/* * Virtio-based remote processor messaging bus * * Copyright (C) 2011 Texas Instruments, Inc. * Copyright (C) 2011 Google, Inc. * * Ohad Ben-Cohen * Brian Swetland * * 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. */ #define pr_fmt(fmt) "%s: " fmt, __func__ #include #include #include #include #include #include #include #include #include #include #include #include /** * struct virtproc_info - virtual remote processor info * * @vdev: the virtio device * @rvq: rx virtqueue (from pov of local processor) * @svq: tx virtqueue (from pov of local processor) * @rbufs: address of rx buffers * @sbufs: address of tx buffers * @last_rbuf: index of last rx buffer used * @last_sbuf: index of last tx buffer used * @sim_base: simulated base addr base to make virtio's virt_to_page happy * @svq_lock: protects the tx virtqueue, to allow several concurrent senders * @num_bufs: total number of buffers allocated for communicating with this * virtual remote processor. half is used for rx and half for tx. * @buf_size: size of buffers allocated for communications * @endpoints: the set of local endpoints * @endpoints_lock: lock of the endpoints set * @sendq: wait queue of sending contexts waiting for free rpmsg buffer * @ns_ept: the bus's name service endpoint * @rproc: a reference to the remote processor object * * This structure stores the rpmsg state of a given virtio remote processor * device (there might be several virtio rproc devices for each physical * remote processor). */ struct virtproc_info { struct virtio_device *vdev; struct virtqueue *rvq, *svq; void *rbufs, *sbufs; int last_rbuf, last_sbuf; void *sim_base; struct mutex svq_lock; int num_bufs; int buf_size; struct idr endpoints; spinlock_t endpoints_lock; wait_queue_head_t sendq; struct rpmsg_endpoint *ns_ept; struct rproc *rproc; }; #define to_rpmsg_channel(d) container_of(d, struct rpmsg_channel, dev) #define to_rpmsg_driver(d) container_of(d, struct rpmsg_driver, drv) /* * Local addresses are dynamically allocated on-demand. * We do not dynamically assign addresses from the low 1024 range, * in order to reserve that address range for predefined services. */ #define RPMSG_RESERVED_ADDRESSES (1024) /* Address 53 is reserved for advertising remote services */ #define RPMSG_NS_ADDR (53) /* show configuration fields */ #define rpmsg_show_attr(field, path, format_string) \ static ssize_t \ field##_show(struct device *dev, \ struct device_attribute *attr, char *buf) \ { \ struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); \ \ return sprintf(buf, format_string, rpdev->path); \ } rpmsg_show_attr(name, id.name, "%s\n"); rpmsg_show_attr(dst, dst, "0x%x\n"); rpmsg_show_attr(src, src, "0x%x\n"); rpmsg_show_attr(announce, announce ? "true" : "false", "%s\n"); /* unique (free running) numbering for rpmsg devices */ static unsigned int rpmsg_dev_index; static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf) { struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); return sprintf(buf, RPMSG_DEVICE_MODALIAS_FMT "\n", rpdev->id.name); } static struct device_attribute rpmsg_dev_attrs[] = { __ATTR_RO(name), __ATTR_RO(modalias), __ATTR_RO(dst), __ATTR_RO(src), __ATTR_RO(announce), __ATTR_NULL }; static inline int rpmsg_id_match(const struct rpmsg_channel *rpdev, const struct rpmsg_device_id *id) { if (strncmp(id->name, rpdev->id.name, RPMSG_NAME_SIZE)) return 0; return 1; } /* match rpmsg channel and rpmsg driver */ static int rpmsg_dev_match(struct device *dev, struct device_driver *drv) { struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); struct rpmsg_driver *rpdrv = to_rpmsg_driver(drv); const struct rpmsg_device_id *ids = rpdrv->id_table; unsigned int i; for (i = 0; ids[i].name[0]; i++) { if (rpmsg_id_match(rpdev, &ids[i])) return 1; } return 0; } static int rpmsg_uevent(struct device *dev, struct kobj_uevent_env *env) { struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); return add_uevent_var(env, "MODALIAS=" RPMSG_DEVICE_MODALIAS_FMT, rpdev->id.name); } static struct rpmsg_endpoint *__rpmsg_create_ept(struct virtproc_info *vrp, struct rpmsg_channel *rpdev, void (*cb)(struct rpmsg_channel *, void *, int, void *, u32), void *priv, u32 addr) { int err, tmpaddr, request; struct rpmsg_endpoint *ept; struct device *dev = rpdev ? &rpdev->dev : &vrp->vdev->dev; if (!idr_pre_get(&vrp->endpoints, GFP_KERNEL)) return NULL; ept = kzalloc(sizeof(*ept), GFP_KERNEL); if (!ept) { dev_err(dev, "failed to kzalloc a new ept\n"); return NULL; } ept->rpdev = rpdev; ept->cb = cb; ept->priv = priv; /* do we need to allocate a local address ? */ request = addr == RPMSG_ADDR_ANY ? RPMSG_RESERVED_ADDRESSES : addr; spin_lock(&vrp->endpoints_lock); /* bind the endpoint to an rpmsg address (and allocate one if needed) */ err = idr_get_new_above(&vrp->endpoints, ept, request, &tmpaddr); if (err) { dev_err(dev, "idr_get_new_above failed: %d\n", err); goto free_ept; } if (addr != RPMSG_ADDR_ANY && tmpaddr != addr) { dev_err(dev, "address 0x%x already in use\n", addr); goto rem_idr; } ept->addr = tmpaddr; spin_unlock(&vrp->endpoints_lock); return ept; rem_idr: idr_remove(&vrp->endpoints, request); free_ept: spin_unlock(&vrp->endpoints_lock); kfree(ept); return NULL; } struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_channel *rpdev, void (*cb)(struct rpmsg_channel *, void *, int, void *, u32), void *priv, u32 addr) { return __rpmsg_create_ept(rpdev->vrp, rpdev, cb, priv, addr); } EXPORT_SYMBOL(rpmsg_create_ept); void rpmsg_destroy_ept(struct rpmsg_endpoint *ept) { struct virtproc_info *vrp = ept->rpdev->vrp; spin_lock(&vrp->endpoints_lock); idr_remove(&vrp->endpoints, ept->addr); spin_unlock(&vrp->endpoints_lock); kfree(ept); } EXPORT_SYMBOL(rpmsg_destroy_ept); static int rpmsg_dev_probe(struct device *dev) { struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); struct rpmsg_driver *rpdrv = to_rpmsg_driver(rpdev->dev.driver); struct virtproc_info *vrp = rpdev->vrp; struct rpmsg_endpoint *ept; int err; ept = rpmsg_create_ept(rpdev, rpdrv->callback, NULL, rpdev->src); if (!ept) { dev_err(dev, "failed to create endpoint\n"); err = -ENOMEM; goto out; } rpdev->ept = ept; rpdev->src = ept->addr; err = rpdrv->probe(rpdev); if (err) { dev_err(dev, "%s: failed: %d\n", __func__, err); rpmsg_destroy_ept(ept); goto out; } /* need to tell remote processor's name service about this channel ? */ if (rpdev->announce && virtio_has_feature(vrp->vdev, VIRTIO_RPMSG_F_NS)) { struct rpmsg_ns_msg nsm; strncpy(nsm.name, rpdev->id.name, RPMSG_NAME_SIZE); nsm.addr = rpdev->src; nsm.flags = RPMSG_NS_CREATE; err = rpmsg_sendto(rpdev, &nsm, sizeof(nsm), RPMSG_NS_ADDR); if (err) dev_err(dev, "failed to announce service %d\n", err); } out: return err; } static int rpmsg_dev_remove(struct device *dev) { struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); struct rpmsg_driver *rpdrv = to_rpmsg_driver(rpdev->dev.driver); struct virtproc_info *vrp = rpdev->vrp; int err = 0; /* tell remote processor's name service we're removing this channel */ if (rpdev->announce && virtio_has_feature(vrp->vdev, VIRTIO_RPMSG_F_NS)) { struct rpmsg_ns_msg nsm; strncpy(nsm.name, rpdev->id.name, RPMSG_NAME_SIZE); nsm.addr = rpdev->src; nsm.flags = RPMSG_NS_DESTROY; err = rpmsg_sendto(rpdev, &nsm, sizeof(nsm), RPMSG_NS_ADDR); if (err) dev_err(dev, "failed to announce service %d\n", err); } rpdrv->remove(rpdev); rpmsg_destroy_ept(rpdev->ept); return err; } static struct bus_type rpmsg_bus = { .name = "rpmsg", .match = rpmsg_dev_match, .dev_attrs = rpmsg_dev_attrs, .uevent = rpmsg_uevent, .probe = rpmsg_dev_probe, .remove = rpmsg_dev_remove, }; int register_rpmsg_driver(struct rpmsg_driver *rpdrv) { rpdrv->drv.bus = &rpmsg_bus; return driver_register(&rpdrv->drv); } EXPORT_SYMBOL(register_rpmsg_driver); void unregister_rpmsg_driver(struct rpmsg_driver *rpdrv) { driver_unregister(&rpdrv->drv); } EXPORT_SYMBOL(unregister_rpmsg_driver); static void rpmsg_release_device(struct device *dev) { struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); kfree(rpdev); } /* match an rpmsg channel with channel info structs */ static int rpmsg_channel_match(struct device *dev, void *data) { struct rpmsg_channel_info *chinfo = data; struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); if (chinfo->src != RPMSG_ADDR_ANY && chinfo->src != rpdev->src) return 0; if (chinfo->dst != RPMSG_ADDR_ANY && chinfo->dst != rpdev->dst) return 0; if (strncmp(chinfo->name, rpdev->id.name, RPMSG_NAME_SIZE)) return 0; return 1; } static struct rpmsg_channel *rpmsg_create_channel(struct virtproc_info *vrp, struct rpmsg_channel_info *chinfo) { struct rpmsg_channel *rpdev; struct device *tmp, *dev = &vrp->vdev->dev; int ret; /* make sure a similar channel doesn't already exist */ tmp = device_find_child(dev, chinfo, rpmsg_channel_match); if (tmp) { dev_err(dev, "channel %s:%x:%x already exist\n", chinfo->name, chinfo->src, chinfo->dst); return NULL; } rpdev = kzalloc(sizeof(struct rpmsg_channel), GFP_KERNEL); if (!rpdev) { pr_err("kzalloc failed\n"); return NULL; } rpdev->vrp = vrp; rpdev->src = chinfo->src; rpdev->dst = chinfo->dst; /* * rpmsg server channels has predefined local address, and their * existence needs to be announced remotely */ rpdev->announce = rpdev->src != RPMSG_ADDR_ANY ? true : false; strncpy(rpdev->id.name, chinfo->name, RPMSG_NAME_SIZE); /* very simple device indexing plumbing which just works (for now) */ dev_set_name(&rpdev->dev, "rpmsg%d", rpmsg_dev_index++); rpdev->dev.parent = &vrp->vdev->dev; rpdev->dev.bus = &rpmsg_bus; rpdev->dev.release = rpmsg_release_device; ret = device_register(&rpdev->dev); if (ret) { dev_err(dev, "device_register failed: %d\n", ret); kfree(rpdev); return NULL; } return rpdev; } static void rpmsg_destroy_channel(struct rpmsg_channel *rpdev) { device_unregister(&rpdev->dev); } static int rpmsg_destroy_channel_by_info(struct virtproc_info *vrp, struct rpmsg_channel_info *chinfo) { struct virtio_device *vdev = vrp->vdev; struct device *dev; dev = device_find_child(&vdev->dev, chinfo, rpmsg_channel_match); if (!dev) return -EINVAL; rpmsg_destroy_channel(to_rpmsg_channel(dev)); return 0; } /* minimal buf "allocator" that is just enough for now */ static void *get_a_buf(struct virtproc_info *vrp) { unsigned int len; void *buf = NULL; /* make sure the descriptors are updated before reading */ rmb(); /* either pick the next unused buffer */ if (vrp->last_sbuf < vrp->num_bufs / 2) buf = vrp->sbufs + vrp->buf_size * vrp->last_sbuf++; /* or recycle a used one */ else buf = virtqueue_get_buf(vrp->svq, &len); return buf; } /* XXX: the blocking 'wait' mechanism hasn't been tested yet */ int rpmsg_send_offchannel_raw(struct rpmsg_channel *rpdev, u32 src, u32 dst, void *data, int len, bool wait) { struct virtproc_info *vrp = rpdev->vrp; struct device *dev = &rpdev->dev; struct scatterlist sg; struct rpmsg_hdr *msg; int err; unsigned long offset; void *sim_addr; if (src == RPMSG_ADDR_ANY || dst == RPMSG_ADDR_ANY) { dev_err(dev, "invalid addr (src 0x%x, dst 0x%x)\n", src, dst); return -EINVAL; } /* the payload's size is currently limited */ if (len > vrp->buf_size - sizeof(struct rpmsg_hdr)) { dev_err(dev, "message is too big (%d)\n", len); return -EMSGSIZE; } /* * protect svq from simultaneous concurrent manipulations, * and serialize the sending of messages */ if (mutex_lock_interruptible(&vrp->svq_lock)) return -ERESTARTSYS; /* grab a buffer */ msg = get_a_buf(vrp); if (!msg && !wait) { err = -ENOMEM; goto out; } /* no free buffer ? wait for one (but bail after 15 seconds) */ if (!msg) { /* enable "tx-complete" interrupts before dozing off */ virtqueue_enable_cb(vrp->svq); /* * sleep until a free buffer is available or 15 secs elapse. * the timeout period is not configurable because frankly * i don't see why drivers need to deal with that. * if later this happens to be required, it'd be easy to add. */ err = wait_event_interruptible_timeout(vrp->sendq, (msg = get_a_buf(vrp)), msecs_to_jiffies(15000)); /* on success, suppress "tx-complete" interrupts again */ virtqueue_disable_cb(vrp->svq); if (err < 0) { err = -ERESTARTSYS; goto out; } if (!msg) { dev_err(dev, "timeout waiting for buffer\n"); err = -ETIMEDOUT; goto out; } } msg->len = len; msg->flags = 0; msg->src = src; msg->dst = dst; msg->unused = 0; memcpy(msg->data, data, len); dev_dbg(dev, "TX From 0x%x, To 0x%x, Len %d, Flags %d, Unused %d\n", msg->src, msg->dst, msg->len, msg->flags, msg->unused); #if 0 print_hex_dump(KERN_DEBUG, "rpmsg_virtio TX: ", DUMP_PREFIX_NONE, 16, 1, msg, sizeof(*msg) + msg->len, true); #endif offset = ((unsigned long) msg) - ((unsigned long) vrp->rbufs); sim_addr = vrp->sim_base + offset; sg_init_one(&sg, sim_addr, sizeof(*msg) + len); /* add message to the remote processor's virtqueue */ err = virtqueue_add_buf_gfp(vrp->svq, &sg, 1, 0, msg, GFP_KERNEL); if (err < 0) { dev_err(dev, "virtqueue_add_buf_gfp failed: %d\n", err); goto out; } /* descriptors must be written before kicking remote processor */ wmb(); /* tell the remote processor it has a pending message to read */ virtqueue_kick(vrp->svq); err = 0; out: mutex_unlock(&vrp->svq_lock); return err; } EXPORT_SYMBOL(rpmsg_send_offchannel_raw); struct rproc *rpmsg_get_rproc_handle(struct rpmsg_channel *rpdev) { if (!rpdev || !rpdev->vrp) return NULL; return rpdev->vrp->rproc; } EXPORT_SYMBOL(rpmsg_get_rproc_handle); static void rpmsg_recv_done(struct virtqueue *rvq) { struct rpmsg_hdr *msg; unsigned int len; struct rpmsg_endpoint *ept; struct scatterlist sg; unsigned long offset; void *sim_addr; struct virtproc_info *vrp = rvq->vdev->priv; struct device *dev = &rvq->vdev->dev; int err; /* make sure the descriptors are updated before reading */ rmb(); msg = virtqueue_get_buf(rvq, &len); if (!msg) { dev_err(dev, "uhm, incoming signal, but no used buffer ?\n"); return; } dev_dbg(dev, "From: 0x%x, To: 0x%x, Len: %d, Flags: %d, Unused: %d\n", msg->src, msg->dst, msg->len, msg->flags, msg->unused); #if 0 print_hex_dump(KERN_DEBUG, "rpmsg_virtio RX: ", DUMP_PREFIX_NONE, 16, 1, msg, sizeof(*msg) + msg->len, true); #endif /* fetch the callback of the appropriate user */ spin_lock(&vrp->endpoints_lock); ept = idr_find(&vrp->endpoints, msg->dst); spin_unlock(&vrp->endpoints_lock); if (ept && ept->cb) ept->cb(ept->rpdev, msg->data, msg->len, ept->priv, msg->src); else dev_warn(dev, "msg received with no recepient\n"); /* add the buffer back to the remote processor's virtqueue */ offset = ((unsigned long) msg) - ((unsigned long) vrp->rbufs); sim_addr = vrp->sim_base + offset; sg_init_one(&sg, sim_addr, sizeof(*msg) + len); err = virtqueue_add_buf_gfp(vrp->rvq, &sg, 0, 1, msg, GFP_KERNEL); if (err < 0) { dev_err(dev, "failed to add a virtqueue buffer: %d\n", err); return; } /* descriptors must be written before kicking remote processor */ wmb(); /* tell the remote processor we added another available rx buffer */ virtqueue_kick(vrp->rvq); } static void rpmsg_xmit_done(struct virtqueue *svq) { struct virtproc_info *vrp = svq->vdev->priv; dev_dbg(&svq->vdev->dev, "%s\n", __func__); /* wake up potential processes that are waiting for a buffer */ wake_up_interruptible(&vrp->sendq); } static void rpmsg_ns_cb(struct rpmsg_channel *rpdev, void *data, int len, void *priv, u32 src) { struct rpmsg_ns_msg *msg = data; struct rpmsg_channel *newch; struct rpmsg_channel_info chinfo; struct virtproc_info *vrp = priv; struct device *dev = &vrp->vdev->dev; int ret; #if 0 print_hex_dump(KERN_DEBUG, __func__, DUMP_PREFIX_NONE, 16, 1, data, len, true); #endif if (len != sizeof(*msg)) { dev_err(dev, "malformed ns msg (%d)\n", len); return; } /* * the name service ept does _not_ belong to a real rpmsg channel, * and is handled by the rpmsg bus itself. * for sanity reasons, make sure a valid rpdev has _not_ sneaked * in somehow. */ if (rpdev) { dev_err(dev, "anomaly: ns ept has an rpdev handle\n"); return; } /* don't trust the remote processor for null terminating the name */ msg->name[RPMSG_NAME_SIZE - 1] = '\0'; dev_dbg(dev, "%sing channel %s addr 0x%x\n", msg->flags & RPMSG_NS_DESTROY ? "destroy" : "creat", msg->name, msg->addr); strncpy(chinfo.name, msg->name, sizeof(chinfo.name)); chinfo.src = RPMSG_ADDR_ANY; chinfo.dst = msg->addr; if (msg->flags & RPMSG_NS_DESTROY) { ret = rpmsg_destroy_channel_by_info(vrp, &chinfo); if (ret) dev_err(dev, "rpmsg_destroy_channel failed: %d\n", ret); } else { newch = rpmsg_create_channel(vrp, &chinfo); if (!newch) dev_err(dev, "rpmsg_create_channel failed\n"); } } static int rpmsg_probe(struct virtio_device *vdev) { vq_callback_t *vq_cbs[] = { rpmsg_recv_done, rpmsg_xmit_done }; const char *names[] = { "input", "output" }; struct virtqueue *vqs[2]; struct virtproc_info *vrp; void *addr; int err, i, num_bufs, buf_size, total_buf_size; struct rpmsg_channel_info *ch; vrp = kzalloc(sizeof(*vrp), GFP_KERNEL); if (!vrp) return -ENOMEM; vrp->vdev = vdev; idr_init(&vrp->endpoints); spin_lock_init(&vrp->endpoints_lock); mutex_init(&vrp->svq_lock); init_waitqueue_head(&vrp->sendq); /* We expect two virtqueues, rx and tx (in this order) */ err = vdev->config->find_vqs(vdev, 2, vqs, vq_cbs, names); if (err) goto free_vi; vrp->rvq = vqs[0]; vrp->svq = vqs[1]; /* Platform must supply pre-allocated uncached buffers for now */ vdev->config->get(vdev, VPROC_BUF_ADDR, &addr, sizeof(addr)); vdev->config->get(vdev, VPROC_BUF_NUM, &num_bufs, sizeof(num_bufs)); vdev->config->get(vdev, VPROC_BUF_SZ, &buf_size, sizeof(buf_size)); total_buf_size = num_bufs * buf_size; dev_dbg(&vdev->dev, "%d buffers, size %d, addr 0x%x, total 0x%x\n", num_bufs, buf_size, (unsigned int) addr, total_buf_size); vrp->num_bufs = num_bufs; vrp->buf_size = buf_size; vrp->rbufs = addr; vrp->sbufs = addr + total_buf_size / 2; /* simulated addr base to make virt_to_page happy */ vdev->config->get(vdev, VPROC_SIM_BASE, &vrp->sim_base, sizeof(vrp->sim_base)); /* also store reference to remote proc */ vdev->config->get(vdev, VPROC_RPROC_REF, &vrp->rproc, sizeof(vrp->rproc)); /* set up the receive buffers */ for (i = 0; i < num_bufs / 2; i++) { struct scatterlist sg; void *tmpaddr = vrp->rbufs + i * buf_size; void *simaddr = vrp->sim_base + i * buf_size; sg_init_one(&sg, simaddr, buf_size); err = virtqueue_add_buf_gfp(vrp->rvq, &sg, 0, 1, tmpaddr, GFP_KERNEL); WARN_ON(err < 0); /* sanity check; this can't really happen */ } /* tell the remote processor it can start sending data */ virtqueue_kick(vrp->rvq); /* suppress "tx-complete" interrupts */ virtqueue_disable_cb(vrp->svq); vdev->priv = vrp; dev_info(&vdev->dev, "rpmsg backend virtproc probed successfully\n"); /* if supported by the remote processor, enable the name service */ if (virtio_has_feature(vdev, VIRTIO_RPMSG_F_NS)) { vrp->ns_ept = __rpmsg_create_ept(vrp, NULL, rpmsg_ns_cb, vrp, RPMSG_NS_ADDR); if (!vrp->ns_ept) { dev_err(&vdev->dev, "failed to create the ns ept\n"); err = -ENOMEM; goto vqs_del; } } /* look for platform-specific static channels */ vdev->config->get(vdev, VPROC_STATIC_CHANNELS, &ch, sizeof(ch)); for (i = 0; ch && ch[i].name[0]; i++) rpmsg_create_channel(vrp, &ch[i]); return 0; vqs_del: vdev->config->del_vqs(vrp->vdev); free_vi: kfree(vrp); return err; } static int rpmsg_remove_device(struct device *dev, void *data) { struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); rpmsg_destroy_channel(rpdev); return 0; } static void __devexit rpmsg_remove(struct virtio_device *vdev) { struct virtproc_info *vrp = vdev->priv; int ret; ret = device_for_each_child(&vdev->dev, NULL, rpmsg_remove_device); if (ret) dev_warn(&vdev->dev, "can't remove rpmsg device: %d\n", ret); idr_remove_all(&vrp->endpoints); idr_destroy(&vrp->endpoints); vdev->config->del_vqs(vrp->vdev); kfree(vrp); } static struct virtio_device_id id_table[] = { { VIRTIO_ID_RPMSG, VIRTIO_DEV_ANY_ID }, { 0 }, }; static unsigned int features[] = { VIRTIO_RPMSG_F_NS, }; static struct virtio_driver virtio_ipc_driver = { .feature_table = features, .feature_table_size = ARRAY_SIZE(features), .driver.name = KBUILD_MODNAME, .driver.owner = THIS_MODULE, .id_table = id_table, .probe = rpmsg_probe, .remove = __devexit_p(rpmsg_remove), }; static int __init init(void) { int ret; ret = bus_register(&rpmsg_bus); if (ret) { pr_err("failed to register rpmsg bus: %d\n", ret); return ret; } return register_virtio_driver(&virtio_ipc_driver); } module_init(init); static void __exit fini(void) { unregister_virtio_driver(&virtio_ipc_driver); bus_unregister(&rpmsg_bus); } module_exit(fini); MODULE_DEVICE_TABLE(virtio, id_table); MODULE_DESCRIPTION("Virtio-based remote processor messaging bus"); MODULE_LICENSE("GPL v2");