xref: /openbmc/linux/drivers/thunderbolt/usb4.c (revision 84b102f5)
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_sb_target {
20 	USB4_SB_TARGET_ROUTER,
21 	USB4_SB_TARGET_PARTNER,
22 	USB4_SB_TARGET_RETIMER,
23 };
24 
25 #define USB4_NVM_READ_OFFSET_MASK	GENMASK(23, 2)
26 #define USB4_NVM_READ_OFFSET_SHIFT	2
27 #define USB4_NVM_READ_LENGTH_MASK	GENMASK(27, 24)
28 #define USB4_NVM_READ_LENGTH_SHIFT	24
29 
30 #define USB4_NVM_SET_OFFSET_MASK	USB4_NVM_READ_OFFSET_MASK
31 #define USB4_NVM_SET_OFFSET_SHIFT	USB4_NVM_READ_OFFSET_SHIFT
32 
33 #define USB4_DROM_ADDRESS_MASK		GENMASK(14, 2)
34 #define USB4_DROM_ADDRESS_SHIFT		2
35 #define USB4_DROM_SIZE_MASK		GENMASK(19, 15)
36 #define USB4_DROM_SIZE_SHIFT		15
37 
38 #define USB4_NVM_SECTOR_SIZE_MASK	GENMASK(23, 0)
39 
40 typedef int (*read_block_fn)(void *, unsigned int, void *, size_t);
41 typedef int (*write_block_fn)(void *, const void *, size_t);
42 
43 static int usb4_switch_wait_for_bit(struct tb_switch *sw, u32 offset, u32 bit,
44 				    u32 value, int timeout_msec)
45 {
46 	ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
47 
48 	do {
49 		u32 val;
50 		int ret;
51 
52 		ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, offset, 1);
53 		if (ret)
54 			return ret;
55 
56 		if ((val & bit) == value)
57 			return 0;
58 
59 		usleep_range(50, 100);
60 	} while (ktime_before(ktime_get(), timeout));
61 
62 	return -ETIMEDOUT;
63 }
64 
65 static int usb4_do_read_data(u16 address, void *buf, size_t size,
66 			     read_block_fn read_block, void *read_block_data)
67 {
68 	unsigned int retries = USB4_DATA_RETRIES;
69 	unsigned int offset;
70 
71 	offset = address & 3;
72 	address = address & ~3;
73 
74 	do {
75 		size_t nbytes = min_t(size_t, size, USB4_DATA_DWORDS * 4);
76 		unsigned int dwaddress, dwords;
77 		u8 data[USB4_DATA_DWORDS * 4];
78 		int ret;
79 
80 		dwaddress = address / 4;
81 		dwords = ALIGN(nbytes, 4) / 4;
82 
83 		ret = read_block(read_block_data, dwaddress, data, dwords);
84 		if (ret) {
85 			if (ret != -ENODEV && retries--)
86 				continue;
87 			return ret;
88 		}
89 
90 		memcpy(buf, data + offset, nbytes);
91 
92 		size -= nbytes;
93 		address += nbytes;
94 		buf += nbytes;
95 	} while (size > 0);
96 
97 	return 0;
98 }
99 
100 static int usb4_do_write_data(unsigned int address, const void *buf, size_t size,
101 	write_block_fn write_next_block, void *write_block_data)
102 {
103 	unsigned int retries = USB4_DATA_RETRIES;
104 	unsigned int offset;
105 
106 	offset = address & 3;
107 	address = address & ~3;
108 
109 	do {
110 		u32 nbytes = min_t(u32, size, USB4_DATA_DWORDS * 4);
111 		u8 data[USB4_DATA_DWORDS * 4];
112 		int ret;
113 
114 		memcpy(data + offset, buf, nbytes);
115 
116 		ret = write_next_block(write_block_data, data, nbytes / 4);
117 		if (ret) {
118 			if (ret == -ETIMEDOUT) {
119 				if (retries--)
120 					continue;
121 				ret = -EIO;
122 			}
123 			return ret;
124 		}
125 
126 		size -= nbytes;
127 		address += nbytes;
128 		buf += nbytes;
129 	} while (size > 0);
130 
131 	return 0;
132 }
133 
134 static int usb4_native_switch_op(struct tb_switch *sw, u16 opcode,
135 				 u32 *metadata, u8 *status,
136 				 const void *tx_data, size_t tx_dwords,
137 				 void *rx_data, size_t rx_dwords)
138 {
139 	u32 val;
140 	int ret;
141 
142 	if (metadata) {
143 		ret = tb_sw_write(sw, metadata, TB_CFG_SWITCH, ROUTER_CS_25, 1);
144 		if (ret)
145 			return ret;
146 	}
147 	if (tx_dwords) {
148 		ret = tb_sw_write(sw, tx_data, TB_CFG_SWITCH, ROUTER_CS_9,
149 				  tx_dwords);
150 		if (ret)
151 			return ret;
152 	}
153 
154 	val = opcode | ROUTER_CS_26_OV;
155 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_26, 1);
156 	if (ret)
157 		return ret;
158 
159 	ret = usb4_switch_wait_for_bit(sw, ROUTER_CS_26, ROUTER_CS_26_OV, 0, 500);
160 	if (ret)
161 		return ret;
162 
163 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_26, 1);
164 	if (ret)
165 		return ret;
166 
167 	if (val & ROUTER_CS_26_ONS)
168 		return -EOPNOTSUPP;
169 
170 	if (status)
171 		*status = (val & ROUTER_CS_26_STATUS_MASK) >>
172 			ROUTER_CS_26_STATUS_SHIFT;
173 
174 	if (metadata) {
175 		ret = tb_sw_read(sw, metadata, TB_CFG_SWITCH, ROUTER_CS_25, 1);
176 		if (ret)
177 			return ret;
178 	}
179 	if (rx_dwords) {
180 		ret = tb_sw_read(sw, rx_data, TB_CFG_SWITCH, ROUTER_CS_9,
181 				 rx_dwords);
182 		if (ret)
183 			return ret;
184 	}
185 
186 	return 0;
187 }
188 
189 static int __usb4_switch_op(struct tb_switch *sw, u16 opcode, u32 *metadata,
190 			    u8 *status, const void *tx_data, size_t tx_dwords,
191 			    void *rx_data, size_t rx_dwords)
192 {
193 	const struct tb_cm_ops *cm_ops = sw->tb->cm_ops;
194 
195 	if (tx_dwords > USB4_DATA_DWORDS || rx_dwords > USB4_DATA_DWORDS)
196 		return -EINVAL;
197 
198 	/*
199 	 * If the connection manager implementation provides USB4 router
200 	 * operation proxy callback, call it here instead of running the
201 	 * operation natively.
202 	 */
203 	if (cm_ops->usb4_switch_op) {
204 		int ret;
205 
206 		ret = cm_ops->usb4_switch_op(sw, opcode, metadata, status,
207 					     tx_data, tx_dwords, rx_data,
208 					     rx_dwords);
209 		if (ret != -EOPNOTSUPP)
210 			return ret;
211 
212 		/*
213 		 * If the proxy was not supported then run the native
214 		 * router operation instead.
215 		 */
216 	}
217 
218 	return usb4_native_switch_op(sw, opcode, metadata, status, tx_data,
219 				     tx_dwords, rx_data, rx_dwords);
220 }
221 
222 static inline int usb4_switch_op(struct tb_switch *sw, u16 opcode,
223 				 u32 *metadata, u8 *status)
224 {
225 	return __usb4_switch_op(sw, opcode, metadata, status, NULL, 0, NULL, 0);
226 }
227 
228 static inline int usb4_switch_op_data(struct tb_switch *sw, u16 opcode,
229 				      u32 *metadata, u8 *status,
230 				      const void *tx_data, size_t tx_dwords,
231 				      void *rx_data, size_t rx_dwords)
232 {
233 	return __usb4_switch_op(sw, opcode, metadata, status, tx_data,
234 				tx_dwords, rx_data, rx_dwords);
235 }
236 
237 static void usb4_switch_check_wakes(struct tb_switch *sw)
238 {
239 	struct tb_port *port;
240 	bool wakeup = false;
241 	u32 val;
242 
243 	if (!device_may_wakeup(&sw->dev))
244 		return;
245 
246 	if (tb_route(sw)) {
247 		if (tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_6, 1))
248 			return;
249 
250 		tb_sw_dbg(sw, "PCIe wake: %s, USB3 wake: %s\n",
251 			  (val & ROUTER_CS_6_WOPS) ? "yes" : "no",
252 			  (val & ROUTER_CS_6_WOUS) ? "yes" : "no");
253 
254 		wakeup = val & (ROUTER_CS_6_WOPS | ROUTER_CS_6_WOUS);
255 	}
256 
257 	/* Check for any connected downstream ports for USB4 wake */
258 	tb_switch_for_each_port(sw, port) {
259 		if (!tb_port_has_remote(port))
260 			continue;
261 
262 		if (tb_port_read(port, &val, TB_CFG_PORT,
263 				 port->cap_usb4 + PORT_CS_18, 1))
264 			break;
265 
266 		tb_port_dbg(port, "USB4 wake: %s\n",
267 			    (val & PORT_CS_18_WOU4S) ? "yes" : "no");
268 
269 		if (val & PORT_CS_18_WOU4S)
270 			wakeup = true;
271 	}
272 
273 	if (wakeup)
274 		pm_wakeup_event(&sw->dev, 0);
275 }
276 
277 static bool link_is_usb4(struct tb_port *port)
278 {
279 	u32 val;
280 
281 	if (!port->cap_usb4)
282 		return false;
283 
284 	if (tb_port_read(port, &val, TB_CFG_PORT,
285 			 port->cap_usb4 + PORT_CS_18, 1))
286 		return false;
287 
288 	return !(val & PORT_CS_18_TCM);
289 }
290 
291 /**
292  * usb4_switch_setup() - Additional setup for USB4 device
293  * @sw: USB4 router to setup
294  *
295  * USB4 routers need additional settings in order to enable all the
296  * tunneling. This function enables USB and PCIe tunneling if it can be
297  * enabled (e.g the parent switch also supports them). If USB tunneling
298  * is not available for some reason (like that there is Thunderbolt 3
299  * switch upstream) then the internal xHCI controller is enabled
300  * instead.
301  */
302 int usb4_switch_setup(struct tb_switch *sw)
303 {
304 	struct tb_port *downstream_port;
305 	struct tb_switch *parent;
306 	bool tbt3, xhci;
307 	u32 val = 0;
308 	int ret;
309 
310 	usb4_switch_check_wakes(sw);
311 
312 	if (!tb_route(sw))
313 		return 0;
314 
315 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_6, 1);
316 	if (ret)
317 		return ret;
318 
319 	parent = tb_switch_parent(sw);
320 	downstream_port = tb_port_at(tb_route(sw), parent);
321 	sw->link_usb4 = link_is_usb4(downstream_port);
322 	tb_sw_dbg(sw, "link: %s\n", sw->link_usb4 ? "USB4" : "TBT3");
323 
324 	xhci = val & ROUTER_CS_6_HCI;
325 	tbt3 = !(val & ROUTER_CS_6_TNS);
326 
327 	tb_sw_dbg(sw, "TBT3 support: %s, xHCI: %s\n",
328 		  tbt3 ? "yes" : "no", xhci ? "yes" : "no");
329 
330 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
331 	if (ret)
332 		return ret;
333 
334 	if (sw->link_usb4 && tb_switch_find_port(parent, TB_TYPE_USB3_DOWN)) {
335 		val |= ROUTER_CS_5_UTO;
336 		xhci = false;
337 	}
338 
339 	/* Only enable PCIe tunneling if the parent router supports it */
340 	if (tb_switch_find_port(parent, TB_TYPE_PCIE_DOWN)) {
341 		val |= ROUTER_CS_5_PTO;
342 		/*
343 		 * xHCI can be enabled if PCIe tunneling is supported
344 		 * and the parent does not have any USB3 dowstream
345 		 * adapters (so we cannot do USB 3.x tunneling).
346 		 */
347 		if (xhci)
348 			val |= ROUTER_CS_5_HCO;
349 	}
350 
351 	/* TBT3 supported by the CM */
352 	val |= ROUTER_CS_5_C3S;
353 	/* Tunneling configuration is ready now */
354 	val |= ROUTER_CS_5_CV;
355 
356 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
357 	if (ret)
358 		return ret;
359 
360 	return usb4_switch_wait_for_bit(sw, ROUTER_CS_6, ROUTER_CS_6_CR,
361 					ROUTER_CS_6_CR, 50);
362 }
363 
364 /**
365  * usb4_switch_read_uid() - Read UID from USB4 router
366  * @sw: USB4 router
367  * @uid: UID is stored here
368  *
369  * Reads 64-bit UID from USB4 router config space.
370  */
371 int usb4_switch_read_uid(struct tb_switch *sw, u64 *uid)
372 {
373 	return tb_sw_read(sw, uid, TB_CFG_SWITCH, ROUTER_CS_7, 2);
374 }
375 
376 static int usb4_switch_drom_read_block(void *data,
377 				       unsigned int dwaddress, void *buf,
378 				       size_t dwords)
379 {
380 	struct tb_switch *sw = data;
381 	u8 status = 0;
382 	u32 metadata;
383 	int ret;
384 
385 	metadata = (dwords << USB4_DROM_SIZE_SHIFT) & USB4_DROM_SIZE_MASK;
386 	metadata |= (dwaddress << USB4_DROM_ADDRESS_SHIFT) &
387 		USB4_DROM_ADDRESS_MASK;
388 
389 	ret = usb4_switch_op_data(sw, USB4_SWITCH_OP_DROM_READ, &metadata,
390 				  &status, NULL, 0, buf, dwords);
391 	if (ret)
392 		return ret;
393 
394 	return status ? -EIO : 0;
395 }
396 
397 /**
398  * usb4_switch_drom_read() - Read arbitrary bytes from USB4 router DROM
399  * @sw: USB4 router
400  * @address: Byte address inside DROM to start reading
401  * @buf: Buffer where the DROM content is stored
402  * @size: Number of bytes to read from DROM
403  *
404  * Uses USB4 router operations to read router DROM. For devices this
405  * should always work but for hosts it may return %-EOPNOTSUPP in which
406  * case the host router does not have DROM.
407  */
408 int usb4_switch_drom_read(struct tb_switch *sw, unsigned int address, void *buf,
409 			  size_t size)
410 {
411 	return usb4_do_read_data(address, buf, size,
412 				 usb4_switch_drom_read_block, sw);
413 }
414 
415 /**
416  * usb4_switch_lane_bonding_possible() - Are conditions met for lane bonding
417  * @sw: USB4 router
418  *
419  * Checks whether conditions are met so that lane bonding can be
420  * established with the upstream router. Call only for device routers.
421  */
422 bool usb4_switch_lane_bonding_possible(struct tb_switch *sw)
423 {
424 	struct tb_port *up;
425 	int ret;
426 	u32 val;
427 
428 	up = tb_upstream_port(sw);
429 	ret = tb_port_read(up, &val, TB_CFG_PORT, up->cap_usb4 + PORT_CS_18, 1);
430 	if (ret)
431 		return false;
432 
433 	return !!(val & PORT_CS_18_BE);
434 }
435 
436 /**
437  * usb4_switch_set_wake() - Enabled/disable wake
438  * @sw: USB4 router
439  * @flags: Wakeup flags (%0 to disable)
440  *
441  * Enables/disables router to wake up from sleep.
442  */
443 int usb4_switch_set_wake(struct tb_switch *sw, unsigned int flags)
444 {
445 	struct tb_port *port;
446 	u64 route = tb_route(sw);
447 	u32 val;
448 	int ret;
449 
450 	/*
451 	 * Enable wakes coming from all USB4 downstream ports (from
452 	 * child routers). For device routers do this also for the
453 	 * upstream USB4 port.
454 	 */
455 	tb_switch_for_each_port(sw, port) {
456 		if (!tb_port_is_null(port))
457 			continue;
458 		if (!route && tb_is_upstream_port(port))
459 			continue;
460 		if (!port->cap_usb4)
461 			continue;
462 
463 		ret = tb_port_read(port, &val, TB_CFG_PORT,
464 				   port->cap_usb4 + PORT_CS_19, 1);
465 		if (ret)
466 			return ret;
467 
468 		val &= ~(PORT_CS_19_WOC | PORT_CS_19_WOD | PORT_CS_19_WOU4);
469 
470 		if (flags & TB_WAKE_ON_CONNECT)
471 			val |= PORT_CS_19_WOC;
472 		if (flags & TB_WAKE_ON_DISCONNECT)
473 			val |= PORT_CS_19_WOD;
474 		if (flags & TB_WAKE_ON_USB4)
475 			val |= PORT_CS_19_WOU4;
476 
477 		ret = tb_port_write(port, &val, TB_CFG_PORT,
478 				    port->cap_usb4 + PORT_CS_19, 1);
479 		if (ret)
480 			return ret;
481 	}
482 
483 	/*
484 	 * Enable wakes from PCIe and USB 3.x on this router. Only
485 	 * needed for device routers.
486 	 */
487 	if (route) {
488 		ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
489 		if (ret)
490 			return ret;
491 
492 		val &= ~(ROUTER_CS_5_WOP | ROUTER_CS_5_WOU);
493 		if (flags & TB_WAKE_ON_USB3)
494 			val |= ROUTER_CS_5_WOU;
495 		if (flags & TB_WAKE_ON_PCIE)
496 			val |= ROUTER_CS_5_WOP;
497 
498 		ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
499 		if (ret)
500 			return ret;
501 	}
502 
503 	return 0;
504 }
505 
506 /**
507  * usb4_switch_set_sleep() - Prepare the router to enter sleep
508  * @sw: USB4 router
509  *
510  * Sets sleep bit for the router. Returns when the router sleep ready
511  * bit has been asserted.
512  */
513 int usb4_switch_set_sleep(struct tb_switch *sw)
514 {
515 	int ret;
516 	u32 val;
517 
518 	/* Set sleep bit and wait for sleep ready to be asserted */
519 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
520 	if (ret)
521 		return ret;
522 
523 	val |= ROUTER_CS_5_SLP;
524 
525 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
526 	if (ret)
527 		return ret;
528 
529 	return usb4_switch_wait_for_bit(sw, ROUTER_CS_6, ROUTER_CS_6_SLPR,
530 					ROUTER_CS_6_SLPR, 500);
531 }
532 
533 /**
534  * usb4_switch_nvm_sector_size() - Return router NVM sector size
535  * @sw: USB4 router
536  *
537  * If the router supports NVM operations this function returns the NVM
538  * sector size in bytes. If NVM operations are not supported returns
539  * %-EOPNOTSUPP.
540  */
541 int usb4_switch_nvm_sector_size(struct tb_switch *sw)
542 {
543 	u32 metadata;
544 	u8 status;
545 	int ret;
546 
547 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_SECTOR_SIZE, &metadata,
548 			     &status);
549 	if (ret)
550 		return ret;
551 
552 	if (status)
553 		return status == 0x2 ? -EOPNOTSUPP : -EIO;
554 
555 	return metadata & USB4_NVM_SECTOR_SIZE_MASK;
556 }
557 
558 static int usb4_switch_nvm_read_block(void *data,
559 	unsigned int dwaddress, void *buf, size_t dwords)
560 {
561 	struct tb_switch *sw = data;
562 	u8 status = 0;
563 	u32 metadata;
564 	int ret;
565 
566 	metadata = (dwords << USB4_NVM_READ_LENGTH_SHIFT) &
567 		   USB4_NVM_READ_LENGTH_MASK;
568 	metadata |= (dwaddress << USB4_NVM_READ_OFFSET_SHIFT) &
569 		   USB4_NVM_READ_OFFSET_MASK;
570 
571 	ret = usb4_switch_op_data(sw, USB4_SWITCH_OP_NVM_READ, &metadata,
572 				  &status, NULL, 0, buf, dwords);
573 	if (ret)
574 		return ret;
575 
576 	return status ? -EIO : 0;
577 }
578 
579 /**
580  * usb4_switch_nvm_read() - Read arbitrary bytes from router NVM
581  * @sw: USB4 router
582  * @address: Starting address in bytes
583  * @buf: Read data is placed here
584  * @size: How many bytes to read
585  *
586  * Reads NVM contents of the router. If NVM is not supported returns
587  * %-EOPNOTSUPP.
588  */
589 int usb4_switch_nvm_read(struct tb_switch *sw, unsigned int address, void *buf,
590 			 size_t size)
591 {
592 	return usb4_do_read_data(address, buf, size,
593 				 usb4_switch_nvm_read_block, sw);
594 }
595 
596 static int usb4_switch_nvm_set_offset(struct tb_switch *sw,
597 				      unsigned int address)
598 {
599 	u32 metadata, dwaddress;
600 	u8 status = 0;
601 	int ret;
602 
603 	dwaddress = address / 4;
604 	metadata = (dwaddress << USB4_NVM_SET_OFFSET_SHIFT) &
605 		   USB4_NVM_SET_OFFSET_MASK;
606 
607 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_SET_OFFSET, &metadata,
608 			     &status);
609 	if (ret)
610 		return ret;
611 
612 	return status ? -EIO : 0;
613 }
614 
615 static int usb4_switch_nvm_write_next_block(void *data, const void *buf,
616 					    size_t dwords)
617 {
618 	struct tb_switch *sw = data;
619 	u8 status;
620 	int ret;
621 
622 	ret = usb4_switch_op_data(sw, USB4_SWITCH_OP_NVM_WRITE, NULL, &status,
623 				  buf, dwords, NULL, 0);
624 	if (ret)
625 		return ret;
626 
627 	return status ? -EIO : 0;
628 }
629 
630 /**
631  * usb4_switch_nvm_write() - Write to the router NVM
632  * @sw: USB4 router
633  * @address: Start address where to write in bytes
634  * @buf: Pointer to the data to write
635  * @size: Size of @buf in bytes
636  *
637  * Writes @buf to the router NVM using USB4 router operations. If NVM
638  * write is not supported returns %-EOPNOTSUPP.
639  */
640 int usb4_switch_nvm_write(struct tb_switch *sw, unsigned int address,
641 			  const void *buf, size_t size)
642 {
643 	int ret;
644 
645 	ret = usb4_switch_nvm_set_offset(sw, address);
646 	if (ret)
647 		return ret;
648 
649 	return usb4_do_write_data(address, buf, size,
650 				  usb4_switch_nvm_write_next_block, sw);
651 }
652 
653 /**
654  * usb4_switch_nvm_authenticate() - Authenticate new NVM
655  * @sw: USB4 router
656  *
657  * After the new NVM has been written via usb4_switch_nvm_write(), this
658  * function triggers NVM authentication process. The router gets power
659  * cycled and if the authentication is successful the new NVM starts
660  * running. In case of failure returns negative errno.
661  *
662  * The caller should call usb4_switch_nvm_authenticate_status() to read
663  * the status of the authentication after power cycle. It should be the
664  * first router operation to avoid the status being lost.
665  */
666 int usb4_switch_nvm_authenticate(struct tb_switch *sw)
667 {
668 	int ret;
669 
670 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_AUTH, NULL, NULL);
671 	switch (ret) {
672 	/*
673 	 * The router is power cycled once NVM_AUTH is started so it is
674 	 * expected to get any of the following errors back.
675 	 */
676 	case -EACCES:
677 	case -ENOTCONN:
678 	case -ETIMEDOUT:
679 		return 0;
680 
681 	default:
682 		return ret;
683 	}
684 }
685 
686 /**
687  * usb4_switch_nvm_authenticate_status() - Read status of last NVM authenticate
688  * @sw: USB4 router
689  * @status: Status code of the operation
690  *
691  * The function checks if there is status available from the last NVM
692  * authenticate router operation. If there is status then %0 is returned
693  * and the status code is placed in @status. Returns negative errno in case
694  * of failure.
695  *
696  * Must be called before any other router operation.
697  */
698 int usb4_switch_nvm_authenticate_status(struct tb_switch *sw, u32 *status)
699 {
700 	const struct tb_cm_ops *cm_ops = sw->tb->cm_ops;
701 	u16 opcode;
702 	u32 val;
703 	int ret;
704 
705 	if (cm_ops->usb4_switch_nvm_authenticate_status) {
706 		ret = cm_ops->usb4_switch_nvm_authenticate_status(sw, status);
707 		if (ret != -EOPNOTSUPP)
708 			return ret;
709 	}
710 
711 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_26, 1);
712 	if (ret)
713 		return ret;
714 
715 	/* Check that the opcode is correct */
716 	opcode = val & ROUTER_CS_26_OPCODE_MASK;
717 	if (opcode == USB4_SWITCH_OP_NVM_AUTH) {
718 		if (val & ROUTER_CS_26_OV)
719 			return -EBUSY;
720 		if (val & ROUTER_CS_26_ONS)
721 			return -EOPNOTSUPP;
722 
723 		*status = (val & ROUTER_CS_26_STATUS_MASK) >>
724 			ROUTER_CS_26_STATUS_SHIFT;
725 	} else {
726 		*status = 0;
727 	}
728 
729 	return 0;
730 }
731 
732 /**
733  * usb4_switch_query_dp_resource() - Query availability of DP IN resource
734  * @sw: USB4 router
735  * @in: DP IN adapter
736  *
737  * For DP tunneling this function can be used to query availability of
738  * DP IN resource. Returns true if the resource is available for DP
739  * tunneling, false otherwise.
740  */
741 bool usb4_switch_query_dp_resource(struct tb_switch *sw, struct tb_port *in)
742 {
743 	u32 metadata = in->port;
744 	u8 status;
745 	int ret;
746 
747 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_QUERY_DP_RESOURCE, &metadata,
748 			     &status);
749 	/*
750 	 * If DP resource allocation is not supported assume it is
751 	 * always available.
752 	 */
753 	if (ret == -EOPNOTSUPP)
754 		return true;
755 	else if (ret)
756 		return false;
757 
758 	return !status;
759 }
760 
761 /**
762  * usb4_switch_alloc_dp_resource() - Allocate DP IN resource
763  * @sw: USB4 router
764  * @in: DP IN adapter
765  *
766  * Allocates DP IN resource for DP tunneling using USB4 router
767  * operations. If the resource was allocated returns %0. Otherwise
768  * returns negative errno, in particular %-EBUSY if the resource is
769  * already allocated.
770  */
771 int usb4_switch_alloc_dp_resource(struct tb_switch *sw, struct tb_port *in)
772 {
773 	u32 metadata = in->port;
774 	u8 status;
775 	int ret;
776 
777 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_ALLOC_DP_RESOURCE, &metadata,
778 			     &status);
779 	if (ret == -EOPNOTSUPP)
780 		return 0;
781 	else if (ret)
782 		return ret;
783 
784 	return status ? -EBUSY : 0;
785 }
786 
787 /**
788  * usb4_switch_dealloc_dp_resource() - Releases allocated DP IN resource
789  * @sw: USB4 router
790  * @in: DP IN adapter
791  *
792  * Releases the previously allocated DP IN resource.
793  */
794 int usb4_switch_dealloc_dp_resource(struct tb_switch *sw, struct tb_port *in)
795 {
796 	u32 metadata = in->port;
797 	u8 status;
798 	int ret;
799 
800 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_DEALLOC_DP_RESOURCE, &metadata,
801 			     &status);
802 	if (ret == -EOPNOTSUPP)
803 		return 0;
804 	else if (ret)
805 		return ret;
806 
807 	return status ? -EIO : 0;
808 }
809 
810 static int usb4_port_idx(const struct tb_switch *sw, const struct tb_port *port)
811 {
812 	struct tb_port *p;
813 	int usb4_idx = 0;
814 
815 	/* Assume port is primary */
816 	tb_switch_for_each_port(sw, p) {
817 		if (!tb_port_is_null(p))
818 			continue;
819 		if (tb_is_upstream_port(p))
820 			continue;
821 		if (!p->link_nr) {
822 			if (p == port)
823 				break;
824 			usb4_idx++;
825 		}
826 	}
827 
828 	return usb4_idx;
829 }
830 
831 /**
832  * usb4_switch_map_pcie_down() - Map USB4 port to a PCIe downstream adapter
833  * @sw: USB4 router
834  * @port: USB4 port
835  *
836  * USB4 routers have direct mapping between USB4 ports and PCIe
837  * downstream adapters where the PCIe topology is extended. This
838  * function returns the corresponding downstream PCIe adapter or %NULL
839  * if no such mapping was possible.
840  */
841 struct tb_port *usb4_switch_map_pcie_down(struct tb_switch *sw,
842 					  const struct tb_port *port)
843 {
844 	int usb4_idx = usb4_port_idx(sw, port);
845 	struct tb_port *p;
846 	int pcie_idx = 0;
847 
848 	/* Find PCIe down port matching usb4_port */
849 	tb_switch_for_each_port(sw, p) {
850 		if (!tb_port_is_pcie_down(p))
851 			continue;
852 
853 		if (pcie_idx == usb4_idx)
854 			return p;
855 
856 		pcie_idx++;
857 	}
858 
859 	return NULL;
860 }
861 
862 /**
863  * usb4_switch_map_usb3_down() - Map USB4 port to a USB3 downstream adapter
864  * @sw: USB4 router
865  * @port: USB4 port
866  *
867  * USB4 routers have direct mapping between USB4 ports and USB 3.x
868  * downstream adapters where the USB 3.x topology is extended. This
869  * function returns the corresponding downstream USB 3.x adapter or
870  * %NULL if no such mapping was possible.
871  */
872 struct tb_port *usb4_switch_map_usb3_down(struct tb_switch *sw,
873 					  const struct tb_port *port)
874 {
875 	int usb4_idx = usb4_port_idx(sw, port);
876 	struct tb_port *p;
877 	int usb_idx = 0;
878 
879 	/* Find USB3 down port matching usb4_port */
880 	tb_switch_for_each_port(sw, p) {
881 		if (!tb_port_is_usb3_down(p))
882 			continue;
883 
884 		if (usb_idx == usb4_idx)
885 			return p;
886 
887 		usb_idx++;
888 	}
889 
890 	return NULL;
891 }
892 
893 /**
894  * usb4_port_unlock() - Unlock USB4 downstream port
895  * @port: USB4 port to unlock
896  *
897  * Unlocks USB4 downstream port so that the connection manager can
898  * access the router below this port.
899  */
900 int usb4_port_unlock(struct tb_port *port)
901 {
902 	int ret;
903 	u32 val;
904 
905 	ret = tb_port_read(port, &val, TB_CFG_PORT, ADP_CS_4, 1);
906 	if (ret)
907 		return ret;
908 
909 	val &= ~ADP_CS_4_LCK;
910 	return tb_port_write(port, &val, TB_CFG_PORT, ADP_CS_4, 1);
911 }
912 
913 static int usb4_port_set_configured(struct tb_port *port, bool configured)
914 {
915 	int ret;
916 	u32 val;
917 
918 	if (!port->cap_usb4)
919 		return -EINVAL;
920 
921 	ret = tb_port_read(port, &val, TB_CFG_PORT,
922 			   port->cap_usb4 + PORT_CS_19, 1);
923 	if (ret)
924 		return ret;
925 
926 	if (configured)
927 		val |= PORT_CS_19_PC;
928 	else
929 		val &= ~PORT_CS_19_PC;
930 
931 	return tb_port_write(port, &val, TB_CFG_PORT,
932 			     port->cap_usb4 + PORT_CS_19, 1);
933 }
934 
935 /**
936  * usb4_port_configure() - Set USB4 port configured
937  * @port: USB4 router
938  *
939  * Sets the USB4 link to be configured for power management purposes.
940  */
941 int usb4_port_configure(struct tb_port *port)
942 {
943 	return usb4_port_set_configured(port, true);
944 }
945 
946 /**
947  * usb4_port_unconfigure() - Set USB4 port unconfigured
948  * @port: USB4 router
949  *
950  * Sets the USB4 link to be unconfigured for power management purposes.
951  */
952 void usb4_port_unconfigure(struct tb_port *port)
953 {
954 	usb4_port_set_configured(port, false);
955 }
956 
957 static int usb4_set_xdomain_configured(struct tb_port *port, bool configured)
958 {
959 	int ret;
960 	u32 val;
961 
962 	if (!port->cap_usb4)
963 		return -EINVAL;
964 
965 	ret = tb_port_read(port, &val, TB_CFG_PORT,
966 			   port->cap_usb4 + PORT_CS_19, 1);
967 	if (ret)
968 		return ret;
969 
970 	if (configured)
971 		val |= PORT_CS_19_PID;
972 	else
973 		val &= ~PORT_CS_19_PID;
974 
975 	return tb_port_write(port, &val, TB_CFG_PORT,
976 			     port->cap_usb4 + PORT_CS_19, 1);
977 }
978 
979 /**
980  * usb4_port_configure_xdomain() - Configure port for XDomain
981  * @port: USB4 port connected to another host
982  *
983  * Marks the USB4 port as being connected to another host. Returns %0 in
984  * success and negative errno in failure.
985  */
986 int usb4_port_configure_xdomain(struct tb_port *port)
987 {
988 	return usb4_set_xdomain_configured(port, true);
989 }
990 
991 /**
992  * usb4_port_unconfigure_xdomain() - Unconfigure port for XDomain
993  * @port: USB4 port that was connected to another host
994  *
995  * Clears USB4 port from being marked as XDomain.
996  */
997 void usb4_port_unconfigure_xdomain(struct tb_port *port)
998 {
999 	usb4_set_xdomain_configured(port, false);
1000 }
1001 
1002 static int usb4_port_wait_for_bit(struct tb_port *port, u32 offset, u32 bit,
1003 				  u32 value, int timeout_msec)
1004 {
1005 	ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
1006 
1007 	do {
1008 		u32 val;
1009 		int ret;
1010 
1011 		ret = tb_port_read(port, &val, TB_CFG_PORT, offset, 1);
1012 		if (ret)
1013 			return ret;
1014 
1015 		if ((val & bit) == value)
1016 			return 0;
1017 
1018 		usleep_range(50, 100);
1019 	} while (ktime_before(ktime_get(), timeout));
1020 
1021 	return -ETIMEDOUT;
1022 }
1023 
1024 static int usb4_port_read_data(struct tb_port *port, void *data, size_t dwords)
1025 {
1026 	if (dwords > USB4_DATA_DWORDS)
1027 		return -EINVAL;
1028 
1029 	return tb_port_read(port, data, TB_CFG_PORT, port->cap_usb4 + PORT_CS_2,
1030 			    dwords);
1031 }
1032 
1033 static int usb4_port_write_data(struct tb_port *port, const void *data,
1034 				size_t dwords)
1035 {
1036 	if (dwords > USB4_DATA_DWORDS)
1037 		return -EINVAL;
1038 
1039 	return tb_port_write(port, data, TB_CFG_PORT, port->cap_usb4 + PORT_CS_2,
1040 			     dwords);
1041 }
1042 
1043 static int usb4_port_sb_read(struct tb_port *port, enum usb4_sb_target target,
1044 			     u8 index, u8 reg, void *buf, u8 size)
1045 {
1046 	size_t dwords = DIV_ROUND_UP(size, 4);
1047 	int ret;
1048 	u32 val;
1049 
1050 	if (!port->cap_usb4)
1051 		return -EINVAL;
1052 
1053 	val = reg;
1054 	val |= size << PORT_CS_1_LENGTH_SHIFT;
1055 	val |= (target << PORT_CS_1_TARGET_SHIFT) & PORT_CS_1_TARGET_MASK;
1056 	if (target == USB4_SB_TARGET_RETIMER)
1057 		val |= (index << PORT_CS_1_RETIMER_INDEX_SHIFT);
1058 	val |= PORT_CS_1_PND;
1059 
1060 	ret = tb_port_write(port, &val, TB_CFG_PORT,
1061 			    port->cap_usb4 + PORT_CS_1, 1);
1062 	if (ret)
1063 		return ret;
1064 
1065 	ret = usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_1,
1066 				     PORT_CS_1_PND, 0, 500);
1067 	if (ret)
1068 		return ret;
1069 
1070 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1071 			    port->cap_usb4 + PORT_CS_1, 1);
1072 	if (ret)
1073 		return ret;
1074 
1075 	if (val & PORT_CS_1_NR)
1076 		return -ENODEV;
1077 	if (val & PORT_CS_1_RC)
1078 		return -EIO;
1079 
1080 	return buf ? usb4_port_read_data(port, buf, dwords) : 0;
1081 }
1082 
1083 static int usb4_port_sb_write(struct tb_port *port, enum usb4_sb_target target,
1084 			      u8 index, u8 reg, const void *buf, u8 size)
1085 {
1086 	size_t dwords = DIV_ROUND_UP(size, 4);
1087 	int ret;
1088 	u32 val;
1089 
1090 	if (!port->cap_usb4)
1091 		return -EINVAL;
1092 
1093 	if (buf) {
1094 		ret = usb4_port_write_data(port, buf, dwords);
1095 		if (ret)
1096 			return ret;
1097 	}
1098 
1099 	val = reg;
1100 	val |= size << PORT_CS_1_LENGTH_SHIFT;
1101 	val |= PORT_CS_1_WNR_WRITE;
1102 	val |= (target << PORT_CS_1_TARGET_SHIFT) & PORT_CS_1_TARGET_MASK;
1103 	if (target == USB4_SB_TARGET_RETIMER)
1104 		val |= (index << PORT_CS_1_RETIMER_INDEX_SHIFT);
1105 	val |= PORT_CS_1_PND;
1106 
1107 	ret = tb_port_write(port, &val, TB_CFG_PORT,
1108 			    port->cap_usb4 + PORT_CS_1, 1);
1109 	if (ret)
1110 		return ret;
1111 
1112 	ret = usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_1,
1113 				     PORT_CS_1_PND, 0, 500);
1114 	if (ret)
1115 		return ret;
1116 
1117 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1118 			    port->cap_usb4 + PORT_CS_1, 1);
1119 	if (ret)
1120 		return ret;
1121 
1122 	if (val & PORT_CS_1_NR)
1123 		return -ENODEV;
1124 	if (val & PORT_CS_1_RC)
1125 		return -EIO;
1126 
1127 	return 0;
1128 }
1129 
1130 static int usb4_port_sb_op(struct tb_port *port, enum usb4_sb_target target,
1131 			   u8 index, enum usb4_sb_opcode opcode, int timeout_msec)
1132 {
1133 	ktime_t timeout;
1134 	u32 val;
1135 	int ret;
1136 
1137 	val = opcode;
1138 	ret = usb4_port_sb_write(port, target, index, USB4_SB_OPCODE, &val,
1139 				 sizeof(val));
1140 	if (ret)
1141 		return ret;
1142 
1143 	timeout = ktime_add_ms(ktime_get(), timeout_msec);
1144 
1145 	do {
1146 		/* Check results */
1147 		ret = usb4_port_sb_read(port, target, index, USB4_SB_OPCODE,
1148 					&val, sizeof(val));
1149 		if (ret)
1150 			return ret;
1151 
1152 		switch (val) {
1153 		case 0:
1154 			return 0;
1155 
1156 		case USB4_SB_OPCODE_ERR:
1157 			return -EAGAIN;
1158 
1159 		case USB4_SB_OPCODE_ONS:
1160 			return -EOPNOTSUPP;
1161 
1162 		default:
1163 			if (val != opcode)
1164 				return -EIO;
1165 			break;
1166 		}
1167 	} while (ktime_before(ktime_get(), timeout));
1168 
1169 	return -ETIMEDOUT;
1170 }
1171 
1172 /**
1173  * usb4_port_enumerate_retimers() - Send RT broadcast transaction
1174  * @port: USB4 port
1175  *
1176  * This forces the USB4 port to send broadcast RT transaction which
1177  * makes the retimers on the link to assign index to themselves. Returns
1178  * %0 in case of success and negative errno if there was an error.
1179  */
1180 int usb4_port_enumerate_retimers(struct tb_port *port)
1181 {
1182 	u32 val;
1183 
1184 	val = USB4_SB_OPCODE_ENUMERATE_RETIMERS;
1185 	return usb4_port_sb_write(port, USB4_SB_TARGET_ROUTER, 0,
1186 				  USB4_SB_OPCODE, &val, sizeof(val));
1187 }
1188 
1189 static inline int usb4_port_retimer_op(struct tb_port *port, u8 index,
1190 				       enum usb4_sb_opcode opcode,
1191 				       int timeout_msec)
1192 {
1193 	return usb4_port_sb_op(port, USB4_SB_TARGET_RETIMER, index, opcode,
1194 			       timeout_msec);
1195 }
1196 
1197 /**
1198  * usb4_port_retimer_read() - Read from retimer sideband registers
1199  * @port: USB4 port
1200  * @index: Retimer index
1201  * @reg: Sideband register to read
1202  * @buf: Data from @reg is stored here
1203  * @size: Number of bytes to read
1204  *
1205  * Function reads retimer sideband registers starting from @reg. The
1206  * retimer is connected to @port at @index. Returns %0 in case of
1207  * success, and read data is copied to @buf. If there is no retimer
1208  * present at given @index returns %-ENODEV. In any other failure
1209  * returns negative errno.
1210  */
1211 int usb4_port_retimer_read(struct tb_port *port, u8 index, u8 reg, void *buf,
1212 			   u8 size)
1213 {
1214 	return usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index, reg, buf,
1215 				 size);
1216 }
1217 
1218 /**
1219  * usb4_port_retimer_write() - Write to retimer sideband registers
1220  * @port: USB4 port
1221  * @index: Retimer index
1222  * @reg: Sideband register to write
1223  * @buf: Data that is written starting from @reg
1224  * @size: Number of bytes to write
1225  *
1226  * Writes retimer sideband registers starting from @reg. The retimer is
1227  * connected to @port at @index. Returns %0 in case of success. If there
1228  * is no retimer present at given @index returns %-ENODEV. In any other
1229  * failure returns negative errno.
1230  */
1231 int usb4_port_retimer_write(struct tb_port *port, u8 index, u8 reg,
1232 			    const void *buf, u8 size)
1233 {
1234 	return usb4_port_sb_write(port, USB4_SB_TARGET_RETIMER, index, reg, buf,
1235 				  size);
1236 }
1237 
1238 /**
1239  * usb4_port_retimer_is_last() - Is the retimer last on-board retimer
1240  * @port: USB4 port
1241  * @index: Retimer index
1242  *
1243  * If the retimer at @index is last one (connected directly to the
1244  * Type-C port) this function returns %1. If it is not returns %0. If
1245  * the retimer is not present returns %-ENODEV. Otherwise returns
1246  * negative errno.
1247  */
1248 int usb4_port_retimer_is_last(struct tb_port *port, u8 index)
1249 {
1250 	u32 metadata;
1251 	int ret;
1252 
1253 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_QUERY_LAST_RETIMER,
1254 				   500);
1255 	if (ret)
1256 		return ret;
1257 
1258 	ret = usb4_port_retimer_read(port, index, USB4_SB_METADATA, &metadata,
1259 				     sizeof(metadata));
1260 	return ret ? ret : metadata & 1;
1261 }
1262 
1263 /**
1264  * usb4_port_retimer_nvm_sector_size() - Read retimer NVM sector size
1265  * @port: USB4 port
1266  * @index: Retimer index
1267  *
1268  * Reads NVM sector size (in bytes) of a retimer at @index. This
1269  * operation can be used to determine whether the retimer supports NVM
1270  * upgrade for example. Returns sector size in bytes or negative errno
1271  * in case of error. Specifically returns %-ENODEV if there is no
1272  * retimer at @index.
1273  */
1274 int usb4_port_retimer_nvm_sector_size(struct tb_port *port, u8 index)
1275 {
1276 	u32 metadata;
1277 	int ret;
1278 
1279 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_GET_NVM_SECTOR_SIZE,
1280 				   500);
1281 	if (ret)
1282 		return ret;
1283 
1284 	ret = usb4_port_retimer_read(port, index, USB4_SB_METADATA, &metadata,
1285 				     sizeof(metadata));
1286 	return ret ? ret : metadata & USB4_NVM_SECTOR_SIZE_MASK;
1287 }
1288 
1289 static int usb4_port_retimer_nvm_set_offset(struct tb_port *port, u8 index,
1290 					    unsigned int address)
1291 {
1292 	u32 metadata, dwaddress;
1293 	int ret;
1294 
1295 	dwaddress = address / 4;
1296 	metadata = (dwaddress << USB4_NVM_SET_OFFSET_SHIFT) &
1297 		  USB4_NVM_SET_OFFSET_MASK;
1298 
1299 	ret = usb4_port_retimer_write(port, index, USB4_SB_METADATA, &metadata,
1300 				      sizeof(metadata));
1301 	if (ret)
1302 		return ret;
1303 
1304 	return usb4_port_retimer_op(port, index, USB4_SB_OPCODE_NVM_SET_OFFSET,
1305 				    500);
1306 }
1307 
1308 struct retimer_info {
1309 	struct tb_port *port;
1310 	u8 index;
1311 };
1312 
1313 static int usb4_port_retimer_nvm_write_next_block(void *data, const void *buf,
1314 						  size_t dwords)
1315 
1316 {
1317 	const struct retimer_info *info = data;
1318 	struct tb_port *port = info->port;
1319 	u8 index = info->index;
1320 	int ret;
1321 
1322 	ret = usb4_port_retimer_write(port, index, USB4_SB_DATA,
1323 				      buf, dwords * 4);
1324 	if (ret)
1325 		return ret;
1326 
1327 	return usb4_port_retimer_op(port, index,
1328 			USB4_SB_OPCODE_NVM_BLOCK_WRITE, 1000);
1329 }
1330 
1331 /**
1332  * usb4_port_retimer_nvm_write() - Write to retimer NVM
1333  * @port: USB4 port
1334  * @index: Retimer index
1335  * @address: Byte address where to start the write
1336  * @buf: Data to write
1337  * @size: Size in bytes how much to write
1338  *
1339  * Writes @size bytes from @buf to the retimer NVM. Used for NVM
1340  * upgrade. Returns %0 if the data was written successfully and negative
1341  * errno in case of failure. Specifically returns %-ENODEV if there is
1342  * no retimer at @index.
1343  */
1344 int usb4_port_retimer_nvm_write(struct tb_port *port, u8 index, unsigned int address,
1345 				const void *buf, size_t size)
1346 {
1347 	struct retimer_info info = { .port = port, .index = index };
1348 	int ret;
1349 
1350 	ret = usb4_port_retimer_nvm_set_offset(port, index, address);
1351 	if (ret)
1352 		return ret;
1353 
1354 	return usb4_do_write_data(address, buf, size,
1355 			usb4_port_retimer_nvm_write_next_block, &info);
1356 }
1357 
1358 /**
1359  * usb4_port_retimer_nvm_authenticate() - Start retimer NVM upgrade
1360  * @port: USB4 port
1361  * @index: Retimer index
1362  *
1363  * After the new NVM image has been written via usb4_port_retimer_nvm_write()
1364  * this function can be used to trigger the NVM upgrade process. If
1365  * successful the retimer restarts with the new NVM and may not have the
1366  * index set so one needs to call usb4_port_enumerate_retimers() to
1367  * force index to be assigned.
1368  */
1369 int usb4_port_retimer_nvm_authenticate(struct tb_port *port, u8 index)
1370 {
1371 	u32 val;
1372 
1373 	/*
1374 	 * We need to use the raw operation here because once the
1375 	 * authentication completes the retimer index is not set anymore
1376 	 * so we do not get back the status now.
1377 	 */
1378 	val = USB4_SB_OPCODE_NVM_AUTH_WRITE;
1379 	return usb4_port_sb_write(port, USB4_SB_TARGET_RETIMER, index,
1380 				  USB4_SB_OPCODE, &val, sizeof(val));
1381 }
1382 
1383 /**
1384  * usb4_port_retimer_nvm_authenticate_status() - Read status of NVM upgrade
1385  * @port: USB4 port
1386  * @index: Retimer index
1387  * @status: Raw status code read from metadata
1388  *
1389  * This can be called after usb4_port_retimer_nvm_authenticate() and
1390  * usb4_port_enumerate_retimers() to fetch status of the NVM upgrade.
1391  *
1392  * Returns %0 if the authentication status was successfully read. The
1393  * completion metadata (the result) is then stored into @status. If
1394  * reading the status fails, returns negative errno.
1395  */
1396 int usb4_port_retimer_nvm_authenticate_status(struct tb_port *port, u8 index,
1397 					      u32 *status)
1398 {
1399 	u32 metadata, val;
1400 	int ret;
1401 
1402 	ret = usb4_port_retimer_read(port, index, USB4_SB_OPCODE, &val,
1403 				     sizeof(val));
1404 	if (ret)
1405 		return ret;
1406 
1407 	switch (val) {
1408 	case 0:
1409 		*status = 0;
1410 		return 0;
1411 
1412 	case USB4_SB_OPCODE_ERR:
1413 		ret = usb4_port_retimer_read(port, index, USB4_SB_METADATA,
1414 					     &metadata, sizeof(metadata));
1415 		if (ret)
1416 			return ret;
1417 
1418 		*status = metadata & USB4_SB_METADATA_NVM_AUTH_WRITE_MASK;
1419 		return 0;
1420 
1421 	case USB4_SB_OPCODE_ONS:
1422 		return -EOPNOTSUPP;
1423 
1424 	default:
1425 		return -EIO;
1426 	}
1427 }
1428 
1429 static int usb4_port_retimer_nvm_read_block(void *data, unsigned int dwaddress,
1430 					    void *buf, size_t dwords)
1431 {
1432 	const struct retimer_info *info = data;
1433 	struct tb_port *port = info->port;
1434 	u8 index = info->index;
1435 	u32 metadata;
1436 	int ret;
1437 
1438 	metadata = dwaddress << USB4_NVM_READ_OFFSET_SHIFT;
1439 	if (dwords < USB4_DATA_DWORDS)
1440 		metadata |= dwords << USB4_NVM_READ_LENGTH_SHIFT;
1441 
1442 	ret = usb4_port_retimer_write(port, index, USB4_SB_METADATA, &metadata,
1443 				      sizeof(metadata));
1444 	if (ret)
1445 		return ret;
1446 
1447 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_NVM_READ, 500);
1448 	if (ret)
1449 		return ret;
1450 
1451 	return usb4_port_retimer_read(port, index, USB4_SB_DATA, buf,
1452 				      dwords * 4);
1453 }
1454 
1455 /**
1456  * usb4_port_retimer_nvm_read() - Read contents of retimer NVM
1457  * @port: USB4 port
1458  * @index: Retimer index
1459  * @address: NVM address (in bytes) to start reading
1460  * @buf: Data read from NVM is stored here
1461  * @size: Number of bytes to read
1462  *
1463  * Reads retimer NVM and copies the contents to @buf. Returns %0 if the
1464  * read was successful and negative errno in case of failure.
1465  * Specifically returns %-ENODEV if there is no retimer at @index.
1466  */
1467 int usb4_port_retimer_nvm_read(struct tb_port *port, u8 index,
1468 			       unsigned int address, void *buf, size_t size)
1469 {
1470 	struct retimer_info info = { .port = port, .index = index };
1471 
1472 	return usb4_do_read_data(address, buf, size,
1473 			usb4_port_retimer_nvm_read_block, &info);
1474 }
1475 
1476 /**
1477  * usb4_usb3_port_max_link_rate() - Maximum support USB3 link rate
1478  * @port: USB3 adapter port
1479  *
1480  * Return maximum supported link rate of a USB3 adapter in Mb/s.
1481  * Negative errno in case of error.
1482  */
1483 int usb4_usb3_port_max_link_rate(struct tb_port *port)
1484 {
1485 	int ret, lr;
1486 	u32 val;
1487 
1488 	if (!tb_port_is_usb3_down(port) && !tb_port_is_usb3_up(port))
1489 		return -EINVAL;
1490 
1491 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1492 			   port->cap_adap + ADP_USB3_CS_4, 1);
1493 	if (ret)
1494 		return ret;
1495 
1496 	lr = (val & ADP_USB3_CS_4_MSLR_MASK) >> ADP_USB3_CS_4_MSLR_SHIFT;
1497 	return lr == ADP_USB3_CS_4_MSLR_20G ? 20000 : 10000;
1498 }
1499 
1500 /**
1501  * usb4_usb3_port_actual_link_rate() - Established USB3 link rate
1502  * @port: USB3 adapter port
1503  *
1504  * Return actual established link rate of a USB3 adapter in Mb/s. If the
1505  * link is not up returns %0 and negative errno in case of failure.
1506  */
1507 int usb4_usb3_port_actual_link_rate(struct tb_port *port)
1508 {
1509 	int ret, lr;
1510 	u32 val;
1511 
1512 	if (!tb_port_is_usb3_down(port) && !tb_port_is_usb3_up(port))
1513 		return -EINVAL;
1514 
1515 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1516 			   port->cap_adap + ADP_USB3_CS_4, 1);
1517 	if (ret)
1518 		return ret;
1519 
1520 	if (!(val & ADP_USB3_CS_4_ULV))
1521 		return 0;
1522 
1523 	lr = val & ADP_USB3_CS_4_ALR_MASK;
1524 	return lr == ADP_USB3_CS_4_ALR_20G ? 20000 : 10000;
1525 }
1526 
1527 static int usb4_usb3_port_cm_request(struct tb_port *port, bool request)
1528 {
1529 	int ret;
1530 	u32 val;
1531 
1532 	if (!tb_port_is_usb3_down(port))
1533 		return -EINVAL;
1534 	if (tb_route(port->sw))
1535 		return -EINVAL;
1536 
1537 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1538 			   port->cap_adap + ADP_USB3_CS_2, 1);
1539 	if (ret)
1540 		return ret;
1541 
1542 	if (request)
1543 		val |= ADP_USB3_CS_2_CMR;
1544 	else
1545 		val &= ~ADP_USB3_CS_2_CMR;
1546 
1547 	ret = tb_port_write(port, &val, TB_CFG_PORT,
1548 			    port->cap_adap + ADP_USB3_CS_2, 1);
1549 	if (ret)
1550 		return ret;
1551 
1552 	/*
1553 	 * We can use val here directly as the CMR bit is in the same place
1554 	 * as HCA. Just mask out others.
1555 	 */
1556 	val &= ADP_USB3_CS_2_CMR;
1557 	return usb4_port_wait_for_bit(port, port->cap_adap + ADP_USB3_CS_1,
1558 				      ADP_USB3_CS_1_HCA, val, 1500);
1559 }
1560 
1561 static inline int usb4_usb3_port_set_cm_request(struct tb_port *port)
1562 {
1563 	return usb4_usb3_port_cm_request(port, true);
1564 }
1565 
1566 static inline int usb4_usb3_port_clear_cm_request(struct tb_port *port)
1567 {
1568 	return usb4_usb3_port_cm_request(port, false);
1569 }
1570 
1571 static unsigned int usb3_bw_to_mbps(u32 bw, u8 scale)
1572 {
1573 	unsigned long uframes;
1574 
1575 	uframes = bw * 512UL << scale;
1576 	return DIV_ROUND_CLOSEST(uframes * 8000, 1000 * 1000);
1577 }
1578 
1579 static u32 mbps_to_usb3_bw(unsigned int mbps, u8 scale)
1580 {
1581 	unsigned long uframes;
1582 
1583 	/* 1 uframe is 1/8 ms (125 us) -> 1 / 8000 s */
1584 	uframes = ((unsigned long)mbps * 1000 *  1000) / 8000;
1585 	return DIV_ROUND_UP(uframes, 512UL << scale);
1586 }
1587 
1588 static int usb4_usb3_port_read_allocated_bandwidth(struct tb_port *port,
1589 						   int *upstream_bw,
1590 						   int *downstream_bw)
1591 {
1592 	u32 val, bw, scale;
1593 	int ret;
1594 
1595 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1596 			   port->cap_adap + ADP_USB3_CS_2, 1);
1597 	if (ret)
1598 		return ret;
1599 
1600 	ret = tb_port_read(port, &scale, TB_CFG_PORT,
1601 			   port->cap_adap + ADP_USB3_CS_3, 1);
1602 	if (ret)
1603 		return ret;
1604 
1605 	scale &= ADP_USB3_CS_3_SCALE_MASK;
1606 
1607 	bw = val & ADP_USB3_CS_2_AUBW_MASK;
1608 	*upstream_bw = usb3_bw_to_mbps(bw, scale);
1609 
1610 	bw = (val & ADP_USB3_CS_2_ADBW_MASK) >> ADP_USB3_CS_2_ADBW_SHIFT;
1611 	*downstream_bw = usb3_bw_to_mbps(bw, scale);
1612 
1613 	return 0;
1614 }
1615 
1616 /**
1617  * usb4_usb3_port_allocated_bandwidth() - Bandwidth allocated for USB3
1618  * @port: USB3 adapter port
1619  * @upstream_bw: Allocated upstream bandwidth is stored here
1620  * @downstream_bw: Allocated downstream bandwidth is stored here
1621  *
1622  * Stores currently allocated USB3 bandwidth into @upstream_bw and
1623  * @downstream_bw in Mb/s. Returns %0 in case of success and negative
1624  * errno in failure.
1625  */
1626 int usb4_usb3_port_allocated_bandwidth(struct tb_port *port, int *upstream_bw,
1627 				       int *downstream_bw)
1628 {
1629 	int ret;
1630 
1631 	ret = usb4_usb3_port_set_cm_request(port);
1632 	if (ret)
1633 		return ret;
1634 
1635 	ret = usb4_usb3_port_read_allocated_bandwidth(port, upstream_bw,
1636 						      downstream_bw);
1637 	usb4_usb3_port_clear_cm_request(port);
1638 
1639 	return ret;
1640 }
1641 
1642 static int usb4_usb3_port_read_consumed_bandwidth(struct tb_port *port,
1643 						  int *upstream_bw,
1644 						  int *downstream_bw)
1645 {
1646 	u32 val, bw, scale;
1647 	int ret;
1648 
1649 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1650 			   port->cap_adap + ADP_USB3_CS_1, 1);
1651 	if (ret)
1652 		return ret;
1653 
1654 	ret = tb_port_read(port, &scale, TB_CFG_PORT,
1655 			   port->cap_adap + ADP_USB3_CS_3, 1);
1656 	if (ret)
1657 		return ret;
1658 
1659 	scale &= ADP_USB3_CS_3_SCALE_MASK;
1660 
1661 	bw = val & ADP_USB3_CS_1_CUBW_MASK;
1662 	*upstream_bw = usb3_bw_to_mbps(bw, scale);
1663 
1664 	bw = (val & ADP_USB3_CS_1_CDBW_MASK) >> ADP_USB3_CS_1_CDBW_SHIFT;
1665 	*downstream_bw = usb3_bw_to_mbps(bw, scale);
1666 
1667 	return 0;
1668 }
1669 
1670 static int usb4_usb3_port_write_allocated_bandwidth(struct tb_port *port,
1671 						    int upstream_bw,
1672 						    int downstream_bw)
1673 {
1674 	u32 val, ubw, dbw, scale;
1675 	int ret;
1676 
1677 	/* Read the used scale, hardware default is 0 */
1678 	ret = tb_port_read(port, &scale, TB_CFG_PORT,
1679 			   port->cap_adap + ADP_USB3_CS_3, 1);
1680 	if (ret)
1681 		return ret;
1682 
1683 	scale &= ADP_USB3_CS_3_SCALE_MASK;
1684 	ubw = mbps_to_usb3_bw(upstream_bw, scale);
1685 	dbw = mbps_to_usb3_bw(downstream_bw, scale);
1686 
1687 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1688 			   port->cap_adap + ADP_USB3_CS_2, 1);
1689 	if (ret)
1690 		return ret;
1691 
1692 	val &= ~(ADP_USB3_CS_2_AUBW_MASK | ADP_USB3_CS_2_ADBW_MASK);
1693 	val |= dbw << ADP_USB3_CS_2_ADBW_SHIFT;
1694 	val |= ubw;
1695 
1696 	return tb_port_write(port, &val, TB_CFG_PORT,
1697 			     port->cap_adap + ADP_USB3_CS_2, 1);
1698 }
1699 
1700 /**
1701  * usb4_usb3_port_allocate_bandwidth() - Allocate bandwidth for USB3
1702  * @port: USB3 adapter port
1703  * @upstream_bw: New upstream bandwidth
1704  * @downstream_bw: New downstream bandwidth
1705  *
1706  * This can be used to set how much bandwidth is allocated for the USB3
1707  * tunneled isochronous traffic. @upstream_bw and @downstream_bw are the
1708  * new values programmed to the USB3 adapter allocation registers. If
1709  * the values are lower than what is currently consumed the allocation
1710  * is set to what is currently consumed instead (consumed bandwidth
1711  * cannot be taken away by CM). The actual new values are returned in
1712  * @upstream_bw and @downstream_bw.
1713  *
1714  * Returns %0 in case of success and negative errno if there was a
1715  * failure.
1716  */
1717 int usb4_usb3_port_allocate_bandwidth(struct tb_port *port, int *upstream_bw,
1718 				      int *downstream_bw)
1719 {
1720 	int ret, consumed_up, consumed_down, allocate_up, allocate_down;
1721 
1722 	ret = usb4_usb3_port_set_cm_request(port);
1723 	if (ret)
1724 		return ret;
1725 
1726 	ret = usb4_usb3_port_read_consumed_bandwidth(port, &consumed_up,
1727 						     &consumed_down);
1728 	if (ret)
1729 		goto err_request;
1730 
1731 	/* Don't allow it go lower than what is consumed */
1732 	allocate_up = max(*upstream_bw, consumed_up);
1733 	allocate_down = max(*downstream_bw, consumed_down);
1734 
1735 	ret = usb4_usb3_port_write_allocated_bandwidth(port, allocate_up,
1736 						       allocate_down);
1737 	if (ret)
1738 		goto err_request;
1739 
1740 	*upstream_bw = allocate_up;
1741 	*downstream_bw = allocate_down;
1742 
1743 err_request:
1744 	usb4_usb3_port_clear_cm_request(port);
1745 	return ret;
1746 }
1747 
1748 /**
1749  * usb4_usb3_port_release_bandwidth() - Release allocated USB3 bandwidth
1750  * @port: USB3 adapter port
1751  * @upstream_bw: New allocated upstream bandwidth
1752  * @downstream_bw: New allocated downstream bandwidth
1753  *
1754  * Releases USB3 allocated bandwidth down to what is actually consumed.
1755  * The new bandwidth is returned in @upstream_bw and @downstream_bw.
1756  *
1757  * Returns 0% in success and negative errno in case of failure.
1758  */
1759 int usb4_usb3_port_release_bandwidth(struct tb_port *port, int *upstream_bw,
1760 				     int *downstream_bw)
1761 {
1762 	int ret, consumed_up, consumed_down;
1763 
1764 	ret = usb4_usb3_port_set_cm_request(port);
1765 	if (ret)
1766 		return ret;
1767 
1768 	ret = usb4_usb3_port_read_consumed_bandwidth(port, &consumed_up,
1769 						     &consumed_down);
1770 	if (ret)
1771 		goto err_request;
1772 
1773 	/*
1774 	 * Always keep 1000 Mb/s to make sure xHCI has at least some
1775 	 * bandwidth available for isochronous traffic.
1776 	 */
1777 	if (consumed_up < 1000)
1778 		consumed_up = 1000;
1779 	if (consumed_down < 1000)
1780 		consumed_down = 1000;
1781 
1782 	ret = usb4_usb3_port_write_allocated_bandwidth(port, consumed_up,
1783 						       consumed_down);
1784 	if (ret)
1785 		goto err_request;
1786 
1787 	*upstream_bw = consumed_up;
1788 	*downstream_bw = consumed_down;
1789 
1790 err_request:
1791 	usb4_usb3_port_clear_cm_request(port);
1792 	return ret;
1793 }
1794