xref: /linux/drivers/cdx/cdx.c (revision b8e85e6f3a09fc56b0ff574887798962ef8a8f80)
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/kernel.h>
60 #include <linux/of.h>
61 #include <linux/of_device.h>
62 #include <linux/of_platform.h>
63 #include <linux/platform_device.h>
64 #include <linux/slab.h>
65 #include <linux/mm.h>
66 #include <linux/idr.h>
67 #include <linux/cdx/cdx_bus.h>
68 #include <linux/iommu.h>
69 #include <linux/dma-map-ops.h>
70 #include <linux/debugfs.h>
71 #include "cdx.h"
72 
73 /* Default DMA mask for devices on a CDX bus */
74 #define CDX_DEFAULT_DMA_MASK	(~0ULL)
75 #define MAX_CDX_CONTROLLERS 16
76 
77 /* IDA for CDX controllers registered with the CDX bus */
78 static DEFINE_IDA(cdx_controller_ida);
79 /* Lock to protect controller ops */
80 static DEFINE_MUTEX(cdx_controller_lock);
81 /* Debugfs dir for cdx bus */
82 static struct dentry *cdx_debugfs_dir;
83 
84 static char *compat_node_name = "xlnx,versal-net-cdx";
85 
86 static void cdx_destroy_res_attr(struct cdx_device *cdx_dev, int num);
87 
88 /**
89  * cdx_dev_reset - Reset a CDX device
90  * @dev: CDX device
91  *
92  * Return: -errno on failure, 0 on success.
93  */
94 int cdx_dev_reset(struct device *dev)
95 {
96 	struct cdx_device *cdx_dev = to_cdx_device(dev);
97 	struct cdx_controller *cdx = cdx_dev->cdx;
98 	struct cdx_device_config dev_config = {0};
99 	struct cdx_driver *cdx_drv;
100 	int ret;
101 
102 	cdx_drv = to_cdx_driver(dev->driver);
103 	/* Notify driver that device is being reset */
104 	if (cdx_drv && cdx_drv->reset_prepare)
105 		cdx_drv->reset_prepare(cdx_dev);
106 
107 	dev_config.type = CDX_DEV_RESET_CONF;
108 	ret = cdx->ops->dev_configure(cdx, cdx_dev->bus_num,
109 				      cdx_dev->dev_num, &dev_config);
110 	if (ret)
111 		dev_err(dev, "cdx device reset failed\n");
112 
113 	/* Notify driver that device reset is complete */
114 	if (cdx_drv && cdx_drv->reset_done)
115 		cdx_drv->reset_done(cdx_dev);
116 
117 	return ret;
118 }
119 EXPORT_SYMBOL_GPL(cdx_dev_reset);
120 
121 /**
122  * reset_cdx_device - Reset a CDX device
123  * @dev: CDX device
124  * @data: This is always passed as NULL, and is not used in this API,
125  *    but is required here as the device_for_each_child() API expects
126  *    the passed function to have this as an argument.
127  *
128  * Return: -errno on failure, 0 on success.
129  */
130 static int reset_cdx_device(struct device *dev, void *data)
131 {
132 	return cdx_dev_reset(dev);
133 }
134 
135 /**
136  * cdx_unregister_device - Unregister a CDX device
137  * @dev: CDX device
138  * @data: This is always passed as NULL, and is not used in this API,
139  *	  but is required here as the bus_for_each_dev() API expects
140  *	  the passed function (cdx_unregister_device) to have this
141  *	  as an argument.
142  *
143  * Return: 0 on success.
144  */
145 static int cdx_unregister_device(struct device *dev,
146 				 void *data)
147 {
148 	struct cdx_device *cdx_dev = to_cdx_device(dev);
149 	struct cdx_controller *cdx = cdx_dev->cdx;
150 
151 	if (cdx_dev->is_bus) {
152 		device_for_each_child(dev, NULL, cdx_unregister_device);
153 		if (cdx_dev->enabled && cdx->ops->bus_disable)
154 			cdx->ops->bus_disable(cdx, cdx_dev->bus_num);
155 	} else {
156 		cdx_destroy_res_attr(cdx_dev, MAX_CDX_DEV_RESOURCES);
157 		debugfs_remove_recursive(cdx_dev->debugfs_dir);
158 		kfree(cdx_dev->driver_override);
159 		cdx_dev->driver_override = NULL;
160 	}
161 
162 	/*
163 	 * Do not free cdx_dev here as it would be freed in
164 	 * cdx_device_release() called from within put_device().
165 	 */
166 	device_del(&cdx_dev->dev);
167 	put_device(&cdx_dev->dev);
168 
169 	return 0;
170 }
171 
172 static void cdx_unregister_devices(struct bus_type *bus)
173 {
174 	/* Reset all the devices attached to cdx bus */
175 	bus_for_each_dev(bus, NULL, NULL, cdx_unregister_device);
176 }
177 
178 /**
179  * cdx_match_one_device - Tell if a CDX device structure has a matching
180  *			  CDX device id structure
181  * @id: single CDX device id structure to match
182  * @dev: the CDX device structure to match against
183  *
184  * Return: matching cdx_device_id structure or NULL if there is no match.
185  */
186 static inline const struct cdx_device_id *
187 cdx_match_one_device(const struct cdx_device_id *id,
188 		     const struct cdx_device *dev)
189 {
190 	/* Use vendor ID and device ID for matching */
191 	if ((id->vendor == CDX_ANY_ID || id->vendor == dev->vendor) &&
192 	    (id->device == CDX_ANY_ID || id->device == dev->device) &&
193 	    (id->subvendor == CDX_ANY_ID || id->subvendor == dev->subsystem_vendor) &&
194 	    (id->subdevice == CDX_ANY_ID || id->subdevice == dev->subsystem_device) &&
195 	    !((id->class ^ dev->class) & id->class_mask))
196 		return id;
197 	return NULL;
198 }
199 
200 /**
201  * cdx_match_id - See if a CDX device matches a given cdx_id table
202  * @ids: array of CDX device ID structures to search in
203  * @dev: the CDX device structure to match against.
204  *
205  * Used by a driver to check whether a CDX device is in its list of
206  * supported devices. Returns the matching cdx_device_id structure or
207  * NULL if there is no match.
208  *
209  * Return: matching cdx_device_id structure or NULL if there is no match.
210  */
211 static inline const struct cdx_device_id *
212 cdx_match_id(const struct cdx_device_id *ids, struct cdx_device *dev)
213 {
214 	if (ids) {
215 		while (ids->vendor || ids->device) {
216 			if (cdx_match_one_device(ids, dev))
217 				return ids;
218 			ids++;
219 		}
220 	}
221 	return NULL;
222 }
223 
224 int cdx_set_master(struct cdx_device *cdx_dev)
225 {
226 	struct cdx_controller *cdx = cdx_dev->cdx;
227 	struct cdx_device_config dev_config;
228 	int ret = -EOPNOTSUPP;
229 
230 	dev_config.type = CDX_DEV_BUS_MASTER_CONF;
231 	dev_config.bus_master_enable = true;
232 	if (cdx->ops->dev_configure)
233 		ret = cdx->ops->dev_configure(cdx, cdx_dev->bus_num,
234 					      cdx_dev->dev_num, &dev_config);
235 
236 	return ret;
237 }
238 EXPORT_SYMBOL_GPL(cdx_set_master);
239 
240 int cdx_clear_master(struct cdx_device *cdx_dev)
241 {
242 	struct cdx_controller *cdx = cdx_dev->cdx;
243 	struct cdx_device_config dev_config;
244 	int ret = -EOPNOTSUPP;
245 
246 	dev_config.type = CDX_DEV_BUS_MASTER_CONF;
247 	dev_config.bus_master_enable = false;
248 	if (cdx->ops->dev_configure)
249 		ret = cdx->ops->dev_configure(cdx, cdx_dev->bus_num,
250 					      cdx_dev->dev_num, &dev_config);
251 
252 	return ret;
253 }
254 EXPORT_SYMBOL_GPL(cdx_clear_master);
255 
256 /**
257  * cdx_bus_match - device to driver matching callback
258  * @dev: the cdx device to match against
259  * @drv: the device driver to search for matching cdx device
260  * structures
261  *
262  * Return: true on success, false otherwise.
263  */
264 static int cdx_bus_match(struct device *dev, struct device_driver *drv)
265 {
266 	struct cdx_device *cdx_dev = to_cdx_device(dev);
267 	struct cdx_driver *cdx_drv = to_cdx_driver(drv);
268 	const struct cdx_device_id *found_id = NULL;
269 	const struct cdx_device_id *ids;
270 
271 	if (cdx_dev->is_bus)
272 		return false;
273 
274 	ids = cdx_drv->match_id_table;
275 
276 	/* When driver_override is set, only bind to the matching driver */
277 	if (cdx_dev->driver_override && strcmp(cdx_dev->driver_override, drv->name))
278 		return false;
279 
280 	found_id = cdx_match_id(ids, cdx_dev);
281 	if (!found_id)
282 		return false;
283 
284 	do {
285 		/*
286 		 * In case override_only was set, enforce driver_override
287 		 * matching.
288 		 */
289 		if (!found_id->override_only)
290 			return true;
291 		if (cdx_dev->driver_override)
292 			return true;
293 
294 		ids = found_id + 1;
295 		found_id = cdx_match_id(ids, cdx_dev);
296 	} while (found_id);
297 
298 	return false;
299 }
300 
301 static int cdx_probe(struct device *dev)
302 {
303 	struct cdx_driver *cdx_drv = to_cdx_driver(dev->driver);
304 	struct cdx_device *cdx_dev = to_cdx_device(dev);
305 	int error;
306 
307 	error = cdx_drv->probe(cdx_dev);
308 	if (error) {
309 		dev_err_probe(dev, error, "%s failed\n", __func__);
310 		return error;
311 	}
312 
313 	return 0;
314 }
315 
316 static void cdx_remove(struct device *dev)
317 {
318 	struct cdx_driver *cdx_drv = to_cdx_driver(dev->driver);
319 	struct cdx_device *cdx_dev = to_cdx_device(dev);
320 
321 	if (cdx_drv && cdx_drv->remove)
322 		cdx_drv->remove(cdx_dev);
323 }
324 
325 static void cdx_shutdown(struct device *dev)
326 {
327 	struct cdx_driver *cdx_drv = to_cdx_driver(dev->driver);
328 	struct cdx_device *cdx_dev = to_cdx_device(dev);
329 
330 	if (cdx_drv && cdx_drv->shutdown)
331 		cdx_drv->shutdown(cdx_dev);
332 }
333 
334 static int cdx_dma_configure(struct device *dev)
335 {
336 	struct cdx_driver *cdx_drv = to_cdx_driver(dev->driver);
337 	struct cdx_device *cdx_dev = to_cdx_device(dev);
338 	struct cdx_controller *cdx = cdx_dev->cdx;
339 	u32 input_id = cdx_dev->req_id;
340 	int ret;
341 
342 	ret = of_dma_configure_id(dev, cdx->dev->of_node, 0, &input_id);
343 	if (ret && ret != -EPROBE_DEFER) {
344 		dev_err(dev, "of_dma_configure_id() failed\n");
345 		return ret;
346 	}
347 
348 	if (!ret && !cdx_drv->driver_managed_dma) {
349 		ret = iommu_device_use_default_domain(dev);
350 		if (ret)
351 			arch_teardown_dma_ops(dev);
352 	}
353 
354 	return 0;
355 }
356 
357 static void cdx_dma_cleanup(struct device *dev)
358 {
359 	struct cdx_driver *cdx_drv = to_cdx_driver(dev->driver);
360 
361 	if (!cdx_drv->driver_managed_dma)
362 		iommu_device_unuse_default_domain(dev);
363 }
364 
365 /* show configuration fields */
366 #define cdx_config_attr(field, format_string)	\
367 static ssize_t	\
368 field##_show(struct device *dev, struct device_attribute *attr, char *buf)	\
369 {	\
370 	struct cdx_device *cdx_dev = to_cdx_device(dev);	\
371 	return sysfs_emit(buf, format_string, cdx_dev->field);	\
372 }	\
373 static DEVICE_ATTR_RO(field)
374 
375 cdx_config_attr(vendor, "0x%04x\n");
376 cdx_config_attr(device, "0x%04x\n");
377 cdx_config_attr(subsystem_vendor, "0x%04x\n");
378 cdx_config_attr(subsystem_device, "0x%04x\n");
379 cdx_config_attr(revision, "0x%02x\n");
380 cdx_config_attr(class, "0x%06x\n");
381 
382 static ssize_t remove_store(struct device *dev,
383 			    struct device_attribute *attr,
384 			    const char *buf, size_t count)
385 {
386 	bool val;
387 
388 	if (kstrtobool(buf, &val) < 0)
389 		return -EINVAL;
390 
391 	if (!val)
392 		return -EINVAL;
393 
394 	if (device_remove_file_self(dev, attr)) {
395 		int ret;
396 
397 		ret = cdx_unregister_device(dev, NULL);
398 		if (ret)
399 			return ret;
400 	}
401 
402 	return count;
403 }
404 static DEVICE_ATTR_WO(remove);
405 
406 static ssize_t reset_store(struct device *dev, struct device_attribute *attr,
407 			   const char *buf, size_t count)
408 {
409 	struct cdx_device *cdx_dev = to_cdx_device(dev);
410 	bool val;
411 	int ret;
412 
413 	if (kstrtobool(buf, &val) < 0)
414 		return -EINVAL;
415 
416 	if (!val)
417 		return -EINVAL;
418 
419 	if (cdx_dev->is_bus)
420 		/* Reset all the devices attached to cdx bus */
421 		ret = device_for_each_child(dev, NULL, reset_cdx_device);
422 	else
423 		ret = cdx_dev_reset(dev);
424 
425 	return ret < 0 ? ret : count;
426 }
427 static DEVICE_ATTR_WO(reset);
428 
429 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
430 			     char *buf)
431 {
432 	struct cdx_device *cdx_dev = to_cdx_device(dev);
433 
434 	return sprintf(buf, "cdx:v%04Xd%04Xsv%04Xsd%04Xc%06X\n", cdx_dev->vendor,
435 			cdx_dev->device, cdx_dev->subsystem_vendor, cdx_dev->subsystem_device,
436 			cdx_dev->class);
437 }
438 static DEVICE_ATTR_RO(modalias);
439 
440 static ssize_t driver_override_store(struct device *dev,
441 				     struct device_attribute *attr,
442 				     const char *buf, size_t count)
443 {
444 	struct cdx_device *cdx_dev = to_cdx_device(dev);
445 	int ret;
446 
447 	if (WARN_ON(dev->bus != &cdx_bus_type))
448 		return -EINVAL;
449 
450 	ret = driver_set_override(dev, &cdx_dev->driver_override, buf, count);
451 	if (ret)
452 		return ret;
453 
454 	return count;
455 }
456 
457 static ssize_t driver_override_show(struct device *dev,
458 				    struct device_attribute *attr, char *buf)
459 {
460 	struct cdx_device *cdx_dev = to_cdx_device(dev);
461 
462 	return sysfs_emit(buf, "%s\n", cdx_dev->driver_override);
463 }
464 static DEVICE_ATTR_RW(driver_override);
465 
466 static ssize_t enable_store(struct device *dev, struct device_attribute *attr,
467 			    const char *buf, size_t count)
468 {
469 	struct cdx_device *cdx_dev = to_cdx_device(dev);
470 	struct cdx_controller *cdx = cdx_dev->cdx;
471 	bool enable;
472 	int ret;
473 
474 	if (kstrtobool(buf, &enable) < 0)
475 		return -EINVAL;
476 
477 	if (enable == cdx_dev->enabled)
478 		return count;
479 
480 	if (enable && cdx->ops->bus_enable)
481 		ret = cdx->ops->bus_enable(cdx, cdx_dev->bus_num);
482 	else if (!enable && cdx->ops->bus_disable)
483 		ret = cdx->ops->bus_disable(cdx, cdx_dev->bus_num);
484 	else
485 		ret = -EOPNOTSUPP;
486 
487 	if (!ret)
488 		cdx_dev->enabled = enable;
489 
490 	return ret < 0 ? ret : count;
491 }
492 
493 static ssize_t enable_show(struct device *dev, struct device_attribute *attr, char *buf)
494 {
495 	struct cdx_device *cdx_dev = to_cdx_device(dev);
496 
497 	return sysfs_emit(buf, "%u\n", cdx_dev->enabled);
498 }
499 static DEVICE_ATTR_RW(enable);
500 
501 static umode_t cdx_dev_attrs_are_visible(struct kobject *kobj, struct attribute *a, int n)
502 {
503 	struct device *dev = kobj_to_dev(kobj);
504 	struct cdx_device *cdx_dev;
505 
506 	cdx_dev = to_cdx_device(dev);
507 	if (!cdx_dev->is_bus)
508 		return a->mode;
509 
510 	return 0;
511 }
512 
513 static umode_t cdx_bus_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 struct attribute *cdx_dev_attrs[] = {
526 	&dev_attr_remove.attr,
527 	&dev_attr_reset.attr,
528 	&dev_attr_vendor.attr,
529 	&dev_attr_device.attr,
530 	&dev_attr_subsystem_vendor.attr,
531 	&dev_attr_subsystem_device.attr,
532 	&dev_attr_class.attr,
533 	&dev_attr_revision.attr,
534 	&dev_attr_modalias.attr,
535 	&dev_attr_driver_override.attr,
536 	NULL,
537 };
538 
539 static const struct attribute_group cdx_dev_group = {
540 	.attrs = cdx_dev_attrs,
541 	.is_visible = cdx_dev_attrs_are_visible,
542 };
543 
544 static struct attribute *cdx_bus_dev_attrs[] = {
545 	&dev_attr_enable.attr,
546 	&dev_attr_reset.attr,
547 	NULL,
548 };
549 
550 static const struct attribute_group cdx_bus_dev_group = {
551 	.attrs = cdx_bus_dev_attrs,
552 	.is_visible = cdx_bus_attrs_are_visible,
553 };
554 
555 static const struct attribute_group *cdx_dev_groups[] = {
556 	&cdx_dev_group,
557 	&cdx_bus_dev_group,
558 	NULL,
559 };
560 
561 static int cdx_debug_resource_show(struct seq_file *s, void *data)
562 {
563 	struct cdx_device *cdx_dev = s->private;
564 	int i;
565 
566 	for (i = 0; i < MAX_CDX_DEV_RESOURCES; i++) {
567 		struct resource *res =  &cdx_dev->res[i];
568 
569 		seq_printf(s, "%pr\n", res);
570 	}
571 
572 	return 0;
573 }
574 DEFINE_SHOW_ATTRIBUTE(cdx_debug_resource);
575 
576 static void cdx_device_debugfs_init(struct cdx_device *cdx_dev)
577 {
578 	cdx_dev->debugfs_dir = debugfs_create_dir(dev_name(&cdx_dev->dev), cdx_debugfs_dir);
579 	if (IS_ERR(cdx_dev->debugfs_dir))
580 		return;
581 
582 	debugfs_create_file("resource", 0444, cdx_dev->debugfs_dir, cdx_dev,
583 			    &cdx_debug_resource_fops);
584 }
585 
586 static ssize_t rescan_store(const struct bus_type *bus,
587 			    const char *buf, size_t count)
588 {
589 	struct cdx_controller *cdx;
590 	struct platform_device *pd;
591 	struct device_node *np;
592 	bool val;
593 
594 	if (kstrtobool(buf, &val) < 0)
595 		return -EINVAL;
596 
597 	if (!val)
598 		return -EINVAL;
599 
600 	mutex_lock(&cdx_controller_lock);
601 
602 	/* Unregister all the devices on the bus */
603 	cdx_unregister_devices(&cdx_bus_type);
604 
605 	/* Rescan all the devices */
606 	for_each_compatible_node(np, NULL, compat_node_name) {
607 		pd = of_find_device_by_node(np);
608 		if (!pd) {
609 			of_node_put(np);
610 			count = -EINVAL;
611 			goto unlock;
612 		}
613 
614 		cdx = platform_get_drvdata(pd);
615 		if (cdx && cdx->controller_registered && cdx->ops->scan)
616 			cdx->ops->scan(cdx);
617 
618 		put_device(&pd->dev);
619 	}
620 
621 unlock:
622 	mutex_unlock(&cdx_controller_lock);
623 
624 	return count;
625 }
626 static BUS_ATTR_WO(rescan);
627 
628 static struct attribute *cdx_bus_attrs[] = {
629 	&bus_attr_rescan.attr,
630 	NULL,
631 };
632 ATTRIBUTE_GROUPS(cdx_bus);
633 
634 struct bus_type cdx_bus_type = {
635 	.name		= "cdx",
636 	.match		= cdx_bus_match,
637 	.probe		= cdx_probe,
638 	.remove		= cdx_remove,
639 	.shutdown	= cdx_shutdown,
640 	.dma_configure	= cdx_dma_configure,
641 	.dma_cleanup	= cdx_dma_cleanup,
642 	.bus_groups	= cdx_bus_groups,
643 	.dev_groups	= cdx_dev_groups,
644 };
645 EXPORT_SYMBOL_GPL(cdx_bus_type);
646 
647 int __cdx_driver_register(struct cdx_driver *cdx_driver,
648 			  struct module *owner)
649 {
650 	int error;
651 
652 	cdx_driver->driver.owner = owner;
653 	cdx_driver->driver.bus = &cdx_bus_type;
654 
655 	error = driver_register(&cdx_driver->driver);
656 	if (error) {
657 		pr_err("driver_register() failed for %s: %d\n",
658 		       cdx_driver->driver.name, error);
659 		return error;
660 	}
661 
662 	return 0;
663 }
664 EXPORT_SYMBOL_GPL(__cdx_driver_register);
665 
666 void cdx_driver_unregister(struct cdx_driver *cdx_driver)
667 {
668 	driver_unregister(&cdx_driver->driver);
669 }
670 EXPORT_SYMBOL_GPL(cdx_driver_unregister);
671 
672 static void cdx_device_release(struct device *dev)
673 {
674 	struct cdx_device *cdx_dev = to_cdx_device(dev);
675 
676 	kfree(cdx_dev);
677 }
678 
679 static const struct vm_operations_struct cdx_phys_vm_ops = {
680 #ifdef CONFIG_HAVE_IOREMAP_PROT
681 	.access = generic_access_phys,
682 #endif
683 };
684 
685 /**
686  * cdx_mmap_resource - map a CDX resource into user memory space
687  * @fp: File pointer. Not used in this function, but required where
688  *      this API is registered as a callback.
689  * @kobj: kobject for mapping
690  * @attr: struct bin_attribute for the file being mapped
691  * @vma: struct vm_area_struct passed into the mmap
692  *
693  * Use the regular CDX mapping routines to map a CDX resource into userspace.
694  *
695  * Return: true on success, false otherwise.
696  */
697 static int cdx_mmap_resource(struct file *fp, struct kobject *kobj,
698 			     struct bin_attribute *attr,
699 			     struct vm_area_struct *vma)
700 {
701 	struct cdx_device *cdx_dev = to_cdx_device(kobj_to_dev(kobj));
702 	int num = (unsigned long)attr->private;
703 	struct resource *res;
704 	unsigned long size;
705 
706 	res = &cdx_dev->res[num];
707 	if (iomem_is_exclusive(res->start))
708 		return -EINVAL;
709 
710 	/* Make sure the caller is mapping a valid resource for this device */
711 	size = ((cdx_resource_len(cdx_dev, num) - 1) >> PAGE_SHIFT) + 1;
712 	if (vma->vm_pgoff + vma_pages(vma) > size)
713 		return -EINVAL;
714 
715 	/*
716 	 * Map memory region and vm->vm_pgoff is expected to be an
717 	 * offset within that region.
718 	 */
719 	vma->vm_page_prot = pgprot_device(vma->vm_page_prot);
720 	vma->vm_pgoff += (cdx_resource_start(cdx_dev, num) >> PAGE_SHIFT);
721 	vma->vm_ops = &cdx_phys_vm_ops;
722 	return io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
723 				  vma->vm_end - vma->vm_start,
724 				  vma->vm_page_prot);
725 }
726 
727 static void cdx_destroy_res_attr(struct cdx_device *cdx_dev, int num)
728 {
729 	int i;
730 
731 	/* removing the bin attributes */
732 	for (i = 0; i < num; i++) {
733 		struct bin_attribute *res_attr;
734 
735 		res_attr = cdx_dev->res_attr[i];
736 		if (res_attr) {
737 			sysfs_remove_bin_file(&cdx_dev->dev.kobj, res_attr);
738 			kfree(res_attr);
739 		}
740 	}
741 }
742 
743 #define CDX_RES_ATTR_NAME_LEN	10
744 static int cdx_create_res_attr(struct cdx_device *cdx_dev, int num)
745 {
746 	struct bin_attribute *res_attr;
747 	char *res_attr_name;
748 	int ret;
749 
750 	res_attr = kzalloc(sizeof(*res_attr) + CDX_RES_ATTR_NAME_LEN, GFP_ATOMIC);
751 	if (!res_attr)
752 		return -ENOMEM;
753 
754 	res_attr_name = (char *)(res_attr + 1);
755 
756 	sysfs_bin_attr_init(res_attr);
757 
758 	cdx_dev->res_attr[num] = res_attr;
759 	sprintf(res_attr_name, "resource%d", num);
760 
761 	res_attr->mmap = cdx_mmap_resource;
762 	res_attr->attr.name = res_attr_name;
763 	res_attr->attr.mode = 0600;
764 	res_attr->size = cdx_resource_len(cdx_dev, num);
765 	res_attr->private = (void *)(unsigned long)num;
766 	ret = sysfs_create_bin_file(&cdx_dev->dev.kobj, res_attr);
767 	if (ret)
768 		kfree(res_attr);
769 
770 	return ret;
771 }
772 
773 int cdx_device_add(struct cdx_dev_params *dev_params)
774 {
775 	struct cdx_controller *cdx = dev_params->cdx;
776 	struct cdx_device *cdx_dev;
777 	int ret, i;
778 
779 	cdx_dev = kzalloc(sizeof(*cdx_dev), GFP_KERNEL);
780 	if (!cdx_dev)
781 		return -ENOMEM;
782 
783 	/* Populate resource */
784 	memcpy(cdx_dev->res, dev_params->res, sizeof(struct resource) *
785 		dev_params->res_count);
786 	cdx_dev->res_count = dev_params->res_count;
787 
788 	/* Populate CDX dev params */
789 	cdx_dev->req_id = dev_params->req_id;
790 	cdx_dev->vendor = dev_params->vendor;
791 	cdx_dev->device = dev_params->device;
792 	cdx_dev->subsystem_vendor = dev_params->subsys_vendor;
793 	cdx_dev->subsystem_device = dev_params->subsys_device;
794 	cdx_dev->class = dev_params->class;
795 	cdx_dev->revision = dev_params->revision;
796 	cdx_dev->bus_num = dev_params->bus_num;
797 	cdx_dev->dev_num = dev_params->dev_num;
798 	cdx_dev->cdx = dev_params->cdx;
799 	cdx_dev->dma_mask = CDX_DEFAULT_DMA_MASK;
800 
801 	/* Initialize generic device */
802 	device_initialize(&cdx_dev->dev);
803 	cdx_dev->dev.parent = dev_params->parent;
804 	cdx_dev->dev.bus = &cdx_bus_type;
805 	cdx_dev->dev.dma_mask = &cdx_dev->dma_mask;
806 	cdx_dev->dev.release = cdx_device_release;
807 
808 	/* Set Name */
809 	dev_set_name(&cdx_dev->dev, "cdx-%02x:%02x",
810 		     ((cdx->id << CDX_CONTROLLER_ID_SHIFT) | (cdx_dev->bus_num & CDX_BUS_NUM_MASK)),
811 		     cdx_dev->dev_num);
812 
813 	ret = device_add(&cdx_dev->dev);
814 	if (ret) {
815 		dev_err(&cdx_dev->dev,
816 			"cdx device add failed: %d", ret);
817 		goto fail;
818 	}
819 
820 	/* Create resource<N> attributes */
821 	for (i = 0; i < MAX_CDX_DEV_RESOURCES; i++) {
822 		if (cdx_resource_flags(cdx_dev, i) & IORESOURCE_MEM) {
823 			/* skip empty resources */
824 			if (!cdx_resource_len(cdx_dev, i))
825 				continue;
826 
827 			ret = cdx_create_res_attr(cdx_dev, i);
828 			if (ret != 0) {
829 				dev_err(&cdx_dev->dev,
830 					"cdx device resource<%d> file creation failed: %d", i, ret);
831 				goto resource_create_fail;
832 			}
833 		}
834 	}
835 
836 	cdx_device_debugfs_init(cdx_dev);
837 
838 	return 0;
839 resource_create_fail:
840 	cdx_destroy_res_attr(cdx_dev, i);
841 	device_del(&cdx_dev->dev);
842 fail:
843 	/*
844 	 * Do not free cdx_dev here as it would be freed in
845 	 * cdx_device_release() called from put_device().
846 	 */
847 	put_device(&cdx_dev->dev);
848 
849 	return ret;
850 }
851 EXPORT_SYMBOL_NS_GPL(cdx_device_add, CDX_BUS_CONTROLLER);
852 
853 struct device *cdx_bus_add(struct cdx_controller *cdx, u8 bus_num)
854 {
855 	struct cdx_device *cdx_dev;
856 	int ret;
857 
858 	cdx_dev = kzalloc(sizeof(*cdx_dev), GFP_KERNEL);
859 	if (!cdx_dev)
860 		return NULL;
861 
862 	device_initialize(&cdx_dev->dev);
863 	cdx_dev->cdx = cdx;
864 
865 	cdx_dev->dev.parent = cdx->dev;
866 	cdx_dev->dev.bus = &cdx_bus_type;
867 	cdx_dev->dev.release = cdx_device_release;
868 	cdx_dev->is_bus = true;
869 	cdx_dev->bus_num = bus_num;
870 
871 	dev_set_name(&cdx_dev->dev, "cdx-%02x",
872 		     ((cdx->id << CDX_CONTROLLER_ID_SHIFT) | (bus_num & CDX_BUS_NUM_MASK)));
873 
874 	ret = device_add(&cdx_dev->dev);
875 	if (ret) {
876 		dev_err(&cdx_dev->dev, "cdx bus device add failed: %d\n", ret);
877 		goto device_add_fail;
878 	}
879 
880 	if (cdx->ops->bus_enable) {
881 		ret = cdx->ops->bus_enable(cdx, bus_num);
882 		if (ret && ret != -EALREADY) {
883 			dev_err(cdx->dev, "cdx bus enable failed: %d\n", ret);
884 			goto bus_enable_fail;
885 		}
886 	}
887 
888 	cdx_dev->enabled = true;
889 	return &cdx_dev->dev;
890 
891 bus_enable_fail:
892 	device_del(&cdx_dev->dev);
893 device_add_fail:
894 	put_device(&cdx_dev->dev);
895 
896 	return NULL;
897 }
898 EXPORT_SYMBOL_NS_GPL(cdx_bus_add, CDX_BUS_CONTROLLER);
899 
900 int cdx_register_controller(struct cdx_controller *cdx)
901 {
902 	int ret;
903 
904 	ret = ida_alloc_range(&cdx_controller_ida, 0,  MAX_CDX_CONTROLLERS - 1, GFP_KERNEL);
905 	if (ret < 0) {
906 		dev_err(cdx->dev,
907 			"No free index available. Maximum controllers already registered\n");
908 		cdx->id = (u8)MAX_CDX_CONTROLLERS;
909 		return ret;
910 	}
911 
912 	mutex_lock(&cdx_controller_lock);
913 	cdx->id = ret;
914 
915 	/* Scan all the devices */
916 	if (cdx->ops->scan)
917 		cdx->ops->scan(cdx);
918 	cdx->controller_registered = true;
919 	mutex_unlock(&cdx_controller_lock);
920 
921 	return 0;
922 }
923 EXPORT_SYMBOL_NS_GPL(cdx_register_controller, CDX_BUS_CONTROLLER);
924 
925 void cdx_unregister_controller(struct cdx_controller *cdx)
926 {
927 	if (cdx->id >= MAX_CDX_CONTROLLERS)
928 		return;
929 
930 	mutex_lock(&cdx_controller_lock);
931 
932 	cdx->controller_registered = false;
933 	device_for_each_child(cdx->dev, NULL, cdx_unregister_device);
934 	ida_free(&cdx_controller_ida, cdx->id);
935 
936 	mutex_unlock(&cdx_controller_lock);
937 }
938 EXPORT_SYMBOL_NS_GPL(cdx_unregister_controller, CDX_BUS_CONTROLLER);
939 
940 static int __init cdx_bus_init(void)
941 {
942 	int ret;
943 
944 	ret = bus_register(&cdx_bus_type);
945 	if (!ret)
946 		cdx_debugfs_dir = debugfs_create_dir(cdx_bus_type.name, NULL);
947 
948 	return ret;
949 }
950 postcore_initcall(cdx_bus_init);
951