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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/slab.h>
21 #include <linux/types.h>
22 #include <linux/uaccess.h>
23 #include <linux/vfio.h>
24 
25 #include "vfio_platform_private.h"
26 
27 #define DRIVER_VERSION  "0.10"
28 #define DRIVER_AUTHOR   "Antonios Motakis <a.motakis@virtualopensystems.com>"
29 #define DRIVER_DESC     "VFIO platform base module"
30 
31 #define VFIO_PLATFORM_IS_ACPI(vdev) ((vdev)->acpihid != NULL)
32 
33 static LIST_HEAD(reset_list);
34 static DEFINE_MUTEX(driver_lock);
35 
vfio_platform_lookup_reset(const char * compat,struct module ** module)36 static vfio_platform_reset_fn_t vfio_platform_lookup_reset(const char *compat,
37 					struct module **module)
38 {
39 	struct vfio_platform_reset_node *iter;
40 	vfio_platform_reset_fn_t reset_fn = NULL;
41 
42 	mutex_lock(&driver_lock);
43 	list_for_each_entry(iter, &reset_list, link) {
44 		if (!strcmp(iter->compat, compat) &&
45 			try_module_get(iter->owner)) {
46 			*module = iter->owner;
47 			reset_fn = iter->of_reset;
48 			break;
49 		}
50 	}
51 	mutex_unlock(&driver_lock);
52 	return reset_fn;
53 }
54 
vfio_platform_acpi_probe(struct vfio_platform_device * vdev,struct device * dev)55 static int vfio_platform_acpi_probe(struct vfio_platform_device *vdev,
56 				    struct device *dev)
57 {
58 	struct acpi_device *adev;
59 
60 	if (acpi_disabled)
61 		return -ENOENT;
62 
63 	adev = ACPI_COMPANION(dev);
64 	if (!adev) {
65 		pr_err("VFIO: ACPI companion device not found for %s\n",
66 			vdev->name);
67 		return -ENODEV;
68 	}
69 
70 #ifdef CONFIG_ACPI
71 	vdev->acpihid = acpi_device_hid(adev);
72 #endif
73 	return WARN_ON(!vdev->acpihid) ? -EINVAL : 0;
74 }
75 
vfio_platform_acpi_call_reset(struct vfio_platform_device * vdev,const char ** extra_dbg)76 static int vfio_platform_acpi_call_reset(struct vfio_platform_device *vdev,
77 				  const char **extra_dbg)
78 {
79 #ifdef CONFIG_ACPI
80 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
81 	struct device *dev = vdev->device;
82 	acpi_handle handle = ACPI_HANDLE(dev);
83 	acpi_status acpi_ret;
84 
85 	acpi_ret = acpi_evaluate_object(handle, "_RST", NULL, &buffer);
86 	if (ACPI_FAILURE(acpi_ret)) {
87 		if (extra_dbg)
88 			*extra_dbg = acpi_format_exception(acpi_ret);
89 		return -EINVAL;
90 	}
91 
92 	return 0;
93 #else
94 	return -ENOENT;
95 #endif
96 }
97 
vfio_platform_acpi_has_reset(struct vfio_platform_device * vdev)98 static bool vfio_platform_acpi_has_reset(struct vfio_platform_device *vdev)
99 {
100 #ifdef CONFIG_ACPI
101 	struct device *dev = vdev->device;
102 	acpi_handle handle = ACPI_HANDLE(dev);
103 
104 	return acpi_has_method(handle, "_RST");
105 #else
106 	return false;
107 #endif
108 }
109 
vfio_platform_has_reset(struct vfio_platform_device * vdev)110 static bool vfio_platform_has_reset(struct vfio_platform_device *vdev)
111 {
112 	if (VFIO_PLATFORM_IS_ACPI(vdev))
113 		return vfio_platform_acpi_has_reset(vdev);
114 
115 	return vdev->of_reset ? true : false;
116 }
117 
vfio_platform_get_reset(struct vfio_platform_device * vdev)118 static int vfio_platform_get_reset(struct vfio_platform_device *vdev)
119 {
120 	if (VFIO_PLATFORM_IS_ACPI(vdev))
121 		return vfio_platform_acpi_has_reset(vdev) ? 0 : -ENOENT;
122 
123 	vdev->of_reset = vfio_platform_lookup_reset(vdev->compat,
124 						    &vdev->reset_module);
125 	if (!vdev->of_reset) {
126 		request_module("vfio-reset:%s", vdev->compat);
127 		vdev->of_reset = vfio_platform_lookup_reset(vdev->compat,
128 							&vdev->reset_module);
129 	}
130 
131 	return vdev->of_reset ? 0 : -ENOENT;
132 }
133 
vfio_platform_put_reset(struct vfio_platform_device * vdev)134 static void vfio_platform_put_reset(struct vfio_platform_device *vdev)
135 {
136 	if (VFIO_PLATFORM_IS_ACPI(vdev))
137 		return;
138 
139 	if (vdev->of_reset)
140 		module_put(vdev->reset_module);
141 }
142 
vfio_platform_regions_init(struct vfio_platform_device * vdev)143 static int vfio_platform_regions_init(struct vfio_platform_device *vdev)
144 {
145 	int cnt = 0, i;
146 
147 	while (vdev->get_resource(vdev, cnt))
148 		cnt++;
149 
150 	vdev->regions = kcalloc(cnt, sizeof(struct vfio_platform_region),
151 				GFP_KERNEL);
152 	if (!vdev->regions)
153 		return -ENOMEM;
154 
155 	for (i = 0; i < cnt;  i++) {
156 		struct resource *res =
157 			vdev->get_resource(vdev, i);
158 
159 		if (!res)
160 			goto err;
161 
162 		vdev->regions[i].addr = res->start;
163 		vdev->regions[i].size = resource_size(res);
164 		vdev->regions[i].flags = 0;
165 
166 		switch (resource_type(res)) {
167 		case IORESOURCE_MEM:
168 			vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_MMIO;
169 			vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ;
170 			if (!(res->flags & IORESOURCE_READONLY))
171 				vdev->regions[i].flags |=
172 					VFIO_REGION_INFO_FLAG_WRITE;
173 
174 			/*
175 			 * Only regions addressed with PAGE granularity may be
176 			 * MMAPed securely.
177 			 */
178 			if (!(vdev->regions[i].addr & ~PAGE_MASK) &&
179 					!(vdev->regions[i].size & ~PAGE_MASK))
180 				vdev->regions[i].flags |=
181 					VFIO_REGION_INFO_FLAG_MMAP;
182 
183 			break;
184 		case IORESOURCE_IO:
185 			vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_PIO;
186 			break;
187 		default:
188 			goto err;
189 		}
190 	}
191 
192 	vdev->num_regions = cnt;
193 
194 	return 0;
195 err:
196 	kfree(vdev->regions);
197 	return -EINVAL;
198 }
199 
vfio_platform_regions_cleanup(struct vfio_platform_device * vdev)200 static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev)
201 {
202 	int i;
203 
204 	for (i = 0; i < vdev->num_regions; i++)
205 		iounmap(vdev->regions[i].ioaddr);
206 
207 	vdev->num_regions = 0;
208 	kfree(vdev->regions);
209 }
210 
vfio_platform_call_reset(struct vfio_platform_device * vdev,const char ** extra_dbg)211 static int vfio_platform_call_reset(struct vfio_platform_device *vdev,
212 				    const char **extra_dbg)
213 {
214 	if (VFIO_PLATFORM_IS_ACPI(vdev)) {
215 		dev_info(vdev->device, "reset\n");
216 		return vfio_platform_acpi_call_reset(vdev, extra_dbg);
217 	} else if (vdev->of_reset) {
218 		dev_info(vdev->device, "reset\n");
219 		return vdev->of_reset(vdev);
220 	}
221 
222 	dev_warn(vdev->device, "no reset function found!\n");
223 	return -EINVAL;
224 }
225 
vfio_platform_release(void * device_data)226 static void vfio_platform_release(void *device_data)
227 {
228 	struct vfio_platform_device *vdev = device_data;
229 
230 	mutex_lock(&driver_lock);
231 
232 	if (!(--vdev->refcnt)) {
233 		const char *extra_dbg = NULL;
234 		int ret;
235 
236 		ret = vfio_platform_call_reset(vdev, &extra_dbg);
237 		if (ret && vdev->reset_required) {
238 			dev_warn(vdev->device, "reset driver is required and reset call failed in release (%d) %s\n",
239 				 ret, extra_dbg ? extra_dbg : "");
240 			WARN_ON(1);
241 		}
242 		vfio_platform_regions_cleanup(vdev);
243 		vfio_platform_irq_cleanup(vdev);
244 	}
245 
246 	mutex_unlock(&driver_lock);
247 
248 	module_put(vdev->parent_module);
249 }
250 
vfio_platform_open(void * device_data)251 static int vfio_platform_open(void *device_data)
252 {
253 	struct vfio_platform_device *vdev = device_data;
254 	int ret;
255 
256 	if (!try_module_get(vdev->parent_module))
257 		return -ENODEV;
258 
259 	mutex_lock(&driver_lock);
260 
261 	if (!vdev->refcnt) {
262 		const char *extra_dbg = NULL;
263 
264 		ret = vfio_platform_regions_init(vdev);
265 		if (ret)
266 			goto err_reg;
267 
268 		ret = vfio_platform_irq_init(vdev);
269 		if (ret)
270 			goto err_irq;
271 
272 		ret = vfio_platform_call_reset(vdev, &extra_dbg);
273 		if (ret && vdev->reset_required) {
274 			dev_warn(vdev->device, "reset driver is required and reset call failed in open (%d) %s\n",
275 				 ret, extra_dbg ? extra_dbg : "");
276 			goto err_rst;
277 		}
278 	}
279 
280 	vdev->refcnt++;
281 
282 	mutex_unlock(&driver_lock);
283 	return 0;
284 
285 err_rst:
286 	vfio_platform_irq_cleanup(vdev);
287 err_irq:
288 	vfio_platform_regions_cleanup(vdev);
289 err_reg:
290 	mutex_unlock(&driver_lock);
291 	module_put(THIS_MODULE);
292 	return ret;
293 }
294 
vfio_platform_ioctl(void * device_data,unsigned int cmd,unsigned long arg)295 static long vfio_platform_ioctl(void *device_data,
296 				unsigned int cmd, unsigned long arg)
297 {
298 	struct vfio_platform_device *vdev = device_data;
299 	unsigned long minsz;
300 
301 	if (cmd == VFIO_DEVICE_GET_INFO) {
302 		struct vfio_device_info info;
303 
304 		minsz = offsetofend(struct vfio_device_info, num_irqs);
305 
306 		if (copy_from_user(&info, (void __user *)arg, minsz))
307 			return -EFAULT;
308 
309 		if (info.argsz < minsz)
310 			return -EINVAL;
311 
312 		if (vfio_platform_has_reset(vdev))
313 			vdev->flags |= VFIO_DEVICE_FLAGS_RESET;
314 		info.flags = vdev->flags;
315 		info.num_regions = vdev->num_regions;
316 		info.num_irqs = vdev->num_irqs;
317 
318 		return copy_to_user((void __user *)arg, &info, minsz) ?
319 			-EFAULT : 0;
320 
321 	} else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
322 		struct vfio_region_info info;
323 
324 		minsz = offsetofend(struct vfio_region_info, offset);
325 
326 		if (copy_from_user(&info, (void __user *)arg, minsz))
327 			return -EFAULT;
328 
329 		if (info.argsz < minsz)
330 			return -EINVAL;
331 
332 		if (info.index >= vdev->num_regions)
333 			return -EINVAL;
334 
335 		/* map offset to the physical address  */
336 		info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index);
337 		info.size = vdev->regions[info.index].size;
338 		info.flags = vdev->regions[info.index].flags;
339 
340 		return copy_to_user((void __user *)arg, &info, minsz) ?
341 			-EFAULT : 0;
342 
343 	} else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
344 		struct vfio_irq_info info;
345 
346 		minsz = offsetofend(struct vfio_irq_info, count);
347 
348 		if (copy_from_user(&info, (void __user *)arg, minsz))
349 			return -EFAULT;
350 
351 		if (info.argsz < minsz)
352 			return -EINVAL;
353 
354 		if (info.index >= vdev->num_irqs)
355 			return -EINVAL;
356 
357 		info.flags = vdev->irqs[info.index].flags;
358 		info.count = vdev->irqs[info.index].count;
359 
360 		return copy_to_user((void __user *)arg, &info, minsz) ?
361 			-EFAULT : 0;
362 
363 	} else if (cmd == VFIO_DEVICE_SET_IRQS) {
364 		struct vfio_irq_set hdr;
365 		u8 *data = NULL;
366 		int ret = 0;
367 
368 		minsz = offsetofend(struct vfio_irq_set, count);
369 
370 		if (copy_from_user(&hdr, (void __user *)arg, minsz))
371 			return -EFAULT;
372 
373 		if (hdr.argsz < minsz)
374 			return -EINVAL;
375 
376 		if (hdr.index >= vdev->num_irqs)
377 			return -EINVAL;
378 
379 		if (hdr.flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
380 				  VFIO_IRQ_SET_ACTION_TYPE_MASK))
381 			return -EINVAL;
382 
383 		if (!(hdr.flags & VFIO_IRQ_SET_DATA_NONE)) {
384 			size_t size;
385 
386 			if (hdr.flags & VFIO_IRQ_SET_DATA_BOOL)
387 				size = sizeof(uint8_t);
388 			else if (hdr.flags & VFIO_IRQ_SET_DATA_EVENTFD)
389 				size = sizeof(int32_t);
390 			else
391 				return -EINVAL;
392 
393 			if (hdr.argsz - minsz < size)
394 				return -EINVAL;
395 
396 			data = memdup_user((void __user *)(arg + minsz), size);
397 			if (IS_ERR(data))
398 				return PTR_ERR(data);
399 		}
400 
401 		mutex_lock(&vdev->igate);
402 
403 		ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
404 						   hdr.start, hdr.count, data);
405 		mutex_unlock(&vdev->igate);
406 		kfree(data);
407 
408 		return ret;
409 
410 	} else if (cmd == VFIO_DEVICE_RESET) {
411 		return vfio_platform_call_reset(vdev, NULL);
412 	}
413 
414 	return -ENOTTY;
415 }
416 
vfio_platform_read_mmio(struct vfio_platform_region * reg,char __user * buf,size_t count,loff_t off)417 static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg,
418 				       char __user *buf, size_t count,
419 				       loff_t off)
420 {
421 	unsigned int done = 0;
422 
423 	if (!reg->ioaddr) {
424 		reg->ioaddr =
425 			ioremap_nocache(reg->addr, reg->size);
426 
427 		if (!reg->ioaddr)
428 			return -ENOMEM;
429 	}
430 
431 	while (count) {
432 		size_t filled;
433 
434 		if (count >= 4 && !(off % 4)) {
435 			u32 val;
436 
437 			val = ioread32(reg->ioaddr + off);
438 			if (copy_to_user(buf, &val, 4))
439 				goto err;
440 
441 			filled = 4;
442 		} else if (count >= 2 && !(off % 2)) {
443 			u16 val;
444 
445 			val = ioread16(reg->ioaddr + off);
446 			if (copy_to_user(buf, &val, 2))
447 				goto err;
448 
449 			filled = 2;
450 		} else {
451 			u8 val;
452 
453 			val = ioread8(reg->ioaddr + off);
454 			if (copy_to_user(buf, &val, 1))
455 				goto err;
456 
457 			filled = 1;
458 		}
459 
460 
461 		count -= filled;
462 		done += filled;
463 		off += filled;
464 		buf += filled;
465 	}
466 
467 	return done;
468 err:
469 	return -EFAULT;
470 }
471 
vfio_platform_read(void * device_data,char __user * buf,size_t count,loff_t * ppos)472 static ssize_t vfio_platform_read(void *device_data, char __user *buf,
473 				  size_t count, loff_t *ppos)
474 {
475 	struct vfio_platform_device *vdev = device_data;
476 	unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
477 	loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
478 
479 	if (index >= vdev->num_regions)
480 		return -EINVAL;
481 
482 	if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ))
483 		return -EINVAL;
484 
485 	if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
486 		return vfio_platform_read_mmio(&vdev->regions[index],
487 							buf, count, off);
488 	else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
489 		return -EINVAL; /* not implemented */
490 
491 	return -EINVAL;
492 }
493 
vfio_platform_write_mmio(struct vfio_platform_region * reg,const char __user * buf,size_t count,loff_t off)494 static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg,
495 					const char __user *buf, size_t count,
496 					loff_t off)
497 {
498 	unsigned int done = 0;
499 
500 	if (!reg->ioaddr) {
501 		reg->ioaddr =
502 			ioremap_nocache(reg->addr, reg->size);
503 
504 		if (!reg->ioaddr)
505 			return -ENOMEM;
506 	}
507 
508 	while (count) {
509 		size_t filled;
510 
511 		if (count >= 4 && !(off % 4)) {
512 			u32 val;
513 
514 			if (copy_from_user(&val, buf, 4))
515 				goto err;
516 			iowrite32(val, reg->ioaddr + off);
517 
518 			filled = 4;
519 		} else if (count >= 2 && !(off % 2)) {
520 			u16 val;
521 
522 			if (copy_from_user(&val, buf, 2))
523 				goto err;
524 			iowrite16(val, reg->ioaddr + off);
525 
526 			filled = 2;
527 		} else {
528 			u8 val;
529 
530 			if (copy_from_user(&val, buf, 1))
531 				goto err;
532 			iowrite8(val, reg->ioaddr + off);
533 
534 			filled = 1;
535 		}
536 
537 		count -= filled;
538 		done += filled;
539 		off += filled;
540 		buf += filled;
541 	}
542 
543 	return done;
544 err:
545 	return -EFAULT;
546 }
547 
vfio_platform_write(void * device_data,const char __user * buf,size_t count,loff_t * ppos)548 static ssize_t vfio_platform_write(void *device_data, const char __user *buf,
549 				   size_t count, loff_t *ppos)
550 {
551 	struct vfio_platform_device *vdev = device_data;
552 	unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
553 	loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;
554 
555 	if (index >= vdev->num_regions)
556 		return -EINVAL;
557 
558 	if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE))
559 		return -EINVAL;
560 
561 	if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
562 		return vfio_platform_write_mmio(&vdev->regions[index],
563 							buf, count, off);
564 	else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
565 		return -EINVAL; /* not implemented */
566 
567 	return -EINVAL;
568 }
569 
vfio_platform_mmap_mmio(struct vfio_platform_region region,struct vm_area_struct * vma)570 static int vfio_platform_mmap_mmio(struct vfio_platform_region region,
571 				   struct vm_area_struct *vma)
572 {
573 	u64 req_len, pgoff, req_start;
574 
575 	req_len = vma->vm_end - vma->vm_start;
576 	pgoff = vma->vm_pgoff &
577 		((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
578 	req_start = pgoff << PAGE_SHIFT;
579 
580 	if (region.size < PAGE_SIZE || req_start + req_len > region.size)
581 		return -EINVAL;
582 
583 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
584 	vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff;
585 
586 	return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
587 			       req_len, vma->vm_page_prot);
588 }
589 
vfio_platform_mmap(void * device_data,struct vm_area_struct * vma)590 static int vfio_platform_mmap(void *device_data, struct vm_area_struct *vma)
591 {
592 	struct vfio_platform_device *vdev = device_data;
593 	unsigned int index;
594 
595 	index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT);
596 
597 	if (vma->vm_end < vma->vm_start)
598 		return -EINVAL;
599 	if (!(vma->vm_flags & VM_SHARED))
600 		return -EINVAL;
601 	if (index >= vdev->num_regions)
602 		return -EINVAL;
603 	if (vma->vm_start & ~PAGE_MASK)
604 		return -EINVAL;
605 	if (vma->vm_end & ~PAGE_MASK)
606 		return -EINVAL;
607 
608 	if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP))
609 		return -EINVAL;
610 
611 	if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)
612 			&& (vma->vm_flags & VM_READ))
613 		return -EINVAL;
614 
615 	if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)
616 			&& (vma->vm_flags & VM_WRITE))
617 		return -EINVAL;
618 
619 	vma->vm_private_data = vdev;
620 
621 	if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
622 		return vfio_platform_mmap_mmio(vdev->regions[index], vma);
623 
624 	else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
625 		return -EINVAL; /* not implemented */
626 
627 	return -EINVAL;
628 }
629 
630 static const struct vfio_device_ops vfio_platform_ops = {
631 	.name		= "vfio-platform",
632 	.open		= vfio_platform_open,
633 	.release	= vfio_platform_release,
634 	.ioctl		= vfio_platform_ioctl,
635 	.read		= vfio_platform_read,
636 	.write		= vfio_platform_write,
637 	.mmap		= vfio_platform_mmap,
638 };
639 
vfio_platform_of_probe(struct vfio_platform_device * vdev,struct device * dev)640 static int vfio_platform_of_probe(struct vfio_platform_device *vdev,
641 			   struct device *dev)
642 {
643 	int ret;
644 
645 	ret = device_property_read_string(dev, "compatible",
646 					  &vdev->compat);
647 	if (ret)
648 		pr_err("VFIO: cannot retrieve compat for %s\n",
649 			vdev->name);
650 
651 	return ret;
652 }
653 
654 /*
655  * There can be two kernel build combinations. One build where
656  * ACPI is not selected in Kconfig and another one with the ACPI Kconfig.
657  *
658  * In the first case, vfio_platform_acpi_probe will return since
659  * acpi_disabled is 1. DT user will not see any kind of messages from
660  * ACPI.
661  *
662  * In the second case, both DT and ACPI is compiled in but the system is
663  * booting with any of these combinations.
664  *
665  * If the firmware is DT type, then acpi_disabled is 1. The ACPI probe routine
666  * terminates immediately without any messages.
667  *
668  * If the firmware is ACPI type, then acpi_disabled is 0. All other checks are
669  * valid checks. We cannot claim that this system is DT.
670  */
vfio_platform_probe_common(struct vfio_platform_device * vdev,struct device * dev)671 int vfio_platform_probe_common(struct vfio_platform_device *vdev,
672 			       struct device *dev)
673 {
674 	struct iommu_group *group;
675 	int ret;
676 
677 	if (!vdev)
678 		return -EINVAL;
679 
680 	ret = vfio_platform_acpi_probe(vdev, dev);
681 	if (ret)
682 		ret = vfio_platform_of_probe(vdev, dev);
683 
684 	if (ret)
685 		return ret;
686 
687 	vdev->device = dev;
688 
689 	ret = vfio_platform_get_reset(vdev);
690 	if (ret && vdev->reset_required) {
691 		pr_err("vfio: no reset function found for device %s\n",
692 		       vdev->name);
693 		return ret;
694 	}
695 
696 	group = vfio_iommu_group_get(dev);
697 	if (!group) {
698 		pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
699 		return -EINVAL;
700 	}
701 
702 	ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
703 	if (ret) {
704 		vfio_iommu_group_put(group, dev);
705 		return ret;
706 	}
707 
708 	mutex_init(&vdev->igate);
709 
710 	return 0;
711 }
712 EXPORT_SYMBOL_GPL(vfio_platform_probe_common);
713 
vfio_platform_remove_common(struct device * dev)714 struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
715 {
716 	struct vfio_platform_device *vdev;
717 
718 	vdev = vfio_del_group_dev(dev);
719 
720 	if (vdev) {
721 		vfio_platform_put_reset(vdev);
722 		vfio_iommu_group_put(dev->iommu_group, dev);
723 	}
724 
725 	return vdev;
726 }
727 EXPORT_SYMBOL_GPL(vfio_platform_remove_common);
728 
__vfio_platform_register_reset(struct vfio_platform_reset_node * node)729 void __vfio_platform_register_reset(struct vfio_platform_reset_node *node)
730 {
731 	mutex_lock(&driver_lock);
732 	list_add(&node->link, &reset_list);
733 	mutex_unlock(&driver_lock);
734 }
735 EXPORT_SYMBOL_GPL(__vfio_platform_register_reset);
736 
vfio_platform_unregister_reset(const char * compat,vfio_platform_reset_fn_t fn)737 void vfio_platform_unregister_reset(const char *compat,
738 				    vfio_platform_reset_fn_t fn)
739 {
740 	struct vfio_platform_reset_node *iter, *temp;
741 
742 	mutex_lock(&driver_lock);
743 	list_for_each_entry_safe(iter, temp, &reset_list, link) {
744 		if (!strcmp(iter->compat, compat) && (iter->of_reset == fn)) {
745 			list_del(&iter->link);
746 			break;
747 		}
748 	}
749 
750 	mutex_unlock(&driver_lock);
751 
752 }
753 EXPORT_SYMBOL_GPL(vfio_platform_unregister_reset);
754 
755 MODULE_VERSION(DRIVER_VERSION);
756 MODULE_LICENSE("GPL v2");
757 MODULE_AUTHOR(DRIVER_AUTHOR);
758 MODULE_DESCRIPTION(DRIVER_DESC);
759