drm/i915: Introduce to_gt() helper

To allow further refactoring and abstract away the fact that GT is
stored inside i915 private.
No functional changes.

Signed-off-by: Michał Winiarski <[e-mail]>
Signed-off-by: Andi Shyti <[e-mail]>
Reviewed-by: Matt Roper <[e-mail]>
Signed-off-by: Matt Roper <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/i915/gt/intel_gt_buffer_pool.c

···
 #include "intel_engine_pm.h"
 #include "intel_gt_buffer_pool.h"
 
-static struct intel_gt *to_gt(struct intel_gt_buffer_pool *pool)
-{
-	return container_of(pool, struct intel_gt, buffer_pool);
-}
-
 static struct list_head *
 bucket_for_size(struct intel_gt_buffer_pool *pool, size_t sz)
 {
···
 node_create(struct intel_gt_buffer_pool *pool, size_t sz,
 	    enum i915_map_type type)
 {
-	struct intel_gt *gt = to_gt(pool);
+	struct intel_gt *gt = container_of(pool, struct intel_gt, buffer_pool);
 	struct intel_gt_buffer_pool_node *node;
 	struct drm_i915_gem_object *obj;
 

drivers/gpu/drm/i915/i915_drv.h

···
 	return pci_get_drvdata(pdev);
 }
 
+static inline struct intel_gt *to_gt(struct drm_i915_private *i915)
+{
+	return &i915->gt;
+}
+
 /* Simple iterator over all initialised engines */
 #define for_each_engine(engine__, dev_priv__, id__) \
 	for ((id__) = 0; \