drm/i915/guc: Use a local cancel_port_requests

Since execlists and the guc have diverged in their port tracking, we
cannot simply reuse the execlists cancellation code as it leads to
unbalanced reference counting. Use a local, simpler routine for the guc.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190812203626.3948-1-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/gt/intel_engine.h b/drivers/gpu/drm/i915/gt/intel_engine.h
index bc694ad..d3c6993 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_engine.h
+++ b/drivers/gpu/drm/i915/gt/intel_engine.h
@@ -136,9 +136,6 @@ execlists_active(const struct intel_engine_execlists *execlists)
        return READ_ONCE(*execlists->active);
 }
 
-void
-execlists_cancel_port_requests(struct intel_engine_execlists * const execlists);
-
 struct i915_request *
 execlists_unwind_incomplete_requests(struct intel_engine_execlists *execlists);
 

diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index b97047d..5c26c4a 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -1297,8 +1297,8 @@ done:
        }
 }
 
-void
-execlists_cancel_port_requests(struct intel_engine_execlists * const execlists)
+static void
+cancel_port_requests(struct intel_engine_execlists * const execlists)
 {
        struct i915_request * const *port, *rq;
 
@@ -2355,7 +2355,7 @@ out_replay:
 
 unwind:
        /* Push back any incomplete requests for replay after the reset. */
-       execlists_cancel_port_requests(execlists);
+       cancel_port_requests(execlists);
        __unwind_incomplete_requests(engine);
 }
 

diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
index deb054e..54c3ae2 100644 (file)
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -517,11 +517,14 @@ static struct i915_request *schedule_in(struct i915_request *rq, int idx)
 {
        trace_i915_request_in(rq, idx);
 
-       if (!rq->hw_context->inflight)
-               rq->hw_context->inflight = rq->engine;
-       intel_context_inflight_inc(rq->hw_context);
-       intel_gt_pm_get(rq->engine->gt);
+       /*
+        * Currently we are not tracking the rq->context being inflight
+        * (ce->inflight = rq->engine). It is only used by the execlists
+        * backend at the moment, a similar counting strategy would be
+        * required if we generalise the inflight tracking.
+        */
 
+       intel_gt_pm_get(rq->engine->gt);
        return i915_request_get(rq);
 }
 
@@ -529,10 +532,6 @@ static void schedule_out(struct i915_request *rq)
 {
        trace_i915_request_out(rq);
 
-       intel_context_inflight_dec(rq->hw_context);
-       if (!intel_context_inflight_count(rq->hw_context))
-               rq->hw_context->inflight = NULL;
-
        intel_gt_pm_put(rq->engine->gt);
        i915_request_put(rq);
 }
@@ -556,6 +555,11 @@ static void __guc_dequeue(struct intel_engine_cs *engine)
                last = NULL;
        }
 
+       /*
+        * We write directly into the execlists->inflight queue and don't use
+        * the execlists->pending queue, as we don't have a distinct switch
+        * event.
+        */
        port = first;
        while ((rb = rb_first_cached(&execlists->queue))) {
                struct i915_priolist *p = to_priolist(rb);
@@ -636,6 +640,19 @@ static void guc_reset_prepare(struct intel_engine_cs *engine)
        __tasklet_disable_sync_once(&execlists->tasklet);
 }
 
+static void
+cancel_port_requests(struct intel_engine_execlists * const execlists)
+{
+       struct i915_request * const *port, *rq;
+
+       /* Note we are only using the inflight and not the pending queue */
+
+       for (port = execlists->active; (rq = *port); port++)
+               schedule_out(rq);
+       execlists->active =
+               memset(execlists->inflight, 0, sizeof(execlists->inflight));
+}
+
 static void guc_reset(struct intel_engine_cs *engine, bool stalled)
 {
        struct intel_engine_execlists * const execlists = &engine->execlists;
@@ -644,7 +661,7 @@ static void guc_reset(struct intel_engine_cs *engine, bool stalled)
 
        spin_lock_irqsave(&engine->active.lock, flags);
 
-       execlists_cancel_port_requests(execlists);
+       cancel_port_requests(execlists);
 
        /* Push back any incomplete requests for replay after the reset. */
        rq = execlists_unwind_incomplete_requests(execlists);
@@ -687,7 +704,7 @@ static void guc_cancel_requests(struct intel_engine_cs *engine)
        spin_lock_irqsave(&engine->active.lock, flags);
 
        /* Cancel the requests on the HW and clear the ELSP tracker. */
-       execlists_cancel_port_requests(execlists);
+       cancel_port_requests(execlists);
 
        /* Mark all executing requests as skipped. */
        list_for_each_entry(rq, &engine->active.requests, sched.link) {