xref: /openbmc/qemu/hw/net/i82596.c (revision 19f70347)
1 /*
2  * QEMU Intel i82596 (Apricot) emulation
3  *
4  * Copyright (c) 2019 Helge Deller <deller@gmx.de>
5  * This work is licensed under the GNU GPL license version 2 or later.
6  *
7  * This software was written to be compatible with the specification:
8  * https://www.intel.com/assets/pdf/general/82596ca.pdf
9  */
10 
11 #include "qemu/osdep.h"
12 #include "qemu/timer.h"
13 #include "net/net.h"
14 #include "net/eth.h"
15 #include "sysemu/sysemu.h"
16 #include "hw/irq.h"
17 #include "hw/qdev-properties.h"
18 #include "migration/vmstate.h"
19 #include "qemu/module.h"
20 #include "trace.h"
21 #include "i82596.h"
22 #include <zlib.h>       /* For crc32 */
23 
24 #if defined(ENABLE_DEBUG)
25 #define DBG(x)          x
26 #else
27 #define DBG(x)          do { } while (0)
28 #endif
29 
30 #define USE_TIMER       0
31 
32 #define BITS(n, m) (((0xffffffffU << (31 - n)) >> (31 - n + m)) << m)
33 
34 #define PKT_BUF_SZ      1536
35 #define MAX_MC_CNT      64
36 
37 #define ISCP_BUSY       0x0001
38 
39 #define I596_NULL       ((uint32_t)0xffffffff)
40 
41 #define SCB_STATUS_CX   0x8000 /* CU finished command with I bit */
42 #define SCB_STATUS_FR   0x4000 /* RU finished receiving a frame */
43 #define SCB_STATUS_CNA  0x2000 /* CU left active state */
44 #define SCB_STATUS_RNR  0x1000 /* RU left active state */
45 
46 #define CU_IDLE         0
47 #define CU_SUSPENDED    1
48 #define CU_ACTIVE       2
49 
50 #define RX_IDLE         0
51 #define RX_SUSPENDED    1
52 #define RX_READY        4
53 
54 #define CMD_EOL         0x8000  /* The last command of the list, stop. */
55 #define CMD_SUSP        0x4000  /* Suspend after doing cmd. */
56 #define CMD_INTR        0x2000  /* Interrupt after doing cmd. */
57 
58 #define CMD_FLEX        0x0008  /* Enable flexible memory model */
59 
60 enum commands {
61         CmdNOp = 0, CmdSASetup = 1, CmdConfigure = 2, CmdMulticastList = 3,
62         CmdTx = 4, CmdTDR = 5, CmdDump = 6, CmdDiagnose = 7
63 };
64 
65 #define STAT_C          0x8000  /* Set to 0 after execution */
66 #define STAT_B          0x4000  /* Command being executed */
67 #define STAT_OK         0x2000  /* Command executed ok */
68 #define STAT_A          0x1000  /* Command aborted */
69 
70 #define I596_EOF        0x8000
71 #define SIZE_MASK       0x3fff
72 
73 #define ETHER_TYPE_LEN 2
74 #define VLAN_TCI_LEN 2
75 #define VLAN_HLEN (ETHER_TYPE_LEN + VLAN_TCI_LEN)
76 
77 /* various flags in the chip config registers */
78 #define I596_PREFETCH   (s->config[0] & 0x80)
79 #define I596_PROMISC    (s->config[8] & 0x01)
80 #define I596_BC_DISABLE (s->config[8] & 0x02) /* broadcast disable */
81 #define I596_NOCRC_INS  (s->config[8] & 0x08)
82 #define I596_CRCINM     (s->config[11] & 0x04) /* CRC appended */
83 #define I596_MC_ALL     (s->config[11] & 0x20)
84 #define I596_MULTIIA    (s->config[13] & 0x40)
85 
86 
87 static uint8_t get_byte(uint32_t addr)
88 {
89     return ldub_phys(&address_space_memory, addr);
90 }
91 
92 static void set_byte(uint32_t addr, uint8_t c)
93 {
94     return stb_phys(&address_space_memory, addr, c);
95 }
96 
97 static uint16_t get_uint16(uint32_t addr)
98 {
99     return lduw_be_phys(&address_space_memory, addr);
100 }
101 
102 static void set_uint16(uint32_t addr, uint16_t w)
103 {
104     return stw_be_phys(&address_space_memory, addr, w);
105 }
106 
107 static uint32_t get_uint32(uint32_t addr)
108 {
109     uint32_t lo = lduw_be_phys(&address_space_memory, addr);
110     uint32_t hi = lduw_be_phys(&address_space_memory, addr + 2);
111     return (hi << 16) | lo;
112 }
113 
114 static void set_uint32(uint32_t addr, uint32_t val)
115 {
116     set_uint16(addr, (uint16_t) val);
117     set_uint16(addr + 2, val >> 16);
118 }
119 
120 
121 struct qemu_ether_header {
122     uint8_t ether_dhost[6];
123     uint8_t ether_shost[6];
124     uint16_t ether_type;
125 };
126 
127 #define PRINT_PKTHDR(txt, BUF) do {                  \
128     struct qemu_ether_header *hdr = (void *)(BUF); \
129     printf(txt ": packet dhost=" MAC_FMT ", shost=" MAC_FMT ", type=0x%04x\n",\
130            MAC_ARG(hdr->ether_dhost), MAC_ARG(hdr->ether_shost),        \
131            be16_to_cpu(hdr->ether_type));       \
132 } while (0)
133 
134 static void i82596_transmit(I82596State *s, uint32_t addr)
135 {
136     uint32_t tdb_p; /* Transmit Buffer Descriptor */
137 
138     /* TODO: Check flexible mode */
139     tdb_p = get_uint32(addr + 8);
140     while (tdb_p != I596_NULL) {
141         uint16_t size, len;
142         uint32_t tba;
143 
144         size = get_uint16(tdb_p);
145         len = size & SIZE_MASK;
146         tba = get_uint32(tdb_p + 8);
147         trace_i82596_transmit(len, tba);
148 
149         if (s->nic && len) {
150             assert(len <= sizeof(s->tx_buffer));
151             address_space_read(&address_space_memory, tba,
152                                MEMTXATTRS_UNSPECIFIED, s->tx_buffer, len);
153             DBG(PRINT_PKTHDR("Send", &s->tx_buffer));
154             DBG(printf("Sending %d bytes\n", len));
155             qemu_send_packet(qemu_get_queue(s->nic), s->tx_buffer, len);
156         }
157 
158         /* was this the last package? */
159         if (size & I596_EOF) {
160             break;
161         }
162 
163         /* get next buffer pointer */
164         tdb_p = get_uint32(tdb_p + 4);
165     }
166 }
167 
168 static void set_individual_address(I82596State *s, uint32_t addr)
169 {
170     NetClientState *nc;
171     uint8_t *m;
172 
173     nc = qemu_get_queue(s->nic);
174     m = s->conf.macaddr.a;
175     address_space_read(&address_space_memory, addr + 8,
176                        MEMTXATTRS_UNSPECIFIED, m, ETH_ALEN);
177     qemu_format_nic_info_str(nc, m);
178     trace_i82596_new_mac(nc->info_str);
179 }
180 
181 static void set_multicast_list(I82596State *s, uint32_t addr)
182 {
183     uint16_t mc_count, i;
184 
185     memset(&s->mult[0], 0, sizeof(s->mult));
186     mc_count = get_uint16(addr + 8) / ETH_ALEN;
187     addr += 10;
188     if (mc_count > MAX_MC_CNT) {
189         mc_count = MAX_MC_CNT;
190     }
191     for (i = 0; i < mc_count; i++) {
192         uint8_t multicast_addr[ETH_ALEN];
193         address_space_read(&address_space_memory, addr + i * ETH_ALEN,
194                            MEMTXATTRS_UNSPECIFIED, multicast_addr, ETH_ALEN);
195         DBG(printf("Add multicast entry " MAC_FMT "\n",
196                     MAC_ARG(multicast_addr)));
197         unsigned mcast_idx = (net_crc32(multicast_addr, ETH_ALEN) &
198                               BITS(7, 2)) >> 2;
199         assert(mcast_idx < 8 * sizeof(s->mult));
200         s->mult[mcast_idx >> 3] |= (1 << (mcast_idx & 7));
201     }
202     trace_i82596_set_multicast(mc_count);
203 }
204 
205 void i82596_set_link_status(NetClientState *nc)
206 {
207     I82596State *d = qemu_get_nic_opaque(nc);
208 
209     d->lnkst = nc->link_down ? 0 : 0x8000;
210 }
211 
212 static void update_scb_status(I82596State *s)
213 {
214     s->scb_status = (s->scb_status & 0xf000)
215         | (s->cu_status << 8) | (s->rx_status << 4);
216     set_uint16(s->scb, s->scb_status);
217 }
218 
219 
220 static void i82596_s_reset(I82596State *s)
221 {
222     trace_i82596_s_reset(s);
223     s->scp = 0;
224     s->scb_status = 0;
225     s->cu_status = CU_IDLE;
226     s->rx_status = RX_SUSPENDED;
227     s->cmd_p = I596_NULL;
228     s->lnkst = 0x8000; /* initial link state: up */
229     s->ca = s->ca_active = 0;
230     s->send_irq = 0;
231 }
232 
233 
234 static void command_loop(I82596State *s)
235 {
236     uint16_t cmd;
237     uint16_t status;
238     uint8_t byte_cnt;
239 
240     DBG(printf("STARTING COMMAND LOOP cmd_p=%08x\n", s->cmd_p));
241 
242     while (s->cmd_p != I596_NULL) {
243         /* set status */
244         status = STAT_B;
245         set_uint16(s->cmd_p, status);
246         status = STAT_C | STAT_OK; /* update, but write later */
247 
248         cmd = get_uint16(s->cmd_p + 2);
249         DBG(printf("Running command %04x at %08x\n", cmd, s->cmd_p));
250 
251         switch (cmd & 0x07) {
252         case CmdNOp:
253             break;
254         case CmdSASetup:
255             set_individual_address(s, s->cmd_p);
256             break;
257         case CmdConfigure:
258             byte_cnt = get_byte(s->cmd_p + 8) & 0x0f;
259             byte_cnt = MAX(byte_cnt, 4);
260             byte_cnt = MIN(byte_cnt, sizeof(s->config));
261             /* copy byte_cnt max. */
262             address_space_read(&address_space_memory, s->cmd_p + 8,
263                                MEMTXATTRS_UNSPECIFIED, s->config, byte_cnt);
264             /* config byte according to page 35ff */
265             s->config[2] &= 0x82; /* mask valid bits */
266             s->config[2] |= 0x40;
267             s->config[7]  &= 0xf7; /* clear zero bit */
268             assert(I596_NOCRC_INS == 0); /* do CRC insertion */
269             s->config[10] = MAX(s->config[10], 5); /* min frame length */
270             s->config[12] &= 0x40; /* only full duplex field valid */
271             s->config[13] |= 0x3f; /* set ones in byte 13 */
272             break;
273         case CmdTDR:
274             /* get signal LINK */
275             set_uint32(s->cmd_p + 8, s->lnkst);
276             break;
277         case CmdTx:
278             i82596_transmit(s, s->cmd_p);
279             break;
280         case CmdMulticastList:
281             set_multicast_list(s, s->cmd_p);
282             break;
283         case CmdDump:
284         case CmdDiagnose:
285             printf("FIXME Command %d !!\n", cmd & 7);
286             assert(0);
287         }
288 
289         /* update status */
290         set_uint16(s->cmd_p, status);
291 
292         s->cmd_p = get_uint32(s->cmd_p + 4); /* get link address */
293         DBG(printf("NEXT addr would be %08x\n", s->cmd_p));
294         if (s->cmd_p == 0) {
295             s->cmd_p = I596_NULL;
296         }
297 
298         /* Stop when last command of the list. */
299         if (cmd & CMD_EOL) {
300             s->cmd_p = I596_NULL;
301         }
302         /* Suspend after doing cmd? */
303         if (cmd & CMD_SUSP) {
304             s->cu_status = CU_SUSPENDED;
305             printf("FIXME SUSPEND !!\n");
306         }
307         /* Interrupt after doing cmd? */
308         if (cmd & CMD_INTR) {
309             s->scb_status |= SCB_STATUS_CX;
310         } else {
311             s->scb_status &= ~SCB_STATUS_CX;
312         }
313         update_scb_status(s);
314 
315         /* Interrupt after doing cmd? */
316         if (cmd & CMD_INTR) {
317             s->send_irq = 1;
318         }
319 
320         if (s->cu_status != CU_ACTIVE) {
321             break;
322         }
323     }
324     DBG(printf("FINISHED COMMAND LOOP\n"));
325     qemu_flush_queued_packets(qemu_get_queue(s->nic));
326 }
327 
328 static void i82596_flush_queue_timer(void *opaque)
329 {
330     I82596State *s = opaque;
331     if (0) {
332         timer_del(s->flush_queue_timer);
333         qemu_flush_queued_packets(qemu_get_queue(s->nic));
334         timer_mod(s->flush_queue_timer,
335               qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + 1000);
336     }
337 }
338 
339 static void examine_scb(I82596State *s)
340 {
341     uint16_t command, cuc, ruc;
342 
343     /* get the scb command word */
344     command = get_uint16(s->scb + 2);
345     cuc = (command >> 8) & 0x7;
346     ruc = (command >> 4) & 0x7;
347     DBG(printf("MAIN COMMAND %04x  cuc %02x ruc %02x\n", command, cuc, ruc));
348     /* and clear the scb command word */
349     set_uint16(s->scb + 2, 0);
350 
351     if (command & BIT(31))      /* ACK-CX */
352         s->scb_status &= ~SCB_STATUS_CX;
353     if (command & BIT(30))      /*ACK-FR */
354         s->scb_status &= ~SCB_STATUS_FR;
355     if (command & BIT(29))      /*ACK-CNA */
356         s->scb_status &= ~SCB_STATUS_CNA;
357     if (command & BIT(28))      /*ACK-RNR */
358         s->scb_status &= ~SCB_STATUS_RNR;
359 
360     switch (cuc) {
361     case 0:     /* no change */
362         break;
363     case 1:     /* CUC_START */
364         s->cu_status = CU_ACTIVE;
365         break;
366     case 4:     /* CUC_ABORT */
367         s->cu_status = CU_SUSPENDED;
368         s->scb_status |= SCB_STATUS_CNA; /* CU left active state */
369         break;
370     default:
371         printf("WARNING: Unknown CUC %d!\n", cuc);
372     }
373 
374     switch (ruc) {
375     case 0:     /* no change */
376         break;
377     case 1:     /* RX_START */
378     case 2:     /* RX_RESUME */
379         s->rx_status = RX_IDLE;
380         if (USE_TIMER) {
381             timer_mod(s->flush_queue_timer, qemu_clock_get_ms(
382                                 QEMU_CLOCK_VIRTUAL) + 1000);
383         }
384         break;
385     case 3:     /* RX_SUSPEND */
386     case 4:     /* RX_ABORT */
387         s->rx_status = RX_SUSPENDED;
388         s->scb_status |= SCB_STATUS_RNR; /* RU left active state */
389         break;
390     default:
391         printf("WARNING: Unknown RUC %d!\n", ruc);
392     }
393 
394     if (command & 0x80) { /* reset bit set? */
395         i82596_s_reset(s);
396     }
397 
398     /* execute commands from SCBL */
399     if (s->cu_status != CU_SUSPENDED) {
400         if (s->cmd_p == I596_NULL) {
401             s->cmd_p = get_uint32(s->scb + 4);
402         }
403     }
404 
405     /* update scb status */
406     update_scb_status(s);
407 
408     command_loop(s);
409 }
410 
411 static void signal_ca(I82596State *s)
412 {
413     uint32_t iscp = 0;
414 
415     /* trace_i82596_channel_attention(s); */
416     if (s->scp) {
417         /* CA after reset -> do init with new scp. */
418         s->sysbus = get_byte(s->scp + 3); /* big endian */
419         DBG(printf("SYSBUS = %08x\n", s->sysbus));
420         if (((s->sysbus >> 1) & 0x03) != 2) {
421             printf("WARNING: NO LINEAR MODE !!\n");
422         }
423         if ((s->sysbus >> 7)) {
424             printf("WARNING: 32BIT LINMODE IN B-STEPPING NOT SUPPORTED !!\n");
425         }
426         iscp = get_uint32(s->scp + 8);
427         s->scb = get_uint32(iscp + 4);
428         set_byte(iscp + 1, 0); /* clear BUSY flag in iscp */
429         s->scp = 0;
430     }
431 
432     s->ca++;    /* count ca() */
433     if (!s->ca_active) {
434         s->ca_active = 1;
435         while (s->ca)   {
436             examine_scb(s);
437             s->ca--;
438         }
439         s->ca_active = 0;
440     }
441 
442     if (s->send_irq) {
443         s->send_irq = 0;
444         qemu_set_irq(s->irq, 1);
445     }
446 }
447 
448 void i82596_ioport_writew(void *opaque, uint32_t addr, uint32_t val)
449 {
450     I82596State *s = opaque;
451     /* printf("i82596_ioport_writew addr=0x%08x val=0x%04x\n", addr, val); */
452     switch (addr) {
453     case PORT_RESET: /* Reset */
454         i82596_s_reset(s);
455         break;
456     case PORT_ALTSCP:
457         s->scp = val;
458         break;
459     case PORT_CA:
460         signal_ca(s);
461         break;
462     }
463 }
464 
465 uint32_t i82596_ioport_readw(void *opaque, uint32_t addr)
466 {
467     return -1;
468 }
469 
470 void i82596_h_reset(void *opaque)
471 {
472     I82596State *s = opaque;
473 
474     i82596_s_reset(s);
475 }
476 
477 int i82596_can_receive(NetClientState *nc)
478 {
479     I82596State *s = qemu_get_nic_opaque(nc);
480 
481     if (s->rx_status == RX_SUSPENDED) {
482         return 0;
483     }
484 
485     if (!s->lnkst) {
486         return 0;
487     }
488 
489     if (USE_TIMER && !timer_pending(s->flush_queue_timer)) {
490         return 1;
491     }
492 
493     return 1;
494 }
495 
496 #define MIN_BUF_SIZE 60
497 
498 ssize_t i82596_receive(NetClientState *nc, const uint8_t *buf, size_t sz)
499 {
500     I82596State *s = qemu_get_nic_opaque(nc);
501     uint32_t rfd_p;
502     uint32_t rbd;
503     uint16_t is_broadcast = 0;
504     size_t len = sz;
505     uint32_t crc;
506     uint8_t *crc_ptr;
507     uint8_t buf1[MIN_BUF_SIZE + VLAN_HLEN];
508     static const uint8_t broadcast_macaddr[6] = {
509                 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
510 
511     DBG(printf("i82596_receive() start\n"));
512 
513     if (USE_TIMER && timer_pending(s->flush_queue_timer)) {
514         return 0;
515     }
516 
517     /* first check if receiver is enabled */
518     if (s->rx_status == RX_SUSPENDED) {
519         trace_i82596_receive_analysis(">>> Receiving suspended");
520         return -1;
521     }
522 
523     if (!s->lnkst) {
524         trace_i82596_receive_analysis(">>> Link down");
525         return -1;
526     }
527 
528     /* Received frame smaller than configured "min frame len"? */
529     if (sz < s->config[10]) {
530         printf("Received frame too small, %zu vs. %u bytes\n",
531                sz, s->config[10]);
532         return -1;
533     }
534 
535     DBG(printf("Received %lu bytes\n", sz));
536 
537     if (I596_PROMISC) {
538 
539         /* promiscuous: receive all */
540         trace_i82596_receive_analysis(
541                 ">>> packet received in promiscuous mode");
542 
543     } else {
544 
545         if (!memcmp(buf,  broadcast_macaddr, 6)) {
546             /* broadcast address */
547             if (I596_BC_DISABLE) {
548                 trace_i82596_receive_analysis(">>> broadcast packet rejected");
549 
550                 return len;
551             }
552 
553             trace_i82596_receive_analysis(">>> broadcast packet received");
554             is_broadcast = 1;
555 
556         } else if (buf[0] & 0x01) {
557             /* multicast */
558             if (!I596_MC_ALL) {
559                 trace_i82596_receive_analysis(">>> multicast packet rejected");
560 
561                 return len;
562             }
563 
564             int mcast_idx = (net_crc32(buf, ETH_ALEN) & BITS(7, 2)) >> 2;
565             assert(mcast_idx < 8 * sizeof(s->mult));
566 
567             if (!(s->mult[mcast_idx >> 3] & (1 << (mcast_idx & 7)))) {
568                 trace_i82596_receive_analysis(">>> multicast address mismatch");
569 
570                 return len;
571             }
572 
573             trace_i82596_receive_analysis(">>> multicast packet received");
574             is_broadcast = 1;
575 
576         } else if (!memcmp(s->conf.macaddr.a, buf, 6)) {
577 
578             /* match */
579             trace_i82596_receive_analysis(
580                     ">>> physical address matching packet received");
581 
582         } else {
583 
584             trace_i82596_receive_analysis(">>> unknown packet");
585 
586             return len;
587         }
588     }
589 
590     /* if too small buffer, then expand it */
591     if (len < MIN_BUF_SIZE + VLAN_HLEN) {
592         memcpy(buf1, buf, len);
593         memset(buf1 + len, 0, MIN_BUF_SIZE + VLAN_HLEN - len);
594         buf = buf1;
595         if (len < MIN_BUF_SIZE) {
596             len = MIN_BUF_SIZE;
597         }
598     }
599 
600     /* Calculate the ethernet checksum (4 bytes) */
601     len += 4;
602     crc = cpu_to_be32(crc32(~0, buf, sz));
603     crc_ptr = (uint8_t *) &crc;
604 
605     rfd_p = get_uint32(s->scb + 8); /* get Receive Frame Descriptor */
606     assert(rfd_p && rfd_p != I596_NULL);
607 
608     /* get first Receive Buffer Descriptor Address */
609     rbd = get_uint32(rfd_p + 8);
610     assert(rbd && rbd != I596_NULL);
611 
612     trace_i82596_receive_packet(len);
613     /* PRINT_PKTHDR("Receive", buf); */
614 
615     while (len) {
616         uint16_t command, status;
617         uint32_t next_rfd;
618 
619         command = get_uint16(rfd_p + 2);
620         assert(command & CMD_FLEX); /* assert Flex Mode */
621         /* get first Receive Buffer Descriptor Address */
622         rbd = get_uint32(rfd_p + 8);
623         assert(get_uint16(rfd_p + 14) == 0);
624 
625         /* printf("Receive: rfd is %08x\n", rfd_p); */
626 
627         while (len) {
628             uint16_t buffer_size, num;
629             uint32_t rba;
630 
631             /* printf("Receive: rbd is %08x\n", rbd); */
632             buffer_size = get_uint16(rbd + 12);
633             /* printf("buffer_size is 0x%x\n", buffer_size); */
634             assert(buffer_size != 0);
635 
636             num = buffer_size & SIZE_MASK;
637             if (num > len) {
638                 num = len;
639             }
640             rba = get_uint32(rbd + 8);
641             /* printf("rba is 0x%x\n", rba); */
642             address_space_write(&address_space_memory, rba,
643                                 MEMTXATTRS_UNSPECIFIED, buf, num);
644             rba += num;
645             buf += num;
646             len -= num;
647             if (len == 0) { /* copy crc */
648                 address_space_write(&address_space_memory, rba - 4,
649                                     MEMTXATTRS_UNSPECIFIED, crc_ptr, 4);
650             }
651 
652             num |= 0x4000; /* set F BIT */
653             if (len == 0) {
654                 num |= I596_EOF; /* set EOF BIT */
655             }
656             set_uint16(rbd + 0, num); /* write actual count with flags */
657 
658             /* get next rbd */
659             rbd = get_uint32(rbd + 4);
660             /* printf("Next Receive: rbd is %08x\n", rbd); */
661 
662             if (buffer_size & I596_EOF) /* last entry */
663                 break;
664         }
665 
666         /* Housekeeping, see pg. 18 */
667         next_rfd = get_uint32(rfd_p + 4);
668         set_uint32(next_rfd + 8, rbd);
669 
670         status = STAT_C | STAT_OK | is_broadcast;
671         set_uint16(rfd_p, status);
672 
673         if (command & CMD_SUSP) {  /* suspend after command? */
674             s->rx_status = RX_SUSPENDED;
675             s->scb_status |= SCB_STATUS_RNR; /* RU left active state */
676             break;
677         }
678         if (command & CMD_EOL) /* was it last Frame Descriptor? */
679             break;
680 
681         assert(len == 0);
682     }
683 
684     assert(len == 0);
685 
686     s->scb_status |= SCB_STATUS_FR; /* set "RU finished receiving frame" bit. */
687     update_scb_status(s);
688 
689     /* send IRQ that we received data */
690     qemu_set_irq(s->irq, 1);
691     /* s->send_irq = 1; */
692 
693     if (0) {
694         DBG(printf("Checking:\n"));
695         rfd_p = get_uint32(s->scb + 8); /* get Receive Frame Descriptor */
696         DBG(printf("Next Receive: rfd is %08x\n", rfd_p));
697         rfd_p = get_uint32(rfd_p + 4); /* get Next Receive Frame Descriptor */
698         DBG(printf("Next Receive: rfd is %08x\n", rfd_p));
699         /* get first Receive Buffer Descriptor Address */
700         rbd = get_uint32(rfd_p + 8);
701         DBG(printf("Next Receive: rbd is %08x\n", rbd));
702     }
703 
704     return sz;
705 }
706 
707 
708 const VMStateDescription vmstate_i82596 = {
709     .name = "i82596",
710     .version_id = 1,
711     .minimum_version_id = 1,
712     .fields = (VMStateField[]) {
713         VMSTATE_UINT16(lnkst, I82596State),
714         VMSTATE_TIMER_PTR(flush_queue_timer, I82596State),
715         VMSTATE_END_OF_LIST()
716     }
717 };
718 
719 void i82596_common_init(DeviceState *dev, I82596State *s, NetClientInfo *info)
720 {
721     if (s->conf.macaddr.a[0] == 0) {
722         qemu_macaddr_default_if_unset(&s->conf.macaddr);
723     }
724     s->nic = qemu_new_nic(info, &s->conf, object_get_typename(OBJECT(dev)),
725                 dev->id, s);
726     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
727 
728     if (USE_TIMER) {
729         s->flush_queue_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
730                                     i82596_flush_queue_timer, s);
731     }
732     s->lnkst = 0x8000; /* initial link state: up */
733 }
734