[PATCH 1/5] drm: introduce sync objects (v2)

Sean Paul seanpaul at chromium.org
Fri May 12 13:33:21 UTC 2017


On Fri, May 12, 2017 at 10:34:53AM +1000, Dave Airlie wrote:
> From: Dave Airlie <airlied at redhat.com>
> 
> Sync objects are new toplevel drm object, that contain a
> pointer to a fence. This fence can be updated via command
> submission ioctls via drivers.
> 
> There is also a generic wait obj API modelled on the vulkan
> wait API (with code modelled on some amdgpu code).
> 
> These objects can be converted to an opaque fd that can be
> passes between processes.
> 
> v2: rename reference/unreference to put/get (Chris)
> fix leaked reference (David Zhou)
> drop mutex in favour of cmpxchg (Chris)
> document drm_syncobj_fence_get
> use ENOENT for syncobj lookup.
> 
> Signed-off-by: Dave Airlie <airlied at redhat.com>

With Daniel's comments addressed,

Reviewed-by: Sean Paul <seanpaul at chromium.org>

> 
> fixup
> ---
>  Documentation/gpu/drm-internals.rst |   3 +
>  Documentation/gpu/drm-mm.rst        |   6 +
>  drivers/gpu/drm/Makefile            |   2 +-
>  drivers/gpu/drm/drm_fops.c          |   8 +
>  drivers/gpu/drm/drm_internal.h      |  13 ++
>  drivers/gpu/drm/drm_ioctl.c         |  12 ++
>  drivers/gpu/drm/drm_syncobj.c       | 385 ++++++++++++++++++++++++++++++++++++
>  include/drm/drmP.h                  |   5 +
>  include/drm/drm_drv.h               |   1 +
>  include/drm/drm_syncobj.h           |  87 ++++++++
>  include/uapi/drm/drm.h              |  25 +++
>  11 files changed, 546 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/gpu/drm/drm_syncobj.c
>  create mode 100644 include/drm/drm_syncobj.h
> 
> diff --git a/Documentation/gpu/drm-internals.rst b/Documentation/gpu/drm-internals.rst
> index e35920d..2ea3bce 100644
> --- a/Documentation/gpu/drm-internals.rst
> +++ b/Documentation/gpu/drm-internals.rst
> @@ -98,6 +98,9 @@ DRIVER_ATOMIC
>      implement appropriate obj->atomic_get_property() vfuncs for any
>      modeset objects with driver specific properties.
>  
> +DRIVER_SYNCOBJ
> +    Driver support drm sync objects.
> +
>  Major, Minor and Patchlevel
>  ~~~~~~~~~~~~~~~~~~~~~~~~~~~
>  
> diff --git a/Documentation/gpu/drm-mm.rst b/Documentation/gpu/drm-mm.rst
> index f5760b1..28aebe8 100644
> --- a/Documentation/gpu/drm-mm.rst
> +++ b/Documentation/gpu/drm-mm.rst
> @@ -483,3 +483,9 @@ DRM Cache Handling
>  
>  .. kernel-doc:: drivers/gpu/drm/drm_cache.c
>     :export:
> +
> +DRM Sync Objects
> +===========================
> +
> +.. kernel-doc:: drivers/gpu/drm/drm_syncobj.c
> +   :export:
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index 3ee9579..b5e565c 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -16,7 +16,7 @@ drm-y       :=	drm_auth.o drm_bufs.o drm_cache.o \
>  		drm_framebuffer.o drm_connector.o drm_blend.o \
>  		drm_encoder.o drm_mode_object.o drm_property.o \
>  		drm_plane.o drm_color_mgmt.o drm_print.o \
> -		drm_dumb_buffers.o drm_mode_config.o
> +		drm_dumb_buffers.o drm_mode_config.o drm_syncobj.o
>  
>  drm-$(CONFIG_DRM_LIB_RANDOM) += lib/drm_random.o
>  drm-$(CONFIG_DRM_VM) += drm_vm.o
> diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
> index afdf5b1..9a61df2 100644
> --- a/drivers/gpu/drm/drm_fops.c
> +++ b/drivers/gpu/drm/drm_fops.c
> @@ -219,6 +219,9 @@ static int drm_open_helper(struct file *filp, struct drm_minor *minor)
>  	if (drm_core_check_feature(dev, DRIVER_GEM))
>  		drm_gem_open(dev, priv);
>  
> +	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
> +		drm_syncobj_open(priv);
> +
>  	if (drm_core_check_feature(dev, DRIVER_PRIME))
>  		drm_prime_init_file_private(&priv->prime);
>  
> @@ -266,6 +269,8 @@ static int drm_open_helper(struct file *filp, struct drm_minor *minor)
>  out_prime_destroy:
>  	if (drm_core_check_feature(dev, DRIVER_PRIME))
>  		drm_prime_destroy_file_private(&priv->prime);
> +	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
> +		drm_syncobj_release(priv);
>  	if (drm_core_check_feature(dev, DRIVER_GEM))
>  		drm_gem_release(dev, priv);
>  	put_pid(priv->pid);
> @@ -400,6 +405,9 @@ int drm_release(struct inode *inode, struct file *filp)
>  		drm_property_destroy_user_blobs(dev, file_priv);
>  	}
>  
> +	if (drm_core_check_feature(dev, DRIVER_SYNCOBJ))
> +		drm_syncobj_release(file_priv);
> +
>  	if (drm_core_check_feature(dev, DRIVER_GEM))
>  		drm_gem_release(dev, file_priv);
>  
> diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h
> index f37388c..44ef903 100644
> --- a/drivers/gpu/drm/drm_internal.h
> +++ b/drivers/gpu/drm/drm_internal.h
> @@ -142,4 +142,17 @@ static inline int drm_debugfs_crtc_crc_add(struct drm_crtc *crtc)
>  {
>  	return 0;
>  }
> +
>  #endif
> +
> +/* drm_syncobj.c */
> +void drm_syncobj_open(struct drm_file *file_private);
> +void drm_syncobj_release(struct drm_file *file_private);
> +int drm_syncobj_create_ioctl(struct drm_device *dev, void *data,
> +			     struct drm_file *file_private);
> +int drm_syncobj_destroy_ioctl(struct drm_device *dev, void *data,
> +			      struct drm_file *file_private);
> +int drm_syncobj_handle_to_fd_ioctl(struct drm_device *dev, void *data,
> +				   struct drm_file *file_private);
> +int drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
> +				   struct drm_file *file_private);
> diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
> index a7c61c2..6da7adc 100644
> --- a/drivers/gpu/drm/drm_ioctl.c
> +++ b/drivers/gpu/drm/drm_ioctl.c
> @@ -240,6 +240,9 @@ static int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_
>  		req->value |= dev->driver->prime_fd_to_handle ? DRM_PRIME_CAP_IMPORT : 0;
>  		req->value |= dev->driver->prime_handle_to_fd ? DRM_PRIME_CAP_EXPORT : 0;
>  		return 0;
> +	case DRM_CAP_SYNCOBJ:
> +		req->value = drm_core_check_feature(dev, DRIVER_SYNCOBJ);
> +		return 0;
>  	}
>  
>  	/* Other caps only work with KMS drivers */
> @@ -641,6 +644,15 @@ static const struct drm_ioctl_desc drm_ioctls[] = {
>  	DRM_IOCTL_DEF(DRM_IOCTL_MODE_ATOMIC, drm_mode_atomic_ioctl, DRM_MASTER|DRM_CONTROL_ALLOW|DRM_UNLOCKED),
>  	DRM_IOCTL_DEF(DRM_IOCTL_MODE_CREATEPROPBLOB, drm_mode_createblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
>  	DRM_IOCTL_DEF(DRM_IOCTL_MODE_DESTROYPROPBLOB, drm_mode_destroyblob_ioctl, DRM_CONTROL_ALLOW|DRM_UNLOCKED),
> +
> +	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_CREATE, drm_syncobj_create_ioctl,
> +		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
> +	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_DESTROY, drm_syncobj_destroy_ioctl,
> +		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
> +	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD, drm_syncobj_handle_to_fd_ioctl,
> +		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
> +	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE, drm_syncobj_fd_to_handle_ioctl,
> +		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
>  };
>  
>  #define DRM_CORE_IOCTL_COUNT	ARRAY_SIZE( drm_ioctls )
> diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
> new file mode 100644
> index 0000000..835e987
> --- /dev/null
> +++ b/drivers/gpu/drm/drm_syncobj.c
> @@ -0,0 +1,385 @@
> +/*
> + * Copyright 2017 Red Hat
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> + * IN THE SOFTWARE.
> + *
> + * Authors:
> + *
> + */
> +
> +/**
> + * DOC: Overview
> + *
> + * DRM synchronisation objects (syncobj) are a persistent objects,
> + * that contain an optional fence. The fence can be updated with a new
> + * fence, or be NULL.
> + *
> + * syncobj's can be export to fd's and back, these fd's are opaque and
> + * have no other use case, except passing the syncobj between processes.
> + *
> + * TODO: sync_file interactions, waiting
> + *
> + * Their primary use-case is to implement Vulkan fences and semaphores.
> + *
> + * syncobj have a kref reference count, but also have an optional file.
> + * The file is only created once the syncobj is exported.
> + * The file takes a reference on the kref.
> + */
> +
> +#include <drm/drmP.h>
> +#include <linux/file.h>
> +#include <linux/fs.h>
> +#include <linux/anon_inodes.h>
> +
> +#include "drm_internal.h"
> +#include <drm/drm_syncobj.h>
> +
> +static struct drm_syncobj *drm_syncobj_find(struct drm_file *file_private,
> +					   u32 handle)
> +{
> +	struct drm_syncobj *syncobj;
> +
> +	spin_lock(&file_private->syncobj_table_lock);
> +
> +	/* Check if we currently have a reference on the object */
> +	syncobj = idr_find(&file_private->syncobj_idr, handle);
> +	if (syncobj)
> +		drm_syncobj_get(syncobj);
> +
> +	spin_unlock(&file_private->syncobj_table_lock);
> +
> +	return syncobj;
> +}
> +
> +/**
> + * drm_syncobj_replace_fence - lookup and replace fence in a sync object.
> + * @file_private - drm file private pointer.
> + * @handle - syncobj handle to lookup
> + * @fence - fence to install in sync file.
> + * Returns:
> + * 0 on success, or -ENOENT when the handle doesn't point at a valid sem file.
> + *
> + * This looks up a sync object and replaces the fence on it, freeing
> + * the old one.
> + */
> +int drm_syncobj_replace_fence(struct drm_file *file_private,
> +			      u32 handle,
> +			      struct dma_fence *fence)
> +{
> +	struct drm_syncobj *syncobj = drm_syncobj_find(file_private, handle);
> +	struct dma_fence *old_fence = NULL;
> +
> +	if (!syncobj)
> +		return -ENOENT;
> +
> +	if (fence)
> +		dma_fence_get(fence);
> +	old_fence = xchg(&syncobj->fence, fence);
> +
> +	dma_fence_put(old_fence);
> +	drm_syncobj_put(syncobj);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(drm_syncobj_replace_fence);
> +
> +/**
> + * drm_syncobj_fence_get - lookup sync object and reference fence
> + * @file_private - drm file private pointer.
> + * @handle - syncobj handle to lookup
> + * @fence - returned referenced fence
> + * Returns:
> + * 0 on success, or -ENOENT where syncobj is invalid,
> + * or -EINVAL when the syncobj has no fence.
> + *
> + * This returns a reference to underlying fence backing the
> + * syncobj if one exists.
> + */
> +int drm_syncobj_fence_get(struct drm_file *file_private,
> +			  u32 handle,
> +			  struct dma_fence **fence)
> +{
> +	struct drm_syncobj *syncobj = drm_syncobj_find(file_private, handle);
> +	int ret = 0;
> +
> +	if (!syncobj)
> +		return -ENOENT;
> +
> +	*fence = dma_fence_get(syncobj->fence);
> +	if (!*fence) {
> +		ret = -EINVAL;
> +	}
> +	drm_syncobj_put(syncobj);
> +	return ret;
> +}
> +EXPORT_SYMBOL(drm_syncobj_fence_get);
> +
> +void drm_syncobj_free(struct kref *kref)
> +{
> +	struct drm_syncobj *syncobj = container_of(kref,
> +						   struct drm_syncobj,
> +						   refcount);
> +	dma_fence_put(syncobj->fence);
> +	kfree(syncobj);
> +}
> +
> +static int drm_syncobj_create(struct drm_file *file_private,
> +			      u32 *handle)
> +{
> +	int ret;
> +	struct drm_syncobj *syncobj;
> +
> +	syncobj = kzalloc(sizeof(struct drm_syncobj), GFP_KERNEL);
> +	if (!syncobj)
> +		return -ENOMEM;
> +
> +	kref_init(&syncobj->refcount);
> +
> +	idr_preload(GFP_KERNEL);
> +	spin_lock(&file_private->syncobj_table_lock);
> +	ret = idr_alloc(&file_private->syncobj_idr, syncobj, 1, 0, GFP_NOWAIT);
> +	spin_unlock(&file_private->syncobj_table_lock);
> +
> +	idr_preload_end();
> +
> +	if (ret < 0) {
> +		drm_syncobj_put(syncobj);
> +		return ret;
> +	}
> +
> +	*handle = ret;
> +	return 0;
> +}
> +
> +static int drm_syncobj_destroy(struct drm_file *file_private,
> +			       u32 handle)
> +{
> +	struct drm_syncobj *syncobj;
> +
> +	spin_lock(&file_private->syncobj_table_lock);
> +	syncobj = idr_remove(&file_private->syncobj_idr, handle);
> +	spin_unlock(&file_private->syncobj_table_lock);
> +
> +	if (!syncobj)
> +		return -ENOENT;
> +
> +	drm_syncobj_put(syncobj);
> +	return 0;
> +}
> +
> +static int drm_syncobj_file_release(struct inode *inode, struct file *file)
> +{
> +	struct drm_syncobj *syncobj = file->private_data;
> +
> +	drm_syncobj_put(syncobj);
> +	return 0;
> +}
> +
> +static const struct file_operations drm_syncobj_file_fops = {
> +	.release = drm_syncobj_file_release,
> +};
> +
> +static int drm_syncobj_alloc_file(struct drm_syncobj *syncobj)
> +{
> +	struct file *file = anon_inode_getfile("syncobj_file",
> +					       &drm_syncobj_file_fops,
> +					       syncobj, 0);
> +	if (IS_ERR(file))
> +		return PTR_ERR(file);
> +
> +	drm_syncobj_get(syncobj);
> +	if (cmpxchg(&syncobj->file, NULL, file)) {
> +		/* lost the race */
> +		fput(file);
> +	}
> +
> +	return 0;
> +}
> +
> +static int drm_syncobj_handle_to_fd(struct drm_file *file_private,
> +				    u32 handle, int *p_fd)
> +{
> +	struct drm_syncobj *syncobj = drm_syncobj_find(file_private, handle);
> +	int ret;
> +	int fd;
> +
> +	if (!syncobj)
> +		return -EINVAL;
> +
> +	fd = get_unused_fd_flags(O_CLOEXEC);
> +	if (fd < 0) {
> +		drm_syncobj_put(syncobj);
> +		return fd;
> +	}
> +
> +	if (!syncobj->file) {
> +		ret = drm_syncobj_alloc_file(syncobj);
> +		if (ret)
> +			goto out_put_fd;
> +	}
> +	fd_install(fd, syncobj->file);
> +	drm_syncobj_put(syncobj);
> +	*p_fd = fd;
> +	return 0;
> +out_put_fd:
> +	put_unused_fd(fd);
> +	drm_syncobj_put(syncobj);
> +	return ret;
> +}
> +
> +static struct drm_syncobj *drm_syncobj_fdget(int fd)
> +{
> +	struct file *file = fget(fd);
> +
> +	if (!file)
> +		return NULL;
> +	if (file->f_op != &drm_syncobj_file_fops)
> +		goto err;
> +
> +	return file->private_data;
> +err:
> +	fput(file);
> +	return NULL;
> +};
> +
> +static int drm_syncobj_fd_to_handle(struct drm_file *file_private,
> +				    int fd, u32 *handle)
> +{
> +	struct drm_syncobj *syncobj = drm_syncobj_fdget(fd);
> +	int ret;
> +
> +	if (!syncobj)
> +		return -EINVAL;
> +
> +	/* take a reference to put in the idr */
> +	drm_syncobj_get(syncobj);
> +
> +	idr_preload(GFP_KERNEL);
> +	spin_lock(&file_private->syncobj_table_lock);
> +	ret = idr_alloc(&file_private->syncobj_idr, syncobj, 1, 0, GFP_NOWAIT);
> +	spin_unlock(&file_private->syncobj_table_lock);
> +	idr_preload_end();
> +
> +	if (ret < 0) {
> +		fput(syncobj->file);
> +		return ret;
> +	}
> +	*handle = ret;
> +	return 0;
> +}
> +
> +/**
> + * drm_syncobj_open - initalizes syncobj file-private structures at devnode open time
> + * @dev: drm_device which is being opened by userspace
> + * @file_private: drm file-private structure to set up
> + *
> + * Called at device open time, sets up the structure for handling refcounting
> + * of sync objects.
> + */
> +void
> +drm_syncobj_open(struct drm_file *file_private)
> +{
> +	idr_init(&file_private->syncobj_idr);
> +	spin_lock_init(&file_private->syncobj_table_lock);
> +}
> +
> +static int
> +drm_syncobj_release_handle(int id, void *ptr, void *data)
> +{
> +	struct drm_syncobj *syncobj = ptr;
> +
> +	drm_syncobj_put(syncobj);
> +	return 0;
> +}
> +
> +/**
> + * drm_syncobj_release - release file-private sync object resources
> + * @dev: drm_device which is being closed by userspace
> + * @file_private: drm file-private structure to clean up
> + *
> + * Called at close time when the filp is going away.
> + *
> + * Releases any remaining references on objects by this filp.
> + */
> +void
> +drm_syncobj_release(struct drm_file *file_private)
> +{
> +	idr_for_each(&file_private->syncobj_idr,
> +		     &drm_syncobj_release_handle, file_private);
> +	idr_destroy(&file_private->syncobj_idr);
> +}
> +
> +int
> +drm_syncobj_create_ioctl(struct drm_device *dev, void *data,
> +			 struct drm_file *file_private)
> +{
> +	struct drm_syncobj_create *args = data;
> +
> +	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
> +		return -ENODEV;
> +
> +	/* no valid flags yet */
> +	if (args->flags)
> +		return -EINVAL;
> +
> +	return drm_syncobj_create(file_private,
> +				  &args->handle);
> +}
> +
> +int
> +drm_syncobj_destroy_ioctl(struct drm_device *dev, void *data,
> +			  struct drm_file *file_private)
> +{
> +	struct drm_syncobj_destroy *args = data;
> +
> +	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
> +		return -ENODEV;
> +
> +	/* make sure padding is empty */
> +	if (args->pad)
> +		return -EINVAL;
> +	return drm_syncobj_destroy(file_private, args->handle);
> +}
> +
> +int
> +drm_syncobj_handle_to_fd_ioctl(struct drm_device *dev, void *data,
> +				   struct drm_file *file_private)
> +{
> +	struct drm_syncobj_handle *args = data;
> +
> +	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
> +		return -ENODEV;
> +
> +	return drm_syncobj_handle_to_fd(file_private, args->handle,
> +					&args->fd);
> +}
> +
> +int
> +drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
> +				   struct drm_file *file_private)
> +{
> +	struct drm_syncobj_handle *args = data;
> +
> +	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
> +		return -ENODEV;
> +
> +	return drm_syncobj_fd_to_handle(file_private, args->fd,
> +					&args->handle);
> +}
> diff --git a/include/drm/drmP.h b/include/drm/drmP.h
> index 6105c05..1d48f6f 100644
> --- a/include/drm/drmP.h
> +++ b/include/drm/drmP.h
> @@ -405,6 +405,11 @@ struct drm_file {
>  	/** Lock for synchronization of access to object_idr. */
>  	spinlock_t table_lock;
>  
> +	/** Mapping of sync object handles to object pointers. */
> +	struct idr syncobj_idr;
> +	/** Lock for synchronization of access to syncobj_idr. */
> +	spinlock_t syncobj_table_lock;
> +
>  	struct file *filp;
>  	void *driver_priv;
>  
> diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
> index 5699f42..48ff06b 100644
> --- a/include/drm/drm_drv.h
> +++ b/include/drm/drm_drv.h
> @@ -53,6 +53,7 @@ struct drm_mode_create_dumb;
>  #define DRIVER_RENDER			0x8000
>  #define DRIVER_ATOMIC			0x10000
>  #define DRIVER_KMS_LEGACY_CONTEXT	0x20000
> +#define DRIVER_SYNCOBJ                  0x40000
>  
>  /**
>   * struct drm_driver - DRM driver structure
> diff --git a/include/drm/drm_syncobj.h b/include/drm/drm_syncobj.h
> new file mode 100644
> index 0000000..3196745
> --- /dev/null
> +++ b/include/drm/drm_syncobj.h
> @@ -0,0 +1,87 @@
> +/*
> + * Copyright © 2017 Red Hat
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> + * IN THE SOFTWARE.
> + *
> + * Authors:
> + *
> + */
> +#ifndef __DRM_SYNCOBJ_H__
> +#define __DRM_SYNCOBJ_H__
> +
> +#include "linux/dma-fence.h"
> +
> +/**
> + * struct drm_syncobj - sync object.
> + *
> + * This structure defines a generic sync object which wraps a dma fence.
> + */
> +struct drm_syncobj {
> +	/**
> +	 * @refcount:
> +	 *
> +	 * Reference count of this object.
> +	 */
> +	struct kref refcount;
> +	/**
> +	 * @fence:
> +	 * NULL or a pointer to the fence bound to this object.
> +	 */
> +	struct dma_fence *fence;
> +	/**
> +	 * @file
> +	 * a file backing for this syncobj.
> +	 */
> +	struct file *file;
> +};
> +
> +void drm_syncobj_free(struct kref *kref);
> +
> +/**
> + * drm_syncobj_get - acquire a syncobj reference
> + * @obj: sync object
> + *
> + * This acquires additional reference to @obj. It is illegal to call this
> + * without already holding a reference. No locks required.
> + */
> +static inline void
> +drm_syncobj_get(struct drm_syncobj *obj)
> +{
> +	kref_get(&obj->refcount);
> +}
> +
> +/**
> + * drm_syncobj_put - release a reference to a sync object.
> + * @obj: sync object.
> + */
> +static inline void
> +drm_syncobj_put(struct drm_syncobj *obj)
> +{
> +	kref_put(&obj->refcount, drm_syncobj_free);
> +}
> +
> +int drm_syncobj_fence_get(struct drm_file *file_private,
> +			  u32 handle,
> +			  struct dma_fence **fence);
> +int drm_syncobj_replace_fence(struct drm_file *file_private,
> +			      u32 handle,
> +			      struct dma_fence *fence);
> +
> +#endif
> diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
> index b2c5284..dd0b99c 100644
> --- a/include/uapi/drm/drm.h
> +++ b/include/uapi/drm/drm.h
> @@ -647,6 +647,7 @@ struct drm_gem_open {
>  #define DRM_CAP_CURSOR_HEIGHT		0x9
>  #define DRM_CAP_ADDFB2_MODIFIERS	0x10
>  #define DRM_CAP_PAGE_FLIP_TARGET	0x11
> +#define DRM_CAP_SYNCOBJ		0x13
>  
>  /** DRM_IOCTL_GET_CAP ioctl argument type */
>  struct drm_get_cap {
> @@ -696,6 +697,25 @@ struct drm_prime_handle {
>  	__s32 fd;
>  };
>  
> +struct drm_syncobj_create {
> +	__u32 handle;
> +	__u32 flags;
> +};
> +
> +struct drm_syncobj_destroy {
> +	__u32 handle;
> +	__u32 pad;
> +};
> +
> +struct drm_syncobj_handle {
> +	__u32 handle;
> +	/** Flags.. only applicable for handle->fd */
> +	__u32 flags;
> +
> +	__s32 fd;
> +	__u32 pad;
> +};
> +
>  #if defined(__cplusplus)
>  }
>  #endif
> @@ -814,6 +834,11 @@ extern "C" {
>  #define DRM_IOCTL_MODE_CREATEPROPBLOB	DRM_IOWR(0xBD, struct drm_mode_create_blob)
>  #define DRM_IOCTL_MODE_DESTROYPROPBLOB	DRM_IOWR(0xBE, struct drm_mode_destroy_blob)
>  
> +#define DRM_IOCTL_SYNCOBJ_CREATE	DRM_IOWR(0xBF, struct drm_syncobj_create)
> +#define DRM_IOCTL_SYNCOBJ_DESTROY	DRM_IOWR(0xC0, struct drm_syncobj_destroy)
> +#define DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD	DRM_IOWR(0xC1, struct drm_syncobj_handle)
> +#define DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE	DRM_IOWR(0xC2, struct drm_syncobj_handle)
> +
>  /**
>   * Device specific ioctls should only be in their respective headers
>   * The device specific ioctl range is from 0x40 to 0x9f.
> -- 
> 2.9.3
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Sean Paul, Software Engineer, Google / Chromium OS


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