diff mbox

[v8,3/3] drm/fence: add out-fences support

Message ID 1478873759-6580-4-git-send-email-gustavo@padovan.org (mailing list archive)
State New, archived
Headers show

Commit Message

Gustavo Padovan Nov. 11, 2016, 2:15 p.m. UTC
From: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

Support DRM out-fences by creating a sync_file with a fence for each CRTC
that sets the OUT_FENCE_PTR property.

We use the out_fence pointer received in the OUT_FENCE_PTR prop to send
the sync_file fd back to userspace.

The sync_file and fd are allocated/created before commit, but the
fd_install operation only happens after we know that commit succeed.

v2: Comment by Rob Clark:
	- Squash commit that adds DRM_MODE_ATOMIC_OUT_FENCE flag here.

    Comment by Daniel Vetter:
	- Add clean up code for out_fences

v3: Comments by Daniel Vetter:
	- create DRM_MODE_ATOMIC_EVENT_MASK
	- userspace should fill out_fences_ptr with the crtc_ids for which
	it wants fences back.

v4: Create OUT_FENCE_PTR properties and remove old approach.

v5: Comments by Brian Starkey:
	- Remove extra fence_get() in atomic_ioctl()
	- Check ret before iterating on the crtc_state
	- check ret before fd_install
	- set fence_state to NULL at the beginning
	- check fence_state->out_fence_ptr before put_user()
	- change order of fput() and put_unused_fd() on failure

     - Add access_ok() check to the out_fence_ptr received
     - Rebase after fence -> dma_fence rename
     - Store out_fence_ptr in the drm_atomic_state
     - Split crtc_setup_out_fence()
     - return -1 as out_fence with TEST_ONLY flag

v6: Comments by Daniel Vetter
	- Add prepare/unprepare_crtc_signaling()
	- move struct drm_out_fence_state to drm_atomic.c
	- mark get_crtc_fence() as static

    Comments by Brian Starkey
	- proper set fence_ptr fence_state array
	- isolate fence_idx increment

    - improve error handling

v7: Comments by Daniel Vetter
	- remove prefix from internal functions
	- make out_fence_ptr an s64 pointer
	- degrade DRM_INFO to DRM_DEBUG_ATOMIC when put_user fail
	- fix doc issues
	- filter out OUT_FENCE_PTR == NULL and do not fail in this case
	- add complete_crtc_signalling()
	- krealloc fence_state on demand

    Comment by Brian Starkey
	- remove unused crtc_state arg from get_out_fence()

v8: Comment by Brian Starkey
	- cancel events before check for !fence_state
	- convert a few lefovers u64 types for out_fence_ptr
	- fix memleak by assign fence_state earlier after realloc
	- proper accout num_fences in case of error

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
---
 drivers/gpu/drm/drm_atomic.c | 243 +++++++++++++++++++++++++++++++++++--------
 drivers/gpu/drm/drm_crtc.c   |   8 ++
 include/drm/drm_atomic.h     |   1 +
 include/drm/drm_crtc.h       |   6 ++
 4 files changed, 213 insertions(+), 45 deletions(-)

Comments

Sean Paul Nov. 11, 2016, 4:48 p.m. UTC | #1
On Fri, Nov 11, 2016 at 9:15 AM, Gustavo Padovan <gustavo@padovan.org> wrote:
> From: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
>
> Support DRM out-fences by creating a sync_file with a fence for each CRTC
> that sets the OUT_FENCE_PTR property.
>
> We use the out_fence pointer received in the OUT_FENCE_PTR prop to send
> the sync_file fd back to userspace.
>
> The sync_file and fd are allocated/created before commit, but the
> fd_install operation only happens after we know that commit succeed.
>
> v2: Comment by Rob Clark:
>         - Squash commit that adds DRM_MODE_ATOMIC_OUT_FENCE flag here.
>
>     Comment by Daniel Vetter:
>         - Add clean up code for out_fences
>
> v3: Comments by Daniel Vetter:
>         - create DRM_MODE_ATOMIC_EVENT_MASK
>         - userspace should fill out_fences_ptr with the crtc_ids for which
>         it wants fences back.
>
> v4: Create OUT_FENCE_PTR properties and remove old approach.
>
> v5: Comments by Brian Starkey:
>         - Remove extra fence_get() in atomic_ioctl()
>         - Check ret before iterating on the crtc_state
>         - check ret before fd_install
>         - set fence_state to NULL at the beginning
>         - check fence_state->out_fence_ptr before put_user()
>         - change order of fput() and put_unused_fd() on failure
>
>      - Add access_ok() check to the out_fence_ptr received
>      - Rebase after fence -> dma_fence rename
>      - Store out_fence_ptr in the drm_atomic_state
>      - Split crtc_setup_out_fence()
>      - return -1 as out_fence with TEST_ONLY flag
>
> v6: Comments by Daniel Vetter
>         - Add prepare/unprepare_crtc_signaling()
>         - move struct drm_out_fence_state to drm_atomic.c
>         - mark get_crtc_fence() as static
>
>     Comments by Brian Starkey
>         - proper set fence_ptr fence_state array
>         - isolate fence_idx increment
>
>     - improve error handling
>
> v7: Comments by Daniel Vetter
>         - remove prefix from internal functions
>         - make out_fence_ptr an s64 pointer
>         - degrade DRM_INFO to DRM_DEBUG_ATOMIC when put_user fail
>         - fix doc issues
>         - filter out OUT_FENCE_PTR == NULL and do not fail in this case
>         - add complete_crtc_signalling()
>         - krealloc fence_state on demand
>
>     Comment by Brian Starkey
>         - remove unused crtc_state arg from get_out_fence()
>
> v8: Comment by Brian Starkey
>         - cancel events before check for !fence_state
>         - convert a few lefovers u64 types for out_fence_ptr
>         - fix memleak by assign fence_state earlier after realloc
>         - proper accout num_fences in case of error
>
> Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

A couple of nits below, other than that, looks good to me

> ---
>  drivers/gpu/drm/drm_atomic.c | 243 +++++++++++++++++++++++++++++++++++--------
>  drivers/gpu/drm/drm_crtc.c   |   8 ++
>  include/drm/drm_atomic.h     |   1 +
>  include/drm/drm_crtc.h       |   6 ++
>  4 files changed, 213 insertions(+), 45 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> index 8e26ad1..34cdc6e 100644
> --- a/drivers/gpu/drm/drm_atomic.c
> +++ b/drivers/gpu/drm/drm_atomic.c
> @@ -290,6 +290,23 @@ drm_atomic_get_crtc_state(struct drm_atomic_state *state,
>  }
>  EXPORT_SYMBOL(drm_atomic_get_crtc_state);
>
> +static void set_out_fence_for_crtc(struct drm_atomic_state *state,
> +                                  struct drm_crtc *crtc, s64 __user *fence_ptr)
> +{
> +       state->crtcs[drm_crtc_index(crtc)].out_fence_ptr = fence_ptr;
> +}
> +
> +static s64 __user * get_out_fence_for_crtc(struct drm_atomic_state *state,
> +                                          struct drm_crtc *crtc)
> +{
> +       s64 __user *fence_ptr;
> +
> +       fence_ptr = state->crtcs[drm_crtc_index(crtc)].out_fence_ptr;
> +       state->crtcs[drm_crtc_index(crtc)].out_fence_ptr = NULL;
> +
> +       return fence_ptr;
> +}
> +
>  /**
>   * drm_atomic_set_mode_for_crtc - set mode for CRTC
>   * @state: the CRTC whose incoming state to update
> @@ -491,6 +508,16 @@ int drm_atomic_crtc_set_property(struct drm_crtc *crtc,
>                                         &replaced);
>                 state->color_mgmt_changed |= replaced;
>                 return ret;
> +       } else if (property == config->prop_out_fence_ptr) {
> +               s64 __user *fence_ptr = u64_to_user_ptr(val);
> +
> +               if (!fence_ptr)
> +                       return 0;
> +
> +               if (!access_ok(VERIFY_WRITE, fence_ptr, sizeof(*fence_ptr)))
> +                       return -EFAULT;
> +
> +               set_out_fence_for_crtc(state->state, crtc, fence_ptr);
>         } else if (crtc->funcs->atomic_set_property)
>                 return crtc->funcs->atomic_set_property(crtc, state, property, val);
>         else
> @@ -533,6 +560,8 @@ drm_atomic_crtc_get_property(struct drm_crtc *crtc,
>                 *val = (state->ctm) ? state->ctm->base.id : 0;
>         else if (property == config->gamma_lut_property)
>                 *val = (state->gamma_lut) ? state->gamma_lut->base.id : 0;
> +       else if (property == config->prop_out_fence_ptr)
> +               *val = 0;
>         else if (crtc->funcs->atomic_get_property)
>                 return crtc->funcs->atomic_get_property(crtc, state, property, val);
>         else
> @@ -1659,11 +1688,9 @@ int drm_atomic_debugfs_init(struct drm_minor *minor)
>   */
>
>  static struct drm_pending_vblank_event *create_vblank_event(
> -               struct drm_device *dev, struct drm_file *file_priv,
> -               struct dma_fence *fence, uint64_t user_data)
> +               struct drm_device *dev, uint64_t user_data)
>  {
>         struct drm_pending_vblank_event *e = NULL;
> -       int ret;
>
>         e = kzalloc(sizeof *e, GFP_KERNEL);
>         if (!e)
> @@ -1673,17 +1700,6 @@ static struct drm_pending_vblank_event *create_vblank_event(
>         e->event.base.length = sizeof(e->event);
>         e->event.user_data = user_data;
>
> -       if (file_priv) {
> -               ret = drm_event_reserve_init(dev, file_priv, &e->base,
> -                                            &e->event.base);
> -               if (ret) {
> -                       kfree(e);
> -                       return NULL;
> -               }
> -       }
> -
> -       e->base.fence = fence;
> -
>         return e;
>  }
>
> @@ -1788,6 +1804,167 @@ void drm_atomic_clean_old_fb(struct drm_device *dev,
>  }
>  EXPORT_SYMBOL(drm_atomic_clean_old_fb);
>
> +static struct dma_fence *get_crtc_fence(struct drm_crtc *crtc)
> +{
> +       struct dma_fence *fence;
> +
> +       fence = kzalloc(sizeof(*fence), GFP_KERNEL);
> +       if (!fence)
> +               return NULL;
> +
> +       dma_fence_init(fence, &drm_crtc_fence_ops, &crtc->fence_lock,
> +                      crtc->fence_context, ++crtc->fence_seqno);
> +
> +       return fence;
> +}
> +
> +struct drm_out_fence_state {
> +       s64 __user *out_fence_ptr;
> +       struct sync_file *sync_file;
> +       int fd;
> +};
> +
> +static int setup_out_fence(struct drm_out_fence_state *fence_state,
> +                          struct dma_fence *fence)
> +{
> +       fence_state->fd = get_unused_fd_flags(O_CLOEXEC);
> +       if (fence_state->fd < 0)
> +               return fence_state->fd;
> +
> +       if (put_user(fence_state->fd, fence_state->out_fence_ptr))
> +               return -EFAULT;
> +
> +       fence_state->sync_file = sync_file_create(fence);
> +       if(!fence_state->sync_file)
> +               return -ENOMEM;
> +
> +       return 0;
> +}
> +
> +static int prepare_crtc_signaling(struct drm_device *dev,
> +                                 struct drm_atomic_state *state,
> +                                 struct drm_mode_atomic *arg,
> +                                 struct drm_file *file_priv,
> +                                 struct drm_out_fence_state **fence_state,
> +                                 unsigned int *num_fences)
> +{
> +       struct drm_crtc *crtc;
> +       struct drm_crtc_state *crtc_state;
> +       int i, ret;
> +
> +       for_each_crtc_in_state(state, crtc, crtc_state, i) {
> +               u64 __user *fence_ptr;
> +
> +               fence_ptr = get_out_fence_for_crtc(crtc_state->state, crtc);
> +
> +               if (arg->flags & DRM_MODE_ATOMIC_TEST_ONLY && fence_ptr) {
> +                       if (put_user(-1, fence_ptr))
> +                               return -EFAULT;
> +
> +                       continue;
> +               }
> +
> +               if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT || fence_ptr) {

pedantic suggestion: If you did the inverse, you could just continue
and save yourself some indentation (and instantiate e once). ie:

if (!(arg->flags & DRM_MODE_PAGE_FLIP_EVENT) && !fence_ptr)
        continue;

...


> +                       struct drm_pending_vblank_event *e;
> +
> +                       e = create_vblank_event(dev, arg->user_data);
> +                       if (!e)
> +                               return -ENOMEM;
> +
> +                       crtc_state->event = e;
> +               }
> +
> +               if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT) {
> +                       struct drm_pending_vblank_event *e = crtc_state->event;
> +
> +                       if (!file_priv)
> +                               continue;
> +
> +                       ret = drm_event_reserve_init(dev, file_priv, &e->base,
> +                                                    &e->event.base);
> +                       if (ret) {
> +                               kfree(e);
> +                               crtc_state->event = NULL;
> +                               return ret;
> +                       }
> +               }
> +
> +               if (fence_ptr) {
> +                       struct dma_fence *fence;
> +                       struct drm_out_fence_state *f;
> +
> +                       f = krealloc(*fence_state, sizeof(**fence_state) *
> +                                    (*num_fences + 1), GFP_KERNEL);
> +                       if (!f)
> +                               return -ENOMEM;
> +
> +                       f[*num_fences].out_fence_ptr = fence_ptr;
> +                       *fence_state = f;
> +
> +                       fence = get_crtc_fence(crtc);
> +                       if (!fence) {
> +                               (*num_fences)++;
> +                               return -ENOMEM;
> +                       }
> +
> +                       ret = setup_out_fence(&f[(*num_fences)++], fence);
> +                       if (ret) {
> +                               dma_fence_put(fence);
> +                               return ret;
> +                       }
> +
> +                       crtc_state->event->base.fence = fence;
> +
> +               }
> +       }
> +
> +       return 0;
> +}
> +
> +static void complete_crtc_signaling(struct drm_device *dev,
> +                                    struct drm_atomic_state *state,
> +                                    struct drm_out_fence_state *fence_state,
> +                                    unsigned int num_fences, int ret)
> +{
> +       struct drm_crtc *crtc;
> +       struct drm_crtc_state *crtc_state;
> +       int i;
> +
> +       if (!ret) {

I don't think there's any reason to smash the fd install and clean-up
into one function. I think splitting into 2 functions and calling the
right one from atomic_ioctl would be better.

> +               for (i = 0; i < num_fences; i++)
> +                       fd_install(fence_state[i].fd,
> +                                  fence_state[i].sync_file->file);
> +               return;
> +       }
> +
> +       for_each_crtc_in_state(state, crtc, crtc_state, i) {
> +               /*
> +                * TEST_ONLY and PAGE_FLIP_EVENT are mutually
> +                * exclusive, if they weren't, this code should be
> +                * called on success for TEST_ONLY too.
> +                */
> +               if (crtc_state->event)
> +                       drm_event_cancel_free(dev, &crtc_state->event->base);
> +       }
> +
> +       if (!fence_state)
> +               return;
> +
> +       for (i = 0; i < num_fences; i++) {
> +               if (fence_state[i].sync_file)
> +                       fput(fence_state[i].sync_file->file);
> +               if (fence_state[i].fd >= 0)
> +                       put_unused_fd(fence_state[i].fd);
> +
> +               /* If this fails log error to the user */
> +               if (fence_state[i].out_fence_ptr &&
> +                   put_user(-1, fence_state[i].out_fence_ptr))
> +                       DRM_DEBUG_ATOMIC("Couldn't clear out_fence_ptr\n");
> +       }
> +
> +       kfree(fence_state);
> +}
> +
>  int drm_mode_atomic_ioctl(struct drm_device *dev,
>                           void *data, struct drm_file *file_priv)
>  {
> @@ -1800,11 +1977,10 @@ int drm_mode_atomic_ioctl(struct drm_device *dev,
>         struct drm_atomic_state *state;
>         struct drm_modeset_acquire_ctx ctx;
>         struct drm_plane *plane;
> -       struct drm_crtc *crtc;
> -       struct drm_crtc_state *crtc_state;
> +       struct drm_out_fence_state *fence_state = NULL;
>         unsigned plane_mask;
>         int ret = 0;
> -       unsigned int i, j;
> +       unsigned int i, j, num_fences = 0;
>
>         /* disallow for drivers not supporting atomic: */
>         if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
> @@ -1919,20 +2095,10 @@ int drm_mode_atomic_ioctl(struct drm_device *dev,
>                 drm_mode_object_unreference(obj);
>         }
>
> -       if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT) {
> -               for_each_crtc_in_state(state, crtc, crtc_state, i) {
> -                       struct drm_pending_vblank_event *e;
> -
> -                       e = create_vblank_event(dev, file_priv, NULL,
> -                                               arg->user_data);
> -                       if (!e) {
> -                               ret = -ENOMEM;
> -                               goto out;
> -                       }
> -
> -                       crtc_state->event = e;
> -               }
> -       }
> +       ret = prepare_crtc_signaling(dev, state, arg, file_priv, &fence_state,
> +                                    &num_fences);
> +       if (ret)
> +               goto out;
>
>         if (arg->flags & DRM_MODE_ATOMIC_TEST_ONLY) {
>                 /*
> @@ -1952,20 +2118,7 @@ int drm_mode_atomic_ioctl(struct drm_device *dev,
>  out:
>         drm_atomic_clean_old_fb(dev, plane_mask, ret);
>
> -       if (ret && arg->flags & DRM_MODE_PAGE_FLIP_EVENT) {
> -               /*
> -                * TEST_ONLY and PAGE_FLIP_EVENT are mutually exclusive,
> -                * if they weren't, this code should be called on success
> -                * for TEST_ONLY too.
> -                */
> -
> -               for_each_crtc_in_state(state, crtc, crtc_state, i) {
> -                       if (!crtc_state->event)
> -                               continue;
> -
> -                       drm_event_cancel_free(dev, &crtc_state->event->base);
> -               }
> -       }
> +       complete_crtc_signaling(dev, state, fence_state, num_fences, ret);
>
>         if (ret == -EDEADLK) {
>                 drm_atomic_state_clear(state);
> diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> index 9b9881b..e8bc1ae 100644
> --- a/drivers/gpu/drm/drm_crtc.c
> +++ b/drivers/gpu/drm/drm_crtc.c
> @@ -274,6 +274,8 @@ int drm_crtc_init_with_planes(struct drm_device *dev, struct drm_crtc *crtc,
>         if (drm_core_check_feature(dev, DRIVER_ATOMIC)) {
>                 drm_object_attach_property(&crtc->base, config->prop_active, 0);
>                 drm_object_attach_property(&crtc->base, config->prop_mode_id, 0);
> +               drm_object_attach_property(&crtc->base,
> +                                          config->prop_out_fence_ptr, 0);
>         }
>
>         return 0;
> @@ -434,6 +436,12 @@ static int drm_mode_create_standard_properties(struct drm_device *dev)
>                 return -ENOMEM;
>         dev->mode_config.prop_in_fence_fd = prop;
>
> +       prop = drm_property_create_range(dev, DRM_MODE_PROP_ATOMIC,
> +                       "OUT_FENCE_PTR", 0, U64_MAX);
> +       if (!prop)
> +               return -ENOMEM;
> +       dev->mode_config.prop_out_fence_ptr = prop;
> +
>         prop = drm_property_create_object(dev, DRM_MODE_PROP_ATOMIC,
>                         "CRTC_ID", DRM_MODE_OBJECT_CRTC);
>         if (!prop)
> diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
> index 331bb10..c0eaec7 100644
> --- a/include/drm/drm_atomic.h
> +++ b/include/drm/drm_atomic.h
> @@ -144,6 +144,7 @@ struct __drm_crtcs_state {
>         struct drm_crtc *ptr;
>         struct drm_crtc_state *state;
>         struct drm_crtc_commit *commit;
> +       s64 __user *out_fence_ptr;
>  };
>
>  struct __drm_connnectors_state {
> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> index 0870de1..44571bc 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -1264,6 +1264,12 @@ struct drm_mode_config {
>          */
>         struct drm_property *prop_in_fence_fd;
>         /**
> +        * @prop_out_fence_ptr: Sync File fd pointer representing the
> +        * outgoing fences for a CRTC. Userspace should provide a pointer to a
> +        * value of type s64, and then cast that pointer to u64.
> +        */
> +       struct drm_property *prop_out_fence_ptr;
> +       /**
>          * @prop_crtc_id: Default atomic plane property to specify the
>          * &drm_crtc.
>          */
> --
> 2.5.5
>
Daniel Vetter Nov. 11, 2016, 5:11 p.m. UTC | #2
On Fri, Nov 11, 2016 at 11:48:09AM -0500, Sean Paul wrote:
> On Fri, Nov 11, 2016 at 9:15 AM, Gustavo Padovan <gustavo@padovan.org> wrote:
> > +static void complete_crtc_signaling(struct drm_device *dev,
> > +                                    struct drm_atomic_state *state,
> > +                                    struct drm_out_fence_state *fence_state,
> > +                                    unsigned int num_fences, int ret)
> > +{
> > +       struct drm_crtc *crtc;
> > +       struct drm_crtc_state *crtc_state;
> > +       int i;
> > +
> > +       if (!ret) {
> 
> I don't think there's any reason to smash the fd install and clean-up
> into one function. I think splitting into 2 functions and calling the
> right one from atomic_ioctl would be better.

Hm, I suggested this because the control flow in one of Gustavo's earlier
patches look really funny. I guess it could be split up again, but with
both callers in the current position. tbh I don't care whether it's this
or that, both are clear improvement over the older version.
-Daniel
Sean Paul Nov. 11, 2016, 5:21 p.m. UTC | #3
On Fri, Nov 11, 2016 at 12:11 PM, Daniel Vetter <daniel@ffwll.ch> wrote:
> On Fri, Nov 11, 2016 at 11:48:09AM -0500, Sean Paul wrote:
>> On Fri, Nov 11, 2016 at 9:15 AM, Gustavo Padovan <gustavo@padovan.org> wrote:
>> > +static void complete_crtc_signaling(struct drm_device *dev,
>> > +                                    struct drm_atomic_state *state,
>> > +                                    struct drm_out_fence_state *fence_state,
>> > +                                    unsigned int num_fences, int ret)
>> > +{
>> > +       struct drm_crtc *crtc;
>> > +       struct drm_crtc_state *crtc_state;
>> > +       int i;
>> > +
>> > +       if (!ret) {
>>
>> I don't think there's any reason to smash the fd install and clean-up
>> into one function. I think splitting into 2 functions and calling the
>> right one from atomic_ioctl would be better.
>
> Hm, I suggested this because the control flow in one of Gustavo's earlier
> patches look really funny. I guess it could be split up again, but with
> both callers in the current position. tbh I don't care whether it's this
> or that, both are clear improvement over the older version.

I really don't have a strong opinion either. Perhaps meet in the
middle and pass bool install_fds instead of ret (since that's kind of
an anti-pattern)?

Sean


> -Daniel
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
Brian Starkey Nov. 11, 2016, 5:38 p.m. UTC | #4
Spotted one more thing on a cleanup path...

On Fri, Nov 11, 2016 at 11:15:59PM +0900, Gustavo Padovan wrote:
>From: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
>
>Support DRM out-fences by creating a sync_file with a fence for each CRTC
>that sets the OUT_FENCE_PTR property.
>
>We use the out_fence pointer received in the OUT_FENCE_PTR prop to send
>the sync_file fd back to userspace.
>
>The sync_file and fd are allocated/created before commit, but the
>fd_install operation only happens after we know that commit succeed.
>
>v2: Comment by Rob Clark:
>	- Squash commit that adds DRM_MODE_ATOMIC_OUT_FENCE flag here.
>
>    Comment by Daniel Vetter:
>	- Add clean up code for out_fences
>
>v3: Comments by Daniel Vetter:
>	- create DRM_MODE_ATOMIC_EVENT_MASK
>	- userspace should fill out_fences_ptr with the crtc_ids for which
>	it wants fences back.
>
>v4: Create OUT_FENCE_PTR properties and remove old approach.
>
>v5: Comments by Brian Starkey:
>	- Remove extra fence_get() in atomic_ioctl()
>	- Check ret before iterating on the crtc_state
>	- check ret before fd_install
>	- set fence_state to NULL at the beginning
>	- check fence_state->out_fence_ptr before put_user()
>	- change order of fput() and put_unused_fd() on failure
>
>     - Add access_ok() check to the out_fence_ptr received
>     - Rebase after fence -> dma_fence rename
>     - Store out_fence_ptr in the drm_atomic_state
>     - Split crtc_setup_out_fence()
>     - return -1 as out_fence with TEST_ONLY flag
>
>v6: Comments by Daniel Vetter
>	- Add prepare/unprepare_crtc_signaling()
>	- move struct drm_out_fence_state to drm_atomic.c
>	- mark get_crtc_fence() as static
>
>    Comments by Brian Starkey
>	- proper set fence_ptr fence_state array
>	- isolate fence_idx increment
>
>    - improve error handling
>
>v7: Comments by Daniel Vetter
>	- remove prefix from internal functions
>	- make out_fence_ptr an s64 pointer
>	- degrade DRM_INFO to DRM_DEBUG_ATOMIC when put_user fail
>	- fix doc issues
>	- filter out OUT_FENCE_PTR == NULL and do not fail in this case
>	- add complete_crtc_signalling()
>	- krealloc fence_state on demand
>
>    Comment by Brian Starkey
>	- remove unused crtc_state arg from get_out_fence()
>
>v8: Comment by Brian Starkey
>	- cancel events before check for !fence_state
>	- convert a few lefovers u64 types for out_fence_ptr
>	- fix memleak by assign fence_state earlier after realloc
>	- proper accout num_fences in case of error
>
>Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
>---
> drivers/gpu/drm/drm_atomic.c | 243 +++++++++++++++++++++++++++++++++++--------
> drivers/gpu/drm/drm_crtc.c   |   8 ++
> include/drm/drm_atomic.h     |   1 +
> include/drm/drm_crtc.h       |   6 ++
> 4 files changed, 213 insertions(+), 45 deletions(-)
>
>diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
>index 8e26ad1..34cdc6e 100644
>--- a/drivers/gpu/drm/drm_atomic.c
>+++ b/drivers/gpu/drm/drm_atomic.c
>@@ -290,6 +290,23 @@ drm_atomic_get_crtc_state(struct drm_atomic_state *state,
> }
> EXPORT_SYMBOL(drm_atomic_get_crtc_state);
>
>+static void set_out_fence_for_crtc(struct drm_atomic_state *state,
>+				   struct drm_crtc *crtc, s64 __user *fence_ptr)
>+{
>+	state->crtcs[drm_crtc_index(crtc)].out_fence_ptr = fence_ptr;
>+}
>+
>+static s64 __user * get_out_fence_for_crtc(struct drm_atomic_state *state,
>+					   struct drm_crtc *crtc)
>+{
>+	s64 __user *fence_ptr;
>+
>+	fence_ptr = state->crtcs[drm_crtc_index(crtc)].out_fence_ptr;
>+	state->crtcs[drm_crtc_index(crtc)].out_fence_ptr = NULL;
>+
>+	return fence_ptr;
>+}
>+
> /**
>  * drm_atomic_set_mode_for_crtc - set mode for CRTC
>  * @state: the CRTC whose incoming state to update
>@@ -491,6 +508,16 @@ int drm_atomic_crtc_set_property(struct drm_crtc *crtc,
> 					&replaced);
> 		state->color_mgmt_changed |= replaced;
> 		return ret;
>+	} else if (property == config->prop_out_fence_ptr) {
>+		s64 __user *fence_ptr = u64_to_user_ptr(val);
>+
>+		if (!fence_ptr)
>+			return 0;
>+
>+		if (!access_ok(VERIFY_WRITE, fence_ptr, sizeof(*fence_ptr)))
>+			return -EFAULT;
>+
>+		set_out_fence_for_crtc(state->state, crtc, fence_ptr);
> 	} else if (crtc->funcs->atomic_set_property)
> 		return crtc->funcs->atomic_set_property(crtc, state, property, val);
> 	else
>@@ -533,6 +560,8 @@ drm_atomic_crtc_get_property(struct drm_crtc *crtc,
> 		*val = (state->ctm) ? state->ctm->base.id : 0;
> 	else if (property == config->gamma_lut_property)
> 		*val = (state->gamma_lut) ? state->gamma_lut->base.id : 0;
>+	else if (property == config->prop_out_fence_ptr)
>+		*val = 0;
> 	else if (crtc->funcs->atomic_get_property)
> 		return crtc->funcs->atomic_get_property(crtc, state, property, val);
> 	else
>@@ -1659,11 +1688,9 @@ int drm_atomic_debugfs_init(struct drm_minor *minor)
>  */
>
> static struct drm_pending_vblank_event *create_vblank_event(
>-		struct drm_device *dev, struct drm_file *file_priv,
>-		struct dma_fence *fence, uint64_t user_data)
>+		struct drm_device *dev, uint64_t user_data)
> {
> 	struct drm_pending_vblank_event *e = NULL;
>-	int ret;
>
> 	e = kzalloc(sizeof *e, GFP_KERNEL);
> 	if (!e)
>@@ -1673,17 +1700,6 @@ static struct drm_pending_vblank_event *create_vblank_event(
> 	e->event.base.length = sizeof(e->event);
> 	e->event.user_data = user_data;
>
>-	if (file_priv) {
>-		ret = drm_event_reserve_init(dev, file_priv, &e->base,
>-					     &e->event.base);
>-		if (ret) {
>-			kfree(e);
>-			return NULL;
>-		}
>-	}
>-
>-	e->base.fence = fence;
>-
> 	return e;
> }
>
>@@ -1788,6 +1804,167 @@ void drm_atomic_clean_old_fb(struct drm_device *dev,
> }
> EXPORT_SYMBOL(drm_atomic_clean_old_fb);
>
>+static struct dma_fence *get_crtc_fence(struct drm_crtc *crtc)
>+{
>+	struct dma_fence *fence;
>+
>+	fence = kzalloc(sizeof(*fence), GFP_KERNEL);
>+	if (!fence)
>+		return NULL;
>+
>+	dma_fence_init(fence, &drm_crtc_fence_ops, &crtc->fence_lock,
>+		       crtc->fence_context, ++crtc->fence_seqno);
>+
>+	return fence;
>+}
>+
>+struct drm_out_fence_state {
>+	s64 __user *out_fence_ptr;
>+	struct sync_file *sync_file;
>+	int fd;
>+};
>+
>+static int setup_out_fence(struct drm_out_fence_state *fence_state,
>+			   struct dma_fence *fence)
>+{
>+	fence_state->fd = get_unused_fd_flags(O_CLOEXEC);
>+	if (fence_state->fd < 0)
>+		return fence_state->fd;
>+
>+	if (put_user(fence_state->fd, fence_state->out_fence_ptr))
>+		return -EFAULT;
>+
>+	fence_state->sync_file = sync_file_create(fence);
>+	if(!fence_state->sync_file)
>+		return -ENOMEM;
>+
>+	return 0;
>+}
>+
>+static int prepare_crtc_signaling(struct drm_device *dev,
>+				  struct drm_atomic_state *state,
>+				  struct drm_mode_atomic *arg,
>+				  struct drm_file *file_priv,
>+				  struct drm_out_fence_state **fence_state,
>+				  unsigned int *num_fences)
>+{
>+	struct drm_crtc *crtc;
>+	struct drm_crtc_state *crtc_state;
>+	int i, ret;
>+
>+	for_each_crtc_in_state(state, crtc, crtc_state, i) {
>+		u64 __user *fence_ptr;
>+
>+		fence_ptr = get_out_fence_for_crtc(crtc_state->state, crtc);
>+
>+		if (arg->flags & DRM_MODE_ATOMIC_TEST_ONLY && fence_ptr) {
>+			if (put_user(-1, fence_ptr))
>+				return -EFAULT;
>+
>+			continue;
>+		}
>+
>+		if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT || fence_ptr) {
>+			struct drm_pending_vblank_event *e;
>+
>+			e = create_vblank_event(dev, arg->user_data);
>+			if (!e)
>+				return -ENOMEM;
>+
>+			crtc_state->event = e;
>+		}
>+
>+		if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT) {
>+			struct drm_pending_vblank_event *e = crtc_state->event;
>+
>+			if (!file_priv)
>+				continue;
>+
>+			ret = drm_event_reserve_init(dev, file_priv, &e->base,
>+						     &e->event.base);
>+			if (ret) {
>+				kfree(e);
>+				crtc_state->event = NULL;
>+				return ret;
>+			}
>+		}
>+
>+		if (fence_ptr) {
>+			struct dma_fence *fence;
>+			struct drm_out_fence_state *f;
>+
>+			f = krealloc(*fence_state, sizeof(**fence_state) *
>+				     (*num_fences + 1), GFP_KERNEL);
>+			if (!f)
>+				return -ENOMEM;

We have to make sure the new bit of fence_state is zeroed, otherwise
failing after the (*num_fences)++ could lead to fput/put_unused_fd on
random numbers.

-Brian

>+
>+			f[*num_fences].out_fence_ptr = fence_ptr;
>+			*fence_state = f;
>+
>+			fence = get_crtc_fence(crtc);
>+			if (!fence) {
>+				(*num_fences)++;
>+				return -ENOMEM;
>+			}
>+
>+			ret = setup_out_fence(&f[(*num_fences)++], fence);
>+			if (ret) {
>+				dma_fence_put(fence);
>+				return ret;
>+			}
>+
>+			crtc_state->event->base.fence = fence;
>+
>+		}
>+	}
>+
>+	return 0;
>+}
>+
>+static void complete_crtc_signaling(struct drm_device *dev,
>+				     struct drm_atomic_state *state,
>+				     struct drm_out_fence_state *fence_state,
>+				     unsigned int num_fences, int ret)
>+{
>+	struct drm_crtc *crtc;
>+	struct drm_crtc_state *crtc_state;
>+	int i;
>+
>+	if (!ret) {
>+		for (i = 0; i < num_fences; i++)
>+			fd_install(fence_state[i].fd,
>+				   fence_state[i].sync_file->file);
>+		return;
>+	}
>+
>+	for_each_crtc_in_state(state, crtc, crtc_state, i) {
>+		/*
>+		 * TEST_ONLY and PAGE_FLIP_EVENT are mutually
>+		 * exclusive, if they weren't, this code should be
>+		 * called on success for TEST_ONLY too.
>+		 */
>+		if (crtc_state->event)
>+			drm_event_cancel_free(dev, &crtc_state->event->base);
>+	}
>+
>+	if (!fence_state)
>+		return;
>+
>+	for (i = 0; i < num_fences; i++) {
>+		if (fence_state[i].sync_file)
>+			fput(fence_state[i].sync_file->file);
>+		if (fence_state[i].fd >= 0)
>+			put_unused_fd(fence_state[i].fd);
>+
>+		/* If this fails log error to the user */
>+		if (fence_state[i].out_fence_ptr &&
>+		    put_user(-1, fence_state[i].out_fence_ptr))
>+			DRM_DEBUG_ATOMIC("Couldn't clear out_fence_ptr\n");
>+	}
>+
>+	kfree(fence_state);
>+}
>+
> int drm_mode_atomic_ioctl(struct drm_device *dev,
> 			  void *data, struct drm_file *file_priv)
> {
>@@ -1800,11 +1977,10 @@ int drm_mode_atomic_ioctl(struct drm_device *dev,
> 	struct drm_atomic_state *state;
> 	struct drm_modeset_acquire_ctx ctx;
> 	struct drm_plane *plane;
>-	struct drm_crtc *crtc;
>-	struct drm_crtc_state *crtc_state;
>+	struct drm_out_fence_state *fence_state = NULL;
> 	unsigned plane_mask;
> 	int ret = 0;
>-	unsigned int i, j;
>+	unsigned int i, j, num_fences = 0;
>
> 	/* disallow for drivers not supporting atomic: */
> 	if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
>@@ -1919,20 +2095,10 @@ int drm_mode_atomic_ioctl(struct drm_device *dev,
> 		drm_mode_object_unreference(obj);
> 	}
>
>-	if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT) {
>-		for_each_crtc_in_state(state, crtc, crtc_state, i) {
>-			struct drm_pending_vblank_event *e;
>-
>-			e = create_vblank_event(dev, file_priv, NULL,
>-						arg->user_data);
>-			if (!e) {
>-				ret = -ENOMEM;
>-				goto out;
>-			}
>-
>-			crtc_state->event = e;
>-		}
>-	}
>+	ret = prepare_crtc_signaling(dev, state, arg, file_priv, &fence_state,
>+				     &num_fences);
>+	if (ret)
>+		goto out;
>
> 	if (arg->flags & DRM_MODE_ATOMIC_TEST_ONLY) {
> 		/*
>@@ -1952,20 +2118,7 @@ int drm_mode_atomic_ioctl(struct drm_device *dev,
> out:
> 	drm_atomic_clean_old_fb(dev, plane_mask, ret);
>
>-	if (ret && arg->flags & DRM_MODE_PAGE_FLIP_EVENT) {
>-		/*
>-		 * TEST_ONLY and PAGE_FLIP_EVENT are mutually exclusive,
>-		 * if they weren't, this code should be called on success
>-		 * for TEST_ONLY too.
>-		 */
>-
>-		for_each_crtc_in_state(state, crtc, crtc_state, i) {
>-			if (!crtc_state->event)
>-				continue;
>-
>-			drm_event_cancel_free(dev, &crtc_state->event->base);
>-		}
>-	}
>+	complete_crtc_signaling(dev, state, fence_state, num_fences, ret);
>
> 	if (ret == -EDEADLK) {
> 		drm_atomic_state_clear(state);
>diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
>index 9b9881b..e8bc1ae 100644
>--- a/drivers/gpu/drm/drm_crtc.c
>+++ b/drivers/gpu/drm/drm_crtc.c
>@@ -274,6 +274,8 @@ int drm_crtc_init_with_planes(struct drm_device *dev, struct drm_crtc *crtc,
> 	if (drm_core_check_feature(dev, DRIVER_ATOMIC)) {
> 		drm_object_attach_property(&crtc->base, config->prop_active, 0);
> 		drm_object_attach_property(&crtc->base, config->prop_mode_id, 0);
>+		drm_object_attach_property(&crtc->base,
>+					   config->prop_out_fence_ptr, 0);
> 	}
>
> 	return 0;
>@@ -434,6 +436,12 @@ static int drm_mode_create_standard_properties(struct drm_device *dev)
> 		return -ENOMEM;
> 	dev->mode_config.prop_in_fence_fd = prop;
>
>+	prop = drm_property_create_range(dev, DRM_MODE_PROP_ATOMIC,
>+			"OUT_FENCE_PTR", 0, U64_MAX);
>+	if (!prop)
>+		return -ENOMEM;
>+	dev->mode_config.prop_out_fence_ptr = prop;
>+
> 	prop = drm_property_create_object(dev, DRM_MODE_PROP_ATOMIC,
> 			"CRTC_ID", DRM_MODE_OBJECT_CRTC);
> 	if (!prop)
>diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
>index 331bb10..c0eaec7 100644
>--- a/include/drm/drm_atomic.h
>+++ b/include/drm/drm_atomic.h
>@@ -144,6 +144,7 @@ struct __drm_crtcs_state {
> 	struct drm_crtc *ptr;
> 	struct drm_crtc_state *state;
> 	struct drm_crtc_commit *commit;
>+	s64 __user *out_fence_ptr;
> };
>
> struct __drm_connnectors_state {
>diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
>index 0870de1..44571bc 100644
>--- a/include/drm/drm_crtc.h
>+++ b/include/drm/drm_crtc.h
>@@ -1264,6 +1264,12 @@ struct drm_mode_config {
> 	 */
> 	struct drm_property *prop_in_fence_fd;
> 	/**
>+	 * @prop_out_fence_ptr: Sync File fd pointer representing the
>+	 * outgoing fences for a CRTC. Userspace should provide a pointer to a
>+	 * value of type s64, and then cast that pointer to u64.
>+	 */
>+	struct drm_property *prop_out_fence_ptr;
>+	/**
> 	 * @prop_crtc_id: Default atomic plane property to specify the
> 	 * &drm_crtc.
> 	 */
>-- 
>2.5.5
>
diff mbox

Patch

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 8e26ad1..34cdc6e 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -290,6 +290,23 @@  drm_atomic_get_crtc_state(struct drm_atomic_state *state,
 }
 EXPORT_SYMBOL(drm_atomic_get_crtc_state);
 
+static void set_out_fence_for_crtc(struct drm_atomic_state *state,
+				   struct drm_crtc *crtc, s64 __user *fence_ptr)
+{
+	state->crtcs[drm_crtc_index(crtc)].out_fence_ptr = fence_ptr;
+}
+
+static s64 __user * get_out_fence_for_crtc(struct drm_atomic_state *state,
+					   struct drm_crtc *crtc)
+{
+	s64 __user *fence_ptr;
+
+	fence_ptr = state->crtcs[drm_crtc_index(crtc)].out_fence_ptr;
+	state->crtcs[drm_crtc_index(crtc)].out_fence_ptr = NULL;
+
+	return fence_ptr;
+}
+
 /**
  * drm_atomic_set_mode_for_crtc - set mode for CRTC
  * @state: the CRTC whose incoming state to update
@@ -491,6 +508,16 @@  int drm_atomic_crtc_set_property(struct drm_crtc *crtc,
 					&replaced);
 		state->color_mgmt_changed |= replaced;
 		return ret;
+	} else if (property == config->prop_out_fence_ptr) {
+		s64 __user *fence_ptr = u64_to_user_ptr(val);
+
+		if (!fence_ptr)
+			return 0;
+
+		if (!access_ok(VERIFY_WRITE, fence_ptr, sizeof(*fence_ptr)))
+			return -EFAULT;
+
+		set_out_fence_for_crtc(state->state, crtc, fence_ptr);
 	} else if (crtc->funcs->atomic_set_property)
 		return crtc->funcs->atomic_set_property(crtc, state, property, val);
 	else
@@ -533,6 +560,8 @@  drm_atomic_crtc_get_property(struct drm_crtc *crtc,
 		*val = (state->ctm) ? state->ctm->base.id : 0;
 	else if (property == config->gamma_lut_property)
 		*val = (state->gamma_lut) ? state->gamma_lut->base.id : 0;
+	else if (property == config->prop_out_fence_ptr)
+		*val = 0;
 	else if (crtc->funcs->atomic_get_property)
 		return crtc->funcs->atomic_get_property(crtc, state, property, val);
 	else
@@ -1659,11 +1688,9 @@  int drm_atomic_debugfs_init(struct drm_minor *minor)
  */
 
 static struct drm_pending_vblank_event *create_vblank_event(
-		struct drm_device *dev, struct drm_file *file_priv,
-		struct dma_fence *fence, uint64_t user_data)
+		struct drm_device *dev, uint64_t user_data)
 {
 	struct drm_pending_vblank_event *e = NULL;
-	int ret;
 
 	e = kzalloc(sizeof *e, GFP_KERNEL);
 	if (!e)
@@ -1673,17 +1700,6 @@  static struct drm_pending_vblank_event *create_vblank_event(
 	e->event.base.length = sizeof(e->event);
 	e->event.user_data = user_data;
 
-	if (file_priv) {
-		ret = drm_event_reserve_init(dev, file_priv, &e->base,
-					     &e->event.base);
-		if (ret) {
-			kfree(e);
-			return NULL;
-		}
-	}
-
-	e->base.fence = fence;
-
 	return e;
 }
 
@@ -1788,6 +1804,167 @@  void drm_atomic_clean_old_fb(struct drm_device *dev,
 }
 EXPORT_SYMBOL(drm_atomic_clean_old_fb);
 
+static struct dma_fence *get_crtc_fence(struct drm_crtc *crtc)
+{
+	struct dma_fence *fence;
+
+	fence = kzalloc(sizeof(*fence), GFP_KERNEL);
+	if (!fence)
+		return NULL;
+
+	dma_fence_init(fence, &drm_crtc_fence_ops, &crtc->fence_lock,
+		       crtc->fence_context, ++crtc->fence_seqno);
+
+	return fence;
+}
+
+struct drm_out_fence_state {
+	s64 __user *out_fence_ptr;
+	struct sync_file *sync_file;
+	int fd;
+};
+
+static int setup_out_fence(struct drm_out_fence_state *fence_state,
+			   struct dma_fence *fence)
+{
+	fence_state->fd = get_unused_fd_flags(O_CLOEXEC);
+	if (fence_state->fd < 0)
+		return fence_state->fd;
+
+	if (put_user(fence_state->fd, fence_state->out_fence_ptr))
+		return -EFAULT;
+
+	fence_state->sync_file = sync_file_create(fence);
+	if(!fence_state->sync_file)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static int prepare_crtc_signaling(struct drm_device *dev,
+				  struct drm_atomic_state *state,
+				  struct drm_mode_atomic *arg,
+				  struct drm_file *file_priv,
+				  struct drm_out_fence_state **fence_state,
+				  unsigned int *num_fences)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *crtc_state;
+	int i, ret;
+
+	for_each_crtc_in_state(state, crtc, crtc_state, i) {
+		u64 __user *fence_ptr;
+
+		fence_ptr = get_out_fence_for_crtc(crtc_state->state, crtc);
+
+		if (arg->flags & DRM_MODE_ATOMIC_TEST_ONLY && fence_ptr) {
+			if (put_user(-1, fence_ptr))
+				return -EFAULT;
+
+			continue;
+		}
+
+		if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT || fence_ptr) {
+			struct drm_pending_vblank_event *e;
+
+			e = create_vblank_event(dev, arg->user_data);
+			if (!e)
+				return -ENOMEM;
+
+			crtc_state->event = e;
+		}
+
+		if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT) {
+			struct drm_pending_vblank_event *e = crtc_state->event;
+
+			if (!file_priv)
+				continue;
+
+			ret = drm_event_reserve_init(dev, file_priv, &e->base,
+						     &e->event.base);
+			if (ret) {
+				kfree(e);
+				crtc_state->event = NULL;
+				return ret;
+			}
+		}
+
+		if (fence_ptr) {
+			struct dma_fence *fence;
+			struct drm_out_fence_state *f;
+
+			f = krealloc(*fence_state, sizeof(**fence_state) *
+				     (*num_fences + 1), GFP_KERNEL);
+			if (!f)
+				return -ENOMEM;
+
+			f[*num_fences].out_fence_ptr = fence_ptr;
+			*fence_state = f;
+
+			fence = get_crtc_fence(crtc);
+			if (!fence) {
+				(*num_fences)++;
+				return -ENOMEM;
+			}
+
+			ret = setup_out_fence(&f[(*num_fences)++], fence);
+			if (ret) {
+				dma_fence_put(fence);
+				return ret;
+			}
+
+			crtc_state->event->base.fence = fence;
+
+		}
+	}
+
+	return 0;
+}
+
+static void complete_crtc_signaling(struct drm_device *dev,
+				     struct drm_atomic_state *state,
+				     struct drm_out_fence_state *fence_state,
+				     unsigned int num_fences, int ret)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *crtc_state;
+	int i;
+
+	if (!ret) {
+		for (i = 0; i < num_fences; i++)
+			fd_install(fence_state[i].fd,
+				   fence_state[i].sync_file->file);
+		return;
+	}
+
+	for_each_crtc_in_state(state, crtc, crtc_state, i) {
+		/*
+		 * TEST_ONLY and PAGE_FLIP_EVENT are mutually
+		 * exclusive, if they weren't, this code should be
+		 * called on success for TEST_ONLY too.
+		 */
+		if (crtc_state->event)
+			drm_event_cancel_free(dev, &crtc_state->event->base);
+	}
+
+	if (!fence_state)
+		return;
+
+	for (i = 0; i < num_fences; i++) {
+		if (fence_state[i].sync_file)
+			fput(fence_state[i].sync_file->file);
+		if (fence_state[i].fd >= 0)
+			put_unused_fd(fence_state[i].fd);
+
+		/* If this fails log error to the user */
+		if (fence_state[i].out_fence_ptr &&
+		    put_user(-1, fence_state[i].out_fence_ptr))
+			DRM_DEBUG_ATOMIC("Couldn't clear out_fence_ptr\n");
+	}
+
+	kfree(fence_state);
+}
+
 int drm_mode_atomic_ioctl(struct drm_device *dev,
 			  void *data, struct drm_file *file_priv)
 {
@@ -1800,11 +1977,10 @@  int drm_mode_atomic_ioctl(struct drm_device *dev,
 	struct drm_atomic_state *state;
 	struct drm_modeset_acquire_ctx ctx;
 	struct drm_plane *plane;
-	struct drm_crtc *crtc;
-	struct drm_crtc_state *crtc_state;
+	struct drm_out_fence_state *fence_state = NULL;
 	unsigned plane_mask;
 	int ret = 0;
-	unsigned int i, j;
+	unsigned int i, j, num_fences = 0;
 
 	/* disallow for drivers not supporting atomic: */
 	if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
@@ -1919,20 +2095,10 @@  int drm_mode_atomic_ioctl(struct drm_device *dev,
 		drm_mode_object_unreference(obj);
 	}
 
-	if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT) {
-		for_each_crtc_in_state(state, crtc, crtc_state, i) {
-			struct drm_pending_vblank_event *e;
-
-			e = create_vblank_event(dev, file_priv, NULL,
-						arg->user_data);
-			if (!e) {
-				ret = -ENOMEM;
-				goto out;
-			}
-
-			crtc_state->event = e;
-		}
-	}
+	ret = prepare_crtc_signaling(dev, state, arg, file_priv, &fence_state,
+				     &num_fences);
+	if (ret)
+		goto out;
 
 	if (arg->flags & DRM_MODE_ATOMIC_TEST_ONLY) {
 		/*
@@ -1952,20 +2118,7 @@  int drm_mode_atomic_ioctl(struct drm_device *dev,
 out:
 	drm_atomic_clean_old_fb(dev, plane_mask, ret);
 
-	if (ret && arg->flags & DRM_MODE_PAGE_FLIP_EVENT) {
-		/*
-		 * TEST_ONLY and PAGE_FLIP_EVENT are mutually exclusive,
-		 * if they weren't, this code should be called on success
-		 * for TEST_ONLY too.
-		 */
-
-		for_each_crtc_in_state(state, crtc, crtc_state, i) {
-			if (!crtc_state->event)
-				continue;
-
-			drm_event_cancel_free(dev, &crtc_state->event->base);
-		}
-	}
+	complete_crtc_signaling(dev, state, fence_state, num_fences, ret);
 
 	if (ret == -EDEADLK) {
 		drm_atomic_state_clear(state);
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 9b9881b..e8bc1ae 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -274,6 +274,8 @@  int drm_crtc_init_with_planes(struct drm_device *dev, struct drm_crtc *crtc,
 	if (drm_core_check_feature(dev, DRIVER_ATOMIC)) {
 		drm_object_attach_property(&crtc->base, config->prop_active, 0);
 		drm_object_attach_property(&crtc->base, config->prop_mode_id, 0);
+		drm_object_attach_property(&crtc->base,
+					   config->prop_out_fence_ptr, 0);
 	}
 
 	return 0;
@@ -434,6 +436,12 @@  static int drm_mode_create_standard_properties(struct drm_device *dev)
 		return -ENOMEM;
 	dev->mode_config.prop_in_fence_fd = prop;
 
+	prop = drm_property_create_range(dev, DRM_MODE_PROP_ATOMIC,
+			"OUT_FENCE_PTR", 0, U64_MAX);
+	if (!prop)
+		return -ENOMEM;
+	dev->mode_config.prop_out_fence_ptr = prop;
+
 	prop = drm_property_create_object(dev, DRM_MODE_PROP_ATOMIC,
 			"CRTC_ID", DRM_MODE_OBJECT_CRTC);
 	if (!prop)
diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
index 331bb10..c0eaec7 100644
--- a/include/drm/drm_atomic.h
+++ b/include/drm/drm_atomic.h
@@ -144,6 +144,7 @@  struct __drm_crtcs_state {
 	struct drm_crtc *ptr;
 	struct drm_crtc_state *state;
 	struct drm_crtc_commit *commit;
+	s64 __user *out_fence_ptr;
 };
 
 struct __drm_connnectors_state {
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 0870de1..44571bc 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -1264,6 +1264,12 @@  struct drm_mode_config {
 	 */
 	struct drm_property *prop_in_fence_fd;
 	/**
+	 * @prop_out_fence_ptr: Sync File fd pointer representing the
+	 * outgoing fences for a CRTC. Userspace should provide a pointer to a
+	 * value of type s64, and then cast that pointer to u64.
+	 */
+	struct drm_property *prop_out_fence_ptr;
+	/**
 	 * @prop_crtc_id: Default atomic plane property to specify the
 	 * &drm_crtc.
 	 */