1 /*
2  * Intel(R) Trace Hub driver core
3  *
4  * Copyright (C) 2014-2015 Intel Corporation.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  */
15 
16 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
17 
18 #include <linux/types.h>
19 #include <linux/module.h>
20 #include <linux/device.h>
21 #include <linux/sysfs.h>
22 #include <linux/kdev_t.h>
23 #include <linux/debugfs.h>
24 #include <linux/idr.h>
25 #include <linux/pci.h>
26 #include <linux/dma-mapping.h>
27 
28 #include "intel_th.h"
29 #include "debug.h"
30 
31 static DEFINE_IDA(intel_th_ida);
32 
33 static int intel_th_match(struct device *dev, struct device_driver *driver)
34 {
35 	struct intel_th_driver *thdrv = to_intel_th_driver(driver);
36 	struct intel_th_device *thdev = to_intel_th_device(dev);
37 
38 	if (thdev->type == INTEL_TH_SWITCH &&
39 	    (!thdrv->enable || !thdrv->disable))
40 		return 0;
41 
42 	return !strcmp(thdev->name, driver->name);
43 }
44 
45 static int intel_th_child_remove(struct device *dev, void *data)
46 {
47 	device_release_driver(dev);
48 
49 	return 0;
50 }
51 
52 static int intel_th_probe(struct device *dev)
53 {
54 	struct intel_th_driver *thdrv = to_intel_th_driver(dev->driver);
55 	struct intel_th_device *thdev = to_intel_th_device(dev);
56 	struct intel_th_driver *hubdrv;
57 	struct intel_th_device *hub = NULL;
58 	int ret;
59 
60 	if (thdev->type == INTEL_TH_SWITCH)
61 		hub = thdev;
62 	else if (dev->parent)
63 		hub = to_intel_th_device(dev->parent);
64 
65 	if (!hub || !hub->dev.driver)
66 		return -EPROBE_DEFER;
67 
68 	hubdrv = to_intel_th_driver(hub->dev.driver);
69 
70 	ret = thdrv->probe(to_intel_th_device(dev));
71 	if (ret)
72 		return ret;
73 
74 	if (thdev->type == INTEL_TH_OUTPUT &&
75 	    !intel_th_output_assigned(thdev))
76 		ret = hubdrv->assign(hub, thdev);
77 
78 	return ret;
79 }
80 
81 static int intel_th_remove(struct device *dev)
82 {
83 	struct intel_th_driver *thdrv = to_intel_th_driver(dev->driver);
84 	struct intel_th_device *thdev = to_intel_th_device(dev);
85 	struct intel_th_device *hub = to_intel_th_device(dev->parent);
86 	int err;
87 
88 	if (thdev->type == INTEL_TH_SWITCH) {
89 		err = device_for_each_child(dev, thdev, intel_th_child_remove);
90 		if (err)
91 			return err;
92 	}
93 
94 	thdrv->remove(thdev);
95 
96 	if (intel_th_output_assigned(thdev)) {
97 		struct intel_th_driver *hubdrv =
98 			to_intel_th_driver(dev->parent->driver);
99 
100 		if (hub->dev.driver)
101 			hubdrv->unassign(hub, thdev);
102 	}
103 
104 	return 0;
105 }
106 
107 static struct bus_type intel_th_bus = {
108 	.name		= "intel_th",
109 	.dev_attrs	= NULL,
110 	.match		= intel_th_match,
111 	.probe		= intel_th_probe,
112 	.remove		= intel_th_remove,
113 };
114 
115 static void intel_th_device_free(struct intel_th_device *thdev);
116 
117 static void intel_th_device_release(struct device *dev)
118 {
119 	intel_th_device_free(to_intel_th_device(dev));
120 }
121 
122 static struct device_type intel_th_source_device_type = {
123 	.name		= "intel_th_source_device",
124 	.release	= intel_th_device_release,
125 };
126 
127 static struct intel_th *to_intel_th(struct intel_th_device *thdev)
128 {
129 	/*
130 	 * subdevice tree is flat: if this one is not a switch, its
131 	 * parent must be
132 	 */
133 	if (thdev->type != INTEL_TH_SWITCH)
134 		thdev = to_intel_th_hub(thdev);
135 
136 	if (WARN_ON_ONCE(!thdev || thdev->type != INTEL_TH_SWITCH))
137 		return NULL;
138 
139 	return dev_get_drvdata(thdev->dev.parent);
140 }
141 
142 static char *intel_th_output_devnode(struct device *dev, umode_t *mode,
143 				     kuid_t *uid, kgid_t *gid)
144 {
145 	struct intel_th_device *thdev = to_intel_th_device(dev);
146 	struct intel_th *th = to_intel_th(thdev);
147 	char *node;
148 
149 	if (thdev->id >= 0)
150 		node = kasprintf(GFP_KERNEL, "intel_th%d/%s%d", th->id,
151 				 thdev->name, thdev->id);
152 	else
153 		node = kasprintf(GFP_KERNEL, "intel_th%d/%s", th->id,
154 				 thdev->name);
155 
156 	return node;
157 }
158 
159 static ssize_t port_show(struct device *dev, struct device_attribute *attr,
160 			 char *buf)
161 {
162 	struct intel_th_device *thdev = to_intel_th_device(dev);
163 
164 	if (thdev->output.port >= 0)
165 		return scnprintf(buf, PAGE_SIZE, "%u\n", thdev->output.port);
166 
167 	return scnprintf(buf, PAGE_SIZE, "unassigned\n");
168 }
169 
170 static DEVICE_ATTR_RO(port);
171 
172 static int intel_th_output_activate(struct intel_th_device *thdev)
173 {
174 	struct intel_th_driver *thdrv = to_intel_th_driver(thdev->dev.driver);
175 
176 	if (thdrv->activate)
177 		return thdrv->activate(thdev);
178 
179 	intel_th_trace_enable(thdev);
180 
181 	return 0;
182 }
183 
184 static void intel_th_output_deactivate(struct intel_th_device *thdev)
185 {
186 	struct intel_th_driver *thdrv = to_intel_th_driver(thdev->dev.driver);
187 
188 	if (thdrv->deactivate)
189 		thdrv->deactivate(thdev);
190 	else
191 		intel_th_trace_disable(thdev);
192 }
193 
194 static ssize_t active_show(struct device *dev, struct device_attribute *attr,
195 			   char *buf)
196 {
197 	struct intel_th_device *thdev = to_intel_th_device(dev);
198 
199 	return scnprintf(buf, PAGE_SIZE, "%d\n", thdev->output.active);
200 }
201 
202 static ssize_t active_store(struct device *dev, struct device_attribute *attr,
203 			    const char *buf, size_t size)
204 {
205 	struct intel_th_device *thdev = to_intel_th_device(dev);
206 	unsigned long val;
207 	int ret;
208 
209 	ret = kstrtoul(buf, 10, &val);
210 	if (ret)
211 		return ret;
212 
213 	if (!!val != thdev->output.active) {
214 		if (val)
215 			ret = intel_th_output_activate(thdev);
216 		else
217 			intel_th_output_deactivate(thdev);
218 	}
219 
220 	return ret ? ret : size;
221 }
222 
223 static DEVICE_ATTR_RW(active);
224 
225 static struct attribute *intel_th_output_attrs[] = {
226 	&dev_attr_port.attr,
227 	&dev_attr_active.attr,
228 	NULL,
229 };
230 
231 ATTRIBUTE_GROUPS(intel_th_output);
232 
233 static struct device_type intel_th_output_device_type = {
234 	.name		= "intel_th_output_device",
235 	.groups		= intel_th_output_groups,
236 	.release	= intel_th_device_release,
237 	.devnode	= intel_th_output_devnode,
238 };
239 
240 static struct device_type intel_th_switch_device_type = {
241 	.name		= "intel_th_switch_device",
242 	.release	= intel_th_device_release,
243 };
244 
245 static struct device_type *intel_th_device_type[] = {
246 	[INTEL_TH_SOURCE]	= &intel_th_source_device_type,
247 	[INTEL_TH_OUTPUT]	= &intel_th_output_device_type,
248 	[INTEL_TH_SWITCH]	= &intel_th_switch_device_type,
249 };
250 
251 int intel_th_driver_register(struct intel_th_driver *thdrv)
252 {
253 	if (!thdrv->probe || !thdrv->remove)
254 		return -EINVAL;
255 
256 	thdrv->driver.bus = &intel_th_bus;
257 
258 	return driver_register(&thdrv->driver);
259 }
260 EXPORT_SYMBOL_GPL(intel_th_driver_register);
261 
262 void intel_th_driver_unregister(struct intel_th_driver *thdrv)
263 {
264 	driver_unregister(&thdrv->driver);
265 }
266 EXPORT_SYMBOL_GPL(intel_th_driver_unregister);
267 
268 static struct intel_th_device *
269 intel_th_device_alloc(struct intel_th *th, unsigned int type, const char *name,
270 		      int id)
271 {
272 	struct device *parent;
273 	struct intel_th_device *thdev;
274 
275 	if (type == INTEL_TH_SWITCH)
276 		parent = th->dev;
277 	else
278 		parent = &th->hub->dev;
279 
280 	thdev = kzalloc(sizeof(*thdev) + strlen(name) + 1, GFP_KERNEL);
281 	if (!thdev)
282 		return NULL;
283 
284 	thdev->id = id;
285 	thdev->type = type;
286 
287 	strcpy(thdev->name, name);
288 	device_initialize(&thdev->dev);
289 	thdev->dev.bus = &intel_th_bus;
290 	thdev->dev.type = intel_th_device_type[type];
291 	thdev->dev.parent = parent;
292 	thdev->dev.dma_mask = parent->dma_mask;
293 	thdev->dev.dma_parms = parent->dma_parms;
294 	dma_set_coherent_mask(&thdev->dev, parent->coherent_dma_mask);
295 	if (id >= 0)
296 		dev_set_name(&thdev->dev, "%d-%s%d", th->id, name, id);
297 	else
298 		dev_set_name(&thdev->dev, "%d-%s", th->id, name);
299 
300 	return thdev;
301 }
302 
303 static int intel_th_device_add_resources(struct intel_th_device *thdev,
304 					 struct resource *res, int nres)
305 {
306 	struct resource *r;
307 
308 	r = kmemdup(res, sizeof(*res) * nres, GFP_KERNEL);
309 	if (!r)
310 		return -ENOMEM;
311 
312 	thdev->resource = r;
313 	thdev->num_resources = nres;
314 
315 	return 0;
316 }
317 
318 static void intel_th_device_remove(struct intel_th_device *thdev)
319 {
320 	device_del(&thdev->dev);
321 	put_device(&thdev->dev);
322 }
323 
324 static void intel_th_device_free(struct intel_th_device *thdev)
325 {
326 	kfree(thdev->resource);
327 	kfree(thdev);
328 }
329 
330 /*
331  * Intel(R) Trace Hub subdevices
332  */
333 static struct intel_th_subdevice {
334 	const char		*name;
335 	struct resource		res[3];
336 	unsigned		nres;
337 	unsigned		type;
338 	unsigned		otype;
339 	unsigned		scrpd;
340 	int			id;
341 } intel_th_subdevices[TH_SUBDEVICE_MAX] = {
342 	{
343 		.nres	= 1,
344 		.res	= {
345 			{
346 				.start	= REG_GTH_OFFSET,
347 				.end	= REG_GTH_OFFSET + REG_GTH_LENGTH - 1,
348 				.flags	= IORESOURCE_MEM,
349 			},
350 		},
351 		.name	= "gth",
352 		.type	= INTEL_TH_SWITCH,
353 		.id	= -1,
354 	},
355 	{
356 		.nres	= 2,
357 		.res	= {
358 			{
359 				.start	= REG_MSU_OFFSET,
360 				.end	= REG_MSU_OFFSET + REG_MSU_LENGTH - 1,
361 				.flags	= IORESOURCE_MEM,
362 			},
363 			{
364 				.start	= BUF_MSU_OFFSET,
365 				.end	= BUF_MSU_OFFSET + BUF_MSU_LENGTH - 1,
366 				.flags	= IORESOURCE_MEM,
367 			},
368 		},
369 		.name	= "msc",
370 		.id	= 0,
371 		.type	= INTEL_TH_OUTPUT,
372 		.otype	= GTH_MSU,
373 		.scrpd	= SCRPD_MEM_IS_PRIM_DEST | SCRPD_MSC0_IS_ENABLED,
374 	},
375 	{
376 		.nres	= 2,
377 		.res	= {
378 			{
379 				.start	= REG_MSU_OFFSET,
380 				.end	= REG_MSU_OFFSET + REG_MSU_LENGTH - 1,
381 				.flags	= IORESOURCE_MEM,
382 			},
383 			{
384 				.start	= BUF_MSU_OFFSET,
385 				.end	= BUF_MSU_OFFSET + BUF_MSU_LENGTH - 1,
386 				.flags	= IORESOURCE_MEM,
387 			},
388 		},
389 		.name	= "msc",
390 		.id	= 1,
391 		.type	= INTEL_TH_OUTPUT,
392 		.otype	= GTH_MSU,
393 		.scrpd	= SCRPD_MEM_IS_PRIM_DEST | SCRPD_MSC1_IS_ENABLED,
394 	},
395 	{
396 		.nres	= 2,
397 		.res	= {
398 			{
399 				.start	= REG_STH_OFFSET,
400 				.end	= REG_STH_OFFSET + REG_STH_LENGTH - 1,
401 				.flags	= IORESOURCE_MEM,
402 			},
403 			{
404 				.start	= TH_MMIO_SW,
405 				.end	= 0,
406 				.flags	= IORESOURCE_MEM,
407 			},
408 		},
409 		.id	= -1,
410 		.name	= "sth",
411 		.type	= INTEL_TH_SOURCE,
412 	},
413 	{
414 		.nres	= 1,
415 		.res	= {
416 			{
417 				.start	= REG_PTI_OFFSET,
418 				.end	= REG_PTI_OFFSET + REG_PTI_LENGTH - 1,
419 				.flags	= IORESOURCE_MEM,
420 			},
421 		},
422 		.id	= -1,
423 		.name	= "pti",
424 		.type	= INTEL_TH_OUTPUT,
425 		.otype	= GTH_PTI,
426 		.scrpd	= SCRPD_PTI_IS_PRIM_DEST,
427 	},
428 	{
429 		.nres	= 1,
430 		.res	= {
431 			{
432 				.start	= REG_DCIH_OFFSET,
433 				.end	= REG_DCIH_OFFSET + REG_DCIH_LENGTH - 1,
434 				.flags	= IORESOURCE_MEM,
435 			},
436 		},
437 		.id	= -1,
438 		.name	= "dcih",
439 		.type	= INTEL_TH_OUTPUT,
440 	},
441 };
442 
443 static int intel_th_populate(struct intel_th *th, struct resource *devres,
444 			     unsigned int ndevres, int irq)
445 {
446 	struct resource res[3];
447 	unsigned int req = 0;
448 	int i, err;
449 
450 	/* create devices for each intel_th_subdevice */
451 	for (i = 0; i < ARRAY_SIZE(intel_th_subdevices); i++) {
452 		struct intel_th_subdevice *subdev = &intel_th_subdevices[i];
453 		struct intel_th_device *thdev;
454 		int r;
455 
456 		thdev = intel_th_device_alloc(th, subdev->type, subdev->name,
457 					      subdev->id);
458 		if (!thdev) {
459 			err = -ENOMEM;
460 			goto kill_subdevs;
461 		}
462 
463 		memcpy(res, subdev->res,
464 		       sizeof(struct resource) * subdev->nres);
465 
466 		for (r = 0; r < subdev->nres; r++) {
467 			int bar = TH_MMIO_CONFIG;
468 
469 			/*
470 			 * Take .end == 0 to mean 'take the whole bar',
471 			 * .start then tells us which bar it is. Default to
472 			 * TH_MMIO_CONFIG.
473 			 */
474 			if (!res[r].end && res[r].flags == IORESOURCE_MEM) {
475 				bar = res[r].start;
476 				res[r].start = 0;
477 				res[r].end = resource_size(&devres[bar]) - 1;
478 			}
479 
480 			if (res[r].flags & IORESOURCE_MEM) {
481 				res[r].start	+= devres[bar].start;
482 				res[r].end	+= devres[bar].start;
483 
484 				dev_dbg(th->dev, "%s:%d @ %pR\n",
485 					subdev->name, r, &res[r]);
486 			} else if (res[r].flags & IORESOURCE_IRQ) {
487 				res[r].start	= irq;
488 			}
489 		}
490 
491 		err = intel_th_device_add_resources(thdev, res, subdev->nres);
492 		if (err) {
493 			put_device(&thdev->dev);
494 			goto kill_subdevs;
495 		}
496 
497 		if (subdev->type == INTEL_TH_OUTPUT) {
498 			thdev->dev.devt = MKDEV(th->major, i);
499 			thdev->output.type = subdev->otype;
500 			thdev->output.port = -1;
501 			thdev->output.scratchpad = subdev->scrpd;
502 		}
503 
504 		err = device_add(&thdev->dev);
505 		if (err) {
506 			put_device(&thdev->dev);
507 			goto kill_subdevs;
508 		}
509 
510 		/* need switch driver to be loaded to enumerate the rest */
511 		if (subdev->type == INTEL_TH_SWITCH && !req) {
512 			th->hub = thdev;
513 			err = request_module("intel_th_%s", subdev->name);
514 			if (!err)
515 				req++;
516 		}
517 
518 		th->thdev[i] = thdev;
519 	}
520 
521 	return 0;
522 
523 kill_subdevs:
524 	for (i-- ; i >= 0; i--)
525 		intel_th_device_remove(th->thdev[i]);
526 
527 	return err;
528 }
529 
530 static int match_devt(struct device *dev, void *data)
531 {
532 	dev_t devt = (dev_t)(unsigned long)data;
533 
534 	return dev->devt == devt;
535 }
536 
537 static int intel_th_output_open(struct inode *inode, struct file *file)
538 {
539 	const struct file_operations *fops;
540 	struct intel_th_driver *thdrv;
541 	struct device *dev;
542 	int err;
543 
544 	dev = bus_find_device(&intel_th_bus, NULL,
545 			      (void *)(unsigned long)inode->i_rdev,
546 			      match_devt);
547 	if (!dev || !dev->driver)
548 		return -ENODEV;
549 
550 	thdrv = to_intel_th_driver(dev->driver);
551 	fops = fops_get(thdrv->fops);
552 	if (!fops)
553 		return -ENODEV;
554 
555 	replace_fops(file, fops);
556 
557 	file->private_data = to_intel_th_device(dev);
558 
559 	if (file->f_op->open) {
560 		err = file->f_op->open(inode, file);
561 		return err;
562 	}
563 
564 	return 0;
565 }
566 
567 static const struct file_operations intel_th_output_fops = {
568 	.open	= intel_th_output_open,
569 	.llseek	= noop_llseek,
570 };
571 
572 /**
573  * intel_th_alloc() - allocate a new Intel TH device and its subdevices
574  * @dev:	parent device
575  * @devres:	parent's resources
576  * @ndevres:	number of resources
577  * @irq:	irq number
578  */
579 struct intel_th *
580 intel_th_alloc(struct device *dev, struct resource *devres,
581 	       unsigned int ndevres, int irq)
582 {
583 	struct intel_th *th;
584 	int err;
585 
586 	th = kzalloc(sizeof(*th), GFP_KERNEL);
587 	if (!th)
588 		return ERR_PTR(-ENOMEM);
589 
590 	th->id = ida_simple_get(&intel_th_ida, 0, 0, GFP_KERNEL);
591 	if (th->id < 0) {
592 		err = th->id;
593 		goto err_alloc;
594 	}
595 
596 	th->major = __register_chrdev(0, 0, TH_POSSIBLE_OUTPUTS,
597 				      "intel_th/output", &intel_th_output_fops);
598 	if (th->major < 0) {
599 		err = th->major;
600 		goto err_ida;
601 	}
602 	th->dev = dev;
603 
604 	dev_set_drvdata(dev, th);
605 
606 	err = intel_th_populate(th, devres, ndevres, irq);
607 	if (err)
608 		goto err_chrdev;
609 
610 	return th;
611 
612 err_chrdev:
613 	__unregister_chrdev(th->major, 0, TH_POSSIBLE_OUTPUTS,
614 			    "intel_th/output");
615 
616 err_ida:
617 	ida_simple_remove(&intel_th_ida, th->id);
618 
619 err_alloc:
620 	kfree(th);
621 
622 	return ERR_PTR(err);
623 }
624 EXPORT_SYMBOL_GPL(intel_th_alloc);
625 
626 void intel_th_free(struct intel_th *th)
627 {
628 	int i;
629 
630 	for (i = 0; i < TH_SUBDEVICE_MAX; i++)
631 		if (th->thdev[i] != th->hub)
632 			intel_th_device_remove(th->thdev[i]);
633 
634 	intel_th_device_remove(th->hub);
635 
636 	__unregister_chrdev(th->major, 0, TH_POSSIBLE_OUTPUTS,
637 			    "intel_th/output");
638 
639 	ida_simple_remove(&intel_th_ida, th->id);
640 
641 	kfree(th);
642 }
643 EXPORT_SYMBOL_GPL(intel_th_free);
644 
645 /**
646  * intel_th_trace_enable() - enable tracing for an output device
647  * @thdev:	output device that requests tracing be enabled
648  */
649 int intel_th_trace_enable(struct intel_th_device *thdev)
650 {
651 	struct intel_th_device *hub = to_intel_th_device(thdev->dev.parent);
652 	struct intel_th_driver *hubdrv = to_intel_th_driver(hub->dev.driver);
653 
654 	if (WARN_ON_ONCE(hub->type != INTEL_TH_SWITCH))
655 		return -EINVAL;
656 
657 	if (WARN_ON_ONCE(thdev->type != INTEL_TH_OUTPUT))
658 		return -EINVAL;
659 
660 	hubdrv->enable(hub, &thdev->output);
661 
662 	return 0;
663 }
664 EXPORT_SYMBOL_GPL(intel_th_trace_enable);
665 
666 /**
667  * intel_th_trace_disable() - disable tracing for an output device
668  * @thdev:	output device that requests tracing be disabled
669  */
670 int intel_th_trace_disable(struct intel_th_device *thdev)
671 {
672 	struct intel_th_device *hub = to_intel_th_device(thdev->dev.parent);
673 	struct intel_th_driver *hubdrv = to_intel_th_driver(hub->dev.driver);
674 
675 	WARN_ON_ONCE(hub->type != INTEL_TH_SWITCH);
676 	if (WARN_ON_ONCE(thdev->type != INTEL_TH_OUTPUT))
677 		return -EINVAL;
678 
679 	hubdrv->disable(hub, &thdev->output);
680 
681 	return 0;
682 }
683 EXPORT_SYMBOL_GPL(intel_th_trace_disable);
684 
685 int intel_th_set_output(struct intel_th_device *thdev,
686 			unsigned int master)
687 {
688 	struct intel_th_device *hub = to_intel_th_device(thdev->dev.parent);
689 	struct intel_th_driver *hubdrv = to_intel_th_driver(hub->dev.driver);
690 
691 	if (!hubdrv->set_output)
692 		return -ENOTSUPP;
693 
694 	return hubdrv->set_output(hub, master);
695 }
696 EXPORT_SYMBOL_GPL(intel_th_set_output);
697 
698 static int __init intel_th_init(void)
699 {
700 	intel_th_debug_init();
701 
702 	return bus_register(&intel_th_bus);
703 }
704 subsys_initcall(intel_th_init);
705 
706 static void __exit intel_th_exit(void)
707 {
708 	intel_th_debug_done();
709 
710 	bus_unregister(&intel_th_bus);
711 }
712 module_exit(intel_th_exit);
713 
714 MODULE_LICENSE("GPL v2");
715 MODULE_DESCRIPTION("Intel(R) Trace Hub controller driver");
716 MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>");
717