drm/i915: Move execlist initialization into intel_engine_cs.c

Move execlist init into a common engine setup. As it is
common to both guc and hw execlists.

v2: rebase with csb changes
v3: rebase

Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20170922124307.10914-2-mika.kuoppala@intel.com

1 files changed, 28 insertions, 2 deletions

diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index bf132266a007..30035e59a784 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -382,6 +382,33 @@ static void intel_engine_init_timeline(struct intel_engine_cs *engine)
         engine->timeline = &engine->i915->gt.global_timeline.engine[engine->id];
 }
 
+static bool csb_force_mmio(struct drm_i915_private *i915)
+{
+        /* GVT emulation depends upon intercepting CSB mmio */
+        if (intel_vgpu_active(i915))
+                return true;
+
+        /*
+         * IOMMU adds unpredictable latency causing the CSB write (from the
+         * GPU into the HWSP) to only be visible some time after the interrupt
+         * (missed breadcrumb syndrome).
+         */
+        if (intel_vtd_active())
+                return true;
+
+        return false;
+}
+
+static void intel_engine_init_execlist(struct intel_engine_cs *engine)
+{
+        struct intel_engine_execlists * const execlists = &engine->execlists;
+
+        execlists->csb_use_mmio = csb_force_mmio(engine->i915);
+
+        execlists->queue = RB_ROOT;
+        execlists->first = NULL;
+}
+
 /**
  * intel_engines_setup_common - setup engine state not requiring hw access
  * @engine: Engine to setup.
@@ -393,8 +420,7 @@ static void intel_engine_init_timeline(struct intel_engine_cs *engine)
  */
 void intel_engine_setup_common(struct intel_engine_cs *engine)
 {
-        engine->execlists.queue = RB_ROOT;
-        engine->execlists.first = NULL;
+        intel_engine_init_execlist(engine);
 
         intel_engine_init_timeline(engine);
         intel_engine_init_hangcheck(engine);