xref: /linux-6.15/drivers/thunderbolt/retimer.c (revision faa1c615) 
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Thunderbolt/USB4 retimer support.
4  *
5  * Copyright (C) 2020, Intel Corporation
6  * Authors: Kranthi Kuntala <[email protected]>
7  *	    Mika Westerberg <[email protected]>
8  */
9 
10 #include <linux/delay.h>
11 #include <linux/pm_runtime.h>
12 #include <linux/sched/signal.h>
13 
14 #include "sb_regs.h"
15 #include "tb.h"
16 
17 #define TB_MAX_RETIMER_INDEX	6
18 
19 static int tb_retimer_nvm_read(void *priv, unsigned int offset, void *val,
20 			       size_t bytes)
21 {
22 	struct tb_nvm *nvm = priv;
23 	struct tb_retimer *rt = tb_to_retimer(nvm->dev);
24 	int ret;
25 
26 	pm_runtime_get_sync(&rt->dev);
27 
28 	if (!mutex_trylock(&rt->tb->lock)) {
29 		ret = restart_syscall();
30 		goto out;
31 	}
32 
33 	ret = usb4_port_retimer_nvm_read(rt->port, rt->index, offset, val, bytes);
34 	mutex_unlock(&rt->tb->lock);
35 
36 out:
37 	pm_runtime_mark_last_busy(&rt->dev);
38 	pm_runtime_put_autosuspend(&rt->dev);
39 
40 	return ret;
41 }
42 
43 static int tb_retimer_nvm_write(void *priv, unsigned int offset, void *val,
44 				size_t bytes)
45 {
46 	struct tb_nvm *nvm = priv;
47 	struct tb_retimer *rt = tb_to_retimer(nvm->dev);
48 	int ret = 0;
49 
50 	if (!mutex_trylock(&rt->tb->lock))
51 		return restart_syscall();
52 
53 	ret = tb_nvm_write_buf(nvm, offset, val, bytes);
54 	mutex_unlock(&rt->tb->lock);
55 
56 	return ret;
57 }
58 
59 static int tb_retimer_nvm_add(struct tb_retimer *rt)
60 {
61 	struct tb_nvm *nvm;
62 	u32 val, nvm_size;
63 	int ret;
64 
65 	nvm = tb_nvm_alloc(&rt->dev);
66 	if (IS_ERR(nvm))
67 		return PTR_ERR(nvm);
68 
69 	ret = usb4_port_retimer_nvm_read(rt->port, rt->index, NVM_VERSION, &val,
70 					 sizeof(val));
71 	if (ret)
72 		goto err_nvm;
73 
74 	nvm->major = val >> 16;
75 	nvm->minor = val >> 8;
76 
77 	ret = usb4_port_retimer_nvm_read(rt->port, rt->index, NVM_FLASH_SIZE,
78 					 &val, sizeof(val));
79 	if (ret)
80 		goto err_nvm;
81 
82 	nvm_size = (SZ_1M << (val & 7)) / 8;
83 	nvm_size = (nvm_size - SZ_16K) / 2;
84 
85 	ret = tb_nvm_add_active(nvm, nvm_size, tb_retimer_nvm_read);
86 	if (ret)
87 		goto err_nvm;
88 
89 	ret = tb_nvm_add_non_active(nvm, NVM_MAX_SIZE, tb_retimer_nvm_write);
90 	if (ret)
91 		goto err_nvm;
92 
93 	rt->nvm = nvm;
94 	return 0;
95 
96 err_nvm:
97 	tb_nvm_free(nvm);
98 	return ret;
99 }
100 
101 static int tb_retimer_nvm_validate_and_write(struct tb_retimer *rt)
102 {
103 	unsigned int image_size, hdr_size;
104 	const u8 *buf = rt->nvm->buf;
105 	u16 ds_size, device;
106 	int ret;
107 
108 	image_size = rt->nvm->buf_data_size;
109 	if (image_size < NVM_MIN_SIZE || image_size > NVM_MAX_SIZE)
110 		return -EINVAL;
111 
112 	/*
113 	 * FARB pointer must point inside the image and must at least
114 	 * contain parts of the digital section we will be reading here.
115 	 */
116 	hdr_size = (*(u32 *)buf) & 0xffffff;
117 	if (hdr_size + NVM_DEVID + 2 >= image_size)
118 		return -EINVAL;
119 
120 	/* Digital section start should be aligned to 4k page */
121 	if (!IS_ALIGNED(hdr_size, SZ_4K))
122 		return -EINVAL;
123 
124 	/*
125 	 * Read digital section size and check that it also fits inside
126 	 * the image.
127 	 */
128 	ds_size = *(u16 *)(buf + hdr_size);
129 	if (ds_size >= image_size)
130 		return -EINVAL;
131 
132 	/*
133 	 * Make sure the device ID in the image matches the retimer
134 	 * hardware.
135 	 */
136 	device = *(u16 *)(buf + hdr_size + NVM_DEVID);
137 	if (device != rt->device)
138 		return -EINVAL;
139 
140 	/* Skip headers in the image */
141 	buf += hdr_size;
142 	image_size -= hdr_size;
143 
144 	ret = usb4_port_retimer_nvm_write(rt->port, rt->index, 0, buf,
145 					 image_size);
146 	if (!ret)
147 		rt->nvm->flushed = true;
148 
149 	return ret;
150 }
151 
152 static int tb_retimer_nvm_authenticate(struct tb_retimer *rt, bool auth_only)
153 {
154 	int ret;
155 
156 	if (auth_only) {
157 		ret = usb4_port_retimer_nvm_set_offset(rt->port, rt->index, 0);
158 		if (ret)
159 			return ret;
160 	}
161 
162 	return usb4_port_retimer_nvm_authenticate(rt->port, rt->index);
163 }
164 
165 static ssize_t device_show(struct device *dev, struct device_attribute *attr,
166 			   char *buf)
167 {
168 	struct tb_retimer *rt = tb_to_retimer(dev);
169 
170 	return sprintf(buf, "%#x\n", rt->device);
171 }
172 static DEVICE_ATTR_RO(device);
173 
174 static ssize_t nvm_authenticate_show(struct device *dev,
175 	struct device_attribute *attr, char *buf)
176 {
177 	struct tb_retimer *rt = tb_to_retimer(dev);
178 	int ret;
179 
180 	if (!mutex_trylock(&rt->tb->lock))
181 		return restart_syscall();
182 
183 	if (!rt->nvm)
184 		ret = -EAGAIN;
185 	else
186 		ret = sprintf(buf, "%#x\n", rt->auth_status);
187 
188 	mutex_unlock(&rt->tb->lock);
189 
190 	return ret;
191 }
192 
193 static ssize_t nvm_authenticate_store(struct device *dev,
194 	struct device_attribute *attr, const char *buf, size_t count)
195 {
196 	struct tb_retimer *rt = tb_to_retimer(dev);
197 	int val, ret;
198 
199 	pm_runtime_get_sync(&rt->dev);
200 
201 	if (!mutex_trylock(&rt->tb->lock)) {
202 		ret = restart_syscall();
203 		goto exit_rpm;
204 	}
205 
206 	if (!rt->nvm) {
207 		ret = -EAGAIN;
208 		goto exit_unlock;
209 	}
210 
211 	ret = kstrtoint(buf, 10, &val);
212 	if (ret)
213 		goto exit_unlock;
214 
215 	/* Always clear status */
216 	rt->auth_status = 0;
217 
218 	if (val) {
219 		if (val == AUTHENTICATE_ONLY) {
220 			ret = tb_retimer_nvm_authenticate(rt, true);
221 		} else {
222 			if (!rt->nvm->flushed) {
223 				if (!rt->nvm->buf) {
224 					ret = -EINVAL;
225 					goto exit_unlock;
226 				}
227 
228 				ret = tb_retimer_nvm_validate_and_write(rt);
229 				if (ret || val == WRITE_ONLY)
230 					goto exit_unlock;
231 			}
232 			if (val == WRITE_AND_AUTHENTICATE)
233 				ret = tb_retimer_nvm_authenticate(rt, false);
234 		}
235 	}
236 
237 exit_unlock:
238 	mutex_unlock(&rt->tb->lock);
239 exit_rpm:
240 	pm_runtime_mark_last_busy(&rt->dev);
241 	pm_runtime_put_autosuspend(&rt->dev);
242 
243 	if (ret)
244 		return ret;
245 	return count;
246 }
247 static DEVICE_ATTR_RW(nvm_authenticate);
248 
249 static ssize_t nvm_version_show(struct device *dev,
250 				struct device_attribute *attr, char *buf)
251 {
252 	struct tb_retimer *rt = tb_to_retimer(dev);
253 	int ret;
254 
255 	if (!mutex_trylock(&rt->tb->lock))
256 		return restart_syscall();
257 
258 	if (!rt->nvm)
259 		ret = -EAGAIN;
260 	else
261 		ret = sprintf(buf, "%x.%x\n", rt->nvm->major, rt->nvm->minor);
262 
263 	mutex_unlock(&rt->tb->lock);
264 	return ret;
265 }
266 static DEVICE_ATTR_RO(nvm_version);
267 
268 static ssize_t vendor_show(struct device *dev, struct device_attribute *attr,
269 			   char *buf)
270 {
271 	struct tb_retimer *rt = tb_to_retimer(dev);
272 
273 	return sprintf(buf, "%#x\n", rt->vendor);
274 }
275 static DEVICE_ATTR_RO(vendor);
276 
277 static struct attribute *retimer_attrs[] = {
278 	&dev_attr_device.attr,
279 	&dev_attr_nvm_authenticate.attr,
280 	&dev_attr_nvm_version.attr,
281 	&dev_attr_vendor.attr,
282 	NULL
283 };
284 
285 static const struct attribute_group retimer_group = {
286 	.attrs = retimer_attrs,
287 };
288 
289 static const struct attribute_group *retimer_groups[] = {
290 	&retimer_group,
291 	NULL
292 };
293 
294 static void tb_retimer_release(struct device *dev)
295 {
296 	struct tb_retimer *rt = tb_to_retimer(dev);
297 
298 	kfree(rt);
299 }
300 
301 struct device_type tb_retimer_type = {
302 	.name = "thunderbolt_retimer",
303 	.groups = retimer_groups,
304 	.release = tb_retimer_release,
305 };
306 
307 static int tb_retimer_add(struct tb_port *port, u8 index, u32 auth_status)
308 {
309 	struct usb4_port *usb4;
310 	struct tb_retimer *rt;
311 	u32 vendor, device;
312 	int ret;
313 
314 	usb4 = port->usb4;
315 	if (!usb4)
316 		return -EINVAL;
317 
318 	ret = usb4_port_retimer_read(port, index, USB4_SB_VENDOR_ID, &vendor,
319 				     sizeof(vendor));
320 	if (ret) {
321 		if (ret != -ENODEV)
322 			tb_port_warn(port, "failed read retimer VendorId: %d\n", ret);
323 		return ret;
324 	}
325 
326 	ret = usb4_port_retimer_read(port, index, USB4_SB_PRODUCT_ID, &device,
327 				     sizeof(device));
328 	if (ret) {
329 		if (ret != -ENODEV)
330 			tb_port_warn(port, "failed read retimer ProductId: %d\n", ret);
331 		return ret;
332 	}
333 
334 	if (vendor != PCI_VENDOR_ID_INTEL && vendor != 0x8087) {
335 		tb_port_info(port, "retimer NVM format of vendor %#x is not supported\n",
336 			     vendor);
337 		return -EOPNOTSUPP;
338 	}
339 
340 	/*
341 	 * Check that it supports NVM operations. If not then don't add
342 	 * the device at all.
343 	 */
344 	ret = usb4_port_retimer_nvm_sector_size(port, index);
345 	if (ret < 0)
346 		return ret;
347 
348 	rt = kzalloc(sizeof(*rt), GFP_KERNEL);
349 	if (!rt)
350 		return -ENOMEM;
351 
352 	rt->index = index;
353 	rt->vendor = vendor;
354 	rt->device = device;
355 	rt->auth_status = auth_status;
356 	rt->port = port;
357 	rt->tb = port->sw->tb;
358 
359 	rt->dev.parent = &usb4->dev;
360 	rt->dev.bus = &tb_bus_type;
361 	rt->dev.type = &tb_retimer_type;
362 	dev_set_name(&rt->dev, "%s:%u.%u", dev_name(&port->sw->dev),
363 		     port->port, index);
364 
365 	ret = device_register(&rt->dev);
366 	if (ret) {
367 		dev_err(&rt->dev, "failed to register retimer: %d\n", ret);
368 		put_device(&rt->dev);
369 		return ret;
370 	}
371 
372 	ret = tb_retimer_nvm_add(rt);
373 	if (ret) {
374 		dev_err(&rt->dev, "failed to add NVM devices: %d\n", ret);
375 		device_unregister(&rt->dev);
376 		return ret;
377 	}
378 
379 	dev_info(&rt->dev, "new retimer found, vendor=%#x device=%#x\n",
380 		 rt->vendor, rt->device);
381 
382 	pm_runtime_no_callbacks(&rt->dev);
383 	pm_runtime_set_active(&rt->dev);
384 	pm_runtime_enable(&rt->dev);
385 	pm_runtime_set_autosuspend_delay(&rt->dev, TB_AUTOSUSPEND_DELAY);
386 	pm_runtime_mark_last_busy(&rt->dev);
387 	pm_runtime_use_autosuspend(&rt->dev);
388 
389 	return 0;
390 }
391 
392 static void tb_retimer_remove(struct tb_retimer *rt)
393 {
394 	dev_info(&rt->dev, "retimer disconnected\n");
395 	tb_nvm_free(rt->nvm);
396 	device_unregister(&rt->dev);
397 }
398 
399 struct tb_retimer_lookup {
400 	const struct tb_port *port;
401 	u8 index;
402 };
403 
404 static int retimer_match(struct device *dev, void *data)
405 {
406 	const struct tb_retimer_lookup *lookup = data;
407 	struct tb_retimer *rt = tb_to_retimer(dev);
408 
409 	return rt && rt->port == lookup->port && rt->index == lookup->index;
410 }
411 
412 static struct tb_retimer *tb_port_find_retimer(struct tb_port *port, u8 index)
413 {
414 	struct tb_retimer_lookup lookup = { .port = port, .index = index };
415 	struct device *dev;
416 
417 	dev = device_find_child(&port->usb4->dev, &lookup, retimer_match);
418 	if (dev)
419 		return tb_to_retimer(dev);
420 
421 	return NULL;
422 }
423 
424 /**
425  * tb_retimer_scan() - Scan for on-board retimers under port
426  * @port: USB4 port to scan
427  * @add: If true also registers found retimers
428  *
429  * Brings the sideband into a state where retimers can be accessed.
430  * Then Tries to enumerate on-board retimers connected to @port. Found
431  * retimers are registered as children of @port if @add is set.  Does
432  * not scan for cable retimers for now.
433  */
434 int tb_retimer_scan(struct tb_port *port, bool add)
435 {
436 	u32 status[TB_MAX_RETIMER_INDEX + 1] = {};
437 	int ret, i, last_idx = 0;
438 
439 	/*
440 	 * Send broadcast RT to make sure retimer indices facing this
441 	 * port are set.
442 	 */
443 	ret = usb4_port_enumerate_retimers(port);
444 	if (ret)
445 		return ret;
446 
447 	/*
448 	 * Enable sideband channel for each retimer. We can do this
449 	 * regardless whether there is device connected or not.
450 	 */
451 	for (i = 1; i <= TB_MAX_RETIMER_INDEX; i++)
452 		usb4_port_retimer_set_inbound_sbtx(port, i);
453 
454 	/*
455 	 * Before doing anything else, read the authentication status.
456 	 * If the retimer has it set, store it for the new retimer
457 	 * device instance.
458 	 */
459 	for (i = 1; i <= TB_MAX_RETIMER_INDEX; i++)
460 		usb4_port_retimer_nvm_authenticate_status(port, i, &status[i]);
461 
462 	for (i = 1; i <= TB_MAX_RETIMER_INDEX; i++) {
463 		/*
464 		 * Last retimer is true only for the last on-board
465 		 * retimer (the one connected directly to the Type-C
466 		 * port).
467 		 */
468 		ret = usb4_port_retimer_is_last(port, i);
469 		if (ret > 0)
470 			last_idx = i;
471 		else if (ret < 0)
472 			break;
473 	}
474 
475 	if (!last_idx)
476 		return 0;
477 
478 	/* Add on-board retimers if they do not exist already */
479 	for (i = 1; i <= last_idx; i++) {
480 		struct tb_retimer *rt;
481 
482 		rt = tb_port_find_retimer(port, i);
483 		if (rt) {
484 			put_device(&rt->dev);
485 		} else if (add) {
486 			ret = tb_retimer_add(port, i, status[i]);
487 			if (ret && ret != -EOPNOTSUPP)
488 				break;
489 		}
490 	}
491 
492 	return 0;
493 }
494 
495 static int remove_retimer(struct device *dev, void *data)
496 {
497 	struct tb_retimer *rt = tb_to_retimer(dev);
498 	struct tb_port *port = data;
499 
500 	if (rt && rt->port == port)
501 		tb_retimer_remove(rt);
502 	return 0;
503 }
504 
505 /**
506  * tb_retimer_remove_all() - Remove all retimers under port
507  * @port: USB4 port whose retimers to remove
508  *
509  * This removes all previously added retimers under @port.
510  */
511 void tb_retimer_remove_all(struct tb_port *port)
512 {
513 	struct usb4_port *usb4;
514 
515 	usb4 = port->usb4;
516 	if (usb4)
517 		device_for_each_child_reverse(&usb4->dev, port,
518 					      remove_retimer);
519 }
520