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-map-ops.h>
13 #include <linux/export.h>
14 #include <linux/of_reserved_mem.h>
15 #include <linux/remoteproc.h>
16 #include <linux/virtio.h>
17 #include <linux/virtio_config.h>
18 #include <linux/virtio_ids.h>
19 #include <linux/virtio_ring.h>
20 #include <linux/err.h>
21 #include <linux/kref.h>
22 #include <linux/slab.h>
23 
24 #include "remoteproc_internal.h"
25 
26 static struct rproc_vdev *vdev_to_rvdev(struct virtio_device *vdev)
27 {
28 	return container_of(vdev->dev.parent, struct rproc_vdev, dev);
29 }
30 
31 static  struct rproc *vdev_to_rproc(struct virtio_device *vdev)
32 {
33 	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
34 
35 	return rvdev->rproc;
36 }
37 
38 /* kick the remote processor, and let it know which virtqueue to poke at */
39 static bool rproc_virtio_notify(struct virtqueue *vq)
40 {
41 	struct rproc_vring *rvring = vq->priv;
42 	struct rproc *rproc = rvring->rvdev->rproc;
43 	int notifyid = rvring->notifyid;
44 
45 	dev_dbg(&rproc->dev, "kicking vq index: %d\n", notifyid);
46 
47 	rproc->ops->kick(rproc, notifyid);
48 	return true;
49 }
50 
51 /**
52  * rproc_vq_interrupt() - tell remoteproc that a virtqueue is interrupted
53  * @rproc: handle to the remote processor
54  * @notifyid: index of the signalled virtqueue (unique per this @rproc)
55  *
56  * This function should be called by the platform-specific rproc driver,
57  * when the remote processor signals that a specific virtqueue has pending
58  * messages available.
59  *
60  * Return: IRQ_NONE if no message was found in the @notifyid virtqueue,
61  * and otherwise returns IRQ_HANDLED.
62  */
63 irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int notifyid)
64 {
65 	struct rproc_vring *rvring;
66 
67 	dev_dbg(&rproc->dev, "vq index %d is interrupted\n", notifyid);
68 
69 	rvring = idr_find(&rproc->notifyids, notifyid);
70 	if (!rvring || !rvring->vq)
71 		return IRQ_NONE;
72 
73 	return vring_interrupt(0, rvring->vq);
74 }
75 EXPORT_SYMBOL(rproc_vq_interrupt);
76 
77 static struct virtqueue *rp_find_vq(struct virtio_device *vdev,
78 				    unsigned int id,
79 				    void (*callback)(struct virtqueue *vq),
80 				    const char *name, bool ctx)
81 {
82 	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
83 	struct rproc *rproc = vdev_to_rproc(vdev);
84 	struct device *dev = &rproc->dev;
85 	struct rproc_mem_entry *mem;
86 	struct rproc_vring *rvring;
87 	struct fw_rsc_vdev *rsc;
88 	struct virtqueue *vq;
89 	void *addr;
90 	int len, size;
91 
92 	/* we're temporarily limited to two virtqueues per rvdev */
93 	if (id >= ARRAY_SIZE(rvdev->vring))
94 		return ERR_PTR(-EINVAL);
95 
96 	if (!name)
97 		return NULL;
98 
99 	/* Search allocated memory region by name */
100 	mem = rproc_find_carveout_by_name(rproc, "vdev%dvring%d", rvdev->index,
101 					  id);
102 	if (!mem || !mem->va)
103 		return ERR_PTR(-ENOMEM);
104 
105 	rvring = &rvdev->vring[id];
106 	addr = mem->va;
107 	len = rvring->len;
108 
109 	/* zero vring */
110 	size = vring_size(len, rvring->align);
111 	memset(addr, 0, size);
112 
113 	dev_dbg(dev, "vring%d: va %pK qsz %d notifyid %d\n",
114 		id, addr, len, rvring->notifyid);
115 
116 	/*
117 	 * Create the new vq, and tell virtio we're not interested in
118 	 * the 'weak' smp barriers, since we're talking with a real device.
119 	 */
120 	vq = vring_new_virtqueue(id, len, rvring->align, vdev, false, ctx,
121 				 addr, rproc_virtio_notify, callback, name);
122 	if (!vq) {
123 		dev_err(dev, "vring_new_virtqueue %s failed\n", name);
124 		rproc_free_vring(rvring);
125 		return ERR_PTR(-ENOMEM);
126 	}
127 
128 	rvring->vq = vq;
129 	vq->priv = rvring;
130 
131 	/* Update vring in resource table */
132 	rsc = (void *)rproc->table_ptr + rvdev->rsc_offset;
133 	rsc->vring[id].da = mem->da;
134 
135 	return vq;
136 }
137 
138 static void __rproc_virtio_del_vqs(struct virtio_device *vdev)
139 {
140 	struct virtqueue *vq, *n;
141 	struct rproc_vring *rvring;
142 
143 	list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
144 		rvring = vq->priv;
145 		rvring->vq = NULL;
146 		vring_del_virtqueue(vq);
147 	}
148 }
149 
150 static void rproc_virtio_del_vqs(struct virtio_device *vdev)
151 {
152 	__rproc_virtio_del_vqs(vdev);
153 }
154 
155 static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
156 				 struct virtqueue *vqs[],
157 				 vq_callback_t *callbacks[],
158 				 const char * const names[],
159 				 const bool * ctx,
160 				 struct irq_affinity *desc)
161 {
162 	int i, ret, queue_idx = 0;
163 
164 	for (i = 0; i < nvqs; ++i) {
165 		if (!names[i]) {
166 			vqs[i] = NULL;
167 			continue;
168 		}
169 
170 		vqs[i] = rp_find_vq(vdev, queue_idx++, callbacks[i], names[i],
171 				    ctx ? ctx[i] : false);
172 		if (IS_ERR(vqs[i])) {
173 			ret = PTR_ERR(vqs[i]);
174 			goto error;
175 		}
176 	}
177 
178 	return 0;
179 
180 error:
181 	__rproc_virtio_del_vqs(vdev);
182 	return ret;
183 }
184 
185 static u8 rproc_virtio_get_status(struct virtio_device *vdev)
186 {
187 	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
188 	struct fw_rsc_vdev *rsc;
189 
190 	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
191 
192 	return rsc->status;
193 }
194 
195 static void rproc_virtio_set_status(struct virtio_device *vdev, u8 status)
196 {
197 	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
198 	struct fw_rsc_vdev *rsc;
199 
200 	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
201 
202 	rsc->status = status;
203 	dev_dbg(&vdev->dev, "status: %d\n", status);
204 }
205 
206 static void rproc_virtio_reset(struct virtio_device *vdev)
207 {
208 	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
209 	struct fw_rsc_vdev *rsc;
210 
211 	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
212 
213 	rsc->status = 0;
214 	dev_dbg(&vdev->dev, "reset !\n");
215 }
216 
217 /* provide the vdev features as retrieved from the firmware */
218 static u64 rproc_virtio_get_features(struct virtio_device *vdev)
219 {
220 	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
221 	struct fw_rsc_vdev *rsc;
222 
223 	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
224 
225 	return rsc->dfeatures;
226 }
227 
228 static void rproc_transport_features(struct virtio_device *vdev)
229 {
230 	/*
231 	 * Packed ring isn't enabled on remoteproc for now,
232 	 * because remoteproc uses vring_new_virtqueue() which
233 	 * creates virtio rings on preallocated memory.
234 	 */
235 	__virtio_clear_bit(vdev, VIRTIO_F_RING_PACKED);
236 }
237 
238 static int rproc_virtio_finalize_features(struct virtio_device *vdev)
239 {
240 	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
241 	struct fw_rsc_vdev *rsc;
242 
243 	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
244 
245 	/* Give virtio_ring a chance to accept features */
246 	vring_transport_features(vdev);
247 
248 	/* Give virtio_rproc a chance to accept features. */
249 	rproc_transport_features(vdev);
250 
251 	/* Make sure we don't have any features > 32 bits! */
252 	BUG_ON((u32)vdev->features != vdev->features);
253 
254 	/*
255 	 * Remember the finalized features of our vdev, and provide it
256 	 * to the remote processor once it is powered on.
257 	 */
258 	rsc->gfeatures = vdev->features;
259 
260 	return 0;
261 }
262 
263 static void rproc_virtio_get(struct virtio_device *vdev, unsigned int offset,
264 			     void *buf, unsigned int len)
265 {
266 	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
267 	struct fw_rsc_vdev *rsc;
268 	void *cfg;
269 
270 	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
271 	cfg = &rsc->vring[rsc->num_of_vrings];
272 
273 	if (offset + len > rsc->config_len || offset + len < len) {
274 		dev_err(&vdev->dev, "rproc_virtio_get: access out of bounds\n");
275 		return;
276 	}
277 
278 	memcpy(buf, cfg + offset, len);
279 }
280 
281 static void rproc_virtio_set(struct virtio_device *vdev, unsigned int offset,
282 			     const void *buf, unsigned int len)
283 {
284 	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
285 	struct fw_rsc_vdev *rsc;
286 	void *cfg;
287 
288 	rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset;
289 	cfg = &rsc->vring[rsc->num_of_vrings];
290 
291 	if (offset + len > rsc->config_len || offset + len < len) {
292 		dev_err(&vdev->dev, "rproc_virtio_set: access out of bounds\n");
293 		return;
294 	}
295 
296 	memcpy(cfg + offset, buf, len);
297 }
298 
299 static const struct virtio_config_ops rproc_virtio_config_ops = {
300 	.get_features	= rproc_virtio_get_features,
301 	.finalize_features = rproc_virtio_finalize_features,
302 	.find_vqs	= rproc_virtio_find_vqs,
303 	.del_vqs	= rproc_virtio_del_vqs,
304 	.reset		= rproc_virtio_reset,
305 	.set_status	= rproc_virtio_set_status,
306 	.get_status	= rproc_virtio_get_status,
307 	.get		= rproc_virtio_get,
308 	.set		= rproc_virtio_set,
309 };
310 
311 /*
312  * This function is called whenever vdev is released, and is responsible
313  * to decrement the remote processor's refcount which was taken when vdev was
314  * added.
315  *
316  * Never call this function directly; it will be called by the driver
317  * core when needed.
318  */
319 static void rproc_virtio_dev_release(struct device *dev)
320 {
321 	struct virtio_device *vdev = dev_to_virtio(dev);
322 	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
323 	struct rproc *rproc = vdev_to_rproc(vdev);
324 
325 	kfree(vdev);
326 
327 	kref_put(&rvdev->refcount, rproc_vdev_release);
328 
329 	put_device(&rproc->dev);
330 }
331 
332 /**
333  * rproc_add_virtio_dev() - register an rproc-induced virtio device
334  * @rvdev: the remote vdev
335  * @id: the device type identification (used to match it with a driver).
336  *
337  * This function registers a virtio device. This vdev's partent is
338  * the rproc device.
339  *
340  * Return: 0 on success or an appropriate error value otherwise
341  */
342 int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id)
343 {
344 	struct rproc *rproc = rvdev->rproc;
345 	struct device *dev = &rvdev->dev;
346 	struct virtio_device *vdev;
347 	struct rproc_mem_entry *mem;
348 	int ret;
349 
350 	if (rproc->ops->kick == NULL) {
351 		ret = -EINVAL;
352 		dev_err(dev, ".kick method not defined for %s\n", rproc->name);
353 		goto out;
354 	}
355 
356 	/* Try to find dedicated vdev buffer carveout */
357 	mem = rproc_find_carveout_by_name(rproc, "vdev%dbuffer", rvdev->index);
358 	if (mem) {
359 		phys_addr_t pa;
360 
361 		if (mem->of_resm_idx != -1) {
362 			struct device_node *np = rproc->dev.parent->of_node;
363 
364 			/* Associate reserved memory to vdev device */
365 			ret = of_reserved_mem_device_init_by_idx(dev, np,
366 								 mem->of_resm_idx);
367 			if (ret) {
368 				dev_err(dev, "Can't associate reserved memory\n");
369 				goto out;
370 			}
371 		} else {
372 			if (mem->va) {
373 				dev_warn(dev, "vdev %d buffer already mapped\n",
374 					 rvdev->index);
375 				pa = rproc_va_to_pa(mem->va);
376 			} else {
377 				/* Use dma address as carveout no memmapped yet */
378 				pa = (phys_addr_t)mem->dma;
379 			}
380 
381 			/* Associate vdev buffer memory pool to vdev subdev */
382 			ret = dma_declare_coherent_memory(dev, pa,
383 							   mem->da,
384 							   mem->len);
385 			if (ret < 0) {
386 				dev_err(dev, "Failed to associate buffer\n");
387 				goto out;
388 			}
389 		}
390 	} else {
391 		struct device_node *np = rproc->dev.parent->of_node;
392 
393 		/*
394 		 * If we don't have dedicated buffer, just attempt to re-assign
395 		 * the reserved memory from our parent. A default memory-region
396 		 * at index 0 from the parent's memory-regions is assigned for
397 		 * the rvdev dev to allocate from. Failure is non-critical and
398 		 * the allocations will fall back to global pools, so don't
399 		 * check return value either.
400 		 */
401 		of_reserved_mem_device_init_by_idx(dev, np, 0);
402 	}
403 
404 	/* Allocate virtio device */
405 	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
406 	if (!vdev) {
407 		ret = -ENOMEM;
408 		goto out;
409 	}
410 	vdev->id.device	= id,
411 	vdev->config = &rproc_virtio_config_ops,
412 	vdev->dev.parent = dev;
413 	vdev->dev.release = rproc_virtio_dev_release;
414 
415 	/*
416 	 * We're indirectly making a non-temporary copy of the rproc pointer
417 	 * here, because drivers probed with this vdev will indirectly
418 	 * access the wrapping rproc.
419 	 *
420 	 * Therefore we must increment the rproc refcount here, and decrement
421 	 * it _only_ when the vdev is released.
422 	 */
423 	get_device(&rproc->dev);
424 
425 	/* Reference the vdev and vring allocations */
426 	kref_get(&rvdev->refcount);
427 
428 	ret = register_virtio_device(vdev);
429 	if (ret) {
430 		put_device(&vdev->dev);
431 		dev_err(dev, "failed to register vdev: %d\n", ret);
432 		goto out;
433 	}
434 
435 	dev_info(dev, "registered %s (type %d)\n", dev_name(&vdev->dev), id);
436 
437 out:
438 	return ret;
439 }
440 
441 /**
442  * rproc_remove_virtio_dev() - remove an rproc-induced virtio device
443  * @dev: the virtio device
444  * @data: must be null
445  *
446  * This function unregisters an existing virtio device.
447  *
448  * Return: 0
449  */
450 int rproc_remove_virtio_dev(struct device *dev, void *data)
451 {
452 	struct virtio_device *vdev = dev_to_virtio(dev);
453 
454 	unregister_virtio_device(vdev);
455 	return 0;
456 }
457