drm syncobj - can we get some r-b/a-bs?

From: Dave Airlie <[email protected]>

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 <[email protected]>

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

Documentation/gpu/drm-internals.rst +3 -0

index e35920d..2ea3bce 100644
@@ -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
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

Documentation/gpu/drm-mm.rst +6 -0

index f5760b1..28aebe8 100644
@@ -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:

drivers/gpu/drm/Makefile +1 -1

index 3ee9579..b5e565c 100644
@@ -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

drivers/gpu/drm/drm_fops.c +8 -0

index afdf5b1..9a61df2 100644
@@ -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);
 

drivers/gpu/drm/drm_internal.h +13 -0

index f37388c..44ef903 100644
@@ -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);

drivers/gpu/drm/drm_ioctl.c +12 -0

index a7c61c2..6da7adc 100644
@@ -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 )

drivers/gpu/drm/drm_syncobj.c new file +385 -0

new file mode 100644
index 0000000..835e987
@@ -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);
+}

include/drm/drmP.h +5 -0

index 6105c05..1d48f6f 100644
@@ -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;
 

include/drm/drm_drv.h +1 -0

index 5699f42..48ff06b 100644
@@ -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

include/drm/drm_syncobj.h new file +87 -0

new file mode 100644
index 0000000..3196745
@@ -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

include/uapi/drm/drm.h +20 -0

index b2c5284..dd0b99c 100644
@@ -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)

From: Dave Airlie <[email protected]>

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 <[email protected]>

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

Documentation/gpu/drm-internals.rst +3 -0

index e35920d..2ea3bce 100644
@@ -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
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

Documentation/gpu/drm-mm.rst +0 -0

index f5760b1..28aebe8 100644

drivers/gpu/drm/Makefile +1 -1

index 3ee9579..b5e565c 100644
@@ -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

drivers/gpu/drm/drm_fops.c +8 -0

index afdf5b1..9a61df2 100644
@@ -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);
 

drivers/gpu/drm/drm_internal.h +13 -0

index f37388c..44ef903 100644
@@ -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);

drivers/gpu/drm/drm_ioctl.c +12 -0

index a7c61c2..6da7adc 100644
@@ -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 )

drivers/gpu/drm/drm_syncobj.c new file +27 -0

new file mode 100644
index 0000000..835e987
@@ -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:
+ *
+ */
+
+/**

drivers/gpu/drm/drm_syncobj.c new file +321 -0

+ *
+ * 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);

drivers/gpu/drm/drm_syncobj.c new file +4 -0

+
+	return drm_syncobj_fd_to_handle(file_private, args->fd,
+					&args->handle);
+}

include/drm/drmP.h +5 -0

index 6105c05..1d48f6f 100644
@@ -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;
 

include/drm/drm_drv.h +1 -0

index 5699f42..48ff06b 100644
@@ -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

include/drm/drm_syncobj.h new file +39 -0

new file mode 100644
index 0000000..3196745
@@ -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:
+	 *

include/drm/drm_syncobj.h new file +38 -0

+	 * 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

include/uapi/drm/drm.h +25 -0

index b2c5284..dd0b99c 100644
@@ -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.

Signature · 6 lines

2.9.3

_______________________________________________
dri-devel mailing list
[email protected]
https://lists.freedesktop.org/mailman/listinfo/dri-devel

From: Dave Airlie <[email protected]>

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 <[email protected]>

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

Documentation/gpu/drm-internals.rst +3 -0

index e35920d..2ea3bce 100644
@@ -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
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

Documentation/gpu/drm-mm.rst +6 -0

index f5760b1..28aebe8 100644
@@ -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:

drivers/gpu/drm/Makefile +1 -1

index 3ee9579..b5e565c 100644
@@ -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

drivers/gpu/drm/drm_fops.c +8 -0

index afdf5b1..9a61df2 100644
@@ -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);
 

drivers/gpu/drm/drm_internal.h +13 -0

index f37388c..44ef903 100644
@@ -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);

drivers/gpu/drm/drm_ioctl.c +12 -0

index a7c61c2..6da7adc 100644
@@ -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 )

drivers/gpu/drm/drm_syncobj.c new file +385 -0

new file mode 100644
index 0000000..835e987
@@ -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);
+}

include/drm/drmP.h +5 -0

index 6105c05..1d48f6f 100644
@@ -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;
 

include/drm/drm_drv.h +1 -0

index 5699f42..48ff06b 100644
@@ -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

include/drm/drm_syncobj.h new file +87 -0

new file mode 100644
index 0000000..3196745
@@ -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

include/uapi/drm/drm.h +25 -0

index b2c5284..dd0b99c 100644
@@ -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.

Signature · 6 lines

2.9.3

_______________________________________________
dri-devel mailing list
[email protected]
https://lists.freedesktop.org/mailman/listinfo/dri-devel

From: Dave Airlie <[email protected]>

This interface will allow sync object to be used to back Vulkan fences. This API is pretty much the vulkan fence waiting API, and I've ported the code from amdgpu.

v2: accept relative timeout, pass remaining time back to userspace.

Signed-off-by Dave Airlie <[email protected]>

---
 drivers/gpu/drm/drm_internal.h |   2 +
 drivers/gpu/drm/drm_ioctl.c    |   2 +
 drivers/gpu/drm/drm_syncobj.c  | 139 ++++++++++++++++++++++++++++++++++++++++-
 include/uapi/drm/drm.h         |  12 ++++
 4 files changed, 154 insertions(+), 1 deletion(-)

drivers/gpu/drm/drm_internal.h +2 -0

index 44ef903..a508ad9 100644
@@ -156,3 +156,5 @@ 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);
+int drm_syncobj_wait_ioctl(struct drm_device *dev, void *data,
+			   struct drm_file *file_private);

drivers/gpu/drm/drm_ioctl.c +2 -0

index 6da7adc..b142466 100644
@@ -653,6 +653,8 @@ static const struct drm_ioctl_desc drm_ioctls[] = {
 		      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),
+	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_WAIT, drm_syncobj_wait_ioctl,
+		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
 };
 
 #define DRM_CORE_IOCTL_COUNT	ARRAY_SIZE( drm_ioctls )

drivers/gpu/drm/drm_syncobj.c +138 -1

index 835e987..9a8c690 100644
@@ -1,5 +1,7 @@
 /*
  * Copyright 2017 Red Hat
+ * Parts ported from amdgpu (fence wait code).
+ * Copyright 2016 Advanced Micro Devices, Inc.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),

@@ -31,10 +33,13 @@
  * that contain an optional fence. The fence can be updated with a new
  * fence, or be NULL.
  *
+ * syncobj's can be waited upon, where it will wait for the underlying
+ * fence.
+ *
  * 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
+ * TODO: sync_file interactions.
  *
  * Their primary use-case is to implement Vulkan fences and semaphores.
  *

@@ -383,3 +388,135 @@ drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
 	return drm_syncobj_fd_to_handle(file_private, args->fd,
 					&args->handle);
 }
+
+static int drm_syncobj_wait_all_fences(struct drm_device *dev,
+				       struct drm_file *file_private,
+				       struct drm_syncobj_wait *wait,
+				       uint32_t *handles)
+{
+	uint32_t i;
+	int ret = 0;
+	unsigned long timeout = nsecs_to_jiffies(wait->timeout_ns);
+
+	for (i = 0; i < wait->count_handles; i++) {
+		struct dma_fence *fence;
+
+		ret = drm_syncobj_fence_get(file_private, handles[i],
+					    &fence);
+		if (ret)
+			return ret;
+
+		if (!fence)
+			continue;
+
+		ret = dma_fence_wait_timeout(fence, true, timeout);
+
+		dma_fence_put(fence);
+		if (ret < 0)
+			return ret;
+		if (ret == 0)
+			break;
+		timeout = ret;
+	}
+
+	if (ret > 0)
+		wait->timeout_ns = jiffies_to_nsecs(ret);
+	wait->out_status = (ret > 0);
+	wait->first_signaled = 0;
+	return 0;
+}
+
+static int drm_syncobj_wait_any_fence(struct drm_device *dev,
+				      struct drm_file *file_private,
+				      struct drm_syncobj_wait *wait,
+				      uint32_t *handles)
+{
+	unsigned long timeout = nsecs_to_jiffies(wait->timeout_ns);
+	struct dma_fence **array;
+	uint32_t i;
+	int ret;
+	uint32_t first = ~0;
+
+	/* Prepare the fence array */
+	array = kcalloc(wait->count_handles,
+			sizeof(struct dma_fence *), GFP_KERNEL);
+
+	if (array == NULL)
+		return -ENOMEM;
+
+	for (i = 0; i < wait->count_handles; i++) {
+		struct dma_fence *fence;
+
+		ret = drm_syncobj_fence_get(file_private, handles[i],
+					    &fence);
+		if (ret)
+			goto err_free_fence_array;
+		else if (fence)
+			array[i] = fence;
+		else { /* NULL, the fence has been already signaled */
+			ret = 1;
+			goto out;
+		}
+	}
+
+	ret = dma_fence_wait_any_timeout(array, wait->count_handles, true, timeout,
+					 &first);
+	if (ret < 0)
+		goto err_free_fence_array;
+out:
+	if (ret > 0)
+		wait->timeout_ns = jiffies_to_nsecs(ret);
+	wait->out_status = (ret > 0);
+	wait->first_signaled = first;
+	/* set return value 0 to indicate success */
+	ret = 0;
+
+err_free_fence_array:
+	for (i = 0; i < wait->count_handles; i++)
+		dma_fence_put(array[i]);
+	kfree(array);
+
+	return ret;
+}
+
+int
+drm_syncobj_wait_ioctl(struct drm_device *dev, void *data,
+		       struct drm_file *file_private)
+{
+	struct drm_syncobj_wait *args = data;
+	uint32_t *handles;
+	int ret = 0;
+
+	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
+		return -ENODEV;
+
+	if (args->flags != 0 && args->flags != DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL)
+		return -EINVAL;
+
+	if (args->count_handles == 0)
+		return 0;
+
+	/* Get the handles from userspace */
+	handles = kmalloc_array(args->count_handles, sizeof(uint32_t),
+				GFP_KERNEL);
+	if (handles == NULL)
+		return -ENOMEM;
+
+	if (copy_from_user(handles,
+			   (void __user *)(unsigned long)(args->handles),
+			   sizeof(uint32_t) * args->count_handles)) {
+		ret = -EFAULT;
+		goto err_free_handles;
+	}
+
+	if (args->flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL)
+		ret = drm_syncobj_wait_all_fences(dev, file_private,
+						  args, handles);
+	else
+		ret = drm_syncobj_wait_any_fence(dev, file_private,
+						 args, handles);
+err_free_handles:
+	kfree(handles);
+
+	return ret;
+}

include/uapi/drm/drm.h +12 -0

index dd0b99c..db9e35e 100644
@@ -716,6 +716,17 @@ struct drm_syncobj_handle {
 	__u32 pad;
 };
 
+/* timeout_ns is relative timeout in nanoseconds */
+#define DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL (1 << 0)
+struct drm_syncobj_wait {
+	__u64 handles;
+	__u64 timeout_ns;
+	__u32 count_handles;
+	__u32 flags;
+	__u32 out_status;
+	__u32 first_signaled; /* on valid when not waiting all */
+};
+
 #if defined(__cplusplus)
 }
 #endif

@@ -838,6 +849,7 @@ extern "C" {
 #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)
+#define DRM_IOCTL_SYNCOBJ_WAIT		DRM_IOWR(0xC3, struct drm_syncobj_wait)
 
 /**
  * Device specific ioctls should only be in their respective headers

Signature · 6 lines

2.9.3

_______________________________________________
dri-devel mailing list
[email protected]
https://lists.freedesktop.org/mailman/listinfo/dri-devel

drivers/gpu/drm/drm_syncobj.c +11 -0

+static int drm_syncobj_wait_all_fences(struct drm_device *dev,
+				       struct drm_file *file_private,
+				       struct drm_syncobj_wait *wait,
+				       uint32_t *handles)
+{
+	uint32_t i;
+	int ret = 0;
+	unsigned long timeout = nsecs_to_jiffies(wait->timeout_ns);
+
+	for (i = 0; i < wait->count_handles; i++) {
+		struct dma_fence *fence;

Quoted 16 lines

drivers/gpu/drm/drm_syncobj.c +16 -0

+static int drm_syncobj_wait_all_fences(struct drm_device *dev,
+				       struct drm_file *file_private,
+				       struct drm_syncobj_wait *wait,
+				       uint32_t *handles)
+{
+	uint32_t i;
+	int ret = 0;
+	unsigned long timeout = nsecs_to_jiffies(wait->timeout_ns);
+
+	for (i = 0; i < wait->count_handles; i++) {
+		struct dma_fence *fence;
+
+		ret = drm_syncobj_fence_get(file_private, handles[i],
+					    &fence);
+		if (ret)
+			return ret;

drivers/gpu/drm/drm_syncobj.c drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data, · line 412

Quoted 5 lines

drivers/gpu/drm/drm_syncobj.c +5 -0

+
+		if (!fence)
+			continue;
+
+		ret = dma_fence_wait_timeout(fence, true, timeout);

Doesn't handle -EINTR yet with timeout. If having a drmIoctl() that can't be tricked into turning a short waiting into an indefinite one is a goal.

-Chris

From: Dave Airlie <[email protected]>

This interface will allow sync object to be used to back Vulkan fences. This API is pretty much the vulkan fence waiting API, and I've ported the code from amdgpu.

v2: accept relative timeout, pass remaining time back to userspace.

Signed-off-by Dave Airlie <[email protected]>

---
 drivers/gpu/drm/drm_internal.h |   2 +
 drivers/gpu/drm/drm_ioctl.c    |   2 +
 drivers/gpu/drm/drm_syncobj.c  | 139 ++++++++++++++++++++++++++++++++++++++++-
 include/uapi/drm/drm.h         |  12 ++++
 4 files changed, 154 insertions(+), 1 deletion(-)

drivers/gpu/drm/drm_internal.h +2 -0

index 44ef903..a508ad9 100644
@@ -156,3 +156,5 @@ 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);
+int drm_syncobj_wait_ioctl(struct drm_device *dev, void *data,
+			   struct drm_file *file_private);

drivers/gpu/drm/drm_ioctl.c +2 -0

index 6da7adc..b142466 100644
@@ -653,6 +653,8 @@ static const struct drm_ioctl_desc drm_ioctls[] = {
 		      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),
+	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_WAIT, drm_syncobj_wait_ioctl,
+		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
 };
 
 #define DRM_CORE_IOCTL_COUNT	ARRAY_SIZE( drm_ioctls )

drivers/gpu/drm/drm_syncobj.c +138 -1

index 835e987..9a8c690 100644
@@ -1,5 +1,7 @@
 /*
  * Copyright 2017 Red Hat
+ * Parts ported from amdgpu (fence wait code).
+ * Copyright 2016 Advanced Micro Devices, Inc.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),

@@ -31,10 +33,13 @@
  * that contain an optional fence. The fence can be updated with a new
  * fence, or be NULL.
  *
+ * syncobj's can be waited upon, where it will wait for the underlying
+ * fence.
+ *
  * 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
+ * TODO: sync_file interactions.
  *
  * Their primary use-case is to implement Vulkan fences and semaphores.
  *

@@ -383,3 +388,135 @@ drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
 	return drm_syncobj_fd_to_handle(file_private, args->fd,
 					&args->handle);
 }
+
+static int drm_syncobj_wait_all_fences(struct drm_device *dev,
+				       struct drm_file *file_private,
+				       struct drm_syncobj_wait *wait,
+				       uint32_t *handles)
+{
+	uint32_t i;
+	int ret = 0;
+	unsigned long timeout = nsecs_to_jiffies(wait->timeout_ns);
+
+	for (i = 0; i < wait->count_handles; i++) {
+		struct dma_fence *fence;
+
+		ret = drm_syncobj_fence_get(file_private, handles[i],
+					    &fence);
+		if (ret)
+			return ret;
+
+		if (!fence)
+			continue;
+
+		ret = dma_fence_wait_timeout(fence, true, timeout);
+
+		dma_fence_put(fence);
+		if (ret < 0)
+			return ret;
+		if (ret == 0)
+			break;
+		timeout = ret;
+	}
+
+	if (ret > 0)
+		wait->timeout_ns = jiffies_to_nsecs(ret);
+	wait->out_status = (ret > 0);
+	wait->first_signaled = 0;
+	return 0;
+}
+
+static int drm_syncobj_wait_any_fence(struct drm_device *dev,
+				      struct drm_file *file_private,
+				      struct drm_syncobj_wait *wait,
+				      uint32_t *handles)
+{
+	unsigned long timeout = nsecs_to_jiffies(wait->timeout_ns);
+	struct dma_fence **array;
+	uint32_t i;
+	int ret;
+	uint32_t first = ~0;
+
+	/* Prepare the fence array */
+	array = kcalloc(wait->count_handles,
+			sizeof(struct dma_fence *), GFP_KERNEL);
+
+	if (array == NULL)
+		return -ENOMEM;
+
+	for (i = 0; i < wait->count_handles; i++) {
+		struct dma_fence *fence;
+
+		ret = drm_syncobj_fence_get(file_private, handles[i],
+					    &fence);
+		if (ret)
+			goto err_free_fence_array;
+		else if (fence)
+			array[i] = fence;
+		else { /* NULL, the fence has been already signaled */
+			ret = 1;
+			goto out;
+		}
+	}
+
+	ret = dma_fence_wait_any_timeout(array, wait->count_handles, true, timeout,
+					 &first);
+	if (ret < 0)
+		goto err_free_fence_array;
+out:
+	if (ret > 0)
+		wait->timeout_ns = jiffies_to_nsecs(ret);
+	wait->out_status = (ret > 0);
+	wait->first_signaled = first;
+	/* set return value 0 to indicate success */
+	ret = 0;
+
+err_free_fence_array:
+	for (i = 0; i < wait->count_handles; i++)
+		dma_fence_put(array[i]);
+	kfree(array);
+
+	return ret;
+}
+
+int
+drm_syncobj_wait_ioctl(struct drm_device *dev, void *data,
+		       struct drm_file *file_private)
+{
+	struct drm_syncobj_wait *args = data;
+	uint32_t *handles;
+	int ret = 0;
+
+	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
+		return -ENODEV;
+
+	if (args->flags != 0 && args->flags != DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL)
+		return -EINVAL;
+
+	if (args->count_handles == 0)
+		return 0;
+
+	/* Get the handles from userspace */
+	handles = kmalloc_array(args->count_handles, sizeof(uint32_t),
+				GFP_KERNEL);
+	if (handles == NULL)
+		return -ENOMEM;
+
+	if (copy_from_user(handles,
+			   (void __user *)(unsigned long)(args->handles),
+			   sizeof(uint32_t) * args->count_handles)) {
+		ret = -EFAULT;
+		goto err_free_handles;
+	}
+
+	if (args->flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL)
+		ret = drm_syncobj_wait_all_fences(dev, file_private,
+						  args, handles);
+	else
+		ret = drm_syncobj_wait_any_fence(dev, file_private,
+						 args, handles);
+err_free_handles:
+	kfree(handles);
+
+	return ret;
+}

include/uapi/drm/drm.h +12 -0

index dd0b99c..db9e35e 100644
@@ -716,6 +716,17 @@ struct drm_syncobj_handle {
 	__u32 pad;
 };
 
+/* timeout_ns is relative timeout in nanoseconds */
+#define DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL (1 << 0)
+struct drm_syncobj_wait {
+	__u64 handles;
+	__u64 timeout_ns;
+	__u32 count_handles;
+	__u32 flags;
+	__u32 out_status;
+	__u32 first_signaled; /* on valid when not waiting all */
+};
+
 #if defined(__cplusplus)
 }
 #endif

@@ -838,6 +849,7 @@ extern "C" {
 #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)
+#define DRM_IOCTL_SYNCOBJ_WAIT		DRM_IOWR(0xC3, struct drm_syncobj_wait)
 
 /**
  * Device specific ioctls should only be in their respective headers

Signature · 6 lines

2.9.3

_______________________________________________
dri-devel mailing list
[email protected]
https://lists.freedesktop.org/mailman/listinfo/dri-devel

From: Dave Airlie <[email protected]>

This interface allows importing the fence from a sync_file into an existing drm sync object, or exporting the fence attached to an existing drm sync object into a new sync file object.

This should only be used to interact with sync files where necessary.

Signed-off-by Dave Airlie <[email protected]>

---
 drivers/gpu/drm/drm_syncobj.c | 56 +++++++++++++++++++++++++++++++++++++++++++
 include/uapi/drm/drm.h        |  6 +++--
 2 files changed, 60 insertions(+), 2 deletions(-)

drivers/gpu/drm/drm_syncobj.c +8 -0

index 9a8c690..69ef20a 100644
@@ -52,6 +52,7 @@
 #include <linux/file.h>
 #include <linux/fs.h>
 #include <linux/anon_inodes.h>
+#include <linux/sync_file.h>
 
 #include "drm_internal.h"
 #include <drm/drm_syncobj.h>

@@ -290,6 +291,48 @@ static int drm_syncobj_fd_to_handle(struct drm_file *file_private,
 	return 0;
 }
 
+int drm_syncobj_import_sync_file_fence(struct drm_file *file_private,
+				       int fd, int handle)
+{
+	struct dma_fence *fence = sync_file_get_fence(fd);
+	if (!fence)
+		return -EINVAL;
+

drivers/gpu/drm/drm_syncobj.c +25 -0

+
+	if (fd < 0)
+		return fd;
+
+	ret = drm_syncobj_fence_get(file_private, handle, &fence);
+	if (ret)
+		goto err_put_fd;
+
+	sync_file = sync_file_create(fence);
+	if (!sync_file) {
+		ret = -EINVAL;
+		goto err_fence_put;
+	}
+
+	fd_install(fd, sync_file->file);
+
+	dma_fence_put(fence);
+	*p_fd = fd;
+	return 0;
+err_fence_put:
+	dma_fence_put(fence);
+err_put_fd:
+	put_unused_fd(fd);
+	return ret;
+}
 /**
  * drm_syncobj_open - initalizes syncobj file-private structures at devnode open time
  * @dev: drm_device which is being opened by userspace

drivers/gpu/drm/drm_syncobj.c +10 -0

+	else if (args->flags)
+		return -EINVAL;
+
 	return drm_syncobj_handle_to_fd(file_private, args->handle,
 					&args->fd);
 }

@@ -385,6 +434,13 @@ drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 		return -ENODEV;
 
+	if (args->flags & DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE_FENCE)
+		return drm_syncobj_import_sync_file_fence(file_private,
+							  args->fd,
+							  args->handle);
+	else if (args->flags)
+		return -EINVAL;
+
 	return drm_syncobj_fd_to_handle(file_private, args->fd,
 					&args->handle);
 }

include/uapi/drm/drm.h +1 -0

index db9e35e..d0e05f4 100644
@@ -707,13 +707,15 @@ struct drm_syncobj_destroy {
 	__u32 pad;
 };
 
+#define DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE_FENCE (1 << 0)

include/uapi/drm/drm.h +0 -0

 };
 
 /* timeout_ns is relative timeout in nanoseconds */

Signature · 6 lines

2.9.3

_______________________________________________
dri-devel mailing list
[email protected]
https://lists.freedesktop.org/mailman/listinfo/dri-devel

From: Dave Airlie <[email protected]>

This interface allows importing the fence from a sync_file into an existing drm sync object, or exporting the fence attached to an existing drm sync object into a new sync file object.

This should only be used to interact with sync files where necessary.

Signed-off-by Dave Airlie <[email protected]>

---
 drivers/gpu/drm/drm_syncobj.c | 56 +++++++++++++++++++++++++++++++++++++++++++
 include/uapi/drm/drm.h        |  6 +++--
 2 files changed, 60 insertions(+), 2 deletions(-)

drivers/gpu/drm/drm_syncobj.c +56 -0

index 9a8c690..69ef20a 100644
@@ -52,6 +52,7 @@
 #include <linux/file.h>
 #include <linux/fs.h>
 #include <linux/anon_inodes.h>
+#include <linux/sync_file.h>
 
 #include "drm_internal.h"
 #include <drm/drm_syncobj.h>

@@ -290,6 +291,48 @@ static int drm_syncobj_fd_to_handle(struct drm_file *file_private,
 	return 0;
 }
 
+int drm_syncobj_import_sync_file_fence(struct drm_file *file_private,
+				       int fd, int handle)
+{
+	struct dma_fence *fence = sync_file_get_fence(fd);
+	if (!fence)
+		return -EINVAL;
+
+	return drm_syncobj_replace_fence(file_private, handle, fence);
+}
+
+int drm_syncobj_export_sync_file(struct drm_file *file_private,
+				 int handle, int *p_fd)
+{
+	int ret;
+	struct dma_fence *fence;
+	struct sync_file *sync_file;
+	int fd = get_unused_fd_flags(O_CLOEXEC);
+
+	if (fd < 0)
+		return fd;
+
+	ret = drm_syncobj_fence_get(file_private, handle, &fence);
+	if (ret)
+		goto err_put_fd;
+
+	sync_file = sync_file_create(fence);
+	if (!sync_file) {
+		ret = -EINVAL;
+		goto err_fence_put;
+	}
+
+	fd_install(fd, sync_file->file);
+
+	dma_fence_put(fence);
+	*p_fd = fd;
+	return 0;
+err_fence_put:
+	dma_fence_put(fence);
+err_put_fd:
+	put_unused_fd(fd);
+	return ret;
+}
 /**
  * drm_syncobj_open - initalizes syncobj file-private structures at devnode open time
  * @dev: drm_device which is being opened by userspace

@@ -372,6 +415,12 @@ drm_syncobj_handle_to_fd_ioctl(struct drm_device *dev, void *data,
 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 		return -ENODEV;
 
+	if (args->flags & DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_FENCE_SYNC_FILE)
+		return drm_syncobj_export_sync_file(file_private, args->handle,
+						    &args->fd);
+	else if (args->flags)
+		return -EINVAL;
+
 	return drm_syncobj_handle_to_fd(file_private, args->handle,
 					&args->fd);
 }

@@ -385,6 +434,13 @@ drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
 	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
 		return -ENODEV;
 
+	if (args->flags & DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE_FENCE)
+		return drm_syncobj_import_sync_file_fence(file_private,
+							  args->fd,
+							  args->handle);
+	else if (args->flags)
+		return -EINVAL;
+
 	return drm_syncobj_fd_to_handle(file_private, args->fd,
 					&args->handle);
 }

include/uapi/drm/drm.h +4 -2

index db9e35e..d0e05f4 100644
@@ -707,13 +707,15 @@ struct drm_syncobj_destroy {
 	__u32 pad;
 };
 
+#define DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE_FENCE (1 << 0)
+#define DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_FENCE_SYNC_FILE (1 << 0)
 struct drm_syncobj_handle {
 	__u32 handle;
 	/** Flags.. only applicable for handle->fd */
-	__u32 flags;
+	__u32 fd_flags;
 
 	__s32 fd;
-	__u32 pad;
+	__u32 flags;
 };
 
 /* timeout_ns is relative timeout in nanoseconds */

Signature · 6 lines

2.9.3

_______________________________________________
dri-devel mailing list
[email protected]
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Quoting Dave Airlie (2017-05-12 01:34:55)

drivers/gpu/drm/drm_syncobj.c drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data, · line 442

Quoted 10 lines

drivers/gpu/drm/drm_syncobj.c +6 -0

@@ -385,6 +434,13 @@ drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
        if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
                return -ENODEV;
 
+       if (args->flags & DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE_FENCE)
+               return drm_syncobj_import_sync_file_fence(file_private,
+                                                         args->fd,
+                                                         args->handle);
+       else if (args->flags)
+               return -EINVAL;

Argh, what I missed before was that importing from a sync_file reuses the handle, but importing from a syncobj fd creates a new handle.

Just venting my ocd. It would be nice if the interface was consistent, and I can see arguments for both approaches (just not a good argument as to why they should differ). A compromise would be a flag to create/reuse handle (or if handle=0, create, if handle!=0 resuse).

Quoted 15 lines

Quoting Dave Airlie (2017-05-12 01:34:55)

drivers/gpu/drm/drm_syncobj.c drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data, · line 442

Quoted 10 lines

drivers/gpu/drm/drm_syncobj.c +6 -0

@@ -385,6 +434,13 @@ drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
        if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
                return -ENODEV;
 
+       if (args->flags & DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE_FENCE)
+               return drm_syncobj_import_sync_file_fence(file_private,
+                                                         args->fd,
+                                                         args->handle);
+       else if (args->flags)
+               return -EINVAL;

Argh, what I missed before was that importing from a sync_file reuses the handle, but importing from a syncobj fd creates a new handle.

Quoted 4 lines

Just venting my ocd. It would be nice if the interface was consistent, and I can see arguments for both approaches (just not a good argument as to why they should differ). A compromise would be a flag to create/reuse handle (or if handle=0, create, if handle!=0 resuse).

The interface is consistent for the objects.

With a sync_fd import you import the state into an existing syncobj.

With a syncobj import you import the object into the current process state (so get a new handle).

I can't think of a use case for anything else, maybe having a sync_fd state imported into a new syncobj? but not sure it really helps.

Userspace should be using different paths to get to these interfaces.

Quoting Dave Airlie (2017-08-04 00:01:10)

Quoted 25 lines · Chris Wilson

Quoted 15 lines

Quoting Dave Airlie (2017-05-12 01:34:55)

Review drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data, · line 442

Quoted 10 lines

(quoted diff) +6 -0

@@ -385,6 +434,13 @@ drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
        if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
                return -ENODEV;
 
+       if (args->flags & DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE_FENCE)
+               return drm_syncobj_import_sync_file_fence(file_private,
+                                                         args->fd,
+                                                         args->handle);
+       else if (args->flags)
+               return -EINVAL;

Argh, what I missed before was that importing from a sync_file reuses the handle, but importing from a syncobj fd creates a new handle.

Quoted 4 lines

Just venting my ocd. It would be nice if the interface was consistent, and I can see arguments for both approaches (just not a good argument as to why they should differ). A compromise would be a flag to create/reuse handle (or if handle=0, create, if handle!=0 resuse).

The interface is consistent for the objects.

With a sync_fd import you import the state into an existing syncobj.

Quoted 2 lines

With a syncobj import you import the object into the current process state (so get a new handle).

You can say the same for either path though, e.g.

With a sync fd import you import the fence into the current process state (so get a new handle).