xref: /linux/drivers/thunderbolt/usb4.c (revision c79c3c34f75d72a066e292b10aa50fc758c97c89)
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 (tb_acpi_may_tunnel_usb3() && sw->link_usb4 &&
335 	    tb_switch_find_port(parent, TB_TYPE_USB3_DOWN)) {
336 		val |= ROUTER_CS_5_UTO;
337 		xhci = false;
338 	}
339 
340 	/*
341 	 * Only enable PCIe tunneling if the parent router supports it
342 	 * and it is not disabled.
343 	 */
344 	if (tb_acpi_may_tunnel_pcie() &&
345 	    tb_switch_find_port(parent, TB_TYPE_PCIE_DOWN)) {
346 		val |= ROUTER_CS_5_PTO;
347 		/*
348 		 * xHCI can be enabled if PCIe tunneling is supported
349 		 * and the parent does not have any USB3 dowstream
350 		 * adapters (so we cannot do USB 3.x tunneling).
351 		 */
352 		if (xhci)
353 			val |= ROUTER_CS_5_HCO;
354 	}
355 
356 	/* TBT3 supported by the CM */
357 	val |= ROUTER_CS_5_C3S;
358 	/* Tunneling configuration is ready now */
359 	val |= ROUTER_CS_5_CV;
360 
361 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
362 	if (ret)
363 		return ret;
364 
365 	return usb4_switch_wait_for_bit(sw, ROUTER_CS_6, ROUTER_CS_6_CR,
366 					ROUTER_CS_6_CR, 50);
367 }
368 
369 /**
370  * usb4_switch_read_uid() - Read UID from USB4 router
371  * @sw: USB4 router
372  * @uid: UID is stored here
373  *
374  * Reads 64-bit UID from USB4 router config space.
375  */
376 int usb4_switch_read_uid(struct tb_switch *sw, u64 *uid)
377 {
378 	return tb_sw_read(sw, uid, TB_CFG_SWITCH, ROUTER_CS_7, 2);
379 }
380 
381 static int usb4_switch_drom_read_block(void *data,
382 				       unsigned int dwaddress, void *buf,
383 				       size_t dwords)
384 {
385 	struct tb_switch *sw = data;
386 	u8 status = 0;
387 	u32 metadata;
388 	int ret;
389 
390 	metadata = (dwords << USB4_DROM_SIZE_SHIFT) & USB4_DROM_SIZE_MASK;
391 	metadata |= (dwaddress << USB4_DROM_ADDRESS_SHIFT) &
392 		USB4_DROM_ADDRESS_MASK;
393 
394 	ret = usb4_switch_op_data(sw, USB4_SWITCH_OP_DROM_READ, &metadata,
395 				  &status, NULL, 0, buf, dwords);
396 	if (ret)
397 		return ret;
398 
399 	return status ? -EIO : 0;
400 }
401 
402 /**
403  * usb4_switch_drom_read() - Read arbitrary bytes from USB4 router DROM
404  * @sw: USB4 router
405  * @address: Byte address inside DROM to start reading
406  * @buf: Buffer where the DROM content is stored
407  * @size: Number of bytes to read from DROM
408  *
409  * Uses USB4 router operations to read router DROM. For devices this
410  * should always work but for hosts it may return %-EOPNOTSUPP in which
411  * case the host router does not have DROM.
412  */
413 int usb4_switch_drom_read(struct tb_switch *sw, unsigned int address, void *buf,
414 			  size_t size)
415 {
416 	return usb4_do_read_data(address, buf, size,
417 				 usb4_switch_drom_read_block, sw);
418 }
419 
420 /**
421  * usb4_switch_lane_bonding_possible() - Are conditions met for lane bonding
422  * @sw: USB4 router
423  *
424  * Checks whether conditions are met so that lane bonding can be
425  * established with the upstream router. Call only for device routers.
426  */
427 bool usb4_switch_lane_bonding_possible(struct tb_switch *sw)
428 {
429 	struct tb_port *up;
430 	int ret;
431 	u32 val;
432 
433 	up = tb_upstream_port(sw);
434 	ret = tb_port_read(up, &val, TB_CFG_PORT, up->cap_usb4 + PORT_CS_18, 1);
435 	if (ret)
436 		return false;
437 
438 	return !!(val & PORT_CS_18_BE);
439 }
440 
441 /**
442  * usb4_switch_set_wake() - Enabled/disable wake
443  * @sw: USB4 router
444  * @flags: Wakeup flags (%0 to disable)
445  *
446  * Enables/disables router to wake up from sleep.
447  */
448 int usb4_switch_set_wake(struct tb_switch *sw, unsigned int flags)
449 {
450 	struct tb_port *port;
451 	u64 route = tb_route(sw);
452 	u32 val;
453 	int ret;
454 
455 	/*
456 	 * Enable wakes coming from all USB4 downstream ports (from
457 	 * child routers). For device routers do this also for the
458 	 * upstream USB4 port.
459 	 */
460 	tb_switch_for_each_port(sw, port) {
461 		if (!tb_port_is_null(port))
462 			continue;
463 		if (!route && tb_is_upstream_port(port))
464 			continue;
465 		if (!port->cap_usb4)
466 			continue;
467 
468 		ret = tb_port_read(port, &val, TB_CFG_PORT,
469 				   port->cap_usb4 + PORT_CS_19, 1);
470 		if (ret)
471 			return ret;
472 
473 		val &= ~(PORT_CS_19_WOC | PORT_CS_19_WOD | PORT_CS_19_WOU4);
474 
475 		if (flags & TB_WAKE_ON_CONNECT)
476 			val |= PORT_CS_19_WOC;
477 		if (flags & TB_WAKE_ON_DISCONNECT)
478 			val |= PORT_CS_19_WOD;
479 		if (flags & TB_WAKE_ON_USB4)
480 			val |= PORT_CS_19_WOU4;
481 
482 		ret = tb_port_write(port, &val, TB_CFG_PORT,
483 				    port->cap_usb4 + PORT_CS_19, 1);
484 		if (ret)
485 			return ret;
486 	}
487 
488 	/*
489 	 * Enable wakes from PCIe and USB 3.x on this router. Only
490 	 * needed for device routers.
491 	 */
492 	if (route) {
493 		ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
494 		if (ret)
495 			return ret;
496 
497 		val &= ~(ROUTER_CS_5_WOP | ROUTER_CS_5_WOU);
498 		if (flags & TB_WAKE_ON_USB3)
499 			val |= ROUTER_CS_5_WOU;
500 		if (flags & TB_WAKE_ON_PCIE)
501 			val |= ROUTER_CS_5_WOP;
502 
503 		ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
504 		if (ret)
505 			return ret;
506 	}
507 
508 	return 0;
509 }
510 
511 /**
512  * usb4_switch_set_sleep() - Prepare the router to enter sleep
513  * @sw: USB4 router
514  *
515  * Sets sleep bit for the router. Returns when the router sleep ready
516  * bit has been asserted.
517  */
518 int usb4_switch_set_sleep(struct tb_switch *sw)
519 {
520 	int ret;
521 	u32 val;
522 
523 	/* Set sleep bit and wait for sleep ready to be asserted */
524 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
525 	if (ret)
526 		return ret;
527 
528 	val |= ROUTER_CS_5_SLP;
529 
530 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
531 	if (ret)
532 		return ret;
533 
534 	return usb4_switch_wait_for_bit(sw, ROUTER_CS_6, ROUTER_CS_6_SLPR,
535 					ROUTER_CS_6_SLPR, 500);
536 }
537 
538 /**
539  * usb4_switch_nvm_sector_size() - Return router NVM sector size
540  * @sw: USB4 router
541  *
542  * If the router supports NVM operations this function returns the NVM
543  * sector size in bytes. If NVM operations are not supported returns
544  * %-EOPNOTSUPP.
545  */
546 int usb4_switch_nvm_sector_size(struct tb_switch *sw)
547 {
548 	u32 metadata;
549 	u8 status;
550 	int ret;
551 
552 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_SECTOR_SIZE, &metadata,
553 			     &status);
554 	if (ret)
555 		return ret;
556 
557 	if (status)
558 		return status == 0x2 ? -EOPNOTSUPP : -EIO;
559 
560 	return metadata & USB4_NVM_SECTOR_SIZE_MASK;
561 }
562 
563 static int usb4_switch_nvm_read_block(void *data,
564 	unsigned int dwaddress, void *buf, size_t dwords)
565 {
566 	struct tb_switch *sw = data;
567 	u8 status = 0;
568 	u32 metadata;
569 	int ret;
570 
571 	metadata = (dwords << USB4_NVM_READ_LENGTH_SHIFT) &
572 		   USB4_NVM_READ_LENGTH_MASK;
573 	metadata |= (dwaddress << USB4_NVM_READ_OFFSET_SHIFT) &
574 		   USB4_NVM_READ_OFFSET_MASK;
575 
576 	ret = usb4_switch_op_data(sw, USB4_SWITCH_OP_NVM_READ, &metadata,
577 				  &status, NULL, 0, buf, dwords);
578 	if (ret)
579 		return ret;
580 
581 	return status ? -EIO : 0;
582 }
583 
584 /**
585  * usb4_switch_nvm_read() - Read arbitrary bytes from router NVM
586  * @sw: USB4 router
587  * @address: Starting address in bytes
588  * @buf: Read data is placed here
589  * @size: How many bytes to read
590  *
591  * Reads NVM contents of the router. If NVM is not supported returns
592  * %-EOPNOTSUPP.
593  */
594 int usb4_switch_nvm_read(struct tb_switch *sw, unsigned int address, void *buf,
595 			 size_t size)
596 {
597 	return usb4_do_read_data(address, buf, size,
598 				 usb4_switch_nvm_read_block, sw);
599 }
600 
601 static int usb4_switch_nvm_set_offset(struct tb_switch *sw,
602 				      unsigned int address)
603 {
604 	u32 metadata, dwaddress;
605 	u8 status = 0;
606 	int ret;
607 
608 	dwaddress = address / 4;
609 	metadata = (dwaddress << USB4_NVM_SET_OFFSET_SHIFT) &
610 		   USB4_NVM_SET_OFFSET_MASK;
611 
612 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_SET_OFFSET, &metadata,
613 			     &status);
614 	if (ret)
615 		return ret;
616 
617 	return status ? -EIO : 0;
618 }
619 
620 static int usb4_switch_nvm_write_next_block(void *data, const void *buf,
621 					    size_t dwords)
622 {
623 	struct tb_switch *sw = data;
624 	u8 status;
625 	int ret;
626 
627 	ret = usb4_switch_op_data(sw, USB4_SWITCH_OP_NVM_WRITE, NULL, &status,
628 				  buf, dwords, NULL, 0);
629 	if (ret)
630 		return ret;
631 
632 	return status ? -EIO : 0;
633 }
634 
635 /**
636  * usb4_switch_nvm_write() - Write to the router NVM
637  * @sw: USB4 router
638  * @address: Start address where to write in bytes
639  * @buf: Pointer to the data to write
640  * @size: Size of @buf in bytes
641  *
642  * Writes @buf to the router NVM using USB4 router operations. If NVM
643  * write is not supported returns %-EOPNOTSUPP.
644  */
645 int usb4_switch_nvm_write(struct tb_switch *sw, unsigned int address,
646 			  const void *buf, size_t size)
647 {
648 	int ret;
649 
650 	ret = usb4_switch_nvm_set_offset(sw, address);
651 	if (ret)
652 		return ret;
653 
654 	return usb4_do_write_data(address, buf, size,
655 				  usb4_switch_nvm_write_next_block, sw);
656 }
657 
658 /**
659  * usb4_switch_nvm_authenticate() - Authenticate new NVM
660  * @sw: USB4 router
661  *
662  * After the new NVM has been written via usb4_switch_nvm_write(), this
663  * function triggers NVM authentication process. The router gets power
664  * cycled and if the authentication is successful the new NVM starts
665  * running. In case of failure returns negative errno.
666  *
667  * The caller should call usb4_switch_nvm_authenticate_status() to read
668  * the status of the authentication after power cycle. It should be the
669  * first router operation to avoid the status being lost.
670  */
671 int usb4_switch_nvm_authenticate(struct tb_switch *sw)
672 {
673 	int ret;
674 
675 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_AUTH, NULL, NULL);
676 	switch (ret) {
677 	/*
678 	 * The router is power cycled once NVM_AUTH is started so it is
679 	 * expected to get any of the following errors back.
680 	 */
681 	case -EACCES:
682 	case -ENOTCONN:
683 	case -ETIMEDOUT:
684 		return 0;
685 
686 	default:
687 		return ret;
688 	}
689 }
690 
691 /**
692  * usb4_switch_nvm_authenticate_status() - Read status of last NVM authenticate
693  * @sw: USB4 router
694  * @status: Status code of the operation
695  *
696  * The function checks if there is status available from the last NVM
697  * authenticate router operation. If there is status then %0 is returned
698  * and the status code is placed in @status. Returns negative errno in case
699  * of failure.
700  *
701  * Must be called before any other router operation.
702  */
703 int usb4_switch_nvm_authenticate_status(struct tb_switch *sw, u32 *status)
704 {
705 	const struct tb_cm_ops *cm_ops = sw->tb->cm_ops;
706 	u16 opcode;
707 	u32 val;
708 	int ret;
709 
710 	if (cm_ops->usb4_switch_nvm_authenticate_status) {
711 		ret = cm_ops->usb4_switch_nvm_authenticate_status(sw, status);
712 		if (ret != -EOPNOTSUPP)
713 			return ret;
714 	}
715 
716 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_26, 1);
717 	if (ret)
718 		return ret;
719 
720 	/* Check that the opcode is correct */
721 	opcode = val & ROUTER_CS_26_OPCODE_MASK;
722 	if (opcode == USB4_SWITCH_OP_NVM_AUTH) {
723 		if (val & ROUTER_CS_26_OV)
724 			return -EBUSY;
725 		if (val & ROUTER_CS_26_ONS)
726 			return -EOPNOTSUPP;
727 
728 		*status = (val & ROUTER_CS_26_STATUS_MASK) >>
729 			ROUTER_CS_26_STATUS_SHIFT;
730 	} else {
731 		*status = 0;
732 	}
733 
734 	return 0;
735 }
736 
737 /**
738  * usb4_switch_query_dp_resource() - Query availability of DP IN resource
739  * @sw: USB4 router
740  * @in: DP IN adapter
741  *
742  * For DP tunneling this function can be used to query availability of
743  * DP IN resource. Returns true if the resource is available for DP
744  * tunneling, false otherwise.
745  */
746 bool usb4_switch_query_dp_resource(struct tb_switch *sw, struct tb_port *in)
747 {
748 	u32 metadata = in->port;
749 	u8 status;
750 	int ret;
751 
752 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_QUERY_DP_RESOURCE, &metadata,
753 			     &status);
754 	/*
755 	 * If DP resource allocation is not supported assume it is
756 	 * always available.
757 	 */
758 	if (ret == -EOPNOTSUPP)
759 		return true;
760 	else if (ret)
761 		return false;
762 
763 	return !status;
764 }
765 
766 /**
767  * usb4_switch_alloc_dp_resource() - Allocate DP IN resource
768  * @sw: USB4 router
769  * @in: DP IN adapter
770  *
771  * Allocates DP IN resource for DP tunneling using USB4 router
772  * operations. If the resource was allocated returns %0. Otherwise
773  * returns negative errno, in particular %-EBUSY if the resource is
774  * already allocated.
775  */
776 int usb4_switch_alloc_dp_resource(struct tb_switch *sw, struct tb_port *in)
777 {
778 	u32 metadata = in->port;
779 	u8 status;
780 	int ret;
781 
782 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_ALLOC_DP_RESOURCE, &metadata,
783 			     &status);
784 	if (ret == -EOPNOTSUPP)
785 		return 0;
786 	else if (ret)
787 		return ret;
788 
789 	return status ? -EBUSY : 0;
790 }
791 
792 /**
793  * usb4_switch_dealloc_dp_resource() - Releases allocated DP IN resource
794  * @sw: USB4 router
795  * @in: DP IN adapter
796  *
797  * Releases the previously allocated DP IN resource.
798  */
799 int usb4_switch_dealloc_dp_resource(struct tb_switch *sw, struct tb_port *in)
800 {
801 	u32 metadata = in->port;
802 	u8 status;
803 	int ret;
804 
805 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_DEALLOC_DP_RESOURCE, &metadata,
806 			     &status);
807 	if (ret == -EOPNOTSUPP)
808 		return 0;
809 	else if (ret)
810 		return ret;
811 
812 	return status ? -EIO : 0;
813 }
814 
815 static int usb4_port_idx(const struct tb_switch *sw, const struct tb_port *port)
816 {
817 	struct tb_port *p;
818 	int usb4_idx = 0;
819 
820 	/* Assume port is primary */
821 	tb_switch_for_each_port(sw, p) {
822 		if (!tb_port_is_null(p))
823 			continue;
824 		if (tb_is_upstream_port(p))
825 			continue;
826 		if (!p->link_nr) {
827 			if (p == port)
828 				break;
829 			usb4_idx++;
830 		}
831 	}
832 
833 	return usb4_idx;
834 }
835 
836 /**
837  * usb4_switch_map_pcie_down() - Map USB4 port to a PCIe downstream adapter
838  * @sw: USB4 router
839  * @port: USB4 port
840  *
841  * USB4 routers have direct mapping between USB4 ports and PCIe
842  * downstream adapters where the PCIe topology is extended. This
843  * function returns the corresponding downstream PCIe adapter or %NULL
844  * if no such mapping was possible.
845  */
846 struct tb_port *usb4_switch_map_pcie_down(struct tb_switch *sw,
847 					  const struct tb_port *port)
848 {
849 	int usb4_idx = usb4_port_idx(sw, port);
850 	struct tb_port *p;
851 	int pcie_idx = 0;
852 
853 	/* Find PCIe down port matching usb4_port */
854 	tb_switch_for_each_port(sw, p) {
855 		if (!tb_port_is_pcie_down(p))
856 			continue;
857 
858 		if (pcie_idx == usb4_idx)
859 			return p;
860 
861 		pcie_idx++;
862 	}
863 
864 	return NULL;
865 }
866 
867 /**
868  * usb4_switch_map_usb3_down() - Map USB4 port to a USB3 downstream adapter
869  * @sw: USB4 router
870  * @port: USB4 port
871  *
872  * USB4 routers have direct mapping between USB4 ports and USB 3.x
873  * downstream adapters where the USB 3.x topology is extended. This
874  * function returns the corresponding downstream USB 3.x adapter or
875  * %NULL if no such mapping was possible.
876  */
877 struct tb_port *usb4_switch_map_usb3_down(struct tb_switch *sw,
878 					  const struct tb_port *port)
879 {
880 	int usb4_idx = usb4_port_idx(sw, port);
881 	struct tb_port *p;
882 	int usb_idx = 0;
883 
884 	/* Find USB3 down port matching usb4_port */
885 	tb_switch_for_each_port(sw, p) {
886 		if (!tb_port_is_usb3_down(p))
887 			continue;
888 
889 		if (usb_idx == usb4_idx)
890 			return p;
891 
892 		usb_idx++;
893 	}
894 
895 	return NULL;
896 }
897 
898 /**
899  * usb4_port_unlock() - Unlock USB4 downstream port
900  * @port: USB4 port to unlock
901  *
902  * Unlocks USB4 downstream port so that the connection manager can
903  * access the router below this port.
904  */
905 int usb4_port_unlock(struct tb_port *port)
906 {
907 	int ret;
908 	u32 val;
909 
910 	ret = tb_port_read(port, &val, TB_CFG_PORT, ADP_CS_4, 1);
911 	if (ret)
912 		return ret;
913 
914 	val &= ~ADP_CS_4_LCK;
915 	return tb_port_write(port, &val, TB_CFG_PORT, ADP_CS_4, 1);
916 }
917 
918 static int usb4_port_set_configured(struct tb_port *port, bool configured)
919 {
920 	int ret;
921 	u32 val;
922 
923 	if (!port->cap_usb4)
924 		return -EINVAL;
925 
926 	ret = tb_port_read(port, &val, TB_CFG_PORT,
927 			   port->cap_usb4 + PORT_CS_19, 1);
928 	if (ret)
929 		return ret;
930 
931 	if (configured)
932 		val |= PORT_CS_19_PC;
933 	else
934 		val &= ~PORT_CS_19_PC;
935 
936 	return tb_port_write(port, &val, TB_CFG_PORT,
937 			     port->cap_usb4 + PORT_CS_19, 1);
938 }
939 
940 /**
941  * usb4_port_configure() - Set USB4 port configured
942  * @port: USB4 router
943  *
944  * Sets the USB4 link to be configured for power management purposes.
945  */
946 int usb4_port_configure(struct tb_port *port)
947 {
948 	return usb4_port_set_configured(port, true);
949 }
950 
951 /**
952  * usb4_port_unconfigure() - Set USB4 port unconfigured
953  * @port: USB4 router
954  *
955  * Sets the USB4 link to be unconfigured for power management purposes.
956  */
957 void usb4_port_unconfigure(struct tb_port *port)
958 {
959 	usb4_port_set_configured(port, false);
960 }
961 
962 static int usb4_set_xdomain_configured(struct tb_port *port, bool configured)
963 {
964 	int ret;
965 	u32 val;
966 
967 	if (!port->cap_usb4)
968 		return -EINVAL;
969 
970 	ret = tb_port_read(port, &val, TB_CFG_PORT,
971 			   port->cap_usb4 + PORT_CS_19, 1);
972 	if (ret)
973 		return ret;
974 
975 	if (configured)
976 		val |= PORT_CS_19_PID;
977 	else
978 		val &= ~PORT_CS_19_PID;
979 
980 	return tb_port_write(port, &val, TB_CFG_PORT,
981 			     port->cap_usb4 + PORT_CS_19, 1);
982 }
983 
984 /**
985  * usb4_port_configure_xdomain() - Configure port for XDomain
986  * @port: USB4 port connected to another host
987  *
988  * Marks the USB4 port as being connected to another host. Returns %0 in
989  * success and negative errno in failure.
990  */
991 int usb4_port_configure_xdomain(struct tb_port *port)
992 {
993 	return usb4_set_xdomain_configured(port, true);
994 }
995 
996 /**
997  * usb4_port_unconfigure_xdomain() - Unconfigure port for XDomain
998  * @port: USB4 port that was connected to another host
999  *
1000  * Clears USB4 port from being marked as XDomain.
1001  */
1002 void usb4_port_unconfigure_xdomain(struct tb_port *port)
1003 {
1004 	usb4_set_xdomain_configured(port, false);
1005 }
1006 
1007 static int usb4_port_wait_for_bit(struct tb_port *port, u32 offset, u32 bit,
1008 				  u32 value, int timeout_msec)
1009 {
1010 	ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
1011 
1012 	do {
1013 		u32 val;
1014 		int ret;
1015 
1016 		ret = tb_port_read(port, &val, TB_CFG_PORT, offset, 1);
1017 		if (ret)
1018 			return ret;
1019 
1020 		if ((val & bit) == value)
1021 			return 0;
1022 
1023 		usleep_range(50, 100);
1024 	} while (ktime_before(ktime_get(), timeout));
1025 
1026 	return -ETIMEDOUT;
1027 }
1028 
1029 static int usb4_port_read_data(struct tb_port *port, void *data, size_t dwords)
1030 {
1031 	if (dwords > USB4_DATA_DWORDS)
1032 		return -EINVAL;
1033 
1034 	return tb_port_read(port, data, TB_CFG_PORT, port->cap_usb4 + PORT_CS_2,
1035 			    dwords);
1036 }
1037 
1038 static int usb4_port_write_data(struct tb_port *port, const void *data,
1039 				size_t dwords)
1040 {
1041 	if (dwords > USB4_DATA_DWORDS)
1042 		return -EINVAL;
1043 
1044 	return tb_port_write(port, data, TB_CFG_PORT, port->cap_usb4 + PORT_CS_2,
1045 			     dwords);
1046 }
1047 
1048 static int usb4_port_sb_read(struct tb_port *port, enum usb4_sb_target target,
1049 			     u8 index, u8 reg, void *buf, u8 size)
1050 {
1051 	size_t dwords = DIV_ROUND_UP(size, 4);
1052 	int ret;
1053 	u32 val;
1054 
1055 	if (!port->cap_usb4)
1056 		return -EINVAL;
1057 
1058 	val = reg;
1059 	val |= size << PORT_CS_1_LENGTH_SHIFT;
1060 	val |= (target << PORT_CS_1_TARGET_SHIFT) & PORT_CS_1_TARGET_MASK;
1061 	if (target == USB4_SB_TARGET_RETIMER)
1062 		val |= (index << PORT_CS_1_RETIMER_INDEX_SHIFT);
1063 	val |= PORT_CS_1_PND;
1064 
1065 	ret = tb_port_write(port, &val, TB_CFG_PORT,
1066 			    port->cap_usb4 + PORT_CS_1, 1);
1067 	if (ret)
1068 		return ret;
1069 
1070 	ret = usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_1,
1071 				     PORT_CS_1_PND, 0, 500);
1072 	if (ret)
1073 		return ret;
1074 
1075 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1076 			    port->cap_usb4 + PORT_CS_1, 1);
1077 	if (ret)
1078 		return ret;
1079 
1080 	if (val & PORT_CS_1_NR)
1081 		return -ENODEV;
1082 	if (val & PORT_CS_1_RC)
1083 		return -EIO;
1084 
1085 	return buf ? usb4_port_read_data(port, buf, dwords) : 0;
1086 }
1087 
1088 static int usb4_port_sb_write(struct tb_port *port, enum usb4_sb_target target,
1089 			      u8 index, u8 reg, const void *buf, u8 size)
1090 {
1091 	size_t dwords = DIV_ROUND_UP(size, 4);
1092 	int ret;
1093 	u32 val;
1094 
1095 	if (!port->cap_usb4)
1096 		return -EINVAL;
1097 
1098 	if (buf) {
1099 		ret = usb4_port_write_data(port, buf, dwords);
1100 		if (ret)
1101 			return ret;
1102 	}
1103 
1104 	val = reg;
1105 	val |= size << PORT_CS_1_LENGTH_SHIFT;
1106 	val |= PORT_CS_1_WNR_WRITE;
1107 	val |= (target << PORT_CS_1_TARGET_SHIFT) & PORT_CS_1_TARGET_MASK;
1108 	if (target == USB4_SB_TARGET_RETIMER)
1109 		val |= (index << PORT_CS_1_RETIMER_INDEX_SHIFT);
1110 	val |= PORT_CS_1_PND;
1111 
1112 	ret = tb_port_write(port, &val, TB_CFG_PORT,
1113 			    port->cap_usb4 + PORT_CS_1, 1);
1114 	if (ret)
1115 		return ret;
1116 
1117 	ret = usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_1,
1118 				     PORT_CS_1_PND, 0, 500);
1119 	if (ret)
1120 		return ret;
1121 
1122 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1123 			    port->cap_usb4 + PORT_CS_1, 1);
1124 	if (ret)
1125 		return ret;
1126 
1127 	if (val & PORT_CS_1_NR)
1128 		return -ENODEV;
1129 	if (val & PORT_CS_1_RC)
1130 		return -EIO;
1131 
1132 	return 0;
1133 }
1134 
1135 static int usb4_port_sb_op(struct tb_port *port, enum usb4_sb_target target,
1136 			   u8 index, enum usb4_sb_opcode opcode, int timeout_msec)
1137 {
1138 	ktime_t timeout;
1139 	u32 val;
1140 	int ret;
1141 
1142 	val = opcode;
1143 	ret = usb4_port_sb_write(port, target, index, USB4_SB_OPCODE, &val,
1144 				 sizeof(val));
1145 	if (ret)
1146 		return ret;
1147 
1148 	timeout = ktime_add_ms(ktime_get(), timeout_msec);
1149 
1150 	do {
1151 		/* Check results */
1152 		ret = usb4_port_sb_read(port, target, index, USB4_SB_OPCODE,
1153 					&val, sizeof(val));
1154 		if (ret)
1155 			return ret;
1156 
1157 		switch (val) {
1158 		case 0:
1159 			return 0;
1160 
1161 		case USB4_SB_OPCODE_ERR:
1162 			return -EAGAIN;
1163 
1164 		case USB4_SB_OPCODE_ONS:
1165 			return -EOPNOTSUPP;
1166 
1167 		default:
1168 			if (val != opcode)
1169 				return -EIO;
1170 			break;
1171 		}
1172 	} while (ktime_before(ktime_get(), timeout));
1173 
1174 	return -ETIMEDOUT;
1175 }
1176 
1177 /**
1178  * usb4_port_enumerate_retimers() - Send RT broadcast transaction
1179  * @port: USB4 port
1180  *
1181  * This forces the USB4 port to send broadcast RT transaction which
1182  * makes the retimers on the link to assign index to themselves. Returns
1183  * %0 in case of success and negative errno if there was an error.
1184  */
1185 int usb4_port_enumerate_retimers(struct tb_port *port)
1186 {
1187 	u32 val;
1188 
1189 	val = USB4_SB_OPCODE_ENUMERATE_RETIMERS;
1190 	return usb4_port_sb_write(port, USB4_SB_TARGET_ROUTER, 0,
1191 				  USB4_SB_OPCODE, &val, sizeof(val));
1192 }
1193 
1194 static inline int usb4_port_retimer_op(struct tb_port *port, u8 index,
1195 				       enum usb4_sb_opcode opcode,
1196 				       int timeout_msec)
1197 {
1198 	return usb4_port_sb_op(port, USB4_SB_TARGET_RETIMER, index, opcode,
1199 			       timeout_msec);
1200 }
1201 
1202 /**
1203  * usb4_port_retimer_read() - Read from retimer sideband registers
1204  * @port: USB4 port
1205  * @index: Retimer index
1206  * @reg: Sideband register to read
1207  * @buf: Data from @reg is stored here
1208  * @size: Number of bytes to read
1209  *
1210  * Function reads retimer sideband registers starting from @reg. The
1211  * retimer is connected to @port at @index. Returns %0 in case of
1212  * success, and read data is copied to @buf. If there is no retimer
1213  * present at given @index returns %-ENODEV. In any other failure
1214  * returns negative errno.
1215  */
1216 int usb4_port_retimer_read(struct tb_port *port, u8 index, u8 reg, void *buf,
1217 			   u8 size)
1218 {
1219 	return usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index, reg, buf,
1220 				 size);
1221 }
1222 
1223 /**
1224  * usb4_port_retimer_write() - Write to retimer sideband registers
1225  * @port: USB4 port
1226  * @index: Retimer index
1227  * @reg: Sideband register to write
1228  * @buf: Data that is written starting from @reg
1229  * @size: Number of bytes to write
1230  *
1231  * Writes retimer sideband registers starting from @reg. The retimer is
1232  * connected to @port at @index. Returns %0 in case of success. If there
1233  * is no retimer present at given @index returns %-ENODEV. In any other
1234  * failure returns negative errno.
1235  */
1236 int usb4_port_retimer_write(struct tb_port *port, u8 index, u8 reg,
1237 			    const void *buf, u8 size)
1238 {
1239 	return usb4_port_sb_write(port, USB4_SB_TARGET_RETIMER, index, reg, buf,
1240 				  size);
1241 }
1242 
1243 /**
1244  * usb4_port_retimer_is_last() - Is the retimer last on-board retimer
1245  * @port: USB4 port
1246  * @index: Retimer index
1247  *
1248  * If the retimer at @index is last one (connected directly to the
1249  * Type-C port) this function returns %1. If it is not returns %0. If
1250  * the retimer is not present returns %-ENODEV. Otherwise returns
1251  * negative errno.
1252  */
1253 int usb4_port_retimer_is_last(struct tb_port *port, u8 index)
1254 {
1255 	u32 metadata;
1256 	int ret;
1257 
1258 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_QUERY_LAST_RETIMER,
1259 				   500);
1260 	if (ret)
1261 		return ret;
1262 
1263 	ret = usb4_port_retimer_read(port, index, USB4_SB_METADATA, &metadata,
1264 				     sizeof(metadata));
1265 	return ret ? ret : metadata & 1;
1266 }
1267 
1268 /**
1269  * usb4_port_retimer_nvm_sector_size() - Read retimer NVM sector size
1270  * @port: USB4 port
1271  * @index: Retimer index
1272  *
1273  * Reads NVM sector size (in bytes) of a retimer at @index. This
1274  * operation can be used to determine whether the retimer supports NVM
1275  * upgrade for example. Returns sector size in bytes or negative errno
1276  * in case of error. Specifically returns %-ENODEV if there is no
1277  * retimer at @index.
1278  */
1279 int usb4_port_retimer_nvm_sector_size(struct tb_port *port, u8 index)
1280 {
1281 	u32 metadata;
1282 	int ret;
1283 
1284 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_GET_NVM_SECTOR_SIZE,
1285 				   500);
1286 	if (ret)
1287 		return ret;
1288 
1289 	ret = usb4_port_retimer_read(port, index, USB4_SB_METADATA, &metadata,
1290 				     sizeof(metadata));
1291 	return ret ? ret : metadata & USB4_NVM_SECTOR_SIZE_MASK;
1292 }
1293 
1294 static int usb4_port_retimer_nvm_set_offset(struct tb_port *port, u8 index,
1295 					    unsigned int address)
1296 {
1297 	u32 metadata, dwaddress;
1298 	int ret;
1299 
1300 	dwaddress = address / 4;
1301 	metadata = (dwaddress << USB4_NVM_SET_OFFSET_SHIFT) &
1302 		  USB4_NVM_SET_OFFSET_MASK;
1303 
1304 	ret = usb4_port_retimer_write(port, index, USB4_SB_METADATA, &metadata,
1305 				      sizeof(metadata));
1306 	if (ret)
1307 		return ret;
1308 
1309 	return usb4_port_retimer_op(port, index, USB4_SB_OPCODE_NVM_SET_OFFSET,
1310 				    500);
1311 }
1312 
1313 struct retimer_info {
1314 	struct tb_port *port;
1315 	u8 index;
1316 };
1317 
1318 static int usb4_port_retimer_nvm_write_next_block(void *data, const void *buf,
1319 						  size_t dwords)
1320 
1321 {
1322 	const struct retimer_info *info = data;
1323 	struct tb_port *port = info->port;
1324 	u8 index = info->index;
1325 	int ret;
1326 
1327 	ret = usb4_port_retimer_write(port, index, USB4_SB_DATA,
1328 				      buf, dwords * 4);
1329 	if (ret)
1330 		return ret;
1331 
1332 	return usb4_port_retimer_op(port, index,
1333 			USB4_SB_OPCODE_NVM_BLOCK_WRITE, 1000);
1334 }
1335 
1336 /**
1337  * usb4_port_retimer_nvm_write() - Write to retimer NVM
1338  * @port: USB4 port
1339  * @index: Retimer index
1340  * @address: Byte address where to start the write
1341  * @buf: Data to write
1342  * @size: Size in bytes how much to write
1343  *
1344  * Writes @size bytes from @buf to the retimer NVM. Used for NVM
1345  * upgrade. Returns %0 if the data was written successfully and negative
1346  * errno in case of failure. Specifically returns %-ENODEV if there is
1347  * no retimer at @index.
1348  */
1349 int usb4_port_retimer_nvm_write(struct tb_port *port, u8 index, unsigned int address,
1350 				const void *buf, size_t size)
1351 {
1352 	struct retimer_info info = { .port = port, .index = index };
1353 	int ret;
1354 
1355 	ret = usb4_port_retimer_nvm_set_offset(port, index, address);
1356 	if (ret)
1357 		return ret;
1358 
1359 	return usb4_do_write_data(address, buf, size,
1360 			usb4_port_retimer_nvm_write_next_block, &info);
1361 }
1362 
1363 /**
1364  * usb4_port_retimer_nvm_authenticate() - Start retimer NVM upgrade
1365  * @port: USB4 port
1366  * @index: Retimer index
1367  *
1368  * After the new NVM image has been written via usb4_port_retimer_nvm_write()
1369  * this function can be used to trigger the NVM upgrade process. If
1370  * successful the retimer restarts with the new NVM and may not have the
1371  * index set so one needs to call usb4_port_enumerate_retimers() to
1372  * force index to be assigned.
1373  */
1374 int usb4_port_retimer_nvm_authenticate(struct tb_port *port, u8 index)
1375 {
1376 	u32 val;
1377 
1378 	/*
1379 	 * We need to use the raw operation here because once the
1380 	 * authentication completes the retimer index is not set anymore
1381 	 * so we do not get back the status now.
1382 	 */
1383 	val = USB4_SB_OPCODE_NVM_AUTH_WRITE;
1384 	return usb4_port_sb_write(port, USB4_SB_TARGET_RETIMER, index,
1385 				  USB4_SB_OPCODE, &val, sizeof(val));
1386 }
1387 
1388 /**
1389  * usb4_port_retimer_nvm_authenticate_status() - Read status of NVM upgrade
1390  * @port: USB4 port
1391  * @index: Retimer index
1392  * @status: Raw status code read from metadata
1393  *
1394  * This can be called after usb4_port_retimer_nvm_authenticate() and
1395  * usb4_port_enumerate_retimers() to fetch status of the NVM upgrade.
1396  *
1397  * Returns %0 if the authentication status was successfully read. The
1398  * completion metadata (the result) is then stored into @status. If
1399  * reading the status fails, returns negative errno.
1400  */
1401 int usb4_port_retimer_nvm_authenticate_status(struct tb_port *port, u8 index,
1402 					      u32 *status)
1403 {
1404 	u32 metadata, val;
1405 	int ret;
1406 
1407 	ret = usb4_port_retimer_read(port, index, USB4_SB_OPCODE, &val,
1408 				     sizeof(val));
1409 	if (ret)
1410 		return ret;
1411 
1412 	switch (val) {
1413 	case 0:
1414 		*status = 0;
1415 		return 0;
1416 
1417 	case USB4_SB_OPCODE_ERR:
1418 		ret = usb4_port_retimer_read(port, index, USB4_SB_METADATA,
1419 					     &metadata, sizeof(metadata));
1420 		if (ret)
1421 			return ret;
1422 
1423 		*status = metadata & USB4_SB_METADATA_NVM_AUTH_WRITE_MASK;
1424 		return 0;
1425 
1426 	case USB4_SB_OPCODE_ONS:
1427 		return -EOPNOTSUPP;
1428 
1429 	default:
1430 		return -EIO;
1431 	}
1432 }
1433 
1434 static int usb4_port_retimer_nvm_read_block(void *data, unsigned int dwaddress,
1435 					    void *buf, size_t dwords)
1436 {
1437 	const struct retimer_info *info = data;
1438 	struct tb_port *port = info->port;
1439 	u8 index = info->index;
1440 	u32 metadata;
1441 	int ret;
1442 
1443 	metadata = dwaddress << USB4_NVM_READ_OFFSET_SHIFT;
1444 	if (dwords < USB4_DATA_DWORDS)
1445 		metadata |= dwords << USB4_NVM_READ_LENGTH_SHIFT;
1446 
1447 	ret = usb4_port_retimer_write(port, index, USB4_SB_METADATA, &metadata,
1448 				      sizeof(metadata));
1449 	if (ret)
1450 		return ret;
1451 
1452 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_NVM_READ, 500);
1453 	if (ret)
1454 		return ret;
1455 
1456 	return usb4_port_retimer_read(port, index, USB4_SB_DATA, buf,
1457 				      dwords * 4);
1458 }
1459 
1460 /**
1461  * usb4_port_retimer_nvm_read() - Read contents of retimer NVM
1462  * @port: USB4 port
1463  * @index: Retimer index
1464  * @address: NVM address (in bytes) to start reading
1465  * @buf: Data read from NVM is stored here
1466  * @size: Number of bytes to read
1467  *
1468  * Reads retimer NVM and copies the contents to @buf. Returns %0 if the
1469  * read was successful and negative errno in case of failure.
1470  * Specifically returns %-ENODEV if there is no retimer at @index.
1471  */
1472 int usb4_port_retimer_nvm_read(struct tb_port *port, u8 index,
1473 			       unsigned int address, void *buf, size_t size)
1474 {
1475 	struct retimer_info info = { .port = port, .index = index };
1476 
1477 	return usb4_do_read_data(address, buf, size,
1478 			usb4_port_retimer_nvm_read_block, &info);
1479 }
1480 
1481 /**
1482  * usb4_usb3_port_max_link_rate() - Maximum support USB3 link rate
1483  * @port: USB3 adapter port
1484  *
1485  * Return maximum supported link rate of a USB3 adapter in Mb/s.
1486  * Negative errno in case of error.
1487  */
1488 int usb4_usb3_port_max_link_rate(struct tb_port *port)
1489 {
1490 	int ret, lr;
1491 	u32 val;
1492 
1493 	if (!tb_port_is_usb3_down(port) && !tb_port_is_usb3_up(port))
1494 		return -EINVAL;
1495 
1496 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1497 			   port->cap_adap + ADP_USB3_CS_4, 1);
1498 	if (ret)
1499 		return ret;
1500 
1501 	lr = (val & ADP_USB3_CS_4_MSLR_MASK) >> ADP_USB3_CS_4_MSLR_SHIFT;
1502 	return lr == ADP_USB3_CS_4_MSLR_20G ? 20000 : 10000;
1503 }
1504 
1505 /**
1506  * usb4_usb3_port_actual_link_rate() - Established USB3 link rate
1507  * @port: USB3 adapter port
1508  *
1509  * Return actual established link rate of a USB3 adapter in Mb/s. If the
1510  * link is not up returns %0 and negative errno in case of failure.
1511  */
1512 int usb4_usb3_port_actual_link_rate(struct tb_port *port)
1513 {
1514 	int ret, lr;
1515 	u32 val;
1516 
1517 	if (!tb_port_is_usb3_down(port) && !tb_port_is_usb3_up(port))
1518 		return -EINVAL;
1519 
1520 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1521 			   port->cap_adap + ADP_USB3_CS_4, 1);
1522 	if (ret)
1523 		return ret;
1524 
1525 	if (!(val & ADP_USB3_CS_4_ULV))
1526 		return 0;
1527 
1528 	lr = val & ADP_USB3_CS_4_ALR_MASK;
1529 	return lr == ADP_USB3_CS_4_ALR_20G ? 20000 : 10000;
1530 }
1531 
1532 static int usb4_usb3_port_cm_request(struct tb_port *port, bool request)
1533 {
1534 	int ret;
1535 	u32 val;
1536 
1537 	if (!tb_port_is_usb3_down(port))
1538 		return -EINVAL;
1539 	if (tb_route(port->sw))
1540 		return -EINVAL;
1541 
1542 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1543 			   port->cap_adap + ADP_USB3_CS_2, 1);
1544 	if (ret)
1545 		return ret;
1546 
1547 	if (request)
1548 		val |= ADP_USB3_CS_2_CMR;
1549 	else
1550 		val &= ~ADP_USB3_CS_2_CMR;
1551 
1552 	ret = tb_port_write(port, &val, TB_CFG_PORT,
1553 			    port->cap_adap + ADP_USB3_CS_2, 1);
1554 	if (ret)
1555 		return ret;
1556 
1557 	/*
1558 	 * We can use val here directly as the CMR bit is in the same place
1559 	 * as HCA. Just mask out others.
1560 	 */
1561 	val &= ADP_USB3_CS_2_CMR;
1562 	return usb4_port_wait_for_bit(port, port->cap_adap + ADP_USB3_CS_1,
1563 				      ADP_USB3_CS_1_HCA, val, 1500);
1564 }
1565 
1566 static inline int usb4_usb3_port_set_cm_request(struct tb_port *port)
1567 {
1568 	return usb4_usb3_port_cm_request(port, true);
1569 }
1570 
1571 static inline int usb4_usb3_port_clear_cm_request(struct tb_port *port)
1572 {
1573 	return usb4_usb3_port_cm_request(port, false);
1574 }
1575 
1576 static unsigned int usb3_bw_to_mbps(u32 bw, u8 scale)
1577 {
1578 	unsigned long uframes;
1579 
1580 	uframes = bw * 512UL << scale;
1581 	return DIV_ROUND_CLOSEST(uframes * 8000, 1000 * 1000);
1582 }
1583 
1584 static u32 mbps_to_usb3_bw(unsigned int mbps, u8 scale)
1585 {
1586 	unsigned long uframes;
1587 
1588 	/* 1 uframe is 1/8 ms (125 us) -> 1 / 8000 s */
1589 	uframes = ((unsigned long)mbps * 1000 *  1000) / 8000;
1590 	return DIV_ROUND_UP(uframes, 512UL << scale);
1591 }
1592 
1593 static int usb4_usb3_port_read_allocated_bandwidth(struct tb_port *port,
1594 						   int *upstream_bw,
1595 						   int *downstream_bw)
1596 {
1597 	u32 val, bw, scale;
1598 	int ret;
1599 
1600 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1601 			   port->cap_adap + ADP_USB3_CS_2, 1);
1602 	if (ret)
1603 		return ret;
1604 
1605 	ret = tb_port_read(port, &scale, TB_CFG_PORT,
1606 			   port->cap_adap + ADP_USB3_CS_3, 1);
1607 	if (ret)
1608 		return ret;
1609 
1610 	scale &= ADP_USB3_CS_3_SCALE_MASK;
1611 
1612 	bw = val & ADP_USB3_CS_2_AUBW_MASK;
1613 	*upstream_bw = usb3_bw_to_mbps(bw, scale);
1614 
1615 	bw = (val & ADP_USB3_CS_2_ADBW_MASK) >> ADP_USB3_CS_2_ADBW_SHIFT;
1616 	*downstream_bw = usb3_bw_to_mbps(bw, scale);
1617 
1618 	return 0;
1619 }
1620 
1621 /**
1622  * usb4_usb3_port_allocated_bandwidth() - Bandwidth allocated for USB3
1623  * @port: USB3 adapter port
1624  * @upstream_bw: Allocated upstream bandwidth is stored here
1625  * @downstream_bw: Allocated downstream bandwidth is stored here
1626  *
1627  * Stores currently allocated USB3 bandwidth into @upstream_bw and
1628  * @downstream_bw in Mb/s. Returns %0 in case of success and negative
1629  * errno in failure.
1630  */
1631 int usb4_usb3_port_allocated_bandwidth(struct tb_port *port, int *upstream_bw,
1632 				       int *downstream_bw)
1633 {
1634 	int ret;
1635 
1636 	ret = usb4_usb3_port_set_cm_request(port);
1637 	if (ret)
1638 		return ret;
1639 
1640 	ret = usb4_usb3_port_read_allocated_bandwidth(port, upstream_bw,
1641 						      downstream_bw);
1642 	usb4_usb3_port_clear_cm_request(port);
1643 
1644 	return ret;
1645 }
1646 
1647 static int usb4_usb3_port_read_consumed_bandwidth(struct tb_port *port,
1648 						  int *upstream_bw,
1649 						  int *downstream_bw)
1650 {
1651 	u32 val, bw, scale;
1652 	int ret;
1653 
1654 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1655 			   port->cap_adap + ADP_USB3_CS_1, 1);
1656 	if (ret)
1657 		return ret;
1658 
1659 	ret = tb_port_read(port, &scale, TB_CFG_PORT,
1660 			   port->cap_adap + ADP_USB3_CS_3, 1);
1661 	if (ret)
1662 		return ret;
1663 
1664 	scale &= ADP_USB3_CS_3_SCALE_MASK;
1665 
1666 	bw = val & ADP_USB3_CS_1_CUBW_MASK;
1667 	*upstream_bw = usb3_bw_to_mbps(bw, scale);
1668 
1669 	bw = (val & ADP_USB3_CS_1_CDBW_MASK) >> ADP_USB3_CS_1_CDBW_SHIFT;
1670 	*downstream_bw = usb3_bw_to_mbps(bw, scale);
1671 
1672 	return 0;
1673 }
1674 
1675 static int usb4_usb3_port_write_allocated_bandwidth(struct tb_port *port,
1676 						    int upstream_bw,
1677 						    int downstream_bw)
1678 {
1679 	u32 val, ubw, dbw, scale;
1680 	int ret;
1681 
1682 	/* Read the used scale, hardware default is 0 */
1683 	ret = tb_port_read(port, &scale, TB_CFG_PORT,
1684 			   port->cap_adap + ADP_USB3_CS_3, 1);
1685 	if (ret)
1686 		return ret;
1687 
1688 	scale &= ADP_USB3_CS_3_SCALE_MASK;
1689 	ubw = mbps_to_usb3_bw(upstream_bw, scale);
1690 	dbw = mbps_to_usb3_bw(downstream_bw, scale);
1691 
1692 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1693 			   port->cap_adap + ADP_USB3_CS_2, 1);
1694 	if (ret)
1695 		return ret;
1696 
1697 	val &= ~(ADP_USB3_CS_2_AUBW_MASK | ADP_USB3_CS_2_ADBW_MASK);
1698 	val |= dbw << ADP_USB3_CS_2_ADBW_SHIFT;
1699 	val |= ubw;
1700 
1701 	return tb_port_write(port, &val, TB_CFG_PORT,
1702 			     port->cap_adap + ADP_USB3_CS_2, 1);
1703 }
1704 
1705 /**
1706  * usb4_usb3_port_allocate_bandwidth() - Allocate bandwidth for USB3
1707  * @port: USB3 adapter port
1708  * @upstream_bw: New upstream bandwidth
1709  * @downstream_bw: New downstream bandwidth
1710  *
1711  * This can be used to set how much bandwidth is allocated for the USB3
1712  * tunneled isochronous traffic. @upstream_bw and @downstream_bw are the
1713  * new values programmed to the USB3 adapter allocation registers. If
1714  * the values are lower than what is currently consumed the allocation
1715  * is set to what is currently consumed instead (consumed bandwidth
1716  * cannot be taken away by CM). The actual new values are returned in
1717  * @upstream_bw and @downstream_bw.
1718  *
1719  * Returns %0 in case of success and negative errno if there was a
1720  * failure.
1721  */
1722 int usb4_usb3_port_allocate_bandwidth(struct tb_port *port, int *upstream_bw,
1723 				      int *downstream_bw)
1724 {
1725 	int ret, consumed_up, consumed_down, allocate_up, allocate_down;
1726 
1727 	ret = usb4_usb3_port_set_cm_request(port);
1728 	if (ret)
1729 		return ret;
1730 
1731 	ret = usb4_usb3_port_read_consumed_bandwidth(port, &consumed_up,
1732 						     &consumed_down);
1733 	if (ret)
1734 		goto err_request;
1735 
1736 	/* Don't allow it go lower than what is consumed */
1737 	allocate_up = max(*upstream_bw, consumed_up);
1738 	allocate_down = max(*downstream_bw, consumed_down);
1739 
1740 	ret = usb4_usb3_port_write_allocated_bandwidth(port, allocate_up,
1741 						       allocate_down);
1742 	if (ret)
1743 		goto err_request;
1744 
1745 	*upstream_bw = allocate_up;
1746 	*downstream_bw = allocate_down;
1747 
1748 err_request:
1749 	usb4_usb3_port_clear_cm_request(port);
1750 	return ret;
1751 }
1752 
1753 /**
1754  * usb4_usb3_port_release_bandwidth() - Release allocated USB3 bandwidth
1755  * @port: USB3 adapter port
1756  * @upstream_bw: New allocated upstream bandwidth
1757  * @downstream_bw: New allocated downstream bandwidth
1758  *
1759  * Releases USB3 allocated bandwidth down to what is actually consumed.
1760  * The new bandwidth is returned in @upstream_bw and @downstream_bw.
1761  *
1762  * Returns 0% in success and negative errno in case of failure.
1763  */
1764 int usb4_usb3_port_release_bandwidth(struct tb_port *port, int *upstream_bw,
1765 				     int *downstream_bw)
1766 {
1767 	int ret, consumed_up, consumed_down;
1768 
1769 	ret = usb4_usb3_port_set_cm_request(port);
1770 	if (ret)
1771 		return ret;
1772 
1773 	ret = usb4_usb3_port_read_consumed_bandwidth(port, &consumed_up,
1774 						     &consumed_down);
1775 	if (ret)
1776 		goto err_request;
1777 
1778 	/*
1779 	 * Always keep 1000 Mb/s to make sure xHCI has at least some
1780 	 * bandwidth available for isochronous traffic.
1781 	 */
1782 	if (consumed_up < 1000)
1783 		consumed_up = 1000;
1784 	if (consumed_down < 1000)
1785 		consumed_down = 1000;
1786 
1787 	ret = usb4_usb3_port_write_allocated_bandwidth(port, consumed_up,
1788 						       consumed_down);
1789 	if (ret)
1790 		goto err_request;
1791 
1792 	*upstream_bw = consumed_up;
1793 	*downstream_bw = consumed_down;
1794 
1795 err_request:
1796 	usb4_usb3_port_clear_cm_request(port);
1797 	return ret;
1798 }
1799