If while we are cancelling the breadcrumb signaling, we find that the
request is already completed, move it to the irq signaler and let it be
signaled.
v2: Tweak reference counting so that we only acquire a new reference on
adding to a signal list, as opposed to a hidden i915_request_put of the
caller's reference.
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/gt/intel_breadcrumbs.c | 41 +++++++++++----------
1 file changed, 22 insertions(+), 19 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c
index a24cc1ff08a0..00918300f53f 100644
--- a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c
+++ b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c
@@ -192,18 +192,6 @@ static void add_retire(struct intel_breadcrumbs *b, struct intel_timeline *tl)
intel_engine_add_retire(b->irq_engine, tl);
}
-static bool __signal_request(struct i915_request *rq)
-{
- GEM_BUG_ON(test_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags));
-
- if (!__dma_fence_signal(&rq->fence)) {
- i915_request_put(rq);
- return false;
- }
-
- return true;
-}
-
static struct llist_node *
slist_add(struct llist_node *node, struct llist_node *head)
{
@@ -274,9 +262,11 @@ static void signal_irq_work(struct irq_work *work)
release = remove_signaling_context(b, ce);
spin_unlock(&ce->signal_lock);
- if (__signal_request(rq))
+ if (__dma_fence_signal(&rq->fence))
/* We own signal_node now, xfer to local list */
signal = slist_add(&rq->signal_node, signal);
+ else
+ i915_request_put(rq);
if (release) {
add_retire(b, ce->timeline);
@@ -363,6 +353,17 @@ void intel_breadcrumbs_free(struct intel_breadcrumbs *b)
kfree(b);
}
+static void irq_signal_request(struct i915_request *rq,
+ struct intel_breadcrumbs *b)
+{
+ if (!__dma_fence_signal(&rq->fence))
+ return;
+
+ i915_request_get(rq);
+ if (llist_add(&rq->signal_node, &b->signaled_requests))
+ irq_work_queue(&b->irq_work);
+}
+
static void insert_breadcrumb(struct i915_request *rq)
{
struct intel_breadcrumbs *b = READ_ONCE(rq->engine)->breadcrumbs;
@@ -372,17 +373,13 @@ static void insert_breadcrumb(struct i915_request *rq)
if (test_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags))
return;
- i915_request_get(rq);
-
/*
* If the request is already completed, we can transfer it
* straight onto a signaled list, and queue the irq worker for
* its signal completion.
*/
if (__request_completed(rq)) {
- if (__signal_request(rq) &&
- llist_add(&rq->signal_node, &b->signaled_requests))
- irq_work_queue(&b->irq_work);
+ irq_signal_request(rq, b);
return;
}
@@ -413,6 +410,8 @@ static void insert_breadcrumb(struct i915_request *rq)
break;
}
}
+
+ i915_request_get(rq);
list_add_rcu(&rq->signal_link, pos);
GEM_BUG_ON(!check_signal_order(ce, rq));
GEM_BUG_ON(test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &rq->fence.flags));
@@ -453,6 +452,7 @@ bool i915_request_enable_breadcrumb(struct i915_request *rq)
void i915_request_cancel_breadcrumb(struct i915_request *rq)
{
+ struct intel_breadcrumbs *b = READ_ONCE(rq->engine)->breadcrumbs;
struct intel_context *ce = rq->context;
bool release;
@@ -461,11 +461,14 @@ void i915_request_cancel_breadcrumb(struct i915_request *rq)
spin_lock(&ce->signal_lock);
list_del_rcu(&rq->signal_link);
- release = remove_signaling_context(rq->engine->breadcrumbs, ce);
+ release = remove_signaling_context(b, ce);
spin_unlock(&ce->signal_lock);
if (release)
intel_context_put(ce);
+ if (__request_completed(rq))
+ irq_signal_request(rq, b);
+
i915_request_put(rq);
}
