1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Intel(R) Trace Hub driver core
4  *
5  * Copyright (C) 2014-2015 Intel Corporation.
6  */
7 
8 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
9 
10 #include <linux/types.h>
11 #include <linux/module.h>
12 #include <linux/device.h>
13 #include <linux/sysfs.h>
14 #include <linux/kdev_t.h>
15 #include <linux/debugfs.h>
16 #include <linux/idr.h>
17 #include <linux/pci.h>
18 #include <linux/pm_runtime.h>
19 #include <linux/dma-mapping.h>
20 
21 #include "intel_th.h"
22 #include "debug.h"
23 
24 static bool host_mode __read_mostly;
25 module_param(host_mode, bool, 0444);
26 
27 static DEFINE_IDA(intel_th_ida);
28 
29 static int intel_th_match(struct device *dev, struct device_driver *driver)
30 {
31 	struct intel_th_driver *thdrv = to_intel_th_driver(driver);
32 	struct intel_th_device *thdev = to_intel_th_device(dev);
33 
34 	if (thdev->type == INTEL_TH_SWITCH &&
35 	    (!thdrv->enable || !thdrv->disable))
36 		return 0;
37 
38 	return !strcmp(thdev->name, driver->name);
39 }
40 
41 static int intel_th_child_remove(struct device *dev, void *data)
42 {
43 	device_release_driver(dev);
44 
45 	return 0;
46 }
47 
48 static int intel_th_probe(struct device *dev)
49 {
50 	struct intel_th_driver *thdrv = to_intel_th_driver(dev->driver);
51 	struct intel_th_device *thdev = to_intel_th_device(dev);
52 	struct intel_th_driver *hubdrv;
53 	struct intel_th_device *hub = NULL;
54 	int ret;
55 
56 	if (thdev->type == INTEL_TH_SWITCH)
57 		hub = thdev;
58 	else if (dev->parent)
59 		hub = to_intel_th_device(dev->parent);
60 
61 	if (!hub || !hub->dev.driver)
62 		return -EPROBE_DEFER;
63 
64 	hubdrv = to_intel_th_driver(hub->dev.driver);
65 
66 	pm_runtime_set_active(dev);
67 	pm_runtime_no_callbacks(dev);
68 	pm_runtime_enable(dev);
69 
70 	ret = thdrv->probe(to_intel_th_device(dev));
71 	if (ret)
72 		goto out_pm;
73 
74 	if (thdrv->attr_group) {
75 		ret = sysfs_create_group(&thdev->dev.kobj, thdrv->attr_group);
76 		if (ret)
77 			goto out;
78 	}
79 
80 	if (thdev->type == INTEL_TH_OUTPUT &&
81 	    !intel_th_output_assigned(thdev))
82 		/* does not talk to hardware */
83 		ret = hubdrv->assign(hub, thdev);
84 
85 out:
86 	if (ret)
87 		thdrv->remove(thdev);
88 
89 out_pm:
90 	if (ret)
91 		pm_runtime_disable(dev);
92 
93 	return ret;
94 }
95 
96 static void intel_th_device_remove(struct intel_th_device *thdev);
97 
98 static int intel_th_remove(struct device *dev)
99 {
100 	struct intel_th_driver *thdrv = to_intel_th_driver(dev->driver);
101 	struct intel_th_device *thdev = to_intel_th_device(dev);
102 	struct intel_th_device *hub = to_intel_th_hub(thdev);
103 
104 	if (thdev->type == INTEL_TH_SWITCH) {
105 		struct intel_th *th = to_intel_th(hub);
106 		int i, lowest;
107 
108 		/*
109 		 * disconnect outputs
110 		 *
111 		 * intel_th_child_remove returns 0 unconditionally, so there is
112 		 * no need to check the return value of device_for_each_child.
113 		 */
114 		device_for_each_child(dev, thdev, intel_th_child_remove);
115 
116 		/*
117 		 * Remove outputs, that is, hub's children: they are created
118 		 * at hub's probe time by having the hub call
119 		 * intel_th_output_enable() for each of them.
120 		 */
121 		for (i = 0, lowest = -1; i < th->num_thdevs; i++) {
122 			/*
123 			 * Move the non-output devices from higher up the
124 			 * th->thdev[] array to lower positions to maintain
125 			 * a contiguous array.
126 			 */
127 			if (th->thdev[i]->type != INTEL_TH_OUTPUT) {
128 				if (lowest >= 0) {
129 					th->thdev[lowest] = th->thdev[i];
130 					th->thdev[i] = NULL;
131 					++lowest;
132 				}
133 
134 				continue;
135 			}
136 
137 			if (lowest == -1)
138 				lowest = i;
139 
140 			intel_th_device_remove(th->thdev[i]);
141 			th->thdev[i] = NULL;
142 		}
143 
144 		if (lowest >= 0)
145 			th->num_thdevs = lowest;
146 	}
147 
148 	if (thdrv->attr_group)
149 		sysfs_remove_group(&thdev->dev.kobj, thdrv->attr_group);
150 
151 	pm_runtime_get_sync(dev);
152 
153 	thdrv->remove(thdev);
154 
155 	if (intel_th_output_assigned(thdev)) {
156 		struct intel_th_driver *hubdrv =
157 			to_intel_th_driver(dev->parent->driver);
158 
159 		if (hub->dev.driver)
160 			/* does not talk to hardware */
161 			hubdrv->unassign(hub, thdev);
162 	}
163 
164 	pm_runtime_disable(dev);
165 	pm_runtime_set_active(dev);
166 	pm_runtime_enable(dev);
167 
168 	return 0;
169 }
170 
171 static struct bus_type intel_th_bus = {
172 	.name		= "intel_th",
173 	.match		= intel_th_match,
174 	.probe		= intel_th_probe,
175 	.remove		= intel_th_remove,
176 };
177 
178 static void intel_th_device_free(struct intel_th_device *thdev);
179 
180 static void intel_th_device_release(struct device *dev)
181 {
182 	intel_th_device_free(to_intel_th_device(dev));
183 }
184 
185 static struct device_type intel_th_source_device_type = {
186 	.name		= "intel_th_source_device",
187 	.release	= intel_th_device_release,
188 };
189 
190 static char *intel_th_output_devnode(struct device *dev, umode_t *mode,
191 				     kuid_t *uid, kgid_t *gid)
192 {
193 	struct intel_th_device *thdev = to_intel_th_device(dev);
194 	struct intel_th *th = to_intel_th(thdev);
195 	char *node;
196 
197 	if (thdev->id >= 0)
198 		node = kasprintf(GFP_KERNEL, "intel_th%d/%s%d", th->id,
199 				 thdev->name, thdev->id);
200 	else
201 		node = kasprintf(GFP_KERNEL, "intel_th%d/%s", th->id,
202 				 thdev->name);
203 
204 	return node;
205 }
206 
207 static ssize_t port_show(struct device *dev, struct device_attribute *attr,
208 			 char *buf)
209 {
210 	struct intel_th_device *thdev = to_intel_th_device(dev);
211 
212 	if (thdev->output.port >= 0)
213 		return scnprintf(buf, PAGE_SIZE, "%u\n", thdev->output.port);
214 
215 	return scnprintf(buf, PAGE_SIZE, "unassigned\n");
216 }
217 
218 static DEVICE_ATTR_RO(port);
219 
220 static void intel_th_trace_prepare(struct intel_th_device *thdev)
221 {
222 	struct intel_th_device *hub = to_intel_th_hub(thdev);
223 	struct intel_th_driver *hubdrv = to_intel_th_driver(hub->dev.driver);
224 
225 	if (hub->type != INTEL_TH_SWITCH)
226 		return;
227 
228 	if (thdev->type != INTEL_TH_OUTPUT)
229 		return;
230 
231 	pm_runtime_get_sync(&thdev->dev);
232 	hubdrv->prepare(hub, &thdev->output);
233 	pm_runtime_put(&thdev->dev);
234 }
235 
236 static int intel_th_output_activate(struct intel_th_device *thdev)
237 {
238 	struct intel_th_driver *thdrv =
239 		to_intel_th_driver_or_null(thdev->dev.driver);
240 	struct intel_th *th = to_intel_th(thdev);
241 	int ret = 0;
242 
243 	if (!thdrv)
244 		return -ENODEV;
245 
246 	if (!try_module_get(thdrv->driver.owner))
247 		return -ENODEV;
248 
249 	pm_runtime_get_sync(&thdev->dev);
250 
251 	if (th->activate)
252 		ret = th->activate(th);
253 	if (ret)
254 		goto fail_put;
255 
256 	intel_th_trace_prepare(thdev);
257 	if (thdrv->activate)
258 		ret = thdrv->activate(thdev);
259 	else
260 		intel_th_trace_enable(thdev);
261 
262 	if (ret)
263 		goto fail_deactivate;
264 
265 	return 0;
266 
267 fail_deactivate:
268 	if (th->deactivate)
269 		th->deactivate(th);
270 
271 fail_put:
272 	pm_runtime_put(&thdev->dev);
273 	module_put(thdrv->driver.owner);
274 
275 	return ret;
276 }
277 
278 static void intel_th_output_deactivate(struct intel_th_device *thdev)
279 {
280 	struct intel_th_driver *thdrv =
281 		to_intel_th_driver_or_null(thdev->dev.driver);
282 	struct intel_th *th = to_intel_th(thdev);
283 
284 	if (!thdrv)
285 		return;
286 
287 	if (thdrv->deactivate)
288 		thdrv->deactivate(thdev);
289 	else
290 		intel_th_trace_disable(thdev);
291 
292 	if (th->deactivate)
293 		th->deactivate(th);
294 
295 	pm_runtime_put(&thdev->dev);
296 	module_put(thdrv->driver.owner);
297 }
298 
299 static ssize_t active_show(struct device *dev, struct device_attribute *attr,
300 			   char *buf)
301 {
302 	struct intel_th_device *thdev = to_intel_th_device(dev);
303 
304 	return scnprintf(buf, PAGE_SIZE, "%d\n", thdev->output.active);
305 }
306 
307 static ssize_t active_store(struct device *dev, struct device_attribute *attr,
308 			    const char *buf, size_t size)
309 {
310 	struct intel_th_device *thdev = to_intel_th_device(dev);
311 	unsigned long val;
312 	int ret;
313 
314 	ret = kstrtoul(buf, 10, &val);
315 	if (ret)
316 		return ret;
317 
318 	if (!!val != thdev->output.active) {
319 		if (val)
320 			ret = intel_th_output_activate(thdev);
321 		else
322 			intel_th_output_deactivate(thdev);
323 	}
324 
325 	return ret ? ret : size;
326 }
327 
328 static DEVICE_ATTR_RW(active);
329 
330 static struct attribute *intel_th_output_attrs[] = {
331 	&dev_attr_port.attr,
332 	&dev_attr_active.attr,
333 	NULL,
334 };
335 
336 ATTRIBUTE_GROUPS(intel_th_output);
337 
338 static struct device_type intel_th_output_device_type = {
339 	.name		= "intel_th_output_device",
340 	.groups		= intel_th_output_groups,
341 	.release	= intel_th_device_release,
342 	.devnode	= intel_th_output_devnode,
343 };
344 
345 static struct device_type intel_th_switch_device_type = {
346 	.name		= "intel_th_switch_device",
347 	.release	= intel_th_device_release,
348 };
349 
350 static struct device_type *intel_th_device_type[] = {
351 	[INTEL_TH_SOURCE]	= &intel_th_source_device_type,
352 	[INTEL_TH_OUTPUT]	= &intel_th_output_device_type,
353 	[INTEL_TH_SWITCH]	= &intel_th_switch_device_type,
354 };
355 
356 int intel_th_driver_register(struct intel_th_driver *thdrv)
357 {
358 	if (!thdrv->probe || !thdrv->remove)
359 		return -EINVAL;
360 
361 	thdrv->driver.bus = &intel_th_bus;
362 
363 	return driver_register(&thdrv->driver);
364 }
365 EXPORT_SYMBOL_GPL(intel_th_driver_register);
366 
367 void intel_th_driver_unregister(struct intel_th_driver *thdrv)
368 {
369 	driver_unregister(&thdrv->driver);
370 }
371 EXPORT_SYMBOL_GPL(intel_th_driver_unregister);
372 
373 static struct intel_th_device *
374 intel_th_device_alloc(struct intel_th *th, unsigned int type, const char *name,
375 		      int id)
376 {
377 	struct device *parent;
378 	struct intel_th_device *thdev;
379 
380 	if (type == INTEL_TH_OUTPUT)
381 		parent = &th->hub->dev;
382 	else
383 		parent = th->dev;
384 
385 	thdev = kzalloc(sizeof(*thdev) + strlen(name) + 1, GFP_KERNEL);
386 	if (!thdev)
387 		return NULL;
388 
389 	thdev->id = id;
390 	thdev->type = type;
391 
392 	strcpy(thdev->name, name);
393 	device_initialize(&thdev->dev);
394 	thdev->dev.bus = &intel_th_bus;
395 	thdev->dev.type = intel_th_device_type[type];
396 	thdev->dev.parent = parent;
397 	thdev->dev.dma_mask = parent->dma_mask;
398 	thdev->dev.dma_parms = parent->dma_parms;
399 	dma_set_coherent_mask(&thdev->dev, parent->coherent_dma_mask);
400 	if (id >= 0)
401 		dev_set_name(&thdev->dev, "%d-%s%d", th->id, name, id);
402 	else
403 		dev_set_name(&thdev->dev, "%d-%s", th->id, name);
404 
405 	return thdev;
406 }
407 
408 static int intel_th_device_add_resources(struct intel_th_device *thdev,
409 					 struct resource *res, int nres)
410 {
411 	struct resource *r;
412 
413 	r = kmemdup(res, sizeof(*res) * nres, GFP_KERNEL);
414 	if (!r)
415 		return -ENOMEM;
416 
417 	thdev->resource = r;
418 	thdev->num_resources = nres;
419 
420 	return 0;
421 }
422 
423 static void intel_th_device_remove(struct intel_th_device *thdev)
424 {
425 	device_del(&thdev->dev);
426 	put_device(&thdev->dev);
427 }
428 
429 static void intel_th_device_free(struct intel_th_device *thdev)
430 {
431 	kfree(thdev->resource);
432 	kfree(thdev);
433 }
434 
435 /*
436  * Intel(R) Trace Hub subdevices
437  */
438 static const struct intel_th_subdevice {
439 	const char		*name;
440 	struct resource		res[3];
441 	unsigned		nres;
442 	unsigned		type;
443 	unsigned		otype;
444 	bool			mknode;
445 	unsigned		scrpd;
446 	int			id;
447 } intel_th_subdevices[] = {
448 	{
449 		.nres	= 1,
450 		.res	= {
451 			{
452 				/* Handle TSCU and CTS from GTH driver */
453 				.start	= REG_GTH_OFFSET,
454 				.end	= REG_CTS_OFFSET + REG_CTS_LENGTH - 1,
455 				.flags	= IORESOURCE_MEM,
456 			},
457 		},
458 		.name	= "gth",
459 		.type	= INTEL_TH_SWITCH,
460 		.id	= -1,
461 	},
462 	{
463 		.nres	= 2,
464 		.res	= {
465 			{
466 				.start	= REG_MSU_OFFSET,
467 				.end	= REG_MSU_OFFSET + REG_MSU_LENGTH - 1,
468 				.flags	= IORESOURCE_MEM,
469 			},
470 			{
471 				.start	= BUF_MSU_OFFSET,
472 				.end	= BUF_MSU_OFFSET + BUF_MSU_LENGTH - 1,
473 				.flags	= IORESOURCE_MEM,
474 			},
475 		},
476 		.name	= "msc",
477 		.id	= 0,
478 		.type	= INTEL_TH_OUTPUT,
479 		.mknode	= true,
480 		.otype	= GTH_MSU,
481 		.scrpd	= SCRPD_MEM_IS_PRIM_DEST | SCRPD_MSC0_IS_ENABLED,
482 	},
483 	{
484 		.nres	= 2,
485 		.res	= {
486 			{
487 				.start	= REG_MSU_OFFSET,
488 				.end	= REG_MSU_OFFSET + REG_MSU_LENGTH - 1,
489 				.flags	= IORESOURCE_MEM,
490 			},
491 			{
492 				.start	= BUF_MSU_OFFSET,
493 				.end	= BUF_MSU_OFFSET + BUF_MSU_LENGTH - 1,
494 				.flags	= IORESOURCE_MEM,
495 			},
496 		},
497 		.name	= "msc",
498 		.id	= 1,
499 		.type	= INTEL_TH_OUTPUT,
500 		.mknode	= true,
501 		.otype	= GTH_MSU,
502 		.scrpd	= SCRPD_MEM_IS_PRIM_DEST | SCRPD_MSC1_IS_ENABLED,
503 	},
504 	{
505 		.nres	= 2,
506 		.res	= {
507 			{
508 				.start	= REG_STH_OFFSET,
509 				.end	= REG_STH_OFFSET + REG_STH_LENGTH - 1,
510 				.flags	= IORESOURCE_MEM,
511 			},
512 			{
513 				.start	= TH_MMIO_SW,
514 				.end	= 0,
515 				.flags	= IORESOURCE_MEM,
516 			},
517 		},
518 		.id	= -1,
519 		.name	= "sth",
520 		.type	= INTEL_TH_SOURCE,
521 	},
522 	{
523 		.nres	= 2,
524 		.res	= {
525 			{
526 				.start	= REG_STH_OFFSET,
527 				.end	= REG_STH_OFFSET + REG_STH_LENGTH - 1,
528 				.flags	= IORESOURCE_MEM,
529 			},
530 			{
531 				.start	= TH_MMIO_RTIT,
532 				.end	= 0,
533 				.flags	= IORESOURCE_MEM,
534 			},
535 		},
536 		.id	= -1,
537 		.name	= "rtit",
538 		.type	= INTEL_TH_SOURCE,
539 	},
540 	{
541 		.nres	= 1,
542 		.res	= {
543 			{
544 				.start	= REG_PTI_OFFSET,
545 				.end	= REG_PTI_OFFSET + REG_PTI_LENGTH - 1,
546 				.flags	= IORESOURCE_MEM,
547 			},
548 		},
549 		.id	= -1,
550 		.name	= "pti",
551 		.type	= INTEL_TH_OUTPUT,
552 		.otype	= GTH_PTI,
553 		.scrpd	= SCRPD_PTI_IS_PRIM_DEST,
554 	},
555 	{
556 		.nres	= 1,
557 		.res	= {
558 			{
559 				.start	= REG_PTI_OFFSET,
560 				.end	= REG_PTI_OFFSET + REG_PTI_LENGTH - 1,
561 				.flags	= IORESOURCE_MEM,
562 			},
563 		},
564 		.id	= -1,
565 		.name	= "lpp",
566 		.type	= INTEL_TH_OUTPUT,
567 		.otype	= GTH_LPP,
568 		.scrpd	= SCRPD_PTI_IS_PRIM_DEST,
569 	},
570 	{
571 		.nres	= 1,
572 		.res	= {
573 			{
574 				.start	= REG_DCIH_OFFSET,
575 				.end	= REG_DCIH_OFFSET + REG_DCIH_LENGTH - 1,
576 				.flags	= IORESOURCE_MEM,
577 			},
578 		},
579 		.id	= -1,
580 		.name	= "dcih",
581 		.type	= INTEL_TH_OUTPUT,
582 	},
583 };
584 
585 #ifdef CONFIG_MODULES
586 static void __intel_th_request_hub_module(struct work_struct *work)
587 {
588 	struct intel_th *th = container_of(work, struct intel_th,
589 					   request_module_work);
590 
591 	request_module("intel_th_%s", th->hub->name);
592 }
593 
594 static int intel_th_request_hub_module(struct intel_th *th)
595 {
596 	INIT_WORK(&th->request_module_work, __intel_th_request_hub_module);
597 	schedule_work(&th->request_module_work);
598 
599 	return 0;
600 }
601 
602 static void intel_th_request_hub_module_flush(struct intel_th *th)
603 {
604 	flush_work(&th->request_module_work);
605 }
606 #else
607 static inline int intel_th_request_hub_module(struct intel_th *th)
608 {
609 	return -EINVAL;
610 }
611 
612 static inline void intel_th_request_hub_module_flush(struct intel_th *th)
613 {
614 }
615 #endif /* CONFIG_MODULES */
616 
617 static struct intel_th_device *
618 intel_th_subdevice_alloc(struct intel_th *th,
619 			 const struct intel_th_subdevice *subdev)
620 {
621 	struct intel_th_device *thdev;
622 	struct resource res[3];
623 	unsigned int req = 0;
624 	int r, err;
625 
626 	thdev = intel_th_device_alloc(th, subdev->type, subdev->name,
627 				      subdev->id);
628 	if (!thdev)
629 		return ERR_PTR(-ENOMEM);
630 
631 	thdev->drvdata = th->drvdata;
632 
633 	memcpy(res, subdev->res,
634 	       sizeof(struct resource) * subdev->nres);
635 
636 	for (r = 0; r < subdev->nres; r++) {
637 		struct resource *devres = th->resource;
638 		int bar = TH_MMIO_CONFIG;
639 
640 		/*
641 		 * Take .end == 0 to mean 'take the whole bar',
642 		 * .start then tells us which bar it is. Default to
643 		 * TH_MMIO_CONFIG.
644 		 */
645 		if (!res[r].end && res[r].flags == IORESOURCE_MEM) {
646 			bar = res[r].start;
647 			err = -ENODEV;
648 			if (bar >= th->num_resources)
649 				goto fail_put_device;
650 			res[r].start = 0;
651 			res[r].end = resource_size(&devres[bar]) - 1;
652 		}
653 
654 		if (res[r].flags & IORESOURCE_MEM) {
655 			res[r].start	+= devres[bar].start;
656 			res[r].end	+= devres[bar].start;
657 
658 			dev_dbg(th->dev, "%s:%d @ %pR\n",
659 				subdev->name, r, &res[r]);
660 		} else if (res[r].flags & IORESOURCE_IRQ) {
661 			/*
662 			 * Only pass on the IRQ if we have useful interrupts:
663 			 * the ones that can be configured via MINTCTL.
664 			 */
665 			if (INTEL_TH_CAP(th, has_mintctl) && th->irq != -1)
666 				res[r].start = th->irq;
667 		}
668 	}
669 
670 	err = intel_th_device_add_resources(thdev, res, subdev->nres);
671 	if (err)
672 		goto fail_put_device;
673 
674 	if (subdev->type == INTEL_TH_OUTPUT) {
675 		if (subdev->mknode)
676 			thdev->dev.devt = MKDEV(th->major, th->num_thdevs);
677 		thdev->output.type = subdev->otype;
678 		thdev->output.port = -1;
679 		thdev->output.scratchpad = subdev->scrpd;
680 	} else if (subdev->type == INTEL_TH_SWITCH) {
681 		thdev->host_mode =
682 			INTEL_TH_CAP(th, host_mode_only) ? true : host_mode;
683 		th->hub = thdev;
684 	}
685 
686 	err = device_add(&thdev->dev);
687 	if (err)
688 		goto fail_free_res;
689 
690 	/* need switch driver to be loaded to enumerate the rest */
691 	if (subdev->type == INTEL_TH_SWITCH && !req) {
692 		err = intel_th_request_hub_module(th);
693 		if (!err)
694 			req++;
695 	}
696 
697 	return thdev;
698 
699 fail_free_res:
700 	kfree(thdev->resource);
701 
702 fail_put_device:
703 	put_device(&thdev->dev);
704 
705 	return ERR_PTR(err);
706 }
707 
708 /**
709  * intel_th_output_enable() - find and enable a device for a given output type
710  * @th:		Intel TH instance
711  * @otype:	output type
712  *
713  * Go through the unallocated output devices, find the first one whos type
714  * matches @otype and instantiate it. These devices are removed when the hub
715  * device is removed, see intel_th_remove().
716  */
717 int intel_th_output_enable(struct intel_th *th, unsigned int otype)
718 {
719 	struct intel_th_device *thdev;
720 	int src = 0, dst = 0;
721 
722 	for (src = 0, dst = 0; dst <= th->num_thdevs; src++, dst++) {
723 		for (; src < ARRAY_SIZE(intel_th_subdevices); src++) {
724 			if (intel_th_subdevices[src].type != INTEL_TH_OUTPUT)
725 				continue;
726 
727 			if (intel_th_subdevices[src].otype != otype)
728 				continue;
729 
730 			break;
731 		}
732 
733 		/* no unallocated matching subdevices */
734 		if (src == ARRAY_SIZE(intel_th_subdevices))
735 			return -ENODEV;
736 
737 		for (; dst < th->num_thdevs; dst++) {
738 			if (th->thdev[dst]->type != INTEL_TH_OUTPUT)
739 				continue;
740 
741 			if (th->thdev[dst]->output.type != otype)
742 				continue;
743 
744 			break;
745 		}
746 
747 		/*
748 		 * intel_th_subdevices[src] matches our requirements and is
749 		 * not matched in th::thdev[]
750 		 */
751 		if (dst == th->num_thdevs)
752 			goto found;
753 	}
754 
755 	return -ENODEV;
756 
757 found:
758 	thdev = intel_th_subdevice_alloc(th, &intel_th_subdevices[src]);
759 	if (IS_ERR(thdev))
760 		return PTR_ERR(thdev);
761 
762 	th->thdev[th->num_thdevs++] = thdev;
763 
764 	return 0;
765 }
766 EXPORT_SYMBOL_GPL(intel_th_output_enable);
767 
768 static int intel_th_populate(struct intel_th *th)
769 {
770 	int src;
771 
772 	/* create devices for each intel_th_subdevice */
773 	for (src = 0; src < ARRAY_SIZE(intel_th_subdevices); src++) {
774 		const struct intel_th_subdevice *subdev =
775 			&intel_th_subdevices[src];
776 		struct intel_th_device *thdev;
777 
778 		/* only allow SOURCE and SWITCH devices in host mode */
779 		if ((INTEL_TH_CAP(th, host_mode_only) || host_mode) &&
780 		    subdev->type == INTEL_TH_OUTPUT)
781 			continue;
782 
783 		/*
784 		 * don't enable port OUTPUTs in this path; SWITCH enables them
785 		 * via intel_th_output_enable()
786 		 */
787 		if (subdev->type == INTEL_TH_OUTPUT &&
788 		    subdev->otype != GTH_NONE)
789 			continue;
790 
791 		thdev = intel_th_subdevice_alloc(th, subdev);
792 		/* note: caller should free subdevices from th::thdev[] */
793 		if (IS_ERR(thdev)) {
794 			/* ENODEV for individual subdevices is allowed */
795 			if (PTR_ERR(thdev) == -ENODEV)
796 				continue;
797 
798 			return PTR_ERR(thdev);
799 		}
800 
801 		th->thdev[th->num_thdevs++] = thdev;
802 	}
803 
804 	return 0;
805 }
806 
807 static int intel_th_output_open(struct inode *inode, struct file *file)
808 {
809 	const struct file_operations *fops;
810 	struct intel_th_driver *thdrv;
811 	struct device *dev;
812 	int err;
813 
814 	dev = bus_find_device_by_devt(&intel_th_bus, inode->i_rdev);
815 	if (!dev || !dev->driver)
816 		return -ENODEV;
817 
818 	thdrv = to_intel_th_driver(dev->driver);
819 	fops = fops_get(thdrv->fops);
820 	if (!fops)
821 		return -ENODEV;
822 
823 	replace_fops(file, fops);
824 
825 	file->private_data = to_intel_th_device(dev);
826 
827 	if (file->f_op->open) {
828 		err = file->f_op->open(inode, file);
829 		return err;
830 	}
831 
832 	return 0;
833 }
834 
835 static const struct file_operations intel_th_output_fops = {
836 	.open	= intel_th_output_open,
837 	.llseek	= noop_llseek,
838 };
839 
840 static irqreturn_t intel_th_irq(int irq, void *data)
841 {
842 	struct intel_th *th = data;
843 	irqreturn_t ret = IRQ_NONE;
844 	struct intel_th_driver *d;
845 	int i;
846 
847 	for (i = 0; i < th->num_thdevs; i++) {
848 		if (th->thdev[i]->type != INTEL_TH_OUTPUT)
849 			continue;
850 
851 		d = to_intel_th_driver(th->thdev[i]->dev.driver);
852 		if (d && d->irq)
853 			ret |= d->irq(th->thdev[i]);
854 	}
855 
856 	return ret;
857 }
858 
859 /**
860  * intel_th_alloc() - allocate a new Intel TH device and its subdevices
861  * @dev:	parent device
862  * @devres:	resources indexed by th_mmio_idx
863  * @irq:	irq number
864  */
865 struct intel_th *
866 intel_th_alloc(struct device *dev, const struct intel_th_drvdata *drvdata,
867 	       struct resource *devres, unsigned int ndevres)
868 {
869 	int err, r, nr_mmios = 0;
870 	struct intel_th *th;
871 
872 	th = kzalloc(sizeof(*th), GFP_KERNEL);
873 	if (!th)
874 		return ERR_PTR(-ENOMEM);
875 
876 	th->id = ida_simple_get(&intel_th_ida, 0, 0, GFP_KERNEL);
877 	if (th->id < 0) {
878 		err = th->id;
879 		goto err_alloc;
880 	}
881 
882 	th->major = __register_chrdev(0, 0, TH_POSSIBLE_OUTPUTS,
883 				      "intel_th/output", &intel_th_output_fops);
884 	if (th->major < 0) {
885 		err = th->major;
886 		goto err_ida;
887 	}
888 	th->irq = -1;
889 	th->dev = dev;
890 	th->drvdata = drvdata;
891 
892 	for (r = 0; r < ndevres; r++)
893 		switch (devres[r].flags & IORESOURCE_TYPE_BITS) {
894 		case IORESOURCE_MEM:
895 			th->resource[nr_mmios++] = devres[r];
896 			break;
897 		case IORESOURCE_IRQ:
898 			err = devm_request_irq(dev, devres[r].start,
899 					       intel_th_irq, IRQF_SHARED,
900 					       dev_name(dev), th);
901 			if (err)
902 				goto err_chrdev;
903 
904 			if (th->irq == -1)
905 				th->irq = devres[r].start;
906 			th->num_irqs++;
907 			break;
908 		default:
909 			dev_warn(dev, "Unknown resource type %lx\n",
910 				 devres[r].flags);
911 			break;
912 		}
913 
914 	th->num_resources = nr_mmios;
915 
916 	dev_set_drvdata(dev, th);
917 
918 	pm_runtime_no_callbacks(dev);
919 	pm_runtime_put(dev);
920 	pm_runtime_allow(dev);
921 
922 	err = intel_th_populate(th);
923 	if (err) {
924 		/* free the subdevices and undo everything */
925 		intel_th_free(th);
926 		return ERR_PTR(err);
927 	}
928 
929 	return th;
930 
931 err_chrdev:
932 	__unregister_chrdev(th->major, 0, TH_POSSIBLE_OUTPUTS,
933 			    "intel_th/output");
934 
935 err_ida:
936 	ida_simple_remove(&intel_th_ida, th->id);
937 
938 err_alloc:
939 	kfree(th);
940 
941 	return ERR_PTR(err);
942 }
943 EXPORT_SYMBOL_GPL(intel_th_alloc);
944 
945 void intel_th_free(struct intel_th *th)
946 {
947 	int i;
948 
949 	intel_th_request_hub_module_flush(th);
950 
951 	intel_th_device_remove(th->hub);
952 	for (i = 0; i < th->num_thdevs; i++) {
953 		if (th->thdev[i] != th->hub)
954 			intel_th_device_remove(th->thdev[i]);
955 		th->thdev[i] = NULL;
956 	}
957 
958 	th->num_thdevs = 0;
959 
960 	for (i = 0; i < th->num_irqs; i++)
961 		devm_free_irq(th->dev, th->irq + i, th);
962 
963 	pm_runtime_get_sync(th->dev);
964 	pm_runtime_forbid(th->dev);
965 
966 	__unregister_chrdev(th->major, 0, TH_POSSIBLE_OUTPUTS,
967 			    "intel_th/output");
968 
969 	ida_simple_remove(&intel_th_ida, th->id);
970 
971 	kfree(th);
972 }
973 EXPORT_SYMBOL_GPL(intel_th_free);
974 
975 /**
976  * intel_th_trace_enable() - enable tracing for an output device
977  * @thdev:	output device that requests tracing be enabled
978  */
979 int intel_th_trace_enable(struct intel_th_device *thdev)
980 {
981 	struct intel_th_device *hub = to_intel_th_device(thdev->dev.parent);
982 	struct intel_th_driver *hubdrv = to_intel_th_driver(hub->dev.driver);
983 
984 	if (WARN_ON_ONCE(hub->type != INTEL_TH_SWITCH))
985 		return -EINVAL;
986 
987 	if (WARN_ON_ONCE(thdev->type != INTEL_TH_OUTPUT))
988 		return -EINVAL;
989 
990 	pm_runtime_get_sync(&thdev->dev);
991 	hubdrv->enable(hub, &thdev->output);
992 
993 	return 0;
994 }
995 EXPORT_SYMBOL_GPL(intel_th_trace_enable);
996 
997 /**
998  * intel_th_trace_switch() - execute a switch sequence
999  * @thdev:	output device that requests tracing switch
1000  */
1001 int intel_th_trace_switch(struct intel_th_device *thdev)
1002 {
1003 	struct intel_th_device *hub = to_intel_th_device(thdev->dev.parent);
1004 	struct intel_th_driver *hubdrv = to_intel_th_driver(hub->dev.driver);
1005 
1006 	if (WARN_ON_ONCE(hub->type != INTEL_TH_SWITCH))
1007 		return -EINVAL;
1008 
1009 	if (WARN_ON_ONCE(thdev->type != INTEL_TH_OUTPUT))
1010 		return -EINVAL;
1011 
1012 	hubdrv->trig_switch(hub, &thdev->output);
1013 
1014 	return 0;
1015 }
1016 EXPORT_SYMBOL_GPL(intel_th_trace_switch);
1017 
1018 /**
1019  * intel_th_trace_disable() - disable tracing for an output device
1020  * @thdev:	output device that requests tracing be disabled
1021  */
1022 int intel_th_trace_disable(struct intel_th_device *thdev)
1023 {
1024 	struct intel_th_device *hub = to_intel_th_device(thdev->dev.parent);
1025 	struct intel_th_driver *hubdrv = to_intel_th_driver(hub->dev.driver);
1026 
1027 	WARN_ON_ONCE(hub->type != INTEL_TH_SWITCH);
1028 	if (WARN_ON_ONCE(thdev->type != INTEL_TH_OUTPUT))
1029 		return -EINVAL;
1030 
1031 	hubdrv->disable(hub, &thdev->output);
1032 	pm_runtime_put(&thdev->dev);
1033 
1034 	return 0;
1035 }
1036 EXPORT_SYMBOL_GPL(intel_th_trace_disable);
1037 
1038 int intel_th_set_output(struct intel_th_device *thdev,
1039 			unsigned int master)
1040 {
1041 	struct intel_th_device *hub = to_intel_th_hub(thdev);
1042 	struct intel_th_driver *hubdrv = to_intel_th_driver(hub->dev.driver);
1043 	int ret;
1044 
1045 	/* In host mode, this is up to the external debugger, do nothing. */
1046 	if (hub->host_mode)
1047 		return 0;
1048 
1049 	/*
1050 	 * hub is instantiated together with the source device that
1051 	 * calls here, so guaranteed to be present.
1052 	 */
1053 	hubdrv = to_intel_th_driver(hub->dev.driver);
1054 	if (!hubdrv || !try_module_get(hubdrv->driver.owner))
1055 		return -EINVAL;
1056 
1057 	if (!hubdrv->set_output) {
1058 		ret = -ENOTSUPP;
1059 		goto out;
1060 	}
1061 
1062 	ret = hubdrv->set_output(hub, master);
1063 
1064 out:
1065 	module_put(hubdrv->driver.owner);
1066 	return ret;
1067 }
1068 EXPORT_SYMBOL_GPL(intel_th_set_output);
1069 
1070 static int __init intel_th_init(void)
1071 {
1072 	intel_th_debug_init();
1073 
1074 	return bus_register(&intel_th_bus);
1075 }
1076 subsys_initcall(intel_th_init);
1077 
1078 static void __exit intel_th_exit(void)
1079 {
1080 	intel_th_debug_done();
1081 
1082 	bus_unregister(&intel_th_bus);
1083 }
1084 module_exit(intel_th_exit);
1085 
1086 MODULE_LICENSE("GPL v2");
1087 MODULE_DESCRIPTION("Intel(R) Trace Hub controller driver");
1088 MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>");
1089