diff options
| -rw-r--r-- | drivers/media/Makefile | 3 | ||||
| -rw-r--r-- | drivers/media/media-device.c | 24 | ||||
| -rw-r--r-- | drivers/media/media-request.c | 464 | ||||
| -rw-r--r-- | include/media/media-device.h | 29 | ||||
| -rw-r--r-- | include/media/media-request.h | 334 |
5 files changed, 849 insertions, 5 deletions
diff --git a/drivers/media/Makefile b/drivers/media/Makefile index 594b462ddf0e..985d35ec6b29 100644 --- a/drivers/media/Makefile +++ b/drivers/media/Makefile @@ -3,7 +3,8 @@ # Makefile for the kernel multimedia device drivers. # -media-objs := media-device.o media-devnode.o media-entity.o +media-objs := media-device.o media-devnode.o media-entity.o \ + media-request.o # # I2C drivers should come before other drivers, otherwise they'll fail diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c index 3bae24b15eaa..4dd2b1dae03d 100644 --- a/drivers/media/media-device.c +++ b/drivers/media/media-device.c @@ -30,6 +30,7 @@ #include <media/media-device.h> #include <media/media-devnode.h> #include <media/media-entity.h> +#include <media/media-request.h> #ifdef CONFIG_MEDIA_CONTROLLER @@ -377,10 +378,19 @@ static long media_device_get_topology(struct media_device *mdev, void *arg) return ret; } +static long media_device_request_alloc(struct media_device *mdev, + int *alloc_fd) +{ + if (!mdev->ops || !mdev->ops->req_validate || !mdev->ops->req_queue) + return -ENOTTY; + + return media_request_alloc(mdev, alloc_fd); +} + static long copy_arg_from_user(void *karg, void __user *uarg, unsigned int cmd) { - /* All media IOCTLs are _IOWR() */ - if (copy_from_user(karg, uarg, _IOC_SIZE(cmd))) + if ((_IOC_DIR(cmd) & _IOC_WRITE) && + copy_from_user(karg, uarg, _IOC_SIZE(cmd))) return -EFAULT; return 0; @@ -388,8 +398,8 @@ static long copy_arg_from_user(void *karg, void __user *uarg, unsigned int cmd) static long copy_arg_to_user(void __user *uarg, void *karg, unsigned int cmd) { - /* All media IOCTLs are _IOWR() */ - if (copy_to_user(uarg, karg, _IOC_SIZE(cmd))) + if ((_IOC_DIR(cmd) & _IOC_READ) && + copy_to_user(uarg, karg, _IOC_SIZE(cmd))) return -EFAULT; return 0; @@ -425,6 +435,7 @@ static const struct media_ioctl_info ioctl_info[] = { MEDIA_IOC(ENUM_LINKS, media_device_enum_links, MEDIA_IOC_FL_GRAPH_MUTEX), MEDIA_IOC(SETUP_LINK, media_device_setup_link, MEDIA_IOC_FL_GRAPH_MUTEX), MEDIA_IOC(G_TOPOLOGY, media_device_get_topology, MEDIA_IOC_FL_GRAPH_MUTEX), + MEDIA_IOC(REQUEST_ALLOC, media_device_request_alloc, 0), }; static long media_device_ioctl(struct file *filp, unsigned int cmd, @@ -691,9 +702,13 @@ void media_device_init(struct media_device *mdev) INIT_LIST_HEAD(&mdev->pads); INIT_LIST_HEAD(&mdev->links); INIT_LIST_HEAD(&mdev->entity_notify); + + mutex_init(&mdev->req_queue_mutex); mutex_init(&mdev->graph_mutex); ida_init(&mdev->entity_internal_idx); + atomic_set(&mdev->request_id, 0); + dev_dbg(mdev->dev, "Media device initialized\n"); } EXPORT_SYMBOL_GPL(media_device_init); @@ -704,6 +719,7 @@ void media_device_cleanup(struct media_device *mdev) mdev->entity_internal_idx_max = 0; media_graph_walk_cleanup(&mdev->pm_count_walk); mutex_destroy(&mdev->graph_mutex); + mutex_destroy(&mdev->req_queue_mutex); } EXPORT_SYMBOL_GPL(media_device_cleanup); diff --git a/drivers/media/media-request.c b/drivers/media/media-request.c new file mode 100644 index 000000000000..8d3c7360c8f3 --- /dev/null +++ b/drivers/media/media-request.c @@ -0,0 +1,464 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Media device request objects + * + * Copyright 2018 Cisco Systems, Inc. and/or its affiliates. All rights reserved. + * Copyright (C) 2018 Intel Corporation + * Copyright (C) 2018 Google, Inc. + * + * Author: Hans Verkuil <hans.verkuil@cisco.com> + * Author: Sakari Ailus <sakari.ailus@linux.intel.com> + */ + +#include <linux/anon_inodes.h> +#include <linux/file.h> +#include <linux/refcount.h> + +#include <media/media-device.h> +#include <media/media-request.h> + +static const char * const request_state[] = { + [MEDIA_REQUEST_STATE_IDLE] = "idle", + [MEDIA_REQUEST_STATE_VALIDATING] = "validating", + [MEDIA_REQUEST_STATE_QUEUED] = "queued", + [MEDIA_REQUEST_STATE_COMPLETE] = "complete", + [MEDIA_REQUEST_STATE_CLEANING] = "cleaning", + [MEDIA_REQUEST_STATE_UPDATING] = "updating", +}; + +static const char * +media_request_state_str(enum media_request_state state) +{ + BUILD_BUG_ON(ARRAY_SIZE(request_state) != NR_OF_MEDIA_REQUEST_STATE); + + if (WARN_ON(state >= ARRAY_SIZE(request_state))) + return "invalid"; + return request_state[state]; +} + +static void media_request_clean(struct media_request *req) +{ + struct media_request_object *obj, *obj_safe; + + /* Just a sanity check. No other code path is allowed to change this. */ + WARN_ON(req->state != MEDIA_REQUEST_STATE_CLEANING); + WARN_ON(req->updating_count); + + list_for_each_entry_safe(obj, obj_safe, &req->objects, list) { + media_request_object_unbind(obj); + media_request_object_put(obj); + } + + req->updating_count = 0; + WARN_ON(req->num_incomplete_objects); + req->num_incomplete_objects = 0; + wake_up_interruptible_all(&req->poll_wait); +} + +static void media_request_release(struct kref *kref) +{ + struct media_request *req = + container_of(kref, struct media_request, kref); + struct media_device *mdev = req->mdev; + + dev_dbg(mdev->dev, "request: release %s\n", req->debug_str); + + /* No other users, no need for a spinlock */ + req->state = MEDIA_REQUEST_STATE_CLEANING; + + media_request_clean(req); + + if (mdev->ops->req_free) + mdev->ops->req_free(req); + else + kfree(req); +} + +void media_request_put(struct media_request *req) +{ + kref_put(&req->kref, media_request_release); +} +EXPORT_SYMBOL_GPL(media_request_put); + +static int media_request_close(struct inode *inode, struct file *filp) +{ + struct media_request *req = filp->private_data; + + media_request_put(req); + return 0; +} + +static __poll_t media_request_poll(struct file *filp, + struct poll_table_struct *wait) +{ + struct media_request *req = filp->private_data; + unsigned long flags; + __poll_t ret = 0; + + if (!(poll_requested_events(wait) & EPOLLPRI)) + return 0; + + spin_lock_irqsave(&req->lock, flags); + if (req->state == MEDIA_REQUEST_STATE_COMPLETE) { + ret = EPOLLPRI; + goto unlock; + } + if (req->state != MEDIA_REQUEST_STATE_QUEUED) { + ret = EPOLLERR; + goto unlock; + } + + poll_wait(filp, &req->poll_wait, wait); + +unlock: + spin_unlock_irqrestore(&req->lock, flags); + return ret; +} + +static long media_request_ioctl_queue(struct media_request *req) +{ + struct media_device *mdev = req->mdev; + enum media_request_state state; + unsigned long flags; + int ret; + + dev_dbg(mdev->dev, "request: queue %s\n", req->debug_str); + + /* + * Ensure the request that is validated will be the one that gets queued + * next by serialising the queueing process. This mutex is also used + * to serialize with canceling a vb2 queue and with setting values such + * as controls in a request. + */ + mutex_lock(&mdev->req_queue_mutex); + + media_request_get(req); + + spin_lock_irqsave(&req->lock, flags); + if (req->state == MEDIA_REQUEST_STATE_IDLE) + req->state = MEDIA_REQUEST_STATE_VALIDATING; + state = req->state; + spin_unlock_irqrestore(&req->lock, flags); + if (state != MEDIA_REQUEST_STATE_VALIDATING) { + dev_dbg(mdev->dev, + "request: unable to queue %s, request in state %s\n", + req->debug_str, media_request_state_str(state)); + media_request_put(req); + mutex_unlock(&mdev->req_queue_mutex); + return -EBUSY; + } + + ret = mdev->ops->req_validate(req); + + /* + * If the req_validate was successful, then we mark the state as QUEUED + * and call req_queue. The reason we set the state first is that this + * allows req_queue to unbind or complete the queued objects in case + * they are immediately 'consumed'. State changes from QUEUED to another + * state can only happen if either the driver changes the state or if + * the user cancels the vb2 queue. The driver can only change the state + * after each object is queued through the req_queue op (and note that + * that op cannot fail), so setting the state to QUEUED up front is + * safe. + * + * The other reason for changing the state is if the vb2 queue is + * canceled, and that uses the req_queue_mutex which is still locked + * while req_queue is called, so that's safe as well. + */ + spin_lock_irqsave(&req->lock, flags); + req->state = ret ? MEDIA_REQUEST_STATE_IDLE + : MEDIA_REQUEST_STATE_QUEUED; + spin_unlock_irqrestore(&req->lock, flags); + + if (!ret) + mdev->ops->req_queue(req); + + mutex_unlock(&mdev->req_queue_mutex); + + if (ret) { + dev_dbg(mdev->dev, "request: can't queue %s (%d)\n", + req->debug_str, ret); + media_request_put(req); + } + + return ret; +} + +static long media_request_ioctl_reinit(struct media_request *req) +{ + struct media_device *mdev = req->mdev; + unsigned long flags; + + spin_lock_irqsave(&req->lock, flags); + if (req->state != MEDIA_REQUEST_STATE_IDLE && + req->state != MEDIA_REQUEST_STATE_COMPLETE) { + dev_dbg(mdev->dev, + "request: %s not in idle or complete state, cannot reinit\n", + req->debug_str); + spin_unlock_irqrestore(&req->lock, flags); + return -EBUSY; + } + req->state = MEDIA_REQUEST_STATE_CLEANING; + spin_unlock_irqrestore(&req->lock, flags); + + media_request_clean(req); + + spin_lock_irqsave(&req->lock, flags); + req->state = MEDIA_REQUEST_STATE_IDLE; + spin_unlock_irqrestore(&req->lock, flags); + + return 0; +} + +static long media_request_ioctl(struct file *filp, unsigned int cmd, + unsigned long arg) +{ + struct media_request *req = filp->private_data; + + switch (cmd) { + case MEDIA_REQUEST_IOC_QUEUE: + return media_request_ioctl_queue(req); + case MEDIA_REQUEST_IOC_REINIT: + return media_request_ioctl_reinit(req); + default: + return -ENOIOCTLCMD; + } +} + +static const struct file_operations request_fops = { + .owner = THIS_MODULE, + .poll = media_request_poll, + .unlocked_ioctl = media_request_ioctl, + .release = media_request_close, +}; + +struct media_request * +media_request_get_by_fd(struct media_device *mdev, int request_fd) +{ + struct file *filp; + struct media_request *req; + + if (!mdev || !mdev->ops || + !mdev->ops->req_validate || !mdev->ops->req_queue) + return ERR_PTR(-EPERM); + + filp = fget(request_fd); + if (!filp) + return ERR_PTR(-ENOENT); + + if (filp->f_op != &request_fops) + goto err_fput; + req = filp->private_data; + if (req->mdev != mdev) + goto err_fput; + + /* + * Note: as long as someone has an open filehandle of the request, + * the request can never be released. The fget() above ensures that + * even if userspace closes the request filehandle, the release() + * fop won't be called, so the media_request_get() always succeeds + * and there is no race condition where the request was released + * before media_request_get() is called. + */ + media_request_get(req); + fput(filp); + + return req; + +err_fput: + fput(filp); + + return ERR_PTR(-ENOENT); +} +EXPORT_SYMBOL_GPL(media_request_get_by_fd); + +int media_request_alloc(struct media_device *mdev, int *alloc_fd) +{ + struct media_request *req; + struct file *filp; + int fd; + int ret; + + /* Either both are NULL or both are non-NULL */ + if (WARN_ON(!mdev->ops->req_alloc ^ !mdev->ops->req_free)) + return -ENOMEM; + + fd = get_unused_fd_flags(O_CLOEXEC); + if (fd < 0) + return fd; + + filp = anon_inode_getfile("request", &request_fops, NULL, O_CLOEXEC); + if (IS_ERR(filp)) { + ret = PTR_ERR(filp); + goto err_put_fd; + } + + if (mdev->ops->req_alloc) + req = mdev->ops->req_alloc(mdev); + else + req = kzalloc(sizeof(*req), GFP_KERNEL); + if (!req) { + ret = -ENOMEM; + goto err_fput; + } + + filp->private_data = req; + req->mdev = mdev; + req->state = MEDIA_REQUEST_STATE_IDLE; + req->num_incomplete_objects = 0; + kref_init(&req->kref); + INIT_LIST_HEAD(&req->objects); + spin_lock_init(&req->lock); + init_waitqueue_head(&req->poll_wait); + req->updating_count = 0; + + *alloc_fd = fd; + + snprintf(req->debug_str, sizeof(req->debug_str), "%u:%d", + atomic_inc_return(&mdev->request_id), fd); + dev_dbg(mdev->dev, "request: allocated %s\n", req->debug_str); + + fd_install(fd, filp); + + return 0; + +err_fput: + fput(filp); + +err_put_fd: + put_unused_fd(fd); + + return ret; +} + +static void media_request_object_release(struct kref *kref) +{ + struct media_request_object *obj = + container_of(kref, struct media_request_object, kref); + struct media_request *req = obj->req; + + if (WARN_ON(req)) + media_request_object_unbind(obj); + obj->ops->release(obj); +} + +void media_request_object_put(struct media_request_object *obj) +{ + kref_put(&obj->kref, media_request_object_release); +} +EXPORT_SYMBOL_GPL(media_request_object_put); + +void media_request_object_init(struct media_request_object *obj) +{ + obj->ops = NULL; + obj->req = NULL; + obj->priv = NULL; + obj->completed = false; + INIT_LIST_HEAD(&obj->list); + kref_init(&obj->kref); +} +EXPORT_SYMBOL_GPL(media_request_object_init); + +int media_request_object_bind(struct media_request *req, + const struct media_request_object_ops *ops, + void *priv, bool is_buffer, + struct media_request_object *obj) +{ + unsigned long flags; + int ret = -EBUSY; + + if (WARN_ON(!ops->release)) + return -EPERM; + + spin_lock_irqsave(&req->lock, flags); + + if (WARN_ON(req->state != MEDIA_REQUEST_STATE_UPDATING)) + goto unlock; + + obj->req = req; + obj->ops = ops; + obj->priv = priv; + + if (is_buffer) + list_add_tail(&obj->list, &req->objects); + else + list_add(&obj->list, &req->objects); + req->num_incomplete_objects++; + ret = 0; + +unlock: + spin_unlock_irqrestore(&req->lock, flags); + return ret; +} +EXPORT_SYMBOL_GPL(media_request_object_bind); + +void media_request_object_unbind(struct media_request_object *obj) +{ + struct media_request *req = obj->req; + unsigned long flags; + bool completed = false; + + if (WARN_ON(!req)) + return; + + spin_lock_irqsave(&req->lock, flags); + list_del(&obj->list); + obj->req = NULL; + + if (req->state == MEDIA_REQUEST_STATE_COMPLETE) + goto unlock; + + if (WARN_ON(req->state == MEDIA_REQUEST_STATE_VALIDATING)) + goto unlock; + + if (req->state == MEDIA_REQUEST_STATE_CLEANING) { + if (!obj->completed) + req->num_incomplete_objects--; + goto unlock; + } + + if (WARN_ON(!req->num_incomplete_objects)) + goto unlock; + + req->num_incomplete_objects--; + if (req->state == MEDIA_REQUEST_STATE_QUEUED && + !req->num_incomplete_objects) { + req->state = MEDIA_REQUEST_STATE_COMPLETE; + completed = true; + wake_up_interruptible_all(&req->poll_wait); + } + +unlock: + spin_unlock_irqrestore(&req->lock, flags); + if (obj->ops->unbind) + obj->ops->unbind(obj); + if (completed) + media_request_put(req); +} +EXPORT_SYMBOL_GPL(media_request_object_unbind); + +void media_request_object_complete(struct media_request_object *obj) +{ + struct media_request *req = obj->req; + unsigned long flags; + bool completed = false; + + spin_lock_irqsave(&req->lock, flags); + if (obj->completed) + goto unlock; + obj->completed = true; + if (WARN_ON(!req->num_incomplete_objects) || + WARN_ON(req->state != MEDIA_REQUEST_STATE_QUEUED)) + goto unlock; + + if (!--req->num_incomplete_objects) { + req->state = MEDIA_REQUEST_STATE_COMPLETE; + wake_up_interruptible_all(&req->poll_wait); + completed = true; + } +unlock: + spin_unlock_irqrestore(&req->lock, flags); + if (completed) + media_request_put(req); +} +EXPORT_SYMBOL_GPL(media_request_object_complete); diff --git a/include/media/media-device.h b/include/media/media-device.h index bcc6ec434f1f..c8ddbfe8b74c 100644 --- a/include/media/media-device.h +++ b/include/media/media-device.h @@ -27,6 +27,7 @@ struct ida; struct device; +struct media_device; /** * struct media_entity_notify - Media Entity Notify @@ -50,10 +51,32 @@ struct media_entity_notify { * struct media_device_ops - Media device operations * @link_notify: Link state change notification callback. This callback is * called with the graph_mutex held. + * @req_alloc: Allocate a request. Set this if you need to allocate a struct + * larger then struct media_request. @req_alloc and @req_free must + * either both be set or both be NULL. + * @req_free: Free a request. Set this if @req_alloc was set as well, leave + * to NULL otherwise. + * @req_validate: Validate a request, but do not queue yet. The req_queue_mutex + * lock is held when this op is called. + * @req_queue: Queue a validated request, cannot fail. If something goes + * wrong when queueing this request then it should be marked + * as such internally in the driver and any related buffers + * must eventually return to vb2 with state VB2_BUF_STATE_ERROR. + * The req_queue_mutex lock is held when this op is called. + * It is important that vb2 buffer objects are queued last after + * all other object types are queued: queueing a buffer kickstarts + * the request processing, so all other objects related to the + * request (and thus the buffer) must be available to the driver. + * And once a buffer is queued, then the driver can complete + * or delete objects from the request before req_queue exits. */ struct media_device_ops { int (*link_notify)(struct media_link *link, u32 flags, unsigned int notification); + struct media_request *(*req_alloc)(struct media_device *mdev); + void (*req_free)(struct media_request *req); + int (*req_validate)(struct media_request *req); + void (*req_queue)(struct media_request *req); }; /** @@ -88,6 +111,9 @@ struct media_device_ops { * @disable_source: Disable Source Handler function pointer * * @ops: Operation handler callbacks + * @req_queue_mutex: Serialise the MEDIA_REQUEST_IOC_QUEUE ioctl w.r.t. + * other operations that stop or start streaming. + * @request_id: Used to generate unique request IDs * * This structure represents an abstract high-level media device. It allows easy * access to entities and provides basic media device-level support. The @@ -158,6 +184,9 @@ struct media_device { void (*disable_source)(struct media_entity *entity); const struct media_device_ops *ops; + + struct mutex req_queue_mutex; + atomic_t request_id; }; /* We don't need to include pci.h or usb.h here */ diff --git a/include/media/media-request.h b/include/media/media-request.h new file mode 100644 index 000000000000..9664ebac5dc4 --- /dev/null +++ b/include/media/media-request.h @@ -0,0 +1,334 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Media device request objects + * + * Copyright 2018 Cisco Systems, Inc. and/or its affiliates. All rights reserved. + * Copyright (C) 2018 Intel Corporation + * + * Author: Hans Verkuil <hans.verkuil@cisco.com> + * Author: Sakari Ailus <sakari.ailus@linux.intel.com> + */ + +#ifndef MEDIA_REQUEST_H +#define MEDIA_REQUEST_H + +#include <linux/list.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/refcount.h> + +#include <media/media-device.h> + +/** + * enum media_request_state - media request state + * + * @MEDIA_REQUEST_STATE_IDLE: Idle + * @MEDIA_REQUEST_STATE_VALIDATING: Validating the request, no state changes + * allowed + * @MEDIA_REQUEST_STATE_QUEUED: Queued + * @MEDIA_REQUEST_STATE_COMPLETE: Completed, the request is done + * @MEDIA_REQUEST_STATE_CLEANING: Cleaning, the request is being re-inited + * @MEDIA_REQUEST_STATE_UPDATING: The request is being updated, i.e. + * request objects are being added, + * modified or removed + * @NR_OF_MEDIA_REQUEST_STATE: The number of media request states, used + * internally for sanity check purposes + */ +enum media_request_state { + MEDIA_REQUEST_STATE_IDLE, + MEDIA_REQUEST_STATE_VALIDATING, + MEDIA_REQUEST_STATE_QUEUED, + MEDIA_REQUEST_STATE_COMPLETE, + MEDIA_REQUEST_STATE_CLEANING, + MEDIA_REQUEST_STATE_UPDATING, + NR_OF_MEDIA_REQUEST_STATE, +}; + +struct media_request_object; + +/** + * struct media_request - Media device request + * @mdev: Media device this request belongs to + * @kref: Reference count + * @debug_str: Prefix for debug messages (process name:fd) + * @state: The state of the request + * @updating_count: count the number of request updates that are in progress + * @objects: List of @struct media_request_object request objects + * @num_incomplete_objects: The number of incomplete objects in the request + * @poll_wait: Wait queue for poll + * @lock: Serializes access to this struct + */ +struct media_request { + struct media_device *mdev; + struct kref kref; + char debug_str[TASK_COMM_LEN + 11]; + enum media_request_state state; + unsigned int updating_count; + struct list_head objects; + unsigned int num_incomplete_objects; + struct wait_queue_head poll_wait; + spinlock_t lock; +}; + +#ifdef CONFIG_MEDIA_CONTROLLER + +/** + * media_request_lock_for_update - Lock the request for updating its objects + * + * @req: The media request + * + * Use before updating a request, i.e. adding, modifying or removing a request + * object in it. A reference to the request must be held during the update. This + * usually takes place automatically through a file handle. Use + * @media_request_unlock_for_update when done. + */ +static inline int __must_check +media_request_lock_for_update(struct media_request *req) +{ + unsigned long flags; + int ret = 0; + + spin_lock_irqsave(&req->lock, flags); + if (req->state == MEDIA_REQUEST_STATE_IDLE || + req->state == MEDIA_REQUEST_STATE_UPDATING) { + req->state = MEDIA_REQUEST_STATE_UPDATING; + req->updating_count++; + } else { + ret = -EBUSY; + } + spin_unlock_irqrestore(&req->lock, flags); + + return ret; +} + +/** + * media_request_unlock_for_update - Unlock a request previously locked for + * update + * + * @req: The media request + * + * Unlock a request that has previously been locked using + * @media_request_lock_for_update. + */ +static inline void media_request_unlock_for_update(struct media_request *req) +{ + unsigned long flags; + + spin_lock_irqsave(&req->lock, flags); + WARN_ON(req->updating_count <= 0); + if (!--req->updating_count) + req->state = MEDIA_REQUEST_STATE_IDLE; + spin_unlock_irqrestore(&req->lock, flags); +} + +/** + * media_request_get - Get the media request + * + * @req: The media request + * + * Get the media request. + */ +static inline void media_request_get(struct media_request *req) +{ + kref_get(&req->kref); +} + +/** + * media_request_put - Put the media request + * + * @req: The media request + * + * Put the media request. The media request will be released + * when the refcount reaches 0. + */ +void media_request_put(struct media_request *req); + +/** + * media_request_alloc - Allocate the media request + * + * @mdev: Media device this request belongs to + * @alloc_fd: Store the request's file descriptor in this int + * + * Allocated the media request and put the fd in @alloc_fd. + */ +int media_request_alloc(struct media_device *mdev, + int *alloc_fd); + +#else + +static inline void media_request_get(struct media_request *req) +{ +} + +static inline void media_request_put(struct media_request *req) +{ +} + +#endif + +/** + * struct media_request_object_ops - Media request object operations + * @prepare: Validate and prepare the request object, optional. + * @unprepare: Unprepare the request object, optional. + * @queue: Queue the request object, optional. + * @unbind: Unbind the request object, optional. + * @release: Release the request object, required. + */ +struct media_request_object_ops { + int (*prepare)(struct media_request_object *object); + void (*unprepare)(struct media_request_object *object); + void (*queue)(struct media_request_object *object); + void (*unbind)(struct media_request_object *object); + void (*release)(struct media_request_object *object); +}; + +/** + * struct media_request_object - An opaque object that belongs to a media + * request + * + * @ops: object's operations + * @priv: object's priv pointer + * @req: the request this object belongs to (can be NULL) + * @list: List entry of the object for @struct media_request + * @kref: Reference count of the object, acquire before releasing req->lock + * @completed: If true, then this object was completed. + * + * An object related to the request. This struct is always embedded in + * another struct that contains the actual data for this request object. + */ +struct media_request_object { + const struct media_request_object_ops *ops; + void *priv; + struct media_request *req; + struct list_head list; + struct kref kref; + bool completed; +}; + +#ifdef CONFIG_MEDIA_CONTROLLER + +/** + * media_request_object_get - Get a media request object + * + * @obj: The object + * + * Get a media request object. + */ +static inline void media_request_object_get(struct media_request_object *obj) +{ + kref_get(&obj->kref); +} + +/** + * media_request_object_put - Put a media request object + * + * @obj: The object + * + * Put a media request object. Once all references are gone, the + * object's memory is released. + */ +void media_request_object_put(struct media_request_object *obj); + +/** + * media_request_object_init - Initialise a media request object + * + * @obj: The object + * + * Initialise a media request object. The object will be released using the + * release callback of the ops once it has no references (this function + * initialises references to one). + */ +void media_request_object_init(struct media_request_object *obj); + +/** + * media_request_object_bind - Bind a media request object to a request + * + * @req: The media request + * @ops: The object ops for this object + * @priv: A driver-specific priv pointer associated with this object + * @is_buffer: Set to true if the object a buffer object. + * @obj: The object + * + * Bind this object to the request and set the ops and priv values of + * the object so it can be found later with media_request_object_find(). + * + * Every bound object must be unbound or completed by the kernel at some + * point in time, otherwise the request will never complete. When the + * request is released all completed objects will be unbound by the + * request core code. + * + * Buffer objects will be added to the end of the request's object + * list, non-buffer objects will be added to the front of the list. + * This ensures that all buffer objects are at the end of the list + * and that all non-buffer objects that they depend on are processed + * first. + */ +int media_request_object_bind(struct media_request *req, + const struct media_request_object_ops *ops, + void *priv, bool is_buffer, + struct media_request_object *obj); + +/** + * media_request_object_unbind - Unbind a media request object + * + * @obj: The object + * + * Unbind the media request object from the request. + */ +void media_request_object_unbind(struct media_request_object *obj); + +/** + * media_request_object_complete - Mark the media request object as complete + * + * @obj: The object + * + * Mark the media request object as complete. Only bound objects can + * be completed. + */ +void media_request_object_complete(struct media_request_object *obj); + +#else + +static inline int __must_check +media_request_lock_for_update(struct media_request *req) +{ + return -EINVAL; +} + +static inline void media_request_unlock_for_update(struct media_request *req) +{ +} + +static inline void media_request_object_get(struct media_request_object *obj) +{ +} + +static inline void media_request_object_put(struct media_request_object *obj) +{ +} + +static inline void media_request_object_init(struct media_request_object *obj) +{ + obj->ops = NULL; + obj->req = NULL; +} + +static inline int media_request_object_bind(struct media_request *req, + const struct media_request_object_ops *ops, + void *priv, bool is_buffer, + struct media_request_object *obj) +{ + return 0; +} + +static inline void media_request_object_unbind(struct media_request_object *obj) +{ +} + +static inline void media_request_object_complete(struct media_request_object *obj) +{ +} + +#endif + +#endif |