1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Remote processor messaging transport (OMAP platform-specific bits)
4 *
5 * Copyright (C) 2011 Texas Instruments, Inc.
6 * Copyright (C) 2011 Google, Inc.
7 *
8 * Ohad Ben-Cohen <ohad@wizery.com>
9 * Brian Swetland <swetland@google.com>
10 */
11
12#include <linux/dma-direct.h>
13#include <linux/dma-map-ops.h>
14#include <linux/dma-mapping.h>
15#include <linux/export.h>
16#include <linux/of_reserved_mem.h>
17#include <linux/platform_device.h>
18#include <linux/remoteproc.h>
19#include <linux/virtio.h>
20#include <linux/virtio_config.h>
21#include <linux/virtio_ids.h>
22#include <linux/virtio_ring.h>
23#include <linux/err.h>
24#include <linux/kref.h>
25#include <linux/slab.h>
26
27#include "remoteproc_internal.h"
28
29static int copy_dma_range_map(struct device *to, struct device *from)
30{
31	const struct bus_dma_region *map = from->dma_range_map, *new_map, *r;
32	int num_ranges = 0;
33
34	if (!map)
35		return 0;
36
37	for (r = map; r->size; r++)
38		num_ranges++;
39
40	new_map = kmemdup(map, array_size(num_ranges + 1, sizeof(*map)),
41			  GFP_KERNEL);
42	if (!new_map)
43		return -ENOMEM;
44	to->dma_range_map = new_map;
45	return 0;
46}
47
48static struct rproc_vdev *vdev_to_rvdev(struct virtio_device *vdev)
49{
50	struct platform_device *pdev;
51
52	pdev = container_of(vdev->dev.parent, struct platform_device, dev);
53
54	return platform_get_drvdata(pdev);
55}
56
57static  struct rproc *vdev_to_rproc(struct virtio_device *vdev)
58{
59	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
60
61	return rvdev->rproc;
62}
63
64/* kick the remote processor, and let it know which virtqueue to poke at */
65static bool rproc_virtio_notify(struct virtqueue *vq)
66{
67	struct rproc_vring *rvring = vq->priv;
68	struct rproc *rproc = rvring->rvdev->rproc;
69	int notifyid = rvring->notifyid;
70
71	dev_dbg(&rproc->dev, "kicking vq index: %d\n", notifyid);
72
73	rproc->ops->kick(rproc, notifyid);
74	return true;
75}
76
77/**
78 * rproc_vq_interrupt() - tell remoteproc that a virtqueue is interrupted
79 * @rproc: handle to the remote processor
80 * @notifyid: index of the signalled virtqueue (unique per this @rproc)
81 *
82 * This function should be called by the platform-specific rproc driver,
83 * when the remote processor signals that a specific virtqueue has pending
84 * messages available.
85 *
86 * Return: IRQ_NONE if no message was found in the @notifyid virtqueue,
87 * and otherwise returns IRQ_HANDLED.
88 */
89irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int notifyid)
90{
91	struct rproc_vring *rvring;
92
93	dev_dbg(&rproc->dev, "vq index %d is interrupted\n", notifyid);
94
95	rvring = idr_find(&rproc->notifyids, notifyid);
96	if (!rvring || !rvring->vq)
97		return IRQ_NONE;
98
99	return vring_interrupt(0, rvring->vq);
100}
101EXPORT_SYMBOL(rproc_vq_interrupt);
102
103static struct virtqueue *rp_find_vq(struct virtio_device *vdev,
104				    unsigned int id,
105				    void (*callback)(struct virtqueue *vq),
106				    const char *name, bool ctx)
107{
108	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
109	struct rproc *rproc = vdev_to_rproc(vdev);
110	struct device *dev = &rproc->dev;
111	struct rproc_mem_entry *mem;
112	struct rproc_vring *rvring;
113	struct fw_rsc_vdev *rsc;
114	struct virtqueue *vq;
115	void *addr;
116	int num, size;
117
118	/* we're temporarily limited to two virtqueues per rvdev */
119	if (id >= ARRAY_SIZE(rvdev->vring))
120		return ERR_PTR(-EINVAL);
121
122	if (!name)
123		return NULL;
124
125	/* Search allocated memory region by name */
126	mem = rproc_find_carveout_by_name(rproc, "vdev%dvring%d", rvdev->index,
127					  id);
128	if (!mem || !mem->va)
129		return ERR_PTR(-ENOMEM);
130
131	rvring = &rvdev->vring[id];
132	addr = mem->va;
133	num = rvring->num;
134
135	/* zero vring */
136	size = vring_size(num, rvring->align);
137	memset(addr, 0, size);
138
139	dev_dbg(dev, "vring%d: va %pK qsz %d notifyid %d\n",
140		id, addr, num, rvring->notifyid);
141
142	/*
143	 * Create the new vq, and tell virtio we're not interested in
144	 * the 'weak' smp barriers, since we're talking with a real device.
145	 */
146	vq = vring_new_virtqueue(id, num, rvring->align, vdev, false, ctx,
147				 addr, rproc_virtio_notify, callback, name);
148	if (!vq) {
149		dev_err(dev, "vring_new_virtqueue %s failed\n", name);
150		rproc_free_vring(rvring);
151		return ERR_PTR(-ENOMEM);
152	}
153
154	vq->num_max = num;
155
156	rvring->vq = vq;
157	vq->priv = rvring;
158
159	/* Update vring in resource table */
160	rsc = (void *)rproc->table_ptr + rvdev->rsc_offset;
161	rsc->vring[id].da = mem->da;
162
163	return vq;
164}
165
166static void __rproc_virtio_del_vqs(struct virtio_device *vdev)
167{
168	struct virtqueue *vq, *n;
169	struct rproc_vring *rvring;
170
171	list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
172		rvring = vq->priv;
173		rvring->vq = NULL;
174		vring_del_virtqueue(vq);
175	}
176}
177
178static void rproc_virtio_del_vqs(struct virtio_device *vdev)
179{
180	__rproc_virtio_del_vqs(vdev);
181}
182
183static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
184				 struct virtqueue *vqs[],
185				 vq_callback_t *callbacks[],
186				 const char * const names[],
187				 const bool * ctx,
188				 struct irq_affinity *desc)
189{
190	int i, ret, queue_idx = 0;
191
192	for (i = 0; i < nvqs; ++i) {
193		if (!names[i]) {
194			vqs[i] = NULL;
195			continue;
196		}
197
198		vqs[i] = rp_find_vq(vdev, queue_idx++, callbacks[i], names[i],
199				    ctx ? ctx[i] : false);
200		if (IS_ERR(vqs[i])) {
201			ret = PTR_ERR(vqs[i]);
202			goto error;
203		}
204	}
205
206	return 0;
207
208error:
209	__rproc_virtio_del_vqs(vdev);
210	return ret;
211}
212
213static u8 rproc_virtio_get_status(struct virtio_device *vdev)
214{
215	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
216	struct fw_rsc_vdev *rsc;
217
218	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
219
220	return rsc->status;
221}
222
223static void rproc_virtio_set_status(struct virtio_device *vdev, u8 status)
224{
225	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
226	struct fw_rsc_vdev *rsc;
227
228	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
229
230	rsc->status = status;
231	dev_dbg(&vdev->dev, "status: %d\n", status);
232}
233
234static void rproc_virtio_reset(struct virtio_device *vdev)
235{
236	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
237	struct fw_rsc_vdev *rsc;
238
239	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
240
241	rsc->status = 0;
242	dev_dbg(&vdev->dev, "reset !\n");
243}
244
245/* provide the vdev features as retrieved from the firmware */
246static u64 rproc_virtio_get_features(struct virtio_device *vdev)
247{
248	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
249	struct fw_rsc_vdev *rsc;
250
251	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
252
253	return rsc->dfeatures;
254}
255
256static void rproc_transport_features(struct virtio_device *vdev)
257{
258	/*
259	 * Packed ring isn't enabled on remoteproc for now,
260	 * because remoteproc uses vring_new_virtqueue() which
261	 * creates virtio rings on preallocated memory.
262	 */
263	__virtio_clear_bit(vdev, VIRTIO_F_RING_PACKED);
264}
265
266static int rproc_virtio_finalize_features(struct virtio_device *vdev)
267{
268	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
269	struct fw_rsc_vdev *rsc;
270
271	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
272
273	/* Give virtio_ring a chance to accept features */
274	vring_transport_features(vdev);
275
276	/* Give virtio_rproc a chance to accept features. */
277	rproc_transport_features(vdev);
278
279	/* Make sure we don't have any features > 32 bits! */
280	BUG_ON((u32)vdev->features != vdev->features);
281
282	/*
283	 * Remember the finalized features of our vdev, and provide it
284	 * to the remote processor once it is powered on.
285	 */
286	rsc->gfeatures = vdev->features;
287
288	return 0;
289}
290
291static void rproc_virtio_get(struct virtio_device *vdev, unsigned int offset,
292			     void *buf, unsigned int len)
293{
294	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
295	struct fw_rsc_vdev *rsc;
296	void *cfg;
297
298	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
299	cfg = &rsc->vring[rsc->num_of_vrings];
300
301	if (offset + len > rsc->config_len || offset + len < len) {
302		dev_err(&vdev->dev, "rproc_virtio_get: access out of bounds\n");
303		return;
304	}
305
306	memcpy(buf, cfg + offset, len);
307}
308
309static void rproc_virtio_set(struct virtio_device *vdev, unsigned int offset,
310			     const void *buf, unsigned int len)
311{
312	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
313	struct fw_rsc_vdev *rsc;
314	void *cfg;
315
316	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
317	cfg = &rsc->vring[rsc->num_of_vrings];
318
319	if (offset + len > rsc->config_len || offset + len < len) {
320		dev_err(&vdev->dev, "rproc_virtio_set: access out of bounds\n");
321		return;
322	}
323
324	memcpy(cfg + offset, buf, len);
325}
326
327static const struct virtio_config_ops rproc_virtio_config_ops = {
328	.get_features	= rproc_virtio_get_features,
329	.finalize_features = rproc_virtio_finalize_features,
330	.find_vqs	= rproc_virtio_find_vqs,
331	.del_vqs	= rproc_virtio_del_vqs,
332	.reset		= rproc_virtio_reset,
333	.set_status	= rproc_virtio_set_status,
334	.get_status	= rproc_virtio_get_status,
335	.get		= rproc_virtio_get,
336	.set		= rproc_virtio_set,
337};
338
339/*
340 * This function is called whenever vdev is released, and is responsible
341 * to decrement the remote processor's refcount which was taken when vdev was
342 * added.
343 *
344 * Never call this function directly; it will be called by the driver
345 * core when needed.
346 */
347static void rproc_virtio_dev_release(struct device *dev)
348{
349	struct virtio_device *vdev = dev_to_virtio(dev);
350	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
351
352	kfree(vdev);
353
354	of_reserved_mem_device_release(&rvdev->pdev->dev);
355	dma_release_coherent_memory(&rvdev->pdev->dev);
356
357	put_device(&rvdev->pdev->dev);
358}
359
360/**
361 * rproc_add_virtio_dev() - register an rproc-induced virtio device
362 * @rvdev: the remote vdev
363 * @id: the device type identification (used to match it with a driver).
364 *
365 * This function registers a virtio device. This vdev's partent is
366 * the rproc device.
367 *
368 * Return: 0 on success or an appropriate error value otherwise
369 */
370static int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id)
371{
372	struct rproc *rproc = rvdev->rproc;
373	struct device *dev = &rvdev->pdev->dev;
374	struct virtio_device *vdev;
375	struct rproc_mem_entry *mem;
376	int ret;
377
378	if (rproc->ops->kick == NULL) {
379		ret = -EINVAL;
380		dev_err(dev, ".kick method not defined for %s\n", rproc->name);
381		goto out;
382	}
383
384	/* Try to find dedicated vdev buffer carveout */
385	mem = rproc_find_carveout_by_name(rproc, "vdev%dbuffer", rvdev->index);
386	if (mem) {
387		phys_addr_t pa;
388
389		if (mem->of_resm_idx != -1) {
390			struct device_node *np = rproc->dev.parent->of_node;
391
392			/* Associate reserved memory to vdev device */
393			ret = of_reserved_mem_device_init_by_idx(dev, np,
394								 mem->of_resm_idx);
395			if (ret) {
396				dev_err(dev, "Can't associate reserved memory\n");
397				goto out;
398			}
399		} else {
400			if (mem->va) {
401				dev_warn(dev, "vdev %d buffer already mapped\n",
402					 rvdev->index);
403				pa = rproc_va_to_pa(mem->va);
404			} else {
405				/* Use dma address as carveout no memmapped yet */
406				pa = (phys_addr_t)mem->dma;
407			}
408
409			/* Associate vdev buffer memory pool to vdev subdev */
410			ret = dma_declare_coherent_memory(dev, pa,
411							   mem->da,
412							   mem->len);
413			if (ret < 0) {
414				dev_err(dev, "Failed to associate buffer\n");
415				goto out;
416			}
417		}
418	} else {
419		struct device_node *np = rproc->dev.parent->of_node;
420
421		/*
422		 * If we don't have dedicated buffer, just attempt to re-assign
423		 * the reserved memory from our parent. A default memory-region
424		 * at index 0 from the parent's memory-regions is assigned for
425		 * the rvdev dev to allocate from. Failure is non-critical and
426		 * the allocations will fall back to global pools, so don't
427		 * check return value either.
428		 */
429		of_reserved_mem_device_init_by_idx(dev, np, 0);
430	}
431
432	/* Allocate virtio device */
433	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
434	if (!vdev) {
435		ret = -ENOMEM;
436		goto out;
437	}
438	vdev->id.device	= id,
439	vdev->config = &rproc_virtio_config_ops,
440	vdev->dev.parent = dev;
441	vdev->dev.release = rproc_virtio_dev_release;
442
443	/* Reference the vdev and vring allocations */
444	get_device(dev);
445
446	ret = register_virtio_device(vdev);
447	if (ret) {
448		put_device(&vdev->dev);
449		dev_err(dev, "failed to register vdev: %d\n", ret);
450		goto out;
451	}
452
453	dev_info(dev, "registered %s (type %d)\n", dev_name(&vdev->dev), id);
454
455out:
456	return ret;
457}
458
459/**
460 * rproc_remove_virtio_dev() - remove an rproc-induced virtio device
461 * @dev: the virtio device
462 * @data: must be null
463 *
464 * This function unregisters an existing virtio device.
465 *
466 * Return: 0
467 */
468static int rproc_remove_virtio_dev(struct device *dev, void *data)
469{
470	struct virtio_device *vdev = dev_to_virtio(dev);
471
472	unregister_virtio_device(vdev);
473	return 0;
474}
475
476static int rproc_vdev_do_start(struct rproc_subdev *subdev)
477{
478	struct rproc_vdev *rvdev = container_of(subdev, struct rproc_vdev, subdev);
479
480	return rproc_add_virtio_dev(rvdev, rvdev->id);
481}
482
483static void rproc_vdev_do_stop(struct rproc_subdev *subdev, bool crashed)
484{
485	struct rproc_vdev *rvdev = container_of(subdev, struct rproc_vdev, subdev);
486	struct device *dev = &rvdev->pdev->dev;
487	int ret;
488
489	ret = device_for_each_child(dev, NULL, rproc_remove_virtio_dev);
490	if (ret)
491		dev_warn(dev, "can't remove vdev child device: %d\n", ret);
492}
493
494static int rproc_virtio_probe(struct platform_device *pdev)
495{
496	struct device *dev = &pdev->dev;
497	struct rproc_vdev_data *rvdev_data = dev->platform_data;
498	struct rproc_vdev *rvdev;
499	struct rproc *rproc = container_of(dev->parent, struct rproc, dev);
500	struct fw_rsc_vdev *rsc;
501	int i, ret;
502
503	if (!rvdev_data)
504		return -EINVAL;
505
506	rvdev = devm_kzalloc(dev, sizeof(*rvdev), GFP_KERNEL);
507	if (!rvdev)
508		return -ENOMEM;
509
510	rvdev->id = rvdev_data->id;
511	rvdev->rproc = rproc;
512	rvdev->index = rvdev_data->index;
513
514	ret = copy_dma_range_map(dev, rproc->dev.parent);
515	if (ret)
516		return ret;
517
518	/* Make device dma capable by inheriting from parent's capabilities */
519	set_dma_ops(dev, get_dma_ops(rproc->dev.parent));
520
521	ret = dma_coerce_mask_and_coherent(dev, dma_get_mask(rproc->dev.parent));
522	if (ret) {
523		dev_warn(dev, "Failed to set DMA mask %llx. Trying to continue... (%pe)\n",
524			 dma_get_mask(rproc->dev.parent), ERR_PTR(ret));
525	}
526
527	platform_set_drvdata(pdev, rvdev);
528	rvdev->pdev = pdev;
529
530	rsc = rvdev_data->rsc;
531
532	/* parse the vrings */
533	for (i = 0; i < rsc->num_of_vrings; i++) {
534		ret = rproc_parse_vring(rvdev, rsc, i);
535		if (ret)
536			return ret;
537	}
538
539	/* remember the resource offset*/
540	rvdev->rsc_offset = rvdev_data->rsc_offset;
541
542	/* allocate the vring resources */
543	for (i = 0; i < rsc->num_of_vrings; i++) {
544		ret = rproc_alloc_vring(rvdev, i);
545		if (ret)
546			goto unwind_vring_allocations;
547	}
548
549	rproc_add_rvdev(rproc, rvdev);
550
551	rvdev->subdev.start = rproc_vdev_do_start;
552	rvdev->subdev.stop = rproc_vdev_do_stop;
553
554	rproc_add_subdev(rproc, &rvdev->subdev);
555
556	/*
557	 * We're indirectly making a non-temporary copy of the rproc pointer
558	 * here, because the platform device or the vdev device will indirectly
559	 * access the wrapping rproc.
560	 *
561	 * Therefore we must increment the rproc refcount here, and decrement
562	 * it _only_ on platform remove.
563	 */
564	get_device(&rproc->dev);
565
566	return 0;
567
568unwind_vring_allocations:
569	for (i--; i >= 0; i--)
570		rproc_free_vring(&rvdev->vring[i]);
571
572	return ret;
573}
574
575static void rproc_virtio_remove(struct platform_device *pdev)
576{
577	struct rproc_vdev *rvdev = dev_get_drvdata(&pdev->dev);
578	struct rproc *rproc = rvdev->rproc;
579	struct rproc_vring *rvring;
580	int id;
581
582	for (id = 0; id < ARRAY_SIZE(rvdev->vring); id++) {
583		rvring = &rvdev->vring[id];
584		rproc_free_vring(rvring);
585	}
586
587	rproc_remove_subdev(rproc, &rvdev->subdev);
588	rproc_remove_rvdev(rvdev);
589
590	put_device(&rproc->dev);
591}
592
593/* Platform driver */
594static struct platform_driver rproc_virtio_driver = {
595	.probe		= rproc_virtio_probe,
596	.remove_new	= rproc_virtio_remove,
597	.driver		= {
598		.name	= "rproc-virtio",
599	},
600};
601builtin_platform_driver(rproc_virtio_driver);
602