/* * 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 bool 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); return true; } /** * 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 int id, void (*callback)(struct virtqueue *vq), const char *name, bool ctx) { struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); struct rproc *rproc = vdev_to_rproc(vdev); struct device *dev = &rproc->dev; 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); if (!name) return NULL; rvring = &rvdev->vring[id]; addr = rvring->va; len = rvring->len; /* zero vring */ size = vring_size(len, rvring->align); memset(addr, 0, size); dev_dbg(dev, "vring%d: va %pK 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(id, len, rvring->align, vdev, false, ctx, addr, rproc_virtio_notify, callback, name); if (!vq) { dev_err(dev, "vring_new_virtqueue %s failed\n", name); rproc_free_vring(rvring); 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_vring *rvring; list_for_each_entry_safe(vq, n, &vdev->vqs, list) { rvring = vq->priv; rvring->vq = NULL; vring_del_virtqueue(vq); } } static void rproc_virtio_del_vqs(struct virtio_device *vdev) { __rproc_virtio_del_vqs(vdev); } static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned int nvqs, struct virtqueue *vqs[], vq_callback_t *callbacks[], const char * const names[], const bool * ctx, struct irq_affinity *desc) { int i, ret; for (i = 0; i < nvqs; ++i) { vqs[i] = rp_find_vq(vdev, i, callbacks[i], names[i], ctx ? ctx[i] : false); if (IS_ERR(vqs[i])) { ret = PTR_ERR(vqs[i]); goto error; } } return 0; error: __rproc_virtio_del_vqs(vdev); return ret; } static u8 rproc_virtio_get_status(struct virtio_device *vdev) { struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); struct fw_rsc_vdev *rsc; rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; return rsc->status; } static void rproc_virtio_set_status(struct virtio_device *vdev, u8 status) { struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); struct fw_rsc_vdev *rsc; rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; rsc->status = status; dev_dbg(&vdev->dev, "status: %d\n", status); } static void rproc_virtio_reset(struct virtio_device *vdev) { struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); struct fw_rsc_vdev *rsc; rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; rsc->status = 0; dev_dbg(&vdev->dev, "reset !\n"); } /* provide the vdev features as retrieved from the firmware */ static u64 rproc_virtio_get_features(struct virtio_device *vdev) { struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); struct fw_rsc_vdev *rsc; rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; return rsc->dfeatures; } static int rproc_virtio_finalize_features(struct virtio_device *vdev) { struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); struct fw_rsc_vdev *rsc; rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; /* Give virtio_ring a chance to accept features */ vring_transport_features(vdev); /* Make sure we don't have any features > 32 bits! */ BUG_ON((u32)vdev->features != vdev->features); /* * Remember the finalized features of our vdev, and provide it * to the remote processor once it is powered on. */ rsc->gfeatures = vdev->features; return 0; } static void rproc_virtio_get(struct virtio_device *vdev, unsigned int offset, void *buf, unsigned int len) { struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); struct fw_rsc_vdev *rsc; void *cfg; rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; cfg = &rsc->vring[rsc->num_of_vrings]; if (offset + len > rsc->config_len || offset + len < len) { dev_err(&vdev->dev, "rproc_virtio_get: access out of bounds\n"); return; } memcpy(buf, cfg + offset, len); } static void rproc_virtio_set(struct virtio_device *vdev, unsigned int offset, const void *buf, unsigned int len) { struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); struct fw_rsc_vdev *rsc; void *cfg; rsc = (void *)rvdev->rproc->table_ptr + rvdev->rsc_offset; cfg = &rsc->vring[rsc->num_of_vrings]; if (offset + len > rsc->config_len || offset + len < len) { dev_err(&vdev->dev, "rproc_virtio_set: access out of bounds\n"); return; } memcpy(cfg + offset, buf, len); } static const 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, .get = rproc_virtio_get, .set = rproc_virtio_set, }; /* * This function is called whenever vdev is released, and is responsible * to decrement the remote processor's refcount which was taken when vdev was * added. * * Never call this function directly; it will be called by the driver * core when needed. */ static void rproc_virtio_dev_release(struct device *dev) { struct virtio_device *vdev = dev_to_virtio(dev); struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); struct rproc *rproc = vdev_to_rproc(vdev); kref_put(&rvdev->refcount, rproc_vdev_release); put_device(&rproc->dev); } /** * 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_virtio_dev_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. */ get_device(&rproc->dev); /* Reference the vdev and vring allocations */ kref_get(&rvdev->refcount); ret = register_virtio_device(vdev); if (ret) { put_device(&vdev->dev); 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); }