drm/i915: Clean up fbc vs. plane checks

Let's record the information whether a plane can do fbc or not under
struct inte_plane.

v2: Rebase due to i9xx_plane_id
    Handle BDW/HSW correctly
v3: Move inte_fbc_init() back since we depend on it happening
    even with i915.disable_display, and populate
    fbc->possible_framebuffer_bits directly from the
    plane init code instead
v4: Add note about plane A being tied to pipe A on HSW+

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180221173101.19385-1-ville.syrjala@linux.intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180221160235.11134-5-ville.syrjala@linux.intel.com

1 files changed, 41 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index a991195e5354..9ca8ba2c894c 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -13215,6 +13215,32 @@ static const struct drm_plane_funcs intel_cursor_plane_funcs = {
 	.format_mod_supported = intel_cursor_plane_format_mod_supported,
 };
 
+static bool i9xx_plane_has_fbc(struct drm_i915_private *dev_priv,
+			       enum i9xx_plane_id i9xx_plane)
+{
+	if (!HAS_FBC(dev_priv))
+		return false;
+
+	if (IS_BROADWELL(dev_priv) || IS_HASWELL(dev_priv))
+		return i9xx_plane == PLANE_A; /* tied to pipe A */
+	else if (IS_IVYBRIDGE(dev_priv))
+		return i9xx_plane == PLANE_A || i9xx_plane == PLANE_B ||
+			i9xx_plane == PLANE_C;
+	else if (INTEL_GEN(dev_priv) >= 4)
+		return i9xx_plane == PLANE_A || i9xx_plane == PLANE_B;
+	else
+		return i9xx_plane == PLANE_A;
+}
+
+static bool skl_plane_has_fbc(struct drm_i915_private *dev_priv,
+			      enum pipe pipe, enum plane_id plane_id)
+{
+	if (!HAS_FBC(dev_priv))
+		return false;
+
+	return pipe == PIPE_A && plane_id == PLANE_PRIMARY;
+}
+
 static struct intel_plane *
 intel_primary_plane_create(struct drm_i915_private *dev_priv, enum pipe pipe)
 {
@@ -13257,6 +13283,21 @@ intel_primary_plane_create(struct drm_i915_private *dev_priv, enum pipe pipe)
 		primary->i9xx_plane = (enum i9xx_plane_id) pipe;
 	primary->id = PLANE_PRIMARY;
 	primary->frontbuffer_bit = INTEL_FRONTBUFFER(pipe, primary->id);
+
+	if (INTEL_GEN(dev_priv) >= 9)
+		primary->has_fbc = skl_plane_has_fbc(dev_priv,
+						     primary->pipe,
+						     primary->id);
+	else
+		primary->has_fbc = i9xx_plane_has_fbc(dev_priv,
+						      primary->i9xx_plane);
+
+	if (primary->has_fbc) {
+		struct intel_fbc *fbc = &dev_priv->fbc;
+
+		fbc->possible_framebuffer_bits |= primary->frontbuffer_bit;
+	}
+
 	primary->check_plane = intel_check_primary_plane;
 
 	if (INTEL_GEN(dev_priv) >= 9) {