xref: /openbmc/linux/drivers/thunderbolt/usb4.c (revision dfc53baa)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * USB4 specific functionality
4  *
5  * Copyright (C) 2019, Intel Corporation
6  * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
7  *	    Rajmohan Mani <rajmohan.mani@intel.com>
8  */
9 
10 #include <linux/delay.h>
11 #include <linux/ktime.h>
12 
13 #include "sb_regs.h"
14 #include "tb.h"
15 
16 #define USB4_DATA_DWORDS		16
17 #define USB4_DATA_RETRIES		3
18 
19 enum usb4_switch_op {
20 	USB4_SWITCH_OP_QUERY_DP_RESOURCE = 0x10,
21 	USB4_SWITCH_OP_ALLOC_DP_RESOURCE = 0x11,
22 	USB4_SWITCH_OP_DEALLOC_DP_RESOURCE = 0x12,
23 	USB4_SWITCH_OP_NVM_WRITE = 0x20,
24 	USB4_SWITCH_OP_NVM_AUTH = 0x21,
25 	USB4_SWITCH_OP_NVM_READ = 0x22,
26 	USB4_SWITCH_OP_NVM_SET_OFFSET = 0x23,
27 	USB4_SWITCH_OP_DROM_READ = 0x24,
28 	USB4_SWITCH_OP_NVM_SECTOR_SIZE = 0x25,
29 };
30 
31 enum usb4_sb_target {
32 	USB4_SB_TARGET_ROUTER,
33 	USB4_SB_TARGET_PARTNER,
34 	USB4_SB_TARGET_RETIMER,
35 };
36 
37 #define USB4_NVM_READ_OFFSET_MASK	GENMASK(23, 2)
38 #define USB4_NVM_READ_OFFSET_SHIFT	2
39 #define USB4_NVM_READ_LENGTH_MASK	GENMASK(27, 24)
40 #define USB4_NVM_READ_LENGTH_SHIFT	24
41 
42 #define USB4_NVM_SET_OFFSET_MASK	USB4_NVM_READ_OFFSET_MASK
43 #define USB4_NVM_SET_OFFSET_SHIFT	USB4_NVM_READ_OFFSET_SHIFT
44 
45 #define USB4_DROM_ADDRESS_MASK		GENMASK(14, 2)
46 #define USB4_DROM_ADDRESS_SHIFT		2
47 #define USB4_DROM_SIZE_MASK		GENMASK(19, 15)
48 #define USB4_DROM_SIZE_SHIFT		15
49 
50 #define USB4_NVM_SECTOR_SIZE_MASK	GENMASK(23, 0)
51 
52 typedef int (*read_block_fn)(void *, unsigned int, void *, size_t);
53 typedef int (*write_block_fn)(void *, const void *, size_t);
54 
55 static int usb4_switch_wait_for_bit(struct tb_switch *sw, u32 offset, u32 bit,
56 				    u32 value, int timeout_msec)
57 {
58 	ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
59 
60 	do {
61 		u32 val;
62 		int ret;
63 
64 		ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, offset, 1);
65 		if (ret)
66 			return ret;
67 
68 		if ((val & bit) == value)
69 			return 0;
70 
71 		usleep_range(50, 100);
72 	} while (ktime_before(ktime_get(), timeout));
73 
74 	return -ETIMEDOUT;
75 }
76 
77 static int usb4_switch_op_read_data(struct tb_switch *sw, void *data,
78 				    size_t dwords)
79 {
80 	if (dwords > USB4_DATA_DWORDS)
81 		return -EINVAL;
82 
83 	return tb_sw_read(sw, data, TB_CFG_SWITCH, ROUTER_CS_9, dwords);
84 }
85 
86 static int usb4_switch_op_write_data(struct tb_switch *sw, const void *data,
87 				     size_t dwords)
88 {
89 	if (dwords > USB4_DATA_DWORDS)
90 		return -EINVAL;
91 
92 	return tb_sw_write(sw, data, TB_CFG_SWITCH, ROUTER_CS_9, dwords);
93 }
94 
95 static int usb4_switch_op_read_metadata(struct tb_switch *sw, u32 *metadata)
96 {
97 	return tb_sw_read(sw, metadata, TB_CFG_SWITCH, ROUTER_CS_25, 1);
98 }
99 
100 static int usb4_switch_op_write_metadata(struct tb_switch *sw, u32 metadata)
101 {
102 	return tb_sw_write(sw, &metadata, TB_CFG_SWITCH, ROUTER_CS_25, 1);
103 }
104 
105 static int usb4_do_read_data(u16 address, void *buf, size_t size,
106 			     read_block_fn read_block, void *read_block_data)
107 {
108 	unsigned int retries = USB4_DATA_RETRIES;
109 	unsigned int offset;
110 
111 	offset = address & 3;
112 	address = address & ~3;
113 
114 	do {
115 		size_t nbytes = min_t(size_t, size, USB4_DATA_DWORDS * 4);
116 		unsigned int dwaddress, dwords;
117 		u8 data[USB4_DATA_DWORDS * 4];
118 		int ret;
119 
120 		dwaddress = address / 4;
121 		dwords = ALIGN(nbytes, 4) / 4;
122 
123 		ret = read_block(read_block_data, dwaddress, data, dwords);
124 		if (ret) {
125 			if (ret != -ENODEV && retries--)
126 				continue;
127 			return ret;
128 		}
129 
130 		memcpy(buf, data + offset, nbytes);
131 
132 		size -= nbytes;
133 		address += nbytes;
134 		buf += nbytes;
135 	} while (size > 0);
136 
137 	return 0;
138 }
139 
140 static int usb4_do_write_data(unsigned int address, const void *buf, size_t size,
141 	write_block_fn write_next_block, void *write_block_data)
142 {
143 	unsigned int retries = USB4_DATA_RETRIES;
144 	unsigned int offset;
145 
146 	offset = address & 3;
147 	address = address & ~3;
148 
149 	do {
150 		u32 nbytes = min_t(u32, size, USB4_DATA_DWORDS * 4);
151 		u8 data[USB4_DATA_DWORDS * 4];
152 		int ret;
153 
154 		memcpy(data + offset, buf, nbytes);
155 
156 		ret = write_next_block(write_block_data, data, nbytes / 4);
157 		if (ret) {
158 			if (ret == -ETIMEDOUT) {
159 				if (retries--)
160 					continue;
161 				ret = -EIO;
162 			}
163 			return ret;
164 		}
165 
166 		size -= nbytes;
167 		address += nbytes;
168 		buf += nbytes;
169 	} while (size > 0);
170 
171 	return 0;
172 }
173 
174 static int usb4_switch_op(struct tb_switch *sw, u16 opcode, u8 *status)
175 {
176 	u32 val;
177 	int ret;
178 
179 	val = opcode | ROUTER_CS_26_OV;
180 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_26, 1);
181 	if (ret)
182 		return ret;
183 
184 	ret = usb4_switch_wait_for_bit(sw, ROUTER_CS_26, ROUTER_CS_26_OV, 0, 500);
185 	if (ret)
186 		return ret;
187 
188 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_26, 1);
189 	if (ret)
190 		return ret;
191 
192 	if (val & ROUTER_CS_26_ONS)
193 		return -EOPNOTSUPP;
194 
195 	*status = (val & ROUTER_CS_26_STATUS_MASK) >> ROUTER_CS_26_STATUS_SHIFT;
196 	return 0;
197 }
198 
199 static bool link_is_usb4(struct tb_port *port)
200 {
201 	u32 val;
202 
203 	if (!port->cap_usb4)
204 		return false;
205 
206 	if (tb_port_read(port, &val, TB_CFG_PORT,
207 			 port->cap_usb4 + PORT_CS_18, 1))
208 		return false;
209 
210 	return !(val & PORT_CS_18_TCM);
211 }
212 
213 /**
214  * usb4_switch_setup() - Additional setup for USB4 device
215  * @sw: USB4 router to setup
216  *
217  * USB4 routers need additional settings in order to enable all the
218  * tunneling. This function enables USB and PCIe tunneling if it can be
219  * enabled (e.g the parent switch also supports them). If USB tunneling
220  * is not available for some reason (like that there is Thunderbolt 3
221  * switch upstream) then the internal xHCI controller is enabled
222  * instead.
223  */
224 int usb4_switch_setup(struct tb_switch *sw)
225 {
226 	struct tb_port *downstream_port;
227 	struct tb_switch *parent;
228 	bool tbt3, xhci;
229 	u32 val = 0;
230 	int ret;
231 
232 	if (!tb_route(sw))
233 		return 0;
234 
235 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_6, 1);
236 	if (ret)
237 		return ret;
238 
239 	parent = tb_switch_parent(sw);
240 	downstream_port = tb_port_at(tb_route(sw), parent);
241 	sw->link_usb4 = link_is_usb4(downstream_port);
242 	tb_sw_dbg(sw, "link: %s\n", sw->link_usb4 ? "USB4" : "TBT3");
243 
244 	xhci = val & ROUTER_CS_6_HCI;
245 	tbt3 = !(val & ROUTER_CS_6_TNS);
246 
247 	tb_sw_dbg(sw, "TBT3 support: %s, xHCI: %s\n",
248 		  tbt3 ? "yes" : "no", xhci ? "yes" : "no");
249 
250 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
251 	if (ret)
252 		return ret;
253 
254 	if (sw->link_usb4 && tb_switch_find_port(parent, TB_TYPE_USB3_DOWN)) {
255 		val |= ROUTER_CS_5_UTO;
256 		xhci = false;
257 	}
258 
259 	/* Only enable PCIe tunneling if the parent router supports it */
260 	if (tb_switch_find_port(parent, TB_TYPE_PCIE_DOWN)) {
261 		val |= ROUTER_CS_5_PTO;
262 		/*
263 		 * xHCI can be enabled if PCIe tunneling is supported
264 		 * and the parent does not have any USB3 dowstream
265 		 * adapters (so we cannot do USB 3.x tunneling).
266 		 */
267 		if (xhci)
268 			val |= ROUTER_CS_5_HCO;
269 	}
270 
271 	/* TBT3 supported by the CM */
272 	val |= ROUTER_CS_5_C3S;
273 	/* Tunneling configuration is ready now */
274 	val |= ROUTER_CS_5_CV;
275 
276 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
277 	if (ret)
278 		return ret;
279 
280 	return usb4_switch_wait_for_bit(sw, ROUTER_CS_6, ROUTER_CS_6_CR,
281 					ROUTER_CS_6_CR, 50);
282 }
283 
284 /**
285  * usb4_switch_read_uid() - Read UID from USB4 router
286  * @sw: USB4 router
287  * @uid: UID is stored here
288  *
289  * Reads 64-bit UID from USB4 router config space.
290  */
291 int usb4_switch_read_uid(struct tb_switch *sw, u64 *uid)
292 {
293 	return tb_sw_read(sw, uid, TB_CFG_SWITCH, ROUTER_CS_7, 2);
294 }
295 
296 static int usb4_switch_drom_read_block(void *data,
297 				       unsigned int dwaddress, void *buf,
298 				       size_t dwords)
299 {
300 	struct tb_switch *sw = data;
301 	u8 status = 0;
302 	u32 metadata;
303 	int ret;
304 
305 	metadata = (dwords << USB4_DROM_SIZE_SHIFT) & USB4_DROM_SIZE_MASK;
306 	metadata |= (dwaddress << USB4_DROM_ADDRESS_SHIFT) &
307 		USB4_DROM_ADDRESS_MASK;
308 
309 	ret = usb4_switch_op_write_metadata(sw, metadata);
310 	if (ret)
311 		return ret;
312 
313 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_DROM_READ, &status);
314 	if (ret)
315 		return ret;
316 
317 	if (status)
318 		return -EIO;
319 
320 	return usb4_switch_op_read_data(sw, buf, dwords);
321 }
322 
323 /**
324  * usb4_switch_drom_read() - Read arbitrary bytes from USB4 router DROM
325  * @sw: USB4 router
326  * @address: Byte address inside DROM to start reading
327  * @buf: Buffer where the DROM content is stored
328  * @size: Number of bytes to read from DROM
329  *
330  * Uses USB4 router operations to read router DROM. For devices this
331  * should always work but for hosts it may return %-EOPNOTSUPP in which
332  * case the host router does not have DROM.
333  */
334 int usb4_switch_drom_read(struct tb_switch *sw, unsigned int address, void *buf,
335 			  size_t size)
336 {
337 	return usb4_do_read_data(address, buf, size,
338 				 usb4_switch_drom_read_block, sw);
339 }
340 
341 static int usb4_set_port_configured(struct tb_port *port, bool configured)
342 {
343 	int ret;
344 	u32 val;
345 
346 	ret = tb_port_read(port, &val, TB_CFG_PORT,
347 			   port->cap_usb4 + PORT_CS_19, 1);
348 	if (ret)
349 		return ret;
350 
351 	if (configured)
352 		val |= PORT_CS_19_PC;
353 	else
354 		val &= ~PORT_CS_19_PC;
355 
356 	return tb_port_write(port, &val, TB_CFG_PORT,
357 			     port->cap_usb4 + PORT_CS_19, 1);
358 }
359 
360 /**
361  * usb4_switch_configure_link() - Set upstream USB4 link configured
362  * @sw: USB4 router
363  *
364  * Sets the upstream USB4 link to be configured for power management
365  * purposes.
366  */
367 int usb4_switch_configure_link(struct tb_switch *sw)
368 {
369 	struct tb_port *up;
370 
371 	if (!tb_route(sw))
372 		return 0;
373 
374 	up = tb_upstream_port(sw);
375 	return usb4_set_port_configured(up, true);
376 }
377 
378 /**
379  * usb4_switch_unconfigure_link() - Un-set upstream USB4 link configuration
380  * @sw: USB4 router
381  *
382  * Reverse of usb4_switch_configure_link().
383  */
384 void usb4_switch_unconfigure_link(struct tb_switch *sw)
385 {
386 	struct tb_port *up;
387 
388 	if (sw->is_unplugged || !tb_route(sw))
389 		return;
390 
391 	up = tb_upstream_port(sw);
392 	usb4_set_port_configured(up, false);
393 }
394 
395 /**
396  * usb4_switch_lane_bonding_possible() - Are conditions met for lane bonding
397  * @sw: USB4 router
398  *
399  * Checks whether conditions are met so that lane bonding can be
400  * established with the upstream router. Call only for device routers.
401  */
402 bool usb4_switch_lane_bonding_possible(struct tb_switch *sw)
403 {
404 	struct tb_port *up;
405 	int ret;
406 	u32 val;
407 
408 	up = tb_upstream_port(sw);
409 	ret = tb_port_read(up, &val, TB_CFG_PORT, up->cap_usb4 + PORT_CS_18, 1);
410 	if (ret)
411 		return false;
412 
413 	return !!(val & PORT_CS_18_BE);
414 }
415 
416 /**
417  * usb4_switch_set_sleep() - Prepare the router to enter sleep
418  * @sw: USB4 router
419  *
420  * Enables wakes and sets sleep bit for the router. Returns when the
421  * router sleep ready bit has been asserted.
422  */
423 int usb4_switch_set_sleep(struct tb_switch *sw)
424 {
425 	int ret;
426 	u32 val;
427 
428 	/* Set sleep bit and wait for sleep ready to be asserted */
429 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
430 	if (ret)
431 		return ret;
432 
433 	val |= ROUTER_CS_5_SLP;
434 
435 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
436 	if (ret)
437 		return ret;
438 
439 	return usb4_switch_wait_for_bit(sw, ROUTER_CS_6, ROUTER_CS_6_SLPR,
440 					ROUTER_CS_6_SLPR, 500);
441 }
442 
443 /**
444  * usb4_switch_nvm_sector_size() - Return router NVM sector size
445  * @sw: USB4 router
446  *
447  * If the router supports NVM operations this function returns the NVM
448  * sector size in bytes. If NVM operations are not supported returns
449  * %-EOPNOTSUPP.
450  */
451 int usb4_switch_nvm_sector_size(struct tb_switch *sw)
452 {
453 	u32 metadata;
454 	u8 status;
455 	int ret;
456 
457 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_SECTOR_SIZE, &status);
458 	if (ret)
459 		return ret;
460 
461 	if (status)
462 		return status == 0x2 ? -EOPNOTSUPP : -EIO;
463 
464 	ret = usb4_switch_op_read_metadata(sw, &metadata);
465 	if (ret)
466 		return ret;
467 
468 	return metadata & USB4_NVM_SECTOR_SIZE_MASK;
469 }
470 
471 static int usb4_switch_nvm_read_block(void *data,
472 	unsigned int dwaddress, void *buf, size_t dwords)
473 {
474 	struct tb_switch *sw = data;
475 	u8 status = 0;
476 	u32 metadata;
477 	int ret;
478 
479 	metadata = (dwords << USB4_NVM_READ_LENGTH_SHIFT) &
480 		   USB4_NVM_READ_LENGTH_MASK;
481 	metadata |= (dwaddress << USB4_NVM_READ_OFFSET_SHIFT) &
482 		   USB4_NVM_READ_OFFSET_MASK;
483 
484 	ret = usb4_switch_op_write_metadata(sw, metadata);
485 	if (ret)
486 		return ret;
487 
488 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_READ, &status);
489 	if (ret)
490 		return ret;
491 
492 	if (status)
493 		return -EIO;
494 
495 	return usb4_switch_op_read_data(sw, buf, dwords);
496 }
497 
498 /**
499  * usb4_switch_nvm_read() - Read arbitrary bytes from router NVM
500  * @sw: USB4 router
501  * @address: Starting address in bytes
502  * @buf: Read data is placed here
503  * @size: How many bytes to read
504  *
505  * Reads NVM contents of the router. If NVM is not supported returns
506  * %-EOPNOTSUPP.
507  */
508 int usb4_switch_nvm_read(struct tb_switch *sw, unsigned int address, void *buf,
509 			 size_t size)
510 {
511 	return usb4_do_read_data(address, buf, size,
512 				 usb4_switch_nvm_read_block, sw);
513 }
514 
515 static int usb4_switch_nvm_set_offset(struct tb_switch *sw,
516 				      unsigned int address)
517 {
518 	u32 metadata, dwaddress;
519 	u8 status = 0;
520 	int ret;
521 
522 	dwaddress = address / 4;
523 	metadata = (dwaddress << USB4_NVM_SET_OFFSET_SHIFT) &
524 		   USB4_NVM_SET_OFFSET_MASK;
525 
526 	ret = usb4_switch_op_write_metadata(sw, metadata);
527 	if (ret)
528 		return ret;
529 
530 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_SET_OFFSET, &status);
531 	if (ret)
532 		return ret;
533 
534 	return status ? -EIO : 0;
535 }
536 
537 static int usb4_switch_nvm_write_next_block(void *data, const void *buf,
538 					    size_t dwords)
539 {
540 	struct tb_switch *sw = data;
541 	u8 status;
542 	int ret;
543 
544 	ret = usb4_switch_op_write_data(sw, buf, dwords);
545 	if (ret)
546 		return ret;
547 
548 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_WRITE, &status);
549 	if (ret)
550 		return ret;
551 
552 	return status ? -EIO : 0;
553 }
554 
555 /**
556  * usb4_switch_nvm_write() - Write to the router NVM
557  * @sw: USB4 router
558  * @address: Start address where to write in bytes
559  * @buf: Pointer to the data to write
560  * @size: Size of @buf in bytes
561  *
562  * Writes @buf to the router NVM using USB4 router operations. If NVM
563  * write is not supported returns %-EOPNOTSUPP.
564  */
565 int usb4_switch_nvm_write(struct tb_switch *sw, unsigned int address,
566 			  const void *buf, size_t size)
567 {
568 	int ret;
569 
570 	ret = usb4_switch_nvm_set_offset(sw, address);
571 	if (ret)
572 		return ret;
573 
574 	return usb4_do_write_data(address, buf, size,
575 				  usb4_switch_nvm_write_next_block, sw);
576 }
577 
578 /**
579  * usb4_switch_nvm_authenticate() - Authenticate new NVM
580  * @sw: USB4 router
581  *
582  * After the new NVM has been written via usb4_switch_nvm_write(), this
583  * function triggers NVM authentication process. If the authentication
584  * is successful the router is power cycled and the new NVM starts
585  * running. In case of failure returns negative errno.
586  */
587 int usb4_switch_nvm_authenticate(struct tb_switch *sw)
588 {
589 	u8 status = 0;
590 	int ret;
591 
592 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_AUTH, &status);
593 	if (ret)
594 		return ret;
595 
596 	switch (status) {
597 	case 0x0:
598 		tb_sw_dbg(sw, "NVM authentication successful\n");
599 		return 0;
600 	case 0x1:
601 		return -EINVAL;
602 	case 0x2:
603 		return -EAGAIN;
604 	case 0x3:
605 		return -EOPNOTSUPP;
606 	default:
607 		return -EIO;
608 	}
609 }
610 
611 /**
612  * usb4_switch_query_dp_resource() - Query availability of DP IN resource
613  * @sw: USB4 router
614  * @in: DP IN adapter
615  *
616  * For DP tunneling this function can be used to query availability of
617  * DP IN resource. Returns true if the resource is available for DP
618  * tunneling, false otherwise.
619  */
620 bool usb4_switch_query_dp_resource(struct tb_switch *sw, struct tb_port *in)
621 {
622 	u8 status;
623 	int ret;
624 
625 	ret = usb4_switch_op_write_metadata(sw, in->port);
626 	if (ret)
627 		return false;
628 
629 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_QUERY_DP_RESOURCE, &status);
630 	/*
631 	 * If DP resource allocation is not supported assume it is
632 	 * always available.
633 	 */
634 	if (ret == -EOPNOTSUPP)
635 		return true;
636 	else if (ret)
637 		return false;
638 
639 	return !status;
640 }
641 
642 /**
643  * usb4_switch_alloc_dp_resource() - Allocate DP IN resource
644  * @sw: USB4 router
645  * @in: DP IN adapter
646  *
647  * Allocates DP IN resource for DP tunneling using USB4 router
648  * operations. If the resource was allocated returns %0. Otherwise
649  * returns negative errno, in particular %-EBUSY if the resource is
650  * already allocated.
651  */
652 int usb4_switch_alloc_dp_resource(struct tb_switch *sw, struct tb_port *in)
653 {
654 	u8 status;
655 	int ret;
656 
657 	ret = usb4_switch_op_write_metadata(sw, in->port);
658 	if (ret)
659 		return ret;
660 
661 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_ALLOC_DP_RESOURCE, &status);
662 	if (ret == -EOPNOTSUPP)
663 		return 0;
664 	else if (ret)
665 		return ret;
666 
667 	return status ? -EBUSY : 0;
668 }
669 
670 /**
671  * usb4_switch_dealloc_dp_resource() - Releases allocated DP IN resource
672  * @sw: USB4 router
673  * @in: DP IN adapter
674  *
675  * Releases the previously allocated DP IN resource.
676  */
677 int usb4_switch_dealloc_dp_resource(struct tb_switch *sw, struct tb_port *in)
678 {
679 	u8 status;
680 	int ret;
681 
682 	ret = usb4_switch_op_write_metadata(sw, in->port);
683 	if (ret)
684 		return ret;
685 
686 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_DEALLOC_DP_RESOURCE, &status);
687 	if (ret == -EOPNOTSUPP)
688 		return 0;
689 	else if (ret)
690 		return ret;
691 
692 	return status ? -EIO : 0;
693 }
694 
695 static int usb4_port_idx(const struct tb_switch *sw, const struct tb_port *port)
696 {
697 	struct tb_port *p;
698 	int usb4_idx = 0;
699 
700 	/* Assume port is primary */
701 	tb_switch_for_each_port(sw, p) {
702 		if (!tb_port_is_null(p))
703 			continue;
704 		if (tb_is_upstream_port(p))
705 			continue;
706 		if (!p->link_nr) {
707 			if (p == port)
708 				break;
709 			usb4_idx++;
710 		}
711 	}
712 
713 	return usb4_idx;
714 }
715 
716 /**
717  * usb4_switch_map_pcie_down() - Map USB4 port to a PCIe downstream adapter
718  * @sw: USB4 router
719  * @port: USB4 port
720  *
721  * USB4 routers have direct mapping between USB4 ports and PCIe
722  * downstream adapters where the PCIe topology is extended. This
723  * function returns the corresponding downstream PCIe adapter or %NULL
724  * if no such mapping was possible.
725  */
726 struct tb_port *usb4_switch_map_pcie_down(struct tb_switch *sw,
727 					  const struct tb_port *port)
728 {
729 	int usb4_idx = usb4_port_idx(sw, port);
730 	struct tb_port *p;
731 	int pcie_idx = 0;
732 
733 	/* Find PCIe down port matching usb4_port */
734 	tb_switch_for_each_port(sw, p) {
735 		if (!tb_port_is_pcie_down(p))
736 			continue;
737 
738 		if (pcie_idx == usb4_idx)
739 			return p;
740 
741 		pcie_idx++;
742 	}
743 
744 	return NULL;
745 }
746 
747 /**
748  * usb4_switch_map_usb3_down() - Map USB4 port to a USB3 downstream adapter
749  * @sw: USB4 router
750  * @port: USB4 port
751  *
752  * USB4 routers have direct mapping between USB4 ports and USB 3.x
753  * downstream adapters where the USB 3.x topology is extended. This
754  * function returns the corresponding downstream USB 3.x adapter or
755  * %NULL if no such mapping was possible.
756  */
757 struct tb_port *usb4_switch_map_usb3_down(struct tb_switch *sw,
758 					  const struct tb_port *port)
759 {
760 	int usb4_idx = usb4_port_idx(sw, port);
761 	struct tb_port *p;
762 	int usb_idx = 0;
763 
764 	/* Find USB3 down port matching usb4_port */
765 	tb_switch_for_each_port(sw, p) {
766 		if (!tb_port_is_usb3_down(p))
767 			continue;
768 
769 		if (usb_idx == usb4_idx)
770 			return p;
771 
772 		usb_idx++;
773 	}
774 
775 	return NULL;
776 }
777 
778 /**
779  * usb4_port_unlock() - Unlock USB4 downstream port
780  * @port: USB4 port to unlock
781  *
782  * Unlocks USB4 downstream port so that the connection manager can
783  * access the router below this port.
784  */
785 int usb4_port_unlock(struct tb_port *port)
786 {
787 	int ret;
788 	u32 val;
789 
790 	ret = tb_port_read(port, &val, TB_CFG_PORT, ADP_CS_4, 1);
791 	if (ret)
792 		return ret;
793 
794 	val &= ~ADP_CS_4_LCK;
795 	return tb_port_write(port, &val, TB_CFG_PORT, ADP_CS_4, 1);
796 }
797 
798 static int usb4_port_wait_for_bit(struct tb_port *port, u32 offset, u32 bit,
799 				  u32 value, int timeout_msec)
800 {
801 	ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
802 
803 	do {
804 		u32 val;
805 		int ret;
806 
807 		ret = tb_port_read(port, &val, TB_CFG_PORT, offset, 1);
808 		if (ret)
809 			return ret;
810 
811 		if ((val & bit) == value)
812 			return 0;
813 
814 		usleep_range(50, 100);
815 	} while (ktime_before(ktime_get(), timeout));
816 
817 	return -ETIMEDOUT;
818 }
819 
820 static int usb4_port_read_data(struct tb_port *port, void *data, size_t dwords)
821 {
822 	if (dwords > USB4_DATA_DWORDS)
823 		return -EINVAL;
824 
825 	return tb_port_read(port, data, TB_CFG_PORT, port->cap_usb4 + PORT_CS_2,
826 			    dwords);
827 }
828 
829 static int usb4_port_write_data(struct tb_port *port, const void *data,
830 				size_t dwords)
831 {
832 	if (dwords > USB4_DATA_DWORDS)
833 		return -EINVAL;
834 
835 	return tb_port_write(port, data, TB_CFG_PORT, port->cap_usb4 + PORT_CS_2,
836 			     dwords);
837 }
838 
839 static int usb4_port_sb_read(struct tb_port *port, enum usb4_sb_target target,
840 			     u8 index, u8 reg, void *buf, u8 size)
841 {
842 	size_t dwords = DIV_ROUND_UP(size, 4);
843 	int ret;
844 	u32 val;
845 
846 	if (!port->cap_usb4)
847 		return -EINVAL;
848 
849 	val = reg;
850 	val |= size << PORT_CS_1_LENGTH_SHIFT;
851 	val |= (target << PORT_CS_1_TARGET_SHIFT) & PORT_CS_1_TARGET_MASK;
852 	if (target == USB4_SB_TARGET_RETIMER)
853 		val |= (index << PORT_CS_1_RETIMER_INDEX_SHIFT);
854 	val |= PORT_CS_1_PND;
855 
856 	ret = tb_port_write(port, &val, TB_CFG_PORT,
857 			    port->cap_usb4 + PORT_CS_1, 1);
858 	if (ret)
859 		return ret;
860 
861 	ret = usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_1,
862 				     PORT_CS_1_PND, 0, 500);
863 	if (ret)
864 		return ret;
865 
866 	ret = tb_port_read(port, &val, TB_CFG_PORT,
867 			    port->cap_usb4 + PORT_CS_1, 1);
868 	if (ret)
869 		return ret;
870 
871 	if (val & PORT_CS_1_NR)
872 		return -ENODEV;
873 	if (val & PORT_CS_1_RC)
874 		return -EIO;
875 
876 	return buf ? usb4_port_read_data(port, buf, dwords) : 0;
877 }
878 
879 static int usb4_port_sb_write(struct tb_port *port, enum usb4_sb_target target,
880 			      u8 index, u8 reg, const void *buf, u8 size)
881 {
882 	size_t dwords = DIV_ROUND_UP(size, 4);
883 	int ret;
884 	u32 val;
885 
886 	if (!port->cap_usb4)
887 		return -EINVAL;
888 
889 	if (buf) {
890 		ret = usb4_port_write_data(port, buf, dwords);
891 		if (ret)
892 			return ret;
893 	}
894 
895 	val = reg;
896 	val |= size << PORT_CS_1_LENGTH_SHIFT;
897 	val |= PORT_CS_1_WNR_WRITE;
898 	val |= (target << PORT_CS_1_TARGET_SHIFT) & PORT_CS_1_TARGET_MASK;
899 	if (target == USB4_SB_TARGET_RETIMER)
900 		val |= (index << PORT_CS_1_RETIMER_INDEX_SHIFT);
901 	val |= PORT_CS_1_PND;
902 
903 	ret = tb_port_write(port, &val, TB_CFG_PORT,
904 			    port->cap_usb4 + PORT_CS_1, 1);
905 	if (ret)
906 		return ret;
907 
908 	ret = usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_1,
909 				     PORT_CS_1_PND, 0, 500);
910 	if (ret)
911 		return ret;
912 
913 	ret = tb_port_read(port, &val, TB_CFG_PORT,
914 			    port->cap_usb4 + PORT_CS_1, 1);
915 	if (ret)
916 		return ret;
917 
918 	if (val & PORT_CS_1_NR)
919 		return -ENODEV;
920 	if (val & PORT_CS_1_RC)
921 		return -EIO;
922 
923 	return 0;
924 }
925 
926 static int usb4_port_sb_op(struct tb_port *port, enum usb4_sb_target target,
927 			   u8 index, enum usb4_sb_opcode opcode, int timeout_msec)
928 {
929 	ktime_t timeout;
930 	u32 val;
931 	int ret;
932 
933 	val = opcode;
934 	ret = usb4_port_sb_write(port, target, index, USB4_SB_OPCODE, &val,
935 				 sizeof(val));
936 	if (ret)
937 		return ret;
938 
939 	timeout = ktime_add_ms(ktime_get(), timeout_msec);
940 
941 	do {
942 		/* Check results */
943 		ret = usb4_port_sb_read(port, target, index, USB4_SB_OPCODE,
944 					&val, sizeof(val));
945 		if (ret)
946 			return ret;
947 
948 		switch (val) {
949 		case 0:
950 			return 0;
951 
952 		case USB4_SB_OPCODE_ERR:
953 			return -EAGAIN;
954 
955 		case USB4_SB_OPCODE_ONS:
956 			return -EOPNOTSUPP;
957 
958 		default:
959 			if (val != opcode)
960 				return -EIO;
961 			break;
962 		}
963 	} while (ktime_before(ktime_get(), timeout));
964 
965 	return -ETIMEDOUT;
966 }
967 
968 /**
969  * usb4_port_enumerate_retimers() - Send RT broadcast transaction
970  * @port: USB4 port
971  *
972  * This forces the USB4 port to send broadcast RT transaction which
973  * makes the retimers on the link to assign index to themselves. Returns
974  * %0 in case of success and negative errno if there was an error.
975  */
976 int usb4_port_enumerate_retimers(struct tb_port *port)
977 {
978 	u32 val;
979 
980 	val = USB4_SB_OPCODE_ENUMERATE_RETIMERS;
981 	return usb4_port_sb_write(port, USB4_SB_TARGET_ROUTER, 0,
982 				  USB4_SB_OPCODE, &val, sizeof(val));
983 }
984 
985 static inline int usb4_port_retimer_op(struct tb_port *port, u8 index,
986 				       enum usb4_sb_opcode opcode,
987 				       int timeout_msec)
988 {
989 	return usb4_port_sb_op(port, USB4_SB_TARGET_RETIMER, index, opcode,
990 			       timeout_msec);
991 }
992 
993 /**
994  * usb4_port_retimer_read() - Read from retimer sideband registers
995  * @port: USB4 port
996  * @index: Retimer index
997  * @reg: Sideband register to read
998  * @buf: Data from @reg is stored here
999  * @size: Number of bytes to read
1000  *
1001  * Function reads retimer sideband registers starting from @reg. The
1002  * retimer is connected to @port at @index. Returns %0 in case of
1003  * success, and read data is copied to @buf. If there is no retimer
1004  * present at given @index returns %-ENODEV. In any other failure
1005  * returns negative errno.
1006  */
1007 int usb4_port_retimer_read(struct tb_port *port, u8 index, u8 reg, void *buf,
1008 			   u8 size)
1009 {
1010 	return usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index, reg, buf,
1011 				 size);
1012 }
1013 
1014 /**
1015  * usb4_port_retimer_write() - Write to retimer sideband registers
1016  * @port: USB4 port
1017  * @index: Retimer index
1018  * @reg: Sideband register to write
1019  * @buf: Data that is written starting from @reg
1020  * @size: Number of bytes to write
1021  *
1022  * Writes retimer sideband registers starting from @reg. The retimer is
1023  * connected to @port at @index. Returns %0 in case of success. If there
1024  * is no retimer present at given @index returns %-ENODEV. In any other
1025  * failure returns negative errno.
1026  */
1027 int usb4_port_retimer_write(struct tb_port *port, u8 index, u8 reg,
1028 			    const void *buf, u8 size)
1029 {
1030 	return usb4_port_sb_write(port, USB4_SB_TARGET_RETIMER, index, reg, buf,
1031 				  size);
1032 }
1033 
1034 /**
1035  * usb4_port_retimer_is_last() - Is the retimer last on-board retimer
1036  * @port: USB4 port
1037  * @index: Retimer index
1038  *
1039  * If the retimer at @index is last one (connected directly to the
1040  * Type-C port) this function returns %1. If it is not returns %0. If
1041  * the retimer is not present returns %-ENODEV. Otherwise returns
1042  * negative errno.
1043  */
1044 int usb4_port_retimer_is_last(struct tb_port *port, u8 index)
1045 {
1046 	u32 metadata;
1047 	int ret;
1048 
1049 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_QUERY_LAST_RETIMER,
1050 				   500);
1051 	if (ret)
1052 		return ret;
1053 
1054 	ret = usb4_port_retimer_read(port, index, USB4_SB_METADATA, &metadata,
1055 				     sizeof(metadata));
1056 	return ret ? ret : metadata & 1;
1057 }
1058 
1059 /**
1060  * usb4_port_retimer_nvm_sector_size() - Read retimer NVM sector size
1061  * @port: USB4 port
1062  * @index: Retimer index
1063  *
1064  * Reads NVM sector size (in bytes) of a retimer at @index. This
1065  * operation can be used to determine whether the retimer supports NVM
1066  * upgrade for example. Returns sector size in bytes or negative errno
1067  * in case of error. Specifically returns %-ENODEV if there is no
1068  * retimer at @index.
1069  */
1070 int usb4_port_retimer_nvm_sector_size(struct tb_port *port, u8 index)
1071 {
1072 	u32 metadata;
1073 	int ret;
1074 
1075 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_GET_NVM_SECTOR_SIZE,
1076 				   500);
1077 	if (ret)
1078 		return ret;
1079 
1080 	ret = usb4_port_retimer_read(port, index, USB4_SB_METADATA, &metadata,
1081 				     sizeof(metadata));
1082 	return ret ? ret : metadata & USB4_NVM_SECTOR_SIZE_MASK;
1083 }
1084 
1085 static int usb4_port_retimer_nvm_set_offset(struct tb_port *port, u8 index,
1086 					    unsigned int address)
1087 {
1088 	u32 metadata, dwaddress;
1089 	int ret;
1090 
1091 	dwaddress = address / 4;
1092 	metadata = (dwaddress << USB4_NVM_SET_OFFSET_SHIFT) &
1093 		  USB4_NVM_SET_OFFSET_MASK;
1094 
1095 	ret = usb4_port_retimer_write(port, index, USB4_SB_METADATA, &metadata,
1096 				      sizeof(metadata));
1097 	if (ret)
1098 		return ret;
1099 
1100 	return usb4_port_retimer_op(port, index, USB4_SB_OPCODE_NVM_SET_OFFSET,
1101 				    500);
1102 }
1103 
1104 struct retimer_info {
1105 	struct tb_port *port;
1106 	u8 index;
1107 };
1108 
1109 static int usb4_port_retimer_nvm_write_next_block(void *data, const void *buf,
1110 						  size_t dwords)
1111 
1112 {
1113 	const struct retimer_info *info = data;
1114 	struct tb_port *port = info->port;
1115 	u8 index = info->index;
1116 	int ret;
1117 
1118 	ret = usb4_port_retimer_write(port, index, USB4_SB_DATA,
1119 				      buf, dwords * 4);
1120 	if (ret)
1121 		return ret;
1122 
1123 	return usb4_port_retimer_op(port, index,
1124 			USB4_SB_OPCODE_NVM_BLOCK_WRITE, 1000);
1125 }
1126 
1127 /**
1128  * usb4_port_retimer_nvm_write() - Write to retimer NVM
1129  * @port: USB4 port
1130  * @index: Retimer index
1131  * @address: Byte address where to start the write
1132  * @buf: Data to write
1133  * @size: Size in bytes how much to write
1134  *
1135  * Writes @size bytes from @buf to the retimer NVM. Used for NVM
1136  * upgrade. Returns %0 if the data was written successfully and negative
1137  * errno in case of failure. Specifically returns %-ENODEV if there is
1138  * no retimer at @index.
1139  */
1140 int usb4_port_retimer_nvm_write(struct tb_port *port, u8 index, unsigned int address,
1141 				const void *buf, size_t size)
1142 {
1143 	struct retimer_info info = { .port = port, .index = index };
1144 	int ret;
1145 
1146 	ret = usb4_port_retimer_nvm_set_offset(port, index, address);
1147 	if (ret)
1148 		return ret;
1149 
1150 	return usb4_do_write_data(address, buf, size,
1151 			usb4_port_retimer_nvm_write_next_block, &info);
1152 }
1153 
1154 /**
1155  * usb4_port_retimer_nvm_authenticate() - Start retimer NVM upgrade
1156  * @port: USB4 port
1157  * @index: Retimer index
1158  *
1159  * After the new NVM image has been written via usb4_port_retimer_nvm_write()
1160  * this function can be used to trigger the NVM upgrade process. If
1161  * successful the retimer restarts with the new NVM and may not have the
1162  * index set so one needs to call usb4_port_enumerate_retimers() to
1163  * force index to be assigned.
1164  */
1165 int usb4_port_retimer_nvm_authenticate(struct tb_port *port, u8 index)
1166 {
1167 	u32 val;
1168 
1169 	/*
1170 	 * We need to use the raw operation here because once the
1171 	 * authentication completes the retimer index is not set anymore
1172 	 * so we do not get back the status now.
1173 	 */
1174 	val = USB4_SB_OPCODE_NVM_AUTH_WRITE;
1175 	return usb4_port_sb_write(port, USB4_SB_TARGET_RETIMER, index,
1176 				  USB4_SB_OPCODE, &val, sizeof(val));
1177 }
1178 
1179 /**
1180  * usb4_port_retimer_nvm_authenticate_status() - Read status of NVM upgrade
1181  * @port: USB4 port
1182  * @index: Retimer index
1183  * @status: Raw status code read from metadata
1184  *
1185  * This can be called after usb4_port_retimer_nvm_authenticate() and
1186  * usb4_port_enumerate_retimers() to fetch status of the NVM upgrade.
1187  *
1188  * Returns %0 if the authentication status was successfully read. The
1189  * completion metadata (the result) is then stored into @status. If
1190  * reading the status fails, returns negative errno.
1191  */
1192 int usb4_port_retimer_nvm_authenticate_status(struct tb_port *port, u8 index,
1193 					      u32 *status)
1194 {
1195 	u32 metadata, val;
1196 	int ret;
1197 
1198 	ret = usb4_port_retimer_read(port, index, USB4_SB_OPCODE, &val,
1199 				     sizeof(val));
1200 	if (ret)
1201 		return ret;
1202 
1203 	switch (val) {
1204 	case 0:
1205 		*status = 0;
1206 		return 0;
1207 
1208 	case USB4_SB_OPCODE_ERR:
1209 		ret = usb4_port_retimer_read(port, index, USB4_SB_METADATA,
1210 					     &metadata, sizeof(metadata));
1211 		if (ret)
1212 			return ret;
1213 
1214 		*status = metadata & USB4_SB_METADATA_NVM_AUTH_WRITE_MASK;
1215 		return 0;
1216 
1217 	case USB4_SB_OPCODE_ONS:
1218 		return -EOPNOTSUPP;
1219 
1220 	default:
1221 		return -EIO;
1222 	}
1223 }
1224 
1225 static int usb4_port_retimer_nvm_read_block(void *data, unsigned int dwaddress,
1226 					    void *buf, size_t dwords)
1227 {
1228 	const struct retimer_info *info = data;
1229 	struct tb_port *port = info->port;
1230 	u8 index = info->index;
1231 	u32 metadata;
1232 	int ret;
1233 
1234 	metadata = dwaddress << USB4_NVM_READ_OFFSET_SHIFT;
1235 	if (dwords < USB4_DATA_DWORDS)
1236 		metadata |= dwords << USB4_NVM_READ_LENGTH_SHIFT;
1237 
1238 	ret = usb4_port_retimer_write(port, index, USB4_SB_METADATA, &metadata,
1239 				      sizeof(metadata));
1240 	if (ret)
1241 		return ret;
1242 
1243 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_NVM_READ, 500);
1244 	if (ret)
1245 		return ret;
1246 
1247 	return usb4_port_retimer_read(port, index, USB4_SB_DATA, buf,
1248 				      dwords * 4);
1249 }
1250 
1251 /**
1252  * usb4_port_retimer_nvm_read() - Read contents of retimer NVM
1253  * @port: USB4 port
1254  * @index: Retimer index
1255  * @address: NVM address (in bytes) to start reading
1256  * @buf: Data read from NVM is stored here
1257  * @size: Number of bytes to read
1258  *
1259  * Reads retimer NVM and copies the contents to @buf. Returns %0 if the
1260  * read was successful and negative errno in case of failure.
1261  * Specifically returns %-ENODEV if there is no retimer at @index.
1262  */
1263 int usb4_port_retimer_nvm_read(struct tb_port *port, u8 index,
1264 			       unsigned int address, void *buf, size_t size)
1265 {
1266 	struct retimer_info info = { .port = port, .index = index };
1267 
1268 	return usb4_do_read_data(address, buf, size,
1269 			usb4_port_retimer_nvm_read_block, &info);
1270 }
1271 
1272 /**
1273  * usb4_usb3_port_max_link_rate() - Maximum support USB3 link rate
1274  * @port: USB3 adapter port
1275  *
1276  * Return maximum supported link rate of a USB3 adapter in Mb/s.
1277  * Negative errno in case of error.
1278  */
1279 int usb4_usb3_port_max_link_rate(struct tb_port *port)
1280 {
1281 	int ret, lr;
1282 	u32 val;
1283 
1284 	if (!tb_port_is_usb3_down(port) && !tb_port_is_usb3_up(port))
1285 		return -EINVAL;
1286 
1287 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1288 			   port->cap_adap + ADP_USB3_CS_4, 1);
1289 	if (ret)
1290 		return ret;
1291 
1292 	lr = (val & ADP_USB3_CS_4_MSLR_MASK) >> ADP_USB3_CS_4_MSLR_SHIFT;
1293 	return lr == ADP_USB3_CS_4_MSLR_20G ? 20000 : 10000;
1294 }
1295 
1296 /**
1297  * usb4_usb3_port_actual_link_rate() - Established USB3 link rate
1298  * @port: USB3 adapter port
1299  *
1300  * Return actual established link rate of a USB3 adapter in Mb/s. If the
1301  * link is not up returns %0 and negative errno in case of failure.
1302  */
1303 int usb4_usb3_port_actual_link_rate(struct tb_port *port)
1304 {
1305 	int ret, lr;
1306 	u32 val;
1307 
1308 	if (!tb_port_is_usb3_down(port) && !tb_port_is_usb3_up(port))
1309 		return -EINVAL;
1310 
1311 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1312 			   port->cap_adap + ADP_USB3_CS_4, 1);
1313 	if (ret)
1314 		return ret;
1315 
1316 	if (!(val & ADP_USB3_CS_4_ULV))
1317 		return 0;
1318 
1319 	lr = val & ADP_USB3_CS_4_ALR_MASK;
1320 	return lr == ADP_USB3_CS_4_ALR_20G ? 20000 : 10000;
1321 }
1322 
1323 static int usb4_usb3_port_cm_request(struct tb_port *port, bool request)
1324 {
1325 	int ret;
1326 	u32 val;
1327 
1328 	if (!tb_port_is_usb3_down(port))
1329 		return -EINVAL;
1330 	if (tb_route(port->sw))
1331 		return -EINVAL;
1332 
1333 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1334 			   port->cap_adap + ADP_USB3_CS_2, 1);
1335 	if (ret)
1336 		return ret;
1337 
1338 	if (request)
1339 		val |= ADP_USB3_CS_2_CMR;
1340 	else
1341 		val &= ~ADP_USB3_CS_2_CMR;
1342 
1343 	ret = tb_port_write(port, &val, TB_CFG_PORT,
1344 			    port->cap_adap + ADP_USB3_CS_2, 1);
1345 	if (ret)
1346 		return ret;
1347 
1348 	/*
1349 	 * We can use val here directly as the CMR bit is in the same place
1350 	 * as HCA. Just mask out others.
1351 	 */
1352 	val &= ADP_USB3_CS_2_CMR;
1353 	return usb4_port_wait_for_bit(port, port->cap_adap + ADP_USB3_CS_1,
1354 				      ADP_USB3_CS_1_HCA, val, 1500);
1355 }
1356 
1357 static inline int usb4_usb3_port_set_cm_request(struct tb_port *port)
1358 {
1359 	return usb4_usb3_port_cm_request(port, true);
1360 }
1361 
1362 static inline int usb4_usb3_port_clear_cm_request(struct tb_port *port)
1363 {
1364 	return usb4_usb3_port_cm_request(port, false);
1365 }
1366 
1367 static unsigned int usb3_bw_to_mbps(u32 bw, u8 scale)
1368 {
1369 	unsigned long uframes;
1370 
1371 	uframes = bw * 512UL << scale;
1372 	return DIV_ROUND_CLOSEST(uframes * 8000, 1000 * 1000);
1373 }
1374 
1375 static u32 mbps_to_usb3_bw(unsigned int mbps, u8 scale)
1376 {
1377 	unsigned long uframes;
1378 
1379 	/* 1 uframe is 1/8 ms (125 us) -> 1 / 8000 s */
1380 	uframes = ((unsigned long)mbps * 1000 *  1000) / 8000;
1381 	return DIV_ROUND_UP(uframes, 512UL << scale);
1382 }
1383 
1384 static int usb4_usb3_port_read_allocated_bandwidth(struct tb_port *port,
1385 						   int *upstream_bw,
1386 						   int *downstream_bw)
1387 {
1388 	u32 val, bw, scale;
1389 	int ret;
1390 
1391 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1392 			   port->cap_adap + ADP_USB3_CS_2, 1);
1393 	if (ret)
1394 		return ret;
1395 
1396 	ret = tb_port_read(port, &scale, TB_CFG_PORT,
1397 			   port->cap_adap + ADP_USB3_CS_3, 1);
1398 	if (ret)
1399 		return ret;
1400 
1401 	scale &= ADP_USB3_CS_3_SCALE_MASK;
1402 
1403 	bw = val & ADP_USB3_CS_2_AUBW_MASK;
1404 	*upstream_bw = usb3_bw_to_mbps(bw, scale);
1405 
1406 	bw = (val & ADP_USB3_CS_2_ADBW_MASK) >> ADP_USB3_CS_2_ADBW_SHIFT;
1407 	*downstream_bw = usb3_bw_to_mbps(bw, scale);
1408 
1409 	return 0;
1410 }
1411 
1412 /**
1413  * usb4_usb3_port_allocated_bandwidth() - Bandwidth allocated for USB3
1414  * @port: USB3 adapter port
1415  * @upstream_bw: Allocated upstream bandwidth is stored here
1416  * @downstream_bw: Allocated downstream bandwidth is stored here
1417  *
1418  * Stores currently allocated USB3 bandwidth into @upstream_bw and
1419  * @downstream_bw in Mb/s. Returns %0 in case of success and negative
1420  * errno in failure.
1421  */
1422 int usb4_usb3_port_allocated_bandwidth(struct tb_port *port, int *upstream_bw,
1423 				       int *downstream_bw)
1424 {
1425 	int ret;
1426 
1427 	ret = usb4_usb3_port_set_cm_request(port);
1428 	if (ret)
1429 		return ret;
1430 
1431 	ret = usb4_usb3_port_read_allocated_bandwidth(port, upstream_bw,
1432 						      downstream_bw);
1433 	usb4_usb3_port_clear_cm_request(port);
1434 
1435 	return ret;
1436 }
1437 
1438 static int usb4_usb3_port_read_consumed_bandwidth(struct tb_port *port,
1439 						  int *upstream_bw,
1440 						  int *downstream_bw)
1441 {
1442 	u32 val, bw, scale;
1443 	int ret;
1444 
1445 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1446 			   port->cap_adap + ADP_USB3_CS_1, 1);
1447 	if (ret)
1448 		return ret;
1449 
1450 	ret = tb_port_read(port, &scale, TB_CFG_PORT,
1451 			   port->cap_adap + ADP_USB3_CS_3, 1);
1452 	if (ret)
1453 		return ret;
1454 
1455 	scale &= ADP_USB3_CS_3_SCALE_MASK;
1456 
1457 	bw = val & ADP_USB3_CS_1_CUBW_MASK;
1458 	*upstream_bw = usb3_bw_to_mbps(bw, scale);
1459 
1460 	bw = (val & ADP_USB3_CS_1_CDBW_MASK) >> ADP_USB3_CS_1_CDBW_SHIFT;
1461 	*downstream_bw = usb3_bw_to_mbps(bw, scale);
1462 
1463 	return 0;
1464 }
1465 
1466 static int usb4_usb3_port_write_allocated_bandwidth(struct tb_port *port,
1467 						    int upstream_bw,
1468 						    int downstream_bw)
1469 {
1470 	u32 val, ubw, dbw, scale;
1471 	int ret;
1472 
1473 	/* Read the used scale, hardware default is 0 */
1474 	ret = tb_port_read(port, &scale, TB_CFG_PORT,
1475 			   port->cap_adap + ADP_USB3_CS_3, 1);
1476 	if (ret)
1477 		return ret;
1478 
1479 	scale &= ADP_USB3_CS_3_SCALE_MASK;
1480 	ubw = mbps_to_usb3_bw(upstream_bw, scale);
1481 	dbw = mbps_to_usb3_bw(downstream_bw, scale);
1482 
1483 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1484 			   port->cap_adap + ADP_USB3_CS_2, 1);
1485 	if (ret)
1486 		return ret;
1487 
1488 	val &= ~(ADP_USB3_CS_2_AUBW_MASK | ADP_USB3_CS_2_ADBW_MASK);
1489 	val |= dbw << ADP_USB3_CS_2_ADBW_SHIFT;
1490 	val |= ubw;
1491 
1492 	return tb_port_write(port, &val, TB_CFG_PORT,
1493 			     port->cap_adap + ADP_USB3_CS_2, 1);
1494 }
1495 
1496 /**
1497  * usb4_usb3_port_allocate_bandwidth() - Allocate bandwidth for USB3
1498  * @port: USB3 adapter port
1499  * @upstream_bw: New upstream bandwidth
1500  * @downstream_bw: New downstream bandwidth
1501  *
1502  * This can be used to set how much bandwidth is allocated for the USB3
1503  * tunneled isochronous traffic. @upstream_bw and @downstream_bw are the
1504  * new values programmed to the USB3 adapter allocation registers. If
1505  * the values are lower than what is currently consumed the allocation
1506  * is set to what is currently consumed instead (consumed bandwidth
1507  * cannot be taken away by CM). The actual new values are returned in
1508  * @upstream_bw and @downstream_bw.
1509  *
1510  * Returns %0 in case of success and negative errno if there was a
1511  * failure.
1512  */
1513 int usb4_usb3_port_allocate_bandwidth(struct tb_port *port, int *upstream_bw,
1514 				      int *downstream_bw)
1515 {
1516 	int ret, consumed_up, consumed_down, allocate_up, allocate_down;
1517 
1518 	ret = usb4_usb3_port_set_cm_request(port);
1519 	if (ret)
1520 		return ret;
1521 
1522 	ret = usb4_usb3_port_read_consumed_bandwidth(port, &consumed_up,
1523 						     &consumed_down);
1524 	if (ret)
1525 		goto err_request;
1526 
1527 	/* Don't allow it go lower than what is consumed */
1528 	allocate_up = max(*upstream_bw, consumed_up);
1529 	allocate_down = max(*downstream_bw, consumed_down);
1530 
1531 	ret = usb4_usb3_port_write_allocated_bandwidth(port, allocate_up,
1532 						       allocate_down);
1533 	if (ret)
1534 		goto err_request;
1535 
1536 	*upstream_bw = allocate_up;
1537 	*downstream_bw = allocate_down;
1538 
1539 err_request:
1540 	usb4_usb3_port_clear_cm_request(port);
1541 	return ret;
1542 }
1543 
1544 /**
1545  * usb4_usb3_port_release_bandwidth() - Release allocated USB3 bandwidth
1546  * @port: USB3 adapter port
1547  * @upstream_bw: New allocated upstream bandwidth
1548  * @downstream_bw: New allocated downstream bandwidth
1549  *
1550  * Releases USB3 allocated bandwidth down to what is actually consumed.
1551  * The new bandwidth is returned in @upstream_bw and @downstream_bw.
1552  *
1553  * Returns 0% in success and negative errno in case of failure.
1554  */
1555 int usb4_usb3_port_release_bandwidth(struct tb_port *port, int *upstream_bw,
1556 				     int *downstream_bw)
1557 {
1558 	int ret, consumed_up, consumed_down;
1559 
1560 	ret = usb4_usb3_port_set_cm_request(port);
1561 	if (ret)
1562 		return ret;
1563 
1564 	ret = usb4_usb3_port_read_consumed_bandwidth(port, &consumed_up,
1565 						     &consumed_down);
1566 	if (ret)
1567 		goto err_request;
1568 
1569 	/*
1570 	 * Always keep 1000 Mb/s to make sure xHCI has at least some
1571 	 * bandwidth available for isochronous traffic.
1572 	 */
1573 	if (consumed_up < 1000)
1574 		consumed_up = 1000;
1575 	if (consumed_down < 1000)
1576 		consumed_down = 1000;
1577 
1578 	ret = usb4_usb3_port_write_allocated_bandwidth(port, consumed_up,
1579 						       consumed_down);
1580 	if (ret)
1581 		goto err_request;
1582 
1583 	*upstream_bw = consumed_up;
1584 	*downstream_bw = consumed_down;
1585 
1586 err_request:
1587 	usb4_usb3_port_clear_cm_request(port);
1588 	return ret;
1589 }
1590