drm/i915/lnl: possibility to enable FBC on first three planes

In LNL onwards, FBC can be associated to the first three planes.
FBC will be enabled on planes first come first served basis
until the userspace can select one of these FBC capable planes
explicitly.

v2:
 - avoid fbc->state.plane check in intel_fbc_check_plane (Ville)
 - simplify plane binding register writes (Matt)
 - Update the subject to reflect that fbc can be enabled only in
   the first three planes (Matt)

v3:
 - use icl_is_hdr_plane(), use wrapper macro for plane binding
   register access, comments update and patch split (Ville)

v4:
 - update to the plane binding register access macro

Bspec: 69560
Signed-off-by: Vinod Govindapillai <vinod.govindapillai@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230922133003.150578-2-vinod.govindapillai@intel.com

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

@@ -593,6 +593,9 @@ static u32 ivb_dpfc_ctl(struct intel_fbc *fbc)
 	if (IS_IVYBRIDGE(i915))
 		dpfc_ctl |= DPFC_CTL_PLANE_IVB(fbc_state->plane->i9xx_plane);
 
+	if (DISPLAY_VER(i915) >= 20)
+		dpfc_ctl |= DPFC_CTL_PLANE_BINDING(fbc_state->plane->id);
+
 	if (fbc_state->fence_id >= 0)
 		dpfc_ctl |= DPFC_CTL_FENCE_EN_IVB;
 

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

@@ -1942,13 +1942,16 @@ static enum intel_fbc_id skl_fbc_id_for_pipe(enum pipe pipe)
 	return pipe - PIPE_A + INTEL_FBC_A;
 }
 
-static bool skl_plane_has_fbc(struct drm_i915_private *dev_priv,
+static bool skl_plane_has_fbc(struct drm_i915_private *i915,
 			      enum intel_fbc_id fbc_id, enum plane_id plane_id)
 {
-	if ((DISPLAY_RUNTIME_INFO(dev_priv)->fbc_mask & BIT(fbc_id)) == 0)
+	if ((DISPLAY_RUNTIME_INFO(i915)->fbc_mask & BIT(fbc_id)) == 0)
 		return false;
 
-	return plane_id == PLANE_PRIMARY;
+	if (DISPLAY_VER(i915) >= 20)
+		return icl_is_hdr_plane(i915, plane_id);
+	else
+		return plane_id == PLANE_PRIMARY;
 }
 
 static struct intel_fbc *skl_plane_fbc(struct drm_i915_private *dev_priv,

drivers/gpu/drm/i915/i915_reg.h

@@ -1327,6 +1327,8 @@
 #define   DPFC_CTL_PLANE_IVB(i9xx_plane)	REG_FIELD_PREP(DPFC_CTL_PLANE_MASK_IVB, (i9xx_plane))
 #define   DPFC_CTL_FENCE_EN_IVB			REG_BIT(28) /* ivb+ */
 #define   DPFC_CTL_PERSISTENT_MODE		REG_BIT(25) /* g4x-snb */
+#define   DPFC_CTL_PLANE_BINDING_MASK		REG_GENMASK(12, 11) /* lnl+ */
+#define   DPFC_CTL_PLANE_BINDING(plane_id)	REG_FIELD_PREP(DPFC_CTL_PLANE_BINDING_MASK, (plane_id))
 #define   DPFC_CTL_FALSE_COLOR			REG_BIT(10) /* ivb+ */
 #define   DPFC_CTL_SR_EN			REG_BIT(10) /* g4x only */
 #define   DPFC_CTL_SR_EXIT_DIS			REG_BIT(9) /* g4x only */