drm/i915: Split I915_RESET_IN_PROGRESS into two flags

I915_RESET_IN_PROGRESS is being used for both signaling the requirement
to i915_mutex_lock_interruptible() to avoid taking the struct_mutex and
to instruct a waiter (already holding the struct_mutex) to perform the
reset. To allow for a little more coordination, split these two meaning
into a couple of distinct flags. I915_RESET_BACKOFF tells
i915_mutex_lock_interruptible() not to acquire the mutex and
I915_RESET_HANDOFF tells the waiter to call i915_reset().

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Michel Thierry <michel.thierry@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170316171305.12972-1-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c
index 1e1d9f2..0e8d101 100644
--- a/drivers/gpu/drm/i915/i915_gem_request.c
+++ b/drivers/gpu/drm/i915/i915_gem_request.c
@@ -1012,7 +1012,7 @@ bool __i915_spin_request(const struct drm_i915_gem_request *req,
 
 static bool __i915_wait_request_check_and_reset(struct drm_i915_gem_request *request)
 {
-	if (likely(!i915_reset_in_progress(&request->i915->gpu_error)))
+	if (likely(!i915_reset_handoff(&request->i915->gpu_error)))
 		return false;
 
 	__set_current_state(TASK_RUNNING);