1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Thunderbolt driver - eeprom access
4 *
5 * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
6 * Copyright (C) 2018, Intel Corporation
7 */
8
9 #include <linux/crc32.h>
10 #include <linux/delay.h>
11 #include <linux/property.h>
12 #include <linux/slab.h>
13 #include "tb.h"
14
15 /*
16 * tb_eeprom_ctl_write() - write control word
17 */
tb_eeprom_ctl_write(struct tb_switch * sw,struct tb_eeprom_ctl * ctl)18 static int tb_eeprom_ctl_write(struct tb_switch *sw, struct tb_eeprom_ctl *ctl)
19 {
20 return tb_sw_write(sw, ctl, TB_CFG_SWITCH, sw->cap_plug_events + ROUTER_CS_4, 1);
21 }
22
23 /*
24 * tb_eeprom_ctl_write() - read control word
25 */
tb_eeprom_ctl_read(struct tb_switch * sw,struct tb_eeprom_ctl * ctl)26 static int tb_eeprom_ctl_read(struct tb_switch *sw, struct tb_eeprom_ctl *ctl)
27 {
28 return tb_sw_read(sw, ctl, TB_CFG_SWITCH, sw->cap_plug_events + ROUTER_CS_4, 1);
29 }
30
31 enum tb_eeprom_transfer {
32 TB_EEPROM_IN,
33 TB_EEPROM_OUT,
34 };
35
36 /*
37 * tb_eeprom_active - enable rom access
38 *
39 * WARNING: Always disable access after usage. Otherwise the controller will
40 * fail to reprobe.
41 */
tb_eeprom_active(struct tb_switch * sw,bool enable)42 static int tb_eeprom_active(struct tb_switch *sw, bool enable)
43 {
44 struct tb_eeprom_ctl ctl;
45 int res = tb_eeprom_ctl_read(sw, &ctl);
46 if (res)
47 return res;
48 if (enable) {
49 ctl.bit_banging_enable = 1;
50 res = tb_eeprom_ctl_write(sw, &ctl);
51 if (res)
52 return res;
53 ctl.fl_cs = 0;
54 return tb_eeprom_ctl_write(sw, &ctl);
55 } else {
56 ctl.fl_cs = 1;
57 res = tb_eeprom_ctl_write(sw, &ctl);
58 if (res)
59 return res;
60 ctl.bit_banging_enable = 0;
61 return tb_eeprom_ctl_write(sw, &ctl);
62 }
63 }
64
65 /*
66 * tb_eeprom_transfer - transfer one bit
67 *
68 * If TB_EEPROM_IN is passed, then the bit can be retrieved from ctl->fl_do.
69 * If TB_EEPROM_OUT is passed, then ctl->fl_di will be written.
70 */
tb_eeprom_transfer(struct tb_switch * sw,struct tb_eeprom_ctl * ctl,enum tb_eeprom_transfer direction)71 static int tb_eeprom_transfer(struct tb_switch *sw, struct tb_eeprom_ctl *ctl,
72 enum tb_eeprom_transfer direction)
73 {
74 int res;
75 if (direction == TB_EEPROM_OUT) {
76 res = tb_eeprom_ctl_write(sw, ctl);
77 if (res)
78 return res;
79 }
80 ctl->fl_sk = 1;
81 res = tb_eeprom_ctl_write(sw, ctl);
82 if (res)
83 return res;
84 if (direction == TB_EEPROM_IN) {
85 res = tb_eeprom_ctl_read(sw, ctl);
86 if (res)
87 return res;
88 }
89 ctl->fl_sk = 0;
90 return tb_eeprom_ctl_write(sw, ctl);
91 }
92
93 /*
94 * tb_eeprom_out - write one byte to the bus
95 */
tb_eeprom_out(struct tb_switch * sw,u8 val)96 static int tb_eeprom_out(struct tb_switch *sw, u8 val)
97 {
98 struct tb_eeprom_ctl ctl;
99 int i;
100 int res = tb_eeprom_ctl_read(sw, &ctl);
101 if (res)
102 return res;
103 for (i = 0; i < 8; i++) {
104 ctl.fl_di = val & 0x80;
105 res = tb_eeprom_transfer(sw, &ctl, TB_EEPROM_OUT);
106 if (res)
107 return res;
108 val <<= 1;
109 }
110 return 0;
111 }
112
113 /*
114 * tb_eeprom_in - read one byte from the bus
115 */
tb_eeprom_in(struct tb_switch * sw,u8 * val)116 static int tb_eeprom_in(struct tb_switch *sw, u8 *val)
117 {
118 struct tb_eeprom_ctl ctl;
119 int i;
120 int res = tb_eeprom_ctl_read(sw, &ctl);
121 if (res)
122 return res;
123 *val = 0;
124 for (i = 0; i < 8; i++) {
125 *val <<= 1;
126 res = tb_eeprom_transfer(sw, &ctl, TB_EEPROM_IN);
127 if (res)
128 return res;
129 *val |= ctl.fl_do;
130 }
131 return 0;
132 }
133
134 /*
135 * tb_eeprom_get_drom_offset - get drom offset within eeprom
136 */
tb_eeprom_get_drom_offset(struct tb_switch * sw,u16 * offset)137 static int tb_eeprom_get_drom_offset(struct tb_switch *sw, u16 *offset)
138 {
139 struct tb_cap_plug_events cap;
140 int res;
141
142 if (!sw->cap_plug_events) {
143 tb_sw_warn(sw, "no TB_CAP_PLUG_EVENTS, cannot read eeprom\n");
144 return -ENODEV;
145 }
146 res = tb_sw_read(sw, &cap, TB_CFG_SWITCH, sw->cap_plug_events,
147 sizeof(cap) / 4);
148 if (res)
149 return res;
150
151 if (!cap.eeprom_ctl.present || cap.eeprom_ctl.not_present) {
152 tb_sw_warn(sw, "no NVM\n");
153 return -ENODEV;
154 }
155
156 if (cap.drom_offset > 0xffff) {
157 tb_sw_warn(sw, "drom offset is larger than 0xffff: %#x\n",
158 cap.drom_offset);
159 return -ENXIO;
160 }
161 *offset = cap.drom_offset;
162 return 0;
163 }
164
165 /*
166 * tb_eeprom_read_n - read count bytes from offset into val
167 */
tb_eeprom_read_n(struct tb_switch * sw,u16 offset,u8 * val,size_t count)168 static int tb_eeprom_read_n(struct tb_switch *sw, u16 offset, u8 *val,
169 size_t count)
170 {
171 u16 drom_offset;
172 int i, res;
173
174 res = tb_eeprom_get_drom_offset(sw, &drom_offset);
175 if (res)
176 return res;
177
178 offset += drom_offset;
179
180 res = tb_eeprom_active(sw, true);
181 if (res)
182 return res;
183 res = tb_eeprom_out(sw, 3);
184 if (res)
185 return res;
186 res = tb_eeprom_out(sw, offset >> 8);
187 if (res)
188 return res;
189 res = tb_eeprom_out(sw, offset);
190 if (res)
191 return res;
192 for (i = 0; i < count; i++) {
193 res = tb_eeprom_in(sw, val + i);
194 if (res)
195 return res;
196 }
197 return tb_eeprom_active(sw, false);
198 }
199
tb_crc8(u8 * data,int len)200 static u8 tb_crc8(u8 *data, int len)
201 {
202 int i, j;
203 u8 val = 0xff;
204 for (i = 0; i < len; i++) {
205 val ^= data[i];
206 for (j = 0; j < 8; j++)
207 val = (val << 1) ^ ((val & 0x80) ? 7 : 0);
208 }
209 return val;
210 }
211
tb_crc32(void * data,size_t len)212 static u32 tb_crc32(void *data, size_t len)
213 {
214 return ~__crc32c_le(~0, data, len);
215 }
216
217 #define TB_DROM_DATA_START 13
218 #define TB_DROM_HEADER_SIZE 22
219 #define USB4_DROM_HEADER_SIZE 16
220
221 struct tb_drom_header {
222 /* BYTE 0 */
223 u8 uid_crc8; /* checksum for uid */
224 /* BYTES 1-8 */
225 u64 uid;
226 /* BYTES 9-12 */
227 u32 data_crc32; /* checksum for data_len bytes starting at byte 13 */
228 /* BYTE 13 */
229 u8 device_rom_revision; /* should be <= 1 */
230 u16 data_len:12;
231 u8 reserved:4;
232 /* BYTES 16-21 - Only for TBT DROM, nonexistent in USB4 DROM */
233 u16 vendor_id;
234 u16 model_id;
235 u8 model_rev;
236 u8 eeprom_rev;
237 } __packed;
238
239 enum tb_drom_entry_type {
240 /* force unsigned to prevent "one-bit signed bitfield" warning */
241 TB_DROM_ENTRY_GENERIC = 0U,
242 TB_DROM_ENTRY_PORT,
243 };
244
245 struct tb_drom_entry_header {
246 u8 len;
247 u8 index:6;
248 bool port_disabled:1; /* only valid if type is TB_DROM_ENTRY_PORT */
249 enum tb_drom_entry_type type:1;
250 } __packed;
251
252 struct tb_drom_entry_generic {
253 struct tb_drom_entry_header header;
254 u8 data[];
255 } __packed;
256
257 struct tb_drom_entry_port {
258 /* BYTES 0-1 */
259 struct tb_drom_entry_header header;
260 /* BYTE 2 */
261 u8 dual_link_port_rid:4;
262 u8 link_nr:1;
263 u8 unknown1:2;
264 bool has_dual_link_port:1;
265
266 /* BYTE 3 */
267 u8 dual_link_port_nr:6;
268 u8 unknown2:2;
269
270 /* BYTES 4 - 5 TODO decode */
271 u8 micro2:4;
272 u8 micro1:4;
273 u8 micro3;
274
275 /* BYTES 6-7, TODO: verify (find hardware that has these set) */
276 u8 peer_port_rid:4;
277 u8 unknown3:3;
278 bool has_peer_port:1;
279 u8 peer_port_nr:6;
280 u8 unknown4:2;
281 } __packed;
282
283 /* USB4 product descriptor */
284 struct tb_drom_entry_desc {
285 struct tb_drom_entry_header header;
286 u16 bcdUSBSpec;
287 u16 idVendor;
288 u16 idProduct;
289 u16 bcdProductFWRevision;
290 u32 TID;
291 u8 productHWRevision;
292 };
293
294 /**
295 * tb_drom_read_uid_only() - Read UID directly from DROM
296 * @sw: Router whose UID to read
297 * @uid: UID is placed here
298 *
299 * Does not use the cached copy in sw->drom. Used during resume to check switch
300 * identity.
301 */
tb_drom_read_uid_only(struct tb_switch * sw,u64 * uid)302 int tb_drom_read_uid_only(struct tb_switch *sw, u64 *uid)
303 {
304 u8 data[9];
305 u8 crc;
306 int res;
307
308 /* read uid */
309 res = tb_eeprom_read_n(sw, 0, data, 9);
310 if (res)
311 return res;
312
313 crc = tb_crc8(data + 1, 8);
314 if (crc != data[0]) {
315 tb_sw_warn(sw, "uid crc8 mismatch (expected: %#x, got: %#x)\n",
316 data[0], crc);
317 return -EIO;
318 }
319
320 *uid = *(u64 *)(data+1);
321 return 0;
322 }
323
tb_drom_parse_entry_generic(struct tb_switch * sw,struct tb_drom_entry_header * header)324 static int tb_drom_parse_entry_generic(struct tb_switch *sw,
325 struct tb_drom_entry_header *header)
326 {
327 const struct tb_drom_entry_generic *entry =
328 (const struct tb_drom_entry_generic *)header;
329
330 switch (header->index) {
331 case 1:
332 /* Length includes 2 bytes header so remove it before copy */
333 sw->vendor_name = kstrndup(entry->data,
334 header->len - sizeof(*header), GFP_KERNEL);
335 if (!sw->vendor_name)
336 return -ENOMEM;
337 break;
338
339 case 2:
340 sw->device_name = kstrndup(entry->data,
341 header->len - sizeof(*header), GFP_KERNEL);
342 if (!sw->device_name)
343 return -ENOMEM;
344 break;
345 case 9: {
346 const struct tb_drom_entry_desc *desc =
347 (const struct tb_drom_entry_desc *)entry;
348
349 if (!sw->vendor && !sw->device) {
350 sw->vendor = desc->idVendor;
351 sw->device = desc->idProduct;
352 }
353 break;
354 }
355 }
356
357 return 0;
358 }
359
tb_drom_parse_entry_port(struct tb_switch * sw,struct tb_drom_entry_header * header)360 static int tb_drom_parse_entry_port(struct tb_switch *sw,
361 struct tb_drom_entry_header *header)
362 {
363 struct tb_port *port;
364 int res;
365 enum tb_port_type type;
366
367 /*
368 * Some DROMs list more ports than the controller actually has
369 * so we skip those but allow the parser to continue.
370 */
371 if (header->index > sw->config.max_port_number) {
372 dev_info_once(&sw->dev, "ignoring unnecessary extra entries in DROM\n");
373 return 0;
374 }
375
376 port = &sw->ports[header->index];
377 port->disabled = header->port_disabled;
378 if (port->disabled)
379 return 0;
380
381 res = tb_port_read(port, &type, TB_CFG_PORT, 2, 1);
382 if (res)
383 return res;
384 type &= 0xffffff;
385
386 if (type == TB_TYPE_PORT) {
387 struct tb_drom_entry_port *entry = (void *) header;
388 if (header->len != sizeof(*entry)) {
389 tb_sw_warn(sw,
390 "port entry has size %#x (expected %#zx)\n",
391 header->len, sizeof(struct tb_drom_entry_port));
392 return -EIO;
393 }
394 port->link_nr = entry->link_nr;
395 if (entry->has_dual_link_port)
396 port->dual_link_port =
397 &port->sw->ports[entry->dual_link_port_nr];
398 }
399 return 0;
400 }
401
402 /*
403 * tb_drom_parse_entries - parse the linked list of drom entries
404 *
405 * Drom must have been copied to sw->drom.
406 */
tb_drom_parse_entries(struct tb_switch * sw,size_t header_size)407 static int tb_drom_parse_entries(struct tb_switch *sw, size_t header_size)
408 {
409 struct tb_drom_header *header = (void *) sw->drom;
410 u16 pos = header_size;
411 u16 drom_size = header->data_len + TB_DROM_DATA_START;
412 int res;
413
414 while (pos < drom_size) {
415 struct tb_drom_entry_header *entry = (void *) (sw->drom + pos);
416 if (pos + 1 == drom_size || pos + entry->len > drom_size
417 || !entry->len) {
418 tb_sw_warn(sw, "DROM buffer overrun\n");
419 return -EIO;
420 }
421
422 switch (entry->type) {
423 case TB_DROM_ENTRY_GENERIC:
424 res = tb_drom_parse_entry_generic(sw, entry);
425 break;
426 case TB_DROM_ENTRY_PORT:
427 res = tb_drom_parse_entry_port(sw, entry);
428 break;
429 }
430 if (res)
431 return res;
432
433 pos += entry->len;
434 }
435 return 0;
436 }
437
438 /*
439 * tb_drom_copy_efi - copy drom supplied by EFI to sw->drom if present
440 */
tb_drom_copy_efi(struct tb_switch * sw,u16 * size)441 static int tb_drom_copy_efi(struct tb_switch *sw, u16 *size)
442 {
443 struct device *dev = &sw->tb->nhi->pdev->dev;
444 int len, res;
445
446 len = device_property_count_u8(dev, "ThunderboltDROM");
447 if (len < 0 || len < sizeof(struct tb_drom_header))
448 return -EINVAL;
449
450 sw->drom = kmalloc(len, GFP_KERNEL);
451 if (!sw->drom)
452 return -ENOMEM;
453
454 res = device_property_read_u8_array(dev, "ThunderboltDROM", sw->drom,
455 len);
456 if (res)
457 goto err;
458
459 *size = ((struct tb_drom_header *)sw->drom)->data_len +
460 TB_DROM_DATA_START;
461 if (*size > len)
462 goto err;
463
464 return 0;
465
466 err:
467 kfree(sw->drom);
468 sw->drom = NULL;
469 return -EINVAL;
470 }
471
tb_drom_copy_nvm(struct tb_switch * sw,u16 * size)472 static int tb_drom_copy_nvm(struct tb_switch *sw, u16 *size)
473 {
474 u16 drom_offset;
475 int ret;
476
477 if (!sw->dma_port)
478 return -ENODEV;
479
480 ret = tb_eeprom_get_drom_offset(sw, &drom_offset);
481 if (ret)
482 return ret;
483
484 if (!drom_offset)
485 return -ENODEV;
486
487 ret = dma_port_flash_read(sw->dma_port, drom_offset + 14, size,
488 sizeof(*size));
489 if (ret)
490 return ret;
491
492 /* Size includes CRC8 + UID + CRC32 */
493 *size += 1 + 8 + 4;
494 sw->drom = kzalloc(*size, GFP_KERNEL);
495 if (!sw->drom)
496 return -ENOMEM;
497
498 ret = dma_port_flash_read(sw->dma_port, drom_offset, sw->drom, *size);
499 if (ret)
500 goto err_free;
501
502 /*
503 * Read UID from the minimal DROM because the one in NVM is just
504 * a placeholder.
505 */
506 tb_drom_read_uid_only(sw, &sw->uid);
507 return 0;
508
509 err_free:
510 kfree(sw->drom);
511 sw->drom = NULL;
512 return ret;
513 }
514
usb4_copy_drom(struct tb_switch * sw,u16 * size)515 static int usb4_copy_drom(struct tb_switch *sw, u16 *size)
516 {
517 int ret;
518
519 ret = usb4_switch_drom_read(sw, 14, size, sizeof(*size));
520 if (ret)
521 return ret;
522
523 /* Size includes CRC8 + UID + CRC32 */
524 *size += 1 + 8 + 4;
525 sw->drom = kzalloc(*size, GFP_KERNEL);
526 if (!sw->drom)
527 return -ENOMEM;
528
529 ret = usb4_switch_drom_read(sw, 0, sw->drom, *size);
530 if (ret) {
531 kfree(sw->drom);
532 sw->drom = NULL;
533 }
534
535 return ret;
536 }
537
tb_drom_bit_bang(struct tb_switch * sw,u16 * size)538 static int tb_drom_bit_bang(struct tb_switch *sw, u16 *size)
539 {
540 int ret;
541
542 ret = tb_eeprom_read_n(sw, 14, (u8 *)size, 2);
543 if (ret)
544 return ret;
545
546 *size &= 0x3ff;
547 *size += TB_DROM_DATA_START;
548
549 tb_sw_dbg(sw, "reading DROM (length: %#x)\n", *size);
550 if (*size < sizeof(struct tb_drom_header)) {
551 tb_sw_warn(sw, "DROM too small, aborting\n");
552 return -EIO;
553 }
554
555 sw->drom = kzalloc(*size, GFP_KERNEL);
556 if (!sw->drom)
557 return -ENOMEM;
558
559 ret = tb_eeprom_read_n(sw, 0, sw->drom, *size);
560 if (ret)
561 goto err;
562
563 return 0;
564
565 err:
566 kfree(sw->drom);
567 sw->drom = NULL;
568 return ret;
569 }
570
tb_drom_parse_v1(struct tb_switch * sw)571 static int tb_drom_parse_v1(struct tb_switch *sw)
572 {
573 const struct tb_drom_header *header =
574 (const struct tb_drom_header *)sw->drom;
575 u32 crc;
576
577 crc = tb_crc8((u8 *) &header->uid, 8);
578 if (crc != header->uid_crc8) {
579 tb_sw_warn(sw,
580 "DROM UID CRC8 mismatch (expected: %#x, got: %#x)\n",
581 header->uid_crc8, crc);
582 return -EIO;
583 }
584 if (!sw->uid)
585 sw->uid = header->uid;
586 sw->vendor = header->vendor_id;
587 sw->device = header->model_id;
588
589 crc = tb_crc32(sw->drom + TB_DROM_DATA_START, header->data_len);
590 if (crc != header->data_crc32) {
591 tb_sw_warn(sw,
592 "DROM data CRC32 mismatch (expected: %#x, got: %#x), continuing\n",
593 header->data_crc32, crc);
594 }
595
596 return tb_drom_parse_entries(sw, TB_DROM_HEADER_SIZE);
597 }
598
usb4_drom_parse(struct tb_switch * sw)599 static int usb4_drom_parse(struct tb_switch *sw)
600 {
601 const struct tb_drom_header *header =
602 (const struct tb_drom_header *)sw->drom;
603 u32 crc;
604
605 crc = tb_crc32(sw->drom + TB_DROM_DATA_START, header->data_len);
606 if (crc != header->data_crc32) {
607 tb_sw_warn(sw,
608 "DROM data CRC32 mismatch (expected: %#x, got: %#x), continuing\n",
609 header->data_crc32, crc);
610 }
611
612 return tb_drom_parse_entries(sw, USB4_DROM_HEADER_SIZE);
613 }
614
tb_drom_parse(struct tb_switch * sw,u16 size)615 static int tb_drom_parse(struct tb_switch *sw, u16 size)
616 {
617 const struct tb_drom_header *header = (const void *)sw->drom;
618 int ret;
619
620 if (header->data_len + TB_DROM_DATA_START != size) {
621 tb_sw_warn(sw, "DROM size mismatch\n");
622 ret = -EIO;
623 goto err;
624 }
625
626 tb_sw_dbg(sw, "DROM version: %d\n", header->device_rom_revision);
627
628 switch (header->device_rom_revision) {
629 case 3:
630 ret = usb4_drom_parse(sw);
631 break;
632 default:
633 tb_sw_warn(sw, "DROM device_rom_revision %#x unknown\n",
634 header->device_rom_revision);
635 fallthrough;
636 case 1:
637 ret = tb_drom_parse_v1(sw);
638 break;
639 }
640
641 if (ret) {
642 tb_sw_warn(sw, "parsing DROM failed\n");
643 goto err;
644 }
645
646 return 0;
647
648 err:
649 kfree(sw->drom);
650 sw->drom = NULL;
651
652 return ret;
653 }
654
tb_drom_host_read(struct tb_switch * sw)655 static int tb_drom_host_read(struct tb_switch *sw)
656 {
657 u16 size;
658
659 if (tb_switch_is_usb4(sw)) {
660 usb4_switch_read_uid(sw, &sw->uid);
661 if (!usb4_copy_drom(sw, &size))
662 return tb_drom_parse(sw, size);
663 } else {
664 if (!tb_drom_copy_efi(sw, &size))
665 return tb_drom_parse(sw, size);
666
667 if (!tb_drom_copy_nvm(sw, &size))
668 return tb_drom_parse(sw, size);
669
670 tb_drom_read_uid_only(sw, &sw->uid);
671 }
672
673 return 0;
674 }
675
tb_drom_device_read(struct tb_switch * sw)676 static int tb_drom_device_read(struct tb_switch *sw)
677 {
678 u16 size;
679 int ret;
680
681 if (tb_switch_is_usb4(sw)) {
682 usb4_switch_read_uid(sw, &sw->uid);
683 ret = usb4_copy_drom(sw, &size);
684 } else {
685 ret = tb_drom_bit_bang(sw, &size);
686 }
687
688 if (ret)
689 return ret;
690
691 return tb_drom_parse(sw, size);
692 }
693
694 /**
695 * tb_drom_read() - Copy DROM to sw->drom and parse it
696 * @sw: Router whose DROM to read and parse
697 *
698 * This function reads router DROM and if successful parses the entries and
699 * populates the fields in @sw accordingly. Can be called for any router
700 * generation.
701 *
702 * Returns %0 in case of success and negative errno otherwise.
703 */
tb_drom_read(struct tb_switch * sw)704 int tb_drom_read(struct tb_switch *sw)
705 {
706 if (sw->drom)
707 return 0;
708
709 if (!tb_route(sw))
710 return tb_drom_host_read(sw);
711 return tb_drom_device_read(sw);
712 }
713