diff mbox series

[2/3] drm/i915: add syncobj timeline support

Message ID 20200406200710.2056-2-venkata.s.dhanalakota@intel.com (mailing list archive)
State New, archived
Headers show
Series [1/3] drm/i915: introduce a mechanism to extend execbuf2 | expand

Commit Message

Venkata Sandeep Dhanalakota April 6, 2020, 8:07 p.m. UTC
Introduces a new parameters to execbuf so that we can specify syncobj
handles as well as timeline points.

v2: Reuse i915_user_extension_fn

v3: Check that the chained extension is only present once (Chris)

v4: Check that dma_fence_chain_find_seqno returns a non NULL fence
(Lionel)

v5: Use BIT_ULL (Chris)

v6: Fix issue with already signaled timeline points,
    dma_fence_chain_find_seqno() setting fence to NULL (Chris)

v7: Report ENOENT with invalid syncobj handle (Lionel)

v8: Check for out of order timeline point insertion (Chris)

v9: After explanations on
    https://lists.freedesktop.org/archives/dri-devel/2019-August/229287.html
    drop the ordering check from v8 (Lionel)

v10: Set first extension enum item to 1 (Jason)

v11: Add wait on previous sync points in timelines (Sandeep)

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Signed-off-by: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota at intel.com>
---
 .../gpu/drm/i915/gem/i915_gem_execbuffer.c    | 312 ++++++++++++++----
 drivers/gpu/drm/i915/i915_drv.c               |   3 +-
 drivers/gpu/drm/i915/i915_getparam.c          |   1 +
 include/uapi/drm/i915_drm.h                   |  38 +++
 4 files changed, 296 insertions(+), 58 deletions(-)

Comments

Lionel Landwerlin April 8, 2020, 4:29 p.m. UTC | #1
On 06/04/2020 23:07, Venkata Sandeep Dhanalakota wrote:
> Introduces a new parameters to execbuf so that we can specify syncobj
> handles as well as timeline points.
>
> v2: Reuse i915_user_extension_fn
>
> v3: Check that the chained extension is only present once (Chris)
>
> v4: Check that dma_fence_chain_find_seqno returns a non NULL fence
> (Lionel)
>
> v5: Use BIT_ULL (Chris)
>
> v6: Fix issue with already signaled timeline points,
>      dma_fence_chain_find_seqno() setting fence to NULL (Chris)
>
> v7: Report ENOENT with invalid syncobj handle (Lionel)
>
> v8: Check for out of order timeline point insertion (Chris)
>
> v9: After explanations on
>      https://lists.freedesktop.org/archives/dri-devel/2019-August/229287.html
>      drop the ordering check from v8 (Lionel)
>
> v10: Set first extension enum item to 1 (Jason)
>
> v11: Add wait on previous sync points in timelines (Sandeep)


Thanks for picking this series up!


Could you point to the changes in v11?

I haven't look at it in a while and I can't remember what you would have 
changed.


Thanks a lot,


-Lionel


>
> Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
> Signed-off-by: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota at intel.com>
> ---
>   .../gpu/drm/i915/gem/i915_gem_execbuffer.c    | 312 ++++++++++++++----
>   drivers/gpu/drm/i915/i915_drv.c               |   3 +-
>   drivers/gpu/drm/i915/i915_getparam.c          |   1 +
>   include/uapi/drm/i915_drm.h                   |  38 +++
>   4 files changed, 296 insertions(+), 58 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> index 16831f715daa..4cb4cd035daa 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> @@ -230,6 +230,13 @@ enum {
>    * the batchbuffer in trusted mode, otherwise the ioctl is rejected.
>    */
>   
> +struct i915_eb_fences {
> +	struct drm_syncobj *syncobj; /* Use with ptr_mask_bits() */
> +	struct dma_fence *dma_fence;
> +	u64 value;
> +	struct dma_fence_chain *chain_fence;
> +};
> +
>   struct i915_execbuffer {
>   	struct drm_i915_private *i915; /** i915 backpointer */
>   	struct drm_file *file; /** per-file lookup tables and limits */
> @@ -292,6 +299,7 @@ struct i915_execbuffer {
>   
>   	struct {
>   		u64 flags; /** Available extensions parameters */
> +		struct drm_i915_gem_execbuffer_ext_timeline_fences timeline_fences;
>   	} extensions;
>   };
>   
> @@ -2244,67 +2252,219 @@ eb_pin_engine(struct i915_execbuffer *eb,
>   }
>   
>   static void
> -__free_fence_array(struct drm_syncobj **fences, unsigned int n)
> +__free_fence_array(struct i915_eb_fences *fences, unsigned int n)
>   {
> -	while (n--)
> -		drm_syncobj_put(ptr_mask_bits(fences[n], 2));
> +	while (n--) {
> +		drm_syncobj_put(ptr_mask_bits(fences[n].syncobj, 2));
> +		dma_fence_put(fences[n].dma_fence);
> +		kfree(fences[n].chain_fence);
> +	}
>   	kvfree(fences);
>   }
>   
> -static struct drm_syncobj **
> -get_fence_array(struct drm_i915_gem_execbuffer2 *args,
> -		struct drm_file *file)
> +static struct i915_eb_fences *
> +get_timeline_fence_array(struct i915_execbuffer *eb, int *out_n_fences)
> +{
> +	struct drm_i915_gem_execbuffer_ext_timeline_fences *timeline_fences =
> +		&eb->extensions.timeline_fences;
> +	struct drm_i915_gem_exec_fence __user *user_fences;
> +	struct i915_eb_fences *fences;
> +	u64 __user *user_values;
> +	u64 num_fences, num_user_fences = timeline_fences->fence_count;
> +	unsigned long n;
> +	int err = 0;
> +
> +	/* Check multiplication overflow for access_ok() and kvmalloc_array() */
> +	BUILD_BUG_ON(sizeof(size_t) > sizeof(unsigned long));
> +	if (num_user_fences > min_t(unsigned long,
> +				    ULONG_MAX / sizeof(*user_fences),
> +				    SIZE_MAX / sizeof(*fences)))
> +		return ERR_PTR(-EINVAL);
> +
> +	user_fences = u64_to_user_ptr(timeline_fences->handles_ptr);
> +	if (!access_ok(user_fences, num_user_fences * sizeof(*user_fences)))
> +		return ERR_PTR(-EFAULT);
> +
> +	user_values = u64_to_user_ptr(timeline_fences->values_ptr);
> +	if (!access_ok(user_values, num_user_fences * sizeof(*user_values)))
> +		return ERR_PTR(-EFAULT);
> +
> +	fences = kvmalloc_array(num_user_fences, sizeof(*fences),
> +				__GFP_NOWARN | GFP_KERNEL);
> +	if (!fences)
> +		return ERR_PTR(-ENOMEM);
> +
> +	BUILD_BUG_ON(~(ARCH_KMALLOC_MINALIGN - 1) &
> +		     ~__I915_EXEC_FENCE_UNKNOWN_FLAGS);
> +
> +	for (n = 0, num_fences = 0; n < timeline_fences->fence_count; n++) {
> +		struct drm_i915_gem_exec_fence user_fence;
> +		struct drm_syncobj *syncobj;
> +		struct dma_fence *fence = NULL;
> +		u64 point;
> +
> +		if (__copy_from_user(&user_fence, user_fences++, sizeof(user_fence))) {
> +			err = -EFAULT;
> +			goto err;
> +		}
> +
> +		if (user_fence.flags & __I915_EXEC_FENCE_UNKNOWN_FLAGS) {
> +			err = -EINVAL;
> +			goto err;
> +		}
> +
> +		if (__get_user(point, user_values++)) {
> +			err = -EFAULT;
> +			goto err;
> +		}
> +
> +		syncobj = drm_syncobj_find(eb->file, user_fence.handle);
> +		if (!syncobj) {
> +			DRM_DEBUG("Invalid syncobj handle provided\n");
> +			err = -ENOENT;
> +			goto err;
> +		}
> +
> +		fence = drm_syncobj_fence_get(syncobj);
> +
> +		if (!fence && user_fence.flags &&
> +		    !(user_fence.flags & I915_EXEC_FENCE_SIGNAL)) {
> +			DRM_DEBUG("Syncobj handle has no fence\n");
> +			drm_syncobj_put(syncobj);
> +			err = -EINVAL;
> +			goto err;
> +		}
> +
> +		if (fence)
> +			err = dma_fence_chain_find_seqno(&fence, point);
> +
> +		if (err && !(user_fence.flags & I915_EXEC_FENCE_SIGNAL)) {
> +			DRM_DEBUG("Syncobj handle missing requested point %llu\n", point);
> +			drm_syncobj_put(syncobj);
> +			goto err;
> +		}
> +
> +		/* A point might have been signaled already and
> +		 * garbage collected from the timeline. In this case
> +		 * just ignore the point and carry on.
> +		 */
> +		if (!fence && (user_fence.flags & I915_EXEC_FENCE_WAIT)) {
> +			drm_syncobj_put(syncobj);
> +			continue;
> +		}
> +
> +		/*
> +		 * For timeline syncobjs we need to preallocate chains for
> +		 * later signaling.
> +		 */
> +		if (point != 0 && user_fence.flags & I915_EXEC_FENCE_SIGNAL) {
> +			/*
> +			 * Waiting and signaling the same point (when point !=
> +			 * 0) would break the timeline.
> +			 */
> +			if (user_fence.flags & I915_EXEC_FENCE_WAIT) {
> +				DRM_DEBUG("Trying to wait & signal the same timeline point.\n");
> +				err = -EINVAL;
> +				drm_syncobj_put(syncobj);
> +				goto err;
> +			}
> +
> +			fences[num_fences].chain_fence =
> +				kmalloc(sizeof(*fences[num_fences].chain_fence),
> +					GFP_KERNEL);
> +			if (!fences[num_fences].chain_fence) {
> +				drm_syncobj_put(syncobj);
> +				err = -ENOMEM;
> +				DRM_DEBUG("Unable to alloc chain_fence\n");
> +				goto err;
> +			}
> +		} else {
> +			fences[num_fences].chain_fence = NULL;
> +		}
> +
> +		fences[num_fences].syncobj = ptr_pack_bits(syncobj, user_fence.flags, 2);
> +		fences[num_fences].dma_fence = fence;
> +		fences[num_fences].value = point;
> +		num_fences++;
> +	}
> +
> +	*out_n_fences = num_fences;
> +
> +	return fences;
> +
> +err:
> +	__free_fence_array(fences, num_fences);
> +	return ERR_PTR(err);
> +}
> +
> +static struct i915_eb_fences *
> +get_legacy_fence_array(struct i915_execbuffer *eb,
> +		       int *out_n_fences)
>   {
> -	const unsigned long nfences = args->num_cliprects;
> +	struct drm_i915_gem_execbuffer2 *args = eb->args;
>   	struct drm_i915_gem_exec_fence __user *user;
> -	struct drm_syncobj **fences;
> +	struct i915_eb_fences *fences;
> +	const u32 num_fences = args->num_cliprects;
>   	unsigned long n;
>   	int err;
>   
> -	if (!(args->flags & I915_EXEC_FENCE_ARRAY))
> -		return NULL;
> +	*out_n_fences = num_fences;
>   
>   	/* Check multiplication overflow for access_ok() and kvmalloc_array() */
>   	BUILD_BUG_ON(sizeof(size_t) > sizeof(unsigned long));
> -	if (nfences > min_t(unsigned long,
> -			    ULONG_MAX / sizeof(*user),
> -			    SIZE_MAX / sizeof(*fences)))
> +	if (*out_n_fences > min_t(unsigned long,
> +				  ULONG_MAX / sizeof(*user),
> +				  SIZE_MAX / sizeof(*fences)))
>   		return ERR_PTR(-EINVAL);
>   
>   	user = u64_to_user_ptr(args->cliprects_ptr);
> -	if (!access_ok(user, nfences * sizeof(*user)))
> +	if (!access_ok(user, *out_n_fences * sizeof(*user)))
>   		return ERR_PTR(-EFAULT);
>   
> -	fences = kvmalloc_array(nfences, sizeof(*fences),
> +	fences = kvmalloc_array(*out_n_fences, sizeof(*fences),
>   				__GFP_NOWARN | GFP_KERNEL);
>   	if (!fences)
>   		return ERR_PTR(-ENOMEM);
>   
> -	for (n = 0; n < nfences; n++) {
> -		struct drm_i915_gem_exec_fence fence;
> +	for (n = 0; n < *out_n_fences; n++) {
> +		struct drm_i915_gem_exec_fence user_fence;
>   		struct drm_syncobj *syncobj;
> +		struct dma_fence *fence = NULL;
>   
> -		if (__copy_from_user(&fence, user++, sizeof(fence))) {
> +		if (__copy_from_user(&user_fence, user++, sizeof(user_fence))) {
>   			err = -EFAULT;
>   			goto err;
>   		}
>   
> -		if (fence.flags & __I915_EXEC_FENCE_UNKNOWN_FLAGS) {
> +		if (user_fence.flags & __I915_EXEC_FENCE_UNKNOWN_FLAGS) {
>   			err = -EINVAL;
>   			goto err;
>   		}
>   
> -		syncobj = drm_syncobj_find(file, fence.handle);
> +		syncobj = drm_syncobj_find(eb->file, user_fence.handle);
>   		if (!syncobj) {
>   			DRM_DEBUG("Invalid syncobj handle provided\n");
>   			err = -ENOENT;
>   			goto err;
>   		}
>   
> +		if (user_fence.flags & I915_EXEC_FENCE_WAIT) {
> +			fence = drm_syncobj_fence_get(syncobj);
> +			if (!fence) {
> +				DRM_DEBUG("Syncobj handle has no fence\n");
> +				drm_syncobj_put(syncobj);
> +				err = -EINVAL;
> +				goto err;
> +			}
> +		}
> +
>   		BUILD_BUG_ON(~(ARCH_KMALLOC_MINALIGN - 1) &
>   			     ~__I915_EXEC_FENCE_UNKNOWN_FLAGS);
>   
> -		fences[n] = ptr_pack_bits(syncobj, fence.flags, 2);
> +		fences[n].syncobj = ptr_pack_bits(syncobj, user_fence.flags, 2);
> +		fences[n].dma_fence = fence;
> +		fences[n].value = 0;
> +		fences[n].chain_fence = NULL;
>   	}
>   
>   	return fences;
> @@ -2314,37 +2474,45 @@ get_fence_array(struct drm_i915_gem_execbuffer2 *args,
>   	return ERR_PTR(err);
>   }
>   
> +static struct i915_eb_fences *
> +get_fence_array(struct i915_execbuffer *eb, int *out_n_fences)
> +{
> +	if (eb->args->flags & I915_EXEC_FENCE_ARRAY)
> +		return get_legacy_fence_array(eb, out_n_fences);
> +
> +	if (eb->extensions.flags & BIT_ULL(DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES))
> +		return get_timeline_fence_array(eb, out_n_fences);
> +
> +	*out_n_fences = 0;
> +	return NULL;
> +}
> +
>   static void
> -put_fence_array(struct drm_i915_gem_execbuffer2 *args,
> -		struct drm_syncobj **fences)
> +put_fence_array(struct i915_eb_fences *fences, int nfences)
>   {
>   	if (fences)
> -		__free_fence_array(fences, args->num_cliprects);
> +		__free_fence_array(fences, nfences);
>   }
>   
>   static int
>   await_fence_array(struct i915_execbuffer *eb,
> -		  struct drm_syncobj **fences)
> +		  struct i915_eb_fences *fences,
> +		  int nfences)
>   {
> -	const unsigned int nfences = eb->args->num_cliprects;
>   	unsigned int n;
>   	int err;
>   
>   	for (n = 0; n < nfences; n++) {
>   		struct drm_syncobj *syncobj;
> -		struct dma_fence *fence;
>   		unsigned int flags;
>   
> -		syncobj = ptr_unpack_bits(fences[n], &flags, 2);
> -		if (!(flags & I915_EXEC_FENCE_WAIT))
> -			continue;
> +		syncobj = ptr_unpack_bits(fences[n].syncobj, &flags, 2);
>   
> -		fence = drm_syncobj_fence_get(syncobj);
> -		if (!fence)
> -			return -EINVAL;
> +		if (!fences[n].dma_fence)
> +			continue;
>   
> -		err = i915_request_await_dma_fence(eb->request, fence);
> -		dma_fence_put(fence);
> +		err = i915_request_await_dma_fence(eb->request,
> +						   fences[n].dma_fence);
>   		if (err < 0)
>   			return err;
>   	}
> @@ -2354,9 +2522,9 @@ await_fence_array(struct i915_execbuffer *eb,
>   
>   static void
>   signal_fence_array(struct i915_execbuffer *eb,
> -		   struct drm_syncobj **fences)
> +		   struct i915_eb_fences *fences,
> +		   int nfences)
>   {
> -	const unsigned int nfences = eb->args->num_cliprects;
>   	struct dma_fence * const fence = &eb->request->fence;
>   	unsigned int n;
>   
> @@ -2364,14 +2532,44 @@ signal_fence_array(struct i915_execbuffer *eb,
>   		struct drm_syncobj *syncobj;
>   		unsigned int flags;
>   
> -		syncobj = ptr_unpack_bits(fences[n], &flags, 2);
> +		syncobj = ptr_unpack_bits(fences[n].syncobj, &flags, 2);
>   		if (!(flags & I915_EXEC_FENCE_SIGNAL))
>   			continue;
>   
> -		drm_syncobj_replace_fence(syncobj, fence);
> +		if (fences[n].chain_fence) {
> +			drm_syncobj_add_point(syncobj, fences[n].chain_fence,
> +					      fence, fences[n].value);
> +			/*
> +			 * The chain's ownership is transferred to the
> +			 * timeline.
> +			 */
> +			fences[n].chain_fence = NULL;
> +		} else {
> +			drm_syncobj_replace_fence(syncobj, fence);
> +		}
>   	}
>   }
>   
> +static int parse_timeline_fences(struct i915_user_extension __user *ext, void *data)
> +{
> +	struct i915_execbuffer *eb = data;
> +
> +	/* Timeline fences are incompatible with the fence array flag. */
> +	if (eb->args->flags & I915_EXEC_FENCE_ARRAY)
> +		return -EINVAL;
> +
> +	if (eb->extensions.flags & BIT_ULL(DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES))
> +		return -EINVAL;
> +
> +	if (copy_from_user(&eb->extensions.timeline_fences, ext,
> +			   sizeof(eb->extensions.timeline_fences)))
> +		return -EFAULT;
> +
> +	eb->extensions.flags |= BIT_ULL(DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES);
> +
> +	return 0;
> +}
> +
>   static void retire_requests(struct intel_timeline *tl, struct i915_request *end)
>   {
>   	struct i915_request *rq, *rn;
> @@ -2438,6 +2636,7 @@ static void eb_request_add(struct i915_execbuffer *eb)
>   }
>   
>   static const i915_user_extension_fn execbuf_extensions[] = {
> +	[DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES] = parse_timeline_fences,
>   };
>   
>   static int
> @@ -2468,16 +2667,17 @@ static int
>   i915_gem_do_execbuffer(struct drm_device *dev,
>   		       struct drm_file *file,
>   		       struct drm_i915_gem_execbuffer2 *args,
> -		       struct drm_i915_gem_exec_object2 *exec,
> -		       struct drm_syncobj **fences)
> +		       struct drm_i915_gem_exec_object2 *exec)
>   {
>   	struct drm_i915_private *i915 = to_i915(dev);
>   	struct i915_execbuffer eb;
>   	struct dma_fence *in_fence = NULL;
>   	struct dma_fence *exec_fence = NULL;
>   	struct sync_file *out_fence = NULL;
> +	struct i915_eb_fences *fences = NULL;
>   	struct i915_vma *batch;
>   	int out_fence_fd = -1;
> +	int nfences = 0;
>   	int err;
>   
>   	BUILD_BUG_ON(__EXEC_INTERNAL_FLAGS & ~__I915_EXEC_ILLEGAL_FLAGS);
> @@ -2521,10 +2721,16 @@ i915_gem_do_execbuffer(struct drm_device *dev,
>   	if (err)
>   		return err;
>   
> +	fences = get_fence_array(&eb, &nfences);
> +	if (IS_ERR(fences))
> +		return PTR_ERR(fences);
> +
>   	if (args->flags & I915_EXEC_FENCE_IN) {
>   		in_fence = sync_file_get_fence(lower_32_bits(args->rsvd2));
> -		if (!in_fence)
> -			return -EINVAL;
> +		if (!in_fence) {
> +			err = -EINVAL;
> +			goto err_fences;
> +		}
>   	}
>   
>   	if (args->flags & I915_EXEC_FENCE_SUBMIT) {
> @@ -2648,7 +2854,7 @@ i915_gem_do_execbuffer(struct drm_device *dev,
>   	}
>   
>   	if (fences) {
> -		err = await_fence_array(&eb, fences);
> +		err = await_fence_array(&eb, fences, nfences);
>   		if (err)
>   			goto err_request;
>   	}
> @@ -2680,7 +2886,7 @@ i915_gem_do_execbuffer(struct drm_device *dev,
>   	eb_request_add(&eb);
>   
>   	if (fences)
> -		signal_fence_array(&eb, fences);
> +		signal_fence_array(&eb, fences, nfences);
>   
>   	if (out_fence) {
>   		if (err == 0) {
> @@ -2715,6 +2921,8 @@ i915_gem_do_execbuffer(struct drm_device *dev,
>   	dma_fence_put(exec_fence);
>   err_in_fence:
>   	dma_fence_put(in_fence);
> +err_fences:
> +	put_fence_array(fences, nfences);
>   	return err;
>   }
>   
> @@ -2809,7 +3017,7 @@ i915_gem_execbuffer_ioctl(struct drm_device *dev, void *data,
>   			exec2_list[i].flags = 0;
>   	}
>   
> -	err = i915_gem_do_execbuffer(dev, file, &exec2, exec2_list, NULL);
> +	err = i915_gem_do_execbuffer(dev, file, &exec2, exec2_list);
>   	if (exec2.flags & __EXEC_HAS_RELOC) {
>   		struct drm_i915_gem_exec_object __user *user_exec_list =
>   			u64_to_user_ptr(args->buffers_ptr);
> @@ -2841,7 +3049,6 @@ i915_gem_execbuffer2_ioctl(struct drm_device *dev, void *data,
>   	struct drm_i915_private *i915 = to_i915(dev);
>   	struct drm_i915_gem_execbuffer2 *args = data;
>   	struct drm_i915_gem_exec_object2 *exec2_list;
> -	struct drm_syncobj **fences = NULL;
>   	const size_t count = args->buffer_count;
>   	int err;
>   
> @@ -2869,15 +3076,7 @@ i915_gem_execbuffer2_ioctl(struct drm_device *dev, void *data,
>   		return -EFAULT;
>   	}
>   
> -	if (args->flags & I915_EXEC_FENCE_ARRAY) {
> -		fences = get_fence_array(args, file);
> -		if (IS_ERR(fences)) {
> -			kvfree(exec2_list);
> -			return PTR_ERR(fences);
> -		}
> -	}
> -
> -	err = i915_gem_do_execbuffer(dev, file, args, exec2_list, fences);
> +	err = i915_gem_do_execbuffer(dev, file, args, exec2_list);
>   
>   	/*
>   	 * Now that we have begun execution of the batchbuffer, we ignore
> @@ -2917,7 +3116,6 @@ end:;
>   	}
>   
>   	args->flags &= ~__I915_EXEC_UNKNOWN_FLAGS;
> -	put_fence_array(args, fences);
>   	kvfree(exec2_list);
>   	return err;
>   }
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index a7a3b4b98572..f7f868c3c510 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -1828,7 +1828,8 @@ static struct drm_driver driver = {
>   	 */
>   	.driver_features =
>   	    DRIVER_GEM |
> -	    DRIVER_RENDER | DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_SYNCOBJ,
> +	    DRIVER_RENDER | DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_SYNCOBJ |
> +	    DRIVER_SYNCOBJ_TIMELINE,
>   	.release = i915_driver_release,
>   	.open = i915_driver_open,
>   	.lastclose = i915_driver_lastclose,
> diff --git a/drivers/gpu/drm/i915/i915_getparam.c b/drivers/gpu/drm/i915/i915_getparam.c
> index 54fce81d5724..b9d3aab53c03 100644
> --- a/drivers/gpu/drm/i915/i915_getparam.c
> +++ b/drivers/gpu/drm/i915/i915_getparam.c
> @@ -132,6 +132,7 @@ int i915_getparam_ioctl(struct drm_device *dev, void *data,
>   	case I915_PARAM_HAS_EXEC_BATCH_FIRST:
>   	case I915_PARAM_HAS_EXEC_FENCE_ARRAY:
>   	case I915_PARAM_HAS_EXEC_SUBMIT_FENCE:
> +	case I915_PARAM_HAS_EXEC_TIMELINE_FENCES:
>   		/* For the time being all of these are always true;
>   		 * if some supported hardware does not have one of these
>   		 * features this value needs to be provided from
> diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
> index 7ea38aa6502c..7b8680e3b49d 100644
> --- a/include/uapi/drm/i915_drm.h
> +++ b/include/uapi/drm/i915_drm.h
> @@ -619,6 +619,12 @@ typedef struct drm_i915_irq_wait {
>    */
>   #define I915_PARAM_PERF_REVISION	54
>   
> +/* Query whether DRM_I915_GEM_EXECBUFFER2 supports supplying an array of
> + * timeline syncobj through drm_i915_gem_execbuf_ext_timeline_fences. See
> + * I915_EXEC_USE_EXTENSIONS.
> + */
> +#define I915_PARAM_HAS_EXEC_TIMELINE_FENCES 55
> +
>   /* Must be kept compact -- no holes and well documented */
>   
>   typedef struct drm_i915_getparam {
> @@ -1047,9 +1053,41 @@ struct drm_i915_gem_exec_fence {
>   };
>   
>   enum drm_i915_gem_execbuffer_ext {
> +	/**
> +	 * See drm_i915_gem_execbuf_ext_timeline_fences.
> +	 */
> +	DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES = 1,
> +
>   	DRM_I915_GEM_EXECBUFFER_EXT_MAX /* non-ABI */
>   };
>   
> +/**
> + * This structure describes an array of drm_syncobj and associated points for
> + * timeline variants of drm_syncobj. It is invalid to append this structure to
> + * the execbuf if I915_EXEC_FENCE_ARRAY is set.
> + */
> +struct drm_i915_gem_execbuffer_ext_timeline_fences {
> +	struct i915_user_extension base;
> +
> +	/**
> +	 * Number of element in the handles_ptr & value_ptr arrays.
> +	 */
> +	__u64 fence_count;
> +
> +	/**
> +	 * Pointer to an array of struct drm_i915_gem_exec_fence of length
> +	 * fence_count.
> +	 */
> +	__u64 handles_ptr;
> +
> +	/**
> +	 * Pointer to an array of u64 values of length fence_count. Values
> +	 * must be 0 for a binary drm_syncobj. A Value of 0 for a timeline
> +	 * drm_syncobj is invalid as it turns a drm_syncobj into a binary one.
> +	 */
> +	__u64 values_ptr;
> +};
> +
>   struct drm_i915_gem_execbuffer2 {
>   	/**
>   	 * List of gem_exec_object2 structs
Venkata Sandeep Dhanalakota April 8, 2020, 5 p.m. UTC | #2
On 20/04/08 07:29, Lionel Landwerlin wrote:
> On 06/04/2020 23:07, Venkata Sandeep Dhanalakota wrote:
> > Introduces a new parameters to execbuf so that we can specify syncobj
> > handles as well as timeline points.
> > 
> > v2: Reuse i915_user_extension_fn
> > 
> > v3: Check that the chained extension is only present once (Chris)
> > 
> > v4: Check that dma_fence_chain_find_seqno returns a non NULL fence
> > (Lionel)
> > 
> > v5: Use BIT_ULL (Chris)
> > 
> > v6: Fix issue with already signaled timeline points,
> >      dma_fence_chain_find_seqno() setting fence to NULL (Chris)
> > 
> > v7: Report ENOENT with invalid syncobj handle (Lionel)
> > 
> > v8: Check for out of order timeline point insertion (Chris)
> > 
> > v9: After explanations on
> >      https://lists.freedesktop.org/archives/dri-devel/2019-August/229287.html
> >      drop the ordering check from v8 (Lionel)
> > 
> > v10: Set first extension enum item to 1 (Jason)
> > 
> > v11: Add wait on previous sync points in timelines (Sandeep)
> 
> 
> Thanks for picking this series up!
> 
> 
> Could you point to the changes in v11?
> 
> I haven't look at it in a while and I can't remember what you would have
> changed.
> 
Hi,

Mainly the changes are in get_timeline_fence_array(), to enforce the
implicit dependencies in signal fence-array. we want have efficient waits
on the last point on timelines so that we signal at a correct point in time along the timeline
the order is controlled so that we always wait on the previous request/sync point in the timeline
and signal after the completion of the current request.

Thank you,
~sandeep
> 
> Thanks a lot,
> 
> 
> -Lionel
> 
> 
> > 
> > Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
> > Signed-off-by: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota at intel.com>
> > ---
> >   .../gpu/drm/i915/gem/i915_gem_execbuffer.c    | 312 ++++++++++++++----
> >   drivers/gpu/drm/i915/i915_drv.c               |   3 +-
> >   drivers/gpu/drm/i915/i915_getparam.c          |   1 +
> >   include/uapi/drm/i915_drm.h                   |  38 +++
> >   4 files changed, 296 insertions(+), 58 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> > index 16831f715daa..4cb4cd035daa 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> > @@ -230,6 +230,13 @@ enum {
> >    * the batchbuffer in trusted mode, otherwise the ioctl is rejected.
> >    */
> > +struct i915_eb_fences {
> > +	struct drm_syncobj *syncobj; /* Use with ptr_mask_bits() */
> > +	struct dma_fence *dma_fence;
> > +	u64 value;
> > +	struct dma_fence_chain *chain_fence;
> > +};
> > +
> >   struct i915_execbuffer {
> >   	struct drm_i915_private *i915; /** i915 backpointer */
> >   	struct drm_file *file; /** per-file lookup tables and limits */
> > @@ -292,6 +299,7 @@ struct i915_execbuffer {
> >   	struct {
> >   		u64 flags; /** Available extensions parameters */
> > +		struct drm_i915_gem_execbuffer_ext_timeline_fences timeline_fences;
> >   	} extensions;
> >   };
> > @@ -2244,67 +2252,219 @@ eb_pin_engine(struct i915_execbuffer *eb,
> >   }
> >   static void
> > -__free_fence_array(struct drm_syncobj **fences, unsigned int n)
> > +__free_fence_array(struct i915_eb_fences *fences, unsigned int n)
> >   {
> > -	while (n--)
> > -		drm_syncobj_put(ptr_mask_bits(fences[n], 2));
> > +	while (n--) {
> > +		drm_syncobj_put(ptr_mask_bits(fences[n].syncobj, 2));
> > +		dma_fence_put(fences[n].dma_fence);
> > +		kfree(fences[n].chain_fence);
> > +	}
> >   	kvfree(fences);
> >   }
> > -static struct drm_syncobj **
> > -get_fence_array(struct drm_i915_gem_execbuffer2 *args,
> > -		struct drm_file *file)
> > +static struct i915_eb_fences *
> > +get_timeline_fence_array(struct i915_execbuffer *eb, int *out_n_fences)
> > +{
> > +	struct drm_i915_gem_execbuffer_ext_timeline_fences *timeline_fences =
> > +		&eb->extensions.timeline_fences;
> > +	struct drm_i915_gem_exec_fence __user *user_fences;
> > +	struct i915_eb_fences *fences;
> > +	u64 __user *user_values;
> > +	u64 num_fences, num_user_fences = timeline_fences->fence_count;
> > +	unsigned long n;
> > +	int err = 0;
> > +
> > +	/* Check multiplication overflow for access_ok() and kvmalloc_array() */
> > +	BUILD_BUG_ON(sizeof(size_t) > sizeof(unsigned long));
> > +	if (num_user_fences > min_t(unsigned long,
> > +				    ULONG_MAX / sizeof(*user_fences),
> > +				    SIZE_MAX / sizeof(*fences)))
> > +		return ERR_PTR(-EINVAL);
> > +
> > +	user_fences = u64_to_user_ptr(timeline_fences->handles_ptr);
> > +	if (!access_ok(user_fences, num_user_fences * sizeof(*user_fences)))
> > +		return ERR_PTR(-EFAULT);
> > +
> > +	user_values = u64_to_user_ptr(timeline_fences->values_ptr);
> > +	if (!access_ok(user_values, num_user_fences * sizeof(*user_values)))
> > +		return ERR_PTR(-EFAULT);
> > +
> > +	fences = kvmalloc_array(num_user_fences, sizeof(*fences),
> > +				__GFP_NOWARN | GFP_KERNEL);
> > +	if (!fences)
> > +		return ERR_PTR(-ENOMEM);
> > +
> > +	BUILD_BUG_ON(~(ARCH_KMALLOC_MINALIGN - 1) &
> > +		     ~__I915_EXEC_FENCE_UNKNOWN_FLAGS);
> > +
> > +	for (n = 0, num_fences = 0; n < timeline_fences->fence_count; n++) {
> > +		struct drm_i915_gem_exec_fence user_fence;
> > +		struct drm_syncobj *syncobj;
> > +		struct dma_fence *fence = NULL;
> > +		u64 point;
> > +
> > +		if (__copy_from_user(&user_fence, user_fences++, sizeof(user_fence))) {
> > +			err = -EFAULT;
> > +			goto err;
> > +		}
> > +
> > +		if (user_fence.flags & __I915_EXEC_FENCE_UNKNOWN_FLAGS) {
> > +			err = -EINVAL;
> > +			goto err;
> > +		}
> > +
> > +		if (__get_user(point, user_values++)) {
> > +			err = -EFAULT;
> > +			goto err;
> > +		}
> > +
> > +		syncobj = drm_syncobj_find(eb->file, user_fence.handle);
> > +		if (!syncobj) {
> > +			DRM_DEBUG("Invalid syncobj handle provided\n");
> > +			err = -ENOENT;
> > +			goto err;
> > +		}
> > +
> > +		fence = drm_syncobj_fence_get(syncobj);
> > +
> > +		if (!fence && user_fence.flags &&
> > +		    !(user_fence.flags & I915_EXEC_FENCE_SIGNAL)) {
> > +			DRM_DEBUG("Syncobj handle has no fence\n");
> > +			drm_syncobj_put(syncobj);
> > +			err = -EINVAL;
> > +			goto err;
> > +		}
> > +
> > +		if (fence)
> > +			err = dma_fence_chain_find_seqno(&fence, point);
> > +
> > +		if (err && !(user_fence.flags & I915_EXEC_FENCE_SIGNAL)) {
> > +			DRM_DEBUG("Syncobj handle missing requested point %llu\n", point);
> > +			drm_syncobj_put(syncobj);
> > +			goto err;
> > +		}
> > +
> > +		/* A point might have been signaled already and
> > +		 * garbage collected from the timeline. In this case
> > +		 * just ignore the point and carry on.
> > +		 */
> > +		if (!fence && (user_fence.flags & I915_EXEC_FENCE_WAIT)) {
> > +			drm_syncobj_put(syncobj);
> > +			continue;
> > +		}
> > +
> > +		/*
> > +		 * For timeline syncobjs we need to preallocate chains for
> > +		 * later signaling.
> > +		 */
> > +		if (point != 0 && user_fence.flags & I915_EXEC_FENCE_SIGNAL) {
> > +			/*
> > +			 * Waiting and signaling the same point (when point !=
> > +			 * 0) would break the timeline.
> > +			 */
> > +			if (user_fence.flags & I915_EXEC_FENCE_WAIT) {
> > +				DRM_DEBUG("Trying to wait & signal the same timeline point.\n");
> > +				err = -EINVAL;
> > +				drm_syncobj_put(syncobj);
> > +				goto err;
> > +			}
> > +
> > +			fences[num_fences].chain_fence =
> > +				kmalloc(sizeof(*fences[num_fences].chain_fence),
> > +					GFP_KERNEL);
> > +			if (!fences[num_fences].chain_fence) {
> > +				drm_syncobj_put(syncobj);
> > +				err = -ENOMEM;
> > +				DRM_DEBUG("Unable to alloc chain_fence\n");
> > +				goto err;
> > +			}
> > +		} else {
> > +			fences[num_fences].chain_fence = NULL;
> > +		}
> > +
> > +		fences[num_fences].syncobj = ptr_pack_bits(syncobj, user_fence.flags, 2);
> > +		fences[num_fences].dma_fence = fence;
> > +		fences[num_fences].value = point;
> > +		num_fences++;
> > +	}
> > +
> > +	*out_n_fences = num_fences;
> > +
> > +	return fences;
> > +
> > +err:
> > +	__free_fence_array(fences, num_fences);
> > +	return ERR_PTR(err);
> > +}
> > +
> > +static struct i915_eb_fences *
> > +get_legacy_fence_array(struct i915_execbuffer *eb,
> > +		       int *out_n_fences)
> >   {
> > -	const unsigned long nfences = args->num_cliprects;
> > +	struct drm_i915_gem_execbuffer2 *args = eb->args;
> >   	struct drm_i915_gem_exec_fence __user *user;
> > -	struct drm_syncobj **fences;
> > +	struct i915_eb_fences *fences;
> > +	const u32 num_fences = args->num_cliprects;
> >   	unsigned long n;
> >   	int err;
> > -	if (!(args->flags & I915_EXEC_FENCE_ARRAY))
> > -		return NULL;
> > +	*out_n_fences = num_fences;
> >   	/* Check multiplication overflow for access_ok() and kvmalloc_array() */
> >   	BUILD_BUG_ON(sizeof(size_t) > sizeof(unsigned long));
> > -	if (nfences > min_t(unsigned long,
> > -			    ULONG_MAX / sizeof(*user),
> > -			    SIZE_MAX / sizeof(*fences)))
> > +	if (*out_n_fences > min_t(unsigned long,
> > +				  ULONG_MAX / sizeof(*user),
> > +				  SIZE_MAX / sizeof(*fences)))
> >   		return ERR_PTR(-EINVAL);
> >   	user = u64_to_user_ptr(args->cliprects_ptr);
> > -	if (!access_ok(user, nfences * sizeof(*user)))
> > +	if (!access_ok(user, *out_n_fences * sizeof(*user)))
> >   		return ERR_PTR(-EFAULT);
> > -	fences = kvmalloc_array(nfences, sizeof(*fences),
> > +	fences = kvmalloc_array(*out_n_fences, sizeof(*fences),
> >   				__GFP_NOWARN | GFP_KERNEL);
> >   	if (!fences)
> >   		return ERR_PTR(-ENOMEM);
> > -	for (n = 0; n < nfences; n++) {
> > -		struct drm_i915_gem_exec_fence fence;
> > +	for (n = 0; n < *out_n_fences; n++) {
> > +		struct drm_i915_gem_exec_fence user_fence;
> >   		struct drm_syncobj *syncobj;
> > +		struct dma_fence *fence = NULL;
> > -		if (__copy_from_user(&fence, user++, sizeof(fence))) {
> > +		if (__copy_from_user(&user_fence, user++, sizeof(user_fence))) {
> >   			err = -EFAULT;
> >   			goto err;
> >   		}
> > -		if (fence.flags & __I915_EXEC_FENCE_UNKNOWN_FLAGS) {
> > +		if (user_fence.flags & __I915_EXEC_FENCE_UNKNOWN_FLAGS) {
> >   			err = -EINVAL;
> >   			goto err;
> >   		}
> > -		syncobj = drm_syncobj_find(file, fence.handle);
> > +		syncobj = drm_syncobj_find(eb->file, user_fence.handle);
> >   		if (!syncobj) {
> >   			DRM_DEBUG("Invalid syncobj handle provided\n");
> >   			err = -ENOENT;
> >   			goto err;
> >   		}
> > +		if (user_fence.flags & I915_EXEC_FENCE_WAIT) {
> > +			fence = drm_syncobj_fence_get(syncobj);
> > +			if (!fence) {
> > +				DRM_DEBUG("Syncobj handle has no fence\n");
> > +				drm_syncobj_put(syncobj);
> > +				err = -EINVAL;
> > +				goto err;
> > +			}
> > +		}
> > +
> >   		BUILD_BUG_ON(~(ARCH_KMALLOC_MINALIGN - 1) &
> >   			     ~__I915_EXEC_FENCE_UNKNOWN_FLAGS);
> > -		fences[n] = ptr_pack_bits(syncobj, fence.flags, 2);
> > +		fences[n].syncobj = ptr_pack_bits(syncobj, user_fence.flags, 2);
> > +		fences[n].dma_fence = fence;
> > +		fences[n].value = 0;
> > +		fences[n].chain_fence = NULL;
> >   	}
> >   	return fences;
> > @@ -2314,37 +2474,45 @@ get_fence_array(struct drm_i915_gem_execbuffer2 *args,
> >   	return ERR_PTR(err);
> >   }
> > +static struct i915_eb_fences *
> > +get_fence_array(struct i915_execbuffer *eb, int *out_n_fences)
> > +{
> > +	if (eb->args->flags & I915_EXEC_FENCE_ARRAY)
> > +		return get_legacy_fence_array(eb, out_n_fences);
> > +
> > +	if (eb->extensions.flags & BIT_ULL(DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES))
> > +		return get_timeline_fence_array(eb, out_n_fences);
> > +
> > +	*out_n_fences = 0;
> > +	return NULL;
> > +}
> > +
> >   static void
> > -put_fence_array(struct drm_i915_gem_execbuffer2 *args,
> > -		struct drm_syncobj **fences)
> > +put_fence_array(struct i915_eb_fences *fences, int nfences)
> >   {
> >   	if (fences)
> > -		__free_fence_array(fences, args->num_cliprects);
> > +		__free_fence_array(fences, nfences);
> >   }
> >   static int
> >   await_fence_array(struct i915_execbuffer *eb,
> > -		  struct drm_syncobj **fences)
> > +		  struct i915_eb_fences *fences,
> > +		  int nfences)
> >   {
> > -	const unsigned int nfences = eb->args->num_cliprects;
> >   	unsigned int n;
> >   	int err;
> >   	for (n = 0; n < nfences; n++) {
> >   		struct drm_syncobj *syncobj;
> > -		struct dma_fence *fence;
> >   		unsigned int flags;
> > -		syncobj = ptr_unpack_bits(fences[n], &flags, 2);
> > -		if (!(flags & I915_EXEC_FENCE_WAIT))
> > -			continue;
> > +		syncobj = ptr_unpack_bits(fences[n].syncobj, &flags, 2);
> > -		fence = drm_syncobj_fence_get(syncobj);
> > -		if (!fence)
> > -			return -EINVAL;
> > +		if (!fences[n].dma_fence)
> > +			continue;
> > -		err = i915_request_await_dma_fence(eb->request, fence);
> > -		dma_fence_put(fence);
> > +		err = i915_request_await_dma_fence(eb->request,
> > +						   fences[n].dma_fence);
> >   		if (err < 0)
> >   			return err;
> >   	}
> > @@ -2354,9 +2522,9 @@ await_fence_array(struct i915_execbuffer *eb,
> >   static void
> >   signal_fence_array(struct i915_execbuffer *eb,
> > -		   struct drm_syncobj **fences)
> > +		   struct i915_eb_fences *fences,
> > +		   int nfences)
> >   {
> > -	const unsigned int nfences = eb->args->num_cliprects;
> >   	struct dma_fence * const fence = &eb->request->fence;
> >   	unsigned int n;
> > @@ -2364,14 +2532,44 @@ signal_fence_array(struct i915_execbuffer *eb,
> >   		struct drm_syncobj *syncobj;
> >   		unsigned int flags;
> > -		syncobj = ptr_unpack_bits(fences[n], &flags, 2);
> > +		syncobj = ptr_unpack_bits(fences[n].syncobj, &flags, 2);
> >   		if (!(flags & I915_EXEC_FENCE_SIGNAL))
> >   			continue;
> > -		drm_syncobj_replace_fence(syncobj, fence);
> > +		if (fences[n].chain_fence) {
> > +			drm_syncobj_add_point(syncobj, fences[n].chain_fence,
> > +					      fence, fences[n].value);
> > +			/*
> > +			 * The chain's ownership is transferred to the
> > +			 * timeline.
> > +			 */
> > +			fences[n].chain_fence = NULL;
> > +		} else {
> > +			drm_syncobj_replace_fence(syncobj, fence);
> > +		}
> >   	}
> >   }
> > +static int parse_timeline_fences(struct i915_user_extension __user *ext, void *data)
> > +{
> > +	struct i915_execbuffer *eb = data;
> > +
> > +	/* Timeline fences are incompatible with the fence array flag. */
> > +	if (eb->args->flags & I915_EXEC_FENCE_ARRAY)
> > +		return -EINVAL;
> > +
> > +	if (eb->extensions.flags & BIT_ULL(DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES))
> > +		return -EINVAL;
> > +
> > +	if (copy_from_user(&eb->extensions.timeline_fences, ext,
> > +			   sizeof(eb->extensions.timeline_fences)))
> > +		return -EFAULT;
> > +
> > +	eb->extensions.flags |= BIT_ULL(DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES);
> > +
> > +	return 0;
> > +}
> > +
> >   static void retire_requests(struct intel_timeline *tl, struct i915_request *end)
> >   {
> >   	struct i915_request *rq, *rn;
> > @@ -2438,6 +2636,7 @@ static void eb_request_add(struct i915_execbuffer *eb)
> >   }
> >   static const i915_user_extension_fn execbuf_extensions[] = {
> > +	[DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES] = parse_timeline_fences,
> >   };
> >   static int
> > @@ -2468,16 +2667,17 @@ static int
> >   i915_gem_do_execbuffer(struct drm_device *dev,
> >   		       struct drm_file *file,
> >   		       struct drm_i915_gem_execbuffer2 *args,
> > -		       struct drm_i915_gem_exec_object2 *exec,
> > -		       struct drm_syncobj **fences)
> > +		       struct drm_i915_gem_exec_object2 *exec)
> >   {
> >   	struct drm_i915_private *i915 = to_i915(dev);
> >   	struct i915_execbuffer eb;
> >   	struct dma_fence *in_fence = NULL;
> >   	struct dma_fence *exec_fence = NULL;
> >   	struct sync_file *out_fence = NULL;
> > +	struct i915_eb_fences *fences = NULL;
> >   	struct i915_vma *batch;
> >   	int out_fence_fd = -1;
> > +	int nfences = 0;
> >   	int err;
> >   	BUILD_BUG_ON(__EXEC_INTERNAL_FLAGS & ~__I915_EXEC_ILLEGAL_FLAGS);
> > @@ -2521,10 +2721,16 @@ i915_gem_do_execbuffer(struct drm_device *dev,
> >   	if (err)
> >   		return err;
> > +	fences = get_fence_array(&eb, &nfences);
> > +	if (IS_ERR(fences))
> > +		return PTR_ERR(fences);
> > +
> >   	if (args->flags & I915_EXEC_FENCE_IN) {
> >   		in_fence = sync_file_get_fence(lower_32_bits(args->rsvd2));
> > -		if (!in_fence)
> > -			return -EINVAL;
> > +		if (!in_fence) {
> > +			err = -EINVAL;
> > +			goto err_fences;
> > +		}
> >   	}
> >   	if (args->flags & I915_EXEC_FENCE_SUBMIT) {
> > @@ -2648,7 +2854,7 @@ i915_gem_do_execbuffer(struct drm_device *dev,
> >   	}
> >   	if (fences) {
> > -		err = await_fence_array(&eb, fences);
> > +		err = await_fence_array(&eb, fences, nfences);
> >   		if (err)
> >   			goto err_request;
> >   	}
> > @@ -2680,7 +2886,7 @@ i915_gem_do_execbuffer(struct drm_device *dev,
> >   	eb_request_add(&eb);
> >   	if (fences)
> > -		signal_fence_array(&eb, fences);
> > +		signal_fence_array(&eb, fences, nfences);
> >   	if (out_fence) {
> >   		if (err == 0) {
> > @@ -2715,6 +2921,8 @@ i915_gem_do_execbuffer(struct drm_device *dev,
> >   	dma_fence_put(exec_fence);
> >   err_in_fence:
> >   	dma_fence_put(in_fence);
> > +err_fences:
> > +	put_fence_array(fences, nfences);
> >   	return err;
> >   }
> > @@ -2809,7 +3017,7 @@ i915_gem_execbuffer_ioctl(struct drm_device *dev, void *data,
> >   			exec2_list[i].flags = 0;
> >   	}
> > -	err = i915_gem_do_execbuffer(dev, file, &exec2, exec2_list, NULL);
> > +	err = i915_gem_do_execbuffer(dev, file, &exec2, exec2_list);
> >   	if (exec2.flags & __EXEC_HAS_RELOC) {
> >   		struct drm_i915_gem_exec_object __user *user_exec_list =
> >   			u64_to_user_ptr(args->buffers_ptr);
> > @@ -2841,7 +3049,6 @@ i915_gem_execbuffer2_ioctl(struct drm_device *dev, void *data,
> >   	struct drm_i915_private *i915 = to_i915(dev);
> >   	struct drm_i915_gem_execbuffer2 *args = data;
> >   	struct drm_i915_gem_exec_object2 *exec2_list;
> > -	struct drm_syncobj **fences = NULL;
> >   	const size_t count = args->buffer_count;
> >   	int err;
> > @@ -2869,15 +3076,7 @@ i915_gem_execbuffer2_ioctl(struct drm_device *dev, void *data,
> >   		return -EFAULT;
> >   	}
> > -	if (args->flags & I915_EXEC_FENCE_ARRAY) {
> > -		fences = get_fence_array(args, file);
> > -		if (IS_ERR(fences)) {
> > -			kvfree(exec2_list);
> > -			return PTR_ERR(fences);
> > -		}
> > -	}
> > -
> > -	err = i915_gem_do_execbuffer(dev, file, args, exec2_list, fences);
> > +	err = i915_gem_do_execbuffer(dev, file, args, exec2_list);
> >   	/*
> >   	 * Now that we have begun execution of the batchbuffer, we ignore
> > @@ -2917,7 +3116,6 @@ end:;
> >   	}
> >   	args->flags &= ~__I915_EXEC_UNKNOWN_FLAGS;
> > -	put_fence_array(args, fences);
> >   	kvfree(exec2_list);
> >   	return err;
> >   }
> > diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> > index a7a3b4b98572..f7f868c3c510 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.c
> > +++ b/drivers/gpu/drm/i915/i915_drv.c
> > @@ -1828,7 +1828,8 @@ static struct drm_driver driver = {
> >   	 */
> >   	.driver_features =
> >   	    DRIVER_GEM |
> > -	    DRIVER_RENDER | DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_SYNCOBJ,
> > +	    DRIVER_RENDER | DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_SYNCOBJ |
> > +	    DRIVER_SYNCOBJ_TIMELINE,
> >   	.release = i915_driver_release,
> >   	.open = i915_driver_open,
> >   	.lastclose = i915_driver_lastclose,
> > diff --git a/drivers/gpu/drm/i915/i915_getparam.c b/drivers/gpu/drm/i915/i915_getparam.c
> > index 54fce81d5724..b9d3aab53c03 100644
> > --- a/drivers/gpu/drm/i915/i915_getparam.c
> > +++ b/drivers/gpu/drm/i915/i915_getparam.c
> > @@ -132,6 +132,7 @@ int i915_getparam_ioctl(struct drm_device *dev, void *data,
> >   	case I915_PARAM_HAS_EXEC_BATCH_FIRST:
> >   	case I915_PARAM_HAS_EXEC_FENCE_ARRAY:
> >   	case I915_PARAM_HAS_EXEC_SUBMIT_FENCE:
> > +	case I915_PARAM_HAS_EXEC_TIMELINE_FENCES:
> >   		/* For the time being all of these are always true;
> >   		 * if some supported hardware does not have one of these
> >   		 * features this value needs to be provided from
> > diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
> > index 7ea38aa6502c..7b8680e3b49d 100644
> > --- a/include/uapi/drm/i915_drm.h
> > +++ b/include/uapi/drm/i915_drm.h
> > @@ -619,6 +619,12 @@ typedef struct drm_i915_irq_wait {
> >    */
> >   #define I915_PARAM_PERF_REVISION	54
> > +/* Query whether DRM_I915_GEM_EXECBUFFER2 supports supplying an array of
> > + * timeline syncobj through drm_i915_gem_execbuf_ext_timeline_fences. See
> > + * I915_EXEC_USE_EXTENSIONS.
> > + */
> > +#define I915_PARAM_HAS_EXEC_TIMELINE_FENCES 55
> > +
> >   /* Must be kept compact -- no holes and well documented */
> >   typedef struct drm_i915_getparam {
> > @@ -1047,9 +1053,41 @@ struct drm_i915_gem_exec_fence {
> >   };
> >   enum drm_i915_gem_execbuffer_ext {
> > +	/**
> > +	 * See drm_i915_gem_execbuf_ext_timeline_fences.
> > +	 */
> > +	DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES = 1,
> > +
> >   	DRM_I915_GEM_EXECBUFFER_EXT_MAX /* non-ABI */
> >   };
> > +/**
> > + * This structure describes an array of drm_syncobj and associated points for
> > + * timeline variants of drm_syncobj. It is invalid to append this structure to
> > + * the execbuf if I915_EXEC_FENCE_ARRAY is set.
> > + */
> > +struct drm_i915_gem_execbuffer_ext_timeline_fences {
> > +	struct i915_user_extension base;
> > +
> > +	/**
> > +	 * Number of element in the handles_ptr & value_ptr arrays.
> > +	 */
> > +	__u64 fence_count;
> > +
> > +	/**
> > +	 * Pointer to an array of struct drm_i915_gem_exec_fence of length
> > +	 * fence_count.
> > +	 */
> > +	__u64 handles_ptr;
> > +
> > +	/**
> > +	 * Pointer to an array of u64 values of length fence_count. Values
> > +	 * must be 0 for a binary drm_syncobj. A Value of 0 for a timeline
> > +	 * drm_syncobj is invalid as it turns a drm_syncobj into a binary one.
> > +	 */
> > +	__u64 values_ptr;
> > +};
> > +
> >   struct drm_i915_gem_execbuffer2 {
> >   	/**
> >   	 * List of gem_exec_object2 structs
> 
>
Lionel Landwerlin April 8, 2020, 5:14 p.m. UTC | #3
On 06/04/2020 23:07, Venkata Sandeep Dhanalakota wrote:
> Introduces a new parameters to execbuf so that we can specify syncobj
> handles as well as timeline points.
>
> v2: Reuse i915_user_extension_fn
>
> v3: Check that the chained extension is only present once (Chris)
>
> v4: Check that dma_fence_chain_find_seqno returns a non NULL fence
> (Lionel)
>
> v5: Use BIT_ULL (Chris)
>
> v6: Fix issue with already signaled timeline points,
>      dma_fence_chain_find_seqno() setting fence to NULL (Chris)
>
> v7: Report ENOENT with invalid syncobj handle (Lionel)
>
> v8: Check for out of order timeline point insertion (Chris)
>
> v9: After explanations on
>      https://lists.freedesktop.org/archives/dri-devel/2019-August/229287.html
>      drop the ordering check from v8 (Lionel)
>
> v10: Set first extension enum item to 1 (Jason)
>
> v11: Add wait on previous sync points in timelines (Sandeep)
>
> Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
> Signed-off-by: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota at intel.com>
> ---
>   .../gpu/drm/i915/gem/i915_gem_execbuffer.c    | 312 ++++++++++++++----
>   drivers/gpu/drm/i915/i915_drv.c               |   3 +-
>   drivers/gpu/drm/i915/i915_getparam.c          |   1 +
>   include/uapi/drm/i915_drm.h                   |  38 +++
>   4 files changed, 296 insertions(+), 58 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> index 16831f715daa..4cb4cd035daa 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> @@ -230,6 +230,13 @@ enum {
>    * the batchbuffer in trusted mode, otherwise the ioctl is rejected.
>    */
>   
> +struct i915_eb_fences {
> +	struct drm_syncobj *syncobj; /* Use with ptr_mask_bits() */
> +	struct dma_fence *dma_fence;
> +	u64 value;
> +	struct dma_fence_chain *chain_fence;
> +};
> +
>   struct i915_execbuffer {
>   	struct drm_i915_private *i915; /** i915 backpointer */
>   	struct drm_file *file; /** per-file lookup tables and limits */
> @@ -292,6 +299,7 @@ struct i915_execbuffer {
>   
>   	struct {
>   		u64 flags; /** Available extensions parameters */
> +		struct drm_i915_gem_execbuffer_ext_timeline_fences timeline_fences;
>   	} extensions;
>   };
>   
> @@ -2244,67 +2252,219 @@ eb_pin_engine(struct i915_execbuffer *eb,
>   }
>   
>   static void
> -__free_fence_array(struct drm_syncobj **fences, unsigned int n)
> +__free_fence_array(struct i915_eb_fences *fences, unsigned int n)
>   {
> -	while (n--)
> -		drm_syncobj_put(ptr_mask_bits(fences[n], 2));
> +	while (n--) {
> +		drm_syncobj_put(ptr_mask_bits(fences[n].syncobj, 2));
> +		dma_fence_put(fences[n].dma_fence);
> +		kfree(fences[n].chain_fence);
> +	}
>   	kvfree(fences);
>   }
>   
> -static struct drm_syncobj **
> -get_fence_array(struct drm_i915_gem_execbuffer2 *args,
> -		struct drm_file *file)
> +static struct i915_eb_fences *
> +get_timeline_fence_array(struct i915_execbuffer *eb, int *out_n_fences)
> +{
> +	struct drm_i915_gem_execbuffer_ext_timeline_fences *timeline_fences =
> +		&eb->extensions.timeline_fences;
> +	struct drm_i915_gem_exec_fence __user *user_fences;
> +	struct i915_eb_fences *fences;
> +	u64 __user *user_values;
> +	u64 num_fences, num_user_fences = timeline_fences->fence_count;
> +	unsigned long n;
> +	int err = 0;
> +
> +	/* Check multiplication overflow for access_ok() and kvmalloc_array() */
> +	BUILD_BUG_ON(sizeof(size_t) > sizeof(unsigned long));
> +	if (num_user_fences > min_t(unsigned long,
> +				    ULONG_MAX / sizeof(*user_fences),
> +				    SIZE_MAX / sizeof(*fences)))
> +		return ERR_PTR(-EINVAL);
> +
> +	user_fences = u64_to_user_ptr(timeline_fences->handles_ptr);
> +	if (!access_ok(user_fences, num_user_fences * sizeof(*user_fences)))
> +		return ERR_PTR(-EFAULT);
> +
> +	user_values = u64_to_user_ptr(timeline_fences->values_ptr);
> +	if (!access_ok(user_values, num_user_fences * sizeof(*user_values)))
> +		return ERR_PTR(-EFAULT);
> +
> +	fences = kvmalloc_array(num_user_fences, sizeof(*fences),
> +				__GFP_NOWARN | GFP_KERNEL);
> +	if (!fences)
> +		return ERR_PTR(-ENOMEM);
> +
> +	BUILD_BUG_ON(~(ARCH_KMALLOC_MINALIGN - 1) &
> +		     ~__I915_EXEC_FENCE_UNKNOWN_FLAGS);
> +
> +	for (n = 0, num_fences = 0; n < timeline_fences->fence_count; n++) {
> +		struct drm_i915_gem_exec_fence user_fence;
> +		struct drm_syncobj *syncobj;
> +		struct dma_fence *fence = NULL;
> +		u64 point;
> +
> +		if (__copy_from_user(&user_fence, user_fences++, sizeof(user_fence))) {
> +			err = -EFAULT;
> +			goto err;
> +		}
> +
> +		if (user_fence.flags & __I915_EXEC_FENCE_UNKNOWN_FLAGS) {
> +			err = -EINVAL;
> +			goto err;
> +		}
> +
> +		if (__get_user(point, user_values++)) {
> +			err = -EFAULT;
> +			goto err;
> +		}
> +
> +		syncobj = drm_syncobj_find(eb->file, user_fence.handle);
> +		if (!syncobj) {
> +			DRM_DEBUG("Invalid syncobj handle provided\n");
> +			err = -ENOENT;
> +			goto err;
> +		}
> +
> +		fence = drm_syncobj_fence_get(syncobj);
> +
> +		if (!fence && user_fence.flags &&
> +		    !(user_fence.flags & I915_EXEC_FENCE_SIGNAL)) {
> +			DRM_DEBUG("Syncobj handle has no fence\n");
> +			drm_syncobj_put(syncobj);
> +			err = -EINVAL;
> +			goto err;
> +		}
> +
> +		if (fence)
> +			err = dma_fence_chain_find_seqno(&fence, point);
> +
> +		if (err && !(user_fence.flags & I915_EXEC_FENCE_SIGNAL)) {
> +			DRM_DEBUG("Syncobj handle missing requested point %llu\n", point);
> +			drm_syncobj_put(syncobj);
> +			goto err;
> +		}
> +
> +		/* A point might have been signaled already and
> +		 * garbage collected from the timeline. In this case
> +		 * just ignore the point and carry on.
> +		 */
> +		if (!fence && (user_fence.flags & I915_EXEC_FENCE_WAIT)) {


I think we can only skip if we're only waiting. If there is a signal 
request we still need to honor it.

So I would replace this function above with :

if (!fence && !(user_fence.flags & I915_EXEC_FENCE_SIGNAL)) {


> +			drm_syncobj_put(syncobj);
> +			continue;
> +		}
> +
> +		/*
> +		 * For timeline syncobjs we need to preallocate chains for
> +		 * later signaling.
> +		 */
> +		if (point != 0 && user_fence.flags & I915_EXEC_FENCE_SIGNAL) {
> +			/*
> +			 * Waiting and signaling the same point (when point !=
> +			 * 0) would break the timeline.
> +			 */
> +			if (user_fence.flags & I915_EXEC_FENCE_WAIT) {
> +				DRM_DEBUG("Trying to wait & signal the same timeline point.\n");
> +				err = -EINVAL;
> +				drm_syncobj_put(syncobj);
> +				goto err;
> +			}


I think we can actually allow this. Wait and signal operations are added 
in order so we could wait a point 3 and then replace it by another point 3.


If we keep this limitation, we need to add :

if (fence)

     dma_fence_put(fence);


> +
> +			fences[num_fences].chain_fence =
> +				kmalloc(sizeof(*fences[num_fences].chain_fence),
> +					GFP_KERNEL);
> +			if (!fences[num_fences].chain_fence) {
> +				drm_syncobj_put(syncobj);


We the change above, we could arrive here with fence != NULL.

We probably need to add :

if (fence)

     dma_fence_put(fence);


> +				err = -ENOMEM;
> +				DRM_DEBUG("Unable to alloc chain_fence\n");
> +				goto err;
> +			}
> +		} else {
> +			fences[num_fences].chain_fence = NULL;
> +		}
> +
> +		fences[num_fences].syncobj = ptr_pack_bits(syncobj, user_fence.flags, 2);
> +		fences[num_fences].dma_fence = fence;
> +		fences[num_fences].value = point;
> +		num_fences++;
> +	}
> +
> +	*out_n_fences = num_fences;
> +
> +	return fences;
> +
> +err:
> +	__free_fence_array(fences, num_fences);
> +	return ERR_PTR(err);
> +}
> +
> +static struct i915_eb_fences *
> +get_legacy_fence_array(struct i915_execbuffer *eb,
> +		       int *out_n_fences)
>   {
> -	const unsigned long nfences = args->num_cliprects;
> +	struct drm_i915_gem_execbuffer2 *args = eb->args;
>   	struct drm_i915_gem_exec_fence __user *user;
> -	struct drm_syncobj **fences;
> +	struct i915_eb_fences *fences;
> +	const u32 num_fences = args->num_cliprects;
>   	unsigned long n;
>   	int err;
>   
> -	if (!(args->flags & I915_EXEC_FENCE_ARRAY))
> -		return NULL;
> +	*out_n_fences = num_fences;
>   
>   	/* Check multiplication overflow for access_ok() and kvmalloc_array() */
>   	BUILD_BUG_ON(sizeof(size_t) > sizeof(unsigned long));
> -	if (nfences > min_t(unsigned long,
> -			    ULONG_MAX / sizeof(*user),
> -			    SIZE_MAX / sizeof(*fences)))
> +	if (*out_n_fences > min_t(unsigned long,
> +				  ULONG_MAX / sizeof(*user),
> +				  SIZE_MAX / sizeof(*fences)))
>   		return ERR_PTR(-EINVAL);
>   
>   	user = u64_to_user_ptr(args->cliprects_ptr);
> -	if (!access_ok(user, nfences * sizeof(*user)))
> +	if (!access_ok(user, *out_n_fences * sizeof(*user)))
>   		return ERR_PTR(-EFAULT);
>   
> -	fences = kvmalloc_array(nfences, sizeof(*fences),
> +	fences = kvmalloc_array(*out_n_fences, sizeof(*fences),
>   				__GFP_NOWARN | GFP_KERNEL);
>   	if (!fences)
>   		return ERR_PTR(-ENOMEM);
>   
> -	for (n = 0; n < nfences; n++) {
> -		struct drm_i915_gem_exec_fence fence;
> +	for (n = 0; n < *out_n_fences; n++) {
> +		struct drm_i915_gem_exec_fence user_fence;
>   		struct drm_syncobj *syncobj;
> +		struct dma_fence *fence = NULL;
>   
> -		if (__copy_from_user(&fence, user++, sizeof(fence))) {
> +		if (__copy_from_user(&user_fence, user++, sizeof(user_fence))) {
>   			err = -EFAULT;
>   			goto err;
>   		}
>   
> -		if (fence.flags & __I915_EXEC_FENCE_UNKNOWN_FLAGS) {
> +		if (user_fence.flags & __I915_EXEC_FENCE_UNKNOWN_FLAGS) {
>   			err = -EINVAL;
>   			goto err;
>   		}
>   
> -		syncobj = drm_syncobj_find(file, fence.handle);
> +		syncobj = drm_syncobj_find(eb->file, user_fence.handle);
>   		if (!syncobj) {
>   			DRM_DEBUG("Invalid syncobj handle provided\n");
>   			err = -ENOENT;
>   			goto err;
>   		}
>   
> +		if (user_fence.flags & I915_EXEC_FENCE_WAIT) {
> +			fence = drm_syncobj_fence_get(syncobj);
> +			if (!fence) {
> +				DRM_DEBUG("Syncobj handle has no fence\n");
> +				drm_syncobj_put(syncobj);
> +				err = -EINVAL;
> +				goto err;
> +			}
> +		}
> +
>   		BUILD_BUG_ON(~(ARCH_KMALLOC_MINALIGN - 1) &
>   			     ~__I915_EXEC_FENCE_UNKNOWN_FLAGS);
>   
> -		fences[n] = ptr_pack_bits(syncobj, fence.flags, 2);
> +		fences[n].syncobj = ptr_pack_bits(syncobj, user_fence.flags, 2);
> +		fences[n].dma_fence = fence;
> +		fences[n].value = 0;
> +		fences[n].chain_fence = NULL;
>   	}
>   
>   	return fences;
> @@ -2314,37 +2474,45 @@ get_fence_array(struct drm_i915_gem_execbuffer2 *args,
>   	return ERR_PTR(err);
>   }
>   
> +static struct i915_eb_fences *
> +get_fence_array(struct i915_execbuffer *eb, int *out_n_fences)
> +{
> +	if (eb->args->flags & I915_EXEC_FENCE_ARRAY)
> +		return get_legacy_fence_array(eb, out_n_fences);
> +
> +	if (eb->extensions.flags & BIT_ULL(DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES))
> +		return get_timeline_fence_array(eb, out_n_fences);
> +
> +	*out_n_fences = 0;
> +	return NULL;
> +}
> +
>   static void
> -put_fence_array(struct drm_i915_gem_execbuffer2 *args,
> -		struct drm_syncobj **fences)
> +put_fence_array(struct i915_eb_fences *fences, int nfences)
>   {
>   	if (fences)
> -		__free_fence_array(fences, args->num_cliprects);
> +		__free_fence_array(fences, nfences);
>   }
>   
>   static int
>   await_fence_array(struct i915_execbuffer *eb,
> -		  struct drm_syncobj **fences)
> +		  struct i915_eb_fences *fences,
> +		  int nfences)
>   {
> -	const unsigned int nfences = eb->args->num_cliprects;
>   	unsigned int n;
>   	int err;
>   
>   	for (n = 0; n < nfences; n++) {
>   		struct drm_syncobj *syncobj;
> -		struct dma_fence *fence;
>   		unsigned int flags;
>   
> -		syncobj = ptr_unpack_bits(fences[n], &flags, 2);
> -		if (!(flags & I915_EXEC_FENCE_WAIT))
> -			continue;
> +		syncobj = ptr_unpack_bits(fences[n].syncobj, &flags, 2);
>   
> -		fence = drm_syncobj_fence_get(syncobj);
> -		if (!fence)
> -			return -EINVAL;
> +		if (!fences[n].dma_fence)
> +			continue;
>   
> -		err = i915_request_await_dma_fence(eb->request, fence);
> -		dma_fence_put(fence);
> +		err = i915_request_await_dma_fence(eb->request,
> +						   fences[n].dma_fence);
>   		if (err < 0)
>   			return err;
>   	}
> @@ -2354,9 +2522,9 @@ await_fence_array(struct i915_execbuffer *eb,
>   
>   static void
>   signal_fence_array(struct i915_execbuffer *eb,
> -		   struct drm_syncobj **fences)
> +		   struct i915_eb_fences *fences,
> +		   int nfences)
>   {
> -	const unsigned int nfences = eb->args->num_cliprects;
>   	struct dma_fence * const fence = &eb->request->fence;
>   	unsigned int n;
>   
> @@ -2364,14 +2532,44 @@ signal_fence_array(struct i915_execbuffer *eb,
>   		struct drm_syncobj *syncobj;
>   		unsigned int flags;
>   
> -		syncobj = ptr_unpack_bits(fences[n], &flags, 2);
> +		syncobj = ptr_unpack_bits(fences[n].syncobj, &flags, 2);
>   		if (!(flags & I915_EXEC_FENCE_SIGNAL))
>   			continue;
>   
> -		drm_syncobj_replace_fence(syncobj, fence);
> +		if (fences[n].chain_fence) {
> +			drm_syncobj_add_point(syncobj, fences[n].chain_fence,
> +					      fence, fences[n].value);
> +			/*
> +			 * The chain's ownership is transferred to the
> +			 * timeline.
> +			 */
> +			fences[n].chain_fence = NULL;
> +		} else {
> +			drm_syncobj_replace_fence(syncobj, fence);
> +		}
>   	}
>   }
>   
> +static int parse_timeline_fences(struct i915_user_extension __user *ext, void *data)
> +{
> +	struct i915_execbuffer *eb = data;
> +
> +	/* Timeline fences are incompatible with the fence array flag. */
> +	if (eb->args->flags & I915_EXEC_FENCE_ARRAY)
> +		return -EINVAL;
> +
> +	if (eb->extensions.flags & BIT_ULL(DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES))
> +		return -EINVAL;
> +
> +	if (copy_from_user(&eb->extensions.timeline_fences, ext,
> +			   sizeof(eb->extensions.timeline_fences)))
> +		return -EFAULT;
> +
> +	eb->extensions.flags |= BIT_ULL(DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES);
> +
> +	return 0;
> +}
> +
>   static void retire_requests(struct intel_timeline *tl, struct i915_request *end)
>   {
>   	struct i915_request *rq, *rn;
> @@ -2438,6 +2636,7 @@ static void eb_request_add(struct i915_execbuffer *eb)
>   }
>   
>   static const i915_user_extension_fn execbuf_extensions[] = {
> +	[DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES] = parse_timeline_fences,
>   };
>   
>   static int
> @@ -2468,16 +2667,17 @@ static int
>   i915_gem_do_execbuffer(struct drm_device *dev,
>   		       struct drm_file *file,
>   		       struct drm_i915_gem_execbuffer2 *args,
> -		       struct drm_i915_gem_exec_object2 *exec,
> -		       struct drm_syncobj **fences)
> +		       struct drm_i915_gem_exec_object2 *exec)
>   {
>   	struct drm_i915_private *i915 = to_i915(dev);
>   	struct i915_execbuffer eb;
>   	struct dma_fence *in_fence = NULL;
>   	struct dma_fence *exec_fence = NULL;
>   	struct sync_file *out_fence = NULL;
> +	struct i915_eb_fences *fences = NULL;
>   	struct i915_vma *batch;
>   	int out_fence_fd = -1;
> +	int nfences = 0;
>   	int err;
>   
>   	BUILD_BUG_ON(__EXEC_INTERNAL_FLAGS & ~__I915_EXEC_ILLEGAL_FLAGS);
> @@ -2521,10 +2721,16 @@ i915_gem_do_execbuffer(struct drm_device *dev,
>   	if (err)
>   		return err;
>   
> +	fences = get_fence_array(&eb, &nfences);
> +	if (IS_ERR(fences))
> +		return PTR_ERR(fences);
> +
>   	if (args->flags & I915_EXEC_FENCE_IN) {
>   		in_fence = sync_file_get_fence(lower_32_bits(args->rsvd2));
> -		if (!in_fence)
> -			return -EINVAL;
> +		if (!in_fence) {
> +			err = -EINVAL;
> +			goto err_fences;
> +		}
>   	}
>   
>   	if (args->flags & I915_EXEC_FENCE_SUBMIT) {
> @@ -2648,7 +2854,7 @@ i915_gem_do_execbuffer(struct drm_device *dev,
>   	}
>   
>   	if (fences) {
> -		err = await_fence_array(&eb, fences);
> +		err = await_fence_array(&eb, fences, nfences);
>   		if (err)
>   			goto err_request;
>   	}
> @@ -2680,7 +2886,7 @@ i915_gem_do_execbuffer(struct drm_device *dev,
>   	eb_request_add(&eb);
>   
>   	if (fences)
> -		signal_fence_array(&eb, fences);
> +		signal_fence_array(&eb, fences, nfences);
>   
>   	if (out_fence) {
>   		if (err == 0) {
> @@ -2715,6 +2921,8 @@ i915_gem_do_execbuffer(struct drm_device *dev,
>   	dma_fence_put(exec_fence);
>   err_in_fence:
>   	dma_fence_put(in_fence);
> +err_fences:
> +	put_fence_array(fences, nfences);
>   	return err;
>   }
>   
> @@ -2809,7 +3017,7 @@ i915_gem_execbuffer_ioctl(struct drm_device *dev, void *data,
>   			exec2_list[i].flags = 0;
>   	}
>   
> -	err = i915_gem_do_execbuffer(dev, file, &exec2, exec2_list, NULL);
> +	err = i915_gem_do_execbuffer(dev, file, &exec2, exec2_list);
>   	if (exec2.flags & __EXEC_HAS_RELOC) {
>   		struct drm_i915_gem_exec_object __user *user_exec_list =
>   			u64_to_user_ptr(args->buffers_ptr);
> @@ -2841,7 +3049,6 @@ i915_gem_execbuffer2_ioctl(struct drm_device *dev, void *data,
>   	struct drm_i915_private *i915 = to_i915(dev);
>   	struct drm_i915_gem_execbuffer2 *args = data;
>   	struct drm_i915_gem_exec_object2 *exec2_list;
> -	struct drm_syncobj **fences = NULL;
>   	const size_t count = args->buffer_count;
>   	int err;
>   
> @@ -2869,15 +3076,7 @@ i915_gem_execbuffer2_ioctl(struct drm_device *dev, void *data,
>   		return -EFAULT;
>   	}
>   
> -	if (args->flags & I915_EXEC_FENCE_ARRAY) {
> -		fences = get_fence_array(args, file);
> -		if (IS_ERR(fences)) {
> -			kvfree(exec2_list);
> -			return PTR_ERR(fences);
> -		}
> -	}
> -
> -	err = i915_gem_do_execbuffer(dev, file, args, exec2_list, fences);
> +	err = i915_gem_do_execbuffer(dev, file, args, exec2_list);
>   
>   	/*
>   	 * Now that we have begun execution of the batchbuffer, we ignore
> @@ -2917,7 +3116,6 @@ end:;
>   	}
>   
>   	args->flags &= ~__I915_EXEC_UNKNOWN_FLAGS;
> -	put_fence_array(args, fences);
>   	kvfree(exec2_list);
>   	return err;
>   }
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index a7a3b4b98572..f7f868c3c510 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -1828,7 +1828,8 @@ static struct drm_driver driver = {
>   	 */
>   	.driver_features =
>   	    DRIVER_GEM |
> -	    DRIVER_RENDER | DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_SYNCOBJ,
> +	    DRIVER_RENDER | DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_SYNCOBJ |
> +	    DRIVER_SYNCOBJ_TIMELINE,
>   	.release = i915_driver_release,
>   	.open = i915_driver_open,
>   	.lastclose = i915_driver_lastclose,
> diff --git a/drivers/gpu/drm/i915/i915_getparam.c b/drivers/gpu/drm/i915/i915_getparam.c
> index 54fce81d5724..b9d3aab53c03 100644
> --- a/drivers/gpu/drm/i915/i915_getparam.c
> +++ b/drivers/gpu/drm/i915/i915_getparam.c
> @@ -132,6 +132,7 @@ int i915_getparam_ioctl(struct drm_device *dev, void *data,
>   	case I915_PARAM_HAS_EXEC_BATCH_FIRST:
>   	case I915_PARAM_HAS_EXEC_FENCE_ARRAY:
>   	case I915_PARAM_HAS_EXEC_SUBMIT_FENCE:
> +	case I915_PARAM_HAS_EXEC_TIMELINE_FENCES:
>   		/* For the time being all of these are always true;
>   		 * if some supported hardware does not have one of these
>   		 * features this value needs to be provided from
> diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
> index 7ea38aa6502c..7b8680e3b49d 100644
> --- a/include/uapi/drm/i915_drm.h
> +++ b/include/uapi/drm/i915_drm.h
> @@ -619,6 +619,12 @@ typedef struct drm_i915_irq_wait {
>    */
>   #define I915_PARAM_PERF_REVISION	54
>   
> +/* Query whether DRM_I915_GEM_EXECBUFFER2 supports supplying an array of
> + * timeline syncobj through drm_i915_gem_execbuf_ext_timeline_fences. See
> + * I915_EXEC_USE_EXTENSIONS.
> + */
> +#define I915_PARAM_HAS_EXEC_TIMELINE_FENCES 55
> +
>   /* Must be kept compact -- no holes and well documented */
>   
>   typedef struct drm_i915_getparam {
> @@ -1047,9 +1053,41 @@ struct drm_i915_gem_exec_fence {
>   };
>   
>   enum drm_i915_gem_execbuffer_ext {
> +	/**
> +	 * See drm_i915_gem_execbuf_ext_timeline_fences.
> +	 */
> +	DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES = 1,
> +
>   	DRM_I915_GEM_EXECBUFFER_EXT_MAX /* non-ABI */
>   };
>   
> +/**
> + * This structure describes an array of drm_syncobj and associated points for
> + * timeline variants of drm_syncobj. It is invalid to append this structure to
> + * the execbuf if I915_EXEC_FENCE_ARRAY is set.
> + */
> +struct drm_i915_gem_execbuffer_ext_timeline_fences {
> +	struct i915_user_extension base;
> +
> +	/**
> +	 * Number of element in the handles_ptr & value_ptr arrays.
> +	 */
> +	__u64 fence_count;
> +
> +	/**
> +	 * Pointer to an array of struct drm_i915_gem_exec_fence of length
> +	 * fence_count.
> +	 */
> +	__u64 handles_ptr;
> +
> +	/**
> +	 * Pointer to an array of u64 values of length fence_count. Values
> +	 * must be 0 for a binary drm_syncobj. A Value of 0 for a timeline
> +	 * drm_syncobj is invalid as it turns a drm_syncobj into a binary one.
> +	 */
> +	__u64 values_ptr;
> +};
> +
>   struct drm_i915_gem_execbuffer2 {
>   	/**
>   	 * List of gem_exec_object2 structs
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index 16831f715daa..4cb4cd035daa 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -230,6 +230,13 @@  enum {
  * the batchbuffer in trusted mode, otherwise the ioctl is rejected.
  */
 
+struct i915_eb_fences {
+	struct drm_syncobj *syncobj; /* Use with ptr_mask_bits() */
+	struct dma_fence *dma_fence;
+	u64 value;
+	struct dma_fence_chain *chain_fence;
+};
+
 struct i915_execbuffer {
 	struct drm_i915_private *i915; /** i915 backpointer */
 	struct drm_file *file; /** per-file lookup tables and limits */
@@ -292,6 +299,7 @@  struct i915_execbuffer {
 
 	struct {
 		u64 flags; /** Available extensions parameters */
+		struct drm_i915_gem_execbuffer_ext_timeline_fences timeline_fences;
 	} extensions;
 };
 
@@ -2244,67 +2252,219 @@  eb_pin_engine(struct i915_execbuffer *eb,
 }
 
 static void
-__free_fence_array(struct drm_syncobj **fences, unsigned int n)
+__free_fence_array(struct i915_eb_fences *fences, unsigned int n)
 {
-	while (n--)
-		drm_syncobj_put(ptr_mask_bits(fences[n], 2));
+	while (n--) {
+		drm_syncobj_put(ptr_mask_bits(fences[n].syncobj, 2));
+		dma_fence_put(fences[n].dma_fence);
+		kfree(fences[n].chain_fence);
+	}
 	kvfree(fences);
 }
 
-static struct drm_syncobj **
-get_fence_array(struct drm_i915_gem_execbuffer2 *args,
-		struct drm_file *file)
+static struct i915_eb_fences *
+get_timeline_fence_array(struct i915_execbuffer *eb, int *out_n_fences)
+{
+	struct drm_i915_gem_execbuffer_ext_timeline_fences *timeline_fences =
+		&eb->extensions.timeline_fences;
+	struct drm_i915_gem_exec_fence __user *user_fences;
+	struct i915_eb_fences *fences;
+	u64 __user *user_values;
+	u64 num_fences, num_user_fences = timeline_fences->fence_count;
+	unsigned long n;
+	int err = 0;
+
+	/* Check multiplication overflow for access_ok() and kvmalloc_array() */
+	BUILD_BUG_ON(sizeof(size_t) > sizeof(unsigned long));
+	if (num_user_fences > min_t(unsigned long,
+				    ULONG_MAX / sizeof(*user_fences),
+				    SIZE_MAX / sizeof(*fences)))
+		return ERR_PTR(-EINVAL);
+
+	user_fences = u64_to_user_ptr(timeline_fences->handles_ptr);
+	if (!access_ok(user_fences, num_user_fences * sizeof(*user_fences)))
+		return ERR_PTR(-EFAULT);
+
+	user_values = u64_to_user_ptr(timeline_fences->values_ptr);
+	if (!access_ok(user_values, num_user_fences * sizeof(*user_values)))
+		return ERR_PTR(-EFAULT);
+
+	fences = kvmalloc_array(num_user_fences, sizeof(*fences),
+				__GFP_NOWARN | GFP_KERNEL);
+	if (!fences)
+		return ERR_PTR(-ENOMEM);
+
+	BUILD_BUG_ON(~(ARCH_KMALLOC_MINALIGN - 1) &
+		     ~__I915_EXEC_FENCE_UNKNOWN_FLAGS);
+
+	for (n = 0, num_fences = 0; n < timeline_fences->fence_count; n++) {
+		struct drm_i915_gem_exec_fence user_fence;
+		struct drm_syncobj *syncobj;
+		struct dma_fence *fence = NULL;
+		u64 point;
+
+		if (__copy_from_user(&user_fence, user_fences++, sizeof(user_fence))) {
+			err = -EFAULT;
+			goto err;
+		}
+
+		if (user_fence.flags & __I915_EXEC_FENCE_UNKNOWN_FLAGS) {
+			err = -EINVAL;
+			goto err;
+		}
+
+		if (__get_user(point, user_values++)) {
+			err = -EFAULT;
+			goto err;
+		}
+
+		syncobj = drm_syncobj_find(eb->file, user_fence.handle);
+		if (!syncobj) {
+			DRM_DEBUG("Invalid syncobj handle provided\n");
+			err = -ENOENT;
+			goto err;
+		}
+
+		fence = drm_syncobj_fence_get(syncobj);
+
+		if (!fence && user_fence.flags &&
+		    !(user_fence.flags & I915_EXEC_FENCE_SIGNAL)) {
+			DRM_DEBUG("Syncobj handle has no fence\n");
+			drm_syncobj_put(syncobj);
+			err = -EINVAL;
+			goto err;
+		}
+
+		if (fence)
+			err = dma_fence_chain_find_seqno(&fence, point);
+
+		if (err && !(user_fence.flags & I915_EXEC_FENCE_SIGNAL)) {
+			DRM_DEBUG("Syncobj handle missing requested point %llu\n", point);
+			drm_syncobj_put(syncobj);
+			goto err;
+		}
+
+		/* A point might have been signaled already and
+		 * garbage collected from the timeline. In this case
+		 * just ignore the point and carry on.
+		 */
+		if (!fence && (user_fence.flags & I915_EXEC_FENCE_WAIT)) {
+			drm_syncobj_put(syncobj);
+			continue;
+		}
+
+		/*
+		 * For timeline syncobjs we need to preallocate chains for
+		 * later signaling.
+		 */
+		if (point != 0 && user_fence.flags & I915_EXEC_FENCE_SIGNAL) {
+			/*
+			 * Waiting and signaling the same point (when point !=
+			 * 0) would break the timeline.
+			 */
+			if (user_fence.flags & I915_EXEC_FENCE_WAIT) {
+				DRM_DEBUG("Trying to wait & signal the same timeline point.\n");
+				err = -EINVAL;
+				drm_syncobj_put(syncobj);
+				goto err;
+			}
+
+			fences[num_fences].chain_fence =
+				kmalloc(sizeof(*fences[num_fences].chain_fence),
+					GFP_KERNEL);
+			if (!fences[num_fences].chain_fence) {
+				drm_syncobj_put(syncobj);
+				err = -ENOMEM;
+				DRM_DEBUG("Unable to alloc chain_fence\n");
+				goto err;
+			}
+		} else {
+			fences[num_fences].chain_fence = NULL;
+		}
+
+		fences[num_fences].syncobj = ptr_pack_bits(syncobj, user_fence.flags, 2);
+		fences[num_fences].dma_fence = fence;
+		fences[num_fences].value = point;
+		num_fences++;
+	}
+
+	*out_n_fences = num_fences;
+
+	return fences;
+
+err:
+	__free_fence_array(fences, num_fences);
+	return ERR_PTR(err);
+}
+
+static struct i915_eb_fences *
+get_legacy_fence_array(struct i915_execbuffer *eb,
+		       int *out_n_fences)
 {
-	const unsigned long nfences = args->num_cliprects;
+	struct drm_i915_gem_execbuffer2 *args = eb->args;
 	struct drm_i915_gem_exec_fence __user *user;
-	struct drm_syncobj **fences;
+	struct i915_eb_fences *fences;
+	const u32 num_fences = args->num_cliprects;
 	unsigned long n;
 	int err;
 
-	if (!(args->flags & I915_EXEC_FENCE_ARRAY))
-		return NULL;
+	*out_n_fences = num_fences;
 
 	/* Check multiplication overflow for access_ok() and kvmalloc_array() */
 	BUILD_BUG_ON(sizeof(size_t) > sizeof(unsigned long));
-	if (nfences > min_t(unsigned long,
-			    ULONG_MAX / sizeof(*user),
-			    SIZE_MAX / sizeof(*fences)))
+	if (*out_n_fences > min_t(unsigned long,
+				  ULONG_MAX / sizeof(*user),
+				  SIZE_MAX / sizeof(*fences)))
 		return ERR_PTR(-EINVAL);
 
 	user = u64_to_user_ptr(args->cliprects_ptr);
-	if (!access_ok(user, nfences * sizeof(*user)))
+	if (!access_ok(user, *out_n_fences * sizeof(*user)))
 		return ERR_PTR(-EFAULT);
 
-	fences = kvmalloc_array(nfences, sizeof(*fences),
+	fences = kvmalloc_array(*out_n_fences, sizeof(*fences),
 				__GFP_NOWARN | GFP_KERNEL);
 	if (!fences)
 		return ERR_PTR(-ENOMEM);
 
-	for (n = 0; n < nfences; n++) {
-		struct drm_i915_gem_exec_fence fence;
+	for (n = 0; n < *out_n_fences; n++) {
+		struct drm_i915_gem_exec_fence user_fence;
 		struct drm_syncobj *syncobj;
+		struct dma_fence *fence = NULL;
 
-		if (__copy_from_user(&fence, user++, sizeof(fence))) {
+		if (__copy_from_user(&user_fence, user++, sizeof(user_fence))) {
 			err = -EFAULT;
 			goto err;
 		}
 
-		if (fence.flags & __I915_EXEC_FENCE_UNKNOWN_FLAGS) {
+		if (user_fence.flags & __I915_EXEC_FENCE_UNKNOWN_FLAGS) {
 			err = -EINVAL;
 			goto err;
 		}
 
-		syncobj = drm_syncobj_find(file, fence.handle);
+		syncobj = drm_syncobj_find(eb->file, user_fence.handle);
 		if (!syncobj) {
 			DRM_DEBUG("Invalid syncobj handle provided\n");
 			err = -ENOENT;
 			goto err;
 		}
 
+		if (user_fence.flags & I915_EXEC_FENCE_WAIT) {
+			fence = drm_syncobj_fence_get(syncobj);
+			if (!fence) {
+				DRM_DEBUG("Syncobj handle has no fence\n");
+				drm_syncobj_put(syncobj);
+				err = -EINVAL;
+				goto err;
+			}
+		}
+
 		BUILD_BUG_ON(~(ARCH_KMALLOC_MINALIGN - 1) &
 			     ~__I915_EXEC_FENCE_UNKNOWN_FLAGS);
 
-		fences[n] = ptr_pack_bits(syncobj, fence.flags, 2);
+		fences[n].syncobj = ptr_pack_bits(syncobj, user_fence.flags, 2);
+		fences[n].dma_fence = fence;
+		fences[n].value = 0;
+		fences[n].chain_fence = NULL;
 	}
 
 	return fences;
@@ -2314,37 +2474,45 @@  get_fence_array(struct drm_i915_gem_execbuffer2 *args,
 	return ERR_PTR(err);
 }
 
+static struct i915_eb_fences *
+get_fence_array(struct i915_execbuffer *eb, int *out_n_fences)
+{
+	if (eb->args->flags & I915_EXEC_FENCE_ARRAY)
+		return get_legacy_fence_array(eb, out_n_fences);
+
+	if (eb->extensions.flags & BIT_ULL(DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES))
+		return get_timeline_fence_array(eb, out_n_fences);
+
+	*out_n_fences = 0;
+	return NULL;
+}
+
 static void
-put_fence_array(struct drm_i915_gem_execbuffer2 *args,
-		struct drm_syncobj **fences)
+put_fence_array(struct i915_eb_fences *fences, int nfences)
 {
 	if (fences)
-		__free_fence_array(fences, args->num_cliprects);
+		__free_fence_array(fences, nfences);
 }
 
 static int
 await_fence_array(struct i915_execbuffer *eb,
-		  struct drm_syncobj **fences)
+		  struct i915_eb_fences *fences,
+		  int nfences)
 {
-	const unsigned int nfences = eb->args->num_cliprects;
 	unsigned int n;
 	int err;
 
 	for (n = 0; n < nfences; n++) {
 		struct drm_syncobj *syncobj;
-		struct dma_fence *fence;
 		unsigned int flags;
 
-		syncobj = ptr_unpack_bits(fences[n], &flags, 2);
-		if (!(flags & I915_EXEC_FENCE_WAIT))
-			continue;
+		syncobj = ptr_unpack_bits(fences[n].syncobj, &flags, 2);
 
-		fence = drm_syncobj_fence_get(syncobj);
-		if (!fence)
-			return -EINVAL;
+		if (!fences[n].dma_fence)
+			continue;
 
-		err = i915_request_await_dma_fence(eb->request, fence);
-		dma_fence_put(fence);
+		err = i915_request_await_dma_fence(eb->request,
+						   fences[n].dma_fence);
 		if (err < 0)
 			return err;
 	}
@@ -2354,9 +2522,9 @@  await_fence_array(struct i915_execbuffer *eb,
 
 static void
 signal_fence_array(struct i915_execbuffer *eb,
-		   struct drm_syncobj **fences)
+		   struct i915_eb_fences *fences,
+		   int nfences)
 {
-	const unsigned int nfences = eb->args->num_cliprects;
 	struct dma_fence * const fence = &eb->request->fence;
 	unsigned int n;
 
@@ -2364,14 +2532,44 @@  signal_fence_array(struct i915_execbuffer *eb,
 		struct drm_syncobj *syncobj;
 		unsigned int flags;
 
-		syncobj = ptr_unpack_bits(fences[n], &flags, 2);
+		syncobj = ptr_unpack_bits(fences[n].syncobj, &flags, 2);
 		if (!(flags & I915_EXEC_FENCE_SIGNAL))
 			continue;
 
-		drm_syncobj_replace_fence(syncobj, fence);
+		if (fences[n].chain_fence) {
+			drm_syncobj_add_point(syncobj, fences[n].chain_fence,
+					      fence, fences[n].value);
+			/*
+			 * The chain's ownership is transferred to the
+			 * timeline.
+			 */
+			fences[n].chain_fence = NULL;
+		} else {
+			drm_syncobj_replace_fence(syncobj, fence);
+		}
 	}
 }
 
+static int parse_timeline_fences(struct i915_user_extension __user *ext, void *data)
+{
+	struct i915_execbuffer *eb = data;
+
+	/* Timeline fences are incompatible with the fence array flag. */
+	if (eb->args->flags & I915_EXEC_FENCE_ARRAY)
+		return -EINVAL;
+
+	if (eb->extensions.flags & BIT_ULL(DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES))
+		return -EINVAL;
+
+	if (copy_from_user(&eb->extensions.timeline_fences, ext,
+			   sizeof(eb->extensions.timeline_fences)))
+		return -EFAULT;
+
+	eb->extensions.flags |= BIT_ULL(DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES);
+
+	return 0;
+}
+
 static void retire_requests(struct intel_timeline *tl, struct i915_request *end)
 {
 	struct i915_request *rq, *rn;
@@ -2438,6 +2636,7 @@  static void eb_request_add(struct i915_execbuffer *eb)
 }
 
 static const i915_user_extension_fn execbuf_extensions[] = {
+	[DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES] = parse_timeline_fences,
 };
 
 static int
@@ -2468,16 +2667,17 @@  static int
 i915_gem_do_execbuffer(struct drm_device *dev,
 		       struct drm_file *file,
 		       struct drm_i915_gem_execbuffer2 *args,
-		       struct drm_i915_gem_exec_object2 *exec,
-		       struct drm_syncobj **fences)
+		       struct drm_i915_gem_exec_object2 *exec)
 {
 	struct drm_i915_private *i915 = to_i915(dev);
 	struct i915_execbuffer eb;
 	struct dma_fence *in_fence = NULL;
 	struct dma_fence *exec_fence = NULL;
 	struct sync_file *out_fence = NULL;
+	struct i915_eb_fences *fences = NULL;
 	struct i915_vma *batch;
 	int out_fence_fd = -1;
+	int nfences = 0;
 	int err;
 
 	BUILD_BUG_ON(__EXEC_INTERNAL_FLAGS & ~__I915_EXEC_ILLEGAL_FLAGS);
@@ -2521,10 +2721,16 @@  i915_gem_do_execbuffer(struct drm_device *dev,
 	if (err)
 		return err;
 
+	fences = get_fence_array(&eb, &nfences);
+	if (IS_ERR(fences))
+		return PTR_ERR(fences);
+
 	if (args->flags & I915_EXEC_FENCE_IN) {
 		in_fence = sync_file_get_fence(lower_32_bits(args->rsvd2));
-		if (!in_fence)
-			return -EINVAL;
+		if (!in_fence) {
+			err = -EINVAL;
+			goto err_fences;
+		}
 	}
 
 	if (args->flags & I915_EXEC_FENCE_SUBMIT) {
@@ -2648,7 +2854,7 @@  i915_gem_do_execbuffer(struct drm_device *dev,
 	}
 
 	if (fences) {
-		err = await_fence_array(&eb, fences);
+		err = await_fence_array(&eb, fences, nfences);
 		if (err)
 			goto err_request;
 	}
@@ -2680,7 +2886,7 @@  i915_gem_do_execbuffer(struct drm_device *dev,
 	eb_request_add(&eb);
 
 	if (fences)
-		signal_fence_array(&eb, fences);
+		signal_fence_array(&eb, fences, nfences);
 
 	if (out_fence) {
 		if (err == 0) {
@@ -2715,6 +2921,8 @@  i915_gem_do_execbuffer(struct drm_device *dev,
 	dma_fence_put(exec_fence);
 err_in_fence:
 	dma_fence_put(in_fence);
+err_fences:
+	put_fence_array(fences, nfences);
 	return err;
 }
 
@@ -2809,7 +3017,7 @@  i915_gem_execbuffer_ioctl(struct drm_device *dev, void *data,
 			exec2_list[i].flags = 0;
 	}
 
-	err = i915_gem_do_execbuffer(dev, file, &exec2, exec2_list, NULL);
+	err = i915_gem_do_execbuffer(dev, file, &exec2, exec2_list);
 	if (exec2.flags & __EXEC_HAS_RELOC) {
 		struct drm_i915_gem_exec_object __user *user_exec_list =
 			u64_to_user_ptr(args->buffers_ptr);
@@ -2841,7 +3049,6 @@  i915_gem_execbuffer2_ioctl(struct drm_device *dev, void *data,
 	struct drm_i915_private *i915 = to_i915(dev);
 	struct drm_i915_gem_execbuffer2 *args = data;
 	struct drm_i915_gem_exec_object2 *exec2_list;
-	struct drm_syncobj **fences = NULL;
 	const size_t count = args->buffer_count;
 	int err;
 
@@ -2869,15 +3076,7 @@  i915_gem_execbuffer2_ioctl(struct drm_device *dev, void *data,
 		return -EFAULT;
 	}
 
-	if (args->flags & I915_EXEC_FENCE_ARRAY) {
-		fences = get_fence_array(args, file);
-		if (IS_ERR(fences)) {
-			kvfree(exec2_list);
-			return PTR_ERR(fences);
-		}
-	}
-
-	err = i915_gem_do_execbuffer(dev, file, args, exec2_list, fences);
+	err = i915_gem_do_execbuffer(dev, file, args, exec2_list);
 
 	/*
 	 * Now that we have begun execution of the batchbuffer, we ignore
@@ -2917,7 +3116,6 @@  end:;
 	}
 
 	args->flags &= ~__I915_EXEC_UNKNOWN_FLAGS;
-	put_fence_array(args, fences);
 	kvfree(exec2_list);
 	return err;
 }
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index a7a3b4b98572..f7f868c3c510 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1828,7 +1828,8 @@  static struct drm_driver driver = {
 	 */
 	.driver_features =
 	    DRIVER_GEM |
-	    DRIVER_RENDER | DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_SYNCOBJ,
+	    DRIVER_RENDER | DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_SYNCOBJ |
+	    DRIVER_SYNCOBJ_TIMELINE,
 	.release = i915_driver_release,
 	.open = i915_driver_open,
 	.lastclose = i915_driver_lastclose,
diff --git a/drivers/gpu/drm/i915/i915_getparam.c b/drivers/gpu/drm/i915/i915_getparam.c
index 54fce81d5724..b9d3aab53c03 100644
--- a/drivers/gpu/drm/i915/i915_getparam.c
+++ b/drivers/gpu/drm/i915/i915_getparam.c
@@ -132,6 +132,7 @@  int i915_getparam_ioctl(struct drm_device *dev, void *data,
 	case I915_PARAM_HAS_EXEC_BATCH_FIRST:
 	case I915_PARAM_HAS_EXEC_FENCE_ARRAY:
 	case I915_PARAM_HAS_EXEC_SUBMIT_FENCE:
+	case I915_PARAM_HAS_EXEC_TIMELINE_FENCES:
 		/* For the time being all of these are always true;
 		 * if some supported hardware does not have one of these
 		 * features this value needs to be provided from
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 7ea38aa6502c..7b8680e3b49d 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -619,6 +619,12 @@  typedef struct drm_i915_irq_wait {
  */
 #define I915_PARAM_PERF_REVISION	54
 
+/* Query whether DRM_I915_GEM_EXECBUFFER2 supports supplying an array of
+ * timeline syncobj through drm_i915_gem_execbuf_ext_timeline_fences. See
+ * I915_EXEC_USE_EXTENSIONS.
+ */
+#define I915_PARAM_HAS_EXEC_TIMELINE_FENCES 55
+
 /* Must be kept compact -- no holes and well documented */
 
 typedef struct drm_i915_getparam {
@@ -1047,9 +1053,41 @@  struct drm_i915_gem_exec_fence {
 };
 
 enum drm_i915_gem_execbuffer_ext {
+	/**
+	 * See drm_i915_gem_execbuf_ext_timeline_fences.
+	 */
+	DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES = 1,
+
 	DRM_I915_GEM_EXECBUFFER_EXT_MAX /* non-ABI */
 };
 
+/**
+ * This structure describes an array of drm_syncobj and associated points for
+ * timeline variants of drm_syncobj. It is invalid to append this structure to
+ * the execbuf if I915_EXEC_FENCE_ARRAY is set.
+ */
+struct drm_i915_gem_execbuffer_ext_timeline_fences {
+	struct i915_user_extension base;
+
+	/**
+	 * Number of element in the handles_ptr & value_ptr arrays.
+	 */
+	__u64 fence_count;
+
+	/**
+	 * Pointer to an array of struct drm_i915_gem_exec_fence of length
+	 * fence_count.
+	 */
+	__u64 handles_ptr;
+
+	/**
+	 * Pointer to an array of u64 values of length fence_count. Values
+	 * must be 0 for a binary drm_syncobj. A Value of 0 for a timeline
+	 * drm_syncobj is invalid as it turns a drm_syncobj into a binary one.
+	 */
+	__u64 values_ptr;
+};
+
 struct drm_i915_gem_execbuffer2 {
 	/**
 	 * List of gem_exec_object2 structs