Am 14.09.2018 um 12:37 schrieb Chunming Zhou:
> This patch is for VK_KHR_timeline_semaphore extension, semaphore is called syncobj in kernel side:
> This extension introduces a new type of syncobj that has an integer payload
> identifying a point in a timeline. Such timeline syncobjs support the
> following operations:
> * CPU query - A host operation that allows querying the payload of the
> timeline syncobj.
> * CPU wait - A host operation that allows a blocking wait for a
> timeline syncobj to reach a specified value.
> * Device wait - A device operation that allows waiting for a
> timeline syncobj to reach a specified value.
> * Device signal - A device operation that allows advancing the
> timeline syncobj to a specified value.
>
> Since it's a timeline, that means the front time point(PT) always is signaled before the late PT.
> a. signal PT design:
> Signal PT fence N depends on PT[N-1] fence and signal opertion fence, when PT[N] fence is signaled,
> the timeline will increase to value of PT[N].
> b. wait PT design:
> Wait PT fence is signaled by reaching timeline point value, when timeline is increasing, will compare
> wait PTs value with new timeline value, if PT value is lower than timeline value, then wait PT will be
> signaled, otherwise keep in list. syncobj wait operation can wait on any point of timeline,
> so need a RB tree to order them. And wait PT could ahead of signal PT, we need a sumission fence to
> perform that.
>
> v2:
> 1. remove unused DRM_SYNCOBJ_CREATE_TYPE_NORMAL. (Christian)
> 2. move unexposed denitions to .c file. (Daniel Vetter)
> 3. split up the change to drm_syncobj_find_fence() in a separate patch. (Christian)
> 4. split up the change to drm_syncobj_replace_fence() in a separate patch.
> 5. drop the submission_fence implementation and instead use wait_event() for that. (Christian)
> 6. WARN_ON(point != 0) for NORMAL type syncobj case. (Daniel Vetter)
>
> v3:
> 1. replace normal syncobj with timeline implemenation. (Vetter and Christian)
> a. normal syncobj signal op will create a signal PT to tail of signal pt list.
> b. normal syncobj wait op will create a wait pt with last signal point, and this wait PT is only signaled by related signal point PT.
> 2. many bug fix and clean up
> 3. stub fence moving is moved to other patch.
>
> v4ï¼?
> 1. fix RB tree loop with while(node=rb_first(...)). (Christian)
> 2. fix syncobj lifecycle. (Christian)
> 3. only enable_signaling when there is wait_pt. (Christian)
> 4. fix timeline path issues.
> 5. write a timeline test in libdrm
>
> v5: (Christian)
> 1. semaphore is called syncobj in kernel side.
> 2. don't need 'timeline' characters in some function name.
> 3. keep syncobj cb
>
> normal syncobj is tested by ./deqp-vk -n dEQP-VK*semaphore*
> timeline syncobj is tested by ./amdgpu_test -s 9
>
> Signed-off-by: Chunming Zhou <david1.zhou at amd.com>
> Cc: Christian Konig <christian.koenig at amd.com>
> Cc: Dave Airlie <airlied at redhat.com>
> Cc: Daniel Rakos <Daniel.Rakos at amd.com>
> Cc: Daniel Vetter <daniel at ffwll.ch>
> ---
> drivers/gpu/drm/drm_syncobj.c | 294 ++++++++++++++++++---
> drivers/gpu/drm/i915/i915_gem_execbuffer.c | 4 +-
> include/drm/drm_syncobj.h | 62 +++--
> include/uapi/drm/drm.h | 1 +
> 4 files changed, 292 insertions(+), 69 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
> index e9ce623d049e..e78d076f2703 100644
> --- a/drivers/gpu/drm/drm_syncobj.c
> +++ b/drivers/gpu/drm/drm_syncobj.c
> @@ -56,6 +56,9 @@
> #include "drm_internal.h"
> #include <drm/drm_syncobj.h>
>
> +/* merge normal syncobj to timeline syncobj, the point interval is 1 */
> +#define DRM_SYNCOBJ_NORMAL_POINT 1
> +
> struct drm_syncobj_stub_fence {
> struct dma_fence base;
> spinlock_t lock;
> @@ -82,6 +85,11 @@ static const struct dma_fence_ops drm_syncobj_stub_fence_ops = {
> .release = drm_syncobj_stub_fence_release,
> };
>
> +struct drm_syncobj_signal_pt {
> + struct dma_fence_array *base;
> + u64 value;
> + struct list_head list;
> +};
>
> /**
> * drm_syncobj_find - lookup and reference a sync object.
> @@ -124,7 +132,7 @@ static int drm_syncobj_fence_get_or_add_callback(struct drm_syncobj *syncobj,
> {
> int ret;
>
> - *fence = drm_syncobj_fence_get(syncobj);
> + ret = drm_syncobj_search_fence(syncobj, 0, 0, fence);
> if (*fence)
Don't we need to check ret here instead?
> return 1;
>
> @@ -133,10 +141,10 @@ static int drm_syncobj_fence_get_or_add_callback(struct drm_syncobj *syncobj,
> * have the lock, try one more time just to be sure we don't add a
> * callback when a fence has already been set.
> */
> - if (syncobj->fence) {
> - *fence = dma_fence_get(rcu_dereference_protected(syncobj->fence,
> - lockdep_is_held(&syncobj->lock)));
> - ret = 1;
> + if (fence) {
> + drm_syncobj_search_fence(syncobj, 0, 0, fence);
> + if (*fence)
> + ret = 1;
That doesn't looks correct to me, drm_syncobj_search_fence() would try
to grab the lock once more.
That should probably be something like checking the signal_pt list and
if it is not empty any more drop the lock and retry.
> } else {
> *fence = NULL;
> drm_syncobj_add_callback_locked(syncobj, cb, func);
> @@ -164,6 +172,151 @@ void drm_syncobj_remove_callback(struct drm_syncobj *syncobj,
> spin_unlock(&syncobj->lock);
> }
>
> +static void drm_syncobj_timeline_init(struct drm_syncobj *syncobj,
> + struct drm_syncobj_timeline *syncobj_timeline)
> +{
> + spin_lock(&syncobj->lock);
> + syncobj_timeline->timeline_context = dma_fence_context_alloc(1);
> + syncobj_timeline->timeline = 0;
> + syncobj_timeline->signal_point = 0;
> + init_waitqueue_head(&syncobj_timeline->wq);
> +
> + INIT_LIST_HEAD(&syncobj_timeline->signal_pt_list);
> + spin_unlock(&syncobj->lock);
> +}
> +
> +static void drm_syncobj_timeline_fini(struct drm_syncobj *syncobj,
> + struct drm_syncobj_timeline *syncobj_timeline)
> +{
> + struct drm_syncobj_signal_pt *signal_pt = NULL, *tmp;
> +
> + spin_lock(&syncobj->lock);
> + list_for_each_entry_safe(signal_pt, tmp,
> + &syncobj_timeline->signal_pt_list, list) {
> + list_del(&signal_pt->list);
> + dma_fence_put(&signal_pt->base->base);
> + kfree(signal_pt);
> + }
> + spin_unlock(&syncobj->lock);
> +}
> +
> +static struct dma_fence
> +*drm_syncobj_find_signal_pt_for_point(struct drm_syncobj *syncobj,
> + uint64_t point)
> +{
> + struct drm_syncobj_timeline *timeline = &syncobj->syncobj_timeline;
> + struct drm_syncobj_signal_pt *signal_pt;
> +
> + if ((syncobj->type == DRM_SYNCOBJ_TYPE_TIMELINE) &&
> + (point <= timeline->timeline)) {
> + struct drm_syncobj_stub_fence *fence =
> + kzalloc(sizeof(struct drm_syncobj_stub_fence),
> + GFP_KERNEL);
> +
> + if (!fence)
> + return NULL;
> + spin_lock_init(&fence->lock);
> + dma_fence_init(&fence->base,
> + &drm_syncobj_stub_fence_ops,
> + &fence->lock,
> + syncobj->syncobj_timeline.timeline_context,
> + point);
> +
> + dma_fence_signal(&fence->base);
> + return &fence->base;
> + }
> +
> + list_for_each_entry(signal_pt, &timeline->signal_pt_list, list) {
> + if (point > signal_pt->value)
> + continue;
> + if ((syncobj->type == DRM_SYNCOBJ_TYPE_NORMAL) &&
> + (point != signal_pt->value))
> + continue;
> + return dma_fence_get(&signal_pt->base->base);
> + }
> + return NULL;
> +}
> +
> +static int drm_syncobj_create_signal_pt(struct drm_syncobj *syncobj,
> + struct dma_fence *fence,
> + u64 point)
> +{
> + struct drm_syncobj_signal_pt *signal_pt =
> + kzalloc(sizeof(struct drm_syncobj_signal_pt), GFP_KERNEL);
> + struct drm_syncobj_signal_pt *tail_pt;
> + struct dma_fence **fences;
> + int num_fences = 0;
> + int ret = 0, i;
> +
> + if (!signal_pt)
> + return -ENOMEM;
> + if (syncobj->syncobj_timeline.signal_point >= point) {
> + DRM_WARN("A later signal is ready!");
> + goto out;
> + }
> + if (!fence)
> + goto out;
> +
> + fences = kmalloc_array(sizeof(void *), 2, GFP_KERNEL);
> + if (!fences)
> + goto out;
> + fences[num_fences++] = dma_fence_get(fence);
> + /* timeline syncobj must take this dependency */
> + if (syncobj->type == DRM_SYNCOBJ_TYPE_TIMELINE) {
> + spin_lock(&syncobj->lock);
> + if (!list_empty(&syncobj->syncobj_timeline.signal_pt_list)) {
> + tail_pt = list_last_entry(&syncobj->syncobj_timeline.signal_pt_list,
> + struct drm_syncobj_signal_pt, list);
> + fences[num_fences++] = dma_fence_get(&tail_pt->base->base);
> + }
> + spin_unlock(&syncobj->lock);
> + }
> + signal_pt->base = dma_fence_array_create(num_fences, fences,
> + syncobj->syncobj_timeline.timeline_context,
> + point, false);
> + if (!signal_pt->base)
> + goto fail;
> +
> + spin_lock(&syncobj->lock);
> + signal_pt->value = point;
> + INIT_LIST_HEAD(&signal_pt->list);
> + list_add_tail(&signal_pt->list, &syncobj->syncobj_timeline.signal_pt_list);
> + syncobj->syncobj_timeline.signal_point = point;
> + spin_unlock(&syncobj->lock);
> + wake_up_all(&syncobj->syncobj_timeline.wq);
> +
> + return 0;
> +fail:
> + for (i = 0; i < num_fences; i++)
> + dma_fence_put(fences[i]);
> + kfree(fences);
> +out:
> + kfree(signal_pt);
> + return ret;
> +}
> +
> +static void drm_syncobj_garbage_collection(struct drm_syncobj *syncobj)
> +{
> + struct drm_syncobj_timeline *timeline = &syncobj->syncobj_timeline;
> + struct drm_syncobj_signal_pt *signal_pt, *tmp;
> +
> + spin_lock(&syncobj->lock);
> + list_for_each_entry_safe(signal_pt, tmp,
> + &timeline->signal_pt_list, list) {
> + if (dma_fence_is_signaled(&signal_pt->base->base)) {
> + timeline->timeline = signal_pt->value;
> + list_del(&signal_pt->list);
> + dma_fence_put(&signal_pt->base->base);
> + kfree(signal_pt);
> + } else {
> + /*signal_pt is in order in list, from small to big, so
> + * the later must not be signal either */
> + break;
> + }
> + }
> +
> + spin_unlock(&syncobj->lock);
> +}
> /**
> * drm_syncobj_replace_fence - replace fence in a sync object.
> * @syncobj: Sync object to replace fence in
> @@ -176,28 +329,37 @@ void drm_syncobj_replace_fence(struct drm_syncobj *syncobj,
> u64 point,
> struct dma_fence *fence)
> {
> - struct dma_fence *old_fence;
> - struct drm_syncobj_cb *cur, *tmp;
> -
> - if (fence)
> - dma_fence_get(fence);
> -
> - spin_lock(&syncobj->lock);
> -
> - old_fence = rcu_dereference_protected(syncobj->fence,
> - lockdep_is_held(&syncobj->lock));
> - rcu_assign_pointer(syncobj->fence, fence);
> + drm_syncobj_garbage_collection(syncobj);
> + if (syncobj->type == DRM_SYNCOBJ_TYPE_TIMELINE) {
> + if (fence)
> + drm_syncobj_create_signal_pt(syncobj, fence, point);
> + } else if (syncobj->type == DRM_SYNCOBJ_TYPE_NORMAL) {
> + u64 pt_value;
> +
> + if (!fence) {
> + drm_syncobj_timeline_fini(syncobj,
> + &syncobj->syncobj_timeline);
> + drm_syncobj_timeline_init(syncobj,
> + &syncobj->syncobj_timeline);
> + return;
> + }
> + pt_value = syncobj->syncobj_timeline.signal_point +
> + DRM_SYNCOBJ_NORMAL_POINT;
Looks like this could be simplified. If we don't have a timeline syncobj
we just finish and reinitialize it.
Adding the fence then becomes common for both code paths.
> + drm_syncobj_create_signal_pt(syncobj, fence, pt_value);
> + } else {
> + DRM_ERROR("the syncobj type isn't support\n");
> + return;
> + }
> + if (fence) {
> + struct drm_syncobj_cb *cur, *tmp;
>
> - if (fence != old_fence) {
> + spin_lock(&syncobj->lock);
> list_for_each_entry_safe(cur, tmp, &syncobj->cb_list, node) {
> list_del_init(&cur->node);
> cur->func(syncobj, cur);
> }
> + spin_unlock(&syncobj->lock);
> }
> -
> - spin_unlock(&syncobj->lock);
> -
> - dma_fence_put(old_fence);
> }
> EXPORT_SYMBOL(drm_syncobj_replace_fence);
>
> @@ -220,6 +382,25 @@ static int drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)
> return 0;
> }
>
> +static struct dma_fence *
> +drm_syncobj_point_get(struct drm_syncobj *syncobj, u64 point, u64 flags)
> +{
> + struct dma_fence *fence;
> + int ret = 0;
> +
> + if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) {
> + ret = wait_event_timeout(syncobj->syncobj_timeline.wq,
> + point <= syncobj->syncobj_timeline.signal_point,
> + msecs_to_jiffies(10000)); /* wait 10s */
Either don't use a timeout or provide the timeout explicitely, but don't
hard code it here.
Additional to that we probably need an incorruptible wait.
> + if (ret <= 0)
> + return NULL;
> + }
> + spin_lock(&syncobj->lock);
> + fence = drm_syncobj_find_signal_pt_for_point(syncobj, point);
> + spin_unlock(&syncobj->lock);
> + return fence;
> +}
> +
> /**
> * drm_syncobj_find_fence - lookup and reference the fence in a sync object
> * @file_private: drm file private pointer
> @@ -234,20 +415,46 @@ static int drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)
> * contains a reference to the fence, which must be released by calling
> * dma_fence_put().
> */
> -int drm_syncobj_find_fence(struct drm_file *file_private,
> - u32 handle, u64 point,
> - struct dma_fence **fence)
> +int drm_syncobj_search_fence(struct drm_syncobj *syncobj, u64 point,
> + u64 flags, struct dma_fence **fence)
> {
> - struct drm_syncobj *syncobj = drm_syncobj_find(file_private, handle);
> int ret = 0;
>
> if (!syncobj)
> return -ENOENT;
>
> - *fence = drm_syncobj_fence_get(syncobj);
> + drm_syncobj_garbage_collection(syncobj);
> + if (syncobj->type == DRM_SYNCOBJ_TYPE_NORMAL) {
> + /*NORMAL syncobj always wait on last pt */
> + u64 tail_pt_value = syncobj->syncobj_timeline.signal_point;
> +
> + if (tail_pt_value == 0)
> + tail_pt_value += DRM_SYNCOBJ_NORMAL_POINT;
> + /* NORMAL syncobj doesn't care point value */
> + WARN_ON(point != 0);
> + *fence = drm_syncobj_point_get(syncobj, tail_pt_value,
> + flags);
> + } else if (syncobj->type == DRM_SYNCOBJ_TYPE_TIMELINE) {
> + *fence = drm_syncobj_point_get(syncobj, point,
> + flags);
Finding the fence is common for normal and timeline fence, only figuring
out the sequence number is different.
So that can probably be simplified further here.
> + } else {
> + DRM_ERROR("Don't support this type syncobj\n");
> + *fence = NULL;
> + }
> if (!*fence) {
> ret = -EINVAL;
> }
> + return ret;
> +}
> +EXPORT_SYMBOL(drm_syncobj_search_fence);
> +int drm_syncobj_find_fence(struct drm_file *file_private,
> + u32 handle, u64 point,
> + struct dma_fence **fence) {
> + struct drm_syncobj *syncobj = drm_syncobj_find(file_private, handle);
> +
> + int ret = drm_syncobj_search_fence(syncobj, point,
> + DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT,
> + fence);
> drm_syncobj_put(syncobj);
> return ret;
> }
> @@ -264,7 +471,7 @@ void drm_syncobj_free(struct kref *kref)
> struct drm_syncobj *syncobj = container_of(kref,
> struct drm_syncobj,
> refcount);
> - drm_syncobj_replace_fence(syncobj, 0, NULL);
> + drm_syncobj_timeline_fini(syncobj, &syncobj->syncobj_timeline);
> kfree(syncobj);
> }
> EXPORT_SYMBOL(drm_syncobj_free);
> @@ -294,6 +501,11 @@ int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags,
> kref_init(&syncobj->refcount);
> INIT_LIST_HEAD(&syncobj->cb_list);
> spin_lock_init(&syncobj->lock);
> + if (flags & DRM_SYNCOBJ_CREATE_TYPE_TIMELINE)
> + syncobj->type = DRM_SYNCOBJ_TYPE_TIMELINE;
> + else
> + syncobj->type = DRM_SYNCOBJ_TYPE_NORMAL;
> + drm_syncobj_timeline_init(syncobj, &syncobj->syncobj_timeline);
>
> if (flags & DRM_SYNCOBJ_CREATE_SIGNALED) {
> ret = drm_syncobj_assign_null_handle(syncobj);
> @@ -576,7 +788,8 @@ drm_syncobj_create_ioctl(struct drm_device *dev, void *data,
> return -ENODEV;
>
> /* no valid flags yet */
> - if (args->flags & ~DRM_SYNCOBJ_CREATE_SIGNALED)
> + if (args->flags & ~(DRM_SYNCOBJ_CREATE_SIGNALED |
> + DRM_SYNCOBJ_CREATE_TYPE_TIMELINE))
> return -EINVAL;
>
> return drm_syncobj_create_as_handle(file_private,
> @@ -669,9 +882,8 @@ static void syncobj_wait_syncobj_func(struct drm_syncobj *syncobj,
> struct syncobj_wait_entry *wait =
> container_of(cb, struct syncobj_wait_entry, syncobj_cb);
>
> - /* This happens inside the syncobj lock */
> - wait->fence = dma_fence_get(rcu_dereference_protected(syncobj->fence,
> - lockdep_is_held(&syncobj->lock)));
> + drm_syncobj_search_fence(syncobj, 0, 0, &wait->fence);
> +
> wake_up_process(wait->task);
> }
>
> @@ -698,7 +910,8 @@ static signed long drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs,
> signaled_count = 0;
> for (i = 0; i < count; ++i) {
> entries[i].task = current;
> - entries[i].fence = drm_syncobj_fence_get(syncobjs[i]);
> + ret = drm_syncobj_search_fence(syncobjs[i], 0, 0,
> + &entries[i].fence);
> if (!entries[i].fence) {
> if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) {
> continue;
> @@ -970,12 +1183,21 @@ drm_syncobj_reset_ioctl(struct drm_device *dev, void *data,
> if (ret < 0)
> return ret;
>
> - for (i = 0; i < args->count_handles; i++)
> - drm_syncobj_replace_fence(syncobjs[i], 0, NULL);
> -
> + for (i = 0; i < args->count_handles; i++) {
> + if (syncobjs[i]->type == DRM_SYNCOBJ_TYPE_TIMELINE) {
> + DRM_ERROR("timeline syncobj cannot reset!\n");
Why not? I mean that should still work or do I miss anything?
> + ret = -EINVAL;
> + goto out;
> + }
> + drm_syncobj_timeline_fini(syncobjs[i],
> + &syncobjs[i]->syncobj_timeline);
> + drm_syncobj_timeline_init(syncobjs[i],
> + &syncobjs[i]->syncobj_timeline);
> + }
> +out:
> drm_syncobj_array_free(syncobjs, args->count_handles);
>
> - return 0;
> + return ret;
> }
>
> int
> diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> index 0a8d2d64f380..579e91a5858b 100644
> --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> @@ -2137,7 +2137,9 @@ await_fence_array(struct i915_execbuffer *eb,
> if (!(flags & I915_EXEC_FENCE_WAIT))
> continue;
>
> - fence = drm_syncobj_fence_get(syncobj);
> + drm_syncobj_search_fence(syncobj, 0,
> + DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT,
Not sure if we can make DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT the
default here.
Maybe better if drivers explicitly need to ask for it?
> + &fence);
> if (!fence)
> return -EINVAL;
>
> diff --git a/include/drm/drm_syncobj.h b/include/drm/drm_syncobj.h
> index 425432b85a87..9535521e6623 100644
> --- a/include/drm/drm_syncobj.h
> +++ b/include/drm/drm_syncobj.h
> @@ -30,6 +30,25 @@
>
> struct drm_syncobj_cb;
>
> +enum drm_syncobj_type {
> + DRM_SYNCOBJ_TYPE_NORMAL,
Does anybody have a better suggestion for _TYPE_NORMAL? That sounds like
timeline would be special.
> + DRM_SYNCOBJ_TYPE_TIMELINE
> +};
> +
> +struct drm_syncobj_timeline {
> + wait_queue_head_t wq;
> + u64 timeline_context;
> + /**
> + * @timeline: syncobj timeline
> + */
> + u64 timeline;
> + u64 signal_point;
> +
> +
> + struct rb_root wait_pt_tree;
Not used any more?
> + struct list_head signal_pt_list;
> +};
> +
> /**
> * struct drm_syncobj - sync object.
> *
> @@ -41,19 +60,19 @@ struct drm_syncobj {
> */
> struct kref refcount;
> /**
> - * @fence:
> - * NULL or a pointer to the fence bound to this object.
> - *
> - * This field should not be used directly. Use drm_syncobj_fence_get()
> - * and drm_syncobj_replace_fence() instead.
> + * @type: indicate syncobj type
> */
> - struct dma_fence __rcu *fence;
> + enum drm_syncobj_type type;
> /**
> - * @cb_list: List of callbacks to call when the &fence gets replaced.
> + * @syncobj_timeline: timeline
> */
> + struct drm_syncobj_timeline syncobj_timeline;
Looks like that can now be embedded into drm_syncobj.
Regards,
Christian.
> + /**
> + * @cb_list: List of callbacks to call when the &fence gets replaced.
> + */
> struct list_head cb_list;
> /**
> - * @lock: Protects &cb_list and write-locks &fence.
> + * @lock: Protects syncobj list and write-locks &fence.
> */
> spinlock_t lock;
> /**
> @@ -68,7 +87,7 @@ typedef void (*drm_syncobj_func_t)(struct drm_syncobj *syncobj,
> /**
> * struct drm_syncobj_cb - callback for drm_syncobj_add_callback
> * @node: used by drm_syncob_add_callback to append this struct to
> - * &drm_syncobj.cb_list
> + * &drm_syncobj.cb_list
> * @func: drm_syncobj_func_t to call
> *
> * This struct will be initialized by drm_syncobj_add_callback, additional
> @@ -106,29 +125,6 @@ drm_syncobj_put(struct drm_syncobj *obj)
> kref_put(&obj->refcount, drm_syncobj_free);
> }
>
> -/**
> - * drm_syncobj_fence_get - get a reference to a fence in a sync object
> - * @syncobj: sync object.
> - *
> - * This acquires additional reference to &drm_syncobj.fence contained in @obj,
> - * if not NULL. It is illegal to call this without already holding a reference.
> - * No locks required.
> - *
> - * Returns:
> - * Either the fence of @obj or NULL if there's none.
> - */
> -static inline struct dma_fence *
> -drm_syncobj_fence_get(struct drm_syncobj *syncobj)
> -{
> - struct dma_fence *fence;
> -
> - rcu_read_lock();
> - fence = dma_fence_get_rcu_safe(&syncobj->fence);
> - rcu_read_unlock();
> -
> - return fence;
> -}
> -
> struct drm_syncobj *drm_syncobj_find(struct drm_file *file_private,
> u32 handle);
> void drm_syncobj_replace_fence(struct drm_syncobj *syncobj, u64 point,
> @@ -142,5 +138,7 @@ int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags,
> int drm_syncobj_get_handle(struct drm_file *file_private,
> struct drm_syncobj *syncobj, u32 *handle);
> int drm_syncobj_get_fd(struct drm_syncobj *syncobj, int *p_fd);
> +int drm_syncobj_search_fence(struct drm_syncobj *syncobj, u64 point,
> + u64 flags, struct dma_fence **fence);
>
> #endif
> diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
> index 300f336633f2..cebdb2541eb7 100644
> --- a/include/uapi/drm/drm.h
> +++ b/include/uapi/drm/drm.h
> @@ -717,6 +717,7 @@ struct drm_prime_handle {
> struct drm_syncobj_create {
> __u32 handle;
> #define DRM_SYNCOBJ_CREATE_SIGNALED (1 << 0)
> +#define DRM_SYNCOBJ_CREATE_TYPE_TIMELINE (1 << 1)
> __u32 flags;
> };
>
