xref: /openbmc/qemu/hw/net/dp8393x.c (revision 502d0f36)
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/sysbus.h"
22 #include "hw/devices.h"
23 #include "net/net.h"
24 #include "qapi/error.h"
25 #include "qemu/timer.h"
26 #include <zlib.h>
27 
28 //#define DEBUG_SONIC
29 
30 #define SONIC_PROM_SIZE 0x1000
31 
32 #ifdef DEBUG_SONIC
33 #define DPRINTF(fmt, ...) \
34 do { printf("sonic: " fmt , ##  __VA_ARGS__); } while (0)
35 static const char* reg_names[] = {
36     "CR", "DCR", "RCR", "TCR", "IMR", "ISR", "UTDA", "CTDA",
37     "TPS", "TFC", "TSA0", "TSA1", "TFS", "URDA", "CRDA", "CRBA0",
38     "CRBA1", "RBWC0", "RBWC1", "EOBC", "URRA", "RSA", "REA", "RRP",
39     "RWP", "TRBA0", "TRBA1", "0x1b", "0x1c", "0x1d", "0x1e", "LLFA",
40     "TTDA", "CEP", "CAP2", "CAP1", "CAP0", "CE", "CDP", "CDC",
41     "SR", "WT0", "WT1", "RSC", "CRCT", "FAET", "MPT", "MDT",
42     "0x30", "0x31", "0x32", "0x33", "0x34", "0x35", "0x36", "0x37",
43     "0x38", "0x39", "0x3a", "0x3b", "0x3c", "0x3d", "0x3e", "DCR2" };
44 #else
45 #define DPRINTF(fmt, ...) do {} while (0)
46 #endif
47 
48 #define SONIC_ERROR(fmt, ...) \
49 do { printf("sonic ERROR: %s: " fmt, __func__ , ## __VA_ARGS__); } while (0)
50 
51 #define SONIC_CR     0x00
52 #define SONIC_DCR    0x01
53 #define SONIC_RCR    0x02
54 #define SONIC_TCR    0x03
55 #define SONIC_IMR    0x04
56 #define SONIC_ISR    0x05
57 #define SONIC_UTDA   0x06
58 #define SONIC_CTDA   0x07
59 #define SONIC_TPS    0x08
60 #define SONIC_TFC    0x09
61 #define SONIC_TSA0   0x0a
62 #define SONIC_TSA1   0x0b
63 #define SONIC_TFS    0x0c
64 #define SONIC_URDA   0x0d
65 #define SONIC_CRDA   0x0e
66 #define SONIC_CRBA0  0x0f
67 #define SONIC_CRBA1  0x10
68 #define SONIC_RBWC0  0x11
69 #define SONIC_RBWC1  0x12
70 #define SONIC_EOBC   0x13
71 #define SONIC_URRA   0x14
72 #define SONIC_RSA    0x15
73 #define SONIC_REA    0x16
74 #define SONIC_RRP    0x17
75 #define SONIC_RWP    0x18
76 #define SONIC_TRBA0  0x19
77 #define SONIC_TRBA1  0x1a
78 #define SONIC_LLFA   0x1f
79 #define SONIC_TTDA   0x20
80 #define SONIC_CEP    0x21
81 #define SONIC_CAP2   0x22
82 #define SONIC_CAP1   0x23
83 #define SONIC_CAP0   0x24
84 #define SONIC_CE     0x25
85 #define SONIC_CDP    0x26
86 #define SONIC_CDC    0x27
87 #define SONIC_SR     0x28
88 #define SONIC_WT0    0x29
89 #define SONIC_WT1    0x2a
90 #define SONIC_RSC    0x2b
91 #define SONIC_CRCT   0x2c
92 #define SONIC_FAET   0x2d
93 #define SONIC_MPT    0x2e
94 #define SONIC_MDT    0x2f
95 #define SONIC_DCR2   0x3f
96 
97 #define SONIC_CR_HTX     0x0001
98 #define SONIC_CR_TXP     0x0002
99 #define SONIC_CR_RXDIS   0x0004
100 #define SONIC_CR_RXEN    0x0008
101 #define SONIC_CR_STP     0x0010
102 #define SONIC_CR_ST      0x0020
103 #define SONIC_CR_RST     0x0080
104 #define SONIC_CR_RRRA    0x0100
105 #define SONIC_CR_LCAM    0x0200
106 #define SONIC_CR_MASK    0x03bf
107 
108 #define SONIC_DCR_DW     0x0020
109 #define SONIC_DCR_LBR    0x2000
110 #define SONIC_DCR_EXBUS  0x8000
111 
112 #define SONIC_RCR_PRX    0x0001
113 #define SONIC_RCR_LBK    0x0002
114 #define SONIC_RCR_FAER   0x0004
115 #define SONIC_RCR_CRCR   0x0008
116 #define SONIC_RCR_CRS    0x0020
117 #define SONIC_RCR_LPKT   0x0040
118 #define SONIC_RCR_BC     0x0080
119 #define SONIC_RCR_MC     0x0100
120 #define SONIC_RCR_LB0    0x0200
121 #define SONIC_RCR_LB1    0x0400
122 #define SONIC_RCR_AMC    0x0800
123 #define SONIC_RCR_PRO    0x1000
124 #define SONIC_RCR_BRD    0x2000
125 #define SONIC_RCR_RNT    0x4000
126 
127 #define SONIC_TCR_PTX    0x0001
128 #define SONIC_TCR_BCM    0x0002
129 #define SONIC_TCR_FU     0x0004
130 #define SONIC_TCR_EXC    0x0040
131 #define SONIC_TCR_CRSL   0x0080
132 #define SONIC_TCR_NCRS   0x0100
133 #define SONIC_TCR_EXD    0x0400
134 #define SONIC_TCR_CRCI   0x2000
135 #define SONIC_TCR_PINT   0x8000
136 
137 #define SONIC_ISR_RBE    0x0020
138 #define SONIC_ISR_RDE    0x0040
139 #define SONIC_ISR_TC     0x0080
140 #define SONIC_ISR_TXDN   0x0200
141 #define SONIC_ISR_PKTRX  0x0400
142 #define SONIC_ISR_PINT   0x0800
143 #define SONIC_ISR_LCD    0x1000
144 
145 #define TYPE_DP8393X "dp8393x"
146 #define DP8393X(obj) OBJECT_CHECK(dp8393xState, (obj), TYPE_DP8393X)
147 
148 typedef struct dp8393xState {
149     SysBusDevice parent_obj;
150 
151     /* Hardware */
152     uint8_t it_shift;
153     qemu_irq irq;
154 #ifdef DEBUG_SONIC
155     int irq_level;
156 #endif
157     QEMUTimer *watchdog;
158     int64_t wt_last_update;
159     NICConf conf;
160     NICState *nic;
161     MemoryRegion mmio;
162     MemoryRegion prom;
163 
164     /* Registers */
165     uint8_t cam[16][6];
166     uint16_t regs[0x40];
167 
168     /* Temporaries */
169     uint8_t tx_buffer[0x10000];
170     int loopback_packet;
171 
172     /* Memory access */
173     void *dma_mr;
174     AddressSpace as;
175 } dp8393xState;
176 
177 /* Accessor functions for values which are formed by
178  * concatenating two 16 bit device registers. By putting these
179  * in their own functions with a uint32_t return type we avoid the
180  * pitfall of implicit sign extension where ((x << 16) | y) is a
181  * signed 32 bit integer that might get sign-extended to a 64 bit integer.
182  */
183 static uint32_t dp8393x_cdp(dp8393xState *s)
184 {
185     return (s->regs[SONIC_URRA] << 16) | s->regs[SONIC_CDP];
186 }
187 
188 static uint32_t dp8393x_crba(dp8393xState *s)
189 {
190     return (s->regs[SONIC_CRBA1] << 16) | s->regs[SONIC_CRBA0];
191 }
192 
193 static uint32_t dp8393x_crda(dp8393xState *s)
194 {
195     return (s->regs[SONIC_URDA] << 16) | s->regs[SONIC_CRDA];
196 }
197 
198 static uint32_t dp8393x_rbwc(dp8393xState *s)
199 {
200     return (s->regs[SONIC_RBWC1] << 16) | s->regs[SONIC_RBWC0];
201 }
202 
203 static uint32_t dp8393x_rrp(dp8393xState *s)
204 {
205     return (s->regs[SONIC_URRA] << 16) | s->regs[SONIC_RRP];
206 }
207 
208 static uint32_t dp8393x_tsa(dp8393xState *s)
209 {
210     return (s->regs[SONIC_TSA1] << 16) | s->regs[SONIC_TSA0];
211 }
212 
213 static uint32_t dp8393x_ttda(dp8393xState *s)
214 {
215     return (s->regs[SONIC_UTDA] << 16) | s->regs[SONIC_TTDA];
216 }
217 
218 static uint32_t dp8393x_wt(dp8393xState *s)
219 {
220     return s->regs[SONIC_WT1] << 16 | s->regs[SONIC_WT0];
221 }
222 
223 static void dp8393x_update_irq(dp8393xState *s)
224 {
225     int level = (s->regs[SONIC_IMR] & s->regs[SONIC_ISR]) ? 1 : 0;
226 
227 #ifdef DEBUG_SONIC
228     if (level != s->irq_level) {
229         s->irq_level = level;
230         if (level) {
231             DPRINTF("raise irq, isr is 0x%04x\n", s->regs[SONIC_ISR]);
232         } else {
233             DPRINTF("lower irq\n");
234         }
235     }
236 #endif
237 
238     qemu_set_irq(s->irq, level);
239 }
240 
241 static void dp8393x_do_load_cam(dp8393xState *s)
242 {
243     uint16_t data[8];
244     int width, size;
245     uint16_t index = 0;
246 
247     width = (s->regs[SONIC_DCR] & SONIC_DCR_DW) ? 2 : 1;
248     size = sizeof(uint16_t) * 4 * width;
249 
250     while (s->regs[SONIC_CDC] & 0x1f) {
251         /* Fill current entry */
252         address_space_rw(&s->as, dp8393x_cdp(s),
253             MEMTXATTRS_UNSPECIFIED, (uint8_t *)data, size, 0);
254         s->cam[index][0] = data[1 * width] & 0xff;
255         s->cam[index][1] = data[1 * width] >> 8;
256         s->cam[index][2] = data[2 * width] & 0xff;
257         s->cam[index][3] = data[2 * width] >> 8;
258         s->cam[index][4] = data[3 * width] & 0xff;
259         s->cam[index][5] = data[3 * width] >> 8;
260         DPRINTF("load cam[%d] with %02x%02x%02x%02x%02x%02x\n", index,
261             s->cam[index][0], s->cam[index][1], s->cam[index][2],
262             s->cam[index][3], s->cam[index][4], s->cam[index][5]);
263         /* Move to next entry */
264         s->regs[SONIC_CDC]--;
265         s->regs[SONIC_CDP] += size;
266         index++;
267     }
268 
269     /* Read CAM enable */
270     address_space_rw(&s->as, dp8393x_cdp(s),
271         MEMTXATTRS_UNSPECIFIED, (uint8_t *)data, size, 0);
272     s->regs[SONIC_CE] = data[0 * width];
273     DPRINTF("load cam done. cam enable mask 0x%04x\n", s->regs[SONIC_CE]);
274 
275     /* Done */
276     s->regs[SONIC_CR] &= ~SONIC_CR_LCAM;
277     s->regs[SONIC_ISR] |= SONIC_ISR_LCD;
278     dp8393x_update_irq(s);
279 }
280 
281 static void dp8393x_do_read_rra(dp8393xState *s)
282 {
283     uint16_t data[8];
284     int width, size;
285 
286     /* Read memory */
287     width = (s->regs[SONIC_DCR] & SONIC_DCR_DW) ? 2 : 1;
288     size = sizeof(uint16_t) * 4 * width;
289     address_space_rw(&s->as, dp8393x_rrp(s),
290         MEMTXATTRS_UNSPECIFIED, (uint8_t *)data, size, 0);
291 
292     /* Update SONIC registers */
293     s->regs[SONIC_CRBA0] = data[0 * width];
294     s->regs[SONIC_CRBA1] = data[1 * width];
295     s->regs[SONIC_RBWC0] = data[2 * width];
296     s->regs[SONIC_RBWC1] = data[3 * width];
297     DPRINTF("CRBA0/1: 0x%04x/0x%04x, RBWC0/1: 0x%04x/0x%04x\n",
298         s->regs[SONIC_CRBA0], s->regs[SONIC_CRBA1],
299         s->regs[SONIC_RBWC0], s->regs[SONIC_RBWC1]);
300 
301     /* Go to next entry */
302     s->regs[SONIC_RRP] += size;
303 
304     /* Handle wrap */
305     if (s->regs[SONIC_RRP] == s->regs[SONIC_REA]) {
306         s->regs[SONIC_RRP] = s->regs[SONIC_RSA];
307     }
308 
309     /* Check resource exhaustion */
310     if (s->regs[SONIC_RRP] == s->regs[SONIC_RWP])
311     {
312         s->regs[SONIC_ISR] |= SONIC_ISR_RBE;
313         dp8393x_update_irq(s);
314     }
315 
316     /* Done */
317     s->regs[SONIC_CR] &= ~SONIC_CR_RRRA;
318 }
319 
320 static void dp8393x_do_software_reset(dp8393xState *s)
321 {
322     timer_del(s->watchdog);
323 
324     s->regs[SONIC_CR] &= ~(SONIC_CR_LCAM | SONIC_CR_RRRA | SONIC_CR_TXP | SONIC_CR_HTX);
325     s->regs[SONIC_CR] |= SONIC_CR_RST | SONIC_CR_RXDIS;
326 }
327 
328 static void dp8393x_set_next_tick(dp8393xState *s)
329 {
330     uint32_t ticks;
331     int64_t delay;
332 
333     if (s->regs[SONIC_CR] & SONIC_CR_STP) {
334         timer_del(s->watchdog);
335         return;
336     }
337 
338     ticks = dp8393x_wt(s);
339     s->wt_last_update = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
340     delay = NANOSECONDS_PER_SECOND * ticks / 5000000;
341     timer_mod(s->watchdog, s->wt_last_update + delay);
342 }
343 
344 static void dp8393x_update_wt_regs(dp8393xState *s)
345 {
346     int64_t elapsed;
347     uint32_t val;
348 
349     if (s->regs[SONIC_CR] & SONIC_CR_STP) {
350         timer_del(s->watchdog);
351         return;
352     }
353 
354     elapsed = s->wt_last_update - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
355     val = dp8393x_wt(s);
356     val -= elapsed / 5000000;
357     s->regs[SONIC_WT1] = (val >> 16) & 0xffff;
358     s->regs[SONIC_WT0] = (val >> 0)  & 0xffff;
359     dp8393x_set_next_tick(s);
360 
361 }
362 
363 static void dp8393x_do_start_timer(dp8393xState *s)
364 {
365     s->regs[SONIC_CR] &= ~SONIC_CR_STP;
366     dp8393x_set_next_tick(s);
367 }
368 
369 static void dp8393x_do_stop_timer(dp8393xState *s)
370 {
371     s->regs[SONIC_CR] &= ~SONIC_CR_ST;
372     dp8393x_update_wt_regs(s);
373 }
374 
375 static int dp8393x_can_receive(NetClientState *nc);
376 
377 static void dp8393x_do_receiver_enable(dp8393xState *s)
378 {
379     s->regs[SONIC_CR] &= ~SONIC_CR_RXDIS;
380     if (dp8393x_can_receive(s->nic->ncs)) {
381         qemu_flush_queued_packets(qemu_get_queue(s->nic));
382     }
383 }
384 
385 static void dp8393x_do_receiver_disable(dp8393xState *s)
386 {
387     s->regs[SONIC_CR] &= ~SONIC_CR_RXEN;
388 }
389 
390 static void dp8393x_do_transmit_packets(dp8393xState *s)
391 {
392     NetClientState *nc = qemu_get_queue(s->nic);
393     uint16_t data[12];
394     int width, size;
395     int tx_len, len;
396     uint16_t i;
397 
398     width = (s->regs[SONIC_DCR] & SONIC_DCR_DW) ? 2 : 1;
399 
400     while (1) {
401         /* Read memory */
402         size = sizeof(uint16_t) * 6 * width;
403         s->regs[SONIC_TTDA] = s->regs[SONIC_CTDA];
404         DPRINTF("Transmit packet at %08x\n", dp8393x_ttda(s));
405         address_space_rw(&s->as,
406             dp8393x_ttda(s) + sizeof(uint16_t) * width,
407             MEMTXATTRS_UNSPECIFIED, (uint8_t *)data, size, 0);
408         tx_len = 0;
409 
410         /* Update registers */
411         s->regs[SONIC_TCR] = data[0 * width] & 0xf000;
412         s->regs[SONIC_TPS] = data[1 * width];
413         s->regs[SONIC_TFC] = data[2 * width];
414         s->regs[SONIC_TSA0] = data[3 * width];
415         s->regs[SONIC_TSA1] = data[4 * width];
416         s->regs[SONIC_TFS] = data[5 * width];
417 
418         /* Handle programmable interrupt */
419         if (s->regs[SONIC_TCR] & SONIC_TCR_PINT) {
420             s->regs[SONIC_ISR] |= SONIC_ISR_PINT;
421         } else {
422             s->regs[SONIC_ISR] &= ~SONIC_ISR_PINT;
423         }
424 
425         for (i = 0; i < s->regs[SONIC_TFC]; ) {
426             /* Append fragment */
427             len = s->regs[SONIC_TFS];
428             if (tx_len + len > sizeof(s->tx_buffer)) {
429                 len = sizeof(s->tx_buffer) - tx_len;
430             }
431             address_space_rw(&s->as, dp8393x_tsa(s),
432                 MEMTXATTRS_UNSPECIFIED, &s->tx_buffer[tx_len], len, 0);
433             tx_len += len;
434 
435             i++;
436             if (i != s->regs[SONIC_TFC]) {
437                 /* Read next fragment details */
438                 size = sizeof(uint16_t) * 3 * width;
439                 address_space_rw(&s->as,
440                     dp8393x_ttda(s) + sizeof(uint16_t) * (4 + 3 * i) * width,
441                     MEMTXATTRS_UNSPECIFIED, (uint8_t *)data, size, 0);
442                 s->regs[SONIC_TSA0] = data[0 * width];
443                 s->regs[SONIC_TSA1] = data[1 * width];
444                 s->regs[SONIC_TFS] = data[2 * width];
445             }
446         }
447 
448         /* Handle Ethernet checksum */
449         if (!(s->regs[SONIC_TCR] & SONIC_TCR_CRCI)) {
450             /* Don't append FCS there, to look like slirp packets
451              * which don't have one */
452         } else {
453             /* Remove existing FCS */
454             tx_len -= 4;
455         }
456 
457         if (s->regs[SONIC_RCR] & (SONIC_RCR_LB1 | SONIC_RCR_LB0)) {
458             /* Loopback */
459             s->regs[SONIC_TCR] |= SONIC_TCR_CRSL;
460             if (nc->info->can_receive(nc)) {
461                 s->loopback_packet = 1;
462                 nc->info->receive(nc, s->tx_buffer, tx_len);
463             }
464         } else {
465             /* Transmit packet */
466             qemu_send_packet(nc, s->tx_buffer, tx_len);
467         }
468         s->regs[SONIC_TCR] |= SONIC_TCR_PTX;
469 
470         /* Write status */
471         data[0 * width] = s->regs[SONIC_TCR] & 0x0fff; /* status */
472         size = sizeof(uint16_t) * width;
473         address_space_rw(&s->as,
474             dp8393x_ttda(s),
475             MEMTXATTRS_UNSPECIFIED, (uint8_t *)data, size, 1);
476 
477         if (!(s->regs[SONIC_CR] & SONIC_CR_HTX)) {
478             /* Read footer of packet */
479             size = sizeof(uint16_t) * width;
480             address_space_rw(&s->as,
481                 dp8393x_ttda(s) +
482                              sizeof(uint16_t) *
483                              (4 + 3 * s->regs[SONIC_TFC]) * width,
484                 MEMTXATTRS_UNSPECIFIED, (uint8_t *)data, size, 0);
485             s->regs[SONIC_CTDA] = data[0 * width] & ~0x1;
486             if (data[0 * width] & 0x1) {
487                 /* EOL detected */
488                 break;
489             }
490         }
491     }
492 
493     /* Done */
494     s->regs[SONIC_CR] &= ~SONIC_CR_TXP;
495     s->regs[SONIC_ISR] |= SONIC_ISR_TXDN;
496     dp8393x_update_irq(s);
497 }
498 
499 static void dp8393x_do_halt_transmission(dp8393xState *s)
500 {
501     /* Nothing to do */
502 }
503 
504 static void dp8393x_do_command(dp8393xState *s, uint16_t command)
505 {
506     if ((s->regs[SONIC_CR] & SONIC_CR_RST) && !(command & SONIC_CR_RST)) {
507         s->regs[SONIC_CR] &= ~SONIC_CR_RST;
508         return;
509     }
510 
511     s->regs[SONIC_CR] |= (command & SONIC_CR_MASK);
512 
513     if (command & SONIC_CR_HTX)
514         dp8393x_do_halt_transmission(s);
515     if (command & SONIC_CR_TXP)
516         dp8393x_do_transmit_packets(s);
517     if (command & SONIC_CR_RXDIS)
518         dp8393x_do_receiver_disable(s);
519     if (command & SONIC_CR_RXEN)
520         dp8393x_do_receiver_enable(s);
521     if (command & SONIC_CR_STP)
522         dp8393x_do_stop_timer(s);
523     if (command & SONIC_CR_ST)
524         dp8393x_do_start_timer(s);
525     if (command & SONIC_CR_RST)
526         dp8393x_do_software_reset(s);
527     if (command & SONIC_CR_RRRA)
528         dp8393x_do_read_rra(s);
529     if (command & SONIC_CR_LCAM)
530         dp8393x_do_load_cam(s);
531 }
532 
533 static uint64_t dp8393x_read(void *opaque, hwaddr addr, unsigned int size)
534 {
535     dp8393xState *s = opaque;
536     int reg = addr >> s->it_shift;
537     uint16_t val = 0;
538 
539     switch (reg) {
540         /* Update data before reading it */
541         case SONIC_WT0:
542         case SONIC_WT1:
543             dp8393x_update_wt_regs(s);
544             val = s->regs[reg];
545             break;
546         /* Accept read to some registers only when in reset mode */
547         case SONIC_CAP2:
548         case SONIC_CAP1:
549         case SONIC_CAP0:
550             if (s->regs[SONIC_CR] & SONIC_CR_RST) {
551                 val = s->cam[s->regs[SONIC_CEP] & 0xf][2* (SONIC_CAP0 - reg) + 1] << 8;
552                 val |= s->cam[s->regs[SONIC_CEP] & 0xf][2* (SONIC_CAP0 - reg)];
553             }
554             break;
555         /* All other registers have no special contrainst */
556         default:
557             val = s->regs[reg];
558     }
559 
560     DPRINTF("read 0x%04x from reg %s\n", val, reg_names[reg]);
561 
562     return val;
563 }
564 
565 static void dp8393x_write(void *opaque, hwaddr addr, uint64_t data,
566                           unsigned int size)
567 {
568     dp8393xState *s = opaque;
569     int reg = addr >> s->it_shift;
570 
571     DPRINTF("write 0x%04x to reg %s\n", (uint16_t)data, reg_names[reg]);
572 
573     switch (reg) {
574         /* Command register */
575         case SONIC_CR:
576             dp8393x_do_command(s, data);
577             break;
578         /* Prevent write to read-only registers */
579         case SONIC_CAP2:
580         case SONIC_CAP1:
581         case SONIC_CAP0:
582         case SONIC_SR:
583         case SONIC_MDT:
584             DPRINTF("writing to reg %d invalid\n", reg);
585             break;
586         /* Accept write to some registers only when in reset mode */
587         case SONIC_DCR:
588             if (s->regs[SONIC_CR] & SONIC_CR_RST) {
589                 s->regs[reg] = data & 0xbfff;
590             } else {
591                 DPRINTF("writing to DCR invalid\n");
592             }
593             break;
594         case SONIC_DCR2:
595             if (s->regs[SONIC_CR] & SONIC_CR_RST) {
596                 s->regs[reg] = data & 0xf017;
597             } else {
598                 DPRINTF("writing to DCR2 invalid\n");
599             }
600             break;
601         /* 12 lower bytes are Read Only */
602         case SONIC_TCR:
603             s->regs[reg] = data & 0xf000;
604             break;
605         /* 9 lower bytes are Read Only */
606         case SONIC_RCR:
607             s->regs[reg] = data & 0xffe0;
608             break;
609         /* Ignore most significant bit */
610         case SONIC_IMR:
611             s->regs[reg] = data & 0x7fff;
612             dp8393x_update_irq(s);
613             break;
614         /* Clear bits by writing 1 to them */
615         case SONIC_ISR:
616             data &= s->regs[reg];
617             s->regs[reg] &= ~data;
618             if (data & SONIC_ISR_RBE) {
619                 dp8393x_do_read_rra(s);
620             }
621             dp8393x_update_irq(s);
622             if (dp8393x_can_receive(s->nic->ncs)) {
623                 qemu_flush_queued_packets(qemu_get_queue(s->nic));
624             }
625             break;
626         /* Ignore least significant bit */
627         case SONIC_RSA:
628         case SONIC_REA:
629         case SONIC_RRP:
630         case SONIC_RWP:
631             s->regs[reg] = data & 0xfffe;
632             break;
633         /* Invert written value for some registers */
634         case SONIC_CRCT:
635         case SONIC_FAET:
636         case SONIC_MPT:
637             s->regs[reg] = data ^ 0xffff;
638             break;
639         /* All other registers have no special contrainst */
640         default:
641             s->regs[reg] = data;
642     }
643 
644     if (reg == SONIC_WT0 || reg == SONIC_WT1) {
645         dp8393x_set_next_tick(s);
646     }
647 }
648 
649 static const MemoryRegionOps dp8393x_ops = {
650     .read = dp8393x_read,
651     .write = dp8393x_write,
652     .impl.min_access_size = 2,
653     .impl.max_access_size = 2,
654     .endianness = DEVICE_NATIVE_ENDIAN,
655 };
656 
657 static void dp8393x_watchdog(void *opaque)
658 {
659     dp8393xState *s = opaque;
660 
661     if (s->regs[SONIC_CR] & SONIC_CR_STP) {
662         return;
663     }
664 
665     s->regs[SONIC_WT1] = 0xffff;
666     s->regs[SONIC_WT0] = 0xffff;
667     dp8393x_set_next_tick(s);
668 
669     /* Signal underflow */
670     s->regs[SONIC_ISR] |= SONIC_ISR_TC;
671     dp8393x_update_irq(s);
672 }
673 
674 static int dp8393x_can_receive(NetClientState *nc)
675 {
676     dp8393xState *s = qemu_get_nic_opaque(nc);
677 
678     if (!(s->regs[SONIC_CR] & SONIC_CR_RXEN))
679         return 0;
680     if (s->regs[SONIC_ISR] & SONIC_ISR_RBE)
681         return 0;
682     return 1;
683 }
684 
685 static int dp8393x_receive_filter(dp8393xState *s, const uint8_t * buf,
686                                   int size)
687 {
688     static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
689     int i;
690 
691     /* Check promiscuous mode */
692     if ((s->regs[SONIC_RCR] & SONIC_RCR_PRO) && (buf[0] & 1) == 0) {
693         return 0;
694     }
695 
696     /* Check multicast packets */
697     if ((s->regs[SONIC_RCR] & SONIC_RCR_AMC) && (buf[0] & 1) == 1) {
698         return SONIC_RCR_MC;
699     }
700 
701     /* Check broadcast */
702     if ((s->regs[SONIC_RCR] & SONIC_RCR_BRD) && !memcmp(buf, bcast, sizeof(bcast))) {
703         return SONIC_RCR_BC;
704     }
705 
706     /* Check CAM */
707     for (i = 0; i < 16; i++) {
708         if (s->regs[SONIC_CE] & (1 << i)) {
709              /* Entry enabled */
710              if (!memcmp(buf, s->cam[i], sizeof(s->cam[i]))) {
711                  return 0;
712              }
713         }
714     }
715 
716     return -1;
717 }
718 
719 static ssize_t dp8393x_receive(NetClientState *nc, const uint8_t * buf,
720                                size_t size)
721 {
722     dp8393xState *s = qemu_get_nic_opaque(nc);
723     uint16_t data[10];
724     int packet_type;
725     uint32_t available, address;
726     int width, rx_len = size;
727     uint32_t checksum;
728 
729     width = (s->regs[SONIC_DCR] & SONIC_DCR_DW) ? 2 : 1;
730 
731     s->regs[SONIC_RCR] &= ~(SONIC_RCR_PRX | SONIC_RCR_LBK | SONIC_RCR_FAER |
732         SONIC_RCR_CRCR | SONIC_RCR_LPKT | SONIC_RCR_BC | SONIC_RCR_MC);
733 
734     packet_type = dp8393x_receive_filter(s, buf, size);
735     if (packet_type < 0) {
736         DPRINTF("packet not for netcard\n");
737         return -1;
738     }
739 
740     /* XXX: Check byte ordering */
741 
742     /* Check for EOL */
743     if (s->regs[SONIC_LLFA] & 0x1) {
744         /* Are we still in resource exhaustion? */
745         size = sizeof(uint16_t) * 1 * width;
746         address = dp8393x_crda(s) + sizeof(uint16_t) * 5 * width;
747         address_space_rw(&s->as, address, MEMTXATTRS_UNSPECIFIED,
748                          (uint8_t *)data, size, 0);
749         if (data[0 * width] & 0x1) {
750             /* Still EOL ; stop reception */
751             return -1;
752         } else {
753             s->regs[SONIC_CRDA] = s->regs[SONIC_LLFA];
754         }
755     }
756 
757     /* Save current position */
758     s->regs[SONIC_TRBA1] = s->regs[SONIC_CRBA1];
759     s->regs[SONIC_TRBA0] = s->regs[SONIC_CRBA0];
760 
761     /* Calculate the ethernet checksum */
762     checksum = cpu_to_le32(crc32(0, buf, rx_len));
763 
764     /* Put packet into RBA */
765     DPRINTF("Receive packet at %08x\n", dp8393x_crba(s));
766     address = dp8393x_crba(s);
767     address_space_rw(&s->as, address,
768         MEMTXATTRS_UNSPECIFIED, (uint8_t *)buf, rx_len, 1);
769     address += rx_len;
770     address_space_rw(&s->as, address,
771         MEMTXATTRS_UNSPECIFIED, (uint8_t *)&checksum, 4, 1);
772     rx_len += 4;
773     s->regs[SONIC_CRBA1] = address >> 16;
774     s->regs[SONIC_CRBA0] = address & 0xffff;
775     available = dp8393x_rbwc(s);
776     available -= rx_len / 2;
777     s->regs[SONIC_RBWC1] = available >> 16;
778     s->regs[SONIC_RBWC0] = available & 0xffff;
779 
780     /* Update status */
781     if (dp8393x_rbwc(s) < s->regs[SONIC_EOBC]) {
782         s->regs[SONIC_RCR] |= SONIC_RCR_LPKT;
783     }
784     s->regs[SONIC_RCR] |= packet_type;
785     s->regs[SONIC_RCR] |= SONIC_RCR_PRX;
786     if (s->loopback_packet) {
787         s->regs[SONIC_RCR] |= SONIC_RCR_LBK;
788         s->loopback_packet = 0;
789     }
790 
791     /* Write status to memory */
792     DPRINTF("Write status at %08x\n", dp8393x_crda(s));
793     data[0 * width] = s->regs[SONIC_RCR]; /* status */
794     data[1 * width] = rx_len; /* byte count */
795     data[2 * width] = s->regs[SONIC_TRBA0]; /* pkt_ptr0 */
796     data[3 * width] = s->regs[SONIC_TRBA1]; /* pkt_ptr1 */
797     data[4 * width] = s->regs[SONIC_RSC]; /* seq_no */
798     size = sizeof(uint16_t) * 5 * width;
799     address_space_rw(&s->as, dp8393x_crda(s),
800         MEMTXATTRS_UNSPECIFIED, (uint8_t *)data, size, 1);
801 
802     /* Move to next descriptor */
803     size = sizeof(uint16_t) * width;
804     address_space_rw(&s->as, dp8393x_crda(s) + sizeof(uint16_t) * 5 * width,
805         MEMTXATTRS_UNSPECIFIED, (uint8_t *)data, size, 0);
806     s->regs[SONIC_LLFA] = data[0 * width];
807     if (s->regs[SONIC_LLFA] & 0x1) {
808         /* EOL detected */
809         s->regs[SONIC_ISR] |= SONIC_ISR_RDE;
810     } else {
811         data[0 * width] = 0; /* in_use */
812         address_space_rw(&s->as, dp8393x_crda(s) + sizeof(uint16_t) * 6 * width,
813             MEMTXATTRS_UNSPECIFIED, (uint8_t *)data, sizeof(uint16_t), 1);
814         s->regs[SONIC_CRDA] = s->regs[SONIC_LLFA];
815         s->regs[SONIC_ISR] |= SONIC_ISR_PKTRX;
816         s->regs[SONIC_RSC] = (s->regs[SONIC_RSC] & 0xff00) | (((s->regs[SONIC_RSC] & 0x00ff) + 1) & 0x00ff);
817 
818         if (s->regs[SONIC_RCR] & SONIC_RCR_LPKT) {
819             /* Read next RRA */
820             dp8393x_do_read_rra(s);
821         }
822     }
823 
824     /* Done */
825     dp8393x_update_irq(s);
826 
827     return size;
828 }
829 
830 static void dp8393x_reset(DeviceState *dev)
831 {
832     dp8393xState *s = DP8393X(dev);
833     timer_del(s->watchdog);
834 
835     memset(s->regs, 0, sizeof(s->regs));
836     s->regs[SONIC_CR] = SONIC_CR_RST | SONIC_CR_STP | SONIC_CR_RXDIS;
837     s->regs[SONIC_DCR] &= ~(SONIC_DCR_EXBUS | SONIC_DCR_LBR);
838     s->regs[SONIC_RCR] &= ~(SONIC_RCR_LB0 | SONIC_RCR_LB1 | SONIC_RCR_BRD | SONIC_RCR_RNT);
839     s->regs[SONIC_TCR] |= SONIC_TCR_NCRS | SONIC_TCR_PTX;
840     s->regs[SONIC_TCR] &= ~SONIC_TCR_BCM;
841     s->regs[SONIC_IMR] = 0;
842     s->regs[SONIC_ISR] = 0;
843     s->regs[SONIC_DCR2] = 0;
844     s->regs[SONIC_EOBC] = 0x02F8;
845     s->regs[SONIC_RSC] = 0;
846     s->regs[SONIC_CE] = 0;
847     s->regs[SONIC_RSC] = 0;
848 
849     /* Network cable is connected */
850     s->regs[SONIC_RCR] |= SONIC_RCR_CRS;
851 
852     dp8393x_update_irq(s);
853 }
854 
855 static NetClientInfo net_dp83932_info = {
856     .type = NET_CLIENT_DRIVER_NIC,
857     .size = sizeof(NICState),
858     .can_receive = dp8393x_can_receive,
859     .receive = dp8393x_receive,
860 };
861 
862 static void dp8393x_instance_init(Object *obj)
863 {
864     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
865     dp8393xState *s = DP8393X(obj);
866 
867     sysbus_init_mmio(sbd, &s->mmio);
868     sysbus_init_mmio(sbd, &s->prom);
869     sysbus_init_irq(sbd, &s->irq);
870 }
871 
872 static void dp8393x_realize(DeviceState *dev, Error **errp)
873 {
874     dp8393xState *s = DP8393X(dev);
875     int i, checksum;
876     uint8_t *prom;
877     Error *local_err = NULL;
878 
879     address_space_init(&s->as, s->dma_mr, "dp8393x");
880     memory_region_init_io(&s->mmio, OBJECT(dev), &dp8393x_ops, s,
881                           "dp8393x-regs", 0x40 << s->it_shift);
882 
883     s->nic = qemu_new_nic(&net_dp83932_info, &s->conf,
884                           object_get_typename(OBJECT(dev)), dev->id, s);
885     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
886 
887     s->watchdog = timer_new_ns(QEMU_CLOCK_VIRTUAL, dp8393x_watchdog, s);
888     s->regs[SONIC_SR] = 0x0004; /* only revision recognized by Linux */
889 
890     memory_region_init_ram_nomigrate(&s->prom, OBJECT(dev),
891                            "dp8393x-prom", SONIC_PROM_SIZE, &local_err);
892     if (local_err) {
893         error_propagate(errp, local_err);
894         return;
895     }
896     memory_region_set_readonly(&s->prom, true);
897     prom = memory_region_get_ram_ptr(&s->prom);
898     checksum = 0;
899     for (i = 0; i < 6; i++) {
900         prom[i] = s->conf.macaddr.a[i];
901         checksum += prom[i];
902         if (checksum > 0xff) {
903             checksum = (checksum + 1) & 0xff;
904         }
905     }
906     prom[7] = 0xff - checksum;
907 }
908 
909 static const VMStateDescription vmstate_dp8393x = {
910     .name = "dp8393x",
911     .version_id = 0,
912     .minimum_version_id = 0,
913     .fields = (VMStateField []) {
914         VMSTATE_BUFFER_UNSAFE(cam, dp8393xState, 0, 16 * 6),
915         VMSTATE_UINT16_ARRAY(regs, dp8393xState, 0x40),
916         VMSTATE_END_OF_LIST()
917     }
918 };
919 
920 static Property dp8393x_properties[] = {
921     DEFINE_NIC_PROPERTIES(dp8393xState, conf),
922     DEFINE_PROP_PTR("dma_mr", dp8393xState, dma_mr),
923     DEFINE_PROP_UINT8("it_shift", dp8393xState, it_shift, 0),
924     DEFINE_PROP_END_OF_LIST(),
925 };
926 
927 static void dp8393x_class_init(ObjectClass *klass, void *data)
928 {
929     DeviceClass *dc = DEVICE_CLASS(klass);
930 
931     set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
932     dc->realize = dp8393x_realize;
933     dc->reset = dp8393x_reset;
934     dc->vmsd = &vmstate_dp8393x;
935     dc->props = dp8393x_properties;
936     /* Reason: dma_mr property can't be set */
937     dc->user_creatable = false;
938 }
939 
940 static const TypeInfo dp8393x_info = {
941     .name          = TYPE_DP8393X,
942     .parent        = TYPE_SYS_BUS_DEVICE,
943     .instance_size = sizeof(dp8393xState),
944     .instance_init = dp8393x_instance_init,
945     .class_init    = dp8393x_class_init,
946 };
947 
948 static void dp8393x_register_types(void)
949 {
950     type_register_static(&dp8393x_info);
951 }
952 
953 type_init(dp8393x_register_types)
954