[PATCH 2/9] drm/i915: Clean up skl+ plane stride limits

[Ville Syrjala <ville.syrjala@linux.intel.com>]

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

skl_plane_max_stride() is pretty messy. Streamline it and
split it into clear skl+ vs. adl+ variants.

TODO: Deal with icl and tgl strude limits properly

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 .../drm/i915/display/skl_universal_plane.c    | 65 +++++++++++--------
 1 file changed, 37 insertions(+), 28 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/skl_universal_plane.c b/drivers/gpu/drm/i915/display/skl_universal_plane.c
index 0a8e781a3648..b8103d6ebc1f 100644
--- a/drivers/gpu/drm/i915/display/skl_universal_plane.c
+++ b/drivers/gpu/drm/i915/display/skl_universal_plane.c
@@ -461,41 +461,46 @@ static int icl_plane_max_height(const struct drm_framebuffer *fb,
 }
 
 static unsigned int
-skl_plane_max_stride(struct intel_plane *plane,
-		     u32 pixel_format, u64 modifier,
-		     unsigned int rotation)
+plane_max_stride(struct intel_plane *plane,
+		 u32 pixel_format, u64 modifier,
+		 unsigned int rotation,
+		 unsigned int max_pixels,
+		 unsigned int max_bytes)
 {
-	struct drm_i915_private *i915 = to_i915(plane->base.dev);
 	const struct drm_format_info *info = drm_format_info(pixel_format);
 	int cpp = info->cpp[0];
-	int max_horizontal_pixels = 8192;
-	int max_stride_bytes;
-
-	if (DISPLAY_VER(i915) >= 13) {
-		/*
-		 * The stride in bytes must not exceed of the size
-		 * of 128K bytes. For pixel formats of 64bpp will allow
-		 * for a 16K pixel surface.
-		 */
-		max_stride_bytes = 131072;
-		if (cpp == 8)
-			max_horizontal_pixels = 16384;
-		else
-			max_horizontal_pixels = 65536;
-	} else {
-		/*
-		 * "The stride in bytes must not exceed the
-		 * of the size of 8K pixels and 32K bytes."
-		 */
-		max_stride_bytes = 32768;
-	}
 
 	if (drm_rotation_90_or_270(rotation))
-		return min(max_horizontal_pixels, max_stride_bytes / cpp);
+		return min(max_pixels, max_bytes / cpp);
 	else
-		return min(max_horizontal_pixels * cpp, max_stride_bytes);
+		return min(max_pixels * cpp, max_bytes);
 }
 
+static unsigned int
+adl_plane_max_stride(struct intel_plane *plane,
+		     u32 pixel_format, u64 modifier,
+		     unsigned int rotation)
+{
+	unsigned int max_pixels = 65536; /* PLANE_OFFSET limit */
+	unsigned int max_bytes = 128 * 1024;
+
+	return plane_max_stride(plane, pixel_format,
+				modifier, rotation,
+				max_pixels, max_bytes);
+}
+
+static unsigned int
+skl_plane_max_stride(struct intel_plane *plane,
+		     u32 pixel_format, u64 modifier,
+		     unsigned int rotation)
+{
+	unsigned int max_pixels = 8192; /* PLANE_OFFSET limit */
+	unsigned int max_bytes = 32 * 1024;
+
+	return plane_max_stride(plane, pixel_format,
+				modifier, rotation,
+				max_pixels, max_bytes);
+}
 
 /* Preoffset values for YUV to RGB Conversion */
 #define PREOFF_YUV_TO_RGB_HI		0x1800
@@ -2357,7 +2362,11 @@ skl_universal_plane_create(struct drm_i915_private *dev_priv,
 		plane->min_cdclk = skl_plane_min_cdclk;
 	}
 
-	plane->max_stride = skl_plane_max_stride;
+	if (DISPLAY_VER(dev_priv) >= 13)
+		plane->max_stride = adl_plane_max_stride;
+	else
+		plane->max_stride = skl_plane_max_stride;
+
 	if (DISPLAY_VER(dev_priv) >= 11) {
 		plane->update_noarm = icl_plane_update_noarm;
 		plane->update_arm = icl_plane_update_arm;
-- 
2.43.2