xref: /openbmc/qemu/hw/net/dp8393x.c (revision 40d6ee94)
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 "net/net.h"
23 #include "qapi/error.h"
24 #include "qemu/timer.h"
25 #include <zlib.h>
26 
27 //#define DEBUG_SONIC
28 
29 #define SONIC_PROM_SIZE 0x1000
30 
31 #ifdef DEBUG_SONIC
32 #define DPRINTF(fmt, ...) \
33 do { printf("sonic: " fmt , ##  __VA_ARGS__); } while (0)
34 static const char* reg_names[] = {
35     "CR", "DCR", "RCR", "TCR", "IMR", "ISR", "UTDA", "CTDA",
36     "TPS", "TFC", "TSA0", "TSA1", "TFS", "URDA", "CRDA", "CRBA0",
37     "CRBA1", "RBWC0", "RBWC1", "EOBC", "URRA", "RSA", "REA", "RRP",
38     "RWP", "TRBA0", "TRBA1", "0x1b", "0x1c", "0x1d", "0x1e", "LLFA",
39     "TTDA", "CEP", "CAP2", "CAP1", "CAP0", "CE", "CDP", "CDC",
40     "SR", "WT0", "WT1", "RSC", "CRCT", "FAET", "MPT", "MDT",
41     "0x30", "0x31", "0x32", "0x33", "0x34", "0x35", "0x36", "0x37",
42     "0x38", "0x39", "0x3a", "0x3b", "0x3c", "0x3d", "0x3e", "DCR2" };
43 #else
44 #define DPRINTF(fmt, ...) do {} while (0)
45 #endif
46 
47 #define SONIC_ERROR(fmt, ...) \
48 do { printf("sonic ERROR: %s: " fmt, __func__ , ## __VA_ARGS__); } while (0)
49 
50 #define SONIC_CR     0x00
51 #define SONIC_DCR    0x01
52 #define SONIC_RCR    0x02
53 #define SONIC_TCR    0x03
54 #define SONIC_IMR    0x04
55 #define SONIC_ISR    0x05
56 #define SONIC_UTDA   0x06
57 #define SONIC_CTDA   0x07
58 #define SONIC_TPS    0x08
59 #define SONIC_TFC    0x09
60 #define SONIC_TSA0   0x0a
61 #define SONIC_TSA1   0x0b
62 #define SONIC_TFS    0x0c
63 #define SONIC_URDA   0x0d
64 #define SONIC_CRDA   0x0e
65 #define SONIC_CRBA0  0x0f
66 #define SONIC_CRBA1  0x10
67 #define SONIC_RBWC0  0x11
68 #define SONIC_RBWC1  0x12
69 #define SONIC_EOBC   0x13
70 #define SONIC_URRA   0x14
71 #define SONIC_RSA    0x15
72 #define SONIC_REA    0x16
73 #define SONIC_RRP    0x17
74 #define SONIC_RWP    0x18
75 #define SONIC_TRBA0  0x19
76 #define SONIC_TRBA1  0x1a
77 #define SONIC_LLFA   0x1f
78 #define SONIC_TTDA   0x20
79 #define SONIC_CEP    0x21
80 #define SONIC_CAP2   0x22
81 #define SONIC_CAP1   0x23
82 #define SONIC_CAP0   0x24
83 #define SONIC_CE     0x25
84 #define SONIC_CDP    0x26
85 #define SONIC_CDC    0x27
86 #define SONIC_SR     0x28
87 #define SONIC_WT0    0x29
88 #define SONIC_WT1    0x2a
89 #define SONIC_RSC    0x2b
90 #define SONIC_CRCT   0x2c
91 #define SONIC_FAET   0x2d
92 #define SONIC_MPT    0x2e
93 #define SONIC_MDT    0x2f
94 #define SONIC_DCR2   0x3f
95 
96 #define SONIC_CR_HTX     0x0001
97 #define SONIC_CR_TXP     0x0002
98 #define SONIC_CR_RXDIS   0x0004
99 #define SONIC_CR_RXEN    0x0008
100 #define SONIC_CR_STP     0x0010
101 #define SONIC_CR_ST      0x0020
102 #define SONIC_CR_RST     0x0080
103 #define SONIC_CR_RRRA    0x0100
104 #define SONIC_CR_LCAM    0x0200
105 #define SONIC_CR_MASK    0x03bf
106 
107 #define SONIC_DCR_DW     0x0020
108 #define SONIC_DCR_LBR    0x2000
109 #define SONIC_DCR_EXBUS  0x8000
110 
111 #define SONIC_RCR_PRX    0x0001
112 #define SONIC_RCR_LBK    0x0002
113 #define SONIC_RCR_FAER   0x0004
114 #define SONIC_RCR_CRCR   0x0008
115 #define SONIC_RCR_CRS    0x0020
116 #define SONIC_RCR_LPKT   0x0040
117 #define SONIC_RCR_BC     0x0080
118 #define SONIC_RCR_MC     0x0100
119 #define SONIC_RCR_LB0    0x0200
120 #define SONIC_RCR_LB1    0x0400
121 #define SONIC_RCR_AMC    0x0800
122 #define SONIC_RCR_PRO    0x1000
123 #define SONIC_RCR_BRD    0x2000
124 #define SONIC_RCR_RNT    0x4000
125 
126 #define SONIC_TCR_PTX    0x0001
127 #define SONIC_TCR_BCM    0x0002
128 #define SONIC_TCR_FU     0x0004
129 #define SONIC_TCR_EXC    0x0040
130 #define SONIC_TCR_CRSL   0x0080
131 #define SONIC_TCR_NCRS   0x0100
132 #define SONIC_TCR_EXD    0x0400
133 #define SONIC_TCR_CRCI   0x2000
134 #define SONIC_TCR_PINT   0x8000
135 
136 #define SONIC_ISR_RBE    0x0020
137 #define SONIC_ISR_RDE    0x0040
138 #define SONIC_ISR_TC     0x0080
139 #define SONIC_ISR_TXDN   0x0200
140 #define SONIC_ISR_PKTRX  0x0400
141 #define SONIC_ISR_PINT   0x0800
142 #define SONIC_ISR_LCD    0x1000
143 
144 #define TYPE_DP8393X "dp8393x"
145 #define DP8393X(obj) OBJECT_CHECK(dp8393xState, (obj), TYPE_DP8393X)
146 
147 typedef struct dp8393xState {
148     SysBusDevice parent_obj;
149 
150     /* Hardware */
151     uint8_t it_shift;
152     qemu_irq irq;
153 #ifdef DEBUG_SONIC
154     int irq_level;
155 #endif
156     QEMUTimer *watchdog;
157     int64_t wt_last_update;
158     NICConf conf;
159     NICState *nic;
160     MemoryRegion mmio;
161     MemoryRegion prom;
162 
163     /* Registers */
164     uint8_t cam[16][6];
165     uint16_t regs[0x40];
166 
167     /* Temporaries */
168     uint8_t tx_buffer[0x10000];
169     int loopback_packet;
170 
171     /* Memory access */
172     void *dma_mr;
173     AddressSpace as;
174 } dp8393xState;
175 
176 /* Accessor functions for values which are formed by
177  * concatenating two 16 bit device registers. By putting these
178  * in their own functions with a uint32_t return type we avoid the
179  * pitfall of implicit sign extension where ((x << 16) | y) is a
180  * signed 32 bit integer that might get sign-extended to a 64 bit integer.
181  */
182 static uint32_t dp8393x_cdp(dp8393xState *s)
183 {
184     return (s->regs[SONIC_URRA] << 16) | s->regs[SONIC_CDP];
185 }
186 
187 static uint32_t dp8393x_crba(dp8393xState *s)
188 {
189     return (s->regs[SONIC_CRBA1] << 16) | s->regs[SONIC_CRBA0];
190 }
191 
192 static uint32_t dp8393x_crda(dp8393xState *s)
193 {
194     return (s->regs[SONIC_URDA] << 16) | s->regs[SONIC_CRDA];
195 }
196 
197 static uint32_t dp8393x_rbwc(dp8393xState *s)
198 {
199     return (s->regs[SONIC_RBWC1] << 16) | s->regs[SONIC_RBWC0];
200 }
201 
202 static uint32_t dp8393x_rrp(dp8393xState *s)
203 {
204     return (s->regs[SONIC_URRA] << 16) | s->regs[SONIC_RRP];
205 }
206 
207 static uint32_t dp8393x_tsa(dp8393xState *s)
208 {
209     return (s->regs[SONIC_TSA1] << 16) | s->regs[SONIC_TSA0];
210 }
211 
212 static uint32_t dp8393x_ttda(dp8393xState *s)
213 {
214     return (s->regs[SONIC_UTDA] << 16) | s->regs[SONIC_TTDA];
215 }
216 
217 static uint32_t dp8393x_wt(dp8393xState *s)
218 {
219     return s->regs[SONIC_WT1] << 16 | s->regs[SONIC_WT0];
220 }
221 
222 static void dp8393x_update_irq(dp8393xState *s)
223 {
224     int level = (s->regs[SONIC_IMR] & s->regs[SONIC_ISR]) ? 1 : 0;
225 
226 #ifdef DEBUG_SONIC
227     if (level != s->irq_level) {
228         s->irq_level = level;
229         if (level) {
230             DPRINTF("raise irq, isr is 0x%04x\n", s->regs[SONIC_ISR]);
231         } else {
232             DPRINTF("lower irq\n");
233         }
234     }
235 #endif
236 
237     qemu_set_irq(s->irq, level);
238 }
239 
240 static void dp8393x_do_load_cam(dp8393xState *s)
241 {
242     uint16_t data[8];
243     int width, size;
244     uint16_t index = 0;
245 
246     width = (s->regs[SONIC_DCR] & SONIC_DCR_DW) ? 2 : 1;
247     size = sizeof(uint16_t) * 4 * width;
248 
249     while (s->regs[SONIC_CDC] & 0x1f) {
250         /* Fill current entry */
251         address_space_rw(&s->as, dp8393x_cdp(s),
252             MEMTXATTRS_UNSPECIFIED, (uint8_t *)data, size, 0);
253         s->cam[index][0] = data[1 * width] & 0xff;
254         s->cam[index][1] = data[1 * width] >> 8;
255         s->cam[index][2] = data[2 * width] & 0xff;
256         s->cam[index][3] = data[2 * width] >> 8;
257         s->cam[index][4] = data[3 * width] & 0xff;
258         s->cam[index][5] = data[3 * width] >> 8;
259         DPRINTF("load cam[%d] with %02x%02x%02x%02x%02x%02x\n", index,
260             s->cam[index][0], s->cam[index][1], s->cam[index][2],
261             s->cam[index][3], s->cam[index][4], s->cam[index][5]);
262         /* Move to next entry */
263         s->regs[SONIC_CDC]--;
264         s->regs[SONIC_CDP] += size;
265         index++;
266     }
267 
268     /* Read CAM enable */
269     address_space_rw(&s->as, dp8393x_cdp(s),
270         MEMTXATTRS_UNSPECIFIED, (uint8_t *)data, size, 0);
271     s->regs[SONIC_CE] = data[0 * width];
272     DPRINTF("load cam done. cam enable mask 0x%04x\n", s->regs[SONIC_CE]);
273 
274     /* Done */
275     s->regs[SONIC_CR] &= ~SONIC_CR_LCAM;
276     s->regs[SONIC_ISR] |= SONIC_ISR_LCD;
277     dp8393x_update_irq(s);
278 }
279 
280 static void dp8393x_do_read_rra(dp8393xState *s)
281 {
282     uint16_t data[8];
283     int width, size;
284 
285     /* Read memory */
286     width = (s->regs[SONIC_DCR] & SONIC_DCR_DW) ? 2 : 1;
287     size = sizeof(uint16_t) * 4 * width;
288     address_space_rw(&s->as, dp8393x_rrp(s),
289         MEMTXATTRS_UNSPECIFIED, (uint8_t *)data, size, 0);
290 
291     /* Update SONIC registers */
292     s->regs[SONIC_CRBA0] = data[0 * width];
293     s->regs[SONIC_CRBA1] = data[1 * width];
294     s->regs[SONIC_RBWC0] = data[2 * width];
295     s->regs[SONIC_RBWC1] = data[3 * width];
296     DPRINTF("CRBA0/1: 0x%04x/0x%04x, RBWC0/1: 0x%04x/0x%04x\n",
297         s->regs[SONIC_CRBA0], s->regs[SONIC_CRBA1],
298         s->regs[SONIC_RBWC0], s->regs[SONIC_RBWC1]);
299 
300     /* Go to next entry */
301     s->regs[SONIC_RRP] += size;
302 
303     /* Handle wrap */
304     if (s->regs[SONIC_RRP] == s->regs[SONIC_REA]) {
305         s->regs[SONIC_RRP] = s->regs[SONIC_RSA];
306     }
307 
308     /* Check resource exhaustion */
309     if (s->regs[SONIC_RRP] == s->regs[SONIC_RWP])
310     {
311         s->regs[SONIC_ISR] |= SONIC_ISR_RBE;
312         dp8393x_update_irq(s);
313     }
314 
315     /* Done */
316     s->regs[SONIC_CR] &= ~SONIC_CR_RRRA;
317 }
318 
319 static void dp8393x_do_software_reset(dp8393xState *s)
320 {
321     timer_del(s->watchdog);
322 
323     s->regs[SONIC_CR] &= ~(SONIC_CR_LCAM | SONIC_CR_RRRA | SONIC_CR_TXP | SONIC_CR_HTX);
324     s->regs[SONIC_CR] |= SONIC_CR_RST | SONIC_CR_RXDIS;
325 }
326 
327 static void dp8393x_set_next_tick(dp8393xState *s)
328 {
329     uint32_t ticks;
330     int64_t delay;
331 
332     if (s->regs[SONIC_CR] & SONIC_CR_STP) {
333         timer_del(s->watchdog);
334         return;
335     }
336 
337     ticks = dp8393x_wt(s);
338     s->wt_last_update = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
339     delay = NANOSECONDS_PER_SECOND * ticks / 5000000;
340     timer_mod(s->watchdog, s->wt_last_update + delay);
341 }
342 
343 static void dp8393x_update_wt_regs(dp8393xState *s)
344 {
345     int64_t elapsed;
346     uint32_t val;
347 
348     if (s->regs[SONIC_CR] & SONIC_CR_STP) {
349         timer_del(s->watchdog);
350         return;
351     }
352 
353     elapsed = s->wt_last_update - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
354     val = dp8393x_wt(s);
355     val -= elapsed / 5000000;
356     s->regs[SONIC_WT1] = (val >> 16) & 0xffff;
357     s->regs[SONIC_WT0] = (val >> 0)  & 0xffff;
358     dp8393x_set_next_tick(s);
359 
360 }
361 
362 static void dp8393x_do_start_timer(dp8393xState *s)
363 {
364     s->regs[SONIC_CR] &= ~SONIC_CR_STP;
365     dp8393x_set_next_tick(s);
366 }
367 
368 static void dp8393x_do_stop_timer(dp8393xState *s)
369 {
370     s->regs[SONIC_CR] &= ~SONIC_CR_ST;
371     dp8393x_update_wt_regs(s);
372 }
373 
374 static int dp8393x_can_receive(NetClientState *nc);
375 
376 static void dp8393x_do_receiver_enable(dp8393xState *s)
377 {
378     s->regs[SONIC_CR] &= ~SONIC_CR_RXDIS;
379     if (dp8393x_can_receive(s->nic->ncs)) {
380         qemu_flush_queued_packets(qemu_get_queue(s->nic));
381     }
382 }
383 
384 static void dp8393x_do_receiver_disable(dp8393xState *s)
385 {
386     s->regs[SONIC_CR] &= ~SONIC_CR_RXEN;
387 }
388 
389 static void dp8393x_do_transmit_packets(dp8393xState *s)
390 {
391     NetClientState *nc = qemu_get_queue(s->nic);
392     uint16_t data[12];
393     int width, size;
394     int tx_len, len;
395     uint16_t i;
396 
397     width = (s->regs[SONIC_DCR] & SONIC_DCR_DW) ? 2 : 1;
398 
399     while (1) {
400         /* Read memory */
401         size = sizeof(uint16_t) * 6 * width;
402         s->regs[SONIC_TTDA] = s->regs[SONIC_CTDA];
403         DPRINTF("Transmit packet at %08x\n", dp8393x_ttda(s));
404         address_space_rw(&s->as,
405             dp8393x_ttda(s) + sizeof(uint16_t) * width,
406             MEMTXATTRS_UNSPECIFIED, (uint8_t *)data, size, 0);
407         tx_len = 0;
408 
409         /* Update registers */
410         s->regs[SONIC_TCR] = data[0 * width] & 0xf000;
411         s->regs[SONIC_TPS] = data[1 * width];
412         s->regs[SONIC_TFC] = data[2 * width];
413         s->regs[SONIC_TSA0] = data[3 * width];
414         s->regs[SONIC_TSA1] = data[4 * width];
415         s->regs[SONIC_TFS] = data[5 * width];
416 
417         /* Handle programmable interrupt */
418         if (s->regs[SONIC_TCR] & SONIC_TCR_PINT) {
419             s->regs[SONIC_ISR] |= SONIC_ISR_PINT;
420         } else {
421             s->regs[SONIC_ISR] &= ~SONIC_ISR_PINT;
422         }
423 
424         for (i = 0; i < s->regs[SONIC_TFC]; ) {
425             /* Append fragment */
426             len = s->regs[SONIC_TFS];
427             if (tx_len + len > sizeof(s->tx_buffer)) {
428                 len = sizeof(s->tx_buffer) - tx_len;
429             }
430             address_space_rw(&s->as, dp8393x_tsa(s),
431                 MEMTXATTRS_UNSPECIFIED, &s->tx_buffer[tx_len], len, 0);
432             tx_len += len;
433 
434             i++;
435             if (i != s->regs[SONIC_TFC]) {
436                 /* Read next fragment details */
437                 size = sizeof(uint16_t) * 3 * width;
438                 address_space_rw(&s->as,
439                     dp8393x_ttda(s) + sizeof(uint16_t) * (4 + 3 * i) * width,
440                     MEMTXATTRS_UNSPECIFIED, (uint8_t *)data, size, 0);
441                 s->regs[SONIC_TSA0] = data[0 * width];
442                 s->regs[SONIC_TSA1] = data[1 * width];
443                 s->regs[SONIC_TFS] = data[2 * width];
444             }
445         }
446 
447         /* Handle Ethernet checksum */
448         if (!(s->regs[SONIC_TCR] & SONIC_TCR_CRCI)) {
449             /* Don't append FCS there, to look like slirp packets
450              * which don't have one */
451         } else {
452             /* Remove existing FCS */
453             tx_len -= 4;
454         }
455 
456         if (s->regs[SONIC_RCR] & (SONIC_RCR_LB1 | SONIC_RCR_LB0)) {
457             /* Loopback */
458             s->regs[SONIC_TCR] |= SONIC_TCR_CRSL;
459             if (nc->info->can_receive(nc)) {
460                 s->loopback_packet = 1;
461                 nc->info->receive(nc, s->tx_buffer, tx_len);
462             }
463         } else {
464             /* Transmit packet */
465             qemu_send_packet(nc, s->tx_buffer, tx_len);
466         }
467         s->regs[SONIC_TCR] |= SONIC_TCR_PTX;
468 
469         /* Write status */
470         data[0 * width] = s->regs[SONIC_TCR] & 0x0fff; /* status */
471         size = sizeof(uint16_t) * width;
472         address_space_rw(&s->as,
473             dp8393x_ttda(s),
474             MEMTXATTRS_UNSPECIFIED, (uint8_t *)data, size, 1);
475 
476         if (!(s->regs[SONIC_CR] & SONIC_CR_HTX)) {
477             /* Read footer of packet */
478             size = sizeof(uint16_t) * width;
479             address_space_rw(&s->as,
480                 dp8393x_ttda(s) +
481                              sizeof(uint16_t) *
482                              (4 + 3 * s->regs[SONIC_TFC]) * width,
483                 MEMTXATTRS_UNSPECIFIED, (uint8_t *)data, size, 0);
484             s->regs[SONIC_CTDA] = data[0 * width] & ~0x1;
485             if (data[0 * width] & 0x1) {
486                 /* EOL detected */
487                 break;
488             }
489         }
490     }
491 
492     /* Done */
493     s->regs[SONIC_CR] &= ~SONIC_CR_TXP;
494     s->regs[SONIC_ISR] |= SONIC_ISR_TXDN;
495     dp8393x_update_irq(s);
496 }
497 
498 static void dp8393x_do_halt_transmission(dp8393xState *s)
499 {
500     /* Nothing to do */
501 }
502 
503 static void dp8393x_do_command(dp8393xState *s, uint16_t command)
504 {
505     if ((s->regs[SONIC_CR] & SONIC_CR_RST) && !(command & SONIC_CR_RST)) {
506         s->regs[SONIC_CR] &= ~SONIC_CR_RST;
507         return;
508     }
509 
510     s->regs[SONIC_CR] |= (command & SONIC_CR_MASK);
511 
512     if (command & SONIC_CR_HTX)
513         dp8393x_do_halt_transmission(s);
514     if (command & SONIC_CR_TXP)
515         dp8393x_do_transmit_packets(s);
516     if (command & SONIC_CR_RXDIS)
517         dp8393x_do_receiver_disable(s);
518     if (command & SONIC_CR_RXEN)
519         dp8393x_do_receiver_enable(s);
520     if (command & SONIC_CR_STP)
521         dp8393x_do_stop_timer(s);
522     if (command & SONIC_CR_ST)
523         dp8393x_do_start_timer(s);
524     if (command & SONIC_CR_RST)
525         dp8393x_do_software_reset(s);
526     if (command & SONIC_CR_RRRA)
527         dp8393x_do_read_rra(s);
528     if (command & SONIC_CR_LCAM)
529         dp8393x_do_load_cam(s);
530 }
531 
532 static uint64_t dp8393x_read(void *opaque, hwaddr addr, unsigned int size)
533 {
534     dp8393xState *s = opaque;
535     int reg = addr >> s->it_shift;
536     uint16_t val = 0;
537 
538     switch (reg) {
539         /* Update data before reading it */
540         case SONIC_WT0:
541         case SONIC_WT1:
542             dp8393x_update_wt_regs(s);
543             val = s->regs[reg];
544             break;
545         /* Accept read to some registers only when in reset mode */
546         case SONIC_CAP2:
547         case SONIC_CAP1:
548         case SONIC_CAP0:
549             if (s->regs[SONIC_CR] & SONIC_CR_RST) {
550                 val = s->cam[s->regs[SONIC_CEP] & 0xf][2* (SONIC_CAP0 - reg) + 1] << 8;
551                 val |= s->cam[s->regs[SONIC_CEP] & 0xf][2* (SONIC_CAP0 - reg)];
552             }
553             break;
554         /* All other registers have no special contrainst */
555         default:
556             val = s->regs[reg];
557     }
558 
559     DPRINTF("read 0x%04x from reg %s\n", val, reg_names[reg]);
560 
561     return val;
562 }
563 
564 static void dp8393x_write(void *opaque, hwaddr addr, uint64_t data,
565                           unsigned int size)
566 {
567     dp8393xState *s = opaque;
568     int reg = addr >> s->it_shift;
569 
570     DPRINTF("write 0x%04x to reg %s\n", (uint16_t)data, reg_names[reg]);
571 
572     switch (reg) {
573         /* Command register */
574         case SONIC_CR:
575             dp8393x_do_command(s, data);
576             break;
577         /* Prevent write to read-only registers */
578         case SONIC_CAP2:
579         case SONIC_CAP1:
580         case SONIC_CAP0:
581         case SONIC_SR:
582         case SONIC_MDT:
583             DPRINTF("writing to reg %d invalid\n", reg);
584             break;
585         /* Accept write to some registers only when in reset mode */
586         case SONIC_DCR:
587             if (s->regs[SONIC_CR] & SONIC_CR_RST) {
588                 s->regs[reg] = data & 0xbfff;
589             } else {
590                 DPRINTF("writing to DCR invalid\n");
591             }
592             break;
593         case SONIC_DCR2:
594             if (s->regs[SONIC_CR] & SONIC_CR_RST) {
595                 s->regs[reg] = data & 0xf017;
596             } else {
597                 DPRINTF("writing to DCR2 invalid\n");
598             }
599             break;
600         /* 12 lower bytes are Read Only */
601         case SONIC_TCR:
602             s->regs[reg] = data & 0xf000;
603             break;
604         /* 9 lower bytes are Read Only */
605         case SONIC_RCR:
606             s->regs[reg] = data & 0xffe0;
607             break;
608         /* Ignore most significant bit */
609         case SONIC_IMR:
610             s->regs[reg] = data & 0x7fff;
611             dp8393x_update_irq(s);
612             break;
613         /* Clear bits by writing 1 to them */
614         case SONIC_ISR:
615             data &= s->regs[reg];
616             s->regs[reg] &= ~data;
617             if (data & SONIC_ISR_RBE) {
618                 dp8393x_do_read_rra(s);
619             }
620             dp8393x_update_irq(s);
621             if (dp8393x_can_receive(s->nic->ncs)) {
622                 qemu_flush_queued_packets(qemu_get_queue(s->nic));
623             }
624             break;
625         /* Ignore least significant bit */
626         case SONIC_RSA:
627         case SONIC_REA:
628         case SONIC_RRP:
629         case SONIC_RWP:
630             s->regs[reg] = data & 0xfffe;
631             break;
632         /* Invert written value for some registers */
633         case SONIC_CRCT:
634         case SONIC_FAET:
635         case SONIC_MPT:
636             s->regs[reg] = data ^ 0xffff;
637             break;
638         /* All other registers have no special contrainst */
639         default:
640             s->regs[reg] = data;
641     }
642 
643     if (reg == SONIC_WT0 || reg == SONIC_WT1) {
644         dp8393x_set_next_tick(s);
645     }
646 }
647 
648 static const MemoryRegionOps dp8393x_ops = {
649     .read = dp8393x_read,
650     .write = dp8393x_write,
651     .impl.min_access_size = 2,
652     .impl.max_access_size = 2,
653     .endianness = DEVICE_NATIVE_ENDIAN,
654 };
655 
656 static void dp8393x_watchdog(void *opaque)
657 {
658     dp8393xState *s = opaque;
659 
660     if (s->regs[SONIC_CR] & SONIC_CR_STP) {
661         return;
662     }
663 
664     s->regs[SONIC_WT1] = 0xffff;
665     s->regs[SONIC_WT0] = 0xffff;
666     dp8393x_set_next_tick(s);
667 
668     /* Signal underflow */
669     s->regs[SONIC_ISR] |= SONIC_ISR_TC;
670     dp8393x_update_irq(s);
671 }
672 
673 static int dp8393x_can_receive(NetClientState *nc)
674 {
675     dp8393xState *s = qemu_get_nic_opaque(nc);
676 
677     if (!(s->regs[SONIC_CR] & SONIC_CR_RXEN))
678         return 0;
679     if (s->regs[SONIC_ISR] & SONIC_ISR_RBE)
680         return 0;
681     return 1;
682 }
683 
684 static int dp8393x_receive_filter(dp8393xState *s, const uint8_t * buf,
685                                   int size)
686 {
687     static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
688     int i;
689 
690     /* Check promiscuous mode */
691     if ((s->regs[SONIC_RCR] & SONIC_RCR_PRO) && (buf[0] & 1) == 0) {
692         return 0;
693     }
694 
695     /* Check multicast packets */
696     if ((s->regs[SONIC_RCR] & SONIC_RCR_AMC) && (buf[0] & 1) == 1) {
697         return SONIC_RCR_MC;
698     }
699 
700     /* Check broadcast */
701     if ((s->regs[SONIC_RCR] & SONIC_RCR_BRD) && !memcmp(buf, bcast, sizeof(bcast))) {
702         return SONIC_RCR_BC;
703     }
704 
705     /* Check CAM */
706     for (i = 0; i < 16; i++) {
707         if (s->regs[SONIC_CE] & (1 << i)) {
708              /* Entry enabled */
709              if (!memcmp(buf, s->cam[i], sizeof(s->cam[i]))) {
710                  return 0;
711              }
712         }
713     }
714 
715     return -1;
716 }
717 
718 static ssize_t dp8393x_receive(NetClientState *nc, const uint8_t * buf,
719                                size_t size)
720 {
721     dp8393xState *s = qemu_get_nic_opaque(nc);
722     uint16_t data[10];
723     int packet_type;
724     uint32_t available, address;
725     int width, rx_len = size;
726     uint32_t checksum;
727 
728     width = (s->regs[SONIC_DCR] & SONIC_DCR_DW) ? 2 : 1;
729 
730     s->regs[SONIC_RCR] &= ~(SONIC_RCR_PRX | SONIC_RCR_LBK | SONIC_RCR_FAER |
731         SONIC_RCR_CRCR | SONIC_RCR_LPKT | SONIC_RCR_BC | SONIC_RCR_MC);
732 
733     packet_type = dp8393x_receive_filter(s, buf, size);
734     if (packet_type < 0) {
735         DPRINTF("packet not for netcard\n");
736         return -1;
737     }
738 
739     /* XXX: Check byte ordering */
740 
741     /* Check for EOL */
742     if (s->regs[SONIC_LLFA] & 0x1) {
743         /* Are we still in resource exhaustion? */
744         size = sizeof(uint16_t) * 1 * width;
745         address = dp8393x_crda(s) + sizeof(uint16_t) * 5 * width;
746         address_space_rw(&s->as, address, MEMTXATTRS_UNSPECIFIED,
747                          (uint8_t *)data, size, 0);
748         if (data[0 * width] & 0x1) {
749             /* Still EOL ; stop reception */
750             return -1;
751         } else {
752             s->regs[SONIC_CRDA] = s->regs[SONIC_LLFA];
753         }
754     }
755 
756     /* Save current position */
757     s->regs[SONIC_TRBA1] = s->regs[SONIC_CRBA1];
758     s->regs[SONIC_TRBA0] = s->regs[SONIC_CRBA0];
759 
760     /* Calculate the ethernet checksum */
761     checksum = cpu_to_le32(crc32(0, buf, rx_len));
762 
763     /* Put packet into RBA */
764     DPRINTF("Receive packet at %08x\n", dp8393x_crba(s));
765     address = dp8393x_crba(s);
766     address_space_rw(&s->as, address,
767         MEMTXATTRS_UNSPECIFIED, (uint8_t *)buf, rx_len, 1);
768     address += rx_len;
769     address_space_rw(&s->as, address,
770         MEMTXATTRS_UNSPECIFIED, (uint8_t *)&checksum, 4, 1);
771     rx_len += 4;
772     s->regs[SONIC_CRBA1] = address >> 16;
773     s->regs[SONIC_CRBA0] = address & 0xffff;
774     available = dp8393x_rbwc(s);
775     available -= rx_len / 2;
776     s->regs[SONIC_RBWC1] = available >> 16;
777     s->regs[SONIC_RBWC0] = available & 0xffff;
778 
779     /* Update status */
780     if (dp8393x_rbwc(s) < s->regs[SONIC_EOBC]) {
781         s->regs[SONIC_RCR] |= SONIC_RCR_LPKT;
782     }
783     s->regs[SONIC_RCR] |= packet_type;
784     s->regs[SONIC_RCR] |= SONIC_RCR_PRX;
785     if (s->loopback_packet) {
786         s->regs[SONIC_RCR] |= SONIC_RCR_LBK;
787         s->loopback_packet = 0;
788     }
789 
790     /* Write status to memory */
791     DPRINTF("Write status at %08x\n", dp8393x_crda(s));
792     data[0 * width] = s->regs[SONIC_RCR]; /* status */
793     data[1 * width] = rx_len; /* byte count */
794     data[2 * width] = s->regs[SONIC_TRBA0]; /* pkt_ptr0 */
795     data[3 * width] = s->regs[SONIC_TRBA1]; /* pkt_ptr1 */
796     data[4 * width] = s->regs[SONIC_RSC]; /* seq_no */
797     size = sizeof(uint16_t) * 5 * width;
798     address_space_rw(&s->as, dp8393x_crda(s),
799         MEMTXATTRS_UNSPECIFIED, (uint8_t *)data, size, 1);
800 
801     /* Move to next descriptor */
802     size = sizeof(uint16_t) * width;
803     address_space_rw(&s->as, dp8393x_crda(s) + sizeof(uint16_t) * 5 * width,
804         MEMTXATTRS_UNSPECIFIED, (uint8_t *)data, size, 0);
805     s->regs[SONIC_LLFA] = data[0 * width];
806     if (s->regs[SONIC_LLFA] & 0x1) {
807         /* EOL detected */
808         s->regs[SONIC_ISR] |= SONIC_ISR_RDE;
809     } else {
810         data[0 * width] = 0; /* in_use */
811         address_space_rw(&s->as, dp8393x_crda(s) + sizeof(uint16_t) * 6 * width,
812             MEMTXATTRS_UNSPECIFIED, (uint8_t *)data, sizeof(uint16_t), 1);
813         s->regs[SONIC_CRDA] = s->regs[SONIC_LLFA];
814         s->regs[SONIC_ISR] |= SONIC_ISR_PKTRX;
815         s->regs[SONIC_RSC] = (s->regs[SONIC_RSC] & 0xff00) | (((s->regs[SONIC_RSC] & 0x00ff) + 1) & 0x00ff);
816 
817         if (s->regs[SONIC_RCR] & SONIC_RCR_LPKT) {
818             /* Read next RRA */
819             dp8393x_do_read_rra(s);
820         }
821     }
822 
823     /* Done */
824     dp8393x_update_irq(s);
825 
826     return size;
827 }
828 
829 static void dp8393x_reset(DeviceState *dev)
830 {
831     dp8393xState *s = DP8393X(dev);
832     timer_del(s->watchdog);
833 
834     memset(s->regs, 0, sizeof(s->regs));
835     s->regs[SONIC_CR] = SONIC_CR_RST | SONIC_CR_STP | SONIC_CR_RXDIS;
836     s->regs[SONIC_DCR] &= ~(SONIC_DCR_EXBUS | SONIC_DCR_LBR);
837     s->regs[SONIC_RCR] &= ~(SONIC_RCR_LB0 | SONIC_RCR_LB1 | SONIC_RCR_BRD | SONIC_RCR_RNT);
838     s->regs[SONIC_TCR] |= SONIC_TCR_NCRS | SONIC_TCR_PTX;
839     s->regs[SONIC_TCR] &= ~SONIC_TCR_BCM;
840     s->regs[SONIC_IMR] = 0;
841     s->regs[SONIC_ISR] = 0;
842     s->regs[SONIC_DCR2] = 0;
843     s->regs[SONIC_EOBC] = 0x02F8;
844     s->regs[SONIC_RSC] = 0;
845     s->regs[SONIC_CE] = 0;
846     s->regs[SONIC_RSC] = 0;
847 
848     /* Network cable is connected */
849     s->regs[SONIC_RCR] |= SONIC_RCR_CRS;
850 
851     dp8393x_update_irq(s);
852 }
853 
854 static NetClientInfo net_dp83932_info = {
855     .type = NET_CLIENT_DRIVER_NIC,
856     .size = sizeof(NICState),
857     .can_receive = dp8393x_can_receive,
858     .receive = dp8393x_receive,
859 };
860 
861 static void dp8393x_instance_init(Object *obj)
862 {
863     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
864     dp8393xState *s = DP8393X(obj);
865 
866     sysbus_init_mmio(sbd, &s->mmio);
867     sysbus_init_mmio(sbd, &s->prom);
868     sysbus_init_irq(sbd, &s->irq);
869 }
870 
871 static void dp8393x_realize(DeviceState *dev, Error **errp)
872 {
873     dp8393xState *s = DP8393X(dev);
874     int i, checksum;
875     uint8_t *prom;
876     Error *local_err = NULL;
877 
878     address_space_init(&s->as, s->dma_mr, "dp8393x");
879     memory_region_init_io(&s->mmio, OBJECT(dev), &dp8393x_ops, s,
880                           "dp8393x-regs", 0x40 << s->it_shift);
881 
882     s->nic = qemu_new_nic(&net_dp83932_info, &s->conf,
883                           object_get_typename(OBJECT(dev)), dev->id, s);
884     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
885 
886     s->watchdog = timer_new_ns(QEMU_CLOCK_VIRTUAL, dp8393x_watchdog, s);
887     s->regs[SONIC_SR] = 0x0004; /* only revision recognized by Linux */
888 
889     memory_region_init_ram(&s->prom, OBJECT(dev),
890                            "dp8393x-prom", SONIC_PROM_SIZE, &local_err);
891     if (local_err) {
892         error_propagate(errp, local_err);
893         return;
894     }
895     memory_region_set_readonly(&s->prom, true);
896     prom = memory_region_get_ram_ptr(&s->prom);
897     checksum = 0;
898     for (i = 0; i < 6; i++) {
899         prom[i] = s->conf.macaddr.a[i];
900         checksum += prom[i];
901         if (checksum > 0xff) {
902             checksum = (checksum + 1) & 0xff;
903         }
904     }
905     prom[7] = 0xff - checksum;
906 }
907 
908 static const VMStateDescription vmstate_dp8393x = {
909     .name = "dp8393x",
910     .version_id = 0,
911     .minimum_version_id = 0,
912     .fields = (VMStateField []) {
913         VMSTATE_BUFFER_UNSAFE(cam, dp8393xState, 0, 16 * 6),
914         VMSTATE_UINT16_ARRAY(regs, dp8393xState, 0x40),
915         VMSTATE_END_OF_LIST()
916     }
917 };
918 
919 static Property dp8393x_properties[] = {
920     DEFINE_NIC_PROPERTIES(dp8393xState, conf),
921     DEFINE_PROP_PTR("dma_mr", dp8393xState, dma_mr),
922     DEFINE_PROP_UINT8("it_shift", dp8393xState, it_shift, 0),
923     DEFINE_PROP_END_OF_LIST(),
924 };
925 
926 static void dp8393x_class_init(ObjectClass *klass, void *data)
927 {
928     DeviceClass *dc = DEVICE_CLASS(klass);
929 
930     set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
931     dc->realize = dp8393x_realize;
932     dc->reset = dp8393x_reset;
933     dc->vmsd = &vmstate_dp8393x;
934     dc->props = dp8393x_properties;
935     /* Reason: dma_mr property can't be set */
936     dc->user_creatable = false;
937 }
938 
939 static const TypeInfo dp8393x_info = {
940     .name          = TYPE_DP8393X,
941     .parent        = TYPE_SYS_BUS_DEVICE,
942     .instance_size = sizeof(dp8393xState),
943     .instance_init = dp8393x_instance_init,
944     .class_init    = dp8393x_class_init,
945 };
946 
947 static void dp8393x_register_types(void)
948 {
949     type_register_static(&dp8393x_info);
950 }
951 
952 type_init(dp8393x_register_types)
953