blob: 26a7144e7f3b9e58919e65b5f2397bd9423d19f7 [file] [log] [blame]
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +02001/*
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>
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +020022#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
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +020032/* kick the remote processor, and let it know which virtqueue to poke at */
33static void rproc_virtio_notify(struct virtqueue *vq)
34{
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +010035 struct rproc_vring *rvring = vq->priv;
36 struct rproc *rproc = rvring->rvdev->rproc;
37 int notifyid = rvring->notifyid;
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +020038
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +010039 dev_dbg(rproc->dev, "kicking vq index: %d\n", notifyid);
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +020040
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +010041 rproc->ops->kick(rproc, notifyid);
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +020042}
43
44/**
45 * rproc_vq_interrupt() - tell remoteproc that a virtqueue is interrupted
46 * @rproc: handle to the remote processor
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +010047 * @notifyid: index of the signalled virtqueue (unique per this @rproc)
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +020048 *
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 *
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +010053 * Returns IRQ_NONE if no message was found in the @notifyid virtqueue,
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +020054 * and otherwise returns IRQ_HANDLED.
55 */
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +010056irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int notifyid)
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +020057{
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +010058 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);
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +020067}
68EXPORT_SYMBOL(rproc_vq_interrupt);
69
70static struct virtqueue *rp_find_vq(struct virtio_device *vdev,
71 unsigned id,
72 void (*callback)(struct virtqueue *vq),
73 const char *name)
74{
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +010075 struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +020076 struct rproc *rproc = vdev_to_rproc(vdev);
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +010077 struct rproc_vring *rvring;
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +020078 struct virtqueue *vq;
79 void *addr;
Ohad Ben-Cohen6db20ea2012-05-17 14:23:59 +030080 int len, size, ret;
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +020081
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +010082 /* we're temporarily limited to two virtqueues per rvdev */
83 if (id >= ARRAY_SIZE(rvdev->vring))
84 return ERR_PTR(-EINVAL);
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +020085
Ohad Ben-Cohen6db20ea2012-05-17 14:23:59 +030086 ret = rproc_alloc_vring(rvdev, id);
87 if (ret)
88 return ERR_PTR(ret);
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +020089
Ohad Ben-Cohen6db20ea2012-05-17 14:23:59 +030090 rvring = &rvdev->vring[id];
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +010091 addr = rvring->va;
92 len = rvring->len;
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +020093
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +010094 /* zero vring */
95 size = vring_size(len, rvring->align);
96 memset(addr, 0, size);
97
98 dev_dbg(rproc->dev, "vring%d: va %p qsz %d notifyid %d\n",
99 id, addr, len, rvring->notifyid);
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200100
Ohad Ben-Cohendd6da1c2012-01-12 09:26:57 +0200101 /*
102 * Create the new vq, and tell virtio we're not interested in
103 * the 'weak' smp barriers, since we're talking with a real device.
104 */
Ohad Ben-Cohen63140e02012-02-29 14:42:13 +0200105 vq = vring_new_virtqueue(len, rvring->align, vdev, false, addr,
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200106 rproc_virtio_notify, callback, name);
107 if (!vq) {
108 dev_err(rproc->dev, "vring_new_virtqueue %s failed\n", name);
Ohad Ben-Cohen6db20ea2012-05-17 14:23:59 +0300109 rproc_free_vring(rvring);
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +0100110 return ERR_PTR(-ENOMEM);
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200111 }
112
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +0100113 rvring->vq = vq;
114 vq->priv = rvring;
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200115
116 return vq;
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200117}
118
119static void rproc_virtio_del_vqs(struct virtio_device *vdev)
120{
121 struct virtqueue *vq, *n;
122 struct rproc *rproc = vdev_to_rproc(vdev);
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +0100123 struct rproc_vring *rvring;
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200124
Ohad Ben-Cohen41a6ee02012-02-13 09:38:23 +0200125 /* power down the remote processor before deleting vqs */
126 rproc_shutdown(rproc);
127
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200128 list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +0100129 rvring = vq->priv;
130 rvring->vq = NULL;
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200131 vring_del_virtqueue(vq);
Ohad Ben-Cohen6db20ea2012-05-17 14:23:59 +0300132 rproc_free_vring(rvring);
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200133 }
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200134}
135
136static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned nvqs,
137 struct virtqueue *vqs[],
138 vq_callback_t *callbacks[],
139 const char *names[])
140{
141 struct rproc *rproc = vdev_to_rproc(vdev);
142 int i, ret;
143
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200144 for (i = 0; i < nvqs; ++i) {
145 vqs[i] = rp_find_vq(vdev, i, callbacks[i], names[i]);
146 if (IS_ERR(vqs[i])) {
147 ret = PTR_ERR(vqs[i]);
148 goto error;
149 }
150 }
151
Ohad Ben-Cohen41a6ee02012-02-13 09:38:23 +0200152 /* now that the vqs are all set, boot the remote processor */
153 ret = rproc_boot(rproc);
154 if (ret) {
155 dev_err(rproc->dev, "rproc_boot() failed %d\n", ret);
156 goto error;
157 }
158
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200159 return 0;
160
161error:
162 rproc_virtio_del_vqs(vdev);
163 return ret;
164}
165
166/*
167 * We don't support yet real virtio status semantics.
168 *
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +0100169 * The plan is to provide this via the VDEV resource entry
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200170 * which is part of the firmware: this way the remote processor
171 * will be able to access the status values as set by us.
172 */
173static u8 rproc_virtio_get_status(struct virtio_device *vdev)
174{
175 return 0;
176}
177
178static void rproc_virtio_set_status(struct virtio_device *vdev, u8 status)
179{
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +0100180 dev_dbg(&vdev->dev, "status: %d\n", status);
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200181}
182
183static void rproc_virtio_reset(struct virtio_device *vdev)
184{
185 dev_dbg(&vdev->dev, "reset !\n");
186}
187
188/* provide the vdev features as retrieved from the firmware */
189static u32 rproc_virtio_get_features(struct virtio_device *vdev)
190{
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +0100191 struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200192
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +0100193 return rvdev->dfeatures;
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200194}
195
196static void rproc_virtio_finalize_features(struct virtio_device *vdev)
197{
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +0100198 struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200199
200 /* Give virtio_ring a chance to accept features */
201 vring_transport_features(vdev);
202
203 /*
204 * Remember the finalized features of our vdev, and provide it
205 * to the remote processor once it is powered on.
206 *
207 * Similarly to the status field, we don't expose yet the negotiated
208 * features to the remote processors at this point. This will be
209 * fixed as part of a small resource table overhaul and then an
210 * extension of the virtio resource entries.
211 */
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +0100212 rvdev->gfeatures = vdev->features[0];
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200213}
214
215static struct virtio_config_ops rproc_virtio_config_ops = {
216 .get_features = rproc_virtio_get_features,
217 .finalize_features = rproc_virtio_finalize_features,
218 .find_vqs = rproc_virtio_find_vqs,
219 .del_vqs = rproc_virtio_del_vqs,
220 .reset = rproc_virtio_reset,
221 .set_status = rproc_virtio_set_status,
222 .get_status = rproc_virtio_get_status,
223};
224
225/*
226 * This function is called whenever vdev is released, and is responsible
227 * to decrement the remote processor's refcount taken when vdev was
228 * added.
229 *
230 * Never call this function directly; it will be called by the driver
231 * core when needed.
232 */
233static void rproc_vdev_release(struct device *dev)
234{
235 struct virtio_device *vdev = dev_to_virtio(dev);
Ohad Ben-Cohen6db20ea2012-05-17 14:23:59 +0300236 struct rproc_vdev *rvdev = vdev_to_rvdev(vdev);
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200237 struct rproc *rproc = vdev_to_rproc(vdev);
238
Ohad Ben-Cohen6db20ea2012-05-17 14:23:59 +0300239 list_del(&rvdev->node);
240 kfree(rvdev);
241
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200242 kref_put(&rproc->refcount, rproc_release);
243}
244
245/**
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +0100246 * rproc_add_virtio_dev() - register an rproc-induced virtio device
247 * @rvdev: the remote vdev
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200248 *
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +0100249 * This function registers a virtio device. This vdev's partent is
250 * the rproc device.
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200251 *
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +0100252 * Returns 0 on success or an appropriate error value otherwise.
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200253 */
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +0100254int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id)
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200255{
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +0100256 struct rproc *rproc = rvdev->rproc;
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200257 struct device *dev = rproc->dev;
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +0100258 struct virtio_device *vdev = &rvdev->vdev;
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200259 int ret;
260
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +0100261 vdev->id.device = id,
262 vdev->config = &rproc_virtio_config_ops,
263 vdev->dev.parent = dev;
264 vdev->dev.release = rproc_vdev_release;
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200265
266 /*
267 * We're indirectly making a non-temporary copy of the rproc pointer
268 * here, because drivers probed with this vdev will indirectly
269 * access the wrapping rproc.
270 *
271 * Therefore we must increment the rproc refcount here, and decrement
272 * it _only_ when the vdev is released.
273 */
274 kref_get(&rproc->refcount);
275
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +0100276 ret = register_virtio_device(vdev);
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200277 if (ret) {
278 kref_put(&rproc->refcount, rproc_release);
279 dev_err(dev, "failed to register vdev: %d\n", ret);
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +0100280 goto out;
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200281 }
282
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +0100283 dev_info(dev, "registered %s (type %d)\n", dev_name(&vdev->dev), id);
284
285out:
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200286 return ret;
287}
288
289/**
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +0100290 * rproc_remove_virtio_dev() - remove an rproc-induced virtio device
291 * @rvdev: the remote vdev
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200292 *
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +0100293 * This function unregisters an existing virtio device.
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200294 */
Ohad Ben-Cohen7a186942012-02-13 22:30:39 +0100295void rproc_remove_virtio_dev(struct rproc_vdev *rvdev)
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200296{
Ohad Ben-Cohenac8954a2011-10-20 18:15:13 +0200297 unregister_virtio_device(&rvdev->vdev);
298}