+++ /dev/null
-// 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);
- WARN_ON(req->access_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;
- req->access_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;
-
- poll_wait(filp, &req->poll_wait, wait);
- 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;
- }
-
-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;
- }
- if (req->access_count) {
- dev_dbg(mdev->dev,
- "request: %s is being accessed, 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,
-#ifdef CONFIG_COMPAT
- .compat_ioctl = media_request_ioctl,
-#endif /* CONFIG_COMPAT */
- .release = media_request_close,
-};
-
-struct media_request *
-media_request_get_by_fd(struct media_device *mdev, int request_fd)
-{
- struct fd f;
- struct media_request *req;
-
- if (!mdev || !mdev->ops ||
- !mdev->ops->req_validate || !mdev->ops->req_queue)
- return ERR_PTR(-EBADR);
-
- f = fdget(request_fd);
- if (!f.file)
- goto err_no_req_fd;
-
- if (f.file->f_op != &request_fops)
- goto err_fput;
- req = f.file->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 fdget() 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);
- fdput(f);
-
- return req;
-
-err_fput:
- fdput(f);
-
-err_no_req_fd:
- dev_dbg(mdev->dev, "cannot find request_fd %d\n", request_fd);
- return ERR_PTR(-EINVAL);
-}
-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;
- req->access_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);
-}
-
-struct media_request_object *
-media_request_object_find(struct media_request *req,
- const struct media_request_object_ops *ops,
- void *priv)
-{
- struct media_request_object *obj;
- struct media_request_object *found = NULL;
- unsigned long flags;
-
- if (WARN_ON(!ops || !priv))
- return NULL;
-
- spin_lock_irqsave(&req->lock, flags);
- list_for_each_entry(obj, &req->objects, list) {
- if (obj->ops == ops && obj->priv == priv) {
- media_request_object_get(obj);
- found = obj;
- break;
- }
- }
- spin_unlock_irqrestore(&req->lock, flags);
- return found;
-}
-EXPORT_SYMBOL_GPL(media_request_object_find);
-
-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 -EBADR;
-
- 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);
git.samba.org / sfrench / cifs-2.6.git / blobdiff