drm/i915: Support more QGV points

According to BSpec 53998, there is a mask of
max 8 SAGV/QGV points we need to support.

Bumping this up to keep the CI happy(currently
preventing tests to run), until all SAGV
changes land.

v2: Fix second plane where QGV points were
    hardcoded as well.

v3: Change the naming of I915_NUM_SAGV_POINTS
    to be I915_NUM_QGV_POINTS, as more meaningful
    (Ville Syrjälä)

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=112189
Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191125160800.14740-1-stanislav.lisovskiy@intel.com
[vsyrjala: Add missing braces around else (checkpatch), fix Bugzilla tag]
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

drivers/gpu/drm/i915/display/intel_bw.c

@@ -15,7 +15,7 @@ struct intel_qgv_point {
 };
 
 struct intel_qgv_info {
-	struct intel_qgv_point points[3];
+	struct intel_qgv_point points[I915_NUM_QGV_POINTS];
 	u8 num_points;
 	u8 num_channels;
 	u8 t_bl;
@@ -276,17 +276,29 @@ void intel_bw_init_hw(struct drm_i915_private *dev_priv)
 static unsigned int intel_max_data_rate(struct drm_i915_private *dev_priv,
 					int num_planes)
 {
-	if (INTEL_GEN(dev_priv) >= 11)
+	if (INTEL_GEN(dev_priv) >= 11) {
+		/*
+		 * Any bw group has same amount of QGV points
+		 */
+		const struct intel_bw_info *bi =
+			&dev_priv->max_bw[0];
+		unsigned int min_bw = UINT_MAX;
+		int i;
+
 		/*
 		 * FIXME with SAGV disabled maybe we can assume
 		 * point 1 will always be used? Seems to match
 		 * the behaviour observed in the wild.
 		 */
-		return min3(icl_max_bw(dev_priv, num_planes, 0),
-			    icl_max_bw(dev_priv, num_planes, 1),
-			    icl_max_bw(dev_priv, num_planes, 2));
-	else
+		for (i = 0; i < bi->num_qgv_points; i++) {
+			unsigned int bw = icl_max_bw(dev_priv, num_planes, i);
+
+			min_bw = min(bw, min_bw);
+		}
+		return min_bw;
+	} else {
 		return UINT_MAX;
+	}
 }
 
 static unsigned int intel_bw_crtc_num_active_planes(const struct intel_crtc_state *crtc_state)

drivers/gpu/drm/i915/i915_drv.h

@@ -621,6 +621,9 @@ struct i915_gem_mm {
 
 #define I915_ENGINE_WEDGED_TIMEOUT  (60 * HZ)  /* Reset but no recovery? */
 
+/* Amount of SAGV/QGV points, BSpec precisely defines this */
+#define I915_NUM_QGV_POINTS 8
+
 struct ddi_vbt_port_info {
 	/* Non-NULL if port present. */
 	const struct child_device_config *child;
@@ -1232,7 +1235,8 @@ struct drm_i915_private {
 	} dram_info;
 
 	struct intel_bw_info {
-		unsigned int deratedbw[3]; /* for each QGV point */
+		/* for each QGV point */
+		unsigned int deratedbw[I915_NUM_QGV_POINTS];
 		u8 num_qgv_points;
 		u8 num_planes;
 	} max_bw[6];