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@amd.com Cc: Christian Konig christian.koenig@amd.com Cc: Dave Airlie airlied@redhat.com Cc: Daniel Rakos Daniel.Rakos@amd.com Cc: Daniel Vetter daniel@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.

...

/**    * 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.  */

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;   };

On 2018年08月30日 15:25, Christian König wrote:

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@amd.com Cc: Christian Konig christian.koenig@amd.com Cc: Dave Airlie airlied@redhat.com Cc: Daniel Rakos Daniel.Rakos@amd.com Cc: Daniel Vetter daniel@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.

Yeah, this is our initial discussion result, but when I tried to do that, I found that cannot meet the advance signal requirement:     a. We need to consider the wait and signal pt value are not one-to-one match, it's difficult to find dependent point, at least, there is some overhead.     b. because we allowed "wait-before-signal", if "wait-before-signal" happens, there isn't signal fence which can be used to create fence array. So timeline value is good to resolve that.

Otherwise somebody can easily construct a situation where timeline sync obj A waits on B and B waits on A.

Same situation also can happens with fence-array, we only can see this is a programming bug with incorrect use.

...

...

...

/**    * 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);

I already get the next node before erasing this node, so the "for (..." sentence is equal with "while (...)"

Thanks, David Zhou

...

...

...

• 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;   };

---

amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx

在 2018/8/30 19:32, Christian König 写道:

[SNIP]

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+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.

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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.

Yeah, this is our initial discussion result, but when I tried to do that, I found that cannot meet the advance signal requirement:     a. We need to consider the wait and signal pt value are not one-to-one match, it's difficult to find dependent point, at least, there is some overhead.

As far as I can see that is independent of using a fence array here. See you can either use a ring buffer or an rb-tree, but when you want to wait for a specific point we need to condense the not yet signaled fences into an array.

again, need to find the range of where the specific point in, we should close to timeline semantics, I also refered the sw_sync.c timeline, usally wait_pt is signalled by timeline point. And I agree we can implement it with several methods, but I don't think there are basical differences.

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b. because we allowed "wait-before-signal", if "wait-before-signal" happens, there isn't signal fence which can be used to create fence array.

Well, again we DON'T support wait-before-signal here. I will certainly NAK any implementation which tries to do this until we haven't figured out all the resource management constraints and I still don't see how we can do this.

yes, we don't support real wait-before-signal in patch now, just a fake wait-before-signal, which still wait on CS submission until signal operation coming through wait_event, which is the conclusion we disscussed before.

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So timeline value is good to resolve that.

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Otherwise somebody can easily construct a situation where timeline sync obj A waits on B and B waits on A.

Same situation also can happens with fence-array, we only can see this is a programming bug with incorrect use.

No, fence-array is initialized only once with a static list of fences. This way it is impossible to add the fence-array to itself for example.

E.g. you can't build circle dependencies with that.

we already wait for signal operation event, so never build circle dependencies with that. The theory is same.

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Better use rbtree_postorder_for_each_entry_safe() for this.

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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.

OK, got it, I will change it in v4.

Thanks, David Zhou

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Regards, Christian.

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Thanks, David Zhou

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Regards, Christian.

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+        wait_pt = rb_entry(node, struct drm_syncobj_wait_pt, node); +        node = rb_next(node);

I already get the next node before erasing this node, so the "for (..." sentence is equal with "while (...)"

That still doesn't work. The problem is the because of an erase the next node might skip some nodes when rebalancing.

What you need to do is to either not erase the nodes at all (because we re-initialize the tree anyway) or always use rb_first().

Regards, Christian.

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Thanks, David Zhou

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• 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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