[PATCH 09/13] drm/i915: Drive request submission through fence callbacks

[Chris Wilson]

---
 drivers/gpu/drm/i915/i915_gem_request.c  | 20 +++++++++++++++++++-
 drivers/gpu/drm/i915/i915_gem_request.h  |  3 +++
 drivers/gpu/drm/i915/intel_breadcrumbs.c |  3 +++
 drivers/gpu/drm/i915/intel_lrc.c         |  5 +++--
 4 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c
index fa5e36de55d0..db45482ea194 100644
--- a/drivers/gpu/drm/i915/i915_gem_request.c
+++ b/drivers/gpu/drm/i915/i915_gem_request.c
@@ -314,6 +314,19 @@ static int i915_gem_get_seqno(struct drm_i915_private *dev_priv, u32 *seqno)
 	return 0;
 }
 
+static int __i915_sw_fence_call submit_notify(struct i915_sw_fence *fence)
+{
+	struct drm_i915_gem_request *request =
+		container_of(fence, typeof(*request), submit);
+
+	if (i915_sw_fence_done(fence))
+		i915_gem_request_put(request);
+	else
+		request->engine->submit_request(request);
+
+	return NOTIFY_DONE;
+}
+
 /**
  * i915_gem_request_alloc - allocate a request structure
  *
@@ -412,6 +425,8 @@ i915_gem_request_alloc(struct intel_engine_cs *engine,
 	 */
 	req->reserved_space = MIN_SPACE_FOR_ADD_REQUEST;
 
+	i915_sw_fence_init(&i915_gem_request_get(req)->submit, submit_notify);
+
 	if (i915.enable_execlists)
 		ret = intel_logical_ring_alloc_request_extras(req);
 	else
@@ -527,7 +542,10 @@ void __i915_add_request(struct drm_i915_gem_request *request, bool flush_caches)
 		  reserved_tail, ret);
 
 	i915_gem_mark_busy(engine);
-	engine->submit_request(request);
+
+	local_bh_disable();
+	i915_sw_fence_commit(&request->submit);
+	local_bh_enable(); /* Kick the execlists tasklet if just scheduled */
 }
 
 static unsigned long local_clock_us(unsigned int *cpu)
diff --git a/drivers/gpu/drm/i915/i915_gem_request.h b/drivers/gpu/drm/i915/i915_gem_request.h
index a231bd318ef0..a85723463978 100644
--- a/drivers/gpu/drm/i915/i915_gem_request.h
+++ b/drivers/gpu/drm/i915/i915_gem_request.h
@@ -28,6 +28,7 @@
 #include <linux/fence.h>
 
 #include "i915_gem.h"
+#include "i915_sw_fence.h"
 
 struct intel_wait {
 	struct rb_node node;
@@ -82,6 +83,8 @@ struct drm_i915_gem_request {
 	struct intel_ring *ring;
 	struct intel_signal_node signaling;
 
+	struct i915_sw_fence submit;
+
 	/** GEM sequence number associated with the previous request,
 	 * when the HWS breadcrumb is equal to this the GPU is processing
 	 * this request.
diff --git a/drivers/gpu/drm/i915/intel_breadcrumbs.c b/drivers/gpu/drm/i915/intel_breadcrumbs.c
index 2491e4c1eaf0..75a7f9565ee7 100644
--- a/drivers/gpu/drm/i915/intel_breadcrumbs.c
+++ b/drivers/gpu/drm/i915/intel_breadcrumbs.c
@@ -462,7 +462,10 @@ static int intel_breadcrumbs_signaler(void *arg)
 			 */
 			intel_engine_remove_wait(engine,
 						 &request->signaling.wait);
+
+			local_bh_disable();
 			fence_signal(&request->fence);
+			local_bh_enable();
 
 			/* Find the next oldest signal. Note that as we have
 			 * not been holding the lock, another client may
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 5e60519ede8d..babeaa8b1273 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -538,14 +538,15 @@ static void intel_lrc_irq_handler(unsigned long data)
 static void execlists_submit_request(struct drm_i915_gem_request *request)
 {
 	struct intel_engine_cs *engine = request->engine;
+	unsigned long flags;
 
-	spin_lock_bh(&engine->execlist_lock);
+	spin_lock_irqsave(&engine->execlist_lock, flags);
 
 	list_add_tail(&request->execlist_link, &engine->execlist_queue);
 	if (execlists_elsp_idle(engine))
 		tasklet_hi_schedule(&engine->irq_tasklet);
 
-	spin_unlock_bh(&engine->execlist_lock);
+	spin_unlock_irqrestore(&engine->execlist_lock, flags);
 }
 
 int intel_logical_ring_alloc_request_extras(struct drm_i915_gem_request *request)
-- 
2.9.3