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