// SPDX-License-Identifier: GPL-2.0 // // Copyright 2019 Google LLC. #include <linux/kernel.h> #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/remoteproc.h> #include <linux/rpmsg/mtk_rpmsg.h> #include <linux/slab.h> #include <linux/workqueue.h> #include "rpmsg_internal.h" struct mtk_rpmsg_rproc_subdev { struct platform_device *pdev; struct mtk_rpmsg_info *info; struct rpmsg_endpoint *ns_ept; struct rproc_subdev subdev; struct work_struct register_work; struct list_head channels; struct mutex channels_lock; }; #define to_mtk_subdev(d) container_of(d, struct mtk_rpmsg_rproc_subdev, subdev) struct mtk_rpmsg_channel_info { struct rpmsg_channel_info info; bool registered; struct list_head list; }; /** * struct rpmsg_ns_msg - dynamic name service announcement message * @name: name of remote service that is published * @addr: address of remote service that is published * * This message is sent across to publish a new service. When we receive these * messages, an appropriate rpmsg channel (i.e device) is created. In turn, the * ->probe() handler of the appropriate rpmsg driver will be invoked * (if/as-soon-as one is registered). */ struct rpmsg_ns_msg { char name[RPMSG_NAME_SIZE]; u32 addr; } __packed; struct mtk_rpmsg_device { struct rpmsg_device rpdev; struct mtk_rpmsg_rproc_subdev *mtk_subdev; }; struct mtk_rpmsg_endpoint { struct rpmsg_endpoint ept; struct mtk_rpmsg_rproc_subdev *mtk_subdev; }; #define to_mtk_rpmsg_device(r) container_of(r, struct mtk_rpmsg_device, rpdev) #define to_mtk_rpmsg_endpoint(r) container_of(r, struct mtk_rpmsg_endpoint, ept) static const struct rpmsg_endpoint_ops mtk_rpmsg_endpoint_ops; static void __mtk_ept_release(struct kref *kref) { struct rpmsg_endpoint *ept = container_of(kref, struct rpmsg_endpoint, refcount); kfree(to_mtk_rpmsg_endpoint(ept)); } static void mtk_rpmsg_ipi_handler(void *data, unsigned int len, void *priv) { struct mtk_rpmsg_endpoint *mept = priv; struct rpmsg_endpoint *ept = &mept->ept; int ret; ret = (*ept->cb)(ept->rpdev, data, len, ept->priv, ept->addr); if (ret) dev_warn(&ept->rpdev->dev, "rpmsg handler return error = %d", ret); } static struct rpmsg_endpoint * __mtk_create_ept(struct mtk_rpmsg_rproc_subdev *mtk_subdev, struct rpmsg_device *rpdev, rpmsg_rx_cb_t cb, void *priv, u32 id) { struct mtk_rpmsg_endpoint *mept; struct rpmsg_endpoint *ept; struct platform_device *pdev = mtk_subdev->pdev; int ret; mept = kzalloc(sizeof(*mept), GFP_KERNEL); if (!mept) return NULL; mept->mtk_subdev = mtk_subdev; ept = &mept->ept; kref_init(&ept->refcount); ept->rpdev = rpdev; ept->cb = cb; ept->priv = priv; ept->ops = &mtk_rpmsg_endpoint_ops; ept->addr = id; ret = mtk_subdev->info->register_ipi(pdev, id, mtk_rpmsg_ipi_handler, mept); if (ret) { dev_err(&pdev->dev, "IPI register failed, id = %d", id); kref_put(&ept->refcount, __mtk_ept_release); return NULL; } return ept; } static struct rpmsg_endpoint * mtk_rpmsg_create_ept(struct rpmsg_device *rpdev, rpmsg_rx_cb_t cb, void *priv, struct rpmsg_channel_info chinfo) { struct mtk_rpmsg_rproc_subdev *mtk_subdev = to_mtk_rpmsg_device(rpdev)->mtk_subdev; return __mtk_create_ept(mtk_subdev, rpdev, cb, priv, chinfo.src); } static void mtk_rpmsg_destroy_ept(struct rpmsg_endpoint *ept) { struct mtk_rpmsg_rproc_subdev *mtk_subdev = to_mtk_rpmsg_endpoint(ept)->mtk_subdev; mtk_subdev->info->unregister_ipi(mtk_subdev->pdev, ept->addr); kref_put(&ept->refcount, __mtk_ept_release); } static int mtk_rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len) { struct mtk_rpmsg_rproc_subdev *mtk_subdev = to_mtk_rpmsg_endpoint(ept)->mtk_subdev; return mtk_subdev->info->send_ipi(mtk_subdev->pdev, ept->addr, data, len, 0); } static int mtk_rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len) { struct mtk_rpmsg_rproc_subdev *mtk_subdev = to_mtk_rpmsg_endpoint(ept)->mtk_subdev; /* * TODO: This currently is same as mtk_rpmsg_send, and wait until SCP * received the last command. */ return mtk_subdev->info->send_ipi(mtk_subdev->pdev, ept->addr, data, len, 0); } static const struct rpmsg_endpoint_ops mtk_rpmsg_endpoint_ops = { .destroy_ept = mtk_rpmsg_destroy_ept, .send = mtk_rpmsg_send, .trysend = mtk_rpmsg_trysend, }; static void mtk_rpmsg_release_device(struct device *dev) { struct rpmsg_device *rpdev = to_rpmsg_device(dev); struct mtk_rpmsg_device *mdev = to_mtk_rpmsg_device(rpdev); kfree(mdev); } static const struct rpmsg_device_ops mtk_rpmsg_device_ops = { .create_ept = mtk_rpmsg_create_ept, }; static struct device_node * mtk_rpmsg_match_device_subnode(struct device_node *node, const char *channel) { struct device_node *child; const char *name; int ret; for_each_available_child_of_node(node, child) { ret = of_property_read_string(child, "mtk,rpmsg-name", &name); if (ret) continue; if (strcmp(name, channel) == 0) return child; } return NULL; } static int mtk_rpmsg_register_device(struct mtk_rpmsg_rproc_subdev *mtk_subdev, struct rpmsg_channel_info *info) { struct rpmsg_device *rpdev; struct mtk_rpmsg_device *mdev; struct platform_device *pdev = mtk_subdev->pdev; mdev = kzalloc(sizeof(*mdev), GFP_KERNEL); if (!mdev) return -ENOMEM; mdev->mtk_subdev = mtk_subdev; rpdev = &mdev->rpdev; rpdev->ops = &mtk_rpmsg_device_ops; rpdev->src = info->src; rpdev->dst = info->dst; strscpy(rpdev->id.name, info->name, RPMSG_NAME_SIZE); rpdev->dev.of_node = mtk_rpmsg_match_device_subnode(pdev->dev.of_node, info->name); rpdev->dev.parent = &pdev->dev; rpdev->dev.release = mtk_rpmsg_release_device; return rpmsg_register_device(rpdev); } static void mtk_register_device_work_function(struct work_struct *register_work) { struct mtk_rpmsg_rproc_subdev *subdev = container_of( register_work, struct mtk_rpmsg_rproc_subdev, register_work); struct platform_device *pdev = subdev->pdev; struct mtk_rpmsg_channel_info *info; int ret; mutex_lock(&subdev->channels_lock); list_for_each_entry(info, &subdev->channels, list) { if (info->registered) continue; ret = mtk_rpmsg_register_device(subdev, &info->info); if (ret) { dev_err(&pdev->dev, "Can't create rpmsg_device\n"); continue; } info->registered = true; } mutex_unlock(&subdev->channels_lock); } static int mtk_rpmsg_create_device(struct mtk_rpmsg_rproc_subdev *mtk_subdev, char *name, u32 addr) { struct mtk_rpmsg_channel_info *info; info = kzalloc(sizeof(*info), GFP_KERNEL); if (!info) return -ENOMEM; strscpy(info->info.name, name, RPMSG_NAME_SIZE); info->info.src = addr; info->info.dst = RPMSG_ADDR_ANY; mutex_lock(&mtk_subdev->channels_lock); list_add(&info->list, &mtk_subdev->channels); mutex_unlock(&mtk_subdev->channels_lock); schedule_work(&mtk_subdev->register_work); return 0; } static int mtk_rpmsg_ns_cb(struct rpmsg_device *rpdev, void *data, int len, void *priv, u32 src) { struct rpmsg_ns_msg *msg = data; struct mtk_rpmsg_rproc_subdev *mtk_subdev = priv; struct device *dev = &mtk_subdev->pdev->dev; int ret; if (len != sizeof(*msg)) { dev_err(dev, "malformed ns msg (%d)\n", len); return -EINVAL; } /* * 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 -EINVAL; } /* don't trust the remote processor for null terminating the name */ msg->name[RPMSG_NAME_SIZE - 1] = '\0'; dev_info(dev, "creating channel %s addr 0x%x\n", msg->name, msg->addr); ret = mtk_rpmsg_create_device(mtk_subdev, msg->name, msg->addr); if (ret) { dev_err(dev, "create rpmsg device failed\n"); return ret; } return 0; } static int mtk_rpmsg_prepare(struct rproc_subdev *subdev) { struct mtk_rpmsg_rproc_subdev *mtk_subdev = to_mtk_subdev(subdev); /* a dedicated endpoint handles the name service msgs */ if (mtk_subdev->info->ns_ipi_id >= 0) { mtk_subdev->ns_ept = __mtk_create_ept(mtk_subdev, NULL, mtk_rpmsg_ns_cb, mtk_subdev, mtk_subdev->info->ns_ipi_id); if (!mtk_subdev->ns_ept) { dev_err(&mtk_subdev->pdev->dev, "failed to create name service endpoint\n"); return -ENOMEM; } } return 0; } static void mtk_rpmsg_unprepare(struct rproc_subdev *subdev) { struct mtk_rpmsg_rproc_subdev *mtk_subdev = to_mtk_subdev(subdev); if (mtk_subdev->ns_ept) { mtk_rpmsg_destroy_ept(mtk_subdev->ns_ept); mtk_subdev->ns_ept = NULL; } } static void mtk_rpmsg_stop(struct rproc_subdev *subdev, bool crashed) { struct mtk_rpmsg_channel_info *info, *next; struct mtk_rpmsg_rproc_subdev *mtk_subdev = to_mtk_subdev(subdev); struct device *dev = &mtk_subdev->pdev->dev; /* * Destroy the name service endpoint here, to avoid new channel being * created after the rpmsg_unregister_device loop below. */ if (mtk_subdev->ns_ept) { mtk_rpmsg_destroy_ept(mtk_subdev->ns_ept); mtk_subdev->ns_ept = NULL; } cancel_work_sync(&mtk_subdev->register_work); mutex_lock(&mtk_subdev->channels_lock); list_for_each_entry(info, &mtk_subdev->channels, list) { if (!info->registered) continue; if (rpmsg_unregister_device(dev, &info->info)) { dev_warn( dev, "rpmsg_unregister_device failed for %s.%d.%d\n", info->info.name, info->info.src, info->info.dst); } } list_for_each_entry_safe(info, next, &mtk_subdev->channels, list) { list_del(&info->list); kfree(info); } mutex_unlock(&mtk_subdev->channels_lock); } struct rproc_subdev * mtk_rpmsg_create_rproc_subdev(struct platform_device *pdev, struct mtk_rpmsg_info *info) { struct mtk_rpmsg_rproc_subdev *mtk_subdev; mtk_subdev = kzalloc(sizeof(*mtk_subdev), GFP_KERNEL); if (!mtk_subdev) return NULL; mtk_subdev->pdev = pdev; mtk_subdev->subdev.prepare = mtk_rpmsg_prepare; mtk_subdev->subdev.stop = mtk_rpmsg_stop; mtk_subdev->subdev.unprepare = mtk_rpmsg_unprepare; mtk_subdev->info = info; INIT_LIST_HEAD(&mtk_subdev->channels); INIT_WORK(&mtk_subdev->register_work, mtk_register_device_work_function); mutex_init(&mtk_subdev->channels_lock); return &mtk_subdev->subdev; } EXPORT_SYMBOL_GPL(mtk_rpmsg_create_rproc_subdev); void mtk_rpmsg_destroy_rproc_subdev(struct rproc_subdev *subdev) { struct mtk_rpmsg_rproc_subdev *mtk_subdev = to_mtk_subdev(subdev); kfree(mtk_subdev); } EXPORT_SYMBOL_GPL(mtk_rpmsg_destroy_rproc_subdev); MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("MediaTek scp rpmsg driver");