summaryrefslogtreecommitdiffstats
path: root/drivers/remoteproc/remoteproc_virtio.c
blob: 25b66b113b69594b7edf01caff62bda8435c9bbb (plain)
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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Remote processor messaging transport (OMAP platform-specific bits)
 *
 * Copyright (C) 2011 Texas Instruments, Inc.
 * Copyright (C) 2011 Google, Inc.
 *
 * Ohad Ben-Cohen <ohad@wizery.com>
 * Brian Swetland <swetland@google.com>
 */

#include <linux/dma-direct.h>
#include <linux/dma-map-ops.h>
#include <linux/dma-mapping.h>
#include <linux/export.h>
#include <linux/of_reserved_mem.h>
#include <linux/platform_device.h>
#include <linux/remoteproc.h>
#include <linux/virtio.h>
#include <linux/virtio_config.h>
#include <linux/virtio_ids.h>
#include <linux/virtio_ring.h>
#include <linux/err.h>
#include <linux/kref.h>
#include <linux/slab.h>

#include "remoteproc_internal.h"

static int copy_dma_range_map(struct device *to, struct device *from)
{
	const struct bus_dma_region *map = from->dma_range_map, *new_map, *r;
	int num_ranges = 0;

	if (!map)
		return 0;

	for (r = map; r->size; r++)
		num_ranges++;

	new_map = kmemdup(map, array_size(num_ranges + 1, sizeof(*map)),
			  GFP_KERNEL);
	if (!new_map)
		return -ENOMEM;
	to->dma_range_map = new_map;
	return 0;
}

static struct rproc_vdev *vdev_to_rvdev(struct virtio_device *vdev)
{
	struct platform_device *pdev;

	pdev = container_of(vdev->dev.parent, struct platform_device, dev);

	return platform_get_drvdata(pdev);
}

static  struct rproc *vdev_to_rproc(struct virtio_device *vdev)
{
	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);

	return rvdev->rproc;
}

/* kick the remote processor, and let it know which virtqueue to poke at */
static bool rproc_virtio_notify(struct virtqueue *vq)
{
	struct rproc_vring *rvring = vq->priv;
	struct rproc *rproc = rvring->rvdev->rproc;
	int notifyid = rvring->notifyid;

	dev_dbg(&rproc->dev, "kicking vq index: %d\n", notifyid);

	rproc->ops->kick(rproc, notifyid);
	return true;
}

/**
 * rproc_vq_interrupt() - tell remoteproc that a virtqueue is interrupted
 * @rproc: handle to the remote processor
 * @notifyid: index of the signalled virtqueue (unique per this @rproc)
 *
 * This function should be called by the platform-specific rproc driver,
 * when the remote processor signals that a specific virtqueue has pending
 * messages available.
 *
 * Return: IRQ_NONE if no message was found in the @notifyid virtqueue,
 * and otherwise returns IRQ_HANDLED.
 */
irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int notifyid)
{
	struct rproc_vring *rvring;

	dev_dbg(&rproc->dev, "vq index %d is interrupted\n", notifyid);

	rvring = idr_find(&rproc->notifyids, notifyid);
	if (!rvring || !rvring->vq)
		return IRQ_NONE;

	return vring_interrupt(0, rvring->vq);
}
EXPORT_SYMBOL(rproc_vq_interrupt);

static struct virtqueue *rp_find_vq(struct virtio_device *vdev,
				    unsigned int id,
				    void (*callback)(struct virtqueue *vq),
				    const char *name, bool ctx)
{
	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
	struct rproc *rproc = vdev_to_rproc(vdev);
	struct device *dev = &rproc->dev;
	struct rproc_mem_entry *mem;
	struct rproc_vring *rvring;
	struct fw_rsc_vdev *rsc;
	struct virtqueue *vq;
	void *addr;
	int num, size;

	/* we're temporarily limited to two virtqueues per rvdev */
	if (id >= ARRAY_SIZE(rvdev->vring))
		return ERR_PTR(-EINVAL);

	if (!name)
		return NULL;

	/* Search allocated memory region by name */
	mem = rproc_find_carveout_by_name(rproc, "vdev%dvring%d", rvdev->index,
					  id);
	if (!mem || !mem->va)
		return ERR_PTR(-ENOMEM);

	rvring = &rvdev->vring[id];
	addr = mem->va;
	num = rvring->num;

	/* zero vring */
	size = vring_size(num, rvring->align);
	memset(addr, 0, size);

	dev_dbg(dev, "vring%d: va %pK qsz %d notifyid %d\n",
		id, addr, num, rvring->notifyid);

	/*
	 * Create the new vq, and tell virtio we're not interested in
	 * the 'weak' smp barriers, since we're talking with a real device.
	 */
	vq = vring_new_virtqueue(id, num, rvring->align, vdev, false, ctx,
				 addr, rproc_virtio_notify, callback, name);
	if (!vq) {
		dev_err(dev, "vring_new_virtqueue %s failed\n", name);
		rproc_free_vring(rvring);
		return ERR_PTR(-ENOMEM);
	}

	vq->num_max = num;

	rvring->vq = vq;
	vq->priv = rvring;

	/* Update vring in resource table */
	rsc = (void *)rproc->table_ptr + rvdev->rsc_offset;
	rsc->vring[id].da = mem->da;

	return vq;
}

static void __rproc_virtio_del_vqs(struct virtio_device *vdev)
{
	struct virtqueue *vq, *n;
	struct rproc_vring *rvring;

	list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
		rvring = vq->priv;
		rvring->vq = NULL;
		vring_del_virtqueue(vq);
	}
}

static void rproc_virtio_del_vqs(struct virtio_device *vdev)
{
	__rproc_virtio_del_vqs(vdev);
}

static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
				 struct virtqueue *vqs[],
				 vq_callback_t *callbacks[],
				 const char * const names[],
				 const bool * ctx,
				 struct irq_affinity *desc)
{
	int i, ret, queue_idx = 0;

	for (i = 0; i < nvqs; ++i) {
		if (!names[i]) {
			vqs[i] = NULL;
			continue;
		}

		vqs[i] = rp_find_vq(vdev, queue_idx++, callbacks[i], names[i],
				    ctx ? ctx[i] : false);
		if (IS_ERR(vqs[i])) {
			ret = PTR_ERR(vqs[i]);
			goto error;
		}
	}

	return 0;

error:
	__rproc_virtio_del_vqs(vdev);
	return ret;
}

static u8 rproc_virtio_get_status(struct virtio_device *vdev)
{
	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
	struct fw_rsc_vdev *rsc;

	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;

	return rsc->status;
}

static void rproc_virtio_set_status(struct virtio_device *vdev, u8 status)
{
	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
	struct fw_rsc_vdev *rsc;

	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;

	rsc->status = status;
	dev_dbg(&vdev->dev, "status: %d\n", status);
}

static void rproc_virtio_reset(struct virtio_device *vdev)
{
	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
	struct fw_rsc_vdev *rsc;

	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;

	rsc->status = 0;
	dev_dbg(&vdev->dev, "reset !\n");
}

/* provide the vdev features as retrieved from the firmware */
static u64 rproc_virtio_get_features(struct virtio_device *vdev)
{
	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
	struct fw_rsc_vdev *rsc;

	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;

	return rsc->dfeatures;
}

static void rproc_transport_features(struct virtio_device *vdev)
{
	/*
	 * Packed ring isn't enabled on remoteproc for now,
	 * because remoteproc uses vring_new_virtqueue() which
	 * creates virtio rings on preallocated memory.
	 */
	__virtio_clear_bit(vdev, VIRTIO_F_RING_PACKED);
}

static int rproc_virtio_finalize_features(struct virtio_device *vdev)
{
	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
	struct fw_rsc_vdev *rsc;

	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;

	/* Give virtio_ring a chance to accept features */
	vring_transport_features(vdev);

	/* Give virtio_rproc a chance to accept features. */
	rproc_transport_features(vdev);

	/* Make sure we don't have any features > 32 bits! */
	BUG_ON((u32)vdev->features != vdev->features);

	/*
	 * Remember the finalized features of our vdev, and provide it
	 * to the remote processor once it is powered on.
	 */
	rsc->gfeatures = vdev->features;

	return 0;
}

static void rproc_virtio_get(struct virtio_device *vdev, unsigned int offset,
			     void *buf, unsigned int len)
{
	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
	struct fw_rsc_vdev *rsc;
	void *cfg;

	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
	cfg = &rsc->vring[rsc->num_of_vrings];

	if (offset + len > rsc->config_len || offset + len < len) {
		dev_err(&vdev->dev, "rproc_virtio_get: access out of bounds\n");
		return;
	}

	memcpy(buf, cfg + offset, len);
}

static void rproc_virtio_set(struct virtio_device *vdev, unsigned int offset,
			     const void *buf, unsigned int len)
{
	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
	struct fw_rsc_vdev *rsc;
	void *cfg;

	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
	cfg = &rsc->vring[rsc->num_of_vrings];

	if (offset + len > rsc->config_len || offset + len < len) {
		dev_err(&vdev->dev, "rproc_virtio_set: access out of bounds\n");
		return;
	}

	memcpy(cfg + offset, buf, len);
}

static const struct virtio_config_ops rproc_virtio_config_ops = {
	.get_features	= rproc_virtio_get_features,
	.finalize_features = rproc_virtio_finalize_features,
	.find_vqs	= rproc_virtio_find_vqs,
	.del_vqs	= rproc_virtio_del_vqs,
	.reset		= rproc_virtio_reset,
	.set_status	= rproc_virtio_set_status,
	.get_status	= rproc_virtio_get_status,
	.get		= rproc_virtio_get,
	.set		= rproc_virtio_set,
};

/*
 * This function is called whenever vdev is released, and is responsible
 * to decrement the remote processor's refcount which was taken when vdev was
 * added.
 *
 * Never call this function directly; it will be called by the driver
 * core when needed.
 */
static void rproc_virtio_dev_release(struct device *dev)
{
	struct virtio_device *vdev = dev_to_virtio(dev);
	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);

	kfree(vdev);

	of_reserved_mem_device_release(&rvdev->pdev->dev);
	dma_release_coherent_memory(&rvdev->pdev->dev);

	put_device(&rvdev->pdev->dev);
}

/**
 * rproc_add_virtio_dev() - register an rproc-induced virtio device
 * @rvdev: the remote vdev
 * @id: the device type identification (used to match it with a driver).
 *
 * This function registers a virtio device. This vdev's partent is
 * the rproc device.
 *
 * Return: 0 on success or an appropriate error value otherwise
 */
static int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id)
{
	struct rproc *rproc = rvdev->rproc;
	struct device *dev = &rvdev->pdev->dev;
	struct virtio_device *vdev;
	struct rproc_mem_entry *mem;
	int ret;

	if (rproc->ops->kick == NULL) {
		ret = -EINVAL;
		dev_err(dev, ".kick method not defined for %s\n", rproc->name);
		goto out;
	}

	/* Try to find dedicated vdev buffer carveout */
	mem = rproc_find_carveout_by_name(rproc, "vdev%dbuffer", rvdev->index);
	if (mem) {
		phys_addr_t pa;

		if (mem->of_resm_idx != -1) {
			struct device_node *np = rproc->dev.parent->of_node;

			/* Associate reserved memory to vdev device */
			ret = of_reserved_mem_device_init_by_idx(dev, np,
								 mem->of_resm_idx);
			if (ret) {
				dev_err(dev, "Can't associate reserved memory\n");
				goto out;
			}
		} else {
			if (mem->va) {
				dev_warn(dev, "vdev %d buffer already mapped\n",
					 rvdev->index);
				pa = rproc_va_to_pa(mem->va);
			} else {
				/* Use dma address as carveout no memmapped yet */
				pa = (phys_addr_t)mem->dma;
			}

			/* Associate vdev buffer memory pool to vdev subdev */
			ret = dma_declare_coherent_memory(dev, pa,
							   mem->da,
							   mem->len);
			if (ret < 0) {
				dev_err(dev, "Failed to associate buffer\n");
				goto out;
			}
		}
	} else {
		struct device_node *np = rproc->dev.parent->of_node;

		/*
		 * If we don't have dedicated buffer, just attempt to re-assign
		 * the reserved memory from our parent. A default memory-region
		 * at index 0 from the parent's memory-regions is assigned for
		 * the rvdev dev to allocate from. Failure is non-critical and
		 * the allocations will fall back to global pools, so don't
		 * check return value either.
		 */
		of_reserved_mem_device_init_by_idx(dev, np, 0);
	}

	/* Allocate virtio device */
	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
	if (!vdev) {
		ret = -ENOMEM;
		goto out;
	}
	vdev->id.device	= id,
	vdev->config = &rproc_virtio_config_ops,
	vdev->dev.parent = dev;
	vdev->dev.release = rproc_virtio_dev_release;

	/* Reference the vdev and vring allocations */
	get_device(dev);

	ret = register_virtio_device(vdev);
	if (ret) {
		put_device(&vdev->dev);
		dev_err(dev, "failed to register vdev: %d\n", ret);
		goto out;
	}

	dev_info(dev, "registered %s (type %d)\n", dev_name(&vdev->dev), id);

out:
	return ret;
}

/**
 * rproc_remove_virtio_dev() - remove an rproc-induced virtio device
 * @dev: the virtio device
 * @data: must be null
 *
 * This function unregisters an existing virtio device.
 *
 * Return: 0
 */
static int rproc_remove_virtio_dev(struct device *dev, void *data)
{
	struct virtio_device *vdev = dev_to_virtio(dev);

	unregister_virtio_device(vdev);
	return 0;
}

static int rproc_vdev_do_start(struct rproc_subdev *subdev)
{
	struct rproc_vdev *rvdev = container_of(subdev, struct rproc_vdev, subdev);

	return rproc_add_virtio_dev(rvdev, rvdev->id);
}

static void rproc_vdev_do_stop(struct rproc_subdev *subdev, bool crashed)
{
	struct rproc_vdev *rvdev = container_of(subdev, struct rproc_vdev, subdev);
	struct device *dev = &rvdev->pdev->dev;
	int ret;

	ret = device_for_each_child(dev, NULL, rproc_remove_virtio_dev);
	if (ret)
		dev_warn(dev, "can't remove vdev child device: %d\n", ret);
}

static int rproc_virtio_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct rproc_vdev_data *rvdev_data = dev->platform_data;
	struct rproc_vdev *rvdev;
	struct rproc *rproc = container_of(dev->parent, struct rproc, dev);
	struct fw_rsc_vdev *rsc;
	int i, ret;

	if (!rvdev_data)
		return -EINVAL;

	rvdev = devm_kzalloc(dev, sizeof(*rvdev), GFP_KERNEL);
	if (!rvdev)
		return -ENOMEM;

	rvdev->id = rvdev_data->id;
	rvdev->rproc = rproc;
	rvdev->index = rvdev_data->index;

	ret = copy_dma_range_map(dev, rproc->dev.parent);
	if (ret)
		return ret;

	/* Make device dma capable by inheriting from parent's capabilities */
	set_dma_ops(dev, get_dma_ops(rproc->dev.parent));

	ret = dma_coerce_mask_and_coherent(dev, dma_get_mask(rproc->dev.parent));
	if (ret) {
		dev_warn(dev, "Failed to set DMA mask %llx. Trying to continue... (%pe)\n",
			 dma_get_mask(rproc->dev.parent), ERR_PTR(ret));
	}

	platform_set_drvdata(pdev, rvdev);
	rvdev->pdev = pdev;

	rsc = rvdev_data->rsc;

	/* parse the vrings */
	for (i = 0; i < rsc->num_of_vrings; i++) {
		ret = rproc_parse_vring(rvdev, rsc, i);
		if (ret)
			return ret;
	}

	/* remember the resource offset*/
	rvdev->rsc_offset = rvdev_data->rsc_offset;

	/* allocate the vring resources */
	for (i = 0; i < rsc->num_of_vrings; i++) {
		ret = rproc_alloc_vring(rvdev, i);
		if (ret)
			goto unwind_vring_allocations;
	}

	rproc_add_rvdev(rproc, rvdev);

	rvdev->subdev.start = rproc_vdev_do_start;
	rvdev->subdev.stop = rproc_vdev_do_stop;

	rproc_add_subdev(rproc, &rvdev->subdev);

	/*
	 * We're indirectly making a non-temporary copy of the rproc pointer
	 * here, because the platform device or the vdev device will indirectly
	 * access the wrapping rproc.
	 *
	 * Therefore we must increment the rproc refcount here, and decrement
	 * it _only_ on platform remove.
	 */
	get_device(&rproc->dev);

	return 0;

unwind_vring_allocations:
	for (i--; i >= 0; i--)
		rproc_free_vring(&rvdev->vring[i]);

	return ret;
}

static void rproc_virtio_remove(struct platform_device *pdev)
{
	struct rproc_vdev *rvdev = dev_get_drvdata(&pdev->dev);
	struct rproc *rproc = rvdev->rproc;
	struct rproc_vring *rvring;
	int id;

	for (id = 0; id < ARRAY_SIZE(rvdev->vring); id++) {
		rvring = &rvdev->vring[id];
		rproc_free_vring(rvring);
	}

	rproc_remove_subdev(rproc, &rvdev->subdev);
	rproc_remove_rvdev(rvdev);

	put_device(&rproc->dev);
}

/* Platform driver */
static struct platform_driver rproc_virtio_driver = {
	.probe		= rproc_virtio_probe,
	.remove_new	= rproc_virtio_remove,
	.driver		= {
		.name	= "rproc-virtio",
	},
};
builtin_platform_driver(rproc_virtio_driver);