[PATCH 3/9] drm/syncobj: add support for timeline point wait v8

Lionel Landwerlin lionel.g.landwerlin at intel.com
Mon Mar 18 16:59:31 UTC 2019


On 15/03/2019 12:09, Chunming Zhou wrote:
> points array is one-to-one match with syncobjs array.
> v2:
> add seperate ioctl for timeline point wait, otherwise break uapi.
> v3:
> userspace can specify two kinds waits::
> a. Wait for time point to be completed.
> b. and wait for time point to become available
> v4:
> rebase
> v5:
> add comment for xxx_WAIT_AVAILABLE
> v6: rebase and rework on new container
> v7: drop _WAIT_COMPLETED, it is the default anyway
> v8: correctly handle garbage collected fences
>
> Signed-off-by: Chunming Zhou <david1.zhou at amd.com>
> Signed-off-by: Christian König <christian.koenig at amd.com>
> Cc: Daniel Rakos <Daniel.Rakos at amd.com>
> Cc: Jason Ekstrand <jason at jlekstrand.net>
> Cc: Bas Nieuwenhuizen <bas at basnieuwenhuizen.nl>
> Cc: Dave Airlie <airlied at redhat.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>   drivers/gpu/drm/drm_internal.h |   2 +
>   drivers/gpu/drm/drm_ioctl.c    |   2 +
>   drivers/gpu/drm/drm_syncobj.c  | 153 ++++++++++++++++++++++++++-------
>   include/uapi/drm/drm.h         |  15 ++++
>   4 files changed, 143 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h
> index 251d67e04c2d..331ac6225b58 100644
> --- a/drivers/gpu/drm/drm_internal.h
> +++ b/drivers/gpu/drm/drm_internal.h
> @@ -182,6 +182,8 @@ 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);
> +int drm_syncobj_timeline_wait_ioctl(struct drm_device *dev, void *data,
> +				    struct drm_file *file_private);
>   int drm_syncobj_reset_ioctl(struct drm_device *dev, void *data,
>   			    struct drm_file *file_private);
>   int drm_syncobj_signal_ioctl(struct drm_device *dev, void *data,
> diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
> index 687943df58e1..c984654646fa 100644
> --- a/drivers/gpu/drm/drm_ioctl.c
> +++ b/drivers/gpu/drm/drm_ioctl.c
> @@ -688,6 +688,8 @@ static const struct drm_ioctl_desc drm_ioctls[] = {
>   		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
>   	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_WAIT, drm_syncobj_wait_ioctl,
>   		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
> +	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT, drm_syncobj_timeline_wait_ioctl,
> +		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
>   	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_RESET, drm_syncobj_reset_ioctl,
>   		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
>   	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_SIGNAL, drm_syncobj_signal_ioctl,
> diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
> index 19a9ce638119..eae51978cda4 100644
> --- a/drivers/gpu/drm/drm_syncobj.c
> +++ b/drivers/gpu/drm/drm_syncobj.c
> @@ -61,6 +61,7 @@ struct syncobj_wait_entry {
>   	struct task_struct *task;
>   	struct dma_fence *fence;
>   	struct dma_fence_cb fence_cb;
> +	u64    point;
>   };
>   
>   static void syncobj_wait_syncobj_func(struct drm_syncobj *syncobj,
> @@ -95,6 +96,8 @@ EXPORT_SYMBOL(drm_syncobj_find);
>   static void drm_syncobj_fence_add_wait(struct drm_syncobj *syncobj,
>   				       struct syncobj_wait_entry *wait)
>   {
> +	struct dma_fence *fence;
> +
>   	if (wait->fence)
>   		return;
>   
> @@ -103,11 +106,15 @@ static void drm_syncobj_fence_add_wait(struct drm_syncobj *syncobj,
>   	 * 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)
> -		wait->fence = dma_fence_get(
> -			rcu_dereference_protected(syncobj->fence, 1));
> -	else
> +	fence = dma_fence_get(rcu_dereference_protected(syncobj->fence, 1));
> +	if (!fence || dma_fence_chain_find_seqno(&fence, wait->point)) {
> +		dma_fence_put(fence);
>   		list_add_tail(&wait->node, &syncobj->cb_list);
> +	} else if (!fence) {
> +		wait->fence = dma_fence_get_stub();
> +	} else {
> +		wait->fence = fence;
> +	}
>   	spin_unlock(&syncobj->lock);
>   }
>   
> @@ -149,10 +156,8 @@ void drm_syncobj_add_point(struct drm_syncobj *syncobj,
>   	dma_fence_chain_init(chain, prev, fence, point);
>   	rcu_assign_pointer(syncobj->fence, &chain->base);
>   
> -	list_for_each_entry_safe(cur, tmp, &syncobj->cb_list, node) {
> -		list_del_init(&cur->node);
> +	list_for_each_entry_safe(cur, tmp, &syncobj->cb_list, node)
>   		syncobj_wait_syncobj_func(syncobj, cur);
> -	}
>   	spin_unlock(&syncobj->lock);
>   
>   	/* Walk the chain once to trigger garbage collection */
> @@ -184,10 +189,8 @@ void drm_syncobj_replace_fence(struct drm_syncobj *syncobj,
>   	rcu_assign_pointer(syncobj->fence, fence);
>   
>   	if (fence != old_fence) {
> -		list_for_each_entry_safe(cur, tmp, &syncobj->cb_list, node) {
> -			list_del_init(&cur->node);
> +		list_for_each_entry_safe(cur, tmp, &syncobj->cb_list, node)
>   			syncobj_wait_syncobj_func(syncobj, cur);
> -		}
>   	}
>   
>   	spin_unlock(&syncobj->lock);
> @@ -644,13 +647,27 @@ static void syncobj_wait_fence_func(struct dma_fence *fence,
>   static void syncobj_wait_syncobj_func(struct drm_syncobj *syncobj,
>   				      struct syncobj_wait_entry *wait)
>   {
> +	struct dma_fence *fence;
> +
>   	/* This happens inside the syncobj lock */
> -	wait->fence = dma_fence_get(rcu_dereference_protected(syncobj->fence,
> -							      lockdep_is_held(&syncobj->lock)));
> +	fence = rcu_dereference_protected(syncobj->fence,
> +					  lockdep_is_held(&syncobj->lock));
> +	dma_fence_get(fence);
> +	if (!fence || dma_fence_chain_find_seqno(&fence, wait->point)) {
> +		dma_fence_put(fence);
> +		return;
> +	} else if (!fence) {
> +		wait->fence = dma_fence_get_stub();
> +	} else {
> +		wait->fence = fence;
> +	}
> +
>   	wake_up_process(wait->task);
> +	list_del_init(&wait->node);
>   }
>   
>   static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs,
> +						  void __user *user_points,
>   						  uint32_t count,
>   						  uint32_t flags,
>   						  signed long timeout,
> @@ -658,12 +675,27 @@ static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs,
>   {
>   	struct syncobj_wait_entry *entries;
>   	struct dma_fence *fence;
> +	uint64_t *points;
>   	uint32_t signaled_count, i;
>   
> -	entries = kcalloc(count, sizeof(*entries), GFP_KERNEL);
> -	if (!entries)
> +	points = kmalloc_array(count, sizeof(*points), GFP_KERNEL);
> +	if (points == NULL)
>   		return -ENOMEM;
>   
> +	if (!user_points) {
> +		memset(points, 0, count * sizeof(uint64_t));
> +
> +	} else if (copy_from_user(points, user_points,
> +				  sizeof(uint64_t) * count)) {
> +		timeout = -EFAULT;
> +		goto err_free_points;
> +	}
> +
> +	entries = kcalloc(count, sizeof(*entries), GFP_KERNEL);
> +	if (!entries) {
> +		timeout = -ENOMEM;
> +		goto err_free_points;
> +	}
>   	/* 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
> @@ -671,9 +703,13 @@ static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs,
>   	 */
>   	signaled_count = 0;
>   	for (i = 0; i < count; ++i) {
> +		struct dma_fence *fence;
> +
>   		entries[i].task = current;
> -		entries[i].fence = drm_syncobj_fence_get(syncobjs[i]);
> -		if (!entries[i].fence) {
> +		entries[i].point = points[i];
> +		fence = drm_syncobj_fence_get(syncobjs[i]);
> +		if (!fence || dma_fence_chain_find_seqno(&fence, points[i])) {
> +			dma_fence_put(fence);
>   			if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) {
>   				continue;
>   			} else {
> @@ -682,7 +718,13 @@ static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs,
>   			}
>   		}
>   
> -		if (dma_fence_is_signaled(entries[i].fence)) {
> +		if (fence)
> +			entries[i].fence = fence;
> +		else
> +			entries[i].fence = dma_fence_get_stub();
> +
> +		if ((flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE) ||


Hey David,

Could you remind me what DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE is used for?

I didn't have a use for it in userspace,

Thanks,

-Lionel


> +		    dma_fence_is_signaled(entries[i].fence)) {
>   			if (signaled_count == 0 && idx)
>   				*idx = i;
>   			signaled_count++;
> @@ -715,7 +757,8 @@ static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs,
>   			if (!fence)
>   				continue;
>   
> -			if (dma_fence_is_signaled(fence) ||
> +			if ((flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE) ||
> +			    dma_fence_is_signaled(fence) ||
>   			    (!entries[i].fence_cb.func &&
>   			     dma_fence_add_callback(fence,
>   						    &entries[i].fence_cb,
> @@ -760,6 +803,9 @@ static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs,
>   	}
>   	kfree(entries);
>   
> +err_free_points:
> +	kfree(points);
> +
>   	return timeout;
>   }
>   
> @@ -799,19 +845,33 @@ EXPORT_SYMBOL(drm_timeout_abs_to_jiffies);
>   static int drm_syncobj_array_wait(struct drm_device *dev,
>   				  struct drm_file *file_private,
>   				  struct drm_syncobj_wait *wait,
> -				  struct drm_syncobj **syncobjs)
> +				  struct drm_syncobj_timeline_wait *timeline_wait,
> +				  struct drm_syncobj **syncobjs, bool timeline)
>   {
> -	signed long timeout = drm_timeout_abs_to_jiffies(wait->timeout_nsec);
> +	signed long timeout = 0;
>   	uint32_t first = ~0;
>   
> -	timeout = drm_syncobj_array_wait_timeout(syncobjs,
> -						 wait->count_handles,
> -						 wait->flags,
> -						 timeout, &first);
> -	if (timeout < 0)
> -		return timeout;
> -
> -	wait->first_signaled = first;
> +	if (!timeline) {
> +		timeout = drm_timeout_abs_to_jiffies(wait->timeout_nsec);
> +		timeout = drm_syncobj_array_wait_timeout(syncobjs,
> +							 NULL,
> +							 wait->count_handles,
> +							 wait->flags,
> +							 timeout, &first);
> +		if (timeout < 0)
> +			return timeout;
> +		wait->first_signaled = first;
> +	} else {
> +		timeout = drm_timeout_abs_to_jiffies(timeline_wait->timeout_nsec);
> +		timeout = drm_syncobj_array_wait_timeout(syncobjs,
> +							 u64_to_user_ptr(timeline_wait->points),
> +							 timeline_wait->count_handles,
> +							 timeline_wait->flags,
> +							 timeout, &first);
> +		if (timeout < 0)
> +			return timeout;
> +		timeline_wait->first_signaled = first;
> +	}
>   	return 0;
>   }
>   
> @@ -897,13 +957,48 @@ drm_syncobj_wait_ioctl(struct drm_device *dev, void *data,
>   		return ret;
>   
>   	ret = drm_syncobj_array_wait(dev, file_private,
> -				     args, syncobjs);
> +				     args, NULL, syncobjs, false);
>   
>   	drm_syncobj_array_free(syncobjs, args->count_handles);
>   
>   	return ret;
>   }
>   
> +int
> +drm_syncobj_timeline_wait_ioctl(struct drm_device *dev, void *data,
> +				struct drm_file *file_private)
> +{
> +	struct drm_syncobj_timeline_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 |
> +			    DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE))
> +		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,
> +				     NULL, args, syncobjs, true);
> +
> +	drm_syncobj_array_free(syncobjs, args->count_handles);
> +
> +	return ret;
> +}
> +
> +
>   int
>   drm_syncobj_reset_ioctl(struct drm_device *dev, void *data,
>   			struct drm_file *file_private)
> diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
> index 300f336633f2..0092111d002c 100644
> --- a/include/uapi/drm/drm.h
> +++ b/include/uapi/drm/drm.h
> @@ -737,6 +737,7 @@ struct drm_syncobj_handle {
>   
>   #define DRM_SYNCOBJ_WAIT_FLAGS_WAIT_ALL (1 << 0)
>   #define DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT (1 << 1)
> +#define DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE (1 << 2)
>   struct drm_syncobj_wait {
>   	__u64 handles;
>   	/* absolute timeout */
> @@ -747,6 +748,19 @@ struct drm_syncobj_wait {
>   	__u32 pad;
>   };
>   
> +struct drm_syncobj_timeline_wait {
> +	__u64 handles;
> +	/* wait on specific timeline point for every handles*/
> +	__u64 points;
> +	/* absolute timeout */
> +	__s64 timeout_nsec;
> +	__u32 count_handles;
> +	__u32 flags;
> +	__u32 first_signaled; /* only valid when not waiting all */
> +	__u32 pad;
> +};
> +
> +
>   struct drm_syncobj_array {
>   	__u64 handles;
>   	__u32 count_handles;
> @@ -909,6 +923,7 @@ extern "C" {
>   #define DRM_IOCTL_MODE_GET_LEASE	DRM_IOWR(0xC8, struct drm_mode_get_lease)
>   #define DRM_IOCTL_MODE_REVOKE_LEASE	DRM_IOWR(0xC9, struct drm_mode_revoke_lease)
>   
> +#define DRM_IOCTL_SYNCOBJ_TIMELINE_WAIT	DRM_IOWR(0xCA, struct drm_syncobj_timeline_wait)
>   /**
>    * Device specific ioctls should only be in their respective headers
>    * The device specific ioctl range is from 0x40 to 0x9f.




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