xref: /openbmc/qemu/hw/net/dp8393x.c (revision 5e437d3c)
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 OBJECT_DECLARE_SIMPLE_TYPE(dp8393xState, DP8393X)
155 
156 struct dp8393xState {
157     SysBusDevice parent_obj;
158 
159     /* Hardware */
160     uint8_t it_shift;
161     bool big_endian;
162     bool last_rba_is_full;
163     qemu_irq irq;
164 #ifdef DEBUG_SONIC
165     int irq_level;
166 #endif
167     QEMUTimer *watchdog;
168     int64_t wt_last_update;
169     NICConf conf;
170     NICState *nic;
171     MemoryRegion mmio;
172     MemoryRegion prom;
173 
174     /* Registers */
175     uint8_t cam[16][6];
176     uint16_t regs[0x40];
177 
178     /* Temporaries */
179     uint8_t tx_buffer[0x10000];
180     uint16_t data[12];
181     int loopback_packet;
182 
183     /* Memory access */
184     MemoryRegion *dma_mr;
185     AddressSpace as;
186 };
187 
188 /* Accessor functions for values which are formed by
189  * concatenating two 16 bit device registers. By putting these
190  * in their own functions with a uint32_t return type we avoid the
191  * pitfall of implicit sign extension where ((x << 16) | y) is a
192  * signed 32 bit integer that might get sign-extended to a 64 bit integer.
193  */
194 static uint32_t dp8393x_cdp(dp8393xState *s)
195 {
196     return (s->regs[SONIC_URRA] << 16) | s->regs[SONIC_CDP];
197 }
198 
199 static uint32_t dp8393x_crba(dp8393xState *s)
200 {
201     return (s->regs[SONIC_CRBA1] << 16) | s->regs[SONIC_CRBA0];
202 }
203 
204 static uint32_t dp8393x_crda(dp8393xState *s)
205 {
206     return (s->regs[SONIC_URDA] << 16) |
207            (s->regs[SONIC_CRDA] & SONIC_DESC_ADDR);
208 }
209 
210 static uint32_t dp8393x_rbwc(dp8393xState *s)
211 {
212     return (s->regs[SONIC_RBWC1] << 16) | s->regs[SONIC_RBWC0];
213 }
214 
215 static uint32_t dp8393x_rrp(dp8393xState *s)
216 {
217     return (s->regs[SONIC_URRA] << 16) | s->regs[SONIC_RRP];
218 }
219 
220 static uint32_t dp8393x_tsa(dp8393xState *s)
221 {
222     return (s->regs[SONIC_TSA1] << 16) | s->regs[SONIC_TSA0];
223 }
224 
225 static uint32_t dp8393x_ttda(dp8393xState *s)
226 {
227     return (s->regs[SONIC_UTDA] << 16) |
228            (s->regs[SONIC_TTDA] & SONIC_DESC_ADDR);
229 }
230 
231 static uint32_t dp8393x_wt(dp8393xState *s)
232 {
233     return s->regs[SONIC_WT1] << 16 | s->regs[SONIC_WT0];
234 }
235 
236 static uint16_t dp8393x_get(dp8393xState *s, int width, int offset)
237 {
238     uint16_t val;
239 
240     if (s->big_endian) {
241         val = be16_to_cpu(s->data[offset * width + width - 1]);
242     } else {
243         val = le16_to_cpu(s->data[offset * width]);
244     }
245     return val;
246 }
247 
248 static void dp8393x_put(dp8393xState *s, int width, int offset,
249                         uint16_t val)
250 {
251     if (s->big_endian) {
252         if (width == 2) {
253             s->data[offset * 2] = 0;
254             s->data[offset * 2 + 1] = cpu_to_be16(val);
255         } else {
256             s->data[offset] = cpu_to_be16(val);
257         }
258     } else {
259         if (width == 2) {
260             s->data[offset * 2] = cpu_to_le16(val);
261             s->data[offset * 2 + 1] = 0;
262         } else {
263             s->data[offset] = cpu_to_le16(val);
264         }
265     }
266 }
267 
268 static void dp8393x_update_irq(dp8393xState *s)
269 {
270     int level = (s->regs[SONIC_IMR] & s->regs[SONIC_ISR]) ? 1 : 0;
271 
272 #ifdef DEBUG_SONIC
273     if (level != s->irq_level) {
274         s->irq_level = level;
275         if (level) {
276             DPRINTF("raise irq, isr is 0x%04x\n", s->regs[SONIC_ISR]);
277         } else {
278             DPRINTF("lower irq\n");
279         }
280     }
281 #endif
282 
283     qemu_set_irq(s->irq, level);
284 }
285 
286 static void dp8393x_do_load_cam(dp8393xState *s)
287 {
288     int width, size;
289     uint16_t index = 0;
290 
291     width = (s->regs[SONIC_DCR] & SONIC_DCR_DW) ? 2 : 1;
292     size = sizeof(uint16_t) * 4 * width;
293 
294     while (s->regs[SONIC_CDC] & 0x1f) {
295         /* Fill current entry */
296         address_space_read(&s->as, dp8393x_cdp(s),
297                            MEMTXATTRS_UNSPECIFIED, s->data, size);
298         s->cam[index][0] = dp8393x_get(s, width, 1) & 0xff;
299         s->cam[index][1] = dp8393x_get(s, width, 1) >> 8;
300         s->cam[index][2] = dp8393x_get(s, width, 2) & 0xff;
301         s->cam[index][3] = dp8393x_get(s, width, 2) >> 8;
302         s->cam[index][4] = dp8393x_get(s, width, 3) & 0xff;
303         s->cam[index][5] = dp8393x_get(s, width, 3) >> 8;
304         DPRINTF("load cam[%d] with %02x%02x%02x%02x%02x%02x\n", index,
305             s->cam[index][0], s->cam[index][1], s->cam[index][2],
306             s->cam[index][3], s->cam[index][4], s->cam[index][5]);
307         /* Move to next entry */
308         s->regs[SONIC_CDC]--;
309         s->regs[SONIC_CDP] += size;
310         index++;
311     }
312 
313     /* Read CAM enable */
314     address_space_read(&s->as, dp8393x_cdp(s),
315                        MEMTXATTRS_UNSPECIFIED, s->data, size);
316     s->regs[SONIC_CE] = dp8393x_get(s, width, 0);
317     DPRINTF("load cam done. cam enable mask 0x%04x\n", s->regs[SONIC_CE]);
318 
319     /* Done */
320     s->regs[SONIC_CR] &= ~SONIC_CR_LCAM;
321     s->regs[SONIC_ISR] |= SONIC_ISR_LCD;
322     dp8393x_update_irq(s);
323 }
324 
325 static void dp8393x_do_read_rra(dp8393xState *s)
326 {
327     int width, size;
328 
329     /* Read memory */
330     width = (s->regs[SONIC_DCR] & SONIC_DCR_DW) ? 2 : 1;
331     size = sizeof(uint16_t) * 4 * width;
332     address_space_read(&s->as, dp8393x_rrp(s),
333                        MEMTXATTRS_UNSPECIFIED, s->data, size);
334 
335     /* Update SONIC registers */
336     s->regs[SONIC_CRBA0] = dp8393x_get(s, width, 0);
337     s->regs[SONIC_CRBA1] = dp8393x_get(s, width, 1);
338     s->regs[SONIC_RBWC0] = dp8393x_get(s, width, 2);
339     s->regs[SONIC_RBWC1] = dp8393x_get(s, width, 3);
340     DPRINTF("CRBA0/1: 0x%04x/0x%04x, RBWC0/1: 0x%04x/0x%04x\n",
341         s->regs[SONIC_CRBA0], s->regs[SONIC_CRBA1],
342         s->regs[SONIC_RBWC0], s->regs[SONIC_RBWC1]);
343 
344     /* Go to next entry */
345     s->regs[SONIC_RRP] += size;
346 
347     /* Handle wrap */
348     if (s->regs[SONIC_RRP] == s->regs[SONIC_REA]) {
349         s->regs[SONIC_RRP] = s->regs[SONIC_RSA];
350     }
351 
352     /* Warn the host if CRBA now has the last available resource */
353     if (s->regs[SONIC_RRP] == s->regs[SONIC_RWP])
354     {
355         s->regs[SONIC_ISR] |= SONIC_ISR_RBE;
356         dp8393x_update_irq(s);
357     }
358 
359     /* Allow packet reception */
360     s->last_rba_is_full = false;
361 }
362 
363 static void dp8393x_do_software_reset(dp8393xState *s)
364 {
365     timer_del(s->watchdog);
366 
367     s->regs[SONIC_CR] &= ~(SONIC_CR_LCAM | SONIC_CR_RRRA | SONIC_CR_TXP | SONIC_CR_HTX);
368     s->regs[SONIC_CR] |= SONIC_CR_RST | SONIC_CR_RXDIS;
369 }
370 
371 static void dp8393x_set_next_tick(dp8393xState *s)
372 {
373     uint32_t ticks;
374     int64_t delay;
375 
376     if (s->regs[SONIC_CR] & SONIC_CR_STP) {
377         timer_del(s->watchdog);
378         return;
379     }
380 
381     ticks = dp8393x_wt(s);
382     s->wt_last_update = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
383     delay = NANOSECONDS_PER_SECOND * ticks / 5000000;
384     timer_mod(s->watchdog, s->wt_last_update + delay);
385 }
386 
387 static void dp8393x_update_wt_regs(dp8393xState *s)
388 {
389     int64_t elapsed;
390     uint32_t val;
391 
392     if (s->regs[SONIC_CR] & SONIC_CR_STP) {
393         timer_del(s->watchdog);
394         return;
395     }
396 
397     elapsed = s->wt_last_update - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
398     val = dp8393x_wt(s);
399     val -= elapsed / 5000000;
400     s->regs[SONIC_WT1] = (val >> 16) & 0xffff;
401     s->regs[SONIC_WT0] = (val >> 0)  & 0xffff;
402     dp8393x_set_next_tick(s);
403 
404 }
405 
406 static void dp8393x_do_start_timer(dp8393xState *s)
407 {
408     s->regs[SONIC_CR] &= ~SONIC_CR_STP;
409     dp8393x_set_next_tick(s);
410 }
411 
412 static void dp8393x_do_stop_timer(dp8393xState *s)
413 {
414     s->regs[SONIC_CR] &= ~SONIC_CR_ST;
415     dp8393x_update_wt_regs(s);
416 }
417 
418 static bool dp8393x_can_receive(NetClientState *nc);
419 
420 static void dp8393x_do_receiver_enable(dp8393xState *s)
421 {
422     s->regs[SONIC_CR] &= ~SONIC_CR_RXDIS;
423     if (dp8393x_can_receive(s->nic->ncs)) {
424         qemu_flush_queued_packets(qemu_get_queue(s->nic));
425     }
426 }
427 
428 static void dp8393x_do_receiver_disable(dp8393xState *s)
429 {
430     s->regs[SONIC_CR] &= ~SONIC_CR_RXEN;
431 }
432 
433 static void dp8393x_do_transmit_packets(dp8393xState *s)
434 {
435     NetClientState *nc = qemu_get_queue(s->nic);
436     int width, size;
437     int tx_len, len;
438     uint16_t i;
439 
440     width = (s->regs[SONIC_DCR] & SONIC_DCR_DW) ? 2 : 1;
441 
442     while (1) {
443         /* Read memory */
444         size = sizeof(uint16_t) * 6 * width;
445         s->regs[SONIC_TTDA] = s->regs[SONIC_CTDA];
446         DPRINTF("Transmit packet at %08x\n", dp8393x_ttda(s));
447         address_space_read(&s->as, dp8393x_ttda(s) + sizeof(uint16_t) * width,
448                            MEMTXATTRS_UNSPECIFIED, s->data, size);
449         tx_len = 0;
450 
451         /* Update registers */
452         s->regs[SONIC_TCR] = dp8393x_get(s, width, 0) & 0xf000;
453         s->regs[SONIC_TPS] = dp8393x_get(s, width, 1);
454         s->regs[SONIC_TFC] = dp8393x_get(s, width, 2);
455         s->regs[SONIC_TSA0] = dp8393x_get(s, width, 3);
456         s->regs[SONIC_TSA1] = dp8393x_get(s, width, 4);
457         s->regs[SONIC_TFS] = dp8393x_get(s, width, 5);
458 
459         /* Handle programmable interrupt */
460         if (s->regs[SONIC_TCR] & SONIC_TCR_PINT) {
461             s->regs[SONIC_ISR] |= SONIC_ISR_PINT;
462         } else {
463             s->regs[SONIC_ISR] &= ~SONIC_ISR_PINT;
464         }
465 
466         for (i = 0; i < s->regs[SONIC_TFC]; ) {
467             /* Append fragment */
468             len = s->regs[SONIC_TFS];
469             if (tx_len + len > sizeof(s->tx_buffer)) {
470                 len = sizeof(s->tx_buffer) - tx_len;
471             }
472             address_space_read(&s->as, dp8393x_tsa(s), MEMTXATTRS_UNSPECIFIED,
473                                &s->tx_buffer[tx_len], len);
474             tx_len += len;
475 
476             i++;
477             if (i != s->regs[SONIC_TFC]) {
478                 /* Read next fragment details */
479                 size = sizeof(uint16_t) * 3 * width;
480                 address_space_read(&s->as,
481                                    dp8393x_ttda(s)
482                                    + sizeof(uint16_t) * width * (4 + 3 * i),
483                                    MEMTXATTRS_UNSPECIFIED, s->data,
484                                    size);
485                 s->regs[SONIC_TSA0] = dp8393x_get(s, width, 0);
486                 s->regs[SONIC_TSA1] = dp8393x_get(s, width, 1);
487                 s->regs[SONIC_TFS] = dp8393x_get(s, width, 2);
488             }
489         }
490 
491         /* Handle Ethernet checksum */
492         if (!(s->regs[SONIC_TCR] & SONIC_TCR_CRCI)) {
493             /* Don't append FCS there, to look like slirp packets
494              * which don't have one */
495         } else {
496             /* Remove existing FCS */
497             tx_len -= 4;
498             if (tx_len < 0) {
499                 SONIC_ERROR("tx_len is %d\n", tx_len);
500                 break;
501             }
502         }
503 
504         if (s->regs[SONIC_RCR] & (SONIC_RCR_LB1 | SONIC_RCR_LB0)) {
505             /* Loopback */
506             s->regs[SONIC_TCR] |= SONIC_TCR_CRSL;
507             if (nc->info->can_receive(nc)) {
508                 s->loopback_packet = 1;
509                 qemu_receive_packet(nc, s->tx_buffer, tx_len);
510             }
511         } else {
512             /* Transmit packet */
513             qemu_send_packet(nc, s->tx_buffer, tx_len);
514         }
515         s->regs[SONIC_TCR] |= SONIC_TCR_PTX;
516 
517         /* Write status */
518         dp8393x_put(s, width, 0,
519                     s->regs[SONIC_TCR] & 0x0fff); /* status */
520         size = sizeof(uint16_t) * width;
521         address_space_write(&s->as, dp8393x_ttda(s),
522                             MEMTXATTRS_UNSPECIFIED, s->data, size);
523 
524         if (!(s->regs[SONIC_CR] & SONIC_CR_HTX)) {
525             /* Read footer of packet */
526             size = sizeof(uint16_t) * width;
527             address_space_read(&s->as,
528                                dp8393x_ttda(s)
529                                + sizeof(uint16_t) * width
530                                  * (4 + 3 * s->regs[SONIC_TFC]),
531                                MEMTXATTRS_UNSPECIFIED, s->data,
532                                size);
533             s->regs[SONIC_CTDA] = dp8393x_get(s, width, 0);
534             if (s->regs[SONIC_CTDA] & SONIC_DESC_EOL) {
535                 /* EOL detected */
536                 break;
537             }
538         }
539     }
540 
541     /* Done */
542     s->regs[SONIC_CR] &= ~SONIC_CR_TXP;
543     s->regs[SONIC_ISR] |= SONIC_ISR_TXDN;
544     dp8393x_update_irq(s);
545 }
546 
547 static void dp8393x_do_halt_transmission(dp8393xState *s)
548 {
549     /* Nothing to do */
550 }
551 
552 static void dp8393x_do_command(dp8393xState *s, uint16_t command)
553 {
554     if ((s->regs[SONIC_CR] & SONIC_CR_RST) && !(command & SONIC_CR_RST)) {
555         s->regs[SONIC_CR] &= ~SONIC_CR_RST;
556         return;
557     }
558 
559     s->regs[SONIC_CR] |= (command & SONIC_CR_MASK);
560 
561     if (command & SONIC_CR_HTX)
562         dp8393x_do_halt_transmission(s);
563     if (command & SONIC_CR_TXP)
564         dp8393x_do_transmit_packets(s);
565     if (command & SONIC_CR_RXDIS)
566         dp8393x_do_receiver_disable(s);
567     if (command & SONIC_CR_RXEN)
568         dp8393x_do_receiver_enable(s);
569     if (command & SONIC_CR_STP)
570         dp8393x_do_stop_timer(s);
571     if (command & SONIC_CR_ST)
572         dp8393x_do_start_timer(s);
573     if (command & SONIC_CR_RST)
574         dp8393x_do_software_reset(s);
575     if (command & SONIC_CR_RRRA) {
576         dp8393x_do_read_rra(s);
577         s->regs[SONIC_CR] &= ~SONIC_CR_RRRA;
578     }
579     if (command & SONIC_CR_LCAM)
580         dp8393x_do_load_cam(s);
581 }
582 
583 static uint64_t dp8393x_read(void *opaque, hwaddr addr, unsigned int size)
584 {
585     dp8393xState *s = opaque;
586     int reg = addr >> s->it_shift;
587     uint16_t val = 0;
588 
589     switch (reg) {
590         /* Update data before reading it */
591         case SONIC_WT0:
592         case SONIC_WT1:
593             dp8393x_update_wt_regs(s);
594             val = s->regs[reg];
595             break;
596         /* Accept read to some registers only when in reset mode */
597         case SONIC_CAP2:
598         case SONIC_CAP1:
599         case SONIC_CAP0:
600             if (s->regs[SONIC_CR] & SONIC_CR_RST) {
601                 val = s->cam[s->regs[SONIC_CEP] & 0xf][2* (SONIC_CAP0 - reg) + 1] << 8;
602                 val |= s->cam[s->regs[SONIC_CEP] & 0xf][2* (SONIC_CAP0 - reg)];
603             }
604             break;
605         /* All other registers have no special contrainst */
606         default:
607             val = s->regs[reg];
608     }
609 
610     DPRINTF("read 0x%04x from reg %s\n", val, reg_names[reg]);
611 
612     return s->big_endian ? val << 16 : val;
613 }
614 
615 static void dp8393x_write(void *opaque, hwaddr addr, uint64_t data,
616                           unsigned int size)
617 {
618     dp8393xState *s = opaque;
619     int reg = addr >> s->it_shift;
620     uint32_t val = s->big_endian ? data >> 16 : data;
621 
622     DPRINTF("write 0x%04x to reg %s\n", (uint16_t)val, reg_names[reg]);
623 
624     switch (reg) {
625         /* Command register */
626         case SONIC_CR:
627             dp8393x_do_command(s, val);
628             break;
629         /* Prevent write to read-only registers */
630         case SONIC_CAP2:
631         case SONIC_CAP1:
632         case SONIC_CAP0:
633         case SONIC_SR:
634         case SONIC_MDT:
635             DPRINTF("writing to reg %d invalid\n", reg);
636             break;
637         /* Accept write to some registers only when in reset mode */
638         case SONIC_DCR:
639             if (s->regs[SONIC_CR] & SONIC_CR_RST) {
640                 s->regs[reg] = val & 0xbfff;
641             } else {
642                 DPRINTF("writing to DCR invalid\n");
643             }
644             break;
645         case SONIC_DCR2:
646             if (s->regs[SONIC_CR] & SONIC_CR_RST) {
647                 s->regs[reg] = val & 0xf017;
648             } else {
649                 DPRINTF("writing to DCR2 invalid\n");
650             }
651             break;
652         /* 12 lower bytes are Read Only */
653         case SONIC_TCR:
654             s->regs[reg] = val & 0xf000;
655             break;
656         /* 9 lower bytes are Read Only */
657         case SONIC_RCR:
658             s->regs[reg] = val & 0xffe0;
659             break;
660         /* Ignore most significant bit */
661         case SONIC_IMR:
662             s->regs[reg] = val & 0x7fff;
663             dp8393x_update_irq(s);
664             break;
665         /* Clear bits by writing 1 to them */
666         case SONIC_ISR:
667             val &= s->regs[reg];
668             s->regs[reg] &= ~val;
669             if (val & SONIC_ISR_RBE) {
670                 dp8393x_do_read_rra(s);
671             }
672             dp8393x_update_irq(s);
673             break;
674         /* The guest is required to store aligned pointers here */
675         case SONIC_RSA:
676         case SONIC_REA:
677         case SONIC_RRP:
678         case SONIC_RWP:
679             if (s->regs[SONIC_DCR] & SONIC_DCR_DW) {
680                 s->regs[reg] = val & 0xfffc;
681             } else {
682                 s->regs[reg] = val & 0xfffe;
683             }
684             break;
685         /* Invert written value for some registers */
686         case SONIC_CRCT:
687         case SONIC_FAET:
688         case SONIC_MPT:
689             s->regs[reg] = val ^ 0xffff;
690             break;
691         /* All other registers have no special contrainst */
692         default:
693             s->regs[reg] = val;
694     }
695 
696     if (reg == SONIC_WT0 || reg == SONIC_WT1) {
697         dp8393x_set_next_tick(s);
698     }
699 }
700 
701 static const MemoryRegionOps dp8393x_ops = {
702     .read = dp8393x_read,
703     .write = dp8393x_write,
704     .impl.min_access_size = 4,
705     .impl.max_access_size = 4,
706     .endianness = DEVICE_NATIVE_ENDIAN,
707 };
708 
709 static void dp8393x_watchdog(void *opaque)
710 {
711     dp8393xState *s = opaque;
712 
713     if (s->regs[SONIC_CR] & SONIC_CR_STP) {
714         return;
715     }
716 
717     s->regs[SONIC_WT1] = 0xffff;
718     s->regs[SONIC_WT0] = 0xffff;
719     dp8393x_set_next_tick(s);
720 
721     /* Signal underflow */
722     s->regs[SONIC_ISR] |= SONIC_ISR_TC;
723     dp8393x_update_irq(s);
724 }
725 
726 static bool dp8393x_can_receive(NetClientState *nc)
727 {
728     dp8393xState *s = qemu_get_nic_opaque(nc);
729 
730     return !!(s->regs[SONIC_CR] & SONIC_CR_RXEN);
731 }
732 
733 static int dp8393x_receive_filter(dp8393xState *s, const uint8_t * buf,
734                                   int size)
735 {
736     static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
737     int i;
738 
739     /* Check promiscuous mode */
740     if ((s->regs[SONIC_RCR] & SONIC_RCR_PRO) && (buf[0] & 1) == 0) {
741         return 0;
742     }
743 
744     /* Check multicast packets */
745     if ((s->regs[SONIC_RCR] & SONIC_RCR_AMC) && (buf[0] & 1) == 1) {
746         return SONIC_RCR_MC;
747     }
748 
749     /* Check broadcast */
750     if ((s->regs[SONIC_RCR] & SONIC_RCR_BRD) && !memcmp(buf, bcast, sizeof(bcast))) {
751         return SONIC_RCR_BC;
752     }
753 
754     /* Check CAM */
755     for (i = 0; i < 16; i++) {
756         if (s->regs[SONIC_CE] & (1 << i)) {
757              /* Entry enabled */
758              if (!memcmp(buf, s->cam[i], sizeof(s->cam[i]))) {
759                  return 0;
760              }
761         }
762     }
763 
764     return -1;
765 }
766 
767 static ssize_t dp8393x_receive(NetClientState *nc, const uint8_t * buf,
768                                size_t pkt_size)
769 {
770     dp8393xState *s = qemu_get_nic_opaque(nc);
771     int packet_type;
772     uint32_t available, address;
773     int width, rx_len, padded_len;
774     uint32_t checksum;
775     int size;
776 
777     s->regs[SONIC_RCR] &= ~(SONIC_RCR_PRX | SONIC_RCR_LBK | SONIC_RCR_FAER |
778         SONIC_RCR_CRCR | SONIC_RCR_LPKT | SONIC_RCR_BC | SONIC_RCR_MC);
779 
780     if (s->last_rba_is_full) {
781         return pkt_size;
782     }
783 
784     rx_len = pkt_size + sizeof(checksum);
785     if (s->regs[SONIC_DCR] & SONIC_DCR_DW) {
786         width = 2;
787         padded_len = ((rx_len - 1) | 3) + 1;
788     } else {
789         width = 1;
790         padded_len = ((rx_len - 1) | 1) + 1;
791     }
792 
793     if (padded_len > dp8393x_rbwc(s) * 2) {
794         DPRINTF("oversize packet, pkt_size is %d\n", pkt_size);
795         s->regs[SONIC_ISR] |= SONIC_ISR_RBAE;
796         dp8393x_update_irq(s);
797         s->regs[SONIC_RCR] |= SONIC_RCR_LPKT;
798         goto done;
799     }
800 
801     packet_type = dp8393x_receive_filter(s, buf, pkt_size);
802     if (packet_type < 0) {
803         DPRINTF("packet not for netcard\n");
804         return -1;
805     }
806 
807     /* Check for EOL */
808     if (s->regs[SONIC_LLFA] & SONIC_DESC_EOL) {
809         /* Are we still in resource exhaustion? */
810         size = sizeof(uint16_t) * 1 * width;
811         address = dp8393x_crda(s) + sizeof(uint16_t) * 5 * width;
812         address_space_read(&s->as, address, MEMTXATTRS_UNSPECIFIED,
813                            s->data, size);
814         s->regs[SONIC_LLFA] = dp8393x_get(s, width, 0);
815         if (s->regs[SONIC_LLFA] & SONIC_DESC_EOL) {
816             /* Still EOL ; stop reception */
817             return -1;
818         }
819         /* Link has been updated by host */
820 
821         /* Clear in_use */
822         size = sizeof(uint16_t) * width;
823         address = dp8393x_crda(s) + sizeof(uint16_t) * 6 * width;
824         dp8393x_put(s, width, 0, 0);
825         address_space_rw(&s->as, address, MEMTXATTRS_UNSPECIFIED,
826                          (uint8_t *)s->data, size, 1);
827 
828         /* Move to next descriptor */
829         s->regs[SONIC_CRDA] = s->regs[SONIC_LLFA];
830         s->regs[SONIC_ISR] |= SONIC_ISR_PKTRX;
831     }
832 
833     /* Save current position */
834     s->regs[SONIC_TRBA1] = s->regs[SONIC_CRBA1];
835     s->regs[SONIC_TRBA0] = s->regs[SONIC_CRBA0];
836 
837     /* Calculate the ethernet checksum */
838     checksum = cpu_to_le32(crc32(0, buf, pkt_size));
839 
840     /* Put packet into RBA */
841     DPRINTF("Receive packet at %08x\n", dp8393x_crba(s));
842     address = dp8393x_crba(s);
843     address_space_write(&s->as, address, MEMTXATTRS_UNSPECIFIED,
844                         buf, pkt_size);
845     address += pkt_size;
846 
847     /* Put frame checksum into RBA */
848     address_space_write(&s->as, address, MEMTXATTRS_UNSPECIFIED,
849                         &checksum, sizeof(checksum));
850     address += sizeof(checksum);
851 
852     /* Pad short packets to keep pointers aligned */
853     if (rx_len < padded_len) {
854         size = padded_len - rx_len;
855         address_space_rw(&s->as, address, MEMTXATTRS_UNSPECIFIED,
856             (uint8_t *)"\xFF\xFF\xFF", size, 1);
857         address += size;
858     }
859 
860     s->regs[SONIC_CRBA1] = address >> 16;
861     s->regs[SONIC_CRBA0] = address & 0xffff;
862     available = dp8393x_rbwc(s);
863     available -= padded_len >> 1;
864     s->regs[SONIC_RBWC1] = available >> 16;
865     s->regs[SONIC_RBWC0] = available & 0xffff;
866 
867     /* Update status */
868     if (dp8393x_rbwc(s) < s->regs[SONIC_EOBC]) {
869         s->regs[SONIC_RCR] |= SONIC_RCR_LPKT;
870     }
871     s->regs[SONIC_RCR] |= packet_type;
872     s->regs[SONIC_RCR] |= SONIC_RCR_PRX;
873     if (s->loopback_packet) {
874         s->regs[SONIC_RCR] |= SONIC_RCR_LBK;
875         s->loopback_packet = 0;
876     }
877 
878     /* Write status to memory */
879     DPRINTF("Write status at %08x\n", dp8393x_crda(s));
880     dp8393x_put(s, width, 0, s->regs[SONIC_RCR]); /* status */
881     dp8393x_put(s, width, 1, rx_len); /* byte count */
882     dp8393x_put(s, width, 2, s->regs[SONIC_TRBA0]); /* pkt_ptr0 */
883     dp8393x_put(s, width, 3, s->regs[SONIC_TRBA1]); /* pkt_ptr1 */
884     dp8393x_put(s, width, 4, s->regs[SONIC_RSC]); /* seq_no */
885     size = sizeof(uint16_t) * 5 * width;
886     address_space_write(&s->as, dp8393x_crda(s),
887                         MEMTXATTRS_UNSPECIFIED,
888                         s->data, size);
889 
890     /* Check link field */
891     size = sizeof(uint16_t) * width;
892     address_space_read(&s->as,
893                        dp8393x_crda(s) + sizeof(uint16_t) * 5 * width,
894                        MEMTXATTRS_UNSPECIFIED, s->data, size);
895     s->regs[SONIC_LLFA] = dp8393x_get(s, width, 0);
896     if (s->regs[SONIC_LLFA] & SONIC_DESC_EOL) {
897         /* EOL detected */
898         s->regs[SONIC_ISR] |= SONIC_ISR_RDE;
899     } else {
900         /* Clear in_use */
901         size = sizeof(uint16_t) * width;
902         address = dp8393x_crda(s) + sizeof(uint16_t) * 6 * width;
903         dp8393x_put(s, width, 0, 0);
904         address_space_write(&s->as, address, MEMTXATTRS_UNSPECIFIED,
905                             s->data, size);
906 
907         /* Move to next descriptor */
908         s->regs[SONIC_CRDA] = s->regs[SONIC_LLFA];
909         s->regs[SONIC_ISR] |= SONIC_ISR_PKTRX;
910     }
911 
912     dp8393x_update_irq(s);
913 
914     s->regs[SONIC_RSC] = (s->regs[SONIC_RSC] & 0xff00) |
915                          ((s->regs[SONIC_RSC] + 1) & 0x00ff);
916 
917 done:
918 
919     if (s->regs[SONIC_RCR] & SONIC_RCR_LPKT) {
920         if (s->regs[SONIC_RRP] == s->regs[SONIC_RWP]) {
921             /* Stop packet reception */
922             s->last_rba_is_full = true;
923         } else {
924             /* Read next resource */
925             dp8393x_do_read_rra(s);
926         }
927     }
928 
929     return pkt_size;
930 }
931 
932 static void dp8393x_reset(DeviceState *dev)
933 {
934     dp8393xState *s = DP8393X(dev);
935     timer_del(s->watchdog);
936 
937     memset(s->regs, 0, sizeof(s->regs));
938     s->regs[SONIC_SR] = 0x0004; /* only revision recognized by Linux/mips */
939     s->regs[SONIC_CR] = SONIC_CR_RST | SONIC_CR_STP | SONIC_CR_RXDIS;
940     s->regs[SONIC_DCR] &= ~(SONIC_DCR_EXBUS | SONIC_DCR_LBR);
941     s->regs[SONIC_RCR] &= ~(SONIC_RCR_LB0 | SONIC_RCR_LB1 | SONIC_RCR_BRD | SONIC_RCR_RNT);
942     s->regs[SONIC_TCR] |= SONIC_TCR_NCRS | SONIC_TCR_PTX;
943     s->regs[SONIC_TCR] &= ~SONIC_TCR_BCM;
944     s->regs[SONIC_IMR] = 0;
945     s->regs[SONIC_ISR] = 0;
946     s->regs[SONIC_DCR2] = 0;
947     s->regs[SONIC_EOBC] = 0x02F8;
948     s->regs[SONIC_RSC] = 0;
949     s->regs[SONIC_CE] = 0;
950     s->regs[SONIC_RSC] = 0;
951 
952     /* Network cable is connected */
953     s->regs[SONIC_RCR] |= SONIC_RCR_CRS;
954 
955     dp8393x_update_irq(s);
956 }
957 
958 static NetClientInfo net_dp83932_info = {
959     .type = NET_CLIENT_DRIVER_NIC,
960     .size = sizeof(NICState),
961     .can_receive = dp8393x_can_receive,
962     .receive = dp8393x_receive,
963 };
964 
965 static void dp8393x_instance_init(Object *obj)
966 {
967     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
968     dp8393xState *s = DP8393X(obj);
969 
970     sysbus_init_mmio(sbd, &s->mmio);
971     sysbus_init_mmio(sbd, &s->prom);
972     sysbus_init_irq(sbd, &s->irq);
973 }
974 
975 static void dp8393x_realize(DeviceState *dev, Error **errp)
976 {
977     dp8393xState *s = DP8393X(dev);
978     int i, checksum;
979     uint8_t *prom;
980     Error *local_err = NULL;
981 
982     address_space_init(&s->as, s->dma_mr, "dp8393x");
983     memory_region_init_io(&s->mmio, OBJECT(dev), &dp8393x_ops, s,
984                           "dp8393x-regs", 0x40 << s->it_shift);
985 
986     s->nic = qemu_new_nic(&net_dp83932_info, &s->conf,
987                           object_get_typename(OBJECT(dev)), dev->id, s);
988     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
989 
990     s->watchdog = timer_new_ns(QEMU_CLOCK_VIRTUAL, dp8393x_watchdog, s);
991 
992     memory_region_init_rom(&s->prom, OBJECT(dev), "dp8393x-prom",
993                            SONIC_PROM_SIZE, &local_err);
994     if (local_err) {
995         error_propagate(errp, local_err);
996         return;
997     }
998     prom = memory_region_get_ram_ptr(&s->prom);
999     checksum = 0;
1000     for (i = 0; i < 6; i++) {
1001         prom[i] = s->conf.macaddr.a[i];
1002         checksum += prom[i];
1003         if (checksum > 0xff) {
1004             checksum = (checksum + 1) & 0xff;
1005         }
1006     }
1007     prom[7] = 0xff - checksum;
1008 }
1009 
1010 static const VMStateDescription vmstate_dp8393x = {
1011     .name = "dp8393x",
1012     .version_id = 0,
1013     .minimum_version_id = 0,
1014     .fields = (VMStateField []) {
1015         VMSTATE_BUFFER_UNSAFE(cam, dp8393xState, 0, 16 * 6),
1016         VMSTATE_UINT16_ARRAY(regs, dp8393xState, 0x40),
1017         VMSTATE_END_OF_LIST()
1018     }
1019 };
1020 
1021 static Property dp8393x_properties[] = {
1022     DEFINE_NIC_PROPERTIES(dp8393xState, conf),
1023     DEFINE_PROP_LINK("dma_mr", dp8393xState, dma_mr,
1024                      TYPE_MEMORY_REGION, MemoryRegion *),
1025     DEFINE_PROP_UINT8("it_shift", dp8393xState, it_shift, 0),
1026     DEFINE_PROP_BOOL("big_endian", dp8393xState, big_endian, false),
1027     DEFINE_PROP_END_OF_LIST(),
1028 };
1029 
1030 static void dp8393x_class_init(ObjectClass *klass, void *data)
1031 {
1032     DeviceClass *dc = DEVICE_CLASS(klass);
1033 
1034     set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
1035     dc->realize = dp8393x_realize;
1036     dc->reset = dp8393x_reset;
1037     dc->vmsd = &vmstate_dp8393x;
1038     device_class_set_props(dc, dp8393x_properties);
1039 }
1040 
1041 static const TypeInfo dp8393x_info = {
1042     .name          = TYPE_DP8393X,
1043     .parent        = TYPE_SYS_BUS_DEVICE,
1044     .instance_size = sizeof(dp8393xState),
1045     .instance_init = dp8393x_instance_init,
1046     .class_init    = dp8393x_class_init,
1047 };
1048 
1049 static void dp8393x_register_types(void)
1050 {
1051     type_register_static(&dp8393x_info);
1052 }
1053 
1054 type_init(dp8393x_register_types)
1055