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ac8954a4 OBC |
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> | |
ac8954a4 OBC |
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 | ||
ac8954a4 OBC |
32 | /* kick the remote processor, and let it know which virtqueue to poke at */ |
33 | static void rproc_virtio_notify(struct virtqueue *vq) | |
34 | { | |
7a186941 OBC |
35 | struct rproc_vring *rvring = vq->priv; |
36 | struct rproc *rproc = rvring->rvdev->rproc; | |
37 | int notifyid = rvring->notifyid; | |
ac8954a4 | 38 | |
7a186941 | 39 | dev_dbg(rproc->dev, "kicking vq index: %d\n", notifyid); |
ac8954a4 | 40 | |
7a186941 | 41 | rproc->ops->kick(rproc, notifyid); |
ac8954a4 OBC |
42 | } |
43 | ||
44 | /** | |
45 | * rproc_vq_interrupt() - tell remoteproc that a virtqueue is interrupted | |
46 | * @rproc: handle to the remote processor | |
7a186941 | 47 | * @notifyid: index of the signalled virtqueue (unique per this @rproc) |
ac8954a4 OBC |
48 | * |
49 | * This function should be called by the platform-specific rproc driver, | |
50 | * when the remote processor signals that a specific virtqueue has pending | |
51 | * messages available. | |
52 | * | |
7a186941 | 53 | * Returns IRQ_NONE if no message was found in the @notifyid virtqueue, |
ac8954a4 OBC |
54 | * and otherwise returns IRQ_HANDLED. |
55 | */ | |
7a186941 | 56 | irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int notifyid) |
ac8954a4 | 57 | { |
7a186941 OBC |
58 | struct rproc_vring *rvring; |
59 | ||
60 | dev_dbg(rproc->dev, "vq index %d is interrupted\n", notifyid); | |
61 | ||
62 | rvring = idr_find(&rproc->notifyids, notifyid); | |
63 | if (!rvring || !rvring->vq) | |
64 | return IRQ_NONE; | |
65 | ||
66 | return vring_interrupt(0, rvring->vq); | |
ac8954a4 OBC |
67 | } |
68 | EXPORT_SYMBOL(rproc_vq_interrupt); | |
69 | ||
70 | static struct virtqueue *rp_find_vq(struct virtio_device *vdev, | |
71 | unsigned id, | |
72 | void (*callback)(struct virtqueue *vq), | |
73 | const char *name) | |
74 | { | |
7a186941 | 75 | struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); |
ac8954a4 | 76 | struct rproc *rproc = vdev_to_rproc(vdev); |
7a186941 | 77 | struct rproc_vring *rvring; |
ac8954a4 OBC |
78 | struct virtqueue *vq; |
79 | void *addr; | |
7a186941 | 80 | int len, size; |
ac8954a4 | 81 | |
7a186941 OBC |
82 | /* we're temporarily limited to two virtqueues per rvdev */ |
83 | if (id >= ARRAY_SIZE(rvdev->vring)) | |
84 | return ERR_PTR(-EINVAL); | |
85 | ||
86 | rvring = &rvdev->vring[id]; | |
ac8954a4 | 87 | |
7a186941 OBC |
88 | addr = rvring->va; |
89 | len = rvring->len; | |
ac8954a4 | 90 | |
7a186941 OBC |
91 | /* zero vring */ |
92 | size = vring_size(len, rvring->align); | |
93 | memset(addr, 0, size); | |
ac8954a4 | 94 | |
7a186941 OBC |
95 | dev_dbg(rproc->dev, "vring%d: va %p qsz %d notifyid %d\n", |
96 | id, addr, len, rvring->notifyid); | |
ac8954a4 | 97 | |
dd6da1c5 OBC |
98 | /* |
99 | * Create the new vq, and tell virtio we're not interested in | |
100 | * the 'weak' smp barriers, since we're talking with a real device. | |
101 | */ | |
102 | vq = vring_new_virtqueue(len, AMP_VRING_ALIGN, vdev, false, addr, | |
ac8954a4 OBC |
103 | rproc_virtio_notify, callback, name); |
104 | if (!vq) { | |
105 | dev_err(rproc->dev, "vring_new_virtqueue %s failed\n", name); | |
7a186941 | 106 | return ERR_PTR(-ENOMEM); |
ac8954a4 OBC |
107 | } |
108 | ||
7a186941 OBC |
109 | rvring->vq = vq; |
110 | vq->priv = rvring; | |
ac8954a4 OBC |
111 | |
112 | return vq; | |
ac8954a4 OBC |
113 | } |
114 | ||
115 | static void rproc_virtio_del_vqs(struct virtio_device *vdev) | |
116 | { | |
117 | struct virtqueue *vq, *n; | |
118 | struct rproc *rproc = vdev_to_rproc(vdev); | |
7a186941 | 119 | struct rproc_vring *rvring; |
ac8954a4 | 120 | |
41a6ee09 OBC |
121 | /* power down the remote processor before deleting vqs */ |
122 | rproc_shutdown(rproc); | |
123 | ||
ac8954a4 | 124 | list_for_each_entry_safe(vq, n, &vdev->vqs, list) { |
7a186941 OBC |
125 | rvring = vq->priv; |
126 | rvring->vq = NULL; | |
ac8954a4 | 127 | vring_del_virtqueue(vq); |
ac8954a4 | 128 | } |
ac8954a4 OBC |
129 | } |
130 | ||
131 | static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned nvqs, | |
132 | struct virtqueue *vqs[], | |
133 | vq_callback_t *callbacks[], | |
134 | const char *names[]) | |
135 | { | |
136 | struct rproc *rproc = vdev_to_rproc(vdev); | |
137 | int i, ret; | |
138 | ||
ac8954a4 OBC |
139 | for (i = 0; i < nvqs; ++i) { |
140 | vqs[i] = rp_find_vq(vdev, i, callbacks[i], names[i]); | |
141 | if (IS_ERR(vqs[i])) { | |
142 | ret = PTR_ERR(vqs[i]); | |
143 | goto error; | |
144 | } | |
145 | } | |
146 | ||
41a6ee09 OBC |
147 | /* now that the vqs are all set, boot the remote processor */ |
148 | ret = rproc_boot(rproc); | |
149 | if (ret) { | |
150 | dev_err(rproc->dev, "rproc_boot() failed %d\n", ret); | |
151 | goto error; | |
152 | } | |
153 | ||
ac8954a4 OBC |
154 | return 0; |
155 | ||
156 | error: | |
157 | rproc_virtio_del_vqs(vdev); | |
158 | return ret; | |
159 | } | |
160 | ||
161 | /* | |
162 | * We don't support yet real virtio status semantics. | |
163 | * | |
7a186941 | 164 | * The plan is to provide this via the VDEV resource entry |
ac8954a4 OBC |
165 | * which is part of the firmware: this way the remote processor |
166 | * will be able to access the status values as set by us. | |
167 | */ | |
168 | static u8 rproc_virtio_get_status(struct virtio_device *vdev) | |
169 | { | |
170 | return 0; | |
171 | } | |
172 | ||
173 | static void rproc_virtio_set_status(struct virtio_device *vdev, u8 status) | |
174 | { | |
7a186941 | 175 | dev_dbg(&vdev->dev, "status: %d\n", status); |
ac8954a4 OBC |
176 | } |
177 | ||
178 | static void rproc_virtio_reset(struct virtio_device *vdev) | |
179 | { | |
180 | dev_dbg(&vdev->dev, "reset !\n"); | |
181 | } | |
182 | ||
183 | /* provide the vdev features as retrieved from the firmware */ | |
184 | static u32 rproc_virtio_get_features(struct virtio_device *vdev) | |
185 | { | |
7a186941 | 186 | struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); |
ac8954a4 | 187 | |
7a186941 | 188 | return rvdev->dfeatures; |
ac8954a4 OBC |
189 | } |
190 | ||
191 | static void rproc_virtio_finalize_features(struct virtio_device *vdev) | |
192 | { | |
7a186941 | 193 | struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); |
ac8954a4 OBC |
194 | |
195 | /* Give virtio_ring a chance to accept features */ | |
196 | vring_transport_features(vdev); | |
197 | ||
198 | /* | |
199 | * Remember the finalized features of our vdev, and provide it | |
200 | * to the remote processor once it is powered on. | |
201 | * | |
202 | * Similarly to the status field, we don't expose yet the negotiated | |
203 | * features to the remote processors at this point. This will be | |
204 | * fixed as part of a small resource table overhaul and then an | |
205 | * extension of the virtio resource entries. | |
206 | */ | |
7a186941 | 207 | rvdev->gfeatures = vdev->features[0]; |
ac8954a4 OBC |
208 | } |
209 | ||
210 | static struct virtio_config_ops rproc_virtio_config_ops = { | |
211 | .get_features = rproc_virtio_get_features, | |
212 | .finalize_features = rproc_virtio_finalize_features, | |
213 | .find_vqs = rproc_virtio_find_vqs, | |
214 | .del_vqs = rproc_virtio_del_vqs, | |
215 | .reset = rproc_virtio_reset, | |
216 | .set_status = rproc_virtio_set_status, | |
217 | .get_status = rproc_virtio_get_status, | |
218 | }; | |
219 | ||
220 | /* | |
221 | * This function is called whenever vdev is released, and is responsible | |
222 | * to decrement the remote processor's refcount taken when vdev was | |
223 | * added. | |
224 | * | |
225 | * Never call this function directly; it will be called by the driver | |
226 | * core when needed. | |
227 | */ | |
228 | static void rproc_vdev_release(struct device *dev) | |
229 | { | |
230 | struct virtio_device *vdev = dev_to_virtio(dev); | |
231 | struct rproc *rproc = vdev_to_rproc(vdev); | |
232 | ||
233 | kref_put(&rproc->refcount, rproc_release); | |
234 | } | |
235 | ||
236 | /** | |
7a186941 OBC |
237 | * rproc_add_virtio_dev() - register an rproc-induced virtio device |
238 | * @rvdev: the remote vdev | |
ac8954a4 | 239 | * |
7a186941 OBC |
240 | * This function registers a virtio device. This vdev's partent is |
241 | * the rproc device. | |
ac8954a4 | 242 | * |
7a186941 | 243 | * Returns 0 on success or an appropriate error value otherwise. |
ac8954a4 | 244 | */ |
7a186941 | 245 | int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id) |
ac8954a4 | 246 | { |
7a186941 | 247 | struct rproc *rproc = rvdev->rproc; |
ac8954a4 | 248 | struct device *dev = rproc->dev; |
7a186941 | 249 | struct virtio_device *vdev = &rvdev->vdev; |
ac8954a4 OBC |
250 | int ret; |
251 | ||
7a186941 OBC |
252 | vdev->id.device = id, |
253 | vdev->config = &rproc_virtio_config_ops, | |
254 | vdev->dev.parent = dev; | |
255 | vdev->dev.release = rproc_vdev_release; | |
ac8954a4 OBC |
256 | |
257 | /* | |
258 | * We're indirectly making a non-temporary copy of the rproc pointer | |
259 | * here, because drivers probed with this vdev will indirectly | |
260 | * access the wrapping rproc. | |
261 | * | |
262 | * Therefore we must increment the rproc refcount here, and decrement | |
263 | * it _only_ when the vdev is released. | |
264 | */ | |
265 | kref_get(&rproc->refcount); | |
266 | ||
7a186941 | 267 | ret = register_virtio_device(vdev); |
ac8954a4 OBC |
268 | if (ret) { |
269 | kref_put(&rproc->refcount, rproc_release); | |
270 | dev_err(dev, "failed to register vdev: %d\n", ret); | |
7a186941 | 271 | goto out; |
ac8954a4 OBC |
272 | } |
273 | ||
7a186941 OBC |
274 | dev_info(dev, "registered %s (type %d)\n", dev_name(&vdev->dev), id); |
275 | ||
276 | out: | |
ac8954a4 OBC |
277 | return ret; |
278 | } | |
279 | ||
280 | /** | |
7a186941 OBC |
281 | * rproc_remove_virtio_dev() - remove an rproc-induced virtio device |
282 | * @rvdev: the remote vdev | |
ac8954a4 | 283 | * |
7a186941 | 284 | * This function unregisters an existing virtio device. |
ac8954a4 | 285 | */ |
7a186941 | 286 | void rproc_remove_virtio_dev(struct rproc_vdev *rvdev) |
ac8954a4 | 287 | { |
ac8954a4 OBC |
288 | unregister_virtio_device(&rvdev->vdev); |
289 | } |