2 * Remote processor messaging transport (OMAP platform-specific bits)
4 * Copyright (C) 2011 Texas Instruments, Inc.
5 * Copyright (C) 2011 Google, Inc.
7 * Ohad Ben-Cohen <ohad@wizery.com>
8 * Brian Swetland <swetland@google.com>
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.
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.
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>
30 #include "remoteproc_internal.h"
32 /* kick the remote processor, and let it know which virtqueue to poke at */
33 static void rproc_virtio_notify(struct virtqueue
*vq
)
35 struct rproc_vring
*rvring
= vq
->priv
;
36 struct rproc
*rproc
= rvring
->rvdev
->rproc
;
37 int notifyid
= rvring
->notifyid
;
39 dev_dbg(rproc
->dev
, "kicking vq index: %d\n", notifyid
);
41 rproc
->ops
->kick(rproc
, notifyid
);
45 * rproc_vq_interrupt() - tell remoteproc that a virtqueue is interrupted
46 * @rproc: handle to the remote processor
47 * @notifyid: index of the signalled virtqueue (unique per this @rproc)
49 * This function should be called by the platform-specific rproc driver,
50 * when the remote processor signals that a specific virtqueue has pending
53 * Returns IRQ_NONE if no message was found in the @notifyid virtqueue,
54 * and otherwise returns IRQ_HANDLED.
56 irqreturn_t
rproc_vq_interrupt(struct rproc
*rproc
, int notifyid
)
58 struct rproc_vring
*rvring
;
60 dev_dbg(rproc
->dev
, "vq index %d is interrupted\n", notifyid
);
62 rvring
= idr_find(&rproc
->notifyids
, notifyid
);
63 if (!rvring
|| !rvring
->vq
)
66 return vring_interrupt(0, rvring
->vq
);
68 EXPORT_SYMBOL(rproc_vq_interrupt
);
70 static struct virtqueue
*rp_find_vq(struct virtio_device
*vdev
,
72 void (*callback
)(struct virtqueue
*vq
),
75 struct rproc_vdev
*rvdev
= vdev_to_rvdev(vdev
);
76 struct rproc
*rproc
= vdev_to_rproc(vdev
);
77 struct rproc_vring
*rvring
;
82 /* we're temporarily limited to two virtqueues per rvdev */
83 if (id
>= ARRAY_SIZE(rvdev
->vring
))
84 return ERR_PTR(-EINVAL
);
86 ret
= rproc_alloc_vring(rvdev
, id
);
90 rvring
= &rvdev
->vring
[id
];
95 size
= vring_size(len
, rvring
->align
);
96 memset(addr
, 0, size
);
98 dev_dbg(rproc
->dev
, "vring%d: va %p qsz %d notifyid %d\n",
99 id
, addr
, len
, rvring
->notifyid
);
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.
105 vq
= vring_new_virtqueue(len
, rvring
->align
, vdev
, false, addr
,
106 rproc_virtio_notify
, callback
, name
);
108 dev_err(rproc
->dev
, "vring_new_virtqueue %s failed\n", name
);
109 rproc_free_vring(rvring
);
110 return ERR_PTR(-ENOMEM
);
119 static void rproc_virtio_del_vqs(struct virtio_device
*vdev
)
121 struct virtqueue
*vq
, *n
;
122 struct rproc
*rproc
= vdev_to_rproc(vdev
);
123 struct rproc_vring
*rvring
;
125 /* power down the remote processor before deleting vqs */
126 rproc_shutdown(rproc
);
128 list_for_each_entry_safe(vq
, n
, &vdev
->vqs
, list
) {
131 vring_del_virtqueue(vq
);
132 rproc_free_vring(rvring
);
136 static int rproc_virtio_find_vqs(struct virtio_device
*vdev
, unsigned nvqs
,
137 struct virtqueue
*vqs
[],
138 vq_callback_t
*callbacks
[],
141 struct rproc
*rproc
= vdev_to_rproc(vdev
);
144 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
]);
152 /* now that the vqs are all set, boot the remote processor */
153 ret
= rproc_boot(rproc
);
155 dev_err(rproc
->dev
, "rproc_boot() failed %d\n", ret
);
162 rproc_virtio_del_vqs(vdev
);
167 * We don't support yet real virtio status semantics.
169 * The plan is to provide this via the VDEV resource entry
170 * which is part of the firmware: this way the remote processor
171 * will be able to access the status values as set by us.
173 static u8
rproc_virtio_get_status(struct virtio_device
*vdev
)
178 static void rproc_virtio_set_status(struct virtio_device
*vdev
, u8 status
)
180 dev_dbg(&vdev
->dev
, "status: %d\n", status
);
183 static void rproc_virtio_reset(struct virtio_device
*vdev
)
185 dev_dbg(&vdev
->dev
, "reset !\n");
188 /* provide the vdev features as retrieved from the firmware */
189 static u32
rproc_virtio_get_features(struct virtio_device
*vdev
)
191 struct rproc_vdev
*rvdev
= vdev_to_rvdev(vdev
);
193 return rvdev
->dfeatures
;
196 static void rproc_virtio_finalize_features(struct virtio_device
*vdev
)
198 struct rproc_vdev
*rvdev
= vdev_to_rvdev(vdev
);
200 /* Give virtio_ring a chance to accept features */
201 vring_transport_features(vdev
);
204 * Remember the finalized features of our vdev, and provide it
205 * to the remote processor once it is powered on.
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.
212 rvdev
->gfeatures
= vdev
->features
[0];
215 static 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
,
226 * This function is called whenever vdev is released, and is responsible
227 * to decrement the remote processor's refcount taken when vdev was
230 * Never call this function directly; it will be called by the driver
233 static void rproc_vdev_release(struct device
*dev
)
235 struct virtio_device
*vdev
= dev_to_virtio(dev
);
236 struct rproc_vdev
*rvdev
= vdev_to_rvdev(vdev
);
237 struct rproc
*rproc
= vdev_to_rproc(vdev
);
239 list_del(&rvdev
->node
);
242 kref_put(&rproc
->refcount
, rproc_release
);
246 * rproc_add_virtio_dev() - register an rproc-induced virtio device
247 * @rvdev: the remote vdev
249 * This function registers a virtio device. This vdev's partent is
252 * Returns 0 on success or an appropriate error value otherwise.
254 int rproc_add_virtio_dev(struct rproc_vdev
*rvdev
, int id
)
256 struct rproc
*rproc
= rvdev
->rproc
;
257 struct device
*dev
= rproc
->dev
;
258 struct virtio_device
*vdev
= &rvdev
->vdev
;
261 vdev
->id
.device
= id
,
262 vdev
->config
= &rproc_virtio_config_ops
,
263 vdev
->dev
.parent
= dev
;
264 vdev
->dev
.release
= rproc_vdev_release
;
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.
271 * Therefore we must increment the rproc refcount here, and decrement
272 * it _only_ when the vdev is released.
274 kref_get(&rproc
->refcount
);
276 ret
= register_virtio_device(vdev
);
278 kref_put(&rproc
->refcount
, rproc_release
);
279 dev_err(dev
, "failed to register vdev: %d\n", ret
);
283 dev_info(dev
, "registered %s (type %d)\n", dev_name(&vdev
->dev
), id
);
290 * rproc_remove_virtio_dev() - remove an rproc-induced virtio device
291 * @rvdev: the remote vdev
293 * This function unregisters an existing virtio device.
295 void rproc_remove_virtio_dev(struct rproc_vdev
*rvdev
)
297 unregister_virtio_device(&rvdev
->vdev
);