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v6.8
  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 */
 18static 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 */
 26static 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
 31enum 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 */
 42static 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 */
 71static 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 */
 96static 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 */
116static 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 */
137static 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 */
168static 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
200static 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
212static 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
221struct 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
239enum 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
245struct 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
252struct tb_drom_entry_generic {
253	struct tb_drom_entry_header header;
254	u8 data[];
255} __packed;
256
257struct 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 */
284struct 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 */
302int 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
324static 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
360static 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 */
407static 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 */
441static 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
466err:
467	kfree(sw->drom);
468	sw->drom = NULL;
469	return -EINVAL;
470}
471
472static 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
509err_free:
510	kfree(sw->drom);
511	sw->drom = NULL;
512	return ret;
513}
514
515static 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
538static 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
565err:
566	kfree(sw->drom);
567	sw->drom = NULL;
568	return ret;
569}
570
571static 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
599static 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
615static 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
648err:
649	kfree(sw->drom);
650	sw->drom = NULL;
651
652	return ret;
653}
654
655static 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
676static 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 */
704int 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}
v6.9.4
  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 */
 18static 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 */
 26static 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
 31enum 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 */
 42static 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 */
 71static 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 */
 96static 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 */
116static 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 */
137static 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 */
168static 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
200static 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
212static 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
221struct 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
239enum 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
245struct 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
252struct tb_drom_entry_generic {
253	struct tb_drom_entry_header header;
254	u8 data[];
255} __packed;
256
257struct 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 */
284struct 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 */
302int 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
324static 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
360static 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 */
407static 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 */
441static 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
466err:
467	kfree(sw->drom);
468	sw->drom = NULL;
469	return -EINVAL;
470}
471
472static 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
509err_free:
510	kfree(sw->drom);
511	sw->drom = NULL;
512	return ret;
513}
514
515static 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
538static 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
565err:
566	kfree(sw->drom);
567	sw->drom = NULL;
568	return ret;
569}
570
571static 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
599static 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
615static 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
648err:
649	kfree(sw->drom);
650	sw->drom = NULL;
651
652	return ret;
653}
654
655static 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
676static 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 */
704int 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}