drm/i915/tdr: Initialize hangcheck struct for each engine

Initialize hangcheck struct during driver load. Since we do the same after
recovering from a reset, this is extracted into a helper function.

v2: remove redundant hangcheck init during load as this is done when
engines are initialized (Chris)

Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Tomas Elf <tomas.elf@intel.com>
Signed-off-by: Arun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458577619-12006-1-git-send-email-arun.siluvery@linux.intel.com

drivers/gpu/drm/i915/i915_drv.h

@@ -2740,6 +2740,7 @@ extern long i915_compat_ioctl(struct file *filp, unsigned int cmd,
 extern int intel_gpu_reset(struct drm_device *dev, u32 engine_mask);
 extern bool intel_has_gpu_reset(struct drm_device *dev);
 extern int i915_reset(struct drm_device *dev);
+extern void intel_engine_init_hangcheck(struct intel_engine_cs *engine);
 extern unsigned long i915_chipset_val(struct drm_i915_private *dev_priv);
 extern unsigned long i915_mch_val(struct drm_i915_private *dev_priv);
 extern unsigned long i915_gfx_val(struct drm_i915_private *dev_priv);

drivers/gpu/drm/i915/intel_lrc.c

@@ -1606,7 +1606,7 @@ static int gen8_init_common_ring(struct intel_engine_cs *engine)
 	engine->next_context_status_buffer = next_context_status_buffer_hw;
 	DRM_DEBUG_DRIVER("Execlists enabled for %s\n", engine->name);
 
-	memset(&engine->hangcheck, 0, sizeof(engine->hangcheck));
+	intel_engine_init_hangcheck(engine);
 
 	return 0;
 }

drivers/gpu/drm/i915/intel_ringbuffer.c

@@ -555,6 +555,11 @@ static bool stop_ring(struct intel_engine_cs *engine)
 	return (I915_READ_HEAD(engine) & HEAD_ADDR) == 0;
 }
 
+void intel_engine_init_hangcheck(struct intel_engine_cs *engine)
+{
+	memset(&engine->hangcheck, 0, sizeof(engine->hangcheck));
+}
+
 static int init_ring_common(struct intel_engine_cs *engine)
 {
 	struct drm_device *dev = engine->dev;
@@ -634,7 +639,7 @@ static int init_ring_common(struct intel_engine_cs *engine)
 	ringbuf->tail = I915_READ_TAIL(engine) & TAIL_ADDR;
 	intel_ring_update_space(ringbuf);
 
-	memset(&engine->hangcheck, 0, sizeof(engine->hangcheck));
+	intel_engine_init_hangcheck(engine);
 
 out:
 	intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);