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1 | /* | |
2 | * Remote processor messaging transport (OMAP platform-specific bits) | |
3 | * | |
4 | * Copyright (C) 2011 Texas Instruments, Inc. | |
5 | * Copyright (C) 2011 Google, Inc. | |
6 | * | |
7 | * Ohad Ben-Cohen <ohad@wizery.com> | |
8 | * Brian Swetland <swetland@google.com> | |
9 | * | |
10 | * This software is licensed under the terms of the GNU General Public | |
11 | * License version 2, as published by the Free Software Foundation, and | |
12 | * may be copied, distributed, and modified under those terms. | |
13 | * | |
14 | * This program is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU General Public License for more details. | |
18 | */ | |
19 | ||
20 | #include <linux/export.h> | |
21 | #include <linux/remoteproc.h> | |
22 | #include <linux/virtio.h> | |
23 | #include <linux/virtio_config.h> | |
24 | #include <linux/virtio_ids.h> | |
25 | #include <linux/virtio_ring.h> | |
26 | #include <linux/err.h> | |
27 | #include <linux/kref.h> | |
28 | #include <linux/slab.h> | |
29 | ||
30 | #include "remoteproc_internal.h" | |
31 | ||
32 | /* kick the remote processor, and let it know which virtqueue to poke at */ | |
33 | static bool rproc_virtio_notify(struct virtqueue *vq) | |
34 | { | |
35 | struct rproc_vring *rvring = vq->priv; | |
36 | struct rproc *rproc = rvring->rvdev->rproc; | |
37 | int notifyid = rvring->notifyid; | |
38 | ||
39 | dev_dbg(&rproc->dev, "kicking vq index: %d\n", notifyid); | |
40 | ||
41 | rproc->ops->kick(rproc, notifyid); | |
42 | return true; | |
43 | } | |
44 | ||
45 | /** | |
46 | * rproc_vq_interrupt() - tell remoteproc that a virtqueue is interrupted | |
47 | * @rproc: handle to the remote processor | |
48 | * @notifyid: index of the signalled virtqueue (unique per this @rproc) | |
49 | * | |
50 | * This function should be called by the platform-specific rproc driver, | |
51 | * when the remote processor signals that a specific virtqueue has pending | |
52 | * messages available. | |
53 | * | |
54 | * Returns IRQ_NONE if no message was found in the @notifyid virtqueue, | |
55 | * and otherwise returns IRQ_HANDLED. | |
56 | */ | |
57 | irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int notifyid) | |
58 | { | |
59 | struct rproc_vring *rvring; | |
60 | ||
61 | dev_dbg(&rproc->dev, "vq index %d is interrupted\n", notifyid); | |
62 | ||
63 | rvring = idr_find(&rproc->notifyids, notifyid); | |
64 | if (!rvring || !rvring->vq) | |
65 | return IRQ_NONE; | |
66 | ||
67 | return vring_interrupt(0, rvring->vq); | |
68 | } | |
69 | EXPORT_SYMBOL(rproc_vq_interrupt); | |
70 | ||
71 | static struct virtqueue *rp_find_vq(struct virtio_device *vdev, | |
72 | unsigned int id, | |
73 | void (*callback)(struct virtqueue *vq), | |
74 | const char *name, bool ctx) | |
75 | { | |
76 | struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); | |
77 | struct rproc *rproc = vdev_to_rproc(vdev); | |
78 | struct device *dev = &rproc->dev; | |
79 | struct rproc_vring *rvring; | |
80 | struct virtqueue *vq; | |
81 | void *addr; | |
82 | int len, size; | |
83 | ||
84 | /* we're temporarily limited to two virtqueues per rvdev */ | |
85 | if (id >= ARRAY_SIZE(rvdev->vring)) | |
86 | return ERR_PTR(-EINVAL); | |
87 | ||
88 | if (!name) | |
89 | return NULL; | |
90 | ||
91 | rvring = &rvdev->vring[id]; | |
92 | addr = rvring->va; | |
93 | len = rvring->len; | |
94 | ||
95 | /* zero vring */ | |
96 | size = vring_size(len, rvring->align); | |
97 | memset(addr, 0, size); | |
98 | ||
99 | dev_dbg(dev, "vring%d: va %p qsz %d notifyid %d\n", | |
100 | id, addr, len, rvring->notifyid); | |
101 | ||
102 | /* | |
103 | * Create the new vq, and tell virtio we're not interested in | |
104 | * the 'weak' smp barriers, since we're talking with a real device. | |
105 | */ | |
106 | vq = vring_new_virtqueue(id, len, rvring->align, vdev, false, ctx, | |
107 | addr, rproc_virtio_notify, callback, name); | |
108 | if (!vq) { | |
109 | dev_err(dev, "vring_new_virtqueue %s failed\n", name); | |
110 | rproc_free_vring(rvring); | |
111 | return ERR_PTR(-ENOMEM); | |
112 | } | |
113 | ||
114 | rvring->vq = vq; | |
115 | vq->priv = rvring; | |
116 | ||
117 | return vq; | |
118 | } | |
119 | ||
120 | static void __rproc_virtio_del_vqs(struct virtio_device *vdev) | |
121 | { | |
122 | struct virtqueue *vq, *n; | |
123 | struct rproc_vring *rvring; | |
124 | ||
125 | list_for_each_entry_safe(vq, n, &vdev->vqs, list) { | |
126 | rvring = vq->priv; | |
127 | rvring->vq = NULL; | |
128 | vring_del_virtqueue(vq); | |
129 | } | |
130 | } | |
131 | ||
132 | static void rproc_virtio_del_vqs(struct virtio_device *vdev) | |
133 | { | |
134 | __rproc_virtio_del_vqs(vdev); | |
135 | } | |
136 | ||
137 | static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned int nvqs, | |
138 | struct virtqueue *vqs[], | |
139 | vq_callback_t *callbacks[], | |
140 | const char * const names[], | |
141 | const bool * ctx, | |
142 | struct irq_affinity *desc) | |
143 | { | |
144 | int i, ret; | |
145 | ||
146 | for (i = 0; i < nvqs; ++i) { | |
147 | vqs[i] = rp_find_vq(vdev, i, callbacks[i], names[i], | |
148 | ctx ? ctx[i] : false); | |
149 | if (IS_ERR(vqs[i])) { | |
150 | ret = PTR_ERR(vqs[i]); | |
151 | goto error; | |
152 | } | |
153 | } | |
154 | ||
155 | return 0; | |
156 | ||
157 | error: | |
158 | __rproc_virtio_del_vqs(vdev); | |
159 | return ret; | |
160 | } | |
161 | ||
162 | static u8 rproc_virtio_get_status(struct virtio_device *vdev) | |
163 | { | |
164 | struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); | |
165 | struct fw_rsc_vdev *rsc; | |
166 | ||
167 | rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; | |
168 | ||
169 | return rsc->status; | |
170 | } | |
171 | ||
172 | static void rproc_virtio_set_status(struct virtio_device *vdev, u8 status) | |
173 | { | |
174 | struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); | |
175 | struct fw_rsc_vdev *rsc; | |
176 | ||
177 | rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; | |
178 | ||
179 | rsc->status = status; | |
180 | dev_dbg(&vdev->dev, "status: %d\n", status); | |
181 | } | |
182 | ||
183 | static void rproc_virtio_reset(struct virtio_device *vdev) | |
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 = 0; | |
191 | dev_dbg(&vdev->dev, "reset !\n"); | |
192 | } | |
193 | ||
194 | /* provide the vdev features as retrieved from the firmware */ | |
195 | static u64 rproc_virtio_get_features(struct virtio_device *vdev) | |
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 | return rsc->dfeatures; | |
203 | } | |
204 | ||
205 | static int rproc_virtio_finalize_features(struct virtio_device *vdev) | |
206 | { | |
207 | struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); | |
208 | struct fw_rsc_vdev *rsc; | |
209 | ||
210 | rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; | |
211 | ||
212 | /* Give virtio_ring a chance to accept features */ | |
213 | vring_transport_features(vdev); | |
214 | ||
215 | /* Make sure we don't have any features > 32 bits! */ | |
216 | BUG_ON((u32)vdev->features != vdev->features); | |
217 | ||
218 | /* | |
219 | * Remember the finalized features of our vdev, and provide it | |
220 | * to the remote processor once it is powered on. | |
221 | */ | |
222 | rsc->gfeatures = vdev->features; | |
223 | ||
224 | return 0; | |
225 | } | |
226 | ||
227 | static void rproc_virtio_get(struct virtio_device *vdev, unsigned int offset, | |
228 | void *buf, unsigned int len) | |
229 | { | |
230 | struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); | |
231 | struct fw_rsc_vdev *rsc; | |
232 | void *cfg; | |
233 | ||
234 | rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; | |
235 | cfg = &rsc->vring[rsc->num_of_vrings]; | |
236 | ||
237 | if (offset + len > rsc->config_len || offset + len < len) { | |
238 | dev_err(&vdev->dev, "rproc_virtio_get: access out of bounds\n"); | |
239 | return; | |
240 | } | |
241 | ||
242 | memcpy(buf, cfg + offset, len); | |
243 | } | |
244 | ||
245 | static void rproc_virtio_set(struct virtio_device *vdev, unsigned int offset, | |
246 | const void *buf, unsigned int len) | |
247 | { | |
248 | struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); | |
249 | struct fw_rsc_vdev *rsc; | |
250 | void *cfg; | |
251 | ||
252 | rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; | |
253 | cfg = &rsc->vring[rsc->num_of_vrings]; | |
254 | ||
255 | if (offset + len > rsc->config_len || offset + len < len) { | |
256 | dev_err(&vdev->dev, "rproc_virtio_set: access out of bounds\n"); | |
257 | return; | |
258 | } | |
259 | ||
260 | memcpy(cfg + offset, buf, len); | |
261 | } | |
262 | ||
263 | static const struct virtio_config_ops rproc_virtio_config_ops = { | |
264 | .get_features = rproc_virtio_get_features, | |
265 | .finalize_features = rproc_virtio_finalize_features, | |
266 | .find_vqs = rproc_virtio_find_vqs, | |
267 | .del_vqs = rproc_virtio_del_vqs, | |
268 | .reset = rproc_virtio_reset, | |
269 | .set_status = rproc_virtio_set_status, | |
270 | .get_status = rproc_virtio_get_status, | |
271 | .get = rproc_virtio_get, | |
272 | .set = rproc_virtio_set, | |
273 | }; | |
274 | ||
275 | /* | |
276 | * This function is called whenever vdev is released, and is responsible | |
277 | * to decrement the remote processor's refcount which was taken when vdev was | |
278 | * added. | |
279 | * | |
280 | * Never call this function directly; it will be called by the driver | |
281 | * core when needed. | |
282 | */ | |
283 | static void rproc_virtio_dev_release(struct device *dev) | |
284 | { | |
285 | struct virtio_device *vdev = dev_to_virtio(dev); | |
286 | struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); | |
287 | struct rproc *rproc = vdev_to_rproc(vdev); | |
288 | ||
289 | kref_put(&rvdev->refcount, rproc_vdev_release); | |
290 | ||
291 | put_device(&rproc->dev); | |
292 | } | |
293 | ||
294 | /** | |
295 | * rproc_add_virtio_dev() - register an rproc-induced virtio device | |
296 | * @rvdev: the remote vdev | |
297 | * | |
298 | * This function registers a virtio device. This vdev's partent is | |
299 | * the rproc device. | |
300 | * | |
301 | * Returns 0 on success or an appropriate error value otherwise. | |
302 | */ | |
303 | int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id) | |
304 | { | |
305 | struct rproc *rproc = rvdev->rproc; | |
306 | struct device *dev = &rproc->dev; | |
307 | struct virtio_device *vdev = &rvdev->vdev; | |
308 | int ret; | |
309 | ||
310 | vdev->id.device = id, | |
311 | vdev->config = &rproc_virtio_config_ops, | |
312 | vdev->dev.parent = dev; | |
313 | vdev->dev.release = rproc_virtio_dev_release; | |
314 | ||
315 | /* | |
316 | * We're indirectly making a non-temporary copy of the rproc pointer | |
317 | * here, because drivers probed with this vdev will indirectly | |
318 | * access the wrapping rproc. | |
319 | * | |
320 | * Therefore we must increment the rproc refcount here, and decrement | |
321 | * it _only_ when the vdev is released. | |
322 | */ | |
323 | get_device(&rproc->dev); | |
324 | ||
325 | /* Reference the vdev and vring allocations */ | |
326 | kref_get(&rvdev->refcount); | |
327 | ||
328 | ret = register_virtio_device(vdev); | |
329 | if (ret) { | |
330 | put_device(&rproc->dev); | |
331 | dev_err(dev, "failed to register vdev: %d\n", ret); | |
332 | goto out; | |
333 | } | |
334 | ||
335 | dev_info(dev, "registered %s (type %d)\n", dev_name(&vdev->dev), id); | |
336 | ||
337 | out: | |
338 | return ret; | |
339 | } | |
340 | ||
341 | /** | |
342 | * rproc_remove_virtio_dev() - remove an rproc-induced virtio device | |
343 | * @rvdev: the remote vdev | |
344 | * | |
345 | * This function unregisters an existing virtio device. | |
346 | */ | |
347 | void rproc_remove_virtio_dev(struct rproc_vdev *rvdev) | |
348 | { | |
349 | unregister_virtio_device(&rvdev->vdev); | |
350 | } |