drm/i915: Group the GT routines together in both code and vtable

Tidy up the routines for interacting with the GT (in particular the
forcewake dance) which are scattered throughout the code in a single
structure.

v2: use wait_for_atomic for polling.

v3: *really* use wait_for_atomic for polling.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index a0c15ab..60f6974 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -262,8 +262,6 @@
 			  struct drm_i915_gem_object *obj);
 	int (*update_plane)(struct drm_crtc *crtc, struct drm_framebuffer *fb,
 			    int x, int y);
-	void (*force_wake_get)(struct drm_i915_private *dev_priv);
-	void (*force_wake_put)(struct drm_i915_private *dev_priv);
 	/* clock updates for mode set */
 	/* cursor updates */
 	/* render clock increase/decrease */
@@ -271,6 +269,11 @@
 	/* pll clock increase/decrease */
 };
 
+struct drm_i915_gt_funcs {
+	void (*force_wake_get)(struct drm_i915_private *dev_priv);
+	void (*force_wake_put)(struct drm_i915_private *dev_priv);
+};
+
 struct intel_device_info {
 	u8 gen;
 	u8 is_mobile:1;
@@ -362,6 +365,8 @@
 	int relative_constants_mode;
 
 	void __iomem *regs;
+
+	struct drm_i915_gt_funcs gt;
 	/** gt_fifo_count and the subsequent register write are synchronized
 	 * with dev->struct_mutex. */
 	unsigned gt_fifo_count;
@@ -1200,6 +1205,7 @@
 void i915_handle_error(struct drm_device *dev, bool wedged);
 
 extern void intel_irq_init(struct drm_device *dev);
+extern void intel_gt_init(struct drm_device *dev);
 
 void i915_error_state_free(struct kref *error_ref);
 
@@ -1517,13 +1523,6 @@
 extern int intel_enable_rc6(const struct drm_device *dev);
 
 extern bool i915_semaphore_is_enabled(struct drm_device *dev);
-extern void __gen6_gt_force_wake_get(struct drm_i915_private *dev_priv);
-extern void __gen6_gt_force_wake_mt_get(struct drm_i915_private *dev_priv);
-extern void __gen6_gt_force_wake_put(struct drm_i915_private *dev_priv);
-extern void __gen6_gt_force_wake_mt_put(struct drm_i915_private *dev_priv);
-
-extern void vlv_force_wake_get(struct drm_i915_private *dev_priv);
-extern void vlv_force_wake_put(struct drm_i915_private *dev_priv);
 
 /* overlay */
 #ifdef CONFIG_DEBUG_FS