xref: /linux/drivers/vfio/platform/vfio_platform_common.c (revision bd628c1bed7902ec1f24ba0fe70758949146abbe)
1 /*
2  * Copyright (C) 2013 - Virtual Open Systems
3  * Author: Antonios Motakis <a.motakis@virtualopensystems.com>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License, version 2, as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  */
14 
15 #include <linux/device.h>
16 #include <linux/acpi.h>
17 #include <linux/iommu.h>
18 #include <linux/module.h>
19 #include <linux/mutex.h>
20 #include <linux/pm_runtime.h>
21 #include <linux/slab.h>
22 #include <linux/types.h>
23 #include <linux/uaccess.h>
24 #include <linux/vfio.h>
25 
26 #include "vfio_platform_private.h"
27 
28 #define DRIVER_VERSION  "0.10"
29 #define DRIVER_AUTHOR   "Antonios Motakis <a.motakis@virtualopensystems.com>"
30 #define DRIVER_DESC     "VFIO platform base module"
31 
32 #define VFIO_PLATFORM_IS_ACPI(vdev) ((vdev)->acpihid != NULL)
33 
34 static LIST_HEAD(reset_list);
35 static DEFINE_MUTEX(driver_lock);
36 
37 static vfio_platform_reset_fn_t vfio_platform_lookup_reset(const char *compat,
38 					struct module **module)
39 {
40 	struct vfio_platform_reset_node *iter;
41 	vfio_platform_reset_fn_t reset_fn = NULL;
42 
43 	mutex_lock(&driver_lock);
44 	list_for_each_entry(iter, &reset_list, link) {
45 		if (!strcmp(iter->compat, compat) &&
46 			try_module_get(iter->owner)) {
47 			*module = iter->owner;
48 			reset_fn = iter->of_reset;
49 			break;
50 		}
51 	}
52 	mutex_unlock(&driver_lock);
53 	return reset_fn;
54 }
55 
56 static int vfio_platform_acpi_probe(struct vfio_platform_device *vdev,
57 				    struct device *dev)
58 {
59 	struct acpi_device *adev;
60 
61 	if (acpi_disabled)
62 		return -ENOENT;
63 
64 	adev = ACPI_COMPANION(dev);
65 	if (!adev) {
66 		pr_err("VFIO: ACPI companion device not found for %s\n",
67 			vdev->name);
68 		return -ENODEV;
69 	}
70 
71 #ifdef CONFIG_ACPI
72 	vdev->acpihid = acpi_device_hid(adev);
73 #endif
74 	return WARN_ON(!vdev->acpihid) ? -EINVAL : 0;
75 }
76 
77 static int vfio_platform_acpi_call_reset(struct vfio_platform_device *vdev,
78 				  const char **extra_dbg)
79 {
80 #ifdef CONFIG_ACPI
81 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
82 	struct device *dev = vdev->device;
83 	acpi_handle handle = ACPI_HANDLE(dev);
84 	acpi_status acpi_ret;
85 
86 	acpi_ret = acpi_evaluate_object(handle, "_RST", NULL, &buffer);
87 	if (ACPI_FAILURE(acpi_ret)) {
88 		if (extra_dbg)
89 			*extra_dbg = acpi_format_exception(acpi_ret);
90 		return -EINVAL;
91 	}
92 
93 	return 0;
94 #else
95 	return -ENOENT;
96 #endif
97 }
98 
99 static bool vfio_platform_acpi_has_reset(struct vfio_platform_device *vdev)
100 {
101 #ifdef CONFIG_ACPI
102 	struct device *dev = vdev->device;
103 	acpi_handle handle = ACPI_HANDLE(dev);
104 
105 	return acpi_has_method(handle, "_RST");
106 #else
107 	return false;
108 #endif
109 }
110 
111 static bool vfio_platform_has_reset(struct vfio_platform_device *vdev)
112 {
113 	if (VFIO_PLATFORM_IS_ACPI(vdev))
114 		return vfio_platform_acpi_has_reset(vdev);
115 
116 	return vdev->of_reset ? true : false;
117 }
118 
119 static int vfio_platform_get_reset(struct vfio_platform_device *vdev)
120 {
121 	if (VFIO_PLATFORM_IS_ACPI(vdev))
122 		return vfio_platform_acpi_has_reset(vdev) ? 0 : -ENOENT;
123 
124 	vdev->of_reset = vfio_platform_lookup_reset(vdev->compat,
125 						    &vdev->reset_module);
126 	if (!vdev->of_reset) {
127 		request_module("vfio-reset:%s", vdev->compat);
128 		vdev->of_reset = vfio_platform_lookup_reset(vdev->compat,
129 							&vdev->reset_module);
130 	}
131 
132 	return vdev->of_reset ? 0 : -ENOENT;
133 }
134 
135 static void vfio_platform_put_reset(struct vfio_platform_device *vdev)
136 {
137 	if (VFIO_PLATFORM_IS_ACPI(vdev))
138 		return;
139 
140 	if (vdev->of_reset)
141 		module_put(vdev->reset_module);
142 }
143 
144 static int vfio_platform_regions_init(struct vfio_platform_device *vdev)
145 {
146 	int cnt = 0, i;
147 
148 	while (vdev->get_resource(vdev, cnt))
149 		cnt++;
150 
151 	vdev->regions = kcalloc(cnt, sizeof(struct vfio_platform_region),
152 				GFP_KERNEL);
153 	if (!vdev->regions)
154 		return -ENOMEM;
155 
156 	for (i = 0; i < cnt;  i++) {
157 		struct resource *res =
158 			vdev->get_resource(vdev, i);
159 
160 		if (!res)
161 			goto err;
162 
163 		vdev->regions[i].addr = res->start;
164 		vdev->regions[i].size = resource_size(res);
165 		vdev->regions[i].flags = 0;
166 
167 		switch (resource_type(res)) {
168 		case IORESOURCE_MEM:
169 			vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_MMIO;
170 			vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ;
171 			if (!(res->flags & IORESOURCE_READONLY))
172 				vdev->regions[i].flags |=
173 					VFIO_REGION_INFO_FLAG_WRITE;
174 
175 			/*
176 			 * Only regions addressed with PAGE granularity may be
177 			 * MMAPed securely.
178 			 */
179 			if (!(vdev->regions[i].addr & ~PAGE_MASK) &&
180 					!(vdev->regions[i].size & ~PAGE_MASK))
181 				vdev->regions[i].flags |=
182 					VFIO_REGION_INFO_FLAG_MMAP;
183 
184 			break;
185 		case IORESOURCE_IO:
186 			vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_PIO;
187 			break;
188 		default:
189 			goto err;
190 		}
191 	}
192 
193 	vdev->num_regions = cnt;
194 
195 	return 0;
196 err:
197 	kfree(vdev->regions);
198 	return -EINVAL;
199 }
200 
201 static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev)
202 {
203 	int i;
204 
205 	for (i = 0; i < vdev->num_regions; i++)
206 		iounmap(vdev->regions[i].ioaddr);
207 
208 	vdev->num_regions = 0;
209 	kfree(vdev->regions);
210 }
211 
212 static int vfio_platform_call_reset(struct vfio_platform_device *vdev,
213 				    const char **extra_dbg)
214 {
215 	if (VFIO_PLATFORM_IS_ACPI(vdev)) {
216 		dev_info(vdev->device, "reset\n");
217 		return vfio_platform_acpi_call_reset(vdev, extra_dbg);
218 	} else if (vdev->of_reset) {
219 		dev_info(vdev->device, "reset\n");
220 		return vdev->of_reset(vdev);
221 	}
222 
223 	dev_warn(vdev->device, "no reset function found!\n");
224 	return -EINVAL;
225 }
226 
227 static void vfio_platform_release(void *device_data)
228 {
229 	struct vfio_platform_device *vdev = device_data;
230 
231 	mutex_lock(&driver_lock);
232 
233 	if (!(--vdev->refcnt)) {
234 		const char *extra_dbg = NULL;
235 		int ret;
236 
237 		ret = vfio_platform_call_reset(vdev, &extra_dbg);
238 		if (ret && vdev->reset_required) {
239 			dev_warn(vdev->device, "reset driver is required and reset call failed in release (%d) %s\n",
240 				 ret, extra_dbg ? extra_dbg : "");
241 			WARN_ON(1);
242 		}
243 		pm_runtime_put(vdev->device);
244 		vfio_platform_regions_cleanup(vdev);
245 		vfio_platform_irq_cleanup(vdev);
246 	}
247 
248 	mutex_unlock(&driver_lock);
249 
250 	module_put(vdev->parent_module);
251 }
252 
253 static int vfio_platform_open(void *device_data)
254 {
255 	struct vfio_platform_device *vdev = device_data;
256 	int ret;
257 
258 	if (!try_module_get(vdev->parent_module))
259 		return -ENODEV;
260 
261 	mutex_lock(&driver_lock);
262 
263 	if (!vdev->refcnt) {
264 		const char *extra_dbg = NULL;
265 
266 		ret = vfio_platform_regions_init(vdev);
267 		if (ret)
268 			goto err_reg;
269 
270 		ret = vfio_platform_irq_init(vdev);
271 		if (ret)
272 			goto err_irq;
273 
274 		ret = pm_runtime_get_sync(vdev->device);
275 		if (ret < 0)
276 			goto err_pm;
277 
278 		ret = vfio_platform_call_reset(vdev, &extra_dbg);
279 		if (ret && vdev->reset_required) {
280 			dev_warn(vdev->device, "reset driver is required and reset call failed in open (%d) %s\n",
281 				 ret, extra_dbg ? extra_dbg : "");
282 			goto err_rst;
283 		}
284 	}
285 
286 	vdev->refcnt++;
287 
288 	mutex_unlock(&driver_lock);
289 	return 0;
290 
291 err_rst:
292 	pm_runtime_put(vdev->device);
293 err_pm:
294 	vfio_platform_irq_cleanup(vdev);
295 err_irq:
296 	vfio_platform_regions_cleanup(vdev);
297 err_reg:
298 	mutex_unlock(&driver_lock);
299 	module_put(THIS_MODULE);
300 	return ret;
301 }
302 
303 static long vfio_platform_ioctl(void *device_data,
304 				unsigned int cmd, unsigned long arg)
305 {
306 	struct vfio_platform_device *vdev = device_data;
307 	unsigned long minsz;
308 
309 	if (cmd == VFIO_DEVICE_GET_INFO) {
310 		struct vfio_device_info info;
311 
312 		minsz = offsetofend(struct vfio_device_info, num_irqs);
313 
314 		if (copy_from_user(&info, (void __user *)arg, minsz))
315 			return -EFAULT;
316 
317 		if (info.argsz < minsz)
318 			return -EINVAL;
319 
320 		if (vfio_platform_has_reset(vdev))
321 			vdev->flags |= VFIO_DEVICE_FLAGS_RESET;
322 		info.flags = vdev->flags;
323 		info.num_regions = vdev->num_regions;
324 		info.num_irqs = vdev->num_irqs;
325 
326 		return copy_to_user((void __user *)arg, &info, minsz) ?
327 			-EFAULT : 0;
328 
329 	} else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
330 		struct vfio_region_info info;
331 
332 		minsz = offsetofend(struct vfio_region_info, offset);
333 
334 		if (copy_from_user(&info, (void __user *)arg, minsz))
335 			return -EFAULT;
336 
337 		if (info.argsz < minsz)
338 			return -EINVAL;
339 
340 		if (info.index >= vdev->num_regions)
341 			return -EINVAL;
342 
343 		/* map offset to the physical address  */
344 		info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index);
345 		info.size = vdev->regions[info.index].size;
346 		info.flags = vdev->regions[info.index].flags;
347 
348 		return copy_to_user((void __user *)arg, &info, minsz) ?
349 			-EFAULT : 0;
350 
351 	} else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
352 		struct vfio_irq_info info;
353 
354 		minsz = offsetofend(struct vfio_irq_info, count);
355 
356 		if (copy_from_user(&info, (void __user *)arg, minsz))
357 			return -EFAULT;
358 
359 		if (info.argsz < minsz)
360 			return -EINVAL;
361 
362 		if (info.index >= vdev->num_irqs)
363 			return -EINVAL;
364 
365 		info.flags = vdev->irqs[info.index].flags;
366 		info.count = vdev->irqs[info.index].count;
367 
368 		return copy_to_user((void __user *)arg, &info, minsz) ?
369 			-EFAULT : 0;
370 
371 	} else if (cmd == VFIO_DEVICE_SET_IRQS) {
372 		struct vfio_irq_set hdr;
373 		u8 *data = NULL;
374 		int ret = 0;
375 		size_t data_size = 0;
376 
377 		minsz = offsetofend(struct vfio_irq_set, count);
378 
379 		if (copy_from_user(&hdr, (void __user *)arg, minsz))
380 			return -EFAULT;
381 
382 		ret = vfio_set_irqs_validate_and_prepare(&hdr, vdev->num_irqs,
383 						 vdev->num_irqs, &data_size);
384 		if (ret)
385 			return ret;
386 
387 		if (data_size) {
388 			data = memdup_user((void __user *)(arg + minsz),
389 					    data_size);
390 			if (IS_ERR(data))
391 				return PTR_ERR(data);
392 		}
393 
394 		mutex_lock(&vdev->igate);
395 
396 		ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
397 						   hdr.start, hdr.count, data);
398 		mutex_unlock(&vdev->igate);
399 		kfree(data);
400 
401 		return ret;
402 
403 	} else if (cmd == VFIO_DEVICE_RESET) {
404 		return vfio_platform_call_reset(vdev, NULL);
405 	}
406 
407 	return -ENOTTY;
408 }
409 
410 static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg,
411 				       char __user *buf, size_t count,
412 				       loff_t off)
413 {
414 	unsigned int done = 0;
415 
416 	if (!reg->ioaddr) {
417 		reg->ioaddr =
418 			ioremap_nocache(reg->addr, reg->size);
419 
420 		if (!reg->ioaddr)
421 			return -ENOMEM;
422 	}
423 
424 	while (count) {
425 		size_t filled;
426 
427 		if (count >= 4 && !(off % 4)) {
428 			u32 val;
429 
430 			val = ioread32(reg->ioaddr + off);
431 			if (copy_to_user(buf, &val, 4))
432 				goto err;
433 
434 			filled = 4;
435 		} else if (count >= 2 && !(off % 2)) {
436 			u16 val;
437 
438 			val = ioread16(reg->ioaddr + off);
439 			if (copy_to_user(buf, &val, 2))
440 				goto err;
441 
442 			filled = 2;
443 		} else {
444 			u8 val;
445 
446 			val = ioread8(reg->ioaddr + off);
447 			if (copy_to_user(buf, &val, 1))
448 				goto err;
449 
450 			filled = 1;
451 		}
452 
453 
454 		count -= filled;
455 		done += filled;
456 		off += filled;
457 		buf += filled;
458 	}
459 
460 	return done;
461 err:
462 	return -EFAULT;
463 }
464 
465 static ssize_t vfio_platform_read(void *device_data, char __user *buf,
466 				  size_t count, loff_t *ppos)
467 {
468 	struct vfio_platform_device *vdev = device_data;
469 	unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
470 	loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
471 
472 	if (index >= vdev->num_regions)
473 		return -EINVAL;
474 
475 	if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ))
476 		return -EINVAL;
477 
478 	if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
479 		return vfio_platform_read_mmio(&vdev->regions[index],
480 							buf, count, off);
481 	else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
482 		return -EINVAL; /* not implemented */
483 
484 	return -EINVAL;
485 }
486 
487 static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg,
488 					const char __user *buf, size_t count,
489 					loff_t off)
490 {
491 	unsigned int done = 0;
492 
493 	if (!reg->ioaddr) {
494 		reg->ioaddr =
495 			ioremap_nocache(reg->addr, reg->size);
496 
497 		if (!reg->ioaddr)
498 			return -ENOMEM;
499 	}
500 
501 	while (count) {
502 		size_t filled;
503 
504 		if (count >= 4 && !(off % 4)) {
505 			u32 val;
506 
507 			if (copy_from_user(&val, buf, 4))
508 				goto err;
509 			iowrite32(val, reg->ioaddr + off);
510 
511 			filled = 4;
512 		} else if (count >= 2 && !(off % 2)) {
513 			u16 val;
514 
515 			if (copy_from_user(&val, buf, 2))
516 				goto err;
517 			iowrite16(val, reg->ioaddr + off);
518 
519 			filled = 2;
520 		} else {
521 			u8 val;
522 
523 			if (copy_from_user(&val, buf, 1))
524 				goto err;
525 			iowrite8(val, reg->ioaddr + off);
526 
527 			filled = 1;
528 		}
529 
530 		count -= filled;
531 		done += filled;
532 		off += filled;
533 		buf += filled;
534 	}
535 
536 	return done;
537 err:
538 	return -EFAULT;
539 }
540 
541 static ssize_t vfio_platform_write(void *device_data, const char __user *buf,
542 				   size_t count, loff_t *ppos)
543 {
544 	struct vfio_platform_device *vdev = device_data;
545 	unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
546 	loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
547 
548 	if (index >= vdev->num_regions)
549 		return -EINVAL;
550 
551 	if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE))
552 		return -EINVAL;
553 
554 	if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
555 		return vfio_platform_write_mmio(&vdev->regions[index],
556 							buf, count, off);
557 	else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
558 		return -EINVAL; /* not implemented */
559 
560 	return -EINVAL;
561 }
562 
563 static int vfio_platform_mmap_mmio(struct vfio_platform_region region,
564 				   struct vm_area_struct *vma)
565 {
566 	u64 req_len, pgoff, req_start;
567 
568 	req_len = vma->vm_end - vma->vm_start;
569 	pgoff = vma->vm_pgoff &
570 		((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
571 	req_start = pgoff << PAGE_SHIFT;
572 
573 	if (region.size < PAGE_SIZE || req_start + req_len > region.size)
574 		return -EINVAL;
575 
576 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
577 	vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff;
578 
579 	return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
580 			       req_len, vma->vm_page_prot);
581 }
582 
583 static int vfio_platform_mmap(void *device_data, struct vm_area_struct *vma)
584 {
585 	struct vfio_platform_device *vdev = device_data;
586 	unsigned int index;
587 
588 	index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT);
589 
590 	if (vma->vm_end < vma->vm_start)
591 		return -EINVAL;
592 	if (!(vma->vm_flags & VM_SHARED))
593 		return -EINVAL;
594 	if (index >= vdev->num_regions)
595 		return -EINVAL;
596 	if (vma->vm_start & ~PAGE_MASK)
597 		return -EINVAL;
598 	if (vma->vm_end & ~PAGE_MASK)
599 		return -EINVAL;
600 
601 	if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP))
602 		return -EINVAL;
603 
604 	if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)
605 			&& (vma->vm_flags & VM_READ))
606 		return -EINVAL;
607 
608 	if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)
609 			&& (vma->vm_flags & VM_WRITE))
610 		return -EINVAL;
611 
612 	vma->vm_private_data = vdev;
613 
614 	if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
615 		return vfio_platform_mmap_mmio(vdev->regions[index], vma);
616 
617 	else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
618 		return -EINVAL; /* not implemented */
619 
620 	return -EINVAL;
621 }
622 
623 static const struct vfio_device_ops vfio_platform_ops = {
624 	.name		= "vfio-platform",
625 	.open		= vfio_platform_open,
626 	.release	= vfio_platform_release,
627 	.ioctl		= vfio_platform_ioctl,
628 	.read		= vfio_platform_read,
629 	.write		= vfio_platform_write,
630 	.mmap		= vfio_platform_mmap,
631 };
632 
633 static int vfio_platform_of_probe(struct vfio_platform_device *vdev,
634 			   struct device *dev)
635 {
636 	int ret;
637 
638 	ret = device_property_read_string(dev, "compatible",
639 					  &vdev->compat);
640 	if (ret)
641 		pr_err("VFIO: Cannot retrieve compat for %s\n", vdev->name);
642 
643 	return ret;
644 }
645 
646 /*
647  * There can be two kernel build combinations. One build where
648  * ACPI is not selected in Kconfig and another one with the ACPI Kconfig.
649  *
650  * In the first case, vfio_platform_acpi_probe will return since
651  * acpi_disabled is 1. DT user will not see any kind of messages from
652  * ACPI.
653  *
654  * In the second case, both DT and ACPI is compiled in but the system is
655  * booting with any of these combinations.
656  *
657  * If the firmware is DT type, then acpi_disabled is 1. The ACPI probe routine
658  * terminates immediately without any messages.
659  *
660  * If the firmware is ACPI type, then acpi_disabled is 0. All other checks are
661  * valid checks. We cannot claim that this system is DT.
662  */
663 int vfio_platform_probe_common(struct vfio_platform_device *vdev,
664 			       struct device *dev)
665 {
666 	struct iommu_group *group;
667 	int ret;
668 
669 	if (!vdev)
670 		return -EINVAL;
671 
672 	ret = vfio_platform_acpi_probe(vdev, dev);
673 	if (ret)
674 		ret = vfio_platform_of_probe(vdev, dev);
675 
676 	if (ret)
677 		return ret;
678 
679 	vdev->device = dev;
680 
681 	ret = vfio_platform_get_reset(vdev);
682 	if (ret && vdev->reset_required) {
683 		pr_err("VFIO: No reset function found for device %s\n",
684 		       vdev->name);
685 		return ret;
686 	}
687 
688 	group = vfio_iommu_group_get(dev);
689 	if (!group) {
690 		pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
691 		ret = -EINVAL;
692 		goto put_reset;
693 	}
694 
695 	ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
696 	if (ret)
697 		goto put_iommu;
698 
699 	mutex_init(&vdev->igate);
700 
701 	pm_runtime_enable(vdev->device);
702 	return 0;
703 
704 put_iommu:
705 	vfio_iommu_group_put(group, dev);
706 put_reset:
707 	vfio_platform_put_reset(vdev);
708 	return ret;
709 }
710 EXPORT_SYMBOL_GPL(vfio_platform_probe_common);
711 
712 struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
713 {
714 	struct vfio_platform_device *vdev;
715 
716 	vdev = vfio_del_group_dev(dev);
717 
718 	if (vdev) {
719 		pm_runtime_disable(vdev->device);
720 		vfio_platform_put_reset(vdev);
721 		vfio_iommu_group_put(dev->iommu_group, dev);
722 	}
723 
724 	return vdev;
725 }
726 EXPORT_SYMBOL_GPL(vfio_platform_remove_common);
727 
728 void __vfio_platform_register_reset(struct vfio_platform_reset_node *node)
729 {
730 	mutex_lock(&driver_lock);
731 	list_add(&node->link, &reset_list);
732 	mutex_unlock(&driver_lock);
733 }
734 EXPORT_SYMBOL_GPL(__vfio_platform_register_reset);
735 
736 void vfio_platform_unregister_reset(const char *compat,
737 				    vfio_platform_reset_fn_t fn)
738 {
739 	struct vfio_platform_reset_node *iter, *temp;
740 
741 	mutex_lock(&driver_lock);
742 	list_for_each_entry_safe(iter, temp, &reset_list, link) {
743 		if (!strcmp(iter->compat, compat) && (iter->of_reset == fn)) {
744 			list_del(&iter->link);
745 			break;
746 		}
747 	}
748 
749 	mutex_unlock(&driver_lock);
750 
751 }
752 EXPORT_SYMBOL_GPL(vfio_platform_unregister_reset);
753 
754 MODULE_VERSION(DRIVER_VERSION);
755 MODULE_LICENSE("GPL v2");
756 MODULE_AUTHOR(DRIVER_AUTHOR);
757 MODULE_DESCRIPTION(DRIVER_DESC);
758