[PATCH 5/5] [RFC]drm: add syncobj timeline support v3
Christian König
christian.koenig at amd.com
Thu Aug 30 07:25:27 UTC 2018
Am 30.08.2018 um 05:50 schrieb zhoucm1:
>
>
> On 2018年08月29日 19:42, Christian König wrote:
>> Am 29.08.2018 um 12:44 schrieb Chunming Zhou:
>>> VK_KHR_timeline_semaphore:
>>> This extension introduces a new type of semaphore that has an
>>> integer payload
>>> identifying a point in a timeline. Such timeline semaphores support the
>>> following operations:
>>> * CPU query - A host operation that allows querying the payload
>>> of the
>>> timeline semaphore.
>>> * CPU wait - A host operation that allows a blocking wait for a
>>> timeline semaphore to reach a specified value.
>>> * Device wait - A device operation that allows waiting for a
>>> timeline semaphore to reach a specified value.
>>> * Device signal - A device operation that allows advancing the
>>> timeline semaphore 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. semaphore 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. some bug fix and clean up
>>> 3. tested by ./deqp-vk -n dEQP-VK*semaphore* for normal syncobj
>>>
>>> TODO:
>>> 1. CPU query and wait on timeline semaphore.
>>>
>>> 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 | 593
>>> ++++++++++++++++-----
>>> drivers/gpu/drm/i915/i915_gem_execbuffer.c | 4 +-
>>> include/drm/drm_syncobj.h | 78 +--
>>> include/uapi/drm/drm.h | 1 +
>>> 4 files changed, 505 insertions(+), 171 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/drm_syncobj.c
>>> b/drivers/gpu/drm/drm_syncobj.c
>>> index ab43559398d0..f701d9ef1b81 100644
>>> --- a/drivers/gpu/drm/drm_syncobj.c
>>> +++ b/drivers/gpu/drm/drm_syncobj.c
>>> @@ -56,6 +56,50 @@
>>> #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;
>>> +};
>>> +
>>> +static const char *drm_syncobj_stub_fence_get_name(struct dma_fence
>>> *fence)
>>> +{
>>> + return "syncobjstub";
>>> +}
>>> +
>>> +static bool drm_syncobj_stub_fence_enable_signaling(struct
>>> dma_fence *fence)
>>> +{
>>> + return !dma_fence_is_signaled(fence);
>>> +}
>>> +static void drm_syncobj_stub_fence_release(struct dma_fence *f)
>>> +{
>>> + kfree(f);
>>> +}
>>> +static const struct dma_fence_ops drm_syncobj_stub_fence_ops = {
>>> + .get_driver_name = drm_syncobj_stub_fence_get_name,
>>> + .get_timeline_name = drm_syncobj_stub_fence_get_name,
>>> + .enable_signaling = drm_syncobj_stub_fence_enable_signaling,
>>> + .release = drm_syncobj_stub_fence_release,
>>> +};
>>
>> Do we really need to move that around? Could reduce the size of the
>> patch quite a bit if we don't.
>
> stub fence is used widely in both normal and timeline syncobj, if you
> think which increase patch size, I can do a separate patch for that.
>
>>
>>> +
>>> +struct drm_syncobj_wait_pt {
>>> + struct drm_syncobj_stub_fence base;
>>> + u64 value;
>>> + struct rb_node node;
>>> +};
>>> +struct drm_syncobj_signal_pt {
>>> + struct drm_syncobj_stub_fence base;
>>> + struct dma_fence *signal_fence;
>>> + struct dma_fence *pre_pt_base;
>>> + struct dma_fence_cb signal_cb;
>>> + struct dma_fence_cb pre_pt_cb;
>>> + struct drm_syncobj *syncobj;
>>> + u64 value;
>>> + struct list_head list;
>>> +};
>>
>> What are those two structures good for
> They are used to record wait ops points and signal ops points.
> For timeline, they are connected by timeline value, works like:
> a. signal pt increase timeline value to signal_pt value when
> signal_pt is signaled. signal_pt is depending on previous pt fence and
> itself signal fence from signal ops.
> b. wait pt tree checks if timeline value over itself value.
>
> For normal, works like:
> a. signal pt increase 1 for syncobj_timeline->signal_point every
> time when signal ops is performed.
> b. when wait ops is comming, wait pt will fetch above last signal
> pt value as its wait point. wait pt will be only signaled by equal
> point value signal_pt.
>
>
>> and why is the stub fence their base?
> Good question, I tried to kzalloc for them as well when I debug them,
> I encountered a problem:
> I lookup/find wait_pt or signal_pt successfully, but when I tried to
> use them, they are freed sometimes, and results in NULL point.
> and generally, when lookup them, we often need their stub fence as
> well, and in the meantime, their lifecycle are same.
> Above reason, I make stub fence as their base.
That sounds like you only did this because you messed up the lifecycle.
Additional to that I don't think you correctly considered the lifecycle
of the waits and the sync object itself. E.g. blocking in
drm_syncobj_timeline_fini() until all waits are done is not a good idea.
What you should do instead is to create a fence_array object with all
the fence we need to wait for when a wait point is requested.
Otherwise somebody can easily construct a situation where timeline sync
obj A waits on B and B waits on A.
>
>>
>>> +
>>> /**
>>> * drm_syncobj_find - lookup and reference a sync object.
>>> * @file_private: drm file private pointer
>>> @@ -82,59 +126,247 @@ struct drm_syncobj *drm_syncobj_find(struct
>>> drm_file *file_private,
>>> }
>>> EXPORT_SYMBOL(drm_syncobj_find);
>>> -static void drm_syncobj_add_callback_locked(struct drm_syncobj
>>> *syncobj,
>>> - struct drm_syncobj_cb *cb,
>>> - drm_syncobj_func_t func)
>>> +static void drm_syncobj_timeline_init(struct drm_syncobj_timeline
>>> + *syncobj_timeline)
>>> {
>>> - cb->func = func;
>>> - list_add_tail(&cb->node, &syncobj->cb_list);
>>> + syncobj_timeline->timeline_context = dma_fence_context_alloc(1);
>>> + syncobj_timeline->timeline = 0;
>>> + syncobj_timeline->signal_point = 0;
>>> + init_waitqueue_head(&syncobj_timeline->wq);
>>> +
>>> + syncobj_timeline->wait_pt_tree = RB_ROOT;
>>> + INIT_LIST_HEAD(&syncobj_timeline->signal_pt_list);
>>> }
>>> -static int drm_syncobj_fence_get_or_add_callback(struct
>>> drm_syncobj *syncobj,
>>> - struct dma_fence **fence,
>>> - struct drm_syncobj_cb *cb,
>>> - drm_syncobj_func_t func)
>>> +static void drm_syncobj_timeline_fini(struct drm_syncobj *syncobj,
>>> + struct drm_syncobj_timeline *syncobj_timeline)
>>> {
>>> - int ret;
>>> + struct rb_node *node = NULL;
>>> + struct drm_syncobj_wait_pt *wait_pt = NULL;
>>> + struct drm_syncobj_signal_pt *signal_pt = NULL, *tmp;
>>> +
>>> + spin_lock(&syncobj->lock);
>>> + for(node = rb_first(&syncobj_timeline->wait_pt_tree);
>>> + node != NULL; ) {
>>
>> Better use rbtree_postorder_for_each_entry_safe() for this.
> From the comments, seems we cannot use it here, we need erase node here.
> Comments:
> * Note, however, that it cannot handle other modifications that
> re-order the
> * rbtree it is iterating over. This includes calling rb_erase() on
> @pos, as
> * rb_erase() may rebalance the tree, causing us to miss some nodes.
> */
Yeah, but your current implementation has the same problem :)
You need to use something like "while (node = rb_first(...))" instead if
you want to destruct the whole tree.
Regards,
Christian.
>
> Thanks,
> David Zhou
>>
>> Regards,
>> Christian.
>>
>>> + wait_pt = rb_entry(node, struct drm_syncobj_wait_pt, node);
>>> + node = rb_next(node);
>>> + rb_erase(&wait_pt->node,
>>> + &syncobj_timeline->wait_pt_tree);
>>> + RB_CLEAR_NODE(&wait_pt->node);
>>> + spin_unlock(&syncobj->lock);
>>> + dma_fence_wait(&wait_pt->base.base, true);
>>> + spin_lock(&syncobj->lock);
>>> + /* kfree(wait_pt) is excuted by fence put */
>>> + dma_fence_put(&wait_pt->base.base);
>>> + }
>>> + list_for_each_entry_safe(signal_pt, tmp,
>>> + &syncobj_timeline->signal_pt_list, list) {
>>> + list_del(&signal_pt->list);
>>> + if (signal_pt->signal_fence) {
>>> + dma_fence_remove_callback(signal_pt->signal_fence,
>>> + &signal_pt->signal_cb);
>>> + dma_fence_put(signal_pt->signal_fence);
>>> + }
>>> + if (signal_pt->pre_pt_base) {
>>> + dma_fence_remove_callback(signal_pt->pre_pt_base,
>>> + &signal_pt->pre_pt_cb);
>>> + dma_fence_put(signal_pt->pre_pt_base);
>>> + }
>>> + dma_fence_put(&signal_pt->base.base);
>>> + }
>>> + spin_unlock(&syncobj->lock);
>>> +}
>>> +
>>> - *fence = drm_syncobj_fence_get(syncobj);
>>> - if (*fence)
>>> - return 1;
>>> +static bool drm_syncobj_normal_signal_wait_pts(struct drm_syncobj
>>> *syncobj,
>>> + u64 signal_pt)
>>> +{
>>> + struct rb_node *node = NULL;
>>> + struct drm_syncobj_wait_pt *wait_pt = NULL;
>>> spin_lock(&syncobj->lock);
>>> - /* We've already tried once to get a fence and failed. Now that we
>>> - * 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;
>>> - } else {
>>> - *fence = NULL;
>>> - drm_syncobj_add_callback_locked(syncobj, cb, func);
>>> - ret = 0;
>>> + for(node = rb_first(&syncobj->syncobj_timeline.wait_pt_tree);
>>> + node != NULL; ) {
>>> + wait_pt = rb_entry(node, struct drm_syncobj_wait_pt, node);
>>> + node = rb_next(node);
>>> + /* for normal syncobj */
>>> + if (wait_pt->value == signal_pt) {
>>> + dma_fence_signal(&wait_pt->base.base);
>>> + rb_erase(&wait_pt->node,
>>> + &syncobj->syncobj_timeline.wait_pt_tree);
>>> + RB_CLEAR_NODE(&wait_pt->node);
>>> + /* kfree(wait_pt) is excuted by fence put */
>>> + dma_fence_put(&wait_pt->base.base);
>>> + spin_unlock(&syncobj->lock);
>>> + return true;
>>> + }
>>> }
>>> spin_unlock(&syncobj->lock);
>>> + return false;
>>> +}
>>> - return ret;
>>> +static void drm_syncobj_timeline_signal_wait_pts(struct drm_syncobj
>>> *syncobj)
>>> +{
>>> + struct rb_node *node = NULL;
>>> + struct drm_syncobj_wait_pt *wait_pt = NULL;
>>> +
>>> + spin_lock(&syncobj->lock);
>>> + for(node = rb_first(&syncobj->syncobj_timeline.wait_pt_tree);
>>> + node != NULL; ) {
>>> + wait_pt = rb_entry(node, struct drm_syncobj_wait_pt, node);
>>> + node = rb_next(node);
>>> + if (wait_pt->value <= syncobj->syncobj_timeline.timeline) {
>>> + dma_fence_signal(&wait_pt->base.base);
>>> + rb_erase(&wait_pt->node,
>>> + &syncobj->syncobj_timeline.wait_pt_tree);
>>> + RB_CLEAR_NODE(&wait_pt->node);
>>> + /* kfree(wait_pt) is excuted by fence put */
>>> + dma_fence_put(&wait_pt->base.base);
>>> + } else {
>>> + /* the loop is from left to right, the later entry
>>> value is
>>> + * bigger, so don't need to check any more */
>>> + break;
>>> + }
>>> + }
>>> + spin_unlock(&syncobj->lock);
>>> }
>>> -void drm_syncobj_add_callback(struct drm_syncobj *syncobj,
>>> - struct drm_syncobj_cb *cb,
>>> - drm_syncobj_func_t func)
>>> +
>>> +
>>> +static void pt_fence_cb(struct drm_syncobj_signal_pt *signal_pt)
>>> {
>>> + struct dma_fence *fence = NULL;
>>> + struct drm_syncobj *syncobj;
>>> + struct drm_syncobj_signal_pt *tail_pt;
>>> + u64 pt_value = signal_pt->value;
>>> +
>>> + dma_fence_signal(&signal_pt->base.base);
>>> + fence = signal_pt->signal_fence;
>>> + signal_pt->signal_fence = NULL;
>>> + dma_fence_put(fence);
>>> + fence = signal_pt->pre_pt_base;
>>> + signal_pt->pre_pt_base = NULL;
>>> + dma_fence_put(fence);
>>> +
>>> + syncobj = signal_pt->syncobj;
>>> spin_lock(&syncobj->lock);
>>> - drm_syncobj_add_callback_locked(syncobj, cb, func);
>>> + syncobj->syncobj_timeline.timeline = pt_value;
>>> + tail_pt =
>>> list_last_entry(&syncobj->syncobj_timeline.signal_pt_list,
>>> + struct drm_syncobj_signal_pt, list);
>>> + if ((syncobj->type == DRM_SYNCOBJ_TYPE_NORMAL && signal_pt !=
>>> tail_pt)
>>> + || syncobj->type == DRM_SYNCOBJ_TYPE_TIMELINE) {
>>> + list_del(&signal_pt->list);
>>> + /* kfree(signal_pt) will be executed by below fence put */
>>> + dma_fence_put(&signal_pt->base.base);
>>> + }
>>> spin_unlock(&syncobj->lock);
>>> + if (syncobj->type == DRM_SYNCOBJ_TYPE_NORMAL)
>>> + drm_syncobj_normal_signal_wait_pts(syncobj, pt_value);
>>> + else
>>> + drm_syncobj_timeline_signal_wait_pts(syncobj);
>>> }
>>> +static void pt_signal_fence_func(struct dma_fence *fence,
>>> + struct dma_fence_cb *cb)
>>> +{
>>> + struct drm_syncobj_signal_pt *signal_pt =
>>> + container_of(cb, struct drm_syncobj_signal_pt, signal_cb);
>>> -void drm_syncobj_remove_callback(struct drm_syncobj *syncobj,
>>> - struct drm_syncobj_cb *cb)
>>> + if (signal_pt->pre_pt_base &&
>>> + !dma_fence_is_signaled(signal_pt->pre_pt_base))
>>> + return;
>>> +
>>> + pt_fence_cb(signal_pt);
>>> +}
>>> +static void pt_pre_fence_func(struct dma_fence *fence,
>>> + struct dma_fence_cb *cb)
>>> +{
>>> + struct drm_syncobj_signal_pt *signal_pt =
>>> + container_of(cb, struct drm_syncobj_signal_pt, pre_pt_cb);
>>> +
>>> + if (signal_pt->signal_fence &&
>>> + !dma_fence_is_signaled(signal_pt->pre_pt_base))
>>> + return;
>>> +
>>> + pt_fence_cb(signal_pt);
>>> +}
>>> +
>>> +static int drm_syncobj_timeline_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_stub_fence *base;
>>> + struct drm_syncobj_signal_pt *tail_pt;
>>> + struct dma_fence *tail_pt_fence = NULL;
>>> + int ret = 0;
>>> +
>>> + 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;
>>> + dma_fence_get(fence);
>>> spin_lock(&syncobj->lock);
>>> - list_del_init(&cb->node);
>>> + base = &signal_pt->base;
>>> + spin_lock_init(&base->lock);
>>> + dma_fence_init(&base->base,
>>> + &drm_syncobj_stub_fence_ops,
>>> + &base->lock,
>>> + syncobj->syncobj_timeline.timeline_context, point);
>>> + signal_pt->signal_fence = fence;
>>> + /* timeline syncobj must take this dependency */
>>> + if (syncobj->type == DRM_SYNCOBJ_TYPE_TIMELINE) {
>>> + 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);
>>> + tail_pt_fence = &tail_pt->base.base;
>>> + if (dma_fence_is_signaled(tail_pt_fence))
>>> + tail_pt_fence = NULL;
>>> + else
>>> + signal_pt->pre_pt_base =
>>> + dma_fence_get(tail_pt_fence);
>>> + }
>>> + }
>>> +
>>> + signal_pt->value = point;
>>> + syncobj->syncobj_timeline.signal_point = point;
>>> + signal_pt->syncobj = syncobj;
>>> + INIT_LIST_HEAD(&signal_pt->list);
>>> + list_add_tail(&signal_pt->list,
>>> &syncobj->syncobj_timeline.signal_pt_list);
>>> spin_unlock(&syncobj->lock);
>>> + wake_up_all(&syncobj->syncobj_timeline.wq);
>>> + /**
>>> + * Every pt is depending on signal fence and previous pt fence,
>>> add
>>> + * callbacks to them
>>> + */
>>> + ret = dma_fence_add_callback(signal_pt->signal_fence,
>>> + &signal_pt->signal_cb,
>>> + pt_signal_fence_func);
>>> +
>>> + if (signal_pt->pre_pt_base) {
>>> + ret = dma_fence_add_callback(signal_pt->pre_pt_base,
>>> + &signal_pt->pre_pt_cb,
>>> + pt_pre_fence_func);
>>> + if (ret == -ENOENT)
>>> + pt_pre_fence_func(signal_pt->pre_pt_base,
>>> + &signal_pt->pre_pt_cb);
>>> + else if (ret)
>>> + goto out;
>>> + } else if (ret == -ENOENT) {
>>> + pt_signal_fence_func(signal_pt->signal_fence,
>>> + &signal_pt->signal_cb);
>>> + } else if (ret) {
>>> + goto out;
>>> + }
>>> +
>>> + return 0;
>>> +out:
>>> + dma_fence_put(&signal_pt->base.base);
>>> + return ret;
>>> }
>>> /**
>>> @@ -149,53 +381,30 @@ 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);
>>> -
>>> - if (fence != old_fence) {
>>> - list_for_each_entry_safe(cur, tmp, &syncobj->cb_list, node) {
>>> - list_del_init(&cur->node);
>>> - cur->func(syncobj, cur);
>>> + if (syncobj->type == DRM_SYNCOBJ_TYPE_TIMELINE) {
>>> + if (fence)
>>> + drm_syncobj_timeline_create_signal_pt(syncobj, fence,
>>> + point);
>>> + return;
>>> + } 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_timeline);
>>> + return;
>>> }
>>> + pt_value = syncobj->syncobj_timeline.signal_point +
>>> + DRM_SYNCOBJ_NORMAL_POINT;
>>> + drm_syncobj_timeline_create_signal_pt(syncobj, fence,
>>> pt_value);
>>> + return;
>>> + } else {
>>> + DRM_ERROR("the syncobj type isn't support\n");
>>> }
>>> -
>>> - spin_unlock(&syncobj->lock);
>>> -
>>> - dma_fence_put(old_fence);
>>> }
>>> EXPORT_SYMBOL(drm_syncobj_replace_fence);
>>> -struct drm_syncobj_stub_fence {
>>> - struct dma_fence base;
>>> - spinlock_t lock;
>>> -};
>>> -
>>> -static const char *drm_syncobj_stub_fence_get_name(struct dma_fence
>>> *fence)
>>> -{
>>> - return "syncobjstub";
>>> -}
>>> -
>>> -static bool drm_syncobj_stub_fence_enable_signaling(struct
>>> dma_fence *fence)
>>> -{
>>> - return !dma_fence_is_signaled(fence);
>>> -}
>>> -
>>> -static const struct dma_fence_ops drm_syncobj_stub_fence_ops = {
>>> - .get_driver_name = drm_syncobj_stub_fence_get_name,
>>> - .get_timeline_name = drm_syncobj_stub_fence_get_name,
>>> - .enable_signaling = drm_syncobj_stub_fence_enable_signaling,
>>> - .release = NULL,
>>> -};
>>> -
>>> static int drm_syncobj_assign_null_handle(struct drm_syncobj
>>> *syncobj)
>>> {
>>> struct drm_syncobj_stub_fence *fence;
>>> @@ -215,6 +424,143 @@ static int
>>> drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)
>>> return 0;
>>> }
>>> +static struct drm_syncobj_wait_pt *
>>> +drm_syncobj_timeline_lookup_wait_pt_fence(struct drm_syncobj *syncobj,
>>> + u64 point,
>>> + struct dma_fence **fence)
>>> +{
>>> + struct rb_node *node =
>>> syncobj->syncobj_timeline.wait_pt_tree.rb_node;
>>> + struct drm_syncobj_wait_pt *wait_pt = NULL;
>>> +
>>> +
>>> + spin_lock(&syncobj->lock);
>>> + while(node) {
>>> + int result;
>>> +
>>> + wait_pt = rb_entry(node, struct drm_syncobj_wait_pt, node);
>>> + result = point - wait_pt->value;
>>> + if (result < 0) {
>>> + node = node->rb_left;
>>> + } else if (result > 0) {
>>> + node = node->rb_right;
>>> + } else {
>>> + if (fence)
>>> + *fence = dma_fence_get(&wait_pt->base.base);
>>> + break;
>>> + }
>>> + }
>>> + spin_unlock(&syncobj->lock);
>>> +
>>> + return wait_pt;
>>> +}
>>> +
>>> +static struct drm_syncobj_wait_pt *
>>> +drm_syncobj_timeline_create_wait_pt_and_return_fence(struct
>>> drm_syncobj *syncobj,
>>> + u64 point,
>>> + struct dma_fence **fence)
>>> +{
>>> + struct drm_syncobj_wait_pt *wait_pt = kzalloc(sizeof(*wait_pt),
>>> + GFP_KERNEL);
>>> + struct drm_syncobj_stub_fence *base;
>>> + struct rb_node **new =
>>> &(syncobj->syncobj_timeline.wait_pt_tree.rb_node), *parent = NULL;
>>> + struct drm_syncobj_signal_pt *tail_signal_pt =
>>> + list_last_entry(&syncobj->syncobj_timeline.signal_pt_list,
>>> + struct drm_syncobj_signal_pt, list);
>>> +
>>> + if (!wait_pt)
>>> + return NULL;
>>> + base = &wait_pt->base;
>>> + spin_lock_init(&base->lock);
>>> + dma_fence_init(&base->base,
>>> + &drm_syncobj_stub_fence_ops,
>>> + &base->lock,
>>> + syncobj->syncobj_timeline.timeline_context, point);
>>> + wait_pt->value = point;
>>> +
>>> + /* wait pt must be in an order, so that we can easily lookup
>>> and signal
>>> + * it */
>>> + spin_lock(&syncobj->lock);
>>> + if (syncobj->type == DRM_SYNCOBJ_TYPE_TIMELINE &&
>>> + point <= syncobj->syncobj_timeline.timeline)
>>> + dma_fence_signal(&wait_pt->base.base);
>>> + if ((syncobj->type == DRM_SYNCOBJ_TYPE_NORMAL) &&
>>> + (point == tail_signal_pt->value) &&
>>> + dma_fence_is_signaled(&tail_signal_pt->base.base))
>>> + dma_fence_signal(&wait_pt->base.base);
>>> + while(*new) {
>>> + struct drm_syncobj_wait_pt *this =
>>> + rb_entry(*new, struct drm_syncobj_wait_pt, node);
>>> + int result = wait_pt->value - this->value;
>>> +
>>> + parent = *new;
>>> + if (result < 0)
>>> + new = &((*new)->rb_left);
>>> + else if (result > 0)
>>> + new = &((*new)->rb_right);
>>> + else
>>> + goto exist;
>>> + }
>>> + if (fence)
>>> + *fence = dma_fence_get(&wait_pt->base.base);
>>> + rb_link_node(&wait_pt->node, parent, new);
>>> + rb_insert_color(&wait_pt->node,
>>> &syncobj->syncobj_timeline.wait_pt_tree);
>>> + spin_unlock(&syncobj->lock);
>>> + return wait_pt;
>>> +exist:
>>> + spin_unlock(&syncobj->lock);
>>> + dma_fence_put(&wait_pt->base.base);
>>> + wait_pt = drm_syncobj_timeline_lookup_wait_pt_fence(syncobj,
>>> point,
>>> + fence);
>>> + return wait_pt;
>>> +}
>>> +
>>> +static struct dma_fence *
>>> +drm_syncobj_timeline_point_get(struct drm_syncobj *syncobj, u64
>>> point, u64 flags)
>>> +{
>>> + struct drm_syncobj_wait_pt *wait_pt;
>>> + struct dma_fence *fence = NULL;
>>> +
>>> + /* already signaled, simply return a signaled stub fence */
>>> + if (syncobj->type == DRM_SYNCOBJ_TYPE_TIMELINE &&
>>> + point <= syncobj->syncobj_timeline.timeline) {
>>> + struct drm_syncobj_stub_fence *fence;
>>> +
>>> + fence = kzalloc(sizeof(*fence), GFP_KERNEL);
>>> + if (fence == NULL)
>>> + return NULL;
>>> +
>>> + spin_lock_init(&fence->lock);
>>> + dma_fence_init(&fence->base, &drm_syncobj_stub_fence_ops,
>>> + &fence->lock, 0, 0);
>>> + dma_fence_signal(&fence->base);
>>> + return &fence->base;
>>> + }
>>> +
>>> + /* check if the wait pt exists */
>>> + wait_pt = drm_syncobj_timeline_lookup_wait_pt_fence(syncobj,
>>> point,
>>> + &fence);
>>> + if (!fence) {
>>> + /* This is a new wait pt, so create it */
>>> + wait_pt =
>>> drm_syncobj_timeline_create_wait_pt_and_return_fence(syncobj, point,
>>> + &fence);
>>> + if (!fence)
>>> + return NULL;
>>> + }
>>> + if (wait_pt) {
>>> + int ret = 0;
>>> +
>>> + if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) {
>>> + ret =
>>> wait_event_interruptible_timeout(syncobj->syncobj_timeline.wq,
>>> + wait_pt->value <=
>>> syncobj->syncobj_timeline.signal_point,
>>> + msecs_to_jiffies(10000)); /*
>>> wait 10s */
>>> + if (ret <= 0)
>>> + return NULL;
>>> + }
>>> + return fence;
>>> + }
>>> + return NULL;
>>> +}
>>> +
>>> /**
>>> * drm_syncobj_find_fence - lookup and reference the fence in a
>>> sync object
>>> * @file_private: drm file private pointer
>>> @@ -229,20 +575,45 @@ 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);
>>> + 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_timeline_point_get(syncobj,
>>> tail_pt_value,
>>> + flags);
>>> + } else if (syncobj->type == DRM_SYNCOBJ_TYPE_TIMELINE) {
>>> + *fence = drm_syncobj_timeline_point_get(syncobj, point,
>>> + flags);
>>> + } 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;
>>> }
>>> @@ -259,7 +630,7 @@ 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);
>>> @@ -287,8 +658,12 @@ int drm_syncobj_create(struct drm_syncobj
>>> **out_syncobj, uint32_t flags,
>>> return -ENOMEM;
>>> 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_timeline);
>>> if (flags & DRM_SYNCOBJ_CREATE_SIGNALED) {
>>> ret = drm_syncobj_assign_null_handle(syncobj);
>>> @@ -646,7 +1021,6 @@ struct syncobj_wait_entry {
>>> struct task_struct *task;
>>> struct dma_fence *fence;
>>> struct dma_fence_cb fence_cb;
>>> - struct drm_syncobj_cb syncobj_cb;
>>> };
>>> static void syncobj_wait_fence_func(struct dma_fence *fence,
>>> @@ -658,18 +1032,6 @@ static void syncobj_wait_fence_func(struct
>>> dma_fence *fence,
>>> wake_up_process(wait->task);
>>> }
>>> -static void syncobj_wait_syncobj_func(struct drm_syncobj *syncobj,
>>> - struct drm_syncobj_cb *cb)
>>> -{
>>> - 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)));
>>> - wake_up_process(wait->task);
>>> -}
>>> -
>>> static signed long drm_syncobj_array_wait_timeout(struct
>>> drm_syncobj **syncobjs,
>>> uint32_t count,
>>> uint32_t flags,
>>> @@ -693,14 +1055,11 @@ 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;
>>> - } else {
>>> - ret = -EINVAL;
>>> - goto cleanup_entries;
>>> - }
>>> + ret = -EINVAL;
>>> + goto cleanup_entries;
>>> }
>>> if (dma_fence_is_signaled(entries[i].fence)) {
>>> @@ -728,15 +1087,6 @@ static signed long
>>> drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs,
>>> * fallthough and try a 0 timeout wait!
>>> */
>>> - if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) {
>>> - for (i = 0; i < count; ++i) {
>>> - drm_syncobj_fence_get_or_add_callback(syncobjs[i],
>>> - &entries[i].fence,
>>> - &entries[i].syncobj_cb,
>>> - syncobj_wait_syncobj_func);
>>> - }
>>> - }
>>> -
>>> do {
>>> set_current_state(TASK_INTERRUPTIBLE);
>>> @@ -784,13 +1134,10 @@ static signed long
>>> drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs,
>>> cleanup_entries:
>>> for (i = 0; i < count; ++i) {
>>> - if (entries[i].syncobj_cb.func)
>>> - drm_syncobj_remove_callback(syncobjs[i],
>>> - &entries[i].syncobj_cb);
>>> + dma_fence_put(entries[i].fence);
>>> if (entries[i].fence_cb.func)
>>> dma_fence_remove_callback(entries[i].fence,
>>> &entries[i].fence_cb);
>>> - dma_fence_put(entries[i].fence);
>>> }
>>> kfree(entries);
>>> @@ -965,12 +1312,20 @@ 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");
>>> + ret = -EINVAL;
>>> + goto out;
>>> + }
>>> + drm_syncobj_timeline_fini(syncobjs[i],
>>> + &syncobjs[i]->syncobj_timeline);
>>> + drm_syncobj_timeline_init(&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 7209dd832d39..bb20d318c9d6 100644
>>> --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
>>> +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
>>> @@ -2182,7 +2182,9 @@ 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,
>>> + &fence);
>>> if (!fence)
>>> return -EINVAL;
>>> diff --git a/include/drm/drm_syncobj.h b/include/drm/drm_syncobj.h
>>> index 425432b85a87..657c97dc25ec 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,
>>> + 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;
>>> + struct list_head signal_pt_list;
>>> +};
>>> +
>>> /**
>>> * struct drm_syncobj - sync object.
>>> *
>>> @@ -41,19 +60,16 @@ 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 list_head cb_list;
>>> + struct drm_syncobj_timeline syncobj_timeline;
>>> +
>>> /**
>>> - * @lock: Protects &cb_list and write-locks &fence.
>>> + * @lock: Protects timeline list and write-locks &fence.
>>> */
>>> spinlock_t lock;
>>> /**
>>> @@ -62,25 +78,6 @@ struct drm_syncobj {
>>> struct file *file;
>>> };
>>> -typedef void (*drm_syncobj_func_t)(struct drm_syncobj *syncobj,
>>> - struct drm_syncobj_cb *cb);
>>> -
>>> -/**
>>> - * 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
>>> - * @func: drm_syncobj_func_t to call
>>> - *
>>> - * This struct will be initialized by drm_syncobj_add_callback,
>>> additional
>>> - * data can be passed along by embedding drm_syncobj_cb in another
>>> struct.
>>> - * The callback will get called the next time
>>> drm_syncobj_replace_fence is
>>> - * called.
>>> - */
>>> -struct drm_syncobj_cb {
>>> - struct list_head node;
>>> - drm_syncobj_func_t func;
>>> -};
>>> -
>>> void drm_syncobj_free(struct kref *kref);
>>> /**
>>> @@ -106,29 +103,6 @@ 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 +116,7 @@ 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;
>>> };
>>
>
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