drm/i915: Use engine to refer to the user's BSD intel_engine_cs

This patch transitions the execbuf engine selection away from using the
ring nomenclature - though we still refer to the user's incoming
selector as their user_ring_id.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1469432687-22756-7-git-send-email-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1469606850-28659-2-git-send-email-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_drv.h

@@ -402,7 +402,7 @@ struct drm_i915_file_private {
 		unsigned boosts;
 	} rps;
 
-	unsigned int bsd_ring;
+	unsigned int bsd_engine;
 };
 
 /* Used by dp and fdi links */
@@ -1331,7 +1331,7 @@ struct i915_gem_mm {
 	bool interruptible;
 
 	/* the indicator for dispatch video commands on two BSD rings */
-	unsigned int bsd_ring_dispatch_index;
+	unsigned int bsd_engine_dispatch_index;
 
 	/** Bit 6 swizzling required for X tiling */
 	uint32_t bit_6_swizzle_x;

drivers/gpu/drm/i915/i915_gem.c

@@ -4782,7 +4782,7 @@ int i915_gem_open(struct drm_device *dev, struct drm_file *file)
 	spin_lock_init(&file_priv->mm.lock);
 	INIT_LIST_HEAD(&file_priv->mm.request_list);
 
-	file_priv->bsd_ring = -1;
+	file_priv->bsd_engine = -1;
 
 	ret = i915_gem_context_open(dev, file);
 	if (ret)

drivers/gpu/drm/i915/i915_gem_execbuffer.c

@@ -1351,23 +1351,24 @@ i915_gem_ringbuffer_submission(struct i915_execbuffer_params *params,
 
 /**
  * Find one BSD ring to dispatch the corresponding BSD command.
- * The ring index is returned.
+ * The engine index is returned.
  */
 static unsigned int
-gen8_dispatch_bsd_ring(struct drm_i915_private *dev_priv, struct drm_file *file)
+gen8_dispatch_bsd_engine(struct drm_i915_private *dev_priv,
+			 struct drm_file *file)
 {
 	struct drm_i915_file_private *file_priv = file->driver_priv;
 
 	/* Check whether the file_priv has already selected one ring. */
-	if ((int)file_priv->bsd_ring < 0) {
+	if ((int)file_priv->bsd_engine < 0) {
 		/* If not, use the ping-pong mechanism to select one. */
 		mutex_lock(&dev_priv->drm.struct_mutex);
-		file_priv->bsd_ring = dev_priv->mm.bsd_ring_dispatch_index;
-		dev_priv->mm.bsd_ring_dispatch_index ^= 1;
+		file_priv->bsd_engine = dev_priv->mm.bsd_engine_dispatch_index;
+		dev_priv->mm.bsd_engine_dispatch_index ^= 1;
 		mutex_unlock(&dev_priv->drm.struct_mutex);
 	}
 
-	return file_priv->bsd_ring;
+	return file_priv->bsd_engine;
 }
 
 #define I915_USER_RINGS (4)
@@ -1404,7 +1405,7 @@ eb_select_engine(struct drm_i915_private *dev_priv,
 		unsigned int bsd_idx = args->flags & I915_EXEC_BSD_MASK;
 
 		if (bsd_idx == I915_EXEC_BSD_DEFAULT) {
-			bsd_idx = gen8_dispatch_bsd_ring(dev_priv, file);
+			bsd_idx = gen8_dispatch_bsd_engine(dev_priv, file);
 		} else if (bsd_idx >= I915_EXEC_BSD_RING1 &&
 			   bsd_idx <= I915_EXEC_BSD_RING2) {
 			bsd_idx >>= I915_EXEC_BSD_SHIFT;