drm/i915: Introduce intel_dumb_fb_max_stride()

Wrap intel_plane_fb_max_stride() in intel_dumb_fb_max_stride()
for the purposes of dumb fb creation. I want to change
intel_plane_fb_max_stride() to take a 'struct drm_format_info'
instead of the 'u32 pixel_format' so we need an excplicit format
info lookup in the dumb fb path and I don't really want to have
that in i915_gem_dumb_create() directly.

This makes intel_plane_fb_max_stride() internal to the display
code again, and thus we can pass in struct intel_display instead
of struct drm_device.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20251107181126.5743-2-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>

Author: vsyrjala

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

@@ -547,16 +547,12 @@ void intel_disable_transcoder(const struct intel_crtc_state *old_crtc_state)
 		intel_wait_for_pipe_off(old_crtc_state);
 }
 
-u32 intel_plane_fb_max_stride(struct drm_device *drm,
+u32 intel_plane_fb_max_stride(struct intel_display *display,
 			      u32 pixel_format, u64 modifier)
 {
-	struct intel_display *display = to_intel_display(drm);
 	struct intel_crtc *crtc;
 	struct intel_plane *plane;
 
-	if (!HAS_DISPLAY(display))
-		return 0;
-
 	/*
 	 * We assume the primary plane for pipe A has
 	 * the highest stride limits of them all,
@@ -572,6 +568,17 @@ u32 intel_plane_fb_max_stride(struct drm_device *drm,
 				 DRM_MODE_ROTATE_0);
 }
 
+u32 intel_dumb_fb_max_stride(struct drm_device *drm,
+			     u32 pixel_format, u64 modifier)
+{
+	struct intel_display *display = to_intel_display(drm);
+
+	if (!HAS_DISPLAY(display))
+		return 0;
+
+	return intel_plane_fb_max_stride(display, pixel_format, modifier);
+}
+
 void intel_set_plane_visible(struct intel_crtc_state *crtc_state,
 			     struct intel_plane_state *plane_state,
 			     bool visible)

drivers/gpu/drm/i915/display/intel_display.h

@@ -402,8 +402,10 @@ void intel_link_compute_m_n(u16 bpp, int nlanes,
 			    int pixel_clock, int link_clock,
 			    int bw_overhead,
 			    struct intel_link_m_n *m_n);
-u32 intel_plane_fb_max_stride(struct drm_device *drm,
+u32 intel_plane_fb_max_stride(struct intel_display *display,
 			      u32 pixel_format, u64 modifier);
+u32 intel_dumb_fb_max_stride(struct drm_device *drm,
+			     u32 pixel_format, u64 modifier);
 enum drm_mode_status
 intel_mode_valid_max_plane_size(struct intel_display *display,
 				const struct drm_display_mode *mode,

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

@@ -1982,7 +1982,7 @@ u32 intel_fb_max_stride(struct intel_display *display,
 	 */
 	if (DISPLAY_VER(display) < 4 || intel_fb_is_ccs_modifier(modifier) ||
 	    intel_fb_modifier_uses_dpt(display, modifier))
-		return intel_plane_fb_max_stride(display->drm, pixel_format, modifier);
+		return intel_plane_fb_max_stride(display, pixel_format, modifier);
 	else if (DISPLAY_VER(display) >= 7)
 		return 256 * 1024;
 	else
@@ -1996,7 +1996,7 @@ intel_fb_stride_alignment(const struct drm_framebuffer *fb, int color_plane)
 	unsigned int tile_width;
 
 	if (is_surface_linear(fb, color_plane)) {
-		unsigned int max_stride = intel_plane_fb_max_stride(display->drm,
+		unsigned int max_stride = intel_plane_fb_max_stride(display,
 								    fb->format->format,
 								    fb->modifier);
 

drivers/gpu/drm/i915/gem/i915_gem_create.c

@@ -194,8 +194,8 @@ i915_gem_dumb_create(struct drm_file *file,
 	args->pitch = ALIGN(args->width * cpp, 64);
 
 	/* align stride to page size so that we can remap */
-	if (args->pitch > intel_plane_fb_max_stride(dev, format,
-						    DRM_FORMAT_MOD_LINEAR))
+	if (args->pitch > intel_dumb_fb_max_stride(dev, format,
+						   DRM_FORMAT_MOD_LINEAR))
 		args->pitch = ALIGN(args->pitch, 4096);
 
 	if (args->pitch < args->width)