Boot Linux faster!

Check our new training course

Boot Linux faster!

Check our new training course
and Creative Commons CC-BY-SA
lecture and lab materials

Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
/*
 * Copyright (C) 2013 - Virtual Open Systems
 * Author: Antonios Motakis <a.motakis@virtualopensystems.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2, as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/device.h>
#include <linux/iommu.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/vfio.h>

#include "vfio_platform_private.h"

#define DRIVER_VERSION  "0.10"
#define DRIVER_AUTHOR   "Antonios Motakis <a.motakis@virtualopensystems.com>"
#define DRIVER_DESC     "VFIO platform base module"

static LIST_HEAD(reset_list);
static DEFINE_MUTEX(driver_lock);

static vfio_platform_reset_fn_t vfio_platform_lookup_reset(const char *compat,
					struct module **module)
{
	struct vfio_platform_reset_node *iter;
	vfio_platform_reset_fn_t reset_fn = NULL;

	mutex_lock(&driver_lock);
	list_for_each_entry(iter, &reset_list, link) {
		if (!strcmp(iter->compat, compat) &&
			try_module_get(iter->owner)) {
			*module = iter->owner;
			reset_fn = iter->reset;
			break;
		}
	}
	mutex_unlock(&driver_lock);
	return reset_fn;
}

static void vfio_platform_get_reset(struct vfio_platform_device *vdev)
{
	char modname[256];

	vdev->reset = vfio_platform_lookup_reset(vdev->compat,
						&vdev->reset_module);
	if (!vdev->reset) {
		snprintf(modname, 256, "vfio-reset:%s", vdev->compat);
		request_module(modname);
		vdev->reset = vfio_platform_lookup_reset(vdev->compat,
							 &vdev->reset_module);
	}
}

static void vfio_platform_put_reset(struct vfio_platform_device *vdev)
{
	if (vdev->reset)
		module_put(vdev->reset_module);
}

static int vfio_platform_regions_init(struct vfio_platform_device *vdev)
{
	int cnt = 0, i;

	while (vdev->get_resource(vdev, cnt))
		cnt++;

	vdev->regions = kcalloc(cnt, sizeof(struct vfio_platform_region),
				GFP_KERNEL);
	if (!vdev->regions)
		return -ENOMEM;

	for (i = 0; i < cnt;  i++) {
		struct resource *res =
			vdev->get_resource(vdev, i);

		if (!res)
			goto err;

		vdev->regions[i].addr = res->start;
		vdev->regions[i].size = resource_size(res);
		vdev->regions[i].flags = 0;

		switch (resource_type(res)) {
		case IORESOURCE_MEM:
			vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_MMIO;
			vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ;
			if (!(res->flags & IORESOURCE_READONLY))
				vdev->regions[i].flags |=
					VFIO_REGION_INFO_FLAG_WRITE;

			/*
			 * Only regions addressed with PAGE granularity may be
			 * MMAPed securely.
			 */
			if (!(vdev->regions[i].addr & ~PAGE_MASK) &&
					!(vdev->regions[i].size & ~PAGE_MASK))
				vdev->regions[i].flags |=
					VFIO_REGION_INFO_FLAG_MMAP;

			break;
		case IORESOURCE_IO:
			vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_PIO;
			break;
		default:
			goto err;
		}
	}

	vdev->num_regions = cnt;

	return 0;
err:
	kfree(vdev->regions);
	return -EINVAL;
}

static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev)
{
	int i;

	for (i = 0; i < vdev->num_regions; i++)
		iounmap(vdev->regions[i].ioaddr);

	vdev->num_regions = 0;
	kfree(vdev->regions);
}

static void vfio_platform_release(void *device_data)
{
	struct vfio_platform_device *vdev = device_data;

	mutex_lock(&driver_lock);

	if (!(--vdev->refcnt)) {
		if (vdev->reset) {
			dev_info(vdev->device, "reset\n");
			vdev->reset(vdev);
		} else {
			dev_warn(vdev->device, "no reset function found!\n");
		}
		vfio_platform_regions_cleanup(vdev);
		vfio_platform_irq_cleanup(vdev);
	}

	mutex_unlock(&driver_lock);

	module_put(vdev->parent_module);
}

static int vfio_platform_open(void *device_data)
{
	struct vfio_platform_device *vdev = device_data;
	int ret;

	if (!try_module_get(vdev->parent_module))
		return -ENODEV;

	mutex_lock(&driver_lock);

	if (!vdev->refcnt) {
		ret = vfio_platform_regions_init(vdev);
		if (ret)
			goto err_reg;

		ret = vfio_platform_irq_init(vdev);
		if (ret)
			goto err_irq;

		if (vdev->reset) {
			dev_info(vdev->device, "reset\n");
			vdev->reset(vdev);
		} else {
			dev_warn(vdev->device, "no reset function found!\n");
		}
	}

	vdev->refcnt++;

	mutex_unlock(&driver_lock);
	return 0;

err_irq:
	vfio_platform_regions_cleanup(vdev);
err_reg:
	mutex_unlock(&driver_lock);
	module_put(THIS_MODULE);
	return ret;
}

static long vfio_platform_ioctl(void *device_data,
				unsigned int cmd, unsigned long arg)
{
	struct vfio_platform_device *vdev = device_data;
	unsigned long minsz;

	if (cmd == VFIO_DEVICE_GET_INFO) {
		struct vfio_device_info info;

		minsz = offsetofend(struct vfio_device_info, num_irqs);

		if (copy_from_user(&info, (void __user *)arg, minsz))
			return -EFAULT;

		if (info.argsz < minsz)
			return -EINVAL;

		if (vdev->reset)
			vdev->flags |= VFIO_DEVICE_FLAGS_RESET;
		info.flags = vdev->flags;
		info.num_regions = vdev->num_regions;
		info.num_irqs = vdev->num_irqs;

		return copy_to_user((void __user *)arg, &info, minsz);

	} else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
		struct vfio_region_info info;

		minsz = offsetofend(struct vfio_region_info, offset);

		if (copy_from_user(&info, (void __user *)arg, minsz))
			return -EFAULT;

		if (info.argsz < minsz)
			return -EINVAL;

		if (info.index >= vdev->num_regions)
			return -EINVAL;

		/* map offset to the physical address  */
		info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index);
		info.size = vdev->regions[info.index].size;
		info.flags = vdev->regions[info.index].flags;

		return copy_to_user((void __user *)arg, &info, minsz);

	} else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
		struct vfio_irq_info info;

		minsz = offsetofend(struct vfio_irq_info, count);

		if (copy_from_user(&info, (void __user *)arg, minsz))
			return -EFAULT;

		if (info.argsz < minsz)
			return -EINVAL;

		if (info.index >= vdev->num_irqs)
			return -EINVAL;

		info.flags = vdev->irqs[info.index].flags;
		info.count = vdev->irqs[info.index].count;

		return copy_to_user((void __user *)arg, &info, minsz);

	} else if (cmd == VFIO_DEVICE_SET_IRQS) {
		struct vfio_irq_set hdr;
		u8 *data = NULL;
		int ret = 0;

		minsz = offsetofend(struct vfio_irq_set, count);

		if (copy_from_user(&hdr, (void __user *)arg, minsz))
			return -EFAULT;

		if (hdr.argsz < minsz)
			return -EINVAL;

		if (hdr.index >= vdev->num_irqs)
			return -EINVAL;

		if (hdr.flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
				  VFIO_IRQ_SET_ACTION_TYPE_MASK))
			return -EINVAL;

		if (!(hdr.flags & VFIO_IRQ_SET_DATA_NONE)) {
			size_t size;

			if (hdr.flags & VFIO_IRQ_SET_DATA_BOOL)
				size = sizeof(uint8_t);
			else if (hdr.flags & VFIO_IRQ_SET_DATA_EVENTFD)
				size = sizeof(int32_t);
			else
				return -EINVAL;

			if (hdr.argsz - minsz < size)
				return -EINVAL;

			data = memdup_user((void __user *)(arg + minsz), size);
			if (IS_ERR(data))
				return PTR_ERR(data);
		}

		mutex_lock(&vdev->igate);

		ret = vfio_platform_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
						   hdr.start, hdr.count, data);
		mutex_unlock(&vdev->igate);
		kfree(data);

		return ret;

	} else if (cmd == VFIO_DEVICE_RESET) {
		if (vdev->reset)
			return vdev->reset(vdev);
		else
			return -EINVAL;
	}

	return -ENOTTY;
}

static ssize_t vfio_platform_read_mmio(struct vfio_platform_region *reg,
				       char __user *buf, size_t count,
				       loff_t off)
{
	unsigned int done = 0;

	if (!reg->ioaddr) {
		reg->ioaddr =
			ioremap_nocache(reg->addr, reg->size);

		if (!reg->ioaddr)
			return -ENOMEM;
	}

	while (count) {
		size_t filled;

		if (count >= 4 && !(off % 4)) {
			u32 val;

			val = ioread32(reg->ioaddr + off);
			if (copy_to_user(buf, &val, 4))
				goto err;

			filled = 4;
		} else if (count >= 2 && !(off % 2)) {
			u16 val;

			val = ioread16(reg->ioaddr + off);
			if (copy_to_user(buf, &val, 2))
				goto err;

			filled = 2;
		} else {
			u8 val;

			val = ioread8(reg->ioaddr + off);
			if (copy_to_user(buf, &val, 1))
				goto err;

			filled = 1;
		}


		count -= filled;
		done += filled;
		off += filled;
		buf += filled;
	}

	return done;
err:
	return -EFAULT;
}

static ssize_t vfio_platform_read(void *device_data, char __user *buf,
				  size_t count, loff_t *ppos)
{
	struct vfio_platform_device *vdev = device_data;
	unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
	loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;

	if (index >= vdev->num_regions)
		return -EINVAL;

	if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ))
		return -EINVAL;

	if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
		return vfio_platform_read_mmio(&vdev->regions[index],
							buf, count, off);
	else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
		return -EINVAL; /* not implemented */

	return -EINVAL;
}

static ssize_t vfio_platform_write_mmio(struct vfio_platform_region *reg,
					const char __user *buf, size_t count,
					loff_t off)
{
	unsigned int done = 0;

	if (!reg->ioaddr) {
		reg->ioaddr =
			ioremap_nocache(reg->addr, reg->size);

		if (!reg->ioaddr)
			return -ENOMEM;
	}

	while (count) {
		size_t filled;

		if (count >= 4 && !(off % 4)) {
			u32 val;

			if (copy_from_user(&val, buf, 4))
				goto err;
			iowrite32(val, reg->ioaddr + off);

			filled = 4;
		} else if (count >= 2 && !(off % 2)) {
			u16 val;

			if (copy_from_user(&val, buf, 2))
				goto err;
			iowrite16(val, reg->ioaddr + off);

			filled = 2;
		} else {
			u8 val;

			if (copy_from_user(&val, buf, 1))
				goto err;
			iowrite8(val, reg->ioaddr + off);

			filled = 1;
		}

		count -= filled;
		done += filled;
		off += filled;
		buf += filled;
	}

	return done;
err:
	return -EFAULT;
}

static ssize_t vfio_platform_write(void *device_data, const char __user *buf,
				   size_t count, loff_t *ppos)
{
	struct vfio_platform_device *vdev = device_data;
	unsigned int index = VFIO_PLATFORM_OFFSET_TO_INDEX(*ppos);
	loff_t off = *ppos & VFIO_PLATFORM_OFFSET_MASK;

	if (index >= vdev->num_regions)
		return -EINVAL;

	if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE))
		return -EINVAL;

	if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
		return vfio_platform_write_mmio(&vdev->regions[index],
							buf, count, off);
	else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
		return -EINVAL; /* not implemented */

	return -EINVAL;
}

static int vfio_platform_mmap_mmio(struct vfio_platform_region region,
				   struct vm_area_struct *vma)
{
	u64 req_len, pgoff, req_start;

	req_len = vma->vm_end - vma->vm_start;
	pgoff = vma->vm_pgoff &
		((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
	req_start = pgoff << PAGE_SHIFT;

	if (region.size < PAGE_SIZE || req_start + req_len > region.size)
		return -EINVAL;

	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
	vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff;

	return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
			       req_len, vma->vm_page_prot);
}

static int vfio_platform_mmap(void *device_data, struct vm_area_struct *vma)
{
	struct vfio_platform_device *vdev = device_data;
	unsigned int index;

	index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT);

	if (vma->vm_end < vma->vm_start)
		return -EINVAL;
	if (!(vma->vm_flags & VM_SHARED))
		return -EINVAL;
	if (index >= vdev->num_regions)
		return -EINVAL;
	if (vma->vm_start & ~PAGE_MASK)
		return -EINVAL;
	if (vma->vm_end & ~PAGE_MASK)
		return -EINVAL;

	if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP))
		return -EINVAL;

	if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)
			&& (vma->vm_flags & VM_READ))
		return -EINVAL;

	if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)
			&& (vma->vm_flags & VM_WRITE))
		return -EINVAL;

	vma->vm_private_data = vdev;

	if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO)
		return vfio_platform_mmap_mmio(vdev->regions[index], vma);

	else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO)
		return -EINVAL; /* not implemented */

	return -EINVAL;
}

static const struct vfio_device_ops vfio_platform_ops = {
	.name		= "vfio-platform",
	.open		= vfio_platform_open,
	.release	= vfio_platform_release,
	.ioctl		= vfio_platform_ioctl,
	.read		= vfio_platform_read,
	.write		= vfio_platform_write,
	.mmap		= vfio_platform_mmap,
};

int vfio_platform_probe_common(struct vfio_platform_device *vdev,
			       struct device *dev)
{
	struct iommu_group *group;
	int ret;

	if (!vdev)
		return -EINVAL;

	ret = device_property_read_string(dev, "compatible", &vdev->compat);
	if (ret) {
		pr_err("VFIO: cannot retrieve compat for %s\n", vdev->name);
		return -EINVAL;
	}

	vdev->device = dev;

	group = iommu_group_get(dev);
	if (!group) {
		pr_err("VFIO: No IOMMU group for device %s\n", vdev->name);
		return -EINVAL;
	}

	ret = vfio_add_group_dev(dev, &vfio_platform_ops, vdev);
	if (ret) {
		iommu_group_put(group);
		return ret;
	}

	vfio_platform_get_reset(vdev);

	mutex_init(&vdev->igate);

	return 0;
}
EXPORT_SYMBOL_GPL(vfio_platform_probe_common);

struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
{
	struct vfio_platform_device *vdev;

	vdev = vfio_del_group_dev(dev);

	if (vdev) {
		vfio_platform_put_reset(vdev);
		iommu_group_put(dev->iommu_group);
	}

	return vdev;
}
EXPORT_SYMBOL_GPL(vfio_platform_remove_common);

void __vfio_platform_register_reset(struct vfio_platform_reset_node *node)
{
	mutex_lock(&driver_lock);
	list_add(&node->link, &reset_list);
	mutex_unlock(&driver_lock);
}
EXPORT_SYMBOL_GPL(__vfio_platform_register_reset);

void vfio_platform_unregister_reset(const char *compat,
				    vfio_platform_reset_fn_t fn)
{
	struct vfio_platform_reset_node *iter, *temp;

	mutex_lock(&driver_lock);
	list_for_each_entry_safe(iter, temp, &reset_list, link) {
		if (!strcmp(iter->compat, compat) && (iter->reset == fn)) {
			list_del(&iter->link);
			break;
		}
	}

	mutex_unlock(&driver_lock);

}
EXPORT_SYMBOL_GPL(vfio_platform_unregister_reset);

MODULE_VERSION(DRIVER_VERSION);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);