text: /*
   * 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"),
   * 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 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.
   *
   * 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 <linux/sync_file.h>
  #include <linux/sched/signal.h>
  
  #include "drm_internal.h"
  #include <drm/drm_syncobj.h>
  
  /**
   * drm_syncobj_find - lookup and reference a sync object.
   * @file_private: drm file private pointer
   * @handle: sync object handle to lookup.
   *
   * Returns a reference to the syncobj pointed to by handle or NULL.
   */
  struct drm_syncobj *drm_syncobj_find(struct drm_file *file_private,
  				     u32 handle)
  {
  	struct drm_syncobj *syncobj;
  
  	lockmgr(&file_private->syncobj_table_lock, LK_EXCLUSIVE);
  
  	/* Check if we currently have a reference on the object */
  	syncobj = idr_find(&file_private->syncobj_idr, handle);
  	if (syncobj)
  		drm_syncobj_get(syncobj);
  
  	lockmgr(&file_private->syncobj_table_lock, LK_RELEASE);
  
  	return syncobj;
  }
  EXPORT_SYMBOL(drm_syncobj_find);
  
  static void drm_syncobj_add_callback_locked(struct drm_syncobj *syncobj,
  					    struct drm_syncobj_cb *cb,
  					    drm_syncobj_func_t func)
  {
  	cb->func = func;
  	list_add_tail(&cb->node, &syncobj->cb_list);
  }
  
  #if 0
  static int drm_syncobj_fence_get_or_add_callback(struct drm_syncobj *syncobj,
  						 struct dma_fence **fence,
  						 struct drm_syncobj_cb *cb,
  						 drm_syncobj_func_t func)
  {
  	int ret;
  
  	*fence = drm_syncobj_fence_get(syncobj);
  	if (*fence)
  		return 1;
  
  	lockmgr(&syncobj->lock, LK_EXCLUSIVE);
  	/* We've already tried once to get a fence and failed.  Now that we
  	 * have the lock, try one more time just to be sure we don't add a
  	 * callback when a fence has already been set.
  	 */
  	if (syncobj->fence) {
  		*fence = dma_fence_get(syncobj->fence);
  		ret = 1;
  	} else {
  		*fence = NULL;
  		drm_syncobj_add_callback_locked(syncobj, cb, func);
  		ret = 0;
  	}
  	lockmgr(&syncobj->lock, LK_RELEASE);
  
  	return ret;
  }
  #endif
  
  /**
   * drm_syncobj_add_callback - adds a callback to syncobj::cb_list
   * @syncobj: Sync object to which to add the callback
   * @cb: Callback to add
   * @func: Func to use when initializing the drm_syncobj_cb struct
   *
   * This adds a callback to be called next time the fence is replaced
   */
  void drm_syncobj_add_callback(struct drm_syncobj *syncobj,
  			      struct drm_syncobj_cb *cb,
  			      drm_syncobj_func_t func)
  {
  	lockmgr(&syncobj->lock, LK_EXCLUSIVE);
  	drm_syncobj_add_callback_locked(syncobj, cb, func);
  	lockmgr(&syncobj->lock, LK_RELEASE);
  }
  EXPORT_SYMBOL(drm_syncobj_add_callback);
  
  /**
   * drm_syncobj_add_callback - removes a callback to syncobj::cb_list
   * @syncobj: Sync object from which to remove the callback
   * @cb: Callback to remove
   */
  void drm_syncobj_remove_callback(struct drm_syncobj *syncobj,
  				 struct drm_syncobj_cb *cb)
  {
  	lockmgr(&syncobj->lock, LK_EXCLUSIVE);
  	list_del_init(&cb->node);
  	lockmgr(&syncobj->lock, LK_RELEASE);
  }
  EXPORT_SYMBOL(drm_syncobj_remove_callback);
  
  /**
   * drm_syncobj_replace_fence - replace fence in a sync object.
   * @syncobj: Sync object to replace fence in
   * @fence: fence to install in sync file.
   *
   * This replaces the fence on a sync object.
   */
  void drm_syncobj_replace_fence(struct drm_syncobj *syncobj,
  			       struct dma_fence *fence)
  {
  	struct dma_fence *old_fence;
  	struct drm_syncobj_cb *cur, *tmp;
  
  	if (fence)
  		dma_fence_get(fence);
  
  	lockmgr(&syncobj->lock, LK_EXCLUSIVE);
  
  	old_fence = syncobj->fence;
  	syncobj->fence = fence;
  
  	if (fence != old_fence) {
  		list_for_each_entry_safe(cur, tmp, &syncobj->cb_list, node) {
  			list_del_init(&cur->node);
  			cur->func(syncobj, cur);
  		}
  	}
  
  	lockmgr(&syncobj->lock, LK_RELEASE);
  
  	dma_fence_put(old_fence);
  }
  EXPORT_SYMBOL(drm_syncobj_replace_fence);
  
  struct drm_syncobj_null_fence {
  	struct dma_fence base;
  	spinlock_t lock;
  };
  
  static const char *drm_syncobj_null_fence_get_name(struct dma_fence *fence)
  {
          return "syncobjnull";
  }
  
  static bool drm_syncobj_null_fence_enable_signaling(struct dma_fence *fence)
  {
      dma_fence_enable_sw_signaling(fence);
      return !dma_fence_is_signaled(fence);
  }
  
  static const struct dma_fence_ops drm_syncobj_null_fence_ops = {
  	.get_driver_name = drm_syncobj_null_fence_get_name,
  	.get_timeline_name = drm_syncobj_null_fence_get_name,
  	.enable_signaling = drm_syncobj_null_fence_enable_signaling,
  	.wait = dma_fence_default_wait,
  	.release = NULL,
  };
  
  static int drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)
  {
  	struct drm_syncobj_null_fence *fence;
  	fence = kzalloc(sizeof(*fence), GFP_KERNEL);
  	if (fence == NULL)
  		return -ENOMEM;
  
  	lockinit(&fence->lock, "dsofl", 0, 0);
  	dma_fence_init(&fence->base, &drm_syncobj_null_fence_ops,
  		       &fence->lock, 0, 0);
  	dma_fence_signal(&fence->base);
  
  	drm_syncobj_replace_fence(syncobj, &fence->base);
  
  	dma_fence_put(&fence->base);
  
  	return 0;
  }
  
  int drm_syncobj_find_fence(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 = drm_syncobj_fence_get(syncobj);
  	if (!*fence) {
  		ret = -EINVAL;
  	}
  	drm_syncobj_put(syncobj);
  	return ret;
  }
  EXPORT_SYMBOL(drm_syncobj_find_fence);
  
  /**
   * drm_syncobj_free - free a sync object.
   * @kref: kref to free.
   *
   * Only to be called from kref_put in drm_syncobj_put.
   */
  void drm_syncobj_free(struct kref *kref)
  {
  	struct drm_syncobj *syncobj = container_of(kref,
  						   struct drm_syncobj,
  						   refcount);
  	drm_syncobj_replace_fence(syncobj, NULL);
  	kfree(syncobj);
  }
  EXPORT_SYMBOL(drm_syncobj_free);
  
  /**
   * drm_syncobj_create - create a new syncobj
   * @out_syncobj: returned syncobj
   * @flags: DRM_SYNCOBJ_* flags
   * @fence: if non-NULL, the syncobj will represent this fence
   */
  int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags,
  		       struct dma_fence *fence)
  {
  	int ret;
  	struct drm_syncobj *syncobj;
  
  	syncobj = kzalloc(sizeof(struct drm_syncobj), GFP_KERNEL);
  	if (!syncobj)
  		return -ENOMEM;
  
  	kref_init(&syncobj->refcount);
  	INIT_LIST_HEAD(&syncobj->cb_list);
  	lockinit(&syncobj->lock, "dsol", 0, 0);
  
  	if (flags & DRM_SYNCOBJ_CREATE_SIGNALED) {
  		ret = drm_syncobj_assign_null_handle(syncobj);
  		if (ret < 0) {
  			drm_syncobj_put(syncobj);
  			return ret;
  		}
  	}
  
  	if (fence)
  		drm_syncobj_replace_fence(syncobj, fence);
  
  	*out_syncobj = syncobj;
  	return 0;
  }
  EXPORT_SYMBOL(drm_syncobj_create);
  
  /**
   * drm_syncobj_get_handle - get a handle from a syncobj
   */
  int drm_syncobj_get_handle(struct drm_file *file_private,
  			   struct drm_syncobj *syncobj, u32 *handle)
  {
  	int ret;
  
  	/* take a reference to put in the idr */
  	drm_syncobj_get(syncobj);
  
  	idr_preload(GFP_KERNEL);
  	lockmgr(&file_private->syncobj_table_lock, LK_EXCLUSIVE);
  	ret = idr_alloc(&file_private->syncobj_idr, syncobj, 1, 0, GFP_NOWAIT);
  	lockmgr(&file_private->syncobj_table_lock, LK_RELEASE);
  
  	idr_preload_end();
  
  	if (ret < 0) {
  		drm_syncobj_put(syncobj);
  		return ret;
  	}
  
  	*handle = ret;
  	return 0;
  }
  EXPORT_SYMBOL(drm_syncobj_get_handle);
  
  static int drm_syncobj_create_as_handle(struct drm_file *file_private,
  					u32 *handle, uint32_t flags)
  {
  	int ret;
  	struct drm_syncobj *syncobj;
  
  	ret = drm_syncobj_create(&syncobj, flags, NULL);
  	if (ret)
  		return ret;
  
  	ret = drm_syncobj_get_handle(file_private, syncobj, handle);
  	drm_syncobj_put(syncobj);
  	return ret;
  }
  
  static int drm_syncobj_destroy(struct drm_file *file_private,
  			       u32 handle)
  {
  	struct drm_syncobj *syncobj;
  
  	lockmgr(&file_private->syncobj_table_lock, LK_EXCLUSIVE);
  	syncobj = idr_remove(&file_private->syncobj_idr, handle);
  	lockmgr(&file_private->syncobj_table_lock, LK_RELEASE);
  
  	if (!syncobj)
  		return -EINVAL;
  
  	drm_syncobj_put(syncobj);
  	return 0;
  }
  
  #if 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,
  };
  #endif
  
  int drm_syncobj_get_fd(struct drm_syncobj *syncobj, int *p_fd)
  {
  	struct file *file;
  	int fd;
  
  	fd = get_unused_fd_flags(O_CLOEXEC);
  	if (fd < 0)
  		return fd;
  
  #if 0
  	file = anon_inode_getfile("syncobj_file",
  				  &drm_syncobj_file_fops,
  				  syncobj, 0);
  	if (IS_ERR(file)) {
  		put_unused_fd(fd);
  		return PTR_ERR(file);
   	}
  #else
  	return -EINVAL;
  #endif
  
  	drm_syncobj_get(syncobj);
  	fd_install(fd, file);
  
  	*p_fd = fd;
  	return 0;
  }
  EXPORT_SYMBOL(drm_syncobj_get_fd);
  
  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;
  
  	if (!syncobj)
  		return -EINVAL;
  
  	ret = drm_syncobj_get_fd(syncobj, p_fd);
  	drm_syncobj_put(syncobj);
  	return ret;
  }
  
  #if 0
  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;
  };
  #endif
  
  static int drm_syncobj_fd_to_handle(struct drm_file *file_private,
  				    int fd, u32 *handle)
  {
  #if 0
  	struct drm_syncobj *syncobj;
  	struct file *file;
  	int ret;
  
  	file = fget(fd);
  	if (!file)
  		return -EINVAL;
  
  	if (file->f_op != &drm_syncobj_file_fops) {
  		fput(file);
  		return -EINVAL;
  	}
  
  	/* take a reference to put in the idr */
  	syncobj = file->private_data;
  	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) {
  		*handle = ret;
  		ret = 0;
  	} else
  		drm_syncobj_put(syncobj);
  
  	fput(file);
  	return ret;
  #endif
  	return -EINVAL;
  }
  
  static 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);
  	struct drm_syncobj *syncobj;
  
  	if (!fence)
  		return -EINVAL;
  
  	syncobj = drm_syncobj_find(file_private, handle);
  	if (!syncobj) {
  		dma_fence_put(fence);
  		return -ENOENT;
  	}
  
  	drm_syncobj_replace_fence(syncobj, fence);
  	dma_fence_put(fence);
  	drm_syncobj_put(syncobj);
  	return 0;
  }
  
  static 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_find_fence(file_private, handle, &fence);
  	if (ret)
  		goto err_put_fd;
  
  	sync_file = sync_file_create(fence);
  
  	dma_fence_put(fence);
  
  	if (!sync_file) {
  		ret = -EINVAL;
  		goto err_put_fd;
  	}
  
  	fd_install(fd, sync_file->file);
  
  	*p_fd = fd;
  	return 0;
  err_put_fd:
  	put_unused_fd(fd);
  	return ret;
  }
  /**
   * drm_syncobj_open - initalizes syncobj file-private structures at devnode open time
   * @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);
  	lockinit(&file_private->syncobj_table_lock, "dsotl", 0, 0);
  }
  
  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
   * @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 & ~DRM_SYNCOBJ_CREATE_SIGNALED)
  		return -EINVAL;
  
  	return drm_syncobj_create_as_handle(file_private,
  					    &args->handle, args->flags);
  }
  
  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;
  
  	if (args->pad)
  		return -EINVAL;
  
  	if (args->flags != 0 &&
  	    args->flags != DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE)
  		return -EINVAL;
  
  	if (args->flags & DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE)
  		return drm_syncobj_export_sync_file(file_private, args->handle,
  						    &args->fd);
  
  	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;
  
  	if (args->pad)
  		return -EINVAL;
  
  	if (args->flags != 0 &&
  	    args->flags != DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE)
  		return -EINVAL;
  
  	if (args->flags & DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE)
  		return drm_syncobj_import_sync_file_fence(file_private,
  							  args->fd,
  							  args->handle);
  
  	return drm_syncobj_fd_to_handle(file_private, args->fd,
  					&args->handle);
  }
  
  #if 0
  struct syncobj_wait_entry {
  	struct task_struct *task;
  	struct dma_fence *fence;
  	struct dma_fence_cb fence_cb;
  	struct drm_syncobj_cb syncobj_cb;
  };
  
  static void syncobj_wait_fence_func(struct dma_fence *fence,
  				    struct dma_fence_cb *cb)
  {
  	struct syncobj_wait_entry *wait =
  		container_of(cb, struct syncobj_wait_entry, fence_cb);
  
  	wake_up_process(wait->task);
  }
  
  static void syncobj_wait_syncobj_func(struct drm_syncobj *syncobj,
  				      struct drm_syncobj_cb *cb)
  {
  	struct syncobj_wait_entry *wait =
  		container_of(cb, struct syncobj_wait_entry, syncobj_cb);
  
  	/* This happens inside the syncobj lock */
  	wait->fence = dma_fence_get(syncobj->fence);
  	wake_up_process(wait->task);
  }
  
  static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs,
  						  uint32_t count,
  						  uint32_t flags,
  						  signed long timeout,
  						  uint32_t *idx)
  {
  	struct syncobj_wait_entry *entries;
  	struct dma_fence *fence;
  	signed long ret;
  	uint32_t signaled_count, i;
  
  	entries = kcalloc(count, sizeof(*entries), GFP_KERNEL);
  	if (!entries)
  		return -ENOMEM;
  
  	/* Walk the list of sync objects and initialize entries.  We do
  	 * this up-front so that we can properly return -EINVAL if there is
  	 * a syncobj with a missing fence and then never have the chance of
  	 * returning -EINVAL again.
  	 */
  	signaled_count = 0;
  	for (i = 0; i < count; ++i) {
  		entries[i].task = current;
  		entries[i].fence = drm_syncobj_fence_get(syncobjs[i]);
  		if (!entries[i].fence) {
  			if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) {
  				continue;
  			} else {
  				ret = -EINVAL;
  				goto cleanup_entries;
  			}
  		}
  
  		if (dma_fence_is_signaled(entries[i].fence)) {
  			if (signaled_count == 0 && idx)
  				*idx = i;
  			signaled_count++;
  		}
  	}
  
  	/* Initialize ret to the max of timeout and 1.  That way, the
  	 * default return value indicates a successful wait and not a
  	 * timeout.
  	 */
  	ret = max_t(signed long, timeout, 1);
  
  	if (signaled_count == count ||
  	    (signaled_count > 0 &&
  	     !(flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL)))
  		goto cleanup_entries;
  
  	/* There's a very annoying laxness in the dma_fence API here, in
  	 * that backends are not required to automatically report when a
  	 * fence is signaled prior to fence->ops->enable_signaling() being
  	 * called.  So here if we fail to match signaled_count, we need to
  	 * fallthough and try a 0 timeout wait!
  	 */
  
  	if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) {
  		for (i = 0; i < count; ++i) {
  			drm_syncobj_fence_get_or_add_callback(syncobjs[i],
  							      &entries[i].fence,
  							      &entries[i].syncobj_cb,
  							      syncobj_wait_syncobj_func);
  		}
  	}
  
  	do {
  		set_current_state(TASK_INTERRUPTIBLE);
  
  		signaled_count = 0;
  		for (i = 0; i < count; ++i) {
  			fence = entries[i].fence;
  			if (!fence)
  				continue;
  
  			if (dma_fence_is_signaled(fence) ||
  			    (!entries[i].fence_cb.func &&
  			     dma_fence_add_callback(fence,
  						    &entries[i].fence_cb,
  						    syncobj_wait_fence_func))) {
  				/* The fence has been signaled */
  				if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL) {
  					signaled_count++;
  				} else {
  					if (idx)
  						*idx = i;
  					goto done_waiting;
  				}
  			}
  		}
  
  		if (signaled_count == count)
  			goto done_waiting;
  
  		if (timeout == 0) {
  			/* If we are doing a 0 timeout wait and we got
  			 * here, then we just timed out.
  			 */
  			ret = 0;
  			goto done_waiting;
  		}
  
  		ret = schedule_timeout(ret);
  
  		if (ret > 0 && signal_pending(current))
  			ret = -ERESTARTSYS;
  	} while (ret > 0);
  
  done_waiting:
  	__set_current_state(TASK_RUNNING);
  
  cleanup_entries:
  	for (i = 0; i < count; ++i) {
  		if (entries[i].syncobj_cb.func)
  			drm_syncobj_remove_callback(syncobjs[i],
  						    &entries[i].syncobj_cb);
  		if (entries[i].fence_cb.func)
  			dma_fence_remove_callback(entries[i].fence,
  						  &entries[i].fence_cb);
  		dma_fence_put(entries[i].fence);
  	}
  	kfree(entries);
  
  	return ret;
  }
  
  /**
   * drm_timeout_abs_to_jiffies - calculate jiffies timeout from absolute value
   *
   * @timeout_nsec: timeout nsec component in ns, 0 for poll
   *
   * Calculate the timeout in jiffies from an absolute time in sec/nsec.
   */
  static signed long drm_timeout_abs_to_jiffies(int64_t timeout_nsec)
  {
  	ktime_t abs_timeout, now;
  	u64 timeout_ns, timeout_jiffies64;
  
  	/* make 0 timeout means poll - absolute 0 doesn't seem valid */
  	if (timeout_nsec == 0)
  		return 0;
  
  	abs_timeout = ns_to_ktime(timeout_nsec);
  	now = ktime_get();
  
  	if (!ktime_after(abs_timeout, now))
  		return 0;
  
  	timeout_ns = ktime_to_ns(ktime_sub(abs_timeout, now));
  
  	timeout_jiffies64 = nsecs_to_jiffies64(timeout_ns);
  	/*  clamp timeout to avoid infinite timeout */
  	if (timeout_jiffies64 >= MAX_SCHEDULE_TIMEOUT - 1)
  		return MAX_SCHEDULE_TIMEOUT - 1;
  
  	return timeout_jiffies64 + 1;
  }
  
  static int drm_syncobj_array_wait(struct drm_device *dev,
  				  struct drm_file *file_private,
  				  struct drm_syncobj_wait *wait,
  				  struct drm_syncobj **syncobjs)
  {
  	signed long timeout = drm_timeout_abs_to_jiffies(wait->timeout_nsec);
  	signed long ret = 0;
  	uint32_t first = ~0;
  
  	ret = drm_syncobj_array_wait_timeout(syncobjs,
  					     wait->count_handles,
  					     wait->flags,
  					     timeout, &first);
  	if (ret < 0)
  		return ret;
  
  	wait->first_signaled = first;
  	if (ret == 0)
  		return -ETIME;
  	return 0;
  }
  #endif
  
  static int drm_syncobj_array_find(struct drm_file *file_private,
  				  void __user *user_handles,
  				  uint32_t count_handles,
  				  struct drm_syncobj ***syncobjs_out)
  {
  	uint32_t i, *handles;
  	struct drm_syncobj **syncobjs;
  	int ret;
  
  	handles = kmalloc_array(count_handles, sizeof(*handles), GFP_KERNEL);
  	if (handles == NULL)
  		return -ENOMEM;
  
  	if (copy_from_user(handles, user_handles,
  			   sizeof(uint32_t) * count_handles)) {
  		ret = -EFAULT;
  		goto err_free_handles;
  	}
  
  	syncobjs = kmalloc_array(count_handles, sizeof(*syncobjs), GFP_KERNEL);
  	if (syncobjs == NULL) {
  		ret = -ENOMEM;
  		goto err_free_handles;
  	}
  
  	for (i = 0; i < count_handles; i++) {
  		syncobjs[i] = drm_syncobj_find(file_private, handles[i]);
  		if (!syncobjs[i]) {
  			ret = -ENOENT;
  			goto err_put_syncobjs;
  		}
  	}
  
  	kfree(handles);
  	*syncobjs_out = syncobjs;
  	return 0;
  
  err_put_syncobjs:
  	while (i-- > 0)
  		drm_syncobj_put(syncobjs[i]);
  	kfree(syncobjs);
  err_free_handles:
  	kfree(handles);
  
  	return ret;
  }
  
  static void drm_syncobj_array_free(struct drm_syncobj **syncobjs,
  				   uint32_t count)
  {
  	uint32_t i;
  	for (i = 0; i < count; i++)
  		drm_syncobj_put(syncobjs[i]);
  	kfree(syncobjs);
  }
  
  int
  drm_syncobj_wait_ioctl(struct drm_device *dev, void *data,
  		       struct drm_file *file_private)
  {
  #if 0
  	struct drm_syncobj_wait *args = data;
  	struct drm_syncobj **syncobjs;
  	int ret = 0;
  
  	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
  		return -ENODEV;
  
  	if (args->flags & ~(DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL |
  			    DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT))
  		return -EINVAL;
  
  	if (args->count_handles == 0)
  		return -EINVAL;
  
  	ret = drm_syncobj_array_find(file_private,
  				     u64_to_user_ptr(args->handles),
  				     args->count_handles,
  				     &syncobjs);
  	if (ret < 0)
  		return ret;
  
  	ret = drm_syncobj_array_wait(dev, file_private,
  				     args, syncobjs);
  
  	drm_syncobj_array_free(syncobjs, args->count_handles);
  
  	return ret;
  #endif
  	return -EINVAL;
  }
  
  int
  drm_syncobj_reset_ioctl(struct drm_device *dev, void *data,
  			struct drm_file *file_private)
  {
  	struct drm_syncobj_array *args = data;
  	struct drm_syncobj **syncobjs;
  	uint32_t i;
  	int ret;
  
  	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
  		return -ENODEV;
  
  	if (args->pad != 0)
  		return -EINVAL;
  
  	if (args->count_handles == 0)
  		return -EINVAL;
  
  	ret = drm_syncobj_array_find(file_private,
  				     u64_to_user_ptr(args->handles),
  				     args->count_handles,
  				     &syncobjs);
  	if (ret < 0)
  		return ret;
  
  	for (i = 0; i < args->count_handles; i++)
  		drm_syncobj_replace_fence(syncobjs[i], NULL);
  
  	drm_syncobj_array_free(syncobjs, args->count_handles);
  
  	return 0;
  }
  
  int
  drm_syncobj_signal_ioctl(struct drm_device *dev, void *data,
  			 struct drm_file *file_private)
  {
  	struct drm_syncobj_array *args = data;
  	struct drm_syncobj **syncobjs;
  	uint32_t i;
  	int ret;
  
  	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
  		return -ENODEV;
  
  	if (args->pad != 0)
  		return -EINVAL;
  
  	if (args->count_handles == 0)
  		return -EINVAL;
  
  	ret = drm_syncobj_array_find(file_private,
  				     u64_to_user_ptr(args->handles),
  				     args->count_handles,
  				     &syncobjs);
  	if (ret < 0)
  		return ret;
  
  	for (i = 0; i < args->count_handles; i++) {
  		ret = drm_syncobj_assign_null_handle(syncobjs[i]);
  		if (ret < 0)
  			break;
  	}
  
  	drm_syncobj_array_free(syncobjs, args->count_handles);
  
  	return ret;
  }
  