xref: /qemu/hw/net/dp8393x.c (revision db1015e92e04835c9eb50c29625fe566d1202dbd)
1 /*
2  * QEMU NS SONIC DP8393x netcard
3  *
4  * Copyright (c) 2008-2009 Herve Poussineau
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License as
8  * published by the Free Software Foundation; either version 2 of
9  * the License, or (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License along
17  * with this program; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "hw/irq.h"
22 #include "hw/qdev-properties.h"
23 #include "hw/sysbus.h"
24 #include "migration/vmstate.h"
25 #include "net/net.h"
26 #include "qapi/error.h"
27 #include "qemu/module.h"
28 #include "qemu/timer.h"
29 #include <zlib.h>
30 #include "qom/object.h"
31 
32 //#define DEBUG_SONIC
33 
34 #define SONIC_PROM_SIZE 0x1000
35 
36 #ifdef DEBUG_SONIC
37 #define DPRINTF(fmt, ...) \
38 do { printf("sonic: " fmt , ##  __VA_ARGS__); } while (0)
39 static const char* reg_names[] = {
40     "CR", "DCR", "RCR", "TCR", "IMR", "ISR", "UTDA", "CTDA",
41     "TPS", "TFC", "TSA0", "TSA1", "TFS", "URDA", "CRDA", "CRBA0",
42     "CRBA1", "RBWC0", "RBWC1", "EOBC", "URRA", "RSA", "REA", "RRP",
43     "RWP", "TRBA0", "TRBA1", "0x1b", "0x1c", "0x1d", "0x1e", "LLFA",
44     "TTDA", "CEP", "CAP2", "CAP1", "CAP0", "CE", "CDP", "CDC",
45     "SR", "WT0", "WT1", "RSC", "CRCT", "FAET", "MPT", "MDT",
46     "0x30", "0x31", "0x32", "0x33", "0x34", "0x35", "0x36", "0x37",
47     "0x38", "0x39", "0x3a", "0x3b", "0x3c", "0x3d", "0x3e", "DCR2" };
48 #else
49 #define DPRINTF(fmt, ...) do {} while (0)
50 #endif
51 
52 #define SONIC_ERROR(fmt, ...) \
53 do { printf("sonic ERROR: %s: " fmt, __func__ , ## __VA_ARGS__); } while (0)
54 
55 #define SONIC_CR     0x00
56 #define SONIC_DCR    0x01
57 #define SONIC_RCR    0x02
58 #define SONIC_TCR    0x03
59 #define SONIC_IMR    0x04
60 #define SONIC_ISR    0x05
61 #define SONIC_UTDA   0x06
62 #define SONIC_CTDA   0x07
63 #define SONIC_TPS    0x08
64 #define SONIC_TFC    0x09
65 #define SONIC_TSA0   0x0a
66 #define SONIC_TSA1   0x0b
67 #define SONIC_TFS    0x0c
68 #define SONIC_URDA   0x0d
69 #define SONIC_CRDA   0x0e
70 #define SONIC_CRBA0  0x0f
71 #define SONIC_CRBA1  0x10
72 #define SONIC_RBWC0  0x11
73 #define SONIC_RBWC1  0x12
74 #define SONIC_EOBC   0x13
75 #define SONIC_URRA   0x14
76 #define SONIC_RSA    0x15
77 #define SONIC_REA    0x16
78 #define SONIC_RRP    0x17
79 #define SONIC_RWP    0x18
80 #define SONIC_TRBA0  0x19
81 #define SONIC_TRBA1  0x1a
82 #define SONIC_LLFA   0x1f
83 #define SONIC_TTDA   0x20
84 #define SONIC_CEP    0x21
85 #define SONIC_CAP2   0x22
86 #define SONIC_CAP1   0x23
87 #define SONIC_CAP0   0x24
88 #define SONIC_CE     0x25
89 #define SONIC_CDP    0x26
90 #define SONIC_CDC    0x27
91 #define SONIC_SR     0x28
92 #define SONIC_WT0    0x29
93 #define SONIC_WT1    0x2a
94 #define SONIC_RSC    0x2b
95 #define SONIC_CRCT   0x2c
96 #define SONIC_FAET   0x2d
97 #define SONIC_MPT    0x2e
98 #define SONIC_MDT    0x2f
99 #define SONIC_DCR2   0x3f
100 
101 #define SONIC_CR_HTX     0x0001
102 #define SONIC_CR_TXP     0x0002
103 #define SONIC_CR_RXDIS   0x0004
104 #define SONIC_CR_RXEN    0x0008
105 #define SONIC_CR_STP     0x0010
106 #define SONIC_CR_ST      0x0020
107 #define SONIC_CR_RST     0x0080
108 #define SONIC_CR_RRRA    0x0100
109 #define SONIC_CR_LCAM    0x0200
110 #define SONIC_CR_MASK    0x03bf
111 
112 #define SONIC_DCR_DW     0x0020
113 #define SONIC_DCR_LBR    0x2000
114 #define SONIC_DCR_EXBUS  0x8000
115 
116 #define SONIC_RCR_PRX    0x0001
117 #define SONIC_RCR_LBK    0x0002
118 #define SONIC_RCR_FAER   0x0004
119 #define SONIC_RCR_CRCR   0x0008
120 #define SONIC_RCR_CRS    0x0020
121 #define SONIC_RCR_LPKT   0x0040
122 #define SONIC_RCR_BC     0x0080
123 #define SONIC_RCR_MC     0x0100
124 #define SONIC_RCR_LB0    0x0200
125 #define SONIC_RCR_LB1    0x0400
126 #define SONIC_RCR_AMC    0x0800
127 #define SONIC_RCR_PRO    0x1000
128 #define SONIC_RCR_BRD    0x2000
129 #define SONIC_RCR_RNT    0x4000
130 
131 #define SONIC_TCR_PTX    0x0001
132 #define SONIC_TCR_BCM    0x0002
133 #define SONIC_TCR_FU     0x0004
134 #define SONIC_TCR_EXC    0x0040
135 #define SONIC_TCR_CRSL   0x0080
136 #define SONIC_TCR_NCRS   0x0100
137 #define SONIC_TCR_EXD    0x0400
138 #define SONIC_TCR_CRCI   0x2000
139 #define SONIC_TCR_PINT   0x8000
140 
141 #define SONIC_ISR_RBAE   0x0010
142 #define SONIC_ISR_RBE    0x0020
143 #define SONIC_ISR_RDE    0x0040
144 #define SONIC_ISR_TC     0x0080
145 #define SONIC_ISR_TXDN   0x0200
146 #define SONIC_ISR_PKTRX  0x0400
147 #define SONIC_ISR_PINT   0x0800
148 #define SONIC_ISR_LCD    0x1000
149 
150 #define SONIC_DESC_EOL   0x0001
151 #define SONIC_DESC_ADDR  0xFFFE
152 
153 #define TYPE_DP8393X "dp8393x"
154 typedef struct dp8393xState dp8393xState;
155 #define DP8393X(obj) OBJECT_CHECK(dp8393xState, (obj), TYPE_DP8393X)
156 
157 struct dp8393xState {
158     SysBusDevice parent_obj;
159 
160     /* Hardware */
161     uint8_t it_shift;
162     bool big_endian;
163     bool last_rba_is_full;
164     qemu_irq irq;
165 #ifdef DEBUG_SONIC
166     int irq_level;
167 #endif
168     QEMUTimer *watchdog;
169     int64_t wt_last_update;
170     NICConf conf;
171     NICState *nic;
172     MemoryRegion mmio;
173     MemoryRegion prom;
174 
175     /* Registers */
176     uint8_t cam[16][6];
177     uint16_t regs[0x40];
178 
179     /* Temporaries */
180     uint8_t tx_buffer[0x10000];
181     uint16_t data[12];
182     int loopback_packet;
183 
184     /* Memory access */
185     MemoryRegion *dma_mr;
186     AddressSpace as;
187 };
188 
189 /* Accessor functions for values which are formed by
190  * concatenating two 16 bit device registers. By putting these
191  * in their own functions with a uint32_t return type we avoid the
192  * pitfall of implicit sign extension where ((x << 16) | y) is a
193  * signed 32 bit integer that might get sign-extended to a 64 bit integer.
194  */
195 static uint32_t dp8393x_cdp(dp8393xState *s)
196 {
197     return (s->regs[SONIC_URRA] << 16) | s->regs[SONIC_CDP];
198 }
199 
200 static uint32_t dp8393x_crba(dp8393xState *s)
201 {
202     return (s->regs[SONIC_CRBA1] << 16) | s->regs[SONIC_CRBA0];
203 }
204 
205 static uint32_t dp8393x_crda(dp8393xState *s)
206 {
207     return (s->regs[SONIC_URDA] << 16) |
208            (s->regs[SONIC_CRDA] & SONIC_DESC_ADDR);
209 }
210 
211 static uint32_t dp8393x_rbwc(dp8393xState *s)
212 {
213     return (s->regs[SONIC_RBWC1] << 16) | s->regs[SONIC_RBWC0];
214 }
215 
216 static uint32_t dp8393x_rrp(dp8393xState *s)
217 {
218     return (s->regs[SONIC_URRA] << 16) | s->regs[SONIC_RRP];
219 }
220 
221 static uint32_t dp8393x_tsa(dp8393xState *s)
222 {
223     return (s->regs[SONIC_TSA1] << 16) | s->regs[SONIC_TSA0];
224 }
225 
226 static uint32_t dp8393x_ttda(dp8393xState *s)
227 {
228     return (s->regs[SONIC_UTDA] << 16) |
229            (s->regs[SONIC_TTDA] & SONIC_DESC_ADDR);
230 }
231 
232 static uint32_t dp8393x_wt(dp8393xState *s)
233 {
234     return s->regs[SONIC_WT1] << 16 | s->regs[SONIC_WT0];
235 }
236 
237 static uint16_t dp8393x_get(dp8393xState *s, int width, int offset)
238 {
239     uint16_t val;
240 
241     if (s->big_endian) {
242         val = be16_to_cpu(s->data[offset * width + width - 1]);
243     } else {
244         val = le16_to_cpu(s->data[offset * width]);
245     }
246     return val;
247 }
248 
249 static void dp8393x_put(dp8393xState *s, int width, int offset,
250                         uint16_t val)
251 {
252     if (s->big_endian) {
253         if (width == 2) {
254             s->data[offset * 2] = 0;
255             s->data[offset * 2 + 1] = cpu_to_be16(val);
256         } else {
257             s->data[offset] = cpu_to_be16(val);
258         }
259     } else {
260         if (width == 2) {
261             s->data[offset * 2] = cpu_to_le16(val);
262             s->data[offset * 2 + 1] = 0;
263         } else {
264             s->data[offset] = cpu_to_le16(val);
265         }
266     }
267 }
268 
269 static void dp8393x_update_irq(dp8393xState *s)
270 {
271     int level = (s->regs[SONIC_IMR] & s->regs[SONIC_ISR]) ? 1 : 0;
272 
273 #ifdef DEBUG_SONIC
274     if (level != s->irq_level) {
275         s->irq_level = level;
276         if (level) {
277             DPRINTF("raise irq, isr is 0x%04x\n", s->regs[SONIC_ISR]);
278         } else {
279             DPRINTF("lower irq\n");
280         }
281     }
282 #endif
283 
284     qemu_set_irq(s->irq, level);
285 }
286 
287 static void dp8393x_do_load_cam(dp8393xState *s)
288 {
289     int width, size;
290     uint16_t index = 0;
291 
292     width = (s->regs[SONIC_DCR] & SONIC_DCR_DW) ? 2 : 1;
293     size = sizeof(uint16_t) * 4 * width;
294 
295     while (s->regs[SONIC_CDC] & 0x1f) {
296         /* Fill current entry */
297         address_space_read(&s->as, dp8393x_cdp(s),
298                            MEMTXATTRS_UNSPECIFIED, s->data, size);
299         s->cam[index][0] = dp8393x_get(s, width, 1) & 0xff;
300         s->cam[index][1] = dp8393x_get(s, width, 1) >> 8;
301         s->cam[index][2] = dp8393x_get(s, width, 2) & 0xff;
302         s->cam[index][3] = dp8393x_get(s, width, 2) >> 8;
303         s->cam[index][4] = dp8393x_get(s, width, 3) & 0xff;
304         s->cam[index][5] = dp8393x_get(s, width, 3) >> 8;
305         DPRINTF("load cam[%d] with %02x%02x%02x%02x%02x%02x\n", index,
306             s->cam[index][0], s->cam[index][1], s->cam[index][2],
307             s->cam[index][3], s->cam[index][4], s->cam[index][5]);
308         /* Move to next entry */
309         s->regs[SONIC_CDC]--;
310         s->regs[SONIC_CDP] += size;
311         index++;
312     }
313 
314     /* Read CAM enable */
315     address_space_read(&s->as, dp8393x_cdp(s),
316                        MEMTXATTRS_UNSPECIFIED, s->data, size);
317     s->regs[SONIC_CE] = dp8393x_get(s, width, 0);
318     DPRINTF("load cam done. cam enable mask 0x%04x\n", s->regs[SONIC_CE]);
319 
320     /* Done */
321     s->regs[SONIC_CR] &= ~SONIC_CR_LCAM;
322     s->regs[SONIC_ISR] |= SONIC_ISR_LCD;
323     dp8393x_update_irq(s);
324 }
325 
326 static void dp8393x_do_read_rra(dp8393xState *s)
327 {
328     int width, size;
329 
330     /* Read memory */
331     width = (s->regs[SONIC_DCR] & SONIC_DCR_DW) ? 2 : 1;
332     size = sizeof(uint16_t) * 4 * width;
333     address_space_read(&s->as, dp8393x_rrp(s),
334                        MEMTXATTRS_UNSPECIFIED, s->data, size);
335 
336     /* Update SONIC registers */
337     s->regs[SONIC_CRBA0] = dp8393x_get(s, width, 0);
338     s->regs[SONIC_CRBA1] = dp8393x_get(s, width, 1);
339     s->regs[SONIC_RBWC0] = dp8393x_get(s, width, 2);
340     s->regs[SONIC_RBWC1] = dp8393x_get(s, width, 3);
341     DPRINTF("CRBA0/1: 0x%04x/0x%04x, RBWC0/1: 0x%04x/0x%04x\n",
342         s->regs[SONIC_CRBA0], s->regs[SONIC_CRBA1],
343         s->regs[SONIC_RBWC0], s->regs[SONIC_RBWC1]);
344 
345     /* Go to next entry */
346     s->regs[SONIC_RRP] += size;
347 
348     /* Handle wrap */
349     if (s->regs[SONIC_RRP] == s->regs[SONIC_REA]) {
350         s->regs[SONIC_RRP] = s->regs[SONIC_RSA];
351     }
352 
353     /* Warn the host if CRBA now has the last available resource */
354     if (s->regs[SONIC_RRP] == s->regs[SONIC_RWP])
355     {
356         s->regs[SONIC_ISR] |= SONIC_ISR_RBE;
357         dp8393x_update_irq(s);
358     }
359 
360     /* Allow packet reception */
361     s->last_rba_is_full = false;
362 }
363 
364 static void dp8393x_do_software_reset(dp8393xState *s)
365 {
366     timer_del(s->watchdog);
367 
368     s->regs[SONIC_CR] &= ~(SONIC_CR_LCAM | SONIC_CR_RRRA | SONIC_CR_TXP | SONIC_CR_HTX);
369     s->regs[SONIC_CR] |= SONIC_CR_RST | SONIC_CR_RXDIS;
370 }
371 
372 static void dp8393x_set_next_tick(dp8393xState *s)
373 {
374     uint32_t ticks;
375     int64_t delay;
376 
377     if (s->regs[SONIC_CR] & SONIC_CR_STP) {
378         timer_del(s->watchdog);
379         return;
380     }
381 
382     ticks = dp8393x_wt(s);
383     s->wt_last_update = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
384     delay = NANOSECONDS_PER_SECOND * ticks / 5000000;
385     timer_mod(s->watchdog, s->wt_last_update + delay);
386 }
387 
388 static void dp8393x_update_wt_regs(dp8393xState *s)
389 {
390     int64_t elapsed;
391     uint32_t val;
392 
393     if (s->regs[SONIC_CR] & SONIC_CR_STP) {
394         timer_del(s->watchdog);
395         return;
396     }
397 
398     elapsed = s->wt_last_update - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
399     val = dp8393x_wt(s);
400     val -= elapsed / 5000000;
401     s->regs[SONIC_WT1] = (val >> 16) & 0xffff;
402     s->regs[SONIC_WT0] = (val >> 0)  & 0xffff;
403     dp8393x_set_next_tick(s);
404 
405 }
406 
407 static void dp8393x_do_start_timer(dp8393xState *s)
408 {
409     s->regs[SONIC_CR] &= ~SONIC_CR_STP;
410     dp8393x_set_next_tick(s);
411 }
412 
413 static void dp8393x_do_stop_timer(dp8393xState *s)
414 {
415     s->regs[SONIC_CR] &= ~SONIC_CR_ST;
416     dp8393x_update_wt_regs(s);
417 }
418 
419 static bool dp8393x_can_receive(NetClientState *nc);
420 
421 static void dp8393x_do_receiver_enable(dp8393xState *s)
422 {
423     s->regs[SONIC_CR] &= ~SONIC_CR_RXDIS;
424     if (dp8393x_can_receive(s->nic->ncs)) {
425         qemu_flush_queued_packets(qemu_get_queue(s->nic));
426     }
427 }
428 
429 static void dp8393x_do_receiver_disable(dp8393xState *s)
430 {
431     s->regs[SONIC_CR] &= ~SONIC_CR_RXEN;
432 }
433 
434 static void dp8393x_do_transmit_packets(dp8393xState *s)
435 {
436     NetClientState *nc = qemu_get_queue(s->nic);
437     int width, size;
438     int tx_len, len;
439     uint16_t i;
440 
441     width = (s->regs[SONIC_DCR] & SONIC_DCR_DW) ? 2 : 1;
442 
443     while (1) {
444         /* Read memory */
445         size = sizeof(uint16_t) * 6 * width;
446         s->regs[SONIC_TTDA] = s->regs[SONIC_CTDA];
447         DPRINTF("Transmit packet at %08x\n", dp8393x_ttda(s));
448         address_space_read(&s->as, dp8393x_ttda(s) + sizeof(uint16_t) * width,
449                            MEMTXATTRS_UNSPECIFIED, s->data, size);
450         tx_len = 0;
451 
452         /* Update registers */
453         s->regs[SONIC_TCR] = dp8393x_get(s, width, 0) & 0xf000;
454         s->regs[SONIC_TPS] = dp8393x_get(s, width, 1);
455         s->regs[SONIC_TFC] = dp8393x_get(s, width, 2);
456         s->regs[SONIC_TSA0] = dp8393x_get(s, width, 3);
457         s->regs[SONIC_TSA1] = dp8393x_get(s, width, 4);
458         s->regs[SONIC_TFS] = dp8393x_get(s, width, 5);
459 
460         /* Handle programmable interrupt */
461         if (s->regs[SONIC_TCR] & SONIC_TCR_PINT) {
462             s->regs[SONIC_ISR] |= SONIC_ISR_PINT;
463         } else {
464             s->regs[SONIC_ISR] &= ~SONIC_ISR_PINT;
465         }
466 
467         for (i = 0; i < s->regs[SONIC_TFC]; ) {
468             /* Append fragment */
469             len = s->regs[SONIC_TFS];
470             if (tx_len + len > sizeof(s->tx_buffer)) {
471                 len = sizeof(s->tx_buffer) - tx_len;
472             }
473             address_space_read(&s->as, dp8393x_tsa(s), MEMTXATTRS_UNSPECIFIED,
474                                &s->tx_buffer[tx_len], len);
475             tx_len += len;
476 
477             i++;
478             if (i != s->regs[SONIC_TFC]) {
479                 /* Read next fragment details */
480                 size = sizeof(uint16_t) * 3 * width;
481                 address_space_read(&s->as,
482                                    dp8393x_ttda(s)
483                                    + sizeof(uint16_t) * width * (4 + 3 * i),
484                                    MEMTXATTRS_UNSPECIFIED, s->data,
485                                    size);
486                 s->regs[SONIC_TSA0] = dp8393x_get(s, width, 0);
487                 s->regs[SONIC_TSA1] = dp8393x_get(s, width, 1);
488                 s->regs[SONIC_TFS] = dp8393x_get(s, width, 2);
489             }
490         }
491 
492         /* Handle Ethernet checksum */
493         if (!(s->regs[SONIC_TCR] & SONIC_TCR_CRCI)) {
494             /* Don't append FCS there, to look like slirp packets
495              * which don't have one */
496         } else {
497             /* Remove existing FCS */
498             tx_len -= 4;
499         }
500 
501         if (s->regs[SONIC_RCR] & (SONIC_RCR_LB1 | SONIC_RCR_LB0)) {
502             /* Loopback */
503             s->regs[SONIC_TCR] |= SONIC_TCR_CRSL;
504             if (nc->info->can_receive(nc)) {
505                 s->loopback_packet = 1;
506                 nc->info->receive(nc, s->tx_buffer, tx_len);
507             }
508         } else {
509             /* Transmit packet */
510             qemu_send_packet(nc, s->tx_buffer, tx_len);
511         }
512         s->regs[SONIC_TCR] |= SONIC_TCR_PTX;
513 
514         /* Write status */
515         dp8393x_put(s, width, 0,
516                     s->regs[SONIC_TCR] & 0x0fff); /* status */
517         size = sizeof(uint16_t) * width;
518         address_space_write(&s->as, dp8393x_ttda(s),
519                             MEMTXATTRS_UNSPECIFIED, s->data, size);
520 
521         if (!(s->regs[SONIC_CR] & SONIC_CR_HTX)) {
522             /* Read footer of packet */
523             size = sizeof(uint16_t) * width;
524             address_space_read(&s->as,
525                                dp8393x_ttda(s)
526                                + sizeof(uint16_t) * width
527                                  * (4 + 3 * s->regs[SONIC_TFC]),
528                                MEMTXATTRS_UNSPECIFIED, s->data,
529                                size);
530             s->regs[SONIC_CTDA] = dp8393x_get(s, width, 0);
531             if (s->regs[SONIC_CTDA] & SONIC_DESC_EOL) {
532                 /* EOL detected */
533                 break;
534             }
535         }
536     }
537 
538     /* Done */
539     s->regs[SONIC_CR] &= ~SONIC_CR_TXP;
540     s->regs[SONIC_ISR] |= SONIC_ISR_TXDN;
541     dp8393x_update_irq(s);
542 }
543 
544 static void dp8393x_do_halt_transmission(dp8393xState *s)
545 {
546     /* Nothing to do */
547 }
548 
549 static void dp8393x_do_command(dp8393xState *s, uint16_t command)
550 {
551     if ((s->regs[SONIC_CR] & SONIC_CR_RST) && !(command & SONIC_CR_RST)) {
552         s->regs[SONIC_CR] &= ~SONIC_CR_RST;
553         return;
554     }
555 
556     s->regs[SONIC_CR] |= (command & SONIC_CR_MASK);
557 
558     if (command & SONIC_CR_HTX)
559         dp8393x_do_halt_transmission(s);
560     if (command & SONIC_CR_TXP)
561         dp8393x_do_transmit_packets(s);
562     if (command & SONIC_CR_RXDIS)
563         dp8393x_do_receiver_disable(s);
564     if (command & SONIC_CR_RXEN)
565         dp8393x_do_receiver_enable(s);
566     if (command & SONIC_CR_STP)
567         dp8393x_do_stop_timer(s);
568     if (command & SONIC_CR_ST)
569         dp8393x_do_start_timer(s);
570     if (command & SONIC_CR_RST)
571         dp8393x_do_software_reset(s);
572     if (command & SONIC_CR_RRRA) {
573         dp8393x_do_read_rra(s);
574         s->regs[SONIC_CR] &= ~SONIC_CR_RRRA;
575     }
576     if (command & SONIC_CR_LCAM)
577         dp8393x_do_load_cam(s);
578 }
579 
580 static uint64_t dp8393x_read(void *opaque, hwaddr addr, unsigned int size)
581 {
582     dp8393xState *s = opaque;
583     int reg = addr >> s->it_shift;
584     uint16_t val = 0;
585 
586     switch (reg) {
587         /* Update data before reading it */
588         case SONIC_WT0:
589         case SONIC_WT1:
590             dp8393x_update_wt_regs(s);
591             val = s->regs[reg];
592             break;
593         /* Accept read to some registers only when in reset mode */
594         case SONIC_CAP2:
595         case SONIC_CAP1:
596         case SONIC_CAP0:
597             if (s->regs[SONIC_CR] & SONIC_CR_RST) {
598                 val = s->cam[s->regs[SONIC_CEP] & 0xf][2* (SONIC_CAP0 - reg) + 1] << 8;
599                 val |= s->cam[s->regs[SONIC_CEP] & 0xf][2* (SONIC_CAP0 - reg)];
600             }
601             break;
602         /* All other registers have no special contrainst */
603         default:
604             val = s->regs[reg];
605     }
606 
607     DPRINTF("read 0x%04x from reg %s\n", val, reg_names[reg]);
608 
609     return s->big_endian ? val << 16 : val;
610 }
611 
612 static void dp8393x_write(void *opaque, hwaddr addr, uint64_t data,
613                           unsigned int size)
614 {
615     dp8393xState *s = opaque;
616     int reg = addr >> s->it_shift;
617     uint32_t val = s->big_endian ? data >> 16 : data;
618 
619     DPRINTF("write 0x%04x to reg %s\n", (uint16_t)val, reg_names[reg]);
620 
621     switch (reg) {
622         /* Command register */
623         case SONIC_CR:
624             dp8393x_do_command(s, val);
625             break;
626         /* Prevent write to read-only registers */
627         case SONIC_CAP2:
628         case SONIC_CAP1:
629         case SONIC_CAP0:
630         case SONIC_SR:
631         case SONIC_MDT:
632             DPRINTF("writing to reg %d invalid\n", reg);
633             break;
634         /* Accept write to some registers only when in reset mode */
635         case SONIC_DCR:
636             if (s->regs[SONIC_CR] & SONIC_CR_RST) {
637                 s->regs[reg] = val & 0xbfff;
638             } else {
639                 DPRINTF("writing to DCR invalid\n");
640             }
641             break;
642         case SONIC_DCR2:
643             if (s->regs[SONIC_CR] & SONIC_CR_RST) {
644                 s->regs[reg] = val & 0xf017;
645             } else {
646                 DPRINTF("writing to DCR2 invalid\n");
647             }
648             break;
649         /* 12 lower bytes are Read Only */
650         case SONIC_TCR:
651             s->regs[reg] = val & 0xf000;
652             break;
653         /* 9 lower bytes are Read Only */
654         case SONIC_RCR:
655             s->regs[reg] = val & 0xffe0;
656             break;
657         /* Ignore most significant bit */
658         case SONIC_IMR:
659             s->regs[reg] = val & 0x7fff;
660             dp8393x_update_irq(s);
661             break;
662         /* Clear bits by writing 1 to them */
663         case SONIC_ISR:
664             val &= s->regs[reg];
665             s->regs[reg] &= ~val;
666             if (val & SONIC_ISR_RBE) {
667                 dp8393x_do_read_rra(s);
668             }
669             dp8393x_update_irq(s);
670             break;
671         /* The guest is required to store aligned pointers here */
672         case SONIC_RSA:
673         case SONIC_REA:
674         case SONIC_RRP:
675         case SONIC_RWP:
676             if (s->regs[SONIC_DCR] & SONIC_DCR_DW) {
677                 s->regs[reg] = val & 0xfffc;
678             } else {
679                 s->regs[reg] = val & 0xfffe;
680             }
681             break;
682         /* Invert written value for some registers */
683         case SONIC_CRCT:
684         case SONIC_FAET:
685         case SONIC_MPT:
686             s->regs[reg] = val ^ 0xffff;
687             break;
688         /* All other registers have no special contrainst */
689         default:
690             s->regs[reg] = val;
691     }
692 
693     if (reg == SONIC_WT0 || reg == SONIC_WT1) {
694         dp8393x_set_next_tick(s);
695     }
696 }
697 
698 static const MemoryRegionOps dp8393x_ops = {
699     .read = dp8393x_read,
700     .write = dp8393x_write,
701     .impl.min_access_size = 4,
702     .impl.max_access_size = 4,
703     .endianness = DEVICE_NATIVE_ENDIAN,
704 };
705 
706 static void dp8393x_watchdog(void *opaque)
707 {
708     dp8393xState *s = opaque;
709 
710     if (s->regs[SONIC_CR] & SONIC_CR_STP) {
711         return;
712     }
713 
714     s->regs[SONIC_WT1] = 0xffff;
715     s->regs[SONIC_WT0] = 0xffff;
716     dp8393x_set_next_tick(s);
717 
718     /* Signal underflow */
719     s->regs[SONIC_ISR] |= SONIC_ISR_TC;
720     dp8393x_update_irq(s);
721 }
722 
723 static bool dp8393x_can_receive(NetClientState *nc)
724 {
725     dp8393xState *s = qemu_get_nic_opaque(nc);
726 
727     return !!(s->regs[SONIC_CR] & SONIC_CR_RXEN);
728 }
729 
730 static int dp8393x_receive_filter(dp8393xState *s, const uint8_t * buf,
731                                   int size)
732 {
733     static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
734     int i;
735 
736     /* Check promiscuous mode */
737     if ((s->regs[SONIC_RCR] & SONIC_RCR_PRO) && (buf[0] & 1) == 0) {
738         return 0;
739     }
740 
741     /* Check multicast packets */
742     if ((s->regs[SONIC_RCR] & SONIC_RCR_AMC) && (buf[0] & 1) == 1) {
743         return SONIC_RCR_MC;
744     }
745 
746     /* Check broadcast */
747     if ((s->regs[SONIC_RCR] & SONIC_RCR_BRD) && !memcmp(buf, bcast, sizeof(bcast))) {
748         return SONIC_RCR_BC;
749     }
750 
751     /* Check CAM */
752     for (i = 0; i < 16; i++) {
753         if (s->regs[SONIC_CE] & (1 << i)) {
754              /* Entry enabled */
755              if (!memcmp(buf, s->cam[i], sizeof(s->cam[i]))) {
756                  return 0;
757              }
758         }
759     }
760 
761     return -1;
762 }
763 
764 static ssize_t dp8393x_receive(NetClientState *nc, const uint8_t * buf,
765                                size_t pkt_size)
766 {
767     dp8393xState *s = qemu_get_nic_opaque(nc);
768     int packet_type;
769     uint32_t available, address;
770     int width, rx_len, padded_len;
771     uint32_t checksum;
772     int size;
773 
774     s->regs[SONIC_RCR] &= ~(SONIC_RCR_PRX | SONIC_RCR_LBK | SONIC_RCR_FAER |
775         SONIC_RCR_CRCR | SONIC_RCR_LPKT | SONIC_RCR_BC | SONIC_RCR_MC);
776 
777     if (s->last_rba_is_full) {
778         return pkt_size;
779     }
780 
781     rx_len = pkt_size + sizeof(checksum);
782     if (s->regs[SONIC_DCR] & SONIC_DCR_DW) {
783         width = 2;
784         padded_len = ((rx_len - 1) | 3) + 1;
785     } else {
786         width = 1;
787         padded_len = ((rx_len - 1) | 1) + 1;
788     }
789 
790     if (padded_len > dp8393x_rbwc(s) * 2) {
791         DPRINTF("oversize packet, pkt_size is %d\n", pkt_size);
792         s->regs[SONIC_ISR] |= SONIC_ISR_RBAE;
793         dp8393x_update_irq(s);
794         s->regs[SONIC_RCR] |= SONIC_RCR_LPKT;
795         goto done;
796     }
797 
798     packet_type = dp8393x_receive_filter(s, buf, pkt_size);
799     if (packet_type < 0) {
800         DPRINTF("packet not for netcard\n");
801         return -1;
802     }
803 
804     /* Check for EOL */
805     if (s->regs[SONIC_LLFA] & SONIC_DESC_EOL) {
806         /* Are we still in resource exhaustion? */
807         size = sizeof(uint16_t) * 1 * width;
808         address = dp8393x_crda(s) + sizeof(uint16_t) * 5 * width;
809         address_space_read(&s->as, address, MEMTXATTRS_UNSPECIFIED,
810                            s->data, size);
811         s->regs[SONIC_LLFA] = dp8393x_get(s, width, 0);
812         if (s->regs[SONIC_LLFA] & SONIC_DESC_EOL) {
813             /* Still EOL ; stop reception */
814             return -1;
815         }
816         /* Link has been updated by host */
817 
818         /* Clear in_use */
819         size = sizeof(uint16_t) * width;
820         address = dp8393x_crda(s) + sizeof(uint16_t) * 6 * width;
821         dp8393x_put(s, width, 0, 0);
822         address_space_rw(&s->as, address, MEMTXATTRS_UNSPECIFIED,
823                          (uint8_t *)s->data, size, 1);
824 
825         /* Move to next descriptor */
826         s->regs[SONIC_CRDA] = s->regs[SONIC_LLFA];
827         s->regs[SONIC_ISR] |= SONIC_ISR_PKTRX;
828     }
829 
830     /* Save current position */
831     s->regs[SONIC_TRBA1] = s->regs[SONIC_CRBA1];
832     s->regs[SONIC_TRBA0] = s->regs[SONIC_CRBA0];
833 
834     /* Calculate the ethernet checksum */
835     checksum = cpu_to_le32(crc32(0, buf, pkt_size));
836 
837     /* Put packet into RBA */
838     DPRINTF("Receive packet at %08x\n", dp8393x_crba(s));
839     address = dp8393x_crba(s);
840     address_space_write(&s->as, address, MEMTXATTRS_UNSPECIFIED,
841                         buf, pkt_size);
842     address += pkt_size;
843 
844     /* Put frame checksum into RBA */
845     address_space_write(&s->as, address, MEMTXATTRS_UNSPECIFIED,
846                         &checksum, sizeof(checksum));
847     address += sizeof(checksum);
848 
849     /* Pad short packets to keep pointers aligned */
850     if (rx_len < padded_len) {
851         size = padded_len - rx_len;
852         address_space_rw(&s->as, address, MEMTXATTRS_UNSPECIFIED,
853             (uint8_t *)"\xFF\xFF\xFF", size, 1);
854         address += size;
855     }
856 
857     s->regs[SONIC_CRBA1] = address >> 16;
858     s->regs[SONIC_CRBA0] = address & 0xffff;
859     available = dp8393x_rbwc(s);
860     available -= padded_len >> 1;
861     s->regs[SONIC_RBWC1] = available >> 16;
862     s->regs[SONIC_RBWC0] = available & 0xffff;
863 
864     /* Update status */
865     if (dp8393x_rbwc(s) < s->regs[SONIC_EOBC]) {
866         s->regs[SONIC_RCR] |= SONIC_RCR_LPKT;
867     }
868     s->regs[SONIC_RCR] |= packet_type;
869     s->regs[SONIC_RCR] |= SONIC_RCR_PRX;
870     if (s->loopback_packet) {
871         s->regs[SONIC_RCR] |= SONIC_RCR_LBK;
872         s->loopback_packet = 0;
873     }
874 
875     /* Write status to memory */
876     DPRINTF("Write status at %08x\n", dp8393x_crda(s));
877     dp8393x_put(s, width, 0, s->regs[SONIC_RCR]); /* status */
878     dp8393x_put(s, width, 1, rx_len); /* byte count */
879     dp8393x_put(s, width, 2, s->regs[SONIC_TRBA0]); /* pkt_ptr0 */
880     dp8393x_put(s, width, 3, s->regs[SONIC_TRBA1]); /* pkt_ptr1 */
881     dp8393x_put(s, width, 4, s->regs[SONIC_RSC]); /* seq_no */
882     size = sizeof(uint16_t) * 5 * width;
883     address_space_write(&s->as, dp8393x_crda(s),
884                         MEMTXATTRS_UNSPECIFIED,
885                         s->data, size);
886 
887     /* Check link field */
888     size = sizeof(uint16_t) * width;
889     address_space_read(&s->as,
890                        dp8393x_crda(s) + sizeof(uint16_t) * 5 * width,
891                        MEMTXATTRS_UNSPECIFIED, s->data, size);
892     s->regs[SONIC_LLFA] = dp8393x_get(s, width, 0);
893     if (s->regs[SONIC_LLFA] & SONIC_DESC_EOL) {
894         /* EOL detected */
895         s->regs[SONIC_ISR] |= SONIC_ISR_RDE;
896     } else {
897         /* Clear in_use */
898         size = sizeof(uint16_t) * width;
899         address = dp8393x_crda(s) + sizeof(uint16_t) * 6 * width;
900         dp8393x_put(s, width, 0, 0);
901         address_space_write(&s->as, address, MEMTXATTRS_UNSPECIFIED,
902                             s->data, size);
903 
904         /* Move to next descriptor */
905         s->regs[SONIC_CRDA] = s->regs[SONIC_LLFA];
906         s->regs[SONIC_ISR] |= SONIC_ISR_PKTRX;
907     }
908 
909     dp8393x_update_irq(s);
910 
911     s->regs[SONIC_RSC] = (s->regs[SONIC_RSC] & 0xff00) |
912                          ((s->regs[SONIC_RSC] + 1) & 0x00ff);
913 
914 done:
915 
916     if (s->regs[SONIC_RCR] & SONIC_RCR_LPKT) {
917         if (s->regs[SONIC_RRP] == s->regs[SONIC_RWP]) {
918             /* Stop packet reception */
919             s->last_rba_is_full = true;
920         } else {
921             /* Read next resource */
922             dp8393x_do_read_rra(s);
923         }
924     }
925 
926     return pkt_size;
927 }
928 
929 static void dp8393x_reset(DeviceState *dev)
930 {
931     dp8393xState *s = DP8393X(dev);
932     timer_del(s->watchdog);
933 
934     memset(s->regs, 0, sizeof(s->regs));
935     s->regs[SONIC_SR] = 0x0004; /* only revision recognized by Linux/mips */
936     s->regs[SONIC_CR] = SONIC_CR_RST | SONIC_CR_STP | SONIC_CR_RXDIS;
937     s->regs[SONIC_DCR] &= ~(SONIC_DCR_EXBUS | SONIC_DCR_LBR);
938     s->regs[SONIC_RCR] &= ~(SONIC_RCR_LB0 | SONIC_RCR_LB1 | SONIC_RCR_BRD | SONIC_RCR_RNT);
939     s->regs[SONIC_TCR] |= SONIC_TCR_NCRS | SONIC_TCR_PTX;
940     s->regs[SONIC_TCR] &= ~SONIC_TCR_BCM;
941     s->regs[SONIC_IMR] = 0;
942     s->regs[SONIC_ISR] = 0;
943     s->regs[SONIC_DCR2] = 0;
944     s->regs[SONIC_EOBC] = 0x02F8;
945     s->regs[SONIC_RSC] = 0;
946     s->regs[SONIC_CE] = 0;
947     s->regs[SONIC_RSC] = 0;
948 
949     /* Network cable is connected */
950     s->regs[SONIC_RCR] |= SONIC_RCR_CRS;
951 
952     dp8393x_update_irq(s);
953 }
954 
955 static NetClientInfo net_dp83932_info = {
956     .type = NET_CLIENT_DRIVER_NIC,
957     .size = sizeof(NICState),
958     .can_receive = dp8393x_can_receive,
959     .receive = dp8393x_receive,
960 };
961 
962 static void dp8393x_instance_init(Object *obj)
963 {
964     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
965     dp8393xState *s = DP8393X(obj);
966 
967     sysbus_init_mmio(sbd, &s->mmio);
968     sysbus_init_mmio(sbd, &s->prom);
969     sysbus_init_irq(sbd, &s->irq);
970 }
971 
972 static void dp8393x_realize(DeviceState *dev, Error **errp)
973 {
974     dp8393xState *s = DP8393X(dev);
975     int i, checksum;
976     uint8_t *prom;
977     Error *local_err = NULL;
978 
979     address_space_init(&s->as, s->dma_mr, "dp8393x");
980     memory_region_init_io(&s->mmio, OBJECT(dev), &dp8393x_ops, s,
981                           "dp8393x-regs", 0x40 << s->it_shift);
982 
983     s->nic = qemu_new_nic(&net_dp83932_info, &s->conf,
984                           object_get_typename(OBJECT(dev)), dev->id, s);
985     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
986 
987     s->watchdog = timer_new_ns(QEMU_CLOCK_VIRTUAL, dp8393x_watchdog, s);
988 
989     memory_region_init_rom(&s->prom, OBJECT(dev), "dp8393x-prom",
990                            SONIC_PROM_SIZE, &local_err);
991     if (local_err) {
992         error_propagate(errp, local_err);
993         return;
994     }
995     prom = memory_region_get_ram_ptr(&s->prom);
996     checksum = 0;
997     for (i = 0; i < 6; i++) {
998         prom[i] = s->conf.macaddr.a[i];
999         checksum += prom[i];
1000         if (checksum > 0xff) {
1001             checksum = (checksum + 1) & 0xff;
1002         }
1003     }
1004     prom[7] = 0xff - checksum;
1005 }
1006 
1007 static const VMStateDescription vmstate_dp8393x = {
1008     .name = "dp8393x",
1009     .version_id = 0,
1010     .minimum_version_id = 0,
1011     .fields = (VMStateField []) {
1012         VMSTATE_BUFFER_UNSAFE(cam, dp8393xState, 0, 16 * 6),
1013         VMSTATE_UINT16_ARRAY(regs, dp8393xState, 0x40),
1014         VMSTATE_END_OF_LIST()
1015     }
1016 };
1017 
1018 static Property dp8393x_properties[] = {
1019     DEFINE_NIC_PROPERTIES(dp8393xState, conf),
1020     DEFINE_PROP_LINK("dma_mr", dp8393xState, dma_mr,
1021                      TYPE_MEMORY_REGION, MemoryRegion *),
1022     DEFINE_PROP_UINT8("it_shift", dp8393xState, it_shift, 0),
1023     DEFINE_PROP_BOOL("big_endian", dp8393xState, big_endian, false),
1024     DEFINE_PROP_END_OF_LIST(),
1025 };
1026 
1027 static void dp8393x_class_init(ObjectClass *klass, void *data)
1028 {
1029     DeviceClass *dc = DEVICE_CLASS(klass);
1030 
1031     set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
1032     dc->realize = dp8393x_realize;
1033     dc->reset = dp8393x_reset;
1034     dc->vmsd = &vmstate_dp8393x;
1035     device_class_set_props(dc, dp8393x_properties);
1036 }
1037 
1038 static const TypeInfo dp8393x_info = {
1039     .name          = TYPE_DP8393X,
1040     .parent        = TYPE_SYS_BUS_DEVICE,
1041     .instance_size = sizeof(dp8393xState),
1042     .instance_init = dp8393x_instance_init,
1043     .class_init    = dp8393x_class_init,
1044 };
1045 
1046 static void dp8393x_register_types(void)
1047 {
1048     type_register_static(&dp8393x_info);
1049 }
1050 
1051 type_init(dp8393x_register_types)
1052