xref: /linux/drivers/thunderbolt/usb4.c (revision d6a5c562214f26e442c8ec3ff1e28e16675d1bcf)
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_RETRIES		3
17 
18 enum usb4_sb_target {
19 	USB4_SB_TARGET_ROUTER,
20 	USB4_SB_TARGET_PARTNER,
21 	USB4_SB_TARGET_RETIMER,
22 };
23 
24 #define USB4_NVM_READ_OFFSET_MASK	GENMASK(23, 2)
25 #define USB4_NVM_READ_OFFSET_SHIFT	2
26 #define USB4_NVM_READ_LENGTH_MASK	GENMASK(27, 24)
27 #define USB4_NVM_READ_LENGTH_SHIFT	24
28 
29 #define USB4_NVM_SET_OFFSET_MASK	USB4_NVM_READ_OFFSET_MASK
30 #define USB4_NVM_SET_OFFSET_SHIFT	USB4_NVM_READ_OFFSET_SHIFT
31 
32 #define USB4_DROM_ADDRESS_MASK		GENMASK(14, 2)
33 #define USB4_DROM_ADDRESS_SHIFT		2
34 #define USB4_DROM_SIZE_MASK		GENMASK(19, 15)
35 #define USB4_DROM_SIZE_SHIFT		15
36 
37 #define USB4_NVM_SECTOR_SIZE_MASK	GENMASK(23, 0)
38 
39 #define USB4_BA_LENGTH_MASK		GENMASK(7, 0)
40 #define USB4_BA_INDEX_MASK		GENMASK(15, 0)
41 
42 enum usb4_ba_index {
43 	USB4_BA_MAX_USB3 = 0x1,
44 	USB4_BA_MIN_DP_AUX = 0x2,
45 	USB4_BA_MIN_DP_MAIN = 0x3,
46 	USB4_BA_MAX_PCIE = 0x4,
47 	USB4_BA_MAX_HI = 0x5,
48 };
49 
50 #define USB4_BA_VALUE_MASK		GENMASK(31, 16)
51 #define USB4_BA_VALUE_SHIFT		16
52 
53 static int usb4_native_switch_op(struct tb_switch *sw, u16 opcode,
54 				 u32 *metadata, u8 *status,
55 				 const void *tx_data, size_t tx_dwords,
56 				 void *rx_data, size_t rx_dwords)
57 {
58 	u32 val;
59 	int ret;
60 
61 	if (metadata) {
62 		ret = tb_sw_write(sw, metadata, TB_CFG_SWITCH, ROUTER_CS_25, 1);
63 		if (ret)
64 			return ret;
65 	}
66 	if (tx_dwords) {
67 		ret = tb_sw_write(sw, tx_data, TB_CFG_SWITCH, ROUTER_CS_9,
68 				  tx_dwords);
69 		if (ret)
70 			return ret;
71 	}
72 
73 	val = opcode | ROUTER_CS_26_OV;
74 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_26, 1);
75 	if (ret)
76 		return ret;
77 
78 	ret = tb_switch_wait_for_bit(sw, ROUTER_CS_26, ROUTER_CS_26_OV, 0, 500);
79 	if (ret)
80 		return ret;
81 
82 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_26, 1);
83 	if (ret)
84 		return ret;
85 
86 	if (val & ROUTER_CS_26_ONS)
87 		return -EOPNOTSUPP;
88 
89 	if (status)
90 		*status = (val & ROUTER_CS_26_STATUS_MASK) >>
91 			ROUTER_CS_26_STATUS_SHIFT;
92 
93 	if (metadata) {
94 		ret = tb_sw_read(sw, metadata, TB_CFG_SWITCH, ROUTER_CS_25, 1);
95 		if (ret)
96 			return ret;
97 	}
98 	if (rx_dwords) {
99 		ret = tb_sw_read(sw, rx_data, TB_CFG_SWITCH, ROUTER_CS_9,
100 				 rx_dwords);
101 		if (ret)
102 			return ret;
103 	}
104 
105 	return 0;
106 }
107 
108 static int __usb4_switch_op(struct tb_switch *sw, u16 opcode, u32 *metadata,
109 			    u8 *status, const void *tx_data, size_t tx_dwords,
110 			    void *rx_data, size_t rx_dwords)
111 {
112 	const struct tb_cm_ops *cm_ops = sw->tb->cm_ops;
113 
114 	if (tx_dwords > NVM_DATA_DWORDS || rx_dwords > NVM_DATA_DWORDS)
115 		return -EINVAL;
116 
117 	/*
118 	 * If the connection manager implementation provides USB4 router
119 	 * operation proxy callback, call it here instead of running the
120 	 * operation natively.
121 	 */
122 	if (cm_ops->usb4_switch_op) {
123 		int ret;
124 
125 		ret = cm_ops->usb4_switch_op(sw, opcode, metadata, status,
126 					     tx_data, tx_dwords, rx_data,
127 					     rx_dwords);
128 		if (ret != -EOPNOTSUPP)
129 			return ret;
130 
131 		/*
132 		 * If the proxy was not supported then run the native
133 		 * router operation instead.
134 		 */
135 	}
136 
137 	return usb4_native_switch_op(sw, opcode, metadata, status, tx_data,
138 				     tx_dwords, rx_data, rx_dwords);
139 }
140 
141 static inline int usb4_switch_op(struct tb_switch *sw, u16 opcode,
142 				 u32 *metadata, u8 *status)
143 {
144 	return __usb4_switch_op(sw, opcode, metadata, status, NULL, 0, NULL, 0);
145 }
146 
147 static inline int usb4_switch_op_data(struct tb_switch *sw, u16 opcode,
148 				      u32 *metadata, u8 *status,
149 				      const void *tx_data, size_t tx_dwords,
150 				      void *rx_data, size_t rx_dwords)
151 {
152 	return __usb4_switch_op(sw, opcode, metadata, status, tx_data,
153 				tx_dwords, rx_data, rx_dwords);
154 }
155 
156 static void usb4_switch_check_wakes(struct tb_switch *sw)
157 {
158 	struct tb_port *port;
159 	bool wakeup = false;
160 	u32 val;
161 
162 	if (!device_may_wakeup(&sw->dev))
163 		return;
164 
165 	if (tb_route(sw)) {
166 		if (tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_6, 1))
167 			return;
168 
169 		tb_sw_dbg(sw, "PCIe wake: %s, USB3 wake: %s\n",
170 			  (val & ROUTER_CS_6_WOPS) ? "yes" : "no",
171 			  (val & ROUTER_CS_6_WOUS) ? "yes" : "no");
172 
173 		wakeup = val & (ROUTER_CS_6_WOPS | ROUTER_CS_6_WOUS);
174 	}
175 
176 	/* Check for any connected downstream ports for USB4 wake */
177 	tb_switch_for_each_port(sw, port) {
178 		if (!tb_port_has_remote(port))
179 			continue;
180 
181 		if (tb_port_read(port, &val, TB_CFG_PORT,
182 				 port->cap_usb4 + PORT_CS_18, 1))
183 			break;
184 
185 		tb_port_dbg(port, "USB4 wake: %s\n",
186 			    (val & PORT_CS_18_WOU4S) ? "yes" : "no");
187 
188 		if (val & PORT_CS_18_WOU4S)
189 			wakeup = true;
190 	}
191 
192 	if (wakeup)
193 		pm_wakeup_event(&sw->dev, 0);
194 }
195 
196 static bool link_is_usb4(struct tb_port *port)
197 {
198 	u32 val;
199 
200 	if (!port->cap_usb4)
201 		return false;
202 
203 	if (tb_port_read(port, &val, TB_CFG_PORT,
204 			 port->cap_usb4 + PORT_CS_18, 1))
205 		return false;
206 
207 	return !(val & PORT_CS_18_TCM);
208 }
209 
210 /**
211  * usb4_switch_setup() - Additional setup for USB4 device
212  * @sw: USB4 router to setup
213  *
214  * USB4 routers need additional settings in order to enable all the
215  * tunneling. This function enables USB and PCIe tunneling if it can be
216  * enabled (e.g the parent switch also supports them). If USB tunneling
217  * is not available for some reason (like that there is Thunderbolt 3
218  * switch upstream) then the internal xHCI controller is enabled
219  * instead.
220  */
221 int usb4_switch_setup(struct tb_switch *sw)
222 {
223 	struct tb_port *downstream_port;
224 	struct tb_switch *parent;
225 	bool tbt3, xhci;
226 	u32 val = 0;
227 	int ret;
228 
229 	usb4_switch_check_wakes(sw);
230 
231 	if (!tb_route(sw))
232 		return 0;
233 
234 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_6, 1);
235 	if (ret)
236 		return ret;
237 
238 	parent = tb_switch_parent(sw);
239 	downstream_port = tb_port_at(tb_route(sw), parent);
240 	sw->link_usb4 = link_is_usb4(downstream_port);
241 	tb_sw_dbg(sw, "link: %s\n", sw->link_usb4 ? "USB4" : "TBT");
242 
243 	xhci = val & ROUTER_CS_6_HCI;
244 	tbt3 = !(val & ROUTER_CS_6_TNS);
245 
246 	tb_sw_dbg(sw, "TBT3 support: %s, xHCI: %s\n",
247 		  tbt3 ? "yes" : "no", xhci ? "yes" : "no");
248 
249 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
250 	if (ret)
251 		return ret;
252 
253 	if (tb_acpi_may_tunnel_usb3() && sw->link_usb4 &&
254 	    tb_switch_find_port(parent, TB_TYPE_USB3_DOWN)) {
255 		val |= ROUTER_CS_5_UTO;
256 		xhci = false;
257 	}
258 
259 	/*
260 	 * Only enable PCIe tunneling if the parent router supports it
261 	 * and it is not disabled.
262 	 */
263 	if (tb_acpi_may_tunnel_pcie() &&
264 	    tb_switch_find_port(parent, TB_TYPE_PCIE_DOWN)) {
265 		val |= ROUTER_CS_5_PTO;
266 		/*
267 		 * xHCI can be enabled if PCIe tunneling is supported
268 		 * and the parent does not have any USB3 dowstream
269 		 * adapters (so we cannot do USB 3.x tunneling).
270 		 */
271 		if (xhci)
272 			val |= ROUTER_CS_5_HCO;
273 	}
274 
275 	/* TBT3 supported by the CM */
276 	val |= ROUTER_CS_5_C3S;
277 	/* Tunneling configuration is ready now */
278 	val |= ROUTER_CS_5_CV;
279 
280 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
281 	if (ret)
282 		return ret;
283 
284 	return tb_switch_wait_for_bit(sw, ROUTER_CS_6, ROUTER_CS_6_CR,
285 				      ROUTER_CS_6_CR, 50);
286 }
287 
288 /**
289  * usb4_switch_read_uid() - Read UID from USB4 router
290  * @sw: USB4 router
291  * @uid: UID is stored here
292  *
293  * Reads 64-bit UID from USB4 router config space.
294  */
295 int usb4_switch_read_uid(struct tb_switch *sw, u64 *uid)
296 {
297 	return tb_sw_read(sw, uid, TB_CFG_SWITCH, ROUTER_CS_7, 2);
298 }
299 
300 static int usb4_switch_drom_read_block(void *data,
301 				       unsigned int dwaddress, void *buf,
302 				       size_t dwords)
303 {
304 	struct tb_switch *sw = data;
305 	u8 status = 0;
306 	u32 metadata;
307 	int ret;
308 
309 	metadata = (dwords << USB4_DROM_SIZE_SHIFT) & USB4_DROM_SIZE_MASK;
310 	metadata |= (dwaddress << USB4_DROM_ADDRESS_SHIFT) &
311 		USB4_DROM_ADDRESS_MASK;
312 
313 	ret = usb4_switch_op_data(sw, USB4_SWITCH_OP_DROM_READ, &metadata,
314 				  &status, NULL, 0, buf, dwords);
315 	if (ret)
316 		return ret;
317 
318 	return status ? -EIO : 0;
319 }
320 
321 /**
322  * usb4_switch_drom_read() - Read arbitrary bytes from USB4 router DROM
323  * @sw: USB4 router
324  * @address: Byte address inside DROM to start reading
325  * @buf: Buffer where the DROM content is stored
326  * @size: Number of bytes to read from DROM
327  *
328  * Uses USB4 router operations to read router DROM. For devices this
329  * should always work but for hosts it may return %-EOPNOTSUPP in which
330  * case the host router does not have DROM.
331  */
332 int usb4_switch_drom_read(struct tb_switch *sw, unsigned int address, void *buf,
333 			  size_t size)
334 {
335 	return tb_nvm_read_data(address, buf, size, USB4_DATA_RETRIES,
336 				usb4_switch_drom_read_block, sw);
337 }
338 
339 /**
340  * usb4_switch_lane_bonding_possible() - Are conditions met for lane bonding
341  * @sw: USB4 router
342  *
343  * Checks whether conditions are met so that lane bonding can be
344  * established with the upstream router. Call only for device routers.
345  */
346 bool usb4_switch_lane_bonding_possible(struct tb_switch *sw)
347 {
348 	struct tb_port *up;
349 	int ret;
350 	u32 val;
351 
352 	up = tb_upstream_port(sw);
353 	ret = tb_port_read(up, &val, TB_CFG_PORT, up->cap_usb4 + PORT_CS_18, 1);
354 	if (ret)
355 		return false;
356 
357 	return !!(val & PORT_CS_18_BE);
358 }
359 
360 /**
361  * usb4_switch_set_wake() - Enabled/disable wake
362  * @sw: USB4 router
363  * @flags: Wakeup flags (%0 to disable)
364  *
365  * Enables/disables router to wake up from sleep.
366  */
367 int usb4_switch_set_wake(struct tb_switch *sw, unsigned int flags)
368 {
369 	struct tb_port *port;
370 	u64 route = tb_route(sw);
371 	u32 val;
372 	int ret;
373 
374 	/*
375 	 * Enable wakes coming from all USB4 downstream ports (from
376 	 * child routers). For device routers do this also for the
377 	 * upstream USB4 port.
378 	 */
379 	tb_switch_for_each_port(sw, port) {
380 		if (!tb_port_is_null(port))
381 			continue;
382 		if (!route && tb_is_upstream_port(port))
383 			continue;
384 		if (!port->cap_usb4)
385 			continue;
386 
387 		ret = tb_port_read(port, &val, TB_CFG_PORT,
388 				   port->cap_usb4 + PORT_CS_19, 1);
389 		if (ret)
390 			return ret;
391 
392 		val &= ~(PORT_CS_19_WOC | PORT_CS_19_WOD | PORT_CS_19_WOU4);
393 
394 		if (tb_is_upstream_port(port)) {
395 			val |= PORT_CS_19_WOU4;
396 		} else {
397 			bool configured = val & PORT_CS_19_PC;
398 
399 			if ((flags & TB_WAKE_ON_CONNECT) && !configured)
400 				val |= PORT_CS_19_WOC;
401 			if ((flags & TB_WAKE_ON_DISCONNECT) && configured)
402 				val |= PORT_CS_19_WOD;
403 			if ((flags & TB_WAKE_ON_USB4) && configured)
404 				val |= PORT_CS_19_WOU4;
405 		}
406 
407 		ret = tb_port_write(port, &val, TB_CFG_PORT,
408 				    port->cap_usb4 + PORT_CS_19, 1);
409 		if (ret)
410 			return ret;
411 	}
412 
413 	/*
414 	 * Enable wakes from PCIe, USB 3.x and DP on this router. Only
415 	 * needed for device routers.
416 	 */
417 	if (route) {
418 		ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
419 		if (ret)
420 			return ret;
421 
422 		val &= ~(ROUTER_CS_5_WOP | ROUTER_CS_5_WOU | ROUTER_CS_5_WOD);
423 		if (flags & TB_WAKE_ON_USB3)
424 			val |= ROUTER_CS_5_WOU;
425 		if (flags & TB_WAKE_ON_PCIE)
426 			val |= ROUTER_CS_5_WOP;
427 		if (flags & TB_WAKE_ON_DP)
428 			val |= ROUTER_CS_5_WOD;
429 
430 		ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
431 		if (ret)
432 			return ret;
433 	}
434 
435 	return 0;
436 }
437 
438 /**
439  * usb4_switch_set_sleep() - Prepare the router to enter sleep
440  * @sw: USB4 router
441  *
442  * Sets sleep bit for the router. Returns when the router sleep ready
443  * bit has been asserted.
444  */
445 int usb4_switch_set_sleep(struct tb_switch *sw)
446 {
447 	int ret;
448 	u32 val;
449 
450 	/* Set sleep bit and wait for sleep ready to be asserted */
451 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
452 	if (ret)
453 		return ret;
454 
455 	val |= ROUTER_CS_5_SLP;
456 
457 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
458 	if (ret)
459 		return ret;
460 
461 	return tb_switch_wait_for_bit(sw, ROUTER_CS_6, ROUTER_CS_6_SLPR,
462 				      ROUTER_CS_6_SLPR, 500);
463 }
464 
465 /**
466  * usb4_switch_nvm_sector_size() - Return router NVM sector size
467  * @sw: USB4 router
468  *
469  * If the router supports NVM operations this function returns the NVM
470  * sector size in bytes. If NVM operations are not supported returns
471  * %-EOPNOTSUPP.
472  */
473 int usb4_switch_nvm_sector_size(struct tb_switch *sw)
474 {
475 	u32 metadata;
476 	u8 status;
477 	int ret;
478 
479 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_SECTOR_SIZE, &metadata,
480 			     &status);
481 	if (ret)
482 		return ret;
483 
484 	if (status)
485 		return status == 0x2 ? -EOPNOTSUPP : -EIO;
486 
487 	return metadata & USB4_NVM_SECTOR_SIZE_MASK;
488 }
489 
490 static int usb4_switch_nvm_read_block(void *data,
491 	unsigned int dwaddress, void *buf, size_t dwords)
492 {
493 	struct tb_switch *sw = data;
494 	u8 status = 0;
495 	u32 metadata;
496 	int ret;
497 
498 	metadata = (dwords << USB4_NVM_READ_LENGTH_SHIFT) &
499 		   USB4_NVM_READ_LENGTH_MASK;
500 	metadata |= (dwaddress << USB4_NVM_READ_OFFSET_SHIFT) &
501 		   USB4_NVM_READ_OFFSET_MASK;
502 
503 	ret = usb4_switch_op_data(sw, USB4_SWITCH_OP_NVM_READ, &metadata,
504 				  &status, NULL, 0, buf, dwords);
505 	if (ret)
506 		return ret;
507 
508 	return status ? -EIO : 0;
509 }
510 
511 /**
512  * usb4_switch_nvm_read() - Read arbitrary bytes from router NVM
513  * @sw: USB4 router
514  * @address: Starting address in bytes
515  * @buf: Read data is placed here
516  * @size: How many bytes to read
517  *
518  * Reads NVM contents of the router. If NVM is not supported returns
519  * %-EOPNOTSUPP.
520  */
521 int usb4_switch_nvm_read(struct tb_switch *sw, unsigned int address, void *buf,
522 			 size_t size)
523 {
524 	return tb_nvm_read_data(address, buf, size, USB4_DATA_RETRIES,
525 				usb4_switch_nvm_read_block, sw);
526 }
527 
528 /**
529  * usb4_switch_nvm_set_offset() - Set NVM write offset
530  * @sw: USB4 router
531  * @address: Start offset
532  *
533  * Explicitly sets NVM write offset. Normally when writing to NVM this
534  * is done automatically by usb4_switch_nvm_write().
535  *
536  * Returns %0 in success and negative errno if there was a failure.
537  */
538 int usb4_switch_nvm_set_offset(struct tb_switch *sw, unsigned int address)
539 {
540 	u32 metadata, dwaddress;
541 	u8 status = 0;
542 	int ret;
543 
544 	dwaddress = address / 4;
545 	metadata = (dwaddress << USB4_NVM_SET_OFFSET_SHIFT) &
546 		   USB4_NVM_SET_OFFSET_MASK;
547 
548 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_SET_OFFSET, &metadata,
549 			     &status);
550 	if (ret)
551 		return ret;
552 
553 	return status ? -EIO : 0;
554 }
555 
556 static int usb4_switch_nvm_write_next_block(void *data, unsigned int dwaddress,
557 					    const void *buf, size_t dwords)
558 {
559 	struct tb_switch *sw = data;
560 	u8 status;
561 	int ret;
562 
563 	ret = usb4_switch_op_data(sw, USB4_SWITCH_OP_NVM_WRITE, NULL, &status,
564 				  buf, dwords, NULL, 0);
565 	if (ret)
566 		return ret;
567 
568 	return status ? -EIO : 0;
569 }
570 
571 /**
572  * usb4_switch_nvm_write() - Write to the router NVM
573  * @sw: USB4 router
574  * @address: Start address where to write in bytes
575  * @buf: Pointer to the data to write
576  * @size: Size of @buf in bytes
577  *
578  * Writes @buf to the router NVM using USB4 router operations. If NVM
579  * write is not supported returns %-EOPNOTSUPP.
580  */
581 int usb4_switch_nvm_write(struct tb_switch *sw, unsigned int address,
582 			  const void *buf, size_t size)
583 {
584 	int ret;
585 
586 	ret = usb4_switch_nvm_set_offset(sw, address);
587 	if (ret)
588 		return ret;
589 
590 	return tb_nvm_write_data(address, buf, size, USB4_DATA_RETRIES,
591 				 usb4_switch_nvm_write_next_block, sw);
592 }
593 
594 /**
595  * usb4_switch_nvm_authenticate() - Authenticate new NVM
596  * @sw: USB4 router
597  *
598  * After the new NVM has been written via usb4_switch_nvm_write(), this
599  * function triggers NVM authentication process. The router gets power
600  * cycled and if the authentication is successful the new NVM starts
601  * running. In case of failure returns negative errno.
602  *
603  * The caller should call usb4_switch_nvm_authenticate_status() to read
604  * the status of the authentication after power cycle. It should be the
605  * first router operation to avoid the status being lost.
606  */
607 int usb4_switch_nvm_authenticate(struct tb_switch *sw)
608 {
609 	int ret;
610 
611 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_AUTH, NULL, NULL);
612 	switch (ret) {
613 	/*
614 	 * The router is power cycled once NVM_AUTH is started so it is
615 	 * expected to get any of the following errors back.
616 	 */
617 	case -EACCES:
618 	case -ENOTCONN:
619 	case -ETIMEDOUT:
620 		return 0;
621 
622 	default:
623 		return ret;
624 	}
625 }
626 
627 /**
628  * usb4_switch_nvm_authenticate_status() - Read status of last NVM authenticate
629  * @sw: USB4 router
630  * @status: Status code of the operation
631  *
632  * The function checks if there is status available from the last NVM
633  * authenticate router operation. If there is status then %0 is returned
634  * and the status code is placed in @status. Returns negative errno in case
635  * of failure.
636  *
637  * Must be called before any other router operation.
638  */
639 int usb4_switch_nvm_authenticate_status(struct tb_switch *sw, u32 *status)
640 {
641 	const struct tb_cm_ops *cm_ops = sw->tb->cm_ops;
642 	u16 opcode;
643 	u32 val;
644 	int ret;
645 
646 	if (cm_ops->usb4_switch_nvm_authenticate_status) {
647 		ret = cm_ops->usb4_switch_nvm_authenticate_status(sw, status);
648 		if (ret != -EOPNOTSUPP)
649 			return ret;
650 	}
651 
652 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_26, 1);
653 	if (ret)
654 		return ret;
655 
656 	/* Check that the opcode is correct */
657 	opcode = val & ROUTER_CS_26_OPCODE_MASK;
658 	if (opcode == USB4_SWITCH_OP_NVM_AUTH) {
659 		if (val & ROUTER_CS_26_OV)
660 			return -EBUSY;
661 		if (val & ROUTER_CS_26_ONS)
662 			return -EOPNOTSUPP;
663 
664 		*status = (val & ROUTER_CS_26_STATUS_MASK) >>
665 			ROUTER_CS_26_STATUS_SHIFT;
666 	} else {
667 		*status = 0;
668 	}
669 
670 	return 0;
671 }
672 
673 /**
674  * usb4_switch_credits_init() - Read buffer allocation parameters
675  * @sw: USB4 router
676  *
677  * Reads @sw buffer allocation parameters and initializes @sw buffer
678  * allocation fields accordingly. Specifically @sw->credits_allocation
679  * is set to %true if these parameters can be used in tunneling.
680  *
681  * Returns %0 on success and negative errno otherwise.
682  */
683 int usb4_switch_credits_init(struct tb_switch *sw)
684 {
685 	int max_usb3, min_dp_aux, min_dp_main, max_pcie, max_dma;
686 	int ret, length, i, nports;
687 	const struct tb_port *port;
688 	u32 data[NVM_DATA_DWORDS];
689 	u32 metadata = 0;
690 	u8 status = 0;
691 
692 	memset(data, 0, sizeof(data));
693 	ret = usb4_switch_op_data(sw, USB4_SWITCH_OP_BUFFER_ALLOC, &metadata,
694 				  &status, NULL, 0, data, ARRAY_SIZE(data));
695 	if (ret)
696 		return ret;
697 	if (status)
698 		return -EIO;
699 
700 	length = metadata & USB4_BA_LENGTH_MASK;
701 	if (WARN_ON(length > ARRAY_SIZE(data)))
702 		return -EMSGSIZE;
703 
704 	max_usb3 = -1;
705 	min_dp_aux = -1;
706 	min_dp_main = -1;
707 	max_pcie = -1;
708 	max_dma = -1;
709 
710 	tb_sw_dbg(sw, "credit allocation parameters:\n");
711 
712 	for (i = 0; i < length; i++) {
713 		u16 index, value;
714 
715 		index = data[i] & USB4_BA_INDEX_MASK;
716 		value = (data[i] & USB4_BA_VALUE_MASK) >> USB4_BA_VALUE_SHIFT;
717 
718 		switch (index) {
719 		case USB4_BA_MAX_USB3:
720 			tb_sw_dbg(sw, " USB3: %u\n", value);
721 			max_usb3 = value;
722 			break;
723 		case USB4_BA_MIN_DP_AUX:
724 			tb_sw_dbg(sw, " DP AUX: %u\n", value);
725 			min_dp_aux = value;
726 			break;
727 		case USB4_BA_MIN_DP_MAIN:
728 			tb_sw_dbg(sw, " DP main: %u\n", value);
729 			min_dp_main = value;
730 			break;
731 		case USB4_BA_MAX_PCIE:
732 			tb_sw_dbg(sw, " PCIe: %u\n", value);
733 			max_pcie = value;
734 			break;
735 		case USB4_BA_MAX_HI:
736 			tb_sw_dbg(sw, " DMA: %u\n", value);
737 			max_dma = value;
738 			break;
739 		default:
740 			tb_sw_dbg(sw, " unknown credit allocation index %#x, skipping\n",
741 				  index);
742 			break;
743 		}
744 	}
745 
746 	/*
747 	 * Validate the buffer allocation preferences. If we find
748 	 * issues, log a warning and fall back using the hard-coded
749 	 * values.
750 	 */
751 
752 	/* Host router must report baMaxHI */
753 	if (!tb_route(sw) && max_dma < 0) {
754 		tb_sw_warn(sw, "host router is missing baMaxHI\n");
755 		goto err_invalid;
756 	}
757 
758 	nports = 0;
759 	tb_switch_for_each_port(sw, port) {
760 		if (tb_port_is_null(port))
761 			nports++;
762 	}
763 
764 	/* Must have DP buffer allocation (multiple USB4 ports) */
765 	if (nports > 2 && (min_dp_aux < 0 || min_dp_main < 0)) {
766 		tb_sw_warn(sw, "multiple USB4 ports require baMinDPaux/baMinDPmain\n");
767 		goto err_invalid;
768 	}
769 
770 	tb_switch_for_each_port(sw, port) {
771 		if (tb_port_is_dpout(port) && min_dp_main < 0) {
772 			tb_sw_warn(sw, "missing baMinDPmain");
773 			goto err_invalid;
774 		}
775 		if ((tb_port_is_dpin(port) || tb_port_is_dpout(port)) &&
776 		    min_dp_aux < 0) {
777 			tb_sw_warn(sw, "missing baMinDPaux");
778 			goto err_invalid;
779 		}
780 		if ((tb_port_is_usb3_down(port) || tb_port_is_usb3_up(port)) &&
781 		    max_usb3 < 0) {
782 			tb_sw_warn(sw, "missing baMaxUSB3");
783 			goto err_invalid;
784 		}
785 		if ((tb_port_is_pcie_down(port) || tb_port_is_pcie_up(port)) &&
786 		    max_pcie < 0) {
787 			tb_sw_warn(sw, "missing baMaxPCIe");
788 			goto err_invalid;
789 		}
790 	}
791 
792 	/*
793 	 * Buffer allocation passed the validation so we can use it in
794 	 * path creation.
795 	 */
796 	sw->credit_allocation = true;
797 	if (max_usb3 > 0)
798 		sw->max_usb3_credits = max_usb3;
799 	if (min_dp_aux > 0)
800 		sw->min_dp_aux_credits = min_dp_aux;
801 	if (min_dp_main > 0)
802 		sw->min_dp_main_credits = min_dp_main;
803 	if (max_pcie > 0)
804 		sw->max_pcie_credits = max_pcie;
805 	if (max_dma > 0)
806 		sw->max_dma_credits = max_dma;
807 
808 	return 0;
809 
810 err_invalid:
811 	return -EINVAL;
812 }
813 
814 /**
815  * usb4_switch_query_dp_resource() - Query availability of DP IN resource
816  * @sw: USB4 router
817  * @in: DP IN adapter
818  *
819  * For DP tunneling this function can be used to query availability of
820  * DP IN resource. Returns true if the resource is available for DP
821  * tunneling, false otherwise.
822  */
823 bool usb4_switch_query_dp_resource(struct tb_switch *sw, struct tb_port *in)
824 {
825 	u32 metadata = in->port;
826 	u8 status;
827 	int ret;
828 
829 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_QUERY_DP_RESOURCE, &metadata,
830 			     &status);
831 	/*
832 	 * If DP resource allocation is not supported assume it is
833 	 * always available.
834 	 */
835 	if (ret == -EOPNOTSUPP)
836 		return true;
837 	else if (ret)
838 		return false;
839 
840 	return !status;
841 }
842 
843 /**
844  * usb4_switch_alloc_dp_resource() - Allocate DP IN resource
845  * @sw: USB4 router
846  * @in: DP IN adapter
847  *
848  * Allocates DP IN resource for DP tunneling using USB4 router
849  * operations. If the resource was allocated returns %0. Otherwise
850  * returns negative errno, in particular %-EBUSY if the resource is
851  * already allocated.
852  */
853 int usb4_switch_alloc_dp_resource(struct tb_switch *sw, struct tb_port *in)
854 {
855 	u32 metadata = in->port;
856 	u8 status;
857 	int ret;
858 
859 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_ALLOC_DP_RESOURCE, &metadata,
860 			     &status);
861 	if (ret == -EOPNOTSUPP)
862 		return 0;
863 	else if (ret)
864 		return ret;
865 
866 	return status ? -EBUSY : 0;
867 }
868 
869 /**
870  * usb4_switch_dealloc_dp_resource() - Releases allocated DP IN resource
871  * @sw: USB4 router
872  * @in: DP IN adapter
873  *
874  * Releases the previously allocated DP IN resource.
875  */
876 int usb4_switch_dealloc_dp_resource(struct tb_switch *sw, struct tb_port *in)
877 {
878 	u32 metadata = in->port;
879 	u8 status;
880 	int ret;
881 
882 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_DEALLOC_DP_RESOURCE, &metadata,
883 			     &status);
884 	if (ret == -EOPNOTSUPP)
885 		return 0;
886 	else if (ret)
887 		return ret;
888 
889 	return status ? -EIO : 0;
890 }
891 
892 static int usb4_port_idx(const struct tb_switch *sw, const struct tb_port *port)
893 {
894 	struct tb_port *p;
895 	int usb4_idx = 0;
896 
897 	/* Assume port is primary */
898 	tb_switch_for_each_port(sw, p) {
899 		if (!tb_port_is_null(p))
900 			continue;
901 		if (tb_is_upstream_port(p))
902 			continue;
903 		if (!p->link_nr) {
904 			if (p == port)
905 				break;
906 			usb4_idx++;
907 		}
908 	}
909 
910 	return usb4_idx;
911 }
912 
913 /**
914  * usb4_switch_map_pcie_down() - Map USB4 port to a PCIe downstream adapter
915  * @sw: USB4 router
916  * @port: USB4 port
917  *
918  * USB4 routers have direct mapping between USB4 ports and PCIe
919  * downstream adapters where the PCIe topology is extended. This
920  * function returns the corresponding downstream PCIe adapter or %NULL
921  * if no such mapping was possible.
922  */
923 struct tb_port *usb4_switch_map_pcie_down(struct tb_switch *sw,
924 					  const struct tb_port *port)
925 {
926 	int usb4_idx = usb4_port_idx(sw, port);
927 	struct tb_port *p;
928 	int pcie_idx = 0;
929 
930 	/* Find PCIe down port matching usb4_port */
931 	tb_switch_for_each_port(sw, p) {
932 		if (!tb_port_is_pcie_down(p))
933 			continue;
934 
935 		if (pcie_idx == usb4_idx)
936 			return p;
937 
938 		pcie_idx++;
939 	}
940 
941 	return NULL;
942 }
943 
944 /**
945  * usb4_switch_map_usb3_down() - Map USB4 port to a USB3 downstream adapter
946  * @sw: USB4 router
947  * @port: USB4 port
948  *
949  * USB4 routers have direct mapping between USB4 ports and USB 3.x
950  * downstream adapters where the USB 3.x topology is extended. This
951  * function returns the corresponding downstream USB 3.x adapter or
952  * %NULL if no such mapping was possible.
953  */
954 struct tb_port *usb4_switch_map_usb3_down(struct tb_switch *sw,
955 					  const struct tb_port *port)
956 {
957 	int usb4_idx = usb4_port_idx(sw, port);
958 	struct tb_port *p;
959 	int usb_idx = 0;
960 
961 	/* Find USB3 down port matching usb4_port */
962 	tb_switch_for_each_port(sw, p) {
963 		if (!tb_port_is_usb3_down(p))
964 			continue;
965 
966 		if (usb_idx == usb4_idx)
967 			return p;
968 
969 		usb_idx++;
970 	}
971 
972 	return NULL;
973 }
974 
975 /**
976  * usb4_switch_add_ports() - Add USB4 ports for this router
977  * @sw: USB4 router
978  *
979  * For USB4 router finds all USB4 ports and registers devices for each.
980  * Can be called to any router.
981  *
982  * Return %0 in case of success and negative errno in case of failure.
983  */
984 int usb4_switch_add_ports(struct tb_switch *sw)
985 {
986 	struct tb_port *port;
987 
988 	if (tb_switch_is_icm(sw) || !tb_switch_is_usb4(sw))
989 		return 0;
990 
991 	tb_switch_for_each_port(sw, port) {
992 		struct usb4_port *usb4;
993 
994 		if (!tb_port_is_null(port))
995 			continue;
996 		if (!port->cap_usb4)
997 			continue;
998 
999 		usb4 = usb4_port_device_add(port);
1000 		if (IS_ERR(usb4)) {
1001 			usb4_switch_remove_ports(sw);
1002 			return PTR_ERR(usb4);
1003 		}
1004 
1005 		port->usb4 = usb4;
1006 	}
1007 
1008 	return 0;
1009 }
1010 
1011 /**
1012  * usb4_switch_remove_ports() - Removes USB4 ports from this router
1013  * @sw: USB4 router
1014  *
1015  * Unregisters previously registered USB4 ports.
1016  */
1017 void usb4_switch_remove_ports(struct tb_switch *sw)
1018 {
1019 	struct tb_port *port;
1020 
1021 	tb_switch_for_each_port(sw, port) {
1022 		if (port->usb4) {
1023 			usb4_port_device_remove(port->usb4);
1024 			port->usb4 = NULL;
1025 		}
1026 	}
1027 }
1028 
1029 /**
1030  * usb4_port_unlock() - Unlock USB4 downstream port
1031  * @port: USB4 port to unlock
1032  *
1033  * Unlocks USB4 downstream port so that the connection manager can
1034  * access the router below this port.
1035  */
1036 int usb4_port_unlock(struct tb_port *port)
1037 {
1038 	int ret;
1039 	u32 val;
1040 
1041 	ret = tb_port_read(port, &val, TB_CFG_PORT, ADP_CS_4, 1);
1042 	if (ret)
1043 		return ret;
1044 
1045 	val &= ~ADP_CS_4_LCK;
1046 	return tb_port_write(port, &val, TB_CFG_PORT, ADP_CS_4, 1);
1047 }
1048 
1049 /**
1050  * usb4_port_hotplug_enable() - Enables hotplug for a port
1051  * @port: USB4 port to operate on
1052  *
1053  * Enables hot plug events on a given port. This is only intended
1054  * to be used on lane, DP-IN, and DP-OUT adapters.
1055  */
1056 int usb4_port_hotplug_enable(struct tb_port *port)
1057 {
1058 	int ret;
1059 	u32 val;
1060 
1061 	ret = tb_port_read(port, &val, TB_CFG_PORT, ADP_CS_5, 1);
1062 	if (ret)
1063 		return ret;
1064 
1065 	val &= ~ADP_CS_5_DHP;
1066 	return tb_port_write(port, &val, TB_CFG_PORT, ADP_CS_5, 1);
1067 }
1068 
1069 static int usb4_port_set_configured(struct tb_port *port, bool configured)
1070 {
1071 	int ret;
1072 	u32 val;
1073 
1074 	if (!port->cap_usb4)
1075 		return -EINVAL;
1076 
1077 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1078 			   port->cap_usb4 + PORT_CS_19, 1);
1079 	if (ret)
1080 		return ret;
1081 
1082 	if (configured)
1083 		val |= PORT_CS_19_PC;
1084 	else
1085 		val &= ~PORT_CS_19_PC;
1086 
1087 	return tb_port_write(port, &val, TB_CFG_PORT,
1088 			     port->cap_usb4 + PORT_CS_19, 1);
1089 }
1090 
1091 /**
1092  * usb4_port_configure() - Set USB4 port configured
1093  * @port: USB4 router
1094  *
1095  * Sets the USB4 link to be configured for power management purposes.
1096  */
1097 int usb4_port_configure(struct tb_port *port)
1098 {
1099 	return usb4_port_set_configured(port, true);
1100 }
1101 
1102 /**
1103  * usb4_port_unconfigure() - Set USB4 port unconfigured
1104  * @port: USB4 router
1105  *
1106  * Sets the USB4 link to be unconfigured for power management purposes.
1107  */
1108 void usb4_port_unconfigure(struct tb_port *port)
1109 {
1110 	usb4_port_set_configured(port, false);
1111 }
1112 
1113 static int usb4_set_xdomain_configured(struct tb_port *port, bool configured)
1114 {
1115 	int ret;
1116 	u32 val;
1117 
1118 	if (!port->cap_usb4)
1119 		return -EINVAL;
1120 
1121 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1122 			   port->cap_usb4 + PORT_CS_19, 1);
1123 	if (ret)
1124 		return ret;
1125 
1126 	if (configured)
1127 		val |= PORT_CS_19_PID;
1128 	else
1129 		val &= ~PORT_CS_19_PID;
1130 
1131 	return tb_port_write(port, &val, TB_CFG_PORT,
1132 			     port->cap_usb4 + PORT_CS_19, 1);
1133 }
1134 
1135 /**
1136  * usb4_port_configure_xdomain() - Configure port for XDomain
1137  * @port: USB4 port connected to another host
1138  * @xd: XDomain that is connected to the port
1139  *
1140  * Marks the USB4 port as being connected to another host and updates
1141  * the link type. Returns %0 in success and negative errno in failure.
1142  */
1143 int usb4_port_configure_xdomain(struct tb_port *port, struct tb_xdomain *xd)
1144 {
1145 	xd->link_usb4 = link_is_usb4(port);
1146 	return usb4_set_xdomain_configured(port, true);
1147 }
1148 
1149 /**
1150  * usb4_port_unconfigure_xdomain() - Unconfigure port for XDomain
1151  * @port: USB4 port that was connected to another host
1152  *
1153  * Clears USB4 port from being marked as XDomain.
1154  */
1155 void usb4_port_unconfigure_xdomain(struct tb_port *port)
1156 {
1157 	usb4_set_xdomain_configured(port, false);
1158 }
1159 
1160 static int usb4_port_wait_for_bit(struct tb_port *port, u32 offset, u32 bit,
1161 				  u32 value, int timeout_msec)
1162 {
1163 	ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
1164 
1165 	do {
1166 		u32 val;
1167 		int ret;
1168 
1169 		ret = tb_port_read(port, &val, TB_CFG_PORT, offset, 1);
1170 		if (ret)
1171 			return ret;
1172 
1173 		if ((val & bit) == value)
1174 			return 0;
1175 
1176 		usleep_range(50, 100);
1177 	} while (ktime_before(ktime_get(), timeout));
1178 
1179 	return -ETIMEDOUT;
1180 }
1181 
1182 static int usb4_port_read_data(struct tb_port *port, void *data, size_t dwords)
1183 {
1184 	if (dwords > NVM_DATA_DWORDS)
1185 		return -EINVAL;
1186 
1187 	return tb_port_read(port, data, TB_CFG_PORT, port->cap_usb4 + PORT_CS_2,
1188 			    dwords);
1189 }
1190 
1191 static int usb4_port_write_data(struct tb_port *port, const void *data,
1192 				size_t dwords)
1193 {
1194 	if (dwords > NVM_DATA_DWORDS)
1195 		return -EINVAL;
1196 
1197 	return tb_port_write(port, data, TB_CFG_PORT, port->cap_usb4 + PORT_CS_2,
1198 			     dwords);
1199 }
1200 
1201 static int usb4_port_sb_read(struct tb_port *port, enum usb4_sb_target target,
1202 			     u8 index, u8 reg, void *buf, u8 size)
1203 {
1204 	size_t dwords = DIV_ROUND_UP(size, 4);
1205 	int ret;
1206 	u32 val;
1207 
1208 	if (!port->cap_usb4)
1209 		return -EINVAL;
1210 
1211 	val = reg;
1212 	val |= size << PORT_CS_1_LENGTH_SHIFT;
1213 	val |= (target << PORT_CS_1_TARGET_SHIFT) & PORT_CS_1_TARGET_MASK;
1214 	if (target == USB4_SB_TARGET_RETIMER)
1215 		val |= (index << PORT_CS_1_RETIMER_INDEX_SHIFT);
1216 	val |= PORT_CS_1_PND;
1217 
1218 	ret = tb_port_write(port, &val, TB_CFG_PORT,
1219 			    port->cap_usb4 + PORT_CS_1, 1);
1220 	if (ret)
1221 		return ret;
1222 
1223 	ret = usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_1,
1224 				     PORT_CS_1_PND, 0, 500);
1225 	if (ret)
1226 		return ret;
1227 
1228 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1229 			    port->cap_usb4 + PORT_CS_1, 1);
1230 	if (ret)
1231 		return ret;
1232 
1233 	if (val & PORT_CS_1_NR)
1234 		return -ENODEV;
1235 	if (val & PORT_CS_1_RC)
1236 		return -EIO;
1237 
1238 	return buf ? usb4_port_read_data(port, buf, dwords) : 0;
1239 }
1240 
1241 static int usb4_port_sb_write(struct tb_port *port, enum usb4_sb_target target,
1242 			      u8 index, u8 reg, const void *buf, u8 size)
1243 {
1244 	size_t dwords = DIV_ROUND_UP(size, 4);
1245 	int ret;
1246 	u32 val;
1247 
1248 	if (!port->cap_usb4)
1249 		return -EINVAL;
1250 
1251 	if (buf) {
1252 		ret = usb4_port_write_data(port, buf, dwords);
1253 		if (ret)
1254 			return ret;
1255 	}
1256 
1257 	val = reg;
1258 	val |= size << PORT_CS_1_LENGTH_SHIFT;
1259 	val |= PORT_CS_1_WNR_WRITE;
1260 	val |= (target << PORT_CS_1_TARGET_SHIFT) & PORT_CS_1_TARGET_MASK;
1261 	if (target == USB4_SB_TARGET_RETIMER)
1262 		val |= (index << PORT_CS_1_RETIMER_INDEX_SHIFT);
1263 	val |= PORT_CS_1_PND;
1264 
1265 	ret = tb_port_write(port, &val, TB_CFG_PORT,
1266 			    port->cap_usb4 + PORT_CS_1, 1);
1267 	if (ret)
1268 		return ret;
1269 
1270 	ret = usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_1,
1271 				     PORT_CS_1_PND, 0, 500);
1272 	if (ret)
1273 		return ret;
1274 
1275 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1276 			    port->cap_usb4 + PORT_CS_1, 1);
1277 	if (ret)
1278 		return ret;
1279 
1280 	if (val & PORT_CS_1_NR)
1281 		return -ENODEV;
1282 	if (val & PORT_CS_1_RC)
1283 		return -EIO;
1284 
1285 	return 0;
1286 }
1287 
1288 static int usb4_port_sb_op(struct tb_port *port, enum usb4_sb_target target,
1289 			   u8 index, enum usb4_sb_opcode opcode, int timeout_msec)
1290 {
1291 	ktime_t timeout;
1292 	u32 val;
1293 	int ret;
1294 
1295 	val = opcode;
1296 	ret = usb4_port_sb_write(port, target, index, USB4_SB_OPCODE, &val,
1297 				 sizeof(val));
1298 	if (ret)
1299 		return ret;
1300 
1301 	timeout = ktime_add_ms(ktime_get(), timeout_msec);
1302 
1303 	do {
1304 		/* Check results */
1305 		ret = usb4_port_sb_read(port, target, index, USB4_SB_OPCODE,
1306 					&val, sizeof(val));
1307 		if (ret)
1308 			return ret;
1309 
1310 		switch (val) {
1311 		case 0:
1312 			return 0;
1313 
1314 		case USB4_SB_OPCODE_ERR:
1315 			return -EAGAIN;
1316 
1317 		case USB4_SB_OPCODE_ONS:
1318 			return -EOPNOTSUPP;
1319 
1320 		default:
1321 			if (val != opcode)
1322 				return -EIO;
1323 			break;
1324 		}
1325 	} while (ktime_before(ktime_get(), timeout));
1326 
1327 	return -ETIMEDOUT;
1328 }
1329 
1330 static int usb4_port_set_router_offline(struct tb_port *port, bool offline)
1331 {
1332 	u32 val = !offline;
1333 	int ret;
1334 
1335 	ret = usb4_port_sb_write(port, USB4_SB_TARGET_ROUTER, 0,
1336 				  USB4_SB_METADATA, &val, sizeof(val));
1337 	if (ret)
1338 		return ret;
1339 
1340 	val = USB4_SB_OPCODE_ROUTER_OFFLINE;
1341 	return usb4_port_sb_write(port, USB4_SB_TARGET_ROUTER, 0,
1342 				  USB4_SB_OPCODE, &val, sizeof(val));
1343 }
1344 
1345 /**
1346  * usb4_port_router_offline() - Put the USB4 port to offline mode
1347  * @port: USB4 port
1348  *
1349  * This function puts the USB4 port into offline mode. In this mode the
1350  * port does not react on hotplug events anymore. This needs to be
1351  * called before retimer access is done when the USB4 links is not up.
1352  *
1353  * Returns %0 in case of success and negative errno if there was an
1354  * error.
1355  */
1356 int usb4_port_router_offline(struct tb_port *port)
1357 {
1358 	return usb4_port_set_router_offline(port, true);
1359 }
1360 
1361 /**
1362  * usb4_port_router_online() - Put the USB4 port back to online
1363  * @port: USB4 port
1364  *
1365  * Makes the USB4 port functional again.
1366  */
1367 int usb4_port_router_online(struct tb_port *port)
1368 {
1369 	return usb4_port_set_router_offline(port, false);
1370 }
1371 
1372 /**
1373  * usb4_port_enumerate_retimers() - Send RT broadcast transaction
1374  * @port: USB4 port
1375  *
1376  * This forces the USB4 port to send broadcast RT transaction which
1377  * makes the retimers on the link to assign index to themselves. Returns
1378  * %0 in case of success and negative errno if there was an error.
1379  */
1380 int usb4_port_enumerate_retimers(struct tb_port *port)
1381 {
1382 	u32 val;
1383 
1384 	val = USB4_SB_OPCODE_ENUMERATE_RETIMERS;
1385 	return usb4_port_sb_write(port, USB4_SB_TARGET_ROUTER, 0,
1386 				  USB4_SB_OPCODE, &val, sizeof(val));
1387 }
1388 
1389 /**
1390  * usb4_port_clx_supported() - Check if CLx is supported by the link
1391  * @port: Port to check for CLx support for
1392  *
1393  * PORT_CS_18_CPS bit reflects if the link supports CLx including
1394  * active cables (if connected on the link).
1395  */
1396 bool usb4_port_clx_supported(struct tb_port *port)
1397 {
1398 	int ret;
1399 	u32 val;
1400 
1401 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1402 			   port->cap_usb4 + PORT_CS_18, 1);
1403 	if (ret)
1404 		return false;
1405 
1406 	return !!(val & PORT_CS_18_CPS);
1407 }
1408 
1409 /**
1410  * usb4_port_margining_caps() - Read USB4 port marginig capabilities
1411  * @port: USB4 port
1412  * @caps: Array with at least two elements to hold the results
1413  *
1414  * Reads the USB4 port lane margining capabilities into @caps.
1415  */
1416 int usb4_port_margining_caps(struct tb_port *port, u32 *caps)
1417 {
1418 	int ret;
1419 
1420 	ret = usb4_port_sb_op(port, USB4_SB_TARGET_ROUTER, 0,
1421 			      USB4_SB_OPCODE_READ_LANE_MARGINING_CAP, 500);
1422 	if (ret)
1423 		return ret;
1424 
1425 	return usb4_port_sb_read(port, USB4_SB_TARGET_ROUTER, 0,
1426 				 USB4_SB_DATA, caps, sizeof(*caps) * 2);
1427 }
1428 
1429 /**
1430  * usb4_port_hw_margin() - Run hardware lane margining on port
1431  * @port: USB4 port
1432  * @lanes: Which lanes to run (must match the port capabilities). Can be
1433  *	   %0, %1 or %7.
1434  * @ber_level: BER level contour value
1435  * @timing: Perform timing margining instead of voltage
1436  * @right_high: Use Right/high margin instead of left/low
1437  * @results: Array with at least two elements to hold the results
1438  *
1439  * Runs hardware lane margining on USB4 port and returns the result in
1440  * @results.
1441  */
1442 int usb4_port_hw_margin(struct tb_port *port, unsigned int lanes,
1443 			unsigned int ber_level, bool timing, bool right_high,
1444 			u32 *results)
1445 {
1446 	u32 val;
1447 	int ret;
1448 
1449 	val = lanes;
1450 	if (timing)
1451 		val |= USB4_MARGIN_HW_TIME;
1452 	if (right_high)
1453 		val |= USB4_MARGIN_HW_RH;
1454 	if (ber_level)
1455 		val |= (ber_level << USB4_MARGIN_HW_BER_SHIFT) &
1456 			USB4_MARGIN_HW_BER_MASK;
1457 
1458 	ret = usb4_port_sb_write(port, USB4_SB_TARGET_ROUTER, 0,
1459 				 USB4_SB_METADATA, &val, sizeof(val));
1460 	if (ret)
1461 		return ret;
1462 
1463 	ret = usb4_port_sb_op(port, USB4_SB_TARGET_ROUTER, 0,
1464 			      USB4_SB_OPCODE_RUN_HW_LANE_MARGINING, 2500);
1465 	if (ret)
1466 		return ret;
1467 
1468 	return usb4_port_sb_read(port, USB4_SB_TARGET_ROUTER, 0,
1469 				 USB4_SB_DATA, results, sizeof(*results) * 2);
1470 }
1471 
1472 /**
1473  * usb4_port_sw_margin() - Run software lane margining on port
1474  * @port: USB4 port
1475  * @lanes: Which lanes to run (must match the port capabilities). Can be
1476  *	   %0, %1 or %7.
1477  * @timing: Perform timing margining instead of voltage
1478  * @right_high: Use Right/high margin instead of left/low
1479  * @counter: What to do with the error counter
1480  *
1481  * Runs software lane margining on USB4 port. Read back the error
1482  * counters by calling usb4_port_sw_margin_errors(). Returns %0 in
1483  * success and negative errno otherwise.
1484  */
1485 int usb4_port_sw_margin(struct tb_port *port, unsigned int lanes, bool timing,
1486 			bool right_high, u32 counter)
1487 {
1488 	u32 val;
1489 	int ret;
1490 
1491 	val = lanes;
1492 	if (timing)
1493 		val |= USB4_MARGIN_SW_TIME;
1494 	if (right_high)
1495 		val |= USB4_MARGIN_SW_RH;
1496 	val |= (counter << USB4_MARGIN_SW_COUNTER_SHIFT) &
1497 		USB4_MARGIN_SW_COUNTER_MASK;
1498 
1499 	ret = usb4_port_sb_write(port, USB4_SB_TARGET_ROUTER, 0,
1500 				 USB4_SB_METADATA, &val, sizeof(val));
1501 	if (ret)
1502 		return ret;
1503 
1504 	return usb4_port_sb_op(port, USB4_SB_TARGET_ROUTER, 0,
1505 			       USB4_SB_OPCODE_RUN_SW_LANE_MARGINING, 2500);
1506 }
1507 
1508 /**
1509  * usb4_port_sw_margin_errors() - Read the software margining error counters
1510  * @port: USB4 port
1511  * @errors: Error metadata is copied here.
1512  *
1513  * This reads back the software margining error counters from the port.
1514  * Returns %0 in success and negative errno otherwise.
1515  */
1516 int usb4_port_sw_margin_errors(struct tb_port *port, u32 *errors)
1517 {
1518 	int ret;
1519 
1520 	ret = usb4_port_sb_op(port, USB4_SB_TARGET_ROUTER, 0,
1521 			      USB4_SB_OPCODE_READ_SW_MARGIN_ERR, 150);
1522 	if (ret)
1523 		return ret;
1524 
1525 	return usb4_port_sb_read(port, USB4_SB_TARGET_ROUTER, 0,
1526 				 USB4_SB_METADATA, errors, sizeof(*errors));
1527 }
1528 
1529 static inline int usb4_port_retimer_op(struct tb_port *port, u8 index,
1530 				       enum usb4_sb_opcode opcode,
1531 				       int timeout_msec)
1532 {
1533 	return usb4_port_sb_op(port, USB4_SB_TARGET_RETIMER, index, opcode,
1534 			       timeout_msec);
1535 }
1536 
1537 /**
1538  * usb4_port_retimer_set_inbound_sbtx() - Enable sideband channel transactions
1539  * @port: USB4 port
1540  * @index: Retimer index
1541  *
1542  * Enables sideband channel transations on SBTX. Can be used when USB4
1543  * link does not go up, for example if there is no device connected.
1544  */
1545 int usb4_port_retimer_set_inbound_sbtx(struct tb_port *port, u8 index)
1546 {
1547 	int ret;
1548 
1549 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_SET_INBOUND_SBTX,
1550 				   500);
1551 
1552 	if (ret != -ENODEV)
1553 		return ret;
1554 
1555 	/*
1556 	 * Per the USB4 retimer spec, the retimer is not required to
1557 	 * send an RT (Retimer Transaction) response for the first
1558 	 * SET_INBOUND_SBTX command
1559 	 */
1560 	return usb4_port_retimer_op(port, index, USB4_SB_OPCODE_SET_INBOUND_SBTX,
1561 				    500);
1562 }
1563 
1564 /**
1565  * usb4_port_retimer_read() - Read from retimer sideband registers
1566  * @port: USB4 port
1567  * @index: Retimer index
1568  * @reg: Sideband register to read
1569  * @buf: Data from @reg is stored here
1570  * @size: Number of bytes to read
1571  *
1572  * Function reads retimer sideband registers starting from @reg. The
1573  * retimer is connected to @port at @index. Returns %0 in case of
1574  * success, and read data is copied to @buf. If there is no retimer
1575  * present at given @index returns %-ENODEV. In any other failure
1576  * returns negative errno.
1577  */
1578 int usb4_port_retimer_read(struct tb_port *port, u8 index, u8 reg, void *buf,
1579 			   u8 size)
1580 {
1581 	return usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index, reg, buf,
1582 				 size);
1583 }
1584 
1585 /**
1586  * usb4_port_retimer_write() - Write to retimer sideband registers
1587  * @port: USB4 port
1588  * @index: Retimer index
1589  * @reg: Sideband register to write
1590  * @buf: Data that is written starting from @reg
1591  * @size: Number of bytes to write
1592  *
1593  * Writes retimer sideband registers starting from @reg. The retimer is
1594  * connected to @port at @index. Returns %0 in case of success. If there
1595  * is no retimer present at given @index returns %-ENODEV. In any other
1596  * failure returns negative errno.
1597  */
1598 int usb4_port_retimer_write(struct tb_port *port, u8 index, u8 reg,
1599 			    const void *buf, u8 size)
1600 {
1601 	return usb4_port_sb_write(port, USB4_SB_TARGET_RETIMER, index, reg, buf,
1602 				  size);
1603 }
1604 
1605 /**
1606  * usb4_port_retimer_is_last() - Is the retimer last on-board retimer
1607  * @port: USB4 port
1608  * @index: Retimer index
1609  *
1610  * If the retimer at @index is last one (connected directly to the
1611  * Type-C port) this function returns %1. If it is not returns %0. If
1612  * the retimer is not present returns %-ENODEV. Otherwise returns
1613  * negative errno.
1614  */
1615 int usb4_port_retimer_is_last(struct tb_port *port, u8 index)
1616 {
1617 	u32 metadata;
1618 	int ret;
1619 
1620 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_QUERY_LAST_RETIMER,
1621 				   500);
1622 	if (ret)
1623 		return ret;
1624 
1625 	ret = usb4_port_retimer_read(port, index, USB4_SB_METADATA, &metadata,
1626 				     sizeof(metadata));
1627 	return ret ? ret : metadata & 1;
1628 }
1629 
1630 /**
1631  * usb4_port_retimer_nvm_sector_size() - Read retimer NVM sector size
1632  * @port: USB4 port
1633  * @index: Retimer index
1634  *
1635  * Reads NVM sector size (in bytes) of a retimer at @index. This
1636  * operation can be used to determine whether the retimer supports NVM
1637  * upgrade for example. Returns sector size in bytes or negative errno
1638  * in case of error. Specifically returns %-ENODEV if there is no
1639  * retimer at @index.
1640  */
1641 int usb4_port_retimer_nvm_sector_size(struct tb_port *port, u8 index)
1642 {
1643 	u32 metadata;
1644 	int ret;
1645 
1646 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_GET_NVM_SECTOR_SIZE,
1647 				   500);
1648 	if (ret)
1649 		return ret;
1650 
1651 	ret = usb4_port_retimer_read(port, index, USB4_SB_METADATA, &metadata,
1652 				     sizeof(metadata));
1653 	return ret ? ret : metadata & USB4_NVM_SECTOR_SIZE_MASK;
1654 }
1655 
1656 /**
1657  * usb4_port_retimer_nvm_set_offset() - Set NVM write offset
1658  * @port: USB4 port
1659  * @index: Retimer index
1660  * @address: Start offset
1661  *
1662  * Exlicitly sets NVM write offset. Normally when writing to NVM this is
1663  * done automatically by usb4_port_retimer_nvm_write().
1664  *
1665  * Returns %0 in success and negative errno if there was a failure.
1666  */
1667 int usb4_port_retimer_nvm_set_offset(struct tb_port *port, u8 index,
1668 				     unsigned int address)
1669 {
1670 	u32 metadata, dwaddress;
1671 	int ret;
1672 
1673 	dwaddress = address / 4;
1674 	metadata = (dwaddress << USB4_NVM_SET_OFFSET_SHIFT) &
1675 		  USB4_NVM_SET_OFFSET_MASK;
1676 
1677 	ret = usb4_port_retimer_write(port, index, USB4_SB_METADATA, &metadata,
1678 				      sizeof(metadata));
1679 	if (ret)
1680 		return ret;
1681 
1682 	return usb4_port_retimer_op(port, index, USB4_SB_OPCODE_NVM_SET_OFFSET,
1683 				    500);
1684 }
1685 
1686 struct retimer_info {
1687 	struct tb_port *port;
1688 	u8 index;
1689 };
1690 
1691 static int usb4_port_retimer_nvm_write_next_block(void *data,
1692 	unsigned int dwaddress, const void *buf, size_t dwords)
1693 
1694 {
1695 	const struct retimer_info *info = data;
1696 	struct tb_port *port = info->port;
1697 	u8 index = info->index;
1698 	int ret;
1699 
1700 	ret = usb4_port_retimer_write(port, index, USB4_SB_DATA,
1701 				      buf, dwords * 4);
1702 	if (ret)
1703 		return ret;
1704 
1705 	return usb4_port_retimer_op(port, index,
1706 			USB4_SB_OPCODE_NVM_BLOCK_WRITE, 1000);
1707 }
1708 
1709 /**
1710  * usb4_port_retimer_nvm_write() - Write to retimer NVM
1711  * @port: USB4 port
1712  * @index: Retimer index
1713  * @address: Byte address where to start the write
1714  * @buf: Data to write
1715  * @size: Size in bytes how much to write
1716  *
1717  * Writes @size bytes from @buf to the retimer NVM. Used for NVM
1718  * upgrade. Returns %0 if the data was written successfully and negative
1719  * errno in case of failure. Specifically returns %-ENODEV if there is
1720  * no retimer at @index.
1721  */
1722 int usb4_port_retimer_nvm_write(struct tb_port *port, u8 index, unsigned int address,
1723 				const void *buf, size_t size)
1724 {
1725 	struct retimer_info info = { .port = port, .index = index };
1726 	int ret;
1727 
1728 	ret = usb4_port_retimer_nvm_set_offset(port, index, address);
1729 	if (ret)
1730 		return ret;
1731 
1732 	return tb_nvm_write_data(address, buf, size, USB4_DATA_RETRIES,
1733 				 usb4_port_retimer_nvm_write_next_block, &info);
1734 }
1735 
1736 /**
1737  * usb4_port_retimer_nvm_authenticate() - Start retimer NVM upgrade
1738  * @port: USB4 port
1739  * @index: Retimer index
1740  *
1741  * After the new NVM image has been written via usb4_port_retimer_nvm_write()
1742  * this function can be used to trigger the NVM upgrade process. If
1743  * successful the retimer restarts with the new NVM and may not have the
1744  * index set so one needs to call usb4_port_enumerate_retimers() to
1745  * force index to be assigned.
1746  */
1747 int usb4_port_retimer_nvm_authenticate(struct tb_port *port, u8 index)
1748 {
1749 	u32 val;
1750 
1751 	/*
1752 	 * We need to use the raw operation here because once the
1753 	 * authentication completes the retimer index is not set anymore
1754 	 * so we do not get back the status now.
1755 	 */
1756 	val = USB4_SB_OPCODE_NVM_AUTH_WRITE;
1757 	return usb4_port_sb_write(port, USB4_SB_TARGET_RETIMER, index,
1758 				  USB4_SB_OPCODE, &val, sizeof(val));
1759 }
1760 
1761 /**
1762  * usb4_port_retimer_nvm_authenticate_status() - Read status of NVM upgrade
1763  * @port: USB4 port
1764  * @index: Retimer index
1765  * @status: Raw status code read from metadata
1766  *
1767  * This can be called after usb4_port_retimer_nvm_authenticate() and
1768  * usb4_port_enumerate_retimers() to fetch status of the NVM upgrade.
1769  *
1770  * Returns %0 if the authentication status was successfully read. The
1771  * completion metadata (the result) is then stored into @status. If
1772  * reading the status fails, returns negative errno.
1773  */
1774 int usb4_port_retimer_nvm_authenticate_status(struct tb_port *port, u8 index,
1775 					      u32 *status)
1776 {
1777 	u32 metadata, val;
1778 	int ret;
1779 
1780 	ret = usb4_port_retimer_read(port, index, USB4_SB_OPCODE, &val,
1781 				     sizeof(val));
1782 	if (ret)
1783 		return ret;
1784 
1785 	switch (val) {
1786 	case 0:
1787 		*status = 0;
1788 		return 0;
1789 
1790 	case USB4_SB_OPCODE_ERR:
1791 		ret = usb4_port_retimer_read(port, index, USB4_SB_METADATA,
1792 					     &metadata, sizeof(metadata));
1793 		if (ret)
1794 			return ret;
1795 
1796 		*status = metadata & USB4_SB_METADATA_NVM_AUTH_WRITE_MASK;
1797 		return 0;
1798 
1799 	case USB4_SB_OPCODE_ONS:
1800 		return -EOPNOTSUPP;
1801 
1802 	default:
1803 		return -EIO;
1804 	}
1805 }
1806 
1807 static int usb4_port_retimer_nvm_read_block(void *data, unsigned int dwaddress,
1808 					    void *buf, size_t dwords)
1809 {
1810 	const struct retimer_info *info = data;
1811 	struct tb_port *port = info->port;
1812 	u8 index = info->index;
1813 	u32 metadata;
1814 	int ret;
1815 
1816 	metadata = dwaddress << USB4_NVM_READ_OFFSET_SHIFT;
1817 	if (dwords < NVM_DATA_DWORDS)
1818 		metadata |= dwords << USB4_NVM_READ_LENGTH_SHIFT;
1819 
1820 	ret = usb4_port_retimer_write(port, index, USB4_SB_METADATA, &metadata,
1821 				      sizeof(metadata));
1822 	if (ret)
1823 		return ret;
1824 
1825 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_NVM_READ, 500);
1826 	if (ret)
1827 		return ret;
1828 
1829 	return usb4_port_retimer_read(port, index, USB4_SB_DATA, buf,
1830 				      dwords * 4);
1831 }
1832 
1833 /**
1834  * usb4_port_retimer_nvm_read() - Read contents of retimer NVM
1835  * @port: USB4 port
1836  * @index: Retimer index
1837  * @address: NVM address (in bytes) to start reading
1838  * @buf: Data read from NVM is stored here
1839  * @size: Number of bytes to read
1840  *
1841  * Reads retimer NVM and copies the contents to @buf. Returns %0 if the
1842  * read was successful and negative errno in case of failure.
1843  * Specifically returns %-ENODEV if there is no retimer at @index.
1844  */
1845 int usb4_port_retimer_nvm_read(struct tb_port *port, u8 index,
1846 			       unsigned int address, void *buf, size_t size)
1847 {
1848 	struct retimer_info info = { .port = port, .index = index };
1849 
1850 	return tb_nvm_read_data(address, buf, size, USB4_DATA_RETRIES,
1851 				usb4_port_retimer_nvm_read_block, &info);
1852 }
1853 
1854 /**
1855  * usb4_usb3_port_max_link_rate() - Maximum support USB3 link rate
1856  * @port: USB3 adapter port
1857  *
1858  * Return maximum supported link rate of a USB3 adapter in Mb/s.
1859  * Negative errno in case of error.
1860  */
1861 int usb4_usb3_port_max_link_rate(struct tb_port *port)
1862 {
1863 	int ret, lr;
1864 	u32 val;
1865 
1866 	if (!tb_port_is_usb3_down(port) && !tb_port_is_usb3_up(port))
1867 		return -EINVAL;
1868 
1869 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1870 			   port->cap_adap + ADP_USB3_CS_4, 1);
1871 	if (ret)
1872 		return ret;
1873 
1874 	lr = (val & ADP_USB3_CS_4_MSLR_MASK) >> ADP_USB3_CS_4_MSLR_SHIFT;
1875 	return lr == ADP_USB3_CS_4_MSLR_20G ? 20000 : 10000;
1876 }
1877 
1878 /**
1879  * usb4_usb3_port_actual_link_rate() - Established USB3 link rate
1880  * @port: USB3 adapter port
1881  *
1882  * Return actual established link rate of a USB3 adapter in Mb/s. If the
1883  * link is not up returns %0 and negative errno in case of failure.
1884  */
1885 int usb4_usb3_port_actual_link_rate(struct tb_port *port)
1886 {
1887 	int ret, lr;
1888 	u32 val;
1889 
1890 	if (!tb_port_is_usb3_down(port) && !tb_port_is_usb3_up(port))
1891 		return -EINVAL;
1892 
1893 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1894 			   port->cap_adap + ADP_USB3_CS_4, 1);
1895 	if (ret)
1896 		return ret;
1897 
1898 	if (!(val & ADP_USB3_CS_4_ULV))
1899 		return 0;
1900 
1901 	lr = val & ADP_USB3_CS_4_ALR_MASK;
1902 	return lr == ADP_USB3_CS_4_ALR_20G ? 20000 : 10000;
1903 }
1904 
1905 static int usb4_usb3_port_cm_request(struct tb_port *port, bool request)
1906 {
1907 	int ret;
1908 	u32 val;
1909 
1910 	if (!tb_port_is_usb3_down(port))
1911 		return -EINVAL;
1912 	if (tb_route(port->sw))
1913 		return -EINVAL;
1914 
1915 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1916 			   port->cap_adap + ADP_USB3_CS_2, 1);
1917 	if (ret)
1918 		return ret;
1919 
1920 	if (request)
1921 		val |= ADP_USB3_CS_2_CMR;
1922 	else
1923 		val &= ~ADP_USB3_CS_2_CMR;
1924 
1925 	ret = tb_port_write(port, &val, TB_CFG_PORT,
1926 			    port->cap_adap + ADP_USB3_CS_2, 1);
1927 	if (ret)
1928 		return ret;
1929 
1930 	/*
1931 	 * We can use val here directly as the CMR bit is in the same place
1932 	 * as HCA. Just mask out others.
1933 	 */
1934 	val &= ADP_USB3_CS_2_CMR;
1935 	return usb4_port_wait_for_bit(port, port->cap_adap + ADP_USB3_CS_1,
1936 				      ADP_USB3_CS_1_HCA, val, 1500);
1937 }
1938 
1939 static inline int usb4_usb3_port_set_cm_request(struct tb_port *port)
1940 {
1941 	return usb4_usb3_port_cm_request(port, true);
1942 }
1943 
1944 static inline int usb4_usb3_port_clear_cm_request(struct tb_port *port)
1945 {
1946 	return usb4_usb3_port_cm_request(port, false);
1947 }
1948 
1949 static unsigned int usb3_bw_to_mbps(u32 bw, u8 scale)
1950 {
1951 	unsigned long uframes;
1952 
1953 	uframes = bw * 512UL << scale;
1954 	return DIV_ROUND_CLOSEST(uframes * 8000, 1000 * 1000);
1955 }
1956 
1957 static u32 mbps_to_usb3_bw(unsigned int mbps, u8 scale)
1958 {
1959 	unsigned long uframes;
1960 
1961 	/* 1 uframe is 1/8 ms (125 us) -> 1 / 8000 s */
1962 	uframes = ((unsigned long)mbps * 1000 *  1000) / 8000;
1963 	return DIV_ROUND_UP(uframes, 512UL << scale);
1964 }
1965 
1966 static int usb4_usb3_port_read_allocated_bandwidth(struct tb_port *port,
1967 						   int *upstream_bw,
1968 						   int *downstream_bw)
1969 {
1970 	u32 val, bw, scale;
1971 	int ret;
1972 
1973 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1974 			   port->cap_adap + ADP_USB3_CS_2, 1);
1975 	if (ret)
1976 		return ret;
1977 
1978 	ret = tb_port_read(port, &scale, TB_CFG_PORT,
1979 			   port->cap_adap + ADP_USB3_CS_3, 1);
1980 	if (ret)
1981 		return ret;
1982 
1983 	scale &= ADP_USB3_CS_3_SCALE_MASK;
1984 
1985 	bw = val & ADP_USB3_CS_2_AUBW_MASK;
1986 	*upstream_bw = usb3_bw_to_mbps(bw, scale);
1987 
1988 	bw = (val & ADP_USB3_CS_2_ADBW_MASK) >> ADP_USB3_CS_2_ADBW_SHIFT;
1989 	*downstream_bw = usb3_bw_to_mbps(bw, scale);
1990 
1991 	return 0;
1992 }
1993 
1994 /**
1995  * usb4_usb3_port_allocated_bandwidth() - Bandwidth allocated for USB3
1996  * @port: USB3 adapter port
1997  * @upstream_bw: Allocated upstream bandwidth is stored here
1998  * @downstream_bw: Allocated downstream bandwidth is stored here
1999  *
2000  * Stores currently allocated USB3 bandwidth into @upstream_bw and
2001  * @downstream_bw in Mb/s. Returns %0 in case of success and negative
2002  * errno in failure.
2003  */
2004 int usb4_usb3_port_allocated_bandwidth(struct tb_port *port, int *upstream_bw,
2005 				       int *downstream_bw)
2006 {
2007 	int ret;
2008 
2009 	ret = usb4_usb3_port_set_cm_request(port);
2010 	if (ret)
2011 		return ret;
2012 
2013 	ret = usb4_usb3_port_read_allocated_bandwidth(port, upstream_bw,
2014 						      downstream_bw);
2015 	usb4_usb3_port_clear_cm_request(port);
2016 
2017 	return ret;
2018 }
2019 
2020 static int usb4_usb3_port_read_consumed_bandwidth(struct tb_port *port,
2021 						  int *upstream_bw,
2022 						  int *downstream_bw)
2023 {
2024 	u32 val, bw, scale;
2025 	int ret;
2026 
2027 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2028 			   port->cap_adap + ADP_USB3_CS_1, 1);
2029 	if (ret)
2030 		return ret;
2031 
2032 	ret = tb_port_read(port, &scale, TB_CFG_PORT,
2033 			   port->cap_adap + ADP_USB3_CS_3, 1);
2034 	if (ret)
2035 		return ret;
2036 
2037 	scale &= ADP_USB3_CS_3_SCALE_MASK;
2038 
2039 	bw = val & ADP_USB3_CS_1_CUBW_MASK;
2040 	*upstream_bw = usb3_bw_to_mbps(bw, scale);
2041 
2042 	bw = (val & ADP_USB3_CS_1_CDBW_MASK) >> ADP_USB3_CS_1_CDBW_SHIFT;
2043 	*downstream_bw = usb3_bw_to_mbps(bw, scale);
2044 
2045 	return 0;
2046 }
2047 
2048 static int usb4_usb3_port_write_allocated_bandwidth(struct tb_port *port,
2049 						    int upstream_bw,
2050 						    int downstream_bw)
2051 {
2052 	u32 val, ubw, dbw, scale;
2053 	int ret;
2054 
2055 	/* Read the used scale, hardware default is 0 */
2056 	ret = tb_port_read(port, &scale, TB_CFG_PORT,
2057 			   port->cap_adap + ADP_USB3_CS_3, 1);
2058 	if (ret)
2059 		return ret;
2060 
2061 	scale &= ADP_USB3_CS_3_SCALE_MASK;
2062 	ubw = mbps_to_usb3_bw(upstream_bw, scale);
2063 	dbw = mbps_to_usb3_bw(downstream_bw, scale);
2064 
2065 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2066 			   port->cap_adap + ADP_USB3_CS_2, 1);
2067 	if (ret)
2068 		return ret;
2069 
2070 	val &= ~(ADP_USB3_CS_2_AUBW_MASK | ADP_USB3_CS_2_ADBW_MASK);
2071 	val |= dbw << ADP_USB3_CS_2_ADBW_SHIFT;
2072 	val |= ubw;
2073 
2074 	return tb_port_write(port, &val, TB_CFG_PORT,
2075 			     port->cap_adap + ADP_USB3_CS_2, 1);
2076 }
2077 
2078 /**
2079  * usb4_usb3_port_allocate_bandwidth() - Allocate bandwidth for USB3
2080  * @port: USB3 adapter port
2081  * @upstream_bw: New upstream bandwidth
2082  * @downstream_bw: New downstream bandwidth
2083  *
2084  * This can be used to set how much bandwidth is allocated for the USB3
2085  * tunneled isochronous traffic. @upstream_bw and @downstream_bw are the
2086  * new values programmed to the USB3 adapter allocation registers. If
2087  * the values are lower than what is currently consumed the allocation
2088  * is set to what is currently consumed instead (consumed bandwidth
2089  * cannot be taken away by CM). The actual new values are returned in
2090  * @upstream_bw and @downstream_bw.
2091  *
2092  * Returns %0 in case of success and negative errno if there was a
2093  * failure.
2094  */
2095 int usb4_usb3_port_allocate_bandwidth(struct tb_port *port, int *upstream_bw,
2096 				      int *downstream_bw)
2097 {
2098 	int ret, consumed_up, consumed_down, allocate_up, allocate_down;
2099 
2100 	ret = usb4_usb3_port_set_cm_request(port);
2101 	if (ret)
2102 		return ret;
2103 
2104 	ret = usb4_usb3_port_read_consumed_bandwidth(port, &consumed_up,
2105 						     &consumed_down);
2106 	if (ret)
2107 		goto err_request;
2108 
2109 	/* Don't allow it go lower than what is consumed */
2110 	allocate_up = max(*upstream_bw, consumed_up);
2111 	allocate_down = max(*downstream_bw, consumed_down);
2112 
2113 	ret = usb4_usb3_port_write_allocated_bandwidth(port, allocate_up,
2114 						       allocate_down);
2115 	if (ret)
2116 		goto err_request;
2117 
2118 	*upstream_bw = allocate_up;
2119 	*downstream_bw = allocate_down;
2120 
2121 err_request:
2122 	usb4_usb3_port_clear_cm_request(port);
2123 	return ret;
2124 }
2125 
2126 /**
2127  * usb4_usb3_port_release_bandwidth() - Release allocated USB3 bandwidth
2128  * @port: USB3 adapter port
2129  * @upstream_bw: New allocated upstream bandwidth
2130  * @downstream_bw: New allocated downstream bandwidth
2131  *
2132  * Releases USB3 allocated bandwidth down to what is actually consumed.
2133  * The new bandwidth is returned in @upstream_bw and @downstream_bw.
2134  *
2135  * Returns 0% in success and negative errno in case of failure.
2136  */
2137 int usb4_usb3_port_release_bandwidth(struct tb_port *port, int *upstream_bw,
2138 				     int *downstream_bw)
2139 {
2140 	int ret, consumed_up, consumed_down;
2141 
2142 	ret = usb4_usb3_port_set_cm_request(port);
2143 	if (ret)
2144 		return ret;
2145 
2146 	ret = usb4_usb3_port_read_consumed_bandwidth(port, &consumed_up,
2147 						     &consumed_down);
2148 	if (ret)
2149 		goto err_request;
2150 
2151 	/*
2152 	 * Always keep 1000 Mb/s to make sure xHCI has at least some
2153 	 * bandwidth available for isochronous traffic.
2154 	 */
2155 	if (consumed_up < 1000)
2156 		consumed_up = 1000;
2157 	if (consumed_down < 1000)
2158 		consumed_down = 1000;
2159 
2160 	ret = usb4_usb3_port_write_allocated_bandwidth(port, consumed_up,
2161 						       consumed_down);
2162 	if (ret)
2163 		goto err_request;
2164 
2165 	*upstream_bw = consumed_up;
2166 	*downstream_bw = consumed_down;
2167 
2168 err_request:
2169 	usb4_usb3_port_clear_cm_request(port);
2170 	return ret;
2171 }
2172