xref: /openbmc/qemu/hw/net/i82596.c (revision 88cd34ee)
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_rw(&address_space_memory, tba,
152                 MEMTXATTRS_UNSPECIFIED, s->tx_buffer, len, 0);
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_rw(&address_space_memory, addr + 8,
176         MEMTXATTRS_UNSPECIFIED, m, ETH_ALEN, 0);
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_rw(&address_space_memory,
194             addr + i * ETH_ALEN, MEMTXATTRS_UNSPECIFIED,
195             multicast_addr, ETH_ALEN, 0);
196         DBG(printf("Add multicast entry " MAC_FMT "\n",
197                     MAC_ARG(multicast_addr)));
198         unsigned mcast_idx = (net_crc32(multicast_addr, ETH_ALEN) &
199                               BITS(7, 2)) >> 2;
200         assert(mcast_idx < 8 * sizeof(s->mult));
201         s->mult[mcast_idx >> 3] |= (1 << (mcast_idx & 7));
202     }
203     trace_i82596_set_multicast(mc_count);
204 }
205 
206 void i82596_set_link_status(NetClientState *nc)
207 {
208     I82596State *d = qemu_get_nic_opaque(nc);
209 
210     d->lnkst = nc->link_down ? 0 : 0x8000;
211 }
212 
213 static void update_scb_status(I82596State *s)
214 {
215     s->scb_status = (s->scb_status & 0xf000)
216         | (s->cu_status << 8) | (s->rx_status << 4);
217     set_uint16(s->scb, s->scb_status);
218 }
219 
220 
221 static void i82596_s_reset(I82596State *s)
222 {
223     trace_i82596_s_reset(s);
224     s->scp = 0;
225     s->scb_status = 0;
226     s->cu_status = CU_IDLE;
227     s->rx_status = RX_SUSPENDED;
228     s->cmd_p = I596_NULL;
229     s->lnkst = 0x8000; /* initial link state: up */
230     s->ca = s->ca_active = 0;
231     s->send_irq = 0;
232 }
233 
234 
235 static void command_loop(I82596State *s)
236 {
237     uint16_t cmd;
238     uint16_t status;
239     uint8_t byte_cnt;
240 
241     DBG(printf("STARTING COMMAND LOOP cmd_p=%08x\n", s->cmd_p));
242 
243     while (s->cmd_p != I596_NULL) {
244         /* set status */
245         status = STAT_B;
246         set_uint16(s->cmd_p, status);
247         status = STAT_C | STAT_OK; /* update, but write later */
248 
249         cmd = get_uint16(s->cmd_p + 2);
250         DBG(printf("Running command %04x at %08x\n", cmd, s->cmd_p));
251 
252         switch (cmd & 0x07) {
253         case CmdNOp:
254             break;
255         case CmdSASetup:
256             set_individual_address(s, s->cmd_p);
257             break;
258         case CmdConfigure:
259             byte_cnt = get_byte(s->cmd_p + 8) & 0x0f;
260             byte_cnt = MAX(byte_cnt, 4);
261             byte_cnt = MIN(byte_cnt, sizeof(s->config));
262             /* copy byte_cnt max. */
263             address_space_rw(&address_space_memory, s->cmd_p + 8,
264                 MEMTXATTRS_UNSPECIFIED, s->config, byte_cnt, 0);
265             /* config byte according to page 35ff */
266             s->config[2] &= 0x82; /* mask valid bits */
267             s->config[2] |= 0x40;
268             s->config[7]  &= 0xf7; /* clear zero bit */
269             assert(I596_NOCRC_INS == 0); /* do CRC insertion */
270             s->config[10] = MAX(s->config[10], 5); /* min frame length */
271             s->config[12] &= 0x40; /* only full duplex field valid */
272             s->config[13] |= 0x3f; /* set ones in byte 13 */
273             break;
274         case CmdTDR:
275             /* get signal LINK */
276             set_uint32(s->cmd_p + 8, s->lnkst);
277             break;
278         case CmdTx:
279             i82596_transmit(s, s->cmd_p);
280             break;
281         case CmdMulticastList:
282             set_multicast_list(s, s->cmd_p);
283             break;
284         case CmdDump:
285         case CmdDiagnose:
286             printf("FIXME Command %d !!\n", cmd & 7);
287             assert(0);
288         }
289 
290         /* update status */
291         set_uint16(s->cmd_p, status);
292 
293         s->cmd_p = get_uint32(s->cmd_p + 4); /* get link address */
294         DBG(printf("NEXT addr would be %08x\n", s->cmd_p));
295         if (s->cmd_p == 0) {
296             s->cmd_p = I596_NULL;
297         }
298 
299         /* Stop when last command of the list. */
300         if (cmd & CMD_EOL) {
301             s->cmd_p = I596_NULL;
302         }
303         /* Suspend after doing cmd? */
304         if (cmd & CMD_SUSP) {
305             s->cu_status = CU_SUSPENDED;
306             printf("FIXME SUSPEND !!\n");
307         }
308         /* Interrupt after doing cmd? */
309         if (cmd & CMD_INTR) {
310             s->scb_status |= SCB_STATUS_CX;
311         } else {
312             s->scb_status &= ~SCB_STATUS_CX;
313         }
314         update_scb_status(s);
315 
316         /* Interrupt after doing cmd? */
317         if (cmd & CMD_INTR) {
318             s->send_irq = 1;
319         }
320 
321         if (s->cu_status != CU_ACTIVE) {
322             break;
323         }
324     }
325     DBG(printf("FINISHED COMMAND LOOP\n"));
326     qemu_flush_queued_packets(qemu_get_queue(s->nic));
327 }
328 
329 static void i82596_flush_queue_timer(void *opaque)
330 {
331     I82596State *s = opaque;
332     if (0) {
333         timer_del(s->flush_queue_timer);
334         qemu_flush_queued_packets(qemu_get_queue(s->nic));
335         timer_mod(s->flush_queue_timer,
336               qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + 1000);
337     }
338 }
339 
340 static void examine_scb(I82596State *s)
341 {
342     uint16_t command, cuc, ruc;
343 
344     /* get the scb command word */
345     command = get_uint16(s->scb + 2);
346     cuc = (command >> 8) & 0x7;
347     ruc = (command >> 4) & 0x7;
348     DBG(printf("MAIN COMMAND %04x  cuc %02x ruc %02x\n", command, cuc, ruc));
349     /* and clear the scb command word */
350     set_uint16(s->scb + 2, 0);
351 
352     if (command & BIT(31))      /* ACK-CX */
353         s->scb_status &= ~SCB_STATUS_CX;
354     if (command & BIT(30))      /*ACK-FR */
355         s->scb_status &= ~SCB_STATUS_FR;
356     if (command & BIT(29))      /*ACK-CNA */
357         s->scb_status &= ~SCB_STATUS_CNA;
358     if (command & BIT(28))      /*ACK-RNR */
359         s->scb_status &= ~SCB_STATUS_RNR;
360 
361     switch (cuc) {
362     case 0:     /* no change */
363         break;
364     case 1:     /* CUC_START */
365         s->cu_status = CU_ACTIVE;
366         break;
367     case 4:     /* CUC_ABORT */
368         s->cu_status = CU_SUSPENDED;
369         s->scb_status |= SCB_STATUS_CNA; /* CU left active state */
370         break;
371     default:
372         printf("WARNING: Unknown CUC %d!\n", cuc);
373     }
374 
375     switch (ruc) {
376     case 0:     /* no change */
377         break;
378     case 1:     /* RX_START */
379     case 2:     /* RX_RESUME */
380         s->rx_status = RX_IDLE;
381         if (USE_TIMER) {
382             timer_mod(s->flush_queue_timer, qemu_clock_get_ms(
383                                 QEMU_CLOCK_VIRTUAL) + 1000);
384         }
385         break;
386     case 3:     /* RX_SUSPEND */
387     case 4:     /* RX_ABORT */
388         s->rx_status = RX_SUSPENDED;
389         s->scb_status |= SCB_STATUS_RNR; /* RU left active state */
390         break;
391     default:
392         printf("WARNING: Unknown RUC %d!\n", ruc);
393     }
394 
395     if (command & 0x80) { /* reset bit set? */
396         i82596_s_reset(s);
397     }
398 
399     /* execute commands from SCBL */
400     if (s->cu_status != CU_SUSPENDED) {
401         if (s->cmd_p == I596_NULL) {
402             s->cmd_p = get_uint32(s->scb + 4);
403         }
404     }
405 
406     /* update scb status */
407     update_scb_status(s);
408 
409     command_loop(s);
410 }
411 
412 static void signal_ca(I82596State *s)
413 {
414     uint32_t iscp = 0;
415 
416     /* trace_i82596_channel_attention(s); */
417     if (s->scp) {
418         /* CA after reset -> do init with new scp. */
419         s->sysbus = get_byte(s->scp + 3); /* big endian */
420         DBG(printf("SYSBUS = %08x\n", s->sysbus));
421         if (((s->sysbus >> 1) & 0x03) != 2) {
422             printf("WARNING: NO LINEAR MODE !!\n");
423         }
424         if ((s->sysbus >> 7)) {
425             printf("WARNING: 32BIT LINMODE IN B-STEPPING NOT SUPPORTED !!\n");
426         }
427         iscp = get_uint32(s->scp + 8);
428         s->scb = get_uint32(iscp + 4);
429         set_byte(iscp + 1, 0); /* clear BUSY flag in iscp */
430         s->scp = 0;
431     }
432 
433     s->ca++;    /* count ca() */
434     if (!s->ca_active) {
435         s->ca_active = 1;
436         while (s->ca)   {
437             examine_scb(s);
438             s->ca--;
439         }
440         s->ca_active = 0;
441     }
442 
443     if (s->send_irq) {
444         s->send_irq = 0;
445         qemu_set_irq(s->irq, 1);
446     }
447 }
448 
449 void i82596_ioport_writew(void *opaque, uint32_t addr, uint32_t val)
450 {
451     I82596State *s = opaque;
452     /* printf("i82596_ioport_writew addr=0x%08x val=0x%04x\n", addr, val); */
453     switch (addr) {
454     case PORT_RESET: /* Reset */
455         i82596_s_reset(s);
456         break;
457     case PORT_ALTSCP:
458         s->scp = val;
459         break;
460     case PORT_CA:
461         signal_ca(s);
462         break;
463     }
464 }
465 
466 uint32_t i82596_ioport_readw(void *opaque, uint32_t addr)
467 {
468     return -1;
469 }
470 
471 void i82596_h_reset(void *opaque)
472 {
473     I82596State *s = opaque;
474 
475     i82596_s_reset(s);
476 }
477 
478 int i82596_can_receive(NetClientState *nc)
479 {
480     I82596State *s = qemu_get_nic_opaque(nc);
481 
482     if (s->rx_status == RX_SUSPENDED) {
483         return 0;
484     }
485 
486     if (!s->lnkst) {
487         return 0;
488     }
489 
490     if (USE_TIMER && !timer_pending(s->flush_queue_timer)) {
491         return 1;
492     }
493 
494     return 1;
495 }
496 
497 #define MIN_BUF_SIZE 60
498 
499 ssize_t i82596_receive(NetClientState *nc, const uint8_t *buf, size_t sz)
500 {
501     I82596State *s = qemu_get_nic_opaque(nc);
502     uint32_t rfd_p;
503     uint32_t rbd;
504     uint16_t is_broadcast = 0;
505     size_t len = sz;
506     uint32_t crc;
507     uint8_t *crc_ptr;
508     uint8_t buf1[MIN_BUF_SIZE + VLAN_HLEN];
509     static const uint8_t broadcast_macaddr[6] = {
510                 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
511 
512     DBG(printf("i82596_receive() start\n"));
513 
514     if (USE_TIMER && timer_pending(s->flush_queue_timer)) {
515         return 0;
516     }
517 
518     /* first check if receiver is enabled */
519     if (s->rx_status == RX_SUSPENDED) {
520         trace_i82596_receive_analysis(">>> Receiving suspended");
521         return -1;
522     }
523 
524     if (!s->lnkst) {
525         trace_i82596_receive_analysis(">>> Link down");
526         return -1;
527     }
528 
529     /* Received frame smaller than configured "min frame len"? */
530     if (sz < s->config[10]) {
531         printf("Received frame too small, %zu vs. %u bytes\n",
532                sz, s->config[10]);
533         return -1;
534     }
535 
536     DBG(printf("Received %lu bytes\n", sz));
537 
538     if (I596_PROMISC) {
539 
540         /* promiscuous: receive all */
541         trace_i82596_receive_analysis(
542                 ">>> packet received in promiscuous mode");
543 
544     } else {
545 
546         if (!memcmp(buf,  broadcast_macaddr, 6)) {
547             /* broadcast address */
548             if (I596_BC_DISABLE) {
549                 trace_i82596_receive_analysis(">>> broadcast packet rejected");
550 
551                 return len;
552             }
553 
554             trace_i82596_receive_analysis(">>> broadcast packet received");
555             is_broadcast = 1;
556 
557         } else if (buf[0] & 0x01) {
558             /* multicast */
559             if (!I596_MC_ALL) {
560                 trace_i82596_receive_analysis(">>> multicast packet rejected");
561 
562                 return len;
563             }
564 
565             int mcast_idx = (net_crc32(buf, ETH_ALEN) & BITS(7, 2)) >> 2;
566             assert(mcast_idx < 8 * sizeof(s->mult));
567 
568             if (!(s->mult[mcast_idx >> 3] & (1 << (mcast_idx & 7)))) {
569                 trace_i82596_receive_analysis(">>> multicast address mismatch");
570 
571                 return len;
572             }
573 
574             trace_i82596_receive_analysis(">>> multicast packet received");
575             is_broadcast = 1;
576 
577         } else if (!memcmp(s->conf.macaddr.a, buf, 6)) {
578 
579             /* match */
580             trace_i82596_receive_analysis(
581                     ">>> physical address matching packet received");
582 
583         } else {
584 
585             trace_i82596_receive_analysis(">>> unknown packet");
586 
587             return len;
588         }
589     }
590 
591     /* if too small buffer, then expand it */
592     if (len < MIN_BUF_SIZE + VLAN_HLEN) {
593         memcpy(buf1, buf, len);
594         memset(buf1 + len, 0, MIN_BUF_SIZE + VLAN_HLEN - len);
595         buf = buf1;
596         if (len < MIN_BUF_SIZE) {
597             len = MIN_BUF_SIZE;
598         }
599     }
600 
601     /* Calculate the ethernet checksum (4 bytes) */
602     len += 4;
603     crc = cpu_to_be32(crc32(~0, buf, sz));
604     crc_ptr = (uint8_t *) &crc;
605 
606     rfd_p = get_uint32(s->scb + 8); /* get Receive Frame Descriptor */
607     assert(rfd_p && rfd_p != I596_NULL);
608 
609     /* get first Receive Buffer Descriptor Address */
610     rbd = get_uint32(rfd_p + 8);
611     assert(rbd && rbd != I596_NULL);
612 
613     trace_i82596_receive_packet(len);
614     /* PRINT_PKTHDR("Receive", buf); */
615 
616     while (len) {
617         uint16_t command, status;
618         uint32_t next_rfd;
619 
620         command = get_uint16(rfd_p + 2);
621         assert(command & CMD_FLEX); /* assert Flex Mode */
622         /* get first Receive Buffer Descriptor Address */
623         rbd = get_uint32(rfd_p + 8);
624         assert(get_uint16(rfd_p + 14) == 0);
625 
626         /* printf("Receive: rfd is %08x\n", rfd_p); */
627 
628         while (len) {
629             uint16_t buffer_size, num;
630             uint32_t rba;
631 
632             /* printf("Receive: rbd is %08x\n", rbd); */
633             buffer_size = get_uint16(rbd + 12);
634             /* printf("buffer_size is 0x%x\n", buffer_size); */
635             assert(buffer_size != 0);
636 
637             num = buffer_size & SIZE_MASK;
638             if (num > len) {
639                 num = len;
640             }
641             rba = get_uint32(rbd + 8);
642             /* printf("rba is 0x%x\n", rba); */
643             address_space_rw(&address_space_memory, rba,
644                 MEMTXATTRS_UNSPECIFIED, (void *)buf, num, 1);
645             rba += num;
646             buf += num;
647             len -= num;
648             if (len == 0) { /* copy crc */
649                 address_space_rw(&address_space_memory, rba - 4,
650                     MEMTXATTRS_UNSPECIFIED, crc_ptr, 4, 1);
651             }
652 
653             num |= 0x4000; /* set F BIT */
654             if (len == 0) {
655                 num |= I596_EOF; /* set EOF BIT */
656             }
657             set_uint16(rbd + 0, num); /* write actual count with flags */
658 
659             /* get next rbd */
660             rbd = get_uint32(rbd + 4);
661             /* printf("Next Receive: rbd is %08x\n", rbd); */
662 
663             if (buffer_size & I596_EOF) /* last entry */
664                 break;
665         }
666 
667         /* Housekeeping, see pg. 18 */
668         next_rfd = get_uint32(rfd_p + 4);
669         set_uint32(next_rfd + 8, rbd);
670 
671         status = STAT_C | STAT_OK | is_broadcast;
672         set_uint16(rfd_p, status);
673 
674         if (command & CMD_SUSP) {  /* suspend after command? */
675             s->rx_status = RX_SUSPENDED;
676             s->scb_status |= SCB_STATUS_RNR; /* RU left active state */
677             break;
678         }
679         if (command & CMD_EOL) /* was it last Frame Descriptor? */
680             break;
681 
682         assert(len == 0);
683     }
684 
685     assert(len == 0);
686 
687     s->scb_status |= SCB_STATUS_FR; /* set "RU finished receiving frame" bit. */
688     update_scb_status(s);
689 
690     /* send IRQ that we received data */
691     qemu_set_irq(s->irq, 1);
692     /* s->send_irq = 1; */
693 
694     if (0) {
695         DBG(printf("Checking:\n"));
696         rfd_p = get_uint32(s->scb + 8); /* get Receive Frame Descriptor */
697         DBG(printf("Next Receive: rfd is %08x\n", rfd_p));
698         rfd_p = get_uint32(rfd_p + 4); /* get Next Receive Frame Descriptor */
699         DBG(printf("Next Receive: rfd is %08x\n", rfd_p));
700         /* get first Receive Buffer Descriptor Address */
701         rbd = get_uint32(rfd_p + 8);
702         DBG(printf("Next Receive: rbd is %08x\n", rbd));
703     }
704 
705     return sz;
706 }
707 
708 
709 const VMStateDescription vmstate_i82596 = {
710     .name = "i82596",
711     .version_id = 1,
712     .minimum_version_id = 1,
713     .fields = (VMStateField[]) {
714         VMSTATE_UINT16(lnkst, I82596State),
715         VMSTATE_TIMER_PTR(flush_queue_timer, I82596State),
716         VMSTATE_END_OF_LIST()
717     }
718 };
719 
720 void i82596_common_init(DeviceState *dev, I82596State *s, NetClientInfo *info)
721 {
722     if (s->conf.macaddr.a[0] == 0) {
723         qemu_macaddr_default_if_unset(&s->conf.macaddr);
724     }
725     s->nic = qemu_new_nic(info, &s->conf, object_get_typename(OBJECT(dev)),
726                 dev->id, s);
727     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
728 
729     if (USE_TIMER) {
730         s->flush_queue_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
731                                     i82596_flush_queue_timer, s);
732     }
733     s->lnkst = 0x8000; /* initial link state: up */
734 }
735