On Mon, Apr 9, 2018 at 11:20 PM Hans Verkuil <hverkuil@xxxxxxxxx> wrote:
> From: Hans Verkuil <hans.verkuil@xxxxxxxxx>
> Add support for allocating a new request. This is only supported
> if mdev->ops->req_queue is set, i.e. the driver indicates that it
> supports queueing requests.
> Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
> ---
> drivers/media/Makefile | 3 ++-
> drivers/media/media-device.c | 14 ++++++++++++++
> drivers/media/media-request.c | 23 +++++++++++++++++++++++
> include/media/media-device.h | 13 +++++++++++++
> include/media/media-request.h | 22 ++++++++++++++++++++++
> 5 files changed, 74 insertions(+), 1 deletion(-)
> create mode 100644 drivers/media/media-request.c
> create mode 100644 include/media/media-request.h
> 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 35e81f7c0d2f..acb583c0eacd 100644
> --- a/drivers/media/media-device.c
> +++ b/drivers/media/media-device.c
> @@ -32,6 +32,7 @@
> #include <media/media-device.h>
> #include <media/media-devnode.h>
> #include <media/media-entity.h>
> +#include <media/media-request.h>
> #ifdef CONFIG_MEDIA_CONTROLLER
> @@ -366,6 +367,15 @@ static long media_device_get_topology(struct
media_device *mdev,
> return ret;
> }
> +static long media_device_request_alloc(struct media_device *mdev,
> + struct media_request_alloc *alloc)
> +{
> + if (!mdev->ops || !mdev->ops->req_queue)
> + return -ENOTTY;
> +
> + return media_request_alloc(mdev, alloc);
> +}
> +
> static long copy_arg_from_user(void *karg, void __user *uarg, unsigned
int cmd)
> {
> /* All media IOCTLs are _IOWR() */
> @@ -414,6 +424,7 @@ 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,
> @@ -686,6 +697,9 @@ void media_device_init(struct media_device *mdev)
> INIT_LIST_HEAD(&mdev->pads);
> INIT_LIST_HEAD(&mdev->links);
> INIT_LIST_HEAD(&mdev->entity_notify);
> +
> + spin_lock_init(&mdev->req_lock);
> + mutex_init(&mdev->req_queue_mutex);
> mutex_init(&mdev->graph_mutex);
> ida_init(&mdev->entity_internal_idx);
> diff --git a/drivers/media/media-request.c b/drivers/media/media-request.c
> new file mode 100644
> index 000000000000..ead78613fdbe
> --- /dev/null
> +++ b/drivers/media/media-request.c
> @@ -0,0 +1,23 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Media device request objects
> + *
> + * Copyright (C) 2018 Intel Corporation
> + * Copyright (C) 2018, The Chromium OS Authors. All rights reserved.
Seconding Tomasz' comment - Chromium authorship should be something like
Copyright (C) 2018 Google, Inc.
(see
https://www.chromium.org/chromium-os/how-tos-and-troubleshooting/kernel-faq#TOC-Which-copyright-header-should-I-use-
)
Sorry since I think I am the one who introduced this line in my early
patches.
> + *
> + * Author: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> + */
> +
> +#include <linux/anon_inodes.h>
> +#include <linux/file.h>
> +#include <linux/mm.h>
> +#include <linux/string.h>
> +
> +#include <media/media-device.h>
> +#include <media/media-request.h>
> +
> +int media_request_alloc(struct media_device *mdev,
> + struct media_request_alloc *alloc)
> +{
> + return -ENOMEM;
Probably not the best error code for now? And this function can probably be
declared later (i.e. along with its full definition) in the series anyway.
> +}
> diff --git a/include/media/media-device.h b/include/media/media-device.h
> index bcc6ec434f1f..07e323c57202 100644
> --- a/include/media/media-device.h
> +++ b/include/media/media-device.h
> @@ -19,6 +19,7 @@
> #ifndef _MEDIA_DEVICE_H
> #define _MEDIA_DEVICE_H
> +#include <linux/anon_inodes.h>
> #include <linux/list.h>
> #include <linux/mutex.h>
> @@ -27,6 +28,7 @@
> struct ida;
> struct device;
> +struct media_device;
> /**
> * struct media_entity_notify - Media Entity Notify
> @@ -50,10 +52,16 @@ 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
> + * @req_free: Free a request
> + * @req_queue: Queue a request
> */
> 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_queue)(struct media_request *req);
Same as above - these ops are introduced but not used at all. The glue code
could already be here, it would actually be helpful to understand the patch.
> };
> /**
> @@ -88,6 +96,8 @@ struct media_device_ops {
> * @disable_source: Disable Source Handler function pointer
> *
> * @ops: Operation handler callbacks
> + * @req_lock: Serialise access to requests
> + * @req_queue_mutex: Serialise validating and queueing requests
> *
> * 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 +168,9 @@ struct media_device {
> void (*disable_source)(struct media_entity *entity);
> const struct media_device_ops *ops;
> +
> + spinlock_t req_lock;
> + struct mutex req_queue_mutex;
> };
> /* 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..dae3eccd9aa7
> --- /dev/null
> +++ b/include/media/media-request.h
> @@ -0,0 +1,22 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Media device request objects
> + *
> + * Copyright (C) 2018 Intel Corporation
> + *
> + * Author: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> + */
> +
> +#ifndef MEDIA_REQUEST_H
> +#define MEDIA_REQUEST_H
> +
> +#include <linux/list.h>
> +#include <linux/slab.h>
> +#include <linux/spinlock.h>
> +
> +#include <media/media-device.h>
> +
> +int media_request_alloc(struct media_device *mdev,
> + struct media_request_alloc *alloc);
> +
> +#endif
> --
> 2.16.3
