xref: /openbmc/qemu/hw/net/dp8393x.c (revision b91a0fa7)
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 #include "trace.h"
32 
33 static const char *reg_names[] = {
34     "CR", "DCR", "RCR", "TCR", "IMR", "ISR", "UTDA", "CTDA",
35     "TPS", "TFC", "TSA0", "TSA1", "TFS", "URDA", "CRDA", "CRBA0",
36     "CRBA1", "RBWC0", "RBWC1", "EOBC", "URRA", "RSA", "REA", "RRP",
37     "RWP", "TRBA0", "TRBA1", "0x1b", "0x1c", "0x1d", "0x1e", "LLFA",
38     "TTDA", "CEP", "CAP2", "CAP1", "CAP0", "CE", "CDP", "CDC",
39     "SR", "WT0", "WT1", "RSC", "CRCT", "FAET", "MPT", "MDT",
40     "0x30", "0x31", "0x32", "0x33", "0x34", "0x35", "0x36", "0x37",
41     "0x38", "0x39", "0x3a", "0x3b", "0x3c", "0x3d", "0x3e", "DCR2" };
42 
43 #define SONIC_CR     0x00
44 #define SONIC_DCR    0x01
45 #define SONIC_RCR    0x02
46 #define SONIC_TCR    0x03
47 #define SONIC_IMR    0x04
48 #define SONIC_ISR    0x05
49 #define SONIC_UTDA   0x06
50 #define SONIC_CTDA   0x07
51 #define SONIC_TPS    0x08
52 #define SONIC_TFC    0x09
53 #define SONIC_TSA0   0x0a
54 #define SONIC_TSA1   0x0b
55 #define SONIC_TFS    0x0c
56 #define SONIC_URDA   0x0d
57 #define SONIC_CRDA   0x0e
58 #define SONIC_CRBA0  0x0f
59 #define SONIC_CRBA1  0x10
60 #define SONIC_RBWC0  0x11
61 #define SONIC_RBWC1  0x12
62 #define SONIC_EOBC   0x13
63 #define SONIC_URRA   0x14
64 #define SONIC_RSA    0x15
65 #define SONIC_REA    0x16
66 #define SONIC_RRP    0x17
67 #define SONIC_RWP    0x18
68 #define SONIC_TRBA0  0x19
69 #define SONIC_TRBA1  0x1a
70 #define SONIC_LLFA   0x1f
71 #define SONIC_TTDA   0x20
72 #define SONIC_CEP    0x21
73 #define SONIC_CAP2   0x22
74 #define SONIC_CAP1   0x23
75 #define SONIC_CAP0   0x24
76 #define SONIC_CE     0x25
77 #define SONIC_CDP    0x26
78 #define SONIC_CDC    0x27
79 #define SONIC_SR     0x28
80 #define SONIC_WT0    0x29
81 #define SONIC_WT1    0x2a
82 #define SONIC_RSC    0x2b
83 #define SONIC_CRCT   0x2c
84 #define SONIC_FAET   0x2d
85 #define SONIC_MPT    0x2e
86 #define SONIC_MDT    0x2f
87 #define SONIC_DCR2   0x3f
88 #define SONIC_REG_COUNT  0x40
89 
90 #define SONIC_CR_HTX     0x0001
91 #define SONIC_CR_TXP     0x0002
92 #define SONIC_CR_RXDIS   0x0004
93 #define SONIC_CR_RXEN    0x0008
94 #define SONIC_CR_STP     0x0010
95 #define SONIC_CR_ST      0x0020
96 #define SONIC_CR_RST     0x0080
97 #define SONIC_CR_RRRA    0x0100
98 #define SONIC_CR_LCAM    0x0200
99 #define SONIC_CR_MASK    0x03bf
100 
101 #define SONIC_DCR_DW     0x0020
102 #define SONIC_DCR_LBR    0x2000
103 #define SONIC_DCR_EXBUS  0x8000
104 
105 #define SONIC_RCR_PRX    0x0001
106 #define SONIC_RCR_LBK    0x0002
107 #define SONIC_RCR_FAER   0x0004
108 #define SONIC_RCR_CRCR   0x0008
109 #define SONIC_RCR_CRS    0x0020
110 #define SONIC_RCR_LPKT   0x0040
111 #define SONIC_RCR_BC     0x0080
112 #define SONIC_RCR_MC     0x0100
113 #define SONIC_RCR_LB0    0x0200
114 #define SONIC_RCR_LB1    0x0400
115 #define SONIC_RCR_AMC    0x0800
116 #define SONIC_RCR_PRO    0x1000
117 #define SONIC_RCR_BRD    0x2000
118 #define SONIC_RCR_RNT    0x4000
119 
120 #define SONIC_TCR_PTX    0x0001
121 #define SONIC_TCR_BCM    0x0002
122 #define SONIC_TCR_FU     0x0004
123 #define SONIC_TCR_EXC    0x0040
124 #define SONIC_TCR_CRSL   0x0080
125 #define SONIC_TCR_NCRS   0x0100
126 #define SONIC_TCR_EXD    0x0400
127 #define SONIC_TCR_CRCI   0x2000
128 #define SONIC_TCR_PINT   0x8000
129 
130 #define SONIC_ISR_RBAE   0x0010
131 #define SONIC_ISR_RBE    0x0020
132 #define SONIC_ISR_RDE    0x0040
133 #define SONIC_ISR_TC     0x0080
134 #define SONIC_ISR_TXDN   0x0200
135 #define SONIC_ISR_PKTRX  0x0400
136 #define SONIC_ISR_PINT   0x0800
137 #define SONIC_ISR_LCD    0x1000
138 
139 #define SONIC_DESC_EOL   0x0001
140 #define SONIC_DESC_ADDR  0xFFFE
141 
142 #define TYPE_DP8393X "dp8393x"
143 OBJECT_DECLARE_SIMPLE_TYPE(dp8393xState, DP8393X)
144 
145 struct dp8393xState {
146     SysBusDevice parent_obj;
147 
148     /* Hardware */
149     uint8_t it_shift;
150     bool big_endian;
151     bool last_rba_is_full;
152     qemu_irq irq;
153     int irq_level;
154     QEMUTimer *watchdog;
155     int64_t wt_last_update;
156     NICConf conf;
157     NICState *nic;
158     MemoryRegion mmio;
159 
160     /* Registers */
161     uint16_t cam[16][3];
162     uint16_t regs[SONIC_REG_COUNT];
163 
164     /* Temporaries */
165     uint8_t tx_buffer[0x10000];
166     int loopback_packet;
167 
168     /* Memory access */
169     MemoryRegion *dma_mr;
170     AddressSpace as;
171 };
172 
173 /*
174  * Accessor functions for values which are formed by
175  * concatenating two 16 bit device registers. By putting these
176  * in their own functions with a uint32_t return type we avoid the
177  * pitfall of implicit sign extension where ((x << 16) | y) is a
178  * signed 32 bit integer that might get sign-extended to a 64 bit integer.
179  */
180 static uint32_t dp8393x_cdp(dp8393xState *s)
181 {
182     return (s->regs[SONIC_URRA] << 16) | s->regs[SONIC_CDP];
183 }
184 
185 static uint32_t dp8393x_crba(dp8393xState *s)
186 {
187     return (s->regs[SONIC_CRBA1] << 16) | s->regs[SONIC_CRBA0];
188 }
189 
190 static uint32_t dp8393x_crda(dp8393xState *s)
191 {
192     return (s->regs[SONIC_URDA] << 16) |
193            (s->regs[SONIC_CRDA] & SONIC_DESC_ADDR);
194 }
195 
196 static uint32_t dp8393x_rbwc(dp8393xState *s)
197 {
198     return (s->regs[SONIC_RBWC1] << 16) | s->regs[SONIC_RBWC0];
199 }
200 
201 static uint32_t dp8393x_rrp(dp8393xState *s)
202 {
203     return (s->regs[SONIC_URRA] << 16) | s->regs[SONIC_RRP];
204 }
205 
206 static uint32_t dp8393x_tsa(dp8393xState *s)
207 {
208     return (s->regs[SONIC_TSA1] << 16) | s->regs[SONIC_TSA0];
209 }
210 
211 static uint32_t dp8393x_ttda(dp8393xState *s)
212 {
213     return (s->regs[SONIC_UTDA] << 16) |
214            (s->regs[SONIC_TTDA] & SONIC_DESC_ADDR);
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 uint16_t dp8393x_get(dp8393xState *s, hwaddr addr, int offset)
223 {
224     const MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED;
225     uint16_t val;
226 
227     if (s->regs[SONIC_DCR] & SONIC_DCR_DW) {
228         addr += offset << 2;
229         if (s->big_endian) {
230             val = address_space_ldl_be(&s->as, addr, attrs, NULL);
231         } else {
232             val = address_space_ldl_le(&s->as, addr, attrs, NULL);
233         }
234     } else {
235         addr += offset << 1;
236         if (s->big_endian) {
237             val = address_space_lduw_be(&s->as, addr, attrs, NULL);
238         } else {
239             val = address_space_lduw_le(&s->as, addr, attrs, NULL);
240         }
241     }
242 
243     return val;
244 }
245 
246 static void dp8393x_put(dp8393xState *s,
247                         hwaddr addr, int offset, uint16_t val)
248 {
249     const MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED;
250 
251     if (s->regs[SONIC_DCR] & SONIC_DCR_DW) {
252         addr += offset << 2;
253         if (s->big_endian) {
254             address_space_stl_be(&s->as, addr, val, attrs, NULL);
255         } else {
256             address_space_stl_le(&s->as, addr, val, attrs, NULL);
257         }
258     } else {
259         addr += offset << 1;
260         if (s->big_endian) {
261             address_space_stw_be(&s->as, addr, val, attrs, NULL);
262         } else {
263             address_space_stw_le(&s->as, addr, val, attrs, NULL);
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     if (level != s->irq_level) {
273         s->irq_level = level;
274         if (level) {
275             trace_dp8393x_raise_irq(s->regs[SONIC_ISR]);
276         } else {
277             trace_dp8393x_lower_irq();
278         }
279     }
280 
281     qemu_set_irq(s->irq, level);
282 }
283 
284 static void dp8393x_do_load_cam(dp8393xState *s)
285 {
286     int width, size;
287     uint16_t index;
288 
289     width = (s->regs[SONIC_DCR] & SONIC_DCR_DW) ? 2 : 1;
290     size = sizeof(uint16_t) * 4 * width;
291 
292     while (s->regs[SONIC_CDC] & 0x1f) {
293         /* Fill current entry */
294         index = dp8393x_get(s, dp8393x_cdp(s), 0) & 0xf;
295         s->cam[index][0] = dp8393x_get(s, dp8393x_cdp(s), 1);
296         s->cam[index][1] = dp8393x_get(s, dp8393x_cdp(s), 2);
297         s->cam[index][2] = dp8393x_get(s, dp8393x_cdp(s), 3);
298         trace_dp8393x_load_cam(index,
299                                s->cam[index][0] >> 8, s->cam[index][0] & 0xff,
300                                s->cam[index][1] >> 8, s->cam[index][1] & 0xff,
301                                s->cam[index][2] >> 8, s->cam[index][2] & 0xff);
302         /* Move to next entry */
303         s->regs[SONIC_CDC]--;
304         s->regs[SONIC_CDP] += size;
305     }
306 
307     /* Read CAM enable */
308     s->regs[SONIC_CE] = dp8393x_get(s, dp8393x_cdp(s), 0);
309     trace_dp8393x_load_cam_done(s->regs[SONIC_CE]);
310 
311     /* Done */
312     s->regs[SONIC_CR] &= ~SONIC_CR_LCAM;
313     s->regs[SONIC_ISR] |= SONIC_ISR_LCD;
314     dp8393x_update_irq(s);
315 }
316 
317 static void dp8393x_do_read_rra(dp8393xState *s)
318 {
319     int width, size;
320 
321     /* Read memory */
322     width = (s->regs[SONIC_DCR] & SONIC_DCR_DW) ? 2 : 1;
323     size = sizeof(uint16_t) * 4 * width;
324 
325     /* Update SONIC registers */
326     s->regs[SONIC_CRBA0] = dp8393x_get(s, dp8393x_rrp(s), 0);
327     s->regs[SONIC_CRBA1] = dp8393x_get(s, dp8393x_rrp(s), 1);
328     s->regs[SONIC_RBWC0] = dp8393x_get(s, dp8393x_rrp(s), 2);
329     s->regs[SONIC_RBWC1] = dp8393x_get(s, dp8393x_rrp(s), 3);
330     trace_dp8393x_read_rra_regs(s->regs[SONIC_CRBA0], s->regs[SONIC_CRBA1],
331                                 s->regs[SONIC_RBWC0], s->regs[SONIC_RBWC1]);
332 
333     /* Go to next entry */
334     s->regs[SONIC_RRP] += size;
335 
336     /* Handle wrap */
337     if (s->regs[SONIC_RRP] == s->regs[SONIC_REA]) {
338         s->regs[SONIC_RRP] = s->regs[SONIC_RSA];
339     }
340 
341     /* Warn the host if CRBA now has the last available resource */
342     if (s->regs[SONIC_RRP] == s->regs[SONIC_RWP]) {
343         s->regs[SONIC_ISR] |= SONIC_ISR_RBE;
344         dp8393x_update_irq(s);
345     }
346 
347     /* Allow packet reception */
348     s->last_rba_is_full = false;
349 }
350 
351 static void dp8393x_do_software_reset(dp8393xState *s)
352 {
353     timer_del(s->watchdog);
354 
355     s->regs[SONIC_CR] &= ~(SONIC_CR_LCAM | SONIC_CR_RRRA | SONIC_CR_TXP |
356                            SONIC_CR_HTX);
357     s->regs[SONIC_CR] |= SONIC_CR_RST | SONIC_CR_RXDIS;
358 }
359 
360 static void dp8393x_set_next_tick(dp8393xState *s)
361 {
362     uint32_t ticks;
363     int64_t delay;
364 
365     if (s->regs[SONIC_CR] & SONIC_CR_STP) {
366         timer_del(s->watchdog);
367         return;
368     }
369 
370     ticks = dp8393x_wt(s);
371     s->wt_last_update = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
372     delay = NANOSECONDS_PER_SECOND * ticks / 5000000;
373     timer_mod(s->watchdog, s->wt_last_update + delay);
374 }
375 
376 static void dp8393x_update_wt_regs(dp8393xState *s)
377 {
378     int64_t elapsed;
379     uint32_t val;
380 
381     if (s->regs[SONIC_CR] & SONIC_CR_STP) {
382         timer_del(s->watchdog);
383         return;
384     }
385 
386     elapsed = s->wt_last_update - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
387     val = dp8393x_wt(s);
388     val -= elapsed / 5000000;
389     s->regs[SONIC_WT1] = (val >> 16) & 0xffff;
390     s->regs[SONIC_WT0] = (val >> 0)  & 0xffff;
391     dp8393x_set_next_tick(s);
392 
393 }
394 
395 static void dp8393x_do_start_timer(dp8393xState *s)
396 {
397     s->regs[SONIC_CR] &= ~SONIC_CR_STP;
398     dp8393x_set_next_tick(s);
399 }
400 
401 static void dp8393x_do_stop_timer(dp8393xState *s)
402 {
403     s->regs[SONIC_CR] &= ~SONIC_CR_ST;
404     dp8393x_update_wt_regs(s);
405 }
406 
407 static bool dp8393x_can_receive(NetClientState *nc);
408 
409 static void dp8393x_do_receiver_enable(dp8393xState *s)
410 {
411     s->regs[SONIC_CR] &= ~SONIC_CR_RXDIS;
412     if (dp8393x_can_receive(s->nic->ncs)) {
413         qemu_flush_queued_packets(qemu_get_queue(s->nic));
414     }
415 }
416 
417 static void dp8393x_do_receiver_disable(dp8393xState *s)
418 {
419     s->regs[SONIC_CR] &= ~SONIC_CR_RXEN;
420 }
421 
422 static void dp8393x_do_transmit_packets(dp8393xState *s)
423 {
424     NetClientState *nc = qemu_get_queue(s->nic);
425     int tx_len, len;
426     uint16_t i;
427 
428     while (1) {
429         /* Read memory */
430         s->regs[SONIC_TTDA] = s->regs[SONIC_CTDA];
431         trace_dp8393x_transmit_packet(dp8393x_ttda(s));
432         tx_len = 0;
433 
434         /* Update registers */
435         s->regs[SONIC_TCR] = dp8393x_get(s, dp8393x_ttda(s), 1) & 0xf000;
436         s->regs[SONIC_TPS] = dp8393x_get(s, dp8393x_ttda(s), 2);
437         s->regs[SONIC_TFC] = dp8393x_get(s, dp8393x_ttda(s), 3);
438         s->regs[SONIC_TSA0] = dp8393x_get(s, dp8393x_ttda(s), 4);
439         s->regs[SONIC_TSA1] = dp8393x_get(s, dp8393x_ttda(s), 5);
440         s->regs[SONIC_TFS] = dp8393x_get(s, dp8393x_ttda(s), 6);
441 
442         /* Handle programmable interrupt */
443         if (s->regs[SONIC_TCR] & SONIC_TCR_PINT) {
444             s->regs[SONIC_ISR] |= SONIC_ISR_PINT;
445         } else {
446             s->regs[SONIC_ISR] &= ~SONIC_ISR_PINT;
447         }
448 
449         for (i = 0; i < s->regs[SONIC_TFC]; ) {
450             /* Append fragment */
451             len = s->regs[SONIC_TFS];
452             if (tx_len + len > sizeof(s->tx_buffer)) {
453                 len = sizeof(s->tx_buffer) - tx_len;
454             }
455             address_space_read(&s->as, dp8393x_tsa(s), MEMTXATTRS_UNSPECIFIED,
456                                &s->tx_buffer[tx_len], len);
457             tx_len += len;
458 
459             i++;
460             if (i != s->regs[SONIC_TFC]) {
461                 /* Read next fragment details */
462                 s->regs[SONIC_TSA0] = dp8393x_get(s, dp8393x_ttda(s),
463                                                   4 + 3 * i);
464                 s->regs[SONIC_TSA1] = dp8393x_get(s, dp8393x_ttda(s),
465                                                   5 + 3 * i);
466                 s->regs[SONIC_TFS] = dp8393x_get(s, dp8393x_ttda(s),
467                                                  6 + 3 * i);
468             }
469         }
470 
471         /* Handle Ethernet checksum */
472         if (!(s->regs[SONIC_TCR] & SONIC_TCR_CRCI)) {
473             /*
474              * Don't append FCS there, to look like slirp packets
475              * which don't have one
476              */
477         } else {
478             /* Remove existing FCS */
479             tx_len -= 4;
480             if (tx_len < 0) {
481                 trace_dp8393x_transmit_txlen_error(tx_len);
482                 break;
483             }
484         }
485 
486         if (s->regs[SONIC_RCR] & (SONIC_RCR_LB1 | SONIC_RCR_LB0)) {
487             /* Loopback */
488             s->regs[SONIC_TCR] |= SONIC_TCR_CRSL;
489             if (nc->info->can_receive(nc)) {
490                 s->loopback_packet = 1;
491                 qemu_receive_packet(nc, s->tx_buffer, tx_len);
492             }
493         } else {
494             /* Transmit packet */
495             qemu_send_packet(nc, s->tx_buffer, tx_len);
496         }
497         s->regs[SONIC_TCR] |= SONIC_TCR_PTX;
498 
499         /* Write status */
500         dp8393x_put(s, dp8393x_ttda(s), 0, s->regs[SONIC_TCR] & 0x0fff);
501 
502         if (!(s->regs[SONIC_CR] & SONIC_CR_HTX)) {
503             /* Read footer of packet */
504             s->regs[SONIC_CTDA] = dp8393x_get(s, dp8393x_ttda(s),
505                                               4 + 3 * s->regs[SONIC_TFC]);
506             if (s->regs[SONIC_CTDA] & SONIC_DESC_EOL) {
507                 /* EOL detected */
508                 break;
509             }
510         }
511     }
512 
513     /* Done */
514     s->regs[SONIC_CR] &= ~SONIC_CR_TXP;
515     s->regs[SONIC_ISR] |= SONIC_ISR_TXDN;
516     dp8393x_update_irq(s);
517 }
518 
519 static void dp8393x_do_halt_transmission(dp8393xState *s)
520 {
521     /* Nothing to do */
522 }
523 
524 static void dp8393x_do_command(dp8393xState *s, uint16_t command)
525 {
526     if ((s->regs[SONIC_CR] & SONIC_CR_RST) && !(command & SONIC_CR_RST)) {
527         s->regs[SONIC_CR] &= ~SONIC_CR_RST;
528         return;
529     }
530 
531     s->regs[SONIC_CR] |= (command & SONIC_CR_MASK);
532 
533     if (command & SONIC_CR_HTX) {
534         dp8393x_do_halt_transmission(s);
535     }
536     if (command & SONIC_CR_TXP) {
537         dp8393x_do_transmit_packets(s);
538     }
539     if (command & SONIC_CR_RXDIS) {
540         dp8393x_do_receiver_disable(s);
541     }
542     if (command & SONIC_CR_RXEN) {
543         dp8393x_do_receiver_enable(s);
544     }
545     if (command & SONIC_CR_STP) {
546         dp8393x_do_stop_timer(s);
547     }
548     if (command & SONIC_CR_ST) {
549         dp8393x_do_start_timer(s);
550     }
551     if (command & SONIC_CR_RST) {
552         dp8393x_do_software_reset(s);
553     }
554     if (command & SONIC_CR_RRRA) {
555         dp8393x_do_read_rra(s);
556         s->regs[SONIC_CR] &= ~SONIC_CR_RRRA;
557     }
558     if (command & SONIC_CR_LCAM) {
559         dp8393x_do_load_cam(s);
560     }
561 }
562 
563 static uint64_t dp8393x_read(void *opaque, hwaddr addr, unsigned int size)
564 {
565     dp8393xState *s = opaque;
566     int reg = addr >> s->it_shift;
567     uint16_t val = 0;
568 
569     switch (reg) {
570     /* Update data before reading it */
571     case SONIC_WT0:
572     case SONIC_WT1:
573         dp8393x_update_wt_regs(s);
574         val = s->regs[reg];
575         break;
576     /* Accept read to some registers only when in reset mode */
577     case SONIC_CAP2:
578     case SONIC_CAP1:
579     case SONIC_CAP0:
580         if (s->regs[SONIC_CR] & SONIC_CR_RST) {
581             val = s->cam[s->regs[SONIC_CEP] & 0xf][SONIC_CAP0 - reg];
582         }
583         break;
584     /* All other registers have no special contraints */
585     default:
586         val = s->regs[reg];
587     }
588 
589     trace_dp8393x_read(reg, reg_names[reg], val, size);
590 
591     return val;
592 }
593 
594 static void dp8393x_write(void *opaque, hwaddr addr, uint64_t val,
595                           unsigned int size)
596 {
597     dp8393xState *s = opaque;
598     int reg = addr >> s->it_shift;
599 
600     trace_dp8393x_write(reg, reg_names[reg], val, size);
601 
602     switch (reg) {
603     /* Command register */
604     case SONIC_CR:
605         dp8393x_do_command(s, val);
606         break;
607     /* Prevent write to read-only registers */
608     case SONIC_CAP2:
609     case SONIC_CAP1:
610     case SONIC_CAP0:
611     case SONIC_SR:
612     case SONIC_MDT:
613         trace_dp8393x_write_invalid(reg);
614         break;
615     /* Accept write to some registers only when in reset mode */
616     case SONIC_DCR:
617         if (s->regs[SONIC_CR] & SONIC_CR_RST) {
618             s->regs[reg] = val & 0xbfff;
619         } else {
620             trace_dp8393x_write_invalid_dcr("DCR");
621         }
622         break;
623     case SONIC_DCR2:
624         if (s->regs[SONIC_CR] & SONIC_CR_RST) {
625             s->regs[reg] = val & 0xf017;
626         } else {
627             trace_dp8393x_write_invalid_dcr("DCR2");
628         }
629         break;
630     /* 12 lower bytes are Read Only */
631     case SONIC_TCR:
632         s->regs[reg] = val & 0xf000;
633         break;
634     /* 9 lower bytes are Read Only */
635     case SONIC_RCR:
636         s->regs[reg] = val & 0xffe0;
637         break;
638     /* Ignore most significant bit */
639     case SONIC_IMR:
640         s->regs[reg] = val & 0x7fff;
641         dp8393x_update_irq(s);
642         break;
643     /* Clear bits by writing 1 to them */
644     case SONIC_ISR:
645         val &= s->regs[reg];
646         s->regs[reg] &= ~val;
647         if (val & SONIC_ISR_RBE) {
648             dp8393x_do_read_rra(s);
649         }
650         dp8393x_update_irq(s);
651         break;
652     /* The guest is required to store aligned pointers here */
653     case SONIC_RSA:
654     case SONIC_REA:
655     case SONIC_RRP:
656     case SONIC_RWP:
657         if (s->regs[SONIC_DCR] & SONIC_DCR_DW) {
658             s->regs[reg] = val & 0xfffc;
659         } else {
660             s->regs[reg] = val & 0xfffe;
661         }
662         break;
663     /* Invert written value for some registers */
664     case SONIC_CRCT:
665     case SONIC_FAET:
666     case SONIC_MPT:
667         s->regs[reg] = val ^ 0xffff;
668         break;
669     /* All other registers have no special contrainst */
670     default:
671         s->regs[reg] = val;
672     }
673 
674     if (reg == SONIC_WT0 || reg == SONIC_WT1) {
675         dp8393x_set_next_tick(s);
676     }
677 }
678 
679 /*
680  * Since .impl.max_access_size is effectively controlled by the it_shift
681  * property, leave it unspecified for now to allow the memory API to
682  * correctly zero extend the 16-bit register values to the access size up to and
683  * including it_shift.
684  */
685 static const MemoryRegionOps dp8393x_ops = {
686     .read = dp8393x_read,
687     .write = dp8393x_write,
688     .impl.min_access_size = 2,
689     .endianness = DEVICE_NATIVE_ENDIAN,
690 };
691 
692 static void dp8393x_watchdog(void *opaque)
693 {
694     dp8393xState *s = opaque;
695 
696     if (s->regs[SONIC_CR] & SONIC_CR_STP) {
697         return;
698     }
699 
700     s->regs[SONIC_WT1] = 0xffff;
701     s->regs[SONIC_WT0] = 0xffff;
702     dp8393x_set_next_tick(s);
703 
704     /* Signal underflow */
705     s->regs[SONIC_ISR] |= SONIC_ISR_TC;
706     dp8393x_update_irq(s);
707 }
708 
709 static bool dp8393x_can_receive(NetClientState *nc)
710 {
711     dp8393xState *s = qemu_get_nic_opaque(nc);
712 
713     return !!(s->regs[SONIC_CR] & SONIC_CR_RXEN);
714 }
715 
716 static int dp8393x_receive_filter(dp8393xState *s, const uint8_t * buf,
717                                   int size)
718 {
719     static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
720     int i;
721 
722     /* Check promiscuous mode */
723     if ((s->regs[SONIC_RCR] & SONIC_RCR_PRO) && (buf[0] & 1) == 0) {
724         return 0;
725     }
726 
727     /* Check multicast packets */
728     if ((s->regs[SONIC_RCR] & SONIC_RCR_AMC) && (buf[0] & 1) == 1) {
729         return SONIC_RCR_MC;
730     }
731 
732     /* Check broadcast */
733     if ((s->regs[SONIC_RCR] & SONIC_RCR_BRD) &&
734          !memcmp(buf, bcast, sizeof(bcast))) {
735         return SONIC_RCR_BC;
736     }
737 
738     /* Check CAM */
739     for (i = 0; i < 16; i++) {
740         if (s->regs[SONIC_CE] & (1 << i)) {
741             /* Entry enabled */
742             if (!memcmp(buf, s->cam[i], sizeof(s->cam[i]))) {
743                 return 0;
744             }
745         }
746     }
747 
748     return -1;
749 }
750 
751 static ssize_t dp8393x_receive(NetClientState *nc, const uint8_t * buf,
752                                size_t pkt_size)
753 {
754     dp8393xState *s = qemu_get_nic_opaque(nc);
755     int packet_type;
756     uint32_t available, address;
757     int rx_len, padded_len;
758     uint32_t checksum;
759     int size;
760 
761     s->regs[SONIC_RCR] &= ~(SONIC_RCR_PRX | SONIC_RCR_LBK | SONIC_RCR_FAER |
762         SONIC_RCR_CRCR | SONIC_RCR_LPKT | SONIC_RCR_BC | SONIC_RCR_MC);
763 
764     if (s->last_rba_is_full) {
765         return pkt_size;
766     }
767 
768     rx_len = pkt_size + sizeof(checksum);
769     if (s->regs[SONIC_DCR] & SONIC_DCR_DW) {
770         padded_len = ((rx_len - 1) | 3) + 1;
771     } else {
772         padded_len = ((rx_len - 1) | 1) + 1;
773     }
774 
775     if (padded_len > dp8393x_rbwc(s) * 2) {
776         trace_dp8393x_receive_oversize(pkt_size);
777         s->regs[SONIC_ISR] |= SONIC_ISR_RBAE;
778         dp8393x_update_irq(s);
779         s->regs[SONIC_RCR] |= SONIC_RCR_LPKT;
780         goto done;
781     }
782 
783     packet_type = dp8393x_receive_filter(s, buf, pkt_size);
784     if (packet_type < 0) {
785         trace_dp8393x_receive_not_netcard();
786         return -1;
787     }
788 
789     /* Check for EOL */
790     if (s->regs[SONIC_LLFA] & SONIC_DESC_EOL) {
791         /* Are we still in resource exhaustion? */
792         s->regs[SONIC_LLFA] = dp8393x_get(s, dp8393x_crda(s), 5);
793         if (s->regs[SONIC_LLFA] & SONIC_DESC_EOL) {
794             /* Still EOL ; stop reception */
795             return -1;
796         }
797         /* Link has been updated by host */
798 
799         /* Clear in_use */
800         dp8393x_put(s, dp8393x_crda(s), 6, 0x0000);
801 
802         /* Move to next descriptor */
803         s->regs[SONIC_CRDA] = s->regs[SONIC_LLFA];
804         s->regs[SONIC_ISR] |= SONIC_ISR_PKTRX;
805     }
806 
807     /* Save current position */
808     s->regs[SONIC_TRBA1] = s->regs[SONIC_CRBA1];
809     s->regs[SONIC_TRBA0] = s->regs[SONIC_CRBA0];
810 
811     /* Calculate the ethernet checksum */
812     checksum = cpu_to_le32(crc32(0, buf, pkt_size));
813 
814     /* Put packet into RBA */
815     trace_dp8393x_receive_packet(dp8393x_crba(s));
816     address = dp8393x_crba(s);
817     address_space_write(&s->as, address, MEMTXATTRS_UNSPECIFIED,
818                         buf, pkt_size);
819     address += pkt_size;
820 
821     /* Put frame checksum into RBA */
822     address_space_write(&s->as, address, MEMTXATTRS_UNSPECIFIED,
823                         &checksum, sizeof(checksum));
824     address += sizeof(checksum);
825 
826     /* Pad short packets to keep pointers aligned */
827     if (rx_len < padded_len) {
828         size = padded_len - rx_len;
829         address_space_write(&s->as, address, MEMTXATTRS_UNSPECIFIED,
830                             "\xFF\xFF\xFF", size);
831         address += size;
832     }
833 
834     s->regs[SONIC_CRBA1] = address >> 16;
835     s->regs[SONIC_CRBA0] = address & 0xffff;
836     available = dp8393x_rbwc(s);
837     available -= padded_len >> 1;
838     s->regs[SONIC_RBWC1] = available >> 16;
839     s->regs[SONIC_RBWC0] = available & 0xffff;
840 
841     /* Update status */
842     if (dp8393x_rbwc(s) < s->regs[SONIC_EOBC]) {
843         s->regs[SONIC_RCR] |= SONIC_RCR_LPKT;
844     }
845     s->regs[SONIC_RCR] |= packet_type;
846     s->regs[SONIC_RCR] |= SONIC_RCR_PRX;
847     if (s->loopback_packet) {
848         s->regs[SONIC_RCR] |= SONIC_RCR_LBK;
849         s->loopback_packet = 0;
850     }
851 
852     /* Write status to memory */
853     trace_dp8393x_receive_write_status(dp8393x_crda(s));
854     dp8393x_put(s, dp8393x_crda(s), 0, s->regs[SONIC_RCR]); /* status */
855     dp8393x_put(s, dp8393x_crda(s), 1, rx_len); /* byte count */
856     dp8393x_put(s, dp8393x_crda(s), 2, s->regs[SONIC_TRBA0]); /* pkt_ptr0 */
857     dp8393x_put(s, dp8393x_crda(s), 3, s->regs[SONIC_TRBA1]); /* pkt_ptr1 */
858     dp8393x_put(s, dp8393x_crda(s), 4, s->regs[SONIC_RSC]); /* seq_no */
859 
860     /* Check link field */
861     s->regs[SONIC_LLFA] = dp8393x_get(s, dp8393x_crda(s), 5);
862     if (s->regs[SONIC_LLFA] & SONIC_DESC_EOL) {
863         /* EOL detected */
864         s->regs[SONIC_ISR] |= SONIC_ISR_RDE;
865     } else {
866         /* Clear in_use */
867         dp8393x_put(s, dp8393x_crda(s), 6, 0x0000);
868 
869         /* Move to next descriptor */
870         s->regs[SONIC_CRDA] = s->regs[SONIC_LLFA];
871         s->regs[SONIC_ISR] |= SONIC_ISR_PKTRX;
872     }
873 
874     dp8393x_update_irq(s);
875 
876     s->regs[SONIC_RSC] = (s->regs[SONIC_RSC] & 0xff00) |
877                          ((s->regs[SONIC_RSC] + 1) & 0x00ff);
878 
879 done:
880 
881     if (s->regs[SONIC_RCR] & SONIC_RCR_LPKT) {
882         if (s->regs[SONIC_RRP] == s->regs[SONIC_RWP]) {
883             /* Stop packet reception */
884             s->last_rba_is_full = true;
885         } else {
886             /* Read next resource */
887             dp8393x_do_read_rra(s);
888         }
889     }
890 
891     return pkt_size;
892 }
893 
894 static void dp8393x_reset(DeviceState *dev)
895 {
896     dp8393xState *s = DP8393X(dev);
897     timer_del(s->watchdog);
898 
899     memset(s->regs, 0, sizeof(s->regs));
900     s->regs[SONIC_SR] = 0x0004; /* only revision recognized by Linux/mips */
901     s->regs[SONIC_CR] = SONIC_CR_RST | SONIC_CR_STP | SONIC_CR_RXDIS;
902     s->regs[SONIC_DCR] &= ~(SONIC_DCR_EXBUS | SONIC_DCR_LBR);
903     s->regs[SONIC_RCR] &= ~(SONIC_RCR_LB0 | SONIC_RCR_LB1 | SONIC_RCR_BRD |
904                             SONIC_RCR_RNT);
905     s->regs[SONIC_TCR] |= SONIC_TCR_NCRS | SONIC_TCR_PTX;
906     s->regs[SONIC_TCR] &= ~SONIC_TCR_BCM;
907     s->regs[SONIC_IMR] = 0;
908     s->regs[SONIC_ISR] = 0;
909     s->regs[SONIC_DCR2] = 0;
910     s->regs[SONIC_EOBC] = 0x02F8;
911     s->regs[SONIC_RSC] = 0;
912     s->regs[SONIC_CE] = 0;
913     s->regs[SONIC_RSC] = 0;
914 
915     /* Network cable is connected */
916     s->regs[SONIC_RCR] |= SONIC_RCR_CRS;
917 
918     dp8393x_update_irq(s);
919 }
920 
921 static NetClientInfo net_dp83932_info = {
922     .type = NET_CLIENT_DRIVER_NIC,
923     .size = sizeof(NICState),
924     .can_receive = dp8393x_can_receive,
925     .receive = dp8393x_receive,
926 };
927 
928 static void dp8393x_instance_init(Object *obj)
929 {
930     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
931     dp8393xState *s = DP8393X(obj);
932 
933     sysbus_init_mmio(sbd, &s->mmio);
934     sysbus_init_irq(sbd, &s->irq);
935 }
936 
937 static void dp8393x_realize(DeviceState *dev, Error **errp)
938 {
939     dp8393xState *s = DP8393X(dev);
940 
941     address_space_init(&s->as, s->dma_mr, "dp8393x");
942     memory_region_init_io(&s->mmio, OBJECT(dev), &dp8393x_ops, s,
943                           "dp8393x-regs", SONIC_REG_COUNT << s->it_shift);
944 
945     s->nic = qemu_new_nic(&net_dp83932_info, &s->conf,
946                           object_get_typename(OBJECT(dev)), dev->id, s);
947     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
948 
949     s->watchdog = timer_new_ns(QEMU_CLOCK_VIRTUAL, dp8393x_watchdog, s);
950 }
951 
952 static const VMStateDescription vmstate_dp8393x = {
953     .name = "dp8393x",
954     .version_id = 1,
955     .minimum_version_id = 1,
956     .fields = (VMStateField []) {
957         VMSTATE_UINT16_2DARRAY(cam, dp8393xState, 16, 3),
958         VMSTATE_UINT16_ARRAY(regs, dp8393xState, SONIC_REG_COUNT),
959         VMSTATE_END_OF_LIST()
960     }
961 };
962 
963 static Property dp8393x_properties[] = {
964     DEFINE_NIC_PROPERTIES(dp8393xState, conf),
965     DEFINE_PROP_LINK("dma_mr", dp8393xState, dma_mr,
966                      TYPE_MEMORY_REGION, MemoryRegion *),
967     DEFINE_PROP_UINT8("it_shift", dp8393xState, it_shift, 0),
968     DEFINE_PROP_BOOL("big_endian", dp8393xState, big_endian, false),
969     DEFINE_PROP_END_OF_LIST(),
970 };
971 
972 static void dp8393x_class_init(ObjectClass *klass, void *data)
973 {
974     DeviceClass *dc = DEVICE_CLASS(klass);
975 
976     set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
977     dc->realize = dp8393x_realize;
978     dc->reset = dp8393x_reset;
979     dc->vmsd = &vmstate_dp8393x;
980     device_class_set_props(dc, dp8393x_properties);
981 }
982 
983 static const TypeInfo dp8393x_info = {
984     .name          = TYPE_DP8393X,
985     .parent        = TYPE_SYS_BUS_DEVICE,
986     .instance_size = sizeof(dp8393xState),
987     .instance_init = dp8393x_instance_init,
988     .class_init    = dp8393x_class_init,
989 };
990 
991 static void dp8393x_register_types(void)
992 {
993     type_register_static(&dp8393x_info);
994 }
995 
996 type_init(dp8393x_register_types)
997