xref: /openbmc/qemu/hw/net/mcf_fec.c (revision 9944d320)
1 /*
2  * ColdFire Fast Ethernet Controller emulation.
3  *
4  * Copyright (c) 2007 CodeSourcery.
5  *
6  * This code is licensed under the GPL
7  */
8 #include "hw/hw.h"
9 #include "net/net.h"
10 #include "hw/m68k/mcf.h"
11 /* For crc32 */
12 #include <zlib.h>
13 #include "exec/address-spaces.h"
14 
15 //#define DEBUG_FEC 1
16 
17 #ifdef DEBUG_FEC
18 #define DPRINTF(fmt, ...) \
19 do { printf("mcf_fec: " fmt , ## __VA_ARGS__); } while (0)
20 #else
21 #define DPRINTF(fmt, ...) do {} while(0)
22 #endif
23 
24 #define FEC_MAX_FRAME_SIZE 2032
25 
26 typedef struct {
27     MemoryRegion *sysmem;
28     MemoryRegion iomem;
29     qemu_irq *irq;
30     NICState *nic;
31     NICConf conf;
32     uint32_t irq_state;
33     uint32_t eir;
34     uint32_t eimr;
35     int rx_enabled;
36     uint32_t rx_descriptor;
37     uint32_t tx_descriptor;
38     uint32_t ecr;
39     uint32_t mmfr;
40     uint32_t mscr;
41     uint32_t rcr;
42     uint32_t tcr;
43     uint32_t tfwr;
44     uint32_t rfsr;
45     uint32_t erdsr;
46     uint32_t etdsr;
47     uint32_t emrbr;
48 } mcf_fec_state;
49 
50 #define FEC_INT_HB   0x80000000
51 #define FEC_INT_BABR 0x40000000
52 #define FEC_INT_BABT 0x20000000
53 #define FEC_INT_GRA  0x10000000
54 #define FEC_INT_TXF  0x08000000
55 #define FEC_INT_TXB  0x04000000
56 #define FEC_INT_RXF  0x02000000
57 #define FEC_INT_RXB  0x01000000
58 #define FEC_INT_MII  0x00800000
59 #define FEC_INT_EB   0x00400000
60 #define FEC_INT_LC   0x00200000
61 #define FEC_INT_RL   0x00100000
62 #define FEC_INT_UN   0x00080000
63 
64 #define FEC_EN      2
65 #define FEC_RESET   1
66 
67 /* Map interrupt flags onto IRQ lines.  */
68 #define FEC_NUM_IRQ 13
69 static const uint32_t mcf_fec_irq_map[FEC_NUM_IRQ] = {
70     FEC_INT_TXF,
71     FEC_INT_TXB,
72     FEC_INT_UN,
73     FEC_INT_RL,
74     FEC_INT_RXF,
75     FEC_INT_RXB,
76     FEC_INT_MII,
77     FEC_INT_LC,
78     FEC_INT_HB,
79     FEC_INT_GRA,
80     FEC_INT_EB,
81     FEC_INT_BABT,
82     FEC_INT_BABR
83 };
84 
85 /* Buffer Descriptor.  */
86 typedef struct {
87     uint16_t flags;
88     uint16_t length;
89     uint32_t data;
90 } mcf_fec_bd;
91 
92 #define FEC_BD_R    0x8000
93 #define FEC_BD_E    0x8000
94 #define FEC_BD_O1   0x4000
95 #define FEC_BD_W    0x2000
96 #define FEC_BD_O2   0x1000
97 #define FEC_BD_L    0x0800
98 #define FEC_BD_TC   0x0400
99 #define FEC_BD_ABC  0x0200
100 #define FEC_BD_M    0x0100
101 #define FEC_BD_BC   0x0080
102 #define FEC_BD_MC   0x0040
103 #define FEC_BD_LG   0x0020
104 #define FEC_BD_NO   0x0010
105 #define FEC_BD_CR   0x0004
106 #define FEC_BD_OV   0x0002
107 #define FEC_BD_TR   0x0001
108 
109 static void mcf_fec_read_bd(mcf_fec_bd *bd, uint32_t addr)
110 {
111     cpu_physical_memory_read(addr, (uint8_t *)bd, sizeof(*bd));
112     be16_to_cpus(&bd->flags);
113     be16_to_cpus(&bd->length);
114     be32_to_cpus(&bd->data);
115 }
116 
117 static void mcf_fec_write_bd(mcf_fec_bd *bd, uint32_t addr)
118 {
119     mcf_fec_bd tmp;
120     tmp.flags = cpu_to_be16(bd->flags);
121     tmp.length = cpu_to_be16(bd->length);
122     tmp.data = cpu_to_be32(bd->data);
123     cpu_physical_memory_write(addr, (uint8_t *)&tmp, sizeof(tmp));
124 }
125 
126 static void mcf_fec_update(mcf_fec_state *s)
127 {
128     uint32_t active;
129     uint32_t changed;
130     uint32_t mask;
131     int i;
132 
133     active = s->eir & s->eimr;
134     changed = active ^s->irq_state;
135     for (i = 0; i < FEC_NUM_IRQ; i++) {
136         mask = mcf_fec_irq_map[i];
137         if (changed & mask) {
138             DPRINTF("IRQ %d = %d\n", i, (active & mask) != 0);
139             qemu_set_irq(s->irq[i], (active & mask) != 0);
140         }
141     }
142     s->irq_state = active;
143 }
144 
145 static void mcf_fec_do_tx(mcf_fec_state *s)
146 {
147     uint32_t addr;
148     mcf_fec_bd bd;
149     int frame_size;
150     int len;
151     uint8_t frame[FEC_MAX_FRAME_SIZE];
152     uint8_t *ptr;
153 
154     DPRINTF("do_tx\n");
155     ptr = frame;
156     frame_size = 0;
157     addr = s->tx_descriptor;
158     while (1) {
159         mcf_fec_read_bd(&bd, addr);
160         DPRINTF("tx_bd %x flags %04x len %d data %08x\n",
161                 addr, bd.flags, bd.length, bd.data);
162         if ((bd.flags & FEC_BD_R) == 0) {
163             /* Run out of descriptors to transmit.  */
164             break;
165         }
166         len = bd.length;
167         if (frame_size + len > FEC_MAX_FRAME_SIZE) {
168             len = FEC_MAX_FRAME_SIZE - frame_size;
169             s->eir |= FEC_INT_BABT;
170         }
171         cpu_physical_memory_read(bd.data, ptr, len);
172         ptr += len;
173         frame_size += len;
174         if (bd.flags & FEC_BD_L) {
175             /* Last buffer in frame.  */
176             DPRINTF("Sending packet\n");
177             qemu_send_packet(qemu_get_queue(s->nic), frame, len);
178             ptr = frame;
179             frame_size = 0;
180             s->eir |= FEC_INT_TXF;
181         }
182         s->eir |= FEC_INT_TXB;
183         bd.flags &= ~FEC_BD_R;
184         /* Write back the modified descriptor.  */
185         mcf_fec_write_bd(&bd, addr);
186         /* Advance to the next descriptor.  */
187         if ((bd.flags & FEC_BD_W) != 0) {
188             addr = s->etdsr;
189         } else {
190             addr += 8;
191         }
192     }
193     s->tx_descriptor = addr;
194 }
195 
196 static void mcf_fec_enable_rx(mcf_fec_state *s)
197 {
198     mcf_fec_bd bd;
199 
200     mcf_fec_read_bd(&bd, s->rx_descriptor);
201     s->rx_enabled = ((bd.flags & FEC_BD_E) != 0);
202     if (!s->rx_enabled)
203         DPRINTF("RX buffer full\n");
204 }
205 
206 static void mcf_fec_reset(mcf_fec_state *s)
207 {
208     s->eir = 0;
209     s->eimr = 0;
210     s->rx_enabled = 0;
211     s->ecr = 0;
212     s->mscr = 0;
213     s->rcr = 0x05ee0001;
214     s->tcr = 0;
215     s->tfwr = 0;
216     s->rfsr = 0x500;
217 }
218 
219 static uint64_t mcf_fec_read(void *opaque, hwaddr addr,
220                              unsigned size)
221 {
222     mcf_fec_state *s = (mcf_fec_state *)opaque;
223     switch (addr & 0x3ff) {
224     case 0x004: return s->eir;
225     case 0x008: return s->eimr;
226     case 0x010: return s->rx_enabled ? (1 << 24) : 0; /* RDAR */
227     case 0x014: return 0; /* TDAR */
228     case 0x024: return s->ecr;
229     case 0x040: return s->mmfr;
230     case 0x044: return s->mscr;
231     case 0x064: return 0; /* MIBC */
232     case 0x084: return s->rcr;
233     case 0x0c4: return s->tcr;
234     case 0x0e4: /* PALR */
235         return (s->conf.macaddr.a[0] << 24) | (s->conf.macaddr.a[1] << 16)
236               | (s->conf.macaddr.a[2] << 8) | s->conf.macaddr.a[3];
237         break;
238     case 0x0e8: /* PAUR */
239         return (s->conf.macaddr.a[4] << 24) | (s->conf.macaddr.a[5] << 16) | 0x8808;
240     case 0x0ec: return 0x10000; /* OPD */
241     case 0x118: return 0;
242     case 0x11c: return 0;
243     case 0x120: return 0;
244     case 0x124: return 0;
245     case 0x144: return s->tfwr;
246     case 0x14c: return 0x600;
247     case 0x150: return s->rfsr;
248     case 0x180: return s->erdsr;
249     case 0x184: return s->etdsr;
250     case 0x188: return s->emrbr;
251     default:
252         hw_error("mcf_fec_read: Bad address 0x%x\n", (int)addr);
253         return 0;
254     }
255 }
256 
257 static void mcf_fec_write(void *opaque, hwaddr addr,
258                           uint64_t value, unsigned size)
259 {
260     mcf_fec_state *s = (mcf_fec_state *)opaque;
261     switch (addr & 0x3ff) {
262     case 0x004:
263         s->eir &= ~value;
264         break;
265     case 0x008:
266         s->eimr = value;
267         break;
268     case 0x010: /* RDAR */
269         if ((s->ecr & FEC_EN) && !s->rx_enabled) {
270             DPRINTF("RX enable\n");
271             mcf_fec_enable_rx(s);
272         }
273         break;
274     case 0x014: /* TDAR */
275         if (s->ecr & FEC_EN) {
276             mcf_fec_do_tx(s);
277         }
278         break;
279     case 0x024:
280         s->ecr = value;
281         if (value & FEC_RESET) {
282             DPRINTF("Reset\n");
283             mcf_fec_reset(s);
284         }
285         if ((s->ecr & FEC_EN) == 0) {
286             s->rx_enabled = 0;
287         }
288         break;
289     case 0x040:
290         /* TODO: Implement MII.  */
291         s->mmfr = value;
292         break;
293     case 0x044:
294         s->mscr = value & 0xfe;
295         break;
296     case 0x064:
297         /* TODO: Implement MIB.  */
298         break;
299     case 0x084:
300         s->rcr = value & 0x07ff003f;
301         /* TODO: Implement LOOP mode.  */
302         break;
303     case 0x0c4: /* TCR */
304         /* We transmit immediately, so raise GRA immediately.  */
305         s->tcr = value;
306         if (value & 1)
307             s->eir |= FEC_INT_GRA;
308         break;
309     case 0x0e4: /* PALR */
310         s->conf.macaddr.a[0] = value >> 24;
311         s->conf.macaddr.a[1] = value >> 16;
312         s->conf.macaddr.a[2] = value >> 8;
313         s->conf.macaddr.a[3] = value;
314         break;
315     case 0x0e8: /* PAUR */
316         s->conf.macaddr.a[4] = value >> 24;
317         s->conf.macaddr.a[5] = value >> 16;
318         break;
319     case 0x0ec:
320         /* OPD */
321         break;
322     case 0x118:
323     case 0x11c:
324     case 0x120:
325     case 0x124:
326         /* TODO: implement MAC hash filtering.  */
327         break;
328     case 0x144:
329         s->tfwr = value & 3;
330         break;
331     case 0x14c:
332         /* FRBR writes ignored.  */
333         break;
334     case 0x150:
335         s->rfsr = (value & 0x3fc) | 0x400;
336         break;
337     case 0x180:
338         s->erdsr = value & ~3;
339         s->rx_descriptor = s->erdsr;
340         break;
341     case 0x184:
342         s->etdsr = value & ~3;
343         s->tx_descriptor = s->etdsr;
344         break;
345     case 0x188:
346         s->emrbr = value & 0x7f0;
347         break;
348     default:
349         hw_error("mcf_fec_write Bad address 0x%x\n", (int)addr);
350     }
351     mcf_fec_update(s);
352 }
353 
354 static int mcf_fec_can_receive(NetClientState *nc)
355 {
356     mcf_fec_state *s = qemu_get_nic_opaque(nc);
357     return s->rx_enabled;
358 }
359 
360 static ssize_t mcf_fec_receive(NetClientState *nc, const uint8_t *buf, size_t size)
361 {
362     mcf_fec_state *s = qemu_get_nic_opaque(nc);
363     mcf_fec_bd bd;
364     uint32_t flags = 0;
365     uint32_t addr;
366     uint32_t crc;
367     uint32_t buf_addr;
368     uint8_t *crc_ptr;
369     unsigned int buf_len;
370 
371     DPRINTF("do_rx len %d\n", size);
372     if (!s->rx_enabled) {
373         fprintf(stderr, "mcf_fec_receive: Unexpected packet\n");
374     }
375     /* 4 bytes for the CRC.  */
376     size += 4;
377     crc = cpu_to_be32(crc32(~0, buf, size));
378     crc_ptr = (uint8_t *)&crc;
379     /* Huge frames are truncted.  */
380     if (size > FEC_MAX_FRAME_SIZE) {
381         size = FEC_MAX_FRAME_SIZE;
382         flags |= FEC_BD_TR | FEC_BD_LG;
383     }
384     /* Frames larger than the user limit just set error flags.  */
385     if (size > (s->rcr >> 16)) {
386         flags |= FEC_BD_LG;
387     }
388     addr = s->rx_descriptor;
389     while (size > 0) {
390         mcf_fec_read_bd(&bd, addr);
391         if ((bd.flags & FEC_BD_E) == 0) {
392             /* No descriptors available.  Bail out.  */
393             /* FIXME: This is wrong.  We should probably either save the
394                remainder for when more RX buffers are available, or
395                flag an error.  */
396             fprintf(stderr, "mcf_fec: Lost end of frame\n");
397             break;
398         }
399         buf_len = (size <= s->emrbr) ? size: s->emrbr;
400         bd.length = buf_len;
401         size -= buf_len;
402         DPRINTF("rx_bd %x length %d\n", addr, bd.length);
403         /* The last 4 bytes are the CRC.  */
404         if (size < 4)
405             buf_len += size - 4;
406         buf_addr = bd.data;
407         cpu_physical_memory_write(buf_addr, buf, buf_len);
408         buf += buf_len;
409         if (size < 4) {
410             cpu_physical_memory_write(buf_addr + buf_len, crc_ptr, 4 - size);
411             crc_ptr += 4 - size;
412         }
413         bd.flags &= ~FEC_BD_E;
414         if (size == 0) {
415             /* Last buffer in frame.  */
416             bd.flags |= flags | FEC_BD_L;
417             DPRINTF("rx frame flags %04x\n", bd.flags);
418             s->eir |= FEC_INT_RXF;
419         } else {
420             s->eir |= FEC_INT_RXB;
421         }
422         mcf_fec_write_bd(&bd, addr);
423         /* Advance to the next descriptor.  */
424         if ((bd.flags & FEC_BD_W) != 0) {
425             addr = s->erdsr;
426         } else {
427             addr += 8;
428         }
429     }
430     s->rx_descriptor = addr;
431     mcf_fec_enable_rx(s);
432     mcf_fec_update(s);
433     return size;
434 }
435 
436 static const MemoryRegionOps mcf_fec_ops = {
437     .read = mcf_fec_read,
438     .write = mcf_fec_write,
439     .endianness = DEVICE_NATIVE_ENDIAN,
440 };
441 
442 static void mcf_fec_cleanup(NetClientState *nc)
443 {
444     mcf_fec_state *s = qemu_get_nic_opaque(nc);
445 
446     memory_region_del_subregion(s->sysmem, &s->iomem);
447     memory_region_destroy(&s->iomem);
448 
449     g_free(s);
450 }
451 
452 static NetClientInfo net_mcf_fec_info = {
453     .type = NET_CLIENT_OPTIONS_KIND_NIC,
454     .size = sizeof(NICState),
455     .can_receive = mcf_fec_can_receive,
456     .receive = mcf_fec_receive,
457     .cleanup = mcf_fec_cleanup,
458 };
459 
460 void mcf_fec_init(MemoryRegion *sysmem, NICInfo *nd,
461                   hwaddr base, qemu_irq *irq)
462 {
463     mcf_fec_state *s;
464 
465     qemu_check_nic_model(nd, "mcf_fec");
466 
467     s = (mcf_fec_state *)g_malloc0(sizeof(mcf_fec_state));
468     s->sysmem = sysmem;
469     s->irq = irq;
470 
471     memory_region_init_io(&s->iomem, &mcf_fec_ops, s, "fec", 0x400);
472     memory_region_add_subregion(sysmem, base, &s->iomem);
473 
474     s->conf.macaddr = nd->macaddr;
475     s->conf.peers.ncs[0] = nd->netdev;
476 
477     s->nic = qemu_new_nic(&net_mcf_fec_info, &s->conf, nd->model, nd->name, s);
478 
479     qemu_format_nic_info_str(qemu_get_queue(s->nic), s->conf.macaddr.a);
480 }
481