| /* |
| * 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 void 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); |
| } |
| |
| /** |
| * 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 rproc_vring *rvring; |
| struct virtqueue *vq; |
| void *addr; |
| int len, size; |
| |
| /* we're temporarily limited to two virtqueues per rvdev */ |
| if (id >= ARRAY_SIZE(rvdev->vring)) |
| return ERR_PTR(-EINVAL); |
| |
| rvring = &rvdev->vring[id]; |
| |
| addr = rvring->va; |
| len = rvring->len; |
| |
| /* zero vring */ |
| size = vring_size(len, rvring->align); |
| memset(addr, 0, size); |
| |
| dev_dbg(rproc->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(len, AMP_VRING_ALIGN, vdev, false, addr, |
| rproc_virtio_notify, callback, name); |
| if (!vq) { |
| dev_err(rproc->dev, "vring_new_virtqueue %s failed\n", name); |
| 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 *rproc = vdev_to_rproc(vdev); |
| struct rproc_vring *rvring; |
| |
| /* power down the remote processor before deleting vqs */ |
| rproc_shutdown(rproc); |
| |
| list_for_each_entry_safe(vq, n, &vdev->vqs, list) { |
| rvring = vq->priv; |
| rvring->vq = NULL; |
| vring_del_virtqueue(vq); |
| } |
| } |
| |
| 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; |
| } |
| |
| /* |
| * We don't support yet real virtio status semantics. |
| * |
| * The plan is to provide this via the VDEV resource entry |
| * which is part of the firmware: this way the remote processor |
| * will be able to access the status values as set by us. |
| */ |
| static u8 rproc_virtio_get_status(struct virtio_device *vdev) |
| { |
| return 0; |
| } |
| |
| static void rproc_virtio_set_status(struct virtio_device *vdev, u8 status) |
| { |
| dev_dbg(&vdev->dev, "status: %d\n", status); |
| } |
| |
| static void rproc_virtio_reset(struct virtio_device *vdev) |
| { |
| dev_dbg(&vdev->dev, "reset !\n"); |
| } |
| |
| /* provide the vdev features as retrieved from the firmware */ |
| static u32 rproc_virtio_get_features(struct virtio_device *vdev) |
| { |
| struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); |
| |
| return rvdev->dfeatures; |
| } |
| |
| static void rproc_virtio_finalize_features(struct virtio_device *vdev) |
| { |
| struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); |
| |
| /* Give virtio_ring a chance to accept features */ |
| vring_transport_features(vdev); |
| |
| /* |
| * Remember the finalized features of our vdev, and provide it |
| * to the remote processor once it is powered on. |
| * |
| * Similarly to the status field, we don't expose yet the negotiated |
| * features to the remote processors at this point. This will be |
| * fixed as part of a small resource table overhaul and then an |
| * extension of the virtio resource entries. |
| */ |
| rvdev->gfeatures = vdev->features[0]; |
| } |
| |
| static 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, |
| }; |
| |
| /* |
| * This function is called whenever vdev is released, and is responsible |
| * to decrement the remote processor's refcount 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 *rproc = vdev_to_rproc(vdev); |
| |
| kref_put(&rproc->refcount, rproc_release); |
| } |
| |
| /** |
| * 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. |
| */ |
| kref_get(&rproc->refcount); |
| |
| ret = register_virtio_device(vdev); |
| if (ret) { |
| kref_put(&rproc->refcount, rproc_release); |
| 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); |
| } |