
142
    s->tx_fifo_done_len--;
143
    for (i = 0; i < s->tx_fifo_done_len; i++)
144
        s->tx_fifo_done[i] = s->tx_fifo_done[i + 1];
145
}
146

    
147
/* Release the memory allocated to a packet.  */
148
static void smc91c111_release_packet(smc91c111_state *s, int packet)
149
{
150
    s->allocated &= ~(1 << packet);
151
    if (s->tx_alloc == 0x80)
152
        smc91c111_tx_alloc(s);
153
}
154

    
155
/* Flush the TX FIFO.  */
156
static void smc91c111_do_tx(smc91c111_state *s)
157
{
158
    int i;
159
    int len;
160
    int control;
161
    int add_crc;
162
    int packetnum;
163
    uint8_t *p;
164

    
165
    if ((s->tcr & TCR_TXEN) == 0)
166
        return;
167
    if (s->tx_fifo_len == 0)
168
        return;
169
    for (i = 0; i < s->tx_fifo_len; i++) {
170
        packetnum = s->tx_fifo[i];
171
        p = &s->data[packetnum][0];
172
        /* Set status word.  */
173
        *(p++) = 0x01;
174
        *(p++) = 0x40;
175
        len = *(p++);
176
        len |= ((int)*(p++)) << 8;
177
        len -= 6;
178
        control = p[len + 1];
179
        if (control & 0x20)
180
            len++;
181
        /* ??? This overwrites the data following the buffer.
182
           Don't know what real hardware does.  */
183
        if (len < 64 && (s->tcr & TCR_PAD_EN)) {
184
            memset(p + len, 0, 64 - len);
185
            len = 64;
186
        }
187
#if 0
188
        /* The card is supposed to append the CRC to the frame.  However
189
           none of the other network traffic has the CRC appended.
190
           Suspect this is low level ethernet detail we don't need to worry
191
           about.  */
192
        add_crc = (control & 0x10) || (s->tcr & TCR_NOCRC) == 0;
193
        if (add_crc) {
194
            uint32_t crc;
195

196
            crc = crc32(~0, p, len);
197
            memcpy(p + len, &crc, 4);
198
            len += 4;
199
        }
200
#else
201
        add_crc = 0;
202
#endif
203
        if (s->ctr & CTR_AUTO_RELEASE)
204
            /* Race?  */
205
            smc91c111_release_packet(s, packetnum);
206
        else if (s->tx_fifo_done_len < NUM_PACKETS)
207
            s->tx_fifo_done[s->tx_fifo_done_len++] = packetnum;
208
        qemu_send_packet(s->vc, p, len);
209
    }
210
    s->tx_fifo_len = 0;
211
    smc91c111_update(s);
212
}
213

    
214
/* Add a packet to the TX FIFO.  */
215
static void smc91c111_queue_tx(smc91c111_state *s, int packet)
216
{
217
    if (s->tx_fifo_len == NUM_PACKETS)
218
        return;
219
    s->tx_fifo[s->tx_fifo_len++] = packet;
220
    smc91c111_do_tx(s);
221
}
222

    
223
static void smc91c111_reset(smc91c111_state *s)
224
{
225
    s->bank = 0;
226
    s->tx_fifo_len = 0;
227
    s->tx_fifo_done_len = 0;
228
    s->rx_fifo_len = 0;
229
    s->allocated = 0;
230
    s->packet_num = 0;
231
    s->tx_alloc = 0;
232
    s->tcr = 0;
233
    s->rcr = 0;
234
    s->cr = 0xa0b1;
235
    s->ctr = 0x1210;
236
    s->ptr = 0;
237
    s->ercv = 0x1f;
238
    s->int_level = INT_TX_EMPTY;
239
    s->int_mask = 0;
240
    smc91c111_update(s);
241
}
242

    
243
#define SET_LOW(name, val) s->name = (s->name & 0xff00) | val
244
#define SET_HIGH(name, val) s->name = (s->name & 0xff) | (val << 8)
245

    
246
static void smc91c111_writeb(void *opaque, target_phys_addr_t offset,
247
                             uint32_t value)
248
{
249
    smc91c111_state *s = (smc91c111_state *)opaque;
250

    
251
    if (offset == 14) {
252
        s->bank = value;
253
        return;
254
    }
255
    if (offset == 15)
256
        return;
257
    switch (s->bank) {
258
    case 0:
259
        switch (offset) {
260
        case 0: /* TCR */
261
            SET_LOW(tcr, value);
262
            return;
263
        case 1:
264
            SET_HIGH(tcr, value);
265
            return;
266
        case 4: /* RCR */
267
            SET_LOW(rcr, value);
268
            return;
269
        case 5:
270
            SET_HIGH(rcr, value);
271
            if (s->rcr & RCR_SOFT_RST)
272
                smc91c111_reset(s);
273
            return;
274
        case 10: case 11: /* RPCR */
275
            /* Ignored */
276
            return;
277
        }
278
        break;
279

    
280
    case 1:
281
        switch (offset) {
282
        case 0: /* CONFIG */
283
            SET_LOW(cr, value);
284
            return;
285
        case 1:
286
            SET_HIGH(cr,value);
287
            return;
288
        case 2: case 3: /* BASE */
289
        case 4: case 5: case 6: case 7: case 8: case 9: /* IA */
290
            /* Not implemented.  */
291
            return;
292
        case 10: /* Genral Purpose */
293
            SET_LOW(gpr, value);
294
            return;
295
        case 11:
296
            SET_HIGH(gpr, value);
297
            return;
298
        case 12: /* Control */
299
            if (value & 1)
300
                fprintf(stderr, "smc91c111:EEPROM store not implemented\n");
301
            if (value & 2)
302
                fprintf(stderr, "smc91c111:EEPROM reload not implemented\n");
303
            value &= ~3;
304
            SET_LOW(ctr, value);
305
            return;
306
        case 13:
307
            SET_HIGH(ctr, value);
308
            return;
309
        }
310
        break;
311

    
312
    case 2:
313
        switch (offset) {
314
        case 0: /* MMU Command */
315
            switch (value >> 5) {
316
            case 0: /* no-op */
317
                break;
318
            case 1: /* Allocate for TX.  */
319
                s->tx_alloc = 0x80;
320
                s->int_level &= ~INT_ALLOC;
321
                smc91c111_update(s);
322
                smc91c111_tx_alloc(s);
323
                break;
324
            case 2: /* Reset MMU.  */
325
                s->allocated = 0;
326
                s->tx_fifo_len = 0;
327
                s->tx_fifo_done_len = 0;
328
                s->rx_fifo_len = 0;
329
                s->tx_alloc = 0;
330
                break;
331
            case 3: /* Remove from RX FIFO.  */
332
                smc91c111_pop_rx_fifo(s);
333
                break;
334
            case 4: /* Remove from RX FIFO and release.  */
335
                if (s->rx_fifo_len > 0) {
336
                    smc91c111_release_packet(s, s->rx_fifo[0]);
337
                }
338
                smc91c111_pop_rx_fifo(s);
339
                break;
340
            case 5: /* Release.  */
341
                smc91c111_release_packet(s, s->packet_num);
342
                break;
343
            case 6: /* Add to TX FIFO.  */
344
                smc91c111_queue_tx(s, s->packet_num);
345
                break;
346
            case 7: /* Reset TX FIFO.  */
347
                s->tx_fifo_len = 0;
348
                s->tx_fifo_done_len = 0;
349
                break;
350
            }
351
            return;
352
        case 1:
353
            /* Ignore.  */
354
            return;
355
        case 2: /* Packet Number Register */
356
            s->packet_num = value;
357
            return;
358
        case 3: case 4: case 5:
359
            /* Should be readonly, but linux writes to them anyway. Ignore.  */
360
            return;
361
        case 6: /* Pointer */
362
            SET_LOW(ptr, value);
363
            return;
364
        case 7:
365
            SET_HIGH(ptr, value);
366
            return;
367
        case 8: case 9: case 10: case 11: /* Data */
368
            {
369
                int p;
370
                int n;
371

    
372
                if (s->ptr & 0x8000)
373
                    n = s->rx_fifo[0];
374
                else
375
                    n = s->packet_num;
376
                p = s->ptr & 0x07ff;
377
                if (s->ptr & 0x4000) {
378
                    s->ptr = (s->ptr & 0xf800) | ((s->ptr + 1) & 0x7ff);
379
                } else {
380
                    p += (offset & 3);
381
                }
382
                s->data[n][p] = value;
383
            }
384
            return;
385
        case 12: /* Interrupt ACK.  */
386
            s->int_level &= ~(value & 0xd6);
387
            if (value & INT_TX)
388
                smc91c111_pop_tx_fifo_done(s);
389
            smc91c111_update(s);
390
            return;
391
        case 13: /* Interrupt mask.  */
392
            s->int_mask = value;
393
            smc91c111_update(s);
394
            return;
395
        }
396
        break;;
397

    
398
    case 3:
399
        switch (offset) {
400
        case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:
401
            /* Multicast table.  */
402
            /* Not implemented.  */
403
            return;
404
        case 8: case 9: /* Management Interface.  */
405
            /* Not implemented.  */
406
            return;
407
        case 12: /* Early receive.  */
408
            s->ercv = value & 0x1f;
409
        case 13:
410
            /* Ignore.  */
411
            return;
412
        }
413
        break;
414
    }
415
    cpu_abort (cpu_single_env, "smc91c111_write: Bad reg %d:%x\n",
416
               s->bank, (int)offset);
417
}
418

    
419
static uint32_t smc91c111_readb(void *opaque, target_phys_addr_t offset)
420
{
421
    smc91c111_state *s = (smc91c111_state *)opaque;
422

    
423
    if (offset == 14) {
424
        return s->bank;
425
    }
426
    if (offset == 15)
427
        return 0x33;
428
    switch (s->bank) {
429
    case 0:
430
        switch (offset) {
431
        case 0: /* TCR */
432
            return s->tcr & 0xff;
433
        case 1:
434
            return s->tcr >> 8;
435
        case 2: /* EPH Status */
436
            return 0;
437
        case 3:
438
            return 0x40;
439
        case 4: /* RCR */
440
            return s->rcr & 0xff;
441
        case 5:
442
            return s->rcr >> 8;
443
        case 6: /* Counter */
444
        case 7:
445
            /* Not implemented.  */
446
            return 0;
447
        case 8: /* Memory size.  */
448
            return NUM_PACKETS;
449
        case 9: /* Free memory available.  */
450
            {
451
                int i;
452
                int n;
453
                n = 0;
454
                for (i = 0; i < NUM_PACKETS; i++) {
455
                    if (s->allocated & (1 << i))
456
                        n++;
457
                }
458
                return n;
459
            }
460
        case 10: case 11: /* RPCR */
461
            /* Not implemented.  */
462
            return 0;
463
        }
464
        break;
465

    
466
    case 1:
467
        switch (offset) {
468
        case 0: /* CONFIG */
469
            return s->cr & 0xff;
470
        case 1:
471
            return s->cr >> 8;
472
        case 2: case 3: /* BASE */
473
            /* Not implemented.  */
474
            return 0;
475
        case 4: case 5: case 6: case 7: case 8: case 9: /* IA */
476
            return s->macaddr[offset - 4];
477
        case 10: /* General Purpose */
478
            return s->gpr & 0xff;
479
        case 11:
480
            return s->gpr >> 8;
481
        case 12: /* Control */
482
            return s->ctr & 0xff;
483
        case 13:
484
            return s->ctr >> 8;
485
        }
486
        break;
487

    
488
    case 2:
489
        switch (offset) {
490
        case 0: case 1: /* MMUCR Busy bit.  */
491
            return 0;
492
        case 2: /* Packet Number.  */
493
            return s->packet_num;
494
        case 3: /* Allocation Result.  */
495
            return s->tx_alloc;
496
        case 4: /* TX FIFO */
497
            if (s->tx_fifo_done_len == 0)
498
                return 0x80;
499
            else
500
                return s->tx_fifo_done[0];
501
        case 5: /* RX FIFO */
502
            if (s->rx_fifo_len == 0)
503
                return 0x80;
504
            else
505
                return s->rx_fifo[0];
506
        case 6: /* Pointer */
507
            return s->ptr & 0xff;
508
        case 7:
509
            return (s->ptr >> 8) & 0xf7;
510
        case 8: case 9: case 10: case 11: /* Data */
511
            {
512
                int p;
513
                int n;
514

    
515
                if (s->ptr & 0x8000)
516
                    n = s->rx_fifo[0];
517
                else
518
                    n = s->packet_num;
519
                p = s->ptr & 0x07ff;
520
                if (s->ptr & 0x4000) {
521
                    s->ptr = (s->ptr & 0xf800) | ((s->ptr + 1) & 0x07ff);
522
                } else {
523
                    p += (offset & 3);
524
                }
525
                return s->data[n][p];
526
            }
527
        case 12: /* Interrupt status.  */
528
            return s->int_level;
529
        case 13: /* Interrupt mask.  */
530
            return s->int_mask;
531
        }
532
        break;
533

    
534
    case 3:
535
        switch (offset) {
536
        case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:
537
            /* Multicast table.  */
538
            /* Not implemented.  */
539
            return 0;
540
        case 8: /* Management Interface.  */
541
            /* Not implemented.  */
542
            return 0x30;
543
        case 9:
544
            return 0x33;
545
        case 10: /* Revision.  */
546
            return 0x91;
547
        case 11:
548
            return 0x33;
549
        case 12:
550
            return s->ercv;
551
        case 13:
552
            return 0;
553
        }
554
        break;
555
    }
556
    cpu_abort (cpu_single_env, "smc91c111_read: Bad reg %d:%x\n",
557
               s->bank, (int)offset);
558
    return 0;
559
}
560

    
561
static void smc91c111_writew(void *opaque, target_phys_addr_t offset,
562
                             uint32_t value)
563
{
564
    smc91c111_writeb(opaque, offset, value & 0xff);
565
    smc91c111_writeb(opaque, offset + 1, value >> 8);
566
}
567

    
568
static void smc91c111_writel(void *opaque, target_phys_addr_t offset,
569
                             uint32_t value)
570
{
571
    /* 32-bit writes to offset 0xc only actually write to the bank select
572
       register (offset 0xe)  */
573
    if (offset != 0xc)
574
        smc91c111_writew(opaque, offset, value & 0xffff);
575
    smc91c111_writew(opaque, offset + 2, value >> 16);
576
}
577

    
578
static uint32_t smc91c111_readw(void *opaque, target_phys_addr_t offset)
579
{
580
    uint32_t val;
581
    val = smc91c111_readb(opaque, offset);
582
    val |= smc91c111_readb(opaque, offset + 1) << 8;
583
    return val;
584
}
585

    
586
static uint32_t smc91c111_readl(void *opaque, target_phys_addr_t offset)
587
{
588
    uint32_t val;
589
    val = smc91c111_readw(opaque, offset);
590
    val |= smc91c111_readw(opaque, offset + 2) << 16;
591
    return val;
592
}
593

    
594
static int smc91c111_can_receive(void *opaque)
595
{
596
    smc91c111_state *s = (smc91c111_state *)opaque;
597

    
598
    if ((s->rcr & RCR_RXEN) == 0 || (s->rcr & RCR_SOFT_RST))
599
        return 1;
600
    if (s->allocated == (1 << NUM_PACKETS) - 1)
601
        return 0;
602
    return 1;
603
}
604

    
605
static void smc91c111_receive(void *opaque, const uint8_t *buf, int size)
606
{
607
    smc91c111_state *s = (smc91c111_state *)opaque;
608
    int status;
609
    int packetsize;
610
    uint32_t crc;
611
    int packetnum;
612
    uint8_t *p;
613

    
614
    if ((s->rcr & RCR_RXEN) == 0 || (s->rcr & RCR_SOFT_RST))
615
        return;
616
    /* Short packets are padded with zeros.  Receiving a packet
617
       < 64 bytes long is considered an error condition.  */
618
    if (size < 64)
619
        packetsize = 64;
620
    else
621
        packetsize = (size & ~1);
622
    packetsize += 6;
623
    crc = (s->rcr & RCR_STRIP_CRC) == 0;
624
    if (crc)
625
        packetsize += 4;
626
    /* TODO: Flag overrun and receive errors.  */
627
    if (packetsize > 2048)
628
        return;
629
    packetnum = smc91c111_allocate_packet(s);
630
    if (packetnum == 0x80)
631
        return;
632
    s->rx_fifo[s->rx_fifo_len++] = packetnum;
633

    
634
    p = &s->data[packetnum][0];
635
    /* ??? Multicast packets?  */
636
    status = 0;
637
    if (size > 1518)
638
        status |= RS_TOOLONG;
639
    if (size & 1)
640
        status |= RS_ODDFRAME;
641
    *(p++) = status & 0xff;
642
    *(p++) = status >> 8;
643
    *(p++) = packetsize & 0xff;
644
    *(p++) = packetsize >> 8;
645
    memcpy(p, buf, size & ~1);
646
    p += (size & ~1);
647
    /* Pad short packets.  */
648
    if (size < 64) {
649
        int pad;
650

    
651
        if (size & 1)
652
            *(p++) = buf[size - 1];
653
        pad = 64 - size;
654
        memset(p, 0, pad);
655
        p += pad;
656
        size = 64;
657
    }
658
    /* It's not clear if the CRC should go before or after the last byte in
659
       odd sized packets.  Linux disables the CRC, so that's no help.
660
       The pictures in the documentation show the CRC aligned on a 16-bit
661
       boundary before the last odd byte, so that's what we do.  */
662
    if (crc) {
663
        crc = crc32(~0, buf, size);
664
        *(p++) = crc & 0xff; crc >>= 8;
665
        *(p++) = crc & 0xff; crc >>= 8;
666
        *(p++) = crc & 0xff; crc >>= 8;
667
        *(p++) = crc & 0xff; crc >>= 8;
668
    }
669
    if (size & 1) {
670
        *(p++) = buf[size - 1];
671
        *(p++) = 0x60;
672
    } else {
673
        *(p++) = 0;
674
        *(p++) = 0x40;
675
    }
676
    /* TODO: Raise early RX interrupt?  */
677
    s->int_level |= INT_RCV;
678
    smc91c111_update(s);
679
}
680

    
681
static CPUReadMemoryFunc *smc91c111_readfn[] = {
682
    smc91c111_readb,
683
    smc91c111_readw,
684
    smc91c111_readl
685
};
686

    
687
static CPUWriteMemoryFunc *smc91c111_writefn[] = {
688
    smc91c111_writeb,
689
    smc91c111_writew,
690
    smc91c111_writel
691
};
692

    
693
void smc91c111_init(NICInfo *nd, uint32_t base, qemu_irq irq)
694
{
695
    smc91c111_state *s;
696
    int iomemtype;
697

    
698
    qemu_check_nic_model(nd, "smc91c111");
699

    
700
    s = (smc91c111_state *)qemu_mallocz(sizeof(smc91c111_state));
701
    iomemtype = cpu_register_io_memory(0, smc91c111_readfn,
702
                                       smc91c111_writefn, s);
703
    cpu_register_physical_memory(base, 16, iomemtype);
704
    s->irq = irq;
705
    memcpy(s->macaddr, nd->macaddr, 6);
706

    
707
    smc91c111_reset(s);
708

    
709
    s->vc = qemu_new_vlan_client(nd->vlan, nd->model, nd->name,
710
                                 smc91c111_receive, smc91c111_can_receive, s);
711
    qemu_format_nic_info_str(s->vc, s->macaddr);
712
    /* ??? Save/restore.  */
713
}