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(p: 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, id: notifyid);
96 if (!rvring || !rvring->vq)
97 return IRQ_NONE;
98
99 return vring_interrupt(irq: 0, vq: 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(error: -EINVAL);
121
122 if (!name)
123 return NULL;
124
125 /* Search allocated memory region by name */
126 mem = rproc_find_carveout_by_name(rproc, name: "vdev%dvring%d", rvdev->index,
127 id);
128 if (!mem || !mem->va)
129 return ERR_PTR(error: -ENOMEM);
130
131 rvring = &rvdev->vring[id];
132 addr = mem->va;
133 num = rvring->num;
134
135 /* zero vring */
136 size = vring_size(num, align: 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(index: id, num, vring_align: rvring->align, vdev, weak_barriers: false, ctx,
147 pages: addr, notify: 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(error: -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, id: queue_idx++, callback: callbacks[i], name: names[i],
199 ctx: ctx ? ctx[i] : false);
200 if (IS_ERR(ptr: vqs[i])) {
201 ret = PTR_ERR(ptr: 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(objp: vdev);
353
354 of_reserved_mem_device_release(dev: &rvdev->pdev->dev);
355 dma_release_coherent_memory(dev: &rvdev->pdev->dev);
356
357 put_device(dev: &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, name: "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 idx: 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(cpu_addr: 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, phys_addr: pa,
411 device_addr: mem->da,
412 size: 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, idx: 0);
430 }
431
432 /* Allocate virtio device */
433 vdev = kzalloc(size: 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(dev: vdev);
447 if (ret) {
448 put_device(dev: &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(dev: 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, id: 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, fn: 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, size: 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(to: dev, from: 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, dma_ops: get_dma_ops(dev: rproc->dev.parent));
520
521 ret = dma_coerce_mask_and_coherent(dev, mask: dma_get_mask(dev: 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, data: 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, subdev: &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(dev: &rproc->dev);
565
566 return 0;
567
568unwind_vring_allocations:
569 for (i--; i >= 0; i--)
570 rproc_free_vring(rvring: &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(dev: &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, subdev: &rvdev->subdev);
588 rproc_remove_rvdev(rvdev);
589
590 put_device(dev: &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

source code of linux/drivers/remoteproc/remoteproc_virtio.c