summaryrefslogtreecommitdiffstats
path: root/drivers/remoteproc/remoteproc_virtio.c
blob: e1a10232a9437b5884e16965d4b5bced5b069ffe (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
/*
 * 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>
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/export.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"

/* 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.
 *
 * Returns 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 id,
				    void (*callback)(struct virtqueue *vq),
				    const char *name)
{
	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
	struct rproc *rproc = vdev_to_rproc(vdev);
	struct device *dev = &rproc->dev;
	struct rproc_vring *rvring;
	struct virtqueue *vq;
	void *addr;
	int len, size, ret;

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

	if (!name)
		return NULL;

	ret = rproc_alloc_vring(rvdev, id);
	if (ret)
		return ERR_PTR(ret);

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

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

	dev_dbg(dev, "vring%d: va %p qsz %d notifyid %d\n",
					id, addr, len, 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, len, rvring->align, vdev, false, 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);
	}

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

	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);
		rproc_free_vring(rvring);
	}
}

static void rproc_virtio_del_vqs(struct virtio_device *vdev)
{
	struct rproc *rproc = vdev_to_rproc(vdev);

	/* power down the remote processor before deleting vqs */
	rproc_shutdown(rproc);

	__rproc_virtio_del_vqs(vdev);
}

static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned nvqs,
		       struct virtqueue *vqs[],
		       vq_callback_t *callbacks[],
		       const char *names[])
{
	struct rproc *rproc = vdev_to_rproc(vdev);
	int i, ret;

	for (i = 0; i < nvqs; ++i) {
		vqs[i] = rp_find_vq(vdev, i, callbacks[i], names[i]);
		if (IS_ERR(vqs[i])) {
			ret = PTR_ERR(vqs[i]);
			goto error;
		}
	}

	/* now that the vqs are all set, boot the remote processor */
	ret = rproc_boot(rproc);
	if (ret) {
		dev_err(&rproc->dev, "rproc_boot() failed %d\n", ret);
		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 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);

	/* 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 offset,
							void *buf, unsigned 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 offset,
		      const void *buf, unsigned 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_vdev_release(struct device *dev)
{
	struct virtio_device *vdev = dev_to_virtio(dev);
	struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
	struct rproc *rproc = vdev_to_rproc(vdev);

	list_del(&rvdev->node);
	kfree(rvdev);

	put_device(&rproc->dev);
}

/**
 * rproc_add_virtio_dev() - register an rproc-induced virtio device
 * @rvdev: the remote vdev
 *
 * This function registers a virtio device. This vdev's partent is
 * the rproc device.
 *
 * Returns 0 on success or an appropriate error value otherwise.
 */
int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id)
{
	struct rproc *rproc = rvdev->rproc;
	struct device *dev = &rproc->dev;
	struct virtio_device *vdev = &rvdev->vdev;
	int ret;

	vdev->id.device	= id,
	vdev->config = &rproc_virtio_config_ops,
	vdev->dev.parent = dev;
	vdev->dev.release = rproc_vdev_release;

	/*
	 * We're indirectly making a non-temporary copy of the rproc pointer
	 * here, because drivers probed with this vdev will indirectly
	 * access the wrapping rproc.
	 *
	 * Therefore we must increment the rproc refcount here, and decrement
	 * it _only_ when the vdev is released.
	 */
	get_device(&rproc->dev);

	ret = register_virtio_device(vdev);
	if (ret) {
		put_device(&rproc->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
 * @rvdev: the remote vdev
 *
 * This function unregisters an existing virtio device.
 */
void rproc_remove_virtio_dev(struct rproc_vdev *rvdev)
{
	unregister_virtio_device(&rvdev->vdev);
}
OpenPOWER on IntegriCloud