drm/i915: Move assertion for iomap access to i915_vma_pin_iomap

Access through the GTT requires the device to be awake. Ideally
i915_vma_pin_iomap() is short-lived and the pinning demarcates the
access through the iomap. This is not entirely true, we have a mixture
of long lived pins that exceed the wakelock (such as legacy ringbuffers)
and short lived pin that do live within the wakelock (such as execlist
ringbuffers).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1471254551-25805-17-git-send-email-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_gem_gtt.c

@@ -3650,6 +3650,9 @@ void __iomem *i915_vma_pin_iomap(struct i915_vma *vma)
 {
 	void __iomem *ptr;
 
+	/* Access through the GTT requires the device to be awake. */
+	assert_rpm_wakelock_held(to_i915(vma->vm->dev));
+
 	lockdep_assert_held(&vma->vm->dev->struct_mutex);
 	if (WARN_ON(!vma->obj->map_and_fenceable))
 		return IO_ERR_PTR(-ENODEV);

drivers/gpu/drm/i915/intel_ringbuffer.c

@@ -1966,9 +1966,6 @@ int intel_ring_pin(struct intel_ring *ring)
 		if (ret)
 			goto err_unpin;
 
-		/* Access through the GTT requires the device to be awake. */
-		assert_rpm_wakelock_held(dev_priv);
-
 		addr = (void __force *)
 			i915_vma_pin_iomap(i915_gem_obj_to_ggtt(obj));
 		if (IS_ERR(addr)) {