diff options
| -rw-r--r-- | drivers/remoteproc/Makefile | 1 | ||||
| -rw-r--r-- | drivers/remoteproc/remoteproc_rpmsg.c | 295 |
2 files changed, 296 insertions, 0 deletions
diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile index 9ffaec43689c..370dffd54fee 100644 --- a/drivers/remoteproc/Makefile +++ b/drivers/remoteproc/Makefile @@ -5,3 +5,4 @@ obj-$(CONFIG_REMOTEPROC) += remoteproc.o remoteproc-y := remoteproc_core.o remoteproc-y += remoteproc_debugfs.o +remoteproc-y += remoteproc_rpmsg.o diff --git a/drivers/remoteproc/remoteproc_rpmsg.c b/drivers/remoteproc/remoteproc_rpmsg.c new file mode 100644 index 000000000000..f30be4c193ef --- /dev/null +++ b/drivers/remoteproc/remoteproc_rpmsg.c @@ -0,0 +1,295 @@ +/* + * 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/rpmsg.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" + +/** + * struct rproc_virtio_vq_info - virtqueue state + * @vq_id: a unique index of this virtqueue (unique for this @rproc) + * @rproc: handle to the remote processor + * + * Such a struct will be maintained for every virtqueue we're + * using to communicate with the remote processor + */ +struct rproc_virtio_vq_info { + __u16 vq_id; + struct rproc *rproc; +}; + +/* kick the remote processor, and let it know which virtqueue to poke at */ +static void rproc_virtio_notify(struct virtqueue *vq) +{ + struct rproc_virtio_vq_info *rpvq = vq->priv; + struct rproc *rproc = rpvq->rproc; + + dev_dbg(rproc->dev, "kicking vq id: %d\n", rpvq->vq_id); + + rproc->ops->kick(rproc, rpvq->vq_id); +} + +/** + * rproc_vq_interrupt() - tell remoteproc that a virtqueue is interrupted + * @rproc: handle to the remote processor + * @vq_id: index of the signalled virtqueue + * + * 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 @vq_id virtqueue, + * and otherwise returns IRQ_HANDLED. + */ +irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int vq_id) +{ + return vring_interrupt(0, rproc->rvdev->vq[vq_id]); +} +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 *rproc = vdev_to_rproc(vdev); + struct rproc_vdev *rvdev = rproc->rvdev; + struct rproc_virtio_vq_info *rpvq; + struct virtqueue *vq; + void *addr; + int ret, len; + + rpvq = kmalloc(sizeof(*rpvq), GFP_KERNEL); + if (!rpvq) + return ERR_PTR(-ENOMEM); + + rpvq->rproc = rproc; + rpvq->vq_id = id; + + addr = rvdev->vring[id].va; + len = rvdev->vring[id].len; + + dev_dbg(rproc->dev, "vring%d: va %p qsz %d\n", id, addr, len); + + vq = vring_new_virtqueue(len, AMP_VRING_ALIGN, vdev, addr, + rproc_virtio_notify, callback, name); + if (!vq) { + dev_err(rproc->dev, "vring_new_virtqueue %s failed\n", name); + ret = -ENOMEM; + goto free_rpvq; + } + + rvdev->vq[id] = vq; + vq->priv = rpvq; + + return vq; + +free_rpvq: + kfree(rpvq); + return ERR_PTR(ret); +} + +static void rproc_virtio_del_vqs(struct virtio_device *vdev) +{ + struct virtqueue *vq, *n; + struct rproc *rproc = vdev_to_rproc(vdev); + + list_for_each_entry_safe(vq, n, &vdev->vqs, list) { + struct rproc_virtio_vq_info *rpvq = vq->priv; + vring_del_virtqueue(vq); + kfree(rpvq); + } + + /* power down the remote processor */ + rproc_shutdown(rproc); +} + +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; + + /* we maintain two virtqueues per remote processor (for RX and TX) */ + if (nvqs != 2) + return -EINVAL; + + /* boot the remote processor */ + ret = rproc_boot(rproc); + if (ret) { + dev_err(rproc->dev, "rproc_boot() failed %d\n", ret); + goto error; + } + + 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; + } + } + + 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 VIRTIO HDR 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, "new 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 *rproc = vdev_to_rproc(vdev); + + /* we only support a single vdev device for now */ + return rproc->rvdev->dfeatures; +} + +static void rproc_virtio_finalize_features(struct virtio_device *vdev) +{ + struct rproc *rproc = vdev_to_rproc(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. + */ + rproc->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_rpmsg_vdev() - create an rpmsg virtio device + * @rproc: the rproc handle + * + * This function is called if virtio rpmsg support was found in the + * firmware of the remote processor. + * + * Today we only support creating a single rpmsg vdev (virtio device), + * but the plan is to remove this limitation. At that point this interface + * will be revised/extended. + */ +int rproc_add_rpmsg_vdev(struct rproc *rproc) +{ + struct device *dev = rproc->dev; + struct rproc_vdev *rvdev = rproc->rvdev; + int ret; + + rvdev->vdev.id.device = VIRTIO_ID_RPMSG, + rvdev->vdev.config = &rproc_virtio_config_ops, + rvdev->vdev.dev.parent = dev; + rvdev->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(&rvdev->vdev); + if (ret) { + kref_put(&rproc->refcount, rproc_release); + dev_err(dev, "failed to register vdev: %d\n", ret); + } + + return ret; +} + +/** + * rproc_remove_rpmsg_vdev() - remove an rpmsg vdev device + * @rproc: the rproc handle + * + * This function is called whenever @rproc is removed _iff_ an rpmsg + * vdev was created beforehand. + */ +void rproc_remove_rpmsg_vdev(struct rproc *rproc) +{ + struct rproc_vdev *rvdev = rproc->rvdev; + + unregister_virtio_device(&rvdev->vdev); +} |