OSCL-LXR linux-6.0.1/​drivers/​rpmsg/​rpmsg_core.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0
 /*
  * remote processor messaging bus
  *
  * Copyright (C) 2011 Texas Instruments, Inc.
  * Copyright (C) 2011 Google, Inc.
  *
  * Ohad Ben-Cohen <ohad@wizery.com>
  * Brian Swetland <swetland@google.com>
  */
 
 #define pr_fmt(fmt) "%s: " fmt, __func__
 
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/rpmsg.h>
 #include <linux/of_device.h>
 #include <linux/pm_domain.h>
 #include <linux/slab.h>
 
 #include "rpmsg_internal.h"
 
 struct class *rpmsg_class;
 EXPORT_SYMBOL(rpmsg_class);
 
 /**
  * rpmsg_create_channel() - create a new rpmsg channel
  * using its name and address info.
  * @rpdev: rpmsg device
  * @chinfo: channel_info to bind
  *
  * Return: a pointer to the new rpmsg device on success, or NULL on error.
  */
 struct rpmsg_device *rpmsg_create_channel(struct rpmsg_device *rpdev,
                       struct rpmsg_channel_info *chinfo)
 {
     if (WARN_ON(!rpdev))
         return NULL;
     if (!rpdev->ops || !rpdev->ops->create_channel) {
         dev_err(&rpdev->dev, "no create_channel ops found\n");
         return NULL;
     }
 
     return rpdev->ops->create_channel(rpdev, chinfo);
 }
 EXPORT_SYMBOL(rpmsg_create_channel);
 
 /**
  * rpmsg_release_channel() - release a rpmsg channel
  * using its name and address info.
  * @rpdev: rpmsg device
  * @chinfo: channel_info to bind
  *
  * Return: 0 on success or an appropriate error value.
  */
 int rpmsg_release_channel(struct rpmsg_device *rpdev,
               struct rpmsg_channel_info *chinfo)
 {
     if (WARN_ON(!rpdev))
         return -EINVAL;
     if (!rpdev->ops || !rpdev->ops->release_channel) {
         dev_err(&rpdev->dev, "no release_channel ops found\n");
         return -ENXIO;
     }
 
     return rpdev->ops->release_channel(rpdev, chinfo);
 }
 EXPORT_SYMBOL(rpmsg_release_channel);
 
 /**
  * rpmsg_create_ept() - create a new rpmsg_endpoint
  * @rpdev: rpmsg channel device
  * @cb: rx callback handler
  * @priv: private data for the driver's use
  * @chinfo: channel_info with the local rpmsg address to bind with @cb
  *
  * Every rpmsg address in the system is bound to an rx callback (so when
  * inbound messages arrive, they are dispatched by the rpmsg bus using the
  * appropriate callback handler) by means of an rpmsg_endpoint struct.
  *
  * This function allows drivers to create such an endpoint, and by that,
  * bind a callback, and possibly some private data too, to an rpmsg address
  * (either one that is known in advance, or one that will be dynamically
  * assigned for them).
  *
  * Simple rpmsg drivers need not call rpmsg_create_ept, because an endpoint
  * is already created for them when they are probed by the rpmsg bus
  * (using the rx callback provided when they registered to the rpmsg bus).
  *
  * So things should just work for simple drivers: they already have an
  * endpoint, their rx callback is bound to their rpmsg address, and when
  * relevant inbound messages arrive (i.e. messages which their dst address
  * equals to the src address of their rpmsg channel), the driver's handler
  * is invoked to process it.
  *
  * That said, more complicated drivers might need to allocate
  * additional rpmsg addresses, and bind them to different rx callbacks.
  * To accomplish that, those drivers need to call this function.
  *
  * Drivers should provide their @rpdev channel (so the new endpoint would belong
  * to the same remote processor their channel belongs to), an rx callback
  * function, an optional private data (which is provided back when the
  * rx callback is invoked), and an address they want to bind with the
  * callback. If @addr is RPMSG_ADDR_ANY, then rpmsg_create_ept will
  * dynamically assign them an available rpmsg address (drivers should have
  * a very good reason why not to always use RPMSG_ADDR_ANY here).
  *
  * Return: a pointer to the endpoint on success, or NULL on error.
  */
 struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_device *rpdev,
                     rpmsg_rx_cb_t cb, void *priv,
                     struct rpmsg_channel_info chinfo)
 {
     if (WARN_ON(!rpdev))
         return NULL;
 
     return rpdev->ops->create_ept(rpdev, cb, priv, chinfo);
 }
 EXPORT_SYMBOL(rpmsg_create_ept);
 
 /**
  * rpmsg_destroy_ept() - destroy an existing rpmsg endpoint
  * @ept: endpoing to destroy
  *
  * Should be used by drivers to destroy an rpmsg endpoint previously
  * created with rpmsg_create_ept(). As with other types of "free" NULL
  * is a valid parameter.
  */
 void rpmsg_destroy_ept(struct rpmsg_endpoint *ept)
 {
     if (ept && ept->ops)
         ept->ops->destroy_ept(ept);
 }
 EXPORT_SYMBOL(rpmsg_destroy_ept);
 
 /**
  * rpmsg_send() - send a message across to the remote processor
  * @ept: the rpmsg endpoint
  * @data: payload of message
  * @len: length of payload
  *
  * This function sends @data of length @len on the @ept endpoint.
  * The message will be sent to the remote processor which the @ept
  * endpoint belongs to, using @ept's address and its associated rpmsg
  * device destination addresses.
  * In case there are no TX buffers available, the function will block until
  * one becomes available, or a timeout of 15 seconds elapses. When the latter
  * happens, -ERESTARTSYS is returned.
  *
  * Can only be called from process context (for now).
  *
  * Return: 0 on success and an appropriate error value on failure.
  */
 int rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len)
 {
     if (WARN_ON(!ept))
         return -EINVAL;
     if (!ept->ops->send)
         return -ENXIO;
 
     return ept->ops->send(ept, data, len);
 }
 EXPORT_SYMBOL(rpmsg_send);
 
 /**
  * rpmsg_sendto() - send a message across to the remote processor, specify dst
  * @ept: the rpmsg endpoint
  * @data: payload of message
  * @len: length of payload
  * @dst: destination address
  *
  * This function sends @data of length @len to the remote @dst address.
  * The message will be sent to the remote processor which the @ept
  * endpoint belongs to, using @ept's address as source.
  * In case there are no TX buffers available, the function will block until
  * one becomes available, or a timeout of 15 seconds elapses. When the latter
  * happens, -ERESTARTSYS is returned.
  *
  * Can only be called from process context (for now).
  *
  * Return: 0 on success and an appropriate error value on failure.
  */
 int rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
 {
     if (WARN_ON(!ept))
         return -EINVAL;
     if (!ept->ops->sendto)
         return -ENXIO;
 
     return ept->ops->sendto(ept, data, len, dst);
 }
 EXPORT_SYMBOL(rpmsg_sendto);
 
 /**
  * rpmsg_send_offchannel() - send a message using explicit src/dst addresses
  * @ept: the rpmsg endpoint
  * @src: source address
  * @dst: destination address
  * @data: payload of message
  * @len: length of payload
  *
  * This function sends @data of length @len to the remote @dst address,
  * and uses @src as the source address.
  * The message will be sent to the remote processor which the @ept
  * endpoint belongs to.
  * In case there are no TX buffers available, the function will block until
  * one becomes available, or a timeout of 15 seconds elapses. When the latter
  * happens, -ERESTARTSYS is returned.
  *
  * Can only be called from process context (for now).
  *
  * Return: 0 on success and an appropriate error value on failure.
  */
 int rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
               void *data, int len)
 {
     if (WARN_ON(!ept))
         return -EINVAL;
     if (!ept->ops->send_offchannel)
         return -ENXIO;
 
     return ept->ops->send_offchannel(ept, src, dst, data, len);
 }
 EXPORT_SYMBOL(rpmsg_send_offchannel);
 
 /**
  * rpmsg_trysend() - send a message across to the remote processor
  * @ept: the rpmsg endpoint
  * @data: payload of message
  * @len: length of payload
  *
  * This function sends @data of length @len on the @ept endpoint.
  * The message will be sent to the remote processor which the @ept
  * endpoint belongs to, using @ept's address as source and its associated
  * rpdev's address as destination.
  * In case there are no TX buffers available, the function will immediately
  * return -ENOMEM without waiting until one becomes available.
  *
  * Can only be called from process context (for now).
  *
  * Return: 0 on success and an appropriate error value on failure.
  */
 int rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len)
 {
     if (WARN_ON(!ept))
         return -EINVAL;
     if (!ept->ops->trysend)
         return -ENXIO;
 
     return ept->ops->trysend(ept, data, len);
 }
 EXPORT_SYMBOL(rpmsg_trysend);
 
 /**
  * rpmsg_trysendto() - send a message across to the remote processor, specify dst
  * @ept: the rpmsg endpoint
  * @data: payload of message
  * @len: length of payload
  * @dst: destination address
  *
  * This function sends @data of length @len to the remote @dst address.
  * The message will be sent to the remote processor which the @ept
  * endpoint belongs to, using @ept's address as source.
  * In case there are no TX buffers available, the function will immediately
  * return -ENOMEM without waiting until one becomes available.
  *
  * Can only be called from process context (for now).
  *
  * Return: 0 on success and an appropriate error value on failure.
  */
 int rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
 {
     if (WARN_ON(!ept))
         return -EINVAL;
     if (!ept->ops->trysendto)
         return -ENXIO;
 
     return ept->ops->trysendto(ept, data, len, dst);
 }
 EXPORT_SYMBOL(rpmsg_trysendto);
 
 /**
  * rpmsg_poll() - poll the endpoint's send buffers
  * @ept:    the rpmsg endpoint
  * @filp:   file for poll_wait()
  * @wait:   poll_table for poll_wait()
  *
  * Return: mask representing the current state of the endpoint's send buffers
  */
 __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
             poll_table *wait)
 {
     if (WARN_ON(!ept))
         return 0;
     if (!ept->ops->poll)
         return 0;
 
     return ept->ops->poll(ept, filp, wait);
 }
 EXPORT_SYMBOL(rpmsg_poll);
 
 /**
  * rpmsg_trysend_offchannel() - send a message using explicit src/dst addresses
  * @ept: the rpmsg endpoint
  * @src: source address
  * @dst: destination address
  * @data: payload of message
  * @len: length of payload
  *
  * This function sends @data of length @len to the remote @dst address,
  * and uses @src as the source address.
  * The message will be sent to the remote processor which the @ept
  * endpoint belongs to.
  * In case there are no TX buffers available, the function will immediately
  * return -ENOMEM without waiting until one becomes available.
  *
  * Can only be called from process context (for now).
  *
  * Return: 0 on success and an appropriate error value on failure.
  */
 int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst,
                  void *data, int len)
 {
     if (WARN_ON(!ept))
         return -EINVAL;
     if (!ept->ops->trysend_offchannel)
         return -ENXIO;
 
     return ept->ops->trysend_offchannel(ept, src, dst, data, len);
 }
 EXPORT_SYMBOL(rpmsg_trysend_offchannel);
 
 /**
  * rpmsg_get_mtu() - get maximum transmission buffer size for sending message.
  * @ept: the rpmsg endpoint
  *
  * This function returns maximum buffer size available for a single outgoing message.
  *
  * Return: the maximum transmission size on success and an appropriate error
  * value on failure.
  */
 
 ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept)
 {
     if (WARN_ON(!ept))
         return -EINVAL;
     if (!ept->ops->get_mtu)
         return -ENOTSUPP;
 
     return ept->ops->get_mtu(ept);
 }
 EXPORT_SYMBOL(rpmsg_get_mtu);
 
 /*
  * match a rpmsg channel with a channel info struct.
  * this is used to make sure we're not creating rpmsg devices for channels
  * that already exist.
  */
 static int rpmsg_device_match(struct device *dev, void *data)
 {
     struct rpmsg_channel_info *chinfo = data;
     struct rpmsg_device *rpdev = to_rpmsg_device(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;
 
     /* found a match ! */
     return 1;
 }
 
 struct device *rpmsg_find_device(struct device *parent,
                  struct rpmsg_channel_info *chinfo)
 {
     return device_find_child(parent, chinfo, rpmsg_device_match);
 
 }
 EXPORT_SYMBOL(rpmsg_find_device);
 
 /* sysfs 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_device *rpdev = to_rpmsg_device(dev);      \
                                     \
     return sprintf(buf, format_string, rpdev->path);        \
 }                                   \
 static DEVICE_ATTR_RO(field);
 
 #define rpmsg_string_attr(field, member)                \
 static ssize_t                              \
 field##_store(struct device *dev, struct device_attribute *attr,    \
           const char *buf, size_t sz)               \
 {                                   \
     struct rpmsg_device *rpdev = to_rpmsg_device(dev);      \
     const char *old;                        \
     char *new;                          \
                                     \
     new = kstrndup(buf, sz, GFP_KERNEL);                \
     if (!new)                           \
         return -ENOMEM;                     \
     new[strcspn(new, "\n")] = '\0';                 \
                                     \
     device_lock(dev);                       \
     old = rpdev->member;                        \
     if (strlen(new)) {                      \
         rpdev->member = new;                    \
     } else {                            \
         kfree(new);                     \
         rpdev->member = NULL;                   \
     }                               \
     device_unlock(dev);                     \
                                     \
     kfree(old);                         \
                                     \
     return sz;                          \
 }                                   \
 static ssize_t                              \
 field##_show(struct device *dev,                    \
          struct device_attribute *attr, char *buf)          \
 {                                   \
     struct rpmsg_device *rpdev = to_rpmsg_device(dev);      \
                                     \
     return sprintf(buf, "%s\n", rpdev->member);         \
 }                                   \
 static DEVICE_ATTR_RW(field)
 
 /* for more info, see Documentation/ABI/testing/sysfs-bus-rpmsg */
 rpmsg_show_attr(name, id.name, "%s\n");
 rpmsg_show_attr(src, src, "0x%x\n");
 rpmsg_show_attr(dst, dst, "0x%x\n");
 rpmsg_show_attr(announce, announce ? "true" : "false", "%s\n");
 rpmsg_string_attr(driver_override, driver_override);
 
 static ssize_t modalias_show(struct device *dev,
                  struct device_attribute *attr, char *buf)
 {
     struct rpmsg_device *rpdev = to_rpmsg_device(dev);
     ssize_t len;
 
     len = of_device_modalias(dev, buf, PAGE_SIZE);
     if (len != -ENODEV)
         return len;
 
     return sprintf(buf, RPMSG_DEVICE_MODALIAS_FMT "\n", rpdev->id.name);
 }
 static DEVICE_ATTR_RO(modalias);
 
 static struct attribute *rpmsg_dev_attrs[] = {
     &dev_attr_name.attr,
     &dev_attr_modalias.attr,
     &dev_attr_dst.attr,
     &dev_attr_src.attr,
     &dev_attr_announce.attr,
     &dev_attr_driver_override.attr,
     NULL,
 };
 ATTRIBUTE_GROUPS(rpmsg_dev);
 
 /* rpmsg devices and drivers are matched using the service name */
 static inline int rpmsg_id_match(const struct rpmsg_device *rpdev,
                   const struct rpmsg_device_id *id)
 {
     return strncmp(id->name, rpdev->id.name, RPMSG_NAME_SIZE) == 0;
 }
 
 /* match rpmsg channel and rpmsg driver */
 static int rpmsg_dev_match(struct device *dev, struct device_driver *drv)
 {
     struct rpmsg_device *rpdev = to_rpmsg_device(dev);
     struct rpmsg_driver *rpdrv = to_rpmsg_driver(drv);
     const struct rpmsg_device_id *ids = rpdrv->id_table;
     unsigned int i;
 
     if (rpdev->driver_override)
         return !strcmp(rpdev->driver_override, drv->name);
 
     if (ids)
         for (i = 0; ids[i].name[0]; i++)
             if (rpmsg_id_match(rpdev, &ids[i])) {
                 rpdev->id.driver_data = ids[i].driver_data;
                 return 1;
             }
 
     return of_driver_match_device(dev, drv);
 }
 
 static int rpmsg_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
     struct rpmsg_device *rpdev = to_rpmsg_device(dev);
     int ret;
 
     ret = of_device_uevent_modalias(dev, env);
     if (ret != -ENODEV)
         return ret;
 
     return add_uevent_var(env, "MODALIAS=" RPMSG_DEVICE_MODALIAS_FMT,
                     rpdev->id.name);
 }
 
 /*
  * when an rpmsg driver is probed with a channel, we seamlessly create
  * it an endpoint, binding its rx callback to a unique local rpmsg
  * address.
  *
  * if we need to, we also announce about this channel to the remote
  * processor (needed in case the driver is exposing an rpmsg service).
  */
 static int rpmsg_dev_probe(struct device *dev)
 {
     struct rpmsg_device *rpdev = to_rpmsg_device(dev);
     struct rpmsg_driver *rpdrv = to_rpmsg_driver(rpdev->dev.driver);
     struct rpmsg_channel_info chinfo = {};
     struct rpmsg_endpoint *ept = NULL;
     int err;
 
     err = dev_pm_domain_attach(dev, true);
     if (err)
         goto out;
 
     if (rpdrv->callback) {
         strncpy(chinfo.name, rpdev->id.name, RPMSG_NAME_SIZE);
         chinfo.src = rpdev->src;
         chinfo.dst = RPMSG_ADDR_ANY;
 
         ept = rpmsg_create_ept(rpdev, rpdrv->callback, NULL, chinfo);
         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);
         goto destroy_ept;
     }
 
     if (ept && rpdev->ops->announce_create) {
         err = rpdev->ops->announce_create(rpdev);
         if (err) {
             dev_err(dev, "failed to announce creation\n");
             goto remove_rpdev;
         }
     }
 
     return 0;
 
 remove_rpdev:
     if (rpdrv->remove)
         rpdrv->remove(rpdev);
 destroy_ept:
     if (ept)
         rpmsg_destroy_ept(ept);
 out:
     return err;
 }
 
 static void rpmsg_dev_remove(struct device *dev)
 {
     struct rpmsg_device *rpdev = to_rpmsg_device(dev);
     struct rpmsg_driver *rpdrv = to_rpmsg_driver(rpdev->dev.driver);
 
     if (rpdev->ops->announce_destroy)
         rpdev->ops->announce_destroy(rpdev);
 
     if (rpdrv->remove)
         rpdrv->remove(rpdev);
 
     dev_pm_domain_detach(dev, true);
 
     if (rpdev->ept)
         rpmsg_destroy_ept(rpdev->ept);
 }
 
 static struct bus_type rpmsg_bus = {
     .name       = "rpmsg",
     .match      = rpmsg_dev_match,
     .dev_groups = rpmsg_dev_groups,
     .uevent     = rpmsg_uevent,
     .probe      = rpmsg_dev_probe,
     .remove     = rpmsg_dev_remove,
 };
 
 /*
  * A helper for registering rpmsg device with driver override and name.
  * Drivers should not be using it, but instead rpmsg_register_device().
  */
 int rpmsg_register_device_override(struct rpmsg_device *rpdev,
                    const char *driver_override)
 {
     struct device *dev = &rpdev->dev;
     int ret;
 
     if (driver_override)
         strscpy_pad(rpdev->id.name, driver_override, RPMSG_NAME_SIZE);
 
     dev_set_name(dev, "%s.%s.%d.%d", dev_name(dev->parent),
              rpdev->id.name, rpdev->src, rpdev->dst);
 
     dev->bus = &rpmsg_bus;
 
     device_initialize(dev);
     if (driver_override) {
         ret = driver_set_override(dev, &rpdev->driver_override,
                       driver_override,
                       strlen(driver_override));
         if (ret) {
             dev_err(dev, "device_set_override failed: %d\n", ret);
             put_device(dev);
             return ret;
         }
     }
 
     ret = device_add(dev);
     if (ret) {
         dev_err(dev, "device_add failed: %d\n", ret);
         kfree(rpdev->driver_override);
         rpdev->driver_override = NULL;
         put_device(dev);
     }
 
     return ret;
 }
 EXPORT_SYMBOL(rpmsg_register_device_override);
 
 int rpmsg_register_device(struct rpmsg_device *rpdev)
 {
     return rpmsg_register_device_override(rpdev, NULL);
 }
 EXPORT_SYMBOL(rpmsg_register_device);
 
 /*
  * find an existing channel using its name + address properties,
  * and destroy it
  */
 int rpmsg_unregister_device(struct device *parent,
                 struct rpmsg_channel_info *chinfo)
 {
     struct device *dev;
 
     dev = rpmsg_find_device(parent, chinfo);
     if (!dev)
         return -EINVAL;
 
     device_unregister(dev);
 
     put_device(dev);
 
     return 0;
 }
 EXPORT_SYMBOL(rpmsg_unregister_device);
 
 /**
  * __register_rpmsg_driver() - register an rpmsg driver with the rpmsg bus
  * @rpdrv: pointer to a struct rpmsg_driver
  * @owner: owning module/driver
  *
  * Return: 0 on success, and an appropriate error value on failure.
  */
 int __register_rpmsg_driver(struct rpmsg_driver *rpdrv, struct module *owner)
 {
     rpdrv->drv.bus = &rpmsg_bus;
     rpdrv->drv.owner = owner;
     return driver_register(&rpdrv->drv);
 }
 EXPORT_SYMBOL(__register_rpmsg_driver);
 
 /**
  * unregister_rpmsg_driver() - unregister an rpmsg driver from the rpmsg bus
  * @rpdrv: pointer to a struct rpmsg_driver
  *
  * Return: 0 on success, and an appropriate error value on failure.
  */
 void unregister_rpmsg_driver(struct rpmsg_driver *rpdrv)
 {
     driver_unregister(&rpdrv->drv);
 }
 EXPORT_SYMBOL(unregister_rpmsg_driver);
 
 
 static int __init rpmsg_init(void)
 {
     int ret;
 
     rpmsg_class = class_create(THIS_MODULE, "rpmsg");
     if (IS_ERR(rpmsg_class)) {
         pr_err("failed to create rpmsg class\n");
         return PTR_ERR(rpmsg_class);
     }
 
     ret = bus_register(&rpmsg_bus);
     if (ret) {
         pr_err("failed to register rpmsg bus: %d\n", ret);
         class_destroy(rpmsg_class);
     }
     return ret;
 }
 postcore_initcall(rpmsg_init);
 
 static void __exit rpmsg_fini(void)
 {
     bus_unregister(&rpmsg_bus);
     class_destroy(rpmsg_class);
 }
 module_exit(rpmsg_fini);
 
 MODULE_DESCRIPTION("remote processor messaging bus");
 MODULE_LICENSE("GPL v2");

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