summaryrefslogtreecommitdiffstats
path: root/drivers/media/mc/mc-request.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/media/mc/mc-request.c')
-rw-r--r--drivers/media/mc/mc-request.c503
1 files changed, 503 insertions, 0 deletions
diff --git a/drivers/media/mc/mc-request.c b/drivers/media/mc/mc-request.c
new file mode 100644
index 000000000000..e3fca436c75b
--- /dev/null
+++ b/drivers/media/mc/mc-request.c
@@ -0,0 +1,503 @@
+// 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);