[v4,2/2] drm/i915: add syncobj timeline support
diff mbox series

Message ID 20190821131233.16885-3-lionel.g.landwerlin@intel.com
State New
Headers show
Series
  • drm/i915: timeline semaphore support
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Commit Message

Lionel Landwerlin Aug. 21, 2019, 1:12 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)

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
---
 .../gpu/drm/i915/gem/i915_gem_execbuffer.c    | 307 ++++++++++++++----
 drivers/gpu/drm/i915/i915_drv.c               |   3 +-
 drivers/gpu/drm/i915/i915_getparam.c          |   1 +
 include/uapi/drm/i915_drm.h                   |  39 +++
 4 files changed, 293 insertions(+), 57 deletions(-)

Comments

Jason Ekstrand Aug. 21, 2019, 5:01 p.m. UTC | #1
On Wed, Aug 21, 2019 at 8:12 AM Lionel Landwerlin <
lionel.g.landwerlin@intel.com> 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)
>
> Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
> ---
>  .../gpu/drm/i915/gem/i915_gem_execbuffer.c    | 307 ++++++++++++++----
>  drivers/gpu/drm/i915/i915_drv.c               |   3 +-
>  drivers/gpu/drm/i915/i915_getparam.c          |   1 +
>  include/uapi/drm/i915_drm.h                   |  39 +++
>  4 files changed, 293 insertions(+), 57 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> index 8d1946556bc0..6d5a234f9f9b 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> @@ -214,6 +214,13 @@ 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 */
> @@ -275,6 +282,7 @@ struct i915_execbuffer {
>
>         struct {
>                 u64 flags; /** Available extensions parameters */
> +               struct drm_i915_gem_execbuffer_ext_timeline_fences
> timeline_fences;
>         } extensions;
>  };
>
> @@ -2295,67 +2303,217 @@ 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)
>  {
> -       const unsigned long nfences = args->num_cliprects;
> +       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;
> +
> +       /* 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;
> +               }
> +
> +               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;
> +                       }
> +
> +                       err = dma_fence_chain_find_seqno(&fence, point);
> +                       if (err) {
> +                               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) {
> +                               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("Tring 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)
> +{
> +       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;
> @@ -2365,37 +2523,44 @@ 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);
> +               syncobj = ptr_unpack_bits(fences[n].syncobj, &flags, 2);
>                 if (!(flags & I915_EXEC_FENCE_WAIT))
>                         continue;
>
> -               fence = drm_syncobj_fence_get(syncobj);
> -               if (!fence)
> -                       return -EINVAL;
> -
> -               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;
>         }
> @@ -2405,9 +2570,9 @@ 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;
>
> @@ -2415,15 +2580,46 @@ 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 transfered 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 const i915_user_extension_fn execbuf_extensions[] = {
> +        [DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES] =
> parse_timeline_fences,
>  };
>
>  static int
> @@ -2454,14 +2650,15 @@ 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 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;
>         int out_fence_fd = -1;
> +       int nfences = 0;
>         int err;
>
>         BUILD_BUG_ON(__EXEC_INTERNAL_FLAGS & ~__I915_EXEC_ILLEGAL_FLAGS);
> @@ -2500,10 +2697,16 @@ 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 +2851,7 @@ 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;
>         }
> @@ -2679,7 +2882,7 @@ i915_gem_do_execbuffer(struct drm_device *dev,
>         i915_request_add(eb.request);
>
>         if (fences)
> -               signal_fence_array(&eb, fences);
> +               signal_fence_array(&eb, fences, nfences);
>
>         if (out_fence) {
>                 if (err == 0) {
> @@ -2714,6 +2917,8 @@ 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;
>  }
>
> @@ -2807,7 +3012,7 @@ 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);
> @@ -2838,7 +3043,6 @@ i915_gem_execbuffer2_ioctl(struct drm_device *dev,
> void *data,
>  {
>         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;
>
> @@ -2866,15 +3070,7 @@ 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
> @@ -2914,7 +3110,6 @@ 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 b5b2a64753e6..4db24f06f323 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -2851,7 +2851,8 @@ 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 5d9101376a3d..da6faa84e5b8 100644
> --- a/drivers/gpu/drm/i915/i915_getparam.c
> +++ b/drivers/gpu/drm/i915/i915_getparam.c
> @@ -130,6 +130,7 @@ 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 0a99c26730e1..e86691c18a56 100644
> --- a/include/uapi/drm/i915_drm.h
> +++ b/include/uapi/drm/i915_drm.h
> @@ -611,6 +611,13 @@ typedef struct drm_i915_irq_wait {
>   * See I915_EXEC_FENCE_OUT and I915_EXEC_FENCE_SUBMIT.
>   */
>  #define I915_PARAM_HAS_EXEC_SUBMIT_FENCE 53
> +
> +/* 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 54
> +
>  /* Must be kept compact -- no holes and well documented */
>
>  typedef struct drm_i915_getparam {
> @@ -1008,9 +1015,41 @@ 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 = 0,
>

Just pointed out a "bug" in the userspace code where it memset the
drm_i915_gem_execbuffer_ext_timeline_fences struct to 0 and never set the
ext name.  It worked because TIMELINE_FENCES magically happens to be 0.  We
should make 0 reserved in the extension API and -EINVAL if we ever see it.


> +
>         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
> --
> 2.23.0
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx

Patch
diff mbox series

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index 8d1946556bc0..6d5a234f9f9b 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -214,6 +214,13 @@  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 */
@@ -275,6 +282,7 @@  struct i915_execbuffer {
 
 	struct {
 		u64 flags; /** Available extensions parameters */
+		struct drm_i915_gem_execbuffer_ext_timeline_fences timeline_fences;
 	} extensions;
 };
 
@@ -2295,67 +2303,217 @@  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)
 {
-	const unsigned long nfences = args->num_cliprects;
+	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;
+
+	/* 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;
+		}
+
+		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;
+			}
+
+			err = dma_fence_chain_find_seqno(&fence, point);
+			if (err) {
+				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) {
+				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("Tring 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)
+{
+	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;
@@ -2365,37 +2523,44 @@  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);
+		syncobj = ptr_unpack_bits(fences[n].syncobj, &flags, 2);
 		if (!(flags & I915_EXEC_FENCE_WAIT))
 			continue;
 
-		fence = drm_syncobj_fence_get(syncobj);
-		if (!fence)
-			return -EINVAL;
-
-		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;
 	}
@@ -2405,9 +2570,9 @@  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;
 
@@ -2415,15 +2580,46 @@  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 transfered 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 const i915_user_extension_fn execbuf_extensions[] = {
+        [DRM_I915_GEM_EXECBUFFER_EXT_TIMELINE_FENCES] = parse_timeline_fences,
 };
 
 static int
@@ -2454,14 +2650,15 @@  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 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;
 	int out_fence_fd = -1;
+	int nfences = 0;
 	int err;
 
 	BUILD_BUG_ON(__EXEC_INTERNAL_FLAGS & ~__I915_EXEC_ILLEGAL_FLAGS);
@@ -2500,10 +2697,16 @@  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 +2851,7 @@  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;
 	}
@@ -2679,7 +2882,7 @@  i915_gem_do_execbuffer(struct drm_device *dev,
 	i915_request_add(eb.request);
 
 	if (fences)
-		signal_fence_array(&eb, fences);
+		signal_fence_array(&eb, fences, nfences);
 
 	if (out_fence) {
 		if (err == 0) {
@@ -2714,6 +2917,8 @@  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;
 }
 
@@ -2807,7 +3012,7 @@  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);
@@ -2838,7 +3043,6 @@  i915_gem_execbuffer2_ioctl(struct drm_device *dev, void *data,
 {
 	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;
 
@@ -2866,15 +3070,7 @@  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
@@ -2914,7 +3110,6 @@  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 b5b2a64753e6..4db24f06f323 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -2851,7 +2851,8 @@  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 5d9101376a3d..da6faa84e5b8 100644
--- a/drivers/gpu/drm/i915/i915_getparam.c
+++ b/drivers/gpu/drm/i915/i915_getparam.c
@@ -130,6 +130,7 @@  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 0a99c26730e1..e86691c18a56 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -611,6 +611,13 @@  typedef struct drm_i915_irq_wait {
  * See I915_EXEC_FENCE_OUT and I915_EXEC_FENCE_SUBMIT.
  */
 #define I915_PARAM_HAS_EXEC_SUBMIT_FENCE 53
+
+/* 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 54
+
 /* Must be kept compact -- no holes and well documented */
 
 typedef struct drm_i915_getparam {
@@ -1008,9 +1015,41 @@  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 = 0,
+
 	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