xref: /linux/drivers/cdx/cdx.c (revision 1553a1c48281243359a9529a10ddb551f3b967ab)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * CDX bus driver.
4  *
5  * Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
6  */
7 
8 /*
9  * Architecture Overview
10  * =====================
11  * CDX is a Hardware Architecture designed for AMD FPGA devices. It
12  * consists of sophisticated mechanism for interaction between FPGA,
13  * Firmware and the APUs (Application CPUs).
14  *
15  * Firmware resides on RPU (Realtime CPUs) which interacts with
16  * the FPGA program manager and the APUs. The RPU provides memory-mapped
17  * interface (RPU if) which is used to communicate with APUs.
18  *
19  * The diagram below shows an overview of the CDX architecture:
20  *
21  *          +--------------------------------------+
22  *          |    Application CPUs (APU)            |
23  *          |                                      |
24  *          |                    CDX device drivers|
25  *          |     Linux OS                |        |
26  *          |                        CDX bus       |
27  *          |                             |        |
28  *          |                     CDX controller   |
29  *          |                             |        |
30  *          +-----------------------------|--------+
31  *                                        | (discover, config,
32  *                                        |  reset, rescan)
33  *                                        |
34  *          +------------------------| RPU if |----+
35  *          |                             |        |
36  *          |                             V        |
37  *          |          Realtime CPUs (RPU)         |
38  *          |                                      |
39  *          +--------------------------------------+
40  *                                |
41  *          +---------------------|----------------+
42  *          |  FPGA               |                |
43  *          |      +-----------------------+       |
44  *          |      |           |           |       |
45  *          | +-------+    +-------+   +-------+   |
46  *          | | dev 1 |    | dev 2 |   | dev 3 |   |
47  *          | +-------+    +-------+   +-------+   |
48  *          +--------------------------------------+
49  *
50  * The RPU firmware extracts the device information from the loaded FPGA
51  * image and implements a mechanism that allows the APU drivers to
52  * enumerate such devices (device personality and resource details) via
53  * a dedicated communication channel. RPU mediates operations such as
54  * discover, reset and rescan of the FPGA devices for the APU. This is
55  * done using memory mapped interface provided by the RPU to APU.
56  */
57 
58 #include <linux/init.h>
59 #include <linux/irqdomain.h>
60 #include <linux/kernel.h>
61 #include <linux/of.h>
62 #include <linux/of_device.h>
63 #include <linux/of_platform.h>
64 #include <linux/platform_device.h>
65 #include <linux/slab.h>
66 #include <linux/mm.h>
67 #include <linux/idr.h>
68 #include <linux/cdx/cdx_bus.h>
69 #include <linux/iommu.h>
70 #include <linux/dma-map-ops.h>
71 #include <linux/debugfs.h>
72 #include "cdx.h"
73 
74 /* Default DMA mask for devices on a CDX bus */
75 #define CDX_DEFAULT_DMA_MASK	(~0ULL)
76 #define MAX_CDX_CONTROLLERS 16
77 
78 /* IDA for CDX controllers registered with the CDX bus */
79 static DEFINE_IDA(cdx_controller_ida);
80 /* Lock to protect controller ops */
81 static DEFINE_MUTEX(cdx_controller_lock);
82 /* Debugfs dir for cdx bus */
83 static struct dentry *cdx_debugfs_dir;
84 
85 static char *compat_node_name = "xlnx,versal-net-cdx";
86 
87 static void cdx_destroy_res_attr(struct cdx_device *cdx_dev, int num);
88 
89 /**
90  * cdx_dev_reset - Reset a CDX device
91  * @dev: CDX device
92  *
93  * Return: -errno on failure, 0 on success.
94  */
95 int cdx_dev_reset(struct device *dev)
96 {
97 	struct cdx_device *cdx_dev = to_cdx_device(dev);
98 	struct cdx_controller *cdx = cdx_dev->cdx;
99 	struct cdx_device_config dev_config = {0};
100 	struct cdx_driver *cdx_drv;
101 	int ret;
102 
103 	cdx_drv = to_cdx_driver(dev->driver);
104 	/* Notify driver that device is being reset */
105 	if (cdx_drv && cdx_drv->reset_prepare)
106 		cdx_drv->reset_prepare(cdx_dev);
107 
108 	dev_config.type = CDX_DEV_RESET_CONF;
109 	ret = cdx->ops->dev_configure(cdx, cdx_dev->bus_num,
110 				      cdx_dev->dev_num, &dev_config);
111 	if (ret)
112 		dev_err(dev, "cdx device reset failed\n");
113 
114 	/* Notify driver that device reset is complete */
115 	if (cdx_drv && cdx_drv->reset_done)
116 		cdx_drv->reset_done(cdx_dev);
117 
118 	return ret;
119 }
120 EXPORT_SYMBOL_GPL(cdx_dev_reset);
121 
122 /**
123  * reset_cdx_device - Reset a CDX device
124  * @dev: CDX device
125  * @data: This is always passed as NULL, and is not used in this API,
126  *    but is required here as the device_for_each_child() API expects
127  *    the passed function to have this as an argument.
128  *
129  * Return: -errno on failure, 0 on success.
130  */
131 static int reset_cdx_device(struct device *dev, void *data)
132 {
133 	return cdx_dev_reset(dev);
134 }
135 
136 /**
137  * cdx_unregister_device - Unregister a CDX device
138  * @dev: CDX device
139  * @data: This is always passed as NULL, and is not used in this API,
140  *	  but is required here as the bus_for_each_dev() API expects
141  *	  the passed function (cdx_unregister_device) to have this
142  *	  as an argument.
143  *
144  * Return: 0 on success.
145  */
146 static int cdx_unregister_device(struct device *dev,
147 				 void *data)
148 {
149 	struct cdx_device *cdx_dev = to_cdx_device(dev);
150 	struct cdx_controller *cdx = cdx_dev->cdx;
151 
152 	if (cdx_dev->is_bus) {
153 		device_for_each_child(dev, NULL, cdx_unregister_device);
154 		if (cdx_dev->enabled && cdx->ops->bus_disable)
155 			cdx->ops->bus_disable(cdx, cdx_dev->bus_num);
156 	} else {
157 		cdx_destroy_res_attr(cdx_dev, MAX_CDX_DEV_RESOURCES);
158 		debugfs_remove_recursive(cdx_dev->debugfs_dir);
159 		kfree(cdx_dev->driver_override);
160 		cdx_dev->driver_override = NULL;
161 	}
162 
163 	/*
164 	 * Do not free cdx_dev here as it would be freed in
165 	 * cdx_device_release() called from within put_device().
166 	 */
167 	device_del(&cdx_dev->dev);
168 	put_device(&cdx_dev->dev);
169 
170 	return 0;
171 }
172 
173 static void cdx_unregister_devices(struct bus_type *bus)
174 {
175 	/* Reset all the devices attached to cdx bus */
176 	bus_for_each_dev(bus, NULL, NULL, cdx_unregister_device);
177 }
178 
179 /**
180  * cdx_match_one_device - Tell if a CDX device structure has a matching
181  *			  CDX device id structure
182  * @id: single CDX device id structure to match
183  * @dev: the CDX device structure to match against
184  *
185  * Return: matching cdx_device_id structure or NULL if there is no match.
186  */
187 static inline const struct cdx_device_id *
188 cdx_match_one_device(const struct cdx_device_id *id,
189 		     const struct cdx_device *dev)
190 {
191 	/* Use vendor ID and device ID for matching */
192 	if ((id->vendor == CDX_ANY_ID || id->vendor == dev->vendor) &&
193 	    (id->device == CDX_ANY_ID || id->device == dev->device) &&
194 	    (id->subvendor == CDX_ANY_ID || id->subvendor == dev->subsystem_vendor) &&
195 	    (id->subdevice == CDX_ANY_ID || id->subdevice == dev->subsystem_device) &&
196 	    !((id->class ^ dev->class) & id->class_mask))
197 		return id;
198 	return NULL;
199 }
200 
201 /**
202  * cdx_match_id - See if a CDX device matches a given cdx_id table
203  * @ids: array of CDX device ID structures to search in
204  * @dev: the CDX device structure to match against.
205  *
206  * Used by a driver to check whether a CDX device is in its list of
207  * supported devices. Returns the matching cdx_device_id structure or
208  * NULL if there is no match.
209  *
210  * Return: matching cdx_device_id structure or NULL if there is no match.
211  */
212 static inline const struct cdx_device_id *
213 cdx_match_id(const struct cdx_device_id *ids, struct cdx_device *dev)
214 {
215 	if (ids) {
216 		while (ids->vendor || ids->device) {
217 			if (cdx_match_one_device(ids, dev))
218 				return ids;
219 			ids++;
220 		}
221 	}
222 	return NULL;
223 }
224 
225 int cdx_set_master(struct cdx_device *cdx_dev)
226 {
227 	struct cdx_controller *cdx = cdx_dev->cdx;
228 	struct cdx_device_config dev_config;
229 	int ret = -EOPNOTSUPP;
230 
231 	dev_config.type = CDX_DEV_BUS_MASTER_CONF;
232 	dev_config.bus_master_enable = true;
233 	if (cdx->ops->dev_configure)
234 		ret = cdx->ops->dev_configure(cdx, cdx_dev->bus_num,
235 					      cdx_dev->dev_num, &dev_config);
236 
237 	return ret;
238 }
239 EXPORT_SYMBOL_GPL(cdx_set_master);
240 
241 int cdx_clear_master(struct cdx_device *cdx_dev)
242 {
243 	struct cdx_controller *cdx = cdx_dev->cdx;
244 	struct cdx_device_config dev_config;
245 	int ret = -EOPNOTSUPP;
246 
247 	dev_config.type = CDX_DEV_BUS_MASTER_CONF;
248 	dev_config.bus_master_enable = false;
249 	if (cdx->ops->dev_configure)
250 		ret = cdx->ops->dev_configure(cdx, cdx_dev->bus_num,
251 					      cdx_dev->dev_num, &dev_config);
252 
253 	return ret;
254 }
255 EXPORT_SYMBOL_GPL(cdx_clear_master);
256 
257 /**
258  * cdx_bus_match - device to driver matching callback
259  * @dev: the cdx device to match against
260  * @drv: the device driver to search for matching cdx device
261  * structures
262  *
263  * Return: true on success, false otherwise.
264  */
265 static int cdx_bus_match(struct device *dev, struct device_driver *drv)
266 {
267 	struct cdx_device *cdx_dev = to_cdx_device(dev);
268 	struct cdx_driver *cdx_drv = to_cdx_driver(drv);
269 	const struct cdx_device_id *found_id = NULL;
270 	const struct cdx_device_id *ids;
271 
272 	if (cdx_dev->is_bus)
273 		return false;
274 
275 	ids = cdx_drv->match_id_table;
276 
277 	/* When driver_override is set, only bind to the matching driver */
278 	if (cdx_dev->driver_override && strcmp(cdx_dev->driver_override, drv->name))
279 		return false;
280 
281 	found_id = cdx_match_id(ids, cdx_dev);
282 	if (!found_id)
283 		return false;
284 
285 	do {
286 		/*
287 		 * In case override_only was set, enforce driver_override
288 		 * matching.
289 		 */
290 		if (!found_id->override_only)
291 			return true;
292 		if (cdx_dev->driver_override)
293 			return true;
294 
295 		ids = found_id + 1;
296 		found_id = cdx_match_id(ids, cdx_dev);
297 	} while (found_id);
298 
299 	return false;
300 }
301 
302 static int cdx_probe(struct device *dev)
303 {
304 	struct cdx_driver *cdx_drv = to_cdx_driver(dev->driver);
305 	struct cdx_device *cdx_dev = to_cdx_device(dev);
306 	struct cdx_controller *cdx = cdx_dev->cdx;
307 	int error;
308 
309 	/*
310 	 * Setup MSI device data so that generic MSI alloc/free can
311 	 * be used by the device driver.
312 	 */
313 	if (cdx->msi_domain) {
314 		error = msi_setup_device_data(&cdx_dev->dev);
315 		if (error)
316 			return error;
317 	}
318 
319 	error = cdx_drv->probe(cdx_dev);
320 	if (error) {
321 		dev_err_probe(dev, error, "%s failed\n", __func__);
322 		return error;
323 	}
324 
325 	return 0;
326 }
327 
328 static void cdx_remove(struct device *dev)
329 {
330 	struct cdx_driver *cdx_drv = to_cdx_driver(dev->driver);
331 	struct cdx_device *cdx_dev = to_cdx_device(dev);
332 
333 	if (cdx_drv && cdx_drv->remove)
334 		cdx_drv->remove(cdx_dev);
335 }
336 
337 static void cdx_shutdown(struct device *dev)
338 {
339 	struct cdx_driver *cdx_drv = to_cdx_driver(dev->driver);
340 	struct cdx_device *cdx_dev = to_cdx_device(dev);
341 
342 	if (cdx_drv && cdx_drv->shutdown)
343 		cdx_drv->shutdown(cdx_dev);
344 }
345 
346 static int cdx_dma_configure(struct device *dev)
347 {
348 	struct cdx_driver *cdx_drv = to_cdx_driver(dev->driver);
349 	struct cdx_device *cdx_dev = to_cdx_device(dev);
350 	struct cdx_controller *cdx = cdx_dev->cdx;
351 	u32 input_id = cdx_dev->req_id;
352 	int ret;
353 
354 	ret = of_dma_configure_id(dev, cdx->dev->of_node, 0, &input_id);
355 	if (ret && ret != -EPROBE_DEFER) {
356 		dev_err(dev, "of_dma_configure_id() failed\n");
357 		return ret;
358 	}
359 
360 	if (!ret && !cdx_drv->driver_managed_dma) {
361 		ret = iommu_device_use_default_domain(dev);
362 		if (ret)
363 			arch_teardown_dma_ops(dev);
364 	}
365 
366 	return 0;
367 }
368 
369 static void cdx_dma_cleanup(struct device *dev)
370 {
371 	struct cdx_driver *cdx_drv = to_cdx_driver(dev->driver);
372 
373 	if (!cdx_drv->driver_managed_dma)
374 		iommu_device_unuse_default_domain(dev);
375 }
376 
377 /* show configuration fields */
378 #define cdx_config_attr(field, format_string)	\
379 static ssize_t	\
380 field##_show(struct device *dev, struct device_attribute *attr, char *buf)	\
381 {	\
382 	struct cdx_device *cdx_dev = to_cdx_device(dev);	\
383 	return sysfs_emit(buf, format_string, cdx_dev->field);	\
384 }	\
385 static DEVICE_ATTR_RO(field)
386 
387 cdx_config_attr(vendor, "0x%04x\n");
388 cdx_config_attr(device, "0x%04x\n");
389 cdx_config_attr(subsystem_vendor, "0x%04x\n");
390 cdx_config_attr(subsystem_device, "0x%04x\n");
391 cdx_config_attr(revision, "0x%02x\n");
392 cdx_config_attr(class, "0x%06x\n");
393 
394 static ssize_t remove_store(struct device *dev,
395 			    struct device_attribute *attr,
396 			    const char *buf, size_t count)
397 {
398 	bool val;
399 
400 	if (kstrtobool(buf, &val) < 0)
401 		return -EINVAL;
402 
403 	if (!val)
404 		return -EINVAL;
405 
406 	if (device_remove_file_self(dev, attr)) {
407 		int ret;
408 
409 		ret = cdx_unregister_device(dev, NULL);
410 		if (ret)
411 			return ret;
412 	}
413 
414 	return count;
415 }
416 static DEVICE_ATTR_WO(remove);
417 
418 static ssize_t reset_store(struct device *dev, struct device_attribute *attr,
419 			   const char *buf, size_t count)
420 {
421 	struct cdx_device *cdx_dev = to_cdx_device(dev);
422 	bool val;
423 	int ret;
424 
425 	if (kstrtobool(buf, &val) < 0)
426 		return -EINVAL;
427 
428 	if (!val)
429 		return -EINVAL;
430 
431 	if (cdx_dev->is_bus)
432 		/* Reset all the devices attached to cdx bus */
433 		ret = device_for_each_child(dev, NULL, reset_cdx_device);
434 	else
435 		ret = cdx_dev_reset(dev);
436 
437 	return ret < 0 ? ret : count;
438 }
439 static DEVICE_ATTR_WO(reset);
440 
441 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
442 			     char *buf)
443 {
444 	struct cdx_device *cdx_dev = to_cdx_device(dev);
445 
446 	return sprintf(buf, "cdx:v%04Xd%04Xsv%04Xsd%04Xc%06X\n", cdx_dev->vendor,
447 			cdx_dev->device, cdx_dev->subsystem_vendor, cdx_dev->subsystem_device,
448 			cdx_dev->class);
449 }
450 static DEVICE_ATTR_RO(modalias);
451 
452 static ssize_t driver_override_store(struct device *dev,
453 				     struct device_attribute *attr,
454 				     const char *buf, size_t count)
455 {
456 	struct cdx_device *cdx_dev = to_cdx_device(dev);
457 	int ret;
458 
459 	if (WARN_ON(dev->bus != &cdx_bus_type))
460 		return -EINVAL;
461 
462 	ret = driver_set_override(dev, &cdx_dev->driver_override, buf, count);
463 	if (ret)
464 		return ret;
465 
466 	return count;
467 }
468 
469 static ssize_t driver_override_show(struct device *dev,
470 				    struct device_attribute *attr, char *buf)
471 {
472 	struct cdx_device *cdx_dev = to_cdx_device(dev);
473 
474 	return sysfs_emit(buf, "%s\n", cdx_dev->driver_override);
475 }
476 static DEVICE_ATTR_RW(driver_override);
477 
478 static ssize_t enable_store(struct device *dev, struct device_attribute *attr,
479 			    const char *buf, size_t count)
480 {
481 	struct cdx_device *cdx_dev = to_cdx_device(dev);
482 	struct cdx_controller *cdx = cdx_dev->cdx;
483 	bool enable;
484 	int ret;
485 
486 	if (kstrtobool(buf, &enable) < 0)
487 		return -EINVAL;
488 
489 	if (enable == cdx_dev->enabled)
490 		return count;
491 
492 	if (enable && cdx->ops->bus_enable)
493 		ret = cdx->ops->bus_enable(cdx, cdx_dev->bus_num);
494 	else if (!enable && cdx->ops->bus_disable)
495 		ret = cdx->ops->bus_disable(cdx, cdx_dev->bus_num);
496 	else
497 		ret = -EOPNOTSUPP;
498 
499 	if (!ret)
500 		cdx_dev->enabled = enable;
501 
502 	return ret < 0 ? ret : count;
503 }
504 
505 static ssize_t enable_show(struct device *dev, struct device_attribute *attr, char *buf)
506 {
507 	struct cdx_device *cdx_dev = to_cdx_device(dev);
508 
509 	return sysfs_emit(buf, "%u\n", cdx_dev->enabled);
510 }
511 static DEVICE_ATTR_RW(enable);
512 
513 static umode_t cdx_dev_attrs_are_visible(struct kobject *kobj, struct attribute *a, int n)
514 {
515 	struct device *dev = kobj_to_dev(kobj);
516 	struct cdx_device *cdx_dev;
517 
518 	cdx_dev = to_cdx_device(dev);
519 	if (!cdx_dev->is_bus)
520 		return a->mode;
521 
522 	return 0;
523 }
524 
525 static umode_t cdx_bus_attrs_are_visible(struct kobject *kobj, struct attribute *a, int n)
526 {
527 	struct device *dev = kobj_to_dev(kobj);
528 	struct cdx_device *cdx_dev;
529 
530 	cdx_dev = to_cdx_device(dev);
531 	if (cdx_dev->is_bus)
532 		return a->mode;
533 
534 	return 0;
535 }
536 
537 static struct attribute *cdx_dev_attrs[] = {
538 	&dev_attr_remove.attr,
539 	&dev_attr_reset.attr,
540 	&dev_attr_vendor.attr,
541 	&dev_attr_device.attr,
542 	&dev_attr_subsystem_vendor.attr,
543 	&dev_attr_subsystem_device.attr,
544 	&dev_attr_class.attr,
545 	&dev_attr_revision.attr,
546 	&dev_attr_modalias.attr,
547 	&dev_attr_driver_override.attr,
548 	NULL,
549 };
550 
551 static const struct attribute_group cdx_dev_group = {
552 	.attrs = cdx_dev_attrs,
553 	.is_visible = cdx_dev_attrs_are_visible,
554 };
555 
556 static struct attribute *cdx_bus_dev_attrs[] = {
557 	&dev_attr_enable.attr,
558 	&dev_attr_reset.attr,
559 	NULL,
560 };
561 
562 static const struct attribute_group cdx_bus_dev_group = {
563 	.attrs = cdx_bus_dev_attrs,
564 	.is_visible = cdx_bus_attrs_are_visible,
565 };
566 
567 static const struct attribute_group *cdx_dev_groups[] = {
568 	&cdx_dev_group,
569 	&cdx_bus_dev_group,
570 	NULL,
571 };
572 
573 static int cdx_debug_resource_show(struct seq_file *s, void *data)
574 {
575 	struct cdx_device *cdx_dev = s->private;
576 	int i;
577 
578 	for (i = 0; i < MAX_CDX_DEV_RESOURCES; i++) {
579 		struct resource *res =  &cdx_dev->res[i];
580 
581 		seq_printf(s, "%pr\n", res);
582 	}
583 
584 	return 0;
585 }
586 DEFINE_SHOW_ATTRIBUTE(cdx_debug_resource);
587 
588 static void cdx_device_debugfs_init(struct cdx_device *cdx_dev)
589 {
590 	cdx_dev->debugfs_dir = debugfs_create_dir(dev_name(&cdx_dev->dev), cdx_debugfs_dir);
591 	if (IS_ERR(cdx_dev->debugfs_dir))
592 		return;
593 
594 	debugfs_create_file("resource", 0444, cdx_dev->debugfs_dir, cdx_dev,
595 			    &cdx_debug_resource_fops);
596 }
597 
598 static ssize_t rescan_store(const struct bus_type *bus,
599 			    const char *buf, size_t count)
600 {
601 	struct cdx_controller *cdx;
602 	struct platform_device *pd;
603 	struct device_node *np;
604 	bool val;
605 
606 	if (kstrtobool(buf, &val) < 0)
607 		return -EINVAL;
608 
609 	if (!val)
610 		return -EINVAL;
611 
612 	mutex_lock(&cdx_controller_lock);
613 
614 	/* Unregister all the devices on the bus */
615 	cdx_unregister_devices(&cdx_bus_type);
616 
617 	/* Rescan all the devices */
618 	for_each_compatible_node(np, NULL, compat_node_name) {
619 		pd = of_find_device_by_node(np);
620 		if (!pd) {
621 			of_node_put(np);
622 			count = -EINVAL;
623 			goto unlock;
624 		}
625 
626 		cdx = platform_get_drvdata(pd);
627 		if (cdx && cdx->controller_registered && cdx->ops->scan)
628 			cdx->ops->scan(cdx);
629 
630 		put_device(&pd->dev);
631 	}
632 
633 unlock:
634 	mutex_unlock(&cdx_controller_lock);
635 
636 	return count;
637 }
638 static BUS_ATTR_WO(rescan);
639 
640 static struct attribute *cdx_bus_attrs[] = {
641 	&bus_attr_rescan.attr,
642 	NULL,
643 };
644 ATTRIBUTE_GROUPS(cdx_bus);
645 
646 struct bus_type cdx_bus_type = {
647 	.name		= "cdx",
648 	.match		= cdx_bus_match,
649 	.probe		= cdx_probe,
650 	.remove		= cdx_remove,
651 	.shutdown	= cdx_shutdown,
652 	.dma_configure	= cdx_dma_configure,
653 	.dma_cleanup	= cdx_dma_cleanup,
654 	.bus_groups	= cdx_bus_groups,
655 	.dev_groups	= cdx_dev_groups,
656 };
657 EXPORT_SYMBOL_GPL(cdx_bus_type);
658 
659 int __cdx_driver_register(struct cdx_driver *cdx_driver,
660 			  struct module *owner)
661 {
662 	int error;
663 
664 	cdx_driver->driver.owner = owner;
665 	cdx_driver->driver.bus = &cdx_bus_type;
666 
667 	error = driver_register(&cdx_driver->driver);
668 	if (error) {
669 		pr_err("driver_register() failed for %s: %d\n",
670 		       cdx_driver->driver.name, error);
671 		return error;
672 	}
673 
674 	return 0;
675 }
676 EXPORT_SYMBOL_GPL(__cdx_driver_register);
677 
678 void cdx_driver_unregister(struct cdx_driver *cdx_driver)
679 {
680 	driver_unregister(&cdx_driver->driver);
681 }
682 EXPORT_SYMBOL_GPL(cdx_driver_unregister);
683 
684 static void cdx_device_release(struct device *dev)
685 {
686 	struct cdx_device *cdx_dev = to_cdx_device(dev);
687 
688 	kfree(cdx_dev);
689 }
690 
691 static const struct vm_operations_struct cdx_phys_vm_ops = {
692 #ifdef CONFIG_HAVE_IOREMAP_PROT
693 	.access = generic_access_phys,
694 #endif
695 };
696 
697 /**
698  * cdx_mmap_resource - map a CDX resource into user memory space
699  * @fp: File pointer. Not used in this function, but required where
700  *      this API is registered as a callback.
701  * @kobj: kobject for mapping
702  * @attr: struct bin_attribute for the file being mapped
703  * @vma: struct vm_area_struct passed into the mmap
704  *
705  * Use the regular CDX mapping routines to map a CDX resource into userspace.
706  *
707  * Return: true on success, false otherwise.
708  */
709 static int cdx_mmap_resource(struct file *fp, struct kobject *kobj,
710 			     struct bin_attribute *attr,
711 			     struct vm_area_struct *vma)
712 {
713 	struct cdx_device *cdx_dev = to_cdx_device(kobj_to_dev(kobj));
714 	int num = (unsigned long)attr->private;
715 	struct resource *res;
716 	unsigned long size;
717 
718 	res = &cdx_dev->res[num];
719 	if (iomem_is_exclusive(res->start))
720 		return -EINVAL;
721 
722 	/* Make sure the caller is mapping a valid resource for this device */
723 	size = ((cdx_resource_len(cdx_dev, num) - 1) >> PAGE_SHIFT) + 1;
724 	if (vma->vm_pgoff + vma_pages(vma) > size)
725 		return -EINVAL;
726 
727 	/*
728 	 * Map memory region and vm->vm_pgoff is expected to be an
729 	 * offset within that region.
730 	 */
731 	vma->vm_page_prot = pgprot_device(vma->vm_page_prot);
732 	vma->vm_pgoff += (cdx_resource_start(cdx_dev, num) >> PAGE_SHIFT);
733 	vma->vm_ops = &cdx_phys_vm_ops;
734 	return io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
735 				  vma->vm_end - vma->vm_start,
736 				  vma->vm_page_prot);
737 }
738 
739 static void cdx_destroy_res_attr(struct cdx_device *cdx_dev, int num)
740 {
741 	int i;
742 
743 	/* removing the bin attributes */
744 	for (i = 0; i < num; i++) {
745 		struct bin_attribute *res_attr;
746 
747 		res_attr = cdx_dev->res_attr[i];
748 		if (res_attr) {
749 			sysfs_remove_bin_file(&cdx_dev->dev.kobj, res_attr);
750 			kfree(res_attr);
751 		}
752 	}
753 }
754 
755 #define CDX_RES_ATTR_NAME_LEN	10
756 static int cdx_create_res_attr(struct cdx_device *cdx_dev, int num)
757 {
758 	struct bin_attribute *res_attr;
759 	char *res_attr_name;
760 	int ret;
761 
762 	res_attr = kzalloc(sizeof(*res_attr) + CDX_RES_ATTR_NAME_LEN, GFP_ATOMIC);
763 	if (!res_attr)
764 		return -ENOMEM;
765 
766 	res_attr_name = (char *)(res_attr + 1);
767 
768 	sysfs_bin_attr_init(res_attr);
769 
770 	cdx_dev->res_attr[num] = res_attr;
771 	sprintf(res_attr_name, "resource%d", num);
772 
773 	res_attr->mmap = cdx_mmap_resource;
774 	res_attr->attr.name = res_attr_name;
775 	res_attr->attr.mode = 0600;
776 	res_attr->size = cdx_resource_len(cdx_dev, num);
777 	res_attr->private = (void *)(unsigned long)num;
778 	ret = sysfs_create_bin_file(&cdx_dev->dev.kobj, res_attr);
779 	if (ret)
780 		kfree(res_attr);
781 
782 	return ret;
783 }
784 
785 int cdx_device_add(struct cdx_dev_params *dev_params)
786 {
787 	struct cdx_controller *cdx = dev_params->cdx;
788 	struct cdx_device *cdx_dev;
789 	int ret, i;
790 
791 	cdx_dev = kzalloc(sizeof(*cdx_dev), GFP_KERNEL);
792 	if (!cdx_dev)
793 		return -ENOMEM;
794 
795 	/* Populate resource */
796 	memcpy(cdx_dev->res, dev_params->res, sizeof(struct resource) *
797 		dev_params->res_count);
798 	cdx_dev->res_count = dev_params->res_count;
799 
800 	/* Populate CDX dev params */
801 	cdx_dev->req_id = dev_params->req_id;
802 	cdx_dev->msi_dev_id = dev_params->msi_dev_id;
803 	cdx_dev->vendor = dev_params->vendor;
804 	cdx_dev->device = dev_params->device;
805 	cdx_dev->subsystem_vendor = dev_params->subsys_vendor;
806 	cdx_dev->subsystem_device = dev_params->subsys_device;
807 	cdx_dev->class = dev_params->class;
808 	cdx_dev->revision = dev_params->revision;
809 	cdx_dev->bus_num = dev_params->bus_num;
810 	cdx_dev->dev_num = dev_params->dev_num;
811 	cdx_dev->cdx = dev_params->cdx;
812 	cdx_dev->dma_mask = CDX_DEFAULT_DMA_MASK;
813 
814 	/* Initialize generic device */
815 	device_initialize(&cdx_dev->dev);
816 	cdx_dev->dev.parent = dev_params->parent;
817 	cdx_dev->dev.bus = &cdx_bus_type;
818 	cdx_dev->dev.dma_mask = &cdx_dev->dma_mask;
819 	cdx_dev->dev.release = cdx_device_release;
820 	cdx_dev->msi_write_pending = false;
821 	mutex_init(&cdx_dev->irqchip_lock);
822 
823 	/* Set Name */
824 	dev_set_name(&cdx_dev->dev, "cdx-%02x:%02x",
825 		     ((cdx->id << CDX_CONTROLLER_ID_SHIFT) | (cdx_dev->bus_num & CDX_BUS_NUM_MASK)),
826 		     cdx_dev->dev_num);
827 
828 	if (cdx->msi_domain) {
829 		cdx_dev->num_msi = dev_params->num_msi;
830 		dev_set_msi_domain(&cdx_dev->dev, cdx->msi_domain);
831 	}
832 
833 	ret = device_add(&cdx_dev->dev);
834 	if (ret) {
835 		dev_err(&cdx_dev->dev,
836 			"cdx device add failed: %d", ret);
837 		goto fail;
838 	}
839 
840 	/* Create resource<N> attributes */
841 	for (i = 0; i < MAX_CDX_DEV_RESOURCES; i++) {
842 		if (cdx_resource_flags(cdx_dev, i) & IORESOURCE_MEM) {
843 			/* skip empty resources */
844 			if (!cdx_resource_len(cdx_dev, i))
845 				continue;
846 
847 			ret = cdx_create_res_attr(cdx_dev, i);
848 			if (ret != 0) {
849 				dev_err(&cdx_dev->dev,
850 					"cdx device resource<%d> file creation failed: %d", i, ret);
851 				goto resource_create_fail;
852 			}
853 		}
854 	}
855 
856 	cdx_device_debugfs_init(cdx_dev);
857 
858 	return 0;
859 resource_create_fail:
860 	cdx_destroy_res_attr(cdx_dev, i);
861 	device_del(&cdx_dev->dev);
862 fail:
863 	/*
864 	 * Do not free cdx_dev here as it would be freed in
865 	 * cdx_device_release() called from put_device().
866 	 */
867 	put_device(&cdx_dev->dev);
868 
869 	return ret;
870 }
871 EXPORT_SYMBOL_NS_GPL(cdx_device_add, CDX_BUS_CONTROLLER);
872 
873 struct device *cdx_bus_add(struct cdx_controller *cdx, u8 bus_num)
874 {
875 	struct cdx_device *cdx_dev;
876 	int ret;
877 
878 	cdx_dev = kzalloc(sizeof(*cdx_dev), GFP_KERNEL);
879 	if (!cdx_dev)
880 		return NULL;
881 
882 	device_initialize(&cdx_dev->dev);
883 	cdx_dev->cdx = cdx;
884 
885 	cdx_dev->dev.parent = cdx->dev;
886 	cdx_dev->dev.bus = &cdx_bus_type;
887 	cdx_dev->dev.release = cdx_device_release;
888 	cdx_dev->is_bus = true;
889 	cdx_dev->bus_num = bus_num;
890 
891 	dev_set_name(&cdx_dev->dev, "cdx-%02x",
892 		     ((cdx->id << CDX_CONTROLLER_ID_SHIFT) | (bus_num & CDX_BUS_NUM_MASK)));
893 
894 	ret = device_add(&cdx_dev->dev);
895 	if (ret) {
896 		dev_err(&cdx_dev->dev, "cdx bus device add failed: %d\n", ret);
897 		goto device_add_fail;
898 	}
899 
900 	if (cdx->ops->bus_enable) {
901 		ret = cdx->ops->bus_enable(cdx, bus_num);
902 		if (ret && ret != -EALREADY) {
903 			dev_err(cdx->dev, "cdx bus enable failed: %d\n", ret);
904 			goto bus_enable_fail;
905 		}
906 	}
907 
908 	cdx_dev->enabled = true;
909 	return &cdx_dev->dev;
910 
911 bus_enable_fail:
912 	device_del(&cdx_dev->dev);
913 device_add_fail:
914 	put_device(&cdx_dev->dev);
915 
916 	return NULL;
917 }
918 EXPORT_SYMBOL_NS_GPL(cdx_bus_add, CDX_BUS_CONTROLLER);
919 
920 int cdx_register_controller(struct cdx_controller *cdx)
921 {
922 	int ret;
923 
924 	ret = ida_alloc_range(&cdx_controller_ida, 0,  MAX_CDX_CONTROLLERS - 1, GFP_KERNEL);
925 	if (ret < 0) {
926 		dev_err(cdx->dev,
927 			"No free index available. Maximum controllers already registered\n");
928 		cdx->id = (u8)MAX_CDX_CONTROLLERS;
929 		return ret;
930 	}
931 
932 	mutex_lock(&cdx_controller_lock);
933 	cdx->id = ret;
934 
935 	/* Scan all the devices */
936 	if (cdx->ops->scan)
937 		cdx->ops->scan(cdx);
938 	cdx->controller_registered = true;
939 	mutex_unlock(&cdx_controller_lock);
940 
941 	return 0;
942 }
943 EXPORT_SYMBOL_NS_GPL(cdx_register_controller, CDX_BUS_CONTROLLER);
944 
945 void cdx_unregister_controller(struct cdx_controller *cdx)
946 {
947 	if (cdx->id >= MAX_CDX_CONTROLLERS)
948 		return;
949 
950 	mutex_lock(&cdx_controller_lock);
951 
952 	cdx->controller_registered = false;
953 	device_for_each_child(cdx->dev, NULL, cdx_unregister_device);
954 	ida_free(&cdx_controller_ida, cdx->id);
955 
956 	mutex_unlock(&cdx_controller_lock);
957 }
958 EXPORT_SYMBOL_NS_GPL(cdx_unregister_controller, CDX_BUS_CONTROLLER);
959 
960 static int __init cdx_bus_init(void)
961 {
962 	int ret;
963 
964 	ret = bus_register(&cdx_bus_type);
965 	if (!ret)
966 		cdx_debugfs_dir = debugfs_create_dir(cdx_bus_type.name, NULL);
967 
968 	return ret;
969 }
970 postcore_initcall(cdx_bus_init);
971